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2025-01-012025-12-31 C011963 ferc:GasUtilityMember aa011183b9d38ca73899eaf20b83a4d4 2024-12-31 C011963 Bob Glanzer 2025-12-31 C011963 ferc:GasUtilityMember HH5CF5843E7EF02523C0E8735AC48F41EB 2025-12-31 C011963 ScheduleExtraordinaryPropertyLossesAbstract 2025-01-012025-12-31 C011963 2804fefe69876442d728984df33ed6ed 2025-01-012025-12-31 C011963 HH02D1374E29D020FC581CB43A788313EA 2024-12-31 C011963 c15de8caee7f79df4e19a432050af117 2025-01-012025-12-31 C011963 ferc:Quarter1Member 2025-01-012025-12-31 C011963 HH101791264CC2D1072B3843D11F5FB150 2025-01-012025-12-31 C011963 3cdebb811ded4f56593661c9b2966f03 2025-01-012025-12-31 C011963 HHFC605604B339AC1A45D8BC2DA6C73C49 2025-12-31 C011963 HH5B2DFF5B695AB5F1B55728ACBC142860 2024-12-31 C011963 HH4AA9433AD9AF89DE189B17D1D0B749DB 2025-12-31 C011963 HH2ED9913DCD3F3EBF4EFF6E8F72D3B7A3 2025-12-31 C011963 HH02D1374E29D020FC581CB43A788313EA 2025-12-31 C011963 HH86FC207E29ABD735661863E6FF0AC9F5 2025-12-31 C011963 Big Stone Oil 2025-01-012025-12-31 C011963 HHC1E6771DC5088C7BC63E17C3DC5D73E8 2025-01-012025-12-31 C011963 aa011183b9d38ca73899eaf20b83a4d4 2025-01-012025-12-31 C011963 HH3F3E9E2E098BC9BEC5B1244087E556B6 2025-01-012025-12-31 C011963 HHBBDCAD31B047D7AC256B0FF11432475E 2025-01-012025-12-31 C011963 Gas 2025-01-012025-12-31 C011963 HHEF06096095AEF7B75F4A0C7BDEE6F001 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember HH25FDCF57EE2E25EAC08A513DA2BAE38F 2025-01-012025-12-31 C011963 a28a16a84157918723d69e5a02d5f47a 2025-01-012025-03-31 C011963 HHD0CE01E562ED98C9C53F1EFC21F5ADA8 2025-01-012025-12-31 C011963 HHA7B127F88885574178D47E046DFC435E 2024-12-31 C011963 ferc:GasUtilityMember 2024-01-012024-12-31 C011963 ferc:SeptemberMember 2025-01-012025-12-31 C011963 HH9C413CCF44D8F4348A9F70C32D540909 2025-12-31 C011963 HH9048F09365ABA14DA50A3636C7A991A5 2025-01-012025-12-31 C011963 7068a6fd8780583e5a81004ea77d9073 2025-01-012025-12-31 C011963 HHA9E61508C6B923D27C0654BA95114461 2025-01-012025-12-31 C011963 HH9BB84AF0422F57822E28729F8D28EEA0 2025-12-31 C011963 ferc:OtherUtilityMember 2025-01-012025-12-31 C011963 ferc:GasUtilityMember 2025-01-012025-12-31 C011963 HHCF17E3D6C0BBBEDC6603E9AE26D0ADA1 2025-01-012025-12-31 C011963 HHB261C9784E59437BD309BFE407BDFAAB 2024-12-31 C011963 0fe2f2c51fed247a594cb538753b2653 2025-01-012025-12-31 C011963 HHFFA6E5D66DDBC4A1CBABB10AACDF6EC6 2025-12-31 C011963 HH6311AE17C1EE52B36E68AAF4AD066387 2024-01-012024-12-31 C011963 HH44904DA4AB6629466F55A15F118625C0 2025-12-31 C011963 HH873A7CCCD531B170C86B3BE912B6A46B 2025-12-31 C011963 HHDE458B788D4277FF3FC8F3E920F6E7FF 2025-12-31 C011963 HHE6DF2ABECF3A58EB156B1C13FB455E92 2025-01-012025-12-31 C011963 8003b4f19091da11a1732b3c6f13ddf0 2025-01-012025-12-31 C011963 HHDD3A38FA91A5AF52A977F82B8A944D4F 2025-01-012025-12-31 C011963 HH25FDCF57EE2E25EAC08A513DA2BAE38F 2024-12-31 C011963 South Dakota Operations 2025-01-012025-12-31 C011963 HH88DCC254FB62671226558EA27ABD46DF 2025-01-012025-12-31 C011963 1bc141b28269984912f08b22a19517fb 2025-01-012025-12-31 C011963 HH402765FD0E75E9A678F5AC3E3621F1ED 2025-12-31 C011963 ferc:ElectricUtilityMember HH4FA44F6986EABEAE551C3EFC27434718 2025-01-012025-12-31 C011963 Beethoven Wind 2025-12-31 C011963 HH5C0F1B45ECE4D0F2D48C8D8573C9CFFD 2025-12-31 C011963 77c66b9f813e6c188832481e4c3a4ef9 2025-01-012025-12-31 C011963 HH04AB2791367F280352414A4AECB0C263 2025-01-012025-12-31 C011963 ferc:LandAndRightsMember HH528175AE1561AFEE1117CA84DDBDA30A 2025-01-012025-12-31 C011963 HH366018BE9D3F904822CE18F998E17EBD 2025-01-012025-12-31 C011963 HH5CF5843E7EF02523C0E8735AC48F41EB 2025-01-012025-12-31 C011963 ScheduleNuclearFuelMaterialsAbstract 2025-01-012025-12-31 C011963 7d9617f302bcd83513771e53c0002b28 2025-01-012025-12-31 C011963 ferc:OtherUtilityMember 2024-12-31 C011963 2025-12-31 C011963 HH8FF0D87CAB5F33D38070528F1E392B21 2025-01-012025-12-31 C011963 HHB1166CDBC50949729D6BB5C347F04644 2025-12-31 C011963 ferc:HydraulicProductionPlantPumpedStorageMemberferc:ElectricUtilityMember 2025-01-012025-12-31 C011963 HH9B389718951AC0F50BBEC00526C6BF3E 2024-01-012024-12-31 C011963 ferc:ElectricUtilityMember HHA5D59F498B924FBDF1591674F810AA71 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember HHB9B4AC257CA1A22401754045F1EFE1D6 2024-12-31 C011963 HHEF06096095AEF7B75F4A0C7BDEE6F001 2024-12-31 C011963 HHF07BEBA82F45005BF1725483FC994E41 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember HHCD0E44E2C1557F8BE1FBE357B5DE8FC5 2025-01-012025-12-31 C011963 HHDD3A38FA91A5AF52A977F82B8A944D4F 2025-12-31 C011963 ferc:CurrentYearMember 2025-12-31 C011963 ferc:Quarter4Member 2025-01-012025-12-31 C011963 HHB1166CDBC50949729D6BB5C347F04644 2025-01-012025-12-31 C011963 HH6A7514731F394284013DD7CDD7391976 2025-01-012025-12-31 C011963 HH83E9AF34300553FF3EB1C63FC9D2BBCB 2025-01-012025-12-31 C011963 ferc:GasUtilityMember HHBCECA9ACF51EA7D6A49E5E9669397527 2025-12-31 C011963 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2025-01-012025-12-31 C011963 HHB6945EF71A0E492F5CC64B3D1CC73320 2025-12-31 C011963 HH21D0EDF1E740A8B184BAEA80C49B2AD5 2025-12-31 C011963 8274ea30e16fb5e639e43249a3d44b81 2025-01-012025-12-31 C011963 HH45649F08ABEB2FC070ABD2846CFDBA8F 2024-12-31 C011963 HH44091F73F74CC40B28EBB17B676FEF56 2025-12-31 C011963 HH36A23D2DBB508979ACD6F221115BC4D1 2025-01-012025-12-31 C011963 ferc:LandAndRightsMember HH528175AE1561AFEE1117CA84DDBDA30A 2025-12-31 C011963 269a457ea8a4973c0181775c78098f14 2025-01-012025-12-31 C011963 ferc:MarchMember South Dakota Operations 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember HHF137667547FDA5A6904DD49BCFA3F7D3 2025-01-012025-12-31 C011963 HHFF66C82A968C746440A84BCA2AEF87A9 2025-12-31 C011963 HH5A4D4DF2A86F1027DC949A007885F67A 2025-01-012025-12-31 C011963 HH7995F418F4E8A58346DF7BA423E9FD53 2025-01-012025-12-31 C011963 HH06ECF7086F0A59ED1610913EFD3F4607 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMemberferc:ElectricPlantHeldForFutureUseMember 2025-12-31 C011963 HH8FF0D87CAB5F33D38070528F1E392B21 2025-12-31 C011963 ferc:JulyMember 2025-01-012025-12-31 C011963 HH7679A77C593EB0B07C2302A67D57731D 2025-12-31 C011963 HHB261C9784E59437BD309BFE407BDFAAB 2025-01-012025-12-31 C011963 HHA0C2DDF97EF237DA0B4D5EA22C0CEA77 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember HH031E9FCA7BBA9732AA3C6D1AA748C84A 2025-01-012025-12-31 C011963 ferc:DirectPayrollDistributionMember 2025-01-012025-12-31 C011963 HH8584FB5473816211F2109B3627962785 2024-12-31 C011963 HHDE458B788D4277FF3FC8F3E920F6E7FF 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember bda039ee8d2c3790e6912f49212662cf 2024-12-31 C011963 HHDEB66DC27C4A4AD63D694098C9AE4E37 2025-01-012025-12-31 C011963 HH9EA64ADD0EAC3535D868EE5449CB560B 2025-12-31 C011963 HHE63FE557EC309D58F2B01C670ED058AF 2024-12-31 C011963 ferc:ElectricUtilityMember HH5492E4AC47183E35584BEE02A551A043 2025-01-012025-12-31 C011963 cacb6be39745edaf8e0eae6497f82e85 2025-01-012025-12-31 C011963 6c8cf6205f46d04a0581f13835cb6c08 2025-01-012025-12-31 C011963 HHB261C9784E59437BD309BFE407BDFAAB 2025-12-31 C011963 ferc:OtherGasUtilityMember 2024-12-31 C011963 HH96C8C75DEEC981F1DE6E7CE10A10D3E7 2025-12-31 C011963 ScheduleCorporationsControlledByRespondentAbstract 2025-01-012025-12-31 C011963 HHDE458B788D4277FF3FC8F3E920F6E7FF 2025-12-31 C011963 HH9ED770E1B5926423C6005E402EFE1DBC 2025-12-31 C011963 HHB9B4AC257CA1A22401754045F1EFE1D6 2025-01-012025-12-31 C011963 HHEF0974A81450ED79F85B6B38DA7C59C5 2025-12-31 C011963 HHFC3042B8A97C05688D6D2C7A482AD4A9 2024-12-31 C011963 ScheduleHydroelectricGeneratingPlantStatisticsAbstract 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember 87f4013d298a46a7a69d3ca4124d1607 2025-01-012025-12-31 C011963 HH4FA44F6986EABEAE551C3EFC27434718 2025-01-012025-12-31 C011963 HH031E9FCA7BBA9732AA3C6D1AA748C84A 2025-12-31 C011963 41640ec0652853ac532ab33810545693 2025-01-012025-12-31 C011963 4b63737cd7baf95e713f5295ff4b19fa 2025-01-012025-12-31 C011963 HH4AA9433AD9AF89DE189B17D1D0B749DB 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2024-12-31 C011963 HHC0C65D966E7B7358B59C8156C31A3849 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember HHCD0E44E2C1557F8BE1FBE357B5DE8FC5 2024-12-31 C011963 Big Stone 2025-12-31 C011963 HHE65F413CACA259AD4D81250A93266C01 2025-12-31 C011963 HH43D33D4C26BAC4A32A0428EAEC41ACF4 2025-01-012025-12-31 C011963 d2a487c0b8aa4461a18a63a478e310aa 2025-01-012025-12-31 C011963 HH5B2DFF5B695AB5F1B55728ACBC142860 2025-01-012025-12-31 C011963 HH6F6C5D7CA203B2D579222F81D690B927 2025-12-31 C011963 HHA6103ED5387BB5B82595AD7213244522 2025-12-31 C011963 HH3B4E2BCDBFF5F38FAEF2E88AD7251445 2025-01-012025-12-31 C011963 a28a16a84157918723d69e5a02d5f47a 2025-01-012025-06-30 C011963 HH50BD4BABB35AF8AC5E01FF03301ED93C 2025-01-012025-12-31 C011963 HH879E069B41555DA138D38C1A153946B3 2025-01-012025-12-31 C011963 HH9EA97C5FFCF0CDDBDA8D50AB3CD1BF1F 2025-01-012025-12-31 C011963 ferc:GenerationStudiesMember 2025-01-012025-12-31 C011963 HHCE746A4076A23AF3EB14C23CB8B85157 2025-01-012025-12-31 C011963 HH96C8C75DEEC981F1DE6E7CE10A10D3E7 2025-01-012025-12-31 C011963 5aba865dee85b40b36750d297c5ac55e 2025-01-012025-12-31 C011963 ferc:GasUtilityMember a0456a99f05778a101aac55ab1b8445f 2025-12-31 C011963 HHA7B127F88885574178D47E046DFC435E 2025-12-31 C011963 HH5492E4AC47183E35584BEE02A551A043 2024-12-31 C011963 HHDAEAF7FB287559D30D6F4ED7B121CAE0 2025-01-012025-12-31 C011963 HHB2F44C444B8E86B2CA19459A49D57A84 2025-12-31 C011963 ferc:ElectricUtilityMember 2025-12-31 C011963 c826d04cbeb72e67edf0dfce89519f61 2025-01-012025-12-31 C011963 2025-01-012025-12-31 C011963 7092eb76c0ff984e9d88fa5b71caf7a3 2025-01-012025-12-31 C011963 Aberdeen #1 2025-12-31 C011963 HH74598AF814F798F2736634D9DD96F01F 2025-01-012025-12-31 C011963 HHEEAB6E8B77680F537FEBC8260AEE441B 2025-12-31 C011963 fed96a6ea0a893b19392fa10658bb34f 2025-01-012025-12-31 C011963 ferc:DirectPayrollDistributionMember ae6888ed3407fb8b7572ca96a7804b3d 2025-01-012025-12-31 C011963 ferc:JanuaryMember South Dakota Operations 2025-01-012025-12-31 C011963 HH55912BA4714F7579CF1F8574AA3EC2ED 2025-12-31 C011963 ScheduleTransmissionOfElectricityByIsoOrRtoAbstract 2025-01-012025-12-31 C011963 HH0D2051E25880561480828E7F4382E3BE 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember HHA5D59F498B924FBDF1591674F810AA71 2025-12-31 C011963 ferc:CurrentYearMember 2025-01-012025-12-31 C011963 HHEEAB6E8B77680F537FEBC8260AEE441B 2025-01-012025-12-31 C011963 Aberdeen #2 2025-12-31 C011963 ferc:NuclearProductionPlantMemberferc:ElectricUtilityMember 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember HHE63FE557EC309D58F2B01C670ED058AF 2025-01-012025-12-31 C011963 df207634125fc5ab0bcf8e9d1579561d 2025-01-012025-12-31 C011963 HH8E50F119A402C17366A6296859EC00EC 2025-01-012025-12-31 C011963 778bf5b889d5503769f669da38cb239f 2025-01-012025-12-31 C011963 HH3B9F93ABF952AF0839839D979FADB334 2025-01-012025-12-31 C011963 ferc:SeptemberMember South Dakota Operations 2025-01-012025-12-31 C011963 HH6EFCC9D66F821E5F1A152DC902BF5665 2025-12-31 C011963 ferc:GasUtilityMember HH6A7514731F394284013DD7CDD7391976 2024-12-31 C011963 ferc:ElectricUtilityMemberferc:ElectricPlantLeasedToOthersMember 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember HHA5D59F498B924FBDF1591674F810AA71 2024-12-31 C011963 HH5631D11D0F8A4E2B405FE784301C5A21 2025-01-012025-12-31 C011963 ferc:DirectPayrollDistributionMember cffa7bb479151d9f48dba87b659bc893 2025-01-012025-12-31 C011963 ferc:OtherProductionPlantMemberferc:ElectricUtilityMember 2025-01-012025-12-31 C011963 ferc:OtherUtilityMember 2025-12-31 C011963 HHC793DDF0091C4F07817DF55F93548023 2024-12-31 C011963 9d5e3786a87795dd916011c071d8d7d6 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember bda039ee8d2c3790e6912f49212662cf 2025-12-31 C011963 HH858C64973FEE236949705AE45578609E 2025-01-012025-12-31 C011963 Coal 2025-01-012025-12-31 C011963 HH15F87D838AA553833164C9A7744D10D6 2025-12-31 C011963 ferc:ElectricUtilityMember HHFC3042B8A97C05688D6D2C7A482AD4A9 2025-01-012025-12-31 C011963 HH456CF5261E72709E557CE343CFEF8D88 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember HH6E19628685CC6F3373A1CF99BF8D970F 2025-01-012025-12-31 C011963 ScheduleUnrecoveredPlantAndRegulatoryStudyCostsAbstract 2025-01-012025-12-31 C011963 HHCD60D194531594C2E9E760168FDEDC70 2025-12-31 C011963 HH528175AE1561AFEE1117CA84DDBDA30A 2025-01-012025-12-31 C011963 HH9048F09365ABA14DA50A3636C7A991A5 2025-12-31 C011963 HHA03A7F00BE61F09B38D6828FD3782499 2025-01-012025-12-31 C011963 HH1A657CEAD53B8D92F8710D48EA961518 2025-01-012025-12-31 C011963 HHA16859FCA84C9EF365706E55D7CB7389 2025-01-012025-12-31 C011963 HH98A0430DFE6121B2478A8EF7ECA99C00 2024-12-31 C011963 HHC793DDF0091C4F07817DF55F93548023 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember HHEF06096095AEF7B75F4A0C7BDEE6F001 2025-01-012025-12-31 C011963 2025-01-012025-09-30 C011963 HH205B5F2926079351DD57BDB8808C57B8 2025-12-31 C011963 eaf3ea777b61ded3febafc0004edda97 2025-01-012025-12-31 C011963 HH6FA9C58E29C1D611B86E261679923D8B 2025-01-012025-12-31 C011963 HH5A2AB9B00CFDCC2D2E6AAA3DBAAE12E2 2025-12-31 C011963 HHCE746A4076A23AF3EB14C23CB8B85157 2025-12-31 C011963 ferc:GasUtilityMember 2025-12-31 C011963 HHA8479ED5F1B6D3C1F64C6F8CBD643996 2025-12-31 C011963 Yankton 2025-12-31 C011963 ferc:OtherUtility3Member 2025-12-31 C011963 HH0E2B507F0B13752E8EF070303917C637 2025-01-012025-12-31 C011963 HH9ED770E1B5926423C6005E402EFE1DBC 2025-01-012025-12-31 C011963 ferc:OperatingUtilityMember 2025-12-31 C011963 HH0C0E63C1974907F700295D1ED584AAEF 2025-01-012025-12-31 C011963 ferc:GasUtilityMember HH59A9B52200CC819BCAC3C72C39D29C5F 2025-12-31 C011963 HHF1EB0D50DE828AB8FECD0F345EC08A5D 2024-01-012024-12-31 C011963 ferc:OtherUtilityMember HHCF1655050BEEEC4F432913340DD993F9 2025-12-31 C011963 HH1BCCCC23E0794ABD1A6B9019305A7B03 2025-12-31 C011963 54e2fd676db7b21d429b8ef5161c4fe7 2025-01-012025-12-31 C011963 ferc:CommonPlantElectricMemberferc:ElectricUtilityMember 2025-01-012025-12-31 C011963 HH2ED9913DCD3F3EBF4EFF6E8F72D3B7A3 2025-01-012025-12-31 C011963 HH5F4BDCBE299BEB86C60F038AD4B1CA66 2025-01-012025-12-31 C011963 4b63737cd7baf95e713f5295ff4b19faferc:ElectricUtilityMember 2025-12-31 C011963 ferc:NovemberMember South Dakota Operations 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMemberferc:ElectricPlantInServiceMember 2025-01-012025-12-31 C011963 HHC6560AC2BE63F6ECA933CB78898DC4CB 2025-01-012025-12-31 C011963 Bob Glanzer Gas 2025-01-012025-12-31 C011963 ScheduleAccumulatedDeferredInvestmentTaxCreditsAbstract 2025-01-012025-12-31 C011963 HH6F6C5D7CA203B2D579222F81D690B927 2025-01-012025-12-31 C011963 ferc:DistributionPlantMemberferc:ElectricUtilityMember 2025-01-012025-12-31 C011963 HH63356649C9480FBD5C0174B7E6580C24 2025-01-012025-12-31 C011963 HH02D1374E29D020FC581CB43A788313EA 2025-01-012025-12-31 C011963 HH6FA9C58E29C1D611B86E261679923D8B 2025-12-31 C011963 HHF13F279E8D9DFF2AA7FCA79847BF3454 2024-01-012024-12-31 C011963 HHA97FEDBCE30ECFBC5F77F23789B0EE00 2025-12-31 C011963 HH6248D13FDF46E2298E1BD48A89899A87 2025-01-012025-12-31 C011963 ferc:OtherRenewableProductionPlantMemberferc:ElectricUtilityMember 2025-01-012025-12-31 C011963 HH3CAD28A2181B66EAF919BB9CDFC62CCE 2024-12-31 C011963 HHEF0974A81450ED79F85B6B38DA7C59C5 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember HH5631D11D0F8A4E2B405FE784301C5A21 2025-01-012025-12-31 C011963 Aberdeen #1 2025-01-012025-12-31 C011963 HH4FCC7F93877D2AC5F186D7B2E3CD9ECF 2025-12-31 C011963 ferc:HydraulicProductionPlantConventionalMemberferc:ElectricUtilityMember 2025-01-012025-12-31 C011963 86ab5b892c578085c4cbed440f2678c1 2025-01-012025-12-31 C011963 HH7E966E726B1C509DE6AE5640B211FFB8 2025-01-012025-12-31 C011963 fa26665df2aed7bd17fa7a1ed84d3eee 2025-01-012025-12-31 C011963 HH86FC207E29ABD735661863E6FF0AC9F5 2025-01-012025-12-31 C011963 159d8b5c8e44da0a20cc1b0546738e0cferc:ElectricUtilityMember 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember bda039ee8d2c3790e6912f49212662cf 2025-01-012025-12-31 C011963 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C011963 79fe6fcfbb311dc807ffcb1c1701433c 2025-01-012025-12-31 C011963 Aberdeen #2 2025-01-012025-12-31 C011963 HHA97FEDBCE30ECFBC5F77F23789B0EE00 2025-01-012025-12-31 C011963 ferc:MayMember South Dakota Operations 2025-01-012025-12-31 C011963 HHA0C2DDF97EF237DA0B4D5EA22C0CEA77 2025-12-31 C011963 HHE945BE208E488E60111BF6C70E0C1AC7 2025-12-31 C011963 HH0E0B507C4E10878188108B8415746957 2025-01-012025-12-31 C011963 HHC6242322B64ED7981CC39B78BE3C2E31 2025-01-012025-12-31 C011963 73cdf198b06e5ed02f7b7b6db983cf5c 2025-01-012025-12-31 C011963 HHC92C699F747779DB6332AF0799EC12DC 2025-12-31 C011963 066ee09f3b16f0491308b0f82a27368f 2025-01-012025-12-31 C011963 Big Stone 2025-01-012025-12-31 C011963 Big Stone Lime 2025-01-012025-12-31 C011963 HHA1A6118132FF9E6BD33EC1DAF2D8F4AA 2025-12-31 C011963 HH14D390DF7D1EE0C60FBD2D32E99F088A 2025-12-31 C011963 HH5E9A3D727D5AA8DE32C77E01FDA51D0B 2025-12-31 C011963 HH77053D1B40826194D20178C7019B768B 2025-01-012025-12-31 C011963 ferc:GasUtilityMember HH6A7514731F394284013DD7CDD7391976 2025-01-012025-12-31 C011963 Neal 2025-12-31 C011963 ferc:JuneMember 2025-01-012025-12-31 C011963 HH96B0141273EABAB320119C467CDCAF17 2025-12-31 C011963 HH1A657CEAD53B8D92F8710D48EA961518 2025-12-31 C011963 HH59A9B52200CC819BCAC3C72C39D29C5F 2025-01-012025-12-31 C011963 HHC0C65D966E7B7358B59C8156C31A3849 2025-12-31 C011963 d2a487c0b8aa4461a18a63a478e310aaferc:ElectricUtilityMember 2025-01-012025-12-31 C011963 HHA0A6C250C667D01C5BCD76A7AFB4DF48 2024-01-012024-12-31 C011963 ferc:OperatingUtilityMember 2024-12-31 C011963 HHCAA0CE1E5897F7AC49A539500BD7C79F 2025-12-31 C011963 HH50BD4BABB35AF8AC5E01FF03301ED93C 2025-12-31 C011963 HHCBDEE3D59E14B74EBE80ACB64943D1C8 2025-01-012025-12-31 C011963 a28a16a84157918723d69e5a02d5f47a 2025-01-012025-12-31 C011963 23a413861e0f0f5afa8825a83526b794 2025-01-012025-12-31 C011963 f24848f0ebd8090b352a34fcd345337b 2025-12-31 C011963 HH115D240F2B78DEB7E06869070953C142 2025-12-31 C011963 HH7995F418F4E8A58346DF7BA423E9FD53 2025-12-31 C011963 ferc:JuneMember South Dakota Operations 2025-01-012025-12-31 C011963 Lime 2025-01-012025-12-31 C011963 HHA5D59F498B924FBDF1591674F810AA71 2025-01-012025-12-31 C011963 6eaa7e78a8b74e0364e07a81c2e5e219 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember HHFFA6E5D66DDBC4A1CBABB10AACDF6EC6 2025-01-012025-12-31 C011963 ferc:GasUtilityMember HHBCECA9ACF51EA7D6A49E5E9669397527 2025-01-012025-12-31 C011963 HHFC605604B339AC1A45D8BC2DA6C73C49 2025-01-012025-12-31 C011963 HH8D4CF91396CE241B4E15CB138A5C01A7 2025-01-012025-12-31 C011963 HHC793DDF0091C4F07817DF55F93548023 2025-12-31 C011963 ferc:GasUtilityMember HH5F4BDCBE299BEB86C60F038AD4B1CA66 2024-12-31 C011963 ferc:Quarter2Member 2025-01-012025-12-31 C011963 HHa8735b9a-3216-48ae-825f-e5b2fa9dde77 2025-01-012025-09-30 C011963 HHED9B5D93B10F95F9330832F1FD93753B 2025-12-31 C011963 HH3AB53E680740F94F31E082620DD99644 2025-12-31 C011963 HH96B0141273EABAB320119C467CDCAF17 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember 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2025-01-012025-12-31 C011963 HH94F9D570F1364C20769322AFB8C4A865 2025-12-31 C011963 829bf300ddeac96ab7debfce913931b1 2025-01-012025-12-31 C011963 47c61da891d23f8e105a21bfe95fab11 2025-01-012025-12-31 C011963 7204e193f07b4c1e33adea8926cec5c1 2025-01-012025-12-31 C011963 HHA2AADAAC981ED188D06A9B629C96CDED 2025-01-012025-12-31 C011963 HH3AB53E680740F94F31E082620DD99644 2025-01-012025-12-31 C011963 ferc:GasUtilityMember 2024-12-31 C011963 ferc:ElectricUtilityMember HHA9E61508C6B923D27C0654BA95114461 2025-01-012025-12-31 C011963 HHF537BB965667D973AFAF42BAC365283C 2025-01-012025-12-31 C011963 Beethoven Wind 2025-01-012025-12-31 C011963 HH86FC207E29ABD735661863E6FF0AC9F5 2024-12-31 C011963 HH8A7CC34B5468AEE1D74754CEEE7F35DE 2025-01-012025-12-31 C011963 HH8DE9E794ADEB8B150D8F088EC29AA373 2025-12-31 C011963 2024-01-012024-12-31 C011963 HHC92C699F747779DB6332AF0799EC12DC 2025-01-012025-12-31 C011963 ferc:OtherUtilityMember 2024-01-012024-12-31 C011963 HH879E069B41555DA138D38C1A153946B3 2025-12-31 C011963 HHFC3042B8A97C05688D6D2C7A482AD4A9 2025-01-012025-12-31 C011963 ScheduleRegionalTransmissionServiceRevenuesAbstract 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember HH688CC27FCF4F2F2A7CE2F97B111E7A87 2025-01-012025-12-31 C011963 a28a16a84157918723d69e5a02d5f47a 2025-01-012025-09-30 C011963 HHB6945EF71A0E492F5CC64B3D1CC73320 2025-01-012025-12-31 C011963 HHDEB66DC27C4A4AD63D694098C9AE4E37 2025-12-31 C011963 HH9EA64ADD0EAC3535D868EE5449CB560B 2025-01-012025-12-31 C011963 HH3F3E9E2E098BC9BEC5B1244087E556B6 2025-12-31 C011963 HH39F261BE52E4DD86EA8944AEA49A560B 2025-01-012025-12-31 C011963 ferc:WindProductionPlantMemberferc:ElectricUtilityMember 2025-01-012025-12-31 C011963 f5c66ee043355aa39c6cd0c788c468a7 2025-01-012025-12-31 C011963 HH21D0EDF1E740A8B184BAEA80C49B2AD5 2025-01-012025-12-31 C011963 HH81E62DA9E378FC960FAD3D7F824CDCC0 2025-12-31 C011963 ferc:GasUtilityMember HH59A9B52200CC819BCAC3C72C39D29C5F 2024-12-31 C011963 HHC5850B515E23FE6821E799D89F1D733A 2025-12-31 C011963 4c4ee87caa91ab64eec8c7ce5d1b8b9a 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember 2024-12-31 C011963 HH851F8E7EEA26AF16C2F26E3BEE281BAC 2025-12-31 C011963 ferc:CommonUtilityMember 2025-12-31 C011963 HHFFA6E5D66DDBC4A1CBABB10AACDF6EC6 2025-01-012025-12-31 C011963 HH6E19628685CC6F3373A1CF99BF8D970F 2025-01-012025-12-31 C011963 HH366018BE9D3F904822CE18F998E17EBD 2025-12-31 C011963 fdab4c55a2734c23110353a85cdd8b1d 2025-01-012025-12-31 C011963 HHEF5F971EFB6E8F84D4103D077DF79735 2025-12-31 C011963 HHF22794F69CE5910CB4BE68FF9026570D 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember HH693c1b7a-40f5-47dd-a956-7b0adc0acbad 2025-01-012025-12-31 C011963 ferc:OtherElectricUtilityMember 2024-12-31 C011963 HH9C413CCF44D8F4348A9F70C32D540909 2025-01-012025-12-31 C011963 50f96dcc0d138b0cbe7cdf5f0890e84b 2025-01-012025-12-31 C011963 2bc78b50681e999dd176a802760525c5 2025-01-012025-12-31 C011963 ferc:DecemberMember 2025-01-012025-12-31 C011963 HH14D390DF7D1EE0C60FBD2D32E99F088A 2025-01-012025-12-31 C011963 HH5E9A3D727D5AA8DE32C77E01FDA51D0B 2025-01-012025-12-31 C011963 HH928C75131011FB27C579411C9093E5B4 2025-12-31 C011963 ferc:ElectricUtilityMember 2024-01-012024-12-31 C011963 HH275975AE44D14278C143B2206BBD0B9B 2025-01-012025-12-31 C011963 HHB1C2E38F43BEECCBBE29B1A207F9BA6B 2025-12-31 C011963 HH5492E4AC47183E35584BEE02A551A043 2025-12-31 C011963 HH031E9FCA7BBA9732AA3C6D1AA748C84A 2024-12-31 C011963 ferc:RegionalTransmissionAndMarketOperationMemberferc:ElectricUtilityMember 2025-01-012025-12-31 C011963 HHE945BE208E488E60111BF6C70E0C1AC7 2025-01-012025-12-31 C011963 a5375d02df4e1b5015df084b6c873811 2025-01-012025-12-31 C011963 HH4A6D3C0C80950006CA9FD4654708F43F 2025-12-31 C011963 HHCF17E3D6C0BBBEDC6603E9AE26D0ADA1 2025-12-31 C011963 HHF137667547FDA5A6904DD49BCFA3F7D3 2025-12-31 C011963 HH43D33D4C26BAC4A32A0428EAEC41ACF4 2025-12-31 C011963 ferc:ElectricUtilityMemberferc:ElectricPlantHeldForFutureUseMember 2025-01-012025-12-31 C011963 HHC5ED3DE06A99A9EDE35DBD12F36A05A0 2025-12-31 C011963 61b6ff9d90076ab3ca5e4c6c0c11ad94 2025-01-012025-12-31 C011963 ferc:GasUtilityMember HH59A9B52200CC819BCAC3C72C39D29C5F 2025-01-012025-12-31 C011963 HH205B5F2926079351DD57BDB8808C57B8 2025-01-012025-12-31 C011963 HHa8735b9a-3216-48ae-825f-e5b2fa9dde77 2025-01-012025-06-30 C011963 HHCAA0CE1E5897F7AC49A539500BD7C79F 2025-01-012025-12-31 C011963 1d965a60fcb814bdc39af15e40efd666 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMemberferc:ElectricPlantInServiceMember 2024-12-31 C011963 HH9B91D8A3CDC9C3201A90AF97DCE32EDB 2025-12-31 C011963 ferc:GasUtilityMember HH5CF5843E7EF02523C0E8735AC48F41EB 2025-01-012025-12-31 C011963 HHA8479ED5F1B6D3C1F64C6F8CBD643996 2025-01-012025-12-31 C011963 HH74598AF814F798F2736634D9DD96F01F 2025-12-31 C011963 HH82FB724804A45BFAD75059B1DBF8E85C 2025-12-31 C011963 HHCD60D194531594C2E9E760168FDEDC70 2025-01-012025-12-31 C011963 HH82FB724804A45BFAD75059B1DBF8E85C 2025-01-012025-12-31 C011963 cedf5a2adda4ac2b4b3f08da3a122d5e 2025-01-012025-12-31 C011963 ScheduleElectricPropertyLeasedToOthersAbstract 2025-01-012025-12-31 C011963 HH8D4CF91396CE241B4E15CB138A5C01A7 2025-12-31 C011963 ferc:OctoberMember South Dakota Operations 2025-01-012025-12-31 C011963 9e2b8d3f9adce7d8b71182dc0f9a3713 2025-01-012025-12-31 C011963 Aberdeen #2 Oil 2025-01-012025-12-31 C011963 HH7679A77C593EB0B07C2302A67D57731D 2025-01-012025-12-31 C011963 Coyote 2025-01-012025-12-31 C011963 HH8757D3473DA62FAD5EDA056F06A85830 2025-01-012025-12-31 C011963 HH858C64973FEE236949705AE45578609E 2025-12-31 C011963 4b63737cd7baf95e713f5295ff4b19faferc:ElectricUtilityMember 2025-01-012025-12-31 C011963 HHB2F44C444B8E86B2CA19459A49D57A84 2024-12-31 C011963 HH6FBBC6768E5374CD464D0517F4EF05AB 2025-12-31 C011963 a526b7facc80da7969bb76f996d965e4 2025-01-012025-12-31 C011963 HH693c1b7a-40f5-47dd-a956-7b0adc0acbad 2025-01-012025-12-31 C011963 ScheduleResearchDevelopmentOrDemonstrationExpendituresAbstract 2025-01-012025-12-31 C011963 HH851F8E7EEA26AF16C2F26E3BEE281BAC 2025-01-012025-12-31 C011963 HH04AB2791367F280352414A4AECB0C263 2025-12-31 C011963 HH32C15D8DC162B4F66DE8A399CEB894F8 2025-01-012025-12-31 C011963 ferc:OperatingUtilityMember 2025-01-012025-12-31 C011963 HHE63FE557EC309D58F2B01C670ED058AF 2025-12-31 C011963 HH9F2D77E1634733DC138D67EED4975509 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember 2025-01-012025-12-31 C011963 HH8DE9E794ADEB8B150D8F088EC29AA373 2025-01-012025-12-31 C011963 HH94F9D570F1364C20769322AFB8C4A865 2025-01-012025-12-31 C011963 ferc:OtherGasUtilityMember 2025-12-31 C011963 HH9DA6FEBDA2D65702DADEB2431A1401F2 2025-01-012025-12-31 C011963 14dec3c46853af07077cc85c444e9299 2025-01-012025-12-31 C011963 ferc:OtherUtilityMember HHCF1655050BEEEC4F432913340DD993F9 2025-01-012025-12-31 C011963 HHF07BEBA82F45005BF1725483FC994E41 2025-12-31 C011963 HH0A67F1EADDC83B25BDC77584F59EC791 2025-01-012025-12-31 C011963 SchedulePumpedStorageGeneratingPlantStatisticsAbstract 2025-01-012025-12-31 C011963 ferc:GasUtilityMember a0456a99f05778a101aac55ab1b8445f 2024-12-31 C011963 HHB1C2E38F43BEECCBBE29B1A207F9BA6B 2025-01-012025-12-31 C011963 HH8757D3473DA62FAD5EDA056F06A85830 2025-12-31 C011963 HH402765FD0E75E9A678F5AC3E3621F1ED 2025-01-012025-12-31 C011963 HH3B9F93ABF952AF0839839D979FADB334 2025-12-31 C011963 HH9EA97C5FFCF0CDDBDA8D50AB3CD1BF1F 2025-12-31 C011963 HHE63FE557EC309D58F2B01C670ED058AF 2025-01-012025-12-31 C011963 HH15F87D838AA553833164C9A7744D10D6 2025-01-012025-12-31 C011963 HHA1A6118132FF9E6BD33EC1DAF2D8F4AA 2025-01-012025-12-31 C011963 Coyote Coal 2025-01-012025-12-31 C011963 Neal 2025-01-012025-12-31 C011963 2025-01-012025-12-31 C011963 HHFE412A537F65D848FA084BD296031969 2024-12-31 C011963 679afc681eed91331f49d420c7255b4b 2025-01-012025-12-31 C011963 HH5C0F1B45ECE4D0F2D48C8D8573C9CFFD 2025-01-012025-12-31 C011963 HH52C29A91C30914A3732A1D8A599B71BA 2025-12-31 C011963 ScheduleElectricPlantHeldForFutureUseAbstract 2025-01-012025-12-31 C011963 HHBA75A082DA336331D7CAAC55CB107F4C 2025-12-31 C011963 HH5A4D4DF2A86F1027DC949A007885F67A 2025-12-31 C011963 HH8BFC9B04444B6E668520F4747145592C 2025-01-012025-12-31 C011963 HHA43D49E56121318DC5DE79F25097EC38 2025-12-31 C011963 HH27A86E5FB3DBBAD194E9DBB6F5A2B7D6 2025-01-012025-12-31 C011963 HH52C29A91C30914A3732A1D8A599B71BA 2025-01-012025-12-31 C011963 HH1BCCCC23E0794ABD1A6B9019305A7B03 2025-01-012025-12-31 C011963 HH9DA6FEBDA2D65702DADEB2431A1401F2 2024-12-31 C011963 HHC6A7FBE869B5D338F26C6BE58100676B 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMemberferc:ElectricPlantHeldForFutureUseMember 2024-12-31 C011963 ferc:AprilMember 2025-01-012025-12-31 C011963 HH27A86E5FB3DBBAD194E9DBB6F5A2B7D6 2025-12-31 C011963 HH87CBF907B7FC67D492272BC68BC667E0 2025-12-31 C011963 159d8b5c8e44da0a20cc1b0546738e0c 2025-01-012025-12-31 C011963 HH805D53C31D88D6655695306EFC12C638 2025-12-31 C011963 HHA2AADAAC981ED188D06A9B629C96CDED 2025-12-31 C011963 ScheduleInvestmentsInSubsidiaryCompaniesAbstract 2025-01-012025-12-31 C011963 Coyote 2025-12-31 C011963 HH4FA44F6986EABEAE551C3EFC27434718 2024-12-31 C011963 HH440E2E1ED176CD5151D619D610D5EDC7 2025-01-012025-12-31 C011963 c4ce6a1e5d2a64e836bac7c9d4ea1b30 2025-01-012025-12-31 C011963 HHBBDCAD31B047D7AC256B0FF11432475E 2025-12-31 C011963 ferc:ElectricUtilityMemberferc:ElectricPlantInServiceMember 2025-12-31 C011963 ferc:FebruaryMember South Dakota Operations 2025-01-012025-12-31 C011963 Coyote Oil 2025-01-012025-12-31 C011963 HHA0A6C250C667D01C5BCD76A7AFB4DF48 2025-01-012025-12-31 C011963 HH374329579AADAAA0E6792356B577E955 2025-01-012025-12-31 C011963 HH72BE145B48838FABD3DCEB99C325E7FD 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember HHCD0E44E2C1557F8BE1FBE357B5DE8FC5 2025-12-31 C011963 fcb42c7e279bec332790c3f4d599a710 2025-01-012025-12-31 C011963 HHa8735b9a-3216-48ae-825f-e5b2fa9dde77 2025-01-012025-12-31 C011963 a0456a99f05778a101aac55ab1b8445f 2025-01-012025-12-31 C011963 HHED9B5D93B10F95F9330832F1FD93753B 2025-01-012025-12-31 C011963 ferc:GasUtilityMember HH5F4BDCBE299BEB86C60F038AD4B1CA66 2025-01-012025-12-31 C011963 797e16bb38b645c9be64e61b9379cdef 2025-01-012025-12-31 C011963 6b7ec20cde3362c07ec56f8ef767a694 2025-01-012025-12-31 C011963 HH6248D13FDF46E2298E1BD48A89899A87 2025-12-31 C011963 ferc:ElectricUtilityMember 87f4013d298a46a7a69d3ca4124d1607 2025-12-31 C011963 ScheduleSalesForResaleAbstract 2025-01-012025-12-31 C011963 ferc:JulyMember South Dakota Operations 2025-01-012025-12-31 C011963 Oil 2025-01-012025-12-31 C011963 HH101791264CC2D1072B3843D11F5FB150 2025-12-31 C011963 555f12117659ec1c27e61dbd21d85f04 2025-01-012025-12-31 C011963 HH98A0430DFE6121B2478A8EF7ECA99C00 2025-01-012025-12-31 C011963 HH8DE9E794ADEB8B150D8F088EC29AA373 2024-12-31 C011963 HH688CC27FCF4F2F2A7CE2F97B111E7A87 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember HH688CC27FCF4F2F2A7CE2F97B111E7A87 2024-12-31 C011963 HHF13F279E8D9DFF2AA7FCA79847BF3454 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember HH802E01C532FA9CB1EF2B3D1810F72DDA 2025-01-012025-12-31 C011963 HH74598AF814F798F2736634D9DD96F01F 2024-12-31 C011963 0f88c87e6bfeceae25da5f1cb0512c06 2025-01-012025-12-31 C011963 HH7E966E726B1C509DE6AE5640B211FFB8 2025-12-31 C011963 HH115D240F2B78DEB7E06869070953C142 2025-01-012025-12-31 C011963 4e2047829c46bc54371d7b4afe1dd687 2025-01-012025-12-31 C011963 ferc:JanuaryMember 2025-01-012025-12-31 C011963 Aberdeen #2 Gas 2025-01-012025-12-31 C011963 HHA03A7F00BE61F09B38D6828FD3782499 2025-12-31 C011963 ferc:GasUtilityMember HH5F4BDCBE299BEB86C60F038AD4B1CA66 2025-12-31 C011963 792fef3a1f555286ad11b781b5b6cabb 2025-01-012025-12-31 C011963 b06080784b4729d1cb8db538b3fc1888 2025-01-012025-12-31 C011963 4ad27bdc97448db8c8b84ba17e937c6b 2025-01-012025-12-31 C011963 aff6febf48d3fdffd8a89a7d2f25d504 2025-01-012025-12-31 C011963 ferc:GasUtilityMember aa011183b9d38ca73899eaf20b83a4d4 2025-01-012025-12-31 C011963 HHCD0E44E2C1557F8BE1FBE357B5DE8FC5 2025-01-012025-12-31 C011963 SchedulePurchasesSalesOfAncillaryServicesAbstract 2025-01-012025-12-31 C011963 HHA6103ED5387BB5B82595AD7213244522 2025-01-012025-12-31 C011963 HHC663AD85C37A2F2218898DD9D44B3F3F 2025-01-012025-12-31 C011963 HH851F8E7EEA26AF16C2F26E3BEE281BAC 2024-12-31 C011963 HH802E01C532FA9CB1EF2B3D1810F72DDA 2024-12-31 C011963 HH7CC108964B28461F4188FE7F0CE491E1 2025-01-012025-12-31 C011963 HH15F87D838AA553833164C9A7744D10D6 2024-12-31 C011963 HHE65F413CACA259AD4D81250A93266C01 2025-01-012025-12-31 C011963 HH928C75131011FB27C579411C9093E5B4 2025-01-012025-12-31 C011963 e3df6b65cce862d10f98d012e1bd3c3f 2025-01-012025-12-31 C011963 HH9934318DC5D65BEA8C15707CF8E006B5 2025-01-012025-12-31 C011963 HHFE412A537F65D848FA084BD296031969 2025-01-012025-12-31 C011963 HH3CAD28A2181B66EAF919BB9CDFC62CCE 2025-12-31 C011963 ScheduleAccumulatedDeferredIncomeTaxesAcceleratedAmortizationPropertyAbstract 2025-01-012025-12-31 C011963 94dfe84167d27eabc8b97670c1059418 2025-01-012025-12-31 C011963 HH83E9AF34300553FF3EB1C63FC9D2BBCB 2025-12-31 C011963 Neal Coal 2025-01-012025-12-31 C011963 7d5b9e93189ba2f03213d0c4b68a8f62 2025-01-012025-12-31 C011963 2025-01-012025-03-31 C011963 HH440E2E1ED176CD5151D619D610D5EDC7 2025-12-31 C011963 HH8584FB5473816211F2109B3627962785 2025-12-31 C011963 HH8E50F119A402C17366A6296859EC00EC 2025-12-31 C011963 HH6821D6B23A748D6F09E8CE0DB67A73C1 2025-01-012025-12-31 C011963 HH06ECF7086F0A59ED1610913EFD3F4607 2024-12-31 C011963 ferc:GenerationStudiesMember 7092eb76c0ff984e9d88fa5b71caf7a3 2025-01-012025-12-31 C011963 HH0C0E63C1974907F700295D1ED584AAEF 2025-12-31 C011963 ef977a1d0273602d6e073985046be1cf 2025-01-012025-12-31 C011963 HHA9E61508C6B923D27C0654BA95114461 2025-12-31 C011963 a077d73c518b9dee7b17d6fdada1769e 2025-01-012025-12-31 C011963 HH0E0B507C4E10878188108B8415746957 2025-12-31 C011963 HH39F261BE52E4DD86EA8944AEA49A560B 2025-12-31 C011963 ferc:ElectricUtilityMember HH96C8C75DEEC981F1DE6E7CE10A10D3E7 2025-01-012025-12-31 C011963 912a547d4ceb56149a9d0fa81a1c1e2a 2025-01-012025-12-31 C011963 HH6EFCC9D66F821E5F1A152DC902BF5665 2025-01-012025-12-31 C011963 HH67658B7C99CE439B5716100DDE7AF9B0 2024-12-31 C011963 HH25FDCF57EE2E25EAC08A513DA2BAE38F 2025-12-31 C011963 HHEF5F971EFB6E8F84D4103D077DF79735 2025-01-012025-12-31 C011963 HH505D917B225DA76B0858B1AA3B67836F 2025-01-012025-12-31 C011963 HH54CF5C79C6EBF19A19B2C2F1ECE40AD7 2025-12-31 C011963 ScheduleAllowanceInventoryAbstract 2025-01-012025-12-31 C011963 HHA7B127F88885574178D47E046DFC435E 2025-01-012025-12-31 C011963 HH45649F08ABEB2FC070ABD2846CFDBA8F 2025-12-31 C011963 HH9EA97C5FFCF0CDDBDA8D50AB3CD1BF1F 2024-12-31 C011963 HH06ECF7086F0A59ED1610913EFD3F4607 2025-12-31 C011963 HH873A7CCCD531B170C86B3BE912B6A46B 2025-01-012025-12-31 C011963 HHC1E6771DC5088C7BC63E17C3DC5D73E8 2025-12-31 C011963 ferc:GasUtilityMember HH5CF5843E7EF02523C0E8735AC48F41EB 2024-12-31 C011963 HH5492E4AC47183E35584BEE02A551A043 2025-01-012025-12-31 C011963 0f6f2f1672f58f9ce63a507bceaed036 2025-01-012025-12-31 C011963 HH6EFCC9D66F821E5F1A152DC902BF5665 2024-12-31 C011963 HH6916CAFD2FAAFB97072A25DDB437F068 2025-01-012025-12-31 C011963 HH4FCC7F93877D2AC5F186D7B2E3CD9ECF 2025-01-012025-12-31 C011963 ferc:FebruaryMember 2025-01-012025-12-31 C011963 HH13954B7099826D0D845B8D74F257E080 2025-12-31 C011963 ferc:TransmissionPlantMemberferc:ElectricUtilityMember 2025-01-012025-12-31 C011963 HH275975AE44D14278C143B2206BBD0B9B 2025-12-31 C011963 HHa8735b9a-3216-48ae-825f-e5b2fa9dde77 2025-01-012025-03-31 C011963 f24848f0ebd8090b352a34fcd345337b 2024-12-31 C011963 HHA16859FCA84C9EF365706E55D7CB7389 2025-12-31 C011963 HHCBDEE3D59E14B74EBE80ACB64943D1C8 2025-12-31 C011963 ferc:OctoberMember 2025-01-012025-12-31 C011963 HH32C15D8DC162B4F66DE8A399CEB894F8 2025-12-31 C011963 HH82FB724804A45BFAD75059B1DBF8E85C 2024-12-31 C011963 ferc:Quarter3Member 2025-01-012025-12-31 C011963 23d440396c5e5c1da48652b0d6e1b814 2025-01-012025-12-31 C011963 HHFD17B8AF4AB1AB4D459EDFDD2B62F04C 2025-01-012025-12-31 C011963 HHB2F44C444B8E86B2CA19459A49D57A84 2025-01-012025-12-31 C011963 Neal Oil 2025-01-012025-12-31 C011963 HH67658B7C99CE439B5716100DDE7AF9B0 2025-01-012025-12-31 C011963 af24c302a68abd4fdd174367b4af1c31 2025-01-012025-12-31 C011963 HH6311AE17C1EE52B36E68AAF4AD066387 2025-01-012025-12-31 C011963 HH51BD5FFB663C8198E1720D742782F5A9 2025-01-012025-12-31 C011963 ferc:OtherUtilityMember HHCF1655050BEEEC4F432913340DD993F9 2024-12-31 C011963 HH9F2D77E1634733DC138D67EED4975509 2025-12-31 C011963 HHC6242322B64ED7981CC39B78BE3C2E31 2025-12-31 C011963 HH36A23D2DBB508979ACD6F221115BC4D1 2024-01-012024-12-31 C011963 159d8b5c8e44da0a20cc1b0546738e0cferc:ElectricUtilityMember 2025-12-31 C011963 ferc:NovemberMember 2025-01-012025-12-31 C011963 HH802E01C532FA9CB1EF2B3D1810F72DDA 2025-12-31 C011963 2023-12-31 C011963 HH13954B7099826D0D845B8D74F257E080 2025-01-012025-12-31 C011963 ferc:GasUtilityMember HHBCECA9ACF51EA7D6A49E5E9669397527 2024-12-31 C011963 HHD36F8CCB77534D64D11B62D3EC04DDEA 2025-01-012025-12-31 C011963 HH5B2DFF5B695AB5F1B55728ACBC142860 2025-12-31 C011963 ferc:OtherUtility2Member 2025-12-31 C011963 ferc:ElectricUtilityMember HHA7B127F88885574178D47E046DFC435E 2025-01-012025-12-31 C011963 ferc:GasUtilityMember a0456a99f05778a101aac55ab1b8445f 2025-01-012025-12-31 C011963 HHF537BB965667D973AFAF42BAC365283C 2025-12-31 C011963 HH5D503FC419A855A7A35C2748DF5AA7D2 2024-12-31 C011963 HHDBDA3D0BE33E21E91176828FEFC7A353 2025-01-012025-12-31 C011963 39e00420b1e9c320bc5326364fa7f311 2025-12-31 C011963 HH4FA44F6986EABEAE551C3EFC27434718 2025-12-31 C011963 HHF137667547FDA5A6904DD49BCFA3F7D3 2024-12-31 C011963 HH031E9FCA7BBA9732AA3C6D1AA748C84A 2025-01-012025-12-31 C011963 ferc:GasUtilityMember aa011183b9d38ca73899eaf20b83a4d4 2025-12-31 C011963 ScheduleEnergyStorageOperationsLargePlantsAbstract 2025-01-012025-12-31 C011963 HHFF66C82A968C746440A84BCA2AEF87A9 2025-01-012025-12-31 C011963 HH21AE08DA148DDDBF07C1F02621A573C3 2025-12-31 C011963 HHA9E61508C6B923D27C0654BA95114461 2024-12-31 C011963 87f4013d298a46a7a69d3ca4124d1607 2025-01-012025-12-31 C011963 ferc:ElectricUtilityMember 87f4013d298a46a7a69d3ca4124d1607 2024-12-31 C011963 HHF137667547FDA5A6904DD49BCFA3F7D3 2025-01-012025-12-31 C011963 ferc:AprilMember South Dakota Operations 2025-01-012025-12-31 C011963 HHDE458B788D4277FF3FC8F3E920F6E7FF 2024-12-31 C011963 cffa7bb479151d9f48dba87b659bc893 2025-01-012025-12-31 xbrli:shares utr:Btu iso4217:USD utr:kWh utr:Btu utr:kWh utr:MWh utr:MW iso4217:USD utr:kWh iso4217:USD utr:MMBTU utr:MVA utr:mi xbrli:pure iso4217:USD utr:MW utr:kV iso4217:USD utr:kW
THIS FILING IS
Item 1:
An Initial (Original) Submission
OR
Resubmission No.

FERC FINANCIAL REPORT
FERC FORM No. 1: Annual Report of
Major Electric Utilities, Licensees
and Others and Supplemental
Form 3-Q: Quarterly Financial Report

These reports are mandatory under the Federal Power Act, Sections 3, 4(a), 304 and 309, and 18 CFR 141.1 and 141.400. Failure to report may result in criminal fines, civil penalties and other sanctions as provided by law. The Federal Energy Regulatory Commission does not consider these reports to be of confidential nature
Exact Legal Name of Respondent (Company)

NorthWestern Energy Public Service Corporation
Year/Period of Report

End of:
2025
/
Q4


INSTRUCTIONS FOR FILING FERC FORM NOS. 1 and 3-Q

GENERAL INFORMATION

  1. Purpose

    FERC Form No. 1 (FERC Form 1) is an annual regulatory requirement for Major electric utilities, licensees and others (18 C.F.R. § 141.1). FERC Form No. 3-Q ( FERC Form 3-Q) is a quarterly regulatory requirement which supplements the annual financial reporting requirement (18 C.F.R. § 141.400). These reports are designed to collect financial and operational information from electric utilities, licensees and others subject to the jurisdiction of the Federal Energy Regulatory Commission. These reports are also considered to be non-confidential public use forms.
  2. Who Must Submit

    Each Major electric utility, licensee, or other, as classified in the Commission’s Uniform System of Accounts Prescribed for Public Utilities, Licensees, and Others Subject To the Provisions of The Federal Power Act (18 C.F.R. Part 101), must submit FERC Form 1 (18 C.F.R. § 141.1), and FERC Form 3-Q (18 C.F.R. § 141.400).

    Note: Major means having, in each of the three previous calendar years, sales or transmission service that exceeds one of the following:
    1. one million megawatt hours of total annual sales,
    2. 100 megawatt hours of annual sales for resale,
    3. 500 megawatt hours of annual power exchanges delivered, or
    4. 500 megawatt hours of annual wheeling for others (deliveries plus losses).
  3. What and Where to Submit

    1. Submit FERC Form Nos. 1 and 3-Q electronically through the eCollection portal at https://eCollection.ferc.gov, and according to the specifications in the Form 1 and 3-Q taxonomies.
    2. The Corporate Officer Certification must be submitted electronically as part of the FERC Forms 1 and 3-Q filings.
    3. Submit immediately upon publication, by either eFiling or mail, two (2) copies to the Secretary of the Commission, the latest Annual Report to Stockholders. Unless eFiling the Annual Report to Stockholders, mail the stockholders report to the Secretary of the Commission at:
      Secretary
      Federal Energy Regulatory Commission 888 First Street, NE
      Washington, DC 20426
    4. For the CPA Certification Statement, submit within 30 days after filing the FERC Form 1, a letter or report (not applicable to filers classified as Class C or Class D prior to January 1, 1984). The CPA Certification Statement can be either eFiled or mailed to the Secretary of the Commission at the address above.

      The CPA Certification Statement should:
      1. Attest to the conformity, in all material aspects, of the below listed (schedules and pages) with the Commission's applicable Uniform System of Accounts (including applicable notes relating thereto and the Chief Accountant's published accounting releases), and
      2. Be signed by independent certified public accountants or an independent licensed public accountant certified or licensed by a regulatory authority of a State or other political subdivision of the U. S. (See 18 C.F.R. §§ 41.10-41.12 for specific qualifications.)

        Schedules
        Pages
        Comparative Balance Sheet 110-113
        Statement of Income 114-117
        Statement of Retained Earnings 118-119
        Statement of Cash Flows 120-121
        Notes to Financial Statements 122-123
    5. The following format must be used for the CPA Certification Statement unless unusual circumstances or conditions, explained in the letter or report, demand that it be varied. Insert parenthetical phrases only when exceptions are reported.

      “In connection with our regular examination of the financial statements of [COMPANY NAME] for the year ended on which we have reported separately under date of [DATE], we have also reviewed schedules [NAME OF SCHEDULES] of FERC Form No. 1 for the year filed with the Federal Energy Regulatory Commission, for conformity in all material respects with the requirements of the Federal Energy Regulatory Commission as set forth in its applicable Uniform System of Accounts and published accounting releases. Our review for this purpose included such tests of the accounting records and such other auditing procedures as we considered necessary in the circumstances.

      Based on our review, in our opinion the accompanying schedules identified in the preceding paragraph (except as noted below) conform in all material respects with the accounting requirements of the Federal Energy Regulatory Commission as set forth in its applicable Uniform System of Accounts and published accounting releases.” The letter or report must state which, if any, of the pages above do not conform to the Commission’s requirements. Describe the discrepancies that exist.
    6. Filers are encouraged to file their Annual Report to Stockholders, and the CPA Certification Statement using eFiling. Further instructions are found on the Commission’s website at https://www.ferc.gov/ferc-online/ferc-online/frequently-asked-questions-faqs-efilingferc-online.
    7. Federal, State, and Local Governments and other authorized users may obtain additional blank copies of FERC Form 1 and 3-Q free of charge from https://www.ferc.gov/general-information-0/electric-industry-forms.
  4. When to Submit

    FERC Forms 1 and 3-Q must be filed by the following schedule:

    1. FERC Form 1 for each year ending December 31 must be filed by April 18th of the following year (18 CFR § 141.1), and
    2. FERC Form 3-Q for each calendar quarter must be filed within 60 days after the reporting quarter (18 C.F.R. § 141.400).
  5. Where to Send Comments on Public Reporting Burden.

    The public reporting burden for the FERC Form 1 collection of information is estimated to average 1,168 hours per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data-needed, and completing and reviewing the collection of information. The public reporting burden for the FERC Form 3-Q collection of information is estimated to average 168 hours per response.

    Send comments regarding these burden estimates or any aspect of these collections of information, including suggestions for reducing burden, to the Federal Energy Regulatory Commission, 888 First Street NE, Washington, DC 20426 (Attention: Information Clearance Officer); and to the Office of Information and Regulatory Affairs, Office of Management and Budget, Washington, DC 20503 (Attention: Desk Officer for the Federal Energy Regulatory Commission). No person shall be subject to any penalty if any collection of information does not display a valid control number (44 U.S.C. § 3512 (a)).

GENERAL INSTRUCTIONS

  1. Prepare this report in conformity with the Uniform System of Accounts (18 CFR Part 101) (USofA). Interpret all accounting words and phrases in accordance with the USofA.
  2. Enter in whole numbers (dollars or MWH) only, except where otherwise noted. (Enter cents for averages and figures per unit where cents are important. The truncating of cents is allowed except on the four basic financial statements where rounding is required.) The amounts shown on all supporting pages must agree with the amounts entered on the statements that they support. When applying thresholds to determine significance for reporting purposes, use for balance sheet accounts the balances at the end of the current reporting period, and use for statement of income accounts the current year's year to date amounts.
  3. Complete each question fully and accurately, even if it has been answered in a previous report. Enter the word "None" where it truly and completely states the fact.
  4. For any page(s) that is not applicable to the respondent, omit the page(s) and enter "NA," "NONE," or "Not Applicable" in column (d) on the List of Schedules, pages 2 and 3.
  5. Enter the month, day, and year for all dates. Use customary abbreviations. The "Date of Report" included in the header of each page is to be completed only for resubmissions (see VII. below).
  6. Generally, except for certain schedules, all numbers, whether they are expected to be debits or credits, must be reported as positive. Numbers having a sign that is different from the expected sign must be reported by enclosing the numbers in parentheses.
  7. For any resubmissions, please explain the reason for the resubmission in a footnote to the data field.
  8. Do not make references to reports of previous periods/years or to other reports in lieu of required entries, except as specifically authorized.
  9. Wherever (schedule) pages refer to figures from a previous period/year, the figures reported must be based upon those shown by the report of the previous period/year, or an appropriate explanation given as to why the different figures were used.
  10. Schedule specific instructions are found in the applicable taxonomy and on the applicable blank rendered form.
Definitions for statistical classifications used for completing schedules for transmission system reporting are as follows:

FNS - Firm Network Transmission Service for Self. "Firm" means service that can not be interrupted for economic reasons and is intended to remain reliable even under adverse conditions. "Network Service" is Network Transmission Service as described in Order No. 888 and the Open Access Transmission Tariff. "Self" means the respondent.

FNO - Firm Network Service for Others. "Firm" means that service cannot be interrupted for economic reasons and is intended to remain reliable even under adverse conditions. "Network Service" is Network Transmission Service as described in Order No. 888 and the Open Access Transmission Tariff.

LFP - for Long-Term Firm Point-to-Point Transmission Reservations. "Long-Term" means one year or longer and” firm" means that service cannot be interrupted for economic reasons and is intended to remain reliable even under adverse conditions. "Point-to-Point Transmission Reservations" are described in Order No. 888 and the Open Access Transmission Tariff. For all transactions identified as LFP, provide in a footnote the termination date of the contract defined as the earliest date either buyer or seller can unilaterally cancel the contract.

OLF - Other Long-Term Firm Transmission Service. Report service provided under contracts which do not conform to the terms of the Open Access Transmission Tariff. "Long-Term" means one year or longer and “firm” means that service cannot be interrupted for economic reasons and is intended to remain reliable even under adverse conditions. For all transactions identified as OLF, provide in a footnote the termination date of the contract defined as the earliest date either buyer or seller can unilaterally get out of the contract.

SFP - Short-Term Firm Point-to-Point Transmission Reservations. Use this classification for all firm point-to-point transmission reservations, where the duration of each period of reservation is less than one-year.

NF - Non-Firm Transmission Service, where firm means that service cannot be interrupted for economic reasons and is intended to remain reliable even under adverse conditions.

OS - Other Transmission Service. Use this classification only for those services which can not be placed in the above-mentioned classifications, such as all other service regardless of the length of the contract and service FERC Form. Describe the type of service in a footnote for each entry.

AD - Out-of-Period Adjustments. Use this code for any accounting adjustments or "true-ups" for service provided in prior reporting periods. Provide an explanation in a footnote for each adjustment.

DEFINITIONS
  1. Commission Authorization (Comm. Auth.) -- The authorization of the Federal Energy Regulatory Commission, or any other Commission. Name the commission whose authorization was obtained and give date of the authorization.
  2. Respondent -- The person, corporation, licensee, agency, authority, or other Legal entity or instrumentality in whose behalf the report is made.

EXCERPTS FROM THE LAW

Federal Power Act, 16 U.S.C. § 791a-825r

Sec. 3. The words defined in this section shall have the following meanings for purposes of this Act, to with:

  1. ’Corporation' means any corporation, joint-stock company, partnership, association, business trust, organized group of persons, whether incorporated or not, or a receiver or receivers, trustee or trustees of any of the foregoing. It shall not include 'municipalities, as hereinafter defined;
  2. 'Person' means an individual or a corporation;
  3. 'Licensee, means any person, State, or municipality Licensed under the provisions of section 4 of this Act, and any assignee or successor in interest thereof;
  1. 'municipality means a city, county, irrigation district, drainage district, or other political subdivision or agency of a State competent under the Laws thereof to carry and the business of developing, transmitting, unitizing, or distributing power; ......
  1. "project' means. a complete unit of improvement or development, consisting of a power house, all water conduits, all dams and appurtenant works and structures (including navigation structures) which are a part of said unit, and all storage, diverting, or fore bay reservoirs directly connected therewith, the primary line or lines transmitting power there from to the point of junction with the distribution system or with the interconnected primary transmission system, all miscellaneous structures used and useful in connection with said unit or any part thereof, and all water rights, rights-of-way, ditches, dams, reservoirs, Lands, or interest in Lands the use and occupancy of which are necessary or appropriate in the maintenance and operation of such unit;

"Sec. 4. The Commission is hereby authorized and empowered
  1. 'To make investigations and to collect and record data concerning the utilization of the water 'resources of any region to be developed, the water-power industry and its relation to other industries and to interstate or foreign commerce, and concerning the location, capacity, development costs, and relation to markets of power sites; ... to the extent the Commission may deem necessary or useful for the purposes of this Act."

"Sec. 304.
  1. Every Licensee and every public utility shall file with the Commission such annual and other periodic or special* reports as the Commission may by rules and regulations or other prescribe as necessary or appropriate to assist the Commission in the proper administration of this Act. The Commission may prescribe the manner and FERC Form in which such reports shall be made, and require from such persons specific answers to all questions upon which the Commission may need information. The Commission may require that such reports shall include, among other things, full information as to assets and Liabilities, capitalization, net investment, and reduction thereof, gross receipts, interest due and paid, depreciation, and other reserves, cost of project and other facilities, cost of maintenance and operation of the project and other facilities, cost of renewals and replacement of the project works and other facilities, depreciation, generation, transmission, distribution, delivery, use, and sale of electric energy. The Commission may require any such person to make adequate provision for currently determining such costs and other facts. Such reports shall be made under oath unless the Commission otherwise specifies*.10
"Sec. 309.
  1. The Commission shall have power to perform any and all acts, and to prescribe, issue, make, and rescind such orders, rules and regulations as it may find necessary or appropriate to carry out the provisions of this Act. Among other things, such rules and regulations may define accounting, technical, and trade terms used in this Act; and may prescribe the FERC Form or FERC Forms of all statements, declarations, applications, and reports to be filed with the Commission, the information which they shall contain, and the time within which they shall be field..."

GENERAL PENALTIES

The Commission may assess up to $1 million per day per violation of its rules and regulations. See FPA § 316(a) (2005), 16 U.S.C. § 825o(a).


FERC FORM NO.
1

REPORT OF MAJOR ELECTRIC UTILITIES, LICENSEES AND OTHER
IDENTIFICATION
01 Exact Legal Name of Respondent

NorthWestern Energy Public Service Corporation
02 Year/ Period of Report


End of:
2025
/
Q4
03 Previous Name and Date of Change (If name changed during year)

/
04 Address of Principal Office at End of Period (Street, City, State, Zip Code)

3010 West 69th Street, Sioux Falls, SD 57108
05 Name of Contact Person

Evan VerWey
06 Title of Contact Person

Manager of Financial Reporting
07 Address of Contact Person (Street, City, State, Zip Code)

3010 West 69th Street, Sioux Falls, SD 57108
08 Telephone of Contact Person, Including Area Code

605-978-2906
09 This Report is An Original / A Resubmission

(1)
An Original

(2)
A Resubmission
10 Date of Report (Mo, Da, Yr)

12/31/2025
Annual Corporate Officer Certification
The undersigned officer certifies that:

I have examined this report and to the best of my knowledge, information, and belief all statements of fact contained in this report are correct statements of the business affairs of the respondent and the financial statements, and other financial information contained in this report, conform in all material respects to the Uniform System of Accounts.

01 Name

Jeff Berzina
02 Title

Controller
03 Signature

Jeff Berzina
04 Date Signed (Mo, Da, Yr)

02/27/2026
Title 18, U.S.C. 1001 makes it a crime for any person to knowingly and willingly to make to any Agency or Department of the United States any false, fictitious or fraudulent statements as to any matter within its jurisdiction.


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
LIST OF SCHEDULES (Electric Utility)

Enter in column (c) the terms "none," "not applicable," or "NA," as appropriate, where no information or amounts have been reported for certain pages. Omit pages where the respondents are "none," "not applicable," or "NA".

Line No.
Title of Schedule
(a)
Reference Page No.
(b)
Remarks
(c)
ScheduleIdentificationAbstract
Identification
1
ScheduleListOfSchedulesAbstract
List of Schedules
2
1
ScheduleGeneralInformationAbstract
General Information
101
2
ScheduleControlOverRespondentAbstract
Control Over Respondent
102
3
ScheduleCorporationsControlledByRespondentAbstract
Corporations Controlled by Respondent
103
Not Applicable
4
ScheduleOfficersAbstract
Officers
104
5
ScheduleDirectorsAbstract
Directors
105
6
ScheduleInformationOnFormulaRatesAbstract
Information on Formula Rates
106
7
ScheduleImportantChangesDuringTheQuarterYearAbstract
Important Changes During the Year
108
8
ScheduleComparativeBalanceSheetAbstract
Comparative Balance Sheet
110
9
ScheduleStatementOfIncomeAbstract
Statement of Income for the Year
114
10
ScheduleRetainedEarningsAbstract
Statement of Retained Earnings for the Year
118
12
ScheduleStatementOfCashFlowsAbstract
Statement of Cash Flows
120
12
ScheduleNotesToFinancialStatementsAbstract
Notes to Financial Statements
122
13
ScheduleStatementOfAccumulatedOtherComprehensiveIncomeAndHedgingActivitiesAbstract
Statement of Accum Other Comp Income, Comp Income, and Hedging Activities
122a
14
ScheduleSummaryOfUtilityPlantAndAccumulatedProvisionsForDepreciationAmortizationAndDepletionAbstract
Summary of Utility Plant & Accumulated Provisions for Dep, Amort & Dep
200
15
ScheduleNuclearFuelMaterialsAbstract
Nuclear Fuel Materials
202
Not Applicable
16
ScheduleElectricPlantInServiceAbstract
Electric Plant in Service
204
17
ScheduleElectricPropertyLeasedToOthersAbstract
Electric Plant Leased to Others
213
Not Applicable
18
ScheduleElectricPlantHeldForFutureUseAbstract
Electric Plant Held for Future Use
214
19
ScheduleConstructionWorkInProgressElectricAbstract
Construction Work in Progress-Electric
216
20
ScheduleAccumulatedProvisionForDepreciationOfElectricUtilityPlantAbstract
Accumulated Provision for Depreciation of Electric Utility Plant
219
21
ScheduleInvestmentsInSubsidiaryCompaniesAbstract
Investment of Subsidiary Companies
224
Not Applicable
22
ScheduleMaterialsAndSuppliesAbstract
Materials and Supplies
227
23
ScheduleAllowanceInventoryAbstract
Allowances and Environmental Credits
228
24
ScheduleExtraordinaryPropertyLossesAbstract
Extraordinary Property Losses
230a
Not Applicable
25
ScheduleUnrecoveredPlantAndRegulatoryStudyCostsAbstract
Unrecovered Plant and Regulatory Study Costs
230b
Not Applicable
26
ScheduleTransmissionServiceAndGenerationInterconnectionStudyCostsAbstract
Transmission Service and Generation Interconnection Study Costs
231
27
ScheduleOtherRegulatoryAssetsAbstract
Other Regulatory Assets
232
28
ScheduleMiscellaneousDeferredDebitsAbstract
Miscellaneous Deferred Debits
233
29
ScheduleAccumulatedDeferredIncomeTaxesAbstract
Accumulated Deferred Income Taxes
234
30
ScheduleCapitalStockAbstract
Capital Stock
250
31
ScheduleOtherPaidInCapitalAbstract
Other Paid-in Capital
253
32
ScheduleCapitalStockExpenseAbstract
Capital Stock Expense
254b
Not Applicable
33
ScheduleLongTermDebtAbstract
Long-Term Debt
256
34
ScheduleReconciliationOfReportedNetIncomeWithTaxableIncomeForFederalIncomeTaxesAbstract
Reconciliation of Reported Net Income with Taxable Inc for Fed Inc Tax
261
35
ScheduleTaxesAccruedPrepaidAndChargedDuringYearDistributionOfTaxesChargedAbstract
Taxes Accrued, Prepaid and Charged During the Year
262
36
ScheduleAccumulatedDeferredInvestmentTaxCreditsAbstract
Accumulated Deferred Investment Tax Credits
266
Not Applicable
37
ScheduleOtherDeferredCreditsAbstract
Other Deferred Credits
269
38
ScheduleAccumulatedDeferredIncomeTaxesAcceleratedAmortizationPropertyAbstract
Accumulated Deferred Income Taxes-Accelerated Amortization Property
272
Not Applicable
39
ScheduleAccumulatedDeferredIncomeTaxesOtherPropertyAbstract
Accumulated Deferred Income Taxes-Other Property
274
40
ScheduleAccumulatedDeferredIncomeTaxesOtherAbstract
Accumulated Deferred Income Taxes-Other
276
41
ScheduleOtherRegulatoryLiabilitiesAbstract
Other Regulatory Liabilities
278
42
ScheduleElectricOperatingRevenuesAbstract
Electric Operating Revenues
300
43
ScheduleRegionalTransmissionServiceRevenuesAbstract
Regional Transmission Service Revenues (Account 457.1)
302
Not Applicable
44
ScheduleSalesOfElectricityByRateSchedulesAbstract
Sales of Electricity by Rate Schedules
304
45
ScheduleSalesForResaleAbstract
Sales for Resale
310
Not Applicable
46
ScheduleElectricOperationsAndMaintenanceExpensesAbstract
Electric Operation and Maintenance Expenses
320
47
SchedulePurchasedPowerAbstract
Purchased Power
326
48
ScheduleTransmissionOfElectricityForOthersAbstract
Transmission of Electricity for Others
328
49
ScheduleTransmissionOfElectricityByIsoOrRtoAbstract
Transmission of Electricity by ISO/RTOs
331
Not Applicable
50
ScheduleTransmissionOfElectricityByOthersAbstract
Transmission of Electricity by Others
332
51
ScheduleMiscellaneousGeneralExpensesAbstract
Miscellaneous General Expenses-Electric
335
52
ScheduleDepreciationDepletionAndAmortizationAbstract
Depreciation and Amortization of Electric Plant (Account 403, 404, 405)
336
53
ScheduleRegulatoryCommissionExpensesAbstract
Regulatory Commission Expenses
350
54
ScheduleResearchDevelopmentOrDemonstrationExpendituresAbstract
Research, Development and Demonstration Activities
352
Not Applicable
55
ScheduleDistributionOfSalariesAndWagesAbstract
Distribution of Salaries and Wages
354
56
ScheduleCommonUtilityPlantAndExpensesAbstract
Common Utility Plant and Expenses
356
57
ScheduleAmountsIncludedInIsoOrRtoSettlementAbstract
Amounts included in ISO/RTO Settlement Statements
397
58
SchedulePurchasesSalesOfAncillaryServicesAbstract
Purchase and Sale of Ancillary Services
398
Not Applicable
59
ScheduleMonthlyTransmissionSystemPeakLoadAbstract
Monthly Transmission System Peak Load
400
Not Applicable
60
ScheduleMonthlyIsoOrRtoTransmissionSystemPeakLoadAbstract
Monthly ISO/RTO Transmission System Peak Load
400a
61
ScheduleElectricEnergyAccountAbstract
Electric Energy Account
401a
62
ScheduleMonthlyPeakAndOutputAbstract
Monthly Peaks and Output
401b
63
ScheduleSteamElectricGeneratingPlantStatisticsAbstract
Steam Electric Generating Plant Statistics
402
63.1
ScheduleRenewableGeneratingPlantStatisticsAbstract
Renewable Generating Plant Statistics
404
64
ScheduleHydroelectricGeneratingPlantStatisticsAbstract
Hydroelectric Generating Plant Statistics
406
Not Applicable
65
SchedulePumpedStorageGeneratingPlantStatisticsAbstract
Pumped Storage Generating Plant Statistics
408
Not Applicable
66
ScheduleGeneratingPlantStatisticsAbstract
Generating Plant Statistics Pages
410
66.1
ScheduleEnergyStorageOperationsLargePlantsAbstract
Energy Storage Operations (Large Plants)
414
Not Applicable
66.2
ScheduleEnergyStorageOperationsSmallPlantsAbstract
Energy Storage Operations (Small Plants)
419
Not Applicable
67
ScheduleTransmissionLineStatisticsAbstract
Transmission Line Statistics Pages
422
68
ScheduleTransmissionLinesAddedAbstract
Transmission Lines Added During Year
424
None
69
ScheduleSubstationsAbstract
Substations
426
70
ScheduleTransactionsWithAssociatedAffiliatedCompaniesAbstract
Transactions with Associated (Affiliated) Companies
429
71
FootnoteDataAbstract
Footnote Data
450
StockholdersReportsAbstract
Stockholders' Reports (check appropriate box)
Stockholders' Reports Check appropriate box:

Two copies will be submitted

No annual report to stockholders is prepared


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
GENERAL INFORMATION
1. Provide name and title of officer having custody of the general corporate books of account and address of office where the general corporate books are kept, and address of office where any other corporate books of account are kept, if different from that where the general corporate books are kept.

Jeff Berzina

Controller

3010 West 69th Street, Sioux Falls, SD 57108
2. Provide the name of the State under the laws of which respondent is incorporated, and date of incorporation. If incorporated under a special law, give reference to such law. If not incorporated, state that fact and give the type of organization and the date organized.

State of Incorporation:
SD

Date of Incorporation:
2023-05-30

Incorporated Under Special Law:
'

'

3. If at any time during the year the property of respondent was held by a receiver or trustee, give (a) name of receiver or trustee, (b) date such receiver or trustee took possession, (c) the authority by which the receivership or trusteeship was created, and (d) date when possession by receiver or trustee ceased.

(a) Name of Receiver or Trustee Holding Property of the Respondent:

(b) Date Receiver took Possession of Respondent Property:

(c) Authority by which the Receivership or Trusteeship was created:

(d) Date when possession by receiver or trustee ceased:
4. State the classes or utility and other services furnished by respondent during the year in each State in which the respondent operated.

Electric and Natural Gas Utility in South Dakota; Natural Gas Utility in Nebraska.
5. Have you engaged as the principal accountant to audit your financial statements an accountant who is not the principal accountant for your previous year's certified financial statements?
(1)
Yes

(2)
No


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
CONTROL OVER RESPONDENT
1. If any corporation, business trust, or similar organization or a combination of such organizations jointly held control over the respondent at the end of the year, state name of controlling corporation or organization, manner in which control was held, and extent of control. If control was in a holding company organization, show the chain of ownership or control to the main parent company or organization. If control was held by a trustee(s), state name of trustee(s), name of beneficiary or beneficiaries for whom trust was maintained, and purpose of the trust.

Respondent is a wholly-owned, direct subsidiary of NorthWestern Energy Group, Inc. At December 31, 2025, NorthWestern Energy Group, Inc. owned 100% of the common stock of Respondent.


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
CORPORATIONS CONTROLLED BY RESPONDENT
  1. Report below the names of all corporations, business trusts, and similar organizations, controlled directly or indirectly by respondent at any time during the year. If control ceased prior to end of year, give particulars (details) in a footnote.
  2. If control was by other means than a direct holding of voting rights, state in a footnote the manner in which control was held, naming any intermediaries involved.
  3. If control was held jointly with one or more other interests, state the fact in a footnote and name the other interests.
Definitions
  1. See the Uniform System of Accounts for a definition of control.
  2. Direct control is that which is exercised without interposition of an intermediary.
  3. Indirect control is that which is exercised by the interposition of an intermediary which exercises direct control.
  4. Joint control is that in which neither interest can effectively control or direct action without the consent of the other, as where the voting control is equally divided between two holders, or each party holds a veto power over the other. Joint control may exist by mutual agreement or understanding between two or more parties who together have control within the meaning of the definition of control in the Uniform System of Accounts, regardless of the relative voting rights of each party.
Line No.
NameOfCompanyControlledByRespondent
Name of Company Controlled
(a)
CompanyControlledByRespondentKindOfBusinessDescription
Kind of Business
(b)
VotingStockOwnedByRespondentPercentage
Percent Voting Stock Owned
(c)
FootnoteReferences
Footnote Ref.
(d)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
OFFICERS
  1. Report below the name, title and salary for each executive officer whose salary is $50,000 or more. An "executive officer" of a respondent includes its president, secretary, treasurer, and vice president in charge of a principal business unit, division or function (such as sales, administration or finance), and any other person who performs similar policy making functions.
  2. If a change was made during the year in the incumbent of any position, show name and total remuneration of the previous incumbent, and the date the change in incumbency was made.
Line No.
OfficerTitle
Title
(a)
OfficerName
Name of Officer
(b)
OfficerSalary
Salary for Year
(c)
DateOfficerIncumbencyStarted
Date Started in Period
(d)
DateOfficerIncumbencyEnded
Date Ended in Period
(e)
1
President and Chief Executive Officer
Brian Bird
921,263
2
Vice President, Chief Financial Officer
Crystal Lail
511,813
3
Vice President, General Counsel and Federal Government Affairs
Shannon Heim
378,741
4
Vice President, Asset Management & Business Development
Bleau Lafave
289,627
5
Vice President, Customer Care, Communications, and Human Resources
Bobbi Schroeppel
358,269
6
Vice President, Distribution
Jason Merkel
298,432
7
Vice President, Technology
Jeanne Vold
286,615
8
Vice President, Supply and Montana Government Affairs
John Hines
353,151
9
Vice President, Transmission
Michael Cashell
353,151


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
DIRECTORS
  1. Report below the information called for concerning each director of the respondent who held office at any time during the year. Include in column (a), name and abbreviated titles of the directors who are officers of the respondent.
  2. Provide the principle place of business in column (b), designate members of the Executive Committee in column (c), and the Chairman of the Executive Committee in column (d).
Line No.
NameAndTitleOfDirector
Name (and Title) of Director
(a)
PrincipalBusinessAddress
Principal Business Address
(b)
MemberOfTheExecutiveCommittee
Member of the Executive Committee
(c)
ChairmanOfTheExecutiveCommittee
Chairman of the Executive Committee
(d)
1
Brian Bird (President and Chief Executive Officer)
Sioux Falls, South Dakota
false
false
2
Crystal Lail (Vice President, Chief Financial Officer)
Sioux Falls, South Dakota
false
false
3
Shannon Heim (Vice President, General Counsel and Federal Government Affairs)
Helena, Montana
false
false
4
Bleau Lafave (Vice President, Asset Management & Business Development)
Sioux Falls, South Dakota
false
false
5
Bobbi Schroeppel (Vice President, Customer Care, Communications, and Human Resources)
Sioux Falls, South Dakota
false
false
6
Jason Merkel (Vice President, Distribution)
Helena, Montana
false
false
7
Jeanne Vold (Vice President, Technology)
Sioux Falls, South Dakota
false
false
8
John Hines (Vice President, Supply and Montana Government Affairs)
Helena, Montana
false
false
9
Michael Cashell (Vice President, Transmission)
Butte, Montana
false
false


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
INFORMATION ON FORMULA RATES
Does the respondent have formula rates?
Yes

No
  1. Please list the Commission accepted formula rates including FERC Rate Schedule or Tariff Number and FERC proceeding (i.e. Docket No) accepting the rate(s) or changes in the accepted rate.
Line No.
RateScheduleTariffNumber
FERC Rate Schedule or Tariff Number
(a)
ProceedingDocketNumber
FERC Proceeding
(b)
1
Addendum 27 to Attachment H of Southwest Power Pool Open Access Transmission Tariff
ER26-71-000
2
Addendum 27 to Attachment H of Southwest Power Pool Open Access Transmission Tariff
ER26-71-001


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
INFORMATION ON FORMULA RATES - FERC Rate Schedule/Tariff Number FERC Proceeding
Does the respondent file with the Commission annual (or more frequent) filings containing the inputs to the formula rate(s)?
Yes

No (Checked by default - Not explicitly defined)
  1. If yes, provide a listing of such filings as contained on the Commission's eLibrary website.
Line No.
AccessionNumber
Accession No.
(a)
DocumentDate
Document Date / Filed Date
(b)
DocketNumber
Docket No.
(c)
DescriptionOfFiling
Description
(d)
RateScheduleTariffNumber
Formula Rate FERC Rate Schedule Number or Tariff Number
(e)
1
12/10/2025
ER26-719-000
Annual Informational Attachment H Filing of NorthWestern Energy Public Service Corporation (South Dakota) (Rate Year 2025)
Addendum 27 to Attachment H of Southwest Power Pool Open Access Transmission Tariff


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
INFORMATION ON FORMULA RATES - Formula Rate Variances
  1. If a respondent does not submit such filings then indicate in a footnote to the applicable Form 1 schedule where formula rate inputs differ from amounts reported in the Form 1.
  2. The footnote should provide a narrative description explaining how the "rate" (or billing) was derived if different from the reported amount in the Form 1.
  3. The footnote should explain amounts excluded from the ratebase or where labor or other allocation factors, operating expenses, or other items impacting formula rate inputs differ from amounts reported in Form 1 schedule amounts.
  4. Where the Commission has provided guidance on formula rate inputs, the specific proceeding should be noted in the footnote.
Line No.
PageNumberOfFormulaRateVariances
Page No(s).
(a)
ScheduleOfFormulaRateVariances
Schedule
(b)
ColumnOfFormulaRateVariances
Column
(c)
LineNumberOfFormulaRateVariances
Line No.
(d)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
IMPORTANT CHANGES DURING THE QUARTER/YEAR

Give particulars (details) concerning the matters indicated below. Make the statements explicit and precise, and number them in accordance with the inquiries. Each inquiry should be answered. Enter "none," "not applicable," or "NA" where applicable. If information which answers an inquiry is given elsewhere in the report, make a reference to the schedule in which it appears.

  1. Changes in and important additions to franchise rights: Describe the actual consideration given therefore and state from whom the franchise rights were acquired. If acquired without the payment of consideration, state that fact.
  2. Acquisition of ownership in other companies by reorganization, merger, or consolidation with other companies: Give names of companies involved, particulars concerning the transactions, name of the Commission authorizing the transaction, and reference to Commission authorization.
  3. Purchase or sale of an operating unit or system: Give a brief description of the property, and of the transactions relating thereto, and reference to Commission authorization, if any was required. Give date journal entries called for by the Uniform System of Accounts were submitted to the Commission.
  4. Important leaseholds (other than leaseholds for natural gas lands) that have been acquired or given, assigned or surrendered: Give effective dates, lengths of terms, names of parties, rents, and other condition. State name of Commission authorizing lease and give reference to such authorization.
  5. Important extension or reduction of transmission or distribution system: State territory added or relinquished and date operations began or ceased and give reference to Commission authorization, if any was required. State also the approximate number of customers added or lost and approximate annual revenues of each class of service. Each natural gas company must also state major new continuing sources of gas made available to it from purchases, development, purchase contract or otherwise, giving location and approximate total gas volumes available, period of contracts, and other parties to any such arrangements, etc.
  6. Obligations incurred as a result of issuance of securities or assumption of liabilities or guarantees including issuance of short-term debt and commercial paper having a maturity of one year or less. Give reference to FERC or State Commission authorization, as appropriate, and the amount of obligation or guarantee.
  7. Changes in articles of incorporation or amendments to charter: Explain the nature and purpose of such changes or amendments.
  8. State the estimated annual effect and nature of any important wage scale changes during the year.
  9. State briefly the status of any materially important legal proceedings pending at the end of the year, and the results of any such proceedings culminated during the year.
  10. Describe briefly any materially important transactions of the respondent not disclosed elsewhere in this report in which an officer, director, security holder reported on Pages 104 or 105 of the Annual Report Form No. 1, voting trustee, associated company or known associate of any of these persons was a party or in which any such person had a material interest.
  11. (Reserved.)
  12. If the important changes during the year relating to the respondent company appearing in the annual report to stockholders are applicable in every respect and furnish the data required by Instructions 1 to 11 above, such notes may be included on this page.
  13. Describe fully any changes in officers, directors, major security holders and voting powers of the respondent that may have occurred during the reporting period.
  14. In the event that the respondent participates in a cash management program(s) and its proprietary capital ratio is less than 30 percent please describe the significant events or transactions causing the proprietary capital ratio to be less than 30 percent, and the extent to which the respondent has amounts loaned or money advanced to its parent, subsidiary, or affiliated companies through a cash management program(s). Additionally, please describe plans, if any to regain at least a 30 percent proprietary ratio.

1.) None

 

 

 

 

2.) None.

 

 

 

 

3.) None

 

 

4.) None

 

 

 

 

5) None

 

 

 

6) See Note 10 Unsecured Credit Faciltiies." Approval by the SDPUC docket GE23-002, approval by the NPUC Application NG-121.

 

 

 

 

 

 

7) None.

8) None.

 

9) See Note 18 "Commitments and Contingencies."

 

 

 

10) None.

12) None.

13) None.

14) N/A.


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
COMPARATIVE BALANCE SHEET (ASSETS AND OTHER DEBITS)
Line No.
Title of Account
(a)
Ref. Page No.
(b)
Current Year End of Quarter/Year Balance
(c)
Prior Year End Balance 12/31
(d)
1
UtilityPlantAbstract
UTILITY PLANT
2
UtilityPlant
Utility Plant (101-106, 114)
200
1,585,099,056
1,535,632,024
3
ConstructionWorkInProgress
Construction Work in Progress (107)
200
64,895,167
30,637,674
4
UtilityPlantAndConstructionWorkInProgress
TOTAL Utility Plant (Enter Total of lines 2 and 3)
1,649,994,223
1,566,269,698
5
AccumulatedProvisionForDepreciationAmortizationAndDepletionOfPlantUtility
(Less) Accum. Prov. for Depr. Amort. Depl. (108, 110, 111, 115)
200
601,060,628
565,615,458
6
UtilityPlantNet
Net Utility Plant (Enter Total of line 4 less 5)
1,048,933,595
1,000,654,240
7
NuclearFuelInProcessOfRefinementConversionEnrichmentAndFabrication
Nuclear Fuel in Process of Ref., Conv., Enrich., and Fab. (120.1)
202
8
NuclearFuelMaterialsAndAssembliesStockAccountMajorOnly
Nuclear Fuel Materials and Assemblies-Stock Account (120.2)
9
NuclearFuelAssembliesInReactorMajorOnly
Nuclear Fuel Assemblies in Reactor (120.3)
10
SpentNuclearFuelMajorOnly
Spent Nuclear Fuel (120.4)
11
NuclearFuelUnderCapitalLeases
Nuclear Fuel Under Capital Leases (120.6)
12
AccumulatedProvisionForAmortizationOfNuclearFuelAssemblies
(Less) Accum. Prov. for Amort. of Nucl. Fuel Assemblies (120.5)
202
13
NuclearFuelNet
Net Nuclear Fuel (Enter Total of lines 7-11 less 12)
14
UtilityPlantAndNuclearFuelNet
Net Utility Plant (Enter Total of lines 6 and 13)
1,048,933,595
1,000,654,240
15
OtherElectricPlantAdjustments
Utility Plant Adjustments (116)
93,779,293
93,779,293
16
GasStoredUndergroundNoncurrent
Gas Stored Underground - Noncurrent (117)
17
OtherPropertyAndInvestmentsAbstract
OTHER PROPERTY AND INVESTMENTS
18
NonutilityProperty
Nonutility Property (121)
19
AccumulatedProvisionForDepreciationAndAmortizationOfNonutilityProperty
(Less) Accum. Prov. for Depr. and Amort. (122)
20
InvestmentInAssociatedCompanies
Investments in Associated Companies (123)
21
InvestmentInSubsidiaryCompanies
Investment in Subsidiary Companies (123.1)
224
23
NoncurrentPortionOfAllowances
Noncurrent Portion of Allowances and Environmental Credits
228
24
OtherInvestments
Other Investments (124)
521,000
521,000
25
SinkingFunds
Sinking Funds (125)
26
DepreciationFund
Depreciation Fund (126)
27
AmortizationFundFederal
Amortization Fund - Federal (127)
28
OtherSpecialFunds
Other Special Funds (128)
29
SpecialFunds
Special Funds (Non Major Only) (129)
30
DerivativeInstrumentAssetsLongTerm
Long-Term Portion of Derivative Assets (175)
31
DerivativeInstrumentAssetsHedgesLongTerm
Long-Term Portion of Derivative Assets - Hedges (176)
32
OtherPropertyAndInvestments
TOTAL Other Property and Investments (Lines 18-21 and 23-31)
521,000
521,000
33
CurrentAndAccruedAssetsAbstract
CURRENT AND ACCRUED ASSETS
34
CashAndWorkingFunds
Cash and Working Funds (Non-major Only) (130)
35
Cash
Cash (131)
2,515,496
1,559,709
36
SpecialDeposits
Special Deposits (132-134)
9,570,111
9,691,457
37
WorkingFunds
Working Fund (135)
5,700
5,250
38
TemporaryCashInvestments
Temporary Cash Investments (136)
39
NotesReceivable
Notes Receivable (141)
40
CustomerAccountsReceivable
Customer Accounts Receivable (142)
18,481,575
16,219,387
41
OtherAccountsReceivable
Other Accounts Receivable (143)
618,365
730,883
42
AccumulatedProvisionForUncollectibleAccountsCredit
(Less) Accum. Prov. for Uncollectible Acct.-Credit (144)
402,857
322,761
43
NotesReceivableFromAssociatedCompanies
Notes Receivable from Associated Companies (145)
44
AccountsReceivableFromAssociatedCompanies
Accounts Receivable from Assoc. Companies (146)
698,512
350,557
45
FuelStock
Fuel Stock (151)
227
6,454,796
7,701,524
46
FuelStockExpensesUndistributed
Fuel Stock Expenses Undistributed (152)
227
47
Residuals
Residuals (Elec) and Extracted Products (153)
227
48
PlantMaterialsAndOperatingSupplies
Plant Materials and Operating Supplies (154)
227
24,789,537
23,261,515
49
Merchandise
Merchandise (155)
227
50
OtherMaterialsAndSupplies
Other Materials and Supplies (156)
227
51
NuclearMaterialsHeldForSale
Nuclear Materials Held for Sale (157)
202/227
52
AllowanceInventoryAndWithheld
Allowances and Environmental Credits (158.1, 158.2, 158.3, and 158.4)
228
53
NoncurrentPortionOfAllowances
(Less) Noncurrent Portion of Allowances and Environmental Credits
228
54
StoresExpenseUndistributed
Stores Expense Undistributed (163)
227
55
GasStoredCurrent
Gas Stored Underground - Current (164.1)
2,687,160
2,471,128
56
LiquefiedNaturalGasStoredAndHeldForProcessing
Liquefied Natural Gas Stored and Held for Processing (164.2-164.3)
57
Prepayments
Prepayments (165)
9,436,198
11,629,819
58
AdvancesForGas
Advances for Gas (166-167)
59
InterestAndDividendsReceivable
Interest and Dividends Receivable (171)
60
RentsReceivable
Rents Receivable (172)
295
6,162
61
AccruedUtilityRevenues
Accrued Utility Revenues (173)
23,137,204
21,060,198
62
MiscellaneousCurrentAndAccruedAssets
Miscellaneous Current and Accrued Assets (174)
1,553
1,553
63
DerivativeInstrumentAssets
Derivative Instrument Assets (175)
64
DerivativeInstrumentAssetsLongTerm
(Less) Long-Term Portion of Derivative Instrument Assets (175)
65
DerivativeInstrumentAssetsHedges
Derivative Instrument Assets - Hedges (176)
66
DerivativeInstrumentAssetsHedgesLongTerm
(Less) Long-Term Portion of Derivative Instrument Assets - Hedges (176)
67
CurrentAndAccruedAssets
Total Current and Accrued Assets (Lines 34 through 66)
97,993,645
94,366,381
68
DeferredDebitsAbstract
DEFERRED DEBITS
69
UnamortizedDebtExpense
Unamortized Debt Expenses (181)
1,779,029
1,514,884
70
ExtraordinaryPropertyLosses
Extraordinary Property Losses (182.1)
230a
71
UnrecoveredPlantAndRegulatoryStudyCosts
Unrecovered Plant and Regulatory Study Costs (182.2)
230b
72
OtherRegulatoryAssets
Other Regulatory Assets (182.3)
232
101,597,915
99,031,157
73
PreliminarySurveyAndInvestigationCharges
Prelim. Survey and Investigation Charges (Electric) (183)
1,903,945
458,462
74
PreliminaryNaturalGasSurveyAndInvestigationChargesAndOtherPreliminarySurveyAndInvestigationCharges
Preliminary Natural Gas Survey and Investigation Charges 183.1)
75
OtherPreliminarySurveyAndInvestigationCharges
Other Preliminary Survey and Investigation Charges (183.2)
76
ClearingAccounts
Clearing Accounts (184)
24,948
77
TemporaryFacilities
Temporary Facilities (185)
78
MiscellaneousDeferredDebits
Miscellaneous Deferred Debits (186)
233
9,024,275
9,766,918
79
DeferredLossesFromDispositionOfUtilityPlant
Def. Losses from Disposition of Utility Plt. (187)
80
ResearchDevelopmentAndDemonstrationExpenditures
Research, Devel. and Demonstration Expend. (188)
352
81
UnamortizedLossOnReacquiredDebt
Unamortized Loss on Reaquired Debt (189)
216,035
793,326
82
AccumulatedDeferredIncomeTaxes
Accumulated Deferred Income Taxes (190)
234
88,048,028
100,962,578
83
UnrecoveredPurchasedGasCosts
Unrecovered Purchased Gas Costs (191)
4,591,011
8,908,673
84
DeferredDebits
Total Deferred Debits (lines 69 through 83)
207,185,186
221,435,998
85
AssetsAndOtherDebits
TOTAL ASSETS (lines 14-16, 32, 67, and 84)
1,448,412,719
1,410,756,912


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
COMPARATIVE BALANCE SHEET (LIABILITIES AND OTHER CREDITS)
Line No.
Title of Account
(a)
Ref. Page No.
(b)
Current Year End of Quarter/Year Balance
(c)
Prior Year End Balance 12/31
(d)
1
ProprietaryCapitalAbstract
PROPRIETARY CAPITAL
2
CommonStockIssued
Common Stock Issued (201)
250
1
1
3
PreferredStockIssued
Preferred Stock Issued (204)
250
4
CapitalStockSubscribed
Capital Stock Subscribed (202, 205)
5
StockLiabilityForConversion
Stock Liability for Conversion (203, 206)
6
PremiumOnCapitalStock
Premium on Capital Stock (207)
7
OtherPaidInCapital
Other Paid-In Capital (208-211)
253
582,103,871
580,991,640
8
InstallmentsReceivedOnCapitalStock
Installments Received on Capital Stock (212)
252
9
DiscountOnCapitalStock
(Less) Discount on Capital Stock (213)
254
10
CapitalStockExpense
(Less) Capital Stock Expense (214)
254b
11
RetainedEarnings
Retained Earnings (215, 215.1, 216)
118
1,713,720
10,186,442
12
UnappropriatedUndistributedSubsidiaryEarnings
Unappropriated Undistributed Subsidiary Earnings (216.1)
118
13
ReacquiredCapitalStock
(Less) Reacquired Capital Stock (217)
250
14
NoncorporateProprietorship
Noncorporate Proprietorship (Non-major only) (218)
15
AccumulatedOtherComprehensiveIncome
Accumulated Other Comprehensive Income (219)
122(a)(b)
1,001,963
829,241
16
ProprietaryCapital
Total Proprietary Capital (lines 2 through 15)
584,819,555
592,007,324
17
LongTermDebtAbstract
LONG-TERM DEBT
18
Bonds
Bonds (221)
256
556,000,000
520,000,000
19
ReacquiredBonds
(Less) Reacquired Bonds (222)
256
20
AdvancesFromAssociatedCompanies
Advances from Associated Companies (223)
256
21
OtherLongTermDebt
Other Long-Term Debt (224)
256
41,000,000
34,000,000
22
UnamortizedPremiumOnLongTermDebt
Unamortized Premium on Long-Term Debt (225)
23
UnamortizedDiscountOnLongTermDebtDebit
(Less) Unamortized Discount on Long-Term Debt-Debit (226)
24
LongTermDebt
Total Long-Term Debt (lines 18 through 23)
597,000,000
554,000,000
25
OtherNoncurrentLiabilitiesAbstract
OTHER NONCURRENT LIABILITIES
26
ObligationsUnderCapitalLeaseNoncurrent
Obligations Under Capital Leases - Noncurrent (227)
135,568
77,964
27
AccumulatedProvisionForPropertyInsurance
Accumulated Provision for Property Insurance (228.1)
28
AccumulatedProvisionForInjuriesAndDamages
Accumulated Provision for Injuries and Damages (228.2)
732,569
377,500
29
AccumulatedProvisionForPensionsAndBenefits
Accumulated Provision for Pensions and Benefits (228.3)
1,374,068
1,587,400
30
AccumulatedMiscellaneousOperatingProvisions
Accumulated Miscellaneous Operating Provisions (228.4)
13,589,151
13,649,142
31
AccumulatedProvisionForRateRefunds
Accumulated Provision for Rate Refunds (229)
32
LongTermPortionOfDerivativeInstrumentLiabilities
Long-Term Portion of Derivative Instrument Liabilities
33
LongTermPortionOfDerivativeInstrumentLiabilitiesHedges
Long-Term Portion of Derivative Instrument Liabilities - Hedges
34
AssetRetirementObligations
Asset Retirement Obligations (230)
8,217,503
6,840,507
35
OtherNoncurrentLiabilities
Total Other Noncurrent Liabilities (lines 26 through 34)
24,048,859
22,532,513
36
CurrentAndAccruedLiabilitiesAbstract
CURRENT AND ACCRUED LIABILITIES
37
NotesPayable
Notes Payable (231)
38
AccountsPayable
Accounts Payable (232)
34,553,654
28,859,817
39
NotesPayableToAssociatedCompanies
Notes Payable to Associated Companies (233)
40
AccountsPayableToAssociatedCompanies
Accounts Payable to Associated Companies (234)
1,782,019
41
CustomerDeposits
Customer Deposits (235)
863,344
924,374
42
TaxesAccrued
Taxes Accrued (236)
262
10,333,470
7,808,262
43
InterestAccrued
Interest Accrued (237)
4,482,409
4,101,896
44
DividendsDeclared
Dividends Declared (238)
45
MaturedLongTermDebt
Matured Long-Term Debt (239)
46
MaturedInterest
Matured Interest (240)
47
TaxCollectionsPayable
Tax Collections Payable (241)
1,765,414
1,624,694
48
MiscellaneousCurrentAndAccruedLiabilities
Miscellaneous Current and Accrued Liabilities (242)
14,208,960
22,361,848
49
ObligationsUnderCapitalLeasesCurrent
Obligations Under Capital Leases-Current (243)
108,352
113,479
50
DerivativesInstrumentLiabilities
Derivative Instrument Liabilities (244)
51
LongTermPortionOfDerivativeInstrumentLiabilities
(Less) Long-Term Portion of Derivative Instrument Liabilities
52
DerivativeInstrumentLiabilitiesHedges
Derivative Instrument Liabilities - Hedges (245)
53
LongTermPortionOfDerivativeInstrumentLiabilitiesHedges
(Less) Long-Term Portion of Derivative Instrument Liabilities-Hedges
54
CurrentAndAccruedLiabilities
Total Current and Accrued Liabilities (lines 37 through 53)
66,315,603
67,576,389
55
DeferredCreditsAbstract
DEFERRED CREDITS
56
CustomerAdvancesForConstruction
Customer Advances for Construction (252)
57
AccumulatedDeferredInvestmentTaxCredits
Accumulated Deferred Investment Tax Credits (255)
266
58
DeferredGainsFromDispositionOfUtilityPlant
Deferred Gains from Disposition of Utility Plant (256)
59
OtherDeferredCredits
Other Deferred Credits (253)
269
10,197,133
9,971,846
60
OtherRegulatoryLiabilities
Other Regulatory Liabilities (254)
278
33,202,440
33,872,400
61
UnamortizedGainOnReacquiredDebt
Unamortized Gain on Reacquired Debt (257)
62
AccumulatedDeferredIncomeTaxesAcceleratedAmortizationProperty
Accum. Deferred Income Taxes-Accel. Amort.(281)
272
63
AccumulatedDeferredIncomeTaxesOtherProperty
Accum. Deferred Income Taxes-Other Property (282)
115,713,564
114,032,986
64
AccumulatedDeferredIncomeTaxesOther
Accum. Deferred Income Taxes-Other (283)
17,115,565
16,763,454
65
DeferredCredits
Total Deferred Credits (lines 56 through 64)
176,228,702
174,640,686
66
LiabilitiesAndOtherCredits
TOTAL LIABILITIES AND STOCKHOLDER EQUITY (lines 16, 24, 35, 54 and 65)
1,448,412,719
1,410,756,912


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
STATEMENT OF INCOME

Quarterly

  1. Report in column (c) the current year to date balance. Column (c) equals the total of adding the data in column (g) plus the data in column (i) plus the data in column (k). Report in column (d) similar data for the previous year. This information is reported in the annual filing only.
  2. Enter in column (e) the balance for the reporting quarter and in column (f) the balance for the same three month period for the prior year.
  3. Report in column (g) the quarter to date amounts for electric utility function; in column (i) the quarter to date amounts for gas utility, and in column (k) the quarter to date amounts for other utility function for the current year quarter.
  4. Report in column (h) the quarter to date amounts for electric utility function; in column (j) the quarter to date amounts for gas utility, and in column (l) the quarter to date amounts for other utility function for the prior year quarter.
  5. If additional columns are needed, place them in a footnote.

Annual or Quarterly if applicable

  1. Do not report fourth quarter data in columns (e) and (f)
  2. Report amounts for accounts 412 and 413, Revenues and Expenses from Utility Plant Leased to Others, in another utility column in a similar manner to a utility department. Spread the amount(s) over Lines 2 thru 26 as appropriate. Include these amounts in columns (c) and (d) totals.
  3. Report amounts in account 414, Other Utility Operating Income, in the same manner as accounts 412 and 413 above.
  4. Use page 122 for important notes regarding the statement of income for any account thereof.
  5. Give concise explanations concerning unsettled rate proceedings where a contingency exists such that refunds of a material amount may need to be made to the utility's customers or which may result in material refund to the utility with respect to power or gas purchases. State for each year affected the gross revenues or costs to which the contingency relates and the tax effects together with an explanation of the major factors which affect the rights of the utility to retain such revenues or recover amounts paid with respect to power or gas purchases.
  6. Give concise explanations concerning significant amounts of any refunds made or received during the year resulting from settlement of any rate proceeding affecting revenues received or costs incurred for power or gas purchases, and a summary of the adjustments made to balance sheet, income, and expense accounts.
  7. If any notes appearing in the report to stockholders are applicable to the Statement of Income, such notes may be included at page 122.
  8. Enter on page 122 a concise explanation of only those changes in accounting methods made during the year which had an effect on net income, including the basis of allocations and apportionments from those used in the preceding year. Also, give the appropriate dollar effect of such changes.
  9. Explain in a footnote if the previous year's/quarter's figures are different from that reported in prior reports.
  10. If the columns are insufficient for reporting additional utility departments, supply the appropriate account titles report the information in a footnote to this schedule.
Line No.
Title of Account
(a)
(Ref.) Page No.
(b)
Total Current Year to Date Balance for Quarter/Year
(c)
Total Prior Year to Date Balance for Quarter/Year
(d)
Current 3 Months Ended - Quarterly Only - No 4th Quarter
(e)
Prior 3 Months Ended - Quarterly Only - No 4th Quarter
(f)
Electric Utility Current Year to Date (in dollars)
(g)
Electric Utility Previous Year to Date (in dollars)
(h)
Gas Utiity Current Year to Date (in dollars)
(i)
Gas Utility Previous Year to Date (in dollars)
(j)
Other Utility Current Year to Date (in dollars)
(k)
Other Utility Previous Year to Date (in dollars)
(l)
1
UtilityOperatingIncomeAbstract
UTILITY OPERATING INCOME
2
OperatingRevenues
Operating Revenues (400)
300
309,626,250
278,227,387
210,715,300
193,637,593
98,910,950
84,589,794
3
OperatingExpensesAbstract
Operating Expenses
4
OperationExpense
Operation Expenses (401)
320
171,996,990
160,647,438
95,286,419
90,784,558
76,710,571
69,862,880
5
MaintenanceExpense
Maintenance Expenses (402)
320
17,195,231
11,117,575
13,346,979
9,424,506
3,848,252
1,693,069
6
DepreciationExpense
Depreciation Expense (403)
336
48,853,542
47,317,787
41,470,688
40,210,341
7,382,854
7,107,446
7
DepreciationExpenseForAssetRetirementCosts
Depreciation Expense for Asset Retirement Costs (403.1)
336
0
0
8
AmortizationAndDepletionOfUtilityPlant
Amort. & Depl. of Utility Plant (404-405)
336
1,494,797
1,375,720
1,299,499
1,197,898
195,298
177,822
9
AmortizationOfElectricPlantAcquisitionAdjustments
Amort. of Utility Plant Acq. Adj. (406)
336
927,997
927,997
927,997
927,997
10
AmortizationOfPropertyLossesUnrecoveredPlantAndRegulatoryStudyCosts
Amort. Property Losses, Unrecov Plant and Regulatory Study Costs (407)
11
AmortizationOfConversionExpenses
Amort. of Conversion Expenses (407.2)
12
RegulatoryDebits
Regulatory Debits (407.3)
1,700,138
4,684,954
698,348
1,240,686
1,001,790
3,444,268
13
RegulatoryCredits
(Less) Regulatory Credits (407.4)
925,533
3,394,999
464,245
1,784,300
461,288
1,610,699
14
TaxesOtherThanIncomeTaxesUtilityOperatingIncome
Taxes Other Than Income Taxes (408.1)
262
8,733,224
8,386,671
6,328,130
6,093,066
2,405,094
2,293,605
15
IncomeTaxesOperatingIncome
Income Taxes - Federal (409.1)
262
10,857,854
6,412,400
11,257,885
5,094,327
400,031
1,318,073
16
IncomeTaxesUtilityOperatingIncomeOther
Income Taxes - Other (409.1)
262
825
825
17
ProvisionsForDeferredIncomeTaxesUtilityOperatingIncome
Provision for Deferred Income Taxes (410.1)
234, 272
(a)
27,894,390
59,340,195
22,425,244
44,110,215
5,469,146
15,229,980
18
ProvisionForDeferredIncomeTaxesCreditOperatingIncome
(Less) Provision for Deferred Income Taxes-Cr. (411.1)
234, 272
13,568,672
60,087,028
8,280,449
41,963,447
5,288,223
18,123,581
19
InvestmentTaxCreditAdjustments
Investment Tax Credit Adj. - Net (411.4)
266
20
GainsFromDispositionOfPlant
(Less) Gains from Disp. of Utility Plant (411.6)
21
LossesFromDispositionOfServiceCompanyPlant
Losses from Disp. of Utility Plant (411.7)
22
GainsFromDispositionOfAllowances
(Less) Gains from Disposition of Allowances (411.8)
23
LossesFromDispositionOfAllowances
Losses from Disposition of Allowances (411.9)
24
AccretionExpense
Accretion Expense (411.10)
24.1
GainsFromDispositionOfEnvironmentalCredits
(Less) Gains from Disposition of Environmental Credits (411.11)
24.2
LossesFromDispositionOfEnvironmentalCredits
Losses from Disposition of Environmental Credits (411.12)
25
UtilityOperatingExpenses
TOTAL Utility Operating Expenses (Enter Total of lines 4 thru 24.2)
253,445,075
223,903,910
161,780,725
145,147,193
91,664,350
78,756,717
0
0
27
NetUtilityOperatingIncome
Net Util Oper Inc (Enter Tot line 2 less 25)
56,181,175
54,323,477
48,934,575
48,490,400
7,246,600
5,833,077
0
0
28
OtherIncomeAndDeductionsAbstract
Other Income and Deductions
29
OtherIncomeAbstract
Other Income
30
NonutilityOperatingIncomeAbstract
Nonutilty Operating Income
31
RevenuesFromMerchandisingJobbingAndContractWork
Revenues From Merchandising, Jobbing and Contract Work (415)
32
CostsAndExpensesOfMerchandisingJobbingAndContractWork
(Less) Costs and Exp. of Merchandising, Job. & Contract Work (416)
33
RevenuesFromNonutilityOperations
Revenues From Nonutility Operations (417)
240
1,339
34
ExpensesOfNonutilityOperations
(Less) Expenses of Nonutility Operations (417.1)
1,430
1,428
35
NonoperatingRentalIncome
Nonoperating Rental Income (418)
36
EquityInEarningsOfSubsidiaryCompanies
Equity in Earnings of Subsidiary Companies (418.1)
119
37
InterestAndDividendIncome
Interest and Dividend Income (419)
959,768
888,538
38
AllowanceForOtherFundsUsedDuringConstruction
Allowance for Other Funds Used During Construction (419.1)
1,146,237
1,089,991
39
MiscellaneousNonoperatingIncome
Miscellaneous Nonoperating Income (421)
371,622
130,994
40
GainOnDispositionOfProperty
Gain on Disposition of Property (421.1)
41
OtherIncome
TOTAL Other Income (Enter Total of lines 31 thru 40)
2,479,297
2,109,434
42
OtherIncomeDeductionsAbstract
Other Income Deductions
43
LossOnDispositionOfProperty
Loss on Disposition of Property (421.2)
44
MiscellaneousAmortization
Miscellaneous Amortization (425)
45
Donations
Donations (426.1)
518,106
563,678
46
LifeInsurance
Life Insurance (426.2)
47
Penalties
Penalties (426.3)
71,471
444
48
ExpendituresForCertainCivicPoliticalAndRelatedActivities
Exp. for Certain Civic, Political & Related Activities (426.4)
252,432
169,708
49
OtherDeductions
Other Deductions (426.5)
355,547
122,677
50
OtherIncomeDeductions
TOTAL Other Income Deductions (Total of lines 43 thru 49)
1,197,556
856,507
51
TaxesApplicableToOtherIncomeAndDeductionsAbstract
Taxes Applic. to Other Income and Deductions
52
TaxesOtherThanIncomeTaxesOtherIncomeAndDeductions
Taxes Other Than Income Taxes (408.2)
262
53
IncomeTaxesFederal
Income Taxes-Federal (409.2)
262
490,037
416,808
54
IncomeTaxesOther
Income Taxes-Other (409.2)
262
55
ProvisionForDeferredIncomeTaxesOtherIncomeAndDeductions
Provision for Deferred Inc. Taxes (410.2)
234, 272
56
ProvisionForDeferredIncomeTaxesCreditOtherIncomeAndDeductions
(Less) Provision for Deferred Income Taxes-Cr. (411.2)
234, 272
57
InvestmentTaxCreditAdjustmentsNonutilityOperations
Investment Tax Credit Adj.-Net (411.5)
58
InvestmentTaxCredits
(Less) Investment Tax Credits (420)
59
TaxesOnOtherIncomeAndDeductions
TOTAL Taxes on Other Income and Deductions (Total of lines 52-58)
490,037
416,808
60
NetOtherIncomeAndDeductions
Net Other Income and Deductions (Total of lines 41, 50, 59)
791,704
836,119
61
InterestChargesAbstract
Interest Charges
62
InterestOnLongTermDebt
Interest on Long-Term Debt (427)
24,948,300
23,515,593
63
AmortizationOfDebtDiscountAndExpense
Amort. of Debt Disc. and Expense (428)
347,505
314,368
64
AmortizationOfLossOnReacquiredDebt
Amortization of Loss on Reaquired Debt (428.1)
577,291
694,902
65
AmortizationOfPremiumOnDebtCredit
(Less) Amort. of Premium on Debt-Credit (429)
66
AmortizationOfGainOnReacquiredDebtCredit
(Less) Amortization of Gain on Reaquired Debt-Credit (429.1)
67
InterestOnDebtToAssociatedCompanies
Interest on Debt to Assoc. Companies (430)
68
OtherInterestExpense
Other Interest Expense (431)
80,025
236,402
69
AllowanceForBorrowedFundsUsedDuringConstructionCredit
(Less) Allowance for Borrowed Funds Used During Construction-Cr. (432)
507,520
534,213
70
NetInterestCharges
Net Interest Charges (Total of lines 62 thru 69)
25,445,601
24,227,052
71
IncomeBeforeExtraordinaryItems
Income Before Extraordinary Items (Total of lines 27, 60 and 70)
31,527,278
30,932,544
72
ExtraordinaryItemsAbstract
Extraordinary Items
73
ExtraordinaryIncome
Extraordinary Income (434)
74
ExtraordinaryDeductions
(Less) Extraordinary Deductions (435)
75
NetExtraordinaryItems
Net Extraordinary Items (Total of line 73 less line 74)
76
IncomeTaxesExtraordinaryItems
Income Taxes-Federal and Other (409.3)
262
77
ExtraordinaryItemsAfterTaxes
Extraordinary Items After Taxes (line 75 less line 76)
78
NetIncomeLoss
Net Income (Total of line 71 and 77)
31,527,278
30,932,544


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
FOOTNOTE DATA

(a) Concept: ProvisionsForDeferredIncomeTaxesUtilityOperatingIncome

Included in the Provision for Deferred Income Taxes, in the Statements of Income, is amortization of the excess and deficient ADIT's as follows:

 

         
                         

Line No.

Description (a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

(i)

(j)

(k)

(l)

                         
 

FERC Method of Amortization

RSG

SL

 

ARAM/RSG

RSG

SL

   

SL (MT) / RSG (SD)

SL

 
 

Amortization period

Book Lives

5 Years

 

Book Lives

Book Lives

5 Years

   

5 years (MT) / Book Lives (SD)

5 Years

 
 

Protected/Unprotected

Protected

Unprotected

 

Protected

Unprotected

Unprotected

   

F/T "as-if" normalized

F/T "as-if" normalized

 
 

FERC Amorization Account

410.1

410.1

 

411.1

411.1

411.1

   

411.1

410.1

 
 

TCJA Excess ADIT Account Reduced

190

190

Subtotal

282

282

283

Subtotal

Total of 182.3

282

190

 
 

Reg Asset Acccount Impacted

182.3

182.3

182.3

254

254

254

254

and 254

254

182.3

Total

      1

 South Dakota:

                     

      2

 Electric

138,138

-

138,138

(590,098)

-

-

(590,098)

(451,960)

(464,843)

-

(916,803)

      3

 Gas

(5,513)

338,365

332,852

(81,017)

(46,238)

(15,815)

(143,070)

189,782

(75,064)

-

114,718

      4

 Total

132,625

338,365

470,990

(671,115)

(46,238)

(15,815)

(733,168)

(262,178)

(539,907)

-

(802,085)

 


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report


End of:
2025
/
Q4
STATEMENT OF RETAINED EARNINGS
  1. Do not report Lines 49-53 on the quarterly report.
  2. Report all changes in appropriated retained earnings, unappropriated retained earnings, and unappropriated undistributed subsidiary earnings for the year.
  3. Each credit and debit during the year should be identified as to the retained earnings account in which recorded (Accounts 433, 436-439 inclusive). Show the contra primary account affected in column (b).
  4. State the purpose and amount for each reservation or appropriation of retained earnings.
  5. List first Account 439, Adjustments to Retained Earnings, reflecting adjustments to the opening balance of retained earnings. Follow by credit, then debit items, in that order.
  6. Show dividends for each class and series of capital stock.
  7. Show separately the State and Federal income tax effect of items shown for Account 439, Adjustments to Retained Earnings.
  8. Explain in a footnote the basis for determining the amount reserved or appropriated. If such reservation or appropriation is to be recurrent, state the number and annual amounts to be reserved or appropriated as well as the totals eventually to be accumulated.
  9. If any notes appearing in the report to stockholders are applicable to this statement, attach them at page 122.
Line No.
Item
(a)
Contra Primary Account Affected
(b)
Current Quarter/Year Year to Date Balance
(c)
Previous Quarter/Year Year to Date Balance
(d)
UnappropriatedRetainedEarningsAbstract
UNAPPROPRIATED RETAINED EARNINGS (Account 216)
1
UnappropriatedRetainedEarnings
Balance-Beginning of Period
10,186,442
0
2
ChangesAbstract
Changes
3
AdjustmentsToRetainedEarningsAbstract
Adjustments to Retained Earnings (Account 439)
4
AdjustmentsToRetainedEarningsCreditAbstract
Adjustments to Retained Earnings Credit
9
AdjustmentsToRetainedEarningsCredit
TOTAL Credits to Retained Earnings (Acct. 439)
10
AdjustmentsToRetainedEarningsDebitAbstract
Adjustments to Retained Earnings Debit
15
AdjustmentsToRetainedEarningsDebit
TOTAL Debits to Retained Earnings (Acct. 439)
16
BalanceTransferredFromIncome
Balance Transferred from Income (Account 433 less Account 418.1)
31,527,278
30,932,544
17
AppropriationsOfRetainedEarningsAbstract
Appropriations of Retained Earnings (Acct. 436)
22
AppropriationsOfRetainedEarnings
TOTAL Appropriations of Retained Earnings (Acct. 436)
23
DividendsDeclaredPreferredStockAbstract
Dividends Declared-Preferred Stock (Account 437)
29
DividendsDeclaredPreferredStock
TOTAL Dividends Declared-Preferred Stock (Acct. 437)
30
DividendsDeclaredCommonStockAbstract
Dividends Declared-Common Stock (Account 438)
36
DividendsDeclaredCommonStock
TOTAL Dividends Declared-Common Stock (Acct. 438)
40,000,000
20,746,102
37
TransfersFromUnappropriatedUndistributedSubsidiaryEarnings
Transfers from Acct 216.1, Unapprop. Undistrib. Subsidiary Earnings
38
UnappropriatedRetainedEarnings
Balance - End of Period (Total 1,9,15,16,22,29,36,37)
1,713,720
10,186,442
39
AppropriatedRetainedEarningsAbstract
APPROPRIATED RETAINED EARNINGS (Account 215)
45
AppropriatedRetainedEarnings
TOTAL Appropriated Retained Earnings (Account 215)
AppropriatedRetainedEarningsAmortizationReserveFederalAbstract
APPROP. RETAINED EARNINGS - AMORT. Reserve, Federal (Account 215.1)
46
AppropriatedRetainedEarningsAmortizationReserveFederal
TOTAL Approp. Retained Earnings-Amort. Reserve, Federal (Acct. 215.1)
47
AppropriatedRetainedEarningsIncludingReserveAmortization
TOTAL Approp. Retained Earnings (Acct. 215, 215.1) (Total 45,46)
48
RetainedEarnings
TOTAL Retained Earnings (Acct. 215, 215.1, 216) (Total 38, 47) (216.1)
1,713,720
10,186,442
UnappropriatedUndistributedSubsidiaryEarningsAbstract
UNAPPROPRIATED UNDISTRIBUTED SUBSIDIARY EARNINGS (Account Report only on an Annual Basis, no Quarterly)
49
UnappropriatedUndistributedSubsidiaryEarnings
Balance-Beginning of Year (Debit or Credit)
50
EquityInEarningsOfSubsidiaryCompanies
Equity in Earnings for Year (Credit) (Account 418.1)
51
DividendsReceived
(Less) Dividends Received (Debit)
52
ChangesUnappropriatedUndistributedSubsidiaryEarningsCredits
TOTAL other Changes in unappropriated undistributed subsidiary earnings for the year
53
UnappropriatedUndistributedSubsidiaryEarnings
Balance-End of Year (Total lines 49 thru 52)


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
STATEMENT OF CASH FLOWS
  1. Codes to be used:(a) Net Proceeds or Payments;(b)Bonds, debentures and other long-term debt; (c) Include commercial paper; and (d) Identify separately such items as investments, fixed assets, intangibles, etc.
  2. Information about noncash investing and financing activities must be provided in the Notes to the Financial statements. Also provide a reconciliation between "Cash and Cash Equivalents at End of Period" with related amounts on the Balance Sheet.
  3. Operating Activities - Other: Include gains and losses pertaining to operating activities only. Gains and losses pertaining to investing and financing activities should be reported in those activities. Show in the Notes to the Financials the amounts of interest paid (net of amount capitalized) and income taxes paid.
  4. Investing Activities: Include at Other (line 31) net cash outflow to acquire other companies. Provide a reconciliation of assets acquired with liabilities assumed in the Notes to the Financial Statements. Do not include on this statement the dollar amount of leases capitalized per the USofA General Instruction 20; instead provide a reconciliation of the dollar amount of leases capitalized with the plant cost.
Line No.
Description (See Instructions No.1 for explanation of codes)
(a)
Current Year to Date Quarter/Year
(b)
Previous Year to Date Quarter/Year
(c)
1
NetCashFlowFromOperatingActivitiesAbstract
Net Cash Flow from Operating Activities
2
NetIncomeLoss
Net Income (Line 78(c) on page 117)
31,527,278
30,932,544
3
NoncashChargesCreditsToIncomeAbstract
Noncash Charges (Credits) to Income:
4
DepreciationAndDepletion
Depreciation and Depletion
48,853,542
47,317,787
5
NoncashAdjustmentsToCashFlowsFromOperatingActivities
Amortization of (Specify) (footnote details)
5.1
NoncashAdjustmentsToCashFlowsFromOperatingActivitiesDescription
Amortization of
2,422,794
2,303,717
5.2
NoncashAdjustmentsToCashFlowsFromOperatingActivitiesDescription
Other Non-cash charges to net income-net
(a)
1,955,424
1,696,594
8
DeferredIncomeTaxesNet
Deferred Income Taxes (Net)
14,325,718
746,833
9
InvestmentTaxCreditAdjustmentsNet
Investment Tax Credit Adjustment (Net)
10
NetIncreaseDecreaseInReceivablesOperatingActivities
Net (Increase) Decrease in Receivables
2,417,529
8,813,403
11
NetIncreaseDecreaseInInventoryOperatingActivities
Net (Increase) Decrease in Inventory
497,326
1,717,343
12
NetIncreaseDecreaseInAllowancesInventoryOperatingActivities
Net (Increase) Decrease in Allowances and Environmental Credits Inventory
13
NetIncreaseDecreaseInPayablesAndAccruedExpensesOperatingActivities
Net Increase (Decrease) in Payables and Accrued Expenses
9,023,065
3,940,641
14
NetIncreaseDecreaseInOtherRegulatoryAssetsOperatingActivities
Net (Increase) Decrease in Other Regulatory Assets
3,239,855
140,520
15
NetIncreaseDecreaseInOtherRegulatoryLiabilitiesOperatingActivities
Net Increase (Decrease) in Other Regulatory Liabilities
669,960
1,688,273
16
AllowanceForOtherFundsUsedDuringConstructionOperatingActivities
(Less) Allowance for Other Funds Used During Construction
1,146,237
1,089,991
17
UndistributedEarningsFromSubsidiaryCompaniesOperatingActivities
(Less) Undistributed Earnings from Subsidiary Companies
18
OtherAdjustmentsToCashFlowsFromOperatingActivities
Other (provide details in footnote):
18.1
OtherAdjustmentsToCashFlowsFromOperatingActivitiesDescription
Other
(b)
5,471,918
8,310,234
22
NetCashFlowFromOperatingActivities
Net Cash Provided by (Used in) Operating Activities (Total of Lines 2 thru 21)
87,562,702
81,311,492
24
CashFlowsFromInvestmentActivitiesAbstract
Cash Flows from Investment Activities:
25
ConstructionAndAcquisitionOfPlantIncludingLandAbstract
Construction and Acquisition of Plant (including land):
26
GrossAdditionsToUtilityPlantLessNuclearFuelInvestingActivities
Gross Additions to Utility Plant (less nuclear fuel)
87,271,206
66,429,970
27
GrossAdditionsToNuclearFuelInvestingActivities
Gross Additions to Nuclear Fuel
28
GrossAdditionsToCommonUtilityPlantInvestingActivities
Gross Additions to Common Utility Plant
3,072,794
3,463,777
29
GrossAdditionsToNonutilityPlantInvestingActivities
Gross Additions to Nonutility Plant
30
AllowanceForOtherFundsUsedDuringConstructionInvestingActivities
(Less) Allowance for Other Funds Used During Construction
1,146,237
1,089,991
31
OtherConstructionAndAcquisitionOfPlantInvestmentActivities
Other (provide details in footnote):
34
CashOutflowsForPlant
Cash Outflows for Plant (Total of lines 26 thru 33)
89,197,763
68,803,756
36
AcquisitionOfOtherNoncurrentAssets
Acquisition of Other Noncurrent Assets (d)
37
ProceedsFromDisposalOfNoncurrentAssets
Proceeds from Disposal of Noncurrent Assets (d)
39
InvestmentsInAndAdvancesToAssociatedAndSubsidiaryCompanies
Investments in and Advances to Assoc. and Subsidiary Companies
40
ContributionsAndAdvancesFromAssociatedAndSubsidiaryCompanies
Contributions and Advances from Assoc. and Subsidiary Companies
41
DispositionOfInvestmentsInAndAdvancesToAssociatedAndSubsidiaryCompaniesAbstract
Disposition of Investments in (and Advances to)
42
DispositionOfInvestmentsInAndAdvancesToAssociatedAndSubsidiaryCompanies
Disposition of Investments in (and Advances to) Associated and Subsidiary Companies
44
PurchaseOfInvestmentSecurities
Purchase of Investment Securities (a)
45
ProceedsFromSalesOfInvestmentSecurities
Proceeds from Sales of Investment Securities (a)
46
LoansMadeOrPurchased
Loans Made or Purchased
47
CollectionsOnLoans
Collections on Loans
49
NetIncreaseDecreaseInReceivablesInvestingActivities
Net (Increase) Decrease in Receivables
50
NetIncreaseDecreaseInInventoryInvestingActivities
Net (Increase) Decrease in Inventory
51
NetIncreaseDecreaseInAllowancesHeldForSpeculationInvestingActivities
Net (Increase) Decrease in Allowances and Environmental Credits Held for Speculation
52
NetIncreaseDecreaseInPayablesAndAccruedExpensesInvestingActivities
Net Increase (Decrease) in Payables and Accrued Expenses
53
OtherAdjustmentsToCashFlowsFromInvestmentActivities
Other (provide details in footnote):
53.1
OtherAdjustmentsToCashFlowsFromInvestmentActivitiesDescription
Other Investing Activities
500,000
57
CashFlowsProvidedFromUsedInInvestmentActivities
Net Cash Provided by (Used in) Investing Activities (Total of lines 34 thru 55)
89,197,763
69,303,756
59
CashFlowsFromFinancingActivitiesAbstract
Cash Flows from Financing Activities:
60
ProceedsFromIssuanceAbstract
Proceeds from Issuance of:
61
ProceedsFromIssuanceOfLongTermDebtFinancingActivities
Long-Term Debt (b)
100,000,000
40,000,000
62
ProceedsFromIssuanceOfPreferredStockFinancingActivities
Preferred Stock
63
ProceedsFromIssuanceOfCommonStockFinancingActivities
Common Stock
64
OtherAdjustmentsToCashFlowsFromFinancingActivities
Other (provide details in footnote):
66
NetIncreaseInShortTermDebt
Net Increase in Short-Term Debt (c)
67
OtherAdjustmentsByOutsideSourcesToCashFlowsFromFinancingActivities
Other (provide details in footnote):
70
CashProvidedByOutsideSources
Cash Provided by Outside Sources (Total 61 thru 69)
100,000,000
40,000,000
72
PaymentsForRetirementAbstract
Payments for Retirement of:
73
PaymentsForRetirementOfLongTermDebtFinancingActivities
Long-term Debt (b)
64,000,000
74
PaymentsForRetirementOfPreferredStockFinancingActivities
Preferred Stock
75
PaymentsForRetirementOfCommonStockFinancingActivities
Common Stock
76
OtherRetirementsOfBalancesImpactingCashFlowsFromFinancingActivities
Other (provide details in footnote):
76.1
DescriptionOfOtherRetirementsImpactingCashFlowsFromFinancingActivities
Debt Financing Costs
530,048
258,384
76.2
DescriptionOfOtherRetirementsImpactingCashFlowsFromFinancingActivities
Line of Credit (Repayments) Borrowings, Net
7,000,000
20,000,000
76.3
DescriptionOfOtherRetirementsImpactingCashFlowsFromFinancingActivities
Distribution of Cash from NorthWestern Corporation
0
253,165
78
NetDecreaseInShortTermDebt
Net Decrease in Short-Term Debt (c)
80
DividendsOnPreferredStock
Dividends on Preferred Stock
81
DividendsOnCommonStock
Dividends on Common Stock
40,000,000
20,746,102
83
CashFlowsProvidedFromUsedInFinancingActivities
Net Cash Provided by (Used in) Financing Activities (Total of lines 70 thru 81)
2,469,952
751,321
85
NetIncreaseDecreaseInCashAndCashEquivalentsAbstract
Net Increase (Decrease) in Cash and Cash Equivalents
86
NetIncreaseDecreaseInCashAndCashEquivalents
Net Increase (Decrease) in Cash and Cash Equivalents (Total of line 22, 57 and 83)
834,891
11,256,415
88
CashAndCashEquivalents
Cash and Cash Equivalents at Beginning of Period
11,256,416
1
90
CashAndCashEquivalents
Cash and Cash Equivalents at End of Period
(c)
12,091,307
11,256,416


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
FOOTNOTE DATA

(a) Concept: NoncashAdjustmentsToCashFlowsFromOperatingActivities
 

12/31/2025

 

12/31/2024

Other Noncash Charges to Income, Net:

     

Amortization of debt issue costs, discount, and deferred hedge gain

                                   843,192

 

                                   917,774

Other noncash gains

                                              -

 

                                     (13,448)

Stock based compensation costs

                                1,112,232

 

                                    792,268

 

                                1,955,424

 

                                 1,696,594

(b) Concept: OtherAdjustmentsToCashFlowsFromOperatingActivities
 

12/31/2025

 

12/31/2024

Other Assets and Liabilities, Net:

     

Net change - other current assets

                                2,199,488

 

                              (1,121,904)

Net change - accrued utility revenues

                              (2,077,006)

 

                                   (44,492)

Net change - deferred debits

                                3,446,772

 

                              (8,813,148)

Net change - deferred credits

                                   225,287

 

                                3,137,256

Net change - noncurrent liabilities

                                1,677,377

 

                              (1,467,946)

 

                                5,471,918

 

                              (8,310,234)

(c) Concept: CashAndCashEquivalents
 

12/31/2025

 

12/31/2024

 

12/31/2023

Cash (131)

         2,515,496

 

1,559,709

 

                    1

Working Funds (135)

                5,700

 

5,250

 

                     -

Other Special Deposits (134)

         9,570,111

 

            9,691,457

 

                     -

     Total

       12,091,307

 

          11,256,416

 

                     1


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
NOTES TO FINANCIAL STATEMENTS
  1. Use the space below for important notes regarding the Balance Sheet, Statement of Income for the year, Statement of Retained Earnings for the year, and Statement of Cash Flows, or any account thereof. Classify the notes according to each basic statement, providing a subheading for each statement except where a note is applicable to more than one statement.
  2. Furnish particulars (details) as to any significant contingent assets or liabilities existing at end of year, including a brief explanation of any action initiated by the Internal Revenue Service involving possible assessment of additional income taxes of material amount, or of a claim for refund of income taxes of a material amount initiated by the utility. Give also a brief explanation of any dividends in arrears on cumulative preferred stock.
  3. For Account 116, Utility Plant Adjustments, explain the origin of such amount, debits and credits during the year, and plan of disposition contemplated, giving references to Commission orders or other authorizations respecting classification of amounts as plant adjustments and requirements as to disposition thereof.
  4. Where Accounts 189, Unamortized Loss on Reacquired Debt, and 257, Unamortized Gain on Reacquired Debt, are not used, give an explanation, providing the rate treatment given these items. See General Instruction 17 of the Uniform System of Accounts.
  5. Give a concise explanation of any retained earnings restrictions and state the amount of retained earnings affected by such restrictions.
  6. If the notes to financial statements relating to the respondent company appearing in the annual report to the stockholders are applicable and furnish the data required by instructions above and on pages 114-121, such notes may be included herein.
  7. For the 3Q disclosures, respondent must provide in the notes sufficient disclosures so as to make the interim information not misleading. Disclosures which would substantially duplicate the disclosures contained in the most recent FERC Annual Report may be omitted.
  8. For the 3Q disclosures, the disclosures shall be provided where events subsequent to the end of the most recent year have occurred which have a material effect on the respondent. Respondent must include in the notes significant changes since the most recently completed year in such items as: accounting principles and practices; estimates inherent in the preparation of the financial statements; status of long-term contracts; capitalization including significant new borrowings or modifications of existing financing agreements; and changes resulting from business combinations or dispositions. However, where material contingencies exist, the disclosure of such matters shall be provided even though a significant change since year end may not have occurred.
  9. Finally, if the notes to the financial statements relating to the respondent appearing in the annual report to the stockholders are applicable and furnish the data required by the above instructions, such notes may be included herein.

 

 

 

 

NOTES TO FINANCIAL STATEMENTS

 

 

(1)           Nature of Operations

 

Northwestern Energy Public Service Corporation (NWE Public Service), a direct wholly-owned subsidiary of NorthWestern Energy Group, Inc., doing business as NorthWestern Energy, provides electricity and / or natural gas to approximately 160,200 customers in South Dakota and Nebraska. We have generated and distributed electricity in South Dakota and distributed natural gas in South Dakota and Nebraska since 1923.

 

The Financial Statements for the periods included herein have been prepared by NWE Public Service (NorthWestern, we or us), pursuant to the rules and regulations of the Federal Energy Regulatory Commission (FERC) as set forth in its applicable Uniform System of Accounts and published accounting releases. The preparation of financial statements in conformity with the accounting requirements of the FERC as set forth in its applicable Uniform System of Accounts and published accounting releases requires management to make estimates and assumptions that may affect the reported amounts of assets, liabilities, revenues and expenses during the reporting period. Actual results could differ from those estimates. Events occurring subsequent to December 31, 2025, have been evaluated as to their potential impact to the Consolidated Financial Statements through the date of issuance.

 

The following notes to the financials statements appear in NWE Public Service’s annual report to the shareholders and are prepared in conformity with GAAP. This report differs from GAAP due to FERC requiring the presentation of subsidiaries on the equity method of accounting, which differs from Accounting Standards Codification (ASC) 810, Consolidation. ASC 810 requires that all majority-owned subsidiaries be consolidated. The other significant differences consist of the following:

 

 Removal and decommissioning costs of generation, transmission and distribution assets are reflected in the Balance Sheets as a component of accumulated depreciation of $99.5 million and $93.2 million as of December 31, 2025 and December 31, 2024, respectively, in accordance with regulatory treatment as compared to regulatory liabilities for GAAP purposes;

 

 Goodwill is reflected in the Balance Sheets as a utility plant adjustments of $93.8 million as of December 31, 2025 and December 31, 2024, respectively, in accordance with regulatory treatment, as compared to goodwill for GAAP purposes (see Note 8);

 

 The current portion of gas stored underground is reflected in the Balance Sheets as current and accrued assets, as compared to inventory for GAAP purposes;

 

 Operating lease right of use assets are reflected in the Balance Sheets as capital leases of $0.2 million as of December 31, 2025 and December 31, 2024, respectfully, in accordance with regulatory treatment, as compared to non-current assets for GAAP purposes;

 

        Operating lease liabilities are reflected in the Balance Sheets as current and long term obligations under capital leases of $0.2 million as of December 31, 2025 and December 31, 2024, respectfully, in accordance with regulatory treatment, as compared to accrued expenses and long term liabilities for GAAP purposes;

 

        Unamortized debt expense is classified in the Balance Sheets as deferred debits in accordance with regulatory treatment, as compared to long-term debt for GAAP purposes;

 

        Current and long-term debt is classified in the Balance Sheets as all long-term debt in accordance with regulatory treatment, while current and long-term debt are presented separately for GAAP reporting;

 

        The current portion of the provision for injuries and damages and the expected insurance proceeds receivable related to the provision for injuries and damages are reported as a current liability for GAAP purposes, as compared to a non-current liability for FERC purposes;

 

        Accumulated deferred tax assets and liabilities are classified in the Balance Sheets as gross non-current deferred debits and credits, respectively, while GAAP presentation reflects a net non-current deferred tax liability;

 

        Stranded tax effects associated with the Tax Cuts and Jobs Act are included in accumulated other comprehensive income (AOCI) in accordance with regulatory treatment, while included in retained earnings for GAAP purposes;

 

        Uncertain tax positions related to temporary differences are classified in the Balance Sheets within the deferred tax accounts in accordance with regulatory treatment, as compared to other noncurrent liabilities for GAAP purposes. In addition, interest related to uncertain tax positions is recognized in interest expense in accordance with regulatory treatment, as compared to income tax expense for GAAP purposes;

 

        Net periodic benefit costs and net periodic post retirement benefit costs are reflected in operating expense for FERC purposes, as compared to the GAAP presentation, which reflects the current service costs component of the net periodic benefit costs in operating expenses and the other components outside of income from operations. In addition, only the service cost component of net periodic benefit cost is eligible for capitalization for GAAP purposes, as compared to the total net periodic benefit costs for FERC purposes;

 

        Regulatory assets and liabilities are reflected in the Balance Sheets as non-current items, while current and non-current amounts are presented separately for GAAP;

 

        Unbilled revenue is reflected in the Balance Sheets in Accrued utility revenues in accordance with regulatory treatment, as compared to Accounts receivable, net for GAAP purposes;

 

         Implementation costs associated with cloud computing arrangements are reflected on the Balance Sheets as Miscellaneous Intangible Plant in accordance with regulatory treatment, as compared to Other current assets for GAAP purposes. Additionally, these cash outflows are presented within investing activities cash outflows in the Statement of Cash Flows in accordance with regulatory treatment, as compared to operating activities cash outflows for GAAP purposes; and

 

         GAAP revenue differs from FERC revenue primarily due to the equity method of accounting as discussed above, netting of electric purchases and sales for resale in revenue for the GAAP presentation as compared to a gross presentation for FERC purposes (with the exception of those transactions in a regional transmission organization (RTO)), the netting of RTO transmission transactions for the GAAP presentation as compared to a gross presentation for FERC purposes, and the classification of regulatory amortizations in revenue for GAAP purposes as compared to expense for FERC purposes.

 

Holding Company Reorganization

 

NWE Public Service was incorporated on May 30, 2023, as a direct wholly-owned subsidiary of NorthWestern Corporation (NW Corp) in preparation of a holding company reorganization. On this date, NWE Public Service issued 100 shares of $0.01 par value common stock to NW Corp for $1. NWE Public Service had no other financial activity during the year ended December 31, 2023.

 

On January 1, 2024, NorthWestern Energy Group, Inc. completed the second and final phase of the holding company reorganization. NW Corp contributed the assets and liabilities of its South Dakota and Nebraska regulated utilities to NWE Public Service, and then distributed its equity interest in NWE Public Service and certain other subsidiaries to NorthWestern Energy Group, Inc., resulting in NW Corp owning and operating the Montana regulated utility and NWE Public Service owning and operating the Nebraska and South Dakota utilities, each as a direct subsidiary of NorthWestern Energy Group, Inc. 

 

The below table represents the net assets that NW Corp contributed to NWE Public Service on January 1, 2024:

 

Net assets contributed to NWE Public Service on January 1, 2024:

ASSETS

 

Current Assets:

 

Cash and cash equivalents

$ 253 

Accounts receivable, net

 37,547 

Inventories

 31,717 

Regulatory assets

 5,681 

Prepaid expenses and other

 10,755 

      Total current assets 

 85,953 

Property, plant, and equipment, net

 1,067,549 

Goodwill

 93,779 

Regulatory assets

 93,933 

Other noncurrent assets

 9,558 

      Total Assets 

$ 1,350,772 

LIABILITIES

 

Current Liabilities:

 

Accounts payable

 28,751 

Accrued expenses

 27,392 

Regulatory liabilities

 20,766 

      Total current liabilities 

 76,909 

Long-term debt

 532,148 

Deferred income taxes

 25,033 

Noncurrent regulatory liabilities

 106,307 

Other noncurrent liabilities

 29,850 

Total Liabilities

$ 770,247 

Total Net Assets Contributed to NWE Public Service

$ 580,525 

  

 

NorthWestern Energy Group, Inc. Pending Merger with Black Hills Corporation

 

On August 18, 2025, NorthWestern Energy Group, Inc. entered into a Merger Agreement with Black Hills and River Merger Sub Inc., a direct wholly owned subsidiary of Black Hills (Merger Sub). The Merger Agreement provides for an all-stock merger of equals between NorthWestern Energy Group, Inc. and Black Hills upon the terms and subject to the conditions set forth therein. The Merger Agreement provides for Merger Sub to merge with and into NorthWestern Energy Group, Inc. (Merger), with NorthWestern Energy Group, Inc. continuing as the surviving entity and a direct wholly owned subsidiary of Black Hills, which would assume the new corporate name of Bright Horizon Energy Corporation as the resulting parent company of the combined corporate group. The completion of the Merger is subject to the satisfaction or waiver of certain conditions to closing. We anticipate the transaction closing in the second half of 2026, subject to the satisfaction or waiver of certain closing conditions.

 

(2)           Significant Accounting Policies

 

Use of Estimates

 

The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the Financial Statements and the reported amounts of revenues and expenses during the reporting period. Estimates are used for such items as long-lived asset values and impairment charges, long-lived asset useful lives, tax provisions, uncertain tax position reserves, AROs, regulatory assets and liabilities, allowances for uncollectible accounts, our QF liability, environmental liabilities, unbilled revenues and actuarially determined benefit costs and liabilities. We revise the recorded estimates when we receive better information or when we can determine actual amounts. Those revisions can affect operating results.

 

Revenue Recognition

 

We recognize revenue as customers obtain control of promised goods and services in an amount that reflects consideration expected in exchange for those goods or services. Generally, the delivery of electricity and natural gas results in the transfer of control to customers at the time the commodity is delivered and the amount of revenue recognized is equal to the amount billed to each customer, including estimated volumes delivered when billings have not yet occurred.

 

Cash Equivalents

 

We consider all highly liquid investments with maturities of three months or less at the time of purchase to be cash equivalents.

 

Restricted Cash

 

Restricted cash consists primarily of funds held in trust accounts to satisfy the requirements of certain stipulation agreements.

 

Accounts Receivable, Net

 

Accounts receivable are net of allowances for uncollectible accounts of $0.4 million and $0.3 million at December 31, 2025 and December 31, 2024, respectively. Receivables include unbilled revenues of $23.1 million and $21.1 million at December 31, 2025 and December 31, 2024, respectively.

 

Inventories

 

Inventories are stated at the lower of average cost or net realizable value.

 

Regulation of Utility Operations

 

Our regulated operations are subject to the provisions of ASC 980, Regulated Operations. Regulated accounting is appropriate provided that (i) rates are established by or subject to approval by independent, third-party regulators, (ii) rates are designed to recover the specific enterprise's cost of service, and (iii) in view of demand for service, it is reasonable to assume that rates are set at levels that will recover costs and can be charged to and collected from customers.

 

Our Financial Statements reflect the effects of the different rate making principles followed by the jurisdictions regulating us. The economic effects of regulation can result in regulated companies recording costs that have been, or are deemed probable to be, allowed in the ratemaking process in a period different from the period in which the costs would be charged to expense by an unregulated enterprise. When this occurs, costs are deferred as regulatory assets and recorded as expenses in the periods when those same amounts are reflected in rates. Additionally, regulators can impose liabilities upon a regulated company for amounts previously collected from customers and for amounts that are expected to be refunded to customers (regulatory liabilities).

 

If we were required to terminate the application of these provisions to our regulated operations, all such deferred amounts would be recognized in the Statements of Income at that time. This would result in a charge to earnings and accumulated other comprehensive income (AOCI), net of applicable income taxes, which could be material. In addition, we would determine any impairment to the carrying costs of deregulated plant and inventory assets.

 

Derivative Financial Instruments

 

We account for derivative instruments in accordance with ASC 815, Derivatives and Hedging. All derivatives are recognized in the Balance Sheets at their fair value unless they qualify for certain exceptions, including the normal purchases and normal sales exception. Additionally, derivatives that qualify and are designated for hedge accounting are classified as either hedges of the fair value of a recognized asset or liability or of an unrecognized firm commitment (fair-value hedge) or hedges of a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability (cash-flow hedge). For fair-value hedges, changes in fair values for both the derivative and the underlying hedged exposure are recognized in earnings each period. For cash-flow hedges, the portion of the derivative gain or loss that is effective in offsetting the change in the cost or value of the underlying exposure is deferred in AOCI and later reclassified into earnings when the underlying transaction occurs. Gains and losses from the ineffective portion of any hedge are recognized in earnings immediately. For other derivative contracts that do not qualify or are not designated for hedge accounting, changes in the fair value of the derivatives are recognized in earnings each period. Cash inflows and outflows related to derivative instruments are included as a component of operating, investing or financing cash flows in the Statements of Cash Flows, depending on the underlying nature of the hedged items. As of December 31, 2025, the only derivative instruments we have qualify for the normal purchases and normal sales exception.

 

Revenues and expenses on contracts that are designated as normal purchases and normal sales are recognized when the underlying physical transaction is completed. While these contracts are considered derivative financial instruments, they are not required to be recorded at fair value, but on an accrual basis of accounting. Normal purchases and normal sales are contracts where physical delivery is probable, quantities are expected to be used or sold in the normal course of business over a reasonable period of time, and price is not tied to an unrelated underlying derivative. As part of our regulated electric and gas operations, we enter into contracts to buy and sell energy to meet the requirements of our customers. These contracts include short-term and long-term commitments to purchase and sell energy in the retail and wholesale markets with the intent and ability to deliver or take delivery. If it were determined that a transaction designated as a normal purchase or a normal sale no longer met the exceptions, the fair value of the related contract would be reflected as an asset or liability and immediately recognized through earnings. See Note 8 - Risk Management and Hedging Activities, for further discussion of our derivative activity.

 

Property, Plant and Equipment

 

Property, plant and equipment are stated at original cost, including contracted services, direct labor and material, allowance for funds used during construction (AFUDC), and indirect charges for engineering, supervision and similar overhead items. All expenditures for maintenance and repairs of utility property, plant and equipment are charged to the appropriate maintenance expense accounts. A betterment or replacement of a unit of property is accounted for as an addition and retirement of utility plant. At the time of such a retirement, the accumulated provision for depreciation is charged with the original cost of the property retired and also for the net cost of removal. Also included in plant and equipment are assets under finance lease, which are stated at the present value of minimum lease payments.

 

AFUDC represents the cost of financing construction projects with borrowed funds and equity funds. While cash is not realized currently from such allowance, it is realized under the ratemaking process over the service life of the related property through increased revenues resulting from a higher rate base and higher depreciation expense. The component of AFUDC attributable to borrowed funds is included as a reduction to interest expense, while the equity component is included in other income. This rate averaged 6.9% in 2025 and 2024. AFUDC capitalized totaled $1.7 million and $1.6 million for the years ended December 31, 2025 and 2024, respectively.

 

We record provisions for depreciation at amounts substantially equivalent to calculations made on a straight-line method by applying various rates based on useful lives of the various classes of properties (ranging from 5 to 95) determined from engineering studies. As a percentage of the depreciable utility plant at the beginning of the year, our provision for depreciation of utility plant was approximately 3.4% for 2025.

 

Depreciation rates include a provision for our share of the estimated costs to decommission our jointly owned plants at the end of the useful life. The annual provision for such costs is included in depreciation expense, while the accumulated provisions are included in noncurrent regulatory liabilities.

 

Pension and Postretirement Benefits

 

We have liabilities under defined benefit retirement plans and a postretirement plan that offers certain health care and life insurance benefits to eligible employees and their dependents. The costs of these plans are dependent upon numerous factors, assumptions and estimates, including determination of discount rate, expected return on plan assets, rate of future compensation increases, age and mortality and employment periods. In determining the projected benefit obligations and costs, assumptions can change from period to period and may result in material changes in the cost and liabilities we recognize.

 

Income Taxes

 

We follow the liability method in accounting for income taxes. Deferred income tax assets and liabilities represent the future effects on income taxes from temporary differences between the bases of assets and liabilities for financial reporting and tax purposes. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to reverse. The probability of realizing deferred tax assets is based on forecasts of future taxable income and the availability of tax planning strategies that can be implemented, if necessary, to realize deferred tax assets. We establish a valuation allowance when it is more likely than not that all, or a portion of, a deferred tax asset will not be realized.

 

Exposures exist related to various tax filing positions, which may require an extended period of time to resolve and may result in income tax adjustments by taxing authorities. On a quarterly basis, we evaluate exposures in light of any additional information and make adjustments as necessary to reflect the best estimate of the future outcomes. We believe our deferred tax assets and established liabilities are appropriate for estimated exposures; however, actual results may differ from these estimates. The resolution of tax matters in a particular future period could have a material impact on our Income Statements and provision for income taxes.

 

Under the Inflation Reduction Act of 2022 our production tax credits may be transferred to an unrelated entity. Our policy is to account for these transferable credits within income tax expense.

 

Environmental Costs

 

We record environmental costs when it is probable we are liable for the costs and we can reasonably estimate the liability. We may defer costs as a regulatory asset if there is precedent for recovering similar costs from customers in rates. Otherwise, we expense the costs. If an environmental cost is related to facilities we currently use, such as pollution control equipment, then we may capitalize and depreciate the costs over the remaining life of the asset, assuming the costs are recoverable in future rates or future cash flows.

 

Our remediation cost estimates are based on the use of an environmental consultant, our experience, our assessment of the current situation and the technology currently available for use in the remediation. We regularly adjust the recorded costs as we revise estimates and as remediation proceeds. If we are one of several designated responsible parties, then we estimate and record only our share of the cost.

 

Supplemental Cash Flow Information

 

Year Ended December 31,

 

2025

 

2024

 

(in thousands)

Cash paid (received) for:

 

 

 

Nebraska state income tax

$ (160)

 

$  

 

 

 

 

Production tax credits(1)

 (12,293)

 

 (6,867)

Interest

 24,060 

 

 22,952 

Significant non-cash transactions:

 

 

 

Capital expenditures included in trade accounts payable

 11,623 

 

 3,840 

(1) Proceeds from production tax credits transferred are included in cash provided by operating activities within the Statement of Cash Flows.

 

The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the Balance Sheets that sum to the total of the same such amounts shown in the Statements of Cash Flows (in thousands):

 

December 31,

 

2025

 

2024

Cash and cash equivalents

$ 2,521 

 

$ 1,565 

Restricted cash

 9,570 

 

 9,691 

Total cash, cash equivalents, and restricted cash shown in the Statements of Cash Flows

$ 12,091 

 

$ 11,256 

 

Restricted cash consists primarily of funds held in trust accounts to satisfy the requirements of certain stipulation agreements.

 

Accounting Standards Issued

 

In December 2023, the Financial Accounting Standards Board issued Accounting Standards Update 2023-09, Improvements to Income Tax Disclosures, which expands income tax disclosures. The expanded disclosures require the disclosure of prescribed categories presented in the income tax rate reconciliation and additional disclosures on income tax expense and taxes paid, net of refunds received, for federal, state, and foreign jurisdictions. We early adopted this standard for the year ended December 31, 2025, and used the retrospective method of adoption, with no material impact on our Consolidated Financial Statements.

 

At this time, we are not expecting the adoption of recently issued accounting standards to have a material impact to our financial condition, results of operations, and cash flows.

 

(3)           Regulatory Matters

 

Nebraska Natural Gas Rate Review

 

In June 2024, we filed a natural gas rate review with the Nebraska Public Service Commission (NPSC). Interim rates, which increased base natural gas rates $2.3 million, were implemented on October 1, 2024. In April 2025, we reached a settlement agreement with certain parties for a base rate annual revenue increase of $2.4 million. In June 2025, the NPSC approved this settlement agreement and final rates were implemented on July 1, 2025.

 

 

 

(4)           Regulatory Assets and Liabilities

 

We prepare our Financial Statements in accordance with the provisions of ASC 980, as discussed in Note 2 - Significant Accounting Policies. Pursuant to this guidance, certain expenses and credits, normally reflected in income as incurred, are deferred and recognized when included in rates and recovered from or refunded to customers. Regulatory assets and liabilities are recorded based on management's assessment that it is probable that a cost will be recovered or that an obligation has been incurred. Accordingly, we have recorded the following major classifications of regulatory assets and liabilities that will be recognized in expenses and revenues in future periods when the matching revenues are collected or refunded. Of these regulatory assets and liabilities, energy supply costs are the only items earning a rate of return. The remaining regulatory items have corresponding assets and liabilities that will be paid for or refunded in future periods.

 

 

Note Reference

 

Remaining Amortization Period

 

December 31,

 

2025

 

2024

 

 

 

(in thousands)

Flow-through income taxes

12

 

Plant Lives

 

$ 74,490 

 

$ 74,250 

Environmental clean-up

17

 

Undetermined

 

 12,081 

 

 11,257 

Supply costs

 

 

1 Year

 

 7,472 

 

 10,309 

Excess deferred income taxes

12

 

Plant Lives

 

 5,983 

 

 6,580 

Pension

14

 

See Note 14

 

 5,526 

 

 5,376 

Deferred financing costs

11

 

See Note 11

 

 216 

 

 793 

State & local taxes & fees

 

 

1 Year

 

 6 

 

 61 

Other

 

 

Various

 

 866 

 

 565 

   Total Regulatory Assets 

 

 

 

 

$ 106,640 

 

$ 109,191 

Removal cost

6

 

Plant Lives

 

$ 99,468 

 

$ 93,152 

Excess deferred income taxes

12

 

Plant Lives

 

 16,797 

 

 17,725 

Supply costs

 

 

1 Year

 

 16,050 

 

 15,840 

State & local taxes & fees

 

 

1 Year

 

 304 

 

 205 

Other

 

 

Various

 

 745 

 

 747 

   Total Regulatory Liabilities 

 

 

 

 

$ 133,364 

 

$ 127,669 

 

Income Taxes

 

Flow-through income taxes primarily reflect the effects of plant related temporary differences such as flow-through of depreciation, repairs related deductions, and removal costs that we will recover or refund in future rates. We amortize these amounts as temporary differences reverse. Excess deferred income tax assets and liabilities are recorded as a result of the Tax Cuts and Jobs Act and will be recovered or refunded in future rates. See Note 12 - Income Taxes for further discussion.

 

Environmental Clean-Up

 

Environmental clean-up costs are the estimated costs of investigating and cleaning up contaminated sites we own. We discuss the specific sites and clean-up requirements further in Note 17 - Commitments and Contingencies. Environmental clean-up costs are typically recoverable in customer rates when they are actually incurred. When cost projections become known and measurable, we coordinate with the appropriate regulatory authority to determine a recovery period.

 

Supply Costs

 

The South Dakota Public Utilities Commission (SDPUC) and NPSC have authorized the use of electric and natural gas supply cost trackers that enable us to track actual supply costs and either recover the under collection or refund the over collection to our customers. Accordingly, we have recorded a regulatory asset and liability to reflect the future recovery of under collections and refunding of over collections through the ratemaking process. We earn interest on natural gas supply costs under collected, or apply interest to an over collection, of 6.8 percent and 6.9 percent for electric and natural gas, respectively, in South Dakota; and 7.1 percent for natural gas in Nebraska.

 

Pension and Employee Related Benefits

 

We recognize the unfunded portion of plan benefit obligations in the Balance Sheets, which is remeasured at each year end, with a corresponding adjustment to regulatory assets/liabilities as the costs associated with these plans are recovered in rates. The SDPUC allows recovery of pension and postretirement benefit costs on an accrual basis.

 

Deferred Financing Costs

 

Consistent with our historical regulatory treatment, a regulatory asset has been established to reflect the remaining deferred financing costs on long-term debt that has been replaced through the issuance of new debt. These amounts are amortized over the life of the new debt.

 

Removal Cost

 

The anticipated costs of removing assets upon retirement are collected from customers in advance of removal activity as a component of depreciation expense. Our depreciation method, including cost of removal, is established by the respective regulatory commissions. Therefore, consistent with this regulated treatment, we reflect this accrual of removal costs for our regulated assets by increasing our regulatory liability. See Note 6 - Asset Retirement Obligations, for further information regarding this item.

 

 



(5)           Property, Plant and Equipment

 

The following table presents the major classifications of our property, plant and equipment (in thousands):

 

 

December 31,

 

2025

 

2024

 

(in thousands)

Electric Plant

$ 1,178,443 

 

$ 1,145,833 

Natural Gas Plant

 303,436 

 

 286,843 

Plant acquisition adjustment(1)

 30,010 

 

 30,010 

Common and Other Plant

 72,360 

 

 72,896 

Construction work in process

 66,793 

 

 31,027 

Total property, plant and equipment

 1,651,042 

 

 1,566,609 

Less accumulated depreciation

 (486,318)

 

 (457,466)

Less accumulated amortization

 (17,128)

 

 (15,904)

Net property, plant and equipment

$ 1,147,596 

 

$ 1,093,239 

 

(1) The plant acquisition adjustment balance above includes our Beethoven wind project acquired in 2015. The acquisition adjustment is amortized on a straight-line basis over the estimated remaining useful life in depreciation expense.

 

Jointly Owned Electric Generating Plant

 

We have an ownership interest in three base-load electric generating plants, all of which are coal fired and operated by other companies. We have an undivided interest in these facilities and are responsible for our proportionate share of the capital and operating costs while being entitled to our proportionate share of the power generated. Our interest in each plant is reflected in the Balance Sheets on a pro rata basis and our share of operating expenses is reflected in the Statements of Income. The participants each finance their own investment.

 

Information relating to our ownership interest in these facilities is as follows (in thousands):

 

Big Stone

(SD)

 

Neal #4

(IA)

 

Coyote

(ND)

December 31, 2025

 

 

 

 

 

Ownership percentages

 23.4 %

 

 8.7 %

 

 10.0 %

Plant in service

$ 157,919 

 

$ 66,740 

 

$ 53,609 

Accumulated depreciation

 54,760 

 

 40,595 

 

 40,564 

December 31, 2024

 

 

 

 

 

Ownership percentages

 23.4 %

 

 8.7 %

 

 10.0 %

Plant in service

$ 157,572 

 

$ 65,426 

 

$ 52,430 

Accumulated depreciation

 49,573 

 

 39,025 

 

 39,887 

 

 

 

(6)           Asset Retirement Obligations

 

We are obligated to dispose of certain long-lived assets upon their abandonment. We recognize a liability for the legal obligation to perform an asset retirement activity in which the timing and/or method of settlement are conditional on a future event. We measure the liability at fair value when incurred and capitalize a corresponding amount as part of the book value of the related assets, which increases our property, plant and equipment and other noncurrent liabilities. The increase in the capitalized cost is included in determining depreciation expense over the estimated useful life of these assets. Since the fair value of the asset retirement obligation (ARO) is determined using a present value approach, accretion of the liability due to the passage of time is recognized each period and recorded as a regulatory asset until the settlement of the liability. Revisions to estimated AROs can result from changes in retirement cost estimates, revisions to estimated inflation rates, and changes in the estimated timing of abandonment. If the obligation is settled for an amount other than the carrying amount of the liability, we will recognize a regulatory asset or liability for the difference, which will be surcharged/refunded to customers through the rate making process. We record regulatory assets and liabilities for differences in timing of asset retirement costs recovered in rates and AROs recorded since asset retirement costs are recovered through rates charged to customers.

 

Our AROs relate to the reclamation and removal costs at our jointly-owned coal-fired generation facilities, U.S. Department of Transportation requirements to cut, purge and cap retired natural gas pipeline segments, and to remove all above-ground wind power facilities and restore the soil surface at the end of their life. The following table presents the change in our ARO (in thousands):

 

December 31,

 

2025

 

2024

Liability at January 1,

$ 6,841 

 

$ 6,616 

Accretion expense

 321 

 

 311 

Liabilities incurred

  

 

  

Liabilities settled

 (177)

 

 (120)

Revisions to cash flows

 1,234 

 

 34 

Liability at December 31,

$ 8,219 

 

$ 6,841 

 

During the twelve months ended December 31, 2025, our ARO liability decreased $0.2 million for partial settlement of the legal obligations at our natural gas pipeline segments. Additionally, during the twelve months ended December 31, 2025, our ARO liability increased $1.2 million related to changes in the timing and amount of retirement cost estimates.

 

In addition, we have identified removal liabilities related to our electric and natural gas transmission and distribution assets that have been installed on easements over property not owned by us. The easements are generally perpetual and only require remediation action upon abandonment or cessation of use of the property for the specified purpose. The ARO liability is not estimable for such easements as we intend to utilize these properties indefinitely. In the event we decide to abandon or cease the use of a particular easement, an ARO liability would be recorded at that time.

 

We collect removal costs in rates for certain transmission and distribution assets that do not have associated AROs. Generally, the accrual of future non-ARO removal obligations is not required; however, long-standing ratemaking practices approved by applicable state and federal regulatory commissions have allowed provisions for such costs in historical depreciation rates. The recorded amounts of costs collected from customers through depreciation rates are classified as a regulatory liability in recognition of the fact that we have collected these amounts that will be used in the future to fund asset retirement costs and do not represent legal retirement obligations. See Note 4 - Regulatory Assets and Liabilities for removal costs recorded as regulatory liabilities on the Balance Sheets as of December 31, 2025 and 2024.

 

 

(7)           Goodwill

 

We completed our annual goodwill impairment test as of April 1, 2025, and no impairment was identified. We calculate the fair value of our reporting units by considering various factors, including valuation studies based primarily on a discounted cash flow analysis, with published industry valuations and market data as supporting information. Key assumptions in the determination of fair value include the use of an appropriate discount rate and estimated future cash flows. In estimating cash flows, we incorporate expected long-term growth rates in our service territory, regulatory stability, and commodity prices (where appropriate), as well as other factors that affect our revenue, expense and capital expenditure projections.

 

Goodwill by segment is as follows (in thousands):

 

December 31,

 

2025

 

2024

Electric

$ 63,667 

 

$ 63,667 

Natural gas

 30,112 

 

 30,112 

Total Goodwill

$ 93,779 

 

$ 93,779 

 

 

 

(8)           Risk Management and Hedging Activities

 

Nature of Our Business and Associated Risks

 

We are exposed to certain risks related to the ongoing operations of our business, including the impact of market fluctuations in the price of electricity and natural gas commodities and changes in interest rates. We rely on market purchases to fulfill a portion of our electric and natural gas supply requirements. Several factors influence price levels and volatility. These factors include, but are not limited to, seasonal changes in demand, weather conditions, available generating assets within regions, transportation availability and reliability within and between regions, fuel availability, market liquidity, and the nature and extent of current and potential federal and state regulations.

 

Objectives and Strategies for Using Derivatives

 

To manage our exposure to fluctuations in commodity prices we routinely enter into derivative contracts. These types of contracts are included in our electric and natural gas supply portfolios and are used to manage price volatility risk by taking advantage of fluctuations in market prices. While individual contracts may be above or below market value, the overall portfolio approach is intended to provide greater price stability for consumers. We do not maintain a trading portfolio, and our derivative transactions are only used for risk management purposes consistent with regulatory guidelines.

 

In addition, we may use interest rate swaps to manage our interest rate exposures associated with new debt issuances or to manage our exposure to fluctuations in interest rates on variable rate debt.

 

Accounting for Derivative Instruments

 

We evaluate new and existing transactions and agreements to determine whether they are derivatives. The permitted accounting treatments include: normal purchase normal sale (NPNS); cash flow hedge; fair value hedge; and mark-to-market.

Mark-to-market accounting is the default accounting treatment for all derivatives unless they qualify, and we specifically designate them, for one of the other accounting treatments. Derivatives designated for any of the elective accounting treatments must meet specific, restrictive criteria both at the time of designation and on an ongoing basis. The changes in the fair value of recognized derivatives are recorded each period in current earnings or other comprehensive income, depending on whether a derivative is designated as part of a hedge transaction and the type of hedge transaction.

 

Normal Purchases and Normal Sales

 

We have applied the NPNS scope exception to our contracts involving the physical purchase and sale of gas and electricity at fixed prices in future periods. During our normal course of business, we enter into full-requirement energy contracts, power purchase agreements and physical capacity contracts, which qualify for NPNS. All of these contracts are accounted for using the accrual method of accounting; therefore, there were no unrealized amounts recorded in the Financial Statements at December 31, 2025 and 2024. Revenues and expenses from these contracts are reported on a gross basis in the appropriate revenue and expense categories as the commodities are received or delivered.

 

Credit Risk

 

Credit risk is the potential loss resulting from counterparty non-performance under an agreement. We manage credit risk with policies and procedures for, among other things, counterparty analysis and exposure measurement, monitoring and mitigation. We limit credit risk in our commodity and interest rate derivatives activities by assessing the creditworthiness of potential counterparties before entering into transactions with them and continuing to evaluate their creditworthiness on an ongoing basis.

 

We are exposed to credit risk through buying and selling electricity and natural gas to serve customers. We may request collateral or other security from our counterparties based on the assessment of creditworthiness and expected credit exposure. It is possible that volatility in commodity prices could cause us to have material credit risk exposures with one or more counterparties. We enter into commodity master enabling agreements with our counterparties to mitigate credit exposure, as these agreements reduce the risk of default by allowing us or our counterparty the ability to make net payments. The agreements generally are: (1) Western Systems Power Pool agreements – standardized power purchase and sales contracts in the electric industry; (2) International Swaps and Derivatives Association agreements – standardized financial gas and electric contracts; (3) North American Energy Standards Board agreements – standardized physical gas contracts; and (4) Edison Electric Institute Master Purchase and Sale Agreements – standardized power sales contracts in the electric industry.

 

Many of our forward purchase contracts contain provisions that require us to maintain an investment grade credit rating from each of the major credit rating agencies. If our credit rating were to fall below investment grade, the counterparties could require immediate payment or demand immediate and ongoing full overnight collateralization on contracts in net liability positions,

 

 

(9)           Fair Value Measurements

 

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (i.e., an exit price). Measuring fair value requires the use of market data or assumptions that market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs can be readily observable, corroborated by market data, or generally unobservable. Valuation techniques are required to maximize the use of observable inputs and minimize the use of unobservable inputs.

 

Applicable accounting guidance establishes a hierarchy that prioritizes the inputs used to measure fair value, and requires fair value measurements to be categorized based on the observability of those inputs. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 inputs) and the lowest priority to unobservable inputs (Level 3 inputs). The three levels of the fair value hierarchy are as follows:

 

          Level 1 – Unadjusted quoted prices available in active markets at the measurement date for identical assets or liabilities;

          Level 2 – Pricing inputs, other than quoted prices included within Level 1, which are either directly or indirectly observable as of the reporting date; and

          Level 3 – Significant inputs that are generally not observable from market activity.

 

We classify assets and liabilities within the fair value hierarchy based on the lowest level of input that is significant to the fair value measurement of each individual asset and liability taken as a whole. Due to the short-term nature of cash and cash equivalents, accounts receivable, net, accounts payable, and short-term borrowings, the carrying amount of each such item approximates fair value. There are no components of our assets or liabilities measured at fair value in the Financial Statements at December 31, 2025 and 2024.

 

Financial Instruments

 

The estimated fair value of financial instruments is summarized as follows (in thousands):

 

December 31, 2025

 

December 31, 2024

 

Carrying Amount

 

Fair Value

 

Carrying Amount

 

Fair Value

Liabilities:

 

 

 

 

 

 

 

Long-term debt

$ 594,998 

 

$ 557,704 

 

$ 552,186 

 

$ 504,498 

 

The estimated fair value amounts have been determined using available market information and appropriate valuation methodologies; however, considerable judgment is required in interpreting market data to develop estimates of fair value. Accordingly, the estimates presented herein are not necessarily indicative of the amounts that we would realize in a current market exchange.

 

We determined fair value for long-term debt based on interest rates that are currently available to us for issuance of debt with similar terms and remaining maturities, except for publicly traded debt, for which fair value is based on market prices for the same or similar issues or upon the quoted market prices of U.S. treasury issues having a similar term to maturity, adjusted for our bond issuance rating and the present value of future cash flows. These are significant other observable inputs, or level 2 inputs, in the fair value hierarchy.

 

 

(10)           Unsecured Credit Facilities

 

We have a $200.0 million unsecured revolver credit facility with base sublimits of $50.0 million for NorthWestern Energy Group and $150.0 million for NWE Public Service (the HoldCo and NWE Public Service Credit Facility). The HoldCo and NWE Public Service Credit Facility has a maturity date of November 29, 2028. The HoldCo and NWE Public Service Credit Facility has uncommitted features that allow both NorthWestern Energy Group and NWE Public Service to request one-year extensions to the maturity date and increase the size of the credit facility by an additional $50.0 million. The credit facility also gives us the flexibility to adjust the sublimits as needed, provided that NorthWestern Energy Group's base sublimit cannot exceed $100.0 million and NWE Public Service's sublimit cannot exceed $200.0 million. Borrowings may be made at interest rates equal to (a) SOFR, plus a credit spread adjustment of 10.0 basis points plus a margin of 100.0 to 175.0 basis points, or (b) a base rate, plus a margin of 0.0 to 75.0 basis points.

 

Commitment fees for the unsecured revolving lines of credit was $0.2 million for the years ended December 31, 2025 and 2024.

 

The availability under the facilities in place for the year ended December 31, 2024, is shown in the following table (in millions):

 

2025

 

2024

Unsecured revolving line of credit, expiring November 2028

$ 150.0 

 

$ 150.0 

 

 

 

 

Amounts outstanding at December 31:

 

 

 

SOFR borrowings

 41.0 

 

 34.0 

Letters of credit

  

 

  

 

 41.0 

 

 34.0 

Net availability as of December 31

$ 109.0 

 

$ 116.0 

 

Our credit facilities include covenants that require us to meet certain financial tests, including a maximum debt to capitalization ratio not to exceed 65 percent. The facilities also contain covenants which, among other things, limit our ability to engage in any consolidation or merger or otherwise liquidate or dissolve, dispose of property, and enter into transactions with affiliates A default on the South Dakota First Mortgage Bonds would trigger a cross default on the NWE Public Service sublimit of the HoldCo and NWE Public Service Credit Facility; however, a default on the HoldCo and NWE Public Service Credit Facility would not trigger a default on the South Dakota First Mortgage Bonds.

 

 

(11)           Long-Term Debt

Long-term debt consisted of the following (in thousands):

 

 

 

December 31,

 

Due

 

2025

 

2024

Unsecured Debt:

 

 

 

 

 

Unsecured Revolving Line of Credit

2028

 

$ 41,000 

 

$ 34,000 

Secured Debt:

 

 

 

 

 

Mortgage bonds—

 

 

 

 

 

South Dakota—5.01%

2025

 

  

 

 64,000 

South Dakota—2.80%

2026

 

 60,000 

 

 60,000 

South Dakota—2.66%

2026

 

 45,000 

 

 45,000 

South Dakota—5.55%

2029

 

 33,000 

 

 33,000 

South Dakota—3.21%

2030

 

 50,000 

 

 50,000 

South Dakota—5.57%

2033

 

 31,000 

 

 31,000 

South Dakota—5.42%

2033

 

 30,000 

 

 30,000 

South Dakota—5.75%

2034

 

 7,000 

 

 7,000 

South Dakota—5.49%

2035

 

 100,000 

 

  

South Dakota—4.26%

2040

 

 70,000 

 

 70,000 

South Dakota—4.15%

2042

 

 30,000 

 

 30,000 

South Dakota—4.85%

2043

 

 50,000 

 

 50,000 

South Dakota—4.22%

2044

 

 30,000 

 

 30,000 

South Dakota—4.30%

2052

 

 20,000 

 

 20,000 

Other Long Term Debt:

 

 

 

 

 

Discount on Notes and Bonds and Debt Issuance Costs, Net

 

 

 (2,002)

 

 (1,814)

Total Long-Term Debt

 

 

$ 594,998 

 

$ 552,186 

Less current maturities (including associated debt issuance costs)

 

 

 (104,967)

 

 (63,991)

Total Long-Term Debt, Net of Current Maturities

 

 

$ 490,031 

 

$ 488,195 

 

Secured Debt

 

First Mortgage Bonds and Pollution Control Obligations

 

The South Dakota First Mortgage Bonds are a series of general obligation bonds issued under our South Dakota indenture. These bonds are secured by substantially all of our electric and natural gas assets associated with our South Dakota and Nebraska utility operations.

 

On March 28, 2024, we issued and sold $33.0 million aggregate principal amount of South Dakota First Mortgage Bonds at a fixed interest rate of 5.55 percent maturing on March 28, 2029, and $7.0 million aggregate principal amount of South Dakota First Mortgage Bonds at a fixed interest rate of 5.75 percent maturing on March 28, 2034. These bonds were issued in transactions exempt from the registration requirements of the Securities Act of 1933. Proceeds were used for general utility purposes. The bonds are secured by our electric and natural gas assets associated with its South Dakota and Nebraska utility operations.

 

On May 1, 2025, we issued and sold $100.0 million aggregate principal amount of South Dakota First Mortgage Bonds at a fixed interest rate of 5.49 percent maturing on May 1, 2035. These bonds were issued in transactions exempt from the registration requirements of the Securities Act of 1933. Proceeds were utilized to repay at maturity $64.0 million of 5.01 percent South Dakota First Mortgage Bonds due on May 1, 2025 and for other general utility purposes.

 

As of December 31, 2025, we were in compliance with our financial debt covenants.

 

Maturities of Long-Term Debt

 

The aggregate minimum principal maturities of long-term debt during the next five years are $105.0 million in 2026, $41.0 million in 2028, $33 million in 2029, and 50.0 million in 2030.

 

 

 

(12)           Income Taxes

 

Income tax (benefit) expense is comprised of the following (in thousands):

 

Year Ended December 31,

 

2025

 

2024

Federal

 

 

 

Current

$ (10,383)

 

$ (5,989)

Deferred

 14,076 

 

 (997)

Investment tax credits

  

 

  

State

 

 

 

Current

  

 

  

Deferred

 250 

 

 250 

Income Tax Expense (Benefit)

$ 3,943 

 

$ (6,736)

Deferred income tax expense is comprised of the following (in thousands):

 

Year Ended December 31,

 

2025

 

2024

Deferred tax benefit excluding items below

$ 1,837 

 

$ (2,934)

Adjustments to other noncurrent liabilities, regulatory assets, and liabilities

 (543)

 

 (5,371)

Tax benefit allocated to other comprehensive income

 (46)

 

 (134)

Adjustments to deferred income taxes for production tax credit cash transfer

 13,078 

 

 7,692 

Deferred tax expense (benefit)

$ 14,326 

 

$ (747)

 

Our effective tax rate typically differs from the federal statutory tax rate primarily due to the regulatory impact of flowing through the federal and state tax benefit of repairs deductions, state tax benefit of accelerated tax depreciation deductions (including bonus depreciation when applicable), and production tax credits. The regulatory accounting treatment of these deductions requires immediate income recognition for temporary tax differences of this type, which is referred to as the flow-through method. When the flow-through method of accounting for temporary differences is reflected in regulated revenues, we record deferred income taxes and establish related regulatory assets and liabilities.

 

The table below reconciles our effective income tax rate to the federal statutory rate and summarizes the significant differences in income tax expense (benefit) based on the differences between our effective tax rate and the federal statutory rate (in thousands). Our income from continuing operations is primarily from domestic operations.

 

Year Ended December 31,

 

2025

 

2024

 

(in dollars)

(in percent)

 

(in dollars)

(in percent)

Income before income taxes

$ 35,470 

 

 

$ 24,197 

 

 

 

 

 

 

 

Income tax calculated at federal statutory rate

7,449

 21.0 %

 

5,081

 21.0 %

 

 

 

 

 

 

State income tax, net of federal provision(1)

 250 

 0.7 

 

250

 1.0 

Tax Credits

 

 

 

 

 

Production tax credits

 (4,296)

 (12.1) 

 

 (8,781)

 (36.3) 

Production tax credits discount on transfer

 785 

 2.2 

 

 825 

 3.4 

Impact of utility ratemaking on income taxes

 

 

 

 

 

Flow-through repairs deductions

 (3,828)

 (10.8) 

 

 (3,859)

 (15.9) 

Amortization of excess deferred income taxes

 (478)

 (1.3) 

 

 (465)

 (1.9) 

AFUDC, net

 (179)

 (0.5) 

 

 (154)

 (0.6) 

Plant and depreciation of flow through items

 3,757 

 10.6 

 

 2,675 

 11.1 

Gas repairs safe harbor method change

  

  

 

 (2,628)

 (10.9) 

Nontaxable and nondeductible items

 162 

 0.5 

 

 133 

 0.5 

Other

 321 

 0.8 

 

 187 

 0.8 

 

 (3,506)

 (9.9) 

 

 (11,817)

 (48.8) 

 

 

 

 

 

 

Income Tax Expense (Benefit) and Effective Tax Rate

$ 3,943 

 11.1 %

 

$ (6,736)

 (27.8) %

(1) For all years presented, the state of Nebraska comprises the majority of the domestic state income taxes, net of federal provisions.

 

We are included in NorthWestern Energy Group, Inc.'s consolidated federal and state income tax returns. In accordance with our tax sharing agreement with NorthWestern Energy Group, Inc., we compute our income taxes based upon the separate return method, where we are assumed to file a separate return with the taxing authority, thereby reporting our taxable income and paying the applicable tax to or receiving the appropriate refund from NorthWestern Energy Group, Inc.

 

In 2023, the Internal Revenue Service (IRS) issued a safe harbor method of accounting for the repair and maintenance of natural gas transmission and distribution property. For the year ending December 31, 2024, after completion of our impact analysis of the gas repairs safe harbor method change, we recorded an income tax benefit of approximately $2.6 million related to tax deductions for repair costs that were previously capitalized in the 2022 and prior tax years.

 

The components of the net deferred income tax liability recognized in our Balance Sheets are related to the following temporary differences (in thousands):

 

 

December 31,

 

2025

 

2024

Production tax credit

$ 52,936 

 

$ 62,094 

NOL carryforward

 26,168 

 

 30,124 

Unbilled revenue

 3,383 

 

 3,350 

Environmental liability

 3,363 

 

 3,283 

Compensation accruals

 1,642 

 

 1,693 

Reserves and accruals

 205 

 

 119 

Other

 2,091 

 

 2,001 

Deferred Tax Asset

 89,788 

 

 102,664 

Excess tax depreciation

 (115,334)

 

 (113,500)

Flow through depreciation

 (13,395)

 

 (13,270)

Pension / postretirement benefits

 (1,230)

 

 (1,291)

Regulatory assets and other

 (4,610)

 

 (4,391)

Deferred Tax Liability

 (134,569)

 

 (132,452)

Deferred Tax Liability, net

$ (44,781)

 

$ (29,788)

 

As of December 31, 2025, our total federal NOL carryforward was approximately $124.6 million. Our federal NOL carryforward does not expire. We believe it is more likely than not that sufficient taxable income will be generated to utilize these NOL carryforwards.

 

At December 31, 2025, our total production tax credit carryforward was approximately $52.9 million. If unused, our production tax credit carryforwards will expire as follows: $0.3 million in 2035, $7.5 million in 2036, $7.5 million in 2037, $7.0 million in 2038, $7.1 million in 2039, $7.7 million in 2040, $7.1 million in 2041, and $8.7 million in 2042. We believe it is more likely than not that sufficient taxable income will be generated to utilize these production tax credit carryforwards.

 

Tax years 2022 and forward remain subject to examination by the IRS and state taxing authorities.

 

 

(13)           Comprehensive Income

 

The following tables display the components of Other Comprehensive Income, after-tax, and the related tax effects (in thousands):

 

December 31,

 

2025

 

2024

 

Before-Tax Amount

 

Tax Benefit

 

Net-of-Tax Amount

 

Before-Tax Amount

 

Tax Benefit

 

Net-of-Tax Amount

Postretirement medical liability adjustment

$ 219 

 

$ (46)

 

$ 173 

 

$ 637 

 

$ (133)

 

$ 504 

Other comprehensive income

$ 219 

 

$ (46)

 

$ 173 

 

$ 637 

 

$ (133)

 

$ 504 

 

Balances by classification included within AOCI on the Balance Sheets are as follows, net of tax (in thousands):

 

December 31,

 

2025

 

2024

Postretirement medical plans

$ 1,002 

 

$ 829 

Accumulated other comprehensive income

$ 1,002 

 

$ 829 

 

 

The following table displays the changes in AOCI by component, net of tax (in thousands):

 

 

 

December 31, 2025

 

December 31, 2024

 

Affected Line Item in the Statements of Income

 

Postretirement Medical Plans

 

Postretirement Medical Plans

Beginning balance

 

 

$ 829 

 

$  

Amounts reclassified from AOCI

 

 

 173 

 

 504 

Net current-period other comprehensive income

 

 

 1,002 

 

 504 

Contribution from Parent

 

 

$  

 

$ 325 

Ending Balance

 

 

$ 1,002 

 

$ 829 

 

 

 

(14)           Employee Benefit Plans

 

Pension and Other Postretirement Benefit Plans

 

We sponsor and/or contribute to pension and postretirement health care and life insurance benefit plans for eligible employees. The pension plan for our South Dakota and Nebraska employees is referred to as the NorthWestern Energy SD/NE Plan (formerly known as the NorthWestern Corporation Plan). We utilize a number of accounting mechanisms that reduce the volatility of reported pension costs. Differences between actuarial assumptions and actual plan results are deferred and are recognized into earnings only when the accumulated differences exceed 10 percent of the greater of the projected benefit obligation or the market-related value of plan assets. If necessary, the excess is amortized over the average remaining service period of active employees. The Plans' funded status is recognized as an asset in our Financial Statements. See Note 4 - Regulatory Assets and Liabilities, for further discussion on how these costs are recovered through rates charged to our customers.

 

Benefit Obligation and Funded Status

 

Following is a reconciliation of the changes in plan benefit obligations and fair value of plan assets, and a statement of the funded status (in thousands):

 

 

Pension Benefits

 

Other Postretirement Benefits

 

December 31,

 

December 31,

 

2025

 

2024

 

2025

 

2024

Change in benefit obligation:

 

 

 

 

 

 

 

Obligation at beginning of period

$ 43,144 

 

$ 46,662 

 

$ 2,387 

 

$ 3,110 

Service cost

 409 

 

 493 

 

 45 

 

 56 

Interest cost

 2,286 

 

 2,219 

 

 89 

 

 101 

Plan amendments

  

 

  

 

  

 

  

Actuarial loss (gain)

 2,057 

 

 (1,719)

 

 (183)

 

 (710)

Settlements

  

 

  

 

  

 

  

Benefits paid

 (3,878)

 

 (4,511)

 

 (303)

 

 (170)

Benefit Obligation at End of Period

$ 44,018 

 

$ 43,144 

 

$ 2,035 

 

$ 2,387 

Change in Fair Value of Plan Assets:

 

 

 

 

 

 

 

Fair value of plan assets at beginning of period

 52,611 

 

 54,537 

 

  

 

  

Return on plan assets

 4,086 

 

 1,385 

 

  

 

  

Employer contributions

  

 

 1,200 

 

 303 

 

 170 

Settlements

  

 

  

 

  

 

  

Benefits paid

 (3,878)

 

 (4,511)

 

 (303)

 

 (170)

Fair value of plan assets at end of period

$ 52,819 

 

$ 52,611 

 

$  

 

$  

Funded Status

$ 8,801 

 

$ 9,467 

 

$ (2,035)

 

$ (2,387)

 

 

 

 

 

 

 

 

Amounts Recognized in the Balance Sheet Consist of:

 

 

 

 

 

 

 

Noncurrent asset

 8,801 

 

 9,467 

 

  

 

  

Total Assets

$ 8,801 

 

$ 9,467 

 

$  

 

$  

Current liability

  

 

  

 

 (661)

 

 (800)

Noncurrent liability

  

 

  

 

 (1,374)

 

 (1,587)

Total Liabilities

  

 

  

 

 (2,035)

 

 (2,387)

Net amount recognized

$ 8,801 

 

$ 9,467 

 

$ (2,035)

 

$ (2,387)

 

 

 

 

 

 

 

 

Amounts Recognized in Regulatory Assets Consist of:

 

 

 

 

 

 

 

Prior service credit

  

 

  

 

  

 

  

   Net actuarial (loss) gain

 (1,265)

 

 (992)

 

  

 

  

Amounts recognized in AOCI consist of:

 

 

 

 

 

 

 

Prior service cost

  

 

  

 

  

 

  

Net actuarial gain

  

 

  

 

 1,268 

 

 1,228 

Total

$ (1,265)

 

$ (992)

 

$ 1,268 

 

$ 1,228 

 

The actuarial gain/loss is primarily due to the change in discount rate assumption and actual asset returns compared with expected amounts.

 

 

Net Periodic Cost (Credit)

 

The components of the net costs (credits) for our pension and other postretirement plans are as follows (in thousands):

 

 

Pension Benefits

 

Other Postretirement Benefits

 

December 31,

 

December 31,

 

2025

 

2024

 

2025

 

2024

Components of Net Periodic Benefit Cost

 

 

 

 

 

 

 

Service cost

$ 409 

 

$ 493 

 

$ 45 

 

$ 56 

Interest cost

 2,285 

 

 2,219 

 

 89 

 

 101 

Expected return on plan assets

 (2,302)

 

 (2,740)

 

  

 

  

Amortization of prior service cost (credit)

  

 

  

 

  

 

  

Recognized actuarial loss (gain)

  

 

  

 

 (142)

 

 (73)

Net Periodic Benefit Cost (Credit)

$ 392 

 

$ (28)

 

$ (8)

 

$ 84 

 

 

 

 

 

 

 

 

Previously deferred costs recognized(1)

 124 

 

 75 

 

  

 

  

Net Periodic Benefit Cost (Credit) Recognized

$ 516 

 

$ 47 

 

$ (8)

 

$ 84 

(1) Net periodic benefit costs for pension and postretirement benefit plans are recognized for financial reporting based on the authorization of each regulatory jurisdiction in which we operate. A portion of these costs are recorded in regulatory assets and recognized in the Statements of Income as those costs are recovered through customer rates.

 

For the year ended December 31, 2025 and 2024, service costs were recorded in Operating, general, and administrative expense while non-service costs were recorded in Other income, net on the Statements of Income.

 

For purposes of calculating the expected return on pension plan assets, the market-related value of assets is used, which is based upon fair value. The difference between actual plan asset returns and estimated plan asset returns are amortized equally over a period not to exceed five years.

 

Actuarial Assumptions

 

The measurement dates used to determine pension and other postretirement benefit measurements for the plans are December 31, 2025. The actuarial assumptions used to compute net periodic pension cost and postretirement benefit cost are based upon information available as of the beginning of the year, specifically, market interest rates, past experience and management's best estimate of future economic conditions. Changes in these assumptions may impact future benefit costs and obligations. In computing future costs and obligations, we must make assumptions about such things as employee mortality and turnover, expected salary and wage increases, discount rate, expected return on plan assets, and expected future cost increases. Two of these assumptions have the most impact on the level of cost: (1) discount rate and (2) expected rate of return on plan assets. During 2022, the plan's actuary conducted an experience study to review five years of plan experience and update these assumptions.

 

On an annual basis, we set the discount rate using a yield curve analysis. This analysis includes constructing a hypothetical bond portfolio whose cash flow from coupons and maturities matches the year-by-year, projected benefit cash flow from our plans. The decrease in the discount rate during 2025 increased our projected benefit obligation by approximately $1.0 million.

 

In determining the expected long-term rate of return on plan assets, we review historical returns, the future expectations for returns for each asset class weighted by the target asset allocation of the pension and postretirement portfolios, and long-term inflation assumptions. Based on the target asset allocation for our pension assets and future expectations for asset returns, we decreased our long term rate of return on assets assumption for NorthWestern Energy SD/NE Pension Plan to 4.96 percent for 2026.

 

The weighted-average assumptions used in calculating the preceding information are as follows:

 

Pension Benefits

 

Other Postretirement Benefits

 

December 31,

 

December 31,

 

2025

 

2024

 

2025

 

2024

Discount rate

 5.20 

 

 5.50 

 

 4.85 

 

 5.30 

Expected rate of return on assets

 4.58 

 

 5.15 

 

N/A

 

N/A

Long-term rate of increase in compensation levels (non-union)

 4.00 

 

 4.00 

 

 4.00 

 

 4.00 

Long-term rate of increase in compensation levels (union)

 4.00 

 

 4.00 

 

 4.00 

 

 4.00 

Interest crediting rate

 3.30 

 

 3.30 

 

N/A

 

N/A

 

The postretirement benefit obligation is calculated assuming that health care costs increase by a 5 percent fixed rate. The company contribution toward the premium cost is capped, therefore future health care cost trend rates are expected to have a minimal impact on company costs and the accumulated postretirement benefit obligation.

 

Investment Strategy

 

Our investment goals with respect to managing the pension and other postretirement assets are to meet current and future benefit payment needs while maximizing total investment returns (income and appreciation) after inflation within the constraints of diversification, prudent risk taking, Prudent Man Rule of the Employee Retirement Income Security Act of 1974 and liability-based considerations. Each plan is diversified across asset classes to achieve optimal balance between risk and return and between income and growth through capital appreciation. Our investment philosophy is based on the following:

 

          Each plan should be substantially invested as long-term cash holdings reduce long-term rates of return;

          Pension Plan portfolio risk is described by volatility in the funded status of the Plans;

          It is prudent to diversify each plan across the major asset classes;

          Equity investments provide greater long-term returns than fixed income investments, although with greater short-term volatility;

          Fixed income investments of the plans should strongly correlate with the interest rate sensitivity of the plan’s aggregate liabilities in order to hedge the risk of change in interest rates negatively impacting the pension plans overall funded status, (such assets will be described as Liability Hedging Fixed Income assets);

          Allocation to foreign equities increases the portfolio diversification and thereby decreases portfolio risk while providing for the potential for enhanced long-term returns;

          Active management can reduce portfolio risk and potentially add value through security selection strategies;

          A portion of plan assets should be allocated to passive, indexed management funds to provide for greater diversification and lower cost; and

          It is appropriate to retain more than one investment manager, provided that such managers offer asset class or style diversification.

 

Investment risk is measured and monitored on an ongoing basis through quarterly investment portfolio reviews, annual liability measurements, and periodic asset/liability studies.

 

The most important component of an investment strategy is the portfolio asset mix, or the allocation between the various classes of securities available. The mix of assets is based on an optimization study that identifies asset allocation targets in order to achieve the maximum return for an acceptable level of risk, while minimizing the expected contributions and pension and postretirement expense. In the optimization study, assumptions are formulated about characteristics, such as expected asset class investment returns, volatility (risk), and correlation coefficients among the various asset classes, and making adjustments to reflect future conditions expected to prevail over the study period. Based on this, the target asset allocation established, within an allowable range of plus or minus 3 - 5 percent, is as follows:

 

 

 

NorthWestern Energy SD/NE Pension

 

 

December 31,

 

 

2025

 

2024

Fixed income securities

 

 90.0 %

 

 90.0 %

Opportunistic fixed income

 

 3.0 

 

 3.0 

Global equities

 

 7.0 

 

 7.0 

 

The actual allocation by plan is as follows:

 

 

NorthWestern Energy SD/NE Pension

 

 

December 31,

 

2025

 

2024

Cash and cash equivalents

 

 0.9 %

 

 0.8 %

Fixed income securities

 

 89.0 

 

 89.4 

Opportunistic fixed income

 

 3.0 

 

 2.9 

Global equities

 

 7.1 

 

 6.9 

 

 

 100.0 %

 

 100.0 %

 

Generally, the asset mix will be rebalanced to the target mix as individual portfolios approach their minimum or maximum levels. The guidelines allow for a transition to targets over time as assets are reallocated to newly-approved asset classes of opportunistic fixed income and private real estate. Debt securities consist of U.S. and international instruments including emerging markets and high yield instruments, as well as government, corporate, asset backed and mortgage backed securities. While the portfolio may invest in high yield securities, the average quality must be rated at least “investment grade" by rating agencies. Equity, real estate and fixed income portfolios may be comprised of both active and passive management strategies. Performance of fixed income investments is measured by both traditional investment benchmarks as well as relative changes in the present value of the plan's liabilities. Equity investments consist primarily of U.S. stocks including large, mid and small cap stocks. We also invest in global equities with exposure to developing and emerging markets. Equity investments may also be diversified across investment styles such as growth and value. Derivatives, options and futures are permitted for the purpose of reducing risk but may not be used for speculative purposes. Real estate investments will consist of global equity or debt interests in tangible property consisting of land, buildings, and other improvements in commercial and residential sectors.

 

All of our plan assets are held by common collective trusts (CCTs). In accordance with our investment policy, these pooled investment funds must have an adequate asset base relative to their asset class, be invested in a diversified manner and have a minimum of three years of verified investment performance experience or have a portfolio manager with a minimum of three years of verified investment experience in a similar investment strategy. The fund must have management and/or oversight by an investment advisor registered with the SEC. Investments in a collective investment vehicle are valued by multiplying the investee company’s NAV per share by the number of units or shares owned at the valuation date. NAV per share is determined by the trustee. Investments held by the CCT, including collateral invested for securities on loan, are valued on the basis of valuations furnished by a pricing service approved by the CCT’s investment manager, which determines valuations using methods based on quoted closing market prices on national securities exchanges, or at fair value as determined in good faith by the CCT’s investment manager if applicable. The direct holding of NorthWestern Energy Group stock is not permitted; however, any holding in a diversified mutual fund or collective investment fund is permitted.

 

Cash Flows

 

In accordance with the Pension Protection Act of 2006 (PPA), and the relief provisions of the Worker, Retiree, and Employer Recovery Act of 2008 (WRERA), we are required to meet minimum funding levels in order to avoid required contributions and benefit restrictions. We have elected to use asset smoothing provided by the WRERA, which allows the use of asset averaging, including expected returns (subject to certain limitations), for a 24-month period in the determination of funding requirements. Additional funding relief was passed in the American Rescue Plan Act of 2021, providing for longer amortization and interest rate smoothing, which we elected to use. We expect to continue to make contributions to the pension plans in 2026 and future years that reflect the minimum requirements and discretionary amounts consistent with the amounts recovered in rates. Additional legislative or regulatory measures, as well as fluctuations in financial market conditions, may impact our funding requirements.

 

Annual contributions to the pension plan are as follows (in thousands):

 

2025

 

2024

NorthWestern Energy Pension Plan

  

 

 1,200 

 

$  

 

$ 1,200 

 

We estimate the plans will make future benefit payments to participants as follows (in thousands):

 

Pension Benefits

 

Other Postretirement Benefits

2026

 4,215 

 

 661 

2027

 3,802 

 

 204 

2028

 4,057 

 

 161 

2029

 3,722 

 

 166 

2030

 3,746 

 

 187 

2031-2035

 17,802 

 

 808 

 

Defined Contribution Plan

 

Our defined contribution plan permits employees to defer receipt of compensation as provided in Section 401(k) of the Internal Revenue Code. Under the plan, employees may elect to direct a percentage of their gross compensation to the plan. We also contribute various percentages of employees' gross compensation to the plan. Company contributions for the years ended December 31, 2025 and 2024 were $3.2 million and $3.1 million respectively.

 

 

(15)           Stock-Based Compensation

 

NorthWestern Corporation employees, which provide all labor related services to us, participate in the NorthWestern Energy Group, Inc. Amended and Restated Equity Compensation Plan (ECP), which includes restricted stock awards and performance share awards. Stock-based compensation expense is allocated to us based on the outstanding awards held by these employees and our allocation of labor costs. We account for share-based compensation arrangements by recognizing compensation costs for all share-based awards over the respective service period for employee services received in exchange for an award of equity or equity-based compensation. The compensation cost is based on the fair value of the grant on the date it was awarded.

 

We recognized total stock-based compensation expense of $0.9 million and $0.6 million for the years ended December 31, 2025 and 2024 respectively, and related income tax benefit of $0.2 million and $0.1 million for the years ended December 31, 2025 and 2024 respectively.

 

 

 

(16)           Common Stock

 

We have 100 shares of common stock authorized with a $0.01 par value. We have 100 shares of common stock issued and outstanding.

 

Dividend Restrictions

 

Under various state regulatory agreements, debt agreements and the Federal Power Act, we have restrictions, including minimum equity ratios, that limit the amount of dividend distributions that can be made.

 

Our ability to pay dividends is limited by the terms of various debt agreements, pursuant to which, we are required to maintain a debt to capitalization ratio of no more than 0.65 to 1.00.

 

As of December 31, 2025, approximately $264.4 million of our net assets were available for the payment of dividends under our most restrictive dividend restriction.

 

 

 

(17)           Commitments and Contingencies

 

Long Term Supply and Capacity Purchase Obligations

 

We have entered into various commitments, largely purchased power, electric transmission, coal and natural gas supply and natural gas transportation contracts. These commitments range from one to 24 years. Costs incurred under these contracts are included in Fuel, purchased power and direct transmission expense in the Statements of Income and were approximately $107.5 million and $100.6 million for the year ended December 31, 2025 and 2024, respectively. As of December 31, 2025, our commitments under these contracts were $76.8 million in 2026, $54.3 million in 2027, $53.1 million in 2028, $50.0 million in 2029, $29.2 million in 2030, and $150.7 million thereafter. These commitments are not reflected in our Financial Statements.

 

ENVIRONMENTAL LIABILITIES AND REGULATION

 

Environmental Matters

 

The operation of electric generating, transmission and distribution facilities, and gas transportation and distribution facilities, along with the development (involving site selection, environmental assessments, and permitting) and construction of these assets, are subject to extensive federal, state, and local environmental and land use laws and regulations. Our activities involve compliance with diverse laws and regulations that address emissions and impacts to the environment, including air and water, protection of natural resources, avian and wildlife. We monitor federal, state, and local environmental initiatives to determine potential impacts on our financial results. As new laws or regulations are implemented, our policy is to assess their applicability and implement the necessary modifications to our facilities or their operation to maintain ongoing compliance.

 

Our environmental exposure includes a number of components, including remediation expenses related to the cleanup of current or former properties, and costs to comply with changing environmental regulations related to our operations. At present, our environmental reserve, which relates primarily to the remediation of former manufactured gas plant sites owned by us or for which we are responsible, is estimated to range between $13.4 million to $19.2 million. As of December 31, 2025, we had a reserve of approximately $16.0 million, which has not been discounted. Environmental costs are recorded when it is probable we are liable for the remediation and we can reasonably estimate the liability. We use a combination of site investigations and monitoring to formulate an estimate of environmental remediation costs for specific sites. Our monitoring procedures and development of actual remediation plans depend not only on site specific information but also on coordination with the different environmental regulatory agencies in our respective jurisdictions; therefore, while remediation exposure exists, it may be many years before costs are incurred.

 

The following summarizes the change in our environmental liability (in thousands):

 

 

December 31,

 

2025

 

2024

Liability at January 1,

$ 15,635 

 

$ 16,848 

Deductions

 (1,347)

 

 (1,846)

Charged to costs and expense

 1,728 

 

 633 

Liability at December 31,

$ 16,016 

 

$ 15,635 

 

We are permitted to recover the remediation costs related to certain environmental liabilities within rates. Over time, as costs become determinable, we may seek authorization to recover such costs in rates or seek insurance reimbursement as available and applicable; therefore, although we cannot guarantee regulatory recovery for all remediation costs, we do not expect these costs to have a material effect on our consolidated financial position or results of operations.

 

Manufactured Gas Plants - Approximately $15.7 million of our environmental reserve accrual is related to the following manufactured gas plants.

 

South Dakota - A formerly operated manufactured gas plant located in Aberdeen, South Dakota, has been identified on the Federal Comprehensive Environmental Response, Compensation, and Liability Information System list as contaminated with coal tar residue. We are currently conducting feasibility studies, implementing remedial actions pursuant to work plans approved by the South Dakota Department of Agriculture and Natural Resources, and conducting ongoing monitoring and operation and maintenance activities. As of December 31, 2025, the reserve for remediation costs at this site was approximately $7.8 million, and we estimate that approximately $2.7 million of this amount will be incurred through 2028. The SDPUC permits the recovery of these costs within rates.

 

Nebraska - We own sites in North Platte, Kearney, and Grand Island, Nebraska on which former manufactured gas facilities were located. We are currently working independently to fully characterize the nature and extent of potential impacts associated with these Nebraska sites. Our reserve estimate includes assumptions for site assessment and remedial action work. At present, we cannot determine with a reasonable degree of certainty the nature and timing of any risk-based remedial action at our Nebraska locations.

 

Global Climate Change - National and international actions have been initiated to address global climate change and the contribution of GHG including, most significantly, carbon dioxide (CO2) and methane emissions from natural gas. These actions include legislative proposals, Executive, Congressional and EPA actions at the federal level, state level activity, investor activism and private party litigation relating to emissions. Coal-fired plants have come under particular scrutiny due to their level of emissions. We have joint ownership interests in three coal-fired electric generating plants, all of which are operated by other companies. We are responsible for our proportionate share of the capital and operating costs while being entitled to our proportionate share of the power generated.

 

EPA Rules - Congress has not passed any federal climate change legislation regarding GHG emissions from coal fired plants, and we cannot predict the timing or form of any potential legislation. Historically, Section 111(d) of the Clean Air Act (CAA) has been interpreted to confer authority on EPA in coordination with the states to regulate emissions, including GHG emissions, from existing stationary sources. On April 25, 2024, the EPA released final rules related to GHG emission standards (GHG Rules) for existing coal-fired facilities and new coal and natural gas-fired facilities as well as final rules strengthening the MATS requirements (MATS Rules). As finalized, compliance with the rules would require expensive upgrades at Colstrip Units 3 and 4 with proposed compliance dates that may not be achievable and / or require technology that is unproven, resulting in significant impacts to costs of the facilities. The final MATS and GHG Rules require compliance as early as 2027 and 2032, respectively.

 

On June 11, 2025, the EPA issued a Notice of Proposed Rulemaking proposing significant changes to the federal regulatory framework for both GHG emissions and hazardous air pollutants from power plants. If either the lead or alternative proposal is adopted, our additional material compliance costs would be eliminated. On February 19, 2026, the EPA rescinded the 2024 MATS Rules, restoring the rule to the 2012 MATS standards.

 

On February 12, 2026, the EPA released a final rule titled Rescission of the Greenhouse Gas Endangerment Finding and Motor Vehicle Greenhouse Gas Emission Standards Under the Clean Air Act. This action reflects a further shift in federal policy regarding the regulation of GHG emissions under the CAA and may have implications for the scope of the EPA's authority to regulate GHG emissions from stationary sources, including power plants. The legal and practical effects of this final rule, including the potential for judicial review or subsequent regulatory action, remain uncertain.

 

Notwithstanding these developments, existing and future federal, state, or regional environmental requirements - including potential revisions to GHG emissions standards, or other air quality regulations could cause us to incur material costs of compliance, increase our costs of procuring electricity, decrease transmission revenue and impact cost recovery. Technology to efficiently capture, remove and/or sequester such GHG emissions or hazardous air pollutants may not be available within a timeframe consistent with the implementation of any such requirements.

 

Regional Haze Rules - In January 2017, the EPA published amendments to the requirements under the CAA for state plans for protection of visibility - regional haze rules. Among other things, these amendments revised the process and requirements for the state implementation plans and extended the due date for the next periodic comprehensive regional haze state implementation plan revisions from 2018 to 2021.

 

The states of North Dakota and South Dakota have developed and submitted to the EPA, for its approval, their respective State Implementation Plans (SIP) for Regional Haze compliance. While these states, among others, did not meet the EPA’s July 31, 2021, submission deadline, they were all submitted in 2022. The draft North Dakota SIP does not require any additional controls at the Coyote generating facility. Similarly, the draft South Dakota SIP does not require any additional controls at the Big Stone generating facility. Until these SIPs are finalized and approved by EPA, the potential remains that installation of additional emissions controls might be required at these facilities.

 

Jointly Owned Plants - We have joint ownership in generation plants located in South Dakota, North Dakota, and Iowa that are or may become subject to the various regulations discussed above that have been or may be issued or proposed.

 

Other - We continue to manage equipment containing polychlorinated biphenyl (PCB) oil in accordance with the EPA's Toxic Substance Control Act regulations. We will continue to use certain PCB-contaminated equipment for its remaining useful life and will, thereafter, dispose of the equipment according to pertinent regulations that govern the use and disposal of such equipment.

 

We routinely engage the services of a third-party environmental consulting firm to assist in performing a comprehensive evaluation of our environmental reserve. Based upon information available at this time, we believe that the current environmental reserve properly reflects our remediation exposure for the sites currently and previously owned by us. The portion of our environmental reserve applicable to site remediation may be subject to change as a result of the following uncertainties:

 

          We may not know all sites for which we are alleged or will be found to be responsible for remediation; and

          Absent performance of certain testing at sites where we have been identified as responsible for remediation, we cannot estimate with a reasonable degree of certainty the total costs of remediation.

 

LEGAL PROCEEDINGS

 

We are subject to various legal proceedings, governmental audits and claims that arise in the ordinary course of business. In our opinion, the amount of ultimate liability with respect to these other actions will not materially affect our financial position, results of operations, or cash flows.

 

 

(18)           Revenue from Contracts with Customers

 

 Accounting Policy

 

Our revenues are primarily from tariff based sales. We provide gas and/or electricity to customers under these tariffs without a defined contractual term (at-will). As the revenue from these arrangements is equivalent to the electricity or gas supplied and billed in that period (including estimated billings), there will not be a shift in the timing or pattern of revenue recognition for such sales. We have also completed the evaluation of our other revenue streams, including those tied to longer term contractual commitments. These revenue streams have performance obligations that are satisfied at a point in time, and do not have a shift in the timing or pattern of revenue recognition.

 

Customers are billed monthly on a cycle basis. To match revenues with associated expenses, we accrue unbilled revenues for electric and natural gas services delivered to customers, but not yet billed at month-end.

 

Nature of Goods and Services

 

We currently provide retail electric and natural gas services to two primary customer classes. Our largest customer class consists of residential customers, which include single private dwellings and individual apartments. Our commercial customers consist primarily of main street businesses.

 

Electric Segment - Our regulated electric utility business primarily provides generation, transmission, and distribution services to our customers. We recognize revenue when electricity is delivered to the customer. Payments on our tariff based sales are generally due in 20-30 days after the billing date.

 

Natural Gas Segment - Our regulated natural gas utility business primarily provides transmission and distribution services to our customers in our South Dakota and Nebraska jurisdictions. We recognize revenue when natural gas is delivered to the customer. Payments on our tariff based sales are generally due in 20-30 days after the billing date.

 

Disaggregation of Revenue

 

The following tables disaggregate our revenue for the twelve months ended by major source and customer class (in thousands):

 

December 31, 2025

Electric

 

Natural Gas

 

Total

South Dakota

$ 77,894 

 

$ 28,948 

 

$ 106,842 

Nebraska

  

 

 25,733 

 

 25,733 

Residential

 77,894 

 

 54,681 

 

 132,575 

South Dakota

 120,108 

 

 21,574 

 

 141,682 

Nebraska

  

 

 13,784 

 

 13,784 

Commercial

 120,108 

 

 35,358 

 

 155,466 

Lighting, governmental, irrigation, and interdepartmental

 3,479 

 

  

 

 3,479 

Total Retail Revenues

 201,481 

 

 90,039 

 

 291,520 

Regulatory Amortization

 1,570 

 

 (5,640)

 

 (4,070)

Transportation, wholesale and other

 1,758 

 

 8,872 

 

 10,630 

Total Revenues

$ 204,809 

 

$ 93,271 

 

$ 298,080 

 

December 31, 2024

Electric

 

Natural Gas

 

Total

South Dakota

$ 70,012 

 

$ 26,884 

 

$ 96,896 

Nebraska

  

 

 21,205 

 

 21,205 

Residential

 70,012 

 

 48,089 

 

 118,101 

South Dakota

 111,813 

 

 18,069 

 

 129,882 

Nebraska

  

 

 11,432 

 

 11,432 

Commercial

 111,813 

 

 29,501 

 

 141,314 

Lighting, governmental, irrigation, and interdepartmental

 3,274 

 

  

 

 3,274 

Total Retail Revenues

 185,099 

 

 77,590 

 

 262,689 

Regulatory Amortization

 3,768 

 

 4,395 

 

 8,163 

Transportation, wholesale and other

 1,599 

 

 7,000 

 

 8,599 

Total Revenues

$ 190,466 

 

$ 88,985 

 

$ 279,451 

 

(19)           Related Party Transactions and Shared Services

 

Our parent, NorthWestern Energy Group, Inc., is organized as a holding company. As part of a holding company we receive services and share costs with Northwestern Energy Group, Inc., and its other subsidiaries pursuant to an Intercompany Services Agreement (ISA) that became effective in 2023. The ISA was approved by the Montana Public Service Commission (MPSC), whom regulates NorthWestern Corporation, a direct and wholly-owned subsidiary of NorthWestern Energy Group, Inc. In accordance with the ISA, NorthWestern Corporation, which employs all or substantially all of the employees of NorthWestern Energy Group, Inc. and its subsidiaries, will provide all labor related services to us. Pursuant to the ISA, all rendered services are at cost. The total cost of labor and benefits associated with the services provided to us by NorthWestern Corporation employees was $39.3 million for each of the years ended December 31, 2025 and 2024.

 

Additionally, pursuant to the ISA, when utility-related operating, administrative, and general costs are attributable to more than one entity within the holding company structure and are unable to be direct charged (Shared OA&G Costs), these costs will be allocated amongst the entities pursuant to a Cost Allocation Manual. The nature of these Shared OA&G Costs includes operations supervision and engineering, energy supply marketing, networking communications, information technology, human resources, accounting, legal, and other such administrative costs.

 

Outstanding payables and receivables associated with related party transactions under the ISA are cash settled monthly.

 

 

 

 

 

 

 

 

 

 


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
STATEMENTS OF ACCUMULATED COMPREHENSIVE INCOME, COMPREHENSIVE INCOME, AND HEDGING ACTIVITIES
  1. Report in columns (b),(c),(d) and (e) the amounts of accumulated other comprehensive income items, on a net-of-tax basis, where appropriate.
  2. Report in columns (f) and (g) the amounts of other categories of other cash flow hedges.
  3. For each category of hedges that have been accounted for as "fair value hedges", report the accounts affected and the related amounts in a footnote.
  4. Report data on a year-to-date basis.
Line No.
Item
(a)
Unrealized Gains and Losses on Available-For-Sale Securities
(b)
Minimum Pension Liability Adjustment (net amount)
(c)
Foreign Currency Hedges
(d)
Other Adjustments
(e)
Other Cash Flow Hedges Interest Rate Swaps
(f)
Other Cash Flow Hedges [Specify]
(g)
Totals for each category of items recorded in Account 219
(h)
Net Income (Carried Forward from Page 116, Line 78)
(i)
Total Comprehensive Income
(j)
1
Balance of Account 219 at Beginning of Preceding Year
0
0
2
Preceding Quarter/Year to Date Reclassifications from Account 219 to Net Income
829,241
829,241
3
Preceding Quarter/Year to Date Changes in Fair Value
4
Total (lines 2 and 3)
829,241
829,241
30,932,544
31,761,785
5
Balance of Account 219 at End of Preceding Quarter/Year
829,241
829,241
6
Balance of Account 219 at Beginning of Current Year
829,241
829,241
7
Current Quarter/Year to Date Reclassifications from Account 219 to Net Income
172,722
172,722
8
Current Quarter/Year to Date Changes in Fair Value
9
Total (lines 7 and 8)
172,722
172,722
31,527,278
31,700,000
10
Balance of Account 219 at End of Current Quarter/Year
1,001,963
1,001,963


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
SUMMARY OF UTILITY PLANT AND ACCUMULATED PROVISIONS FOR DEPRECIATION. AMORTIZATION AND DEPLETION

Report in Column (c) the amount for electric function, in column (d) the amount for gas function, in column (e), (f), and (g) report other (specify) and in column (h) common function.

Line No.
Classification
(a)
Total Company For the Current Year/Quarter Ended
(b)
Electric
(c)
Gas
(d)
Other (Specify)
(e)
Other (Specify)
(f)
Other (Specify)
(g)
Common
(h)
1
UtilityPlantAbstract
UTILITY PLANT
2
UtilityPlantInServiceAbstract
In Service
3
UtilityPlantInServiceClassified
Plant in Service (Classified)
1,551,974,769
1,175,572,241
304,757,414
71,645,114
4
UtilityPlantInServicePropertyUnderCapitalLeases
Property Under Capital Leases
243,921
(b)
243,921
5
UtilityPlantInServicePlantPurchasedOrSold
Plant Purchased or Sold
6
UtilityPlantInServiceCompletedConstructionNotClassified
Completed Construction not Classified
7
UtilityPlantInServiceExperimentalPlantUnclassified
Experimental Plant Unclassified
8
UtilityPlantInServiceClassifiedAndUnclassified
Total (3 thru 7)
1,552,218,690
1,175,572,241
304,757,414
243,921
71,645,114
9
UtilityPlantLeasedToOthers
Leased to Others
10
UtilityPlantHeldForFutureUse
Held for Future Use
2,870,523
2,870,523
11
ConstructionWorkInProgress
Construction Work in Progress
64,895,167
53,295,277
9,391,834
0
2,208,056
12
UtilityPlantAcquisitionAdjustment
Acquisition Adjustments
30,009,843
30,009,843
13
UtilityPlantAndConstructionWorkInProgress
Total Utility Plant (8 thru 12)
1,649,994,223
1,261,747,884
314,149,248
243,921
73,853,170
14
AccumulatedProvisionForDepreciationAmortizationAndDepletionOfPlantUtility
Accumulated Provisions for Depreciation, Amortization, & Depletion
601,060,628
451,977,835
122,952,451
0
26,130,342
15
UtilityPlantNet
Net Utility Plant (13 less 14)
1,048,933,595
809,770,049
191,196,797
243,921
47,722,828
16
DetailOfAccumulatedProvisionsForDepreciationAmortizationAndDepletionAbstract
DETAIL OF ACCUMULATED PROVISIONS FOR DEPRECIATION, AMORTIZATION AND DEPLETION
17
AccumulatedProvisionForDepreciationAmortizationAndDepletionUtilityPlantInServiceAbstract
In Service:
18
DepreciationUtilityPlantInService
Depreciation
583,682,986
439,328,653
122,952,451
21,401,882
19
AmortizationAndDepletionOfProducingNaturalGasLandAndLandRightsutilityPlantInService
Amortization and Depletion of Producing Natural Gas Land and Land Rights
20
AmortizationOfUndergroundStorageLandAndLandRightsutilityPlantInService
Amortization of Underground Storage Land and Land Rights
0
21
AmortizationOfOtherUtilityPlantUtilityPlantInService
Amortization of Other Utility Plant
5,618,401
(a)
889,941
4,728,460
22
DepreciationAmortizationAndDepletionUtilityPlantInService
Total in Service (18 thru 21)
589,301,387
440,218,594
122,952,451
0
26,130,342
23
DepreciationAmortizationAndDepletionUtilityPlantLeasedToOthersAbstract
Leased to Others
24
DepreciationUtilityPlantLeasedToOthers
Depreciation
0
25
AmortizationAndDepletionUtilityPlantLeasedToOthers
Amortization and Depletion
0
26
DepreciationAmortizationAndDepletionUtilityPlantLeasedToOthers
Total Leased to Others (24 & 25)
0
0
0
0
0
0
0
27
DepreciationAndAmortizationUtilityPlantHeldForFutureUseAbstract
Held for Future Use
28
DepreciationUtilityPlantHeldForFutureUse
Depreciation
0
29
AmortizationUtilityPlantHeldForFutureUse
Amortization
0
30
DepreciationAndAmortizationUtilityPlantHeldForFutureUse
Total Held for Future Use (28 & 29)
0
0
0
0
0
0
0
31
AbandonmentOfLeases
Abandonment of Leases (Natural Gas)
0
32
AmortizationOfPlantAcquisitionAdjustment
Amortization of Plant Acquisition Adjustment
11,759,241
11,759,241.00
33
AccumulatedProvisionForDepreciationAmortizationAndDepletionOfPlantUtility
Total Accum Prov (equals 14) (22,26,30,31,32)
601,060,628
451,977,835
122,952,451
0
26,130,342


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
FOOTNOTE DATA

(a) Concept: AmortizationOfOtherUtilityPlantUtilityPlantInService

Balance as of December 31, 2024 - $493,761

(b) Concept: UtilityPlantInServicePropertyUnderCapitalLeases

This column represents our right of use (operating lease) assets.


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
NUCLEAR FUEL MATERIALS (Account 120.1 through 120.6 and 157)
  1. Report below the costs incurred for nuclear fuel materials in process of fabrication, on hand, in reactor, and in cooling; owned by the respondent.
  2. If the nuclear fuel stock is obtained under leasing arrangements, attach a statement showing the amount of nuclear fuel leased, the quantity used and quantity on hand, and the costs incurred under such leasing arrangements.
Line No.
Description of item
(a)
Balance Beginning of Year
(b)
Changes during Year Additions
(c)
Changes during Year Amortization
(d)
Changes during Year Other Reductions (Explain in a footnote)
(e)
Balance End of Year
(f)
1
Nuclear Fuel in process of Refinement, Conv, Enrichment & Fab (120.1)
2
Fabrication
3
Nuclear Materials
4
Allowance for Funds Used during Construction
5
(Other Overhead Construction Costs, provide details in footnote)
6
SUBTOTAL (Total 2 thru 5)
7
Nuclear Fuel Materials and Assemblies
8
In Stock (120.2)
9
In Reactor (120.3)
10
SUBTOTAL (Total 8 & 9)
11
Spent Nuclear Fuel (120.4)
12
Nuclear Fuel Under Capital Leases (120.6)
13
(Less) Accum Prov for Amortization of Nuclear Fuel Assem (120.5)
14
TOTAL Nuclear Fuel Stock (Total 6, 10, 11, 12, less 13)
15
Estimated Net Salvage Value of Nuclear Materials in Line 9
16
Estimated Net Salvage Value of Nuclear Materials in Line 11
17
Est Net Salvage Value of Nuclear Materials in Chemical Processing
18
Nuclear Materials held for Sale (157)
19
Uranium
20
Plutonium
21
Other (Provide details in footnote)
22
TOTAL Nuclear Materials held for Sale (Total 19, 20, and 21)


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
ELECTRIC PLANT IN SERVICE (Account 101, 102, 103 and 106)
  1. Report below the original cost of electric plant in service according to the prescribed accounts.
  2. In addition to Account 101, Electric Plant in Service (Classified), this page and the next include Account 102, Electric Plant Purchased or Sold; Account 103, Experimental Electric Plant Unclassified; and Account 106, Completed Construction Not Classified-Electric.
  3. Include in column (c) or (d), as appropriate, corrections of additions and retirements for the current or preceding year.
  4. For revisions to the amount of initial asset retirement costs capitalized, included by primary plant account, increases in column (c) additions and reductions in column (e) adjustments.
  5. Enclose in parentheses credit adjustments of plant accounts to indicate the negative effect of such accounts.
  6. Classify Account 106 according to prescribed accounts, on an estimated basis if necessary, and include the entries in column (c). Also to be included in column (c) are entries for reversals of tentative distributions of the prior year reported in column (b). Likewise, if the respondent has a significant amount of plant retirements which have not been classified to primary accounts at the end of the year, include in column (d) a tentative distribution of such retirements, on an estimated basis, with appropriate contra entry to the account for accumulated depreciation provision. Include also in column (d) distributions of these tentative classifications in columns (c) and (d), including the reversals of the prior years tentative account distributions of these amounts. Careful observance of the above instructions and the texts of Accounts 101 and 106 will avoid serious omissions of the reported amount of respondent’s plant actually in service at end of year.
  7. Show in column (f) reclassifications or transfers within utility plant accounts. Include also in column (f) the additions or reductions of primary account classifications arising from distribution of amounts initially recorded in Account 102, include in column (e) the amounts with respect to accumulated provision for depreciation, acquisition adjustments, etc., and show in column (f) only the offset to the debits or credits distributed in column (f) to primary account classifications.
  8. For Account 399, state the nature and use of plant included in this account and if substantial in amount submit a supplementary statement showing subaccount classification of such plant conforming to the requirement of these pages.
  9. For each amount comprising the reported balance and changes in Account 102, state the property purchased or sold, name of vendor or purchase, and date of transaction. If proposed journal entries have been filed with the Commission as required by the Uniform System of Accounts, give also date.
Line No.
Account
(a)
Balance Beginning of Year
(b)
Additions
(c)
Retirements
(d)
Adjustments
(e)
Transfers
(f)
Balance at End of Year
(g)
1
1. INTANGIBLE PLANT
2
(301) Organization
0
0
0
0
0
0
3
(302) Franchise and Consents
0
0
0
0
0
4
(303) Miscellaneous Intangible Plant
2,609,021
0
0
0
2,609,021
0
5
TOTAL Intangible Plant (Enter Total of lines 2, 3, and 4)
2,609,021
0
0
0
2,609,021
0
6
2. PRODUCTION PLANT
7
A. Steam Production Plant
8
(310) Land and Land Rights
366,511
23,642
0
0
0
342,869
9
(311) Structures and Improvements
28,409,104
743,637
357,514
0
0
28,795,227
10
(312) Boiler Plant Equipment
202,801,303
1,765,081
612,800
0
36,403
203,917,181
11
(313) Engines and Engine-Driven Generators
0
0
0
0
0
0
12
(314) Turbogenerator Units
27,255,916
761,596
57,229
0
1,019
27,959,264
13
(315) Accessory Electric Equipment
13,247,310
36,806
287
0
0
13,283,829
13.1
(315.1) Computer Hardware
0
9,076
499
0
44,421
52,998
13.2
(315.2) Computer Software
0
0
0
0
83,578
83,578
13.3
(315.3) Communication Equipment
0
0
0
0
120,241
120,241
14
(316) Misc. Power Plant Equipment
3,348,059
576,544
309
0
210,818
3,713,476
15
(317) Asset Retirement Costs for Steam Production
2,023,902
1,139,171
0
0
0
3,163,073
16
TOTAL Steam Production Plant (Enter Total of lines 8 thru 15)
277,452,105
5,008,268
1,028,639
0
0
281,431,734
17
B. Nuclear Production Plant
18
(320) Land and Land Rights
0
0
0
0
0
0
19
(321) Structures and Improvements
0
0
0
0
0
0
20
(322) Reactor Plant Equipment
0
0
0
0
0
0
21
(323) Turbogenerator Units
0
0
0
0
0
0
22
(324) Accessory Electric Equipment
0
0
0
0
0
0
22.1
(324.1) Computer Hardware
0
0
0
0
0
0
22.2
(324.2) Computer Software
0
0
0
0
0
0
22.3
(324.3) Communication Equipment
0
0
0
0
0
0
23
(325) Misc. Power Plant Equipment
0
0
0
0
0
0
24
(326) Asset Retirement Costs for Nuclear Production
0
0
0
0
0
0
25
TOTAL Nuclear Production Plant (Enter Total of lines 18 thru 24)
0
0
0
0
0
0
26
C. Hydraulic Production Plant
27
(330) Land and Land Rights
0
0
0
0
0
0
28
(331) Structures and Improvements
0
0
0
0
0
0
29
(332) Reservoirs, Dams, and Waterways
0
0
0
0
0
0
30
(333) Water Wheels, Turbines, and Generators
0
0
0
0
0
0
31
(334) Accessory Electric Equipment
0
0
0
0
0
0
31.1
(334.1) Computer Hardware
0
0
0
0
0
0
31.2
(334.2) Computer Software
0
0
0
0
0
0
31.3
(334.3) Communication Equipment
0
0
0
0
0
0
32
(335) Misc. Power Plant Equipment
0
0
0
0
0
0
33
(336) Roads, Railroads, and Bridges
0
0
0
0
0
0
34
(337) Asset Retirement Costs for Hydraulic Production
0
0
0
0
0
0
35
TOTAL Hydraulic Production Plant (Enter Total of lines 27 thru 34)
0
0
0
0
0
0
35.1
D. Solar Production Plant
35.2
(338.1) Land and Land Rights
0
0
0
0
0
0
35.3
(338.2) Structures and Improvements
0
0
0
0
0
0
35.5
(338.4) Solar Panels
0
0
0
0
0
0
35.6
(338.5) Collector System
0
0
0
0
0
0
35.7
(338.6) Generator Step-up Transformers (GSU)
0
0
0
0
0
0
35.8
(338.7) Inverters
0
0
0
0
0
0
35.9
(338.8) Other Accessory Electrical Equipment
0
0
0
0
0
0
35.10
(338.9) Computer Hardware
0
0
0
0
0
0
35.11
(338.10) Computer Software
0
0
0
0
0
0
35.12
(338.11) Communication Equipment
0
0
0
0
0
0
35.13
(338.12) Miscellaneous Power Plant Equipment
0
0
0
0
0
0
35.14
(338.13) Asset Retirement Costs for Solar Production
0
0
0
0
0
0
35.15
TOTAL Solar Production Plant (Enter Total of lines 35.2 thru 35.14)
0
0
0
0
0
0
35.16
E. Wind Production Plant
35.17
(338.20) Land and Land Rights
0
0
0
0
0
0
35.18
(338.21) Structures and Improvements
0
0
0
0
14,557,823
14,557,823
35.20
(338.23) Wind Turbines
0
0
0
0
79,926,259
79,926,259
35.21
(338.24) Wind Towers and Fixtures
0
0
0
0
0
0
35.23
(338.26) Collector System
0
0
0
0
0
0
35.24
(338.27) Generator Step-up Transformers (GSU)
0
0
0
0
0
0
35.25
(338.28) Inverters
0
0
0
0
0
0
35.26
(338.29) Other Accessory Electrical Equipment
0
0
0
0
4,648,825
4,648,825
35.27
(338.30) Computer Hardware
0
0
0
0
0
0
35.28
(338.31) Computer Software
0
0
0
0
0
0
35.29
(338.32) Communication Equipment
0
0
0
0
0
0
35.30
(338.33) Miscellaneous Power Plant Equipment
0
0
0
0
15,504,815
15,504,815
35.31
(338.34) Asset Retirement Costs for Wind Production
0
0
0
0
1,351,541
1,351,541
35.32
TOTAL Wind Production Plant (Enter Total of lines 35.17 thru 35.31)
0
0
0
0
115,989,262
115,989,262
35.33
F. Other Renewable Production Plant
35.34
(339.1) Land and Land Rights
0
0
0
0
0
0
35.35
(339.2) Structures and Improvements
0
0
0
0
0
0
35.36
(339.3) Fuel Holders
0
0
0
0
0
0
35.37
(339.4) Boilers
0
0
0
0
0
0
35.39
(339.6) Generators
0
0
0
0
0
0
35.41
(339.8) Other Accessory Electrical Equipment
0
0
0
0
0
0
35.42
(339.9) Computer Hardware
0
0
0
0
0
0
35.43
(339.10) Computer Software
0
0
0
0
0
0
35.44
(339.11) Communication Equipment
0
0
0
0
0
0
35.45
(339.12) Miscellaneous Power Plant Equipment
0
0
0
0
0
0
35.46
(339.13) Asset Retirement Costs for Other Renewable Production
0
0
0
0
0
0
35.47
TOTAL Other Renewable Production Plant (Enter Total of lines 35.34 thru 35.46)
0
0
0
0
0
0
36
G. Other Production Plant
37
(340) Land and Land Rights
261,179
0
0
0
0
261,179
38
(341) Structures and Improvements
40,750,024
0
8,436
0
14,557,823
26,183,765
39
(342) Fuel Holders, Products, and Accessories
6,482,313
0
0
0
0
6,482,313
40
(343) Prime Movers
81,399,485
3,668,087
3,976,764
0
0
81,090,808
41
(344) Generators
89,658,455
0
0
0
79,926,259
9,732,196
42
(345) Accessory Electric Equipment
34,169,705
342,145
544,641
0
4,648,825
29,318,384
42.1
(345.1) Computer Hardware
0
59,268
0
0
0
59,268
42.2
(345.2) Computer Software
0
4,461
0
0
0
4,461
42.3
(345.3) Communication Equipment
0
0
0
0
0
0
43
(346) Misc. Power Plant Equipment
24,872,819
68,360
0
0
15,504,815
9,436,364
44
(347) Asset Retirement Costs for Other Production
1,351,541
0
0
0
1,351,541
0
45
TOTAL Other Prod. Plant (Enter Total of lines 37 thru 44)
278,945,521
4,142,321
4,529,841
0
115,989,263
162,568,738
46
TOTAL Prod. Plant (Enter Total of lines 16, 25, 35, 35.15, 35.32, 35.47, and 45)
556,397,626
9,150,589
5,558,480
0
0
559,989,735
47
3. Transmission Plant
48
(350) Land and Land Rights
1,874,405
0
0
0
0
1,874,405
48.2
(351.1) Computer Hardware
0
0
0
0
0
0
48.3
(351.2) Computer Software
0
0
0
0
0
0
48.4
(351.3) Communication Equipment
0
0
0
0
1,871,873
1,871,873
49
(352) Structures and Improvements
13,577,614
246,432
0
0
0
13,824,046
50
(353) Station Equipment
112,813,137
2,257,540
231,812
0
24,167
114,814,698
51
(354) Towers and Fixtures
0
0
0
0
0
0
52
(355) Poles and Fixtures
65,640,703
3,669,221
299,213
0
0
69,010,711
53
(356) Overhead Conductors and Devices
34,305,484
831,721
320,586
0
0
34,816,619
54
(357) Underground Conduit
640,802
895,483
0
0
0
1,536,285
55
(358) Underground Conductors and Devices
4,707,009
1,533,306
0
0
0
6,240,315
56
(359) Roads and Trails
0
0
0
0
0
0
57
(359.1) Asset Retirement Costs for Transmission Plant
0
0
0
0
0
0
58
TOTAL Transmission Plant (Enter Total of lines 48 thru 57)
233,559,154
9,433,702
851,611
0
1,847,707
243,988,952
59
4. Distribution Plant
60
(360) Land and Land Rights
639,546
0
0
0
0
639,546
61
(361) Structures and Improvements
1,532,775
161,546
0
0
0
1,694,321
62
(362) Station Equipment
50,742,187
4,849,101
102,962
0
24,167
55,512,493
63.1
(363.1) Computer Hardware
0
0
0
0
0
0
63.2
(363.2) Computer Software
0
418,642
0
0
0
418,642
63.3
(363.3) Communication Equipment
0
21,344
0
0
833,059
854,403
64
(364) Poles, Towers, and Fixtures
64,143,049
3,716,118
610,011
0
0
67,249,156
65
(365) Overhead Conductors and Devices
24,196,864
1,405,647
832,465
0
0
24,770,046
66
(366) Underground Conduit
13,052,930
218,818
0
0
0
13,271,748
67
(367) Underground Conductors and Devices
71,632,716
2,476,465
312,672
0
0
73,796,509
68
(368) Line Transformers
48,110,263
2,634,546
243,513
0
0
50,501,296
69
(369) Services
24,660,848
1,200,472
154,491
0
0
25,706,829
70
(370) Meters
15,539,993
531,002
74,496
0
0
15,996,499
71
(371) Installations on Customer Premises
743,177
12,177
34,393
0
0
720,961
72
(372) Leased Property on Customer Premises
0
0
0
0
0
0
73
(373) Street Lighting and Signal Systems
13,683,447
388,677
8,806
0
0
14,063,318
74
(374) Asset Retirement Costs for Distribution Plant
0
0
0
0
0
0
75
TOTAL Distribution Plant (Enter Total of lines 60 thru 74)
328,677,795
18,034,555
2,373,807
0
857,226
345,195,769
76
5. REGIONAL TRANSMISSION AND MARKET OPERATION PLANT
77
(380) Land and Land Rights
0
0
0
0
0
0
78
(381) Structures and Improvements
0
0
0
0
0
0
79
(382) Computer Hardware
0
0
0
0
0
0
80
(383) Computer Software
0
0
0
0
0
0
81
(384) Communication Equipment
0
0
0
0
0
0
82
(385) Miscellaneous Regional Transmission and Market Operation Plant
0
0
0
0
0
0
83
(386) Asset Retirement Costs for Regional Transmission and Market Oper
0
0
0
0
0
0
84
TOTAL Transmission and Market Operation Plant (Total lines 77 thru 83)
0
0
0
0
0
0
84.1
6. ENERGY STORAGE PLANT
84.2
(387.1) Land and Land Rights
0
0
0
0
0
0
84.3
(387.2) Structures and Improvements
0
0
0
0
0
0
84.4
(387.3) Energy Storage Equipment
0
0
0
0
0
0
84.6
(387.5) Collector System
0
0
0
0
0
0
84.7
(387.6) Generator Step-up Transformers (GSU)
0
0
0
0
0
0
84.8
(387.7) Inverters
0
0
0
0
0
0
84.9
(387.8) Computer Hardware
0
0
0
0
0
0
84.10
(387.9) Computer Software
0
0
0
0
0
0
84.11
(387.10) Communication Equipment
0
0
0
0
0
0
84.12
(387.11) Miscellaneous Energy Storage Equipment
0
0
0
0
0
0
84.13
(387.12) Asset Retirement Costs for Energy Storage
0
0
0
0
0
0
84.14
TOTAL Energy Storage Plant (Total lines 84.2 thru 84.13)
0
0
0
0
0
0
85
7. General Plant
86
(389) Land and Land Rights
105,508
0
0
0
0
105,508
87
(390) Structures and Improvements
1,855,475
25,093
8,900
0
0
1,871,668
88
(391) Office Furniture and Equipment
91,019
0
0
0
1,365
89,654
89
(392) Transportation Equipment
16,812,422
1,774,986
301,714
0
0
18,285,694
90
(393) Stores Equipment
0
0
0
0
0
0
91
(394) Tools, Shop and Garage Equipment
2,081,204
203,880
134,823
0
0
2,150,261
92
(395) Laboratory Equipment
0
0
0
0
0
0
93
(396) Power Operated Equipment
938,987
345,628
0
0
0
1,284,615
94
(397.1) Computer Hardware
2,704,932
0
0
0
2,615,086
89,846
94.1
(397.2) Computer Software
0
0
0
0
2,540,864
2,540,864
94.2
(397.3) Communication Equipment
0
0
0
0
20,325
20,325
95
(398) Miscellaneous Equipment
0
0
0
0
0
0
96
SUBTOTAL (Enter Total of lines 86 thru 95)
24,589,547
2,349,587
445,437
0
95,912
26,397,785
97
(399) Other Tangible Property
0
0
0
0
0
0
98
(399.1) Asset Retirement Costs for General Plant
0
0
0
0
0
0
99
TOTAL General Plant (Enter Total of lines 96, 97, and 98)
24,589,547
2,349,587
445,437
0
95,912
26,397,785
100
TOTAL (Accounts 101 and 106)
1,145,833,143
38,968,433
9,229,335
0
0
1,175,572,241
101
(102) Electric Plant Purchased (See Instr. 8)
0
0
0
0
0
0
102
(Less) (102) Electric Plant Sold (See Instr. 8)
0
0
0
0
0
0
103
(103) Experimental Plant Unclassified
0
0
0
0
0
0
104
TOTAL Electric Plant in Service (Enter Total of lines 100 thru 103)
1,145,833,143
38,968,433
9,229,335
0
0
1,175,572,241


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
ELECTRIC PLANT LEASED TO OTHERS (Account 104)
Line No.
LesseeName
Name of Lessee
(a)
IndicationOfAssociatedCompany
* (Designation of Associated Company)
(b)
LeaseDescription
Description of Property Leased
(c)
CommissionAuthorization
Commission Authorization
(d)
ExpirationDateOfLease
Expiration Date of Lease
(e)
ElectricPlantLeasedToOthers
Balance at End of Year
(f)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
TOTAL


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
ELECTRIC PLANT HELD FOR FUTURE USE (Account 105)
  1. Report separately each property held for future use at end of the year having an original cost of $250,000 or more. Group other items of property held for future use.
  2. For property having an original cost of $250,000 or more previously used in utility operations, now held for future use, give in column (a), in addition to other required information, the date that utility use of such property was discontinued, and the date the original cost was transferred to Account 105.
Line No.
ElectricPlantHeldForFutureUseDescription
Description and Location of Property
(a)
ElectricPlantPropertyClassifiedAsHeldForFutureUseOriginalDate
Date Originally Included in This Account
(b)
ElectricPlantPropertyClassifiedAsHeldForFutureUseExpectedUseInServiceDate
Date Expected to be used in Utility Service
(c)
ElectricPlantHeldForFutureUse
Balance at End of Year
(d)
1 Land and Rights:
2
Land for Aberdeen Generation site
10/01/2025
12/31/2030
2,870,523
21 Other Property:
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47 TOTAL
2,870,523


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
CONSTRUCTION WORK IN PROGRESS - - ELECTRIC (Account 107)
  1. Report below descriptions and balances at end of year of projects in process of construction (107).
  2. Show items relating to "research, development, and demonstration" projects last, under a caption Research, Development, and Demonstrating (see Account 107 of the Uniform System of Accounts).
  3. Minor projects (5% of the Balance End of the Year for Account 107 or $1,000,000, whichever is less) may be grouped.
Line No.
ConstructionWorkInProgressProjectDescription
Description of Project
(a)
ConstructionWorkInProgress
Construction work in progress - Electric (Account 107)
(b)
1
Aberdeen Generating Station
39,072,398
2
Huron Redfield Plant
3,465,443
3
Huron GT Plant
1,115,556
4
Minor Projects (Less than $1,000,000 - 147 items)
9,641,880
43
Total
53,295,277


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
ACCUMULATED PROVISION FOR DEPRECIATION OF ELECTRIC UTILITY PLANT (Account 108)
  1. Explain in a footnote any important adjustments during year.
  2. Explain in a footnote any difference between the amount for book cost of plant retired, Line 12, column (c), and that reported for electric plant in service, page 204, column (d), excluding retirements of non-depreciable property.
  3. The provisions of Account 108 in the Uniform System of Accounts require that retirements of depreciable plant be recorded when such plant is removed from service. If the respondent has a significant amount of plant retired at year end which has not been recorded and/or classified to the various reserve functional classifications, make preliminary closing entries to tentatively functionalize the book cost of the plant retired. In addition, include all costs included in retirement work in progress at year end in the appropriate functional classifications.
  4. Show separately interest credits under a sinking fund or similar method of depreciation accounting.
Line No.
Item
(a)
Total (c + d + e)
(b)
Electric Plant in Service
(c)
Electric Plant Held for Future Use
(d)
Electric Plant Leased To Others
(e)
Section A. Balances and Changes During Year
1
AccumulatedProvisionForDepreciationOfElectricUtilityPlant
Balance Beginning of Year
413,115,909
413,115,909
0
0
2
Depreciation Provisions for Year, Charged to
3
DepreciationExpenseExcludingAdjustments
(403) Depreciation Expense
37,850,483
37,850,483
4
DepreciationExpenseForAssetRetirementCosts
(403.1) Depreciation Expense for Asset Retirement Costs
0
5
ExpensesOfElectricPlantLeasedToOthers
(413) Exp. of Elec. Plt. Leas. to Others
0
6
TransportationExpensesClearing
Transportation Expenses-Clearing
0
7
OtherClearingAccounts
Other Clearing Accounts
0
8
OtherAccounts
Other Accounts (Specify, details in footnote):
0
9.1
0
10
DepreciationProvision
TOTAL Deprec. Prov for Year (Enter Total of lines 3 thru 9)
37,850,483
37,850,483
0
0
11
Net Charges for Plant Retired:
12
BookCostOfRetiredPlant
Book Cost of Plant Retired
9,229,335
9,229,335
13
CostOfRemovalOfPlant
Cost of Removal
2,642,343
2,642,343
14
SalvageValueOfRetiredPlant
Salvage (Credit)
285,018
285,018
15
NetChargesForRetiredPlant
TOTAL Net Chrgs. for Plant Ret. (Enter Total of lines 12 thru 14)
11,586,660
11,586,660
0
0
16
OtherAdjustmentsToAccumulatedDepreciation
Other Debit or Cr. Items (Describe, details in footnote):
51,079
51,079
17.1
Transfers
18
BookCostOfAssetRetirementCosts
Book Cost or Asset Retirement Costs Retired
0
19
AccumulatedProvisionForDepreciationOfElectricUtilityPlant
Balance End of Year (Enter Totals of lines 1, 10, 15, 16, and 18)
439,328,653
439,328,653
0
0
Section B. Balances at End of Year According to Functional Classification
20
AccumulatedDepreciationSteamProduction
Steam Production
135,897,963
135,897,963
0
0
21
AccumulatedDepreciationNuclearProduction
Nuclear Production
0
0
0
0
22
AccumulatedDepreciationHydraulicProductionConventional
Hydraulic Production-Conventional
0
0
0
0
23
AccumulatedDepreciationHydraulicProductionPumpedStorage
Hydraulic Production-Pumped Storage
0
0
0
0
23.1
AccumulatedDepreciationSolarProduction
Solar Production
0
0
0
0
23.2
AccumulatedDepreciationWindProduction
Wind Production
47,721,393
47,721,393
0
0
23.3
AccumulatedDepreciationOtherRenewableProduction
Other Renewable Production
0
0
0
0
24
AccumulatedDepreciationOtherProduction
Other Production
26,236,170
26,236,170
0
0
25
AccumulatedDepreciationTransmission
Transmission
96,241,892
(a)
96,241,892
0
0
26
AccumulatedDepreciationDistribution
Distribution
122,878,159
122,878,159
0
0
27
AccumulatedDepreciationRegionalTransmissionAndMarketOperation
Regional Transmission and Market Operation
0
0
0
0
27.1
AccumulatedDepreciationEnergyStorage
Energy Storage
0
0
0
0
28
AccumulatedDepreciationGeneral
General
10,353,076
(b)
10,353,076
0
0
29
AccumulatedProvisionForDepreciationOfElectricUtilityPlant
TOTAL (Enter Total of lines 20 thru 28)
439,328,653
439,328,653
0
0


FOOTNOTE DATA

(a) Concept: AccumulatedDepreciationTransmission

Balance as of December 31, 2024 - $91,052,316

(b) Concept: AccumulatedDepreciationGeneral

Balance as of December 31, 2024 - $10,079,181


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
INVESTMENTS IN SUBSIDIARY COMPANIES (Account 123.1)
  1. Report below investments in Account 123.1, Investments in Subsidiary Companies.
  2. Provide a subheading for each company and list thereunder the information called for below. Sub-TOTAL by company and give a TOTAL in columns (e), (f), (g) and (h). (a) Investment in Securities - List and describe each security owned. For bonds give also principal amount, date of issue, maturity, and interest rate. (b) Investment Advances - Report separately the amounts of loans or investment advances which are subject to repayment, but which are not subject to current settlement. With respect to each advance show whether the advance is a note or open account. List each note giving date of issuance, maturity date, and specifying whether note is a renewal.
  3. Report separately the equity in undistributed subsidiary earnings since acquisition. The TOTAL in column (e) should equal the amount entered for Account 418.1.
  4. For any securities, notes, or accounts that were pledged designate such securities, notes, or accounts in a footnote, and state the name of pledgee and purpose of the pledge.
  5. If Commission approval was required for any advance made or security acquired, designate such fact in a footnote and give name of Commission, date of authorization, and case or docket number.
  6. Report column (f) interest and dividend revenues from investments, including such revenues from securities disposed of during the year.
  7. In column (h) report for each investment disposed of during the year, the gain or loss represented by the difference between cost of the investment (or the other amount at which carried in the books of account if different from cost) and the selling price thereof, not including interest adjustment includible in column (f).
  8. Report on Line 42, column (a) the TOTAL cost of Account 123.1.
Line No.
DescriptionOfInvestmentsInSubsidiaryCompanies
Description of Investment
(a)
DateOfAcquisitionInvestmentsInSubsidiaryCompanies
Date Acquired
(b)
DateOfMaturityInvestmentsInSubsidiaryCompanies
Date of Maturity
(c)
InvestmentInSubsidiaryCompanies
Amount of Investment at Beginning of Year
(d)
EquityInEarningsOfSubsidiaryCompanies
Equity in Subsidiary Earnings of Year
(e)
InterestAndDividendRevenueFromInvestments
Revenues for Year
(f)
InvestmentInSubsidiaryCompanies
Amount of Investment at End of Year
(g)
InvestmentGainLossOnDisplosal
Gain or Loss from Investment Disposed of
(h)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
Total Cost of Account 123.1 $
Total


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
MATERIALS AND SUPPLIES
  1. For Account 154, report the amount of plant materials and operating supplies under the primary functional classifications as indicated in column (a); estimates of amounts by function are acceptable. In column (d), designate the department or departments which use the class of material.
  2. Give an explanation of important inventory adjustments during the year (in a footnote) showing general classes of material and supplies and the various accounts (operating expenses, clearing accounts, plant, etc.) affected debited or credited. Show separately debit or credits to stores expense clearing, if applicable.
Line No.
Account
(a)
Balance Beginning of Year
(b)
Balance End of Year
(c)
Department or Departments which Use Material
(d)
1
Fuel Stock (Account 151)
7,701,524
6,454,796
2
Fuel Stock Expenses Undistributed (Account 152)
3
Residuals and Extracted Products (Account 153)
4
Plant Materials and Operating Supplies (Account 154)
5
Assigned to - Construction (Estimated)
21,961,870
20,820,420
6
Assigned to - Operations and Maintenance
7
Production Plant (Estimated)
473,626
1,313,048
Electric & Gas
8
Transmission Plant (Estimated)
272,069
856,554
Electric & Gas
9
Distribution Plant (Estimated)
553,950
1,799,515
Electric & Gas
10
Regional Transmission and Market Operation Plant (Estimated)
0
10.1
Energy Storage Plant (Estimated)
11
Assigned to - Other (provide details in footnote)
12
TOTAL Account 154 (Enter Total of lines 5 thru 11)
23,261,515
24,789,537
13
Merchandise (Account 155)
14
Other Materials and Supplies (Account 156)
15
Nuclear Materials Held for Sale (Account 157) (Not applic to Gas Util)
16
Stores Expense Undistributed (Account 163)
17
18
19
20
TOTAL Materials and Supplies
30,963,039
(a)
31,244,333


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
FOOTNOTE DATA

(a) Concept: MaterialsAndOperatingSupplies

Line
No.

Account


(a)

Balance
Beginning of Year

(b)

Balance
End of Year

(c)

Estimate of Portion Attributable to Construction

Balance
End of Year w/ Assigned to Construction

(c )

Department or
Departments which
Use Material
(d)

1

Fuel Stock (Account 151)

         7,701,524

         6,454,796

                      -  

        6,454,796

Electric & Gas

2

Fuel Stock Expense Undistributed (Account 152)

 

 

 

 

 

3

Residuals and Extracted Products (Account 153)

 

 

 

 

 

4

Plant Materials and Operating Supplies (Account 154)

 

 

 

 

 

5

Assigned to - Construction (Estimated)

                      -  

                      -  

       20,820,420

       20,820,420

Electric & Gas

6

Assigned to - Operatons and Maintenance

 

 

 

 

 

7

Production Plant (Estimated)

         8,477,126

         8,200,780

       (6,887,731)

         1,313,048

Electric & Gas

8

Transmission Plant (Estimated)

         4,869,591

         5,349,699

       (4,493,144)

            856,554

Electric & Gas

9

Distribution Plant (Estimated)

         9,914,798

       11,239,058

       (9,439,545)

         1,799,515

Electric & Gas

10

Regional Transmission and Market Operation Plant (Estimated)

                      -  

                      -  

 

 

 

11

Assigned to - Other

 

 

 

                      -  

Common

12

TOTAL Account 154 (Enter Total of lines 5 thru 10)

       23,261,515

       24,789,537

                      -  

       24,789,537

 

13

Merchandise (Account 155)

                      -  

                      -  

 

 

 

14

Other Materials and Supplies (Account 156)

 

 

 

 

Electric & Gas

15

Nuclear Materials Held for Sale (Account 157)

                      -  

                      -  

 

 

 

16

Store Expense Undistributed (Account 163)

 

 

 

 

Electric & Gas

17

 

 

 

 

 

 

18

 

 

 

 

 

 

19

 

 

 

 

 

 

20

TOTAL Materials and Supplies (Per Balance Sheet)

       30,963,039

       31,244,333

                      -  

       31,244,333

 


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
Allowances and Environmental Credits (Accounts 158.1, 158.2, 158.3, and 158.4)
  1. Report below the details related to allowances and environmental credits. Additional information about the type of allowances/environmental credits required by other regulatory bodies can be disclosed within the footnote data.
  2. Report all acquisitions of allowances and environmental credits at cost.
  3. Report allowances and environmental credits in accordance with a weighted average cost allocation method and other accounting as prescribed by General Instruction No. 21 in the Uniform System of Accounts.
  4. Report the allowances and environmental credits transactions by the period they are first eligible for use: the current year’s allowances and environmental credits in columns (b)-(c), allowances and environmental credits for the three succeeding years in columns (d)-(i), starting with the following year, and allowances and environmental credits for the remaining succeeding years in columns (j)-(k).
  5. Report on Line 4 authoritative agency issued allowances. Report withheld portions Lines 36-40.
  6. Report on Line 5 allowances returned by an authoritative agency. Report on Line 39 the authoritative agency’s sales of the withheld allowances. Report on Lines 43-46 the net sales proceeds and gains/losses resulting from the authoritative agency’s sale or auction of the withheld allowances.
  7. Report on Lines 8-14 the names of vendors/transferors of allowances and environmental credits acquired and identify associated companies (See "associated company" under "Definitions" in the Uniform System of Accounts).
  8. Report on Lines 22 - 27 the name of purchasers/ transferees of allowances and environmental credits disposed of and identify associated companies.
  9. Report the net costs and benefits of hedging transactions on a separate line under purchases/transfers and sales/transfers.
  10. Report on Lines 32-35 and 43-46 the net sales proceeds and gains or losses from allowance and environmental credits sales.
Current Year Year One Year Two Year Three Future Years Totals
Line No.
Allowances and Environmental Credits Inventory (Accounts 158.1, 158.3, and 158.4)
(a)
No.
(b)
Amt.
(c)
No.
(d)
Amt.
(e)
No.
(f)
Amt.
(g)
No.
(h)
Amt.
(i)
No.
(j)
Amt.
(k)
No.
(l)
Amt.
(m)
1
Balance-Beginning of Year
0.00
0
2
3
Acquired During Year:
4
Issued (Less Withheld Allow)
336,409
0
5
Returned by authoritative agency
6
7
8
9
10
11
12
13
14
15
Total
336,409
0.00
16
17
Relinquished During Year:
18
Charges to Account 509, 555.2, and 555.3
336,409
0.00
19
Other:
20
Allowances Used
21
Cost of Sales/Transfers:
22
23
24
25
26
27
28
Total
336,409
0.00
29
Balance-End of Year
0.00
0.00
30
31
Sales:
32
Net Sales Proceeds(Assoc. Co.)
33
Net Sales Proceeds (Other)
34
Gains
35
Losses
Allowances Withheld (Acct 158.2)
36
Balance-Beginning of Year
37
Add: Withheld by authoritative agency
38
Deduct: Returned by authoritative agency
39
Cost of Sales
40
Balance-End of Year
41
42
Sales
43
Net Sales Proceeds (Assoc. Co.)
44
Net Sales Proceeds (Other)
45
Gains
46
Losses


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
EXTRAORDINARY PROPERTY LOSSES (Account 182.1)
WRITTEN OFF DURING YEAR
Line No.
DescriptionOfExtraordinaryPropertyLoss
Description of Extraordinary Loss [Include in the description the date of Commission Authorization to use Acc 182.1 and period of amortization (mo, yr to mo, yr).]
(a)
ExtraordinaryPropertyLossesNotYetRecognized
Total Amount of Loss
(b)
ExtraordinaryPropertyLossesRecognized
Losses Recognized During Year
(c)
ExtraordinaryPropertyLossesWrittenOffAccountCharged
Account Charged
(d)
ExtraordinaryPropertyLossesWrittenOff
Amount
(e)
ExtraordinaryPropertyLosses
Balance at End of Year
(f)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
20 TOTAL


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
UNRECOVERED PLANT AND REGULATORY STUDY COSTS (182.2)
WRITTEN OFF DURING YEAR
Line No.
DescriptionOfUnrecoveredPlantAndRegulatoryStudyCosts
Description of Unrecovered Plant and Regulatory Study Costs [Include in the description of costs, the date of COmmission Authorization to use Acc 182.2 and period of amortization (mo, yr to mo, yr)]
(a)
UnrecoveredPlantAndRegulatoryStudyCostsNotYetRecognized
Total Amount of Charges
(b)
UnrecoveredPlantAndRegulatoryStudyCostsRecognized
Costs Recognized During Year
(c)
UnrecoveredPlantAndRegulatoryStudyCostsWrittenOffAccountCharged
Account Charged
(d)
UnrecoveredPlantAndRegulatoryStudyCostsWrittenOff
Amount
(e)
UnrecoveredPlantAndRegulatoryStudyCosts
Balance at End of Year
(f)
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
TOTAL


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
Transmission Service and Generation Interconnection Study Costs
  1. Report the particulars (details) called for concerning the costs incurred and the reimbursements received for performing transmission service and generator interconnection studies.
  2. List each study separately.
  3. In column (a) provide the name of the study.
  4. In column (b) report the cost incurred to perform the study at the end of period.
  5. In column (c) report the account charged with the cost of the study.
  6. In column (d) report the amounts received for reimbursement of the study costs at end of period.
  7. In column (e) report the account credited with the reimbursement received for performing the study.
Line No.
DescriptionOfStudyPerformed
Description
(a)
StudyCostsIncurred
Costs Incurred During Period
(b)
StudyCostsAccountCharged
Account Charged
(c)
StudyCostsReimbursements
Reimbursements Received During the Period
(d)
StudyCostsAccountReimbursed
Account Credited With Reimbursement
(e)
1
Transmission Studies
20
Total
21
Generation Studies
22
Aberdeen
2,262
39
Total
2,262
40 Grand Total
2,262


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
OTHER REGULATORY ASSETS (Account 182.3)
  1. Report below the particulars (details) called for concerning other regulatory assets, including rate order docket number, if applicable.
  2. Minor items (5% of the Balance in Account 182.3 at end of period, or amounts less than $100,000 which ever is less), may be grouped by classes.
  3. For Regulatory Assets being amortized, show period of amortization.
CREDITS
Line No.
DescriptionAndPurposeOfOtherRegulatoryAssets
Description and Purpose of Other Regulatory Assets
(a)
OtherRegulatoryAssets
Balance at Beginning of Current Quarter/Year
(b)
IncreaseDecreaseInOtherRegulatoryAssets
Debits
(c)
OtherRegulatoryAssetsWrittenOffAccountCharged
Written off During Quarter/Year Account Charged
(d)
OtherRegulatoryAssetsWrittenOffRecovered
Written off During the Period Amount
(e)
OtherRegulatoryAssets
Balance at end of Current Quarter/Year
(f)
1
Flow-through Income Taxes (South Dakota)
74,250,220
1,007,249
767,222
74,490,247
2
Excess Deferred Income Taxes (South Dakota)
6,579,645
125,114
721,305
(a)
5,983,454
3
Pension Plan (South Dakota)
5,376,058
242,762
92,702
5,526,118
4
Manufactured Gas Plants (South Dakota) - Docket NG 11-003
11,256,555
1,333,777
510,075
12,080,257
5
Rate Case Costs (South Dakota) Docket EL 23-016
188,411
67,498
88,767
167,141
6
Field Inventory (South Dakota) - Docket EL 14-106
82,416
0
82,416
0
7
Asset Retirement Obligation (South Dakota)
0
158,535
158,535
0
8
SD Electric Phased in Rate Plan Tracker (South Dakota)
0
730,350
656,773
73,577
9
SD Nuclear Study Tracker (South Dakota)
0
540,285
54,028
486,257
10
Electric Supply Tracker (South Dakota)
1,297,852
8,336,256
6,843,245
2,790,863
44
TOTAL
99,031,157
12,541,826
9,975,068
101,597,915


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
FOOTNOTE DATA

(a) Concept: OtherRegulatoryAssets

Line No.

Description (a)

 (b)

 (c)

 (d)

         

1

SOUTH DAKOTA:

     

2

 

12/31/2024

3

 

Protected

Unprotected

 

4

TCJA Excess ADIT Account Reduced

190

190

Subtotal

5

Reg Asset Acccount Impacted

182.3

182.3

182.3

6

Electric:

     

7

Regulatory Assets / Liabilities

 

-

-

8

Unbilled Revenue

 

-

-

9

Compensation Accruals

 

-

-

10

Reserves & Accruals

 

-

-

11

Intangible amortization

 

-

-

12

Pension / Postretirement Benefits

 

-

-

13

Environmental Liability

 

-

-

14

Interest Rate Hedge

 

-

-

15

Customer Advances

 

-

-

16

Excess Tax Depreciation / Other Property

   

-

17

Net Operating Loss

3,587,409

-

3,587,409

18

Total Electric

3,587,409

-

3,587,409

19

Gas:

     

20

Regulatory Assets / Liabilities

 

-

-

21

Unbilled Revenue

 

237,268

237,268

22

Compensation Accruals

 

895,742

895,742

23

Reserves & Accruals

 

66,862

66,862

24

Intangible amortization

 

-

-

25

Pension / Postretirement Benefits

 

(67,853)

(67,853)

26

Environmental Liability

 

491,773

491,773

27

Interest Rate Hedge

 

-

-

28

Customer Advances

 

-

-

29

Excess Tax Depreciation / Other Property

   

-

30

Net Operating Loss

(143,211)

-

(143,211)

31

Total Gas

(143,211)

1,623,792

1,480,581

32

Other (Specify)

-

129,930

129,930

33

Subtotal

3,444,198

1,753,722

5,197,920

34

Gross-up

915,546

466,179

1,381,725

35

Total

4,359,744

2,219,901

6,579,645

36

       

37

Other (Specify)

     

38

QF Obligations

-

-

-

39

NOL Carryforward

-

-

-

40

AMT Credit Carryforward

-

-

-

41

Production Tax Credit

-

-

-

42

Regulatory Assets / Liabilities

-

-

-

43

Other, net

-

129,930

129,930

44

Total

-

129,930

129,930

45

       

46

       

47

 

12/31/2025

48

 

Protected

Unprotected

 

49

TCJA Excess ADIT Account Reduced

190

190

Subtotal

50

Reg Asset Acccount Impacted

182.3

182.3

182.3

51

Electric:

     

52

Regulatory Assets / Liabilities

 

-

-

53

Unbilled Revenue

 

-

-

54

Compensation Accruals

 

-

-

55

Reserves & Accruals

 

-

-

56

Intangible amortization

 

-

-

57

Pension / Postretirement Benefits

 

-

-

58

Environmental Liability

 

-

-

59

Interest Rate Hedge

 

-

-

60

Customer Advances

 

-

-

61

Excess Tax Depreciation / Other Property

   

-

62

Net Operating Loss

3,449,271

-

3,449,271

63

Total Electric

3,449,271

-

3,449,271

64

Gas:

     

65

Regulatory Assets / Liabilities

 

-

-

66

Unbilled Revenue

 

-

-

67

Compensation Accruals

 

836,026

836,026

68

Reserves & Accruals

 

62,404

62,404

69

Intangible amortization

 

-

-

70

Pension / Postretirement Benefits

 

(63,329)

(63,329)

71

Environmental Liability

 

458,988

458,988

72

Interest Rate Hedge

 

-

-

73

Customer Advances

 

-

-

74

Excess Tax Depreciation / Other Property

   

-

75

Net Operating Loss

(137,698)

-

(137,698)

76

Total Gas

(137,698)

1,294,089

1,156,391

77

Other (Specify)

-

121,268

121,268

78

Subtotal

3,311,573

1,415,357

4,726,930

79

Gross-up

880,291

376,233

1,256,524

80

Total

4,191,864

1,791,590

5,983,454

81

       

82

Other (Specify)

     

83

QF Obligations

-

-

-

84

NOL Carryforward

-

-

-

85

AMT Credit Carryforward

-

-

-

86

Production Tax Credit

-

-

-

87

Regulatory Assets / Liabilities

-

-

-

88

Other, net

-

121,268

121,268

89

Total

-

121,268

121,268


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
MISCELLANEOUS DEFFERED DEBITS (Account 186)
  1. Report below the particulars (details) called for concerning miscellaneous deferred debits.
  2. For any deferred debit being amortized, show period of amortization in column (a)
  3. Minor item (1% of the Balance at End of Year for Account 186 or amounts less than $100,000, whichever is less) may be grouped by classes.
CREDITS
Line No.
Description of Miscellaneous Deferred Debits
(a)
Balance at Beginning of Year
(b)
Debits
(c)
Credits Account Charged
(d)
Credits Amount
(e)
Balance at End of Year
(f)
1
Pension Requirement
9,467,339
666,155
8,801,184
2
Unamortized Debt Expense
299,579
76,488
223,091
47
Miscellaneous Work in Progress
48
Deferred Regulatory Comm. Expenses (See pages 350 - 351)
49
TOTAL
9,766,918
9,024,275


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
ACCUMULATED DEFERRED INCOME TAXES (Account 190)
  1. Report the information called for below concerning the respondent’s accounting for deferred income taxes.
  2. At Other (Specify), include deferrals relating to other income and deductions.
Line No.
DescriptionOfAccumulatedDeferredIncomeTax
Description and Location
(a)
AccumulatedDeferredIncomeTaxes
Balance at Beginning of Year
(b)
AccumulatedDeferredIncomeTaxes
Balance at End of Year
(c)
1
Electric
2
Unbilled Revenue
1,977,771
1,996,847
3
Compensation Accruals
1,005,276
975,746
4
Reserves & Accruals
292,505
551,314
5
Pension / Postretirement Benefits
765,014
729,568
7
Other
(a)
20,521,761
17,006,487
8
TOTAL Electric (Enter Total of lines 2 thru 7)
23,032,299
19,800,826
9
Gas
10
Regulatory Asset/Liability
170,277
181,475
11
Unbilled Revenue
1,372,678
1,386,492
12
Compensation Accruals
687,677
666,293
13
Reserves & Accruals
203,323
390,737
14
Pension / Postretirement Benefits
525,674
500,007
15
Other
(b)
12,665,183
12,258,325
16
TOTAL Gas (Enter Total of lines 10 thru 15)
14,232,910
14,020,365
17.1
Other
(c)
63,697,369
54,226,837
17
Other (Specify)
18
TOTAL (Acct 190) (Total of lines 8, 16 and 17)
100,962,578
88,048,028
Notes


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
FOOTNOTE DATA

(a) Concept: AccumulatedDeferredIncomeTaxes

Schedule Page: 234  Line No.:7  Column: b and c

   
 

Balance at Beginning of Year

Balance at End of  Year

 

(b)

( c)

Environmental Liability

1,937,734

1,984,141

Interest Rate Hedge

(129,189)

(155,819)

Customer Advances

-

-

NOL Carryforward

18,713,216

15,178,165

 

20,521,761

17,006,487

(b) Concept: AccumulatedDeferredIncomeTaxes

Schedule Page: 234  Line No.: 15  Column: b and c

   
 

Balance at Beginning of Year

Balance at End of  Year

 

(b)

( c)

Environmental Liability

                     1,345,645

                     1,379,250

Interest Rate Hedge

                        (91,241)

                      (110,525)

Customer Advances

                                  -

                                  -

NOL Carryforward

                   11,410,779

                   10,989,600

 

                   12,665,183

                   12,258,325

(c) Concept: AccumulatedDeferredIncomeTaxes

Account 190 Other (Specify)

Balance at Beginning of Year

Balance at End of  Year

Production Tax Credit

62,093,063

52,935,759

Other, net

1,604,306

1,291,078

Total

63,697,369

54,226,837


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
CAPITAL STOCKS (Account 201 and 204)
  1. Report below the particulars (details) called for concerning common and preferred stock at end of year, distinguishing separate series of any general class. Show separate totals for common and preferred stock. If information to meet the stock exchange reporting requirement outlined in column (a) is available from the SEC 10-K Report Form filing, a specific reference to report form (i.e., year and company title) may be reported in column (a) provided the fiscal years for both the 10-K report and this report are compatible.
  2. Entries in column (b) should represent the number of shares authorized by the articles of incorporation as amended to end of year.
  3. Give details concerning shares of any class and series of stock authorized to be issued by a regulatory commission which have not yet been issued.
  4. The identification of each class of preferred stock should show the dividend rate and whether the dividends are cumulative or noncumulative.
  5. State in a footnote if any capital stock that has been nominally issued is nominally outstanding at end of year.
  6. Give particulars (details) in column (a) of any nominally issued capital stock, reacquired stock, or stock in sinking and other funds which is pledged, stating name of pledgee and purpose of pledge.
Line No.
Class and Series of Stock and Name of Stock Series
(a)
Number of Shares Authorized by Charter
(b)
Par or Stated Value per Share
(c)
Call Price at End of Year
(d)
Outstanding per Bal. Sheet (Total amount outstanding without reduction for amounts held by respondent) Shares
(e)
Outstanding per Bal. Sheet (Total amount outstanding without reduction for amounts held by respondent) Amount
(f)
Held by Respondent As Reacquired Stock (Acct 217) Shares
(g)
Held by Respondent As Reacquired Stock (Acct 217) Cost
(h)
Held by Respondent In Sinking and Other Funds Shares
(i)
Held by Respondent In Sinking and Other Funds Amount
(j)
1
Common Stock (Account 201)
2
3
4
5
Total
100
100
1
6
Preferred Stock (Account 204)
7
8
9
10
Total


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

2025-12-31
Year/Period of Report

End of:
2025
/
Q4
Other Paid-in Capital
1. Report below the balance at the end of the year and the information specified below for the respective other paid-in capital accounts. Provide a subheading for each account and show a total for the account, as well as a total of all accounts for reconciliation with the balance sheet, page 112. Explain changes made in any account during the year and give the accounting entries effecting such change.
  1. Donations Received from Stockholders (Account 208) - State amount and briefly explain the origin and purpose of each donation.
  2. Reduction in Par or Stated Value of Capital Stock (Account 209) - State amount and briefly explain the capital changes that gave rise to amounts reported under this caption including identification with the class and series of stock to which related.
  3. Gain or Resale or Cancellation of Reacquired Capital Stock (Account 210) - Report balance at beginning of year, credits, debits, and balance at end of year with a designation of the nature of each credit and debit identified by the class and series of stock to which related.
  4. Miscellaneous Paid-In Capital (Account 211) - Classify amounts included in this account according to captions that, together with brief explanations, disclose the general nature of the transactions that gave rise to the reported amounts.
Line No.
Item
(a)
Amount
(b)
1
DonationsReceivedFromStockholdersAbstract
Donations Received from Stockholders (Account 208)
2
DonationsReceivedFromStockholders
Beginning Balance Amount
3
IncreasesDecreasesFromSalesOfDonationsReceivedFromStockholders
Increases (Decreases) from Sales of Donations Received from Stockholders
4
DonationsReceivedFromStockholders
Ending Balance Amount
5
ReductionInParOrStatedValueOfCapitalStockAbstract
Reduction in Par or Stated Value of Capital Stock (Account 209)
6
ReductionInParOrStatedValueOfCapitalStock
Beginning Balance Amount
7
IncreasesDecreasesDueToReductionsInParOrStatedValueOfCapitalStock
Increases (Decreases) Due to Reductions in Par or Stated Value of Capital Stock
8
ReductionInParOrStatedValueOfCapitalStock
Ending Balance Amount
9
GainOrResaleOrCancellationOfReacquiredCapitalStockAbstract
Gain or Resale or Cancellation of Reacquired Capital Stock (Account 210)
10
GainOnResaleOrCancellationOfReacquiredCapitalStock
Beginning Balance Amount
11
IncreasesDecreasesFromGainOrResaleOrCancellationOfReacquiredCapitalStock
Increases (Decreases) from Gain or Resale or Cancellation of Reacquired Capital Stock
12
GainOnResaleOrCancellationOfReacquiredCapitalStock
Ending Balance Amount
13
MiscellaneousPaidInCapitalAbstract
Miscellaneous Paid-In Capital (Account 211)
14
MiscellaneousPaidInCapital
Beginning Balance Amount
580,991,640
15.1
IncreasesDecreasesDueToMiscellaneousPaidInCapital
Stock Compensation
1,112,231
15
IncreasesDecreasesDueToMiscellaneousPaidInCapital
Increases (Decreases) Due to Miscellaneous Paid-In Capital
1,112,231
16
MiscellaneousPaidInCapital
Ending Balance Amount
582,103,871
17
OtherPaidInCapitalAbstract
Other Paid in Capital
18
OtherPaidInCapitalDetail
Beginning Balance Amount
19
IncreasesDecreasesInOtherPaidInCapital
Increases (Decreases) in Other Paid-In Capital
20
OtherPaidInCapitalDetail
Ending Balance Amount
40
OtherPaidInCapital
Total
582,103,871


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
CAPITAL STOCK EXPENSE (Account 214)
  1. Report the balance at end of the year of discount on capital stock for each class and series of capital stock.
  2. If any change occurred during the year in the balance in respect to any class or series of stock, attach a statement giving particulars (details) of the change. State the reason for any charge-off of capital stock expense and specify the account charged.
Line No.
NameOfClassAndSeriesOfStock
Class and Series of Stock
(a)
CapitalStockExpense
Balance at End of Year
(b)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
TOTAL


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
LONG-TERM DEBT (Account 221, 222, 223 and 224)
  1. Report by Balance Sheet Account the details concerning long-term debt included in Accounts 221, Bonds, 222, Reacquired Bonds, 223, Advances from Associated Companies, and 224, Other Long-Term Debt.
  2. For bonds assumed by the respondent, include in column (a) the name of the issuing company as well as a description of the bonds, and in column (b) include the related account number.
  3. For Advances from Associated Companies, report separately advances on notes and advances on open accounts. Designate demand notes as such. Include in column (a) names of associated companies from which advances were received, and in column (b) include the related account number.
  4. For receivers' certificates, show in column (a) the name of the court and date of court order under which such certificates were issued, and in column (b) include the related account number.
  5. In a supplemental statement, give explanatory details for Accounts 223 and 224 of net changes during the year. With respect to long-term advances, show for each company: (a)principal advanced during year (b) interest added to principal amount, and (c) principal repaid during year. Give Commission authorization numbers and dates.
  6. If the respondent has pledged any of its long-term debt securities, give particulars (details) in a footnote, including name of the pledgee and purpose of the pledge.
  7. If the respondent has any long-term securities that have been nominally issued and are nominally outstanding at end of year, describe such securities in a footnote.
  8. If interest expense was incurred during the year on any obligations retired or reacquired before end of year, include such interest expense in column (m). Explain in a footnote any difference between the total of column (m) and the total Account 427, Interest on Long-Term Debt and Account 430, Interest on Debt to Associated Companies.
  9. Give details concerning any long-term debt authorized by a regulatory commission but not yet issued.
Line No.
ClassAndSeriesOfObligationCouponRateDescription
Class and Series of Obligation, Coupon Rate (For new issue, give commission Authorization numbers and dates)
(a)
RelatedAccountNumber
Related Account Number
(b)
Principal Amount of Debt Issued
(c)
LongTermDebtIssuanceExpensePremiumOrDiscount
Total Expense, Premium or Discount
(d)
LongTermDebtIssuanceExpenses
Total Expense
(e)
LongTermDebtPremium
Total Premium
(f)
LongTermDebtDiscount
Total Discount
(g)
NominalDateOfIssue
Nominal Date of Issue
(h)
DateOfMaturity
Date of Maturity
(i)
AmortizationPeriodStartDate
AMORTIZATION PERIOD Date From
(j)
AmortizationPeriodEndDate
AMORTIZATION PERIOD Date To
(k)
Outstanding (Total amount outstanding without reduction for amounts held by respondent)
(l)
Interest for Year Amount
(m)
1
Bonds (Account 221)
2
First Mortgage Bonds 5.01% (South Dakota)
(a)
64,000,000
412,254
1,880,320
05/27/2010
05/01/2025
05/27/2010
05/01/2025
0
1,068,800
3
First Mortgage Bonds 4.15% (South Dakota)
30,000,000
184,030
08/10/2012
08/10/2042
08/10/2012
08/10/2042
30,000,000
1,245,000
4
First Mortgage Bonds 4.30% (South Dakota)
20,000,000
122,686
08/10/2012
08/10/2052
08/10/2012
08/10/2052
20,000,000
860,000
5
First Mortgage Bonds 4.85% (South Dakota)
50,000,000
278,988
12/19/2013
12/19/2043
12/19/2013
12/19/2043
50,000,000
2,425,000
6
First Mortgage Bonds 4.22% (South Dakota)
30,000,000
207,702
12/19/2014
12/19/2044
12/19/2014
12/19/2044
30,000,000
1,266,000
7
First Mortgage Bonds 4.26% (South Dakota)
70,000,000
314,529
09/29/2015
09/29/2040
09/29/2015
09/29/2040
70,000,000
2,982,000
8
First Mortgage Bonds 2.80% (South Dakota)
60,000,000
377,548
4,928,484
06/15/2016
06/15/2026
06/15/2016
06/15/2026
60,000,000
1,680,000
9
First Mortgage Bonds 2.66% (South Dakota)
45,000,000
250,872
09/30/2016
09/30/2026
09/30/2016
09/30/2026
45,000,000
1,197,000
10
First Mortgage Bonds 3.21% (South Dakota)
50,000,000
352,905
05/15/2020
05/15/2030
05/15/2020
05/15/2030
50,000,000
1,605,000
11
First Mortgage Bonds 5.57% (South Dakota)
31,000,000
173,454
03/30/2023
03/30/2033
03/30/2023
03/30/2033
31,000,000
1,726,700
12
First Mortgage Bonds 5.42% (South Dakota)
30,000,000
167,866
05/01/2023
05/01/2033
05/01/2023
05/01/2033
30,000,000
1,626,000
13
First Mortgage Bonds 5.55% (South Dakota)
33,000,000
212,437
03/28/2024
03/28/2029
03/28/2024
03/28/2029
33,000,000
1,831,500
14
First Mortgage Bonds 5.75% (South Dakota)
7,000,000
45,947
03/28/2024
03/28/2034
03/28/2024
03/28/2034
7,000,000
402,500
15
First Mortgage Bonds 5.49% (South Dakota)
100,000,000
530,048
05/01/2025
05/01/2035
05/01/2025
05/01/2035
100,000,000
3,660,000
16
Subtotal
620,000,000
3,631,266
6,808,804
556,000,000
23,575,500
17
Reacquired Bonds (Account 222)
18
19
20
21
Subtotal
22
Advances from Associated Companies (Account 223)
23
24
25
26
Subtotal
27
Other Long Term Debt (Account 224)
28
Senior Unsecured Revolving Line of Credit ($150m)
41,000,000
11/30/2023
11/30/2028
11/30/2023
11/30/2028
41,000,000
1,372,800
29
Subtotal
41,000,000
41,000,000
1,372,800
33 TOTAL
661,000,000
597,000,000
24,948,300


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
FOOTNOTE DATA

(a) Concept: BondsPrincipalAmountIssued
As issuances are redeemed, the related expense and premium or discount, as applicable, is charged to Loss on Reacquired Debt.

Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
RECONCILIATION OF REPORTED NET INCOME WITH TAXABLE INCOME FOR FEDERAL INCOME TAXES
  1. Report the reconciliation of reported net income for the year with taxable income used in computing Federal income tax accruals and show computation of such tax accruals. Include in the reconciliation, as far as practicable, the same detail as furnished on Schedule M-1 of the tax return for the year. Submit a reconciliation even though there is no taxable income for the year. Indicate clearly the nature of each reconciling amount.
  2. If the utility is a member of a group which files a consolidated Federal tax return, reconcile reported net income with taxable net income as if a separate return were to be filed, indicating, however, intercompany amounts to be eliminated in such a consolidated return. State names of group member, tax assigned to each group member, and basis of allocation, assignment, or sharing of the consolidated tax among the group members.
  3. A substitute page, designed to meet a particular need of a company, may be used as long as the data is consistent and meets the requirements of the above instructions. For electronic reporting purposes complete Line 27 and provide the substitute Page in the context of a footnote.
Line No.
Particulars (Details)
(a)
Amount
(b)
1
Net Income for the Year (Page 117)
31,527,278
2
Reconciling Items for the Year
3
4
Taxable Income Not Reported on Books
5
6
7
8
9
Deductions Recorded on Books Not Deducted for Return
10
Meals and Entertainment
163,887
11
Non-Deductible Dues/Lobbying Expense/Penalties/Professional Fees/Non-Deductible Parking/GILTI Inclusion
524,135
12
Federal Income Taxes
3,468,689
13
State Tax Adjustment
490,037
14
Income Recorded on Books Not Included in Return
15
16
17
18
19
Deductions on Return Not Charged Against Book Income
20
Net Tax Greater Than Book Depreciation
7,728,011
21
Plant Flow Through Items
656,620
22
Reserves & Accruals
2,250,070
23
Deferred Book Revenue & Gains
1,057,043
24
Contributions & Advances for Construction
429,023
25
NOL Carryforward
18,839,193
26
Other Miscellaneous
44,528
27
Federal Tax Net Income
10,616,780
28
Show Computation of Tax:
29
Federal Tax Expense/(Benefit) @ 21%
2,229,524


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
TAXES ACCRUED, PREPAID AND CHARGES DURING YEAR
  1. Give particulars (details) of the combined prepaid and accrued tax accounts and show the total taxes charged to operations and other accounts during the year. Do not include gasoline and other sales taxes which have been charged to the accounts to which the taxed material was charged. If the actual, or estimated amounts of such taxes are known, show the amounts in a footnote and designate whether estimated or actual amounts.
  2. Include on this page, taxes paid during the year and charged direct to final accounts, (not charged to prepaid or accrued taxes.) Enter the amounts in both columns (g) and (h). The balancing of this page is not affected by the inclusion of these taxes.
  3. Include in column (g) taxes charged during the year, taxes charged to operations and other accounts through (a) accruals credited to taxes accrued, (b)amounts credited to proportions of prepaid taxes chargeable to current year, and (c) taxes paid and charged direct to operations or accounts other than accrued and prepaid tax accounts.
  4. List the aggregate of each kind of tax in such manner that the total tax for each State and subdivision can readily be ascertained.
  5. If any tax (exclude Federal and State income taxes) covers more than one year, show the required information separately for each tax year, identifying the year in column (d).
  6. Enter all adjustments of the accrued and prepaid tax accounts in column (i) and explain each adjustment in a foot- note. Designate debit adjustments by parentheses.
  7. Do not include on this page entries with respect to deferred income taxes or taxes collected through payroll deductions or otherwise pending transmittal of such taxes to the taxing authority.
  8. Report in columns (l) through (o) how the taxes were distributed. Report in column (o) only the amounts charged to Accounts 408.1 and 409.1 pertaining to electric operations. Report in column (l) the amounts charged to Accounts 408.1 and 409.1 pertaining to other utility departments and amounts charged to Accounts 408.2 and 409.2. Also shown in column (o) the taxes charged to utility plant or other balance sheet accounts.
  9. For any tax apportioned to more than one utility department or account, state in a footnote the basis (necessity) of apportioning such tax.
BALANCE AT BEGINNING OF YEAR BALANCE AT END OF YEAR DISTRIBUTION OF TAXES CHARGED
Line No.
DescriptionOfTaxesAccruedPrepaidAndCharged
Kind of Tax (See Instruction 5)
(a)
TypeOfTax
Type of Tax
(b)
TaxJurisdiction
State
(c)
TaxYear
Tax Year
(d)
TaxesAccrued
Taxes Accrued (Account 236)
(e)
PrepaidTaxes
Prepaid Taxes (Include in Account 165)
(f)
TaxesCharged
Taxes Charged During Year
(g)
TaxesPaid
Taxes Paid During Year
(h)
TaxAdjustments
Adjustments
(i)
TaxesAccrued
Taxes Accrued (Account 236)
(j)
PrepaidTaxes
Prepaid Taxes (Included in Account 165)
(k)
TaxesAccruedPrepaidAndCharged
Electric (Account 408.1, 409.1)
(l)
IncomeTaxesExtraordinaryItems
Extraordinary Items (Account 409.3)
(m)
AdjustmentsToRetainedEarnings
Adjustment to Ret. Earnings (Account 439)
(n)
TaxesIncurredOther
Other
(o)
1
FICA and Medicare
Federal Tax
South Dakota
2025
0
2,651,335
2,651,335
0
759,317
1,892,018
2
State Income Tax
State Tax
South Dakota/Nebraska
2025
187,000
825
26,013
(a)
231,954
19,766
0
825
3
Gross Receipts Tax
Other Taxes
South Dakota
2024
366,592
0
366,592
0
0
0
4
Gross Receipts Tax
Other Taxes
South Dakota
2025
0
402,974
0
402,974
318,378
84,596
5
Coal Conversion Tax
Other Taxes
North Dakota
2025
0
29,703
29,703
0
29,703
0
6
Property Tax
Property Tax
South Dakota
2024
5,653,332
353,324
5,300,008
0
353,324
0
7
Property Tax
Property Tax
South Dakota
2025
0
6,114,240
0
6,114,240
5,334,880
779,360
8
Property Tax
Property Tax
Nebraska
2024
867,888
103,412
764,476
0
0
103,412
9
Property Tax
Property Tax
Nebraska
2025
0
906,480
0
906,480
0
906,480
10
Property Tax
Property Tax
North Dakota
2024
16,848
1,611
15,237
0
1,611
0
11
Property Tax
Property Tax
North Dakota
2025
0
15,480
0
15,480
15,480
0
12
Property Tax
Property Tax
Iowa
2023
16,089
49,342
65,431
0
49,342
0
13
Property Tax
Property Tax
Iowa
2024
123,935
7,541
61,797
69,679
7,541
0
14
Property Tax
Property Tax
Iowa
2025
0
142,800
1,463
141,337
142,800
0
15
Federal Unemplyment Tax
Unemployment Tax
South Dakota
2024
228
0
228
0
0
0
16
Federal Unemplyment Tax
Unemployment Tax
South Dakota
2025
0
14,384
14,191
193
2,309
12,075
17
State Unemployment Tax
Unemployment Tax
South Dakota
2024
146
0
146
0
0
0
18
State Unemployment Tax
Unemployment Tax
South Dakota
2025
0
8,814
8,672
142
1,715
7,099
19
Use Tax
Sales And Use Tax
South Dakota
2024
73,877
0
73,877
0
0
0
20
Use Tax
Sales And Use Tax
South Dakota
2025
0
691,005
573,047
117,958
0
691,005
21
Federal Income Tax
Income Tax
South Dakota/Nebraska
2025
876,327
10,367,817
0
(b)
12,036,711
2,545,221
11,257,885
890,068
22
Delaware Franchise Tax
Franchise Tax
South Dakota
2025
0
38,400
38,400
0
21,600
16,800
40
TOTAL
7,808,262
247,159
9,990,616
12,268,665
10,333,470
(c)
4,929,755
5,176,914


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
FOOTNOTE DATA

(a) Concept: TaxAdjustments

State refund and uncertain tax position adjustment.

(b) Concept: TaxAdjustments

Primarily the proceeds from production tax credits transferred.

(c) Concept: TaxesAccruedPrepaidAndCharged

South Dakota Electric - taxes accrued, exclusive of federal and state income taxes

 Taxes Charged During the Year 2025

(b)

 (c) 

Property-South Dakota

                              4,981,556

Property-North Dakota

                                   13,870

Property - Iowa

                                 199,684

Coal Conversion Facility - N Dakota

                                   29,703

Gross Revenue - South Dakota

                                 318,378

Delaware Franchise

                                   21,600

Payroll Tax - FICA

                                 599,888

Payroll Tax - Medicare

                                 159,428

Payroll Tax - FUT

                                     2,308

Payroll Tax - SUT - SD

                                     1,715

 

                              6,328,130


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
ACCUMULATED DEFERRED INVESTMENT TAX CREDITS (Account 255)

Report below information applicable to Account 255. Where appropriate, segregate the balances and transactions by utility and nonutility operations. Explain by footnote any correction adjustments to the account balance shown in column (g). Include in column (i) the average period over which the tax credits are amortized.

Deferred for Year Allocations to Current Year's Income
Line No.
Account Subdivisions
(a)
Balance at Beginning of Year
(b)
Account No.
(c)
Amount
(d)
Account No.
(e)
Amount
(f)
Adjustments
(g)
Balance at End of Year
(h)
Average Period of Allocation to Income
(i)
ADJUSTMENT EXPLANATION
(j)
1
Electric Utility
2
3%
3
4%
4
7%
5
10%
8
TOTAL Electric (Enter Total of lines 2 thru 7)
9
Other (List separately and show 3%, 4%, 7%, 10% and TOTAL)
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
47 OTHER TOTAL
48 GRAND TOTAL


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
OTHER DEFERRED CREDITS (Account 253)
  1. Report below the particulars (details) called for concerning other deferred credits.
  2. For any deferred credit being amortized, show the period of amortization.
  3. Minor items (5% of the Balance End of Year for Account 253 or amounts less than $100,000, whichever is greater) may be grouped by classes.
DEBITS
Line No.
Description and Other Deferred Credits
(a)
Balance at Beginning of Year
(b)
Contra Account
(c)
Amount
(d)
Credits
(e)
Balance at End of Year
(f)
1
Family Protector Plan Future Payments
0
123,362
123,362
0
2
Projects & Studies Prepaid by Customer
11,541
2,297
35
9,279
3
Permanent Uncertain Tax Positions
35,085
47,469
82,554
0
4
Other Minor Items (4) - some are amortized over various periods
9,995,390
1,151,917
1,344,381
10,187,854
47
TOTAL
9,971,846
1,325,045
1,550,332
10,197,133


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report


End of:
2025
/
Q4
ACCUMULATED DEFERRED INCOME TAXES - ACCELERATED AMORTIZATION PROPERTY (Account 281)
  1. Report the information called for below concerning the respondent’s accounting for deferred income taxes rating to amortizable property.
  2. For other (Specify),include deferrals relating to other income and deductions.
  3. Use footnotes as required.
CHANGES DURING YEAR ADJUSTMENTS
Debits Credits
Line No.
Account
(a)
Balance at Beginning of Year
(b)
Amounts Debited to Account 410.1
(c)
Amounts Credited to Account 411.1
(d)
Amounts Debited to Account 410.2
(e)
Amounts Credited to Account 411.2
(f)
Account Credited
(g)
Amount
(h)
Account Debited
(i)
Amount
(j)
Balance at End of Year
(k)
1
Accelerated Amortization (Account 281)
2
Electric
3
Defense Facilities
4
Pollution Control Facilities
5
Other
5.1
Other
5.2
Other
8
TOTAL Electric (Enter Total of lines 3 thru 7)
9
Gas
10
Defense Facilities
11
Pollution Control Facilities
12
Other
12.1
Other
12.2
Other
15
TOTAL Gas (Enter Total of lines 10 thru 14)
16
Other
16.1
Other
16.2
Other
17
TOTAL (Acct 281) (Total of 8, 15 and 16)
18
Classification of TOTAL
19
Federal Income Tax
20
State Income Tax
21
Local Income Tax


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
ACCUMULATED DEFERRED INCOME TAXES - OTHER PROPERTY (Account 282)
  1. Report the information called for below concerning the respondent’s accounting for deferred income taxes rating to property not subject to accelerated amortization.
  2. For other (Specify),include deferrals relating to other income and deductions.
  3. Use footnotes as required.
CHANGES DURING YEAR ADJUSTMENTS
Debits Credits
Line No.
Account
(a)
Balance at Beginning of Year
(b)
Amounts Debited to Account 410.1
(c)
Amounts Credited to Account 411.1
(d)
Amounts Debited to Account 410.2
(e)
Amounts Credited to Account 411.2
(f)
Account Credited
(g)
Amount
(h)
Account Debited
(i)
Amount
(j)
Balance at End of Year
(k)
1 Account 282
2
Electric
93,215,960
1,916,116
95,132,076
3
Gas
20,817,026
235,538
20,581,488
4
Other (Specify)
5
Total (Total of lines 2 thru 4)
114,032,986
1,916,116
235,538
115,713,564
6
7
8
9
TOTAL Account 282 (Total of Lines 5 thru 8)
114,032,986
1,916,116
235,538
115,713,564
10
Classification of TOTAL
11
Federal Income Tax
114,032,986
1,916,116
235,538
115,713,564
12
State Income Tax
13
Local Income Tax


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
ACCUMULATED DEFERRED INCOME TAXES - OTHER (Account 283)
  1. Report the information called for below concerning the respondent's accounting for deferred income taxes relating to amounts recorded in Account 283.
  2. For other (Specify),include deferrals relating to other income and deductions.
  3. Provide in the space below explanations for Page 276. Include amounts relating to insignificant items listed under Other.
  4. Use footnotes as required.
CHANGES DURING YEAR ADJUSTMENTS
Debits Credits
Line No.
Account
(a)
Balance at Beginning of Year
(b)
Amounts Debited to Account 410.1
(c)
Amounts Credited to Account 411.1
(d)
Amounts Debited to Account 410.2
(e)
Amounts Credited to Account 411.2
(f)
Account Credited
(g)
Amount
(h)
Account Debited
(i)
Amount
(j)
Balance at End of Year
(k)
1 Account 283
2
Electric
3
Regulatory Assets
930,066
82,522
1,012,588
4
Excess Tax Depreciation
9,354,853
66,467
9,421,320
9 TOTAL Electric (Total of lines 3 thru 8)
10,284,919
82,522
66,467
10,433,908
10
Gas
11
Regulatory Assets
3,069,980
80,128
3,150,108
12
Excess Tax Depreciation
3,512,127
143,843
3,655,970
17 TOTAL Gas (Total of lines 11 thru 16)
6,582,107
80,128
143,843
6,806,078
18 TOTAL Other
103,572
20,849
124,421
19 TOTAL (Acct 283) (Enter Total of lines 9, 17 and 18)
16,763,454
162,650
210,310
20,849
17,115,565
20
Classification of TOTAL
21
Federal Income Tax
16,763,454
162,650
210,310
20,849
17,115,565
22
State Income Tax
23
Local Income Tax
NOTES


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
OTHER REGULATORY LIABILITIES (Account 254)
  1. Report below the particulars (details) called for concerning other regulatory liabilities, including rate order docket number, if applicable.
  2. Minor items (5% of the Balance in Account 254 at end of period, or amounts less than $100,000 which ever is less), may be grouped by classes.
  3. For Regulatory Liabilities being amortized, show period of amortization.
DEBITS
Line No.
Description and Purpose of Other Regulatory Liabilities
(a)
Balance at Beginning of Current Quarter/Year
(b)
Account Credited
(c)
Amount
(d)
Credits
(e)
Balance at End of Current Quarter/Year
(f)
1
Excess Deferred Income Taxes (South Dakota)
17,724,721
1,073,979
145,920
(a)
16,796,662
2
Current Ad Valorem True-Up (South Dakota) - Docket GE98-001
204,702
324,834
424,050
303,918
3
Unbilled Revenues (South Dakota)
15,839,645
4,465,373
4,675,921
16,050,193
4
Tax Cut Jobs Act Deferral (South Dakota) - Docket GE17-003 & EL23-016
103,332
51,665
0
51,667
41 TOTAL
33,872,400
5,915,851
5,245,891
33,202,440


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
FOOTNOTE DATA

(a) Concept: OtherRegulatoryLiabilities

Line No.

Description (a)

 (b)

 (c)

 (d)

 (e)

 (f)

 (g)

 (h)

          1

SOUTH DAKOTA:

             

          2

 

12/31/2024

          3

 

Protected

Unprotected

Unprotected

   

Normalizing EDIT

 

          4

TCJA Excess ADIT Account Reduced

282

282

283

Subtotal

Total of 182.3

Subtotal

282

          5

Reg Asset Acccount Impacted

254

254

254

254

and 254

182.3

254

          6

Electric:

             

          7

Regulatory Assets / Liabilities

 

 

                                -

                                -

                                -

                                -

                                -

          8

Unbilled Revenue

 

 

                                -

                                -

                                -

                                -

                                -

          9

Compensation Accruals

 

 

                                -

                                -

                                -

                                -

                                -

       10

Reserves & Accruals

 

 

                                -

                                -

                                -

                                -

                                -

       11

Intangible amortization

 

 

                                -

                                -

                                -

                                -

                                -

       12

Pension / Postretirement Benefits

 

 

                                -

                                -

                                -

                                -

                                -

       13

Environmental Liability

 

 

                                -

                                -

                                -

                                -

                                -

       14

Interest Rate Hedge

 

 

                                -

                                -

                                -

                                -

                                -

       15

Customer Advances

 

 

                                -

                                -

                                -

                                -

                                -

       16

Excess Tax Depreciation / Other Property

          (13,207,310)

                                -

                                -

          (13,207,310)

          (13,207,310)

          (12,071,806)

          (25,279,116)

       17

Net Operating Loss

 

 

 

                                -

               3,587,409

                                -

               3,587,409

       18

Total Electric

          (13,207,310)

                                -

                                -

          (13,207,310)

            (9,619,901)

          (12,071,806)

          (21,691,707)

       19

Gas:

             

       20

Regulatory Assets / Liabilities

 

 

                (238,951)

                (238,951)

                (238,951)

                                -

                (238,951)

       21

Unbilled Revenue

 

 

                                -

                                -

                  237,268

                                -

                  237,268

       22

Compensation Accruals

 

 

                                -

                                -

                  895,742

                                -

                  895,742

       23

Reserves & Accruals

 

 

                                -

                                -

                     66,862

                                -

                     66,862

       24

Intangible amortization

 

 

                                -

                                -

                                -

                                -

                                -

       25

Pension / Postretirement Benefits

 

 

                                -

                                -

                  (67,853)

                                -

                  (67,853)

       26

Environmental Liability

 

 

                                -

                                -

                  491,773

                                -

                  491,773

       27

Interest Rate Hedge

 

 

                                -

                                -

                                -

                                -

                                -

       28

Customer Advances

 

 

                                -

                                -

                                -

                                -

                                -

       29

Excess Tax Depreciation / Other Property

                  644,161

            (1,202,150)

                                -

                (557,989)

                (557,989)

            (1,949,378)

            (2,507,367)

       30

Net Operating Loss

 

 

 

                                -

                (143,211)

                                -

                (143,211)

       31

Total Gas

                  644,161

            (1,202,150)

                (238,951)

                (796,940)

                  683,641

            (1,949,378)

            (1,265,737)

       32

Other (Specify)

                                -

                                -

                       1,719

                       1,719

                  131,649

                                -

                  131,649

       33

Subtotal

          (12,563,149)

            (1,202,150)

                (237,232)

          (14,002,531)

            (8,804,611)

          (14,021,184)

          (22,825,795)

       34

Gross-up

            (3,339,570)

                (319,559)

                  (63,061)

            (3,722,190)

            (2,340,465)

            (3,727,151)

            (6,067,616)

       35

Total

          (15,902,719)

            (1,521,709)

                (300,293)

          (17,724,721)

          (11,145,076)

          (17,748,335)

          (28,893,411)

       36

               

       37

Other (Specify)

             

       38

QF Obligations

                                -

                                -

                                -

                                -

                                -

                                -

                                -

       39

NOL Carryforward

                                -

                                -

                                -

                                -

                                -

                                -

                                -

       40

AMT Credit Carryforward

                                -

                                -

                                -

                                -

                                -

                                -

                                -

       41

Production Tax Credit

                                -

                                -

                                -

                                -

                                -

                                -

                                -

       42

Regulatory Assets / Liabilities

                                -

                                -

                                -

                                -

                                -

                                -

                                -

       43

Other, net

                                -

                                -

                       1,719

                       1,719

                  131,649

                                -

                  131,649

       44

Total

                                -

                                -

                       1,719

                       1,719

                  131,649

                                -

                  131,649

       45

               

       46

               

       47

 

12/31/2025

       48

 

Protected

Unprotected

Unprotected

   

Normalizing EDIT

 

       49

TCJA Excess ADIT Account Reduced

282

282

283

Subtotal

Total of 182.3

Subtotal

282

       50

Reg Asset Acccount Impacted

254

254

254

254

and 254

182.3

254

       51

Electric:

             

       52

Regulatory Assets / Liabilities

 

 

                                -

                                -

                                -

                                -

                                -

       53

Unbilled Revenue

 

 

                                -

                                -

                                -

                                -

                                -

       54

Compensation Accruals

 

 

                                -

                                -

                                -

                                -

                                -

       55

Reserves & Accruals

 

 

                                -

                                -

                                -

                                -

                                -

       56

Intangible amortization

 

 

                                -

                                -

                                -

                                -

                                -

       57

Pension / Postretirement Benefits

 

 

                                -

                                -

                                -

                                -

                                -

       58

Environmental Liability

 

 

                                -

                                -

                                -

                                -

                                -

       59

Interest Rate Hedge

 

 

                                -

                                -

                                -

                                -

                                -

       60

Customer Advances

 

 

                                -

                                -

                                -

                                -

                                -

       61

Excess Tax Depreciation / Other Property

          (12,617,212)

                                -

                                -

          (12,617,212)

          (12,617,212)

          (11,606,963)

          (24,224,175)

       62

Net Operating Loss

 

 

 

                                -

               3,449,271

                                -

               3,449,271

       63

Total Electric

          (12,617,212)

                                -

                                -

          (12,617,212)

            (9,167,941)

          (11,606,963)

          (20,774,904)

       64

Gas:

             

       65

Regulatory Assets / Liabilities

 

 

                (223,021)

                (223,021)

                (223,021)

                                -

                (223,021)

       66

Unbilled Revenue

 

 

                                -

                                -

                                -

                                -

                                -

       67

Compensation Accruals

 

 

                                -

                                -

                  836,026

                                -

                  836,026

       68

Reserves & Accruals

 

 

                                -

                                -

                     62,404

                                -

                     62,404

       69

Intangible amortization

 

 

                                -

                                -

                                -

                                -

                                -

       70

Pension / Postretirement Benefits

 

 

                                -

                                -

                  (63,329)

                                -

                  (63,329)

       71

Environmental Liability

 

 

                                -

                                -

                  458,988

                                -

                  458,988

       72

Interest Rate Hedge

 

 

                                -

                                -

                                -

                                -

                                -

       73

Customer Advances

 

 

                                -

                                -

                                -

                                -

                                -

       74

Excess Tax Depreciation / Other Property

                  725,178

            (1,155,912)

                                -

                (430,734)

                (430,734)

            (1,874,314)

            (2,305,048)

       75

Net Operating Loss

 

 

 

                                -

                (137,698)

                                -

                (137,698)

       76

Total Gas

                  725,178

            (1,155,912)

                (223,021)

                (653,755)

                  502,636

            (1,874,314)

            (1,371,678)

       77

Other (Specify)

                                -

                                -

                       1,604

                       1,604

                  122,872

                                -

                  122,872

       78

Subtotal

          (11,892,034)

            (1,155,912)

                (221,417)

          (13,269,363)

            (8,542,433)

          (13,481,277)

          (22,023,710)

       79

Gross-up

            (3,161,174)

                (307,267)

                  (58,858)

            (3,527,299)

            (2,270,775)

            (3,583,631)

            (5,854,406)

       80

Total

          (15,053,208)

            (1,463,179)

                (280,275)

          (16,796,662)

          (10,813,208)

          (17,064,908)

          (27,878,116)

       81

               

       82

Other (Specify)

             

       83

QF Obligations

                                -

                                -

                                -

                                -

                                -

                                -

                                -

       84

NOL Carryforward

                                -

                                -

                                -

                                -

                                -

                                -

                                -

       85

AMT Credit Carryforward

                                -

                                -

                                -

                                -

                                -

                                -

                                -

       86

Production Tax Credit

                                -

                                -

                                -

                                -

                                -

                                -

                                -

       87

Regulatory Assets / Liabilities

                                -

                                -

                                -

                                -

                                -

                                -

                                -

       88

Other, net

                                -

                                -

                       1,604

                       1,604

                  122,872

                                -

                  122,872

       89

Total

                                -

                                -

                       1,604

                       1,604

                  122,872

                                -

                  122,872

       90

               

       91

               

Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
Electric Operating Revenues
  1. The following instructions generally apply to the annual version of these pages. Do not report quarterly data in columns (c), (e), (f), and (g). Unbilled revenues and MWH related to unbilled revenues need not be reported separately as required in the annual version of these pages.
  2. Report below operating revenues for each prescribed account, and manufactured gas revenues in total.
  3. Report number of customers, columns (f) and (g), on the basis of meters, in addition to the number of flat rate accounts; except that where separate meter readings are added for billing purposes, one customer should be counted for each group of meters added. The average number of customers means the average of twelve figures at the close of each month.
  4. If increases or decreases from previous period (columns (c),(e), and (g)), are not derived from previously reported figures, explain any inconsistencies in a footnote.
  5. Disclose amounts of $250,000 or greater in a footnote for accounts 451, 456, and 457.2.
  6. Commercial and industrial Sales, Account 442, may be classified according to the basis of classification (Small or Commercial, and Large or Industrial) regularly used by the respondent if such basis of classification is not generally greater than 1000 Kw of demand. (See Account 442 of the Uniform System of Accounts. Explain basis of classification in a footnote.)
  7. See page 108, Important Changes During Period, for important new territory added and important rate increase or decreases.
  8. For Lines 2,4,5,and 6, see Page 304 for amounts relating to unbilled revenue by accounts.
  9. Include unmetered sales. Provide details of such Sales in a footnote.
Line No.
Title of Account
(a)
Operating Revenues Year to Date Quarterly/Annual
(b)
Operating Revenues Previous year (no Quarterly)
(c)
MEGAWATT HOURS SOLD Year to Date Quarterly/Annual
(d)
MEGAWATT HOURS SOLD Amount Previous year (no Quarterly)
(e)
AVG.NO. CUSTOMERS PER MONTH Current Year (no Quarterly)
(f)
AVG.NO. CUSTOMERS PER MONTH Previous Year (no Quarterly)
(g)
1
SalesOfElectricityHeadingAbstract
Sales of Electricity
2
ResidentialSalesAbstract
(440) Residential Sales
77,894,264
70,012,031
583,439
557,457
51,787
51,467
3
CommercialAndIndustrialSalesAbstract
(442) Commercial and Industrial Sales
4
CommercialSalesAbstract
Small (or Comm.) (See Instr. 4)
85,934,154
77,064,550
674,554
654,020
13,132
13,024
5
IndustrialSalesAbstract
Large (or Ind.) (See Instr. 4)
34,174,000
34,748,000
386,156
438,660
58
60
6
PublicStreetAndHighwayLightingAbstract
(444) Public Street and Highway Lighting
2,554,620
2,400,327
5,478
8,062
146
146
7
OtherSalesToPublicAuthoritiesAbstract
(445) Other Sales to Public Authorities
923,894
873,897
6,621
6,752
273
274
8
SalesToRailroadsAndRailwaysAbstract
(446) Sales to Railroads and Railways
9
InterdepartmentalSalesAbstract
(448) Interdepartmental Sales
10
SalesToUltimateConsumersAbstract
TOTAL Sales to Ultimate Consumers
201,480,931
185,098,805
1,656,248
1,664,951
65,396
64,971
11
SalesForResaleAbstract
(447) Sales for Resale
12
SalesOfElectricityAbstract
TOTAL Sales of Electricity
201,480,931
185,098,805
13
ProvisionForRateRefundsAbstract
(Less) (449.1) Provision for Rate Refunds
14
RevenuesNetOfProvisionForRefundsAbstract
TOTAL Revenues Before Prov. for Refunds
201,480,931
185,098,805
15
OtherOperatingRevenuesAbstract
Other Operating Revenues
16
ForfeitedDiscounts
(450) Forfeited Discounts
473,048
431,605
17
MiscellaneousServiceRevenues
(451) Miscellaneous Service Revenues
206,529
205,806
18
SalesOfWaterAndWaterPower
(453) Sales of Water and Water Power
19
RentFromElectricProperty
(454) Rent from Electric Property
182,637
189,559
20
InterdepartmentalRents
(455) Interdepartmental Rents
21
OtherElectricRevenue
(456) Other Electric Revenues
(a)
898,897
720,595
22
RevenuesFromTransmissionOfElectricityOfOthers
(456.1) Revenues from Transmission of Electricity of Others
7,473,258
6,991,223
23
RegionalTransmissionServiceRevenues
(457.1) Regional Control Service Revenues
24
MiscellaneousRevenue
(457.2) Miscellaneous Revenues
25
OtherMiscellaneousOperatingRevenues
Other Miscellaneous Operating Revenues
26
OtherOperatingRevenues
TOTAL Other Operating Revenues
9,234,369
8,538,788
27
ElectricOperatingRevenues
TOTAL Electric Operating Revenues
210,715,300
193,637,593
Line12, column (b) includes $
of unbilled revenues.
Line12, column (d) includes
MWH relating to unbilled revenues


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
FOOTNOTE DATA

(a) Concept: OtherElectricRevenue

YTD Dec

YTD Dec

YTD Dec

Total Electric Revenue

2025

2024

Steam Sales

808,197

699,779

Sale of Materials

21,670

19,495

Miscellaneous

69,030

1,321

 

898,897

720,595


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
REGIONAL TRANSMISSION SERVICE REVENUES (Account 457.1)
  1. The respondent shall report below the revenue collected for each service (i.e., control area administration, market administration, etc.) performed pursuant to a Commission approved tariff. All amounts separately billed must be detailed below.
Line No.
Description of Service
(a)
Balance at End of Quarter 1
(b)
Balance at End of Quarter 2
(c)
Balance at End of Quarter 3
(d)
Balance at End of Year
(e)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
TOTAL


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
SALES OF ELECTRICITY BY RATE SCHEDULES
  1. Report below for each rate schedule in effect during the year the MWH of electricity sold, revenue, average number of customer, average Kwh per customer, and average revenue per Kwh, excluding date for Sales for Resale which is reported on Page 310.
  2. Provide a subheading and total for each prescribed operating revenue account in the sequence followed in "Electric Operating Revenues," Page 300. If the sales under any rate schedule are classified in more than one revenue account, list the rate schedule and sales data under each applicable revenue account subheading.
  3. Where the same customers are served under more than one rate schedule in the same revenue account classification (such as a general residential schedule and an off peak water heating schedule), the entries in column (d) for the special schedule should denote the duplication in number of reported customers.
  4. The average number of customers should be the number of bills rendered during the year divided by the number of billing periods during the year (12 if all billings are made monthly).
  5. For any rate schedule having a fuel adjustment clause state in a footnote the estimated additional revenue billed pursuant thereto.
  6. Report amount of unbilled revenue as of end of year for each applicable revenue account subheading.
Line No.
Number and Title of Rate Schedule
(a)
MWh Sold
(b)
Revenue
(c)
Average Number of Customers
(d)
KWh of Sales Per Customer
(e)
Revenue Per KWh Sold
(f)
1
SD 10 Residential
392,304
55,760,672
39,375
9,963
0.1421
2
SD 11 Residential
177,393
20,815,473
11,350
15,629
0.1173
3
SD 14 Resid Space Htg 2 Meters
13,224
1,031,193
1,019
12,977
0.078
4
SD 15 Residential Dual-Fuel
72
5,401
7
10,320
0.0748
5
SD 95 Reddy Guard
446
281,525
36
12,401
0.6306
41 TOTAL Billed Residential Sales
583,439
77,894,264
51,787
11,266
0.1335
42 TOTAL Unbilled Rev. (See Instr. 6)
43 TOTAL
583,439
77,894,264
51,787
11,266
0.1335


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
SALES OF ELECTRICITY BY RATE SCHEDULES
  1. Report below for each rate schedule in effect during the year the MWH of electricity sold, revenue, average number of customer, average Kwh per customer, and average revenue per Kwh, excluding date for Sales for Resale which is reported on Page 310.
  2. Provide a subheading and total for each prescribed operating revenue account in the sequence followed in "Electric Operating Revenues," Page 300. If the sales under any rate schedule are classified in more than one revenue account, list the rate schedule and sales data under each applicable revenue account subheading.
  3. Where the same customers are served under more than one rate schedule in the same revenue account classification (such as a general residential schedule and an off peak water heating schedule), the entries in column (d) for the special schedule should denote the duplication in number of reported customers.
  4. The average number of customers should be the number of bills rendered during the year divided by the number of billing periods during the year (12 if all billings are made monthly).
  5. For any rate schedule having a fuel adjustment clause state in a footnote the estimated additional revenue billed pursuant thereto.
  6. Report amount of unbilled revenue as of end of year for each applicable revenue account subheading.
Line No.
Number and Title of Rate Schedule
(a)
MWh Sold
(b)
Revenue
(c)
Average Number of Customers
(d)
KWh of Sales Per Customer
(e)
Revenue Per KWh Sold
(f)
1
SD 16 Inter Irrigation
791
127,414
70
11,298
0.1611
2
SD 17 Irrigation Power
308
58,137
18
17,097
0.1889
3
SD 21 General Service
72,634
13,024,447
8,859
8,199
0.1793
4
SD 23 Comm Water Heat
601
64,510
56
10,731
0.1074
5
SD 24 Comm Space Heat
40,935
3,307,154
596
68,683
0.0808
6
SD 25 Comm Heating
36,048
4,172,851
750
48,064
0.1158
7
SD 33 Industrial Power
167,072
25,697,222
2,156
77,492
0.1538
8
SD 34 Industrial Power
353,798
38,487,401
432
818,977
0.1088
9
SD 70 Controlled Off-Peak
1,165
140,863
4
291,306
0.1209
10
SD 95 Reddy Guard
1,202
612,040
173
6,949
0.5091
11
Small Qual Facility Rider 38 P to P
242,115
18
0
0
41 TOTAL Billed Small or Commercial
674,554
85,934,154
13,132
51,367
0.1274
42 TOTAL Unbilled Rev. Small or Commercial (See Instr. 6)
43 TOTAL Small or Commercial
674,554
85,934,154
13,132
51,367
0.1274


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
SALES OF ELECTRICITY BY RATE SCHEDULES
  1. Report below for each rate schedule in effect during the year the MWH of electricity sold, revenue, average number of customer, average Kwh per customer, and average revenue per Kwh, excluding date for Sales for Resale which is reported on Page 310.
  2. Provide a subheading and total for each prescribed operating revenue account in the sequence followed in "Electric Operating Revenues," Page 300. If the sales under any rate schedule are classified in more than one revenue account, list the rate schedule and sales data under each applicable revenue account subheading.
  3. Where the same customers are served under more than one rate schedule in the same revenue account classification (such as a general residential schedule and an off peak water heating schedule), the entries in column (d) for the special schedule should denote the duplication in number of reported customers.
  4. The average number of customers should be the number of bills rendered during the year divided by the number of billing periods during the year (12 if all billings are made monthly).
  5. For any rate schedule having a fuel adjustment clause state in a footnote the estimated additional revenue billed pursuant thereto.
  6. Report amount of unbilled revenue as of end of year for each applicable revenue account subheading.
Line No.
Number and Title of Rate Schedule
(a)
MWh Sold
(b)
Revenue
(c)
Average Number of Customers
(d)
KWh of Sales Per Customer
(e)
Revenue Per KWh Sold
(f)
1
SD 34 Large Industrial
386,156
34,174,000
58
6,657,862
0.0885
41 TOTAL Billed Large (or Ind.) Sales
386,156
34,174,000
58
6,657,862
0.0885
42 TOTAL Unbilled Rev. Large (or Ind.) (See Instr. 6)
43 TOTAL Large (or Ind.)
386,156
34,174,000
58
6,657,862
0.0885


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
SALES OF ELECTRICITY BY RATE SCHEDULES
  1. Report below for each rate schedule in effect during the year the MWH of electricity sold, revenue, average number of customer, average Kwh per customer, and average revenue per Kwh, excluding date for Sales for Resale which is reported on Page 310.
  2. Provide a subheading and total for each prescribed operating revenue account in the sequence followed in "Electric Operating Revenues," Page 300. If the sales under any rate schedule are classified in more than one revenue account, list the rate schedule and sales data under each applicable revenue account subheading.
  3. Where the same customers are served under more than one rate schedule in the same revenue account classification (such as a general residential schedule and an off peak water heating schedule), the entries in column (d) for the special schedule should denote the duplication in number of reported customers.
  4. The average number of customers should be the number of bills rendered during the year divided by the number of billing periods during the year (12 if all billings are made monthly).
  5. For any rate schedule having a fuel adjustment clause state in a footnote the estimated additional revenue billed pursuant thereto.
  6. Report amount of unbilled revenue as of end of year for each applicable revenue account subheading.
Line No.
Number and Title of Rate Schedule
(a)
MWh Sold
(b)
Revenue
(c)
Average Number of Customers
(d)
KWh of Sales Per Customer
(e)
Revenue Per KWh Sold
(f)
1
SD 95 Public Lighting
5,478
2,554,620
146
37,523
0.4663
41 TOTAL Billed Public Street and Highway Lighting
5,478
2,554,620
146
37,523
0.4663
42 TOTAL Unbilled Rev. (See Instr. 6)
43 TOTAL
5,478
2,554,620
146
37,523
0.4663


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
SALES OF ELECTRICITY BY RATE SCHEDULES
  1. Report below for each rate schedule in effect during the year the MWH of electricity sold, revenue, average number of customer, average Kwh per customer, and average revenue per Kwh, excluding date for Sales for Resale which is reported on Page 310.
  2. Provide a subheading and total for each prescribed operating revenue account in the sequence followed in "Electric Operating Revenues," Page 300. If the sales under any rate schedule are classified in more than one revenue account, list the rate schedule and sales data under each applicable revenue account subheading.
  3. Where the same customers are served under more than one rate schedule in the same revenue account classification (such as a general residential schedule and an off peak water heating schedule), the entries in column (d) for the special schedule should denote the duplication in number of reported customers.
  4. The average number of customers should be the number of bills rendered during the year divided by the number of billing periods during the year (12 if all billings are made monthly).
  5. For any rate schedule having a fuel adjustment clause state in a footnote the estimated additional revenue billed pursuant thereto.
  6. Report amount of unbilled revenue as of end of year for each applicable revenue account subheading.
Line No.
Number and Title of Rate Schedule
(a)
MWh Sold
(b)
Revenue
(c)
Average Number of Customers
(d)
KWh of Sales Per Customer
(e)
Revenue Per KWh Sold
(f)
1
SD 41 Municipal Pumping
6,621
923,894
273
24,253
0.1395
41 TOTAL Billed Other Sales to Public Authorities
6,621
923,894
273
24,253
0.1395
42 TOTAL Unbilled Rev. (See Instr. 6)
43 TOTAL
6,621
923,894
273
24,253
0.1395


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
SALES OF ELECTRICITY BY RATE SCHEDULES
  1. Report below for each rate schedule in effect during the year the MWH of electricity sold, revenue, average number of customer, average Kwh per customer, and average revenue per Kwh, excluding date for Sales for Resale which is reported on Page 310.
  2. Provide a subheading and total for each prescribed operating revenue account in the sequence followed in "Electric Operating Revenues," Page 300. If the sales under any rate schedule are classified in more than one revenue account, list the rate schedule and sales data under each applicable revenue account subheading.
  3. Where the same customers are served under more than one rate schedule in the same revenue account classification (such as a general residential schedule and an off peak water heating schedule), the entries in column (d) for the special schedule should denote the duplication in number of reported customers.
  4. The average number of customers should be the number of bills rendered during the year divided by the number of billing periods during the year (12 if all billings are made monthly).
  5. For any rate schedule having a fuel adjustment clause state in a footnote the estimated additional revenue billed pursuant thereto.
  6. Report amount of unbilled revenue as of end of year for each applicable revenue account subheading.
Line No.
Number and Title of Rate Schedule
(a)
MWh Sold
(b)
Revenue
(c)
Average Number of Customers
(d)
KWh of Sales Per Customer
(e)
Revenue Per KWh Sold
(f)
41 TOTAL Billed - All Accounts
1,656,248
201,480,931
65,396
25,326
0.1216
42 TOTAL Unbilled Rev. (See Instr. 6) - All Accounts
43 TOTAL - All Accounts
1,656,248
201,480,931
65,396
25,326
0.1216


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
SALES FOR RESALE (Account 447)
  1. Report all sales for resale (i.e., sales to purchasers other than ultimate consumers) transacted on a settlement basis other than power exchanges during the year. Do not report exchanges of electricity ( i.e., transactions involving a balancing of debits and credits for energy, capacity, etc.) and any settlements for imbalanced exchanges on this schedule. Power exchanges must be reported on the Purchased Power schedule (Page 326).
  2. Enter the name of the purchaser in column (a). Do note abbreviate or truncate the name or use acronyms. Explain in a footnote any ownership interest or affiliation the respondent has with the purchaser.
  3. In column (b), enter a Statistical Classification Code based on the original contractual terms and conditions of the service as follows:

    RQ - for requirements service. Requirements service is service which the supplier plans to provide on an ongoing basis (i.e., the supplier includes projected load for this service in its system resource planning). In addition, the reliability of requirements service must be the same as, or second only to, the supplier's service to its own ultimate consumers.

    LF - for long-term service. "Long-term" means five years or longer and "firm" means that service cannot be interrupted for economic reasons and is intended to remain reliable even under adverse conditions (e.g., the supplier must attempt to buy emergency energy from third parties to maintain deliveries of LF service). This category should not be used for long-term firm service which meets the definition of RQ service. For all transactions identified as LF, provide in a footnote the termination date of the contract defined as the earliest date that either buyer or setter can unilaterally get out of the contract.

    IF - for intermediate-term firm service. The same as LF service except that "intermediate-term" means longer than one year but less than five years.

    SF - for short-term firm service. Use this category for all firm services where the duration of each period of commitment for service is one year or less.

    LU - for long-term service from a designated generating unit. "Long-term" means five years or longer. The availability and reliability of service, aside from transmission constraints, must match the availability and reliability of designated unit.

    IU - for intermediate-term service from a designated generating unit. The same as LU service except that "intermediate-term" means longer than one year but less than five years.

    OS - for other service. Use this category only for those services which cannot be placed in the above-defined categories, such as all non-firm service regardless of the length of the contract and service from designated units of less than one year. Describe the nature of the service in a footnote.

    AD - for out-of-period adjustment. Use this code for any accounting adjustments or "true-ups" for service provided in prior reporting years. Provide an explanation in a footnote for each adjustment.

  4. Group requirements RQ sales together and report them starting at line number one. After listing all RQ sales, enter "Subtotal - RQ" in column (a). The remaining sales may then be listed in any order. Enter "Subtotal-Non-RQ" in column (a) after this Listing. Enter "Total'' in column (a) as the last line of the schedule. Report subtotals and total for columns (g) through (k).
  5. In Column (c), identify the FERC Rate Schedule or Tariff Number. On separate lines, list all FERC rate schedules or tariffs under which service, as identified in column (b), is provided.
  6. For requirements RQ sales and any type of-service involving demand charges imposed on a monthly (or longer) basis, enter the average monthly billing demand in column (d), the average monthly non-coincident peak (NCP) demand in column (e), and the average monthly coincident peak (CP) demand in column (f). For all other types of service, enter NA in columns (d), (e) and (f). Monthly NCP demand is the maximum metered hourly (60-minute integration) demand in a month. Monthly CP demand is the metered demand during the hour (60-minute integration) in which the supplier's system reaches its monthly peak. Demand reported in columns (e) and (f) must be in megawatts. Footnote any demand not stated on a megawatt basis and explain.
  7. Report in column (g) the megawatt hours shown on bills rendered to the purchaser.
  8. Report demand charges in column (h), energy charges in column (i), and the total of any other types of charges, including out-of-period adjustments, in column (j). Explain in a footnote all components of the amount shown in column (j). Report in column (k) the total charge shown on bills rendered to the purchaser.
  9. The data in column (g) through (k) must be subtotaled based on the RQ/Non-RQ grouping (see instruction 4), and then totaled on the last line of the schedule. The "Subtotal - RQ" amount in column (g) must be reported as Requirements Sales For Resale on Page 401, line 23. The "Subtotal - Non-RQ" amount in column (g) must be reported as Non-Requirements Sales For Resale on Page 401,line 24.
  10. Footnote entries as required and provide explanations following all required data.
ACTUAL DEMAND (MW) REVENUE
Line No.
Name of Company or Public Authority (Footnote Affiliations)
(a)
Statistical Classification
(b)
FERC Rate Schedule or Tariff Number
(c)
Average Monthly Billing Demand (MW)
(d)
Average Monthly NCP Demand
(e)
Average Monthly CP Demand
(f)
Megawatt Hours Sold
(g)
Demand Charges ($)
(h)
Energy Charges ($)
(i)
Other Charges ($)
(j)
Total ($) (h+i+j)
(k)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Subtotal - RQ
16
Subtotal-Non-RQ
17 Total


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
ELECTRIC OPERATION AND MAINTENANCE EXPENSES

If the amount for previous year is not derived from previously reported figures, explain in footnote.

Line No.
Account
(a)
Amount for Current Year
(b)
Amount for Previous Year (c)
(c)
1
PowerProductionExpensesAbstract
1. POWER PRODUCTION EXPENSES
2
SteamPowerGenerationAbstract
A. Steam Power Generation
3
SteamPowerGenerationOperationAbstract
Operation
4
OperationSupervisionAndEngineeringSteamPowerGeneration
(500) Operation Supervision and Engineering
991,816
797,853
5
FuelSteamPowerGeneration
(501) Fuel
23,780,286
19,909,740
6
SteamExpensesSteamPowerGeneration
(502) Steam Expenses
1,496,329
1,326,668
7
SteamFromOtherSources
(503) Steam from Other Sources
8
SteamTransferredCredit
(Less) (504) Steam Transferred-Cr.
9
ElectricExpensesSteamPowerGeneration
(505) Electric Expenses
675,115
648,319
10
MiscellaneousSteamPowerExpenses
(506) Miscellaneous Steam Power Expenses
1,281,054
1,157,423
11
RentsSteamPowerGeneration
(507) Rents
43,772
37,478
12
Allowances
(509) Allowances
13
SteamPowerGenerationOperationsExpense
TOTAL Operation (Enter Total of Lines 4 thru 12)
28,268,372
23,877,481
14
SteamPowerGenerationMaintenanceAbstract
Maintenance
15
MaintenanceSupervisionAndEngineeringSteamPowerGeneration
(510) Maintenance Supervision and Engineering
299,598
369,992
16
MaintenanceOfStructuresSteamPowerGeneration
(511) Maintenance of Structures
387,923
337,820
17
MaintenanceOfBoilerPlantSteamPowerGeneration
(512) Maintenance of Boiler Plant
3,472,424
2,752,687
18
MaintenanceOfElectricPlantSteamPowerGeneration
(513) Maintenance of Electric Plant
820,221
306,593
18.1
MaintenanceOfComputerHardwareSteamPowerGeneration
(513.1) Maintenance of Computer Hardware
18.2
MaintenanceOfComputerSoftwareSteamPowerGeneration
(513.2) Maintenance of Computer Software
18.3
MaintenanceOfCommunicationEquipmentSteamPowerGeneration
(513.3) Maintenance of Communication Equipment
19
MaintenanceOfMiscellaneousSteamPlant
(514) Maintenance of Miscellaneous Steam Plant
575,121
475,329
20
SteamPowerGenerationMaintenanceExpense
TOTAL Maintenance (Enter Total of Lines 15 thru 19)
5,555,287
4,242,421
21
PowerProductionExpensesSteamPower
TOTAL Power Production Expenses-Steam Power (Enter Total of Lines 13 & 20)
33,823,659
28,119,902
22
NuclearPowerGenerationAbstract
B. Nuclear Power Generation
23
NuclearPowerGenerationOperationAbstract
Operation
24
OperationSupervisionAndEngineeringNuclearPowerGeneration
(517) Operation Supervision and Engineering
25
NuclearFuelExpense
(518) Fuel
26
CoolantsAndWater
(519) Coolants and Water
27
SteamExpensesNuclearPowerGeneration
(520) Steam Expenses
28
SteamFromOtherSourcesNuclearPowerGeneration
(521) Steam from Other Sources
29
SteamTransferredCreditNuclearPowerGeneration
(Less) (522) Steam Transferred-Cr.
30
ElectricExpensesNuclearPowerGeneration
(523) Electric Expenses
31
MiscellaneousNuclearPowerExpenses
(524) Miscellaneous Nuclear Power Expenses
32
RentsNuclearPowerGeneration
(525) Rents
33
NuclearPowerGenerationOperationsExpense
TOTAL Operation (Enter Total of lines 24 thru 32)
34
NuclearPowerGenerationMaintenanceAbstract
Maintenance
35
MaintenanceSupervisionAndEngineeringNuclearPowerGeneration
(528) Maintenance Supervision and Engineering
36
MaintenanceOfStructuresNuclearPowerGeneration
(529) Maintenance of Structures
37
MaintenanceOfReactorPlantEquipmentNuclearPowerGeneration
(530) Maintenance of Reactor Plant Equipment
38
MaintenanceOfElectricPlantNuclearPowerGeneration
(531) Maintenance of Electric Plant
38.1
MaintenanceOfComputerHardwareNuclearPowerGeneration
(531.1) Maintenance of Computer Hardware
38.2
MaintenanceOfComputerSoftwareNuclearPowerGeneration
(531.2) Maintenance of Computer Software
38.3
MaintenanceOfCommunicationEquipmentNuclearPowerGeneration
(531.3) Maintenance of Communication Equipment
39
MaintenanceOfMiscellaneousNuclearPlant
(532) Maintenance of Miscellaneous Nuclear Plant
40
NuclearPowerGenerationMaintenanceExpense
TOTAL Maintenance (Enter Total of lines 35 thru 39)
41
PowerProductionExpensesNuclearPower
TOTAL Power Production Expenses-Nuclear. Power (Enter Total of lines 33 & 40)
42
HydraulicPowerGenerationAbstract
C. Hydraulic Power Generation
43
HydraulicPowerGenerationOperationAbstract
Operation
44
OperationSupervisionAndEngineeringHydraulicPowerGeneration
(535) Operation Supervision and Engineering
45
WaterForPower
(536) Water for Power
46
HydraulicExpenses
(537) Hydraulic Expenses
47
ElectricExpensesHydraulicPowerGeneration
(538) Electric Expenses
48
MiscellaneousHydraulicPowerGenerationExpenses
(539) Miscellaneous Hydraulic Power Generation Expenses
49
RentsHydraulicPowerGeneration
(540) Rents
50
HydraulicPowerGenerationOperationsExpense
TOTAL Operation (Enter Total of Lines 44 thru 49)
51
HydraulicPowerGenerationContinuedAbstract
C. Hydraulic Power Generation (Continued)
52
HydraulicPowerGenerationMaintenanceAbstract
Maintenance
53
MaintenanceSupervisionAndEngineeringHydraulicPowerGeneration
(541) Maintenance Supervision and Engineering
54
MaintenanceOfStructuresHydraulicPowerGeneration
(542) Maintenance of Structures
55
MaintenanceOfReservoirsDamsAndWaterways
(543) Maintenance of Reservoirs, Dams, and Waterways
56
MaintenanceOfElectricPlantHydraulicPowerGeneration
(544) Maintenance of Electric Plant
56.1
MaintenanceOfComputerHardwareHydraulicPowerGeneration
(544.1) Maintenance of Computer Hardware
56.2
MaintenanceOfComputerSoftwareHydraulicPowerGeneration
(544.2) Maintenance of Computer Software
56.3
MaintenanceOfCommunicationEquipmentHydraulicPowerGeneration
(544.3) Maintenance of Communication Equipment
57
MaintenanceOfMiscellaneousHydraulicPlant
(545) Maintenance of Miscellaneous Hydraulic Plant
58
HydraulicPowerGenerationMaintenanceExpense
TOTAL Maintenance (Enter Total of lines 53 thru 57)
59
PowerProductionExpensesHydraulicPower
TOTAL Power Production Expenses-Hydraulic Power (Total of Lines 50 & 58)
60
OtherPowerGenerationAbstract
D. Other Power Generation
61
OtherPowerGenerationOperationAbstract
Operation
62
OperationSupervisionAndEngineeringOtherPowerGeneration
(546) Operation Supervision and Engineering
54,366
124,354
63
Fuel
(547) Fuel
4,957,642
4,674,299
64
GenerationExpenses
(548) Generation Expenses
2,072,907
4,801,586
65
MiscellaneousOtherPowerGenerationExpenses
(549) Miscellaneous Other Power Generation Expenses
455,772
66
RentsOtherPowerGeneration
(550) Rents
67
OtherPowerGenerationOperationsExpense
TOTAL Operation (Enter Total of Lines 62 thru 67)
7,084,915
10,056,011
68
OtherPowerGenerationMaintenanceAbstract
Maintenance
69
MaintenanceSupervisionAndEngineeringOtherPowerGeneration
(551) Maintenance Supervision and Engineering
54,673
46,829
70
MaintenanceOfStructures
(552) Maintenance of Structures
71
MaintenanceOfGeneratingAndElectricPlant
(553) Maintenance of Generating and Electric Plant
1,818,569
1,325,699
71.1
MaintenanceOfComputerHardwareOtherPowerGeneration
(553.1) Maintenance of Computer Hardware
71.2
MaintenanceOfComputerSoftwareOtherPowerGeneration
(553.2) Maintenance of Computer Software
120,060
71.3
MaintenanceOfCommunicationEquipmentOtherPowerGeneration
(553.3) Maintenance of Communication Equipment
895
72
MaintenanceOfMiscellaneousOtherPowerGenerationPlant
(554) Maintenance of Miscellaneous Other Power Generation Plant
33,765
73
OtherPowerGenerationMaintenanceExpense
TOTAL Maintenance (Enter Total of Lines 69 thru 72)
1,994,197
1,406,293
74
PowerProductionExpensesOtherPower
TOTAL Power Production Expenses-Other Power (Enter Total of Lines 67 & 73)
9,079,112
11,462,304
75
OtherPowerSuplyExpensesAbstract
E. Other Power Supply Expenses
76
PurchasedPower
(555) Purchased Power
16,641,666
19,278,652
76.1
PowerPurchasedForStorageOperations
(555.1) Power Purchased for Storage Operations
76.2
BundledEnvironmentalCredits
(555.2) Bundled Environmental Credits
76.3
UnbundledEnvironmentalCredits
(555.3) Unbundled Environmental Credits
77
SystemControlAndLoadDispatchingElectric
(556) System Control and Load Dispatching
373,968
264,838
78
OtherExpensesOtherPowerSupplyExpenses
(557) Other Expenses
588,364
2,434,072
79
OtherPowerSupplyExpense
TOTAL Other Power Supply Exp (Enter Total of Lines 76 thru 78)
16,427,270
17,109,418
79.1
SolarGenerationAbstract
F. Solar Generation
79.2
SolarGenerationOperationAbstract
Operation
79.3
OperationSupervisionAndEngineeringSolarGeneration
(558.1) Operation Supervision and Engineering
79.4
SolarPanelGenerationAndOtherPlantOperatingExpensesSolarGeneration
(558.2) Solar Panel Generation and Other Plant Operating Expenses
79.6
RentsSolarGeneration
(558.4) Rents
79.7
SolarGenerationOperationsExpense
TOTAL Operation (Enter Total of lines 79.3 thru 79.6)
79.8
SolarGenerationMaintenanceAbstract
Maintenance
79.9
MaintenanceSupervisionAndEngineeringSolarGeneration
(558.6) Maintenance Supervision and Engineering
79.10
MaintenanceOfSolarPanelsStructuresAndEquipmentSolarGeneration
(558.7) Maintenance of Solar Panels, Structures, and Equipment
79.11
MaintenanceOfComputerHardwareSolarGeneration
(558.8) Maintenance of Computer Hardware
79.12
MaintenanceOfComputerSoftwareSolarGeneration
(558.9) Maintenance of Computer Software
79.13
MaintenanceOfCommunicationEquipmentSolarGeneration
(558.10) Maintenance of Communication Equipment
79.14
MaintenanceOfMiscellaneousSolarGenerationPlant
(558.11) Maintenance of Miscellaneous Solar Generation Plant
79.15
SolarGenerationMaintenanceExpense
TOTAL Maintenance (Enter Total of lines 79.9 thru 79.14)
79.16
PowerProductionExpensesSolar
TOTAL Power Production Expenses-Solar (total of lines 79.7 & 79.15)
79.17
WindGenerationAbstract
G. Wind Generation
79.18
WindGenerationOperationAbstract
Operation
79.19
OperationSupervisionAndEngineeringWindGeneration
(558.13) Operation Supervision and Engineering
103,515
79.20
WindTurbineGenerationAndOtherPlantOperatingExpensesWindGeneration
(558.14) Wind Turbine Generation and Other Plant Operating Expenses
2,834,524
79.21
RentsWindGeneration
(558.16) Rents
428,630
79.22
WindGenerationOperationsExpense
TOTAL Operation (Enter Total of lines 79.19 thru 79.21)
3,366,669
79.23
WindGenerationMaintenanceAbstract
Maintenance
79.24
MaintenanceSupervisionAndEngineeringWindGeneration
(558.18) Maintenance Supervision and Engineering
79.25
MaintenanceOfWindTurbinesStructuresAndEquipmentWindGeneration
(558.19) Maintenance of Wind Turbines, Structures, and Equipment
193,092
79.26
MaintenanceOfComputerHardwareWindGeneration
(558.20) Maintenance of Computer Hardware
79.27
MaintenanceOfComputerSoftwareWindGeneration
(558.21) Maintenance of Computer Software
2,923
79.28
MaintenanceOfCommunicationEquipmentWindGeneration
(558.22) Maintenance of Communication Equipment
3,889
79.29
MaintenanceOfMiscellaneousWindGenerationPlant
(558.23) Maintenance of Miscellaneous Wind Generation Plant
8,383
79.30
WindGenerationMaintenanceExpense
TOTAL Maintenance (Enter Total of lines 79.24 thru 79.29)
208,287
79.31
PowerProductionExpensesWind
TOTAL Power Production Expenses-Wind (total of lines 79.22 & 79.30)
3,574,956
79.32
OtherRenewableGenerationAbstract
H. Other Renewable Generation
79.33
OtherRenewableGenerationOperationAbstract
Operation
79.34
OperationSupervisionAndEngineeringOtherRenewableGeneration
(559.1) Operation Supervision and Engineering
79.35
OtherMiscellaneousGenerationAndOtherPlantOperatingExpensesOtherRenewableGeneration
(559.2) Other Miscellaneous Generation and Other Plant Operating Expenses
79.36
FuelOtherRenewableGeneration
(559.3) Fuel
79.37
RentsOtherRenewableGeneration
(559.4) Rents
79.38
OtherRenewableGenerationOperationsExpense
TOTAL Operation (Enter Total of lines 79.34 thru 79.37)
79.39
OtherRenewableGenerationMaintenanceAbstract
Maintenance
79.40
MaintenanceSupervisionAndEngineeringOtherRenewableGeneration
(559.6) Maintenance Supervision and Engineering
79.41
MaintenanceOfStructuresOtherRenewableGeneration
(559.7) Maintenance of Structures
79.42
MaintenanceOfBoilersOtherRenewableGeneration
(559.9) Maintenance of Boilers
79.43
MaintenanceOfGeneratingAndElectricEquipmentOtherRenewableGeneration
(559.10) Maintenance of Generating and Electric Equipment
79.44
MaintenanceOfComputerHardwareOtherRenewableGeneration
(559.12) Maintenance of Computer Hardware
79.45
MaintenanceOfComputerSoftwareOtherRenewableGeneration
(559.13) Maintenance of Computer Software
79.46
MaintenanceOfCommunicationEquipmentOtherRenewableGeneration
(559.14) Maintenance of Communication Equipment
79.47
MaintenanceOfMiscellaneousRenewableProductionPlantOtherRenewableGeneration
(559.15) Maintenance of Miscellaneous Renewable Production Plant
79.48
OtherRenewableGenerationMaintenanceExpense
TOTAL Maintenance (Enter Total of lines 79.40 thru 79.47)
79.49
PowerProductionExpensesOtherRenewable
TOTAL Power Production Expenses-Other Renewable (total of lines 79.38 & 79.48)
80
PowerProductionExpenses
TOTAL Power Production Expenses (Total of Lines 21, 41, 59, 74, 79, 79.16, 79.31, & 79.49)
62,904,997
56,691,624
81
TransmissionExpensesAbstract
2. TRANSMISSION EXPENSES
82
TransmissionExpensesOperationAbstract
Operation
83
OperationSupervisionAndEngineeringElectricTransmissionExpenses
(560) Operation Supervision and Engineering
271,634
201,949
85
LoadDispatchReliability
(561.1) Load Dispatch-Reliability
97,513
60,845
86
LoadDispatchMonitorAndOperateTransmissionSystem
(561.2) Load Dispatch-Monitor and Operate Transmission System
87
LoadDispatchTransmissionServiceAndScheduling
(561.3) Load Dispatch-Transmission Service and Scheduling
3,000
88
SchedulingSystemControlAndDispatchServices
(561.4) Scheduling, System Control and Dispatch Services
89
ReliabilityPlanningAndStandardsDevelopment
(561.5) Reliability, Planning and Standards Development
128,925
118,331
90
TransmissionServiceStudies
(561.6) Transmission Service Studies
91
GenerationInterconnectionStudies
(561.7) Generation Interconnection Studies
92
ReliabilityPlanningAndStandardsDevelopmentServices
(561.8) Reliability, Planning and Standards Development Services
93
StationExpensesTransmissionExpense
(562) Station Expenses
309,335
328,545
94
OverheadLineExpense
(563) Overhead Lines Expenses
140,300
242,692
95
UndergroundLineExpensesTransmissionExpense
(564) Underground Lines Expenses
96
TransmissionOfElectricityByOthers
(565) Transmission of Electricity by Others
21,402,534
18,874,675
97
MiscellaneousTransmissionExpenses
(566) Miscellaneous Transmission Expenses
75,788
81,922
98
RentsTransmissionElectricExpense
(567) Rents
21,415
19,732
99
TransmissionOperationExpense
TOTAL Operation (Enter Total of Lines 83 thru 98)
22,447,444
19,931,691
100
TransmissionMaintenanceAbstract
Maintenance
101
MaintenanceSupervisionAndEngineeringElectricTransmissionExpenses
(568) Maintenance Supervision and Engineering
78,297
78,564
102
MaintenanceOfStructuresTransmissionExpense
(569) Maintenance of Structures
5,880
1,180
103
MaintenanceOfComputerHardwareTransmission
(569.1) Maintenance of Computer Hardware
104
MaintenanceOfComputerSoftwareTransmission
(569.2) Maintenance of Computer Software
105
MaintenanceOfCommunicationEquipmentElectricTransmission
(569.3) Maintenance of Communication Equipment
356
106
MaintenanceOfMiscellaneousRegionalTransmissionPlant
(569.4) Maintenance of Miscellaneous Regional Transmission Plant
107
MaintenanceOfStationEquipmentTransmission
(570) Maintenance of Station Equipment
35,602
60,151
108
MaintenanceOfOverheadLinesTransmission
(571) Maintenance of Overhead Lines
494,281
195,781
109
MaintenanceOfUndergroundLinesTransmission
(572) Maintenance of Underground Lines
1,815
110
MaintenanceOfMiscellaneousTransmissionPlant
(573) Maintenance of Miscellaneous Transmission Plant
111
TransmissionMaintenanceExpenseElectric
TOTAL Maintenance (Total of Lines 101 thru 110)
545,027
335,676
112
TransmissionExpenses
TOTAL Transmission Expenses (Total of Lines 99 and 111)
22,992,471
20,267,367
113
RegionalMarketExpensesAbstract
3. REGIONAL MARKET EXPENSES
114
RegionalMarketExpensesOperationAbstract
Operation
115
OperationSupervision
(575.1) Operation Supervision
116
DayAheadAndRealTimeMarketAdministration
(575.2) Day-Ahead and Real-Time Market Facilitation
355,371
355,300
117
TransmissionRightsMarketAdministration
(575.3) Transmission Rights Market Facilitation
118
CapacityMarketAdministration
(575.4) Capacity Market Facilitation
119
AncillaryServicesMarketAdministration
(575.5) Ancillary Services Market Facilitation
101,535
101,515
120
MarketMonitoringAndCompliance
(575.6) Market Monitoring and Compliance
50,767
50,757
121
MarketFacilitationMonitoringAndComplianceServices
(575.7) Market Facilitation, Monitoring and Compliance Services
122
RentsRegionalMarketExpenses
(575.8) Rents
123
RegionalMarketOperationExpense
Total Operation (Lines 115 thru 122)
507,673
507,572
124
RegionalMarketExpensesMaintenanceAbstract
Maintenance
125
MaintenanceOfStructuresAndImprovementsRegionalMarketExpenses
(576.1) Maintenance of Structures and Improvements
126
MaintenanceOfComputerHardware
(576.2) Maintenance of Computer Hardware
127
MaintenanceOfComputerSoftware
(576.3) Maintenance of Computer Software
128
MaintenanceOfCommunicationEquipmentRegionalMarketExpenses
(576.4) Maintenance of Communication Equipment
129
MaintenanceOfMiscellaneousMarketOperationPlant
(576.5) Maintenance of Miscellaneous Market Operation Plant
130
RegionalMarketMaintenanceExpense
Total Maintenance (Lines 125 thru 129)
131
RegionalMarketExpenses
TOTAL Regional Transmission and Market Operation Expenses (Enter Total of Lines 123 and 130)
507,673
507,572
131.1
EnergyStorageExpensesAbstract
4. ENERGY STORAGE EXPENSES
131.2
EnergyStorageExpensesOperationAbstract
Operation
131.3
OperationSupervisionAndEngineeringEnergyStorageExpenses
(577.1) Operation Supervision and Engineering
131.4
OperationOfEnergyStorageEquipmentEnergyStorageExpense
(577.2) Operation of Energy Storage Equipment
131.5
StorageFuelEnergyStorageExpense
(577.3) Storage Fuel
131.6
RentsEnergyStorageExpense
(577.4) Rents
131.7
EnergyStorageOperationExpenses
Total Operation (Lines 131.3 thru 131.6)
131.8
EnergyStorageMaintenanceAbstract
Maintenance
131.9
MaintenanceSupervisionAndEngineeringEnergyStorageExpenses
(578.1) Maintenance Supervision and Engineering
131.10
MaintenanceOfEnergyStorageEquipmentAndStructuresEnergyStorageExpenses
(578.2) Maintenance of Energy Storage Equipment and Structures
131.11
MaintenanceOfComputerHardwareEnergyStorageExpenses
(578.3) Maintenance of Computer Hardware
131.12
MaintenanceOfComputerSoftwareEnergyStorageExpenses
(578.4) Maintenance of Computer Software
131.13
MaintenanceOfCommunicationEquipmentEnergyStorageExpenses
(578.5) Maintenance of Communication Equipment
131.14
MaintenanceOfMiscellaneousOtherEnergyStoragePlantEnergyStorageExpenses
(578.6) Maintenance of Miscellaneous Other Energy Storage Plant
131.15
EnergyStorageMaintenanceExpenses
Total Maintenance (Lines 131.9 thru 131.14)
131.16
EnergyStorageExpenses
TOTAL Energy Storage Expenses (Total of 131.7 and 131.15)
132
DistributionExpensesAbstract
5. DISTRIBUTION EXPENSES
133
DistributionExpensesOperationAbstract
Operation
134
OperationSupervisionAndEngineeringDistributionExpense
(580) Operation Supervision and Engineering
483,724
462,610
135
LoadDispatching
(581) Load Dispatching
136
StationExpensesDistribution
(582) Station Expenses
289,078
272,616
137
OverheadLineExpenses
(583) Overhead Line Expenses
402,751
291,024
138
UndergroundLineExpenses
(584) Underground Line Expenses
652,976
628,535
139
StreetLightingAndSignalSystemExpenses
(585) Street Lighting and Signal System Expenses
42,211
16,356
140
MeterExpenses
(586) Meter Expenses
210,296
272,087
141
CustomerInstallationsExpenses
(587) Customer Installations Expenses
233,698
173,104
142
MiscellaneousDistributionExpenses
(588) Miscellaneous Expenses
663,825
595,516
143
RentsDistributionExpense
(589) Rents
144
DistributionOperationExpensesElectric
TOTAL Operation (Enter Total of Lines 134 thru 143)
2,978,559
2,711,848
145
DistributionExpensesMaintenanceAbstract
Maintenance
146
MaintenanceSupervisionAndEngineering
(590) Maintenance Supervision and Engineering
264,400
278,163
147
MaintenanceOfStructuresDistributionExpense
(591) Maintenance of Structures
148
MaintenanceOfStationEquipment
(592) Maintenance of Station Equipment
98,007
107,921
148.1
MaintenanceOfComputerHardwareDistribution
(592.2) Maintenance of Computer Hardware
148.2
MaintenanceOfComputerSoftwareDistribution
(592.3) Maintenance of Computer Software
6,394
148.3
MaintenanceOfCommunicationEquipmentDistribution
(592.4) Maintenance of Communication Equipment
11,498
149
MaintenanceOfOverheadLines
(593) Maintenance of Overhead Lines
1,745,057
1,732,180
150
MaintenanceOfUndergroundLines
(594) Maintenance of Underground Lines
166,165
205,035
151
MaintenanceOfLineTransformers
(595) Maintenance of Line Transformers
14,204
23,928
152
MaintenanceOfStreetLightingAndSignalSystems
(596) Maintenance of Street Lighting and Signal Systems
92,116
111,767
153
MaintenanceOfMeters
(597) Maintenance of Meters
197,008
353,009
154
MaintenanceOfMiscellaneousDistributionPlant
(598) Maintenance of Miscellaneous Distribution Plant
22,446
11,833
155
DistributionMaintenanceExpenseElectric
TOTAL Maintenance (Total of Lines 146 thru 154)
2,617,295
2,823,836
156
DistributionExpenses
TOTAL Distribution Expenses (Total of Lines 144 and 155)
5,595,854
5,535,684
157
CustomerAccountsExpensesAbstract
6. CUSTOMER ACCOUNTS EXPENSES
158
CustomerAccountsExpensesOperationsAbstract
Operation
159
SupervisionCustomerAccountExpenses
(901) Supervision
160
MeterReadingExpenses
(902) Meter Reading Expenses
48,121
48,847
161
CustomerRecordsAndCollectionExpenses
(903) Customer Records and Collection Expenses
1,337,368
1,324,703
162
UncollectibleAccounts
(904) Uncollectible Accounts
324,217
97,870
163
MiscellaneousCustomerAccountsExpenses
(905) Miscellaneous Customer Accounts Expenses
49,331
50,105
164
CustomerAccountExpenses
TOTAL Customer Accounts Expenses (Enter Total of Lines 159 thru 163)
1,759,037
1,521,525
165
CustomerServiceAndInformationalExpensesAbstract
7. CUSTOMER SERVICE AND INFORMATIONAL EXPENSES
166
CustomerServiceAndInformationalExpensesOperationAbstract
Operation
167
SupervisionCustomerServiceAndInformationExpenses
(907) Supervision
168
CustomerAssistanceExpenses
(908) Customer Assistance Expenses
897,030
906,535
169
InformationalAndInstructionalAdvertisingExpenses
(909) Informational and Instructional Expenses
32,728
43,522
170
MiscellaneousCustomerServiceAndInformationalExpenses
(910) Miscellaneous Customer Service and Informational Expenses
104,566
106,116
171
CustomerServiceAndInformationExpenses
TOTAL Customer Service and Information Expenses (Total Lines 167 thru 170)
1,034,324
1,056,173
172
SalesExpenseAbstract
8. SALES EXPENSES
173
SalesExpenseOperationAbstract
Operation
174
SupervisionSalesExpense
(911) Supervision
175
DemonstratingAndSellingExpenses
(912) Demonstrating and Selling Expenses
176
AdvertisingExpenses
(913) Advertising Expenses
54,972
38,114
177
MiscellaneousSalesExpenses
(916) Miscellaneous Sales Expenses
178
SalesExpenses
TOTAL Sales Expenses (Enter Total of Lines 174 thru 177)
54,972
38,114
179
AdministrativeAndGeneralExpensesAbstract
9. ADMINISTRATIVE AND GENERAL EXPENSES
180
AdministrativeAndGeneralExpensesOperationAbstract
Operation
181
AdministrativeAndGeneralSalaries
(920) Administrative and General Salaries
4,123,736
4,524,441
182
OfficeSuppliesAndExpenses
(921) Office Supplies and Expenses
961,391
2,611,946
183
AdministrativeExpensesTransferredCredit
(Less) (922) Administrative Expenses Transferred-Credit
1,586,954
1,430,796
184
OutsideServicesEmployed
(923) Outside Services Employed
1,178,478
1,471,843
185
PropertyInsurance
(924) Property Insurance
544,051
548,950
186
InjuriesAndDamages
(925) Injuries and Damages
2,421,961
1,958,886
187
EmployeePensionsAndBenefits
(926) Employee Pensions and Benefits
3,081,794
3,438,109
188
FranchiseRequirements
(927) Franchise Requirements
189
RegulatoryCommissionExpenses
(928) Regulatory Commission Expenses
81,138
190
DuplicateChargesCredit
(929) (Less) Duplicate Charges-Cr.
191
GeneralAdvertisingExpenses
(930.1) General Advertising Expenses
101,251
79,060
192
MiscellaneousGeneralExpenses
(930.2) Miscellaneous General Expenses
(a)
542,718
619,780
193
RentsAdministrativeAndGeneralExpense
(931) Rents
11,242
71,367
194
AdministrativeAndGeneralOperationExpense
TOTAL Operation (Enter Total of Lines 181 thru 193)
11,357,184
13,974,725
195
AdministrativeAndGeneralExpensesMaintenanceAbstract
Maintenance
196
MaintenanceOfGeneralPlant
(935) Maintenance of General Plant
299,063
616,280
196.1
MaintenanceOfComputerHardwareAdministrativeAndGeneralExpenses
(935.1) Maintenance of Computer Hardware
3,211
196.2
MaintenanceOfComputerSoftwareAdministrativeAndGeneralExpenses
(935.2) Maintenance of Computer Software
1,702,104
196.3
MaintenanceOfCommunicationEquipmentAdministrativeAndGeneralExpenses
(935.3) Maintenance of Communication Equipment
422,507
196.4
AdministrativeAndGeneralMaintenanceExpenses
TOTAL Maintenance (Enter Total of lines 196 thru 196.3)
2,426,886
616,280
197
AdministrativeAndGeneralExpenses
TOTAL Administrative & General Expenses (Total of Lines 194 and 196.4)
(b)
13,784,070
14,591,005
198
OperationsAndMaintenanceExpensesElectric
TOTAL Electric Operation and Maintenance Expenses (Total of Lines 80, 112, 131, 131.16, 156, 164, 171, 178, and 197)
108,633,398
100,209,064


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
FOOTNOTE DATA

(a) Concept: MiscellaneousGeneralExpenses
  2025 2024

Board of Directors Fees

217,478

237,414

Amortization of upfront fees

129,288

124,806

Industry & Association Dues

174,469

228,386

Human Resources general expenses (non-labor and not provided for elsewhere)

3,430

 

 

14,142

Miscellaneous

-3,000

962

Shareholder Expenses

21,053

14,070

Subtotal

542,718

619,780

     

Total Account 930.2

542,718

619,780

(b) Concept: AdministrativeAndGeneralExpenses

Merger transaction-related costs associated with the pending merger with Black Hills Corporation totaled $134,316 for 2025.


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
PURCHASED POWER (Account 555)
  1. Report all power purchases made during the year. Also report exchanges of electricity (i.e., transactions involving a balancing of debits and credits for energy, capacity, etc.) and any settlements for imbalanced exchanges.
  2. Enter the name of the seller or other party in an exchange transaction in column (a). Do not abbreviate or truncate the name or use acronyms. Explain in a footnote any ownership interest or affiliation the respondent has with the seller.
  3. In column (b), enter a Statistical Classification Code based on the original contractual terms and conditions of the service as follows:

    RQ - for requirements service. Requirements service is service which the supplier plans to provide on an ongoing basis (i.e., the supplier includes projects load for this service in its system resource planning). In addition, the reliability of requirement service must be the same as, or second only to, the supplier's service to its own ultimate consumers.

    LF - for long-term firm service. "Long-term" means five years or longer and "firm" means that service cannot be interrupted for economic reasons and is intended to remain reliable even under adverse conditions (e.g., the supplier must attempt to buy emergency energy from third parties to maintain deliveries of LF service). This category should not be used for long-term firm service firm service which meets the definition of RQ service. For all transaction identified as LF, provide in a footnote the termination date of the contract defined as the earliest date that either buyer or seller can unilaterally get out of the contract.

    IF - for intermediate-term firm service. The same as LF service expect that "intermediate-term" means longer than one year but less than five years.

    SF - for short-term service. Use this category for all firm services, where the duration of each period of commitment for service is one year or less.

    LU - for long-term service from a designated generating unit. "Long-term" means five years or longer. The availability and reliability of service, aside from transmission constraints, must match the availability and reliability of the designated unit.

    IU - for intermediate-term service from a designated generating unit. The same as LU service expect that "intermediate-term" means longer than one year but less than five years.

    EX - For exchanges of electricity. Use this category for transactions involving a balancing of debits and credits for energy, capacity, etc. and any settlements for imbalanced exchanges.

    OS - for other service. Use this category only for those services which cannot be placed in the above-defined categories, such as all non-firm service regardless of the length of the contract and service from designated units of less than one year. Describe the nature of the service in a footnote for each adjustment.

    AD - for out-of-period adjustment. Use this code for any accounting adjustments or "true-ups" for service provided in prior reporting years. Provide an explanation in a footnote for each adjustment.

  4. In column (c), identify the FERC Rate Schedule Number or Tariff, or, for non-FERC jurisdictional sellers, include an appropriate designation for the contract. On separate lines, list all FERC rate schedules, tariffs or contract designations under which service, as identified in column (b), is provided.
  5. For requirements RQ purchases and any type of service involving demand charges imposed on a monnthly (or longer) basis, enter the monthly average billing demand in column (d), the average monthly non-coincident peak (NCP) demand in column (e), and the average monthly coincident peak (CP) demand in column (f). For all other types of service, enter NA in columns (d), (e) and (f). Monthly NCP demand is the maximum metered hourly (60-minute integration) demand in a month. Monthly CP demand is the metered demand during the hour (60-minute integration) in which the supplier's system reaches its monthly peak. Demand reported in columns (e) and (f) must be in megawatts. Footnote any demand not stated on a megawatt basis and explain.
  6. Report in column (g) the megawatthours shown on bills rendered to the respondent, excluding purchases for energy storage. Report in column (h) the megawatthours shown on bills rendered to the respondent for energy storage purchases. Report in columns (i) and (j) the megawatthours of power exchanges received and delivered, used as the basis for settlement. Do not report net exchange.
  7. Report demand charges in column (k), energy charges in column (l), and the total of any other types of charges, including out-of-period adjustments, in column (m). Explain in a footnote all components of the amount shown in column (m). Report in column (n) the total charge shown on bills received as settlement by the respondent. For power exchanges, report in column (n) the settlement amount for the net receipt of energy. If more energy was delivered than received, enter a negative amount. If the settlement amount (m) include credits or charges other than incremental generation expenses, or (2) excludes certain credits or charges covered by the agreement, provide an explanatory footnote.
  8. The data in columns (g) through (n) must be totaled on the last line of the schedule. The total amount in columns (g) and (h) must be reported as Purchases on Page 401, line 10. The total amount in column (i) must be reported as Exchange Received on Page 401, line 12. The total amount in column (j) must be reported as Exchange Delivered on Page 401, line 13.
  9. Footnote entries as required and provide explanations following all required data.
Actual Demand (MW) POWER EXCHANGES COST/SETTLEMENT OF POWER
Line No.
NameOfCompanyOrPublicAuthorityProvidingPurchasedPower
Name of Company or Public Authority (Footnote Affiliations)
(a)
StatisticalClassificationCode
Statistical Classification
(b)
RateScheduleTariffNumber
Ferc Rate Schedule or Tariff Number
(c)
AverageMonthlyBillingDemand
Average Monthly Billing Demand (MW)
(d)
AverageMonthlyNonCoincidentPeakDemand
Average Monthly NCP Demand
(e)
AverageMonthlyCoincidentPeakDemand
Average Monthly CP Demand
(f)
MegawattHoursPurchasedOtherThanStorage
MegaWatt Hours Purchased (Excluding for Energy Storage)
(g)
MegawattHoursPurchasedForEnergyStorage
MegaWatt Hours Purchased for Energy Storage
(h)
EnergyReceivedThroughPowerExchanges
MegaWatt Hours Received
(i)
EnergyDeliveredThroughPowerExchanges
MegaWatt Hours Delivered
(j)
DemandChargesOfPurchasedPower
Demand Charges ($)
(k)
EnergyChargesOfPurchasedPower
Energy Charges ($)
(l)
OtherChargesOfPurchasedPower
Other Charges ($)
(m)
SettlementOfPower
Total (k+l+m) of Settlement ($)
(n)
1
WAPA (Various)
160,543
160,543
2
TEA & NextEra
2,104,509
2,104,509
3
Southwest Power Pool
99,351
303,895
303,895
4
Titan Wind (PPA Wind #1)
84,038
6,507,565
6,507,565
5
Oak Tree (PPA Wind #2)
66,344
3,398,716
3,398,716
6
Aurora Wind
79,811
2,147,640
2,147,640
7
Brule Wind
79,525
2,139,802
2,139,802
8
Redfield Solar
11,911
439,850
439,850
9
Codington Clark Electric
16,114
16,114
10
MidAmerican Energy
30,822
30,822
15 TOTAL
420,980
2,104,509
14,537,157
16,641,666


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
TRANSMISSION OF ELECTRICITY FOR OTHERS (Account 456.1) (Including transactions referred to as "wheeling")
  1. Report all transmission of electricity, i.e., wheeling, provided for other electric utilities, cooperatives, other public authorities, qualifying facilities, non-traditional utility suppliers and ultimate customers for the quarter.
  2. Use a separate line of data for each distinct type of transmission service involving the entities listed in column (a), (b) and (c).
  3. Report in column (a) the company or public authority that paid for the transmission service. Report in column (b) the company or public authority that the energy was received from and in column (c) the company or public authority that the energy was delivered to. Provide the full name of each company or public authority. Do not abbreviate or truncate name or use acronyms. Explain in a footnote any ownership interest in or affiliation the respondent has with the entities listed in columns (a), (b) or (c).
  4. In column (d) enter a Statistical Classification code based on the original contractual terms and conditions of the service as follows: FNO - Firm Network Service for Others, FNS - Firm Network Transmission Service for Self, LFP - "Long-Term Firm Point to Point Transmission Service, OLF - Other Long-Term Firm Transmission Service, SFP - Short-Term Firm Point to Point Transmission Reservation, NF - non-firm transmission service, OS - Other Transmission Service and AD - Out-of-Period Adjustments. Use this code for any accounting adjustments or "true-ups" for service provided in prior reporting periods. Provide an explanation in a footnote for each adjustment. See General Instruction for definitions of codes.
  5. In column (e), identify the FERC Rate Schedule or Tariff Number, On separate lines, list all FERC rate schedules or contract designations under which service, as identified in column (d), is provided.
  6. Report receipt and delivery locations for all single contract path, "point to point" transmission service. In column (f), report the designation for the substation, or other appropriate identification for where energy was received as specified in the contract. In column (g) report the designation for the substation, or other appropriate identification for where energy was delivered as specified in the contract.
  7. Report in column (h) the number of megawatts of billing demand that is specified in the firm transmission service contract. Demand reported in column (h) must be in megawatts. Footnote any demand not stated on a megawatts basis and explain.
  8. Report in column (i) and (j) the total megawatthours received and delivered.
  9. In column (k) through (n), report the revenue amounts as shown on bills or vouchers. In column (k), provide revenues from demand charges related to the billing demand reported in column (h). In column (I), provide revenues from energy charges related to the amount of energy transferred. In column (m), provide the total revenues from all other charges on bills or vouchers rendered, including out of period adjustments. Explain in a footnote all components of the amount shown in column (m). Report in column (n) the total charge shown on bills rendered to the entity listed in column (a). If no monetary settlement was made, enter zero (0) in column (n). Provide a footnote explaining the nature of the non-monetary settlement, including the amount and type of energy or service rendered.
  10. The total amounts in columns (i) and (j) must be reported as Transmission Received and Transmission Delivered for annual report purposes only on Page 401, Lines 16 and 17, respectively.
  11. Footnote entries and provide explanations following all required data.
TRANSFER OF ENERGY REVENUE FROM TRANSMISSION OF ELECTRICITY FOR OTHERS
Line No.
PaymentByCompanyOrPublicAuthority
Payment By (Company of Public Authority) (Footnote Affiliation)
(a)
TransmissionEnergyReceivedFromCompanyOrPublicAuthorityName
Energy Received From (Company of Public Authority) (Footnote Affiliation)
(b)
TransmissionEnergyDeliveredToCompanyOrPublicAuthorityName
Energy Delivered To (Company of Public Authority) (Footnote Affiliation)
(c)
StatisticalClassificationCode
Statistical Classification
(d)
RateScheduleTariffNumber
Ferc Rate Schedule of Tariff Number
(e)
TransmissionPointOfReceipt
Point of Receipt (Substation or Other Designation)
(f)
TransmissionPointOfDelivery
Point of Delivery (Substation or Other Designation)
(g)
BillingDemand
Billing Demand (MW)
(h)
TransmissionOfElectricityForOthersEnergyReceived
Megawatt Hours Received
(i)
TransmissionOfElectricityForOthersEnergyDelivered
Megawatt Hours Delivered
(j)
Demand Charges ($)
(k)
Energy Charges ($)
(l)
Other Charges ($)
(m)
RevenuesFromTransmissionOfElectricityForOthers
Total Revenues ($) (k+l+m)
(n)
1
BRYANT, CITY OF
WAPA
BRYANT
HURON 115 KV BUS
BRYANT 25 KV
4,617
4,617
33,722
33,722
2
GROTON, CITY OF
WAPA
GROTON
HURON 115 KV BUS
GROTON 69 KV
16,379
16,379
1,075
1,075
3
LANGFORD, CITY OF
WAPA
LANGFORD
HURON 115 KV BUS
LANGFORD 12.5 KV
3,199
3,199
23,206
23,206
4
EAST RIVER ELECTRIC POWER COOP
WAPA
WEBSTER
WEBSTER
0
5
Southwest Power Pool (SPP)
SPP
Various
Various
Various
(a)
208,586
208,586
6
Southwest Power Pool (SPP)
SPP
Various
Various
Various
(b)
84,308
84,308
7
Southwest Power Pool (SPP)
SPP
Various
Various
Various
(c)
6,940,413
6,940,413
8
Southwest Power Pool (SPP)
SPP
Various
Various
Various
(d)
168,704
168,704
9
Southwest Power Pool (SPP)
SPP
Various
Various
Various
(e)
13,243
13,243
35 TOTAL
24,195
24,195
58,003
7,415,255
7,473,258


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
FOOTNOTE DATA

(a) Concept: OtherChargesRevenueTransmissionOfElectricityForOthers

Firm and Non-Firm Point to Point Transmission Sales

(b) Concept: OtherChargesRevenueTransmissionOfElectricityForOthers

Non-Firm Point to Point Transmission Sales

(c) Concept: OtherChargesRevenueTransmissionOfElectricityForOthers

Network Integration Transmission Services

(d) Concept: OtherChargesRevenueTransmissionOfElectricityForOthers

Firm and Non-Firm Point to Point Transmission Sales

(e) Concept: OtherChargesRevenueTransmissionOfElectricityForOthers

Firm and Non-Firm Point to Point Transmission Sales


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
TRANSMISSION OF ELECTRICITY BY ISO/RTOs
  1. Report in Column (a) the Transmission Owner receiving revenue for the transmission of electricity by the ISO/RTO.
  2. Use a separate line of data for each distinct type of transmission service involving the entities listed in Column (a).
  3. In Column (b) enter a Statistical Classification code based on the original contractual terms and conditions of the service as follows: FNO – Firm Network Service for Others, FNS – Firm Network Transmission Service for Self, LFP – Long-Term Firm Point-to-Point Transmission Service, OLF – Other Long-Term Firm Transmission Service, SFP – Short-Term Firm Point-to-Point Transmission Reservation, NF – Non-Firm Transmission Service, OS – Other Transmission Service and AD- Out-of-Period Adjustments. Use this code for any accounting adjustments or “true-ups” for service provided in prior reporting periods. Provide an explanation in a footnote for each adjustment. See General Instruction for definitions of codes.
  4. In column (c) identify the FERC Rate Schedule or tariff Number, on separate lines, list all FERC rate schedules or contract designations under which service, as identified in column (b) was provided.
  5. In column (d) report the revenue amounts as shown on bills or vouchers.
  6. Report in column (e) the total revenues distributed to the entity listed in column (a).
Line No.
Payment Received by (Transmission Owner Name)
(a)
Statistical Classification
(b)
FERC Rate Schedule or Tariff Number
(c)
Total Revenue by Rate Schedule or Tariff
(d)
Total Revenue
(e)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
40
TOTAL


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
TRANSMISSION OF ELECTRICITY BY OTHERS (Account 565)
  1. Report all transmission, i.e. wheeling or electricity provided by other electric utilities, cooperatives, municipalities, other public authorities, qualifying facilities, and others for the quarter.
  2. In column (a) report each company or public authority that provided transmission service. Provide the full name of the company, abbreviate if necessary, but do not truncate name or use acronyms. Explain in a footnote any ownership interest in or affiliation with the transmission service provider. Use additional columns as necessary to report all companies or public authorities that provided transmission service for the quarter reported.
  3. In column (b) enter a Statistical Classification code based on the original contractual terms and conditions of the service as follows:
    FNS - Firm Network Transmission Service for Self, LFP - Long-Term Firm Point-to-Point Transmission Reservations. OLF - Other Long-Term Firm Transmission Service, SFP - Short-Term Firm Point-to- Point Transmission Reservations, NF - Non-Firm Transmission Service, and OS - Other Transmission Service. See General Instructions for definitions of statistical classifications.
  4. Report in column (c) and (d) the total megawatt hours received and delivered by the provider of the transmission service.
  5. Report in column (e), (f) and (g) expenses as shown on bills or vouchers rendered to the respondent. In column (e) report the demand charges and in column (f) energy charges related to the amount of energy transferred. On column (g) report the total of all other charges on bills or vouchers rendered to the respondent, including any out of period adjustments. Explain in a footnote all components of the amount shown in column (g). Report in column (h) the total charge shown on bills rendered to the respondent. If no monetary settlement was made, enter zero in column (h). Provide a footnote explaining the nature of the non-monetary settlement, including the amount and type of energy or service rendered.
  6. Enter ""TOTAL"" in column (a) as the last line.
  7. Footnote entries and provide explanations following all required data.
TRANSFER OF ENERGY EXPENSES FOR TRANSMISSION OF ELECTRICITY BY OTHERS
Line No.
NameOfCompanyOrPublicAuthorityTransmissionOfElectricityByOthers
Name of Company or Public Authority (Footnote Affiliations)
(a)
StatisticalClassificationCode
Statistical Classification
(b)
TransmissionOfElectricityByOthersEnergyReceived
MegaWatt Hours Received
(c)
TransmissionOfElectricityByOthersEnergyDelivered
MegaWatt Hours Delivered
(d)
DemandChargesTransmissionOfElectricityByOthers
Demand Charges ($)
(e)
EnergyChargesTransmissionOfElectricityByOthers
Energy Charges ($)
(f)
OtherChargesTransmissionOfElectricityByOthers
Other Charges ($)
(g)
ChargesForTransmissionOfElectricityByOthers
Total Cost of Transmission ($)
(h)
1
East River
52,162
52,162
2
Southwest Power Pool
21,350,372
21,350,372
TOTAL
21,402,534
21,402,534


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
MISCELLANEOUS GENERAL EXPENSES (Account 930.2) (ELECTRIC)
Line No.
Description
(a)
Amount
(b)
1
IndustryAssociationDues
Industry Association Dues
174,469
2
NuclearPowerResearchExpenses
Nuclear Power Research Expenses
3
OtherExperimentalAndGeneralResearchExpenses
Other Experimental and General Research Expenses
4
PublicationAndDistributionExpensesForSecuritiesToStockholders
Pub and Dist Info to Stkhldrs...expn servicing outstanding Securities
21,053
5
OtherMiscellaneousGeneralExpenses
Oth Expn greater than or equal to 5,000 show purpose, recipient, amount. Group if less than $5,000
6
Board of Director Fees
217,478
7
Amortization of Upfront Fees
129,288
8
Human Resources General Expenses (non-labor and not provided elsewhere)
3,430
9
Miscellaneous
3,000
46
MiscellaneousGeneralExpenses
TOTAL
(a)
542,718


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
FOOTNOTE DATA

(a) Concept: MiscellaneousGeneralExpenses
  2025 2024

Board of Directors Fees

217,478

237,414

Amortization of upfront fees

129,288

124,806

Industry & Association Dues

174,469

228,386

Human Resources general expenses (non-labor and not provided for elsewhere)

3,430

 

 

14,142

Miscellaneous

-3,000

962

Shareholder Expenses

21,053

14,070

Subtotal

542,718

619,780

     

Total Account 930.2

542,718

619,780


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
Depreciation and Amortization of Electric Plant (Account 403, 404, 405)
  1. Report in section A for the year the amounts for: (b) Depreciation Expense (Account 403); (c) Depreciation Expense for Asset Retirement Costs (Account 403.1); (d) Amortization of Limited-Term Electric Plant (Account 404); and (e) Amortization of Other Electric Plant (Account 405).
  2. Report in Section B the rates used to compute amortization charges for electric plant (Accounts 404 and 405). State the basis used to compute charges and whether any changes have been made in the basis or rates used from the preceding report year.
  3. Report all available information called for in Section C every fifth year beginning with report year 1971, reporting annually only changes to columns (c) through (g) from the complete report of the preceding year.
    Unless composite depreciation accounting for total depreciable plant is followed, list numerically in column (a) each plant subaccount, account or functional classification, as appropriate, to which a rate is applied. Identify at the bottom of Section C the type of plant included in any sub-account used.
    In column (b) report all depreciable plant balances to which rates are applied showing subtotals by functional Classifications and showing composite total. Indicate at the bottom of section C the manner in which column balances are obtained. If average balances, state the method of averaging used.
    For columns (c), (d), and (e) report available information for each plant subaccount, account or functional classification listed in column (a). If plant mortality studies are prepared to assist in estimating average service lives, show in column (f) the type of mortality curve selected as most appropriate for the account and in column (g), if available, the weighted average remaining life of surviving plant. If composite depreciation accounting is used, report available information called for in columns (b) through (g) on this basis.
  4. If provisions for depreciation were made during the year in addition to depreciation provided by application of reported rates, state at the bottom of section C the amounts and nature of the provisions and the plant items to which related.
A. Summary of Depreciation and Amortization Charges
Line No.
FunctionalClassificationAxis
Functional Classification
(a)
DepreciationExpenseExcludingAmortizationOfAcquisitionAdjustments
Depreciation Expense (Account 403)
(b)
DepreciationExpenseForAssetRetirementCostsExcludingAmortizationgOfAcquisitionAdjustments
Depreciation Expense for Asset Retirement Costs (Account 403.1)
(c)
AmortizationOfLimitedTermPlantOrProperty
Amortization of Limited Term Electric Plant (Account 404)
(d)
AmortizationOfOtherElectricPlant
Amortization of Other Electric Plant (Acc 405)
(e)
DepreciationAndAmortization
Total
(f)
1
Intangible Plant
0
0
274,185
0
274,185
2
Steam Production Plant
8,592,083
0
0
0
8,592,083
3
Nuclear Production Plant
0
0
0
0
0
4
Hydraulic Production Plant-Conventional
0
0
0
0
0
5
Hydraulic Production Plant-Pumped Storage
0
0
0
0
0
5.1
Solar Production Plant
0
0
0
0
0
5.2
Wind Production Plant
4,433,197
0
0
0
4,433,197
5.3
Other Renewable Production Plant
0
0
0
0
0
6
Other Production Plant
4,778,277
0
0
0
4,778,277
7
Transmission Plant
6,341,566
0
0
0
6,341,566
8
Distribution Plant
12,771,344
0
0
0
12,771,344
9
Regional Transmission and Market Operation
0
0
0
0
0
9.1
Energy Storage Plant
10
General Plant
1,134,768
0
0
0
1,134,768
11
Common Plant-Electric
3,419,453
0
1,025,314
0
4,444,767
12
TOTAL
41,470,688
0
1,299,499
0
42,770,187
B. Basis for Amortization Charges
For our South Dakota operations, the rates used to compute amortization charges for 'Intangible Plant - Electric' (Account 404) are as follows: 303 Intangible Plant: Five Year Software 17.24%; 303 Intangible Plant: 10 Year Software 8.66%. Common amortization expense is allocated 84% to electric and 16% to gas based on allocation studies.
C. Factors Used in Estimating Depreciation Charges
Line No.
AccountNumberFactorsUsedInEstimatingDepreciationCharges
Account No.
(a)
DepreciablePlantBase
Depreciable Plant Base (in Thousands)
(b)
UtilityPlantEstimatedAverageServiceLife
Estimated Avg. Service Life
(c)
UtilityPlantNetSalvageValuePercentage
Net Salvage (Percent)
(d)
UtilityPlantAppliedDepreciationRate
Applied Depr. Rates (Percent)
(e)
MortalityCurveType
Mortality Curve Type
(f)
UtilityPlantWeightedAverageRemainingLife
Average Remaining Life
(g)
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
REGULATORY COMMISSION EXPENSES
  1. Report particulars (details) of regulatory commission expenses incurred during the current year (or incurred in previous years, if being amortized) relating to format cases before a regulatory body, or cases in which such a body was a party.
  2. Report in columns (b) and (c), only the current year's expenses that are not deferred and the current year's amortization of amounts deferred in previous years.
  3. Show in column (k) any expenses incurred in prior years which are being amortized. List in column (a) the period of amortization.
  4. List in columns (f), (g), and (h), expenses incurred during the year which were charged currently to income, plant, or other accounts.
  5. Minor items (less than $25,000) may be grouped.
EXPENSES INCURRED DURING YEAR AMORTIZED DURING YEAR
CURRENTLY CHARGED TO
Line No.
RegulatoryCommissionDescription
Description (Furnish name of regulatory commission or body the docket or case number and a description of the case)
(a)
RegulatoryExpensesAssessedByRegulatoryCommission
Assessed by Regulatory Commission
(b)
RegulatoryExpensesOfUtility
Expenses of Utility
(c)
RegulatoryCommissionExpensesAmount
Total Expenses for Current Year (b) + (c)
(d)
OtherRegulatoryAssetsRegulatoryCommissionExpenses
Deferred in Account 182.3 at Beginning of Year
(e)
NameOfDepartmentRegulatoryCommissionExpensesCharged
Department
(f)
AccountNumberRegulatoryCommissionExpensesCharged
Account No.
(g)
RegulatoryComissionExpensesIncurredAndCharged
Amount
(h)
RegulatoryCommissionExpensesDeferredToOtherRegulatoryAssets
Deferred to Account 182.3
(i)
DeferredRegulatoryCommissionExpensesAmortizedInContraAccount
Contra Account
(j)
DeferredRegulatoryCommissionExpensesAmortized
Amount
(k)
OtherRegulatoryAssetsRegulatoryCommissionExpenses
Deferred in Account 182.3 End of Year
(l)
1
South Dakota PUC Electric Rate Filings
127,083
Electric
63,541
63,542
2
South Dakota PUC Natural Gas Rate Filings
50,829
Natural Gas
17,426
33,403
3
Nebraska PSC Natural Gas Rate FIlings
10,498
Natural Gas
67,498
7,800
70,196
46
TOTAL
188,410
67,498
88,767
167,141


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
RESEARCH, DEVELOPMENT, AND DEMONSTRATION ACTIVITIES
  1. Describe and show below costs incurred and accounts charged during the year for technological research, development, and demonstration (R, D and D) project initiated, continued or concluded during the year. Report also support given to others during the year for jointly-sponsored projects.(Identify recipient regardless of affiliation.) For any R, D and D work carried with others, show separately the respondent's cost for the year and cost chargeable to others (See definition of research, development, and demonstration in Uniform System of Accounts).
  2. Indicate in column (a) the applicable classification, as shown below:
    Classifications:
    1. Electric R, D and D Performed Internally:
      1. Generation
        1. hydroelectric
          1. Recreation fish and wildlife
          2. Other hydroelectric
        2. Fossil-fuel steam
        3. Internal combustion or gas turbine
        4. Nuclear
        5. Solar
        6. Wind
        7. Other renewable
        8. Unconventional generation
        9. Siting and heat rejection
      2. Transmission
        1. Overhead
        2. Underground
      3. Distribution
      4. Regional Transmission and Market Operation
      5. Energy Storage
      6. Environment (other than equipment)
      7. Other (Classify and include items in excess of $50,000.)
      8. Total Cost Incurred
    2. Electric, R, D and D Performed Externally:
      1. Research Support to the electrical Research Council or the Electric Power Research Institute
      2. Research Support to Edison Electric Institute
      3. Research Support to Nuclear Power Groups
      4. Research Support to Others (Classify)
      5. Total Cost Incurred
  3. Include in column (c) all R, D and D items performed internally and in column (d) those items performed outside the company costing $50,000 or more, briefly describing the specific area of R, D and D (such as safety, corrosion control, pollution, automation, measurement, insulation, type of appliance, etc.). Group items under $50,000 by classifications and indicate the number of items grouped. Under Other, (A (6) and B (4)) classify items by type of R, D and D activity.
  4. Show in column (e) the account number charged with expenses during the year or the account to which amounts were capitalized during the year, listing Account 107, Construction Work in Progress, first. Show in column (f) the amounts related to the account charged in column (e).
  5. Show in column (g) the total unamortized accumulating of costs of projects. This total must equal the balance in Account 188, Research, Development, and Demonstration Expenditures, Outstanding at the end of the year.
  6. If costs have not been segregated for R, D and D activities or projects, submit estimates for columns (c), (d), and (f) with such amounts identified by ""Est.""
  7. Report separately research and related testing facilities operated by the respondent.
AMOUNTS CHARGED IN CURRENT YEAR
Line No.
ResearchDevelopmentAndDemonstrationClassification
Classification
(a)
ResearchDevelopmentAndDemonstrationDescription
Description
(b)
ResearchDevelopmentAndDemonstrationCostsIncurredInternally
Costs Incurred Internally Current Year
(c)
ResearchDevelopmentAndDemonstrationCostsIncurredExternally
Costs Incurred Externally Current Year
(d)
AccountNumberForResearchDevelopmentAndDemonstrationCosts
Amounts Charged In Current Year: Account
(e)
ResearchDevelopmentAndDemonstrationCosts
Amounts Charged In Current Year: Amount
(f)
ResearchDevelopmentAndDemonstrationExpenditures
Unamortized Accumulation
(g)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
DISTRIBUTION OF SALARIES AND WAGES

Report below the distribution of total salaries and wages for the year. Segregate amounts originally charged to clearing accounts to Utility Departments, Construction, Plant Removals, and Other Accounts, and enter such amounts in the appropriate lines and columns provided. In determining this segregation of salaries and wages originally charged to clearing accounts, a method of approximation giving substantially correct results may be used.

Line No.
Classification
(a)
Direct Payroll Distribution
(b)
Allocation of Payroll Charged for Clearing Accounts
(c)
Total
(d)
1
SalariesAndWagesElectricAbstract
Electric
2
SalariesAndWagesElectricOperationAbstract
Operation
3
SalariesAndWagesElectricOperationProduction
Production
817,664
4
SalariesAndWagesElectricOperationTransmission
Transmission
658,445
5
SalariesAndWagesElectricOperationRegionalMarket
Regional Market
5.1
SalariesAndWagesElectricOperationEnergyStorage
Energy Storage
6
SalariesAndWagesElectricOperationDistribution
Distribution
2,163,325
7
SalariesAndWagesElectricOperationCustomerAccounts
Customer Accounts
612,470
8
SalariesAndWagesElectricOperationCustomerServiceAndInformational
Customer Service and Informational
994,807
9
SalariesAndWagesElectricOperationSales
Sales
10
SalariesAndWagesElectricOperationAdministrativeAndGeneral
Administrative and General
3,997,502
11
SalariesAndWagesElectricOperation
TOTAL Operation (Enter Total of lines 3 thru 10)
9,244,213
12
SalariesAndWagesElectricMaintenanceAbstract
Maintenance
13
SalariesAndWagesElectricMaintenanceProduction
Production
254,957
14
SalariesAndWagesElectricMaintenanceTransmission
Transmission
251,697
15
SalariesAndWagesElectricMaintenanceRegionalMarket
Regional Market
15.1
SalariesAndWagesElectricMaintenanceEnergyStorage
Energy Storage
16
SalariesAndWagesElectricMaintenanceDistribution
Distribution
1,607,434
17
SalariesAndWagesElectricMaintenanceAdministrativeAndGeneral
Administrative and General
237,538
18
SalariesAndWagesElectricMaintenance
TOTAL Maintenance (Total of lines 13 thru 17)
2,351,626
19
SalariesAndWagesElectricOperationAndMaintenanceAbstract
Total Operation and Maintenance
20
SalariesAndWagesElectricProduction
Production (Enter Total of lines 3 and 13)
1,072,621
21
SalariesAndWagesElectricTransmission
Transmission (Enter Total of lines 4 and 14)
910,142
22
SalariesAndWagesElectricRegionalMarket
Regional Market (Enter Total of Lines 5 and 15)
22.1
SalariesAndWagesElectricEnergyStorage
Energy Storage (Enter Total of Lines 5.1 and 15.1)
23
SalariesAndWagesElectricDistribution
Distribution (Enter Total of lines 6 and 16)
3,770,759
24
SalariesAndWagesElectricCustomerAccounts
Customer Accounts (Transcribe from line 7)
612,470
25
SalariesAndWagesElectricCustomerServiceAndInformational
Customer Service and Informational (Transcribe from line 8)
994,807
26
SalariesAndWagesElectricSales
Sales (Transcribe from line 9)
27
SalariesAndWagesElectricAdministrativeAndGeneral
Administrative and General (Enter Total of lines 10 and 17)
4,235,040
28
SalariesAndWagesElectricOperationAndMaintenance
TOTAL Oper. and Maint. (Total of lines 20 thru 27)
11,595,839
11,595,839
29
SalariesAndWagesGasAbstract
Gas
30
SalariesAndWagesGasOperationAbstract
Operation
31
SalariesAndWagesGasOperationProductionManufacturedGas
Production - Manufactured Gas
32
SalariesAndWagesGasOperationProductionNaturalGas
Production-Nat. Gas (Including Expl. And Dev.)
33
SalariesAndWagesGasOperationOtherGasSupply
Other Gas Supply
34
SalariesAndWagesGasOperationStorageLiquifiedNaturalGasTerminalingAndProcessing
Storage, LNG Terminaling and Processing
35
SalariesAndWagesGasOperationTransmission
Transmission
43,747
36
SalariesAndWagesGasOperationDistribution
Distribution
3,921,933
37
SalariesAndWagesGasCustomerAccounts
Customer Accounts
595,145
38
SalariesAndWagesGasCustomerServiceAndInformational
Customer Service and Informational
646,047
39
SalariesAndWagesGasSales
Sales
40
SalariesAndWagesGasOperationAdministrativeAndGeneral
Administrative and General
3,319,751
41
SalariesAndWagesGasOperation
TOTAL Operation (Enter Total of lines 31 thru 40)
8,526,623
42
SalariesAndWagesGasMaintenanceAbstract
Maintenance
43
SalariesAndWagesGasMaintenanceProductionManufacturedGas
Production - Manufactured Gas
44
SalariesAndWagesGasMaintenanceProductionNaturalGas
Production-Natural Gas (Including Exploration and Development)
45
SalariesAndWagesGasMaintenanceOtherGasSupply
Other Gas Supply
46
SalariesAndWagesGasMaintenanceStorageLngTerminalingAndProcessing
Storage, LNG Terminaling and Processing
47
SalariesAndWagesGasMaintenanceTransmission
Transmission
11,065
48
SalariesAndWagesGasMaintenanceDistribution
Distribution
1,476,230
49
SalariesAndWagesGasMaintenanceAdministrativeAndGeneral
Administrative and General
220,061
50
SalariesAndWagesGasMaintenance
TOTAL Maint. (Enter Total of lines 43 thru 49)
1,707,356
51
SalariesAndWagesGasOperationAndMaintenanceAbstract
Total Operation and Maintenance
52
SalariesAndWagesGasProductionManufacturedGas
Production-Manufactured Gas (Enter Total of lines 31 and 43)
53
SalariesAndWagesGasProductionNaturalGas
Production-Natural Gas (Including Expl. and Dev.) (Total lines 32,
54
SalariesAndWagesGasOtherGasSupply
Other Gas Supply (Enter Total of lines 33 and 45)
55
SalariesAndWagesGasStorageLngTerminalingAndProcessing
Storage, LNG Terminaling and Processing (Total of lines 31 thru
56
SalariesAndWagesGasTransmission
Transmission (Lines 35 and 47)
54,812
57
SalariesAndWagesGasDistribution
Distribution (Lines 36 and 48)
5,398,163
58
SalariesAndWagesGasCustomerAccounts
Customer Accounts (Line 37)
595,145
59
SalariesAndWagesGasCustomerServiceAndInformational
Customer Service and Informational (Line 38)
646,047
60
SalariesAndWagesGasSales
Sales (Line 39)
61
SalariesAndWagesGasAdministrativeAndGeneral
Administrative and General (Lines 40 and 49)
3,539,812
62
SalariesAndWagesGasOperationAndMaintenance
TOTAL Operation and Maint. (Total of lines 52 thru 61)
10,233,979
10,233,979
63
SalariesAndWagesOtherUtilityDepartmentsAbstract
Other Utility Departments
64
SalariesAndWagesOtherUtilityDepartmentsOperationAndMaintenance
Operation and Maintenance
65
SalariesAndWagesOperationsAndMaintenance
TOTAL All Utility Dept. (Total of lines 28, 62, and 64)
21,829,818
21,829,818
66
SalariesAndWagesUtilityPlantAbstract
Utility Plant
67
SalariesAndWagesUtilityPlantConstructionAbstract
Construction (By Utility Departments)
68
SalariesAndWagesUtilityPlantConstructionElectricPlant
Electric Plant
5,852,510
5,852,510
69
SalariesAndWagesUtilityPlantConstructionGasPlant
Gas Plant
2,584,078
2,584,078
70
SalariesAndWagesUtilityPlantConstructionOther
Other (provide details in footnote):
395,892
395,892
71
SalariesAndWagesUtilityPlantConstruction
TOTAL Construction (Total of lines 68 thru 70)
8,832,480
8,832,480
72
SalariesAndWagesPlantRemovalAbstract
Plant Removal (By Utility Departments)
73
SalariesAndWagesPlantRemovalElectricPlant
Electric Plant
74
SalariesAndWagesPlantRemovalGasPlant
Gas Plant
75
SalariesAndWagesPlantRemovalOther
Other (provide details in footnote):
76
SalariesAndWagesPlantRemoval
TOTAL Plant Removal (Total of lines 73 thru 75)
77
SalariesAndWagesOtherAccountsAbstract
Other Accounts (Specify, provide details in footnote):
78
SalariesAndWagesOtherAccountsDescription
A/R ASSOCIATED COMPANIES (ACCT 146)
11,638,190
11,638,190
79
SalariesAndWagesOtherAccountsDescription
EXPENSES OF NON-UTILITY OP (ACCT 417)
43,957
43,957
80
SalariesAndWagesOtherAccountsDescription
81
SalariesAndWagesOtherAccountsDescription
82
SalariesAndWagesOtherAccountsDescription
83
SalariesAndWagesOtherAccountsDescription
84
SalariesAndWagesOtherAccountsDescription
85
SalariesAndWagesOtherAccountsDescription
86
SalariesAndWagesOtherAccountsDescription
87
SalariesAndWagesOtherAccountsDescription
88
SalariesAndWagesOtherAccountsDescription
89
SalariesAndWagesOtherAccountsDescription
90
SalariesAndWagesOtherAccountsDescription
91
SalariesAndWagesOtherAccountsDescription
92
SalariesAndWagesOtherAccountsDescription
93
SalariesAndWagesOtherAccountsDescription
94
SalariesAndWagesOtherAccountsDescription
95
SalariesAndWagesOtherAccounts
TOTAL Other Accounts
11,682,147
11,682,147
96
SalariesAndWagesGeneralExpense
TOTAL SALARIES AND WAGES
42,344,445
42,344,445


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
COMMON UTILITY PLANT AND EXPENSES
  1. Describe the property carried in the utility's accounts as common utility plant and show the book cost of such plant at end of year classified by accounts as provided by Electric Plant Instruction 13, Common Utility Plant, of the Uniform System of Accounts. Also show the allocation of such plant costs to the respective departments using the common utility plant and explain the basis of allocation used, giving the allocation factors.
  2. Furnish the accumulated provisions for depreciation and amortization at end of year, showing the amounts and classifications of such accumulated provisions, and amounts allocated to utility departments using the common utility plant to which such accumulated provisions relate, including explanation of basis of allocation and factors used.
  3. Give for the year the expenses of operation, maintenance, rents, depreciation, and amortization for common utility plant classified by accounts as provided by the Uniform System of Accounts. Show the allocation of such expenses to the departments using the common utility plant to which such expenses are related. Explain the basis of allocation used and give the factors of allocation.
  4. Give date of approval by the Commission for use of the common utility plant classification and reference to the order of the Commission or other authorization.
       

Item   #  1

           
       

Common Utility Plant at December 31, 2025

     
                     

PLANT

                   

ACCOUNT

 

    Description

 

Total

 

Electric

 

Natural Gas

   
                     
                     

303

 

Misc. Intangible Plant

 

10,178,980.20

 

8,550,343.37

 

1,628,636.83

   

389

 

Land & Land Rights

 

1,210,473.57

 

1,016,797.80

 

193,675.77

   

390

 

Structures & Improvements

 

41,822,237.67

 

35,130,679.64

 

6,691,558.03

   

391

 

Office Furniture & Equipment

 

7,182,949.62

 

6,033,677.68

 

1,149,271.94

   

392

 

Transportation Equipment

 

3,962,584.92

 

3,328,571.33

 

634,013.59

   

393

 

Stores Equipment

 

108,544.71

 

91,177.56

 

17,367.15

   

394

 

Tools/Shop/Garage Equipment

 

202,864.64

 

170,406.30

 

32,458.34

   

395

 

Laboratory Equipment

 

0.00

 

0.00

 

0.00

   

396

 

Power Operated Equipment

 

2,807,654.85

 

2,358,430.07

 

449,224.78

   

397

 

Communication Equipment

 

4,140,992.54

 

3,478,433.73

 

662,558.81

   

398

 

Miscellaneous

 

27,831.23

 

23,378.23

 

4,453.00

   
               

 

   

Sub -Total

     

71,645,113.95

 

60,181,895.71

 

11,463,218.24

   
                     
                     

Construction Work In Progress

 

2,208,056.43

 

1,854,767.40

 

353,289.03

 

CWIP breakout

                     
       

 

           
   

Total

 

73,853,170.38

           
                     
                     

Common utility plant is allocated to utility departments based on estimated individual facility utilization.

   

 

 

       

Item   #  2

       
       

Common Utility Accumulated Depreciation Reserve At December 31, 2025

                 

PLANT

               

ACCOUNT

 

    Description

 

Total

 

Electric

 

Natural Gas

                 
                 

303

 

Misc. Intangible Plant

 

      4,728,459.79

 

      3,971,906.22

 

         756,553.57

389

 

Land & Land Rights

 

                      -  

 

                      -  

 

                      -  

390

 

Structures & Improvements

 

    11,625,867.76

 

      9,765,728.92

 

      1,860,138.84

391

 

Office Furniture & Equipment

 

      2,823,743.76

 

      2,371,944.76

 

         451,799.00

392

 

Transportation Equipment

 

      2,157,027.37

 

      1,811,902.99

 

         345,124.38

393

 

Stores Equipment

 

          19,149.84

 

          16,085.87

 

            3,063.97

394

 

Tools/Shop/Garage Equipment

 

          97,475.53

 

          81,879.45

 

          15,596.08

395

 

Laboratory Equipment

 

                      -  

 

                      -  

 

                      -  

396

 

Power Operated Equipment

 

      1,259,505.55

 

      1,057,984.66

 

         201,520.89

397

 

Communication Equipment

 

      3,478,211.72

 

      2,921,697.84

 

         556,513.88

398

 

Miscellaneous

 

         (59,098.97)

 

         (49,643.13)

 

           (9,455.84)

                 

Total

     

26,130,342.35

 

21,949,487.58

 

4,180,854.77

                 

 

                 

ITEM #3

     

                    Real Estate

 

                Depreciation

   
   

                           General

 

                    & Personal

 

               &

   

Common Expenses

 

                           Building

 

                 Property Tax

 

              Amortization

 

                   Total

                 

Electric:

               

Depreciation

         

3,419,453

 

3,419,453

Amortization

         

1,025,314

 

1,025,314

Taxes Other than Income

     

284,721

     

284,721

Administrative & General

 

670,287

         

670,287

                 

Subtotal

 

670,287

 

284,721

 

4,444,767

 

5,399,775

                 

Natural Gas:

               

Depreciation

         

651,324

 

651,324

Amortization

         

195,298

 

195,298

Taxes Other than Income

     

54,232

     

54,232

Administrative & General

 

485,381

         

485,381

                 

Subtotal

 

485,381

 

54,232

 

846,622

 

1,386,235

                 
                 

Total Common Expense

 

1,155,668

 

338,953

 

5,291,389

 

6,786,010

                 
                 
                 
                 
                 

(1)

 

General building expense is allocated to departmental expense accounts based on estimated facility

utilization, as evidenced by a 3-factor allocation method.

                 

(2)

 

Real Estate & Personal Property Taxes are allocated to departmental expense accounts based on the

   

 estimated rate base allocation, using the property tax rate from Kari Randall

                 

(3)

 

Depreciation & Amortization expense is allocated to utility departmental expense accounts based on the

   

 estimated rate base allocation.

       
                 
   

ITEM #4

           
                 
   

FERC staff recommendation dated January 19, 1967 gave approval for the use of the common plant classification.


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
AMOUNTS INCLUDED IN ISO/RTO SETTLEMENT STATEMENTS
  1. The respondent shall report below the details called for concerning amounts it recorded in Account 555, Purchase Power, and Account 447, Sales for Resale, for items shown on ISO/RTO Settlement Statements. Transactions should be separately netted for each ISO/RTO administered energy market for purposes of determining whether an entity is a net seller or purchaser in a given hour. Net megawatt hours are to be used as the basis for determining whether a net purchase or sale has occurred. In each monthly reporting period, the hourly sale and purchase net amounts are to be aggregated and separately reported in Account 447, Sales for Resale, or Account 555, Purchase Power, respectively.
Line No.
Description of Item(s)
(a)
Balance at End of Quarter 1
(b)
Balance at End of Quarter 2
(c)
Balance at End of Quarter 3
(d)
Balance at End of Year
(e)
1 Energy
2 Net Purchases (Account 555)
32,473,799
24,521,663
48,769,693
37,012,540
2.1 Net Purchases (Account 555.1)
3 Net Sales (Account 447)
31,913,684
26,184,846
50,948,839
36,413,444
4 Transmission Rights
5 Ancillary Services
25,024
25,475
25,250
25,784
6 Other Items (list separately)
7
Day Ahead & Real Time Admin
87,584
89,163
88,373
90,252
8
Market Monitoring & Compliance
12,512
12,738
12,625
12,893
46 TOTAL
685,234
1,535,808
2,052,898
728,025


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
PURCHASES AND SALES OF ANCILLARY SERVICES
Report the amounts for each type of ancillary service shown in column (a) for the year as specified in Order No. 888 and defined in the respondents Open Access Transmission Tariff.
In columns for usage, report usage-related billing determinant and the unit of measure.
  1. On Line 1 columns (b), (c), (d), and (e) report the amount of ancillary services purchased and sold during the year.
  2. On Line 2 columns (b), (c), (d), and (e) report the amount of reactive supply and voltage control services purchased and sold during the year.
  3. On Line 3 columns (b), (c), (d), and (e) report the amount of regulation and frequency response services purchased and sold during the year.
  4. On Line 4 columns (b), (c), (d), and (e) report the amount of energy imbalance services purchased and sold during the year.
  5. On Lines 5 and 6, columns (b), (c), (d), and (e) report the amount of operating reserve spinning and supplement services purchased and sold during the period.
  6. On Line 7 columns (b), (c), (d), and (e) report the total amount of all other types ancillary services purchased or sold during the year. Include in a footnote and specify the amount for each type of other ancillary service provided.
Amount Purchased for the Year Amount Sold for the Year
Usage - Related Billing Determinant Usage - Related Billing Determinant
Line No.
Type of Ancillary Service
(a)
Number of Units
(b)
Unit of Measure
(c)
Dollar
(d)
Number of Units
(e)
Unit of Measure
(f)
Dollars
(g)
1
Scheduling, System Control and Dispatch
2
Reactive Supply and Voltage
3
Regulation and Frequency Response
4
Energy Imbalance
5
Operating Reserve - Spinning
6
Operating Reserve - Supplement
7
Other
8
Total (Lines 1 thru 7)


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
MONTHLY TRANSMISSION SYSTEM PEAK LOAD
  1. Report the monthly peak load on the respondent's transmission system. If the respondent has two or more power systems which are not physically integrated, furnish the required information for each non-integrated system.
  2. Report on Column (b) by month the transmission system's peak load.
  3. Report on Columns (c ) and (d) the specified information for each monthly transmission - system peak load reported on Column (b).
  4. Report on Columns (e) through (j) by month the system' monthly maximum megawatt load by statistical classifications. See General Instruction for the definition of each statistical classification.
Line No.
Month
(a)
Monthly Peak MW - Total
(b)
Day of Monthly Peak
(c)
Hour of Monthly Peak
(d)
Firm Network Service for Self
(e)
Firm Network Service for Others
(f)
Long-Term Firm Point-to-point Reservations
(g)
Other Long-Term Firm Service
(h)
Short-Term Firm Point-to-point Reservation
(i)
Other Service
(j)
NAME OF SYSTEM:
1
January
2
February
3
March
4
Total for Quarter 1
5
April
6
May
7
June
8
Total for Quarter 2
9
July
10
August
11
September
12
Total for Quarter 3
13
October
14
November
15
December
16
Total for Quarter 4
17
Total
NAME OF SYSTEM: South Dakota Operations
1
January
2
February
3
March
4
Total for Quarter 1
5
April
6
May
7
June
8
Total for Quarter 2
9
July
10
August
11
September
12
Total for Quarter 3
13
October
14
November
15
December
16
Total for Quarter 4
17
Total


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
Monthly ISO/RTO Transmission System Peak Load
  1. Report the monthly peak load on the respondent's transmission system. If the Respondent has two or more power systems which are not physically integrated, furnish the required information for each non-integrated system.
  2. Report on Column (b) by month the transmission system's peak load.
  3. Report on Column (c) and (d) the specified information for each monthly transmission - system peak load reported on Column (b).
  4. Report on Columns (e) through (i) by month the system’s transmission usage by classification. Amounts reported as Through and Out Service in Column (g) are to be excluded from those amounts reported in Columns (e) and (f).
  5. Amounts reported in Column (j) for Total Usage is the sum of Columns (h) and (i).
Line No.
Month
(a)
Monthly Peak MW - Total
(b)
Day of Monthly Peak
(c)
Hour of Monthly Peak
(d)
Import into ISO/RTO
(e)
Exports from ISO/RTO
(f)
Through and Out Service
(g)
Network Service Usage
(h)
Point-to-Point Service Usage
(i)
Total Usage
(j)
NAME OF SYSTEM:
1
January
327.00
21
9
340
13
353
2
February
333.00
18
9
346
13
359
3
March
269.00
5
9
280
10
290
4
Total for Quarter 1
966
37
1,003
5
April
235.00
8
8
246
10
256
6
May
260.00
13
17
272
12
284
7
June
347.00
20
17
361
15
376
8
Total for Quarter 2
879
37
916
9
July
281.00
9
17
296
15
311
10
August
279.00
21
16
294
15
309
11
September
278.00
12
17
291
13
304
12
Total for Quarter 3
881
43
924
13
October
285
3
17
296
11
307
14
November
195
10
11
205
10
215
15
December
302
18
12
314
12
326
16
Total for Quarter 4
815
33
848
17
Total Year to Date/Year
3,541
150
3,691


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

2025-12-31
Year/Period of Report

End of:
2025
/
Q4
ELECTRIC ENERGY ACCOUNT

Report below the information called for concerning the disposition of electric energy generated, purchased, exchanged and wheeled during the year.

Line No. Item
(a)
MegaWatt Hours
(b)
Line No. Item
(a)
MegaWatt Hours
(b)
1
SOURCES OF ENERGY
21
DISPOSITION OF ENERGY
2
Generation (Excluding Station Use):
22
Sales to Ultimate Consumers (Including Interdepartmental Sales)
1,656,248
3
Steam
792,815
23
Requirements Sales for Resale (See instruction 4, page 311.)
4
Nuclear
24
Non-Requirements Sales for Resale (See instruction 4, page 311.)
5
Hydro-Conventional
25
Energy Furnished Without Charge
6
Hydro-Pumped Storage
26
Energy Used by the Company (Electric Dept Only, Excluding Station Use)
8,716
6.1
Solar
27
Total Energy Losses
10,166
6.2
Wind
282,265
27.1
Total Energy Stored
0
6.3
Other Renewable
28
TOTAL (Enter Total of Lines 22 Through 27.1) MUST EQUAL LINE 20 UNDER SOURCES
1,654,798
7
Other
158,738
8
Less Energy for Pumping
9
Net Generation (Enter Total of lines 3 through 8)
1,233,818
10
Purchases (other than for Energy Storage)
420,980
10.1
Purchases for Energy Storage
11
Power Exchanges:
12
Received
13
Delivered
14
Net Exchanges (Line 12 minus line 13)
15
Transmission For Other (Wheeling)
16
Received
24,195
17
Delivered
24,195
18
Net Transmission for Other (Line 16 minus line 17)
0
19
Transmission By Others Losses
20
TOTAL (Enter Total of Lines 9, 10, 10.1, 14, 18 and 19)
1,654,798


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
MONTHLY PEAKS AND OUTPUT
  1. Report the monthly peak load and energy output. If the respondent has two or more power which are not physically integrated, furnish the required information for each non- integrated system.
  2. Report in column (b) by month the system’s output in Megawatt hours for each month.
  3. Report in column (c) by month the non-requirements sales for resale. Include in the monthly amounts any energy losses associated with the sales.
  4. Report in column (d) by month the system’s monthly maximum megawatt load (60 minute integration) associated with the system.
  5. Report in column (e) and (f) the specified information for each monthly peak load reported in column (d).
Line No.
MonthAxis
Month
(a)
EnergyActivity
Total Monthly Energy
(b)
NonRequiredSalesForResaleEnergy
Monthly Non-Requirement Sales for Resale & Associated Losses
(c)
MonthlyPeakLoad
Monthly Peak - Megawatts
(d)
DayOfMonthlyPeak
Monthly Peak - Day of Month
(e)
HourOfMonthlyPeak
Monthly Peak - Hour
(f)
NAME OF SYSTEM: South Dakota Operations
29
January
173,605
0
327
21
9
30
February
154,995
0
333
18
9
31
March
148,199
0
269
5
9
32
April
124,271
0
235
8
8
33
May
103,776
0
260
13
17
34
June
91,476
0
347
20
17
35
July
118,412
0
281
9
17
36
August
157,128
0
279
21
16
37
September
165,656
0
278
12
17
38
October
167,176
0
285
3
17
39
November
94,569
0
195
10
11
40
December
155,535
0
302
18
12
41
Total
1,654,798


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
Steam Electric Generating Plant Statistics

1. Report data for plant in Service only.
2. Large plants are steam plants with installed capacity (name plate rating) of 25,000 Kw or more. Report in this page gas-turbine and internal combustion plants of 10,000 Kw or more, and nuclear plants.
3. Indicate by a footnote any plant leased or operated as a joint facility.
4. If net peak demand for 60 minutes is not available, give data which is available, specifying period.
5. If any employees attend more than one plant, report on line 11 the approximate average number of employees assignable to each plant.
6. If gas is used and purchased on a therm basis report the Btu content or the gas and the quantity of fuel burned converted to Mcf.
7. Quantities of fuel burned (Line 38) and average cost per unit of fuel burned (Line 41) must be consistent with charges to expense accounts 501 and 547 (Line 42) as show on Line 20.
8. If more than one fuel is burned in a plant furnish only the composite heat rate for all fuels burned.
9. Items under Cost of Plant are based on USofA accounts. Production expenses do not include Purchased Power, System Control and Load Dispatching, and Other Expenses Classified as Other Power Supply Expenses.
10. For IC and GT plants, report Operating Expenses, Account Nos. 547 and 549 on Line 25 "Electric Expenses," and Maintenance Account Nos. 553 and 554 on Line 32, "Maintenance of Electric Plant." Indicate plants designed for peak load service. Designate automatically operated plants.
11. For a plant equipped with combinations of fossil fuel steam, nuclear steam, hydro, internal combustion or gas-turbine equipment, report each as a separate plant. However, if a gas-turbine unit functions in a combined cycle operation with a conventional steam unit, include the gas-turbine with the steam plant.
12. If a nuclear power generating plant, briefly explain by footnote (a) accounting method for cost of power generated including any excess costs attributed to research and development; (b) types of cost units used for the various components of fuel cost; and (c) any other informative data concerning plant type fuel used, fuel enrichment type and quantity for the report period and other physical and operating characteristics of plant.

Line No.
Item
(a)
Plant Name:
Aberdeen #1
Plant Name:
Aberdeen #2
Plant Name:
(a)
Big Stone
Plant Name:
Bob Glanzer
Plant Name:
Coyote
Plant Name:
Neal
Plant Name:
Yankton
1
PlantKind
Kind of Plant (Internal Comb, Gas Turb, Nuclear)
(b)
Combustion Turbine
Combustion Turbine
(c)
Steam
(d)
Gas Turbine
(e)
Steam
(f)
Steam
(g)
Internal Combustion
2
PlantConstructionType
Type of Constr (Conventional, Outdoor, Boiler, etc)
Conventional
Conventional
Conventional
Conventional
Conventional
Conventional
Conventional
3
YearPlantOriginallyConstructed
Year Originally Constructed
1978
2013
1975
2022
1981
1979
1974
4
YearLastUnitOfPlantInstalled
Year Last Unit was Installed
1978
2013
1975
2022
1981
1979
1990
5
InstalledCapacityOfPlant
Total Installed Cap (Max Gen Name Plate Ratings-MW)
28.8
82.2
122.85
58.5
45.58
55.56
13.53
6
NetPeakDemandOnPlant
Net Peak Demand on Plant - MW (60 minutes)
28
60
112
55.7
43
55
13
7
PlantHoursConnectedToLoad
Plant Hours Connected to Load
0
1,069
7,563
9,766
6,405
2,880
0
8
NetContinuousPlantCapability
Net Continuous Plant Capability (Megawatts)
0
0
0
55.7
0
0
0
9
NetContinuousPlantCapabilityNotLimitedByCondenserWater
When Not Limited by Condenser Water
(h)
28
60
111
55.7
43
55
13
10
NetContinuousPlantCapabilityLimitedByCondenserWater
When Limited by Condenser Water
(i)
21
52
110
55.7
43
55
13
11
PlantAverageNumberOfEmployees
Average Number of Employees
0
9
0
12
NetGenerationExcludingPlantUse
Net Generation, Exclusive of Plant Use - kWh
0
56,170,000
425,641,000
103,273,000
194,968,000
172,206,000
(n)
52,000
13
CostOfLandAndLandRightsSteamProduction
Cost of Plant: Land and Land Rights
1,314
36,647
138,987
192,378
203,882
0
9,631
14
CostOfStructuresAndImprovementsSteamProduction
Structures and Improvements
20,586
10,385,543
10,417,529
15,296,974
9,861,345
8,516,350
348,247
15
CostOfEquipmentSteamProduction
Equipment Costs
298,520
40,575,915
147,362,609
71,872,752
43,544,209
58,223,749
7,790,041
16
AssetRetirementCostsSteamProduction
Asset Retirement Costs
0
0
1,447,835
0
1,412,834
302,404
0
17
CostOfPlant
Total Cost (10-23)
320,420
50,998,105
159,366,960
87,362,104
55,022,270
67,042,503
8,147,919
18
CostPerKilowattOfInstalledCapacity
Cost per KW of Installed Capacity (line 17/5) Including
11.13
620
1,297.25
1,493.37
1,207.16
1,206.67
602.21
19
OperationSupervisionAndEngineeringExpense
Production Expenses: Oper, Supv, & Engr
19,383
290,998
33,373
245,155
455,663
638
20
FuelSteamPowerGeneration
Fuel
0
2,229,450
12,097,855
2,716,165
6,506,771
5,175,660
0
21
CoolantsAndWater
Coolants and Water (Nuclear Plants Only)
0
0
0
0
0
0
0
22
SteamExpensesSteamPowerGeneration
Steam Expenses
0
0
486,554
0
456,017
553,756
0
23
SteamFromOtherSources
Steam From Other Sources
0
0
0
0
0
0
0
24
SteamTransferredCredit
Steam Transferred (Cr)
0
0
0
0
0
0
0
25
ElectricExpensesSteamPowerGeneration
Electric Expenses
0
733,397
420,023
1,274,269
245,378
9,715
24,136
26
MiscellaneousSteamPowerExpenses
Misc Steam (or Nuclear) Power Expenses
0
0
746,542
0
281,012
253,500
0
27
RentsSteamPowerGeneration
Rents
0
0
0
0
13,797
29,976
0
28
Allowances
Allowances
0
0
0
0
0
0
0
29
MaintenanceSupervisionAndEngineeringSteamPowerGeneration
Maintenance Supervision and Engineering
0
19,384
168,117
33,679
85,843
45,639
638
30
MaintenanceOfStructuresSteamPowerGeneration
Maintenance of Structures
0
0
137,373
0
97,334
153,216
0
31
MaintenanceOfBoilerPlantSteamPowerGeneration
Maintenance of Boiler (or reactor) Plant
0
0
1,390,115
0
1,307,808
774,501
0
32
MaintenanceOfElectricPlantSteamPowerGeneration
Maintenance of Electric Plant
0
1,318,503
98,985
292,115
522,600
198,636
101,252
33
MaintenanceOfMiscellaneousSteamPlant
Maintenance of Misc Steam (or Nuclear) Plant
0
0
172,742
0
276,853
125,525
0
34
PowerProductionExpensesSteamPower
Total Production Expenses
0
4,320,117
16,009,304
4,349,601
10,038,568
7,775,787
126,664
35
ExpensesPerNetKilowattHour
Expenses per Net kWh
0
0.076911
0.03761
0.042118
0.051488
0.045154
2.435846
35
FuelKindAxis
Plant Name
Aberdeen #2
Aberdeen #2
Big Stone
Big Stone
Big Stone
Bob Glanzer
Coyote
Coyote
Coyote
Neal
Neal
36
FuelKind
Fuel Kind
Gas
Oil
Coal
Lime
Oil
Gas
Coal
Lime
Oil
Coal
Oil
37
FuelUnit
Fuel Unit
MMBTU
bbl
T
T
bbl
MMBTU
T
T
bbl
T
bbl
38
QuantityOfFuelBurned
Quantity (Units) of Fuel Burned
687,477
0
319,802
2,515
1,687
839,689
181,672
1,304
1,495
107,763
2,807
39
FuelBurnedAverageHeatContent
Avg Heat Cont - Fuel Burned (btu/indicate if nuclear)
1,000
140,000
4,795
0
140,000
1,000
6,963
0
140,000
8,593
139,000
40
AverageCostOfFuelPerUnitAsDelivered
Avg Cost of Fuel/unit, as Delvd f.o.b. during year
2.5277
2.5277
34.5521
244.5355
97.8171
0.3356
31.7293
143.4130
92.4666
42.8985
166.7435
41
AverageCostOfFuelPerUnitBurned
Average Cost of Fuel per Unit Burned
2.5277
2.5277
34.5521
244.5355
97.8171
0.3356
31.7293
143.4130
92.4666
42.8985
166.7435
42
AverageCostOfFuelBurnedPerMillionBritishThermalUnit
Average Cost of Fuel Burned per Million BTU
2.5277
2.5277
3.6029
0.0000
16.6358
0.3356
2.2784
0.0000
15.7204
2.4961
28.5601
43
AverageCostOfFuelBurnedPerKilowattHourNetGeneration
Average Cost of Fuel Burned per kWh Net Gen
0.0397
0.0397
(o)
0.0284
0.0284
0.0284
0.0263
(p)
0.0334
0.0334
0.0334
(q)
0.0301
0.0301
44
AverageBritishThermalUnitPerKilowattHourNetGeneration
Average BTU per kWh Net Generation
12,239.2202
12,239.2202
(r)
7,228.6757
7,228.6757
7,228.6757
8,130.7699
(s)
6,533.2400
13,021.3926
13,021.3926
(t)
10,849.8089
10,849.8089


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
FOOTNOTE DATA

(a) Concept: PlantName

We have included this footnote due to rendering issues on page 404 to ensure information is submitted for our Renewable Generating Plant Statistics.

404 - Schedule - Renewable Generating Plant Statistics (Large Plants)

 

 

 

       

Line No.

Item
(a)

-

Value
(b)

0

Plant Name

Renewable Plant Name [Axis]

 

0.5

Beethoven Wind

Beethoven Wind

 

1

Kind of Plant (Solar, Wind, Biomass, etc.)

 

Wind

2

Type of Constr (PV Tracking, Offshore, Boiler, etc)

 

Wind turbine

3

Year Originally Constructed

 

2015

4

Year Last Unit was Installed

 

2015

5

Total Installed Cap (Max Gen Name Plate Ratings-MW)

 

80.00

6

Net Peak Demand on Plant - MW (60 minutes)

 

80.00

7

Plant Hours Connected to Load

 

8,760

8

Net Continuous Plant Capability (Megawatts)

 

79.00

9

Net Generation, Exclusive of Plant Use - KWh

 

282,265,000

10

Cost of Plant: Land and Land Rights

 

0

11

Structures and Improvements

 

14,557,823

12

Solar Panels, Wind Turbines and Generators

 

79,926,258

13

Fuel Holders

 

 

14

Boilers

 

 

15

Collector System

 

 

16

Generator Step-up Transformers (GSU)

 

 

17

Inverters

 

 

18

Other Accessory Electrical Equipment

 

4,648,825

19

Computer Hardware

 

 

20

Computer Software

 

 

21

Communication Equipment

 

 

22

Miscellaneous Power Plant Equipment

 

15,504,815

23

Asset Retirement Costs

 

1,351,541

24

Total Cost (10-23)

 

115,989,262

25

Cost per KW of Installed Capacity (line 24/5) Including

 

1,450.87

26

Production Expenses: Oper, Supv, & Engr

 

82,117

27

Generation and Other Plant Operating Expenses

 

2,834,524

28

Fuel

 

 

29

Steam Expenses

 

 

30

Electric Expenses

 

 

31

Misc Steam Power Expenses

 

 

32

Rents

 

428,630

33

Environmental Credits

 

 

34

Maintenance Supervision and Engineering

 

21,398

35

Maintenance of Structures and Equipment

 

193,092

36

Maintenance of Boiler Plant

 

 

37

Maintenance of Electric Plant

 

 

38

Maintenance of Computer Hardware

 

0

39

Maintenance of Computer Software

 

2,923

40

Maintenance of Communication Equipment

 

3,889

41

Maintenance of Misc Plant

 

8,383

42

Total Production Expenses

 

3,574,956

43

Expenses per Net KWh

 

0.01267

(b) Concept: PlantKind
Designed for peak load service.
(c) Concept: PlantKind

Big Stone - Respondent's share is 23.4%. Generation expenses and revenue are shared on ownership basis. This page represents the respondent's share of plant costs, production expenses and other data.

(d) Concept: PlantKind

Designed for peak load service. 

(e) Concept: PlantKind

Coyote - Respondent's share is 10%. Generation expenses and revenue are shared on ownership basis. This page represents the respondent's share of plant costs, production expenses and other data.

(f) Concept: PlantKind

Neal#4 - Respondent's share is 8.681%. Generation expenses and revenue are shared on ownership basis. This page represents the respondent's share of plant costs, production expenses and other data.

(g) Concept: PlantKind

Designed for peak load service. 

(h) Concept: NetContinuousPlantCapabilityNotLimitedByCondenserWater

Site 40F., Base

(i) Concept: NetContinuousPlantCapabilityLimitedByCondenserWater

Site 80F., Base

(j) Concept: PlantAverageNumberOfEmployees

All plant employees are employed by the plant operator, Otter Tail Power Co. 

(k) Concept: PlantAverageNumberOfEmployees

All employees are employed by the plant operator, CAT. 

(l) Concept: PlantAverageNumberOfEmployees

All plant employees are employed by the plant operator, Otter Tail Power Co.

(m) Concept: PlantAverageNumberOfEmployees

All plant employees are employed by the plant operator, Mid American Energy. 

(n) Concept: NetGenerationExcludingPlantUse

Station use exceeded generation

(o) Concept: AverageCostOfFuelBurnedPerKilowattHourNetGeneration
Average cost of all fuels burned per net KWh generated.
(p) Concept: AverageCostOfFuelBurnedPerKilowattHourNetGeneration
Average cost of all fuels burned per net KWh generated.
(q) Concept: AverageCostOfFuelBurnedPerKilowattHourNetGeneration
Average cost of all fuels burned per net KWh generated.
(r) Concept: AverageBritishThermalUnitPerKilowattHourNetGeneration
Average BTU per net KWh generated for all fuels.
(s) Concept: AverageBritishThermalUnitPerKilowattHourNetGeneration
Average BTU per net KWh generated for all fuels.
(t) Concept: AverageBritishThermalUnitPerKilowattHourNetGeneration
Average BTU per net KWh generated for all fuels.

Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
Hydroelectric Generating Plant Statistics
  1. Large plants are hydro plants of 10,000 Kw or more of installed capacity (name plate ratings).
  2. If any plant is leased, operated under a license from the Federal Energy Regulatory Commission, or operated as a joint facility, indicate such facts in a footnote. If licensed project, give project number.
  3. If net peak demand for 60 minutes is not available, give that which is available specifying period.
  4. If a group of employees attends more than one generating plant, report on line 11 the approximate average number of employees assignable to each plant.
  5. The items under Cost of Plant represent accounts or combinations of accounts prescribed by the Uniform System of Accounts. Production Expenses do not include Purchased Power, System control and Load Dispatching, and Other Expenses classified as "Other Power Supply Expenses."
  6. Report as a separate plant any plant equipped with combinations of steam, hydro, internal combustion engine, or gas turbine equipment.
Line No.
Item
(a)
FERC Licensed Project No.
Plant Name:
FERC Licensed Project No.
Plant Name:
FERC Licensed Project No.
Plant Name:
FERC Licensed Project No.
Plant Name:
FERC Licensed Project No.
Plant Name:
1
PlantKind
Kind of Plant (Run-of-River or Storage)
2
PlantConstructionType
Plant Construction type (Conventional or Outdoor)
3
YearPlantOriginallyConstructed
Year Originally Constructed
4
YearLastUnitOfPlantInstalled
Year Last Unit was Installed
5
InstalledCapacityOfPlant
Total installed cap (Gen name plate Rating in MW)
6
NetPeakDemandOnPlant
Net Peak Demand on Plant-Megawatts (60 minutes)
7
PlantHoursConnectedToLoad
Plant Hours Connect to Load
8
NetPlantCapabilityAbstract
Net Plant Capability (in megawatts)
9
NetPlantCapabilityUnderMostFavorableOperatingConditions
(a) Under Most Favorable Oper Conditions
10
NetPlantCapabilityUnderMostAdverseOperatingConditions
(b) Under the Most Adverse Oper Conditions
11
PlantAverageNumberOfEmployees
Average Number of Employees
12
NetGenerationExcludingPlantUse
Net Generation, Exclusive of Plant Use - kWh
13
CostOfPlantAbstract
Cost of Plant
14
CostOfLandAndLandRightsHydroelectricProduction
Land and Land Rights
15
CostOfStructuresAndImprovementsHydroelectricProduction
Structures and Improvements
16
CostOfReservoirsDamsAndWaterwaysHydroelectricProduction
Reservoirs, Dams, and Waterways
17
EquipmentCostsHydroelectricProduction
Equipment Costs
18
CostOfRoadsRailroadsAndBridgesHydroelectricProduction
Roads, Railroads, and Bridges
19
AssetRetirementCostsHydroelectricProduction
Asset Retirement Costs
20
CostOfPlant
Total Cost (10-23)
21
CostPerKilowattOfInstalledCapacity
Cost per KW of Installed Capacity (line 20 / 5)
22
ProductionExpensesAbstract
Production Expenses
23
OperationSupervisionAndEngineeringExpense
Operation Supervision and Engineering
24
WaterForPower
Water for Power
25
HydraulicExpenses
Hydraulic Expenses
26
ElectricExpensesHydraulicPowerGeneration
Electric Expenses
27
MiscellaneousHydraulicPowerGenerationExpenses
Misc Hydraulic Power Generation Expenses
28
RentsHydraulicPowerGeneration
Rents
29
MaintenanceSupervisionAndEngineeringHydraulicPowerGeneration
Maintenance Supervision and Engineering
30
MaintenanceOfStructuresHydraulicPowerGeneration
Maintenance of Structures
31
MaintenanceOfReservoirsDamsAndWaterways
Maintenance of Reservoirs, Dams, and Waterways
32
MaintenanceOfElectricPlantHydraulicPowerGeneration
Maintenance of Electric Plant
33
MaintenanceOfMiscellaneousHydraulicPlant
Maintenance of Misc Hydraulic Plant
34
PowerProductionExpensesHydraulicPower
Total Production Expenses (total 23 thru 33)
35
ExpensesPerNetKilowattHour
Expenses per net kWh


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
Pumped Storage Generating Plant Statistics
  1. Large plants and pumped storage plants of 10,000 Kw or more of installed capacity (name plate ratings).
  2. If any plant is leased, operating under a license from the Federal Energy Regulatory Commission, or operated as a joint facility, indicate such facts in a footnote. Give project number.
  3. If net peak demand for 60 minutes is not available, give that which is available, specifying period.
  4. If a group of employees attends more than one generating plant, report on Line 8 the approximate average number of employees assignable to each plant.
  5. The items under Cost of Plant represent accounts or combinations of accounts prescribed by the Uniform System of Accounts. Production Expenses do not include Purchased Power System Control and Load Dispatching, and Other Expenses classified as "Other Power Supply Expenses."
  6. Pumping energy (Line 10) is that energy measured as input to the plant for pumping purposes.
  7. Include on Line 36 the cost of energy used in pumping into the storage reservoir. When this item cannot be accurately computed leave Lines 36, 37 and 38 blank and describe at the bottom of the schedule the company's principal sources of pumping power, the estimated amounts of energy from each station or other source that individually provides more than 10 percent of the total energy used for pumping, and production expenses per net MWH as reported herein for each source described. Group together stations and other resources which individually provide less than 10 percent of total pumping energy. If contracts are made with others to purchase power for pumping, give the supplier contract number, and date of contract.
Line No.
Item
(a)
FERC Licensed Project No.
Plant Name:
FERC Licensed Project No.
Plant Name:
FERC Licensed Project No.
Plant Name:
FERC Licensed Project No.
Plant Name:
1
PlantConstructionType
Type of Plant Construction (Conventional or Outdoor)
2
YearPlantOriginallyConstructed
Year Originally Constructed
3
YearLastUnitOfPlantInstalled
Year Last Unit was Installed
4
InstalledCapacityOfPlant
Total installed cap (Gen name plate Rating in MW)
5
NetPeakDemandOnPlant
Net Peak Demaind on Plant-Megawatts (60 minutes)
6
PlantHoursConnectedToLoad
Plant Hours Connect to Load While Generating
7
NetContinuousPlantCapability
Net Plant Capability (in megawatts)
8
PlantAverageNumberOfEmployees
Average Number of Employees
9
NetGenerationExcludingPlantUse
Generation, Exclusive of Plant Use - kWh
10
EnergyUsedForPumping
Energy Used for Pumping
11
NetOutputForLoad
Net Output for Load (line 9 - line 10) - Kwh
12
CostOfPlantAbstract
Cost of Plant
13
CostOfLandAndLandRightsPumpedStoragePlant
Land and Land Rights
14
CostOfStructuresAndImprovementsPumpedStoragePlant
Structures and Improvements
15
CostOfReservoirsDamsAndWaterwaysPumpedStoragePlant
Reservoirs, Dams, and Waterways
16
CostOfWaterWheelsTurbinesAndGeneratorsPumpedStoragePlant
Water Wheels, Turbines, and Generators
17
CostOfAccessoryElectricEquipmentPumpedStoragePlant
Accessory Electric Equipment
18
CostOfMiscellaneousPowerPlantEquipmentPumpedStoragePlant
Miscellaneous Powerplant Equipment
19
CostOfRoadsRailroadsAndBridgesPumpedStoragePlant
Roads, Railroads, and Bridges
20
AssetRetirementCostsPumpedStoragePlant
Asset Retirement Costs
21
CostOfPlant
Total Cost (10-23)
22
CostPerKilowattOfInstalledCapacity
Cost per KW of installed cap (line 21 / 4)
23
ProductionExpensesAbstract
Production Expenses
24
OperationSupervisionAndEngineeringExpense
Operation Supervision and Engineering
25
WaterForPower
Water for Power
26
PumpedStorageExpenses
Pumped Storage Expenses
27
ElectricExpensesPumpedStoragePlant
Electric Expenses
28
MiscellaneousPumpedStoragePowerGenerationExpenses
Misc Pumped Storage Power generation Expenses
29
RentsPumpedStoragePlant
Rents
30
MaintenanceSupervisionAndEngineeringPumpedStoragePlant
Maintenance Supervision and Engineering
31
MaintenanceOfStructuresPumpedStoragePlant
Maintenance of Structures
32
MaintenanceOfReservoirsDamsAndWaterwaysPumpedStoragePlant
Maintenance of Reservoirs, Dams, and Waterways
33
MaintenanceOfElectricPlantPumpedStoragePlant
Maintenance of Electric Plant
34
MaintenanceOfMiscellaneousPumpedStoragePlant
Maintenance of Misc Pumped Storage Plant
35
PowerProductionExpenseBeforePumpingExpenses
Production Exp Before Pumping Exp (24 thru 34)
36
PumpingExpenses
Pumping Expenses
37
PowerProductionExpensesPumpedStoragePlant
Total Production Exp (total 35 and 36)
38
ExpensesPerNetKilowattHour
Expenses per kWh (line 37 / 9)
39
ExpensesPerNetKilowattHourGenerationAndPumping
Expenses per KWh of Generation and Pumping (line 37/(line 9 + line 10))


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
GENERATING PLANT STATISTICS (Small Plants)
  1. Small generating plants are steam plants of, less than 25,000 Kw; internal combustion and gas turbine-plants, conventional hydro plants, pumped storage plants, and renewable plants of less than 10,000 Kw installed capacity (name plate rating).
  2. Designate any plant leased from others, operated under a license from the Federal Energy Regulatory Commission, or operated as a joint facility, and give a concise statement of the facts in a footnote. If licensed project, give project number in footnote.
  3. List plants appropriately under subheadings for steam, hydro, nuclear, renewable, internal combustion and gas turbine plants. For nuclear, see instruction 11, Page 402.
  4. If net peak demand for 60 minutes is not available, give the which is available, specifying period.
  5. If any plant is equipped with combinations of steam, hydro internal combustion or gas turbine equipment, report each as a separate plant. However, if the exhaust heat from the gas turbine is utilized in a steam turbine regenerative feed water cycle, or for preheated combustion air in a boiler, report as one plant.
Production Expenses
Line No.
PlantName
Name of Plant
(a)
YearPlantOriginallyConstructed
Year Orig. Const.
(b)
InstalledCapacityOfPlant
Installed Capacity Name Plate Rating (MW)
(c)
NetPeakDemandOnPlant
Net Peak Demand MW (60 min)
(d)
NetGenerationExcludingPlantUse
Net Generation Excluding Plant Use
(e)
CostOfPlant
Cost of Plant
(f)
PlantCostPerMw
Plant Cost (Incl Asset Retire. Costs) Per MW
(g)
OperatingExpensesExcludingFuel
Operation Exc'l. Fuel
(h)
FuelProductionExpenses
Fuel Production Expenses
(i)
MaintenanceProductionExpenses
Maintenance Production Expenses
(j)
FuelKind
Kind of Fuel
(k)
FuelCostPerMmbtus
Fuel Costs (in cents (per Million Btu)
(l)
GenerationType
Generation Type
(m)
1
Clark
1970
2.75
2.72
141,000
955,824
347,572
2,089
0
26,189
Oil
0
Internal Combustion
2
Faulkton
1969
2.75
2.5
161,000
1,682,420
611,789
2,225
456
19,090
Oil
2,011.652
Internal Combustion
3
Highmore
1948
4.785
4.68
0
50,385
10,530
0
0
0
Oil
0
Internal Combustion
4
Redfield
1962
4.08
3.96
0
554,692
135,954
0
0
0
Oil/Gas
0
Internal Combustion
5
Mobile B
1991
1.75
1.75
52,000
563,424
321,956
0
2,651
15,534
Oil
3,310.639
Internal Combustion
6
Mobile C
2008
2.5
2
51,000
1,064,946
425,978
0
919
15,856
Oil
3,046.912
Internal Combustion
7
Mobile 1
2020
1
1
42,000
1,293,539
1,293,539
0
871
26,674
Oil
1,454.523
Internal Combustion
8
Mobile 2
2020
1
1
23,000
1,293,539
1,293,539
0
667
18,921
Oil
2,855.216
Internal Combustion
9
Mobile 3
2020
1
1
34,000
1,293,539
1,293,539
36,198
1,337
19,559
Oil
1,962.605
Internal Combustion
10
Mobile 4
2020
1
1
26,000
1,293,539
1,293,539
0
807
18,750
Oil
2,765.742
Internal Combustion
11
Mobile 5
2020
1
1
38,000
1,293,539
1,293,539
77
1,565
15,227
Oil
2,426.709
Internal Combustion
12
Mobile 6
2020
1
1
22,000
1,293,539
1,293,539
0
826
18,162
Oil
2,816.291
Internal Combustion
13
Mobile 7
2020
1
1
28,000
1,293,539
1,293,539
471
808
18,408
Oil
2,794.099
Internal Combustion
14
Mobile 8
2020
1
1
35,000
1,293,539
1,293,539
1,017
1,121
16,256
Oil
1,296.456
Internal Combustion
15
Mobile 9
2025
1
1
0
260,095
260,095
0
0
0
Oil
0
Internal Combustion
16
Mobile 10
2025
1
1
0
260,095
260,095
0
0
0
Oil
0
Internal Combustion
17
Total
653,000
15,740,190
12,202,091
(a)
42,077
12,028
228,626
26,740.844


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
FOOTNOTE DATA

(a) Concept: OperatingExpensesExcludingFuel

Net Generation:

 

Page 402-403

                                   952,206

Page 404

                                   282,265

Page 410-411

                                        (653)

Ties to Page 401, line 9

                                1,233,818

 

Production Expenses:

 

Big Stone, Coyote, Neal (Page 402) agrees total Steam Power Production - page 320 line 21

33,823,659

Yankton, Aberdeen #1, Aberdeen #2, Bob Glanzer (Page 402)

8,796,382

Other power generation (Page 410)

282,730

Total Other Power Production expense page 320 line 74

9,079,112

Beethoven Wind (Page 404) agrees total Wind Power Production expense page 320 line 79.31

3,574,956

Ties to total of Page 320, lines 21, 74, and 79.31, column (b)

46,477,727


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
ENERGY STORAGE OPERATIONS (Large Plants)
  1. Large Plants are plants of 10,000 Kw or more.
  2. In columns (a) and (b) report the name of the energy storage project and location.
  3. In column (c), report Megawatt hours (MWH) purchased, generated, or received in exchange transactions for storage.
  4. In column (d) report MWHs delivered to the grid to support production, transmission and distribution. The amount reported in column (c) should include MWHs delivered/provided to a generator’s own load requirements or used for the provision of ancillary services.
  5. In column (e) report MWHs lost during conversion, storage and discharge of energy.
  6. In column (f) report the MWHs sold.
  7. In column (g), report revenues from energy storage operations. In a footnote, disclose the revenue accounts and revenue amounts related to the income generating activity.
  8. In column (h), report the cost of power purchased for storage operations and reported in Account 555.1, Power Purchased for Storage Operations. If power was purchased from an affiliated seller specify how the cost of the power was determined. In columns (i) and (j), report fuel costs for storage operations associated with self-generated power and other costs associated with self-generated power.
  9. In column (l) report the total project plant costs including but not exclusive of land and land rights, structures and improvements, energy storage equipment, turbines, compressors, generators, switching and conversion equipment, lines and equipment whose primary purpose is to integrate or tie energy storage assets into the power grid, and any other costs associated with the energy storage project included in the property accounts listed.
Line No.
Name of the Energy Storage Project
(a)
Location of the Project
(b)
MWHs
(c)
MWHs delivered to the grid
(d)
MWHs Lost During Conversion, Storage and Discharge of Energy
(e)
MWHs Sold
(f)
Revenues from Energy Storage Operations
(g)
Power Purchased for Storage Operations (555.1) (Dollars)
(h)
Fuel Costs from associated fuel accounts for Storage Operations Associated with Self-Generated Power (Dollars)
(i)
Other Costs Associated with Self-Generated Power (Dollars)
(j)
Account for Project Costs
(k)
Total Project Plant Costs
(l)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35 TOTAL


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
ENERGY STORAGE OPERATIONS (Small Plants)
  1. Small Plants are plants less than 10,000 Kw.
  2. In columns (a) and (b) report the name of the energy storage project, and location.
  3. In column (c), report project plant cost including but not exclusive of land and land rights, structures and improvements, energy storage equipment and any other costs associated with the energy storage project.
  4. In column (d), report operation expenses excluding fuel, (e), maintenance expenses, (f) fuel costs for storage operations and (g) cost of power purchased for storage operations and reported in Account 555.1, Power Purchased for Storage Operations. If power was purchased from an affiliated seller specify how the cost of the power was determined.
  5. If any other expenses, report in column (h) and footnote the nature of the item(s).
Plant Operating Expenses
Line No.
Name of the Energy Storage Project
(a)
Location of the Project
(b)
Project Cost
(c)
Operations (Excluding Fuel used in Storage Operations)
(d)
Maintenance
(e)
Cost of fuel used in storage operations
(f)
Account No. 555.1, Power Purchased for Storage Operations
(g)
Other Expenses
(h)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36 TOTAL


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
TRANSMISSION LINE STATISTICS
  1. Report information concerning transmission lines, cost of lines, and expenses for year. List each transmission line having nominal voltage of 132 kilovolts or greater. Report transmission lines below these voltages in group totals only for each voltage. If required by a State commission to report individual lines for all voltages, do so but do not group totals for each voltage under 132 kilovolts.
  2. Transmission lines include all lines covered by the definition of transmission system plant as given in the Uniform System of Accounts. Do not report substation costs and expenses on this page.
  3. Exclude from this page any transmission lines for which plant costs are included in Account 121, Nonutility Property.
  4. Indicate whether the type of supporting structure reported in column (e) is: (1) single pole wood or steel; (2) H-frame wood, or steel poles; (3) tower; or (4) underground construction If a transmission line has more than one type of supporting structure, indicate the mileage of each type of construction by the use of brackets and extra lines. Minor portions of a transmission line of a different type of construction need not be distinguished from the remainder of the line.
  5. Report in columns (f) and (g) the total pole miles of each transmission line. Show in column (f) the pole miles of line on structures the cost of which is reported for the line designated; conversely, show in column (g) the pole miles of line on structures the cost of which is reported for another line. Report pole miles of line on leased or partly owned structures in column (g). In a footnote, explain the basis of such occupancy and state whether expenses with respect to such structures are included in the expenses reported for the line designated.
  6. Do not report the same transmission line structure twice. Report lower voltage lines and higher voltage lines as one line. Designate in a footnote if you do not include lower voltage lines with higher voltage lines. If two or more transmission line structures support lines of the same voltage, report the pole miles of the primary structure in column (f) and the pole miles of the other line(s) in column (g).
  7. Designate any transmission line or portion thereof for which the respondent is not the sole owner. If such property is leased from another company, give name of lessor, date and terms of lease, and amount of rent for year. For any transmission line other than a leased line, or portion thereof, for which the respondent is not the sole owner but which the respondent operates or shares in the operation of, furnish a succinct statement explaining the arrangement and giving particulars (details) of such matters as percent ownership by respondent in the line, name of co-owner, basis of sharing expenses of the line, and how the expenses borne by the respondent are accounted for, and accounts affected. Specify whether lessor, co-owner, or other party is an associated company.
  8. Designate any transmission line leased to another company and give name of lessee, date and terms of lease, annual rent for year, and how determined. Specify whether lessee is an associated company.
  9. Base the plant cost figures called for in columns (j) to (l) on the book cost at end of year.
DESIGNATION VOLTAGE (KV) - (Indicate where other than 60 cycle, 3 phase) LENGTH (Pole miles) - (In the case of underground lines report circuit miles) COST OF LINE (Include in column (j) Land, Land rights, and clearing right-of-way) EXPENSES, EXCEPT DEPRECIATION AND TAXES
Line No.
TransmissionLineStartPoint
From
TransmissionLineEndPoint
To
OperatingVoltageOfTransmissionLine
Operating
DesignedVoltageOfTransmissionLine
Designated
SupportingStructureOfTransmissionLineType
Type of Supporting Structure
LengthForStandAloneTransmissionLines
On Structure of Line Designated
LengthForTransmissionLinesAggregatedWithOtherStructures
On Structures of Another Line
NumberOfTransmissionCircuits
Number of Circuits
SizeOfConductorAndMaterial
Size of Conductor and Material
CostOfLandAndLandRightsTransmissionLines
Land
ConstructionAndOtherCostsTransmissionLines
Construction Costs
OverallCostOfTransmissionLine
Total Costs
OperatingExpensesOfTransmissionLine
Operation Expenses
MaintenanceExpensesOfTransmissionLine
Maintenance Expenses
RentExpensesOfTransmissionLine
Rents
OverallExpensesOfTransmissionLine
Total Expenses
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
(k)
(l)
(m)
(n)
(o)
(p)
1
(a)
Big Stone SD
Gary, SD
230
230
18
1
1272 MCM
8,674
1,278,111
1,286,785
0
0
0
0
2
(b)
Coyote, ND
Center, ND
345
345
23
1
954 MCM
223,226
3,211,876
3,435,102
0
0
0
0
3
(c)
Neal, IA
Hinton, IA
345
345
24
1
954 MCM
16,579
616,871
633,450
0
0
0
0
4
Less non-NWE 345kV partial ownership miles
22
5
Various
115
354
6
Various
69
262
7
Various
34.5
685
Various
1,625,928
106,497,066
108,122,994
216,089
494,281
21,415
731,784
8
Rounding
1
1
36 TOTAL
1,344
0
3
1,874,407
111,603,925
113,478,331
216,089
494,281
21,415
731,784


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
FOOTNOTE DATA

(a) Concept: TransmissionLineStartPoint

Big Stone - Respondent's share is 23.4%. Generation expenses and revenue are shared on ownership basis. Operator issues an operating report monthly. Production accounts are generally affected. None of the co-owners are associated companies. Data reported is respondent's share plus any company expense.

(b) Concept: TransmissionLineStartPoint

Coyote - Respondent's share is 10%. Generation expenses and revenue are shared on ownership basis. Operator issues an operating report monthly. Production accounts are generally affected. None of the co-owners are associated companies. Data reported is respondent's share plus any company expense.

(c) Concept: TransmissionLineStartPoint

Neal #4 - Respondent's share is 8.681%. Generation expenses and revenue are shared on ownership basis. Operator issues an operating report monthly. Production accounts are generally affected. None of the co-owners are associated companies. Data reported is respondent's share plus any company expense.


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
TRANSMISSION LINES ADDED DURING YEAR
  1. Report below the information called for concerning Transmission lines added or altered during the year. It is not necessary to report minor revisions of lines.
  2. Provide separate subheadings for overhead and under- ground construction and show each transmission line separately. If actual costs of competed construction are not readily available for reporting columns (l) to (o), it is permissible to report in these columns the costs. Designate, however, if estimated amounts are reported. Include costs of Clearing Land and Rights-of-Way, and Roads and Trails, in column (l) with appropriate footnote, and costs of Underground Conduit in column (m).
  3. If design voltage differs from operating voltage, indicate such fact by footnote; also where line is other than 60 cycle, 3 phase, indicate such other characteristic.
LINE DESIGNATION SUPPORTING STRUCTURE CIRCUITS PER STRUCTURE CONDUCTORS LINE COST
Line No.
TransmissionLineStartPoint
From
TransmissionLineEndPoint
To
LengthOfTransmissionLineAdded
Line Length in Miles
SupportingStructureOfTransmissionLineType
Type
AverageNumberOfSupportingStructuresOfTransmissionLinePerMiles
Average Number per Miles
NumberOfTransmissionCircuitsPerStructurePresent
Present
NumberOfTransmissionCircuitsPerStructureUltimate
Ultimate
ConductorSize
Size
ConductorSpecification
Specification
ConductorConfigurationAndSpacing
Configuration and Spacing
OperatingVoltageOfTransmissionLine
Voltage KV (Operating)
CostOfLandAndLandRightsTransmissionLinesAdded
Land and Land Rights
CostOfPolesTowersAndFixturesTransmissionLinesAdded
Poles, Towers and Fixtures
CostOfConductorsAndDevicesTransmissionLinesAdded
Conductors and Devices
Asset Retire. Costs
CostOfTransmissionLinesAdded
Total
SupportingStructureConstructionType
Construction
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
(k)
(l)
(m)
(n)
(o)
(p)
(q)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
TOTAL


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
SUBSTATIONS
  1. Report below the information called for concerning substations of the respondent as of the end of the year.
  2. Substations which serve only one industrial or street railway customer should not be listed below.
  3. Substations with capacities of Less than 10 MVA except those serving customers with energy for resale, may be grouped according to functional character, but the number of such substations must be shown.
  4. Indicate in column (b) the functional character of each substation, designating whether transmission or distribution and whether attended or unattended. At the end of the page, summarize according to function the capacities reported for the individual stations in column (f).
  5. Show in columns (I), (j), and (k) special equipment such as rotary converters, rectifiers, condensers, etc. and auxiliary equipment for increasing capacity.
  6. Designate substations or major items of equipment leased from others, jointly owned with others, or operated otherwise than by reason of sole ownership by the respondent. For any substation or equipment operated under lease, give name of lessor, date and period of lease, and annual rent. For any substation or equipment operated other than by reason of sole ownership or lease, give name of co-owner or other party, explain basis of sharing expenses or other accounting between the parties, and state amounts and accounts affected in respondent's books of account. Specify in each case whether lessor, co-owner, or other party is an associated company.
Character of Substation VOLTAGE (In MVa) Conversion Apparatus and Special Equipment
Line No.
SubstationNameAndLocation
Name and Location of Substation
(a)
SubstationCharacterDescription
Transmission or Distribution
(b)
SubstationCharacterAttendedOrUnattended
Attended or Unattended
(b-1)
PrimaryVoltageLevel
Primary Voltage (In MVa)
(c)
SecondaryVoltageLevel
Secondary Voltage (In MVa)
(d)
TertiaryVoltageLevel
Tertiary Voltage (In MVa)
(e)
SubstationInServiceCapacity
Capacity of Substation (In Service) (In MVa)
(f)
NumberOfTransformersInService
Number of Transformers In Service
(g)
Number of Spare Transformers
(h)
ConversionApparatusAndSpecialEquipmentType
Type of Equipment
(i)
NumberOfConversionApparatusAndSpecialEquipmentUnits
Number of Units
(j)
CapacityOfConversionApparatusAndSpecialEquipment
Total Capacity (In MVa)
(k)
1
Groton Basin Operated (SD)
Transmission
Unattended
345
115
195
1
2
Webster NW (SD)
Transmission
Unattended
69
4.16
5
1
3
Clark Jct. (SD)
Transmission
Unattended
69
4.16
7
1
Fans
5
4
WMU West Sub (SD)
Transmission
Unattended
115
69
25
1
Fans
13
5
Yankton East Plant A (SD)
Transmission
Unattended
34.4
12.5
7
1
6
Yankton East Plant B (SD)
Transmission
Unattended
34.4
12.5
20
1
Fans
8
7
Chamberlin (SD)
Transmission
Unattended
69
12.5
12
1
Fans
3
8
WAPA Mt. Vernon (SD)
Transmission
Unattended
115
69
13.8
40
1
Fans
16
9
Stickney Jct. (SD)
Transmission
Unattended
69
34.5
25
1
Fans
10
10
Aberdeen Industrial Park (SD)
Transmission
Unattended
115
34.4
60
1
Fans
36
11
Redfield A (SD)
Transmission
Unattended
115
34.4
42
1
Fans
17
12
Redfield B (SD)
Transmission
Unattended
34.4
4.16
1
3
13
Redfield C (SD)
Transmission
Unattended
67
34.4
20
1
Fans, Pumps
8
14
Redfield D (SD)
Transmission
Unattended
34.4
12.5
4
1
Fans
1
15
WAPA Broadland (SD)
Transmission
Unattended
230
115
100
3
16
Aberdeen Siebrecht A (SD)
Transmission
Unattended
115
34.4
60
1
Fans
24
17
Aberdeen Siebrecht B (SD)
Transmission
Unattended
34.5
13.2
28
1
Fans
13
18
Aberdeen Siebrecht C (SD)
Transmission
Unattended
34.5
12.47
14
1
Fans
2
19
Aberdeen Siebrecht D (SD)
Transmission
Unattended
115
13.8
84
1
Fans
34
20
Huron West Park A (SD)
Transmission
Unattended
67
34.4
20
1
Fans
8
21
Huron West Park B (SD)
Transmission
Unattended
110
69
60
1
Fans
24
22
Huron West Park C (SD)
Transmission
Unattended
110
69
60
1
Fans
24
23
Dakota Access A (SD)
Transmission
Unattended
115
4.16
20
1
Fans
6
24
Dakota Access B (SD)
Transmission
Unattended
115
4.16
20
1
Fans
6
25
Mitchell A (SD)
Transmission
Unattended
115
34.4
40
1
Fans
16
26
Mitchell B (SD)
Transmission
Unattended
115
34.4
40
1
Fans
16
27
Mitchell NW (SD)
Transmission
Unattended
115
34.4
42
1
Fans
17
28
Huron Gas Turbine Plant A (SD)
Transmission
Unattended
69
12.47
20
1
OA/FA/FA
8
29
Huron Gas Turbnie Plant B (SD)
Transmission
Unattended
69
24.9
14
1
Fans
3
30
Huron Gas Turbine Plant C (SD)
Transmission
Unattended
69
13.8
75
1
Fans
45
31
Highmore Plant A (SD)
Transmission
Unattended
67
34.4
11
1
Fans
3
32
Highmore Plant B (SD)
Transmission
Unattended
34.5
4.16
6
1
Fans
1
33
Highmore ER Interconnect (SD)
Transmission
Unattended
69
69
20
8
34
Aberdeen A (SD)
Transmission
Unattended
115
12.47
25
1
Fans
10
35
Aberdeen B (SD)
Transmission
Unattended
115
34.4
60
1
Fans
24
36
Tripp Jct. (SD)
Transmission
Unattended
115
34.4
40
1
Fans
16
37
Yankton Jct. A (SD)
Transmission
Unattended
115
34.4
42
1
Fans
17
38
Yankton Jct. B (SD)
Transmission
Unattended
115
34.4
42
1
Fans
17
39
Menno Jct. (SD)
Transmission
Unattended
115
34.4
20
1
Fans
8
40
Yankton East A (SD)
Transmission
Unattended
115
34.5
60
1
Fans
41
Yankton East B (SD)
Transmission
Unattended
34.4
12.5
25
1
Fans
25
42
Schroeder (Beethoven Wind) (SD)
Transmission
Unattended
115
34.5
83
1
Fans
33
43
Big Stone Plant A (SD)
Transmission
Unattended
230
115
13.8
54
1
1
44
Big Stone Plant B (SD)
Transmission
Unattended
22.9
230
123
1
45
Neal #4, Iowa (SD)
Transmission
Unattended
24
345
61
1
1
46
Coyote, North Dakota (SD)
Transmission
Unattended
22.9
345
48
1
1
47
Redfield City (SD)
Transmission
Unattended
34.4
4.16
15
1
Fans
2
48
Yankton Hilltop (SD)
Transmission
Unattended
34.4
12.5
24
1
Fans
13
49
12 others under 10,000 MVA (SD)
Transmission
Unattended
49.375
10
50
Total Transmission
51
Alpena (SD)
Distribution
Unattended
34.4
12.5
14
1
Fans
4
52
Platte A (SD)
Distribution
Unattended
34.4
4.16
5
1
Fans
1
53
Platte B (SD)
Distribution
Unattended
67
34.5
14
1
Fans
4
54
Wagner (SD)
Distribution
Unattended
34.4
12.5
10
1
Fans
4
55
SW Wagner (SD)
Distribution
Unattended
34.4
12.5
10
1
Fans
4
56
SW Freeman (SD)
Distribution
Unattended
34.4
25
12.47
12
1
Fans
4
57
Cham. Missouri View (SD)
Distribution
Unattended
67
12.5
10
1
Fans
4
58
Aberdeen 4th Street (SD)
Distribution
Unattended
34.4
12.5
14
1
Fans
4
59
Aberdeen 8th Avenue (SD)
Distribution
Unattended
34.4
12.5
14
1
Fans
4
60
Aberdeen Cemetary (SD)
Distribution
Unattended
34.4
12.5
14
1
Fans
4
61
Aberdeen Fairgrounds (SD)
Distribution
Unattended
34.5
12.5
14
4
62
Aberdeen Country Club (SD)
Distribution
Unattended
34.4
12.47
14
1
Fans
4
63
Aberdeen (NW CC) (SD)
Distribution
Unattended
34.4
12.5
10
1
64
Aberdeen Industrial Park (SD)
Distribution
Unattended
34.4
12.5
24
1
Fans
13
65
Aberdeen SE A (SD)
Distribution
Unattended
34.4
12.5
14
1
Fans
4
66
Aberdeen SE B (SD)
Distribution
Unattended
34.4
12.5
14
1
Fans
4
67
Aberdeen NE Gas Plant A (SD)
Distribution
Unattended
34.4
12.5
10
1
68
Aberdeen NE Gas Plant B (SD)
Distribution
Unattended
34.4
12.5
14
1
Fans
4
69
Aberdeen Ethanol (SD)
Distribution
Unattended
34.4
12.5
14
1
Fans
4
70
Henry (SD)
Distribution
Unattended
69
24.9
14
1
Fans
3
71
Huron SW (SD)
Distribution
Unattended
67
12.5
10
1
72
Huron Frank Avenue (SD)
Distribution
Unattended
67
12.5
12
1
73
Huron City A (SD)
Distribution
Unattended
69
12.5
20
1
Fans
8
74
Huron City B (SD)
Distribution
Unattended
69
12.5
20
1
Fans
8
75
Mitchell Lake Mitchell (SD)
Distribution
Unattended
34.4
12.5
14
1
Fans
4
76
Mitchell Bridle Acres (SD)
Distribution
Unattended
34.4
12.5
20
1
Fans
8
77
Mitchell Jr. High A (SD)
Distribution
Unattended
34.4
12.5
6
1
Fans
1
78
Mitchell Jr. High B (SD)
Distribution
Unattended
34.4
12.5
5
1
Fans
5
79
Mitchell Park A (SD)
Distribution
Unattended
34.4
12.5
25
1
Fans
15
80
Mitchell Park B (SD)
Distribution
Unattended
34.4
12.5
25
1
Fans
15
81
Ohlman Substation (SD)
Distribution
Unattended
34.4
12.5
14
1
Fans
4
82
Mitchell S. Edgerton (SD)
Distribution
Unattended
34.4
12.5
14
1
Fans
4
83
Mitchell S. Kimball (SD)
Distribution
Unattended
34.4
12.5
14
1
Fans
4
84
(116H) Scotland-Town
Distribution
Unattended
34.4
4.16
14
1
Fans
4
85
Yankton NW (SD)
Distribution
Unattended
34.4
12.5
20
1
Fans
8
86
Yankton Warehouse (SD)
Distribution
Unattended
34.4
12.5
14
1
Fans
87
Yankton Sacred Heart (SD)
Distribution
Unattended
34.4
12.5
14
1
Fans
4
88
Yankton SE (SD)
Distribution
Unattended
34.4
12.5
14
1
Fans
4
89
Yankton City (SD)
Distribution
Unattended
34.4
12.5
14
1
Fans
4
90
48 Others Under 10,000 KVA (SD)
Distribution
Unattended
139.98
91
92
Total
5,953
2,920.02
40.07
2,656.355
190
3
717


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
TRANSACTIONS WITH ASSOCIATED (AFFILIATED) COMPANIES
  1. Report below the information called for concerning all non-power goods or services received from or provided to associated (affiliated) companies.
  2. The reporting threshold for reporting purposes is $250,000. The threshold applies to the annual amount billed to the respondent or billed to an associated/affiliated company for non-power goods and services. The good or service must be specific in nature. Respondents should not attempt to include or aggregate amounts in a nonspecific category such as "general".
  3. Where amounts billed to or received from the associated (affiliated) company are based on an allocation process, explain in a footnote.
Line No.
Description of the Good or Service
(a)
Name of Associated/Affiliated Company
(b)
Account(s) Charged or Credited
(c)
Amount Charged or Credited
(d)
1
Non-power Goods or Services Provided by Affiliated
2
Labor and Benefits
NorthWestern Corporation
39,286,974
3
Board of Director Fees
NorthWestern Energy Group, Inc
174,125
19
20
Non-power Goods or Services Provided for Affiliated
21
Administration Fee
NorthWestern Energy Group, Inc
9,650
42


Name of Respondent:

NorthWestern Energy Public Service Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2025
Year/Period of Report

End of:
2025
/
Q4
FOOTNOTE DATA

(a) Concept: AccountsChargedOrCreditedTransactionsWithAssociatedAffiliatedCompanies

Labor and Benefits are charged to FERC account based on time card coding.