Contact Information
Tom Glanzer
South Dakota/Nebraska Area Community Relations Manager
Aberdeen III Natural Gas Plant
Reliable, flexible energy to support South Dakota’s growing power needs
Project overview
Project overview
NorthWestern Energy is evaluating the feasibility of constructing the Aberdeen III Natural Gas Plant, a 131‑megawatt simple cycle natural gas fired generation facility consisting of three Solar Titan 350 Combustion Turbine Generator Sets.
A final decision on the project, designed to support long‑term electric reliability in South Dakota, is expected in the third quarter of 2026.
The project will follow the Southwest Power Pool’s Expedited Resource Adequacy Study (ERAS) process. The facility would be built just north of NorthWestern Energy’s existing Siebrecht Substation, on a 165-acre plot NorthWestern Energy owns. The site is zoned for industrial use.
Building the plant near the existing NorthWestern Energy Siebrecht substation will allow for shared infrastructure and more efficient operations.
Aberdeen III Natural Gas Plant
131
Megawatts
24/7
Dispatchable capacity resource
2030
Helps meet the required amount of power NorthWestern Energy must have available by 2030 to meet resource adequacy requirements.
Energy reliability and system benefits
Energy reliability and system benefits
- Helps meet the required amount of power NorthWestern Energy must have available by
2030 to meet resource adequacy requirements. - Supports future growth and increased electricity demand in NorthWestern Energy’s South Dakota service area.
- Provides 24/7, flexible, dispatchable generation, meaning power is available when it is needed by South Dakotans.
- Strengthens grid stability using modern, efficient technology
Know the truth about the Aberdeen III Natural Gas Plant:
Construction jobs
The project is expected to create 250 jobs at peak construction during the 3-4 year
construction phase.
Long‑term employment
Once operational, the facility will require about 20 permanent, qualified skilled positions to support ongoing operations and maintenance.
Infrastructure upgrades
Upgrades to local infrastructure has the potential to support additional industry growth in the Aberdeen area.
Property taxes
The facility would generate new property tax revenue that supports local governments and public services.
Project Timeline
Upcoming key milestones:
- Q3 2026: Final decision expected
- Q4 2026: Engineering, procurement and construction contract awarded
- Q1 2027: Detailed engineering begins
- Q4 2027: Pre-construction activities
- Q2 2028: Construction begins
- Q2 2030: Operations begin
- Oct. 2, 2030: Fully operational
The project schedule anticipates awarding the engineering, procurement, and construction contract in the fourth quarter of 2026, followed by detailed engineering beginning in the first quarter of 2027.
Construction activities are expected to enter pre‑mobilization in the fourth quarter of 2027, with installation work starting in the second quarter of 2028.
The project is planned to reach substantial completion and begin commercial operation in the second quarter of 2030, with the system required to be fully in service by Oct. 2, 2030, to meet regulatory requirements.
Project Location
The project site was selected because it is:
- Located on NorthWestern Energy‑owned property
- Zoned for industrial use
- Located near existing electric transmission and natural gas infrastructure
Environmental Considerations
The plant will include modern air quality control systems designed to reduce nitrogen oxide (NOx) and carbon dioxide (CO₂) emissions and comply with environmental requirements.
Regional Reliability Planning
The Southwest Power Pool recently updated its resource accreditation and Planning Reserve Margin requirements in response to growing reliability concerns.
The Southwest Power Pool is requiring additional accredited capacity by 2030 to meet the updated Planning Reserve Margin targets.
The 131-megawatt Aberdeen III Natural Gas Plant was submitted with the Southwest Power Pool under the Expediated Resource Adequacy Study program to meet regional capacity needs by 2030.
For more information about the project, please contact: