Net metering for private solar and wind generation

How net metering works for private solar, wind and small hydro generation.

Private Generation

How net metering works

A graphic showing how net metering works.

How net metering works

  1. Solar panels or wind turbines convert energy from the sun or wind into electricity.
  2. An inverter converts the electricity for the customer's use.
  3. The electricity is used by the customer.
  4. A net meter measures the difference between energy used and energy produced.
  5. Excess energy travels on NorthWestern Energy's power lines.

When NorthWestern Energy customers install solar panels, small winds turbine and/or small scale hydro at their house, they can produce energy themselves to electrify their homes. These customers can request a “net meter” from NorthWestern Energy. Net metering allows any energy not used by the customer to be exported back to the electric grid, and this unused energy is available as a credit to the customer on future bills.

This unused energy is tracked and made available as a credit to the customer on future bills until their selected 12-month billing period ends. At the end of the 12-month billing period Montana law mandates that the energy credit resets to zero.

For more information about net metering of NorthWestern Energy’s Small Generator Interconnection process email or call 406-497-4165

Becoming a Qualified Installer

Solar installers attend a training in our Butte General Office.

Becoming a Qualified Installer

Renewable energy companies that meet our professional, safety and independent contractor standards for renewable generation installations are included on our list of qualified installers.

If you are a contractor or consultant/designer or engineer/architect and would like to become a Qualified Solar PV or Small Wind Installer, contact us at


Small Generator Interconnection and Net Metering Contact Information

NorthWestern Energy’s Small Generator Interconnection process (including Net Metering) is governed by Rules 16-23 of the Electric Tariff. Links to the process documents can be found in this page, as well as educational resources and application materials for renewable energy customers. 

Questions pertaining to Small Generator Interconnection may be directed to our Interconnect Specialist at, by telephone 406-497-4165, or at the address given below. 

NorthWestern Energy
Attn: Interconnect Specialist
11 E. Park St.
Butte, MT  59701-1711