NorthWestern Energy operates 15 power plants across 2 countries, with a combined installed capacity of 696 MW. Its plants with measured data emit a combined 149,320 t CO₂/yr.
| Plant | Fuel | Country | MW | t CO₂/yr |
|---|---|---|---|---|
| Yellowstone County Generating Station | Gas | United States | 207 | 149,320 |
| Thompson Falls | Hydro | United States of America | 98 | — |
| Morony | Hydro | United States of America | 63 | — |
| Cochrane | Hydro | United States of America | 60 | — |
| Rainbow (MT) | Hydro | United States of America | 59 | — |
| Ryan | Hydro | United States of America | 53 | — |
| Spion Kop Wind Farm | Wind | United States of America | 40 | — |
| Holter | Hydro | United States of America | 38 | — |
| Black Eagle | Hydro | United States of America | 24 | — |
| Hauser | Hydro | United States of America | 18 | — |
| Mystic | Hydro | United States of America | 12 | — |
| Two Dot Wind Farm | Wind | United States of America | 10 | — |
| Madison Dam | Hydro | United States of America | 9 | — |
| Lake (WY) | Oil | United States of America | 3 | — |
| Old Faithful | Oil | United States of America | 2 | — |
Ownership & capacity: WRI Global Power Plant Database (CC BY 4.0). Measured CO₂ where reported to EPA/EU ETS/Climate TRACE.
