Power plants in the NorthWestern Energy balancing area
The NorthWestern Energy balancing area takes in 52 power plants with 4,265 MW of nameplate capacity, the 31st-largest of the 40 areas covered here. Its plants sit in two states, with Montana holding 100% of the capacity. Coal makes up 42% of the mix, and the largest plant is Colstrip (1,647 MW). Since 2020, 1,043 MW has come online here, 61% of it wind.
- Coal1,811 MW42%
- Wind1,012 MW24%
- Hydroelectric716 MW17%
- Natural gas471 MW11%
- Solar181 MW4.2%
- Oil and petroleum72.7 MW1.7%
- Other sources1.6 MW0.0%
Capacity by decade it came online
CoalNatural gasOil and petroleumHydroelectricWindSolarOther sources
Above the line: capacity operating in 2025. Below: capacity retired at plants that still run.
The 25 largest plants in the area
| Rank | Plant | State | Runs on | Capacity | First unit |
|---|---|---|---|---|---|
| 1 | Colstrip | Montana | Coal | 1,647 MW | 1984 |
| 2 | Beaver Creek Wind Facility | Montana | Wind | 248 MW | 2025 |
| 3 | Selis Ksanka Qlispe | Montana | Hydroelectric | 228 MW | 1938 |
| 4 | Clearwater Wind East | Montana | Wind | 208 MW | 2024 |
| 5 | Yellowstone County Generating Station | Montana | Natural gas | 207 MW | 2024 |
| 6 | Dave Gates Generating Station | Montana | Natural gas | 203 MW | 2011 |
| 7 | Judith Gap Wind Energy Center | Montana | Wind | 135 MW | 2005 |
| 8 | Hardin Generator Project | Montana | Coal | 116 MW | 2006 |
| 9 | Clearwater Wind II | Montana | Wind | 103 MW | 2023 |
| 10 | Thompson Falls | Montana | Hydroelectric | 98.1 MW | 1915 |
| 11 | Apex Solar | Montana | Solar | 80 MW | 2023 |
| 12 | MTSUN | Montana | Solar | 80 MW | 2023 |
| 13 | South Peak Wind | Montana | Wind | 80 MW | 2020 |
| 14 | Stillwater Wind, LLC | Montana | Wind | 79.7 MW | 2018 |
| 15 | Yellowstone Energy LP | Montana | Oil and petroleum | 68 MW | 1995 |
| 16 | Morony | Montana | Hydroelectric | 63 MW | 1930 |
| 17 | Cochrane | Montana | Hydroelectric | 59.4 MW | 1958 |
| 18 | Rainbow (MT) | Montana | Hydroelectric | 59 MW | 2013 |
| 19 | Ryan | Montana | Hydroelectric | 55.2 MW | 1915 |
| 20 | Basin Creek Plant | Montana | Natural gas | 54.9 MW | 2006 |
| 21 | Holter | Montana | Hydroelectric | 54.6 MW | 1918 |
| 22 | Colstrip Energy LP | Montana | Coal | 46.1 MW | 1990 |
| 23 | Spion Kop Wind Farm | Montana | Wind | 40 MW | 2012 |
| 24 | Black Eagle | Montana | Hydroelectric | 26.7 MW | 1927 |
| 25 | Big Timber Wind Farm | Montana | Wind | 25 MW | 2018 |
Operators with the most capacity
| Operator | Plants | Capacity |
|---|---|---|
| Talen Montana LLC | 1 | 1,647 MW |
| NorthWestern Energy (MT wind/thermal) | 6 | 464 MW |
| NorthWestern Energy (MT Hydro) | 10 | 461 MW |
| Puget Sound Energy Inc | 1 | 248 MW |
| Energy Keepers Inc | 1 | 228 MW |
| Portland General Electric Co | 1 | 208 MW |
| Invenergy Services LLC | 1 | 135 MW |
| Heorot Power Management | 1 | 116 MW |
| Greenbacker Renewable Energy Corporation | 3 | 115 MW |
| Clearwater Wind II, LLC | 1 | 103 MW |