Power Plants in Montana

Montana's power sector in numbers

Bywatts maps 48 operating power plants with 6.2 GW of nameplate capacity in Montana. Hydro leads with 42% of that capacity across 21 plants, followed by Coal (39%) and Wind (10%). The inventory also includes 4 plants (219 MW) that EIA-860 lists as retired and 1 partly retired with no operable units of its recorded fuel; the largest retired plant is J E CORETTE PLANT (173 MW, retired 2015).

The largest operating plants are COLSTRIP (2,272 MW, Coal, PPL MONTANA LLC), NOXON RAPIDS (532 MW, Hydro, AVISTA CORP) and LIBBY (525 MW, Hydro, USACE NORTHWESTERN DIVISION).

Of the 46 operating plants with a recorded commissioning year, 23 came online in 2000 or later and 12 in 2010 or later; the busiest decade for new capacity was the 1980s (2.3 GW).

The largest operators by operating capacity are PPL MONTANA LLC (12 plants, 2.9 GW), U S BUREAU OF RECLAMATION (3 plants, 728 MW) and AVISTA CORP (1 plant, 532 MW).

Retail electricity sales in Montana reached 15.4 TWh in 2025, up 8.2% over ten years and down 1.3% year on year; residential customers took 37.7% of it. The average retail price across all sectors was 10.90 cents per kWh, up 22.7% since 2015.

The database also maps 252 named substations (5 of the 63 with a recorded voltage are rated 345 kV or above), 4 data centers (operators include iConnect Montana, Johnson Services and YRIX), 36 solar installers and 10 solar companies in Montana.

Operating capacity by fuel

Retail electricity sales

Sources: HIFLD power-plant inventory (capacity, fuel, operator), EIA-860 (commissioning year, retirements, operable capacity), EIA retail sales and revenue series through January 2026. Counts are of plants Bywatts lists, not every generator in the state.