Power Plants in Maine

Maine's power sector in numbers

Bywatts maps 83 operating power plants with 4.3 GW of nameplate capacity in Maine. Natural Gas leads with 43% of that capacity across 5 plants, followed by Oil (21%) and Hydro (15%). The inventory also includes 24 plants (464 MW) that EIA-860 lists as retired and 5 never built; the largest retired plant is MILLINOCKET MILL (86 MW, retired 2013).

The largest operating plants are WILLIAM F WYMAN (846 MW, Oil, FPL ENERGY WYMAN LLC), WESTBROOK ENERGY CENTER POWER PLANT (564 MW, Natural Gas, WESTBROOK ENERGY CENTER) and MAINE INDEPENDENCE STATION (550 MW, Natural Gas, CASCO BAY ENERGY CO LLC).

Of the 81 operating plants with a recorded commissioning year, 19 came online in 2000 or later and 7 in 2010 or later; the busiest decade for new capacity was the 2000s (1.9 GW).

The largest operators by operating capacity are FPL ENERGY WYMAN LLC (1 plant, 846 MW), WESTBROOK ENERGY CENTER (1 plant, 564 MW) and CASCO BAY ENERGY CO LLC (1 plant, 550 MW).

Retail electricity sales in Maine reached 11.0 TWh in 2025, down 7.1% over ten years and down 2.7% year on year; residential customers took 43.3% of it. The average retail price across all sectors was 22.81 cents per kWh, up 78.5% since 2015.

The database also maps 16 named substations (9 of the 9 with a recorded voltage are rated 345 kV or above), no data centers, 53 solar installers and 14 solar companies in Maine.

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.