Power Plants in Connecticut

Connecticut's power sector in numbers

Bywatts maps 68 operating power plants with 9.3 GW of nameplate capacity in Connecticut. Natural Gas leads with 36% of that capacity across 13 plants, followed by Nuclear (23%) and Oil (18%). The inventory also includes 15 plants (777 MW) that EIA-860 lists as retired, the largest being NRG NORWALK HARBOR (343 MW, retired 2013).

The largest operating plants are MILLSTONE (2,163 MW, Nuclear, DOMINION NUCLEAR CONN INC), LAKE ROAD GENERATING PLANT (840 MW, Natural Gas, LAKE ROAD GENERATING CO LP) and MIDDLETOWN (786 MW, Natural Gas, MIDDLETOWN POWER LLC).

Of the 66 operating plants with a recorded commissioning year, 33 came online in 2000 or later and 16 in 2010 or later; the busiest decade for new capacity was the 1970s (2.8 GW).

The largest operators by operating capacity are DOMINION NUCLEAR CONN INC (1 plant, 2.2 GW), PSEG POWER CONNECTICUT LLC (2 plants, 1.2 GW) and LAKE ROAD GENERATING CO LP (1 plant, 840 MW).

Retail electricity sales in Connecticut reached 27.6 TWh in 2025, down 6.5% over ten years and up 0.8% year on year; residential customers took 48.4% of it. The average retail price across all sectors was 25.68 cents per kWh, up 44.5% since 2015.

The database also maps 132 named substations (16 of the 16 with a recorded voltage are rated 345 kV or above), no data centers, 126 solar installers and 28 solar companies in Connecticut.

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.