Power Plants in Illinois

Illinois holds 52.7 gigawatts of generating capacity, the fifth-largest fleet among the 51 states and territories tracked. This is capacity — what the equipment could produce running flat out — not generation, which varies with how often plants run and how much fuel they convert to electricity. The state's 578 plants in service rely most heavily on natural gas at 35.3% of capacity, followed by nuclear at 23.6%, wind at 16.5%, coal at 13.9%, and solar at 9.0%.

The five largest plants are all nuclear. Braidwood Generation Station and Byron Generating Station each hold 2,450 megawatts, LaSalle Generating Station holds 2,340 megawatts, and Dresden Generating Station and Quad Cities Generating Station each hold 2,019 megawatts. The fleet spans from Rockton, first online in January 1929, to AC IL - Hillsboro CSG, which came online in May 2026. The 72 natural gas plants account for the second-largest share of capacity, while six nuclear plants deliver nearly a quarter of the state's potential output.