Power Plants in Iowa

Iowa's generating fleet holds 24.9 GW of nameplate capacity, ranking 19th of the 50 states and DC. This is what the equipment could produce running flat out; actual generation is a different measure on a different page, since a megawatt of solar and a megawatt of coal produce very different amounts over a year. Wind dominates the state's fleet, accounting for 53.9% of capacity across 124 plants. Coal provides 20.9%, natural gas 17.5%, solar 3.2%, and other sources the remainder.

The largest plants by capacity are the Walter Scott Jr Energy Center, a 1,648 MW coal facility that came online in 1978, and the Louisa coal plant at 812 MW from 1983. The Ottumwa coal plant follows at 726 MW, built in 1981, while the Marshalltown Generating Station, a 709 MW natural gas facility, is the newest of the state's five largest generators, entering service in 2017. The fleet spans from the Keokuk plant, which first came online in August 1913, to the Shenandoah Hills Wind Farm, which entered service in December 2025.

The state maintains 306 plants in total, though plant counts include sub-megawatt backup generators and do not reflect fleet size — capacity is the meaningful measure. Of these, 305 were in service as of August 2026.