Nuclear power posted a 91% capacity factor among major U.S. electricity sources in 2025, the highest of any generation type, according to data compiled by Visual Capitalist using U.S. Energy Information Administration figures. Capacity factor measures how much electricity a plant actually produces compared with its theoretical maximum output over a full year, making it a standard gauge of how consistently a power source runs.

Geothermal ranked second at 66%, followed by biomass at 59% and combined cycle natural gas at 58%. Coal came in at 49%, while hydroelectric power posted 35% and wind posted 34%. Solar photovoltaic generation trailed at 24%, and petroleum-fired steam turbines were lowest at 11%.

That reliability gap is a growing factor in utility planning as data centers and other large industrial loads raise electricity demand. Duke Energy filed an early site permit application in December 2025 for a potential new nuclear site at Belews Creek in North Carolina. Georgia Power's most recently approved integrated resource plan similarly builds around its existing nuclear fleet, alongside new gas, storage and renewable additions, to meet a growing state's power needs.

Capacity factor measures operational consistency, the share of time a plant delivers power at full output relative to its theoretical maximum. Nuclear plants nationwide continue to run near that ceiling for most of the year, a track record utilities are citing as they plan new generation to meet rising demand.

Source: Visual Capitalist (National Public Utilities Council, using EIA data) - https://www.visualcapitalist.com/sp/npuc26-ranked-the-most-consistent-us-power-sources/