According to U.S. Energy Information Administration (EIA) data on power plant operations, 9 of the 10 U.S. power plants that generated the most electricity in 2019 were nuclear plants. These 10 plants generated a combined 230 million megawatthours (MWh) of electricity in 2019, accounting for 5.6% of all electricity generation in the United States. The makeup of power plants that generate the most electricity has shifted in the past 10 years from a mix of nuclear and coal plants to almost all nuclear in 2019.