The U.S. nuclear energy sector may be struggling to hold its own in the generation mix, but those plants are once again proving to be the most productive in the nation.
A recent federal Energy Information Administration report showed that nine of the 10 highest-generating power plants in the U.S. last year were nuclear. The top 10 power plants generated a combined 230 million MWh in 2019, according to the EIA. That total is nearly 6 percent of all U.S. electricity generation.
Ten years earlier, the top producing U.S. generating stations were a combination of coal-fired and nuclear. At that time, coal-fired capacity was 45 percent of the U.S. mix, now falling to 23 percent, statistics show.
Nuclear is holding steady at between 19-21 percent of the nationwide generation capacity. The Palo Verde, Browns Ferry, and Oconee nuclear power plants have consistently been among the 10 largest generators of electricity in the United States because they are the only nuclear plants with three reactor units, which gives them more generating capacity.
The top 10 plants, from highest generation down, are Palo Verde (Arizona, pictured) Browns Ferry (Alabama), Peach Bottom (Pennsylvania), South Texas, Oconee (South Carolina), West County Energy Center (Florida), Susquehanna (Pennsylvania), Braidwood, Bryon (both Illinois) and Vogtle (Georgia).The natural gas-fired West County project is the only non-nuclear plant in the ranking.
Electric power plants that have relatively large electricity generating capacities generally also operate at high capacity factors, or utilization rates. The capacity (the maximum amount of electricity a power plant can produce) of the top 10 highest-generating power plants in 2019 ranged from 2,300 megawatts (MW) (Byron) to 3,937 MW (Palo Verde).
Although these plants have a lower nameplate capacity than the Grand Coulee hydroelectric facility (6,809 MW of capacity) in Washington, they generate more electric power each year. Grand Coulee operated at a lower utilization rate and generated 16.6 million MWh of electricity in 2019.
Nuclear power plants have the highest capacity factor of any energy source in the United States, at 94% fleet-wide in 2019, because nuclear plants generally operate around-the-clock until they are taken offline for maintenance or refueling. Capacity factors for the nine nuclear plants in the top 10 range from 89% (Browns Ferry) to 99% (Byron and Peach Bottom).
Owner Exelon Corp. said it plans to close Byron in 2021, due to economic issues stemming from Illinois state rules which Exelon says favors carbon-emitting plants.
Nuclear-powered generation produces more than half of the nation’s carbon-free electricity. The only new reactor construction going on is Georgia Power’s Vogtle Units 3 and 4 expansion scheduled to come online in 2021 and 2022.