Exelon Generation's 10 nuclear power plants in Illinois, Pennsylvania and New Jersey produced 134 million net MWh of electricity in 2013, the highest annual production ever for the nation's largest operator of commercial nuclear reactors.
The new power generation record exceeded the previous record, set in 2007 by the same power plants, by 1.6 million MWh. A MWh is a million watts flowing for an hour. The 2013 total is enough electricity to power 15 million typical U.S. homes uninterrupted through the year.
The Exelon fleet last year operated at a 94.1 percent capacity factor, a measure of reliability. The industry average capacity factor in 2012, the latest year for which figures are available, was 89.1 percent. Capacity factor refers to amount of electricity actually produced compared with the theoretical maximum possible.
Exelon's nuclear plants sustained reliability momentum into 2014 as heavy snow, ice and record low temperatures plagued much of the country. The fleet operated continuously during that period. Nuclear energy is by far the largest clean energy source and the only one that can produce large amounts of electricity around the clock through severe weather.
Exelon's 17 nuclear reactors represent about 20 percent of the nation's nuclear power capacity.