S&P Global Market Intelligence data show that 19,716 MW of U.S. power generation capacity was retired in 2019, a total 16.7% higher than the 16,900 MW shuttered permanently in 2018.

Coal-fired resources continued to account for the lion's share of retired capacity in 2019, at 70%, equivalent to 13,703 MW. Gas-fired capacity retirements totaled 3,336 MW for a 17% share, and nuclear retirements added up to 1,512 MW for an 8% share.

Year-over-year trends varied across these fuel types. Capacity retirements were up 16.1% year on year for coal, but down 12.0% over the same period for gas. The two nuclear plants that were shut down in 2019, Entergy Corp.'s 683-MW Pilgrim Nuclear Power Station in Massachusetts in May and Exelon Corp.'s 829-MW Three Mile Island in Pennsylvania in September, had more than double the capacity that was retired the year before.

By power market region, the PJM Interconnection saw the largest amount of retired capacity in 2019 at 6,527 MW, two-thirds of which was coal-fired. Within that amount was FirstEnergy Corp.'s 2,490-MW Bruce Mansfield plant in Pennsylvania, which shuttered in two phases in February and November. Coal-fired resources made up about three-fourths of the 4,918 MW in capacity retirements in the Midcontinent ISO, where Vistra Energy Corp. shut down four coal-fired plants in Illinois with a combined capacity of 2,068 MW in November and December to comply with a state emissions rule.

Some 5,924 MW of capacity was permanently taken offline in areas outside an independent system operator. Among the larger unit retirements are the 2,250-MW Navajo coal-fired plant in Arizona majority-owned by the Salt River Project, and 1,063 MW at the Gorgas coal-fired plant in Alabama owned by Southern Co. subsidiary Alabama Power Co.