According to preliminary statistics released by the US Energy Information Administration (EIA), 31.3 GW of power generation capacity were added in the United States in 2018 while 18.7 GW of capacity were retired. The additions consisted primarily of gas-fired plants (62%), onshore wind (21%) and solar PV (16%). The remaining 2% entailed mostly hydroelectric and battery storage capacity. 90% of the gas-fired capacity was combined-cycle generators.
As for the retirements, a total of 12.9 GW of coal-fired capacity was shut down in 2018 and 80% of the retirements originated in four US states, namely Texas (4.3 GW), Ohio (2.3 GW), Florida (2.0 GW), and Wisconsin (1.7 GW). 4.7 GW of U.S. natural gas-fired capacity retired in 2018, 93% of which consisted of natural gas steam and combustion turbine units, which are less efficient than combined-cycle units. 0.6 GW of nuclear capacity were retired at the Oyster Creek power plant in New Jersey.
Besides, the EIA also predicted that the bulk of the electricity generation capacity additions installed in the United States through 2050 will be either solar photovoltaic (PV) or natural gas combined-cycle (CCGT) projects. In total, 235 GW of CCGT units will be added over the period, while utility-scale PV and onshore wind capacity additions will stand respectively at 175 GW and 24 GW. More specifically, CCGT units will account for the largest share of new power plants, i.e. 43% of the utility-scale total new capacity deployed from 2021 through 2050. Onshore wind will be competitive in several regions only before the legislated phase-out of the production tax credit (PTC) and is then slated to become more competitive over time as the cost for installing wind turbines will decrease.