In 2018, 31.3 gigawatts of utility-scale electricity generating capacity were added in the United States while 18.7 gigawatts of the capacity were retired, according to the U.S. Energy Information Administration. The amount of capacity added in 2018 was the highest level since 48.8 gigawatts were added in 2003. The majority of the additions were in the second half of 2018, and most of the retirements were in the first half of the year.
Natural gas accounted for 62% of the capacity added in 2018, while wind and solar comprised 21% and 16%, respectively. The remaining 2% of additions came mostly from hydroelectric and battery storage capacity. Nearly 90% of the 19.3 gigawatts of natural gas-fired capacity added were combined-cycle generators, which is the most efficient natural gas-fired generating technology. Almost 60% of the 6.6 gigawatts of wind capacity added started operating in December. About 60% of the new solar capacity was installed in California, Florida and North Carolina.
About 69% of the generating capacity retired in 2018 was coal, while natural gas and nuclear comprised 25% and 3%, respectively. The remaining 3% retired were mostly hydroelectric and petroleum generating capacity. Nearly 80% of the 12.9 gigawatts of coal capacity retired were in Texas, Ohio, Florida and Wisconsin. About 93% of the 4.7 gigawatts of natural gas capacity retired were from natural gas steam and combustion turbine units, which are less efficient natural gas-fired generating technologies that often operate at lower capacity factors than more efficient combined-cycle units. The only nuclear capacity retirement was the 0.6 gigawatt Oyster Creek plant in New Jersey.