The US Energy Information Administration reports that power sector generation from renewable sources totalled 795 million MWh in the USA during 2021, overtaking nuclear generation, which totalled 778 million MWh. The US electric power sector does not include some electricity generators in the industrial, commercial, or residential sectors, such as small-scale solar or wind or some combined-heat-and-power systems. Renewable generation includes electricity generated from wind, hydropower, solar, biomass, and geothermal sources.
Natural gas remained the most prevalent source of energy for electricity generation, accounting for 1474 million MWh in 2021. Although several US coal-fired power plants retired in 2021, coal-fired generation increased for the first time since 2014 and was the source of more electricity than either renewables or nuclear power. Total electricity generation increased slightly in 2021, but it remained less than its record-high year of 2018.
The increase in renewable generation during 2021 came mainly from more wind (total c 375 MWh) and solar generation (c 112 MWh) as a result of more wind turbines and utility-scale solar power plants coming online. Wind generation increased by 12%, while utility-scale solar generation increased by 28%. The hydroelectric component decreased to its lowest level since 2015, 260 MWh, mainly because of dry conditions in the western United States. Biomass and geothermal electricity generation remained relatively unchanged in 2021.
Nuclear generation has remained relatively steady in the United States during the past decade because uprates at existing facilities have offset the retirement of several reactors. Only one reactor, New York’s Indian Point Unit 3, was retired in 2021. Despite a slight increase in the capacity factor of the US nuclear fleet in 2021, nuclear generation fell to its lowest level since 2012.