Electricity generation from solar resources in the U.S. reached 77 million MWh in 2017, surpassing, for the first time, annual generation from biomass resources, which generated 64 million MWh, according to the U.S. Energy Information Administration (EIA).
Among renewable sources, only hydro and wind generated more electricity in 2017, at 300 million MWh and 254 million MWh, respectively. Biomass generating capacity has remained relatively unchanged in recent years, while solar generating capacity has consistently grown, says EIA.
According to the agency, annual growth in solar generation often lags annual capacity additions because generating capacity tends to be added late in the year. For example, in 2016, 29% of total utility-scale solar generating capacity additions occurred in December, leaving few days for an installed project to contribute to total annual generation – despite being counted in annual generating capacity additions. In 2017, December solar additions accounted for 21% of the annual total, says EIA. Overall, solar technologies operate at lower annual capacity factors and experience more seasonal variation than biomass technologies, the agency adds.
Biomass electricity generation comes from multiple fuel sources, such as wood solids (68% of total biomass electricity generation in 2017), landfill gas (17%), municipal solid waste (11%), and other biogenic and nonbiogenic materials (4%). These shares of biomass generation have remained relatively constant in recent years, according to EIA.
Generation from solar thermal sources has remained relatively flat in recent years, at about 3 million MWh, the agency says. The most recent addition of solar thermal capacity was the Crescent Dunes Solar Energy plant, installed in Nevada in 2015, and currently, no solar thermal generators are under construction in the U.S.
Solar photovoltaic systems, however, have consistently grown in recent years. In 2014, large-scale solar PV systems generated 15 million MWh, and small-scale PV systems generated 11 million MWh. By 2017, annual electricity from those sources had increased to 50 million MWh and 24 million MWh, respectively. By the end of 2018, EIA expects an additional 5,067 MW of large-scale PV to come online.
Charts courtesy of EIA