Solar eclipses biomass to become third-largest renewable power source in the US
Electricity generation from solar resources in the United States (US) reached 77 million MWh in 2017, surpassing for the first time annual generation from biomass resources, which generated 64 million MWh in 2017. Among renewable sources, only hydro and wind generated more electricity in 2017, at 300 million MWh and 254 million MWh, respectively according to figures released by the US Energy Information Agency (EIA).
Solar can be divided into three types: solar thermal, which converts sunlight to steam to produce power; large-scale solar photovoltaic (PV), which uses PV cells to directly produce electricity from sunlight; and small-scale solar, which are PV installations of 1 MW or smaller.
Generation from solar thermal sources has remained relatively flat in recent years, at about 3 million MWh. 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 United States.
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, according to EIA’s Preliminary Monthly Electric Generator Inventory. Information about planned small-scale PV systems, 1 MW and below, is not collected in that survey.
EIA data also shows that biomass generating capacity has remained relatively unchanged in recent years, while solar generating capacity has consistently grown. However, annual growth in solar generation often lags annual capacity additions because generating capacity tends to be added late in the year.
In 2017, December solar capacity additions accounted for 21 percent of the annual total leaving few days for an installed project to contribute to total annual generation despite being counted in annual generating capacity additions.
Overall, solar technologies operate at lower annual capacity factors and experience more seasonal variation than biomass technologies. Biomass electricity generation comes from multiple fuel sources which in 2017 had the following make-up of the 64 million MWh generated:
- wood solids 68%,
- landfill gas (LFG) 17%
- municipal solid waste (MSW) 11%
- other biogenic and nonbiogenic materials 4%
These shares of biomass generation have remained relatively constant in recent years.