Renewable generation in the U.S. has doubled over the past 10 years. In 2018, generation from solar, wind, hydro, and other renewables soared to a record 742 TWh—or 17.6% of total U.S. generation.
According to the Energy Information Administration (EIA), since 2008—when renewables provided 382 TWh—wind generation rose from 55 TWh and generated 275 TWh (6.5% of total electricity generation) in 2018. Conventional hydropower dominated the renewables mix in 2018, retaining a slight lead over wind at 292 TWh (6.9% of total generation).
However, the EIA expects wind to surpass hydro generation over 2019. The EIA’s most recent Preliminary Monthly Electric Generator Inventory survey shows wind capacity increasing by 8.3 GW in 2018 and 8.0 GW in 2019. By the end of 2018, 94 GW of wind generating capacity was operating on the electric grid. With the exception of one 30-MW offshore wind plant located on Block Island, off the coast of Rhode Island, all that capacity was onshore. “If these new generating units come online as scheduled, they would add 9% to U.S. utility-scale wind capacity by the end of 2018 and another 8% by the end of 2019,” the agency said.
The EIA noted conventional hydropower generation has remained relatively unchanged since 2008, increasing by only 2%. “Changes in hydroelectric generation year-over-year typically reflect changes in precipitation and drought conditions,” the agency noted. “Between 2008 and 2018, annual U.S. hydroelectric generation was as low as 249 million MWh and as high as 319 million MWh, with hydroelectric generation in 2018 totaling 292 million MWh.” Few new hydro plants are expected to come online over the next two years, which means that hydro generation will continue to largely depend on precipitation and water runoff.
U.S. solar generation, meanwhile, increased from 2 TWh in 2008 to 96 TWh in 2018, the majority (69% or 67 TWh) of which was produced by utility-scale solar installations. Solar accounted for about 2.3% of power generation in 2018. Installed solar capacity grew from less than 1 GW in 2008 to 51 GW in 2018, the EIA noted. In 2018, 1.8 GW of this solar capacity was solar thermal, 30 GW was utility-scale solar photovoltaics (PV), and the remaining 20 GW was small-scale solar PV.
Generation from other renewable resources, including biomass and geothermal, increased from 70 million MWh to 79 million MWh in the U.S. between 2008 and 2018, and it collectively represented 1.9% of total generation in 2018, the EIA said.