Notably, during some months in 2017, wind accounted for more than 50% of in-state electricity generation in Iowa and Kansas, and solar accounted for more than 20% of in-state electricity generation in California, the agency says, citing its Electric Power Monthly report.
Further, total annual generation from wind and solar in the U.S. in 2017 reached 8% for the year and peaked at 11% in April.
Of the 10 states with the highest shares of wind and solar generation, almost all of them are driven by wind generation, EIA points out. For example, Iowa has annual wind and solar generation of 37% (36.8% wind and 0.2% solar). However, in some states – such as California, Nevada, Massachusetts and Arizona – solar generation is higher than wind generation. California’s annual solar share was 15.6%, compared with 6.4% for wind. In May, California’s wind and solar share reached 28% of in-state electricity generation.
EIA points out that the statistics reflect the portions of total utility-scale electricity and small-scale solar photovoltaic electricity generated in each state. Because the electric system in the lower 48 states essentially operates as three large interconnections, the electricity generated in one state may be consumed in another, the agency explains.