Impact of combined solar, wind power examined

The Energy Information Administration (EIA) said the combination of wind and solar electric output met or exceeded 20 percent of total generation in 10 states last year.

Officials said wind accounted for more than 50 percent of in-state electricity generation in Iowa and Kansas during some portions of 2017 while solar accounted for more than 20 percent of in-state electricity generation in California.

Total annual generation from wind and solar in the United States in 2017 reached 8 percent for the year and peaked at 11 percent in April of that year.

Among the 10 states with the highest shares of wind and solar generation, almost all of them are driven by wind generation.

Iowa has annual wind and solar generation of 37 percent while 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 percent, compared with 6.4 percent for wind. In May of last year, California’s wind and solar share reached 28 percent of in-state electricity generation.

Industry officials acknowledge wind and solar resources are unique among sources of electricity. Unlike most other generating technologies, grid operators generally do not dispatch wind and solar generation because these generators produce electricity only when the associated resources are available.