The Performance of U.S. Wind and Solar Generating Units

Abstract

Government subsidies have driven rapid growth in U.S. wind and solar generation. Using data on hourly outputs and prices for 25 wind and nine solar generating plants, some results of those subsidies are studied in detail: the value of these plants' outputs, the variability of output at plant and regional levels, and the variation in performance among plants and regions. Output from solar plants was about 32% more valuable on average than output from wind plants. Output variability differs substantially among plants and, on some dimensions, among regions. Policy implications of high generation when prices are negative and dramatic differences in capacity factors are discussed.