By Genevieve J. Essig
Approximately what percentage of of the U.S.'s electricity demand is supplied by wind power? According to the U.S. Department of Energy's recent report Wind Vision: A New Era for Wind Power in the United States, as of 2013, U.S. electricity demand served by wind energy had tripled from 1.5% of total end-use demand in 2008 to 4.5%.