Wind turbines wring energy out of a free-flowing fuel supply that may be losing some of its punch. Surface winds appear to be weakening across the Northern Hemisphere, including in the United States, Western Europe, and China—the world’s top three markets for wind power. And climate change threatens to weaken them further during this century as faster warming over northern latitudes trims the temperature gradients that energize airflows.
China could be the hardest hit, according to modeling by University of Texas–Austin research scientist Diandong Ren in the November issue of the Journal of Renewable and Sustainable Energy. He projects a 4 to 12 percent decrease in wind speeds in China for the last three decades of the 21st century (compared to the corresponding decades of the 20th). Since the energy in wind increases with the cube of the wind speed, Ren estimates that the slower winds would trim power from Chinese turbines by at least 14 percent.