Five industrial wind turbines form part of the Gorona del Viento power plant on the island of El Hierro. By the end of this year, the power plant is set to generate 100 percent of the energy El Hierro needs, making it the world's first energy-independent island powered only by renewables. Lauren Frayer for NPR hide caption

itoggle caption Lauren Frayer for NPR

The Department of the Interior is proposing a large expansion of U.S. efforts to make energy from offshore winds, with a plan centered off the Massachusetts coast. Here, a 2010 photo shows a sunrise over Nantucket Sound. Julia Cumes/AP hide caption

itoggle caption Julia Cumes/AP

The offshore wind farm in the North Sea near Borkum, Germany, is nearly complete. The Riffgat facility, seen here on June 23, includes 30 turbines, each with a generating capacity of 3.6 megawatts. David Hecker/Getty Images hide caption

itoggle caption David Hecker/Getty Images

A maintenance worker looks out over an off-shore wind farm in Liverpool, England in 2008. Some people are concerned about the potential health effects of noise from wind turbines. Christopher Furlong/Getty Images hide caption

itoggle caption Christopher Furlong/Getty Images