Many countries may soon find that the cheapest way to produce electricity is to pull it out of the air. Global wind generating capacity now stands at 9,600 megawatts—a 26 percent increase from a year earlier. This double-digit growth rate could make the wind a major power supplier soon. Flavin also points out that wind power is one of the world's most rapidly expanding industries and has become a major investment opportunity. In the longer run, wind power—both onshore and off—could easily exceed hydropower—which now supplies 20 percent of the world's electricity—as an energy source.