Watch this video about wind energy on HowStuffWorks. Wind is the fastest growing energy source in the world and here in the U.S., wind farms have popped up in more than 30 states, producing enough energy to power an estimated 2.5 million homes a day. Thanks to growing concerns over natural gas prices, a desire for energy independence and incentives for renewable energy production, it's expected this trend will continue. See how wind energy works in this video from Medialink