As of 2006, the United States produced about 12 gigawatts (GW) of electricity from wind (today that number has increased to about 18 GW). To generate enough electricity to provide 20 percent of our electricity from wind power in 2030 will require a little more than 300 GW however, this number pales in comparison to the estimated total potential wind energy electricity generation in the US 8,000 GW. And that 8,000 GW number is only for potential wind generation viewed as economically feasible to capture, a calculation that can always change. The DOE report estimates that it will cost approximately $197 billion in capital costs to build the wind turbines and transmission network and to create a 20 percent wind reality.
Center for Rural Affairs, August 2008 Newsletter