From Scientific American:
A team of scientists estimates that wind turbines in the continental U.S. could produce 16 times more electricity than we currently use. They present their data in the current Proceedings of the National Academy of Sciences....
They concluded that a global network of land-based turbines could make 40 times more electricity than the world currently consumes—even if they only operated at 20 percent of their capacity.
I have not read this report and don't know if wind could do this economically. A group of wind turbines along a low ridge in Iowa is picturesque; a sea of them everywhere seems ugly (and yet, there is a sea of cell phone towers we barely notice). And the bird population seems likely to suffer. Still, it seems to me to be encouraging news.