A little more than 5 years ago, it was common to rebut wind skepticism by pointing out that Denmark got then nearly 20% of its power from wind. Today, there is no need to look across the Atlantic to find examples of wind's substantial capabilities.
Right here in America, wind is providing nearly 25% of the electricity in Iowa and South Dakota.
http://www.earth-policy.org/data_highlights/2013/highlights37. Those extraordinary numbers prove that wind can be a main means of powering whole states!