As reported in the Guardian on July 10, unusually high winds allowed Denmark to meet all of its electricity needs – with plenty to spare for Germany, Norway and Sweden. On an unusually windy day, Denmark found itself producing 116% of its national electricity needs from wind turbines during the evening. By 3am, when electricity demand dropped, that figure had risen to 140%. Interconnectors allowed all of the power surplus to be shared between Germany, Norway, and Sweden.
Although Denmark is a small country relative to the United States with significantly higher wind energy potential per capita, it is still a significant achievement that demonstrates to the rest of the world that a 100% renewable electrical power system is achievable.
For more information, see theguardian: Denmark Wind Energy.