Demark claimed 26 percent from wind and couldn’t close a single power plant. There are enormous crticisms..hardly a model for America.
Still, they have used it for years to SOME effect. Even 25% would be amazing.
The story is far worse than this one basic fact. The only reason why it works at all is that Denmark has three countries beside it that are much larger than they are.....Norway, Sweden and Germany and their grid is linked with them. When Denmark has excess power (which is quite a bit of time), they just dump the power and since their neighbours are larger (and have cut a huge sweet deal on it), it can be absorbed. Also for much of the time, there is inadequate wind which is why they yet to close a single power plant. This isn’t the best link to illustrate this point but it will do the trick. http://docs.wind-watch.org/sharman-winddenmark.pdf