German wind power expansion plans will fail due to turbine density – study

The plans for wind power expansion in Germany are “illusory” since the growing density of turbines across the country is set to diminish the yield per installation so much that power production targets can no longer be met by simply increasing the number of units, a study conducted by Harvard researcher Lee Miller is quoted in an article by Johann Grolle in the Spiegel Plus online magazine. Germany must face the fact that the large number of turbines both on land and at sea means that the wind cannot blow unobstructed and that one turbine will reduce the power yield of another, Miller argues, adding that he has “great respect” for the German Energiewende. Miller’s finding that average wind power yields are much lower than assumed by many wind farm planners is a "disastrous" finding for Germany, Grolle writes. In a second study cited in the article, Miller argues that wind turbines cause a rise in local temperatures by mixing air from different altitudes, which for Germany “could mean a rise in temperature across the whole country,” he says.

Find the article in German here (paywall), an article in the Harvard Gazette in English here, and the studies on density and climate impacts in English here and here.

See the CLEW factsheets on onshore and offshore wind power in Germany for background.