Germany is generating so much electricity from renewable power plants that customers are actually paid to use it.
According to Bloomberg, 15 mph winds forced German utilities to pay their customers to take electricity off the grid on July 24. At its peak, it produced nearly 12,000 megawatts of power.
Germany has already produced "too much power" for 31 hours so far this year, and is becoming the norm. This happened even before Germany began opening parts of the world's largest PV solar park.
This is because they have grown their solar and wind generation so much in recent years. BP reports that, as of 2010, Germany has 43.5% of the world's solar and 13.7% of the world's wind capacity.
Germany is demonstrating the potential of renewable energy, at least on a good day. But, in the four days afterwards, the wind parks never produced more than 315 megawatts; a fraction of the production on July 24.