The article sounds as if it is a good thing that Germany has to pay people to use electricity. Actually it is exactly this problem that sets the upper limit to how much renewable energy can be used in a modern economy with current technology. The market correctly valued that the power produced by renewable sources had negative value, yet the producers of renewable energy were paid exactly the same feed-in tariff as they get on a cold windless evening. Doubling renewable energy production will not result in doubling the amount of electricity usefully used by Germany over the course of a year. It will be dumped somewhere in the system. Germany must solve the engineering problems required to efficiently store and recover vast amounts of energy as well as building more renewable energy generating systems to reach its goals.
I'm totally surprised that this is not a major topic of discourse in a country with such a large body of technical talent.