For Germany, 2020 was a banner year in the production of renewable energy. Clean energy sources—wind farms and solar arrays as well as hydroelectric and biogas plants—ratcheted their share of power consumption up to 46 percent, nearly equaling that of coal, gas, oil, and nuclear power combined. And after a period of stagnation in the 2010s, the greenhouse emissions of the world’s fourth-largest economy have been dropping again, last year by around 80 million tons of carbon dioxide. That puts Germany 42 percent down from its 1990 emissions level, thus surpassing its decade target by 2 percentage points. This trajectory is good news for Germany—and for the EU, which wants to turn the continent carbon-neutral by 2050.
Yet Germany’s move to a power system largely reliant on weather-dependent renewables is quickly running up against limits—issues that all countries exchanging conventional fuels for wind and solar will eventually face. What happens when the sun doesn’t shine and the wind doesn’t blow for hours or even days at a time? And what about the short, dark, cold days of midwinter when renewables of Germany’s power demand?
