The sun went out, but the lights stayed on. Last week’s partial solar eclipse in Europe provided an ideal stress test for the world’s most solar-powered country, Germany, and so for the future of solar power itself. It passed.
Because solar power output varies with the intensity of sunshine, grid operators must use other power sources to balance out any fluctuations, or risk blackouts or power surges. Since 2006, the European Union has spent €3 billion on research and deployment of smart grids that do this balancing automatically.
Germany gets around 26 per cent of its power from variable solar and wind, and already has some smart systems in place. Their biggest challenge is rapid fluctuation in supply – just what the eclipse caused when it partly blotted out sunlight, then restored it three times faster than happens when the sun rises and sets, says Volcker Quashning of the University of Applied Sciences in Berlin.