On the morning of March 20, 2020, a solar eclipse will pass over all of Europe, visible from Turkey to Greenland. A decade ago, that probably wouldn't have mattered to anyone except people who love astronomy (and all the schoolchildren building pinhole cameras to observe the sun.) But now, three percent of Europe's electricity grid comes from solar power, making the March event a proving ground for this renewable energy technology.
In the span of two hours, 35,000 megawatts of electricity will fade from the grid, and then return. To put that in perspective, a typical coal plant in the United States generates about 600 megawatts. The European Network of Transmission System Operators for Electricity (ENTSO-E) calls the eclipse an "unprecedented test for Europe's electricity system."
“It will have a cascading effect,” ENTSO-E spokesperson Claire Camus told the Financial Times. “It's definitely going to be a challenge for control rooms.”
Luckily, we've known about the solar eclipse for a while. For the past year, energy companies in Europe prepared for the event, and there is now a network of contacts among control rooms all over the continent, hoping to respond more effectively to problems (like power outages) caused by the eclipse.