On the morning of March 20, 2015, 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, 3 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.

Financial Times