On March 20, Europe will experience a total solar eclipse–the first in over a decade. It’s a highly anticipated event for stargazers. Germany’s utilities, however, aren’t so excited.
That’s because the country has spent years building up its solar energy capacity, which makes up over a quarter of all solar capacity on the planet. Now, Germany derives 7% of its total power from its 1.4 million solar power systems. When it’s really sunny, those solar installations can provide up to half of the country’s energy. But when the sun casts a shadow across the Earth–well, you can imagine what happens.
How will Germany be affected? Energy data company Opower has put together this handy chart:
The whole thing will happen pretty quickly, as Opower explains in its blog post. On the morning of March 20, the moon will go from blocking 1% to 73% of the sun in the span of 75 minutes. When that happens, solar power generation will drop dramatically. Cloud cover could cause it to drop even further than it would otherwise during an eclipse.
Then everything will go in reverse, and the moon will once again block 1% of the sun. Solar power output could grow 3.5 times faster than usual.
The good news for Germany is that the country is prepared. After all, it has known about the eclipse for quite awhile. As Opower points out, Germany is good at real-time power grid flexibility–switching between renewables and non-renewables–since it gets 17% of its power from wind and solar. This will just be a more dramatic version of what it already does.
Germany could employ a number of strategies during the eclipse: importing electricity from elsewhere, turning on natural gas power plants, using energy stored by hydroelectric dams, and asking residents to use less power during that time. Then, when the solar energy comes flooding back post-eclipse, Germany could use the inverse of all those strategies to store power and make some money selling the excess to others.
The world will be paying close attention to how Germany handles the eclipse–not out of a deep, abiding concern for our German neighbors, but because these types of events will become more common as other countries ramp up their solar usage.
Opower writes: “Grid authorities are facing a similar future in renewable energy powerhouses like California, which is striving toward 33% renewable electricity by 2020. One oft-cited statewide scenario suggests that at sunset during some parts of the year, the sudden drop in solar power will necessitate an extremely brisk ramp-up of non-solar resources. … To compensate for the sun’s departure and, simultaneously, to meet the evening’s high electric demand.”
Germany’s experience with the solar eclipse will just be one giant fire drill for the many similar situations yet to come.