A maintenance man works on solar panels at the Norsol solar energy company in Villaldemiro, northern Spain, on Feb. 10, 2015. (Cesar Manso/AFP via Getty Images)

In the United States, power outages are usually caused by extreme weather events such as blizzards or hurricanes. In Europe, however, experts are getting worried about a phenomenon that originates far away from the Earth's atmosphere.

On March 20, Europeans will witness a rare solar eclipse that is expected to affect nearly all countries on the continent for several hours. Whereas some can't wait for the event to take place, the European Network Transmission System Operators for Electricity (ENTSO-E), a Brussels-based body, is much less excited. It fears that the sudden, continent-wide absence of sunlight may cause serious power outages. In a statement, the organization called the moment "an unprecedented test for Europe’s electricity system." About 3 percent of Europe's power supply comes from solar energy.

So, is Europe facing a solar eclipse with catastrophic consequences? In fact, it is much more likely that nothing is going to happen and that March 20 will pass like any other day.

Three percent does not sound like a lot, but if all sunlight suddenly disappears, the drop in the supply of energy might indeed have serious consequences. ENTSO-E expects that the loss of sunlight would have the same effect as if one turned off 80 medium-size power plants. "This will happen on the morning of a weekday, when demand is rising," Claire Camus, a spokeswoman for ENTSO-E, told The Washington Post.

Around noon, when the solar eclipse is supposed to come to an end, Europe would suddenly be flooded with a surplus of energy — a second risky repercussion that has never occurred to such an extent. However, European energy providers have known the risks for months and have carefully prepared for the unique incident.


The solar eclipse will move from the southwest of the continent toward the northeast. Hence, as the video below shows, different European countries will be affected at slightly different times. Given that Europe is the largest interconnected energy grid area in the world, according to ENTSO-E, this will allow coordinators to quickly move resources to affected countries.

"Ahead of March 20, and during the eclipse, Transmission System Operators will put in place continuous on line coordination between control rooms across Europe to better coordinate the scheduled (...) actions," Camus said in her statement.

German energy expert Thomas Gobmaier told the business weekly Wirtschaftswoche that in the worst-case scenario, European nations could decide to stop supplying industrial factories with energy for a certain duration to prevent nationwide power outages.

Whereas a solar eclipse is a rare phenomenon, some are more concerned about the daily challenges of Europe's power grid. A 2013 study conducted by Hamburg-based HWWI found that Germany's increasing reliance on renewable energy sources had made it more vulnerable to power outages due to extreme weather events.

The costs of such outages could be enormous: According to the researchers, one hour of blackout in Berlin around lunchtime would cost at least $25 million. If all of Germany were affected, about $600 million.