Some parts of Europe witnessed a near total solar eclipse this morning, an event which, while fun to observe (not without the proper equipment please), presents a challenge for solar panels: namely, a lack of sun. As it turns out this same problem happens at night but, as WSJ reports, the rapidity with which an eclipse darkens the earth could cause blackouts if the energy grid can’t tack up the slack quick enough. Here’s more: The solar eclipse will provide an acid test for a continent that has placed a big bet on renewable energy—but whose aging electricity grids could buckle under the strain of a sudden drop in solar power. “Given the growth of renewables across Europe in recent years, this will require an unprecedented amount of careful balancing of supply and demand across the grid,” said Valentin de Miguel of consulting firm Accenture... The partial disappearance of the sun Friday will place a huge strain on Europe’s energy system. Normally, when the sun goes down, it takes about an hour for the light to fade. That gives time for electricity grids to substitute the power flowing from solar panels with electricity generated from traditional sources such as coal and natural gas. An eclipse blocks the sun in just a few minutes, though, leading to a potential sudden drop of up to 35,000 megawatts of generation capacity. That is the equivalent of about 20 large coal-fired power plants coming off the grid at the same time. Conventional electricity suppliers will have to seamlessly substitute power to prevent blackouts, and then they must shut down capacity as solar power rebounds. A break in the switch from solar to conventional power sources could “result in a cascade of electricity blackouts, similar to when a tree falls on a local power line but across the country,” said Alessandro Abate, a professor at Oxford University’s Department of Computer Science, who is studying Friday’s eclipse. Since the last solar eclipse occurred over Europe in 1999, the region’s energy supply has radically changed. Europe has made a major push into renewable energy, with the share of electricity coming from such sources rising to about 20% by 2012 from 12% in 2002, according to Eurostat. As recently as five years ago, there was “no idea that Europe would have been so full of photovoltaic panels at that time,” said Francesco Starace, CEO of Italian utility Enel SpA on Thursday. But the addition of so many intermittent power sources, including wind, has raised concerns about the potential instability of electricity grids that were built to distribute power from huge, central power plants with relatively stable output. “The grids were built decades ago when there was really no renewables, especially solar,” Mr. Abate said. And a bit more from BBC… Oxford University scientists are using the event to try to understand how eclipses affect electricity grids. The deep shadow will reduce the output from solar panels, which now supply a significant proportion of power needs right across Europe. The researchers will look to see how this dip in performance impacts the stability of grid networks. ...and here’s a map from BBC which shows where the display will be the most spectacular… … and some pictures from around the world...