A solar eclipse in March next year will be an unprecedented test of European electricity grids because of the massive increase in solar power production on the continent, French power grid RTE said on Friday.
On the morning of March 20, 2015, an almost total solar eclipse will block direct sunlight over Norway and northern Europe for about one hour and a half and will also be visible in other parts of Europe, North Africa and Russia.
Europe's solar power capacity has significantly increased since the last major eclipse in August 1999, and, depending on the weather that day, the eclipse could cause rapid swings in output that will require adjustments by the grids.
"The passage of this shadow will considerably reduce photovoltaic power production,'' Dominique Maillard, the head of France's power grid operator RTE, owned by EDF, told reporters during its winter outlook presentation.
"According to our calculations, the impact could be a drop in production of as much as 30,000 megawatts across Europe, it's the equivalent of a six degrees Celsius drop in temperatures in half an hour,'' Maillard said.
That is also the capacity equivalent of 30 nuclear reactors.
Maillard said RTE had started talks with other European grid operators to co-ordinate their response and prepare back-up power capacity.
"If it's a cloudy day, it will go almost unnoticed. We will only know almost at the last minute, but that doesn't prevent us from getting our contingency plans ready,'' he said.
Germany is Europe's leading country in terms of solar power capacity, with nearly 37,000 MW of installed solar capacity meeting 28.5 percent of its domestic power demand in the first half of 2014.