An eclipse of the sun next month could disrupt Europe’s power supplies because so many countries now use solar energy, electricity system operators have warned.
"The risk of incident cannot be completely ruled out,” the European Network Transmission System Operators for Electricity said on Monday, adding the eclipse on March 20 would be "an unprecedented test for Europe’s electricity system”.
Solar power covered just 0.1 per cent of all the electricity produced in Europe from renewable energy sources around the time of the last large solar eclipse in Europe in 1999, according to the network, known as ENTSO-E.
But since then solar power generation has soared to at least 10.5 per cent, as countries subsidise green power to meet EU renewable energy targets.
ENTSO-E said the eclipse could play a bigger role in places such as Germany, Europe’s largest economy, which now gets more than a quarter of its electricity from renewable generators and like other EU nations is connected with neighbouring countries’ grid systems.
The organisation also said it had been planning co-ordinated "countermeasures” for several months to help protect the continent’s power system from the eclipse, which is due begin at 08:40 on March 20 and end at 12:50 Central European Time and should be visible across Europe.
Patrick Graichen, executive director of Agora Energiewende, a Berlin renewable energy think-tank, said the March 20 eclipse was unlikely to cause any problems because there are several well-known ways of balancing power supplies and there has been plenty of time to plan.
But the eclipse will still be a "stress test” of the flexibility of the European power system, he added, because it will have to adapt to a more abrupt shift in solar power generation than would normally occur, especially if it is a sunny day and all solar power stations were producing at full load.
"Within 30 minutes the solar power production would decrease from 17.5 gigawatts to 6.2GW and then increase again up to 24.6GW. This means that within 30 minutes the system will have to adapt to a load change of -10GW to +15GW,” he said.
This type of shift is expected to become more common by 2030 as more renewable energy comes on stream, Mr Graichen added, "so in a way March 20 is a glimpse into the future of our power systems”.
Solar eclipses have occurred across Europe before, but the increase in solar power across the continent’s interconnected grids since 1999 means system operators are paying more attention to this one.
"It will have a cascading effect,” said Claire Camus, an ENTSO-E spokeswoman, explaining that countries would draw on each other’s reserves of electricity in turn as the path of the eclipse cuts solar power at much faster rates than under natural conditions such as sunset or cloudy days.
Coal, gas and hydropower generators are likely to be used to ensure balance in the system, which has to produce as much electricity as is used at all times.
"It’s definitely going to be a challenge for control rooms,” Ms Camus told the Financial Times.
ENTSO-E released several papers on the impact of the eclipse on Monday, and said: "The whole of the European area is concerned either directly or indirectly.”
About 35,000 megawatts of solar energy, equal to nearly 80 medium-sized conventional power plants, would gradually fade from Europe’s electrical system before being gradually reinjected, the network said, "all in the space of two hours while Europeans and their offices begin a normal working weekday”.
"The reduction in solar radiation will directly affect the output of the [solar] photovoltaics and for the first time this is expected to have a relevant impact on the secure operation of the European power system,” it said.
The network group added: "The solar eclipse is a perfect illustration that maintaining system security with more and more volatile and dispersed generation is becoming increasingly challenging.
"What makes this year’s solar eclipse so special is the fact that there is now a non-negligible amount of energy generation units connected to the grid that are highly sensitive to variations in solar radiation.
"This solar eclipse will thus be an unprecedented test for Europe’s electricity system, and useful to better understand the relationship between ambitious EU targets and the security of operation which all Europeans are very much depending on.”
(Financial Times)
