European electricity grid operators are preparing backup generation and balancing measures ahead of Wednesday’s solar eclipse to prevent disruptions to power supplies.
The eclipse is expected between 17:15 and 19:30 GMT, as the moon passes between the Earth and the sun, temporarily reducing solar power generation across Europe.
Data from ENTSO-E and Spain’s Red Electrica show the event could cut solar generation by as much as 9.7 gigawatts, with about 5 gigawatts of the reduction expected in Spain and Portugal.
Grid operators in Germany, France, Ireland and Northern Ireland have put measures in place to manage the anticipated decline in solar output, ENTSO-E said.
The measures include temporarily increasing electricity generation from gas and coal plants and adjusting frequency restoration reserves to keep the grid stable.
Solar power accounts for about 13% of the European Union’s electricity generation and has become increasingly important in meeting summer demand, particularly when air-conditioning use rises.
The eclipse comes as parts of Europe’s power systems are already facing pressure from extreme heat and low river levels, which have affected nuclear power generation in countries including Romania and Hungary.
Several grid operators have spent more than a year modelling the eclipse’s potential impact on electricity production and preparing contingency measures.
Operators in France, Spain and Britain said they do not expect the eclipse to cause power disruptions, partly because it will occur later in the day when solar generation is already declining.
In France, for example, the eclipse could temporarily reduce solar generation by up to 1.8 gigawatts, equivalent to about 6% of the country’s 30 gigawatts of installed solar capacity.