PV industry, grid operators must work together to survive next big solar eclipses

The key takeaway from a new policy brief, The Successful Stress Test of Europe’s Power Grid – More Ahead, released by SolarPower Europe and the European Network of Transmission System Operators for Electricity (Entsoe), is that developers of solar PV technology and grid operators at both the distribution and transmission levels must work together in preparation for the next two solar eclipses, in 2021 and 2026.

The European electricity grid successfully weathered the March 20 near total solar eclipse, which lasted almost four hours. It was unique, in that no power grid has ever had to deal with the combination of a large amount of installed PV power (90 GW), often in concentrated clumps, and a large-scale eclipse.

During the highest point of the solar eclipse, the key challenge was to deal with a feed-in decrease of 14 GW at 10 am and then an injection of 35 GW at 12 pm. However, SolarPower and Entsoe say that thanks to effective planning, preparation and communication by transmission system operators (TSOs) both on a national and European level, power remained switched on.

Five action areas

While positive, the two add that in order to effectively deal with the next two eclipses in 2021 and 2016, where cumulative PV capacity is expected to reach 170 GW and 250 GW, respectively, and account for 7% and 15% of European electricity demand, respectively, up from 3.5% today, more work needs to be done.

"Managing a solar eclipse of a significant scale with 90 gigawatts took a year’s meticulous preparation and coordination," they say. "Managing similar eclipses in 2021 and 2026 with twice and three times as much PV in Europe calls for change and rapid action in key areas."

Overall, they recommend action to be taken in five areas: upgraded market- and system rules; reinforced regional cooperation; active customers; new system services provided notably by PV; and an enhanced TSO/DSO (distributed system operator) cooperation.

A "great deal" of regulatory and policy effort will be required to link retail and wholesale. Specifically, DSOs will need to take a more active role, which should be supported by new regulations. "The next legislative push has to be about opening up possibilities," write the report’s authors.

According to SolarPower and Entsoe, large-scale PV generation costs in Europe already compare with conventional electricity production, while solar costs at the distributed level are already below retail prices in many countries. "By 2025, large scale power system are expected to produce at 4 to 6ct€/kWh, going down to 2 to 4ct€/kWh by 2050," they say.