20 March Solar Eclipse: An Unprecedented Test for Europe’s Electricity System

European transmission system operators (TSOs) have been preparing for the 20 March solar eclipse for several months. Due to the amount of solar generation involved, it was necessary to evaluate and mitigate the risk, with the aim of bringing the risk of an incident back to the security level equal to that of a standard operating day. The ENTSO-E Solar Eclipse Impact Analysis outlines how TSOs are cooperating to maintain security of supply on the eclipse day, and in this changing environment.

Under a clear morning sky on 20 March 2015, some 35,000 MW of solar energy, which is the equivalent of nearly 80 medium size conventional generation units, will gradually fade from Europe’s electrical system before being gradually re-injected: all in the space of two hours while Europeans and their offices begin a normal working week day.

Managing this event on the world’s largest interconnected grid is an unprecedented challenge for European TSOs. Solar eclipses have happened before but with the increase of installed photovoltaic energy generation, the risk of an incident could be serious without appropriate countermeasures, as was pointed out in ENTSO-E’s Winter Outlook Report of last December.

The main conclusion of ENTSO-E’s Solar Eclipse Impact Analysis is that operational coordination among European TSOs will be crucial. After thorough operational planning work, TSOs will put in place continuous on line coordination between control rooms across Europe ahead of, and during the eclipse to better coordinate the scheduled remedial actions.

While it is clear from the report that TSOs are taking all necessary measures to mitigate the risks, the solar eclipse is a perfect illustration that maintaining system security with more and more volatile and dispersed generation is becoming increasingly challenging.

In several reports, policy and position papers, ENTSO-E has pointed out that in order to guarantee security of supply, a series of policy and regulatory changes are needed to take into account the evolution of Europe’s energy mix. All of ENTSO-E’s work products are designed to ensure that the transition towards a decarbonised economy is as smooth, efficient, secure and cost effective as possible.

ENTSO-E’s Scenario Outlook & Adequacy Forecast (SO&AF), Seasonal Outlooks, Ten-Year Network Development Plan, etc., provide objective assessments on the impacts, opportunities and risks of the different policy options.

Together with the Solar Eclipse Impact Analysis, ENTSO-E has also published a list of frequently asked questions, and will continue to communicate on the eclipse as the date approaches and beyond.

> more information: https://www.entsoe.eu/Documents/Publications/SOC/150219_Solar_Eclipse_Impact_Analysis_Final.pdf