The solar eclipse of August 12 will put the Spanish electrical system to the test

Among all the scientific, social, security or environmental derivatives, the total solar eclipse that can be seen in a good part of Spain on August 12 also has an energy one.

Around 8:30 p.m., the setting of the sun will gradually cancel out the generation of electricity with photovoltaic energy in the affected areas, which is once again showing its muscle. In July, 28.3% of the electricity consumed in Spain came from the sun.

The eclipse will be at dusk and at a time of decline in photovoltaic production, which means that neither Red Eléctrica Española (REE) nor this sector expect it to affect the availability of electricity. But, just in case, the system operator plans to make an "additional reserve" of generation sources on a day in which it estimates that solar production may decrease by 5,000 MW, 13% "of the maximum demand for a typical Wednesday in August."

In a similar way to the reinforced operation that it has applied since the blackout on April 28 of last year and by which it schedules more synchronous power plants to guarantee the stability of the system, Red Eléctrica will increase the usual reserves and safety margins on the eve of August 12. In this case, in the event that the decrease in photovoltaic generation due to the eclipse makes it necessary to resort to them.

Using its own mathematical model, the operator calculates that the setting of the sun in the late afternoon of that day will lead to a drop of 5,000 MW in solar generation, equivalent to 13% of maximum demand for a typical Wednesday in August. To put it in perspective, on Wednesday, August 5 at eight in the afternoon it was 37,400 MW, of which 13,000 MW were of solar origin.

In any case, Red Eléctrica will not make an extra generation reserve stockpile for those 5,000 MW because it considers that the technologies that participate in the auctions of the hours corresponding to the eclipse to match supply and demand of electricity will be those that are available to generate electricity at that time, something that will foreseeably exclude the solar parks located in the northern half of the country, which, on the other hand, generates less electricity from solar sources than the south.

At dusk and in areas with little photovoltaic

The general director of the Spanish Photovoltaic Union (UNEF), José Donoso, highlights two main reasons why the eclipse will not become an energy problem. First of all, because at the time at which it will occur "there is already little solar generation." Secondly, it points out that "it will travel through areas of Spain that do not have so much installed photovoltaic power", through the north of Castilla y León, Aragón and Valencia while this year it will not pass through Extremadura, the south of Castilla-La Mancha or Andalusia

Companies in the photovoltaic sector also estimate that thanks to the "possibility of anticipating electrical generation with necessary backup" in advance, there will be no problems in the face of the eclipse, a type of event that, as has been planned for a long time, has "relatively simple electrical management," they add in the sector.

European Operators Task Force

Other "preventive measures" that Red Eléctrica will take to mitigate an impact of the eclipse on solar generation that it considers "limited" will be closer cooperation with other European operators and with electricity generation and distribution centers in Spain and "constant monitoring and follow-up" of the phenomenon.