Spain Power Outage: Let’s Wait

The Iberian Peninsula, Spain and Portugal, experienced a complete electric power outage Monday April 28, 2025.  The outage began at about 12:30 pm local time and power was out for most of Spain’s 48 million citizens for ten hours. The Spanish system lost 15 gigawatts, about 60% of national demand, in five seconds. By 5 am Tuesday morning over 92% of customers were back in service. The cause is not known but advocates for and against high levels of renewable (solar) energy have already postulated about whether Spain’s high solar production was or was not the singe cause. The Spanish grid operator Red Electrica ruled out a cyber attack as the cause.

At the time of the blackout solar supplied 59% of Spain’s electricity, wind 12%, nuclear 11% and gas (CCGT) about 5%. The good news is that restoration of power from a “black start, the first in 50 years, went well and will provide a textbook lesson for other systems recovering from total power loss with a predominately renewable power system.

This side of the Atlantic the outage in Spain renewed the debate over what level of renewables is optimal for an electric system. On the one side, we have commentators saying that the incident signals there are vulnerabilities caused by the growing dominance of inverter-based renewable energy sources. On the other side proponents of renewable energy blame inappropriate “old” control settings that have not kept up with the Spanish grids shift to lower inertia inverter-driven resources.

The two camps also have appeared in Europe. Writing on the Wall Street Journal two Spanish analysts charge that “By continuously reducing inertia, Spain’s policymakers engineered a vulnerability. The grid collapse was the result of a series of missteps by lawmakers.” How the Lights Went Out In Spain” Gabriel Calzada and Manual Fernandez Ordonez, WSJ April 30, 2025). In addition, a recent financial report by the electric holding company Redeia, parent of grid operator Red Electrica warned that “high penetration of renewable generation without necessary technical capacity to deal adequately with disturbances” could “lead to production cuts… blackouts could become severe.”

In the other camp Spain’s Environmental Minister Sara Aagesen stated, “The system has worked to perfection with a similar demand situation and similar energetic mix [in the past] so pointing the finger at renewables when the system has functioned perfectly in the same context doesn’t seem very appropriate.”  Red Electrica’s President Beatriz Corredor also joined Aagesen in saying “Linking what happened on Monday to renewables isn’t correct. Renewables work in a stable way.”

The European Union and the governments of Spain and Portugal have all initiated studies to determine the true cause of the Monday blackout.  Hopefully their panels of electrical engineering experts will be able to review all the data to determine the sequence and cause of he events. No politicians are required.