ENTSO-E Report Cites Multiple Factors in 2025 Spain Blackout

A final investigation into the April 28, 2025, blackout that plunged most of Spain and parts of Portugal into darkness has concluded that no single factor triggered the outage, but rather a combination of systemic vulnerabilities in voltage control and grid operations. The report, released Thursday by a 49-member expert panel convened by the European Network of Transmission System Operators for Electricity (ENTSO-E), describes the incident as the most severe blackout in the European power system in more than two decades.

The blackout began at 12:33 p.m. Central European Summer Time, affecting nearly 60 million people across continental Spain and Portugal for approximately 10 hours. Power was cut to homes, businesses, railways, metro systems and telecommunications networks, halting trains, disrupting internet and phone services, and leaving cities in darkness. A small area in southwestern France near the Spanish border experienced brief disruptions, but the rest of the European grid remained stable.

According to the panel's analysis, the outage stemmed from interacting issues, including unusual oscillations in the power system's frequency, gaps in voltage and reactive power...