Unprecedented Blackout Strikes Spain and Portugal: First-Ever Overvoltage Crisis Revealed

A Power Surge That Shook the Iberian Peninsula

A massive power surge triggered a widespread blackout across Spain and Portugal, marking the most severe incident in Europe over the past two decades and the first known blackout caused by overvoltage. This event, which occurred in April, led to nearly a day of significant disruptions, plunging areas into darkness, cutting internet and telephone connections, and halting transport links.

The Report's Findings

Damian Cortinas, president of the association of electricity grid operators Entso-e, described the incident as entering "new territory," emphasizing that it was the first of its kind due to overvoltage—a condition where electrical voltage exceeds safe limits. The report, released recently, detailed that a series of cascading overvoltages were behind the outage, potentially caused by network surges from oversupply, lightning strikes, or inadequate protective equipment.

Despite automatic defense plans being activated, they failed to prevent the system shutdown. The blackout not only affected large parts of Spain and Portugal but also briefly impacted southwestern France, highlighting vulnerabilities in the regional power infrastructure.

Political and Industry Fallout

The outage sparked a heated political debate in Spain, with the opposition suggesting that the government's push for renewable energy and reduction in nuclear power contributed to the crisis. However, the government rejected these claims, and the Entso-e report avoided assigning blame, focusing instead on the event sequence and system conditions.

Sara Aagesen, Spain's minister for ecological transition, stated that the report aligns with a government-commissioned investigation pointing to faults in both the national grid provider Red Eléctrica and private electricity companies. In contrast, Redeia, owner of Red Eléctrica, blamed power plants for failing to maintain voltage, while utilities cited poor grid planning.

Real-World Impacts and Ongoing Investigations

The blackout had immediate and severe consequences:

• Madrid Open Tennis matches were halted mid-play.
• Spain's nuclear power plants automatically shut down.
• Oil refineries operated by Moeve suspended operations.
• Buildings went dark, mobile phones and traffic lights failed, leading to long queues for cash and overcrowded buses as other transport systems stalled.
• Emergency services responded to 286 elevator rescues in the Madrid region, and hospitals canceled routine procedures under emergency plans.

The Entso-e report noted challenges in data collection, with a final analysis on root causes and voltage control measures expected in the first quarter of next year. This incident underscores the need for improved grid resilience and has intensified scrutiny on Europe's energy policies.