Spain, Portugal recover from massive power outage, cause still under investigation

A widespread power outage plunged Spain, Portugal, and parts of southwest France into chaos on Monday, April 28, 2025, affecting millions and disrupting daily life across the countries.

As electricity gradually returns, authorities in both countries are racing to pinpoint the cause of what is being described as one of Europe’s largest power cuts in recent history.

The blackout, which began around midday, halted trains, shut down traffic lights, and paralyzed critical infrastructure, including airports and subway systems in major cities like Madrid, Barcelona, and Lisbon.

Spain’s grid operator, Red Eléctrica de España (REE), reported that the outage, termed “el cero” (the zero), resulted from a sudden loss of 15 gigawatts of power in just five seconds, equivalent to 60 percent of Spain’s electricity demand.

By Tuesday morning, over 99 percent of Spain’s power and 80 percent of Portugal’s had been restored, with REE and Portugal’s Redes Energéticas Nacionais (REN) working tirelessly to stabilize the grid.

While the immediate crisis is easing, the cause remains unclear. Portuguese Prime Minister Luís Montenegro stated there is “no indication” of a cyberattack, a sentiment echoed by European Council President António Costa.

Some reports suggest a “strong oscillation” in the European grid, possibly linked to a technical issue in the energy connection between Spain and France.

Portugal’s REN initially pointed to a “rare atmospheric phenomenon” causing voltage imbalances, but later clarified it may have stemmed from Spain’s grid. Spain’s reliance on renewable energy, which accounted for 56 percent of its electricity last year, has raised questions about grid stability, though experts stress the need for advanced technologies like flywheels to manage frequency in renewable-heavy systems.

Both nations declared states of emergency, with Spain’s National Security Council and Portugal’s Cabinet convening to address the crisis. In Catalonia, over 7,000 police officers were deployed to maintain order and prevent looting.

The outage briefly affected France, which supplied emergency power to Spain via interconnections. Spanish Prime Minister Pedro Sánchez urged the public to avoid speculation, emphasizing that no theory has been ruled out.

As life returns to normal, the incident has sparked concerns about energy security in Europe. With power restored to most areas, the focus now shifts to preventing future outages and addressing vulnerabilities in the region’s interconnected grids.