Spain, Portugal reconnect after sudden grid collapse, cause still unknown

Electricity has been restored to most of Spain and Portugal following one of the largest power outages in Europe’s recent history, though the exact cause of the sudden blackout remains under investigation.

As power returned on April 29, life began to normalize across the Iberian Peninsula. Schools and offices reopened, public transportation resumed operations after significant delays, and traffic congestion began to ease. While most hospitals had regained power, a few in Spain continued to rely on generators, Caliber.Az reports citing foreign media.

Actualizamos información⬇️11:15h.

✅Normalizado el funcionamiento del sistema eléctrico peninsular.
✅Tras superar la punta de demanda de la mañana a las 8.35 con 28.677MW, el pico nocturno se espera a las 21:10h con 31.200 MW.

— Red Eléctrica (@RedElectricaREE) April 29, 2025

Spain’s grid operator Red Eléctrica confirmed that it was supplying “virtually all of the country’s electricity demand” by April 29 morning. Portugal’s national grid operator, REN, reported that by April 28, all 89 of the country’s power substations were back online.

Pressure is now mounting on both governments to explain the origins of the massive outage, which disrupted everyday life for millions. Spanish Prime Minister Pedro Sánchez, speaking on April 28, revealed that the country had experienced a “precipitous loss of 15GW of electricity generation in five seconds at around midday,” amounting to approximately 60 per cent of the national demand.

Eduardo Prieto, chief of operations at Red Eléctrica, elaborated that the sudden grid instability had caused the interconnection between the Spanish and French power systems across the Pyrenees to collapse, triggering a broader failure of Spain’s grid. Some regions in France experienced brief outages as a result.

Spain, a major producer of renewable energy, is now facing scrutiny over whether its high reliance on wind and solar power may have contributed to the vulnerability of its electrical infrastructure. “The region has one of the world’s highest penetrations of renewable generation from wind and solar so the blackout will be a case study of how renewable generators impact on reliability as well as restarting after widespread failure,” said John Kemp, an energy analyst and public policy specialist. He warned that pinpointing the precise sequence of failures “could take investigators several months.”

In Portugal, hospitals and airports have resumed normal operations, although delays persisted in Lisbon. The city’s metro and national train services were also returning to service.

French Industry Minister Marc Ferracci addressed the incident in an interview with RTL radio, stating that France had been minimally affected. “France was better prepared to prevent blackouts such as the one suffered by Spain and Portugal,” he said, adding that the overall impact in France had been “minimal.”

 Spanish Prime Minister Pedro Sánchez said that the cause of the blackout remains undetermined, adding that “no hypothesis or possibility is being ruled out.” Red Electrica similarly described the outage as “exceptional and totally extraordinary.”

In Portugal, Prime Minister Luís Montenegro pointed to Spain as the source of the issue. “It is related to an abrupt increase in voltage in the Spanish electricity grid, the origin of which we are unable to explain. We know that it was the increase in this voltage that triggered the safety mechanisms that led to this blackout. We will calmly assess with the Spanish authorities what happened and try to design better response instruments,” he said.

Portugal’s grid operator REN supported this assessment, attributing the disruption to a “fault in the Spanish electricity grid” caused by a “rare atmospheric phenomenon,” noting that “extreme temperature variations in Spain contributed to the outage.”

Officials in both countries, along with European Council President António Costa, confirmed there was “no indication” of a cyberattack.

By Vafa Guliyeva