Madrid, Spain (April 29, 2025) – A widespread power outage plunged much of Spain and Portugal into darkness on Monday, April 28th, at approximately 12:30 PM CEST. The blackout significantly affected an estimated 60 million people across the Iberian Peninsula, with minor impacts felt in Andorra and parts of southwestern France.

Impact of the Blackout

• Transportation networks faced severe disruptions, including the shutdown and evacuation of metro systems in major cities, the halting of train services that stranded thousands of passengers, and non-functional traffic lights causing widespread congestion. Airports like Madrid-Barajas experienced significant delays and flight cancellations.
• Communication networks were heavily affected, with mobile phone voice calls largely unavailable and internet access substantially reduced, hindering communication efforts.
• Essential services experienced significant strain. Hospitals relied on backup generators, gas stations were unable to operate, and ATMs ceased functioning, limiting access to essential resources.

Causes of the Blackout

Investigations are underway to determine the precise cause of the extensive power failure. Initial theories and reports include:

• Portugal’s grid operator, REN, suggested a “rare atmospheric phenomenon” involving extreme temperature variations in Spain leading to disruptive oscillations in high-voltage lines.
• Spain’s grid operator, Red Eléctrica, reported a “very strong oscillation in the power flow” that triggered a major loss of power generation, causing the Spanish grid to disconnect and collapse. Low grid inertia has also been cited as a potential contributing factor.
• While initial assessments downplayed the possibility, the Spanish government has stated that a cyberattack has not been ruled out, and a judicial investigation into potential computer sabotage has been opened.

Restoration Efforts

Power restoration commenced gradually on Monday afternoon. By Tuesday morning, Spain reported that 99% of its power demand had been restored. Portugal’s grid operator announced the full restoration of power to all customers by the same day.

Aftermath

This extensive blackout highlights the critical importance of stable energy infrastructure. Investigations are ongoing to pinpoint the exact cause and implement preventative measures. The incident has also sparked discussions regarding grid resilience and the integration of renewable energy sources.