Decoded: Reasons behind massive power outage in Spain and Portugal

Business Standard

29-04-2025

A large-scale power outage brought life to a standstill across Spain, Portugal, and parts of France on Monday, leaving millions without electricity.
The blackout hit major cities including Madrid, Barcelona, Lisbon, Seville, and Valencia, disrupting public transport, air travel, mobile networks, and internet services.
In Spain and Portugal, residents reported widespread mobile network outages and disruptions to internet services. Trains in Lisbon and Madrid were stuck inside tunnels between stations, forcing passengers to wait in complete darkness. Metro services in Lisbon and Porto were suspended entirely, and traffic signals stopped working in several areas, creating confusion and congestion on the roads. Even Madrid's Barajas International Airport was affected, along with other airports that had to stop operations temporarily.
Outage affected all services
Shops, restaurants, and offices across major cities turned dark. In Madrid, many businesses were forced to close early, and residents found themselves cut off from essential services. The blackout also disrupted events such as the Madrid Open tennis tournament.
According to Euronews, the power failure stretched beyond the Iberian Peninsula, impacting nearby countries like Andorra and parts of southwest France. Some areas in Belgium also reported brief disruptions. The blackout was so serious that the Spanish government called an emergency session in Moncloa to monitor the situation and coordinate a response.
Reason for the power outage
At first, the exact cause of the outage was unclear. However, local media reported two possible reasons. One possibility was a technical issue within the European power grid system, which caused a widespread disturbance across interconnected networks. Another suspected cause was a wildfire on Mount Alaric in southwest France. The fire reportedly destroyed a high-voltage power cable that runs between Perpignan and Narbonne, which may have added stress to the grid system.
Later, Portuguese Prime Minister Luis Montenegro said that the outage began in Spain and may have been caused by a rare atmospheric event. Energy experts explained that sudden and extreme changes in temperature across Spain could have affected power lines and created vibrations in the high-voltage cables.
These vibrations caused irregularities in the electricity supply, which led to widespread system failures. The phenomenon, known as 'induced atmospheric vibration', caused the system to fall out of sync, triggering further disturbances across the European grid.
Despite the scale of the problem, officials ruled out the possibility of a cyberattack. Antonio Costa, President of the European Council, said there was no sign of any malicious activity. Spain's representative to the European Commission, Teresa Ribera, also told Spanish radio that the blackout did not appear to be intentional or the result of sabotage.
Challenges of shared power grids
International experts noted that while shared electricity grids allow countries to use clean energy more efficiently, they also make the entire system more vulnerable. A problem in one country can now easily spread to others. This has happened before — in 2003, Italy suffered a 12-hour blackout due to a power line issue in Switzerland. In 2006, a German power surge caused blackouts in Portugal and Morocco.
Efforts to restore electricity began almost immediately. Spain's national grid operator, Red Electrica, said it started bringing back power in the north and south of the country. Portugal's grid operator, REN, also worked throughout the day to bring systems back online. By late Monday evening, Spain had restored 61 per cent of its power supply.