Spain and Portugal reeling after massive blackout as investigations deepen

Department of Research, Studies and International News 29-04-2025

In the aftermath of a major blackout that plunged large areas of Spain and Portugal into darkness, Spanish Prime Minister Pedro Sánchez has pledged a thorough investigation to uncover the root cause of the unprecedented outage. While energy companies have ruled out a cyber-attack, authorities remain cautious, leaving all possibilities open.

The power failure, which occurred on Monday, had widespread consequences. Public transportation was severely disrupted, stranding tens of thousands of passengers, while emergency services struggled to respond to multiple fatal incidents believed to be linked to the outage. Among the reported fatalities were three family members in northwestern Spain, who are thought to have succumbed to carbon monoxide poisoning after using a generator. Elsewhere, a woman reliant on an oxygen machine died in Valencia, and another lost her life in a candle-induced fire in Madrid.

By Tuesday morning, power had been fully restored across both nations. Speaking to the press, Prime Minister Sánchez emphasized the gravity of the situation, declaring that such a failure must not happen again. He announced the formation of a dedicated commission to investigate the incident, which will also scrutinize the roles of private energy providers. “We will identify the cause and act decisively,” he stated, underlining his commitment to implementing reforms and introducing measures to reinforce the grid’s resilience.

Sánchez reiterated that, although cyber-attacks had been ruled out by Spanish and Portuguese electricity operators, no theory was being discounted. Spain’s intelligence services remain engaged in analyzing the events leading up to the blackout. “We must not fall prey to disinformation,” he warned, addressing the spread of unfounded claims linking the outage to the government’s ongoing phase-out of nuclear power. He dismissed such narratives as either deliberately misleading or based on a fundamental misunderstanding of how energy systems work, noting that nuclear energy does not guarantee greater reliability than other sources.

Meanwhile, Portuguese Prime Minister Luís Montenegro called for a broader European assessment, urging the EU Agency for the Cooperation of Energy Regulators to carry out an independent audit of the affected national power systems. He said this step was essential to accurately identify the failure’s origins and avoid future disruptions.

Despite energy providers’ reassurances, Spain’s National Court has launched a parallel investigation. A judge there stated that while a cyberattack has not been confirmed, cyberterrorism remains a potential explanation. The court’s inquiry will focus on whether sabotage targeting critical infrastructure could have caused the collapse.

Red Eléctrica, Spain’s main electricity operator, provided some technical insight into the event. Eduardo Prieto, head of services, stated that initial findings ruled out any unauthorized intrusion into the control system. According to Prieto, two successive incidents occurred within a span of 1.5 seconds around midday Monday. While the grid withstood the first event, it failed to cope with the second, resulting in a widespread disconnection. The source of the problem, he noted, appears to have originated in the southwestern region of Spain, a key area for solar power generation.

Portuguese authorities echoed Spain’s findings, also dismissing the possibility of cyber sabotage. A government spokesperson confirmed that no hostile activity had been detected and suggested the issue likely stemmed from Spain’s power transmission network.

By late Monday night, Portugal’s grid operator REN announced that its national network had been fully restored and stabilized. Spain reported a similar recovery, with all substations operational by Tuesday morning.

Adding clarity to the investigation, Spain’s meteorological agency, Aemet, ruled out extreme weather as a possible cause. The agency confirmed there had been no unusual atmospheric conditions or significant temperature fluctuations on the day of the blackout. Additionally, REN discredited a viral social media message attributing the outage to a rare atmospheric disturbance. The company clarified that it had not issued such a statement.

Although normalcy has largely returned, residual disruptions remain. Spain’s airports were functioning by Tuesday, but the transport ministry urged travelers to verify their routes due to lingering public transport delays. State rail operator Renfe reported that while the national rail service was gradually resuming, regional services in areas such as Andalucía, Murcia, and Extremadura remained suspended.

An estimated 35,000 train passengers had to be evacuated from more than 100 trains when the blackout struck.

Such large-scale power failures are rare in Europe. Historical precedents include a 12-hour outage in 2003 triggered by a hydroelectric line failure between Italy and Switzerland, and another in 2006, when overloading in Germany’s grid caused widespread blackouts across several EU countries.

With the Iberian Peninsula still reeling from the shock, the coming weeks will be critical in determining both the cause of the failure and the steps needed to secure the region’s energy future.