Lights flickered back to life across most of Spain and Portugal on Tuesday, April 29, 2025, following a massive blackout that struck the Iberian Peninsula the previous day, leaving millions without power and causing widespread disruption. By early Tuesday morning, electricity had been restored to nearly 90% of mainland Spain, according to the national grid operator Red Eléctrica de España (REE). In Portugal, power was restored to around 6.2 million households out of 6.5 million, marking a significant recovery from the outage.
The blackout, which began shortly after noon on Monday, April 28, affected cities across Spain and Portugal, with the Balearic and Canary Islands largely spared. The outage was unprecedented, as Prime Minister Pedro Sánchez noted that approximately 15 gigawatts of energy—equivalent to 60% of the country's consumption at that moment—vanished in just five seconds. "That’s something that has never happened before," he stated, emphasizing the need for a thorough investigation into the cause of the sudden energy loss.
Despite the rapid restoration of power, the exact cause of the blackout remains unclear. Both Sánchez and Portuguese Prime Minister Luis Montenegro indicated that the source of the outage was likely in Spain. Authorities are currently analyzing all potential causes, with no hypotheses ruled out. The Spanish Ministry of Internal Affairs declared a state of emergency to facilitate recovery efforts in the affected regions.
Reports have suggested that the blackout might have been linked to a rare atmospheric phenomenon known as "induced atmospheric vibrations". These vibrations reportedly caused abnormal fluctuations in the high-voltage lines of Spain's energy system, leading to failures in synchronization between electrical systems. According to the Portuguese energy company REN, these fluctuations triggered disruptions in interconnected European networks, although REN later clarified that it had not officially attributed the blackout to this phenomenon.
Experts have weighed in on the situation, with Solomon Brown, a professor at the University of Sheffield, explaining that such vibrations can be likened to a small surge in the local electromagnetic field, potentially causing imbalances in electricity flows. "Energy distributors can use various measures for control, such as asking electricity sources to adjust their output," Brown noted.
Onyema Ndukka, a senior lecturer in sustainable energy development at the University of London, added that electrical networks are typically interconnected, meaning an outage in one area can lead to cascading effects elsewhere. "Ideally, reserves are built into the system to prevent widespread outages," he explained, suggesting that the current situation highlights the need for robust contingency planning.
As the investigation continues, Red Eléctrica Española has tentatively ruled out the possibility of a cyberattack, stating that no signs of interference from external agents were found. Reports from cybersecurity experts support this conclusion, indicating that hackers were not involved in the outage. Earlier statements by regional officials had suggested that a cyberattack could not be excluded, but these claims have since been dismissed by higher authorities.
In the aftermath of the blackout, many residents found themselves stranded in trains and elevators, with mobile networks down and internet access severely disrupted. Hospitals postponed routine operations but managed to attend to critical cases using backup generators. Public transport was halted, traffic lights extinguished, and many people were left to navigate pitch-black streets, relying on phone torches.
In Madrid, the mayor urged residents to minimize travel to allow emergency services to operate effectively. The disruption also affected the Madrid Open tennis tournament, which had to pause play due to the power failure.
As the situation began to stabilize, citizens expressed their relief as power gradually returned. In many cities, the restoration of electricity was met with applause and joyful cries. By 10 PM on Monday, 62% of Spain’s substations were back online, and 43.3% of the power demand had been met. Meanwhile, Portugal's REN reported that it had restored power to 85 out of 89 substations.
Pedro Sánchez thanked neighboring countries such as France and Morocco for their assistance in supplying additional electricity to Spain during the crisis. He acknowledged that the current shortfall would be addressed using gas and hydroelectric power while emphasizing the importance of a coordinated response to restore normalcy.
The blackout was not just a local issue; it had ramifications across the Iberian Peninsula, affecting nearly 60 million people. Traffic lights were out across Portugal, and the metro systems in Lisbon and Porto were closed. Reports indicated that queues formed at ATMs as electronic payment systems failed, leading to a return to cash transactions in many places.
As recovery efforts progress, the Spanish government has announced the establishment of a commission under the Ministry of Ecology to investigate the causes of the blackout. Meanwhile, citizens are encouraged to remain patient as services return to normal. Schools in the most affected regions will be open but will not conduct regular classes on Tuesday.
In summary, while power has been largely restored, the investigation into the causes of the blackout continues, and authorities are working diligently to ensure a reliable energy supply in the future. The incident serves as a reminder of the vulnerabilities inherent in interconnected electrical systems and the importance of preparedness in the face of unexpected challenges.
