Massive power outage exposed unprecedented overvoltage phenomenon in Europe

On April 28, 2025, a massive power outage occurred in Spain and Portugal, severely disrupting daily life by cutting access to electricity, internet, and mobile phone services. This significant incident has been characterized by Damian Cortinas, the president of the ENTSO-E council, as the most severe power outage Europe has experienced in the last two decades. Experts revealed that this outage is linked to a novel phenomenon called cascading overvoltages, which they claim has never been witnessed before in Europe and likely not globally. While the incident's immediate effects were apparent, the panel of 45 European experts involved in the investigation has yet to identify the underlying causes driving these unprecedented overvoltages. In the aftermath of this incident, residents of both nations expressed considerable frustration and confusion over the sudden lack of electricity and communication services. The chaos stemming from the outage highlighted vulnerabilities in the electrical infrastructure not just in Spain and Portugal but across Europe, emphasizing the need for robust measures to prevent such occurrences in the future. As the investigation unfolds, the preliminary report from the expert panel indicated the necessity to analyze the electrical systems thoroughly to prevent similar incidents from recurring. Moreover, the investigation brings attention to the importance of understanding overvoltages more comprehensively to mitigate their impact going forward. The cascading nature of these overvoltages poses a complex challenge for electrical systems, which often rely on precise voltage levels to operate efficiently. This incident is not only a wake-up call for the authorities in Spain and Portugal but also for European electrical operators who must now reconsider their strategies to guarantee the stability and reliability of their networks in light of this rupture. As the investigation into the outage continues, experts are likely to explore various facets of electrical transmission and potential risk factors related to the systems’ resilience against overvoltages. With many lives disrupted, the onus falls on European leaders and energy system operators to take appropriate steps based on the findings to enhance the security of power supplies for millions of residents who rely on uninterrupted electricity flows.