A recent report has revealed that a massive power surge in April, which led to a widespread blackout across Spain and Portugal, was the most severe incident of its kind in Europe over the past two decades. This unprecedented event, caused by overvoltage—a condition where electrical voltage exceeds normal levels—resulted in significant disruptions, including the loss of internet and telephone connections, halted transport systems, and widespread darkness for nearly a day. The blackout also briefly affected southwestern France. Damian Cortinas, president of the association of electricity grid operators Entso-e, described the incident as uncharted territory, emphasizing that the organization’s role was not to assign blame but to analyze the event. The report, released on Friday, identified a series of cascading overvoltages as the primary cause of the outage. Overvoltage can result from network surges due to oversupply, lightning strikes, or insufficient protective equipment. Although automatic defense mechanisms were activated, they failed to prevent the system shutdown. The Spanish government has welcomed the Entso-e report, stating that it aligns with its own findings, which concluded that both the national grid provider Red Eléctrica and private electricity companies were at fault. However, Red Eléctrica and private firms have denied responsibility, with Redeia, the owner of Red Eléctrica, attributing the blackout to the failure of some coal, gas, and nuclear power plants to maintain appropriate voltage. The incident has sparked a broader political debate in Spain about the country’s energy model, with critics suggesting that the government’s heavy reliance on renewable energy and reduced nuclear capacity may have contributed to the crisis. The government has dismissed these claims, and the Entso-e report has refrained from taking sides. The blackout had far-reaching consequences, including the suspension of a Madrid Open tennis match, the shutdown of Spain’s nuclear power plants, and the halting of operations at oil refineries. Emergency services were called to rescue people trapped in elevators, and hospitals implemented emergency plans, postponing routine procedures. A final report, expected in the first quarter of next year, will delve deeper into the root causes of the overvoltage and the measures taken to control voltage in the system.