A power surge that caused a widespread blackout in Spain and Portugal was the most severe in Europe in the last 20 years, and the first of its kind, a report has found.
Damian Cortinas, president of the association of electricity grid operators Entso-e, stated that this incident was the first known blackout triggered by overvoltage, a situation where excessive electrical voltage exists in a network.
April's outage, described as significant, caused almost a day of darkness, disrupting internet and phone services and halting transport. The blackout affected large regions in Spain and Portugal and briefly impacted southwestern France.
The investigation disclosed that a series of cascading overvoltages—increases in voltage above the normal supply—were responsible for the outage. Automatic defense plans that were activated could not prevent the total power system shut down.
In the wake of the outage, many pointed to the increasing reliance on renewable energy by the left-wing government led by Pedro Sánchez as a potential cause. Critics argued that the decreasing reliance on nuclear energy left the grid vulnerable. However, the government rejected these claims, insisting the report did not assign blame to any particular source.
The situation even led to interruption of sporting events, as the Madrid Open Tennis matches had to be paused, and various emergency responses were enacted, including freeing individuals trapped in elevators due to the blackout.
Both the Spanish government and the private energy companies involved have mentioned different causes for the blackout, with the entities blaming each other for failures to maintain appropriate voltage levels. An additional final report is set to come out in early 2024, aiming to dissect the specific reasons behind the overvoltage and associated control actions taken in the power system.
