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, said the incident was the first known blackout to be caused by overvoltage, which occurs when there is too much electrical voltage in a network.
'This is new territory,' Cortinas said, adding the role of Entso-e was 'not to apportion blame to any party' over the cause.
April's outage caused significant disruption for nearly a day when it plunged large areas into darkness, causing internet and phone outages and halting transport links.
The blackout affected vast regions of Spain and Portugal while also briefly impacting parts of southwestern France. The report released on Friday detailed the sequences leading to the outage.
The conclusion pointed to a series of 'cascading overvoltages' causing the blackout, which can stem from surges due to oversupply or lightning strikes, or inadequate protective systems.
While automatic defense plans were activated, they failed to prevent the shutdown of the power system. Several investigations into the outage's cause are being conducted by the Spanish government and power companies.
The report indicated that both the national grid provider Red Eléctrica and private electricity firms were at fault, yet they deny responsibility, attributing it instead to failures at some energy plants to ensure voltage stability.
Notably, the outage triggered a political debate regarding Spain's energy model, with the opposition claiming that the current reliance on renewable energy could have contributed to the blackout.
Emergency services responded to numerous calls for assistance, including freeing individuals trapped in elevators. Hospitals executed emergency plans to manage the unexpected power loss.
