Spain blackout: Government says it was a voltage problem and blames both the grid operator and utility companies

A Spanish government investigation has blamed both the grid operator, Red Eléctrica, and energy companies for the catastrophic blackout across the Iberian Peninsula, saying the April outage was caused by a combination of “poor planning” and power plant failures, according to the Financial Times.

Announcing the findings of a 49-day investigation, Sara Aagesen, Spain’s energy and environment minister, said several factors contributed to the country’s inability to control a surge in power that would normally have been manageable.

The Socialist-led government expects the findings to lead to a wave of compensation claims. “The next stage will be the administrative and judicial procedures that will determine how this process will end,” Aagesen said. The blackout on April 28 left 60 million people without electricity in Spain and Portugal.

However, the minister said the government’s full report, to be published later, would not name the electricity companies or plants involved, citing “confidentiality” reasons.

Spain’s three major energy suppliers — Iberdrola, Endesa and Naturgy — traded accusations with grid operator Red Eléctrica over the blackout.

Aagesen confirmed that the immediate cause of the outage was a sudden surge in grid voltage, which triggered a cascade of power cuts, affecting the electricity system in Spain and Portugal. Criticizing Red Eléctrica, she called the decision not to replace a gas or nuclear power plant scheduled to operate the next day but which had become unavailable “poor planning.”

“What Red Eléctrica told us is that they did their calculations and estimated that it was not necessary,” Aagesen said. That plant was one of 10 that were supposed to help regulate the voltage on the grid, not just supply power.

The minister also blamed the power companies. Many plants automatically disconnected to protect their equipment, but she said that “from the information available, we can say that some of these disconnections were inappropriate.”

The companies were also at fault — without naming them — because some plants did not contribute to the absorption of “reactive power,” a type of energy that helps maintain the stability of the voltage on the grid.

“Either they were not programmed correctly, or those that were programmed did not deliver what the standard requires,” she said. “But what we can say today is that there was no lack of production. The generation capacity was sufficient.”

Beatriz Corredor, the president of the parent company of Red Eléctrica, had already accused the plant operators of deficiencies.

Aagesen also stated that the government concluded that it was not a cyberattack, although the analysis identified major IT vulnerabilities that need to be remedied.