Spain’s top security and defense officials were meeting on Wednesday morning to discuss the blackout on the Iberian Peninsula this week, which halted critical infrastructure for up to 18 hours in some areas.
The authorities in Spain and Portugal are under pressure to figure out what caused the power grid to shut down. The Spanish government has asked European regulators and various domestic agencies to investigate what happened.
Spain’s National Security Council convened in Madrid at 9 a.m. local time to discuss the blackout. Prime Minister Pedro Sánchez, the chief of his Defense Staff and the directors of the country’s National Intelligence Center and Department of National Security were expected to attend.
Spain’s Council of Ministers held a meeting focused on the outage at 10 a.m.
The blackout, which began on Monday afternoon, halted much of daily life in Spain and Portugal until electricity was restored to the two countries by Tuesday morning. It has raised questions about whether a rapid shift by Spain’s national grid operator, Red Eléctrica, to relying on renewable energy made the grid more vulnerable to outages.
Mr. Sánchez said on Tuesday that his government had created a commission led by the Ministry for the Ecological Transition to investigate what had happened.
But Beatriz Corredor, the chairwoman of Red Eléctrica, said in an interview with the Spanish radio station Cadena SER on Wednesday that “it is not correct to link the incident to renewable energy.”
The Spanish authorities are also looking at other possible explanations.
Red Eléctrica has said there is no evidence of a cyberattack on the transmission grid. But a judge on Tuesday ordered Red Eléctrica, the intelligence service and the police to produce reports within 10 days about whether a cyberattack was behind the power outage, according to a court document.
Mr. Sánchez said the National Cryptologic Center, a department of the National Intelligence Center in charge of cyberthreats, was reviewing “the risks arising from this electrical emergency.”
“The computer records of Red Eléctrica and private operators are already being examined to ensure no hypothesis is ruled out,” he said at a news conference.
After power was restored, Spain’s Interior Ministry on Tuesday night deactivated most of the emergency declarations that had been instituted during the blackout, downgrading many regions from the highest of three alert levels to a medium one, which allows the national government to assist regional governments.
Madrid and the western region of Extremadura remained at the highest level on Wednesday, the ministry said.
In Portugal, Prime Minister Luís Montenegro said after an emergency government meeting on Tuesday that the outage was related to an abrupt increase in voltage in the Spanish electricity grid, which triggered safety mechanisms that led to the blackout.
“We will calmly assess with the Spanish authorities what happened and try to design better response instruments in the future to avoid a repeat of this occurrence,” he said.
The outage is expected to be a key topic during a debate on Wednesday between Mr. Montenegro and the opposition leader, Pedro Nuno Santos, ahead of a parliamentary election on May 18. The two had originally been scheduled to debate on Monday.
Tiago Carrasco contributed reporting from Lisbon.
