Many traffic lights were changing from red to green again. All except one of Madrid’s metro lines were operational. Baristas at cafés in the Spanish capital were offering café con leche to the few customers who were out on the calm streets Tuesday morning.
By that time, practically all of Spain and Portugal had regained power, about 18 hours after both countries had widespread blackouts. Many people were glad when electricity was restored, but concerns about what had transpired grew sharper.
A representative for Portugal’s electricity and gas supplier, REN, stated on Tuesday that power had been restored to all of the country’s grid substations and that everything was “100 percent operational.”
The origin of the blackout, which had trapped tens of millions of people on the Iberian Peninsula, was unknown early Tuesday.
Eduardo Prieto, the director of services for Spain’s national power utility, Red Eléctrica, told media on Tuesday morning that there were no “definitive conclusions” on the cause of the outage.
He joined a chorus of authorities who claimed that there had been no cyberattack. However, he ruled out both human mistake and weather reasons.
He stated that the Spanish energy system had gone down as a result of two independent power failures, each lasting under a second.
“This may seem like a small amount,” remarked the engineer, “but in the electrical world, it’s a significant amount.” He stated that the shutdowns had happened in southwestern Spain.
Kristian Ruby, secretary general of Eurelectric, a trade association representing the European energy sector, stated that the technical investigation necessary to properly comprehend the outage might take weeks or perhaps months.
However, some preliminary material has already surfaced, he added. Around midday on Monday, a high-voltage connecting cable between France and Spain was cut. The power outage happened slightly over 30 minutes later.
While the disruption would have been annoying, it would not ordinarily result in a “system collapse” like what occurred on Monday, according to Mr. Ruby. Something more would normally be required, “like a sudden outage at a power plant, a sudden development on the demand side,” he stated. “Then you can have an incident like this.”
