Power had almost fully returned to Spain early in the morning of Tuesday, April 29, as many questions remained about what caused one of Europe's most severe blackouts that grounded flights, paralyzed metro systems, disrupted mobile communications and shut down ATMs across the Iberian Peninsula.
By 6:30 am, more than 99% of energy demand in Spain had been restored, the country's electricity operator Red Eléctrica said. Power supplies were back to normal in Portugal, the operator REN said. "All the sub-stations of the national transport network have been re-established" and "we can now affirm that the network has been perfectly stabilized," an REN spokesman told Agence France-Presse.
On Tuesday morning, Madrid's metro system said service would be restored on all but one line by 8 am, meaning that 80% of trains were back operating during rush hour.
Officials did not say what caused the blackout, the second such serious European power outage in as many months after a fire at Heathrow Airport shut down Britain's busiest travel hub on March 20.
They said there was little precedent for this kind of widespread electric failure across all of the Iberian Peninsula, with a combined population of some 60 million. Across the Mediterranean Sea, Spain's Balearic Islands and the territories of Ceuta and Melilla were spared. The Canary Islands off the northwest coast of Africa were also spared.
"We have never had a complete collapse of the system," Sánchez said, explaining how Spain's power grid lost 15 gigawatts, the equivalent of 60% of its national demand, in just five seconds. In his televised address late Monday, Sánchez said that authorities were still investigating what happened. Portugal's National Cybersecurity Center threw cold water on feverish speculation about foul play, saying there was no sign that the outage resulted from a cyberattack.
Speaking to reporters in Brussels, Teresa Ribera, an executive vice president of the European Commission, also ruled out sabotage. Nonetheless, the outage "is one of the most serious episodes recorded in Europe in recent times," she said.