Unlock the Editor’s Digest for free
Roula Khalaf, Editor of the FT, selects her favourite stories in this weekly newsletter.
Spain and parts of Portugal and France were hit by a huge power cut on Monday that paralysed transport networks and disrupted mobile communications, with authorities warning it could continue into the evening.
Local media said authorities were looking for the cause of the outage, which immobilised the rail system, delayed flights and made traffic lights go dark.
Data from the Spanish electricity operator showed that more than 10GW of demand was cut off when the blackout hit shortly after 12.30pm local time, suggesting that it was one of the biggest in recent European history.
In Portugal, which was also affected by the outage, the national grid operator blamed the cut on a fault in the Spanish electricity network, related to a rare atmospheric phenomenon, Reuters reported.
Weather data showed that temperatures in southern Spain increased sharply between midday and 1pm local time. Higher temperatures can limit how much electricity cables can carry.
Eduardo Prieto, director of services at Spain’s operator, Red Eléctrica, said that a “very strong oscillation” in the network during that time had cut off Spain’s electricity grid from the rest of continental Europe, which had led to the collapse of the system.
In comments reported by Reuters, Luís Montenegro, Portuguese prime minister, said that there was no indication the outage was a cyber attack, but added that “nothing is off the table”.
Red Eléctrica said power had been restored across northern and southern Spain by mid-afternoon. But it cautioned that restoring full power for the country as a whole would take between six and 10 hours.
By mid-afternoon, all of the country’s nuclear power stations remained offline, according to Montel, the energy data specialist, as they sought to respond to the disruption.
Prime Minister Pedro Sánchez held a crisis meeting with top government officials as local media reported that the Spanish national cyber security institute was investigating the outage.
The cut affected millions of people across Spain in cities such as Madrid and Barcelona, while the Portuguese grid operator said it had hit electricity supply across the Iberian peninsula as a whole.
Spain’s chief traffic authority called on people not to drive their cars, because traffic lights were out of operation due to the cut. The government added that it was not likely that medium- or long-distance rail transport would resume during the day.
In Madrid, people spilled out on to the streets, as metro stations were evacuated and shops, restaurants and offices closed. Mobile phone coverage was also initially hit. Local media said some — but not all — hospitals were functioning as normal with the aid of backup generators.
Isabel Díaz Ayuso, the conservative leader of the Madrid regional government, called on Spain’s Socialist-led national administration to activate emergency plans “to allow the army to keep order, if necessary”.
Alberto Núñez Feijóo, the head of Spain’s opposition People’s party, criticised Sánchez’s government for being slow to provide updates on the blackout. “We need timely information,” he said.
Nearly 400 flights were delayed at Madrid airport as of mid-afternoon, including more than half of scheduled departures, while at Lisbon airport, 171 flights were delayed and almost 200 flights cancelled.
Aena, which runs Madrid airport and 45 others across Spain, said it was relying on backup power supplies to operate, adding that the extent of the delays would depend on whether crews and passengers could get to the airports.
Spain gets 43 per cent of its electricity from wind and solar power, but grid and storage capacity has not kept pace with the country’s rapid development of renewable energy.
The country has long lamented being an “energy island” due to its poor connections with France.
French grid operator RTE said parts of France had been briefly affected by the outage but that power had been quickly restored.
It added that the Iberian peninsula’s power grid was automatically disconnected from the main continental European network at 12.38pm but was reconnected an hour later.
RTE said it did not know the origin of the outage but was attempting to support the Iberian peninsula in restoring power. It believes the outage originated in the Iberian peninsula, not in France.
Parts of the Spanish national grid’s website were down on Monday. The company describes itself as the “backbone of the electricity system”.
The European Commission said it was in contact with Spain, Portugal and Europe’s grid operators “to understand the underlying cause and the impact of the situation”.
Additional reporting by Philip Georgiadis and Andy Bounds