An inexplicable power outage hit Spain and Portugal on Monday, knocking out traffic lights, causing congestion and disrupting airport operations and other means of transport. The countries were left reeling, and the authorities declared a state of emergency.
Major cities, including Madrid, Barcelona, and Lisbon, were impacted by Monday's severe power outage, which swept through Spain, Portugal, and parts of southwest France, The Guardian reported.
Millions were affected as homes, workplaces, trains, traffic signals, and the Madrid Open tennis event came to a standstill.
This prompted the governments of Spain and Portugal, and the network operators, into action to resolve the issue.
What happened?
What caused the power outage remains a mystery, but its effects were huge: transport hubs were shut down, and governments in the two nations, with a combined population of almost 60 million, hurriedly called emergency meetings to coordinate a response.
Several towns in the Iberian region, including Madrid, Lisbon, Barcelona, Seville, and Valencia -- all centres for tourism, finance, and transportation -- suffered a blackout.
Portugal's grid operator Redes Energticas Nacionais (REN) said the interruption began at 11:33 am Western European summer time and power was cut off throughout the Iberian Peninsula and in some areas of France, CNN reported.
Spain's electric network, Red Electricade Espana (REE), reported that "el cero"-the zero-had struck Spain and Portugal.
Lighting and power outlets were cut off during the blackout, and tube systems suddenly stopped working. The streets of Madrid were jammed with traffic as the lights went out.
The Spanish operator reported it began restoring voltage in the Iberian Peninsula's north, south, and west by mid-afternoon.
Endesa, the country's largest utility with 10 million consumers, and Iberdrola, the second-largest energy provider in Spain, said that they were collaborating with REE in compliance with established procedures.
What caused it?
According to the Portuguese Prime Minister Luis Montenegro, the issue began in Spain. He claimed the extensive shutdowns were prompted by a severe temperature anomaly produced by a "rare atmospheric phenomenon."
"Due to the variation of the temperature, the parameters of the conductor change slightly," Taco Engelaar, general director of Neara, said.
"It creates an imbalance in the frequency," Engelaar added.
The REN said that "extreme temperature variations in the interior of Spain" have resulted in "anomalous oscillations in the very high voltage lines (400 kV)," known as the "induced atmospheric vibration."
These oscillations led to electrical system synchronisation problems, which in turn produced "successive disturbances across the interconnected European network."
Is it a cyber-attack?
Antonio Costa, the President of the European Council, said: "There is no evidence that it was a cyber-attack."
But he warned that the cause of such a massive power outage across Spain and Portugal was still unknown.
"Grid operators in both countries are working on finding the cause, and on restoring the electricity supply," Mr Costa said on X (formerly Twitter).
Teresa Ribera, the senior vice president of the European Commission, also told Spain's Radio 5 that there was no proof that the disruption was the result of an intentional act.
Are international connections responsible for the power outage?
According to Engelaar, international connectivity is essential for "vital for sharing clean energy," but it also opens up new avenues for failure to spread rapidly.
Georg Zachmann, a senior fellow at Bruegel, believes that interconnections also serve to prevent issues from getting worse.
It will be "much easier to bring the electricity system back" owing to the French interconnector.
In 2003, a hydroelectric power line issue between Italy and Switzerland resulted in a massive 12-hour outage across Italy. In 2006, Portugal and Morocco experienced power outages due to a German power surge.
Power begins to return in Spain and Portugal.
By late Monday, the national grid operator in Spain reported that about 61 per cent of the power had been restored, Reuters reported.
Late Monday, power slowly returned to several Portuguese municipalities, including the Lisbon city centre. According to grid operator REN, 85 of the 89 power substations were operational again.
