A massive power outage occurred across Spain and Portugal, stranding about 60 million people.
As the causes remain open to interpretation among the power grid operators of each country, the structural vulnerabilities of the European power grid have come under scrutiny.
According to the Spanish media El País, at around 12:30 p.m. local time on the 28th, Spain's electricity demand dropped sharply from 27,500 megawatts to 15,000 megawatts, causing the power grid to collapse.
The Associated Press noted this as "an unprecedented event that affected millions" and reported that "the entire Iberian Peninsula turned dark in an instant."
The blackout suspended operations of traffic lights, subways, and airports in Spain and Portugal, which imports electricity from Spain. Hospitals activated emergency generators. Due to a paralyzed electronic payment system, supermarkets experienced stockpiling. Important sports events, including the Madrid Open tennis tournament, were also halted.
The Spanish government declared a state of emergency in the regions of Madrid, Andalusia, and Extremadura. At the same time, 30,000 police officers were deployed to maintain public order. Prime Minister Pedro Sánchez promised full restoration by the 29th, referring to it as a "unprecedented power grid collapse."
As of 7 a.m. on the 29th, about 20 hours after the incident, power supply near the capital Madrid was restored to 100%. The Madrid urban railway system is also gradually resuming operations.
Spain is urgently importing electricity from neighboring Morocco and France, while increasing the operation of hydro and combined-cycle power plants in response. It has also requested emergency power coordination at the EU level.
The aftermath extended to southwestern France. The French power grid operator RTE stated, "Some areas were affected due to the disruptions in the Spanish power consolidation."
Despite the unprecedented scale of the blackout, the cause has not yet been properly identified. Interpretations vary among relevant agencies and experts. The Portuguese power grid operator REN initially claimed that extreme temperature fluctuations in inland Spain led to atmospheric induced vibrations, causing the 400 kV high-voltage line to malfunction.
However, according to The New York Times, REN later retracted this explanation, calling it "a misanalysis."
Eduardo Prieto, the operation manager of the Spanish power grid operator REE, explained to Reuters, "The collapse of the power consolidation with France caused an overall imbalance in the system," adding that "when such a system imbalance occurs, a chain trip (automatic shutdown) is triggered, leading to the network's collapse."
Spanish fire authorities are not ruling out the possibility of damage to high-voltage lines due to fires. However, the possibility of a cyberattack has been dismissed early on.
Past global blackout cases show that the 2003 North American blackout was caused by poor transmission line management and software bugs. The 2012 Indian blackout was attributed to issues with power network connectivity, while the 2019 Argentina and Uruguay blackout was primarily due to missing system updates.
Experts estimated that the incident resulted from technical instability compounded by the aging European power grid.
Georg Zachmann, a researcher at the Belgian think tank Bruegel, said in an interview with The Guardian, "Extreme temperature fluctuations due to climate change, difficulties in frequency management from expanding renewable energy, and aging infrastructure can collectively trigger similar incidents anywhere in Europe."