Mystery Grows Over What Caused Crippling Spain Blackout

Spain and Portugal were returning to some semblance of normality early Tuesday, with many questions remaining about what caused one of Europe's worst blackouts in years across the Iberian peninsula the previous day.

Spanish power supplies were back to nearly 100% capacity at around 7 a.m. in Madrid, and urban trains were slowly returning to regular service, according to operators. Portugal said power has been restored for all users, and grid operator REN said the network is "perfectly stabilized." Service had already returned to homes across large parts of greater Lisbon by Monday night.

Bloomberg Portugal Bureau Chief Sofia Horta e Costa joins Stephen Carroll and Lizzy Burden on Bloomberg Radio with the details.

Spain’s grid operator offered the most detailed account yet of the confusing set of events that led to a blackout which spilled over to Portugal, describing a series of disruptions over a few seconds that plunged the countries into darkness for hours.

The information still leaves major questions about the root of the faults unanswered, but it shows how stress on the network — which has since been restored — makes it vulnerable and will need investment to become more resilient.

“These are not definitive conclusions,” Eduardo Prieto, director of services and operations at Spanish grid operator Red Electrica, said Tuesday before describing the events that preceded the blackout. “We don’t have the complete information.”

Adding to the confusion were conflicting views over a possible cyberattack. While the grid operator ruled out a hack, public officials were more cautious. A judge in Spain’s national court opened an investigation, and Prime Minister Pedro Sanchez pleaded for patience.

“It would not be wise to say it was a cyberattack nor to rule it out,” Sanchez said on Tuesday. “The important thing is to have exact knowledge of what happened in those five seconds and from there make the necessary decisions.”

The search for what exactly caused the faults will be critical to determine how to better protect the system. That’s key not just for Spain, but for all of Europe, where an increasingly interconnected power network allows countries to help each other during times of stress, but also raises the risk that problems in one nation flow into another.

It’s clear that the Spanish “electricity system didn’t work and showed a strong vulnerability and clearly shows a need of investment and proper planning,” said Fernando Garcia, an analyst at RBC Capital Markets.

A key point of concern is the role that renewable power played in the outage. Spain has been one of the leaders in rolling out wind and solar, which lacks the inertia of spinning turbines to help keep grids stable.

While tools exist to offset those risks, Spain’s grid investment is less than half the European average and lacks battery storage, which could have helped react more quickly to a drop in generation, according to Kesavarthiniy Savarimuthu, an analyst with BloombergNEF.

“A few factors that, combined, triggered the event,” she said. “But we can’t put our finger on what the factors were — we have to wait and see.”

An excess of solar output could have contributed to the incident. Spain has reported an unprecedented number of hours with negative power prices in recent months as more solar and wind power gets injected into the grid. Still, the oversupply of power hasn’t previously caused blackouts in the country.

But on Monday, a cascade of failures started at just after 12:33 p.m. in Madrid. The initial event was consistent with a loss of power generation, which occurred in southwest Spain, according to Red Electrica, which didn’t provide details about the exact site or the type of generation, but said it was likely solar.

While the system recovered as it should, just 1.5 seconds later another event occurred — likely a loss of more supply. Then 3.5 seconds later, there was a disruption in the connection between Spain and France, which isolated the peninsula.

--------

Watch Bloomberg Radio LIVE on YouTube

Weekdays 7am-6pm ET

Follow us on X

Subscribe to our Podcasts:

Bloomberg Daybreak

Bloomberg Surveillance

Bloomberg Intelligence

Balance of Power

Bloomberg Businessweek

Listen on Apple CarPlay and Android Auto with the Bloomberg Business app:

Apple CarPlay

Android Auto

Visit our YouTube channels:

Bloomberg Podcasts

Bloomberg Television

Bloomberg Originals