No Proof of Cyberattack: What Triggered Today's Massive Blackout?

A Sudden Blackout Across Spain and Portugal

On Monday, April 28, 2025, large parts of Spain, Portugal, and even areas in southwest France lost power. Major cities like Madrid, Barcelona, and Lisbon experienced unexpected blackouts. Homes, businesses, trains, traffic lights, and even the Madrid Open tennis tournament were affected..

How Did the Blackout Start?

Spain’s national grid operator, Red Eléctrica de España (REE), reported that the country experienced a full electrical "zero," meaning the entire system lost stability. In Portugal, the operator Redes Energéticas Nacionais (REN) said the blackout began at 11:33 a.m.

By the afternoon, REE announced that they had started restoring power, step by step, across the Iberian Peninsula. They needed to be careful not to overload parts of the system when reconnecting power sources. Major energy providers like Endesa and Iberdrola confirmed they were working under emergency protocols with the national grid.

What Caused the Power Outage?

Portugal’s Prime Minister, Luís Montenegro, explained that the problem started in Spain. REN said a rare weather event caused big temperature changes inside Spain. These changes created strong movements on high-voltage power lines (400 kV), something experts call "atmospheric-induced vibration." This led to problems syncing the electrical systems, and caused failures across Europe’s interconnected grid.

Georg Zachmann, a researcher at the Bruegel think tank in Brussels, said the exact first cause is still unknown. However, after the initial problem, power plants began shutting down one after another, including one in France, when the grid frequency dropped below the normal 50 hertz.

No Evidence of Cyberattack or Sabotage — But Still Too Early to Confirm

So far, leaders have not found signs of a cyber-attack. António Costa, President of the European Council and former Portuguese Prime Minister, said there was no evidence of a digital attack but warned that the real cause is still under review.

Spain’s National Security Council met on Monday to discuss the event. Teresa Ribera, Spain’s Senior Vice President at the European Commission, also said there were no signs of intentional sabotage. However, Montenegro warned that it is too early to be completely certain.

What Role Did Renewable Energy Play?

Spain is moving fast toward using mostly renewable energy, thanks to its sunny and windy climate. In 2024, 56% of its electricity came from renewables, and this number is expected to rise to 81% by 2030.

While this shift helps Spain depend less on imported energy, it also brings challenges. Power from the sun and wind is less stable than traditional sources. This makes managing the electricity network much more complicated.

In the past, gas turbines helped keep the grid stable. Now, new technologies like advanced power electronics and flywheels are needed to support the system. International connections between countries make it easier to share energy, but they can also cause problems to spread faster. Experts said that, while these links can carry failures across borders, they also make it easier to restore power after big disruptions.