Iberian Peninsula recovers 90% of power after unprecedented power outage

Department of Research, Studies and International News 29-04-2025

A major power outage brought daily life to a standstill across Spain and Portugal on Monday, plunging much of the Iberian Peninsula into darkness and severely disrupting transportation, communication, and essential services. By early Tuesday, authorities reported significant progress in restoring power, with nearly 90% of Spain’s electricity supply back online and the vast majority of Portugal’s households reconnected to the grid.

The blackout, which began abruptly at 12:33 p.m. local time, affected nearly all regions of both countries, impacting almost 60 million people. In its initial assessments, Portugal’s grid operator REN attributed the outage to rare and extreme atmospheric conditions, specifically sudden temperature shifts that triggered anomalies in the high-voltage transmission system.

In both Lisbon and Madrid, the capitals of Portugal and Spain respectively, power was gradually restored late Monday. By nightfall, 62% of Spain’s substations were operational, and 43% of the country’s energy demand was being met. In Portugal, only four of 89 substations remained offline by that time.

The disruption had widespread consequences. Public transport systems, including metros and trains, ground to a halt. Traffic lights failed, causing major congestion in urban centers, while numerous individuals were trapped in elevators and stranded aboard trains. Air traffic also experienced interruptions, although Spanish Prime Minister Pedro Sánchez later confirmed that only 344 out of 6,000 scheduled flights had been canceled. The rail sector, however, faced the brunt of the crisis, with over 100 trains immobilized and around 35,000 passengers requiring emergency assistance, including intervention by military units.

Telecommunications suffered as well, with phone and internet access lost across large swathes of both countries. In many areas, mobile networks collapsed due to power failures at transmission antennas. Supermarkets operated on a cash-only basis, hospitals postponed non-urgent surgeries, and electronic payment systems were rendered useless. Some citizens resorted to walking home, navigating darkened streets and tunnels with flashlights.

While no definitive cause has yet been identified, Spanish and Portuguese authorities continue to investigate the root of the disruption. Spain’s Prime Minister Sánchez emphasized that experts were exploring all possibilities and urged the public to avoid speculation that could lead to misinformation. According to Sánchez, a staggering 15 gigawatts, equivalent to 60% of active energy usage, vanished from the system in just five seconds, an event he described as entirely unprecedented.

Portugal’s REN provided further technical insight, pointing to a rare event called “induced atmospheric vibration.” This phenomenon, caused by significant temperature fluctuations, reportedly led to synchronization issues across the high-voltage systems that interconnect much of Europe’s power grid. The resulting cascade effect caused a series of automatic shutdowns, rippling across the continent’s energy infrastructure.

Despite the severity of the outage, cooperation from neighboring nations helped mitigate some of the damage. France and Morocco provided emergency electricity supplies to support Spain’s recovery efforts. Spanish officials also mobilized additional police and emergency personnel to ensure public safety throughout the night.

The impact was especially severe in eight Spanish autonomous communities, including Madrid, Andalucía, and Valencia, which activated level 3 emergency protocols. In these regions, control of emergency responses shifted to the central government. Though schools reopened the following day, classes were suspended to allow systems to stabilize.

Visuals from the aftermath captured the surreal nature of the event: passengers navigating unlit metro tunnels in Madrid with only their phone lights, restaurant diners eating by candlelight in Burgos, and journalists working by flashlight in newsrooms. The national road authority urged residents to limit travel as much as possible due to the failure of traffic control systems.

In Portugal, similar scenes unfolded. Lisbon’s metro system was evacuated, and electronic services across banking, commerce, and healthcare sectors were disrupted. By Tuesday, most of these services were gradually coming back online.

Although large-scale blackouts are uncommon in Europe, the event has drawn comparisons to earlier incidents, such as the 2003 power failure in North America and the 2006 blackout caused by grid issues in Germany. The recent Iberian outage stands out due to its scale, sudden onset, and the challenge of pinpointing a specific trigger.

In the days ahead, energy officials across Europe are expected to reassess grid resilience and coordination to prevent a recurrence. Meanwhile, life across Spain and Portugal slowly returns to normal, though the memory of the outage, and the vulnerabilities it revealed, will linger.