Power Outage on the Iberian Peninsula

On April 28, 2025, a major electrical system failure occurred on the Iberian Peninsula, significantly affecting the power supply in both Spain and Portugal. During the early afternoon hours, Spain’s system load dropped from the planned 25,000 MW to just 10,000 MW — a loss of 15,000 MW of generation capacity within approximately one and a half minutes. This sudden and severe drop triggered immediate, chain-reaction-like consequences across other generation units and grid components as well.

Source: FRANCE24

Since Portugal’s electrical system is almost exclusively connected to the Spanish grid, the effects of the disturbance quickly spread across the border. Portugal’s entire power system collapsed, resulting in a near-total blackout that lasted for approximately six hours — a disruption with severe consequences for a country of 10 million people. Cross-border electricity flows between the two countries ceased, leaving neither system able to support the other. Later, France assisted in restarting the Spanish grid, supplying 1,500–2,000 MW via existing interconnections, which helped accelerate the restoration process.

There are no official investigative findings yet regarding the technical causes of the incident, but cyberattack and extreme weather have been ruled out. It is more likely that a malfunction at a solar power plant or substation triggered a sequence of events in which overloaded grid elements failed progressively, leading to a cascading regional blackout.

The vulnerability of the system was exacerbated by the Iberian Peninsula’s relative isolation — due to both geographical and network characteristics — from the rest of the continental European power grid, limiting its ability to receive external support during such disturbances.

The incident had serious consequences: the loss of supply caused disruptions at both residential and industrial levels, led to significant economic damage, and drew attention to the technical challenges associated with the dominance of renewable energy sources, as well as the crucial importance of energy storage.

Source: Aszódi Attila: Mi vezetett a történelmi áramszünethez az ibériai-félszigeten