On April 28, 2025, a power outage affected millions across Spain, Portugal, Andorra and parts of southwest France for up to 18 hours. The incident has raised concerns about the stability and reliability of the region’s power grid, which heavily relies on renewable energy sources.

The exact cause of the power outage is still being investigated. However, experts and early reports point to several contributing factors that may have played a role:

• Two so-called “disconnections of generation” were recorded, though their origin remains unclear. It is speculated that these may be linked to the inherent variability of certain energy sources.
• The Iberian Peninsula has one of the world’s highest shares of renewable energy generation, particularly from wind and solar. While this supports decarbonization, it also presents unique challenges for grid stability and system recovery after major failures.
• Experts believe that such a widespread blackout likely required a combination of unusual events or technical faults occurring simultaneously. Unusual frequency fluctuations were observed in the grid before the outage, which may have triggered automatic shutdown mechanisms at generation facilities.

The blackout has highlighted the need for a balanced energy mix, robust grid infrastructure and enhanced interconnectivity with neighboring regions to ensure grid stability and prevent similar occurrences in the future.