Expert panel to investigate blackout in Portugal and Spain
What is it about?
On 28 April 2025, a large-scale blackout occurred in Spain and Portugal shortly after 12.30 CEST. There was widespread interruption in power supply in the Iberian Peninsula. Some areas in France close to the border were also affected, albeit for a very short period.
Electricity supply in the affected area has been restored, with the help of power generation resources (such as hydro-power plants) and power interconnections with France and Morocco.
Expert Panel to investigate
An expert panel is being set up by ENTSO-E to investigate the incident. This panel includes transmission system operators, regional coordination centres, ENTSO-E. The relevant national regulatory authorities and ACER are also invited to participate.
The panel will collect the data and first prepare a factual report, followed by the final report that will analyse the causes of the incident and include recommendations to make the system more resilient.
ACER stands ready to participate in ENTSO-E’s expert panel and to assist in identifying the root causes of this incident, including possible implications to draw going forward.
Background
Large-scale blackouts are rare in Europe, although they have occurred before:
- 8 January 2021: A disturbance split the European grid into two parts, causing frequency deviations and temporary outages across several countries. The re-synchronization of the two regions incident was resolved within an hour.
- 4 November 2006: Imperfect cross-border coordination on a planned transmission line outage led to a cascading grid failure resulting in a system split and outages across continental Europe.
28 September 2003: A power line touching a tree led to other lines overheating, leading to a series of grid failures and a blackout affecting more than 50 million consumers in Italy and Switzerland.
The lessons learned from these incidents led to improvements in cross-border coordination, system operation, and market integration.