The 2025 Iberian Peninsula Blackout: Lessons for Modern Power Systems and Policy Implications

On April 28, 2025, the Iberian Peninsula experienced a complete electrical blackout affecting 47 million people across Spain and Portugal. Drawing from the ENTSO-E investigation, this paper examines the policy implications of this event for power system management during rapid decarbonization. The investigation identified an unprecedented cascade of generation disconnections triggered by overvoltage conditions, tracing the root cause to institutional rather than technical failures: regulatory barriers prevented the utilization of renewable capacity with certified voltage control capability, market design incentives misaligned operational decisions with real-time stability requirements, and governance fragmentation impeded coordinated crisis response.

These findings offer lessons for policymakers navigating the tension between market efficiency and system security in renewable-dominated grids.