Designing Resilient Power Systems: Lessons from the Iberian Blackout Ep. 296

This week on Energy Unplugged, Richard Howard, Aurora Energy Research’s Global Research Director, is joined by Christina Rentell, Research Lead for Aurora’s French and Iberian power markets. Drawing on her expertise in renewable energy, battery storage, market design, and electricity system modelling, Christina helps explain what really caused the April 2025 Iberian blackout and what it means for power systems operating with high levels of renewable generation.

Together, they take a deep dive into the April 2025 blackout, which left around 60 million people across Spain and Portugal without power for up to 18 hours. Richard and Christina unpack the events that led to the outage, examine the role of record-breaking solar generation, and explore whether renewables were truly to blame for one of Europe’s most significant power system disruptions in recent history.

The discussion looks beyond the headlines to investigate the technical causes of the blackout, including voltage instability, system oscillations, and the lack of sufficient inertia and flexibility services on the grid. Christina explains why a highly renewable power system requires new operational tools, market mechanisms, and grid capabilities, and why the blackout was ultimately as much a challenge of system design as it was of renewable penetration.

You will learn:

• Why the Iberian blackout was not caused by renewables alone, but by the interaction between high renewable penetration and insufficient system readiness.

• How voltage instability, oscillations, and a lack of inertia triggered a cascading failure across the Iberian grid.

• Why are batteries, storage technologies, and ancillary service markets becoming essential for reliable power system operation.

• How Spain’s grid operators and policymakers have responded through new market mechanisms, enhanced system visibility, and operational reforms.

• What the blackout reveals about the challenges of managing curtailment, grid congestion, and investment risk in increasingly renewable-dominated power systems.