Risk register · entry
Q3 · EngineeredIberian Peninsula blackout
Cascading generator trips blacked out Spain and Portugal for hours.
Tightly coupled systems where one small fault cascades and takes down the whole machine.
Why this room
The payoff structure was simple and mechanical, a physics-level voltage and frequency threshold, but once that threshold broke, the interconnected grid's feedback loops produced a fat-tailed, near-instantaneous cascade rather than a proportional, contained fault, the hallmark of engineered-system risk.
The record
- 31 GW total load lost (25.2 GW Spain, 5.9 GW Portugal)certain
- Blackout onset 12:33 CEST, 28 April 2025certain
- 582 MW generation trip at Badajoz-area substation at 12:33:16.460, followed 360 ms later by a second PV plant disconnectioncertain
- Restoration: Portugal by 00:22 CEST, Spain by approx. 04:00 CEST on 29 April (approx. 10 hours)certain
- At least 8 deaths (7 in Spain, 1 in Portugal)likely
- Approximately 35,000 train/metro passengers required rescue in Spainlikely
- Estimated business losses of about €1.6 billion (CEOE estimate, not an official government figure)uncertain
- ENTSO-E Expert Panel final report released 20 March 2026, panel of 49 memberscertain
- Red Eléctrica's own incident report submitted 18 June 2025certain
Sources
The book
This entry is one of 111 in the register. The full story, and what it cost the people who lived it, is in Risky Business by Claudia Zeisberger, David Munro and Joanna Reijgersberg-Siew.
Join the waiting list