Massive Iberian Peninsula Blackout Exposes Grid Vulnerabilities as Renewable Energy Reaches New Heights
Low inertia and reactive power imbalances emerge as key factors in April 28 system collapse that plunged 60 million people into darkness On 28 April 2025, at 12:33 CEST, a catastrophic power failure swept across the Iberian Peninsula, plunging Spain and Portugal into their worst blackout in history. The system collapse, which left approximately 60 million people without electricity for up to 24 hours, has intensified debates about grid stability in an era of rapidly expanding renewable energy deployment. The blackout began with a dramatic 15-gigawatt drop in Spanish electricity generation—equivalent to 60% of the country's demand at the time—that triggered a cascade of failures across the interconnected European grid. Within seconds, the Iberian electrical system became isolated from the broader European network, leading to a complete collapse that extended beyond Spain's borders to affect Portugal and portions of southwestern France. A Perfect Storm of Technical Facto...