Iberian blackout (2025)
The collapse of the Spanish and Portuguese power grid within seconds on April 28, 2025, attributed to a cascade of overvoltages.
Major European blackouts had until then been associated with overloads and tripping lines; the Iberian one showed that a grid can also fall to excess voltage, once voltage control capacity can no longer keep up. The Spanish government's report described a sequence of power plant disconnections in response to overvoltages, each worsening the next, until the Iberian grid separated. Restoration took nearly a day, starting from hydro plants able to restart without outside power and from the interconnectors with France and Morocco. For insurance, the event was massive with no physical damage, which pushes losses toward utility service interruption alone. It also reopened the debate on the stability of a grid heavy in solar generation, whose inverters do not naturally provide the support that spinning machines used to.
At 12:33 p.m. on April 28, 2025, about 15 gigawatts of generation vanished in five seconds, close to 60% of Spanish demand, and both Spain and Portugal lost power; the Spanish government's report, published on June 17, 2025, pointed to a failure of voltage control.
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