The countries’ top officials were trying to determine the cause of an outage that left tens of millions of people across the Iberian Peninsula without power.

Electricity is pulsing through Spain and Portugal again after a massive outage knocked out power in both countries on Monday. So too are questions.

On 28 April 2025, an unprecedented collapse of the Iberian Peninsula's electricity grid brought Spain and Portugal to a standstill. The likelihood of this ever happening was extremely low and—speculation about its causes aside—the episode has caused serious social disruption,