Spain's grid operator denied on Wednesday dependence on solar power was to blame for the country's worst blackout, while Prime Minister Pedro Sanchez came under increasing pressure to explain what went wrong.

BUDAPEST, Hungary (AP) — An unprecedented blackout across Spain and Portugal upended the lives of millions across the Iberian Peninsula, a stark reminder of modern society’s reliance on electricity, and how quickly life can descend into chaos when the grid goes down.

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