Spain's government said it had asked private energy companies for "maximum collaboration and transparency" to help identify the cause of the outage.

The mass electrical blackout across Spain, Portugal and parts of France sparked hours of chaos before power returned – with the after-effects still being felt. At such a critical moment in US history, we need reporters on the ground. Your donation allows us to keep sending journalists to speak to both sides of the story.

This week’s blackout in Spain and Portugal confronted authorities with an unprecedented event: the first mass electrical outage on a grid largely powered by wind and solar energy.