The blackout across Spain and Portugal knocked out communications and transport systems, shut down industry and offices and brought commerce to a virtual standstill. The blackout could have shaved 1.6 billion euros ($1.82 billion), or 0.1%, off GDP, Spain's business lobby estimated.

The inability of Spain’s electricity grid to manage an unusually high supply of solar power was a key factor in Monday’s catastrophic blackout, former regulators and some experts have said.