The Iberian blackout: the day the grid went dark
On 28 April 2025 a large-scale blackout cut power across much of Spain and Portugal for hours. This view replays what the grid data recorded around the event and how the system was restored. It does not assign a cause — that is the work of the official investigation, which it links to.
Total load across Spain and Portugal through the day. A normal morning, a sudden collapse around 12:33, a trough near zero, and a staged recovery overnight. Spain's metered load is missing through the outage — the reporting itself went down — and is shown as a gap; Portugal's recorded load collapses to near zero and rebuilds in stages.
Supply was rebuilt over the following hours: black-start from hydro and a gas plant, then interconnections with France and Morocco re-energised, then the Spain–Portugal tie-lines, with full transmission restoration in the early hours of the 29th. Each step below is from the public record and the official report.
The event renewed a hard engineering question about grid stability — examined by the official investigation, framed here as open and sourced, not as a Wattlas verdict.