Final analysis of 2025 Iberian blackout: Policies left Spain at risk
Roughly a year ago, Spain and Portugal went dark when the electrical grid of the entire Iberian Peninsula failed. While the grid operators did a heroic job of restarting the grid quickly, there were obvious questions about what had led to the blackout in the first place. A preliminary report suggested that a combination of grid-level voltage oscillations and early disconnections was the main factor.
Over the weekend, the European grid coordinator, ENTSO-e, released its final, detailed report on the event. While it's largely consistent with the preliminary conclusions, the report provides much more detail about what went wrong and, more significantly, offers a clear picture of how the Iberian grid operators could make changes to prevent a similar event in the future.
Oscillations
The expert committee that prepared the report had access to a wealth of data, including status logs from most of the major hardware on the Spanish and Portuguese grid, often recorded with sub-second precision. There's also data from the two major interchanges between the Spanish grid and those in France and Morocco. The group even obtained data from two manufacturers of the small inverters used for rooftop solar about the performance of their hardware on the day in question.