Barely a year has passed since that fateful day when the Spanish electrical grid went dark. Efforts are still underway to piece together what exactly happened on April 28, 2025, when at 12:33 p.m. the so-called zero electricity in the Iberian Peninsula.
Although it was already known that the problem originated in the Granada region, the investigation has progressed to pinpoint the exact location of the trigger. The focus of attention has now shifted to the Huéneja electrical substation, which is in the eye of the regulatory hurricane.
Sanctions and proceedings of the CNMC
The National Commission for Markets and Competition (CNMC) has not remained idle and has launched a Disciplinary proceedings against the Huéneja connectionThe agency, led by Cani Fernández, considers that there was a serious infringement, specifically related to the non-compliance with several points of article 64 (sections 15, 16 and 17), although it has been clarified that this did not pose a direct risk to the guarantee of supply.
This move is not an isolated case, but rather part of a package of 66 information files which the regulator has opened to analyze the collapse. This list includes industry heavyweights such as Red Eléctrica de España, Endesa, Iberdrola and Naturgyas well as companies like Repsol and TotalEnergies. However, the CNMC has made it clear that opening these investigations does not mean these companies are solely responsible, as the blackout was the result of a multifactorial origin.
The anatomy of a systemic collapse
To understand how it all happened, you have to look at the seconds. The chaos began at exactly 12:32 and 57 seconds, when a substation in northern Granada went offline. lose generation capacityAccording to technical analyses, this installation could not withstand voltage levels that, by law, it should have been able to handle, causing what experts call a divergent shot.
The regulations require that the disconnection not occur until 440 kV is reached, but in this case the jump occurred at about 418 kV, a value far below the legal limit.This premature drop resulted in the immediate loss of 335 MW from wind, photovoltaic and solar thermal sources, eliminating the resource that stabilized the grid voltage.
From there, a real domino effect occurred. Just seconds later, the problem spread to other provinces:
- At 12:33 and 16 seconds, a loss of generation was recorded in Badajoz.
- A second later, the cascade of disconnections was activated in Segovia, Huelva, Seville and Cáceres.
- In just five seconds, Dozens of substations went downleaving Spain, Portugal and part of southern France without power.
Deadlines and potential multimillion-dollar fines
The administrative process now enters a waiting phase. The CNMC has a margin of up to 18 months to resolve the situation of the Huéneja substation. During this time, the companies involved will be able to submit their arguments and propose evidence to defend their position.
The economic impact of these rulings can be brutal. If the administration classifies the offenses as very serious, the penalties could escalate to as much as 60 millones de eurosIn the case of serious infractions, the maximum fine would be... 6 millones de euros.
The incident was a perfect storm where voltage fluctuations and technical failures converged. While the Granada substation was the spark, reports suggest that a more robust electrical system It would have been able to absorb the blow without the total collapse of the Peninsula.
The investigation continues, focused on determining the administrative and technical responsibilities for the failure in Granada and the subsequent chain reaction that affected the entire territory, while awaiting the final resolution of the sanctioning files opened by the national regulator.