Spain's regulator launches investigations into the historic blackout after discovering violations of regulations.

Spain's energy and competition regulator announced on Friday that it has initiated formal investigations into last year's unprecedented blackout affecting Spain and Portugal after discovering evidence of breaches in power sector regulations over prolonged periods.

The National Commission on Markets and Competition (CNMC) indicated that although these violations did not directly cause the blackout, they may have influenced the functioning of the power system and could be considered administrative breaches, warranting a formal inquiry.

In a recent report, the regulator suggested measures to address voltage fluctuations in the national power grid following the blackout, as well as enhancing connections with the French power network. It refrained from assigning blame at that stage, stating that it was examining potential breaches independently.

On Friday, the CNMC revealed it had identified a series of events that gradually destabilized the power system, culminating in the significant outage on April 28, 2025, which was triggered by a voltage surge. The commission noted that while some suspected violations had continued for extended periods, these alone did not justify blaming the involved companies for the blackout's origin.

The investigation process may take between nine to 18 months, depending on the severity of any violations, and those affected will have the opportunity to present their arguments and evidence.