Another investigation into the cause of the blackout that ended without being able to point to a clear and detailed cause as to why Spain went black on April 28, 2025. This Friday, the conclusions of the final report of the European organization that brings together electricity network managers, ENTSO-e, have emerged, with an outcome similar to that of other investigations carried out on zero energy last spring.
Yes, it has been determined that there was a surge that was responsible for the blackout, but it is motivated by different causes that constitute a tangle of failures and gaps that encompass the electricity companies themselves and the generation plants, but also renewable energies and the regulatory body itself, Red Eléctrica.
This is what the report prepared by fifty European experts concludes, as they have advanced. and the a document that focuses on making a series of 22 recommendations to prevent another blackout from occurring in the future in Spain by improving management in these types of situations and scenarios.
Overvoltage?: the “key to the incident was the ineffectiveness of voltage control in the Spanish electrical system”
In said European report, the experts resolve that “the key phenomenon of the incident was the ineffectiveness of voltage control in the Spanish electrical system”, pointing again to this amalgam of gaps or failures, but pointing out what happened in each area that contributed to zero energy.
- Electrical Network: Experts point to a loss of time in terms of decision-making, because the connection and disconnection of critical components for voltage control was done manually. According to The Countrythe fact that the difference between the reactive power of the plants’ generation and the amount that the operator expected to receive was not monitored in real time was also responsible for not identifying the risk of blackout.
- The large electrical companies: The contribution of reactive power from some conventional generators from large firms (Iberdrola, Endesa and Naturgy) was insufficient and less than 75% of the requests from the system operator – Red Eléctrica – were met at the most critical moments.
- Renewable energies: Their operation with a fixed power factor had an impact, which prevented them from reacting to the voltage changes made to try to stabilize the network, in addition to the automatic disconnection of many of them that occurred without reaching the maximum voltage limits. It is necessary to highlight that from ENTSO-e, despite having requested it, they did not receive the data related to the trigger voltage of those renewable plants that jumped without reaching said limits.
- National regulators: The report also mentions the Spanish regulators as responsible, that is, the Ministry for the Ecological Transition and the National Market and Competition Commission (CNMC).
- The voltage range in Spain: Finally, the report of the group of experts points out another fundamental ingredient in the fatal cocktail of the blackout of 2025. It is a characteristic of the network in our country, its network voltage range of 400 kV (kilowatts). Spain has regulations that open the door to having a wider voltage range than its European neighbors and, in this case, it was a factor that explains why there was no margin between the usual operating limit of the network and the voltage generated by the domino effect derived from the automatic disconnection that occurred based on the generators’ safety protocol.
