Madrid, June 17, 2025 (Lusa) - The April blackout was the result of a "combination of factors" that caused a high voltage overload that Spain's electricity system was unable to absorb for various reasons, including "poor planning" by the operator, the Spanish government revealed on Tuesday.
In addition to failures on the part of the Spanish electricity grid operator in terms of management and planning, there were also failures in the response of other energy operators and distributors in Spain, with suspicions of non-compliance with the protocols laid down for voltage overload situations, according to Spain's Minister for Ecological Transition, Sara Aagesen.
The minister also said that the commission set up by the Spanish government to investigate the blackout on the Iberian Peninsula had concluded that there had been no cyberattack on 28 April, as the Spanish government had previously stated.
Sara Aagesen was speaking at a press conference in Madrid, at the end of the weekly meeting of the Spanish cabinet, where she presented the conclusions of the commission investigating the 28 April blackout set up by the government.
According to the minister, who will meet with her Portuguese counterpart, Maria da Graça Carvalho, in Lisbon this evening, there were a series of oscillations in Spain's electricity generation system on the morning of the blackout - which occurred at 11:33 on 28 April, mainland Portugal time - and also in the days before. The usual protocols and measures to respond to these phenomena were activated by the company Red Eléctrica (REE), the operator of the Spanish grid.
These measures to respond to fluctuations, which include "knitting the grid" or reducing the export of electricity outside the Peninsula, such as to France, also cause an increase in voltage load. The response, therefore, also requires measures to control the overload.
However, according to the minister, Red Eléctrica's programming and forecasting were not sufficient, and there was "poor planning".
At the same time, there were "undue" actions by other companies, since the "synchronous generation" plants (combined cycle, nuclear or hydro) requested to operate by Red Eléctrica were not absorbing the voltage as they should.
On the other hand, the Spanish minister added that the investigation concluded there were power plants that were also shut down improperly, when they shouldn't have been under the protocols and regulations in force, through disconnections that couldn't have been the normal and automatic response to a voltage overload scenario.
"The generation groups that had to control the voltage and which, moreover, many of them were being paid economically for doing so, did not absorb all the reactive [energy] that was expected in a context of high voltages," said Sara Aagesen, who explained that the disconnection of installations also caused an even greater overload.
According to the minister, all of the ten power stations scheduled by Red Eléctrica to be in operation and to respond to voltage fluctuations and overloads in the system, "had some kind of failure" in absorbing the reactive energy that corresponded to them on the day of the blackout.
"The system could not regulate the voltage," although Spain has "enough generation to respond" to a situation like the one that occurred, said Sara Aagesen.
Thus, as a result of this succession of events and failures, in the moments before the blackout "a point of no return was reached, with an uncontrollable chain reaction", when a very high "voltage overload phenomenon" led to successive disconnections of electricity generation facilities, which themselves caused "new disconnections", the minister summarised.
The disconnections began in power stations in southern and southwestern Spain, specifically in Granada and Badajoz.
According to the Spanish government, all the oscillations in the electricity system detected in the days, hours and minutes prior to the blackout were considered normal and within normal parameters, except for one, identified at a generation plant in south-west Spain at 12:03 pm on 28 April (11:03 am in Lisbon).
According to the minister, it was a "not typical or known" oscillation, but she didn't give any more details. She didn't confirm the information published in the Spanish press in recent weeks, which stated that it was a photovoltaic generation plant.
In light of the conclusions and recommendations of the Spanish commission that investigated the blackout, the government will approve legislation next week to respond to the faults identified and prevent further similar cases, said Sara Aagesen.
MP/ADB // ADB.
Lusa
