Spain’s power grid operator and the country’s electricity companies are in disagreement regarding the April blackout that affected the Iberian Peninsula. This follows a government report released a day earlier that pointed to their responsibility.

The ongoing dispute may prolong discussions concerning one of Europe’s most important power outages, which has raised concerns about Spain’s dedication to renewable energy and its planned phasing out of nuclear power.

According to the government report, a grid “overvoltage” initiated a “chain reaction” throughout mainland Spain and Portugal, causing the system to fail on April 28.

Overvoltage occurs when there is excessive electrical voltage in a network, which overloads equipment and triggers protective systems to shut down portions of the grid.

The government stated that the system “lacked sufficient voltage control capacity” and that the Spanish grid operator Red eléctrica (REE) and other energy companies disconnected their plants “inappropriately… to protect their installations”.

The report indicated that REE had reduced its capacity to regulate tension on that day, and electricity companies did not contribute as much as anticipated to control voltage through their power stations.

REE released its own report on Wednesday, stating that it “carried out the relevant calculations to schedule technical constraints, always ensuring that all groups comply with the obligations imposed by current regulations”.

REE’s operations director,Concha Sánchez,stated at a news conference that if energy producers responsible for regulating the voltage “had met their tension control obligations… we would not have had a blackout”.

“We have evidence that power stations of Aelec members met the regulatory requirements in terms of controlling tension… even operating above the regulatory obligations to contribute to the stability of the electric system,”

Aelec, an industry association representing power companies including sector giants Iberdrola and Endesa, stated that controlling tension “falls on Red Eléctrica, as the system operator”.

Aelec said in a statement: “We have evidence that power stations of Aelec members met the regulatory requirements in terms of controlling tension… even operating above the regulatory obligations to contribute to the stability of the electric system.”

Aelec added that REE “had enough resources to guarantee the control of voltage… which it still decided not to dispatch”, claiming that the operator “left the system in a situation of vulnerability”.