In January 2025, the Spanish government was informed that the protection systems of the national electricity grid could fail due to the massive influx of renewable energy sources.

These mechanisms are designed to safeguard the electrical system from disturbances by disconnecting partially or completely, a scenario that occurred recently.

Red Eléctrica, the national grid operator, acknowledged in a document from May 2024 that the "massive integration of renewable generation" could lead to "undesirable behavior of the current protection system." This report was delivered to the Ministry of Ecological Transition months prior to a nationwide blackout experienced on January 24.

Typically, anomalies in the grid are mitigated through local outages.

However, Spain encountered a total system failure, known as an energy zero, for the first time in its history.

Red Eléctrica acknowledged the risk of such an occurrence and detailed it in a technical report that had been on the desk of the Directorate General for Energy Policy and Mines since January.

This report was the result of a public consultation launched by the company led by Beatriz Corredor, which involved industry stakeholders.

To implement the recommendations of the document titled "General Criteria for the Protection of the Spanish Electrical System," which was initially released in 1996, the approval of Manuel García Hernández is required.

Red Eléctrica had previously recognized the "need" to revise the criteria to adapt to technological advancements and changes in the national energy mix over the past 27 years.

Officials from the Ministry of Ecological Transition emphasized that the document proposes changes for the future, stating that Red Eléctrica plans to apply the new protection mechanisms within five years from the approval of the necessary procedures, should that be deemed necessary.

Ministry sources suggested that the operator did not indicate that the proposals required urgent actions and noted that there was no immediate need for implementing the measures.

The report from Red Eléctrica indicated that certain areas of the electrical infrastructure, which traditionally were not considered critical, could become so with the integration of significant amounts of renewable generation sources.

This necessitated modifications and enhancements to their protection systems.

Studies from the operator confirmed that solar photovoltaic and wind energy could result in undesirable behavior in the current protection system, a concern that would not arise if levels of hydraulic, nuclear, or natural gas generation were maintained.

On the day of the blackout, 70% of generation was solar, with minimal backup from firm sources, involving only four operational nuclear reactors and limited contributions from gas and hydropower.

Red Eléctrica warned that there are situations where the protection systems may not correctly identify certain faults.

In such cases, if the issue goes unregistered, "the protections may not activate effectively, thus failing to clear the fault properly."

The report stated that there is no guarantee of the correct functioning of the protection system, as situations may arise where a fault is not cleared as expected or, in the most severe cases, where some protection functions may be unable to detect issues.

It is believed that these protection systems failed during the recent incident, which led to the total blackout.

In response to the situation, electric utilities have demanded greater involvement in the investigative committee led by García Hernández.

They assert that they have provided the necessary data and wish to remain informed about the conclusions drawn by the government.

However, sources from the Ministry of Ecological Transition have denied the request for utility participation in the committee, following discussions between Hernández and Marina Serrano, the president of Aelec, which represents companies such as Iberdrola, Endesa, and EDP.

The third vice president communicated to Serrano that Red Eléctrica, the system operator, is also not participating in the investigation committee, indicating that it is not an open committee for business front participation.

"It is the committee's responsibility to gather information from all operators, including on-site activities, as was done on Saturday when the committee met at Red Eléctrica’s headquarters.

It cannot be ruled out that such practices may also be conducted in the future with other stakeholders," sources from the department stated.