La National Commission of Markets and Competition has taken a new step in the investigation of the great power outage On April 28, 2025, the regulator began focusing, for the first time directly, on the renewable energy sector. Following investigations into Red Eléctrica as the system operator, large power generators, and nuclear power plants, the regulator is now opening proceedings against Mercuria, a group specializing in solar projects.
This is the first sanctioning procedure that directly affects a company linked to the management of renewable infrastructure within an investigation that already encompasses more than sixty proceedings. Despite this, the Competition Authority insists that, for the moment, renewable energy cannot be singled out as directly responsible for the blackout, the origin of which continues to be considered multifactorial.
The Mercuria case: the entry of renewables in the spotlight
The CNMC has initiated a disciplinary proceedings against Mercuria, through its companies Mercuria Solar and Mercuria Sostenible, for an alleged serious violation of the Electricity Sector Law. The opening agreement, published on the agency's website on May 13, is based on evidence detected within the framework of the investigation into the so-called "electricity zero."
The regulator points to a possible breach of the Articles 64.15, 64.16 and 64.17 of the electrical regulations, precepts that regulate respect for the instructions of the system operator, compliance with the safety standards of the service and the obligations of maintenance of the facilities when their condition may affect availability.
Depending on the final classification of the conduct, the infraction categorized as serious could entail fines of up to 60 millionWhile those considered very serious, affecting other companies involved in the case, allow for fines of up to €60 million. In the specific case of Mercuria, the Competition Authority emphasizes that, although it is a serious infringement, the described events do not, in themselves, pose an imminent risk to the security of supply or severe damage to the system.
The opening of the file does not imply an automatic sanction. A period for allegations and the presentation of evidence now begins. The company will be able to defend its actions, provide documentation, and request additional expert reports or technical analyses. The procedure has a maximum timeframe of between nine and eighteen months for resolution, in line with the other cases opened regarding the blackout.
Who is Mercuria and what is its role in the electrical system?
Mercuria is a Spanish company based in Madrid Dedicated to the design, maintenance, and operation of renewable energy plants, primarily photovoltaic solar installations. Its work extends beyond generation; it also plays a key role in electrical evacuation, that is, in the infrastructure that enables the energy produced to be delivered to the grid. reach the transport network.
Within the sector, Mercuria acts as internal network and evacuation asset managerOperating substations, high-voltage lines, and connection elements that consolidate the production of various plants, this role places it at a particularly sensitive level of the system, where a large amount of renewable generation concentrated in specific nodes is integrated into the grid.
The company is linked to the Bruc group, an investment network specializing in solar projects that uses vehicle companies for the development and operation of assetsThis scheme allows combining generation and evacuation in the same industrial and financial design, with the aim of optimizing access to the grid and the management of the energy produced.
One of the areas where this model is most intensely implemented is the province of Seville, which has become one of the most important solar poles in southern EuropeThere, large photovoltaic complexes are concentrated, feeding their production into the grid through shared infrastructure, which, in situations of system stress, can multiply the impact of any anomaly in the operation.
The focus on renewable energy evacuation: the Don Rodrigo node and the Cartago complex
The case against Mercuria shifts the focus from simple energy production to the electrical evacuation managementThe surroundings of Don Rodrigo node, one of the main renewable energy connection points in Andalusia, around which a network of large solar plants has been built.
In that area, the following stand out: Cartago photovoltaic complexPromoted by the Bruc group and developed with the participation of Magtel, the project brings together some 18 solar plants connected to a single evacuation point, which implies very demanding coordination between all the operators involved to guarantee electrical stability.
Mercuria appears linked to this scheme as manager of the infrastructure that channels energy to the transmission networkIts activity encompasses the operation of substations, the control of high-voltage lines, and the supervision of elements that allow the joint evacuation of electricity generated by several independent installations.
The design extends across municipalities such as Carmona, El Viso del Alcor, Mairena del Alcor and Alcalá de Guadaíra, following a model of shared evacuation which concentrates a high level of renewable energy capacity at a few connection points. This architecture increases the importance of the daily operation of these infrastructures and explains why the Competition Authority is monitoring them more closely after the blackout.
According to the regulator, the file shows that The potential deficiencies detected are not limited to generation capacitybut rather they fully encompass how that energy is safely integrated into the grid. Voltage control, response to system operator instructions, and proper maintenance of evacuation facilities become central elements of the analysis.
A blackout with multiple causes and a cascade of reports
The power outage of April 28, 2025, popularly known as the “zero electricity”This triggered a series of investigations by the Government, the CNMC and the EntsoE European expert panelThe published reports agree that the incident had a multifactorial origin and ultimate cause not fully determined, the result of a sequence of events that progressively strained the system until it caused a collapse due to overvoltage.
Since that day, Competition has already opened more than 60 disciplinary proceedings to various agents in the electricity system: from large electricity companies to the system operator itself, including nuclear power plants and now companies linked to the renewable energy value chain. Only three of these proceedings have been classified as very serious: the one affecting Red Eléctrica and those involving the Almaraz-Trillo and Cofrentes nuclear power plants.
The first few hours after the blackout placed the renewable energy installations at the center of the debateThis was due to the massive influx of these types of plants into the grid and their automatic disconnections in response to certain disturbances. The system operator and regulator agreed that this dynamic increases voltage fluctuations and can exacerbate an ongoing incident, although subsequent official reports ruled out renewables as the direct cause of the collapse. The great Iberian blackout It reopened many of the technical debates on integration.
Despite this, the investigations have uncovered significant weaknesses in tension control of the Spanish electricity system. In response, the CNMC approved, a few weeks after the incident, the operating procedure 7.4, considered a key piece to strengthen control mechanisms and provide greater robustness to the system in the face of stressful situations.
The regulator has also focused on recorded behaviors before and after the blackout itselfIt is not just about reconstructing what happened on April 28, but about analyzing operating patterns that may have contributed to deteriorating the stability of the system over time, and which could now be classified as sector-specific infractions.
Tension between Red Eléctrica and the CNMC over the updating of regulations
The investigation into the blackout has uncovered a open war between Red Eléctrica and the CNMCThis is unprecedented in the Spanish electricity system. The group, chaired by Beatriz Corredor, has filed formal objections and accused the regulator of having a “conflict of interest” in the handling of the cases.
The company strongly criticizes the existing “legal vacuum” regarding voltage controlThey argue that the Competition Authority failed to update the procedure in place since 2000, precisely the one that should have guided the management of situations like the one that resulted in the "zero electricity." The major electricity companies largely support this argument, pointing to outdated regulations in a system increasingly dominated by renewables.
The president of the CNMC, Cani Fernández, has flatly rejected these accusations in Parliament. During her appearance before the Congress's Committee on Economy, she defended the agency's actions. did not keep the standard update blocked and assured that, even before the approval of the new procedure 7.4, there were sufficient mechanisms for tension control.
This institutional clash unfolds in parallel to the processing of dozens of sanctioning filesThis raises the political and business stakes surrounding the blackout investigation. Each new indictment, like the one affecting Mercuria, adds pressure to a debate where technical, regulatory, and network investment responsibilities intersect.
The Competition Authority insists that the opening of proceedings “does not prejudge the final outcome of the investigation” and emphasizes that The facts analyzed do not in themselves imply attribution of the cause of the blackout to the companies under investigation. In all cases, it is emphasized that the incident resulted from a combination of factors, some of them external to the direct control of the agents under investigation.
What's at stake for the renewable energy sector with this case?
Mercuria's inclusion on the list of companies under investigation marks a turning point for the renewable sector In Spain. Until now, the main protagonists of the research had been traditional companies and nuclear infrastructure, but the growing penetration of photovoltaics and wind power in the electricity mix requires a close review of how this generation is integrated into the grid.
For renewable energy companies, the case serves as a reminder that compliance with the system operator's instructionsThe stability of the grid depends not only on how much energy is produced, but also on how, when, and through what channels that energy is distributed. This includes safety and maintenance protocols, which are not a secondary aspect but a central element of their operations.
At the same time, the CNMC investigation points to the need to Strengthen coordination between generation, evacuation networks and transportLarge connection points, such as Don Rodrigo in Seville, have become true renewable integration hubs and require more sophisticated operating schemes, capable of responding in an orderly manner to disturbances in the system.
From a regulatory perspective, the case opens the door to potential regulatory adjustments in Spain and, potentially, within the European frameworkThis relates to how renewable energy evacuation infrastructure is designed, operated, and monitored. The goal is to minimize the risks of cascading disconnections and voltage fluctuations associated with massive concentrations of non-dispatchable generation.
In this context, the renewable energy sector faces the challenge of reconciling its strong growth with greater technical demands and regulatory compliance. What happens with the Mercuria case and the other open proceedings will be closely watched by developers, investment funds, and grid operators, both in Spain and in other European countries that are moving towards electricity mixes with an increasing share of photovoltaics and wind power.
The CNMC's investigation into Mercuria and the other actions stemming from the 2025 blackout paint a picture in which the Renewable energies are no longer a peripheral player but have moved to the center of the debate on security of supplyThe regulator maintains that the origin of the "electrical zero" was multifactorial and that the responsibility does not lie exclusively with one type of technology, but the entry of renewable evacuation infrastructures shows that the electrical system will have to adapt, technically and normatively, to a reality in which green generation plays a leading role and, at the same time, is subject to increasing scrutiny.
