CNMC widens Spain blackout probe

Spain’s competition and energy regulator has widened the fallout from the April 28, 2025 Iberian blackout to include renewable-energy operators. The CNMC has opened sanction proceedings against Mercuria-linked solar companies, adding the first publicly identified renewables case to a probe that already covered grid operator Red Eléctrica, large utilities and individual plants. The move comes a year after the outage cut power across Spain and Portugal and after official and industry reports pointed to multiple causes rather than a single trigger. The CNMC’s own case database shows a proceeding opened on May 13 against Mercuria Sostenible, while industry reporting says Mercuria Solar is also in scope. ### Which renewable companies have now been pulled into the case? May 13 is the key date in the latest expansion. The CNMC’s decisions page lists case SNC/DE/093/26 against Mercuria Sostenible S.L. for an alleged infringement under Spain’s electricity law. A CPI/PYMNTS report, citing a CNMC statement, said the regulator also opened proceedings against Mercuria Solar and described the alleged conduct as a “serious infraction” linked to voltage fluctuations detected in the months before the blackout. (cnmc.es) The CNMC has not, in the public case listing available through its website, published a detailed narrative assigning responsibility for the blackout to Mercuria. What the public record shows is that the renewables-linked action is part of a broader sanctions track that has been building since April 2026. ### How broad was the probe before renewables were added? April 17, 2026 marked the first formal wave of cases. Reuters reported that the CNMC opened probes into Red Eléctrica, a Redeia unit, and major energy companies Iberdrola, Naturgy, Endesa and Repsol, as well as individual power plants, after finding evidence that some electricity-sector rules may have been breached over extended periods. (cnmc.es) Red Eléctrica was being examined for “very serious infringements,” while the others faced “serious infringements,” according to Reuters’ account of CNMC records. April 24, 2026 brought a second widening. Reuters reported that the CNMC added more companies, including local units of TotalEnergies and Engie, and said CNMC chair Cani Fernández had previously stated that the most serious breaches could carry fines of up to 60 million euros. Reuters also said sanction procedures can last from nine to 18 months depending on the severity of the alleged infraction. (globalbankingandfinance.com) May 17 reporting by CPI/PYMNTS put the total number of investigations launched since April 17 at 66. That figure is the clearest measure of how far the probe has spread across Spain’s power sector. ### Did official reports blame renewables for causing the blackout? June 17, 2025 is the date of the Spanish government’s main public account. The energy ministry said the “cero eléctrico” was caused by an overvoltage problem with a “multifactorial” origin, citing insufficient voltage-control capability, oscillations that affected system operation, and the disconnection of generation facilities, in some cases apparently improperly. (sahmcapital.com) (pymnts.com) June 18, 2025 is the date of Red Eléctrica’s own report. The system operator said some generation disconnected incorrectly and some did not comply with voltage-control rules under operating procedure 7.4. The company said the incident resulted from a series of cumulative circumstances that exceeded the N-1 safety criterion and triggered a cascading shutdown. Neither of those public accounts, as summarized in the official materials available online, presented a single-cause finding centered on renewable generation alone. (miteco.gob.es) The CNMC’s latest action instead shows that the sanctions process is testing whether specific operators, including in solar, complied with technical and maintenance obligations before the outage. That is an inference from the regulator’s case expansion and the earlier official reports, not a formal CNMC conclusion on causation. (ree.es) ### Why does operating procedure 7.4 keep coming up? June 12, 2025 is when the CNMC updated operating procedure 7.4 and related rules for voltage control in the peninsular electricity system. The CNMC case page says the resolution modified procedures 3.1, 3.6, 7.4, 9.1 and 14.4 to develop a voltage-control service. October 20, 2025 is when the CNMC approved temporary emergency changes to several operating procedures after a public consultation on Red Eléctrica’s proposals. (miteco.gob.es) The regulator said those measures were intended to give the system operator more tools to reinforce security of supply during abrupt voltage swings, initially for 30 days and extendable to three months. Those dates matter because both the government report and Red Eléctrica’s report put voltage control at the center of the blackout analysis. (cnmc.es) The sanctions cases now unfolding will test whether market participants followed the rules in force before the outage and whether any failures warrant penalties. ### What happens next in the case? The next milestones are procedural rather than political. (cnmc.es) Reuters reported that CNMC sanction proceedings can run for nine to 18 months, depending on the seriousness of the alleged infringement, and that the most serious cases can carry fines of up to 60 million euros. The CNMC’s public decisions database is the main place where new case openings and resolutions appear. (miteco.gob.es) Red Eléctrica, the government and the European Commission have already published separate blackout-related materials, and further filings or rulings from those bodies are likely to shape how the responsibilities from the April 28, 2025 outage are documented. (cnmc.es) (sahmcapital.com)