CNMC adds renewables to probes

Spain’s competition and energy regulator has widened its sanctioning cases over the April 28, 2025 blackout to include the renewable-energy sector, adding a first known renewable operator to the docket this week. The National Commission on Markets and Competition, or CNMC, opened the case against Mercuria Sostenible on May 13, according to its case registry. The move comes after the regulator in April opened formal proceedings against Red Eléctrica, large distribution groups and several thermal plants as part of its blackout investigation. (publicnow.com) CNMC has said the outage had a “multifactorial” origin that ended in a peninsula-wide shutdown caused by overvoltage. ### Which renewable company was added to the blackout cases? Mercuria Sostenible appears on CNMC’s public docket in case SNC/DE/093/26, listed as “in processing” with a latest update dated May 13, 2026. The file describes an alleged serious infringement under article 65.8 of Spain’s Electricity Sector Law tied to non-compliance with articles 64.15, 64.16 and 64.17. La Vanguardia reported the case concerns a facility in Seville owned by Mercuria Sostenible. CNMC’s public registry entry identifies the company but does not, in the excerpt available online, name the plant. (publicnow.com) ### How much broader is the CNMC investigation now? April 17 marked the first formal sanctioning step by CNMC against major energy companies and the grid operator after the blackout. Reuters reported then that CNMC had opened probes into Red Eléctrica, a Redeia unit, and companies including Iberdrola, Naturgy, Endesa and Repsol, as well as individual plants. (publicnow.com) By May 15, Spanish media reports said the regulator had already opened more than 60 sanctioning files linked to the blackout. The addition of Mercuria Sostenible extends that enforcement net into renewables after earlier cases had centered on the transmission operator, distributors and combined-cycle gas plants. (lavanguardia.com) ### What is CNMC examining in the blackout sequence? March 19, 2026, CNMC said its investigation had identified improvement areas in Spain’s technical, operational and regulatory frameworks as the power system changes with high renewable penetration, greater operational complexity and more volatile voltages. (cnmc.es) The regulator said it saw a need for measures to mitigate abrupt voltage changes, strengthen coordination between network operators and improve visibility over their networks. ENTSO-E, the European transmission system operators’ body, said in its final report updated March 20 that the blackout resulted from “many interacting factors,” including oscillations, gaps in voltage and reactive-power control, rapid output reductions and generator disconnections in Spain. (lavanguardia.com) Those factors led to fast voltage increases and cascading generation disconnections across Spain, it said. ### Did regulators already point to generator disconnections? June 17, 2025, Spain’s Energy Ministry said the government’s crisis committee had found insufficient voltage-control capability, oscillations that affected system operation and the disconnection of generation facilities, “in some cases apparently improperly.” The ministry said the sequence of events progressively destabilized the system and ended in an overvoltage-driven blackout. (cnmc.es) April 21, 2026, CNMC Chair Cani Fernández told Spain’s Congress that the system had “sufficient” regulatory mechanisms to control voltage on the day of the outage, according to media reports. (entsoe.eu) La Vanguardia also reported that Fernández said the regulator had detected disconnections that did not match criteria set by Spanish regulation during the blackout day. ### What are companies saying as the cases proceed? Redeia Chair Beatriz Corredor said on May 13 that Red Eléctrica had already submitted its arguments in response to CNMC’s sanctioning file. (miteco.gob.es) Corredor said the company maintained that “Red Eléctrica no falló” and that official reports supported its position that the event was “inédito, imprevisible y multifactorial.” The Mercuria Sostenible case remains at the opening stage on CNMC’s registry. (europapress.es) CNMC’s March recommendations report and ENTSO-E’s final engineering report are both publicly available, and the regulator’s case list continues to show new entries tied to the April 28, 2025 incident. (publicnow.com) (redeia.com)