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The Federal Electricity Commission (CFE) has submitted a new Environmental Impact Assessment (MIA) to SEMARNAT for Phase III of the Concepción Mendizábal Mendoza photovoltaic project in Nava, Coahuila. Proposing an additional 339 MWac of solar capacity backed by a MX$8.47 billion investment, the infrastructure will feature over 643,000 solar panels and 55 battery energy storage system (BESS) containers. Strategically integrated into the existing grid infrastructure of the 1,400 MW Carbón II complex—Latin America’s largest coal-fired power station—this development forms a major part of Mexico’s planned coal-to-solar transitions. Rather than executing an abrupt structural shutdown, the Sheinbaum administration is pacing out a managed transition, maintaining regional mining employment and grid stability via batteries while scheduling the parallel deployment of utility-scale clean energy.
CFE has submitted a new Manifestación de Impacto Ambiental to SEMARNAT for the Concepción Mendizábal Mendoza Fase III photovoltaic plant in Nava, Coahuila, proposing an additional 339MWac of solar generation capacity at the site of the Carbón II thermoelectric complex — Latin America’s largest coal-fired power station, and simultaneously one of Mexico’s most significant planned coal-to-solar transitions.
The project carries an estimated investment of MX$8.47 billion and is designed to operate commercially for a minimum of 25 years. It will incorporate more than 643,000 solar panels, 55 battery storage containers, single-axis horizontal trackers, and a new 400kV aerial transmission line. The environmental plan allocates MX$196 million for ecological mitigation, biodiversity rescue, and reforestation in the surrounding zone.
What Phase III Adds to the Growing Concepción Mendizábal Complex
The Fase III submission is the latest element of CFE’s expanding photovoltaic program at the Carbón II site. In January 2026, CFE had already submitted the Carbón II photovoltaic project — referred to in that filing as 400 MWac — for environmental review, with 761,964 crystalline-silicon modules, a transmission line, and expansion of the Carbón II electrical substation, on a total footprint of 576.65 hectares.
CFE has described the combined Coahuila solar program as representing an investment exceeding MX$15 billion across two photovoltaic plants — the Carbón II installation and the separate Río Escondido plant of 180 MW — together totaling 556 MW for the state. The Carbón II complex is expected to include a storage component equivalent to 30% of its generation capacity.
The Fase III filing reported by Global Energy Mexico — at 339 MWac with 55 BESS containers — appears to represent the newest phase of the broader Concepción Mendizábal complex that has been building in regulatory filings throughout 2025 and into 2026. CFE’s national expansion plan already listed “CFV Concepción Mendizabal, Fases I y II / 576 MW” under the category of projects in the technical specification and bidding phase. The Fase III application expands that footprint further, adding 339 MW with integrated storage and a new high-voltage transmission connection.
The Site: Converting Latin America’s Largest Coal Station
Carbón II is not a neutral backdrop for a solar project announcement. Operated by CFE since 1993, the plant is one of Latin America’s largest coal-fired power stations, with four 350 MW generating units totaling 1,400 MW of capacity. The Mexican government’s 15-year energy development plan for 2018-2032 called for all four units to be taken offline in 2029, removing 1,400 MW of coal-fired electricity from the national energy mix and making Carbón II the only coal-fired power plant in the country with a specific proposed shutdown date.
The transition from coal generation to solar at the same physical site is a textbook just transition scenario: existing grid interconnection infrastructure, land area already in industrial use, and a workforce and regional economy historically dependent on coal mining that must be reoriented toward new energy activities. CFE Director General Calleja Alor stated that “these plants do not replace existing generation, they complement it and strengthen system stability,” framing the Coahuila solar projects as additive to the national grid rather than as a forced displacement of the existing coal fleet.
The coal supply dimension of that transition is complicated. In April 2026, coal producers in the Región Carbonífera of Coahuila began receiving notifications of formalized coal supply contracts with CFE covering the period 2026-2030, guaranteeing coal deliveries to the Carbón II and José López Portillo power stations through the end of the decade. Mexico is simultaneously planning solar generation at Carbón II’s footprint while contracting coal deliveries to the same site through 2030 — a sequenced transition that keeps the existing coal units running while solar phases in, rather than an abrupt shutdown.
The BESS Component: Why 55 Containers
The 55 battery storage containers specified in the Fase III filing address the same grid stability requirement embedded in all of CFE’s recent photovoltaic projects and in the mixed development scheme guidelines — a storage component providing at least 30% of generation capacity for three hours minimum. At 339 MWac of generation, that implies approximately 100 MW of storage, consistent with the BESS container count disclosed.
The storage mandate is particularly relevant at the Carbón II site given its grid role. The complex feeds into Coahuila’s industrial corridor — the same northern industrial cluster whose electricity reliability challenges Chihuahua’s state government described as “operating at the limit” in early July. A solar-plus-storage installation at Carbón II that can dispatch during evening demand peaks, not just during solar generation hours, would contribute meaningfully to relieving the grid stress that has been generating outages across the region during the 2026 summer demand season.
Coahuila’s Solar Emergence
Coahuila is accelerating solar energy projects with CFE and renewable energy, positioning the state as a key entity in the national energy transition. Beyond the Concepción Mendizábal and Río Escondido projects, the state is evaluating the reactivation of wind parks and maintains an active coal supply relationship with CFE for its existing thermoelectric fleet — making it one of the few states where coal, gas, wind, and solar are developing simultaneously under a single regional energy portfolio.
For the Carbón II community specifically — Nava and the broader Región Carbonífera whose economy has depended on coal mining for generations — the solar project represents a transition that is being managed through sequenced contracts rather than abrupt closure. That approach carries its own risks: a decade of parallel coal and solar operation keeps carbon emissions and subsidy costs elevated during the overlap period. But it also avoids the economic shock of an immediate plant shutdown in a region where mining employment is concentrated and alternatives take years to materialize.
The MX$196 million environmental mitigation plan embedded in the Fase III MIA — covering biodiversity rescue and reforestation — signals that the SEMARNAT review process will apply the same social and environmental accountability standards to CFE’s own solar portfolio that the MISSE framework established for private sector energy projects.

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