New legal framework for storage projects in Mexico

On 16 April 2026, the National Energy Commission (Comisión Nacional de Energía, "CNE") published the Guidelines for Storage Systems Integrated to the National Grid (Disposiciones Administrativas de Carácter General para la integración de Sistemas de Almacenamiento de Energía Eléctrica al Sistema Eléctrico Nacional, the "Guidelines") in the Official Gazette. The Guidelines are Mexico's first comprehensive rulebook for integrating electric energy storage systems ("SAEE") into the National Electric System ("SEN").

The Guidelines entered into force on 17 April 2026. They cover the full range of electricity storage technologies and set out the conditions under which CENACE (the system operator), generators, suppliers, storage operators, and end users may develop, interconnect, and operate storage assets.

Five Modalities of Participation

The Guidelines establish five ways in which storage projects can participate in the market:

Co-located with power plants: the storage is treated as part of the generating asset, so no separate permit is needed. Systems with at least three hours' duration can qualify as firm capacity and sell into the capacity balance market. This is the modality most relevant for renewable developers looking to improve bankability.
Behind the meter at load centres: the storage forms part of the consumer's installation. No permit is required, but stored energy cannot be exported or sold as it is strictly for own consumption.
Self-consumption projects: similar to load centres but storage may also serve holders of self-consumption generation permits. Self-consumption projects cannot export to the grid unless the project is authorised to sell surplus to CFE (the state utility).
Transmission and distribution infrastructure: these are deployed by CFE to strengthen grid reliability. This modality does not allow for market participation, so the costs are recovered via regulated tariffs. Private parties may partner with CFE, but ownership of these projects stays with the State.
Standalone systems (≥0.7 MW): these systems require a storage permit from the CNE and may participate directly in the Wholesale Electricity Market (MEM). They can qualify as firm capacity and contract with CENACE where central planning identifies storage as an efficient reliability solution.

Key Obligations for storage projects

Interconnection studies are mandatory: adding storage to an existing plant or load centre counts as a "significant technical modification," triggering CENACE interconnection or connection studies. For new standalone projects, injection requires interconnection studies and withdrawal requires connection studies, though both can be combined into one application.
Transitional market rules apply: until the Wholesale Electricity Market Rules are updated for storage, systems withdrawing energy are treated as load and those injecting are treated as generation. This creates some uncertainty around compensation and scheduling that participants should factor into their planning.
Backup obligations for renewables: self-consumption projects with solar or wind that sell surplus must meet the backup obligation (criterio de respaldo propio) by either integrating their own storage, contracting backup with CFE, or contracting with a third party offering firm capacity.
Mandatory migration to new regime for pre-2025 permits: existing power plants with pre-2025 generation permits must migrate to the new regime before adding storage.

Key considerations

Considering these requirements, developers should assess whether co-located storage (minimum three hours' duration) would quality their project as firm capacity, with potential to improve its revenues and bankability.

In fact, investors and lenders should treat storage as a bankability variable. Financing documents need conditions precedent tied to storage permits, compliance covenants, and remedies for permit modification or revocation risk. The transitional market uncertainty should be reflected in pricing assumptions.