Mexico’s National Energy Commission (CNE) has approved a new operational framework for electricity storage, opening the door to multiple deployment models and offering greater clarity on how-and where-storage can participate in the power system.
The regulations set out how electric energy storage systems (SAEE, by its acronym in Spanish) may be developed, interconnected and sell products in the market, as applicable. Storage systems may take part in generation and marketing activities, either on a standalone basis or alongside power plants or load centers. They may also be installed as part of transmission and distribution infrastructure to support system reliability.
Standalone storage systems of 0.7 MW or more must obtain a storage permit from the CNE and be represented in the Wholesale Electricity Market (WEM) by a market participant, such as a generator, supplier or storage company.
The framework sets out several distinct development options:
These storage systems are treated as part of the generation asset, share the same interconnection point and do not require a separate storage permit.
This option is available only for renewable generation and allows storage systems with at least three hours’ duration to qualify and be accredited as firm capacity in the capacity market, including for sale through the capacity balance market, subject to interconnection studies based on physical deliverability criteria.
These storage systems may charge either from the grid or from the associated plant, and their market products are sold through the market participant representing the generator.
If the storage system is charged from the grid, the market participant representing the power plant must submit offers to purchase power in the short term market.
If charged from the associated power plant, the project’s sale offers in the WEM must discount the energy used to charge the storage system.
Existing power plants with generation permits granted under legal regimes predating the issuance of the Electricity Sector Law (LSE) in March 2025 must migrate those permits to the new regime before integrating storage equipment.
Power injected into the grid by power plants with an associated storage system may not exceed the nameplate capacity indicated in their interconnection agreement.
If a generator intends to install a storage system to increase the capacity under its interconnection agreement, it must request interconnection studies, amend its generation permit and interconnection agreement accordingly, complete the applicable testing and obtain from CENACE commercial operation approval for the new equipment.
In this modality, the energy storage systems are treated as part of the consumer’s installation, share the same grid connection point and do not require a storage permit.
Their use is limited to behind-the-meter consumption: stored energy cannot be injected into the grid or sold.
These systems must charge from the grid and must source electricity either through a supplier or by participating directly in the WEM as a qualified user.
In self-consumption projects, storage systems may be installed either by the end user or by the holder of the self-consumption generation permit.
End users may install energy storage systems as part of their consumption facilities without a storage permit, provided the storage capacity does not exceed the load center’s demand.
Holders of self‑consumption generation permits may also integrate energy storage systems into the generating facility without a storage permit. In this case, installing an energy storage system must not increase the project’s permitted generation capacity.
Energy stored in these storage systems must be used on-site and cannot be exported to the grid, except in the limited case of interconnected self-consumption projects authorized to sell excess energy to CFE.
These storage systems are deployed by CFE, as owner of the transmission and distribution grids, to enhance grid reliability.
These storage systems do not require a storage permit, cannot participate in the WEM and do not receive compensation for the energy they manage.
Instead, their costs are recovered through regulated transmission and distribution tariffs.
CFE may partner with private parties to develop these systems, subject to SENER’s authorization and alignment with the central planning criteria, although ownership of the assets must remain exclusively with CFE.
These systems are not linked to a power plant, load center or grid infrastructure. They must obtain a storage permit, interconnect to the grid, and may participate directly in the WEM as storage providers or be represented by generators or suppliers.
They may qualify as firm capacity, and be accredited as such, if interconnection studies meet physical delivery criteria.
The storage permit will specify the services each standalone project may provide, including frequency regulation, backup, ancillary services, congestion management and renewable integration.
Standalone projects may enter into short-, medium-, and long-term contracts with CENACE, the independent system operator, if storage is identified under the central planning system as an efficient solution for system reliability. CENACE, as part of its central planning activities, must identify zones, regions and nodes where integration of energy storage systems will benefit the grid.
Standalone storage systems may also offer backup services to interconnected self-consumption projects to meet the statutory backup requirements, as well as to generation projects that must mitigate intermittency but choose not to install their own storage systems.
Integrating storage into existing generation or load facilities is treated as a “technical modification” for interconnection purposes, requiring – as applicable - interconnection or connection studies from CENACE, which will determine the scope of the required analysis. Storage projects must request interconnection studies if they intend to inject energy into the grid, and connection studies if they intend to withdraw energy, although both processes may be combined into a single application.
In interconnection studies, CENACE will assess variability in generation projects and may require the integration of storage or equivalent backup arrangements as a condition for interconnection. Where storage is used to mitigate variability, developers must maintain its operational capacity throughout the life of the project, including replacing or upgrading systems if performance degrades over time.
Storage systems also may be used by groups of market participants. Grouping is permitted only among parties that share the same legal or market status: generators, basic supply service users, qualified users or applicants for interconnection of power plants or connection of load centers. Grouping must comply with central planning criteria, and may occur solely within the same substation, node or electrical area that CENACE deems technically appropriate.
Storage systems that charge from the grid and participate in the WEM as non-dispatchable resources are treated as load serving entities, meaning they must acquire capacity and clean energy certificates in connection with their electricity consumption. Storage systems that charge from the grid but participate as dispatchable resources are exempt from these obligations. Storage systems participating in the WEM may enter into bilateral long-term agreements with other market participants to sell capacity and other associated products.
Standalone storage systems and those associated with power plants may enter into long-term agreements with load-serving entities to supply the energy and capacity these entities are legally required to procure for future periods, reinforcing the role of storage as a planning and compliance tool within the sector.
The regulatory framework for storage systems is not yet complete. Several key market rules still need to be updated to align with these provisions, including interconnection manuals, short-term market bidding functionality for storage, and the methodology for the variability analysis to be carried out by CENACE. Until those changes are in place, there will be a transitional period in which storage systems will be treated as load when withdrawing energy from the grid and as generation when injecting electricity into the grid.