New Provisions for Integrating Electric Energy Storage Systems into the National Electric System

On March 7, 2025, the Energy Regulatory Commission ("CRE") published the new "General Administrative Provisions for the Integration of Electric Energy Storage Systems to the National Electric System" (the "Provisions").¹

General Aspects of the Provisions

The purpose of the Provisions is to establish the general conditions under which Electric Energy Storage Systems ("ESS") will be integrated to the National Electric System ("SEN").

The Provisions aim to establish the general conditions under which Electric Energy Storage Systems ("ESS") will be integrated into the National Electric System (Sistema Eléctrico Nacional, "SEN"). The document is composed of eight chapters detailing the following: (a) general conditions applicable to ESS for their integration into the SEN; (b) modalities of ESS for their integration into the SEN; and (c) general requirements and interconnection and/or connection procedures for parties interested in integrating their ESS into the SEN.

ESS Modalities

The Provisions establish the following types of ESS, each with certain legal and technical requirements described below:

1. ESS associated to a Power Plant ("ESS-Power Plant");
2. ESS associated to a Load Center ("ESS-Load Center");
3. ESS associated to an Isolated Supply scheme ("ESS-Isolated Supply");
4. ESS are not associated with a power plant or load center ("Non-Associated ESS"); and
5. ESS associated to an Exempt Generator ("ESS-Exempt Generator").

ESS-Power Plant modality

• In this modality the ESS-Power Plant is considered part of the power plant and must be represented by the same market participant in the Wholesale Electricity Market (Mercado Eléctrico Mayorista, "MEM").
• New intermittent power plants intending to include an ESS must apply to the CRE for a generation permit. Existing intermittent power plants must request a modification to their existing power generation permit to incorporate an ESS.
• The ESS-Power Plant must comply with the corresponding interconnection process.

ESS-Load Center modality

• In this modality, the ESS-Load Center shares the same connection point with the load center and must be represented by the same market participant in the MEM.
• ESS-Load Center does not require a power generation permit from the CRE but must be registered with the CRE within 90 business days after their installation.
• The ESS-Load Center must comply with the corresponding connection process.

ESS-Isolated Supply modality

• The ESS-Isolated Supply is integrated with a power plant and a load center operating in the isolated supply modality.
• New power plants intending to include an ESS must request a generation permit from the CRE. For existing intermittent power plants, a modification of the corresponding electric power generation permit must be requested.
• The ESS-Isolated Supply is regulated by the current provisions regarding isolated supply.

Non-Associated ESS modality

• Non-Associated ESS operate independently, not integrated into a power plant or load center. They require an electric power generation permit from the CRE.
• Non-Associated ESS must comply with the corresponding interconnection and connection processes. Their offers to purchase and sale energy in the MEM are made like any power plant or load center.

ESS-Generator Exempt modality

ESS-Exempt Generator is regulated in accordance with the provisions on distributed generation. 

ESS and legacy interconnection agreements

Power plants and load centers included in a Legacy Interconnection Contract cannot incorporate an ESS unless they are fully excluded from it and from the corresponding permits obtained under the now-repealed Public Electricity Service Law (Ley del Servicio Público de Energía Eléctrica).

^{1 Available at: https://dof.gob.mx/nota_detalle.php?codigo=5751230&fecha=07/03/2025}

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_{This article is prepared for the general information of interested persons. It is not, and does not attempt to be, comprehensive in nature. Due to the general nature of its content, it should not be regarded as legal advice.}

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