Energy storage is beginning to redefine the architecture of new photovoltaic projects in Mexico linked to the Federal Electricity Commission's (CFE) mixed-use scheme. The requirement to incorporate 30% storage no longer simply means adding battery capacity; it necessitates a review of the electrical design, control systems, interconnection, safety, and performance of the power plants.
The scope of these requirements is detailed in the “Specifications and Minimum Requirements to be Met in Photovoltaic Projects with Energy Storage” , published by the Government of Mexico for developments contemplated within the Mixed Development scheme with the Federal Electricity Commission (CFE).
The document states that the battery storage system must be designed as an asset fully integrated into the photovoltaic plant and the electrical grid, capable of providing operational flexibility, reliability and auxiliary services in accordance with the Grid Code and the requirements of the National Energy Control Center (CENACE).
In that scenario, Alejandra Matus, Sustainability Developer Projects at Siemens , identifies that the discussion is beginning to shift from the existence of demand towards the technical resolution of projects.
“ There is a significant opportunity to implement these new technologies. The market exists, the demand is there, and I believe the technical aspects now need to be refined, ” Matus stated during an exclusive interview at the Future Energy Summit (FES) Mexico 2026 .
The issue is gaining importance because battery integration is already part of the new portfolio that Mexico is seeking to mobilize . In CFE's mixed-sector projects, storage must account for 30% of capacity for three hours, according to the requirements reported for the awarded initiatives.
The trend is not starting from scratch either. In the previous call for bids aimed at private companies, approximately 3.3 GW of renewable capacity and 1.2 GW of battery systems were awarded, forming one of the first large blocks of projects with storage under the new Mexican framework.
Added to this is the first call under the mixed scheme with CFE, which resulted in 37 selected projects from 31 developers for around 7,411 MW of capacity , after a process that initially received more than 200 proposals and nearly 38 GW under evaluation.
For Siemens, this new volume of projects requires a more detailed look at the earlier stages of development. “ From our perspective, we focus heavily on the basic engineering for the electrical circuits used in power generation plants with storage, right? Because now we're adding this component ,” the executive explained.
What will BESSs have to comply with?
The official specifications allow us to understand the scale of this complexity. The systems must achieve a cycle efficiency of 90% or higher, a minimum depth of discharge of 90%, and a lifespan of at least 6,000 cycles.
However, the requirements don't end with battery performance. The Mexican government mandates the following functionalities: frequency regulation, ramp control, voltage regulation, black start, grid forming operation, and support for primary, secondary, and tertiary regulation .
This implies that storage will need to play an active role in the electrical system, rather than simply shifting solar energy between different times of the day.
It must also have an integrated battery management system, communication with the DCS and PPC control systems and continuous monitoring of the state of charge and health status , in addition to ventilation systems, fire detection and protections suitable for the installation.
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The bases also incorporate specific regulatory requirements, including IEC 62619, IEC 62933 and UL 9540 , along with documented acceptance tests both at the factory and on site.
“ So it is critical that this scope is well structured, mainly regulations, certifications... The part about interconnection studies is also something we see as crucial ,” Matus warned.
Interconnection is gaining importance in the design
Inverters must respond to active and reactive power control, voltage regulation, ramp control and frequency and voltage variations , in addition to complying with harmonic distortion limits and dynamic behavior in relation to the National Electric System.
In configurations with string inverters, CFE requires that the set can operate aggregated as a single system to the grid , maintaining redundancy and coordinated control capacity at the plant level.
Furthermore, the project must integrate centralized control systems and comply with the Grid Code and the Power Plant Interconnection Manual , which increases the importance of correctly carrying out studies and simulations from the early stages.
“ We have the software and tools to be able to size it ,” Matus said during the exclusive interview at FES Mexico 2026 , referring to the technological support that Siemens offers for this type of development.
The technical document also requires a significant battery of preliminary studies. These include corrosivity, dynamic soil characterization, seismic hazard, electrical resistivity, geotechnical analysis, topography, hydrology and climatology , as well as single-line diagrams, interconnection centers, collector circuits, and control systems.
Thus, the 30% requirement practically alters the entire project architecture . The developer will not only have to decide how many megawatts or megawatt-hours to install, but also how to integrate generation, storage, inverters, control systems, and the point of interconnection under a single operational strategy.
“ The main change is that the sector is already being reactivated ,” added the company representative.
Beyond the utility
Although this new portfolio puts the utility segment front and center, Siemens also sees an expansion of opportunities towards industrial and commercial consumers , particularly as self-consumption schemes evolve.
The company, however, maintains its primary focus on large power plants. “ We are mainly focusing on utilities, but we are also looking at and supporting industrial projects. So yes, we are diversifying these areas ,” Matus explained.
“I believe that day-to-day operations will improve significantly due to the compensation for potential power outages at the utility level. And in the transmission sector, it will greatly help to have a more precise and flattened power curve. For industry, it will allow them to mitigate power failures or other outages and maintain the continuity of their operations; this will be phenomenal,” he added.
In this context, Siemens seeks to participate from the technological integration and engineering associated with the new generation of projects.
“Our goals are to be technological and strategic partners for companies and to support them in these processes of implementing network technologies,” Matus concluded during the exclusive interview at Future Energy Summit Mexico 2026.