Brazil's National Electric System Operator (ONS) and the Energy Research Office (EPE) released, on October 22, 2026, a revised version of the technical note that sets out the minimum requirements for projects intending to compete in the Capacity Reserve Auction (LRCAP) dedicated to energy storage in 2026. The update was made to align the document with the guidelines of Normative Ordinance No. 136/2026 issued by the Ministry of Mines and Energy (MME). For those who develop, build or supply battery systems, the message is clear: projects need to be checked against the new version of the text before the qualification stage.
What was published
The joint ONS and EPE technical note is the document that translates into engineering criteria what the government has defined at the public policy level for the auction. It establishes the minimum threshold a project must meet to be considered eligible to participate. The version now released replaces the previous one and becomes the reference for preparing bids.
The core of the revision is its alignment with Normative Ordinance No. 136/2026. In other words, the changes in the note stem from the rules set by the MME, not from an isolated initiative of the technical institutions. This reinforces the view that the auction framework is being consolidated in layers: first the ministerial guideline, then the technical detail.
Why minimum requirements matter
In a capacity reserve auction, the goal is not to buy energy but to ensure the system has power available when it needs it, especially at times of higher demand or a rapid drop in renewable generation. Battery energy storage systems, known as BESS, fit this role because they can absorb energy during periods of surplus and return it to the grid within seconds or minutes.
For this contribution to be reliable, the operator needs to know in advance what each plant delivers. That is where minimum requirements come in. In general, documents of this kind cover topics such as:
- Performance: the ability to sustain the contracted power for the required duration and to respond to the operator's commands;
- Connection: the project's compatibility with the chosen access point and with the available grid connection margin;
- Operation and control: supervision, telemetry and integration capabilities with the operation centers;
- Verification: documentation that makes it possible to confirm, at qualification and afterwards, that the project delivers what it promised.
Any adjustment to these parameters can change a project's sizing, the choice of equipment and, consequently, the cost of the bid.
The regulatory basis: Normative Ordinance No. 136/2026
The MME ordinance works as the backbone of the auction. It defines the general outline of the product to be contracted, and the technical note must faithfully reflect those choices. When the ordinance brings new or adjusted definitions, ONS and EPE revise the technical document to avoid mismatches between the rule and its application.
For developers, this means the revised note should be read together with the ordinance. An isolated technical requirement may seem minor, but it gains different weight when understood in light of the purpose defined by the ministry.
What this means in the Northeast
Since the auction depends on grid points capable of receiving the new systems, the availability of connection margin is one of the first filters any project faces. According to a survey by ENLACE, among the Northeast substations eligible for LRCAP 2026 listed in the ONS connection margin technical note, 14 in Bahia, 10 in Ceará and 6 in Piauí have a margin of 500 MW or more.
These figures indicate there is physical room on the region's grid for sizable projects, but they do not replace individual verification. With the revised requirements note, those who had already chosen a connection point should confirm that the project still complies with the updated criteria, and those still in the prospecting phase can use the new version as a guide from the start.
Our view
In our assessment, the revision is a positive sign of the battery auction's maturation. By aligning the technical note with the ordinance, ONS and EPE reduce the risk of divergent interpretations and give the market a more stable basis for budgeting and structuring bids. We see this as a necessary step for storage to enter Brazil's power system planning in an orderly way.
At the same time, successive revisions call for extra attention. Projects designed based on the previous version may contain assumptions that no longer apply, and small technical differences can weigh on qualification. Further adjustments are also possible if regulation keeps evolving, which calls for caution before closing supply contracts with very rigid specifications.
In the coming weeks, we will follow the publication of the other auction documents, any clarifications from the institutions and any update to the qualification schedule. The source does not detail new deadlines, so we recommend monitoring the official channels of ONS, EPE and MME.
What changes in practice for the BESS sector
- Developers: compare the current project, item by item, with the revised note and with Normative Ordinance No. 136/2026, adjusting studies and documentation before qualification.
- EPCs: review engineering assumptions, connection arrangements and control systems that may be affected by the updated criteria.
- Manufacturers: check whether their equipment specifications meet the minimum requirements and prepare the technical documentation that clients will need to submit.
- Suppliers and integrators: keep flexibility in commercial proposals while the auction's set of rules is consolidated.
ENLACE continues to follow the topic and is available to support the technical review of projects in light of the new version of the note.
Original source: ONS — ONS e EPE revisam Nota Técnica com os requisitos mínimos para o Leilão de Reserva de Capacidade (LRCAP) de Armazenamento de 2026
Julio Martinez