On 27 April 2026, the Ministry of Mines and Energy (“MME”) published MME Normative Ordinance No. 129/2026 (“Ordinance”), following MME Public Consultation No. 217/2026. The regulation establishes the guidelines applicable to the Access Seasons provided for in Decree No. 12,772 of 5 December 2025, which established the National Policy on Access to the Transmission System (“PNAST”).
The PNAST is a response to the significant growth in requests for access to the transmission grid and introduces a periodic and coordinated model for the joint assessment of access requests, by the National Grid Operator (“ONS”). In case the requested volumes exceed available capacity, a Competitive Process is initiated for the allocation of capacity.
Registration for Access Seasons: the Ordinance sets out the registration procedure for agents interested in accessing the transmission grid or increasing the volumes of use already contracted. In this context, the ONS is responsible for:
- publishing the instructions applicable to each Access Season, at least 30 (thirty) days prior to the opening of the registration period;
- operating the registration process; and
- verifying the admissibility of applications within 15 (fifteen) days of the close of the registration period.
Calculation and publication of Remaining Capacity: the Ordinance assigns to the Energy Research Company (“EPE”) and the ONS, jointly, the responsibility for preparing the Technical Note on Methodology, Assumptions and Criteria, which will form the basis for calculating the Remaining Capacity at the busbars of the transmission grid for each Access Season. This Technical Note must be published at least 30 days prior to the opening of registration.
The calculation of Remaining Capacity must comply with the criteria established in the Grid Procedures and take into account the system configuration throughout the current horizon of the Medium-Term Electricity Operation Plan – PAR/PEL, including, amongst other elements:
- transmission facilities granted or authorized by ANEEL;
- facilities provided for in the Electricity Transmission Concession Plan – POTEE;
- facilities resulting from sectioning covered by current access opinions.
For calculation purposes, the Ordinance specifies that consumers and generators shall be considered who, by the close of registration, are in commercial operation or who possess:
- a Transmission System Use Agreement (“CUST”) in place;
- a Distribution System Use Agreement (“CUSD”) in place;
- a valid access opinion; or
- access requests accepted by ONS.
Remaining capacity must be presented separately for the consumption and generation segments, with priority given to the consumption segment in the absence of specific guidelines from the MME.
In addition, the Technical Note on the quantities of remaining capacity in the National Grid (SIN), to be published by the ONS and EPE, shall indicate, for each Candidate Busbar, Sub-area and Area of the SIN:
- the available remaining capacity;
- the transmission facilities that determine the calculated capacity; and
- whether or not a Competitive Process needs to be initiated.
Preliminary Access Assessment and contracting of system use: in each Access Season, the ONS shall issue a Preliminary Access Assessment:
- to the winning agents of the Competitive Process, subject to payment of the premium;
- to agents admitted to interconnections where the remaining capacity is sufficient to fully meet the requested amounts; and
- to the winners of energy or capacity reserve auctions that use transmission margin as a selection criterion.
The execution of the CUST remains subject to the provision of the financial guarantees required by current regulations. Failure to comply with the obligations associated with the Preliminary Access Assessment may result, amongst other consequences, in the loss of the allocated usage amount, the enforcement of the participation guarantee, and exclusion from participation in the two subsequent Access Seasons.
Competitive Process: whenever the requested usage amounts exceed the remaining available capacity, a Competitive Process will be initiated for the allocation of capacity. The Ordinance establishes as the main classification criterion the highest bid, expressed in Brazilian reais per kilowatt (R$/kW) of intended capacity.
The premium must be paid in cash by the winning agent prior to the issuance of the Preliminary Access Assessment; it is independent of transmission system usage charges and is non-refundable. The Ordinance permits the use of additional selection criteria, provided that, within a certain range relative to the best bid, they result in a reduction in the SIN’s operating costs greater than that achieved by simple competition for the highest bid, whilst preserving competition, system security and risk perception.
Participation guarantees provided by unsuccessful bidders must be refunded within the timeframes set out in the Access Season Procedures.
Integration with energy auctions: the Ordinance provides that auctions for the procurement of electricity and capacity reserves that use dispatch margin as a selection criterion may adopt the Access Seasons as a preliminary stage. In this case, the initial phase of the auction may be treated as equivalent to the Access Season for the purposes of classifying projects.
This equivalence, however, will apply exclusively to the auction winners, who must register in a subsequent Access Season for the purposes of issuing the Preliminary Access Assessment, and will be taken into account in the calculation of Remaining Capacity.
Other provisions:
The amounts collected as premiums in Competitive Processes shall be allocated to tariff moderation, in accordance with Decree No. 12,772/2025. The Ordinance also provides that the results of the Access Seasons may inform planning studies for the expansion of the transmission system within the scope of the POTEE, and that the ONS must submit proposals to ANEEL for the adaptation of the Grid Procedures.
Finally, the regulation specifies that an agent with a signed CUST assumes the risk of being unable to connect on the date scheduled for its entry into commercial operation, where such impossibility arises from a delay in the deployment of the transmission facilities necessary for the access obtained in the Access Season, without entitlement to reimbursement or financial compensation.
1) ONS External Consultation: system for the 1st Access Season of 2026
In parallel, ONS is conducting an External Consultation on the system applicable to the 1st Access Season, based on the guidelines established by MME Normative Ordinance No. 129/2026. The deadline for contributions has been extended to 5 May.
2) Access to the system: what is at stake?
Since the establishment of PNAST, there have been several developments relating to access to the electricity grid, including regulatory disputes and ongoing initiatives to improve the applicable regulatory framework.
The energy team at Cescon Barrieu continues to monitor legal and regulatory developments relating to the PNAST and grid access.