On June 24, 2026, ANEEL published Normative Resolutions 1.161 and 1.162, which close Public Consultation 39/2023 and regulate Law 15.269/2025 with respect to electrical energy storage systems (SAE). The rules came out about seven months after the law, but they are the result of a longer debate, whose second round of contributions ended on January 30, 2025. For those developing battery projects (BESS) in Brazil, the package defines how to obtain authorization, how to contract grid use and which charges apply to the operation.
Authorization: standalone SAE and co-located SAE
REN 1.161/2026 addresses authorization requirements and procedures. The starting point is the distinction between two models:
- Standalone SAE: operates independently, with its own connection point and individual regulatory responsibilities. For this reason, it requires specific authorization.
- Co-located SAE: is treated as an asset associated with the power plant or consumer unit where it is installed, without needing to form a separate agent.
The choice of model is not merely formal. It determines the access regime, metering, grid use contracting and the project's revenue possibilities. The rule also sets requirements for the authorization request, implementation deadlines and agents' obligations. REN 1.162/2026, in turn, incorporates storage into the Transmission Rules, with adjustments to the glossary, the classification of facilities, the criteria for commercial operation and, above all, the access conditions.
Grid use, tariffs and charges
Contracting MUST and MUSD, the amounts of use of the transmission and distribution systems, was the most sensitive economic issue. The outcome was as follows:
- Standalone SAE without full ONS dispatch: contracts capacity in both directions, as a load when charging and as an injector when discharging.
- Standalone SAE with full ONS dispatch: the consumption amount for charging is zero, and the generation amount corresponds to the maximum discharge power.
- Plants with co-located SAE: may reduce injection MUST/MUSD by up to 30%, provided there is technical justification. In existing contracts, the first reduction linked to the battery installation can be made at no cost, subject to prior notice rules.
The reduction applies to the contracted amount, not to the unit tariff. TUST and TUSD continue to follow actual use, with the consumption tariff on absorption and the generation tariff on injection.
Regarding sector charges (CDE, PROINFA, ESS, EER and ERCAP), the agency did not classify storage as a final consumer based on gross consumption. The balance between energy absorbed and returned, which reflects cycle losses and auxiliary consumption, was understood as a cost inherent to the service provided to the system, not as use for its own benefit. Thus, energy charged for later reinjection is not subject to these charges on the gross volume.
MMGD, ancillary services and next steps
ANEEL recognized the compatibility of co-located SAE with distributed micro and mini generation (MMGD) and with the Electric Energy Compensation System, through an amendment to REN 1.000/2021. With MMGD, the battery can charge from the grid or from its own generation and then supply the unit or inject energy. Without MMGD, the system is restricted to supplying its own unit, with no injection into the grid.
Ancillary services are now permitted for standalone SAE and plants with co-located SAE, but contracting, settlement, technical requirements and remuneration still depend on the Grid Procedures, CCEE and ONS rules and specific processes. ONS and CCEE have 180 days to submit their adjustment proposals to ANEEL. ONS is expected to detail the requirements for grid forming technology, in which the battery inverter behaves as a voltage source, providing synthetic inertia and short-circuit support. This requirement is already included in the LRCAP 2026 for Storage, the capacity reserve auction focused on batteries.
What changes in practice for the BESS value chain
For developers, there is now a clear authorization path and a strategic decision between the standalone and co-located models. Existing plants gain a concrete argument for adding batteries: the cut of up to 30% in the injection amount, with the first reduction at no cost. The absence of charges on gross consumption improves project economics, but revenues from ancillary services and revenue stacking cannot yet be taken for granted in financial models.
For EPCs, manufacturers and suppliers, the message is technical: connection specifications and grid forming capability are likely to carry increasing weight. It is worth closely following the ONS and CCEE proposals over the next 180 days, because that is where equipment and metering requirements will be detailed.
Original source: ABSAE — Resultado da CP 39/2023 consolida marco regulatório para o Armazenamento de Energia