Electrical Energy Storage Systems (EES) officially enter the regulatory agenda of the Brazilian electricity sector with the publication on June 24, 2026 by ANEEL published in the Official Gazette of the Union (DOU) in Normative Resolutions 1.161/2026 and 1.162/2026.
The central point is clear: energy storage has ceased to be merely a technological solution and has become a regulated asset, with requirements for authorization, connection, network usage contracts, metering, operation, billing, and penalties.
The new regulations from the National Electric Energy Agency distinguish, for example, between the autonomous self-contained system (SAE): which absorbs energy from the grid for subsequent injection or provision of services to the system, and the co-located self-contained system (SAE): which is installed next to a generating plant or consumer unit.
This distinction is essential because it defines distinct obligations regarding network access, metering, demand contracting, and the possibility of energy injection.
In the case of a consumer unit with a co-located water supply system without micro or mini-distributed generation, for example, the rule is explicit: power injection into the grid is not permitted, and the contracted injection demand must be zero.
Therefore, for the connection process: storage requires technical and legal planning, since the implementation of autonomous or co-located storage systems becomes part of the formal connection process with the distributor or the transmission system.
The distributor must prepare a specific connection quote and, in the case of installation with a co-located water supply system, a single connection quote. The user must provide the maximum charging and discharging power values, in kW.
Furthermore, when the generator intends to reduce the contracted injection demand due to the installation of the SAE (Storage and Energy Efficiency System), it must present a technical study demonstrating that the system is compatible and configured for this reduction.
In other words, simply installing the battery is not enough. It is necessary to demonstrate, both technically and legally, how it will operate within the network..
There is also a requirement for mandatory contracts: CUSD, CUST, and an operating agreement. The Resolution makes it clear that autonomous SAE (Storage and Energy Services) and generating plants with storage must observe the contractual logic of the electricity sector.
For connection to the distribution network, a CUSD (Contract for the Use of the Distribution System) must be signed. For projects dispatched centrally by the ONS (National System Operator), a CUST (Contract for the Use of the Distribution System) with the ONS will be necessary. In addition, an operating agreement must be signed in other applicable cases.
The autonomous SAE (which uses the same connection point to consume and inject energy) must have a single, permanent CUSD (Centralized Distribution System).
This point is extremely relevant for companies: the contractual strategy directly impacts monthly costs, contracted demand, revenue, and the risk of penalties.
And, the new economic focus of storage is contracted demand, where the standard establishes a specific rule for contracted injection demand in generating plants with a co-located energy storage system.
In this case, the demand calculation should consider the maximum injectable power of the generating plant, although the maximum load power of the storage system may be deducted. However, this deduction is limited to 30% of the maximum injectable power of the generating plant.
For power plants that already have an existing CUSD (Centralized Distribution System), the reduction in injection demand will be limited to 5% every 12 months, except for the first request after the SAE (System for Energy Efficiency) connection, in which case there may be different treatment.
This is a sensitive economic issue, as a poorly designed contractual structure can lead to undue demand payments, overcharges, loss of financial efficiency, and regulatory uncertainty. Therefore, seek professional help (a lawyer specializing in the electricity sector, regulation, and contracts).
Regarding billing, energy consumption and injection are now analyzed together. Normative Resolution 1.162/2026 establishes that billing for a generating plant with a co-located or autonomous water storage system must cumulatively include the portion associated with consumption and the portion associated with injection. In practice, storage may generate charges for both energy consumed for load and the demand for injection into the grid.
This design requires a detailed analysis of the tariff model, demand contracting, operating hours, loading and unloading strategy, and the relationship with CCEE, ONS, or the distributor.
And there is also the application of penalties (including storage systems under the inspection and penalties regime of ANEEL) also included in REN 1.162 where the storage provider will now be held accountable as a regulated agent.
And the regulatory risks for any breach of contract range from failure to comply with registration obligations; operation without proper measurement; failures in the separate accounting of revenues, costs and investments; non-compliance with technical limits; failure to comply with operating, connection and marketing rules, among others, since the two new resolutions revoke several previous resolutions and amend others that already exist.
For example: the basis for calculating the fine for SAE (Storage and Energy Management) will be estimated based on the energy injected in a year, considering the maximum discharge power and regulatory capacity factor. This means that storage now has its own sanctioning risk, requiring regulatory governance from the project structuring phase.
The opportunities for companies are enormous, provided that the new storage rules are complied with legally sound: Resolution No. 1.162/2026 opens a new avenue of business for batteries, demand response, ancillary services, reversible power plants, energy arbitrage, demand optimization and integration with renewable generation.
But it also raises a warning: storage projects cannot be treated solely as engineering or equipment acquisition. They require integrated regulatory, contractual, tax, and commercial analysis.
Therefore, companies intending to invest in SAE (Storage and Energy Services) need to assess the regulatory viability of the model, its classification as an autonomous or co-located SAE, the need for authorization or registration, the connection process, the issuance of the connection budget, the signing of CUSD (Contract for the Use of the Distribution System), CUST (Contract for the Use of the Distribution System) and operating agreement, the contracted demand for consumption and injection, the risk of exceeding demand, the metering and billing specific to each SAE, participation in ancillary services or demand response, applicable penalties, and finally, the interface with the distributors, ONS (National System Operator), CCEE (Chamber of Electric Energy Commercialization) and... ANEEL.
The two new resolutions transform energy storage into a new regulatory asset for the Brazilian electricity sector.
The future of batteries in Brazil will be promising, but it won't be informal. Those who correctly structure their contracts, connectivity, demand, measurement, and regulatory strategy will have a competitive advantage, while those who treat storage merely as equipment may face unexpected costs, connectivity issues, unfair charges, and regulatory penalties.
As a lawyer specializing in Energy Regulatory Law, my legal expertise becomes essential in guiding companies, investors, generators, consumers, and service providers in the safe implementation of energy storage projects in Brazil!
The opinions and information expressed are the sole responsibility of the author and do not necessarily represent the official position of the author. Canal Solar.
