The energy storage sector in Brazil is experiencing a crucial week. The director of ANEEL (National Electric Energy Agency), Fernando Mosna, announced that he will include the Public Consultation 39/2023 process on the agenda for the next in-person meeting of the regulatory body's board, scheduled for March 10.
The decision is eagerly awaited by the market, as the process has been suspended since August of last year due to a request for review by the director himself, motivated by disagreements regarding the method of taxation for the use of the network by storage systems.
Criticisms of double pricing
The central point of divergence lies in the so-called "Double fare". Currently, the technical area of ANEEL He argues that batteries should be charged as consumers when charging and as generators when injecting energy into the system.
The vote of MosnaHowever, it signals a position contrary to this technical recommendation, seeking to eliminate the charge at the moment the equipment is being charged.
According to the director, the storage system acts as an intermediary that merely shifts the idea of generation and consumption in time. He argued that what the energy storage device does is shift the idea of generation and consumption in real time. Therefore, it is an intermediary and should not pay for electricity when it is charging the battery, Mosna defended.
The director had previously expressed concern that maintaining the dual tariff could act as a "market annihilator" for technology in the country.
This public statement was made yesterday, March 3rd, during an event promoted by the Megawhat agency in Brasília. On that occasion, Fernando Mosna made it clear that his political assessment seeks to unlock the sector, opposing the strict revenue-collecting approach that still prevails in the agency's technical reports.
Market expectations
Mosna's position finds strong resonance among industry players. Associations such as ABSOLAR ABSAE argues that batteries should be treated as grid assets and not as the final destination of energy, referring to the model adopted in the United Kingdom, where charging only occurs at the time of injection.
Battery manufacturers emphasize that the transmission tariff model is the most decisive factor for the competitiveness of the technology in Brazil.
Market expectations are high, as the sector expresses the desire for the future auction for the technology, scheduled for 2026, to have a demand of around 5 GW.
The Ministry of Mines and Energy (MME) has already mentioned a minimum demand of 2 GW, but the viability of these projects depends directly on determining the cost of the transmission lines.
The Director of Operations at ONS, Christiano Vieira, who was present at the event in Brasília, also highlighted the importance of batteries in providing resilience and reliability to the system, helping to reduce curtailment and shift peak loads.
Long history
The trajectory of CP 39/2023 is marked by technical impasses and partial legislative progress. The process began in July 2023, with the opening of the original technical discussions.
The first major disruption occurred in August 2025, when director Fernando Mosna requested to review the case files precisely because he questioned the economic viability of the dual-tariff model proposed by the agency itself.
In December 2025, there was a legislative breakthrough with the enactment of Law No. 15.269/2025, which created the legal framework for storage, but was criticized for recognizing the activity without, however, indicating a solution to the tariff issue for the use of the network.
More recently, in February 2026, the technical area of ANEEL Technical Note No. 03/2026 was issued, maintaining the recommendation for double billing of TUST/TUSD, arguing that the 2025 law did not grant an express exemption.
Now, with the agenda confirmed for March 10th, the sector hopes that Mosna's dissenting opinion will end this power struggle and establish regulations that allow for the large-scale development of battery projects in the country.
In addition to the tariff issue, the ANEEL It will still need to regulate how the cost of batteries contracted for backup capacity will be distributed among the generators, as determined by recent legislation.
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Answers of 2
If a battery discharges energy into the grid, it must pay for the use of the grid.
Similarly, if the battery is charged via the mains, should you pay for the use of the mains or not? I believe so! This should be done even if it is surplus energy that is not usable at the moment.
Only in cases where charging is done via a solar panel, solar generator, or any other source, directly onto the battery, without using the grid, do I understand that no charge should be made for its use, since the grid is not being used.
Treating batteries as network assets, as ABSAE and the ABSOLAR The proposal (according to the article) is to link energy source to transmission/distribution. Doesn't this mean, among other things, returning to the vertical integration of the sector, something that has long been abandoned?
If they want to discuss incentives for the deployment of batteries, that's another matter...
Dear Sirs, once again our country is notable for the legal uncertainty that characterizes us. There is no doubt that energy storage has enormous potential to help address the problems afflicting the country regarding the lack of rain, especially in the headwaters of rivers, and other related problems. Are we or are we not a strange nation? Engineer and professor, Master of Science in Electrical Engineering, designer in solar generation and heating, energy efficiency and electric vehicle charging stations. WhatsApp and phone: (21)997716277.