Brazil will hold its first capacity reserve auction for battery energy storage in December 2026, but a dispute over who will pay project charges remains a key controversy among the government, Congress, and market players.
Speaking on the CNN television program Alta Voltagem, Engeform Energia Chief Executive Gilberto Feldman called the auction a long-awaited decision for the electrical sector. He emphasized, however, that discussion on financing the projects is far from a consensus.
Feldman said batteries are not a definitive solution for cuts to renewable power generation, known as curtailment. Even so, he noted that storage helps reduce the impact of cuts by offering greater flexibility for grid operations.
The auction design aligns storage projects with the model used for transmission assets, according to Feldman. Remuneration is based on equipment availability regardless of energy volume or electricity prices, requiring a facility only to be available for the National Electrical System Operator, or ONS, when needed.
Dispute over battery charges
Because batteries serve the entire electrical system, Feldman argued that costs should be paid through a shared charge by all consumers rather than solely by power generators. He stated that renewable generation companies already face financial losses from ONS production cuts, and imposing another cost could threaten the economic viability of new investments.
Current rules under Law 15,269 and draft bidding documents from regulator Aneel make generators directly responsible for paying battery charges. Associations in the wind and solar sectors have criticized the rule, arguing that storage benefits are systemic and should not be paid by a single segment.
However, shifting expenses to consumers faces resistance over concerns about higher energy tariffs. Industry experts noted that consumers may already bear other sector costs, such as potential curtailment reimbursements under government Ordinance 140.
Congressional proposal
With the debate unresolved, the National Congress is attempting to alter the statutory model. Bill 3,716/2026, reported by Congressman Arnaldo Jardim, seeks to change how batteries are funded before the auction inaugurates large-scale storage in the country.
