Mercado de baterias elétricas vive boom de vendas

Electric energy storage systems, known by the acronym BESS, are selling like never before in the country. While the government's auction for large battery project contracts is scheduled for December but faces uncertainties, the market has found its path in retail. Smaller installations in industries, businesses, condominiums and residences, often associated with rooftop solar systems, have propelled the industry at record pace.

In 2025, the volume sold and contracted reached 730 MWh, more than the combined five years prior. In the first half of this year, it was another 504 MWh, on track for a new historical mark for the sector, according to a Greener consultancy survey. "The auction is important, of course, but the distributed BESS, let's call it that way, will be in my view one of the big sources of flexibility for the electric system in the country," Marcio Takata, Greener CEO, told Brazil Journal.

He drew a comparison with the solar energy industry, which began moving with government auctions for large projects and in the following years had a burst forward driven by the market of small installations on rooftops and minigrids. Distributed solar generation capacity today amounts to more than 53 gigawatts, compared to 23.6 gigawatts in centralized generation plants, according to data from the National Electricity Agency (Aneel).

Currently, accumulated capacity in battery systems in the country represents 1.9 GWh, with companies including WEG and Grupo Moura betting on the sector. The auction scheduled for December is expected to contract at least 2 gigawatts for daily operation of 4 hours, according to signals from Brasilia, equivalent to 8 GWh – although part of the market expects larger volumes.

The Ministry of Mines and Energy also plans annual auctions until 2029 for capacity reserve contracts, which will have space for battery systems. However, these tenders will promote a technology dispute with thermal power plants and hydroelectric plants, including so-called reversible hydroelectric plants – which in practice function like a battery by storing water to produce more when the system needs it.

Contracting this capacity reserve is seen as important to help the power grid cope with the variation of wind and solar generation, which sometimes results in excess energy, forcing plants to forced shutdowns known as curtailment. "Today the hottest topic in the sector is batteries. And reversible hydroelectric plants. Because of this need for the system," said André Millions, director of consulting firm Thymos Capital.

Despite intense investor interest, the December auction is at risk due to discussions about who will pay the cost of storage projects, according to various industry sources. The current legislation defines the distribution of costs among all generation companies, a rule that generates threats of judicialization. At the moment, sector companies are moving to convince the government to work for the approval of a project by deputado Arnaldo Jardim that would alter the law to pass the bill to consumers, as occurs in other energy market auctions.