Brazil hits 56 GW of connection headroom for battery auctions

Brazil’s National Electric System Operator (ONS) estimates about 56 GW of remaining grid connection capacity for battery energy storage systems (BESS) in upcoming capacity reserve auctions, based on Technical Note 0095/2026. The headroom is calculated at substations nationwide, with priority given to locations under MME Ordinance No. 136/2026. The ONS assessment measures available capacity at specific grid points to determine eligibility for the December 2 and 4 auctions.

The Brazilian Association of Energy Storage Solutions (Absae) highlights that 93 of 129 designated substations have available connection capacity, primarily in Bahia, Piauí, Ceará, and northern Minas Gerais. Individual substations offer up to 3.7 GW of headroom, while others share smaller blocks or face constraints due to space or technical limitations. Projects are ranked by substation and area, with strategic substations receiving a 10% price bonus to encourage grid-supporting battery installations.

Absae notes that the planned battery systems could function as grid-forming assets, enhancing voltage stability and reducing reliance on synchronous condensers. Connection headroom at non-preferred substations totals about 36 GW, expanding the pool of eligible projects beyond the 13.7 GW at preferential locations. The association emphasizes that the distribution of capacity across regions lowers the risk of widespread grid constraints during the auction process.

Brazil’s Energy Research Office (EPE) received 6,091 project registrations for the auctions, totaling 296.8 GW of capacity. While technical analysis will reduce the number of qualified projects, Absae expects competition to remain high due to the large pool of registrations and available connection headroom. The association suggests that price will likely be the key differentiator among bids, benefiting consumers as the sector meets auction deadlines.