ISA Energia raises a red flag regarding data center expansion on the transmission grid.
The rapid expansion of data centers in Brazil has created an unexpected bottleneck in energy infrastructure. ISA Energia Brasil, a player in the transmission sector, has submitted a request to the National Electric Energy Agency (Aneel) seeking clear guidelines on the priority order for connecting large consumers to the Basic Grid. The concern arises in situations where the National Electric System Operator (ONS) issues technical feasibility reports, but the physical capacity of substations proves insufficient to meet the demand of all projects.
The core issue lies in the difficulty of reconciling the issuance of multiple access opinions with the actual physical space available at transmission facilities. This scenario has become more critical given the growing volume of connection requests for large-scale projects, especially those focused on data center operations, which require a high and constant power supply.
The Anhanguera Substation Case: An Imminent Warning
An emblematic example was presented by ISA Energia regarding the 345 kV Anhanguera substation, which falls under its concession. The ONS had issued four access opinions for the Basic Grid to various data center projects, including developments by Odata Sampa and Data Center Rodoanel. The requests were filed within a short interval, between May 27 and 29, 2026.
Initially, ISA Energia’s analysis indicated physical space for the installation of two new connection modules. However, after the four opinions were issued, the transmitter’s detailed studies revealed that, considering GIS (Gas Insulated Switchgear) technology, the substation could only accommodate two connections. Physical capacity, therefore, became a limiting factor, unable to accommodate all connections covered by the documents issued by the ONS.
Proposals for an Ordered Connection Process
Given the absence of specific regulatory rules for such dilemmas, ISA Energia has been adopting the chronological order of the requests as the criterion for defining priority. However, the company is seeking validation from Aneel regarding the adequacy of this procedure. Questions were raised about defining priority when multiple requests are filed on the same day, and whether a preliminary inquiry regarding physical availability grants priority to the interested party, even if the formal request is made later.
Additionally, the transmission company inquired whether a consumer who does not obtain connection priority could, at their own risk and expense, propose and fund alternative solutions to enable their access, bypassing other similarly sidelined parties.
Impact and Next Steps
The demand for power by data centers is a reality that drives the sector and innovation, but it requires robust planning and coordination among all agents in the electrical system. ISA Energia’s statement is a call to action for Aneel and the ONS to establish clear and transparent criteria.
Defining consistent guidelines is fundamental to ensuring the security and reliability of energy supply, while simultaneously fostering the growth of strategic sectors like information technology, without compromising transmission infrastructure for other consumers or the overall development of the power sector. The regulatory agency’s response and the potential creation of new regulations will shape the future of large-scale consumer expansion on the Brazilian transmission grid.