American Transmission Co. (ATC) projects its 2027 transmission network rate will decrease approximately 6% from the 2026 rate if the Federal Energy Regulatory Commission (FERC) approves pending filings addressing the costs of serving large new electric loads.

If approved, ATC expects to bill $138 million in 2027 related to large-load data center projects.

ATC’s proposal would assign transmission charges to large electricity users based on the capacity they request and the transmission service they receive. The proposed mechanisms are also intended to limit the risk that existing customers will bear costs if anticipated electricity demand from new projects does not materialize. Without these mechanisms, ATC’s 2027 network rate would be 16% higher than projected under the proposal.

“Growing electricity demand presents another opportunity to deliver sustained value to our customers and communities,” said Teresa Mogensen, ATC chair, president and chief executive officer. “By aligning transmission charges with the capacity and transmission service required to meet that demand, we can support economic growth, help keep downward pressure on transmission costs and continue investing responsibly in a safe, reliable and resilient grid.”

ATC’s pending filings include two mechanisms intended to address different stages of large-load development.

During construction, a Construction Work in Progress (CWIP) charge would cover financing costs and associated taxes for transmission facilities needed to serve qualifying large-load projects. Those costs would ultimately be assigned to the large customer.

After the facilities enter service, a Minimum Transmission Charge (MTC) would require new large-load customers to pay 100% of the costs incurred to build facilities needed to serve them. The MTC would apply only when regular network service payments do not reflect the full capacity requested.

ATC’s proposal accounts for both facilities built specifically to serve large loads and the use of the broader transmission network. The company’s federally regulated rates cover the costs of new and existing transmission facilities, while its local distribution company customers are charged based on their use of the transmission system. As more customers share the costs of the broader transmission grid, costs for existing customers can decrease.

The proposed mechanisms would apply to qualifying projects involving a new or expanded load of at least 100 megawatts or requiring $100 million or more in transmission facilities. They are intended to address cost-shifting risks during construction and after facilities enter service, including situations in which a project is canceled or substantially modified or its anticipated load does not fully materialize.

ATC’s projected 2027 network transmission rate also reflects a reduction of more than $100 million in costs that will be shared across the Midcontinent Independent System Operator (MISO) region for Multi-Value Projects built and owned by ATC, including the Grid Forward Project.

ATC said the proposed mechanisms are intended to support the allocation of transmission costs while maintaining a safe, reliable and resilient electric grid capable of serving existing customers and future electricity demand.