FERC Rejects PJM Data Center Capacity Rules, Approves Large-Load Registry

The Federal Energy Regulatory Commission on Oct. 9 partially approved PJM Interconnection proposal to track large electricity users but rejected its proposed capacity requirements and emergency curtailment framework. The decision follows PJM’s warning that it could face a capacity shortfall beginning in the 2027/2028 delivery year due to data center load growth and the pace of interconnections.

Under its August 13 proposal, PJM sought to establish an Interim Resource Adequacy Service, requiring load-serving entities serving new large loads to designate new capacity equal to peak demand. Loads unable to meet this requirement could face consumption reductions during periods of insufficient resources. The filing also proposed rules for bringing new capacity into the market and excluding eligible new large loads from the Variable Resource Requirement curve beginning in the 2029/2030 delivery year.

The approved provisions establish a definition of large load and a Large Load Registry, effective Oct. 12, 2026. The definition covers demand of at least 50 megawatts at a single electrical site, aggregating affiliated facilities within a one-mile radius. The registry will help PJM track existing and planned large loads, forecast demand growth, and plan transmission infrastructure. PJM must submit a compliance filing within 30 days, removing references to the rejected frameworks. Access to registry information will follow existing confidentiality protections, with only aggregated data made public.

The rejected provisions however raised concerns about federal and state jurisdiction, particularly requirements affecting retail customer curtailment and arrangements that could establish retail rates. The order also questioned charging for capacity that PJM would not procure on behalf of the affected loads, whether designated resources could reliably serve the relevant locations, and the potential disruption of existing commercial agreements.

The decision leaves the grid operator without approval for its proposed mechanism to address the anticipated capacity shortfall, although the commission provided guidance for a revised filing.