FERC Accepts PJM's Large Load Definition and Registry, and Rejects Its Other Proposed Tariff Revisions

On October 9, 2026 the Federal Energy Regulatory Commission issued its order on a proposal PJM Interconnection filed on August 13. PJM states that, "beginning in the 2027/2028 Delivery Year, it will be short of sufficient capacity to meet the PJM Region Reliability Requirement, particularly due to data center load growth and the pace of data center interconnection." The proposal's elements, the order says, are "intended to address the capacity shortfall."

The commission accepted a definition of Large Load and a Large Load Registry, effective October 12, 2026, as PJM had asked. It rejected PJM's remaining proposed tariff revisions. Parts of the order follow, not the whole.

What PJM Proposed

The proposal included a new service, the Interim Resource Adequacy Service, which the order shortens to IRAS. Underpinning it was a new obligation on load serving entities, defined in a footnote as, among other things, entities "serving end-users within the PJM Region." One that uses Network Integration Transmission Service, or NITS, a firm transmission service, to serve a New Large Load would have to designate new capacity resources "in an amount at least equal to the load's peak demand." If it failed to designate sufficient capacity resources, the New Large Load would be "subject to load reduction requests" when there are insufficient resources to reliably meet demand in real-time operations.

PJM's own filing, as the order quotes it in a footnote, says that IRAS, "as proposed, is a service that specifically allows for Large Loads to interconnect without bringing their own capacity, on the condition that they must reduce their load or switch to on-site backup resources under specific, limited emergency conditions."

The new capacity had a name of its own, Bring Your Own New Capacity, or BYONC: a new category of capacity resources "that may be designated to address the needs of New Large Loads." PJM states that BYONC "would include new UCAP and eligible generation, storage, and eligible demand-side resources that satisfy gating criteria demonstrating their newness to the capacity market and PJM system," with UCAP, unforced capacity in the order's terms, "fixed when the resource first clears." A New Large Load, in the proposal's definition, included a Large Load "that goes into service after June 1, 2027." Most of the revisions, the order says, were not intended to take effect until that date.

The Definition and the Registry

The definition the commission accepted makes a Large Load any end-use customer load with a cumulative peak of 50 MW or greater at a single electrical site behind one or more points of interconnection. All affiliated load facilities "within a one-mile radius" count as a single electrical site, as further described in PJM's manuals. The commission agreed with PJM that this will preclude, for example, a scenario where a data center load "is not categorized as Large Load simply because the owner has elected to site a number of smaller data centers," each below the threshold, close together.

Some protesters wanted the definition to cover data centers alone. The commission disagreed, and found reasonable PJM's proposal "to include all types of large loads in the Large Load definition."

The registry will require load serving entities to give PJM information about the Large Loads they serve. The commission found it will "enable PJM to better forecast load growth and to plan and manage its transmission system."

The order gave PJM 30 days from October 9 for a compliance filing that carries the definition and the registry, and none of the language of IRAS or BYONC.

IRAS and BYONC

The commission wrote that it recognizes "the imminent capacity shortfall in PJM." It found that "two key aspects of PJM's proposal," IRAS and BYONC, "are either outside of the Commission's authority or have not been sufficiently demonstrated to be just and reasonable and not unduly discriminatory or preferential." It added that it does not take this decision lightly.

On retail rates, the eligible loads are, the order says, "for the most part, retail customers," and the law leaves the regulation of retail sales to the states. It found that the tariff language "appears to place obligations directly on the Eligible New Large Loads and requires Electric Distributors to curtail the Eligible New Large Loads." By setting a compensation rate payable to those loads, the proposed tariff also "appears to impermissibly set a retail rate." The commission pointed to "significant discrepancies between PJM's transmittal letter description of its proposed IRAS framework and its proposed Tariff revisions." The proposal as that letter described it "may be within the Commission's jurisdiction," the order says. Its finding was on the plain language of the tariff.

On undue discrimination, the order notes that PJM's capacity market has historically treated all load taking NITS comparably. PJM, it finds, "has not at this time produced evidence sufficient" to show how the characteristics of these retail customers are material to the resource adequacy challenges its proposal seeks to address.

On BYONC, the commission found that PJM had not sufficiently justified locking in a resource's capacity accreditation over the lifetime of the arrangement. The risk that a locked-in value "be higher than the capacity that it can actually provide," it wrote, "has the potential to create a new resource adequacy risk for the entire PJM Region."

The commission found the remaining elements "inextricably linked." So it rejected "the entirety of the package."

The order does not dispute the shortfall. It sends back the tool PJM built for it.

If PJM Refiles

The order lists concerns it encourages PJM to address should it refile. Describing PJM's affidavit, it says NERC's Energy Emergency Alerts have three levels, "with an EEA3 being the highest alert level." The order says the mandatory standard EOP-011-4 only permits firm loads to be curtailed following initiation by the reliability coordinator of an EEA3. PJM's proposal would curtail certain load "earlier in the emergency process, at EEA1, when all generation is committed and non-firm wholesale energy sales have been curtailed." The proposal, the order says, "would shed firm load on an involuntary basis."

It questions why load serving entities would be charged for capacity for Eligible New Large Load "when PJM does not procure capacity on behalf of that load." And it notes that the proposal "may disrupt existing commercial arrangements," as the record suggests. The proposed tariff "appears to treat existing NITS customers differently even on the basis of small MW increases," the order says, "such that a 49 MW existing load that increased its consumption by 1 MW would become a 50 MW New Large Load and impose new requirements on the existing NITS customer for the entire 50 MW."

The order also says that a non-firm transmission service similar to the Non-Firm Contract Demand service, proposed in the commission's show cause proceeding on co-located load, "with appropriate adjustments, might be considered as a potential avenue to achieve some of the aims" of IRAS. It notes a difference: that service "is affirmatively a voluntary option, while the product or service here is not." And it says states "have a crucial role to play in this challenge by designating which retail customers must be curtailed when the system is stressed."