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On January 14, 2026, the Federal Energy Regulatory Commission (FERC) accepted new rules proposed by Southwest Power Pool, Inc. (SPP) regarding the interconnection of High Impact Large Loads (HILLs) and the interconnection of new generation facilities that will be used to serve them, called High Impact Large Load Generation Assessment (HILLGA) in Docket No. ER26-247. This order, along with the recent order directing PJM Interconnection, L.L.C. (PJM) to propose rules for Co-Located generation and large loads, offer the first glimpse into how FERC will address the challenges facing the nation’s electricity grid. These include balancing resource adequacy, grid reliability, and fair cost allocation for any needed grid expansions to accommodate new AI-driven data centers.

FERC’s January 14, 2026 Order Accepting SPP’s HILL and HILLGA Processes

HILL Process—Requirements for Large Load Interconnections

FERC accepted SPP’s proposal to establish HILLs as a new category of load along with enhanced study requirements for HILLs that will allow SPP to assess the load’s reliability impact on the transmission system and new operational requirements to ensure continued reliability of the transmission system. A HILL is defined, in part, as:

A new or increased commercial or industrial load at a single site, connected via one or more shared POIs or delivery points, qualifies if it is (1) at least 10 MW on transmission systems at or below 69 kV, or (2) at least 50 MW on systems above 69 kV.

Transmission Customers requesting to add (or modify) a delivery point associated with HILL will have to undergo additional studies so that SPP can study the load’s impact on the transmission system. These studies, outlined in the new Attachment BA, will use more rigorous analyses than those in Attachments AQ or AX due to the potentially greater impact of large loads.

HILLs will also be subject to ongoing reliability requirements for non-conforming loads, including providing hourly load forecast data in real time. This will give the transmission operator remote disconnect capability from the transmission system, limiting up/down ramp rate that does not exceed 20 MW per minute, and complying with ride-through requirements.

HILLGA Process- Requirements for Generators Serving HILLs

FERC also accepted SPP’s proposed HILLGA process, which is an optional new generator interconnection service and related interconnection process that will expedite the interconnection of generating facilities that are specifically identified for, and limited to, serving a HILL. Unlike the Definitive Interconnection System Impact Study (DISIS) process that specifies a request window for generators requesting to interconnect with SPP facilities, requests to interconnect under the HILLGA process can be made any time. Along with the required study agreements, site control, and development milestones, HILLGA requests are subject to application fees and security deposits that are double those required in the DISIS process. The study deposits can reach up to $500,000 for HILLGA requests over 500 MW (versus the $250,000 cap for DISIS projects).

HILLGA interconnections are subject to several limitations to ensure that the generator can support the HILL in a localized area:

  • The point of interconnection can be no more than two substations away from the HILL.
  • A generating facility can support multiple HILLs if no more than five substations are involved and no more than two existing transmission line segments are used between each substation.
  • The Generator’s capacity accreditation MW value will be capped at the requested MW HILL load amount times the higher of either (1) 110% plus the highest approved Planning Reserve Margin percentage effective at the time of the HILLGA Study Agreement; or (2) 125%.
  • HILLGA requests will be reviewed in order but won’t have higher priority than DISIS requests, nor will they lead to additional costs or restudies for DISIS clusters. Since HILLGA studies follow a simplified process focused mainly on local injection within the HILL area, they require much less time than DISIS studies: system impact studies take 90 days, and any necessary restudies are completed in just 30–60 days.

HILLGA facilities will be granted a new limited type of interconnection service, called Load Limited Resource Interconnection Service (LLRIS), which allows interconnection solely to support the associated HILL. The maximum economic capacity operating limits of the HILLGA Customer’s facility will be limited to the hourly load forecast value of the corresponding HILL (except when directed by the SPP Reliability Coordinator to mitigate emergency conditions).

Finally, a HILLGA Interconnection Agreement (HILLGIA) and the corresponding LLRIS will automatically terminate five years after the commercial operation date of a generating facility. If the generator wants to remain interconnected beyond five years, it must submit a separate interconnection request through the DISIS process.

What This Order Means for You

FERC’s order accepting the new SPP HILL and HILLGA processes and the December 18, 2025 order directing PJM to create new rules around the co-location of generation and data centers (Docket Nos. EL25-49, AD24-11, EL25-20) mark significant steps toward clarifying and modernizing transmission and interconnection policy for large load interconnections and the generation to serve them. These orders will expedite the interconnection process, provide additional certainty to data center developers, and ensure that new generation can be interconnected expeditiously to meet the growing need for data centers. By establishing new transmission service options, revising interconnection procedures, and ensuring equitable cost recovery, FERC aims to balance reliability, fairness, and the evolving needs of energy consumers and generators.

Interested parties can expect additional guidance from FERC in the coming weeks. FERC is expected to issue a proposed rulemaking as directed by the Department of Energy (DOE) with additional direction on how it plans to shape the future of data center development in the U.S.