Identified For and Limited to Serving a Large Load: FERC Accepts SPP's Processes for High Impact Large Loads

On January 14, 2026, the Federal Energy Regulatory Commission issued an order on two new processes the Southwest Power Pool had filed for its tariff. One is a study process for what SPP calls High Impact Large Loads, or HILLs. The other, the HILL Generation Assessment, or HILLGA, is an expedited study process, with a new and limited interconnection service, for generating facilities that support such a load. The order accepts both, "effective January 15, 2026, as requested, subject to condition." The condition is a compliance filing within 30 days that corrects a list of ministerial errors. Parts of the order follow, not the whole.

Why SPP Asked

In the order's account, SPP "states that it is experiencing an unprecedented surge in requests for large-scale load interconnections to its transmission system from data centers, cryptocurrency mining operations, electrification of industrial processes, and other energy-intensive" facilities. Requests from large loads of over 100 MW peaked in 2022 at nearly 11 GW, SPP says, then fell to approximately 6 GW in 2024. That drop, according to SPP, "could be due in part to SPP's inability to study and interconnect large loads quickly enough to meet their commercial needs."

Large load developments, SPP contends, "frequently request transmission service within months rather than years of their intended commercial operation," and large load customers are "requesting faster deployment timelines for generating facilities supporting the load compared to typical interconnection study timelines."

What Counts as a High Impact Large Load

A HILL, in the definition SPP proposed and the order accepts, is a new or increased commercial or industrial load at a single site of 10 MW or more where it connects at 69 kV or less, or 50 MW or more where it connects at a higher voltage. "An Electric Storage Resource is not considered a HILL." Existing loads are not HILLs unless they seek to increase load and otherwise meet the definition.

Every request for a HILL needs a HILL Delivery Point Study, "a broader, more rigorous set of analyses compared to those under Attachment AQ or Attachment AX," the tariff's existing processes for studying a delivery point addition or modification. The customer must send back a study agreement with a $10,000 non-refundable application fee and a $100,000 deposit within 30 calendar days, unless otherwise agreed, or SPP treats the request as withdrawn. A HILL must also meet ongoing requirements, among them telemetry in real time, a remote capability to disconnect the load made available to the transmission operator, and "an up/down ramp rate not exceeding 20 MW per minute unless otherwise directed." The Commission finds that the study deposits "will help discourage speculative HILL study requests."

Generation That Comes With the Load

HILLGA is optional, and SPP proposed it "to facilitate the prompt interconnection of generating facilities that are specifically identified for and limited to serving a HILL." A request needs, among other things, a study deposit of $250,000 for up to 500 MW and $500,000 above that, a security deposit of $8,000 per megawatt of requested injection capability, site control, and a commercial operation date within five years of signing the study agreement.

What it gets is a new kind of service, Load Limited Resource Interconnection Service. Under it, the generator's maximum economic capacity operating limits "cannot exceed the hourly load forecast value of the corresponding HILL except when directed by the SPP Reliability Coordinator to mitigate emergency conditions or as specified in the HILLGIA." The service ends five years after the generator's commercial operation date. A generator that wants to stay connected beyond that must go through SPP's standard interconnection process, and the service "does not convey any type of transmission service."

The generator is let in for its load and for five years. After that, staying connected means the standard line.

Not Higher Queued

SPP proposes "to accept HILLGA Requests at any time and complete the entire HILLGA process within 150 days, which is a significantly faster timeline than the current DISIS process, which, as designed, takes 12 months to complete." DISIS is SPP's standard study process for generators. "At the same time, HILLGA Requests will not be considered higher queued than pending interconnection requests in the standard DISIS queue and will not appear in the DISIS models until such models have been updated to include new ITP models," ITP being SPP's Integrated Transmission Planning. SPP also says the process will not affect the timing of pending standard requests, because outside consultants paid for through the customers' study deposits will do most of the work.

A concurring statement by one commissioner, attached to the order, says the proposal also encourages bring-your-own-new-generation solutions in SPP, a phrase it sets in quotation marks, and that the two processes "work together to pair shovel-ready generation with large loads and allow them to interconnect to the grid in less than half the time typically required for generators to clear SPP's generator interconnection queue." That is one commissioner's statement, not the order's finding.

SPP says it will monitor the processes as it monitors every service under its tariff. What becomes of a large load's supply when its generator's five years run out?