By end of June 2026, FERC has stated it will act on docket RM26-4-000 — the proposed rulemaking that would pull data centers, electric arc furnaces, and industrial campuses drawing ≥20 MW into a federalized interconnection process modeled on generator queues. With a single hyperscale data center demanding 20–300 MW and U.S. data center power demand forecast to hit 106 GW by 2035, the threshold would likely capture most hyperscale projects at the cited site-demand range.
June 2026 is a stated FERC action target, not a final-rule effective date or a binding buyer obligation. The proceeding was triggered by a rare DOE Section 403 directive and remains at the proposed-rule stage, subject to final rule promulgation and likely court challenges. For procurement teams already chasing transformer, switchgear, and gas turbine slots, the question is how to hedge equipment orders against both adoption and non-adoption scenarios while a 200 MW nameplate hyperscale campus moves through queue uncertainty that current state-led frameworks were not designed to handle.
Key Takeaways
- June 2026 action target, not effective date: FERC has stated it will act by end of June 2026 on RM26-4-000; the proceeding remains at the proposed-rule stage and is not yet a binding obligation on buyers.
- 20 MW threshold likely captures most hyperscale sites: loads ≥20 MW are in scope; with hyperscale sites at 20–300 MW each, most major hyperscale campuses would fall in scope if the threshold survives notice-and-comment.
- DOE 180-day clock: DOE directed FERC to begin rulemaking within 180 days under a rarely used Section 403 authority, per analyst summaries.
- Parallel approvals already in force: FERC unanimously approved the PJM co-location tariff change in December 2025 and a PJM emergency program covering roughly 50 ready-to-build projects — these are separate proceedings, not implementations of RM26-4-000.
- Open cost risk: transmission upgrade cost allocation is a contested issue in the docket — buyers should reserve contingency rather than assume socialization.
Rulemaking Status — Docket RM26-4-000 and the June 2026 Action Target
End of June 2026 is the procedural date FERC has fixed for itself, not the date any obligations attach. FERC has stated it will act by end of June 2026 on docket RM26-4-000, the proceeding that would establish federal procedures for interconnecting large loads to the interstate transmission system. The docket is currently at the proposed-rule stage, meaning no binding obligations attach to buyers or transmission owners until a final rule is promulgated and survives compliance and court review.
The procedural distinction matters. A stated action target is not the same as a final rule effective date, and analyst commentary confirms RM26-4-000 remains at the proposed-rule stage. Buyers should treat this as a pending regulatory pathway, not a settled framework.
June 2026 — the date FERC has stated it will act on a final rule, not the date any obligations bind buyers or transmission providers.
If adopted in the form proposed, the framework would extend FERC's reach over large electricity consumers in a way the agency has not historically exercised. The substantive consequence for procurement teams is that the regulatory pathway connecting a 200 MW nameplate data center load to the grid could shift from a state-led, utility-tariff process to a federally standardized one — but only if the rule is finalized and withstands challenge.
Any procurement model that assumes a single regulatory outcome carries asymmetric risk. Buyers placing orders for major substation equipment in the first half of 2026 will be doing so before the procedural posture changes, and the rulemaking calendar does not align with manufacturing lead times for transformers and switchgear. Treat the docket as a parallel input to procurement planning, not a gating one.
RM26-4-000 Procedural Timeline
| Date / Phrasing | Procedural Event | Source |
|---|---|---|
| October 2025 | DOE issued the ANOPR that triggered the proceeding | Power Magazine |
| Within 180 days of directive | DOE directed FERC to begin rulemaking proceedings | Beveridge & Diamond (analyst summary) |
| December 2025 | FERC unanimously approved PJM co-location tariff change (separate proceeding) | Associated Press |
| End of June 2026 | FERC has stated it will act on RM26-4-000 — action target, not effective date | Power Magazine |
| Downstream | PJM compliance filings and full activation referenced as later milestones | Power Magazine |
How We Got Here — DOE's Section 403 Directive and the 180-Day Clock
The DOE-directed timeline is the structural fact behind RM26-4-000's compressed schedule. According to a White & Case client alert summarizing the directive, DOE issued a Section 403 directive to FERC under the Department of Energy Organization Act — a rarely used authority that allows the Energy Secretary to direct FERC to consider specific regulatory matters. Per a Beveridge & Diamond analysis, DOE directed FERC to begin rulemaking proceedings within 180 days, establishing the procedural clock that produced the docket. Buyers underwriting against this timeline should consult the underlying DOE directive and the FERC docket materials directly; the law-firm summaries above are analyst context, not primary authority.
The substantive rationale: federal officials view existing state-led, utility-tariff processes for connecting large loads as inadequate for the pace of AI-era demand. U.S. data center power demand is forecast to hit 106 GW by 2035 — a 36% upward revision from prior forecasts. Georgia Power alone is seeking a 50% increase in capacity over six years, costing approximately $15 billion.
The Section 403 invocation accelerates FERC's calendar but does not change the legal standards a final rule must meet. The DOE directive can put a docket on FERC's agenda; it cannot guarantee a substantive outcome, and it cannot foreclose Administrative Procedure Act challenges. Legal challenges over FERC's jurisdiction are considered likely by counsel tracking the proceeding. Plan against rule timing slippage even if FERC meets its June 2026 action target — a final rule could still be stayed, remanded, or partially vacated.
What the Proposed Framework Would Do for Loads ≥20 MW
20 MW is the threshold, and the arithmetic against site-level demand explains its reach. The proposed framework targets loads ≥20 MW, primarily AI-driven data centers. A single hyperscale data center can demand 20–300 MW, which means the threshold would likely capture most hyperscale campuses in active development. Sub-20 MW edge and smaller enterprise sites would remain outside the federal framework.
If adopted, the proposed rule would significantly change how large loads connect to the grid. Ultra-large loads would be treated similar to power plants in the interconnection process — a 200 MW nameplate AI data center or new electric arc furnace would move through procedures historically reserved for generators, not customers.
20 MW threshold vs. 20–300 MW per hyperscale site — most hyperscale campuses would likely fall in scope if the threshold survives notice-and-comment.
The operational core of the proposed framework is standardization. The proposed rule would standardize and expedite interconnection agreements and studies for loads above the 20 MW threshold, introducing pro forma procedures analogous to generator interconnection. The jurisdictional shift is more contested: the proposed framework would extend the agency's reach over large electricity consumers in a way it has not historically exercised. State public utility commissions have traditionally retained primary authority over load interconnection within their jurisdictions, and that boundary will be tested.
For procurement, the practical question is what "like a generator" means in study scope and cost responsibility. Generator interconnection studies typically assign network upgrades to the interconnecting party. Until the final rule is promulgated, treat scope and cost responsibility as open.
Parallel FERC Actions — PJM Co-Location Tariff and Emergency Generation Program
These are separate proceedings, not implementations of RM26-4-000, and should be tracked on their own dockets. In December 2025, FERC unanimously approved a PJM tariff change for co-location deals — a final action that established a working framework for co-located generation-load arrangements within PJM under existing FERC-approved tariffs. Separately, FERC approved a PJM emergency program covering roughly 50 ready-to-build power projects to address near-term capacity needs in the mid-Atlantic. Buyers underwriting against either action should pull the relevant FERC order and PJM tariff filing directly, as the AP coverage cited here is secondary reporting on the approvals.
The AWS–Talen Energy arrangement is the highest-profile co-location reference point: AWS plans to co-locate data centers at Talen Energy's 2.5 GW gross capacity Susquehanna nuclear plant in Pennsylvania. Deals of this structure are the practical use case the PJM tariff change addresses.
The buyer implication: co-location and behind-the-meter pathways exist under approved frameworks today, independent of RM26-4-000. Developers do not need to wait for the rulemaking to pursue alternatives to standard grid-tied interconnection. The trade-off is that the approved PJM framework may itself be modified — directly or indirectly — by whatever FERC finalizes in June 2026, and behind-the-meter configurations without proper thresholds risk cost shifts that could be re-litigated.
Buyer Implications — Lead Times, Transmission Upgrade Costs, and Equipment Demand
Standardized procedures, if adopted, could accelerate ≥20 MW data center integrations by replacing inconsistent state and utility processes with a single pro forma queue. The procurement gain is conditional on adoption and on the rule surviving challenge. Buyers cannot bank study-timeline compression into a base-case schedule today.
Transmission upgrade cost allocation for co-located generators is a contested issue in the docket. Developers should plan for potential transmission upgrade cost increases under the proposed reforms, since assigning network upgrade responsibility to interconnecting loads would shift cost burdens that today are partially socialized through transmission rates.
Practical hedge: reserve contingency for cost-allocation shifts and assume neither full socialization nor full direct assignment in your base-case underwriting.
The procurement implication runs in both directions, in SecondWatt's view. If RM26-4-000 is adopted and accelerates ≥20 MW interconnections, more grid-tied projects would compete for substation transformers and medium-voltage switchgear inside a tighter window. If the rule is delayed or litigated, more developers are likely to pursue co-location and behind-the-meter alternatives — shifting emphasis toward on-site gas turbines, reciprocating engine sets, BESS, and step-up transformers serving private generation. Either pathway leaves long-lead equipment as the binding constraint.
As an advisory judgment based on current procurement engagements, long-lead equipment orders should not wait for the final rule. Transformer and switchgear delivery windows commonly run multi-year, and gas turbine slot availability has tightened materially as data center demand has accelerated — buyers should validate current ranges directly with OEMs and EPCs against their own project schedules. The bottleneck for the data center power buildout, in SecondWatt's assessment, is bounded by manufacturing capacity at least as much as by regulatory text.
Affected-Parties Matrix
Impact descriptions below combine cited regulatory mechanics with SecondWatt's reading of buyer-risk implications; treat the rightmost column as inference where the rule design is unresolved.
| Party Type | In-Scope Threshold / Trigger | Likely Impact If Adopted (inferred where noted) | Source |
|---|---|---|---|
| Hyperscale data center developers | Sites ≥20 MW; hyperscale sites 20–300 MW | Federalized interconnection procedures (sourced); potential direct cost responsibility for network upgrades (inferred from contested cost-allocation issue) | Power Magazine |
| Industrial loads (e.g., electric arc furnaces) | ≥20 MW transmission-tied | Treated similar to power plants in interconnection | Beveridge & Diamond |
| Co-located generation-load projects | Hybrid setups (e.g., AWS–Talen Susquehanna 2.5 GW gross capacity) | Standardized pro forma procedures (sourced); contested cost allocation (sourced) | AP News |
| Transmission providers / RTOs | PJM and peers | PJM compliance filings referenced as later milestone; specific implementation pathway is inferred | Power Magazine |
| Residential ratepayers | Indirect | Possible subsidization of data center growth depending on cost allocation design (sourced as possibility, not verified outcome) | Axios |
| State PUCs | Jurisdictional boundary | Federal reach extended in a way not historically exercised; preemption scope is open | ENR |
Risks and Open Regulatory Questions
Four risk vectors deserve explicit modeling. First, legal challenges over FERC's jurisdiction are considered likely. Any final rule asserting federal authority over large electricity consumers in a manner the agency has not historically exercised will face challenge from states, retail utilities, or ratepayer advocates.
Second, grid overload, reliability risk and ratepayer cost hikes are concerns if large new loads come online faster than generation and transmission. Secondary reporting has flagged a NERC reliability alert tied to rapid load growth; buyers underwriting reliability assumptions should reference the primary NERC assessment directly rather than rely on the secondary summary.
Third, cost shifts. Residential ratepayers could subsidize data center growth depending on rule design, and behind-the-meter configurations without proper thresholds risk cost shifts to other ratepayers.
Fourth, regional shortage exposure. Potential electricity shortages have been flagged for the mid-Atlantic region as data center growth outpaces new generation. Procurement teams in PJM should not assume regulatory action will resolve a supply-demand imbalance on the timeline of the rulemaking.
SecondWatt tracks pricing, availability, and procurement risk across generators, gas turbines, transformers, switchgear, and related power infrastructure. The Shadow Grid Tracker provides procurement-grade visibility into where rule outcomes will collide with equipment lead times.
What Buyers Should Do Now
Treat RM26-4-000 as a pending regulatory pathway, not a settled framework. Five concrete actions while the rule remains proposed:
- Run dual-scenario procurement models. Build a base case (rule adopted) and a delay/litigation case. Do not anchor equipment ordering on a single regulatory outcome.
- Lock in long-lead equipment now, where project economics support it. In SecondWatt's experience, transformer, switchgear, and gas turbine lead times commonly exceed the rulemaking's own action timeline. Waiting risks slot availability without delivering procedural certainty — validate current windows with OEMs against your own schedule.
- Evaluate co-location and behind-the-meter pathways under existing approved frameworks, subject to interconnection-study outcome. The PJM co-location tariff approved in December 2025 is a working framework today. Use the power system configurator to scope on-site generation alternatives.
- File or monitor comments in RM26-4-000. Buyers with material exposure to threshold design, cost allocation, or jurisdictional scope should be in the docket.
- Reserve contingency for transmission upgrade cost shifts, if the rule is adopted. [Developers should