FERC issued the orders on 18 June, giving PJM, MISO, SPP, CAISO, ISO-NE and NYISO 60 days to justify their existing tariffs for connecting data centres and other large loads to the grid, or to propose changes.
The commission set a 45-day window, to 3 August, for operators to request abeyance instead: a pause of up to 90 days to develop proposals through their own stakeholder processes. The delays add to what is already one of the sector’s biggest limiting factors: grid infrastructure that hasn’t kept pace with AI-driven demand.
PJM filed its abeyance motion early, on 28 July. MISO, SPP, CAISO, ISO-NE and NYISO followed on 3 August, the deadline itself. The response has drawn broad support from industrial customer coalitions, Constellation Energy and state committees, with one exception: American Municipal Power opposed MISO’s request, arguing it fails to meet the standard FERC set for granting abeyance in the original order.
CAISO is the one operator to have moved to substance rather than delay. It published a straw proposal on 12 August answering its show cause order, offering two new flexible interconnection services and setting a 50 MW threshold for what counts as a large load. FERC granted CAISO’s abeyance request, capping it at 90 days and setting 16 November as the deadline for its enforceable Section 205 filing. The commission said it would look unfavourably on any request to extend that date.
The pattern points to a wider gap between FERC’s push for “speed to power” and the pace at which grid operators are able to move. FERC’s June orders were explicit that large load growth, driven chiefly by AI data centres, is outpacing the addition of new generation capacity in several regions. Yet with five of six operators opting to extend their own timelines rather than file reforms this month, the practical effect of the commission’s deadline has been to formalise further delay, not resolve it.
The outcome also underlines how uneven progress is across regions. PJM and SPP had already been credited by FERC for prior large-load reforms, including PJM’s co-location rules and SPP’s High Impact Large Load framework. MISO and NYISO, by contrast, are still developing basic large-load definitions through their own working groups — NYISO’s stall echoes the state’s own 12GW interconnection queue behind its hyperscale moratorium — and now have until mid-November at the earliest to formalise proposals.
For data centre developers, the abeyance wave means continued uncertainty on interconnection timelines in most of the country’s largest markets, even as demand for gigawatt-scale sites accelerates.
That uncertainty is already playing out in ERCOT’s own queue, where Texas has paused new approvals pending a 300-project audit and private capital has started underwriting the interconnection deposits that speculative requests now require. CAISO’s straw proposal offers the clearest near-term signal of what a revised tariff might look like, but its own terms remain non-binding until California’s transmission owners write conforming provisions into their own tariffs.
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