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Data Centres: Boom and Backlash
4AUG

PJM wants 50 MW loads curtailable

2 min read
10:53UTC

A Federal Register notice on 4 August opened comment on PJM's Interim Resource Adequacy Service, which would make loads of 50 MW and above curtailable as a condition of connection from June 2027.

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Key takeaway

PJM would make curtailment a standing condition of connection for loads above 50 MW.

PJM Interconnection, the grid operator that runs wholesale power markets across 13 Mid-Atlantic and Midwest states, filed at the Federal Energy Regulatory Commission (FERC, which regulates interstate electricity transmission) on 31 July under docket ER26-3380-000. The filing bundles the Reliability Backstop Procurement we covered with an Interim Resource Adequacy Service (IRAS), which makes loads of 50 MW and above curtailable as a condition of connection from 1 June 2027 unless they bring their own capacity. The Federal Register notice opening comment published on 4 August, comments close at 5pm Eastern on 21 August, and PJM asks for an effective date of 29 September⁠1.

PJM's capacity auction fell 6,623 MW short in July. That shortfall is the arithmetic sitting under both halves of the docket: one half procures backstop capacity, the other reduces the load the system has to guarantee.

Draw a line no source draws. IRAS writes curtailability into the terms of connection and stays there until FERC changes it, a market rule of indefinite duration. The Department of Energy's Section 202(c) grant to PJM, which let the operator cut backup-equipped data centres during a heat event, ran as an emergency order under statute, temporary and exceptional by design. Different instrument, different authority, different permanence.

For a developer, the practical consequence lands in the financing model rather than in the engineering. A load that accepts IRAS accepts curtailment as its ordinary condition of service, which changes the availability assumption a lender underwrites, and the escape route, bringing your own capacity, means generation on site or contracted firm supply. Comments close before the operator can know how many will take it.

Deep Analysis

In plain English

PJM Interconnection runs the electricity grid across 13 US states and Washington DC. On 4 August, the government's Federal Register published PJM's request to make any electricity user drawing 50 megawatts or more, enough to power tens of thousands of homes, subject to being switched off during grid stress unless it has its own backup power. The rule would take effect from June 2027 and would replace the emergency curtailment orders regulators have already used twice this year with a permanent, standing requirement.

Deep Analysis
Root Causes

PJM's 2027/28 capacity auction cleared 6,623 MW short of its reliability requirement in July, and a separate 6,831 MW shortfall against the 2028/29 delivery year is what PJM's reliability backstop auction, filed in the same docket as IRAS, is trying to close. IRAS addresses the demand side of that gap: rather than paying more generators to exist, as the backstop auction does, it makes large loads bring their own capacity or accept curtailment.

The structural driver behind both halves of docket ER26-3380-000 is the same shortfall counted two ways. PJM's reliability requirement has outpaced the generation actually connecting to its grid, which is why IRAS addresses demand while the backstop auction addresses supply, and neither alone closes the gap on its own.

What could happen next?
  • Precedent

    IRAS would convert emergency curtailment, used twice by DOE in 2026, into a standing condition of grid connection.

First Reported In

Update #13 · GPUs now collateral as Nebius borrows $775m

Scottish Government Planning and Environmental Appeals Division· 14 Aug 2026
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