PJM Interconnection
US grid operator; 2027/28 capacity auction cleared 6,623 MW short of its reserve target.
PJM Interconnection, the largest US grid operator, opened a backstop capacity auction on 31 July at a $555/MW-day cap to close a 6,831 MW shortfall against its 2028/29 reliability requirement.
Last refreshed: 4 August 2026 · Appears in 1 active topic
PJM's capacity auction fell short years ahead of delivery - is the grid already overcommitted?
Timeline for PJM Interconnection
Mentioned in: Five grid operators miss FERC deadline
Data Centres: Boom and BacklashFiled a curtailment rule for 50 MW-plus loads at FERC under docket ER26-3380-000
Data Centres: Boom and Backlash: PJM wants 50 MW loads curtailablePJM's backstop auction opens at $555
Data Centres: Boom and BacklashFell 6,623 MW short in its 2027/28 capacity auction, setting a 21 July procurement deadline
Data Centres: Boom and Backlash: PJM auction falls 6,623 MW shortFERC sets a 20 July adequacy deadline
Data Centres: Boom and BacklashBackground
PJM Interconnection is the largest regional transmission organisation in the United States, coordinating electricity transmission across a 14-state region plus Washington DC, including Northern Virginia, the world's largest data-centre market. Founded in 1927 as the Pennsylvania-New Jersey Interconnection and designated an RTO by FERC in 2001, it now manages roughly 182 GW of generating capacity over 88,333 miles of transmission line.
Data-centre demand has driven roughly 5% annual load growth across PJM's territory since 2024, straining a grid built for slower growth. The Department of Energy has invoked emergency Section 202(c) authority three times in 2026 to force large PJM-area data centres onto backup generation during heat emergencies, the first such curtailment of data-centre load in RTO history.
That pressure has pushed PJM into the centre of a federal reckoning over who pays for grid expansion driven by co-located computing load, with FERC's RM26-4-000 rulemaking treating PJM's tariff filings as the template other US grid operators will be measured against.
PJM opens a backstop capacity auction
PJM's 2027/28 capacity auction cleared 6,623 MW short of its reliability requirement, so on 31 July it filed with FERC for a one-time backstop auction running 30 September to 21 October at a $555/MW-day price cap, well above the $325 base cap. The backstop targets a 6,831 MW gap against the 2028/29 delivery year, a shortfall Utility Dive separately estimated could cost up to $20bn through 2027.
The shortfall sits inside a wider federal process: FERC's RM26-4-000 docket required PJM and five peer grid operators to file generation-adequacy reports by 20 July, and PJM's own show-cause response on large-load tariffs is due 17 August. PJM's board separately warned 13 governors in May that reinforcement costs could land on household bills unless states set cost-allocation rules first.
PJM opens a backstop capacity auction
Why did PJM's 2027/28 capacity auction fall short?
What is the FERC show-cause order served on PJM in June 2026?
How much new generating capacity has been added to the US grid to handle data-centre growth?
Why has PJM's capacity auction cost risen eightfold?
Did PJM actually switch off data centres in 2026?
What is PJM Interconnection and why is it important for data centres?
Why is PJM's electricity grid struggling with data-centre demand?
Reference
What states are in the PJM grid region?
What happens if PJM's capacity shortfall is not resolved before 2027/28?
How many times has the DOE ordered PJM to curtail data centres in 2026?
Written with AI from Lowdown's published reporting. Not individually reviewed by an editor. Updated 4 August 2026. Editorial standards.