PJM backstop auction targets a past deficit as gas turbine backlogs slow the capacity response to future data center load
A one-time 6.8 GW procurement addresses last auction's shortfall while 65-90 GW of projected data center additions through 2029 remain outside the procurement scope.
PJM Western Hub spot power reached $119.29/MWh on Wednesday (2026-09-09), sitting well above most summer planning assumptions even as the consensus market view on PJM real-time runs 77% weighted bearish. Most of that bearish positioning treats data center demand as a cost story, one already priced through the capacity market. The September backstop auction, now the central event traders are tracking, was designed to address a specific past deficit, not the load growth still in the pipeline.4
Joseph Bowring, president of Monitoring Analytics, PJM's independent market monitor, told Utility Dive on July 20 (2026-07-20) that data centers drove $6.3 billion, or 38%, of the $16.4 billion in charges from the grid operator's most recent base capacity auction. Across PJM's last four base capacity auctions, data center-driven charges totaled $29.4 billion, representing 46% of the $63.6 billion collected over that period.4
PJM moved up its backstop reliability auction to September, E&E News reported on May 21 (2026-05-21), rather than waiting until 2027. The PJM board proposed on July 28 (2026-07-28) to procure around 6.8 GW, the shortfall from the last base capacity auction, alongside curtailment provisions for large industrial loads. Charles River Associates was hired to run a bilateral matchmaking process, with eligible resources required to be online by June 1, 2032.2,5
But critics flagged a design gap in that proposal. According to the PJM board's July 28 (2026-07-28) filing, one objection was that an auction targeting only a past auction's deficit fails to address "new large loads which have yet to materialize." Grid Strategies projected, in material cited by Datacenter Dynamics on May 19 (2026-05-19), that US data center capacity would grow by at least 65 GW and as much as 90 GW by 2029. A 6.8 GW one-time procurement does not reach that range.5,1
The supply response that PJM approved is also less certain than a greenlight implies. Canary Media reported on August 24 (2026-08-24) that PJM cleared a substantial tranche of new clean power through its interconnection queue. Yet manufacturing backlogs for gas turbines and competition for engineering and construction firms are pushing new gas plant completions well past the schedules that backstop resources would need to meet. Battery storage reaches operation faster, but earns less in PJM's capacity market than gas capacity does, which makes the project economics difficult to underwrite at the volumes needed.7
The regulatory picture compounds those timelines. US regional grid operators requested an extension on the FERC transmission upgrade directive originally issued in 2021, a delay that Datacenter Dynamics reported in May (2026-05-19) could have material consequences for data center siting and power contracting. On August 5 (2026-08-05), Canary Media reported that PJM's approach to managing data center integration effectively delegates hard procurement decisions to individual states, a structure that cannot align transmission investment with the multi-year development horizons that large new loads require.1,6
MISO data introduce a separate pressure. MISO logged 17 GW in incremental unplanned outages against a 108 GW peak demand period, pushing the MISO real-time signal to a bullish contrarian position relative to PJM's bearish consensus. Sustained unplanned outages in a neighboring footprint narrow the export margin available to PJM dispatchers when demand peaks in their own territory, and that kind of tightness tends to surface in real-time prices before capacity market instruments move.3
The September backstop clearance will offer the first measurable read on whether there is enough committed supply at prices that can support delivery by 2032. Gas turbine lead times, now extending well beyond the development cycles backstop resources would need to meet, are the operational variable to track after the auction settles. A thin clearance in volume or weak price discovery would be the signal that PJM's formal procurement mechanism is running behind its actual load trajectory.5,7