New supply is building faster than PJM's capacity shortfall implies
PSEG enters bilateral data center contracting and PJM accelerates its backstop auction to September, pressuring the bullish case for 2028/29 power prices.
PJM Western Hub spot power was trading at $78.03/MWh on Wednesday (2026-08-12), with the market still priced around the assumption that capacity stays scarce into the late decade. The setup for that view is well-documented: PJM's 2028/29 capacity auction came up 6.8 gigawatts short and cleared at the $554.72/MW-day regulatory cap across most zones, with the COMED local delivery area hitting $776.69 — and PJM's own independent market monitor calculated that absent the cap, prices would have been 70% higher.5
The demand case looks equally airtight. PJM load hit roughly 163 gigawatts on Thursday (2026-07-02) during a mid-Atlantic heat dome, falling just short of the grid's 2006 all-time peak of 165,563 megawatts. Operating reserves collapsed to 5,091 megawatts that day from 10,996 megawatts a day earlier. Monitoring Analytics, PJM's independent market monitor, tied 63% of a $9.3 billion ratepayer cost run-up to data center demand.4
But the supply response is accelerating in ways the auction price alone does not capture.
Public Service Enterprise Group's unregulated generation arm said on Tuesday (2026-08-04), during an earnings conference call, that it was actively exploring bilateral supply contracts with data centers through PJM's backstop reliability initiative. PSEG is not a peripheral actor. Its decision to pursue direct data center contracting signals that large incumbent generators now see the bilateral market as commercially attractive — which should bring more capacity to bear than a centralized auction alone would produce.8
PJM is simultaneously pulling forward its timeline. The grid operator announced plans to move its backstop reliability auction to September this year, abandoning a 2027 schedule. "Waiting until 2027 to execute the centralized procurement, considered too long," PJM said, per E&E News reporting.1 Stakeholders had already approved the two-part backstop structure on Tuesday (2026-06-30), opening participation not just to utilities but potentially to data centers acting as their own load-serving entities.3 Qualifying supply includes new gas plants, solar, wind, batteries and demand response, a wider pool than the standard auction process has historically attracted.7
The bullish gas demand thesis also deserves scrutiny. Atlantic Council analysis found that even a massive 4-to-6 gigawatt data center complex consumes roughly 1 billion cubic feet per day of natural gas, depending on turbine efficiency.2 That is a meaningful regional increment, not a structural shift in fuel markets. NYMEX Henry Hub front-month gas was unchanged Wednesday (2026-08-12) at $2.79/MMBtu, suggesting fuel costs are not yet transmitting additional upward pressure into PJM power prices. The Atlantic LNG arbitrage would need to tighten considerably before European gas benchmarks move in response to US data center gas demand, and that chain is not currently live.2
There is also a demand-flexibility angle that receives little attention. The same Atlantic Council research noted that data centers could curtail inference workloads during high-demand periods and that some operators are already repositioning facilities as demand-response assets capable of responding to price signals.2 If even a fraction of the large-load data center capacity queued in PJM is dispatchable downward at peak, the effective peak the grid must plan around is smaller than gross demand numbers imply.
The structural backdrop shows how badly the supply response has lagged. Just under 4 gigawatts of new capacity entered capacity auctions since 2024, against roughly 20 gigawatts across the five prior auctions.6 The September backstop is the mechanism designed to close that gap faster than the normal three-year procurement cycle allows.
If September's auction draws large commitments from generators including PSEG, the 6.8-gigawatt shortfall underpinning the current spot price starts to look less durable. Watch the participation rate and volume of capacity committed when PJM publishes those results in the fourth quarter — that is the number that tests whether the supply build is genuine or still prospective.1,5