​On July 14, 2026, PJM released the results of its capacity auction for the June 1, 2028–May 31, 2029 delivery period.

Prices cleared at the legislated maximum for a third consecutive auction, holding at $325/MW-day. Reliability requirements continue to outpace available generation.

The cleared price is a 2.5% drop from the prior auction's $333/MW-day, but the muted decline is attributable only to a lowered cap rather than any reflection of easing system conditions.

For batteries, capacity revenue per MW-day held steady. A four-hour system earns about the same as it did in the last auction, holding onto the 17.5% gain it captured for 2027/28.

Without the cap, the 2028/29 auction would have cleared at $555/MW-day

PJM sets its clearing price where offered supply meets a predetermined demand curve. When supply falls short of the reliability target, the price climbs the curve until it hits a regulated cap.

For the third auction running, the clearing price hit that cap. All four load zones cleared at the same $325/MW-day, with no locational separation.

Without the cap, the picture changes. PJM's own simulation shows the auction clearing at $555/MW-day, 71% higher. ComEd alone would have separated to $777/MW-day. That uncapped market would have cost $29.7 billion, against the $16.4 billion buyers will actually pay.

The uncapped price sat 18% above the cap for 2026/27, then 59% above for 2027/28, and 71% above now. Administrative suppression is widening, not easing.

Cleared capacity fell 6.8 GW short of the reliability requirement

PJM needed 156 GW of unforced capacity to meet its one-day-in-ten-year reliability standard. It procured 149 GW, 138 GW through the base auction and 11 GW through additional regional procurements. The 6.8 GW shortfall is wider than the prior auction's 6.5 GW shortfall.

The reserve margin gap also reflects system scarcity. Total installed capacity covered 14.7% above peak load, against a 20% target. This is the second consecutive auction to fall more than a percentage point short.

Demand is driving the gap. PJM's forecast peak rose about 2,000 MW from the prior auction, led by continued data center growth. New generation and uprates added just 525 MW of UCAP. New supply is barely moving while load climbs.

ELCC class ratings changed, as did the cleared resource mix

Each technology earns capacity credit through its Effective Load Carrying Capability (ELCC), the share of nameplate capacity that reliably shows up at peak load. PJM re-rates every class each auction, signaling which resources it counts on for reliability.

Wind took the deepest cut. Onshore fell from 41% to 34%, offshore from 67% to 60%. Thermal ratings rose across gas and coal. Four-hour storage edged up from 58% to 59%.

The cleared mix shifted too, though not only because of the ratings. Coal fell 2.9 GW to 18% of the fleet, primarily from planned deactivations. Natural gas cleared 5.6 GW more UCAP and now makes up 46%, driven by higher accreditation, units switching to gas, and previously excepted units returning to the market.

Battery participation keeps rising, but returns have stabilized

Batteries recorded another large jump in participation. They offered 205 MW of UCAP for 2027/28 and 478 MW for 2028/29, an increase of 133%. Assuming four-hour systems, that is roughly 810 MW of nameplate capacity, up from about 350 MW.

Battery revenue held onto the prior auction's gains. A hypothetical four-hour battery clearing this auction would earn about $192/MW-day ($69,989/MW-year) at the $325/MW-day clearing price.

The same asset earned $193/MW-day ($70,591/MW-year) for 2027/28, a difference of less than 1%. After the 17.5% jump in that auction, capacity payments for storage have settled at a new, higher level, with the improved ELCC offsetting the lower cap.

What PJM is doing about the crunch

Three straight auctions at the cap have pushed PJM and policymakers toward new tools. The near-term fixes are stopgaps: emergency backstop auctions, curtailment rules for large new loads, bring-your-own-generation incentives, and fast-track interconnection.

The longer-term question is whether the capacity market survives in its current form. PJM has floated three structural redesigns, from mandatory long-term hedging to shrinking the market into a backstop while energy-market scarcity pricing does more of the work.

Batteries gain from both. Speed-to-market rules favor storage now, and a shift toward energy-market volatility would reward it later.

PJM needs more capacity than the market is delivering. Until supply catches load, prices will keep pressing the cap, and storage is placed to capture a growing share of the response.