PJM Interconnection's capacity market exists to guarantee enough generation is under contract to keep the lights on. Its own \" 2027/2028 Base Residual Auction Reserve Target Shortfall Report,\" dated February 9, 2026, disclosed a shortfall of 6,517 MW of unforced capacity against the reliability requirement — an installed reserve margin of 14.4% against a 20% target, the first time in the capacity market's history the full RTO missed its target.[1] Five months later, PJM's own July 14, 2026 release confirmed the following auction, for the 2028/2029 delivery year, came in short again: 6,831 MW below target, a 14.7% margin — a second consecutive shortfall, and a larger one in absolute terms.[2] This isn't a single bad auction. It's a market mechanism specifically designed to guarantee reliability missing its own target twice in a row, with the gap widening rather than closing. This case documents the shortfall as PJM itself disclosed it — not a projection or an outside estimate.
PJM's capacity market runs an annual Base Residual Auction three years ahead of delivery, designed to lock in enough generation to meet a 20% installed reserve margin above expected peak demand — a buffer specifically sized to keep the grid reliable even under stress. PJM's own February 9, 2026 report on the 2027/2028 delivery year disclosed the auction cleared at a 14.4% installed reserve margin — 6,517 MW of unforced capacity short of the 20% target.[1] PJM's own characterization: the first time the full RTO has missed its reliability target since the capacity market began.
The obvious question after a first-ever miss is whether it was a one-time event or the start of a trend. PJM's own July 14, 2026 release answers it: the next auction, for the 2028/2029 delivery year, cleared at a 14.7% margin — 6,831 MW short of target.[2] The percentage margin improved marginally (14.4% to 14.7%), but the absolute shortfall grew (6,517 MW to 6,831 MW), because the reliability requirement itself grows as expected peak demand rises. Two consecutive auctions, two consecutive misses, a larger absolute gap the second time.
PJM's own communications don't attribute the shortfall to a single cause, and this case doesn't either — generator retirements, interconnection-queue delays for new supply, and rising demand (data centers among several drivers, not the only one) all contribute. What's confirmed and precise is the outcome: a capacity market purpose-built to guarantee a reliability margin has now missed that margin twice running, with PJM's own numbers showing the gap growing in absolute terms.
The honest limit of this case: a capacity shortfall is a market signal, not an automatic blackout — PJM has other tools (including the emergency generation orders documented in this cluster's diagnostic case) to manage reliability even with a capacity margin below target. What this case supports precisely is that the structural cushion the market is designed to guarantee has now failed to materialize twice in a row, and the response tools being used to cover the gap are, on the evidence in this cluster, becoming more frequent rather than less.
How a first-ever capacity-market shortfall became a two-auction pattern within five months.
PJM's own report discloses the 2027/2028 Base Residual Auction cleared 6,517 MW short of the reliability target — the first full-RTO miss in the capacity market's history.[1]
First MissFERC orders PJM and five other RTOs to justify their large-load interconnection tariffs, with a response deadline in mid-August — a regulatory response to the pattern this case documents.[3]
Regulatory ResponsePJM's release shows the 2028/2029 auction cleared 6,831 MW short — a larger absolute gap than the first miss, five months later.[2]
Second MissPJM's own July release confirms it will seek FERC approval for a special backstop procurement — a direct response to the consecutive shortfalls.[2]
The ResponseThe 2029/2030 delivery year Base Residual Auction is scheduled — a third consecutive shortfall would be a major structural confirmation.[2]
Next TestThe first time the full RTO has missed its reliability requirement. — PJM Interconnection, 2027/2028 Base Residual Auction Reserve Target Shortfall Report, February 9, 2026
| Dimension | Evidence |
|---|---|
| Revenue (D2) Origin · 86 | The lever is a capacity-market mechanism — a financial structure specifically designed to guarantee a reliability margin — missing its own target twice consecutively, on its own disclosed numbers.[1][2] D2 is the origin because this entire case is about a market outcome, not a physical event.The Market Missed Its Target |
| Operational (D6) L1 · 78 | A widening capacity shortfall directly increases reliance on the emergency generation mechanism documented in this cluster's diagnostic case — a real operational consequence of the market missing its target.[1][2] D6 amplifies from D2 as the physical consequence of the financial shortfall.More Frequent Emergency Reliance |
| Regulatory (D4) L1 · 74 | FERC's June 2026 show-cause orders to PJM and five other RTOs on large-load interconnection tariffs are a direct regulatory response to the pattern this case documents.[3] D4 amplifies alongside D6 as the institutional response to the shortfall.FERC's Own Scrutiny |
| Customer (D1) L2 · 60 | Every customer on the PJM grid is exposed to whatever reliability or price consequence follows from a capacity market missing its own target twice — the population this case's outcome ultimately touches.[1][2] D1 sits here as that broad exposed population. |
| Quality (D5) L2 · 52 | The honest distinction between a capacity-market signal and an imminent reliability failure is the discipline keeping this case precise rather than alarmist — PJM has other tools even with a shortfall on the books.[1][2] D5 sits here as that boundary. |
| Employee (D3) 30 | Deliberately the thinnest dimension. This is a capacity-market and grid-infrastructure cascade; no comparable workforce-level finding exists in the research. |
The cascade originates in D2 — Revenue — because the lever is a capacity-market mechanism, a financial structure designed to price and guarantee reliability, missing its own target on its own numbers.[1][2] From D2 it amplifies into D6 (the operational consequence — more frequent reliance on emergency generation tools) and D4 (the regulatory response — FERC's own scrutiny of the large-load interconnection process feeding this shortfall).[3] It then reaches D1 (every customer on the PJM grid, exposed to whatever reliability or price consequence follows) and D5 (the honest distinction between a market signal and an imminent reliability failure). D3 is deliberately thin — a capacity-market and grid-infrastructure cascade, not a workforce one. Cross-references: [UC-285] documents the emergency-generation mechanism increasingly covering this shortfall; [UC-287] shows one major demand source removing itself from the market this shortfall describes; [UC-288] scoreboards whether the next auction narrows or widens the gap further.
-- UC-286: The Auction That Keeps Coming Up Short: 6D At-Risk Cascade
-- PJM capacity market missed reliability target 2 consecutive auctions (6,517 MW then 6,831 MW short), gap widening (cluster: UC-285/287/288)
FORAGE auction_keeps_coming_up_short
WHERE first_shortfall_confirmed = true
AND second_shortfall_confirmed = true
AND absolute_gap_widened = true
ACROSS D2, D6, D4, D1, D5, D3
DEPTH 3
SURFACE auction_keeps_coming_up_short
DIVE INTO one_time_versus_trend
WHEN first_auction_misses_target = true
AND second_auction_misses_by_more = true
TRACE capacity_shortfall_cascade
EMIT reliability_margin_signal
WATCH third_consecutive_auction WHEN december_2026_bra_results_confirm_or_break_trend = true
DRIFT auction_keeps_coming_up_short
METHODOLOGY 86
PERFORMANCE 40
FETCH auction_keeps_coming_up_short
THRESHOLD 1000
ON MONITOR CHIRP high 'PJM's own Feb 9 2026 report: 2027/2028 Base Residual Auction cleared 14.4pct IRM vs 20pct target, 6,517 MW UCAP short - first-ever full-RTO shortfall in the capacity market's history. PJM's Jul 14 2026 release: 2028/2029 auction cleared 14.7pct IRM, 6,831 MW short - percentage margin improved slightly but absolute shortfall grew. Two consecutive misses, gap widening in absolute terms'
SURFACE analysis AS jsonRuntime: @stratiqx/cal-runtime · Spec: cal.semanticintent.dev · DOI: 10.5281/zenodo.18905193
14.4% to 14.7% reads like modest improvement. 6,517 MW to 6,831 MW short is the more honest number — the reliability requirement itself grows with demand, so a flat percentage still means a bigger real-world hole.[1][2]
This case isn't built on an outside estimate or advocacy framing — both shortfall figures come from PJM's own published reports about its own market's performance.[1][2]
PJM has other reliability tools, including the emergency generation orders this cluster's diagnostic case documents — the shortfall is a market-design failure to hit its own target, not an imminent failure of the grid itself.
Two consecutive misses could still be a two-auction anomaly. A third consecutive shortfall in December 2026 would be much harder to read as anything but a structural trend.
Three sources: PJM's own two shortfall reports for consecutive Base Residual Auctions, and FERC's June 2026 show-cause orders on large-load interconnection tariffs, the regulatory backdrop feeding into the shortfall.
The percentage margin barely moved. The absolute gap got bigger. PJM's own numbers, both auctions.