Data-center demand has now accounted for 45 percent of the capacity costs in PJM's last three power auctions — $21.3 billion of $47.2 billion in cleared costs, according to the grid's independent market monitor. [1] It is the price receipt under every AI-campus claim, and it lands the same week the emergency tool that could curtail those loads expired.

The paper's July 7 note on how data-center load pushed PJM capacity costs to a record tracked a string of record clears; today the market monitor put a share on it. In PJM's December base auction, data-center load accounted for $6.5 billion — 40 percent — of $16.4 billion in total capacity cost, the auction that cleared at the FERC-approved cap of $333.44 per megawatt-day. [1] Across the three most recent auctions, forecasts of data-center growth beyond existing load totaled $21.3 billion, or 45 percent of the $47.2 billion cleared. [1] Without that demand, the monitor found, the most recent auction would have totaled roughly $10 billion instead of $16.5 billion — a 65 percent increase attributable to data centers.

Those costs do not stay on a chart. PJM's footprint spans 13 states and about 67 million people, and the capacity charge flows into residential bills. Data-center load has already raised regional costs by more than $13 billion, with estimates of roughly $37 billion more attributable in Illinois alone — the same figure anchoring the state's two-year freeze on data-center tax breaks. [2]

The divergence is about what the number means. MSM covers the auction as a market outcome — supply short, demand up, price cleared, transparency concerns noted for later. [3] On X, the same clear reads as dumping: data centers securing firm power at a record price and letting 65 million households absorb the difference before any regulator reallocates it.

The paper's middle is the instrument. A capacity price is a cost-allocation fact, and this record cleared in the precise gap the paper has been tracking — after the DOE's emergency curtailment authority lapsed on July 7 and before FERC's August 17 large-load docket produces any binding reassignment. During that gap, the record cost sits with existing ratepayers by default. Whether FERC's proceeding shifts it back toward the loads that drove it, or the record simply compounds in next year's bills, is the open question. The chart is not the story. Whose meter spins faster is.

-- DARA OSEI, London