PJM Capacity Auction Data Center Cost Impact: $329/MW-Day and the $9.3B Question

The 2025/26 Base Residual Auction cleared at $269.92/MW-day, up from $28.92/MW-day the prior year. The primary driver was a surge in data center load forecasts — particularly in Virginia, Ohio, and New Jersey — that exceeded available generation capacity reserves. PJM's demand curve design amplifies price signals when reserve margins tighten: small changes in the supply-demand balance produce large price movements. Simultaneously, coal and gas plant retirements reduced supply. Data center demand accounted for 63% of the price increase.

At $329.17/MW-day, a 100 MW data center operating at 85% capacity factor pays approximately $10.2M/year in capacity charges alone. Spread across annual consumption, this adds roughly $12-15/MWh to the all-in power cost. For context, PJM capacity charges were effectively negligible ($28.92/MW-day = ~$1/MWh) just two years ago. Combined with energy ($30-45/MWh), transmission ($8-15/MWh), and distribution ($3-8/MWh), total all-in PJM power cost now ranges $55-90/MWh depending on zone and contract structure.

PJM analysis shows data center load growth drove 63% of the capacity price increase in the 2025/26 auction. The total PJM capacity bill for that delivery year is $16.1B, making the data-center-attributable share approximately $9.3B. This calculation reflects the marginal price impact: because PJM uses a uniform clearing price auction, every megawatt of new data center demand that pushed prices up the demand curve increased costs for all load-serving entities across the 13-state footprint.

ERCOT operates as an energy-only market — there is no capacity auction and no capacity charge. The entire $12-15/MWh capacity cost layer that PJM imposes on data centers does not exist in Texas. For a 100 MW facility, this structural difference represents $10-15M/year in savings. ERCOT has its own cost risks (real-time scarcity pricing, weather-driven price spikes, congestion), but the baseline cost structure is fundamentally lower for capacity-sensitive loads. This is why major hyperscalers are accelerating Texas expansion.

Starting June 2026, PJM ratepayers will pay an additional $1.4B in capacity market costs. The impact varies by utility territory: Pepco customers in Washington DC face approximately $21/month in increases, western Maryland customers +$18/month, and Ohio customers +$16/month. These are capacity-driven increases only and do not include energy or transmission cost growth. The political visibility of these bill increases is directly driving state-level regulatory action targeting data centers.

Multiple PJM states are responding to capacity cost shifts with data-center-specific measures. Virginia is creating a separate electricity rate class for data centers to prevent cost-shifting to residential customers. Pennsylvania has a precedent-setting rate case with the same goal. Ohio's PUCO approved AEP's 85% minimum bill ratchet tariff requiring 12-year contracts for loads over 25 MW. Maryland and New Jersey are reviewing similar policies. The trend is toward isolation of data center costs from general ratepayer exposure.

The structural drivers suggest sustained high prices. PJM projects 40+ GW of new data center load in the interconnection queue through 2030, while 30+ GW of coal and gas retirements are scheduled in the same timeframe. The 2027/28 auction already cleared at $333/MW-day, above the prior year's record. The FERC reliability backstop cap may be adjusted upward. For planning purposes, model capacity costs at $300-400/MW-day through 2030. The supply-demand imbalance is structural, not cyclical.

Capacity costs now represent the single largest variable in PJM data center power economics — a cost layer that was negligible three years ago. Site selection within PJM must now account for zone-level capacity price differentials (DOM, MAAC, EMAAC clear differently), state-level regulatory risk (tariffs, rate classes, moratoriums), and forward capacity price trajectory. For operators comparing regions, the $12-15/MWh capacity cost adder in PJM versus $0 in ERCOT is a $10-15M/year decision per 100 MW facility.