PJM Monitor: Data Centers Added $9.95/MWh; 9-Month Cost Hits $70.81B

PJM Interconnection's wholesale power cost $70.81 billion in January through September 2026, up 45.7% from $48.60 billion a year earlier, according to the Independent Market Monitor's third-quarter State of the Market report released Nov. 12.

Monitoring Analytics, the monitor, puts the average at $111.61 per MWh, up 40.9% from $79.19. Energy rose 46.3% to $70.89/MWh, capacity rose 81.1% to $19.42/MWh and transmission rose 4.6% to $19.16/MWh. Real-time hourly average load grew 3.4%, from 93,683 MWh to 96,845 MWh.

The monitor isolates what data centers did to the capacity piece. Without data center load in the 2025/2026 and 2026/2027 capacity auctions, the nine-month cost would have been $101.66/MWh, so their inclusion added $9.95/MWh, or 9.8%. The monitor says that figure excludes any effect on energy or transmission costs.

What the monitor expects next

The report warns that PJM's next base residual auction, for 2029/2030 and scheduled for December 2026, will use a forecast that still includes data centers the monitor says are canceled or unlikely to reach projected demand. It says that will clear the auction at the maximum price and add another $5 billion to $10 billion of data center costs for all customers. It recommends postponing the auction until large data center load can be removed and a reliability backstop auction run.

The monitor also repeats its cumulative figure: data center load has caused an irreversible $29.4 billion increase in capacity market costs across the four auctions through 2028/2029. That total was first published in July, and it is a capacity-market sum across auctions, not a nine-month cost, so it should not be set against the $70.81 billion.

PJM fell short of its reliability target by 6,831.3 MW in the 2028/2029 auction, up from 208.7 MW in the 2026/2027 auction, the monitor said. For data center developers, the reading is that load still waiting to connect is feeding forecasts that set prices and shortfalls for every customer class.

Proportion and PJM's response

Utility Dive reported that the monitor's first-half report put data center load at 9%, or $10.48/MWh, of the wholesale price through July, and that an Aug. 24 presentation gave a seven-month cost of $56.7 billion, up 46%. The nine-month figures continue that trend, but the periods differ, so each number stands on its own basis.

PJM spokesman Jeffrey Shields told the Pennsylvania Capital-Star that PJM fundamentally disagrees with the monitor's view that PJM can control how data center costs are shared, arguing that is for state regulators. He said PJM's proposals let states assign data center costs to those customers.

The Capital-Star reported that FERC rejected a reliability backstop auction plan and much of PJM's large-load framework, and that PJM has submitted amended proposals. Voltgrid covered PJM's amended backstop filing, which targets a March 1, 2027 auction start, and Exelon's complaint over the capacity auction timing. The monitor's energy market verdict is separate: it called energy results competitive and the capacity auctions not competitive.

What is not confirmed yet

The monitor's $5 billion to $10 billion estimate for the December auction is a forecast, not an auction result. FERC has not ruled on PJM's amended filings in the sources reviewed here, and PJM has not said it will delay the December auction. The report's recommendations are the monitor's, not PJM rules.