Grid operator PJM Interconnection has increased its coal-fired power purchases for the first time in three years.
Generators cleared 23,757MW of coal capacity in PJM's residual capacity auction covering June 2025 to May 2026, up from 21,478MW for the 2024-25 delivery year, the grid operator said on Tuesday.
Prior to the latest auction, PJM coal capacity clearances had consistently fallen every year since the grid operator resumed base residual auctions in 2021.
Generators actually offered 1,303MW less in this round than in the previous auction, and PJM purchased all of the coal capacity made available. The capacity results indicate some tightness in overall residual generating supply. Two PJM zones purchased only slightly above minimum requirements for reserve capacity.
As a result, coal will make up 18pc of the grid's resource mix, trailing natural gas at 48pc and nuclear at 21pc.
Excluding energy efficiency measures, generators offered 135,694MW of capacity, down from the previous 148,946MW, and the amount of total capacity cleared also fell to 134,672MW from 140,416MW.
Capacity clearance prices increased to record levels for the 2025-26 auction. The price for most of PJM's footprint climbed to $269.92/MWd from $28.92/MWd in the 2024-25 auction.
"The market is sending a price signal that should incent investment in resources," PJM chief executive officer Manu Asthana said.
The grid operator said the higher prices were at least partly driven by fewer supply offers into the auction as a result of increased generator retirements in recent years.
Since the 2024-25 capacity auction, 6,600MW of generating capacity has retired or been put under a must-run agreement with PJM, the grid operator said. That includes the closing of 4,570MW of coal capacity.
Expected increased electricity demand also contributed to the higher clearance prices. PJM's forecast for peak load demand rose to 153,883MW compared with 150,640MW for the year earlier delivery period.
In two of PJM's zones, the capacity cleared was just above the zone's required minimum reserves.
In addition, PJM said prices grew in response to changes recently approved by the Federal Energy Regulatory Commission designed to improve estimates for extreme weather's effects on load demand and to more accurately determine each energy resource's contribution to reliability.
The total amount of natural gas generation to clear the 2025-26 auction declined to 64,569MW from 71,504MW a year earlier, while nuclear power increased to 28,477MW from 25,818MW.
Some renewable results were mixed, with PJM generators clearing 4,835MW of wind capacity, up from 3,715MW in the previous auction, while solar power dropped to 1,333MW from 2,765MW.
