Power grids serving over 100 million North Americans are straining under unseasonable heat that has coincided with scheduled maintenance outages, driving wholesale prices to crisis levels and exposing structural capacity deficits.
The Midcontinent Independent System Operator (MISO) reported temperatures more than 20 degrees Fahrenheit above normal across its service area, with demand forecast to reach 105.2 gigawatts even as 51 gigawatts of generation sit offline for maintenance. PJM Interconnection, covering Chicago, Washington D.C. and Virginia's Data Center Alley, faces a sharper squeeze: demand expected to surpass 132 gigawatts with 37 gigawatts of capacity unavailable.
On the Western hub benchmark, spot prices jumped above $4,300 per megawatt-hour Wednesday evening. PJM requested an emissions waiver from the Department of Energy to allow plants to run at full capacity, and DOE authorized backup generation deployment Thursday.
The timing exposes a critical vulnerability in the grid calendar. Autumn maintenance windows—historically the industry's only true off-season due to milder weather and reduced air-conditioning demand—are being compressed by erratic weather patterns and the relentless electricity demand surge from artificial intelligence infrastructure. Plant operators no longer have predictable repair windows.
Gary Cunningham, director at Tradition Energy, said PJM's generation fleet "is starting to show signs of its age when trying to stay working." He noted in an email that unseasonable weather "plays well into the narrative of PJM needing more generation capacity, and needing it NOW, even before new demands to meet data center requirements come."
Wholesale power prices are expected to remain elevated across Virginia, Ohio, Kentucky and western Pennsylvania through Thursday, reflecting both the immediate supply-demand imbalance and the operational strain on aging coal and gas assets forced to run continuously without relief.
