A severe heat wave across the eastern United States pushed the PJM Interconnection, the nation's largest electric grid operator, to the brink of an all-time demand record in the first days of July, as air conditioning load surged across a 13-state footprint stretching from Illinois to the mid-Atlantic. The PJM record power demand event triggered federal emergency action and offered a real-time stress test of grid capacity that HVAC equipment across the region depends on to function during peak conditions.
How Close the Grid Came to a Record
PJM's forecast peak for July 2 stood at 166,147 megawatts, which would have broken the grid's all-time record of 165,563 megawatts set in 2006. Actual demand came in just short of that mark, reaching roughly 163 gigawatts on the day, according to PJM's own hot-weather operations updates. The near-miss came after the National Weather Service forecast highs of 102 to 104 degrees Fahrenheit across parts of Maryland and Virginia heading into the July 4th weekend, with heat indices reaching 110 degrees in New York City, 112 degrees in Philadelphia and 113 degrees in Washington, D.C. Atlantic City, New Jersey, recorded a high of 106 degrees on July 4.
Federal Emergency Orders
The U.S. Department of Energy issued two emergency orders under Section 202(c) of the Federal Power Act allowing PJM to curtail power delivery to data centers and to waive certain power plant pollution limits as the heat wave pushed demand toward record territory. Those two orders were part of a broader pattern this year: the DOE has issued 34 Section 202(c) emergency orders across U.S. grid operators in 2026, spanning PJM, ERCOT in Texas, ISO New England, NYISO, MISO and utilities serving the Southeast and Puerto Rico.
The Grid Held, Barely
PJM's roughly 18 gigawatts of fast-start reserves held through the peak demand period, and the grid avoided rolling blackouts despite conditions PJM itself described as very tight. Wholesale power prices spiked sharply during the event, with some reports describing prices in the PJM footprint roughly tripling as the combination of extreme heat and rising data center electricity consumption strained available generation capacity across a grid that serves more than 65 million people.
A Grid Increasingly Shaped by Two Forces
The near-record demand reflects the convergence of two trends reshaping electricity markets in PJM's territory and beyond: extreme heat events that push residential and commercial air conditioning load to its ceiling, and the rapid buildout of data center capacity that has added enormous, largely inflexible electricity demand to the same grid. PJM's territory has become a particular focus of this collision because it hosts one of the largest concentrations of data centers in the country alongside a dense residential and commercial population reliant on air conditioning during summer heat events.
Implications for HVAC Equipment and Service
For the HVAC industry, grid events of this kind translate directly into service call volume, equipment stress and, in some cases, utility-driven demand response participation. Air conditioning and heat pump systems operating continuously at or near capacity during multi-day heat waves face elevated failure rates, a pattern that typically drives a spike in emergency service calls for residential and commercial HVAC contractors in affected regions during and immediately after major heat events.
The emergency orders directing data centers to curtail consumption and shift toward backup generation during peak hours also illustrate a growing operational reality for utilities: balancing traditional weather-driven cooling demand against a new category of large, continuous industrial load that does not fluctuate with temperature the way residential and commercial HVAC systems do.
How the Event Compares to 2006
PJM's prior all-time peak of 165,563 megawatts was set in 2006, two decades before this year's near-record event, during a period when the grid's territory carried far less data center load than it does today. The fact that this summer's heat wave came within roughly 2,600 megawatts of that two-decade-old record, even without breaking it outright, underscores how much additional baseline demand data centers have layered onto the same grid footprint since that prior peak was set, on top of the weather-driven air conditioning load that has always dominated PJM's summer peak days.
What's Next
PJM has not indicated whether the July event will require longer-term changes to its capacity planning, though the near-record peak adds to a growing body of evidence that grid operators across the country are increasingly managing demand growth driven simultaneously by climate-driven cooling load and data center expansion. Utility Dive and other grid-focused outlets have reported that PJM anticipated the possibility of a new peak demand record heading into the event, underscoring that capacity planners are treating this summer's heat as a preview of conditions the grid will need to manage more frequently in coming years.
