When PJM demand surged during the summer heat wave, gas and coal supplied the additional power.

Summer isn’t over. More heat waves can be expected during this season and in subsequent years. How is the grid coping?

The first major heat wave of summer 2026 pushed temperatures above 100°F across the eastern United States. Midday load on PJM, the nation’s largest grid operator, surged to near-record levels, approaching the all-time peak of 165,563 megawatts (MW) set in 2006.

When the heat spikes, PJM doesn’t turn to the sun. It turns to gas and coal. Gas generation rose to 55 gigawatts (GW), up from 44 GW the week before. Coal ran at 24 GW, up from 14 GW, a 69 percent increase. Nuclear held steady at 32 GW. Solar and wind averaged 7 GW both during the heat wave and the week prior—unchanged. The intermittent fleet didn’t move, and the dispatchable fleet absorbed the entire increase.

PJM wasn’t alone. New York’s grid operator asked customers to limit air conditioner and large-appliance use during peak afternoon hours, and the Midcontinent Independent System Operator (MISO), which spans 15 states across the Midwest and South, issued a conservative operations declaration of its own. The strain was regional, not confined to one grid.

The US Department of Energy responded by issuing its third emergency order of the year for PJM, waiving Clean Air Act limits on coal plant emissions and authorizing PJM to curtail large data-center loads as a last resort if needed. Wholesale prices, which normally run near $40/MWh, peaked above $2,000/MWh. Most residential customers on fixed-rate plans won’t see that spike directly on their bills, but customers on variable-rate plans, and businesses billed on peak demand charges, will.

Data Center Demand Is Raising the Stakes for PJM

This is less a heat-wave story than a preview. PJM sits at the center of US data center growth, with the largest concentration in Northern Virginia, where major internet trunk lines converge, and where more facilities are already scheduled to come online. PJM expects nearly all of its demand growth through 2030 to come from data centers, and industry estimates put new data-center demand nationally at up to 166 GW over the next five years. This growth is outpacing the current buildout of new generation.

Making matters more challenging, PJM’s territory needs substantial power for both cooling and heating. That dual demand is one reason legacy coal units keep getting called back into service: plants once slated for retirement remain operational under DOE’s emergency authority, which was invoked both during Winter Storm Fern in late January and early February and again during this summer’s heat.

But that authority is not a permanent fix. It requires renewal every 90 days, plant by plant. Summer isn’t over; more heat waves can be expected during this season and in subsequent years. The Clean Air Act’s Section 202(c) orders will keep getting used. What the moment calls for, though, is a durable policy response that matches the pace of data-center buildout with the pace of new, dispatchable generation.

PJM Needs More Dispatchable Generation

That starts with an honest accounting of demand. Utilities and regulators need a clear-eyed view of how much new load is coming, and where, so that generation and transmission planning isn’t done in the dark. Without it, project timelines stall and grid stability suffers.

It also requires capital, and capital requires returns. Financing new generation at the pace this growth demands means structuring projects so that ratepayers, data-center operators, and other beneficiaries of that new capacity all share fairly in the cost of building it.

The lesson of this heat wave isn’t complicated. When the grid needed power most, it was gas and coal that stepped up, because they were the only resources that could be dispatched on demand. As data centers multiply and summers grow hotter, PJM will need more 24-hour power, particularly gas, coal, and nuclear, built faster and financed sensibly. The alternative is a grid that keeps surviving its emergencies one 90-day waiver at a time.

About the Authors: Matthew Sawoski and Max Pyziur

Matthew Sawoski is a senior research analyst at EPRINC, focusing on national and energy security. He leads EPRINC’s work in modeling and AI. He received his BA in advanced mathematics with a minor in history from the University of Michigan. He can be reached at MatthewS@eprinc.org.

Max Pyziur is EPRINC’s research director for downstream, transportation fuels, electricity, and natural gas programs. Previously, he held senior analytical roles at PIRA Energy and CPM Group, both commodities market consultancies. He received his MBA from Washington University in St. Louis, and his BA from St. Louis University. He can be reached at MaxP@eprinc.org.

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