67 Million Face Power Grid Emergency as Heat Dome Settles Over Eastern US

A heat dome is trapping hot air over the eastern US. Temperatures from Washington to Boston may reach 100 degrees. That could push the power grid past its limits for 67 million people. Grid operators are taking rare steps to keep the lights on.

The Emergency Order

The United States Department of Energy issued two emergency orders at the request of PJM Interconnection LLC, the operator of the largest US power grid. These orders let power plants run at maximum output and skip some environmental requirements. Backup generators can be used "as a last resort," PJM said.

The orders are temporary. They expire at 11:59 PM New York time on July 3, 2026. This grid spans 13 states, stretching from the Midwest to the East Coast.

The PJM grid is one of the largest and most complex in the world, carrying electricity for tens of millions of homes and businesses. Its territory spans a broad swath of the country, including major metropolitan areas like Washington, D.C., Philadelphia, and Chicago. With temperatures forecast to break records, the system is being pushed to its limits.

Get your free investing masterclass bonus when you join Market Briefs, our free daily newsletter

Emergency measures like these are rare but have become more frequent in recent years as extreme heat events strain aging infrastructure.

Why the Grid Is Under Pressure

The National Weather Service has issued excessive heat alerts for more than two dozen states. Hundreds of daily temperature records are expected to be tied or broken. The heat dome - a large area of high pressure - is locking warm air in place.

On Monday, PJM approached the Energy Department for this authorization, cautioning that electricity consumption could reach unprecedented levels as predicted highs surpass 100 degrees Fahrenheit (38 Celsius).

Still, the system is already strained. Last month, the DOE granted a comparable emergency order for PJM, allowing the use of reserve generators to prevent power failures across the Mid-Atlantic region.

This is not the first time PJM has faced such strain. In recent years, the grid operator has repeatedly sought emergency measures during summer heat waves. The growing demand from data centers and the retirement of older power plants have compounded the problem, raising concerns about the long-term resilience of the nation's electrical infrastructure.

What Happens Next

Broader pressure on the power system is not going away. America's electrical infrastructure is facing considerable strain this summer, as it struggles to keep up with rising consumption driven by data centers.

For now, the emergency order buys time until the heat wave passes.

Subscribe to Market Briefs, our free daily newsletter, and claim your bonus investing masterclass