US heat wave pushes power demand, triggers emergency electricity curbs and July 4 event disruptions

An intense heat wave gripping the eastern United States has pushed electricity demand to near-record levels, forcing the nation's largest power grid operator to implement emergency measures. PJM Interconnection, which supplies electricity to approximately 67 million people across parts of the East Coast, Midwest, and Washington D.C., ordered customers in emergency demand-response programs to cut power usage during peak evening hours.

The grid operator cited generator outages, strained transmission lines, and soaring air-conditioning demand as reasons for the emergency action. PJM aims to increase reserve capacity and prevent blackouts amid the surge in demand. The operator also alerted neighboring grids, including those in New York and the Midwest, about potential curtailment of power exports if necessary. This situation unfolds as around 160 million Americans are under heat warnings for the July 4 holiday weekend, with temperatures approaching or breaking records in many areas.

On Thursday, PJM's electricity demand reached about 163 gigawatts, narrowly missing its all-time record of 165.6 gigawatts set two decades ago. The operator managed to avoid outages by utilizing demand-response programs, which compensate customers for reducing electricity use, and by relying on expensive standby power plants. A hot weather alert remains in effect across the PJM region through Saturday and has been extended through Sunday for parts of the Mid-Atlantic and Dominion transmission zones, areas known for a high concentration of data centers.

The surge in demand has also caused wholesale electricity prices to skyrocket. Spot power prices in some parts of the Mid-Atlantic and Dominion zones exceeded $2,500 per megawatt-hour this week, a stark contrast to the usual $40 per megawatt-hour. The extreme heat has disrupted July 4 celebrations nationwide. In Washington D.C., events on the National Mall were temporarily halted due to heat-related illnesses, and the city's Independence Day parade was canceled. New York City expanded cooling centers and extended pool hours, while utility provider Con Edison restored power to about 60,000 customers affected by heat-related outages, though over 22,000 users remained without electricity Friday afternoon.