U.S. declares grid emergency as heat strains PJM power supply

Federal officials declared an emergency across PJM Interconnection on June 30 as extreme heat pushed electricity demand toward levels that could strain the nation’s largest power market. The order, issued under Section 202(c) of the Federal Power Act, came after PJM warned of an “imminent electricity reliability emergency” and projected peak loads of 159,563 megawatts on July 1 and 162,860 megawatts on July 2.

PJM had already been bracing for the heat. It issued a Hot Weather Alert for its Western Region on June 29 and then extended a Hot Weather Alert across its entire footprint from June 30 through July 3 ahead of prolonged 90-plus-degree weather. By June 30, PJM’s emergency procedures page listed a Maximum Generation Alert, a Load Management Alert, a Low Voltage Alert and a Post Contingency Local Load Relief Warning in the Dominion region.

PJM’s May summer outlook projected a typical summer peak load of about 156,400 megawatts and a high-demand scenario of 169,100 megawatts, backed by about 180,200 megawatts of installed generating capacity and roughly 7,800 megawatts of contracted demand response. The outlook resembled last year’s and reflected continued load growth from data centers that is outpacing new generation. Last summer, PJM called on non-emergency demand response six times.

The strain was already visible in late June. During an early-season heat wave in 2025, PJM hit peaks of about 161,300 megawatts on June 23 and 160,900 megawatts on June 24, the third- and fifth-highest summer peaks in its history. Its July 2, 2026 forecast had climbed to about 166,304 megawatts, which would top the all-time summer record of 165,563 megawatts set in 2006.

The emergency order gave PJM authority to direct backup generation resources at data centers and other major facilities as a last resort before voltage reduction or load shed. That followed a May 18 emergency order that had already allowed PJM to deploy backup generation at data centers and other large load customers. PJM’s territory covers all or parts of Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia and Washington, D.C.