PJM grid nears record demand as heat wave hits eastern US

The nation's largest power grid was pushed to the brink of a historic demand record this week as a severe heat wave blanketed the eastern United States, forcing federal and grid officials to enact emergency measures to prevent blackouts. PJM Interconnection, which serves 67 million people across 13 states and Washington, D.C., saw electricity demand surge to approximately 163 gigawatts on Thursday, July 2, narrowly missing its all-time peak of 165.563 gigawatts set in August 2006.

The intense heat, with temperatures soaring above 100 degrees Fahrenheit and heat indices reaching as high as 115 degrees in parts of the mid-Atlantic, drove the surge in power consumption for air conditioning. PJM had forecasted demand could reach as high as 166 gigawatts. The grid operator stated that conservation measures likely suppressed the final peak load, which occurred between 5 p.m. and 6 p.m. on Thursday, and that the actual peak likely surpassed the 2006 record. Preliminary figures from Wednesday also showed demand hitting nearly 162 gigawatts, among the highest readings PJM has ever recorded.

In preparation for the crisis, the U.S. Department of Energy issued an emergency order on Tuesday,...