Largest electric grid operator in US issues alert as temperatures climb

The largest U.S. electric grid operator issued a level one emergency alert Thursday as millions of Americans face soaring temperatures amid a sprawling heat wave.

PJM Interconnection issued a Maximum Generation Emergency/Load Management Alert for Thursday, which is an early notification that the conditions may need the operator’s emergency procedures. It also issued an Energy Emergency Alert 1 (EEA-1) to signal that all generating resources are already online or are scheduled to be online.

“PJM has issued this series of alerts to help prepare generators for the onset of intense heat, acting conservatively in light of recent extreme weather events that have occurred within the region and across the country,” a PJM spokesperson said in a statement to The Hill.

PJM provides wholesale electricity in all or parts of 13 states — including most of the Middle Atlantic and part of the Midwest — and Washington, D.C.

PJM also issued a hot weather alert earlier this week “to prepare transmission and generation personnel and facilities for extreme heat and/or humidity that may cause capacity problems on the grid.” PJM noted that this year’s forecasted summer peak demand for electricity is about 156,000 megawatts, which is higher than last year’s peak demand of 149,000 megawatts.

“A dedicated team of operators uses sophisticated technology to balance supply and demand and direct the power grid 24/7 from PJM’s control rooms,” the hot weather alert reads. “They adjust resource output with changes in demand and ensure that no transmission lines or facilities are overloaded.”

On Thursday, PJM predicted it will serve about 150,700 megawatts across its regional transmission organization (RTO).

Large portions of the country were placed under heat advisories as of Thursday, according to the National Weather Service (NWS), with high temperatures expected in the Southwest, the central U.S. and the East Coast through Saturday.

“The long-duration heatwave will continue in the Southwest U.S. through Saturday while hot temperatures are forecast to spread from the Central to the Eastern U.S.,” the NWS said in its daily discussion.

“Dangerously hot conditions with heat index values up to 115 degrees Fahrenheit are possible. Widespread Heat Advisories and Excessive Heat Warnings have been issued. Heat is the leading cause of weather-related deaths most years.”