DOE emergency order allows Duke to exceed plant emissions limits amid heat wave

The US Energy Department issued an emergency order to allow Duke Energy Corp. subsidiary Duke Energy Carolinas LLC to operate some power plants beyond their permitted emissions limits to reduce the risk of outages during a heat wave across the Southeast this week.

Duke Energy told the DOE that about 1,500 MW of its generating assets were offline in the Carolinas and others may be limited by environmental permitting requirements. The utility had "exhausted its ability to obtain more power through other means," including tapping into its reserve sharing group and purchasing external capacity, the DOE said in the order.

The emergency order, signed by Energy Secretary Chris Wright and dated at 3:50 a.m. ET June 24, was issued under the Federal Power Act section 202(c) and allows the utility to operate power plants at their maximum generation output levels and exceed power plant emissions limits when it declares an Energy Emergency Alert Level 2 (EEA 2).

An EEA 2 is declared when a grid operator is no longer able to provide its expected energy requirements but is still able to maintain minimum contingency reserve requirements. Under the alert, the grid operator also has implemented its operating plans to mitigate emergencies, excluding customer interruptions, according to the North American Electric Reliability Corporation.

Duke told the DOE it expects to declare that emergency level during the heat wave. The order is set to expire at 10 p.m. Wednesday, when temperatures are expected to begin to drop. When the EEA 2 event is over, Duke is required by the order to return its generating facilities to their previously permitted limits.

"This order ensures Duke Energy Carolinas can supply its customers with consistent and reliable power throughout peak summer demand," Wright said in a statement accompanying an announcement of the order.

Duke requested June 23 that customers reduce power usage during the heat wave, and the DOE said Duke had curtailed all recallable energy sales and implemented its load management program, "including implementing residential demand response programs and large load curtailments," to help mitigate the effects of increasing demand.

The DOE issued a similar order for Duke Energy Florida LLC for conditions caused by Hurricane Milton in October 2024.