Hot fall, equipment downtime lead to problems within PJM

Due to unseasonably hot weather, PJM Interconnection set a new record for September peak power use on Sept. 10 by meeting the demand for 144,370 MW.

By comparison, the 2012 September peak demand was 129,959 MW, and the PJM peak demand in July of this year was 157,509 MW, PJM said in a Sept. 11 statement. The hot weather continued in many areas on Sept. 11 and electricity supplies remain tight.

The unusual, extreme heat on Sept. 10 combined with local equipment problems to create emergency conditions in Indiana, Michigan, Ohio and Pennsylvania. PJM was forced to direct local utilities in those areas to immediately and temporarily cut electricity to some customers to avoid the possibility of an uncontrolled blackout over a larger area. Continued heat in some areas on Sept. 11 would require load reductions through demand response, but PJM and its members are working to prevent additional emergency customer curtailments.

“Extreme heat in the western region of PJM resulted in record demand for September at a time when many power plants and some transmission lines were off for seasonal maintenance,” said Terry Boston, PJM CEO. “Our only option to prevent a potential equipment overload and failures that would cause a much bigger interruption was to call for emergency relief in the form of controlled outages.”

As a grid operator, PJM determines the necessary steps to maintain operation of the power grid that makes electric power supplies available to consumers. In emergency cases, like on Sept. 10, PJM must immediately call for the last resort of cutting the power to some customers. PJM identifies the general area where power use reductions are necessary and the amount of reductions. A utility, which operates the transmission lines, determines how to make the reductions.

PJM Interconnection ensures the reliability of the high-voltage electric power system serving 61 million people in all or parts of Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia and the District of Columbia.

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.