VALLEY FORGE, Pa., Sept. 11, 2013 /PRNewswire/ -- Due to unseasonably hot weather, PJM Interconnection, the electricity grid operator for 13 states and the District of Columbia, set a new record for September peak power use yesterday by meeting the demand for 144,370 megawatts. 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. The hot weather continues in many areas today and electricity supplies remain tight.

PJM is responsible for keeping the grid running safely and reliably. Tuesday's unusual, extreme heat 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 that would have affected many more people. Continued heat in some areas today will 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."

"We sincerely regret that conditions on the grid yesterday required us to call for emergency reductions in consumer demand," Boston added.

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 yesterday, 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. In these emergency situations, time is of the essence, and there is little lead time to notify all who would be impacted.

PJM Interconnection, founded in 1927, 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. PJM coordinates and directs the operation of the region's transmission grid, which includes 62,556 miles of transmission lines; administers a competitive wholesale electricity market; and plans regional transmission expansion improvements to maintain grid reliability and relieve congestion. Visit PJM at www.pjm.com.

SOURCE PJM Interconnection

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