August 17, 2008 ARC event

Sunday August 17th 2008 15:30 EST through 15:50 EST the Midwest ISO invoked the ARC procedure due to loss of generation for ~300 MW and a Net Schedule Interchange obligation of ~500 MW while load increased higher than projected. Up to 89 percent of the available ARC operating reserves were utilized during this period to assist in correcting the imbalance. There were no ARS events initiated during the event.