Lake Jocassee and Jocassee Pumped Storage Facility
The four-unit Jocassee Pumped Storage Facility is a 710 megawatt generating facility located in Pickens County, South Carolina. The commercial operation of units 1 and 2 began in 1973. Commercial operation of units 3 and 4 began in 1975.
The average annual generation from the Jocassee Development is 811,000 megawatt hours and the pumping energy requirement is 988,000 megawatt hours. When generating electricity, the facility works as a conventional hydroelectric station. However, the Jocassee Pumped Storage Facility can also reverse its turbines and pump back previously used water from Lake Keowee into Lake Jocassee. This allows Duke Energy to reuse the water to generate electricity at a later time. For more information, read How Do Pumped-Storage Hydro Plants Work?
Lake Jocassee’s full pond elevation is 1,100 feet above mean sea level (msl) with a maximum licensed drawdown of 30 feet. At full pond, the surface area is approximately 7,980 acres with approximately 92 miles of shoreline. The Jocassee Dam is a zoned earth and rockfill structure approximately 385 feet high and 1,800 feet in length. The dam includes two circular structures with eight openings that direct water to the generating units.
Lake Jocassee also serves as the lower reservoir for the Bad Creek Pumped Storage Facility. When electricity is being generated at the Bad Creek Pumped Storage Facility, water stored in the upper Bad Creek reservoir is released into Lake Jocassee through an underwater opening or discharge portal. The portal is located on the Whitewater River arm of Lake Jocassee. During the refilling of the upper Bad Creek reservoir, the Bad Creek Pumped Storage Facility turbines are reversed to pump water back from Lake Jocassee into the upper Bad Creek reservoir. Bad Creek Pumped Storage Facility began operating in 1991; its FERC license expires in 2027.