Introduction Pumped-Storage Hydro
In addition to our traditional hydroelectric plants, Duke Energy has two pumped-storage plants óJocassee and Bad Creek. A pumped-storage hydroelectric plant works much like a conventional hydroelectric station, except that the same water can be used over and over again to produce electricity.
When demand for electricity is low, Duke Energy operators can refill the lake, as if they were recharging a battery. Using power from other Duke Energy stations, the huge turbines spin backward and pump water back up the power tunnels into the upper lake. Water is generally pumped back to the upper reservoir at night and on weekends.
Pumped-storage plants typically generate power during times of peak electric demand. In the southeastern part of the country, peaks are usually on hot summer afternoons and cold winter mornings during the work week. Water power uses no fuel in the generation of electricity, making for very low operating costs.
The pumped-storage process actually consumes more electricity than it generates. What makes it useful is the fact that pumped-storage can be used to capture unused electricity during times of low use. Pumped storage allows us to keep our coal-fired and nuclear plants running longer and more efficiently.
When used in a well-planned generating scheme, pumped-storage plays an important role and can be one of the most economical forms of electric power generation available today.