Duke Energy recently completed upgrades to the four units at the Bad Creek pumped storage facility in Salem, S.C.
Duke Energy officials said the upgrades add a total of 320 megawatts of carbon-free energy to the company's system and brings the total capacity of the station to 1,680 megawatts.
Bad Creek pumped storage technology supports the operational needs of Duke Energy's system, particularly as more solar is added, and the station can now power more than 1.3 million homes, the officials said.
A flexible, dynamic, efficient and green way to store and deliver large quantities of energy, pumped storage hydro plants store and generate energy by moving water between two reservoirs at different elevations.
Coming online in 1991, Bad Creek is designed to produce significant amounts of energy when customers need it most, performing a vital role as the largest "battery" on the company's system, Duke Energy officials said.
"This investment in Bad Creek demonstrates our commitment to improving reliability across the Carolinas. Pumped storage technology gives us operational flexibility, allowing us to store energy and then deploy that energy when customer demand is highest," said Preston Gillespie, executive vice president and chief generation officer and enterprise operational excellence.
Gillespie added, "Expanding our energy storage capabilities is just one of the many steps we are taking in the next phase of our energy transition."
The units were upgraded in phases, adding 80 MW of capacity to each new pump turbine. Unit 2 was completed in 2020, unit 1 was completed in 2021, unit three was completed in 2023 and unit 4 was completed in April.
Duke Energy is working to extend the license of the Bad Creek pumped hydro storage facility, which is set to expire in 2027.
In addition to the upgrade project, Duke Energy is evaluating the potential to add a second powerhouse at Bad Creek that would further help Duke Energy add capacity to the system as well as address increasing system variability, from the growth of solar and customer usage, in a reliable and affordable way.
"From population growth to the expansion of manufacturing and other major economic development wins, the Carolinas are booming," said Mike Callahan, Duke Energy's South Carolina president.
Callahan added, "We must have a diverse energy mix to account for this growth on the coldest winter nights and the warmest summer days. We continue to look at solutions like expanding Bad Creek to make sure the power is there when customers need it, and it is as affordable as possible – providing certainty as they go about their daily lives."
Duke Energy officials said expanding operations at Bad Creek also provides significant economic benefits of $7.3 billion to South Carolina, as the state benefits from construction and general infrastructure activity, by 2033.
Duke Energy Carolinas, a subsidiary of Duke Energy, owns 20,700 megawatts of energy capacity, supplying electricity to 2.9 million residential, commercial and industrial customers across a 24,000-square-mile service area in North Carolina and South Carolina.