Duke Energy has started operating a 50-megawatt battery energy storage system (BESS) at its former Allen coal plant on Lake Wylie, serving customers in North Carolina and South Carolina. The company also announced plans for additional battery storage and new jobs at the Gaston County site.
The initial BESS, which cost about $100 million, was completed under budget and ahead of schedule. It began serving customers in November, with final testing finishing this month. Construction of a second BESS—expected to be Duke Energy’s largest at 167 megawatts—will begin in May on land where the plant’s emissions control system once stood.
Both lithium-ion battery systems qualify for federal investment tax credits that will offset 40% of their costs for Duke Energy customers. This includes an extra 10% credit for reinvesting into an energy community, as the coal plant retired in December 2024.
“We’re building new resources to keep the Carolinas’ economy thriving, while reinvesting in a former coal plant community that helped power this region for decades,” said Kendal Bowman, Duke Energy’s North Carolina president. “Repurposing existing energy infrastructure and taking advantage of federal funding significantly offset costs for our customers while continuing to support rapid growth across the region.”
Utility-scale batteries are seen as especially valuable during cold winter mornings before solar generation is available. They can also store excess energy produced during low-demand periods—including clean power from Catawba Nuclear Station nearby—for use when demand rises.
Duke Energy intends to expand battery storage investments across multiple counties in the Carolinas. According to its proposed 2025 Carolinas Resource Plan, currently under regulatory review, the company projects adding 6,550 megawatts of batteries by 2035 to help maintain reliability and meet increasing electricity needs in North Carolina and South Carolina.
The plan maintains a diverse mix of solar, storage, nuclear and natural gas generation as electricity demand grows faster than it has over the past decade and a half.
Battery storage is also planned at both retired coal plant sites along the Catawba River: Allen (1957-2024) in Belmont and Riverbend (1929-2013) in Mount Holly. Construction on a 115-megawatt BESS at Riverbend is scheduled to start late next year with completion expected by late 2027.
“We are proud of how this site and its people continue to support our customers,” said Bryan Walsh, Duke Energy’s vice president of Regulated Renewables and Lake Services. “Multiple former Allen plant employees now work on our Regulated Renewables team, which maintains and operates the new batteries at Allen and elsewhere in the Carolinas. Duke Energy’s test site for new battery technologies, its Emerging Technology and Innovation Center, is also in Mount Holly.”
As part of an ongoing rate review before state regulators, Duke Energy has proposed a third BESS at Allen by late 2028 along with plans for a regional operations facility that could employ up to 50 people; these proposals await regulatory approval.
Duke Energy Carolinas supplies electricity to nearly three million residential, commercial and industrial customers across North Carolina and South Carolina through its network totaling more than 20 gigawatts of capacity within a service area covering about 24,000 square miles.
Duke Energy itself serves more than eight million electric utility customers across six states through subsidiaries owning over fifty-five gigawatts of generating capacity. Its natural gas utilities serve another nearly two million customers across five states.
