BESS brightens former Duke Energy coal plant in N.C.
Duke Energy’s Allen coal plant is now home to a pair of battery energy storage systems (BESS) that will serve customers in North and South Carolina.
The utility company brought the first system online in November, a 50 MW, four-hour facility located on Lake Wylie in Gaston County, N.C., which cost approximately $100 million and was completed under budget and ahead of schedule. Final testing is being completed this month.
Construction of a second BESS, a 167‑MW, four-hour system — Duke’s largest — will begin in May on 10 acres where the coal plant’s now-demolished emissions control system once stood.
Both lithium-ion battery systems qualify for federal investment tax credits, which will offset 40% of the cost for Duke Energy customers. That figure includes an extra 10% for reinvesting into an energy community. 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.”
Duke’s BESS investments
Utility-scale battery systems are particularly useful for cold winter mornings before the sun comes up, filling the gap before solar generation is available. During low-demand periods, they can also store excess energy — such as the power generated by Catawba Nuclear Station just across Lake Wylie — for use during high-demand periods.
Duke Energy plans to make similar battery storage investments in multiple counties across the Carolinas. The company’s 2025 Carolinas Resource Plan, now under review by state regulators, projects the addition of 6,550 MW of batteries by 2035 to protect reliability and meet growth needs in North Carolina and South Carolina. That’s enough storage to power more than 5 million homes during times of peak energy use.
Duke Energy’s long-term plan maintains a diverse energy mix, adding solar, storage, nuclear and natural gas generation to meet electricity demand that’s rising at an unprecedented pace. Across the Carolinas, customer energy needs over the next 15 years are expected to grow at eight times the growth rate of the prior 15 years.
Retiring coal plants
The plan also maintains Gaston County’s legacy of supporting the company’s customers across both states. Duke Energy’s plans call for battery storage at both of the county’s retired coal plant sites along the Catawba River, Allen (1957-2024 in Belmont) and Riverbend (1929-2013 in Mount Holly). Construction of the latter, a 115 MW, four-hour BESS, is expected to begin in late 2026, coming on line in late 2027.
“We are proud of how this site and its people continue to support our customers,” said Bryan Walsh, Duke Energy’s VP 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 the company’s rate review now before the North Carolina Utilities Commission, Duke Energy has proposed a third BESS at Allen to come on line by the end of 2028, as well as a regional operations, training and warehouse facility for batteries and renewables that could house 20-50 employees. Plans for both are still evolving and subject to regulator approval.
