CHARLOTTE, N.C. — Duke Energy has officially brought a new 50-megawatt (MW) battery energy storage system online at the site of the former Allen coal plant on Lake Wylie. The milestone marks a significant step in the utility’s transition toward cleaner energy and grid reliability for North and South Carolina.
The $100 million project, which was completed under budget and ahead of schedule, began serving customers in November, with final testing concluding this month. This activation is just the beginning of a larger transformation for the site; the company announced plans to begin construction this May on a second, significantly larger 167-MW battery system—the largest in Duke Energy’s fleet.
Turning a Legacy Site into a Modern Hub
The new infrastructure is located in Belmont at the site of the Allen coal plant, which retired in December 2024. By repurposing this land, Duke Energy is leveraging existing grid connections while benefiting from federal incentives.
Both the newly active battery and the upcoming 167-MW system qualify for investment tax credits that will offset roughly 40% of the costs for customers. This includes a 30% base credit plus an additional 10% bonus for reinvesting in an “energy community” affected by coal plant closures.
“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.”
Enhancing Grid Reliability
Utility-scale batteries are becoming critical tools for managing energy demand. According to the company, these systems are essential for cold winter mornings, filling the generation gap before solar power ramps up. During periods of low energy demand, the batteries can store excess clean power—such as that generated by the nearby Catawba Nuclear Station—and release it during high-demand windows.
This capability is vital as the region faces unprecedented growth. Duke Energy projects that customer energy needs over the next 15 years will grow at eight times the rate of the previous 15 years.
A Broader Strategy for the Carolinas
The activity at the Allen site is part of a sweeping long-term strategy. Duke Energy’s “2025 Carolinas Resource Plan,” currently under review by regulators, targets the addition of 6,550 MW of battery storage by 2035—enough to power over 5 million homes during peak usage.
Upcoming projects include:
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Allen Site (Phase 2): Construction of the 167-MW battery begins May 2026 on the footprint of the former coal plant’s emissions control system.
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Riverbend Site: A 115-MW battery is planned for the retired Riverbend coal plant site in Mount Holly, with construction expected in late 2026.
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Future Proposals: The company has proposed a third battery for the Allen site by 2028, alongside a potential regional operations and training facility that could house 20 to 50 employees.
“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, noting that multiple former Allen plant employees have transitioned to roles within the renewables team.
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