Duke Energy turns former coal plant into $100 million battery storage space
Duke Energy’s former Allen Steam Station in Belmont is getting a new life, powered by batteries.
A 50-megawatt, four-hour battery energy storage system (BESS) was launched at the old coal plant on Wednesday, marking the beginning of the utility’s investment in that form of energy. The new storage system costs about $100 million, according to a news release.
Roughly, 50-megawatts could power 38,000 homes, if the batteries were used in that way.
But battery storage is what it sounds like. When energy demand is low or when prices are cheaper, the utility can store energy in these battery systems for future high usages, such as an extremely hot summer day or a chilly early winter morning. And those usages would be in four-hour intervals.
So, the batteries wouldn’t power the grid consistently, just when necessary. It’s one way the Charlotte-based utility giant plans to diversify its energy sources to meet a growing need, according to the release and Duke Energy’s Carolinas Resource Plan.
Duke Energy, growth and battery usage
According to Duke Energy, customer needs over the next 15 years will grow at eight times the rate of the previous 15 years.
To put it in perspective, South Carolina uses about 80 terawatt hours per year, Glen Snider, the managing director of integrated resource planning, previously said. The expected growth “is equivalent to what South Carolina consumes today,” Snider said.
One of the ways the utility wants to meet the need is through battery storage. And one of the main reasons the utility wants to use that form of energy is because tax credits are available to subsidize the cost.
Using the federal tax credits will offset customer costs by 30%, according to the company.
Another 10% is being offset because Duke Energy is reusing the former coal plant to build the storage units. The Allen plant was retired in December 2024.
In the utility’s next battery phases, Duke Energy plans to build another storage system at the Allen plant. It will be the utility’s largest at 167-megawatt. Construction will being in May.
The goal is to add 6,550 MW of batteries to the utility’s belt by 2035, according to the resource plan, which is still under review by the state.
That would power more than 5 million homes during high-energy times, the company said.
What’s next for Duke Energy?
To get to that 6,550 MW goal, more battery storage systems will need to come online.
Duke Energy also plans to use the former Riverbend Steam Station in Mount Holly. It will put a 115 MW, four-hour system there. Construction should begin this year.
Duke Energy’s plans call for battery storage at both of Gaston 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.
The utility is also proposing to construct a third battery system at the Allen Plant and a warehouse for batteries and renewables. The plan is wrapped into Duke Energy’s rate-increase review, which is also being looked at by the state.
The proposal would see the utility spend $1.7 billion in battery storage projects. To do that, Duke Energy wants to see a 15% rate increase for customers between 2027 and 2028.
For Duke Energy Carolinas customers, the monthly bill would increase by $17.22 in 2027 and again by $6.34 in 2028. In the first year, that would take average bills from $144.98 to $162.20.
For Duke Energy Progress customers, bills would increase by $23.11 in 2027 and $6.59 in 2028. That would take the monthly bill in the first year from $163.84 to $186.95.
The proposal is sitting before the state utilities commission. Public hearings on the proposal are set for the spring and a decision would be made later this year.
This story was originally published January 15, 2026 at 5:34 AM with the headline "Duke Energy turns former coal plant into $100 million battery storage space."
