As Duke Energy prepares to shut down and demolish its coal-fired Allen plant west of Charlotte, it's planning a new use for the site — huge batteries to store electricity generated elsewhere.
Allen, named for a former Duke president and chairman, has been a workhorse among Duke's power plants since it opened in 1957 on Lake Wylie in Gaston County. The plant supplies electricity to a wide area of western North Carolina and South Carolina.
It's shutting down along with other coal plants as Duke shifts to energy sources that emit less of the carbon pollution that causes climate change.
"This plant has been faithfully serving customers in North Carolina and South Carolina since 1957," Duke spokesman Bill Norton said during a media tour Thursday. "But it has reached the end of its useful life. So we're beginning the demolition phase of the power plant so it can make way for future battery storage."
Duke said it will initially build two arrays of batteries on the site to store electricity from other plants, primarily nuclear and solar energy. About 40% of the cost will be paid by the federal government, with Inflation Reduction Act funds. Norton said Duke doesn't have cost estimates yet for the battery projects.
One set of batteries will open by the end of 2025 on 7.5 acres next to an electrical substation across the street from the plant. The other is expected to be ready in October 2027, on the site of the plant's large main smokestack.
The first array of lithium-ion batteries — the same material as in your phone — will be able to supply 50 megawatts of electricity for four hours, enough for about 50,000 homes. When it opens, it will be Duke's largest battery.
The second array of batteries will be even larger, covering about 10 acres and having a capacity of 167 megawatts and four hours.
Duke has been shutting Allen's five coal-burning units gradually since 2021. The final unit will close at year's end. Its current capacity of 426 megawatts is a little less than one-third of its peak output.
When the Allen plant retires, the lost electricity will be replaced by a new gas-fired generating unit in Lincoln County.
Duke is currently preparing the old plant for demolition. Neighbors will see the plant's iconic red and white striped smokestacks start coming down next year.
About half the plant's remaining 45 employees will move to other jobs at Duke. The rest will retire.
Norton said Duke chose to put batteries on the Allen site, instead of a new generating plant, because most of the land is needed for disposal of coal ash, the toxic residue left after burning coal.
A legal settlement requires Duke to dig up 20 million tons of ash dumped in pits at the site and move it to a series of new lined landfills being built there. That work will continue through 2038.
