Duke Energy Carolinas LLC identified early retirement plans for five coal units in an annual depreciation study filed with North Carolina regulators as part of its new rate case.
Units at the G.G. Allen, James E. Rogers Energy Complex (Cliffside) and Marshall coal plants "have life spans that are planned to be shorter than currently approved," the Duke Energy Corp. subsidiary wrote in testimony filed Sept. 30 with the North Carolina Utilities Commission.
Duke Energy Carolinas, or DEC, highlighted the probable retirement of Allen units 4 and 5 in 2024, which is four years earlier than previously planned. The utility's 2018 integrated resource plan called for retiring all five units at the 1,130-MW G.G. Allen coal plant in Gaston County, N.C., by December 2028, beginning with units 1-3 in December 2024.
The 2018 integrated resource plan also assumes the retirement of the 546-MW unit 5 at the former Cliffside coal plant in December 2032. The depreciation study moves this retirement up to 2026.
DEC said in October 2016 that it would spend about $56 million to modify units 5 and 6 at its 1,390-MW James E. Rogers Energy Complex in Cleveland County, N.C., to co-fire on natural gas.
In addition, DEC plans to retire Marshall units 1 and 2 in 2034. The utility said in February 2018 that it plans to spend about $200 million to retrofit all four units at its 2,078-MW Marshall coal plant in Catawba County, N.C., to co-fire on natural gas.
The revised retirement plans come as DEC filed Sept. 30 for a $445.3 million base rate increase in North Carolina to cover "costs incurred to maintain and modernize the company's electric system" while generating cleaner power, improving reliability and restoring service after major storms.
The company said it also will use funds to "responsibly close coal ash basins and operate active coal plants" as it seeks to reduce its reliance on coal.
DEC said it plans to partially offset the 9.2% increase with a rate reduction of $154.6 million achieved by refunding certain tax benefits tied to the federal tax overhaul of 2017.
(NCUC docket E-7 Sub 1214)