Duke Energy Carolinas LLC will invest about $200 million as part of a plan to retrofit all four units at its 2,078-MW Marshall coal plant in North Carolina to co-fire on natural gas.
Duke Energy Corp. on its fourth-quarter 2017 earnings call said it has added the Marshall plant to its list of planned conversions. Duke Energy has previously outlined plans to convert the 2,220-MW Belews Creek and 1,400-MW James E. Rogers Energy Complex (Cliffside) facilities, each of which has two units, to co-fire on natural gas. All of the facilities are owned and operated by Duke Energy Carolinas.
"We will use co-firing of coal and natural gas at Rogers, Creek and Marshall to reduce our carbon emissions and increase our flexibility to manage costs, providing savings for customers," Duke Energy Chairman, President and CEO Lynn Good said on the Feb. 20 call.
Once the retrofits at Marshall are complete, supercritical units 3 and 4 will be able to run on up to 50% natural gas with units 1 and 2 able to run on up to 30% natural gas, according to Duke Energy spokesman Rick Rhodes.
The retrofit of units 3 and 4 is expected to be complete by 2020 with the older units, which first came online in 1965 and 1966, operating under dual fuel in 2021, Rhodes said.
The natural gas will be supplied by Duke Energy subsidiary Piedmont Natural Gas Co. Inc.
Rhodes said the retrofits will allow the units to cycle up and down more quickly to back up Duke's renewable fleet.