Duke Energy Carolinas, a unit of Duke Energy (NYSE: DUK), will retire 1,667 MW of coal-fired capacity that do not have emissions control technology installed as part of an air permit-related settlement the utility reached with several environmental groups on Jan. 17.

Duke reached the settlement with the groups, including the Environmental Defense Fund, the National Parks Conservation Association and the Sierra Club, to resolve an administrative challenge to an air permit for the 825 MW Cliffside Unit 6 in North Carolina. The unit is under construction and near completion.

Duke previously committed to retiring the coal-fired capacity in its annual Integrated Resource Plans. The settlement makes the plan enforceable. The settlement also calls for Duke Energy to demonstrate best practices to decrease emissions during malfunction, shut down and start up situations.

"We are pleased to have reached this agreement with the environmental groups regarding our Cliffside project - to make enforceable our plans before the state utility commissions to retire our older coal plants," said Thomas Williams, spokesman for Duke Energy. "The agreement removes the final legal issue related to the Cliffside project."

The Cliffside Unit 6 under construction will use a selective catalytic reduction system, a baghouse and two flue gas desulfurization systems, or scrubbers. A scrubber was added to Unit 5 in 2010.

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