CHARLOTTE -- Duke Energy won approval Tuesday for the last coal-fired boiler, a technology used since the 1920s, it might ever build.
But as an old era ends, a new one begins: controlling the planet-warming carbon dioxide that coal plants pump out by the millions of tons a year.
In approving the expansion of the Cliffside plant 50 miles west of Charlotte, North Carolina apparently became the first state to force a utility to retire old power plants to offset the carbon emissions of a new one.
To compensate for the new 800-megawatt unit at Cliffside, Duke will retire four old boilers there and shut down other plants to trim 800 megawatts by 2018. The utility plans other carbon-saving measures, including a new nuclear plant in South Carolina.
"What we are signaling through these actions is our intention to reduce our carbon footprint and our openness to the public for ideas on how to do this," said Duke Carolinas President Ellen Ruff.
Critics, who have been fighting the plant for two years, claim energy efficiency and the expanded use of renewable sources such as wind power could eliminate the need for the expansion.
They also point out that five other states have blocked new coal plants because of global-warming concerns. The N.C. permit, they add, neither shrinks nor increases Duke's carbon output.
"They're not proposing to make the problem worse," said Bruce Nilles, who heads the Sierra Club's national coal campaign.
Duke could benefit from Tuesday's agreement if the federal government, as widely expected, places limits on carbon dioxide emissions. Regulation of the gas is expected to expand a marketplace for carbon "credits" that Duke could claim.
"We saw the writing on the wall," said Keith Overcash, the N.C. air-quality chief, "and I think Duke did too."
Critics might fight expansion
Critics were mixed on whether the new permit would be challenged in court. They have 60 days to decide.
In Charlotte, the Catawba Riverkeeper Foundation said it will fight the plant. The Carolinas Clean Air Coalition vowed the permit "will not go unchallenged."
Duke says it will start construction immediately. Cliffside's new coal unit will be the first Duke has built since finishing the Belews Creek plant, near the Virginia line, in 1974.
Business and political leaders in Rutherford and Cleveland counties widely supported the expansion. Duke expects 1,600 construction workers, with a payroll of more than $100 million, to do the work.