The Charlotte-based utility was given its final air permit to build an 800-megawatt unit, and company officials said they plan to begin construction immediately. The permit imposes emissions standards stricter than federal or state requirements for sulfur dioxide and nitrogen oxide, and mercury standards tougher than federal limits.
"This is the final milestone prior to beginning construction on the new unit, which will serve increasing customer demand and population growth in the Carolinas," said James L. Turner, Duke Energy president and chief operating officer.
Construction is expected to take four years, and officials said it will create 1,600 new jobs with a total payroll of about $100 million. The cost of the plant stands at $2.4 billion.
Once the unit is operational, Duke Energy said it will shut down four smaller coal-burning plants, all built in the 1940s. The generator is an upgrade to Duke Energy's Cliffside plant, which straddles Rutherford and Cleveland counties, about 50 miles west of Charlotte.
The project has been strongly opposed by several environmental groups, and many have accused Duke Energy of not fully considering the use of conservation efforts and renewable fuels, such as solar and wind power.
One group said Tuesday the generator will "increase hazy skies, worsen acid rain, and deposit large amounts of toxic mercury" in Great Smoky Mountains National Park, the county's most-visited national park.
"While permit improvements have been made that could lessen impact on the Smokies, no one can know for sure because the state has excused Duke from fully analyzing the fate of its pollution," said Stephanie Kodish, an attorney for the Coal Litigation Program National Parks Conservation Association.
The company originally sought a permit for two new 800-megawatt coal-fired units, but won permission from the North Carolina Utilities Commission to build only one generator at the site.
Most expected the permit to be granted, but the legal challenges and appeals promised by opponents on the upgrade could drag on for more than a year. In that time, the cost of the plant -- which increased from $1.53 billion in March to its current $2.4 billion -- could rise again.
Environmental groups said they will try to delay the project until it Duke Energy no longer considers it a cost-effective solution.