According to Duke's 2007-08 Sustainability Report, Duke Energy Carolinas could retire about one-third of its coal-fired plants, while tripling its gas-fired plants and doubling its nuclear power plants. 

The plan lays out a 22-year plan for reducing the company's dependence on coal and cutting greenhouse-gas emissions. While the goals are not hard and fast, the company believes they provide a realistic baseline for discussions about cleaner energy production, a Duke spokesman says. 

For instance, the company says it could double its natural gas-fired generating plants in the Midwest by 2030 and retire about one-fourth of its coal-generating capacity by then. 

Renewable sources of energy could provide about 10 percent of the company's power generation by 2030, Duke says. 

The company's goals also include: 

Reducing nitrogen oxide and sulfur dioxide emissions this year from its coal-fired plants by 10 percent and 35 percent, respectively, from 2006 levels; 

Reducing emissions from its on-road and off-road vehicles by an average of 35 percent by 2012, compared with 2006; and 

Replacing older natural gas lines to reduce leaks. 

Charlotte-based Duke Energy (NYSE:DUK) has operations in the Carolinas, Ohio, Kentucky and Indiana.