Duke Energy, one of the nation's biggest users of coal, is trying to gauge what it would cost to stop buying coal mined by the controversial practice of mountain coal removal.
The Charlotte power company, which sells electricity in five states and has 1.8 million customers in North Carolina, is asking its suppliers to estimate the cost of coal that doesn't include any mined by removing mountaintops.
Duke said it is internally reviewing its position on mountaintop-surface mining as federal regulators focus attention on the practice. Other power companies, such as American Electric Power, are considering adopting environmental review standards for coal suppliers that could penalize mountaintop mining.
Mountaintop mining is a form of strip-mining that exposes coal veins near the surface. It is cheaper and considered safer for miners than underground coal extraction. But the practice can bury streams with mounds of refuse rock, harming habitats and degrading water quality.
The mining practice is primarily used in Kentucky and West Virginia. Duke and Raleigh-based Progress Energy import nearly all their coal from Appalachian coal mines. About half the coal - about 15 million tons a year - comes from mountaintop removal, while the rest comes from underground coal mines. North Carolina is one of the nation's top users of mountaintop coal.
About half the electricity used in North Carolina comes from coal-burning power plants, and about half the coal for those plants comes from mountaintop blasting.
Duke warned that excluding coal mined in this fashion could raise fuel costs and increase power bills for customers.
