Is 'clean' coal the answer?

Duke Energy pushes for energy created with coal; skeptics call the fuel filthy

As coal use goes, the power plant expansion proposed by Duke Energy outside Charlotte would be as clean as they come.

New units proposed at the Cliffside plant would trap most environmental pollutants, such as fly ash, sulphur and nitrogen oxides. It would generate electricity more efficiently, burning 10 percent less coal than a conventional power plant. And it has qualified for $125 million in federal tax credits to promote emerging clean-coal technologies.

But critics say that even the cleanest coal plant is obsolete. When coal burns, it emits carbon dioxide, the heat-trapping gas that's taking most of the heat for global warming.

Coal-burning power plants are among of the biggest sources of the greenhouse gases that are accumulating in the Earth's atmosphere. Scientists have projected that unabated, global warming could increase the planet's average annual temperature by 4 to 8 degrees in this century, melting polar ice caps, raising ocean levels and causing widespread economic disruptions.

Duke Energy's Cliffside plant, proposed to be built west of Charlotte, showcases how far coal-burning technology has advanced in recent decades. But it's also a reminder that coal remains a problematic energy source that's too cheap and too abundant for most utilities and their customers to pass up.

To supporters, new power plants such as Cliffside represent an important technological step in the federal government's slow march toward a distant goal: a virtually zero-emissions coal-fired power plant.

"These are pristine compared to the old systems," said Bob Romanosky, a technology manager for advanced power research in the U.S. Department of Energy's National Energy Technology Laboratory in Morgantown, W.Va.

The goal -- a power plant able to trap carbon dioxide and safeguard the gas in permanent subterranean storage -- is at least several decades away. Trapping the gas in North Carolina would require hundreds of miles of pipelines to transmit the gas to the nearest geologic depository, likely offshore.

With nowhere to go but up, the proposed Cliffside project would release 11.5 million tons of carbon dioxide annually, equivalent to nearly one million automobiles.

"Cliffside is filthy," Sierra Club lawyer Bruce Nilles said of the proposal. "In essence, it would emit as much carbon dioxide as [a power plant] built 60 years ago."

The project is opposed by the state attorney general, energy efficiency advocates and at least 600 residents who wrote e-mail or letters to state officials.

Duke is asking the state Utilities Commission to approve the Cliffside project by Feb. 28 so that the company can begin building to satisfy projected energy demand. Company officials are in a rush, hoping to avoid an environmental tax on coal-fired plants that's widely expected from the new Democratic majority in Congress, which is making global warming issues a priority.

The Cliffside proposal is supported by the Public Staff, the consumer advocacy arm of the utilities commission. The Public Staff agrees with Duke that a coal-burning plant is the most cost-effective way to satisfy increasing energy demand in a booming region. The cost of the plant -- $3 billion plus several hundred million dollars in financing -- would be paid by Duke's 2.1 million customers in the Carolinas.

It's been two decades since the nation's last major phase of coal-fired power-plant development, but coal is on the cusp of a new wave. About 150 coal-fired power plants could be built by 2030, the Department of Energy says. About half the nation's electricity comes from coal, the single-largest fuel source for electricity generation.