Why Clean Coal Is Years Away

America runs on coal. It's cheap, plentiful (at least for another 100 years or so), and comfortingly domestic. Two hundred years ago, it powered the industrial revolution. Today, it spits out nearly half of the country's electricity.

Coal smoke and steam vapor pour out of the Bruce Mansfield Power Plant over a nearby residential area in Shippingport, Pennsylvania.

Coal's problems, however, are getting to be so big and serious that they are not just overshadowing the industry but threatening to render it obsolete. About 80 percent of the electricity sector's carbon dioxide emissions come from burning coal. A price on CO2 pollution, which Congress might impose as early as this year, is expected to be so costly that the mere prospect of it is already shaking things up. Some states have banned new coal plants, and many companies are canceling their plans in other places.

The industry's greatest hope for survival, as far as CO2 emissions go, is a work-in-progress technological arsenal known as carbon capture and storage, or CCS. With all the makings—and risk—of a classic American gamble, it is in some ways the energy equivalent of missile defense. It's ambitious, expensive, intricate, and wildly controversial.

Cue the requisite political theatrics in Washington and, behind them, more serious questions about the promise of "clean coal" versus the reality. Last fall, at a campaign rally, then Sen. Barack Obama said, "Clean coal technology is something that can make America energy independent." The coal industry itself is spending millions of dollars on ads—placed in newspapers, pasted to public buses, and shellacked across subway station entryways—that boast of its commitment to "clean coal technology." Environmentalists have aggressively volleyed back. Clean coal, they say, doesn't exist.

It would be helpful if everyone were using the same definition. The term "clean coal," though alliteratively pleasing, is far from straightforward. Besides CO2, coal plants emit mercury, particulate matter, nitrogen oxides, and sulfur dioxides. What doesn't go into the air often ends up in the ground as fly ash, a sludgelike material that became big news last year when a retaining wall at an ash dump in Tennessee suddenly gave way, releasing thousands of pounds of waste into people's front yards. So, it's not just CO2 that's problematic. In fact, in the early 1990s, clean coal referred almost exclusively to efforts aimed at curbing nitrogen and sulfur pollution. Today, clean coal has morphed to mean coal from a plant that doesn't emit CO2. And it doesn't exist yet.

Making it happen, roughly speaking, will require three steps: capturing the carbon dioxide discharge from a plant's smokestack before it escapes; compressing it into a liquid and transporting that through a pipeline; and storing the compressed CO2 underground in a repository for hundreds, if not thousands, of years.

To get a sense of where the field stands, take a look at the Mountaineer power plant in New Haven, W.Va., a coal-fired facility that sits on the Ohio border. Built in 1980, it emits about 8.5 million metric tons of carbon dioxide annually. But it's undergoing a series of major changes to convert it by the end of the year, if all goes well, into one of the country's most ambitious, active clean coal projects. Battelle, the project's main contractor, is currently drilling several deep underground wells at the site. Special chemicals are being added to the smokestack to separate CO2 from the rest of the emissions. Initially, the goal is to capture and store about 100,000 to 300,000 metric tons of CO2 annually, and then to go up from there, says Neeraj Gupta, Battelle's research leader. "It's happening now. We can do it," says Gupta. "Just like with oil and natural gas, it's a matter of where, under what conditions, and at what cost."

Just getting to this point—100,000 tons of CO2 is, after all, slightly over 1 percent of the plant's annual emissions—has taken years of work and research, many false starts, new leads, exciting breakthroughs, and thousands of hours of laboratory testing and analysis. On the other hand, it wasn't until 1998, a mere decade ago, that the Department of Energy formally carved out a budget for this type of work.