Why Clean Coal Is Years Away

Coal is here to stay, but efforts to cut emissions are ambitious, expensive, and have largely stumbled.

Coal smoke and steam vapor pour out of the Bruce Mansfield Power Plant over a nearby residential area in Shippingport, Pennsylvania. The 2460 MW coal-fired plant in western Pennsylvania is one of the 12 biggest carbon dioxide polluting power plants in the U.S.

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

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In fact, it has really been the oil and natural gas companies, as well as private contractors, that have been the biggest backers of capture technology. Around 2001, a group of eight oil firms, including Chevron and BP, started the CO2 Capture Project. During the first few years, they waded through thousands of technical reports and papers on all sorts of schemes for capturing carbon, from gasifying coal to using new chemical solvents and biological membranes. By 2005, they had narrowed their list to the most promising ideas and headed to the laboratory. "What we are looking for is trying to gain more options, newer breakthrough technologies," says Arthur Lee, a principal adviser at Chevron. "The whole chain still needs some work. Capture costs are high, but if those can come down, that will make a huge difference." The next step, slated to begin this year, is to deploy these technologies in small-scale pilot tests.

On the storage side, the work dates back even further and spans the Atlantic. Oil companies have for decades been pumping carbon dioxide into oil wells to force out the stubborn hydrocarbons that don't come up with conventional methods. Of course, the idea there is mainly to inject gas—not to put it in, store it, and keep it there permanently.

Elements of the storage portion are clearly doable. Norway has, since the mid-1990s, been investing huge amounts to inject and store carbon dioxide under the North Sea. So far, so good. The Sleipner Project, as it's known, stores about 1 million metric tons of CO2 annually. But the site itself is singularly important. What works in one place might not work in another. Each underground site has unique curves, gradients, mineral compositions, porosity values, dips and rises, and seismic activity. Certain types of sites, such as salty aquifers, are more promising because they tend not to leak. In fact, according to Chevron's Lee, as well as the United Nations Intergovernmental Panel on Climate Change, if the appropriate geological site is picked, more than 99 percent of CO2 pumped in is "very likely" to remain there for 100 years, and that amount is "likely" to stay trapped for 1,000 years. Still, every potential site—and there are many of them throughout the United States—has to be scouted out, assessed, analyzed, and modeled.

The most daunting challenge, then, is for companies to begin combining the capture and storage parts together in real life, at the right location, and to scale it up to a level that might actually help reduce global warming pollution. That's part of the idea behind the Mountaineer project, although it is admittedly well below commercial scale. Another so-called milestone project, in Wisconsin, isn't even that far along. It's merely trying to capture the CO2 from 1 percent of its waste stream, but with no plans for storage, it must release the CO2 back into the air. "The big hurdle is getting the first couple built," says Steve Caldwell of the Pew Center on Global Warming. "No one has built one of these yet; no one has gotten the money to build a 500-megawatt plant with CCS."

In fact, there have been a number of plans to do so, but they haven't turned out so well. In most cases, they've been heralded by news releases and applause. Then, they quietly fall apart. A prime example is an effort by BP and mining giant Rio Tinto in western Australia called Kwinana. When the project was first rolled out in 2007, the companies planned to spend up to $2 billion on a state-of-the-art, coal-fired power plant that would capture 90 percent of its carbon dioxide emissions and store them underground. In May 2008, however, the companies canceled the project. It turned out that the site they picked had too many cracks in it.

Cost overruns. A more high-profile debacle came with an ambitious project known as FutureGen, which was pitched in 2003 as the first zero-emissions coal plant in the United States. Today, it is truly a zero-emissions project—because it doesn't exist. The idea was to have it work as a cost-share between the government and the private sector. By 2006, a number of private companies and several foreign governments were on board. The project was showing promise. The question was where it would be built. By late 2007, the Department of Energy had narrowed its list of sites under review to four: two in Texas, two in Illinois. Ultimately, the winner was Mattoon, Ill., a nice rural area about 50 miles east of Springfield. A month and a half later, however, the Bush administration abruptly pulled out—yanking some $1.3 billion, at last count—citing cost overruns. The project is now stuck in legal-political-economic purgatory, Illinois lawmakers are asking President Obama to restore its funding, and the whole thing has become a nagging counterpoint to the idea that clean coal will ever be a reality.