A convenient untruth

- If shooting carbon dioxide emissions back underground is such a great idea, why is no one doing it? The convenient lie about coal is that it can be "clean."

True, there are varieties of coal that, when burned to make electricity, emit somewhat less sulphur, nitric oxides and other nasties than "dirty" coal does. There are also technologies that improve combustion efficiency. But there's no technology that allows coal to be burned without producing carbon dioxide, the main greenhouse gas.

Fear not, say the propeller heads, because we bring you CCS-carbon capture and storage. The carbon dioxide is stripped from a coal-fired power plant's inlet or outlet stream, compressed and injected into leak-proof geological formations in the bowels of the Earth. The technology exists.

CCS sounds like a wonderful, planet-cooling idea except for one thing: It's unaffordable. As a rule of thumb, a power plant with a CCS system would cost about 50% more to build than one without. The suggested total price tag for a CCS-equipped plant is $1 billion plus (all currency in U.S. dollars). The electricity generated by the plant would cost consumers about 50% more, too.

The reason is that it takes huge amounts of energy to capture and compress the carbon dioxide. In a 2005 report, the Intergovernmental Panel on Climate Change estimated that a CCS plant requires 10% to 40% more energy than a conventional plant. Greenpeace says a coal plant with CCS actually consumes 30% more coal.

But the enormous cost of CCS hasn't stopped coal producers, power utilities and, to a lesser extent, oil and gas companies, from using it to pump up their environmental propaganda. The American Council for Clean Coal Electricity, whose 48 coal companies and power suppliers say they're spending $3.5 billion on CCS projects, runs TV ads that say CCS is part of a clean coal strategy to preserve "the American way of life we all know and love." The International Energy Agency has called for governments to invest $20 billion in CCS development. Dozens of CCS projects, from Alberta (TransAlta's Project Pioneer) to Germany, are under way. Within years, the carbon dioxide problem should be buried, literally.

But just as several CCS projects are being launched with green-soaked fanfare, more than a few are being quietly dropped. About a year ago, Norway's StatoilHydro and Shell scrapped plans to build a gas-fired power plant that would have stuffed stripped-out carbon dioxide in two offshore oil wells.

About the same time, BP (the former British Petroleum) pulled out of two CCS developments-one in Scotland and one in Australia. Last year, the U.S. Department of Energy killed the much-hyped, $1.8-billion FutureGen project, which would have buried the carbon dioxide produced by Illinois coal plants. The inconvenient truth is that not a single industrial-scale, power-related CCS project is up and running anywhere on the planet. Climate Change Capital, a London firm that invests in clean energy projects, has tried without success to find a CCS project with any commercial potential.

Sheer expense, not technology, is the barrier. The technology, in fact, has been used for decades by the oil and gas industry. Producers in Texas use a vast underground carbon dioxide storage reservoir as a sort of gas bank. Carbon dioxide is withdrawn and injected into ailing fields to "sweep" stubborn oil to the pumping wells. The technique is also used in some fields in the Middle East.

What is new is the idea of burying the carbon dioxide produced by coal-fired power plants (coal generates about half of the electricity in the U.S. and 20% of Canada's). The goal is to store it permanently in, say, deep saline aquifers, or in reservoirs that the oil companies can tap later. It's a shame about the price, though.

True, some CCS projects will work. If cap-and-trade programs for greenhouse gas emitters become the global norm, the high carbon values would make some CCS projects economical. Distance is the other key variable. A coal-fired power plant that is close to both a coal reserve (shorter rail journeys) and an oil reserve (shorter pipelines) might make economic sense. But that geological convenience is elusive, although bits of Western Canada might make the short list.

If CCS were cheaper, it would become ubiquitous, and carbon levels in the atmosphere would stabilize. CCS projects could, of course, go ahead with huge subsidies. But subsidies often disappear, potentially leading to a double tragedy: white-elephant CCS projects and no reduction of carbon dioxide output from coal-fired plants. It might be time to take another look at energy conservation and nuclear generating plants instead.