Cleaning up coal

Fifth in a series

HALF OF all the electricity in the United States is produced by burning coal, the fossil fuel that creates the most carbon dioxide. China, which trails only the United States in production of greenhouse gases like CO₂, also has large coal reserves and plans to build more than 500 new coal-burning power plants by 2012. If it does, and if the United States doesn't change the way it generates power, the CO₂ emissions from all these plants will greatly exceed the cutbacks promised by nations that have signed the Kyoto Protocol. Climate change will speed up, with unpredictable effects.

But what if there were a way to use all this abundant coal without emitting CO₂?

Happily, there is. The trick is first to gasify it to produce a fuel similar to natural gas. Before that gas is burned to spin turbines and generate power, the CO₂ can be extracted, along with sulfur dioxide, mercury, and other pollutants. After it is captured, the CO₂ can be pumped deep into the earth.

The one drawback to the technology is the cost. Gasifying coal adds as much as 1 cent to the 4.5-cent cost of a kilowatt-hour generated by a conventional coal plant. Capturing and storing the CO₂ from the coal adds an additional 1.5 to 2 cents. Coal gasification will not make much headway in either competitive or regulated power markets unless the United States tilts the board by taxing power producers' CO₂ emissions or putting a cap on them.

Even without such a clear signal from Washington, two large power companies, Cinergy and American Electric Power, are considering coal gasification projects. Leaders of companies like these are only too aware that if Congress ever imposes carbon limits, extracting CO₂ from the exhaust of conventional coal plants will be much more costly than from a gasification plant.

If built, these demonstration gasification plants would also serve a political purpose. Unless the Midwestern, Western, and border states that produce most of the nation's coal are shown that their fuel has a role in an America that is serious about global warming, their elected representatives will oppose stiff measures to limit greenhouse gases.

From the beginning of the Industrial Age, when CO₂ emissions from fossil fuels started building a greenhouse layer in the atmosphere, coal has been the worst offender. Gasification and storage provide it a chance for a Cinderella transformation, in the United States and elsewhere. But it won't happen in a meaningful way in this country until cheap, conventional coal-burning is forced, through a tax on carbon or a carbon cap, to pay its true cost to the planet's health.