The United States has substantial coal reserves. (AP Photo/Daniel R. Patmore)

In the United States close to 50 percent of the nation’s electricity comes from the burning of coal. It is not a clean source. World-wide about 20 percent of all greenhouse gas emission comes from coal-fired plants, and the U.S alone put out close to two billion tons of CO2 yearly.

But the United States has substantial coal reserves and the coal industry is today working on technologies that will make it possible to burn coal without causing major CO2 pollution.

Most methods fall under the headline “carbon capture and storage” (CCS), where CO2 is stripped out of the coal-burning or coal-gasifying process and stored underground. The underground storage of CO2 has two advantages. It reduces CO2 significantly, and it forces reluctant liquids, like oil, to the surface.

Carbon capture can occur at three different points. Before coal is burned, after it is burned, and during the actual combustion process. Tenaska’s planned coal-burning plant in Texas will, for example, focus on the gas that remains after the coal is burned capturing 90 percent of the CO2.

Although environmental groups have said that there is no such thing as clean coal, the technology has already been put into commercial practice. CO2 is, for example, stripped out of natural gas produced at the Sleipner Field in the Norwegian North Sea and injected into a layer of porous sandstone 2,600 feet under the surface, and the Weyburn project has been taking the CO2 produced at a synfuels plant in North Dakota and sent it to oilfields in Saskatchewan.

Here Dr. Greg Kunkel Tenaska’s vice president of environmental affairs, talks about the planned Trailblazer Energy Center in Texas.