Recently, I did an admittedly quick study of the scientific literature using SCIRUS and Academic Search Premier as search engines about underground-coal gasification (UCG). I found that there is research being conducted that looks very promising, especially in China and secondarily in India and the U.S.
My anti-coal credentials are fairly strong, as I went back to school in 1976 just so I could become a Surface Mining Inspector for the Kentucky Dept. of Natural Resources. I saw firsthand the destructive nature of coal mining. In fact, my position was largely as an enforcer of environmental laws.
Contra my anti-coal sentiments, what I found out perusing the literature about UCG--which, again, was a very quick study on my part, and which addresses some of the objections some have voiced--is that the surface ground is little disturbed since the coal is processed underground. In fact, old mines could be reused to extract their remaining energy. It seems that three holes are dug down to the coal seams. This, then, eliminates above-ground transportation and processing (which are huge problems in Eastern Kentucky). It would also eliminate pollution of surface streams which, again, is a huge problem in places such as Eastern Kentucky. It sounds promising to me that the coal remains in the ground, while the energy is processed in the ground, too, and then brought out clean (as far as I know).
Here is a recent news article from "Science Daily" about UCG. http://www.sciencedaily.com/releases/2008/02/080215135731.htm
Much criticism about "clean-coal" technologies is about ABOVE-ground carbon sequestration, which does have more problems.
Both China and India have large coal reserves, which is the reason they are interested in UCG technologies. China has the world's largest reserves, while the U.S. is second and has reserves that would last 350 years at current use-rates.
Also, both U.S. presidential candidates have said they will pursue "clean coal" technologies, thus we should be educating ourselves about their potentials. I hope that more Americans (and Canadians) will research UCG. I will be happy to be realigned about their possible dangers and inadequacies. Let us begin a discussion based on at least a semblance of research. But, so far, UCG seems very promising--and hopeful.
Truthfully, nearly every new energy technology is about a decade away from any large-scale production. Question: Where does this leave us?