Coal is by far the most abundant fossil fuel in the United States, accounting for approximately half the electricity generated each year. Concerns about acid rain, “greenhouse” gases, toxic hydrocarbons, and heavy metals released by coal combustion have raised questions, however, about continued use of coal as an energy source. Some recent advances in coal technology may change this picture dramatically. One of the most promising new technologies is the integrated gasification combined-cycle (IGCC) system developed at Stanford University. A demonstration model of this system was built by Southern California Edison Company near Barstow in the Mojave Desert in the 1980s.