recoverability, and transportation issues may substantially reduce the number of years of supply. Future policy will continue to be developed in the absence of accurate estimates until more detailed reserve analyses—which take into account the full suite of geographical, geological, economic, legal, and environmental characteristics—are completed. (NRC, 2007)
Recently, the Energy Information Administration estimated the proven U.S. coal reserves to be about 260 billion tons (EIA, 2009). A key conclusion of these two studies is that coal reserves in the United States are probably sufficient to meet the nation’s needs for more than 100 years at current rates of consumption—and possibly even with increased rates of consumption. The primary issue is likely not to be reserves per se, however, but rather the increased mining of coal and the opening of many new mines. Increased mining would have numerous potential environmental impacts—and, possibly, heightened public opposition—which would need to be addressed in acceptable ways. Meanwhile, the cost of coal, which currently is low relative to the cost of biomass, would undoubtedly increase.
Despite the vast coal resource in the United States, it is not a forgone conclusion that adequate coal will be mined and available to meet the needs of a growing coal-to-fuels industry and the needs of the power industry. The potential for a rapid expansion of the U.S. coal-supply industry would have to be analyzed by the U.S. coal industry, the U.S. Environmental Protection Agency, the U.S. Department of Energy, and the U.S. Department of Transportation so that the critical barriers to growth, environmental effects, and their effects on coal costs could be delineated. The analysis could include several scenarios, one of which would assume that the United States will move rapidly toward increasing use of coal-based liquid fuels for transportation to improve energy security. An improved understanding of the immediate and long-term environmental effects of increased mining, transportation, and use of coal would be an important goal of the analysis.
Two key technologies, biochemical conversion and indirect liquefaction, are used for the conversion of biomass and coal into fuels, as illustrated in Figure 5.2.