transport—depend largely on the supply and demand for rail transportation, as well as on prevailing business practices, the investment climate, and the nature of regulatory oversight of the railroad industry. The capacity, reliability, and price of rail transportation of coal depend to a far lesser degree upon research and development. Reliable and sufficient waterborne transportation—the second most prevalent method of coal transport—depends on the construction and maintenance of waterway infrastructures, especially lock-and-dam infrastructure and port capacity.
Much of the nation’s coal-fired electric generating capacity is located at some distance from the urbanized areas that have the largest and most concentrated demands for electricity. Projections of higher coal use depend on sufficient capacity to transmit electricity from coal-based power plants to such areas reliably and at a reasonable cost. Conversely, the projected increases in coal use will diminish if these high-demand areas satisfy much of their growing demand for electricity not by expanding their ability to import electricity from other regions, but by a combination of energy efficiency, demand response, and local electric generation from sources other than coal.
The coal transportation and electric transmission systems are large and complex networks in which localized disruptions can have severe and widespread impacts. Weather and other natural phenomena, as well as societal factors such as sabotage and terrorism, impose a range of risks on these systems. These characteristics make it difficult to guarantee that there will be sufficient capacity to transport coal or coal-based energy (primarily electricity) reliably and cost-effectively to the various end users, particularly in light of scenarios that predict substantially increased coal use. Research is needed to better understand the factors that control these large and complex networks to minimize the risks of cascading system disruptions.
Although the committee’s task was broad and encompassed the entire coal fuel cycle, the congressional framers of this study requested that it focus primarily on the upstream aspects of the coal fuel cycle. Accordingly, only a brief overview of coal use technologies and related issues is presented in Chapter 6, with greater emphasis on describing the factors associated with coal use that are likely to impose constraints on future demands for coal.
The analysis presented in Chapter 2 indicates overwhelmingly that the environmental impacts of coal use—especially carbon dioxide emissions associated with global climate change—pose the greatest potential constraint on future coal utilization. The committee found the following:
Potential regulatory requirements to further reduce emissions of NOx, SO2, mercury, and particulate matter in the future are not expected to significantly