escape control. Increasingly, state public utility commissions are requiring externality costs to be included in comparing different investment options and associated environmental impacts and risks. The effect is to put further downward pressure on all emissions from coal-based power systems.
The principal findings from the preceding review, summarized here, form the basis for the strategic planning scenarios developed by the committee and presented in Chapter 4.
Coal supplies are expected to be abundant for the periods considered in this study. The steady decline in domestic coal prices over the past 10 years is a trend expected to continue in the near- term. In the mid to long-term (2006 through 2040), coal production costs are expected to be stable. Given the continuing availability of low-cost domestic coal, and the evolutionary rather than revolutionary nature of changes in energy consumption patterns in the United States, coal will likely continue to satisfy a significant part of growing U.S. energy demands over the next several decades.
Electricity demand is projected to grow through 2010 as the U.S. economy grows. Estimates of new capacity requirements over the next 15 years differ widely, but there appear to be significant markets for retrofit and repowering options, as well as for new capacity construction. Changes in regulatory structure and practice in the electric utility industry since 1979 have contributed to a trend toward more widely distributed, smaller-scale power generation facilities that have relatively low risk and low capital costs. In addition, increased competition is reducing the willingness of the utility industry to develop and deploy advanced power generation technologies that are perceived as having higher risk.
In the near-term, natural gas-fired systems will likely be the primary source of new capacity additions, driven by demands for peak and intermediate power, low gas prices, and low capital costs relative to coal. However, coal is expected to remain the largest single energy source for power generation, and resource limitations for domestic natural gas, combined with a substantial need for new baseload generating capacity between 2006 and 2040, are anticipated to result in a resurgence of coal-based power generation facilities in the mid-term period. In the longer term, growth of nuclear energy using advanced reactor designs is possible, and such energy could begin displacing coal after 2020. Renewable energy sources are expected to play a growing role in U.S. electric power generation, but they are not anticipated to become a large source of bulk electricity within the periods covered by this study.
Environmental concerns will probably be the most significant influence on future coal use in the United States, and requirements to reduce the environmental and health risks of waste streams from coal technology are expected to grow more stringent. In the near- to mid-term periods, control of SO2, NOx, and fine