U.S. Geological Survey


INTRODUCTION

Coal resource assessments are commonly concerned with determining the amount and quality of coal that has some potential for production, by State, by region, or by country (for example, see Averitt, 1975; Energy Information Administration, 1995). Although this information is useful, a more useful, albeit more difficult, goal would be the capability to predict coal production rates for the various coal-producing States and regions of the country. Production rate predictions may be the outgrowth of detailed economic studies of the coal industry and markets or, more simply, may be projected from existing production trends, such as production decline rates and reserve decline rates. Extrapolation of current coal production trends into the future can provide only a general overview of future production trends. In essence, current economic and technological conditions related to coal production and consumption and the historical rate of change of those conditions are projected into the future to determine future coal production rates by State and by region. These projections are more than simple extrapolations, however, inasmuch as they depend greatly on coal reserve estimates (commonly hypothetical) that are derived from available data on coal quantity and coal quality.

The life-cycle process for coal resource development, utilization, and depletion may be divided into several phases:

As used in this report, "depletion" means that, given the current economic and technological situation, the production of coal in a given State or region is in a general long-term production decline or has been mined out. It does not mean that all of the technically producible coal is gone. For example, for all practical purposes, Pennsylvania anthracite has been depleted to the extent that current production is only about 5 percent of maximum production. Nevertheless, Energy Information Administration (1996) estimates that there are 763 million tons of recoverable reserves of anthracite remaining in the ground, and Eggleston and Edmunds (1981, p. 26) estimate 16 billion short tons of remaining anthracite reserve, of which "over 7 billion tons are deemed recoverable." In addition, they (Eggleston and Edmunds, 1981) point out that there may be "vast resources at depth" that have not yet been drilled out. In contrast, reported recoverable reserves of anthracite at producing mines (Energy Information Administration, 1996) are 49 million tons, supply for about 10 years at current production rates. For planning purposes, 100 to 150 million tons, 20 to 30 years supply at current production rates, might be considered a reasonable hypothetical reserve; the 763 million ton reserve figure of the EIA (1996) might better be considered as technically recoverable coal rather than as a reserve, however hypothetical.

Our purpose in this report is to provide data showing that Virginia's coal production life cycle has entered maturity, is past peak production, and now is entering the initial stages of a depletion-driven decline. Although use of the life-cycle method for prediction of production rates can provide insight into the general long-term ebb and flow of energy resources, it cannot predict perturbations in production caused by unforeseen near-term economic changes. Accordingly, long term life-cycle projections should not be used as a substitute for detailed economic studies of Virginia's coal industry in order to forecast detailed perturbations in coal production over the next few years or decade (see Crabtree, 1995, for an example of a detailed analysis). Coming events do "cast forth their shadows," however, and regional production declines are preceded by reserve declines at producing mines and declines in production from the major coal beds as these beds are preferentially mined out, as they have been in Virginia.

In addition, the projection of future coal production rates for Virginia is based on an estimate of Virginia's coal reserves. Without detailed economic feasibility studies of individual mine blocks, this estimate must be regarded as hypothetical and subject to change with the addition of new geologic, engineering, and economic information. The capability of estimating a likely range for long-term future coal production for Virginia, however, is essential for planning the economic future of localities in the coal-producing regions of the State.


Next




Return to Circular 1147


This page is URL: https://pubs.usgs.gov/circular/c1147/intro.html
For more information, please contact Robert C. Milici
Last revised 9-16-97 (Kathie Watson)