ESTIMATION OF U.S. PEAK COAL PRODUCTION

Following M. King Hubbert's analysis of U.S. oil production and examples from U.S coalfields with declining coal production, such as Pennsylvania anthracite and the Appalachian bituminous coal fields, we assumed that U.S. coal production will increase steadily until half of the original economically recoverable reserves are produced, after which U.S. coal production will enter a period of irreversible decline. The timing of this decline is the topic of this paper.

To determine the potential timing of this irreversible decline, estimates of original reserves (EOR) were obtained by adding cumulative production data obtained from government sources to the estimated recoverable reserves (ERR) published by the Energy Information Administration (EIA). The ERR data were adjusted with additional information on coal reserves from the Southern States Energy Board (SSEB) and the U.S. Geological Survey (USGS). Of special importance were the additions to reserves that were compiled from state data by SSEB to the ERR estimates made by EIA, and recent additions to reserves made by USGS for the Powder River Basin. Using this information, we calculated original reserves three ways: (1) cumulative production plus ERR only; (2) cumulative production plus ERR plus USGS addition for the PRB; and (3) cumulative production plus ERR plus USGS additions for the PRB plus SSEB additions. Calculated EOR of U.S. coal for these scenarios were 338, 408, and 590 billion short tons, with half of the EOR estimates being produced in 2062, 2076, and 2105, respectively. In each case, production rates were extrapolated to 2030 using EIA data, and production rates beyond 2030 were calculated as increasing 1 percent per year until half of the EOR was reached. Thereafter, production rates were reduced by 1 percent per year.

U.S. peak coal production will probably occur sometime in the latter part of this century as the increasing price of coal makes the generation of electricity from renewable sources more competitive. Furthermore, it is also likely that introduction of a carbon tax on coal combustion will change the definition of "economically producible coal" so that "peak coal production" may occur earlier, perhaps sometime within the next several decades.