FIGURE 4.-TRENDS IN THE MIX OF ENERGY SOURCES, UNITED STATES, 1850-2000

ILLUSTRATION ADAPTED FROM COOK, EARL. "THE FLOW OF ENERGY IN AN INDUSTRIAL SOCIETY," SCIENTIFIC AMERICAN, VOL. 224, NO. 3 (SEPTEMBER 1971), P. 137.

TABLE 6.-FORECASTS OF U.S. COAL CONSUMPTION WITH PERCENT OF TOTAL ENERGY CONSUMPTION

• Stationary sources only, excludes transport.

7 Assumes no significant synthetic fuel production from coal in year 2000.

• Assumes 44 percent of coal requirement in 2000 is for synthetic gas and liquids, and 55 percent for conventional energy

uses.

TABLE 7.-FORECASTS OF U.S. PETROLEUM AND NGL CONSUMPTION WITH PERCENT OF TOTAL ENERGY

1 Specifically excludes non-energy fuel use.

2 Converting the forecasted barrels of oil to B.t.u. at 5,800,000 B.t.u, per barrel.

3 Medium projection, includes agriculture, asphalt and road oil, liquid refinery gas, miscellaneous uses, and exports. 4 Stationary sources only, excludes transport.

* Excluded from graph of petroleum and NGL forecasts given on following page.