ABSTRACT
There are different ways of measuring overall energy consumption and of breaking down that total into its various components. The most widely employed present-day yardstick of U.S. energy use is the summed total, expressed in a common measurement unit, of gross energy inputs entering various energy-using sectors of the economy. The term gross signifies the inclusion of losses occurring when primary energy sources are converted into the secondary, or net, energy forms that are delivered to ultimate consumers. Under current measurements, the difference between gross and net energy consumption arises almost exclusively from electric power generation. That is, gross energy inputs include the thermal content of fuels delivered to power stations; while net energy consumption includes only the thermal equivalent of the electricity being sent out. (Typically, some two-thirds of a utility’s energy inputs are dissipated in the form of waste heat; even in the most modern conventional power plants, losses of around 60 percent are unavoidable.)
