Environmental Engineering Reference
In-Depth Information
ting energy as the standard of value, society would
realign itself with natural systems, where energy's impor-
tance could be never in doubt. That is why Technocracy
(1937) advocated the radical step of replacing money by
energy certificates within a system based on a centralized
continuous registry of energy conversions that would
record ''the desires of every citizen in his choice of con-
sumable goods and available services'' and allow individ-
uals ''the widest latitude of choice'' in consuming their
share of the annually allotted net energy total. This hy-
brid of egalitarian utopianism and mind-boggling super-
bureaucracy had no chance of implementation.
Calls for energy-based valuation came back in the
wake of the energy ''crisis'' of the 1970s. Ritchie-Calder
(1979) argued that energy accounting rather than mone-
tary accounting might straighten out the energy prob-
lem and set the real value of materials and commodities.
Odum (1975, 99) concluded, ''Money . . . does not flow
along the paths to the energy sources or the energy in-
teractions of the environment. Thus money cannot be
used to evaluate either energy sources or environmental
impacts. Energy analysis is required.'' There was even a
new call for national and personal energy budgets: ''The
annual budget would represent a portion—dictated
by our value of the future—of the proven energy
reserves. . . . The flow of the currency would be regulated
by the amount of energy budgeted for a given period. If
less energy existed at the end of the period, then cur-
rency flow would have to be reduced proportionately
during the next period'' (Hannon 1973, 153). Some of
these ideas were actually enacted. The Nonnuclear En-
ergy Research and Development Act of December 31,
1974, required net energy analysis for any conversion
technique entering commercial application (U.S. Con-
gress 1974).
A more fundamental approach includes exergy-based
valuations (Sciubba 2004; Sciubba and Ulgiati 2005;
Tonon et al. 2006). Because exergy is a property of
all energies and materials, it can provide an all-
encompassing biophysical framework by quantifying all
inputs as well as resulting wastes. Ayres, Ayres, and Warr
(2003) identified the declining price of useful work
(product of exergy and conversion efficiency) as the
growth engine of the U.S. economy during the twentieth
century (fig. 12.4). Solow (1957) credited technical
change with some 88% of the increase in the productivity
of the U.S. economy, and Denison (1985) linked most
of this share to advances in knowledge and the rest to
12.4 Declining ratios of exergy inputs to the U.S. economy,
1900-2000. From Ayres, Ayres, and Warr (2003).
