From Thermodynamics to Economics and Ecology - Thanatia: The Destiny of the Earth's Mineral Resources - page 72

3.3.1 Basics of Thermoeconomics
Thermoeconomics is a word coined and promoted in the early sixties by Myron
Tribus, Robert Evans and Yehia El Sayed (Tribus and Evans, 1962; Evans and
Tribus, 1965; El-Sayed and Evans, 1970; El-Sayed and Aplenc, 1970) when they al-
located costs of water and energy streams in desalination plants using exergy. Their
original work consisted of relating monetary cost of physical flows, including fuel and
investment costs expended throughout the plant, with their thermodynamic utility,
named at that time “availability”. Since then, a good number of scientific contribu-
tions have further developed this new scientific discipline (a historical overview can
be obtained in Valero and Torres (2003) 5 ).
Thermoeconomics is, in its widest sense, the science of saving natural resources
which connects Physics and Economics by means of the Second Law. This is a
fairly strong sentence. The keyword is “saving”, since saving has a sense of purpose.
Those involved in its application try to avoid squandering natural resources used for
a given purpose in the best possible way. As seen before, avoiding irreversibilities
is the universal way to achieve it. Almost all human actions have an associated
consumption of physical resources - that can be measured through the irreversibility
caused. On the other hand, accounting for all natural resources means costing,
which is a genuine concept from Economics as has been seen in Sec. 2.3. This is how
the connection between Physics and Economics is established in Thermoeconomics.
Consequently, Thermoeconomics is not so much interested in price or value but
rather cost. This is because Physics (in all its branches) aims to objectify and
quantify natural facts. Therefore, if one were to pretend to search for the physical
cost of things, one would need to look for tools that are as independent, as is possible,
from human will. In this respect, it is obvious that money cannot (and could never)
be the best unit measure, since its value depends on different “subjective” factors
such as market exchange. Quantifying Nature in monetary terms, is opening the
door to arbitrariness. Nature sells nothing.
So, what should be the physical measuring unit of cost? The answer to this
question lies in the Second Law: if the cost is a sacrifice of resources, and the
already consumed resources have been consumed forever, one may see this fact as
the basis of physical accountability. Thermodynamics provides the necessary tools
for costs analysis: energy, entropy or exergy. The first has the problem that it only
measures quantity and is insensitive to quality: a kWh of work is not equivalent
to the same amount of heat. One finds a better answer with entropy. Coal, for
instance, has a lower entropy than the gases generated after its combustion and
spontaneous processes only occur if entropy increases. However, even if entropy is
5 Early and prominent contributors include Tribus and Evans (1962); El-Sayed and Aplenc (1970);
Reistad (1970); Gaggioli and Wepfer (1980). The interest and works regarding thermoeconomic
analysis highly increased in the 1980s. Relevant contributions are those of Tsatsaronis and Winhold
(1985), Frangopoulos (1983), von Spakovsky (1986), Valero et al. (1986, 1992) or Szargut and
Morris (1987).