Theory of exergy cost and thermo-ecological cost

The aim of the chapter is to introduce thermoeconomics and thermoecology, which are methodologies based on exergy and cost. After introducing thermoeconomics, the concept of exergy cost and a theory that enables its calculation is presented. Exergy cost of a flow within a system is the amount of exergy resources consumed by that system that are needed for producing the flow. Afterwards, symbolic thermoeconomics is presented in detail; this is a matrix-based methodology that enables not only the calculation of exergy cost, but also other relevant issues such as the effect of residues and the detailed analysis of exergy cost formation. In a following section, thermoecological cost is presented; this cost is also based on exergy but has the main differences that it only takes into account non-renewable exergy resources and considers also the effect of emissions of harmful substances. Finally, a methodology for connecting thermoecological cost with symbolic thermoeconomics is presented. Simple examples have been introduced along the chapter in order to show the capabilities of the proposed approaches. Furthermore, the concepts and formulae introduced will be applied in later chapters of the book.