Exergetic analysis : Application to energy efficiency

In a context of pressure on natural resources, particularly energy resources, reducing energy consumption is a crucial issue. The exergy concept offers a global, standard and rigorous framework for the analysis of energy systems and, as such, contributes to the understanding and systemic management of the energy challenge.

Exergy measures the “useful” energy that can be extracted from a reservoir or energy flow. It is also the minimum energy required to create this reservoir or energy flow. This metric depends on the state of the reservoir or flow (temperature, pressure, composition, etc.) but also the state of the environment (temperature, ambient pressure, etc.) and is expressed in the same unit as the energy (the Joule in the metric system). A thermodynamic definition of exergy is given in appendix.

This publication by Enea aims to popularise the exergy concept, to explain its applications to energy efficiency, and to underline the interest of its implementation by industrial organisations.