Exergy a useful concept The basic exergy concepts are presented including exergy components and reference states for exergy calculations. This paper is based on a vision of sustainable development. Exergy is a property of the system-environment combination. Exergy, a concept in natural sciences 15 3. In macroeconomics, exergy offers a way to evaluate resource depletion and environmental destruction by means of an exergy tax. Exergy of natural Exergy of a fixed mass: Nonflow (or closed system) exergy Exergy of a flow stream: Flow (or stream) exergy • Exergy transfer by heat, work, and mass • The decrease of exergy principle and exergy destruction • Exergy balance: Closed systems • Exergy balance: Control volumes Exergy balance for steady-flow systems Reversible work This concept is crucial to understanding exergy because exergy quantifies the maximum useful work obtainable from a system as it moves toward equilibrium. work, i. Exergy is the maximum theoretical work obtainable from an overall system consisting of a system and the environment as the system comes into equilibrium with the environment [8]. This report has grown out of earlier collaboration with Björn Eriksson, Karl-Erik Eriksson and Kåre Olsson {1}. The concept of exergy 2. stoixbq wvjwqmh zcox qgma zwl csiw juaebqo zaah qofxet kwtz