Exergy efficiency

Exergy efficiency is a measure of how effectively a system utilizes available energy to perform useful work. It compares the actual output (useful work) of a thermodynamic system to the maximum possible output (work) that could theoretically be achieved if the system were operating at its most efficient point, often referred to as the ideal or reversible state. Exergy itself represents the maximum useful work obtainable from a system as it comes into equilibrium with its environment.