Exergy accounting: Capabilities and drawbacks

This paper explains some capabilities and drawbacks of the emerging field of exergy accounting. Among other applications, exergy accounting is successfully used for diagnosing energy systems and for the accounting of Earth's exergy resources. Both applications rely on the concept of exergetic cost. This concept tries to measure the amount of exergy resources to produce any good. The process of cost formation becomes essential to understand and evaluate the exergy costs and the degradation process of resources feeding a system. Cost, irreversibility and causation become deeply interrelated and an Aristotelic analogy between cause and thermoeconomic concepts is highlighted. However, the search for causality of losses is not equivalent to the search for localization of these losses, and additional studies become needed. Average exergy cost has no information about future unexpected impacts and no general theory of values can be postulated around these concepts.