Review of exergy and energy analysis of fuel cells

Recently, to reach zero emission levels, some new energy systems based on fuel cells have been developed. This paper presents a review of investigations of these systems by thermodynamics performance, mainly, energy and exergy analysis. With energy analysis, the performance of an energy conversion system cannot be effectively and accurately evaluated. But exergy analysis complements and reinforces energy analysis. Using exergy analysis in relation to the degree of irreversibility in each section is a quality method and can be useful in fuel cell analysis. Analysis based on the first and second laws of thermodynamics seems useful in most cases and here reviews for low-temperature and high-temperature fuel cells are given. As a result, regardless of the type of the FC-system and its application, there is always a need of thermo-economic analysis to investigate the effect of various parameters on the system performance, such as different fuel sources, different operating conditions, different subsystems and energy sources to combine with the fuel cell.