Analysis of Energy Conversion Systems, Including Material and Global Warming Aspects

Abstract

This paper addresses a method for the overall evaluation of energy conversion systems, including material and global environmental aspects. To limit the scope of the work reported here, the global environmental aspects have been limited to global warming aspects. A method is presented that uses exergy as an overall evaluation measure of energy conversion systems for their lifetime. The method takes the direct exergy consumption (fuel consumption) of the conventional exergy analyses and adds (1) the exergy of the energy conversion system equipment materials, (2) the fuel production exergy and material exergy, and (3) the exergy needed to recover the total global warming gases (equivalent) of the energy conversion system. This total, termed “Total Equivalent Resource Exergy” (TERE), provides a measure of the effectiveness of the energy conversion system in its use of natural resources. The results presented here for several example systems illustrate how the method can be used to screen candidate energy conversion systems and perhaps, as data becomes more available, to optimize systems. It appears that this concept may be particularly useful for comparing systems that have quite different direct energy and/or environmental impacts. This work should be viewed in the context of being primarily a “concept” paper in that the lack of detailed data available to the authors at this time limits the accuracy of the overall results. The authors are working on refinements to data used in the evaluation.