ANALYSIS OF ENERGY-CONVERSION SYSTEMS, INCLUDING MATERIAL AND GLOBAL WARMING ASPECTS

This paper addresses a method for the overall evaluation of energy con version 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 pres ented that uses exergy as an overall evaluation measure of energy conv ersion 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 materia ls, (2) the fuel production exergy and material exergy, and (3) the ex ergy needed to recover the total global warming gases (equivalent) of the energy conversion system. This total, termed ''Total Equivalent Re source Exergy,'' (TERE), provides a measure of the effectiveness of th e energy conversion system in its use of natural resources. The result s 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 ha ve quite different direct energy and/or environmental impacts. This wo rk should be viewed in the context of being primarily a ''concept'' pa per in that the lack of detailed data available to the authors at this time limits the accuracy of the overall results. The authors are work ing on refinements to data used in the evaluation.