... 13 and 14 show the performance indexes for all the optimal cases Figure 13 Economic performance index for examined cases ISSN 2076-2895 (Print), ISSN 2076-2909 (Online) ©2010 International Energy ... 583 Economic-environmental performances indexes for Palermo, Madrid and Athens These indexes consider, either the investment and exercise costs of the absorption system, also the environmental performances ... ,max − C Inv C Inv ,max − C Inv ,min + Cann ,max − Cann Cann ,max − Cann ,min (7) where CInv,max and CInv,min are, respectively, maximum and minimum investment cost among the configuration system...