The Reliability indices in first and second scenario are illustrated in Figs. 7 and 8. As it is clear that in Figs. 7 and 8, better reliability indices are resulted in first scenario compared to second scenario because of complete availability of PFWHS components. Also the expectation of stored energy in HST in two scenarios is illustrated in Figs. 9 and 10. As shown as in Figs. 9 and 10, the stored energy rate in second scenario is more than first scenario and causes more OCE. According to obtained results, neglecting the rate of components availability in hybrid power generation systems has unsuitable results on reliability of load supply, so the rate of PFWHS components availability causes actual insight to designer for reliable and economic designing the hybrid power generation systems.