Exergy analysis has become an important tool for thermodynamic assessment of power generation systems. In the present study, thermodynamic performance (energy and exergy) analysis is performed for a solar thermal power plant located in Shiraz, Iran. In addition, a computational exergy analysis is performed to show the possible improvement of this power plant integrating with Phase Change Material (PCM) storage. Consequently, it is found that overall energy efficiency without PCM storage is about 30% while the exergy efficiency is about 10%. However, about 30% overall exergy efficiency can be achieved for the case of using PCM storage along with the solar collector. (C) 2013 Elsevier Ltd. All rights reserved.