Development of the thermal energy storage systems which are driven by low temperature heat attracts increasing interest day by day. Storage of low temperature heat as well as studies about this subject have shown great potential in thermal energy storage field. Due to the limitations of the conventional porous host materials such as natural porous rock currently used, research has focused on new materials for these systems. In this study anodic alumina oxide (AAO) templates were used as a porous host material. Aluminium oxide pores were fabricated on aluminium by using a two-step anodisation method. AAO templates with three different pore sizes were filled with 4 different salts as CaCl2, LiCl, MgCl2 and LiNO3 via a vacuum impregnation method obtained using the same experimental parameters for thermal energy storage system. The aim of this study was to investigate the effect on the heat storage capacity when changing the salt type in the AAO templates with different pore volumes. Thermal storage capacities were determined using DSC (Differential scanning calorimetry). The results from DSC were compared and the most suitable salt for use in thermal energy storage systems selected by determining the energy storage capacities of the obtained templates.