The present study prepared nanocomposite phase change materials (PCMs) based on calcium chloride hexahydrate (CaCl2 center dot 6H(2)O) with gamma aluminum oxide (gamma-Al2O3) nanoparticles to characterize phase change behavior, such as the supercooling degree, phase change temperature, latent heat, thermal conductivity, and thermal stability. Results demonstrate that thermal conductivity and heat transfer of the CaCl2 center dot 6H(2)O/gamma-Al2O3 nanocomposite PCMs are significantly enhanced and supercooling of CaCl2 center dot 6H(2)O/gamma-Al2O3 nanocomposite PCMs is suppressed. Moreover, a 50 run cycling test verifies that the CaCl2 center dot 6H(2)O nanocomposite PCMs contained with 1 wt % gamma-Al2O3 possesses enhanced thermal behavior. The degree of supercooling is within the range of 0.3-1.1 C; the maximum reductions in the latent heat is S.9%; and no phase segregation was observed. The CaCl2 center dot 6H(2)O/gamma-Al2O3 nanocomposite PCMs presented acceptable thermal reliability, chemical stability, and heat transfer characteristics, thereby reflecting its acceptability for low-temperature solar thermal energy storage applications.