Solar Heat Storage and Application

Thermochemical heat storage materials offer high-energy storage densities and clean means of long-term solar energy storage. The aim of the study is to assess the potential heat storage efficiency of salt hydrates, based on sufficient hydration/dehydration performance, water sorption, and cycliability. Pure MgSO4¿7H2O, ZnSO4¿7H2O, and FeSO4¿7H2O and their salt-salt and salt-zeolite were evaluate based on preselected criteria. The booming progress of ZnSO4¿7H2O illustrates that likewise MgSO4¿7H2O, it is also the potential candidate and can be used in thermochemical heat storage devices. Composite of ZnSO4/13X-zeolite showed the highest water sorption (0.26 g/g) at 75% relative humidity under 45 °C air temperature, which is double than of pure ZnSO4·7H2O. MgSO4/ZnSO4 (MZ9) composite was prepared and characterized for their long-term heat storage application. The hydration behavior of MZ9 reveals an ideal thermochemical heat storage candidate for thermal storage devices.