**2. Selection of phase change materials**

Selection of PCMs for solar energy applications need to be considered the following properties.

## **2.1 Thermal point of view**

PCMs should have high thermal conductivity during solid to liquid and liquid to solid for thermal cycling. PCMs should have high latent heat of fusion to store amount of energy required volume of the vessel prerequisite is less.

#### **2.2 Physical point of view**

PCMs should have high specific heat to absorb more heat during solid to solid i.e. sensible heat. PCMs should have high energy density per unit volume.

## **2.3 Kinetic point of view**

PCMs should have high nucleation rate to avoid super cooling during liquid to solid. High crystal growth rate hassles for heat recovery.
