The purpose of the work is to store the solar energy using Phase Change Materials (PCMs) to ensure hot water is available even at night time. The system consists of a shell & tube heat exchanger which is the core part of the system. Shell consists of heat transfer fluid which is mainly water and the tube consists of Phase Change Materials (PCM). The storage unit absorbs the heat of the heat transfer fluid whereas the fluid is heated by the solar radiations during sunshine period. The Paraffin wax is used as a Phase Change Material (PCM). At the start of the day, the receiver of the solar collector is filled with the water completely. When the receiver produces the required output quantity of hot water, then the excess water will be stored in the storage tank with certain heat loss. While water is flowing through the heat exchanger, the PCM changes its phase by absorbing latent heat. The efficiency of the system is in inverse proportion with the amount of heat energy lost in the time interval between the charging & discharging phase of the PCM. © 2021 Elsevier Ltd. All rights reserved.