EXPERIMENTAL CHARACTERIZATION OF A PCM SOLAR ENERGY STORAGE SYSTEM

This study is on the development and characterization of a phase change material (PCM)-based solar energy storage system. An evacuated tube solar collector was used to transfer thermal energy to water circulated by a solar-operated pump. The water flows through a heat exchanger embedded in the phase change material in a storage tank, thus transferring energy to the PCM which changes phase and stores thermal energy. The system is completely renewable as solar energy conversion was applied in the system to power all the electrical components. The PCM used in this system is vegetable-based, therefore non-toxic. Analytical and experimental studies were performed to investigate the performance of the system. Average thermal energy stored over the six months of testing was 50.63 MJ with just about 45 kg of PCM. The system performed best in the summer period with an efficiency of 63.6% when the lowest thermal energy loss was recorded. A low heat transfer fluid flowrates of 3 L/min (0.05 kg/s) and 2 L/min (0.033 kg/s) produced the best heat storage and heat recovery processes respectively.