Experimental Investigations on a Solar Tracking Concentrated Photovoltaic-Thermal System with Phase Change Material Cooling By Chen Jun Ru Thesis Supervisor: Dr. Yan Su M.Sc. in Electromechanical Engineering With the development of technology, more and more investigations and researches were taken on the use of phase change material in the photovoltaic thermal system. A solar tracking concentrated photovoltaic thermal (CPV-T) system with phase change material cooling system has been set up and investigated to increase the photovoltaic system’s efficiency. The one-year experimental investigation has been done to obtain the data of the PV system, the efficiencies of the PV system and the surroundings parameter. With the different design of the experiment, the present study obtained the more suitable design of the phase change material (PCM) cooling system. And this design was used for the solar tracking concentrated photovoltaic–thermal system in this study. This natural convection based phase change material cooling system is more economical and more stable because it does not need the pump to circulate the water flow in comparison with the conventional water cooling system. The results show that by using phase change material cooling, the efficiency of the CPVT system increased. Also, the results may give some guidance for the researchers to enhance the CPVT systems’ efficiency.