Experimental and theoretical investigation of photovoltaic thermal system containing phase change material

In today's world, where there is an increasing trend towards renewable energy sources, new methods and technologies are being developed to utilize these sources. It is worth noting that each technical term abbreviation will be explained when it is initially used in the text. This thesis utilized three monocrystalline PV panels, two of which were designed as PV/T systems using the same equipment and technical specifications. Conventional photovoltaic panels and PV/T systems, which feature distinct heat transfer fluids being circulated, are situated in proximity within the experimental setup, aligned in the same direction and at the same angle of inclination. Their performances are analyzed using both experimental and theoretical approaches. The PV/T systems have increased electrical efficiency while also providing hot water for various applications. Water and Mobilterm 605 high-performance heat transfer oil were utilized as heat transfer fluids in the experiments. Experiments were conducted at mass flow rates of 0,007 kg/s and 0,0187 kg/s. Comparing the electrical efficiencies of the designed PV/T systems with a standard PV panel reveals a negligible difference of approximately 4%. Furthermore, it was noted that storing the heat energy obtained from the system resulted in an 87% increase in the temperature of the stored water in set-1 during the first stage of the experiment with the mains water at approximately 25 ℃. The rate of increase was 96% in set-2. In the second phase of the experiment, which commenced at 4:00 pm, it was observed that both sets of experiments exhibited a 50% increase in the stored water temperature, due to the mains water at around 25 ℃, between 10:30 pm and 11:00 pm. If the water stored was not consumed, the temperature of the water in set-1 was measured at ambient temperature the following day at 08:00. Meanwhile, the temperature of the water in set-2 was measured at 32 ℃. Secondly, according to the mathematical thermal model results, the system's thermal efficiency is 8% higher compared to the thermal efficiency determined through experimental results. This difference varies depending on certain parameters, particularly the heat transfer coefficients of the system equipment that were included in the simulation program when solving the mathematical thermal model equations. The electrical systems exhibit an approximately 12% higher level of efficiency as per the analysis of the mathematical electrical model as compared to the efficiency level obtained from the experimental data. Using the developed model, we obtained current versus voltage (IPV-VPV) and power versus voltage (PPV-VPV) curves based on various parameters, including irradiance, temperature, series resistance, ideality factor, and the number of series and parallel cells.