The numerical and experimental analysis of system efficiency effects of different passive methods in integrated photovoltaic panels

Photovoltaic panels are energy systems that generate electricity by absorbing solar irradiation. However, when the sun's rays are converted to electricity, a high amount of waste heat is generated. There is a non-linear relationship between the temperature and the current and voltage values produced by the photovoltaic (PV) panels. Especially, PV panels in hot climatic conditions are affected more adversely and their performances are decreasing. In this thesis study, cell temperatures, output powers, power loss ratios and energy-exergy efficiencies of 75 W power PV panels with polycrystalline cell structure under Elazig climatic conditions were investigated. At the end of the experiments, the current values of PV panels are seriously affected by solar radiation and the voltage values are seriously affected by cell temperature. In addition, when the temperature values obtained from the thermocouples placed on the PV panel are compared, it is seen that the temperature is not distributed homogeneously on the panel. In the second part of the work, PV panels were subjected to partial shading to analyze the power and temperature conditions. The cells exposed to the shade created resistance to other cells that were not exposed to shading, causing hot spot formation. The between shaded and unshaded PV panels have occurred temperature differences and critical power losses. In the third part, different passive cooling methods were applied to PV panels and the effects on system performance were investigated. Passive cooling methods; Aluminum fins, closed-cell aluminum foam fins, phase change materials (PCM), Thermoelectric (TE) module and hybrid module (FDM + TE) were integrated into different panels. In the aluminum fins model were examined 10 different situations and the staggered array of 7 cm length, 20 cm length gave the best result. In the aluminum foam fins, two different conditions were analyzed, 6 mm and 10 mm in thickness and 5x10 cm dimensions, and the 10 mm thick fin model gave the best results. Phase-changing materials were selected at three different melting temperatures and compared with each other. At the melting temperature of 29.17 oC, calcium chloride hexahydrate (CaCl2.6H2O) is chemical material the most reducing temperature and increasing efficiency of the PV panel. The thermoelectric modules were placed on PV panels in two different numbers, 6 and 10. The compared to PV panels with two different TE numbers, the case with the higher number of thermoelectric was the most increasing in output power.