Investigating the impact of using different fluids as liquid spectrum filters on photovoltaic-thermal system performance

One practical solution to the issue of solar cells overheating and deteriorating electrical efficiency due to the cell's failure to convert all of the solar radiation that strikes it into electrical energy is to use spectral splitting technology. This technology prohibits the solar spectrum portion that creates the issue from reaching the cell by allowing just the part that is responsible for producing electrical power to reach it. The system developed for this study combines a fluid absorption-based spectral splitting mechanism with a compound parabolic solar concentrator. Several practical experiments were carried out to compare the thermal and electrical performance of some liquids, including water, ethanol, methanol, and propylene glycol. Additionally, a theoretical simulation of electrical performance was conducted, and its outcomes were compared with the practical ones. Based on the experimental results, ethanol was shown to have the highest percentage improvement in power and electrical efficiency (272.3 % and 74.6 %), whereas propylene glycol experienced the lowest percentage improvements (167.8 % and 25.6 %). This can be explained by the fact that the temperature of the PV cells was reduced by the greatest percentage (10.2 %) for ethanol and the least percentage (6.1 %) for propylene glycol. Moreover, the highest thermal and total efficiencies were demonstrated by ethanol (9.5 % and 11 %), whereas the lowest efficiencies were recorded by propylene glycol (6.9 % and 8.7 %). In addition, the practical and theoretical results exhibit a high degree of consistency, with error percentages less than 5 %.