Feasibility Study of Liquid-Based Spectral Beam Splitting Technique for Solar Panel Cooling

The total terrestrial solar radiation reaching the earth’s surface lies in the wavelength range of 250–2500 nm. Radiation with a wavelength of 1120 nm is required for the excitation of electrons in a single junction c-Si solar cell with a 1.1 eV bandgap. So, the solar cells perform better when they are exposed to the radiation spectrum of 750–1125 nm. To improve the PV performance, the remaining radiations should be filtered off from the available solar radiation. In this paper, the performance of the solar PV module under the influence of different fluid filters are studied and presented. Fluids such as water, coconut oil, propylene glycol, mineral oil, and transformer oil are tested for its feasibility. The effect of these fluid filters on the PV performance with different air gaps and liquid thicknesses are studied. Water is found to be a better filter among the selected fluids. PV performance is found to be reduced as the fluid thickness or air gap is increased. A 5% efficiency improvement with 30 °C reduction in the back-panel temperature is attained for a 100 W PV panel with water filter having fluid thickness 1 cm and air gap 2.5 cm. The detailed experimentation, findings, and its future scopes with a conceptual prototype are discussed in this paper.