The Performance of SiO2 Nanofluid-based Split-frequency PV/T Energy

Abstract

The efficiency of both solar photovoltaic and thermal power generation is relatively low, with the maximum panel temperature of conventional PV/T modules reaching 68.4 °C at noon, and the average electrical efficiency is only 12.98%. In this paper, the energy performance of a PV/T module based on SiO2 nanofluid was studied. Firstly, three different types of nanofluids, SiO2 nanofluid with a mass fraction of 0.3%, mass fraction of 0.5%, and mass fraction of 0.7%, were prepared and tested for their solar spectrum transmittance, and the results manifested that only the SiO2 nanofluid with 0.5% mass fraction exhibited strong absorption characteristics in the band after 400–1150 nm. Three liquid film thicknesses of 5 mm, 10 mm, and 15 mm, and three nanofluid mass fractions of 0.3%, 0.5%, and 0.7% were selected for the calculation of the spectral transmittance and the experiments on the thermal efficiency of the whole PV/T module. After conducting twenty-minute experimental tests on the power generation efficiency, thermal efficiency, and panel temperature of the flat panel, the results turned out the maximum efficiency reached 52.19%, which was found at a liquid film thickness of 10 mm and a nanofluid mass fraction of 0.7%, with a lower temperature of 40 °C, and an average of 10 °C lower than conventional PV panels.