Investigating the Potential of Al2O3 Nanocomposites for Innovative Self-cooling Photovoltaic Technology

Abstract

In this research, we investigate the use of a passive radiative self-cooling layer made of an Al₂O₃ nanocomposite on the backside of a compact 10W PV module. The coating, composed of Al₂O₃ nanoparticles (with a particle size of 30nm) blended with Na₂SiO₃.9H₂O in a specific ratio, forms a ceramic glue applied to the module's rear surface in both horizontal and vertical directions using a standard paintbrush. The experiments were carried out in the 50°C ambient temperature of Baghdad summer. The results indicate a significant decrease in the temperature of the PV module in hot weather, reducing from 63°C to 58°C with the application of the nanocomposite layer. Additionally, the nanocomposite coating improves key performance parameters, such as open circuit voltage, short circuit current, voltage at maximum power, and current at maximum power. This enhancement results in a notable 10% increase in PV module power output, from 6.58W before coating to 7.22W after coating. The observed temperature reduction is attributed to the high emissivity of the ceramic layer, measured at 0.96 using a Fluke thermal camera. Extrapolating these findings to a larger scale, calculations for a 500W coated panel show a substantial power increase of 50W in hot weather conditions. Moreover, the annual energy gain is estimated to be 87kWh, with an impressive payback time of 1.5 years. Additionally, there is a noteworthy environmental impact, with a yearly reduction of 60kg of CO₂ emissions.