Quantifying the effects of dust characteristics on the performance of radiative cooling PV systems

Radiative cooling technology addresses the self-heating issue in solar cells, improving power output. However, dust accumulation poses a significant challenge for radiative cooling PV systems. This study theoretically explores the radiative properties and power efficiency of radiative cooling PV systems under dust accumulation, employing the Monte Carlo Ray Tracing method to simulate light transfer through dust with varying characteristics. The influence of dust particle size, coverage area, and solar incidence angle on system performance is examined. Results show that dust accumulation decreases solar transmittance and infrared emissivity of the radiative cooling covers, thereby reducing system efficiency. The effect of highly absorptive dust on the radiative cooling cover is more pronounced than that of non-absorptive dust. For every 1 g/m2 increase in deposition density, the power generation of RC-PVs covered with non-absorptive and absorptive dust accumulation decreases by approximately 0.96% and 4.01%, respectively. Functional relationships have been established between dust density and solar transmittance, infrared emissivity, and power generation. Additionally, optimal cleaning intervals for the systems under different dust conditions are determined. For full-automatic cleaning at a dust accumulation rate of 200 mg/m2/day, the recommended intervals for non- absorptive and absorptive dust are 44.2 and 22.1 days, respectively. These findings provide quantitative relationships between dust accumulation and its impacts on radiative cooling PV systems, highlighting the importance of regular maintenance to optimize system performance and associated costs. The results of this study offer valuable insights for the effective deployment, design, and maintenance of radiative cooling PV systems in practical applications, particularly in dusty environments.