Synergistic optimization analysis of droplet cleaning efficiency on photovoltaic surfaces through volume regulation and dust removal dynamic mechanism

Abstract

Dust accumulation on photovoltaic (PV) modules can result in significant energy losses. While conventional cleaning methods require amounts of water, the application of droplets cleaning technology on superhydrophobic surfaces offers a more sustainable solution. Our study presents an investigation into the optimization of droplet cleaning efficiency on superhydrophobic PV glass by regulating droplet volume. The study explored the dynamics of droplet motion and critical dust carrying capacity, introduced a quantitative relationship between droplet volume and dust removal efficiency, systematically analyzed droplet dynamics and dust entrainment mechanism, and revealed three findings: (1) The dust carrying motion of the droplet exhibits two distinct motion stages, from accelerated linear motion to trailing state triggered by saturated dust capacity (4.8 mg, 5.9 mg, and 6.2 mg for 10, 30, 50 μL droplets). (2) Post trailing velocity declines sharply by 84.90 %, 53.66 %, and 41.81 % for 10, 30, 50 μL droplets. (3) A linear volume efficiency relationship is established, where 50 μL droplets achieve 28 % dust removal efficiency (14 mg capacity), with each 1 μL volume increment enhancing mass removal by 0.28 mg and efficiency by 6.25 %. Our research optimizes the self-cleaning technology of photovoltaic module. Research results are expected to further improve the cleaning efficiency and water saving advantages of the droplet cleaning method, which is essential for the sustainability of solar systems, especially in water-scarce regions.