Experimental study on the influence of rainfall and compressed airflow dust removal on the optical performance of trough solar concentrator in alpine areas

The performance of trough solar systems is significantly affected by dust in outdoor environments. Typical climate in alpine areas, varying rainfall during summer have a dual effect on the cleaning of trough concentrators. This study experimentally investigates the impact of rainfall on the optical performance of concentrators in alpine areas. Rainwater and dust mixing would lead to more significant dust adhesion, compressed air was used to further remove dust. Finally, Response Surface Methodology (RSM) was employed to analyze the influence of various factors affecting the cleaning efficiency. The results indicate that: small-rainfall has a dual cleaning effect on the concentrator, with a threshold observed between 2 and 5.4 mm, beyond which there is a positive cleaning effect. High-rainfall improves cleaning efficiency by 38 %–50 %. After combined medium-rainfall and a 0.4 MPa compressed air flow, the cleaning efficiency can reach 70 %, when the nozzle angle is 33°, the cleaning efficiency of lower concentrators region 1 can reach 24.239 %, the reflectivity is over 0.8, indicating that compressed airflow for cleaning after rainfall is effective. The RSM indicates the rainfall has the most significant effect. The study can provide theoretical guidance for the clean and efficient operation in solar power plants. © 2025