Study of soiling on PV module performance under different environmental parameters using an indoor soiling station

Soiling of PV modules is a rather overlooked complex phenomenon and to better understand the phenomenon, the direction of research has now shifted towards studying soiling in controlled environment. In this work, the effect of tilt angle, humidity, temperature, and wind speed on soil deposition process and consequently the effect on PV module performance was investigated using recently developed homemade soiling station. Results showed that at tilt angles of 0 degrees, 33.6 degrees, and 60 degrees, the corresponding soiling loss was 25.71%, 19.57%, and 15.8% respectively. Similarly, for temperature values of 25 degrees C, 40 degrees C, 55 degrees C, and 70 degrees C, the soiling loss was found to be 4.85%, 3.87%, 3.13 %, and 1.12% respectively. Furthermore, current gain due to air cleaning at 85% humidity was comparatively very low even at higher wind speeds owing to firm settlement of soil on module surface. Besides, at higher humidity levels self-cleaning patterns due to trickling of droplets with variations in tilt angles were also observed. These findings can help design and optimize the performance of outdoor PV systems and need to develop environment-specific cleaning systems for optimal performance of PV modules as well keeping the dominant contributing soiling factor in view.