Created by M.L., OST, on 19.03.2025
- Typically, regular cleaning of the PV modules is important to minimize the losses due to soiling.
- Since PV-modules in alpine regions are mounted steeper than in the lowlands, and the typical dirt sources (roads, industries, pollen, …) are absent, soiling is less of an issue. So far, the experience acquired on existing alpine PV installations suggests that cleaning can be omitted [1,2].
- The IEA-PVPS Task 13 suggest to remove snow from 0.7 m on [3]. Since alpine sites are often inaccessible during winter, manual snow removal is not a practical solution. And experience shows that operating moving parts is challenging, and prone to damages, due to ice formation [1,4]. Here again, the steep mounting angles prove beneficial, since they minimize snow deposition [5]. The critical angle seems to be around 60°, as observed by AXPO on the Alpin Solar power plant on the damn of the Muttsee: On the upper panels, placed with an inclination of 65°, the snow doesn’t stick; whereas it stays on the lower panels, which are placed with an inclination of 51°, and glides off during the first hours of sunshine [1].
- In conclusion, cleaning of alpine PV installation and snow removal is practically almost impossible, due to the remote location and harsh environment. Luckily, it can be avoided thanks to steep inclination and careful design of the mounting structure.
References
- Heierli C. Interview about alpine PV: AXPO, Alpin Solar (Muttsee-Staumauer) 2025.
- Schläppi M. Interview about alpine PV: KWO 2025.
- Jahn U, Herteleer B, Tjengdrawira C, Tsanakas I, Richter M, Dickeson G, et al. Guidelines for Operation and Maintenance of Photovoltaic Power Plants in Different Climates. International Energy Agency (IEA); 2022.
- Strebel S. Interview about alpine PV: Test installations of ZHAW (in Davos) 2025.
- Szacsvay T. Untersuchung zum Alterungsverhalten von PVModulen einer hochalpinen PV-Anlage. Bern: REECH; 2024.
