Cover Picture: Microstructural analysis of the cementation process during soiling on glass surfaces in arid and semi-arid climates (Phys. Status Solidi RRL 7/2016)

No is available for this article. Accumulation of dust (soiling) on PV modules and solar reflectors leads to significant power losses due to shading or scattering of sunlight. The cover image shows cleaned and dirty PV modules at a test site in Qatar. Especially in arid and semi‐arid regions like deserts, output power losses of more than 1% per day can be observed – a severe PV module performance issue. The adhesion of particles to glass surfaces can be strongly enhanced by the so called cementation process, which is attributed to frequent humid/dry‐cycles like dew in the morning and surface temperatures up to 80 °C during midday. In their Letter (pp. 525–529), Ilse et al. present a microstructural study of the soiling process on glass surfaces in desert regions, identifying fibrous clay minerals as a main reason for particle cementation. This goes beyond the common perception that cementation occurs via the precipitation of salt (sodium chloride). Therefore, these findings are of outstanding importance for global solar power installations with respect to improved glass coatings and cleaning strategies against soiling