with increasing soiling rates. In some cases efficiency losses of 30 % and more are found [4]. However, extreme
events like a nearby construction site can increase this value significantly [5]. Fig. 1 illustrates soiling on a thermal
collector over a long period of time without cleaning on Gran Canaria (Spain). Our own initial indoor soiling
experiment with one short simulated dust event and different solar glass produced an average transmittance loss of
about 10 %.
Thus, soiling is a potential key factor for the economic feasibility of larger solar energy plants in particular [6]. In
addition to the accumulation of particles on glazing, longer periods of exposure in critical conditions can also cause
an irreversible degradation of components by abrasion