Daily Power Output Increase of Over 3% with the Use of Structured Glass in Monocrystalline Silicon PV Modules

Various types of structured glass have been evaluated in terms of module efficiency and total energy yield. A glass with fine round pits has been selected as optimum as a result of our evaluation taking into account efficiency gain, improved energy yield, outdoor performance and material cost. The benefit from such glass with reduced reflectance is observed through a nominal power boost of around 1%. The largest benefit from this glass, however, is obtained when rays arrive to the front module surface at low incident angles. In this case a power increase of over 15% can be measured, at the early morning and evening hours. Overall, this is translated in an increase in a measured daily energy output of more than 3%, which is a substantial gain in terms of electricity production per module. The benefit can be even larger in installations where the inclination of the module is not optimal as, for instance, on facades. The long-term performance of modules with structured glass has been evaluated in an outdoor monitoring station, showing no accumulation of dust in the glass features even after long periods with complete absence of rains in southern Spain