REDUCTION OF REFLECTION LOSSES OF PV-MODULES BY STRUCTURED SURFACES

Structuring the transparent cover of solar cell modules reduces reflec tion losses, particularly at large angles of incidence. Relevant aspec ts are good transmission efficiency independent of wavelength and a lo w sensitivity to pollution. The macroscopic, linearly grooved structur e proposed in this article shows good performance only in combination with a textured cell because large angles are likely to occur inside t he structured cover. A classification is made with the concept of annu al averaged transmission efficiency for the climatic zone of Freiburg. Calculations and measurements for different combinations of smooth an d structured covers and solar cells are presented. From the calculated 97.8% entering the structured glass cover, a measured 93.2% can be co upled into a pyramidal textured monocrystalline solar cell. This is an absolute improvement of 17% compared to a smooth, uncoated solar cell with a smooth glass cover. Outdoor measurements showed that a texture d solar cell with a structured cover has between 5 and 10% higher valu es of short-circuit current than a textured cell with a smooth cover.