Angle Dependence of Solar Cells and Modules: The Role of Cell Texturization

The angle-dependent spectral response is measured for six differently textured silicon solar cells before and after encapsulation. Deviations from Lambert's cosine law and differences due to the textures can be clearly determined by means of an uncertainty analysis. This effort in highly accurate angle-dependent measurement is needed for reliable prediction of annual performance. Energy rating using common simulation models for three different climate zones shows differences of more than 1% in yearly energy yield solely due to the different angle-dependent behavior of the textures. Modules featuring solar cells with random upright pyramids exhibit the largest angular losses of the studied textures.