Effect of the Angle Dependence of Solar Cells on the Results of Indoor and Outdoor Calibrations

Abstract

A typically unconsidered difference during solar cell measurements using the natural sun light, on the one hand, and a sun simulator on the other hand is their angular distribution. While a sun simulator creates mainly direct radiation, the natural sunlight contains a reasonably diffuse portion, in addition. The angle dependence of different types of typical reference solar cells was measured with a two axis solar cell goniometer. Thus the effect of neglecting the angular distribution of global sunlight by using direct light, only, was calculated to be 0.5% to 1.2%. Hence, the authors recommend the definition of the angular distribution within a standard.