The starting values are invented. The model uses endless east-west rows facing due south, opaque panels, solar time and a simple sun-position formula. Direct light is weighted by horizontal beam (constant direct normal irradiance times the sine of the sun's elevation) and ignores sun below 1 degree. Sky light is an isotropic view factor. It is geometry only: it is not a crop, energy or light-sum result. Type 9.5 or 9,5; 1.000 is rejected as ambiguous.