A solar roof shingle for providing AC electrical power when exposed to sunlight includes a shingle frame having a bottom panel supportable on a roof deck, a top panel, and a thickness between the bottom panel and the top panel. At least one reference distribution of the stray radiation intensity is determined in the row direction of the detector matrix, and a stray radiation component of each measured value of intensity is determined starting from this at least one reference distribution, and the measured intensity values are corrected as a function of their respective stray radiation component. For this purpose, it is possible for the conveying elements of the conveyor to be arranged or designed correspondingly andor for the walls of the conveyor pockets to be dimensioned correspondingly. The measuring device comprises a plurality of carriers which are arranged in a row and which are thermally insulated from each other. This description is not intended to be a complete description of, or limit the scope of, the invention.