Described herein is a photovoltaic module, which includes PV cells capable of converting light incoming from a front side and from a rear side (3) and a transparent rear side including a rear surface carrying a structured layer (9), where the lower surface of the structured layer (9) is the lower surface of the module, and where the surface of layer (9) is structured by parallel V-shaped grooves of depth h2 or less than h2, where the lateral faces of the grooves of depth less than h2 form a groove angle beta and adjacent faces of neighbouring grooves form a peak of apex angle alpha, characterized in that h2 is from the range 5 to 200 micrometer, and each pair of neighbouring grooves includes one groove of depth h2 and one groove of depth (h2−h1), where h1 ranges from 0.1 h2 to 0.9 h2.