The present invention relates generally to roofing products. The present invention relates more particularly to roofing products for use with photovoltaic elements, and to photovoltaic systems that include one or more photovoltaic elements is joined to a roofing substrate. In one embodiment, a roofing product includes a flexible roofing substrate having a top surface, the top surface having one or more receptor zones thereon, each receptor zone being adapted to receive one or more photovoltaic elements, each receptor zone having a different surfacing than the area of the top surface adjacent to it.