US Patent 8375653 Photovoltaic roofing elements including tie layer systems

The present invention relates generally to photovoltaic devices. The present invention relates more particularly to photovoltaic roofing products in which a photovoltaic element is joined to a roofing substrate. In one embodiment, the present invention provides a photovoltaic roofing element comprising: an encapsulated photovoltaic element having a top surface and a bottom surface, a top layer material at its top surface and a bottom layer material at its bottom surface; a roofing substrate having a top surface; and a tie layer system disposed between the encapsulated photovoltaic element and the roofing substrate and joining the bottom surface of the encapsulated photovoltaic element to the top surface of the roofing substrate.