Embodiments of the invention generally relate to a busing sub-assembly and methods of forming photovoltaic modules having busing sub-assemblies. The busing sub-assembly generally includes a carrier backsheet and a plurality of conductive ribbons coupled to the carrier backsheet. An electrically insulating cover is disposed over the conductive ribbons and the carrier backsheet. The ends of each conductive ribbon remain exposed for making an electrical connection to the conductive foil or a junction box. Methods of forming photovoltaic modules generally include positioning a flexible backsheet having an opening therethrough and a conductive foil thereon on a support. A busing sub-assembly is disposed on the flexible backsheet over the opening and in electrical contact with the conductive foil. The busing sub-assembly includes the components necessary to bus electrical current from a plurality of solar cells to a junction box, and can be applied to a photovoltaic module in a singe process step.