A system including a plurality of photovoltaic shingles installed on a roof deck, a plurality of roofing shingles, such as asphalt shingles, installed on the roof deck, and a plurality of step flaps. One end of the roofing shingle overlays a first side of a corresponding one of the step flaps, and one end of photovoltaic shingle overlays a second side of the corresponding one of the step flaps.