A first plurality of roofing shingles installed in on a roof deck, and a second plurality of roofing shingles installed in a second plurality of rows. An edge of one of the second roofing shingles in each of the second rows is offset from the edge of another one of the second roofing shingles in another adjacent one of the second rows. An edge of a first photovoltaic shingle is juxtaposed with the edge of a first roofing shingle of the second roofing shingles in a first row of the second rows. The edge of at least another photovoltaic shingle in at least one of another row of the second rows is substantially aligned with the edge of the first photovoltaic shingle. An additional roofing shingle is installed intermediate one of the second roofing shingles and one of the photovoltaic shingles.