Photovoltaic shingles and methods of installing same

A system, comprising:

• a roof deck;
• at least three photovoltaic shingles installed on a slope of the roof deck,
• wherein a first photovoltaic shingle of the at least three photovoltaic shingles is horizontally adjacent to a second photovoltaic shingle of the at least three photovoltaic shingles,
• wherein a third photovoltaic shingle of the at least three photovoltaic shingles is vertically adjacent to the first photovoltaic shingle,
• wherein each of the first photovoltaic shingle, the second photovoltaic shingle, and the third photovoltaic shingle includes:
• a first end, a second end opposite the first end, a first edge extending from the first end to the second end, and a second edge opposite the first edge and extending from the first end to the second end,
• wherein the first ends of the first and third photovoltaic shingles are substantially aligned with each other,
• wherein the second ends of the first and third photovoltaic shingles are substantially aligned with each other,
• a first layer including
• a head lap portion, and
• a step flap located at the first end, wherein the step flap includes a length extending from the first end to a location between the first end and the second end,
• wherein the head lap portion extends from the first end to the second end and from the first edge to a location between the first edge and the second edge,
• a second layer overlaying the first layer,
• wherein the second layer includes at least one solar cell, and
• wherein the first photovoltaic shingle overlays at least a part of the head lap portion of the third photovoltaic shingle, wherein the second photovoltaic shingle overlays at least a part of the step flap of the first photovoltaic shingle;
• and
• at least one wireway installed proximate to the first end of at least the first photovoltaic shingle.