Photovoltaic roofing elements and photovoltaic roofing systems
The present invention relates generally to the photovoltaic generation of electrical energy. The present invention relates more particularly to photovoltaic arrays for use in photovoltaically generating electrical energy. Aspects of the present invention provide a variety of photovoltaic roofing elements and systems that include, for example, interlocking geometries to provide for water handling and integration with conventional roofing materials; and wire management features that can protect wiring and associated electrical components from physical and/or environmental damage.
1. A photovoltaic roofing system disposed on a roof deck having a top end and a bottom end, the photovoltaic roofing system comprising:
a plurality of photovoltaic roofing elements each comprising
a frame structure having an upward-facing surface and a downward-facing surface having a top end and a bottom end, the frame structure having a headlap zone and an exposure zone, with the exposure zone disposed toward the bottom end of the frame structure, and the headlap zone disposed toward the top end of the frame structure; and
one or more photovoltaic elements held in the exposure zone of the frame structure,
the photovoltaic roofing elements being contiguously disposed on the roof deck to provide contiguously-disposed photovoltaic elements, the contiguously-disposed photovoltaic elements together having a top edge facing the top end of the roof deck, a bottom edge facing the bottom end of the roof deck, and two side edges, wherein in each photovoltaic roofing element the frame structure includes sidelap portions disposed at lateral edges of the frame structure, the sidelap portions having geometries interlocking with sidelap portions of adjacent photovoltaic roofing elements to provide water drainage channels;
a plurality of roofing elements disposed adjacent and along the side edges of the contiguously-disposed photovoltaic roofing elements, along their side edges; and
side flashing elements disposed along the side edges of the contiguously-disposed photovoltaic roofing elements, each of the side flashing elements having a cross-sectional shape comprising a vertically-extending feature disposed adjacent one of the side edges of the contiguously-disposed photovoltaic elements and a flange extending away from a lateral side at a downward end of the vertically-extending feature, with the flange facing away from the contiguously-disposed photovoltaic roofing elements and being at least partially disposed between at least one of the plurality of roofing elements and the roof deck,
wherein
in each photovoltaic roofing element, the sidelap portion at one lateral edge includes an upward-facing channel; and the sidelap portion at the other lateral edge includes a downward-facing flange disposed in the upward-facing channel of an adjacent photovoltaic roofing element;
in each photovoltaic roofing element, the frame structure is rigid;
the contiguously-disposed photovoltaic roofing elements together are in a rectangular arrangement; and
the photovoltaic roofing elements of the contiguously-disposed photovoltaic roofing elements are disposed in a plurality of overlapping rows, with the headlap zones of the photovoltaic roofing elements of an overlapped row being covered by the exposure zones of an overlapping row;
the photovoltaic roofing system further comprising
one or more top flashing elements disposed along the top edge of the contiguously-disposed photovoltaic roofing elements, the one or more top flashing elements having a bottom end disposed over the top edge of the contiguously-disposed photovoltaic roofing elements, and a top end disposed under one or more of the plurality of roofing elements disposed along the top edge of the contiguously-disposed photovoltaic roofing elements; and
a cant strip disposed under the bottom edge of the contiguously-disposed photovoltaic elements and on top of an underlying course of roofing elements of the plurality of roofing elements.
2. The photovoltaic roofing system according to claim 1 , wherein in each photovoltaic roofing element, the headlap zone is an attachment zone in which the photovoltaic roofing element is attached to the roof deck.
3. The photovoltaic roofing system according to claim 1 , wherein in each photovoltaic roofing element, the frame structure is unitary and the headlap zone of the frame structure has at the top end thereof a first raised lip extending upward with respect to the upward-facing surface of the frame structure in the headlap zone.
4. The photovoltaic roofing system according to claim 1 , wherein in each photovoltaic roofing element, at least one lateral side edge of the headlap zone does not include a ridge, such that water in the headlap zone can flow off of a side thereof.
5. The photovoltaic roofing system according to claim 1 , wherein the one or more photovoltaic elements are sealed to the frame with a sealant.
6. The photovoltaic roofing system according to claim 1 , wherein in each side flashing element, the flange extends at least 2 inches under the at least one of the plurality of roofing elements.
7. The photovoltaic roofing system according to claim 1 , wherein the photovoltaic roofing elements are electrically interconnected.
8. The photovoltaic roofing system according to claim 1 , wherein the roofing elements are roofing shingles.