ROOFTOP SYSTEM WITH INTEGRATED PHOTOVOLTAIC MODULES AND METHOD FOR CONSTRUCTING THE SAME
This invention provides a novel design of a rooftop with structurally and functionally integrated photovoltaic modules that includes photovoltaic modules, which can be commercially available and which are augmented with additional framing including additional structural and functional layers. The modules are mounted on a grid like supporting structure sitting on vertical elevation structures, such as building walls or columns. The design enables cost reduction, fast installation and improved performance of rooftops with photovoltaic power.
This application claims the benefit of U.S. Provisional Application Ser. No. 61/431,901, filed Jan. 12, 2011, entitled ROOFTOP SYSTEM WITH INTEGRATED PHOTOVOLTAIC MODULES AND METHOD FOR CONSTRUCTING THE SAME, the entire disclosure of which is herein incorporated by reference.
FIELD OF THE INVENTIONThis invention relates to rooftop construction techniques in which photovoltaic modules are used as integral components of the roofing structure.
BACKGROUND OF THE INVENTIONAs mankind continues to develop around the world, the demand for energy rises. Most energy used to power machines and generate electricity is derived from fossil fuels, such as coal, natural gas or oil. These supplies are limited and their combustion causes atmospheric pollution and the production of Carbon Dioxide, which is suspected to accelerate the greenhouse effect and lead to global climate change. Some alternative approaches to produce energy include the harnessing of nuclear energy, wind, moving water (hydropower), geothermal energy or solar energy. Each of these alternative approaches has drawbacks. Nuclear power requires large capital investments and safety and waste disposal are concerns. Wind power is effective, but wind turbines require a windy site, often far away from grid connections and take up large footprints of land. Hydropower requires the construction of large, potentially environmentally harmful dams and the displacement of large volumes of flowing water. Geothermal power requires a source of energy that is relatively near the surface—a characteristic not common to a large portion of the Earth—and has the potential to disrupt the balance of forces that exist inside the Earth's crust. Solar is one of the cleanest and most available forms of renewable energy and it can be harnessed by direct conversion into electricity (solar photovoltaic) or by heating a working fluid (solar thermal).
Solar photovoltaic (PV) technology relies on the direct conversion of solar power into electricity through the photoelectric effect: solar radiation's quantized particles, or photons, impinging on semiconductor junctions may excite pairs of conduction electrons and valence holes. These charged particles travel through the junction and may be collected at electrically conductive electrodes to form an electric current in an external circuit.
Photovoltaic is one of the most promising technologies for producing electricity from renewable resources, for a number of reasons: 1. The photovoltaic effect in Si and other solid-state semiconductors is well understood and the technology fully validated; 2. PV power plants convert directly solar power into electrical power, have no moving parts and require low maintenance; 3. Solar radiation is quite predictable and is maximum during hours of peak electricity consumptions; and 4. The industry has been aggressively pursuing a performance improvement and cost reduction path similar to the Moore's law in semiconductor electronics, approaching the condition of market competitiveness with traditional energy resources in many parts of the world. In 2010, approximately 16 GW of solar photovoltaic were installed globally, over a 100% growth from global installations in 2009.
However, PV is still more expensive than traditional energy resources in most parts of the world: while economy of scale and low cost manufacturing will contribute to further reduce cost, technological innovation is needed to achieve market competitiveness more rapidly and on an economically sound and sustainable basis.
Applications exist where the value-added features of photovoltaic module technology would offset their cost premium and the market would readily accept it. For example, in the case of new rooftops, it is desirable to incorporate photovoltaic modules as roofing elements in a manner that would displace the cost of rooftop construction materials and reduce the installation time.
SUMMARY OF THE INVENTIONThis invention overcomes disadvantages of the prior art by providing a rooftop construction system and method in which photovoltaic modules are used as integral components of the roofing structure, and provide electricity generation as well as structural, acoustic, and thermal insulation capabilities to reduce the overall cost and increase the speed of installation of rooftops with photovoltaic power. In an illustrative embodiment, a system, comprising a Rooftop with Structurally and Functionally Integrated Photovoltaic Modules (RSFIPM) overcomes the following deficiencies of previous methods of installing photovoltaic modules on new construction rooftops: the high cost of installation of a PV array onto a rooftop; the duplication of materials and labor; the perforation of the building envelope by fixating means such as bolts or nails; The extra load on the structure caused by non-integrated PV arrays. By implementing a grid-like support structure and by tessellating it with photovoltaic modules augmented with extra structural and functional layers, many benefits, including faster installation time, lower material and labor cost, total architectural integration of photovoltaic power generation, lightweight roofing structure, etc. can be realized.
Illustratively, a system and a method for constructing rooftops with structurally and functionally integrated photovoltaic modules includes the steps of creating a grid-like structure of interconnected beams and mounting rails sitting on vertical elevation structures, such as walls or columns. Photovoltaic modules, which can be adapted from commercially available units, and are augmented with at least one additional structural and functional layer are then mounted in the grid-like structure. The grid-like structure illustratively includes members arranged in parallel that are constructed and arranged to slidably receive, capture and retain the photovoltaic modules between respective pairs of the members. These members can include a cross section shape formed with a plurality of shoulders and slots sized to receive, capture and retain an edge of the module and edges of other structures, such as insulating and supporting layers. The members can be formed as extrusions that are symmetrically slotted on both sides (e.g. along the inner area of the roof surface) or asymmetrical (e.g. where used at the end of the roof).
In a further illustrative embodiment, an integrated photovoltaic roofing system includes a photovoltaic module, a lateral frame, a frontal frame and a plurality of layers with structural and functional properties that can include structural support, acoustic insulation, thermal insulation and other advantageous roofing properties.
In yet another illustrative embodiment, an integrated photovoltaic roofing system includes a photovoltaic module with customized frame and a second mated frame, which is fixated onto a pair of mounting members including a plurality of shoulders and slots sized to receive, capture and retain an edge of the mated frame and edges of other structures, such as insulating and supporting layers.
An illustrative, dedicated mounting arrangement for roofing is also provided, comprising a mounting rail a corresponding (matching) retaining fixture. This mounting arrangement can be employed to receive photovoltaic modules in accordance with illustrative embodiments herein.
The invention description below refers to the accompanying drawings, of which:
A Rooftop with Structurally and Functionally Integrated Photovoltaic Modules (RSFIPM), according to the illustrative embodiments described below, is a rooftop construction method where photovoltaic panels are adapted for use as integral components of the roofing structure and provide electricity generation as well as structural and acoustic and thermal insulation capabilities, to overall reduce the cost of rooftops with photovoltaic power.
The dominant technique for the realization of rooftops of commercial and industrial facilities today consists of the interconnection of large segments of a multi-layer structure comprising a top layer of galvanized steel, aluminum or copper; a mid layer of polyurethane foam, mineral wool or other insulating and fireproof material; a bottom layer of galvanized steel, aluminum, or plastic materials (PVC, fiberglass, etc.).
In its generalized implementation, the RSFIPM replaces the multi-layer structure with a grid-like supporting structure and by tessellating it with photovoltaic modules augmented with extra structural and functional layers. The modules' frames are also modified so that when they are placed by one another and anchored to the mounting rails, a continuous, waterproof structure results.
A top view of RSFIPM is shown in
The foregoing has been a detailed description of illustrative embodiments of the invention. Various modifications and additions can be made without departing from the spirit and scope of this invention. Each of the various embodiments described above may be combined with other described embodiments in order to provide multiple features. Furthermore, while the foregoing describes a number of separate embodiments of the apparatus and method of the present invention, what has been described herein is merely illustrative of the application of the principles of the present invention. For example, the sizes, shapes and form factors of components described herein can be varied to suit a particular application. Likewise, additional layers, enclosures, housings and mounting assemblies can be employed in conjunction with RSFIPM and IPM as appropriate. Accordingly, this description is meant to be taken only by way of example, and not to otherwise limit the scope of this invention.
Claims
1-20. (canceled)
21. A roof system with structurally and functionally integrated photovoltaic (PV) modules, the roof system comprising:
- at least one photovoltaic module;
- a grid-like structure of beams sitting on vertical elevation structures;
- a grid-like structure of mounting rails, at least one of the mounting rails comprising a base and at least one horizontal plane disposed parallel to and above the base;
- at least one vertically stacked bracket assembly received by the horizontal plane, the bracket assembly engaging the photovoltaic module at a location exposed to an outside environment;
- a first plurality of stacked structural and functional layers engaged with the at least one vertically stacked bracket assembly, the photovoltaic module being separated from the first plurality of stacked structural and functional layers to provide passive or active cooling;
- a second plurality of stacked structural and functional layers engaged with the at least one mounting rail, the second plurality of stacked structural and functional layers being distinct from the first plurality of stacked structural and function layers and being disposed above the grid-like structure of beams.
22. The system of claim 21, wherein the at least one horizontal plane comprises a horizontal extension.
23. The system of claim 21, wherein the at least one photovoltaic module comprises a plurality of photovoltaic modules, the plurality of photovoltaic modules defining a roof surface.
24. The system of claim 21, wherein at least one of the first plurality of stacked structural and functional layers and the second plurality of stacked structural and functional layers extend into an interior building environment.
25. The system of claim 21, wherein the photovoltaic module being separated from the first plurality of stacked structural and functional layers by a first gap sized and arranged to provide passive or active cooling.
26. The system of claim 21, wherein the second plurality of stacked structural and function layers are disposed adjacent to the base,
27. The system of claim 26, wherein the second plurality of stacked structural and functional layers are disposed atop the base.
28. The system of claim 26, wherein the second plurality of stacked structural and functional layers are separated from the first plurality of stacked structural and functional layers by a second gap.
29. The system of claim 21, wherein at least one of the first plurality of stacked structural and functional layers and the second plurality of stacked structural and functional layers comprise insulating layers and supporting layers.
30. The system of claim 21, wherein the beams are interconnected.
31. The system of claim 21, wherein the bracket assembly is secured to the at least one mounting rail with an overlying retaining fixture having a fastener extending downwardly into the at least one mounting rail.
32. The system of claim 21, wherein the base has a first length and the mounting rail has a second length such that the second length is greater than the first length.
33. The system of claim 22, further comprising:
- a first channel on a first upper side of each of the mounting rail and a second channel on an opposing second upper side of the mounting rail, wherein the first channel includes at least one vertical extension and the at least one horizontal extension, the at least one vertically stacked bracket assembly being received by both the horizontal extension and the vertical extension.
34. The system of claim 23, wherein the base is disposed below each of the first channel, the second channel, the vertical extension, and the horizontal extension
35. A method for conducting a roof system with structurally and functionally integrated photovoltaic modules, the method comprising:
- providing at least one photovoltaic module;
- providing a grid-like structure of beams sitting on vertical elevation structures;
- providing a grid-like structure of mounting rails, at least one of the mounting rails comprising a base and at least one horizontal extension disposed parallel to and above the base;
- providing at least one vertically stacked bracket assembly received by the horizontal extension, the bracket assembly engaging the photovoltaic module at a location exposed to an outside environment;
- providing a first plurality of stacked structural and functional layers engaged with the at least one vertically stacked bracket assembly, the photovoltaic module being separated from the first plurality of stacked structural and functional layers to provide passive or active cooling;
- a second plurality of stacked structural and functional layers engaged with the at least one mounting rail, the second plurality of stacked structural and functional layers being distinct from the first plurality of stacked structural and function layers and being disposed above the grid-like structure of beams.
Type: Application
Filed: Mar 31, 2014
Publication Date: Aug 7, 2014
Inventor: Pierino Ferrara (Tossicia)
Application Number: 14/230,730
International Classification: H01L 31/048 (20060101);