Patent Application
20150207458
Building Integrated Photovoltaic (BIPV) systems are emerging photovoltaic materials, which are built into the building or vehicle architecture. Solar energy is an important part of our biosphere. Photovoltaic technologies should be integrated into our environment with architectural flare. We have to build with people's need in mind, not just energy, but also beauty, comfort, simplicity, mobility, and flexibility.
We propose to build solar panels called Lotus Awning panels. The Lotus Awning solar panels are a basic BIPV system that gives people shade, portability, foldability, heat, and electricity. These panels are designed to be used as awnings as attachment to buildings.
We want strong, yet lightweight solar panels. Conventional solar panels are covered on top by glass and framed with aluminum. They are mounted rigidly on fixed structures that have to be put in places where people cannot reach such as on rooftops. We want the panels to withstand storms not just by strength but also by retracting. Beauty and brand are important, as much as usefulness.
Simplicity in buying, installing, maintaining servicing, and relocating solar panels is what people want. They don't just want heavy and ugly solar panels on a rooftop or in a solar farm. They want something they can touch, move, and see. They want to be able open these panels when the sun rises and to fold them when the sun sets.
The Lotus Awning uses solar panels in a foldable structure on the side of a building to give people shade, electricity, and hot water. That is much needed here in Arizona, where sun exposure can cause health hazards quickly. Yet people here prefer to eat and drink outside as a form of alfresco dining. Also, homes here tend to avoid a southerly exposure because that tends to increase house temperature. Awnings shading windows are a necessity to avoid heat.
In general there is a strong need to make rigid panels that are very lightweight, able to produce not only electricity but also to collect heat. The heat collection also reduces the temperature of the solar panels. High temperature reduces the efficiency of photovoltaic generation and also can cause degradation to the solar panel over time. Besides the Lotus Awning application, we are also using these composite panels for mobile applications such as solar charging of electric cars. We can also mount these composite panels on much larger solar panel systems that track the sun on two axes for another 40% increase of energy production. These panels are used for the Lotus Mobile, Lotus Heat, and Lotus Max systems for which a disclosure has been filed for an umbrella like folding of these solar panels during strong wind.
We invented a building integrated photovoltaic and heat (BIPVAH) solar panel system comprising solar panels comprising a top photovoltaic composite layer, a middle heat exchanging fiber composite frame, and a bottom fiber composite layer. These three layers in turn form a composite structure for a strong and lightweight structure for the purposes of electricity and heat generation. We use these panels as shading structures such as awning and a flower like solar tracking system that can close at night and under adverse climate conditions.
The present invention includes a lightweight solar panel that can collect both heat and solar electrical energy. The provision of the lightweight supported panels allows for new applications of solar panels, for instance as awnings, shade structures, or otherwise applications onto residential, commercial, and other structures. By placing the BIPVAH on a residential building, such as a home or apartment building, the panels can be mounted on one side as awnings. Preferably, the awnings can be swung from hinges mounted on the wall, to allow for deployment for shade, etc. as well as solar energy collection in the dual forms of heat (i.e. for a hot water heater) and electricity, i.e. through solar panels to power the home, and/or supply an electrical grid.
In one exemplary embodiment, we use a fluorocarbon top window for solar cells that are encapsulated by ionomer to adhere to both the top window and a bottom fiber glass composite layer. The resulting photovoltaic layer is glued onto a carbon fiber frame of rectangular tubes through which a coolant, preferably such as glycol, flows. A bottom layer of fiberglass composite sheet, as is known in the art, is glued onto the carbon fiber frame, making a strong composite of a solar panel of two strong composite sheets enclosing a strong carbon fiber frame. The resulting composite structure is lightweight and very strong to hold its weight and withstand wind force.
The solar panels can be mounted to the side of a building, such as on a wall, by means of brackets. The brackets can swing the orientation of the solar panels, such as to allow them to be brought down when unneeded, or for their protection. The panels can also be mounted on an eastern facing wall and track the sun as it rises, rotating along the hinge axis to first show to the east in the morning, rise parallel with the ground at noon, and continue to rise to track the sun to the west. For instance, the panels can begin at −90 (vertical) or preferably −60 degrees from the horizontal, rise to 0 degree at horizontal, and extend past +5 degrees and possibly towards preferably +60, if not +90 degrees (vertical) facing west.
For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts, wherein:
This disclosure provides a new method and apparatus of a fiber composite solar panel that produces photovoltaic electricity and collects solar thermal energy by means of an integrated composite structure which is lightweight, strong, and easy to fold. U.S. Patent Publ. No. 2013/0327371 entitled Foldable Solar Power Receiver, filed Jan. 16, 2013 is hereby incorporated by reference.
The preferred fiber materials we use include but are not limited to, fiberglass and carbon fiber. Other polymers and materials known in the art to have sufficient strength and similar features of these materials are also acceptable for the present invention.
The preferred polymers we use, include but are not limited to, polytetrafluoroethylene (PTFE) to replace glass as window for solar cells, ionomer or ethylene-vinyl acetate (EVA) as adhesives, as well as polypropylene, polyethylene, or epoxy as fiber reinforced polymer.
The preferred photovoltaic materials we use include but are not limited to mono-crystalline silicon cells, poly-crystalline silicon cells, and other thin film solar cells such as those based on amorphous silicon, cadmium telluride, and copper-indium-gallium-selenium (CIGS).
We disclose manners of layering these materials together to build a strong composite structure based on the use of adhesives, heat and pressure lamination, as well as clamping.
We disclose how the laminated panel structure is designed for lightweight, while having high tensile strength to handle its weight and wind load. We increase or build the depth of the laminated structure through a fiber composite frame using a small amount of strong material such as carbon fiber. The stiffness of the panel is based on the use of fiber composite sheet sandwiching a hollow carbon fiber frame of sufficient thickness. The entire structure is an integrated composite for both electricity and heat collection. In the prior art, most heat collecting systems are an add-on to existing solar panels, which are heavy and increase the load requirement of supporting structure rather than adding strength to the system.
The present invention includes a coolant circulated within the laminated solar panel structure, for cooling the solar panel and for heat collection for the purposes of water and space heating. The coolant runs directly in carbon fiber tubes underneath the solar cells, or solar cell layer. The coolant cools the solar cells which has an added benefit for increased electricity production. The use of carbon fiber tubes is preferred as it is very strong and also a very good conductor of heat.
The present invention includes panels that are preferably mounted and propped up against the side of a building. Thereby the panels could be folded at night or during strong wind. These lightweight panels could be folded like an umbrella or as a deck to avoid wind force.
The individual layers 100 of this composite structure are shown in
The top transparent layer 101 protects the solar panel from outside elements such as water, wind, hail, and other impacting objects. The material is preferably a strong transparent layer, such as PTFE, that prevents abrasion, water infusion, tear, heat and light degradation, electric breakdown, and soiling by dust and rain.
The solar cells 102 are positioned in an array and are connected in series by tabbing wires (as is known in the art), forming the photovoltaic layer 103. These cells are encapsulated in two layers of encapsulants top encapsulant 104 and bottom encapsulant 105 by adhesives such as ionomer or EVA or other encapsulants known in the art. The encapsulant layer 104 also serves as an adhesive for the solar cells to adhere to the window layer 101.
A composite layer 106, preferably a fiberglass sheet, is preferably embedded in a polypropylene or nylon polymer and provides back sheet support for the photovoltaic layer 103. The encapsulant layer 105 also serves as an adhesive for the solar cells to adhere to the composite layer 106.
After these layers 101-106 are assembled, the assembly is laminated by heat and pressure to form one single laminated composite layer labeled as 107. We call the composite layers 101, 103, 104, 105, and 106 the photovoltaic composite layer 107. It is preferred that heat pressure is accomplished at an appropriate temperature to ensure proper adhesive and chemical and property changes while not raising the temperature too high to weaken the polypropylene sheet. While the solar cells can withstand temperatures over 300 degrees Celsius, it is preferred to combine the laminate at approximately 140 degrees Celsius, but not higher than 180 degree Celsius, due to potential degradation of the layer materials and to avoid unnecessary deformation.
The frame 108 is preferably formed of carbon fiber composite. The frame preferably includes as many lengths of hollow carbon fiber rods with rectangular cross sections. These lengths are joined together using bibs (as shown in
The bottom layer of the entire assembly is preferably made of another fiber composite layer 109. This composite layer 109 together with the laminated photovoltaic top layer 107 sandwich the carbon fiber composite frame 108. We use a strong adhesive, such as silicone, to form a strong single laminate of the layers 107, 108, and 109 to form a solar panel 100. We add two aluminum frames 110 and 111 at both ends of the solar panel 100 for the purpose of attaching the solar panel 100 to the wall (not shown).
The glycol flows down two carbon fiber tubes 304 and 305 towards bottom carbon fiber tube 306. Glycol flows through tubes 304 and 305 to bottom tube 306 and is then distributed as cool glycol up carbon fiber tubes 307, 308, 309, 310, 311, and 312. In our implementation, the tubes 307, 308, 309, 310, and 311 are located at the center of the six columns of solar cells, providing best support to the cell and central dissipation of heat from the cell.
Glycol routed upward through these tubes collects heat from solar cells. Glycol is collected at the top tube 302 and routed out through bib 313. Directional flow of fluid in these tubes is indicated by arrows.
Rods 304, 305, 307, etc. should be spaced so as to run along the center of each solar cell, so as to properly collect the heat from the appropriate areas. By pulling directly adjacent to cells, the heat dissipation from the cells is increased and therefore further increases the beneficial impact of keeping the solar cells cooled for electrical generation efficiency. Typically the tubes are placed between 4 and 8 inches apart, preferably just over 6 inches, or more preferably spaced 6.4 inches apart.
Modifications, additions, or omissions may be made to the systems, apparatuses, and methods described herein without departing from the scope of the invention. The components of the systems and apparatuses may be integrated or separated. Moreover, the operations of the systems and apparatuses may be performed by more, fewer, or other components. The methods may include more, fewer, or other steps. Additionally, steps may be performed in any suitable order. As used in this document. “each” refers to each member of a set or each member of a subset of a set. To aid the Patent Office, and any readers of any patent issued on this application in interpreting the claims appended hereto, applicants wish to note that they do not intend any of the appended claims or claim elements to invoke paragraph 6 of 35 U.S.C. Section 112 as it exists on the date of filing hereof unless the words “means for” or “step for” are explicitly used in the particular claim.
This application claims priority of U.S. Provisional Patent Application Ser. No. 61/930,270 entitled A FIBER COMPOSITE SOLAR PANEL FOR ELECTRICITY GENERATION AND HEAT COLLECTION filed Jan. 22, 2014, the teachings of which are included herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61930270 | Jan 2014 | US |
