This invention relates generally to photovoltaic devices, and more specifically, to solar cells and/or solar cell modules designed for large-scale electric power generating installations.
Solar cells and solar cell modules convert sunlight into electricity. Traditional solar cell modules are typically comprised of polycrystalline and/or monocrystalline silicon solar cells mounted on a support with a rigid glass top layer to provide environmental and structural protection to the underlying silicon based cells. This package is then typically mounted in a rigid aluminum or metal frame that supports the glass and provides attachment points for securing the solar module to the installation site. A host of other materials are also included to make the solar module functional. This may include junction housings, bypass diodes, sealants, and/or multi-contact connectors used to complete the module and allow for electrical connection to other solar modules and/or electrical devices. Certainly, the use of traditional silicon solar cells with conventional module packaging is a safe, conservative choice based on well understood technology.
Drawbacks associated with traditional solar module package designs, however, have limited the ability to install large numbers of solar panels in a cost-effective manner. This is particularly true for large scale deployments where it is desirable to have large numbers of solar modules setup in a defined, dedicated area. Traditional solar module packaging comes with a great deal of redundancy and excess equipment cost. For example, a recent installation of conventional solar modules in Pocking, Germany deployed 57,912 monocrystalline and polycrystalline-based solar modules. This meant that there were also 57,912 junction housings, 57,912 aluminum frames, untold meters of cablings, and numerous other components. These traditional module designs inherit a large number of legacy parts that hamper the ability of installers to rapidly and cost-efficiently deploy solar modules at a large scale.
Although subsidies and incentives have created some large solar-based electric power installations, the potential for greater numbers of these large solar-based electric power installations has not been fully realized. There remains substantial improvement that can be made to photovoltaic cells and photovoltaic modules that can greatly reduce their cost of manufacturing, increase their ease of installation, and create much greater market penetration and commercial adoption of such products, particularly for large scale installations.
Embodiments of the present invention address at least some of the drawbacks set forth above. The present invention provides for the improved solar module designs that reduce manufacturing costs and redundant parts in each module. These improved module designs are well suited for installation at dedicated sites where redundant elements can be eliminated since some common elements or features may be shared by many modules. It should be understood that at least some embodiments of the present invention may be applicable to any type of solar cell, whether they are rigid or flexible in nature or the type of material used in the absorber layer. Embodiments of the present invention may be adaptable for roll-to-roll and/or batch manufacturing processes. At least some of these and other objectives described herein will be met by various embodiments of the present invention.
In one embodiment of the present invention, a central junction-boxless photovoltaic module is used comprising of a plurality of photovoltaic cells and a module support layer providing a mounting surface for the cells. The module has a first electrical lead extending outward from one of the photovoltaic cells, the lead coupled to an adjacent module without passing the lead through a central junction box. The module may have a second electrical lead extending outward from one of the photovoltaic cells, the lead coupled to another adjacent module without passing the lead through a central junction box. Without central junction boxes, the module may use connectors along the edges of the modules which can substantially reduce the amount of wire or connector ribbon used for such connections.
In another embodiment of the present invention, a photovoltaic module is provided comprising of a plurality of photovoltaic cells positioned between a transparent module layer and a backside module layer. The module includes a first electrical lead extending outward from an edge of the module from between the transparent module layer and the backside module layer, wherein the lead is couplable to an adjacent module without passing the lead through a central junction box or an opening in either the transparent module layer or the backside module layer. Optionally, some embodiments may use electrical leads that exit though an opening in the module. Optionally, some embodiments may use electrical leads that exit though an opening in the transparent module layer or the backside module layer. The module may include a second electrical lead extending outward from an edge of the module from between the transparent module layer and the backside module layer, wherein the lead is couplable to another adjacent module without passing the lead through a central junction box or an opening in either the transparent module layer or the backside module layer.
Optionally, the following may also be adapted for use with any of the embodiments disclosed herein. The module support layer may be frameless and thus creates a frameless photovoltaic module. The backside module layer, transparent module layer, and the cells therebetween may be coupled together without a frame extending partially around or completely around a perimeter of the module layers. The module may be a glass-glass module. The transparent module layer may be comprised of solar glass. The transparent module layer may have a thickness of about 4.0 mm or less. The transparent module layer may have a thickness of about 3.2 mm or less. The backside module layer may be comprised of non-solar glass. The backside module layer may have a thickness of about 3.0 mm or less. The backside module layer may have a thickness of about 2.0 mm or less. The module may further include a pottant layer between the photovoltaic cells and either the transparent module layer or the backside layer, wherein the pottant layer has thickness of about 100 microns or less. In other embodiments, the pottant layer may have a thickness of about 50 microns or less. The pottant layer between the photovoltaic cells and either the transparent module layer or the backside layer may be comprised of one or more of the following: ethyl vinyl acetate (EVA), polyvinyl butyral (PVB), ionomer, silicone, thermoplastic polyurethane (TPU), thermoplastic elastomer polyolefin (TPO), tetrafluoroethylene hexafluoropropylene vinylidene (THV), fluorinated ethylene-propylene (FEP), saturated rubber, butyl rubber, thermoplastic elastomer (TPE), flexibilized epoxy, epoxy, amorphous polyethylene terephthalate (PET), urethane acrylic, acrylic, other fluoroelastomers, or combinations thereof. The first electrical lead may be a flat, square, rectangular, triangular, round, or connector with other cross-sectional shape. The second electrical lead may be the same or different shape as the first electrical lead.
Optionally, the following may also be adapted for use with any of the embodiments disclosed herein. The photovoltaic cells may be in direct contact with the transparent module layer. The photovoltaic cells may be in direct contact with the backside module layer. The photovoltaic cells comprise of thin-film photovoltaic cells. The photovoltaic cells may be comprised of non-silicon solar cells. The photovoltaic cells may be comprised of amorphous silicon-base solar cells. Optionally, the photovoltaic cells each have an absorber layer with one or more inorganic materials from the group consisting of: titania (TiO2), nanocrystalline TiO2, zinc oxide (ZnO), copper oxide (CuO or Cu2O or CuxOy), zirconium oxide, lanthanum oxide, niobium oxide, tin oxide, indium oxide, indium tin oxide (ITO), vanadium oxide, molybdenum oxide, tungsten oxide, strontium oxide, calcium/titanium oxide and other oxides, sodium titanate, potassium niobate, cadmium selenide (CdSe), cadmium sulfide (CdS), copper sulfide (Cu2S), cadmium telluride (CdTe), cadmium-tellurium selenide (CdTeSe), copper-indium selenide (CuInSe2), cadmium oxide (CdOx), CuI, CuSCN, a semiconductive material, silicon, or combinations of the above. Optionally, the photovoltaic cells may each have an absorber layer with one or more organic materials from the group consisting of: a conjugated polymer, poly(phenylene) and derivatives thereof, poly(phenylene vinylene) and derivatives thereof (e.g., poly(2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene vinylene (MEH-PPV), poly(para-phenylene vinylene), (PPV)), PPV copolymers, poly(thiophene) and derivatives thereof (e.g., poly(3-octylthiophene-2,5-diyl), regioregular, poly(3-octylthiophene-2,5-diyl), regiorandom, Poly(3-hexylthiophene-2,5-diyl), regioregular, poly(3-hexylthiophene-2,5-diyl), regiorandom), poly(thienylenevinylene) and derivatives thereof, and poly(isothianaphthene) and derivatives thereof, 2,2′7,7′tetrakis(N,N-di-p-methoxyphenyl-amine)-9,9′-spirobifluorene(spiro-Me OTAD), organometallic polymers, polymers containing perylene units, poly(squaraines) and their derivatives, and discotic liquid crystals, organic pigments or dyes, a Ruthenium-based dye, a liquid iodide/triiodide electrolyte, azo-dyes having azo chromofores (—N═N—) linking aromatic groups, phthalocyanines including metal-free phthalocyanine; (HPc), perylenes, perylene derivatives, copper phthalocyanines (CuPc), zinc phthalocyanines (ZnPc), naphthalocyanines, squaraines, merocyanines and their respective derivatives, poly(silanes), poly(germinates), 2,9-Di(pent-3-yl)-anthra[2,1,9-def:6,5,10-d′e′f′]diisoquinoline-1,3,8,10-tetrone, and 2,9-Bis-(1-hexyl-hept-1-yl)-anthra[2,1,9-def:6,5,10-d′e′f′]diisoquinoline-1,3,8,10-tetrone and pentacene, pentacene derivatives and/or pentacene precursors, an N-type ladder polymer, poly(benzimidazobenzophenanthroline ladder) (BBL), or combinations of the above. The photovoltaic cells may each have an absorber layer with one or more materials from the group consisting of: an oligomeric material, micro-crystalline silicon, inorganic nanorods dispersed in an organic matrix, inorganic tetrapods dispersed in an organic matrix, quantum dot materials, ionic conducting polymer gels, sol-gel nanocomposites containing an ionic liquid, ionic conductors, low molecular weight organic hole conductors, C60 and/or other small molecules, or combinations of the above.
Optionally, the following may also be adapted for use with any of the embodiments disclosed herein. The first electrical lead or the second electrical lead may be comprised of a flat wire or ribbon. The first electrical lead or the second electrical lead may be comprised of a flat aluminum wire. The first electrical lead or the second electrical lead may be comprised of a length no more than about 2× a distance from one edge of the module to an edge of a closest adjacent module. Optionally, the first electrical lead or the second electrical lead may have a length no more than about 30 cm. The module may be in landscape configuration defined by a long dimension and a short dimension, wherein the first electrical lead extends from the module along the short dimension. The module may be in landscape configuration defined by a long dimension and a short dimension, wherein the first electrical lead extends from the module along the long dimension, closer to one end of the module than a middle of the module. The first electrical lead may extend outward from one edge of the module and the second electrical lead may extend outward from the same edge of the module. In another embodiment, the first electrical lead extends outward from along one edge of the module and the second electrical lead extends outward from a different edge of the module.
Optionally, the following may also be adapted for use with any of the embodiments disclosed herein. The module may include a first edge housing for securing the first electrical lead to the module and providing a moisture barrier at a first electrical lead exit from the module. The module may also include a second edge housing for securing the second electrical lead to the module and providing a moisture barrier at a second electrical lead exit from the module. The first edge housing and the second edge housing may each define an interior space configured to accommodate encapsulant material injected into the space to form the moisture barrier. The first edge housing and the second edge housing may each have an opening allowing encapsulant material to be injected into the connecter to form a moisture barrier after the connecter is mounted onto the module. The first edge housing and the second edge housing may each have a surface that engages the transparent module layer and a second surface that engages the backside module layer. The first edge housing and the second edge housing may engage only one of the following: the transparent module layer or the backside module layer. The first edge housing and the second edge housing may each sized to receive a flat wire entering the edge housing and couple the flat wire to a round wiring exiting the edge housing. The first edge housing and the second edge housing may each be sized to receive a flat aluminum-based wire entering the edge housing and couple the flat aluminum-based wire to a round copper-based wire exiting the edge housing. The first edge housing and the second edge housing may be spaced apart from one another, with the first edge housing closer to one end of the module and the second edge housing to an opposite end of the module. The first edge housing and the second edge housing may each be positioned on the module to cover a corner of the module. The first edge housing and the second edge housing may extend no more than about 1 cm above the transparent module layer. The first edge housing and the second edge housing may extend no more than about 0.5 cm above the transparent module layer. The first edge housing and the second edge housing may extend no more than about 0.5 cm below the backside module layer. In another embodiment, the height may be no more than about 0.25 cm above the module layer. In another embodiment, the height may be no more than about 0.10 cm above the module layer. The first edge housing and the second edge housing may be mounted in a manner along the edges of the module to allow for substantially flush stacking of modules against one another. It should be understood that the term edge does not necessarily mean that the edge housing is coupled to the edge or side edge of the module. Although some embodiments of the edge housings do have this configuration, others are merely away for the centerline of the module and typically closer to an adjacent module than a centerline and/or center point of the module.
Optionally, the following may also be adapted for use with any of the embodiments disclosed herein. A first cell in the module may be comprised of a dummy cell of non-photovoltaic material to facilitate electrical connection to other solar cells in the module. A flat, inline bypass diode takes the place of one of the cells in the module. The module may be without a bypass diode. The module may include a moisture barrier extending along the perimeter of the module to prevent moisture entry into the module. Although not limited to the following, the moisture barrier may be a butyl rubber based material such as that available from TruSeal Technologies, Inc. A desiccant loaded edge seal may be used to act as a moisture barrier around the module. The moisture barrier may be one or more of the following: butyl tape or butyl tape loaded with desiccant. An edge seal may be provided as a moisture barrier. A desiccant loaded edge seal may be provided a moisture barrier. The module may have a weight of about 16 kg or less. The module may have a weight of about 16 kg or less without including any mounting bracket. The module may have a cross-sectional thickness of about 6 mm or less, including at least the thickness of the cells, the transparent module layer, and the backside module layer. The module may have a cross-sectional thickness of about 7 mm or less, including at least the thickness of the cells, the transparent module layer, and the backside module layer. The module may have a length between about 1660 mm and about 1666 mm. The module may have a width between about 700 mm and about 706 mm. The module may be designed to be coupled to a plurality of clips to couple the module to support structures. The module may be designed to be coupled to four clips attached to edges of the module to couple the module to support rails. Although modules may be shown oriented in portrait orientation, it should be understood they may also be in landscape orientation. The electrical connector may exit from edges closest to next module or device that the current module is connected to. Optionally, the electrical connector may exit from the orthogonal edge. The electrical connectors may exit from the same edge, from opposing edges, or form other different edges. The thickness of the modules layers may optionally be the same or different.
In yet another embodiment of the present invention, an edge housing provided use with a solar module may be comprised of a housing defining an opening for receiving an electrical lead from the module and a module interface surface on the housing configured to mount the housing along an edge of the module. The housing may define a cavity for receiving encapsulant to create a waterproof seal with the module and the electrical lead.
Optionally, the following may also be adapted for use with any of the embodiments disclosed herein. The housing may be comprised of an upper part and a lower part separable from one another. The housing may have a clam-shell design wherein an upper part of the housing is hinged to a lower part of the housing. The housing may define an interior space along one or more surfaces facing the module and configured to accommodate encapsulant material injected into the space to form a moisture barrier against the module. The housing may include an opening to allow encapsulant material to be injected into the housing after the housing is mounted to the solar module. The housing may have a surface that engages the transparent module layer and a second surface that engages the backside module layer. The housing optionally engages only one of the following: the transparent module layer or the backside module layer. The housing may be sized to receive a flat wire entering the edge housing and couple the flat wire to a round wiring exiting the housing. The housing may be sized to compress a flat wire entering the housing against a round wiring exiting the housing. The first edge housing and the second edge housing may each be sized to receive a flat aluminum-based wire entering the edge housing and couple the flat aluminum-based wire to a round copper-based wire exiting the edge housing. The housing may be comprised of injection molded plastic. The housing may include locators and/or locator marks to align parts of the housing together. The housing may be shaped to cover a corner of the module to increase surface area contact between the housing and the module. The module may be without a central junction box that comprises a junction housing that contains both an electrical lead from an upstream solar module and an electrical lead to a downstream solar module.
In yet another embodiment of the present invention, a photovoltaic power installation is provided comprised of a plurality of frameless photovoltaic modules. A plurality of electrical leads from each of the modules, wherein adjacent modules are coupled together by at least one of the electrical leads extending outward from the modules, each of the leads extending outward without passing through a central junction box. In some embodiment, each of the photovoltaic modules includes at least two edge housings for electrical leads extending outward from each module.
Optionally, the following may also be adapted for use with any of the embodiments disclosed herein. The edge housings may be filled with encapsulant after being mounted on the modules. The edge housings may be electrically coupled a flat wire from the modules to a round wire extending from the edge housings. The edge housings may optionally extend no more than about 0.5 cm above or below a top or bottom surface of the modules to minimize stacking height. The edge housings may optionally extend no more than about 0.25 cm above or below a top or bottom surface of the modules to minimize stacking height. The edge housings may optionally extend no more than about 0.1 cm above or below a top or bottom surface of the modules to minimize stacking height. The edge housings on one module may be spaced apart from one another. The electrical leads may each have a length less than about 2× a distance separating adjacent modules. The modules may be coupled in a series interconnection. The modules may be glass-glass modules with a glass-based top layer and a glass-based bottom layer. The modules may be frameless and mounted on a plurality of rails. The modules may be frameless and mounted on a plurality of rails, wherein the rails carry electrical charge between modules.
In a still further embodiment of the invention, a method is provided comprising of providing a plurality of frameless, rigid photovoltaic modules and mounting a plurality of edge housings over electrical leads extending outward from the edges of the modules, wherein all electrical leads on one module exits the module without passing through the same edge housing and without passing through a central junction box.
Optionally, the following may also be adapted for use with any of the embodiments disclosed herein. Mounting the edge housings comprises adhering the edge connecters to at least one planar surface on the modules. The method may include mounting the edge housings comprises adhering the edge connecters to both top and bottom surfaces of the modules. Edge housings may be positioned on the modules without substantially covering any solar cells in the module. The modules may be glass-glass modules. The edge housings may be filled with encapsulant before mounting on the modules. The edge housings may be filled with encapsulant after mounting on the modules. Electrical leads may extend outward from the module between module layers and without passing through openings in the module layers. Mechanical pressure may be used to electrically connect two bare electrical conductors within the housing. Each of the electrical connectors provides a sealing surface of at least about 2 cm2 areas. Optionally, each of the electrical connectors provides a sealing surface of at least about 1 cm2 area. The photovoltaic modules may be electrically coupled together at the installation site in a series interconnected manner, wherein the electrically coupling step comprises at least one of the following methods for joining electrical leads: welding, spot welding, reflow soldering, ultrasonic welding, arc welding, cold welding, laser welding, induction welding, or combinations thereof. Adjacent electrical leads may be joined together to form a V-shape or Y-shape connection. Optionally, adjacent electrical leads may be joined together to form a U-shape connection.
In one embodiment of the present invention, a central junction-boxless photovoltaic module is used comprising of a plurality of photovoltaic cells, a transparent module layer, and a backside module layer. The module may have a first edge-exiting electrical lead extends outward from the module from between the transparent module layer and the backside module layer, wherein the first edge-exiting electrical lead is couplable to an adjacent module without passing the lead through a central junction box; and a second edge-exiting electrical lead extending outward from the module from between the transparent module layer and the backside module layer, wherein the second edge-exiting electrical lead is couplable to another adjacent module without passing the lead through a central junction box. Optionally, the edge exiting leads are each housed within an edge mounted edge housing that contains only one connection directly connected to at least one cell in the module. Optionally, the edge exiting leads are each housed within an edge mounted edge housing that contains only one connection directly connected to only one cell in the module. Optionally, the edge exiting leads are each housed within an edge mounted edge housing that connects to a wire exiting through an opening in the backside module layer.
A further understanding of the nature and advantages of the invention will become apparent by reference to the remaining portions of the specification and drawings.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. It may be noted that, as used in the specification and the appended claims, the singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a material” may include mixtures of materials, reference to “a compound” may include multiple compounds, and the like. References cited herein are hereby incorporated by reference in their entirety, except to the extent that they conflict with teachings explicitly set forth in this specification.
In this specification and in the claims which follow, reference will be made to a number of terms which shall be defined to have the following meanings:
“Optional” or “optionally” means that the subsequently described circumstance may or may not occur, so that the description includes instances where the circumstance occurs and instances where it does not. For example, if a device optionally contains a feature for an anti-reflective film, this means that the anti-reflective film feature may or may not be present, and, thus, the description includes both structures wherein a device possesses the anti-reflective film feature and structures wherein the anti-reflective film feature is not present.
Referring now to
It should be understood that the simplified module 10 is not limited to any particular type of solar cell. The solar cells 16 may be silicon-based or non-silicon based solar cells. By way of nonlimiting example the solar cells 16 may have absorber layers comprised of silicon (monocrystalline or polycrystalline), amorphous silicon, organic oligomers or polymers (for organic solar cells), bi-layers or interpenetrating layers or inorganic and organic materials (for hybrid organic/inorganic solar cells), dye-sensitized titania nanoparticles in a liquid or gel-based electrolyte (for Graetzel cells in which an optically transparent film comprised of titanium dioxide particles a few nanometers in size is coated with a monolayer of charge transfer dye to sensitize the film for light harvesting), copper-indium-gallium-selenium (for CIGS solar cells), CdSe, CdTe, Cu(In,Ga)(S,Se)2, Cu(In,Ga,Al)(S,Se,Te)2, and/or combinations of the above, where the active materials are present in any of several forms including but not limited to bulk materials, micro-particles, nano-particles, or quantum dots. Advantageously, thin-film solar cells have a substantially reduced thickness as compared to silicon-based cells. The decreased thickness and concurrent reduction in weight allows thin-film cells to form modules that are significantly thinner than silicon-based cells without substantial reduction in structural integrity (for modules of similar design).
The pottant layer 18 may be any of a variety of pottant materials such as but not limited to EVA, Tefzel®, PVB, ionomer, silicone, TPU, TPO, THV, FEP, saturated rubber, butyl rubber, TPE, flexibilized epoxy, epoxy, amorphous PET, urethane acrylic, acrylic, other fluoroelastomers, other materials of similar qualities, or combinations thereof as previously described for
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For any of the embodiments herein, a perimeter seal 92 (shown in phantom) may optionally be applied around the module 10 to improve the barrier seal along the side perimeter of the module. This perimeter seal 92 will reinforce the barrier properties along the sides of the module 10 and prevent sideway entry of fluid into the module. The seal 92 may be comprised of one or more of the following materials such as but not limited to desiccant loaded versions of EVA, Tefzel®, PVB, ionomer, silicone, TPU, TPO, THV, FEP, saturated rubber, butyl rubber, TPE, flexibilized epoxy, epoxy, amorphous PET, urethane acrylic, acrylic, other fluoroelastomers, other materials of similar qualities, or combinations thereof. By way of nonlimiting example, the desiccant may be selected from porous internal surface area particle of aluminosilicates, aluminophosphosilicates, or similar material. It should be understood that the seal 92 may be applied to any of the modules described herein to reinforce their barrier properties. In some embodiments, the seal 92 may also act as strain relief for ribbons, wires, or other elements exiting the module. Optionally, the seal 92 may also be used to house certain components such as bypass diodes or the like which may be embedded in the seal material.
Referring now to
Optionally, the modules may be configured so that they are limited to weighing no more than about 36 kg. Optionally, the modules may be configured so that they are limited to weighing no more than about 32 kg. Optionally, the modules may be configured so that they are limited to weighing no more than about 30 kg. Optionally, the modules may be configured so that they are limited to weighing no more than about 28 kg. In one embodiment, the module may be sized to provide at least about 170 watts of power at AM 1.5G. In one embodiment, the module may be sized to provide at least about 180 watts of power at AM 1.5G. In another embodiment, the module may be sized to provide at least about 200 watts of power at AM 1.5G. In another embodiment, the module may be sized to provide at least about 220 watts of power at AM 1.5G. In another embodiment, the module may be sized to provide at least about 240 watts of power at AM 1.5G.
The ability of the cells 360 and 370 to be sized to fit into the modules 302 or 304 is in part due to the ability to customize the sizes of the cells. In one embodiment, the cells in the present invention may be non-silicon based cells such as but not limited to thin-film solar cells that may be sized as desired while still providing a certain total output. For example, the module 302 of the present size may still provide at least 100 W of power at AM 1.5G exposure. Optionally, the module 302 may also provide at least 5 amp of current and at least 21 volts of voltage at AM1.5G exposure. Details of some suitable cells can be found in U.S. patent application Ser. No. 11/362,266 filed Feb. 23, 2006, and Ser. No. 11/207,157 filed Aug. 16, 2005, both of which are fully incorporated herein by reference for all purposes. In one embodiment, cells 370 weigh less than 14 grams and cells 360 weigh less than 7 grams. Total module weight may be less than about 16 kg. In another embodiment, the module weight may be less than about 18 kg. Further details of suitable modules may be found in commonly assigned, co-pending U.S. patent application Ser. No. 11/537,657 filed Oct. 1, 2006, fully incorporated herein by reference for all purposes. Industry standard mount clips 393 may also be included with each module to attach the module to support rails.
Although not limited to the following, the modules of
Referring still to FIGS. 8 and 9A/9B, it should be understood that removal of the central junction box, in addition to reducing cost, also changes module design to enable novel methods for electrical interconnection between modules. As seen in
By way of nonlimiting example, the connector 380 may comprise of copper, aluminum, copper alloys, aluminum alloys, tin, tin-silver, tin-lead, solder material, nickel, gold, silver, noble metals, or combinations thereof. These materials may also be present as coatings to provide improved electrical contact. Although not limited to the following, in one embodiment, a tool may use a soldering technique to join the electrical leads together at the installation site. Optionally, in other embodiments, techniques such as welding, spot welding, reflow soldering, ultrasonic welding, arc welding, cold welding, laser welding, induction welding, or combinations thereof may be used. Soldering may involve using solder paste and/or solder wire with built-in flux.
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Other embodiments, some cells may be connected in parallel electrical connection. In such embodiments, additional edge housings may be used to couple parallel strings. As seen in
Referring now to
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Using the edge as an exit area for the electrical lead in a solar module provides several cost advantages due to not requiring any holes to be cut in the glass or potting material. However, in this method the edge sealant for the module is breached by the conductor which makes environmentally sealing the edge of the panel difficult. The present embodiment of the invention provides an insulated electrical joint and mechanical strain relief for the second cable leading away from the edge housing. This advantageously allows for the transition of a flat wire to round wire. In addition to providing a method for sealing and securing an edge exiting flat conductor, the present embodiment of the invention provides a housing that is easy to assembly in an automated many by providing locating and retaining features for the two conductors involved in the connection.
Referring now to the embodiment of
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Although not limited to the following, the potting material 450 may be comprised of one or more of the following: Tru-Seal®, ethyl vinyl acetate (EVA), polyvinyl butyral (PVB), ionomer, silicone, thermoplastic polyurethane (TPU), thermoplastic elastomer polyolefin (TPO), tetrafluoroethylene hexafluoropropylene vinylidene (THV), fluorinated ethylene-propylene (FEP), saturated rubber, butyl rubber, thermoplastic elastomer (TPE), flexibilized epoxy, epoxy, amorphous polyethylene terephthalate (PET), urethane acrylic, acrylic, other fluoroelastomers, other materials of similar qualities, or combinations thereof.
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Referring to
While the invention has been described and illustrated with reference to certain particular embodiments thereof, those skilled in the art will appreciate that various adaptations, changes, modifications, substitutions, deletions, or additions of procedures and protocols may be made without departing from the spirit and scope of the invention. For example, with any of the above embodiments, although glass is the layer most often described as the top layer for the module, it should be understood that other material may be used and some multi-laminate materials may be used in place of or in combination with the glass. Some embodiments may use flexible top layers or coversheets. By way of nonlimiting example, the backsheet is not limited to rigid modules and may be adapted for use with flexible solar modules and flexible photovoltaic building materials. Embodiments of the present invention may be adapted for use with superstrate or substrate designs. It may be used with modules that have flat solar cells, elongate solar cells, tubular solar cells, conical solar cells, or cells of other shapes. Details of modules with thermally conductive backplanes and heat sinks can be found in commonly assigned, co-pending U.S. patent application Ser. No. 11/465,783 (Attorney Docket NSL-089) filed Aug. 18, 2006 and fully incorporated herein by reference for all purposes. Other backsheet materials may also be used and is not limited to glass only embodiments. The housing of the edge housing could be made of any material by any method. The edge housing could be designed for hand assembly instead of automated assembly, leaving out locating features. The edge housing could be designed without the channel and holes to allow potting. The edge housing could be designed to allow two or more edge housings to exit the solar module, and could include diode linked between the exiting conductors. Some embodiments may have lower surfaces 422 greater in area than the surface 424. Optionally, some embodiments may have surfaces 424 greater than surfaces 422. In one embodiment, both electrical leads or edge housings are on the same side of module. In another embodiment, they are on different sides. In a still further embodiment, they are diagonal from each other. In yet another embodiment, they are on opposing sides. The shape of the edge housing may be those as shown herein or may oval, curved, square, triangular, hexagonal, circular, polygonal, combinations thereof, or other shaped (as viewed from above or from the side). Additionally, at least some of the embodiments herein only have one wire exiting from the edge housing. Some embodiments of edge housing may have one or more openings 732 to allow for connection of electrical connections in the housing and/or to allow ease of filling of encapsulant or pottant therein. Some embodiments have at least two openings 732 which may be on the same or different surfaces of the edge housing.
Furthermore, those of skill in the art will recognize that any of the embodiments of the present invention can be applied to almost any type of solar cell material and/or architecture. For example, the absorber layer in solar cell 10 may be an absorber layer comprised of silicon, amorphous silicon, organic oligomers or polymers (for organic solar cells), bi-layers or interpenetrating layers or inorganic and organic materials (for hybrid organic/inorganic solar cells), dye-sensitized titania nanoparticles in a liquid or gel-based electrolyte (for Graetzel cells in which an optically transparent film comprised of titanium dioxide particles a few nanometers in size is coated with a monolayer of charge transfer dye to sensitize the film for light harvesting), copper-indium-gallium-selenium (for CIGS solar cells), CdSe, CdTe, Cu(In,Ga)(S,Se)2, Cu(In,Ga,Al)(S,Se,Te)2, and/or combinations of the above, where the active materials are present in any of several forms including but not limited to bulk materials, micro-particles, nano-particles, or quantum dots. The CIGS cells may be formed by vacuum or non-vacuum processes. The processes may be one stage, two stage, or multi-stage CIGS processing techniques. Additionally, other possible absorber layers may be based on amorphous silicon (doped or undoped), a nanostructured layer having an inorganic porous semiconductor template with pores filled by an organic semiconductor material (see e.g., US Patent Application Publication US 2005-0121068 A1, which is incorporated herein by reference), a polymer/blend cell architecture, organic dyes, and/or C60 molecules, and/or other small molecules, micro-crystalline silicon cell architecture, randomly placed nanorods and/or tetrapods of inorganic materials dispersed in an organic matrix, quantum dot-based cells, or combinations of the above. Many of these types of cells can be fabricated on flexible substrates.
Additionally, concentrations, amounts, and other numerical data may be presented herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a thickness range of about 1 nm to about 200 nm should be interpreted to include not only the explicitly recited limits of about 1 nm and about 200 nm, but also to include individual sizes such as but not limited to 2 nm, 3 nm, 4 nm, and sub-ranges such as 10 nm to 50 nm, 20 nm to 100 nm, etc. . . .
The publications discussed or cited herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed. All publications mentioned herein are incorporated herein by reference to disclose and describe the structures and/or methods in connection with which the publications are cited. For example, U.S. patent application Ser. No. 11/465,787 filed Aug. 18, 2006 and PCT patent application PCT/US07/76259 Aug. 18, 2007 are both fully incorporated herein by reference for all purposes.
While the above is a complete description of the preferred embodiment of the present invention, it is possible to use various alternatives, modifications and equivalents. Therefore, the scope of the present invention should be determined not with reference to the above description but should, instead, be determined with reference to the appended claims, along with their full scope of equivalents. Any feature, whether preferred or not, may be combined with any other feature, whether preferred or not. In the claims that follow, the indefinite article “A”, or “An” refers to a quantity of one or more of the item following the article, except where expressly stated otherwise. The appended claims are not to be interpreted as including means-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase “means for.”
This application claims the benefit of priority to U.S. Provisional Application Ser. No. 60/862,979 filed Oct. 25, 2006, fully incorporated herein by reference for all purposes.
Number | Date | Country | |
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60862979 | Oct 2006 | US |