The present invention relates generally to glass solar panels that can be used for the generation of electricity and for architectural building elements. More particularly, the present invention deals with glass solar panels, where solar layers are disposed onto surfaces of electrically conductive coatings that are disposed onto glass sheets in laminate structures, insulated glass (IG) units, or combinations thereof. Most particularly, the present invention deals with improving electrical connections to and within glass solar panels.
The generation of electricity, by way of solar cell technology, has been developing over the last thirty years. However, solar cell technology could still be improved in various ways, for example: (1) the electrically conductive coating could be disposed more uniformly onto the glass sheet, (2) the electrical connection to the electrically conductive coating that is disposed onto the glass sheet could be made physically simpler and more robust, (3) electrical conduction of the electrical connections could be improved, and (4) the connections could be produced less expensively.
Architectural applications could benefit from improvements in the use of glass solar panels as structural members if the external electrical connections to individual glass panels could be made more robust while multiple glass solar panels could be more easily interconnected by interconnection through glazing channels.
In addition, more efficient architectural glass solar panel, for the generation of electricity from light, could be produced if it was better able to take advantage of improvements in the deposition of the electrically conductive coatings, which are now available. In the past, spray-coating techniques delivered non-uniform coatings, which resulted in less reliable electrical connections and less efficient electricity generation. Recently, the deposition of the coatings has improved through the use of chemical vapor deposition (CVD), which allows for improvements in electrical connections and electricity generation.
Electricity generating glass solar panels are typically formed by disposing electrically conductive; doped tin oxide on an interior surface of laminate structures or IG units. These structures/units typically are connected to one or more solar layers, where exposure to light can provide electricity for homes and businesses. Commercial buildings, sloped glazing in atria, canopies, and general fenestration applications, could benefit from the use of architectural glass solar panels but conventional connection means have limited such usage. Expanding the adoption of this technology, however, is hampered by the complexity of safely, reliably, and cost effectively combining glass and electricity.
Interconnections between the glass solar panels, typically, have not been designed as part of an integrated connection circuit. For example, where bus bars have been used, they have typically been screen-printed or fired, conductive silver frits. These may exhibit poor adhesion to the glass and result in rigid electrical terminations at the peripheral edge of the glass, which: (1) makes them vulnerable to mechanical flexing, (2) can expose them to condensation, and (3) typically are expensive. In addition, metallic tapes, with adhesive backing, may be readily applied. However, the tapes possess poor conduction properties and the adhesive can dry out and, subsequently, electrically break down.
As an example, U.S. Pat. No. 2,235,681 to Haven et al., teaches the attaching of metal bus bars to a glass sheet as it applies to structural solder elements but not for glass solar applications.
In the crystalline solar cell technology area, ways have been sought to dispose metal-on-glass. U.S. Pat. No. 6,065,424 to Shacham-Diamand et al., teaches thin metal film coatings sprayed onto glass by use of an aqueous solution and then the electrically conductive coatings are annealed.
In U.S. Pat. No. 4,511,600 to Leas, a conductive metal grid is deposited atop a crystalline solar cell by the use of a mask and orifices (without the use of gas or air pressure to impart dispersion or velocity to the metal particles). The '600 patent also advocates the use of a powdered metal that is heated to a molten temperature in a refractory crucible. In U.S. Pat. No. 4,331,703 to Lindmayer, a conductive metal is flame sprayed onto a silicon solar cell.
In U.S. Pat. No. 4,297,391, also to Lindmayer, particles of a material are formed at a temperature in excess of the alloying temperature of the material and the silicon, and then the two are sprayed onto the surface of the glass at a distance, which causes the material and the silicon to firmly adhere to the surface. The '391 patent also teaches the use of a mask.
As another example, in order to connect wiring to the glass solar panels (as well as electrically heated glass panels), it is common for holes to be drilled in the glass panels at the time of manufacturing, as well as in a frame that is often used to hold the panels, or at the time of installation and termination of wiring that is done in the field. When the assembly of the glass solar panels is completed, some of the wiring and associated parts are visible to users of these panel systems. Termination of system wiring to existing facility electrical services, as well as on-site glazing operations, is not done with the integrated connection circuit approach in mind.
Some of the key factors which should be considered in designing an integrated connection circuit are: (1) ease of installation, (2) redundancy of the wiring, since changing individual glass solar panels is quite difficult and expensive, (3) ease of assembly of the complete system, (4) control of unwanted moisture, (5) minimization of damage to the panels, (6) reduction of voids in the glazing, (7) thermal overload protection, and (8) reliability of the total system. Thus, those skilled in the art continued to seek a solution to the problem of how to provide better glass solar panels.
The present invention relates to improvements in the manufacturing and application of glass solar panels. Glass solar panels are provided that, if exposed to light, will generate electricity for storage or powering electrical loads and can be used as architectural building elements. The glass-solar panels are interconnected by an integrated connection circuit that includes electricity generating solar layers, which transmit the electricity to conductive coatings, on the glass solar panels, where bus bars have been deposited on the coated glass by way of a circularly rotating or inline heating head and mask apparatus. Each bus bar transmits the electricity externally by way of a metallic tab that is deposited on it, where the tabs extend from the panels' peripheral edges.
Subsequently, the tabs are electrically attached to glazing channels, which are the electrical connection means for the electrical loads. Depending on the application, this assemblage could be configured as insulated glass (IG) panels, laminate structures, or combinations of the two.
Further objects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description of preferred embodiments and appended claims, when read in light of accompanying drawings forming a part of a specification, wherein like reference characters designate corresponding parts of several views.
a is a schematic of an interconnection of a glass solar panel and a first glazing channel in accordance with the present invention;
b is a schematic of an interconnection of a glass solar panel and a second glazing channel in accordance with the present invention;
a is a diagrammatic view of a circularly rotating heating head and mask apparatus in accordance with the present invention;
b is a diagrammatic view of an inline heating head and mask apparatus in accordance with the present invention;
c is a perspective view of a belt-based inline heating head and mask apparatus in accordance with the present invention;
d is a top plan view of the belt-based inline heating head and mask apparatus of
e is a side plan view of the belt based inline heating head and mask apparatus of
a, is a cross sectional view of the laminated glass solar panel and the base setting block in a non-abutting/non-clasped position in accordance with
b is a cross sectional view of the laminated glass solar panel and the base setting block in a fully abutting/clasped connection position in accordance with
c is a perspective view of the laminated glass solar panel and the connection clip in accordance with
There is shown in
Disposed onto the electrically conductive coating surface 19 are at least two bus bars 12, which are in electrical contact with the solar layers 16 and the electrically conductive coating 18. The bus bars 12 preferably comprise copper, which is a good conductor, although other suitable conductive metals like silver may be used. If preferred, the bus bars 12 may be tapered toward a glass panel peripheral edge 17 of the glass sheet 22, and/or could be tapered on end. Further, metallic tabs 14, which extend beyond the glass panel peripheral edge 17 of the glass solar panel 15, are disposed onto and are in electrical contact with the bus bars 12. An extended portion of the metallic tabs 14, so produced, is readily conductively affixed to external wiring as part of the integrated electrical connection circuit 11.
Also shown in
Consequently, the electrical current (I) that is generated in the solar layers 16 is conducted through the first glazing channel 40, by way of the channel conductors 27 and connection clips 25. Since the connection clips 25 clasp the metallic tabs 14, the electrical current (I) passes through the bus bars 12, the metallic tabs 14, the connection clips 25, and the first glazing channels 40. Outside of the first glazing channels 40 the electrical current (I) is available for storage in, for example, a fuel cell, or for powering an electrical load 26.
b is similar to
In
Also shown in
Further, the metallic tab 14 is disposed onto each bus bar 12, where a portion of the metallic tabs 14 extend beyond the glass panel peripheral edge 17 of the laminated glass solar panel 30. Subsequently, the metal foil 24 is disposed on and is in electrical contact with the metallic tab 14, while also being disposed on and in electrical contact with the coating 18 from the peripheral edge 17 of and within the laminated glass solar panel 30, up to the sight line 29. To complete an assemblage of the laminated glass solar panel 30 thus described, is brought together with the glass sheet 22 while an interlayer 44 of polymeric 25 material is disposed therebetween. The interlayer 44 of polymeric material may comprise polyvinyl butyral (PVB).
a, which involves the deposition of the bus bars 12 onto the coating 18 that is deposited on the glass sheet 22, illustrates a diagramatic view of a circularly rotating heating head and mask apparatus 50 in accordance with yet another aspect of the present invention. The bus bars 12, as shown in
a illustrates the deposition of bus bars 12 on the coating surface 19 of the coated glass sheet 42, which may be deposited through the use of improved deposition methods in accordance with further aspects of the invention. For example, the coating deposition may comprise chemical vapor deposition, where the coating 18 is deposited onto the major glass surface 21 of the glass sheet 22. The coated glass sheet 42 may then be exposed to a preheat zone 70 upstream and, if “edge deletion” is required, the conveyor 88 transports the coated glass sheet 42 to a circular edge mask 66. While moving within the circular edge mask 66, a first area 92 of the coated glass sheet 42 is heated by a coating heater 76. The coating heater 76 could comprise, as examples, an oxyacetylene burner, a plasma device, an electric arc gun, or a flame spray gun.
In the first area 92, temperatures up to and about 1300 degrees Fahrenheit may be attained in order to heat, thermally shock, and evaporate away the electrically conductive coating 18.
Edge deletion may also be achieved without the use of the edge mask 66. This may be accomplished through precise placement of the heat, thermal control, and set up of the coating heater 76, such that the coating 44 is precisely thermally shock heated and evaporated.
By either edge deletion method, a residue of the electrically conductive coating 44 is formed and may, subsequently, be removed by a coating remover 68, for example, a buffer or a burnishing tool. The coating remover 68 may be required for the IG solar panels 20 (shown in
Next, as
Heating is achieved by a reducing flame 78 that heats the second area 94 in a stoichiometric atmosphere, where oxidation of a molten metal 64 is controlled during bus bar 12 deposition, while not fracturing or de-tempering the coated glass sheet 42. The reducing flame 78 could comprise oxyacetylene or hydrogen. As a result, the second area 94 is taken to a temperature of about 500 degrees Fahrenheit.
Subsequently, a metal feeding and heating device 62, which may be supplied by gas one 82, gas two 84, and gas three 86, feeds conductive metal 56, preferably in the form of a wire (note that the metal 56 could be a powder or other form and the device 62 an electric arc or flame spray gun), melts the conductive metal 56, and then propels and impinges particles of the molten metal 64 in a predetermined manner, for example, a uniform manner, onto the second area 94. The metal feeding and heating device 62 preferably comprises a plasma gun, while the three gases 82, 84, and 86 preferably comprise oxygen, air, and acetylene, respectively, and the conductive metal 56 preferably comprises copper.
Imparting a high velocity to the molten metal particles 64 results in the bus bars 12 being uniformly formed on, and adhering strongly to, the electrically conductive coating 18. The formation of the bus bar 12 occurs, for example, near the glass panel peripheral edges 17, before the laminated glass solar panel 30, as shown in
Added advantages of the circularly rotating heating head and mask apparatus 50 are that its rotation and size allow for: (1) dissipation of built up heat, (2) the excess molten metal 64 to be scraped, brushed, or blown clean, and (3) accurately depositing the molten metal 64 onto the electrically conductive coating 18 so as to shape the bus bars 12. The shaping of the bus bars 12, if so preferred, may be tapered toward the glass panel peripheral edge 17 and/or tapered on end, as well.
Further, the circularly rotating heating head and mask apparatus 50 accurately controls the thickness of the resulting copper bus bars 12. The thicker the bus bars 12; as shown in
An additional advantage of this process is that it allows the bus bars 12 to be deposited after thermal tempering of the glass solar panels 15. Although not wishing to be bound by any theory, it is believed that there is no alloying of the molten metal 64, for example, copper, with the electrically conductive coating 18, since the electrically conductive coating 18 is highly chemically inactive and stable. The electrically conductive coating 18 preferably comprises tin oxide.
To form the bus bars 12, the circularly rotating heating head and mask apparatus 50 of the present invention does not use an aqueous solution. Instead, it heats and shapes the bus bars 12 onto the electrically conductive coating 18 by melting the conductive metal 56, and imparting pressure, through the gasses one 82, two 84, and three 86, to impinge, at a high velocity, the molten metal 64 onto the heated and masked second area 94 on the electrically conductive coating 18.
Further, the metallic tabs 14 may then be readily conductively affixed to external wiring, possibly channel conductors 27, as part of the integrated connection circuit 11. The bus bar deposition thus described, may also be used, to form IG solar panels 20, 20′, laminated panels 30, or combination thereof.
Illustrated in
Note that edge deletion may also be achieved by the apparatus 50, 50′ without the use of the edge masks 66, 66′. This may be accomplished through precise placement of the heat and thermal control, and set up of the coating heater 76, such that the coating 18 is precisely thermally shock heated. This process may be required by the IG solar panels 20, 20′ (shown in
As the coated glass sheet 42 moves further on the conveyor 88, the bus bar 12 can be disposed on the coating 18 in a similar manner to that described above for the circularly rotating heating head and mask apparatus 50, except that an inline inner mask 72′ and an inline outer mask 74′ are used instead of the circular masks 72 and 74. The inline masks 72′ and 74′ can also result in the same precise formation of the bus bars 12 as the circularly rotating heating head and mask apparatus 50.
A variant of the inline heating head and mask apparatus 50′ is a dual belt based inline heating head and mask apparatus 140 that is shown in
The apparatus 140 comprises: 1) a work piece input area 160, including a first belt 144, first rollers 158, and a first speed and tension adjuster 178, 2) a second belt 142, second rollers 156, and a second tension adjuster 16, being driven by second motor 154, second motor pulley 172, motor belt two 174, 3) a third belt 146, third rollers 162, and a third tension adjuster 182, and being driven by third motor 152, third motor pulley 166, and motor belt three 168, 4) a thermo spray area 150, 5) a work piece output area 170, including a fourth belt 148, fourth rollers 162, and a fourth speed and tension adjuster 184, and 6) an overspray removing device 190.
This inline apparatus 140 may also be practiced by employing other means for driving the belts, for example, sprocket gears and, chains, racks and pinions, and the like, while still remaining within the scope and spirit of the present invention.
In operation, an incoming coated glass sheet 42 is conveyed by the first belt 144 to an adjustable stop 188. Note that the coating 18 is on a side of the coated sheet 42 that will make direct contact with the second belt 142. Note also that the stop 188 is capable of adjustment so as to position varying sizes of coated glass sheets 42 at the discharge end of the first belt 144.
Upon reaching the stop 188, the coated glass sheet 42 is positioned inline with a roller area 198 that is between the second belt 142 and the third belt 146 while centrally spanning the second belt 142. The belts 142, 146, which operate in a parallel spaced apart manner, wherein the width of the second belt 142 is chosen to be less than the width of the sheet 42 so as to allow the second belt 142 to act as a mask while exposing opposite edges of the coating 18 on the sheet 42. Note that the dual belt based inline heating head and mask apparatus 140 forms the bus bars 12 near the glass panel peripheral edge 17 so that the inline outer mask 74′ may not be required.
Subsequently, a cylinder 199 (shown in
Upon reaching the thermo spray area 150, the exposed opposite edges of the sheet 42 may be heated by at least one reducing flame 78 (not shown but similar to those illustrated in
Following bus bar deposition in the thermo spray area 150, the sheet 42 is conveyed to a fourth belt 148 having fourth belt rollers 164 and fourth speed and tension adjuster 184 and driven by a means (not shown) that is similar to the previously described motor, pulley, and belt, which in turn conveys the sheet 42 to a work piece output area 170. After drop-off of the sheet 42 onto the fourth belt 148, the second belt 142 may be exposed to the overspray removing device 190 in order to remove any conductive metal overspray that may have been deposited on the second belt 142.
The overspray removing device 190 may be, for example, a tank containing a coolant 196 and having an outlet 192 and an inlet 194, where the overspray is removed by thermal shock and scraping. However, the present invention may be practiced where the overspray removing device 190 is at least one fan, scraper, or the like.
The dual belt based inline heating head and mask apparatus 140 is designed to produce panels 15 (note that solar panels 15 may be any one or a combination of solar panels 20, 20′, 30) in a fast and simple manner. In these applications a high speed, low cost process is advantageous and the apparatus 140 is capable of achieving those goals while producing high quality electrical connectivity to the coating 44. However, the apparatus 140 may be used for producing panels other than solar panels 15, for example, heated glass and burner applications where glass, ceramic, and glass-ceramic substrates may be used.
Although not shown in
In the present invention, the masks 66, 66′, 72, 72′, 74, 74′, 142 may comprise steel with a layer of chrome plating disposed on the steel. This has been found to inhibit the adhesion of copper and other metals to the masks 66, 66′, 72, 72′, 74, 74′, 142 thus allowing a simple spring loaded scraper to continually clean the overspray from the masks 66, 66′, 72, 72′, 74, 74′, 142 during production of the bus bars 12. This operation allows the overspray and dust of the conductive metal 56 to be collected and re-sold.
The present invention may further deposit soft electrically conductive materials (not shown) that include metal and metal oxides, often in combination with each other, onto the bus bars 12, following bus bar deposition on the coating 18. Note that the deposition of soft electrically conductive materials would also apply to all heating head and mask apparatus 50, 50′, 140.
Examples of the soft conductive materials are silver based systems like (metal oxide/silver/metal oxide) and variants including double silver stacks and indium-tin-oxide (also known as ITO.) All constructs of the bus bars 12, metallic tabs 14 and the panels 20, 20′, and 30 that have been disclosed herein apply with the addition of the deposition of the soft conductive materials.
The soft coatings may be deposited in a vacuum deposition process like that produced by DC Magenetron Sputtering (incorporated herein by reference) after the bus bars 12 are deposited on the coatings 18. For example, these soft coatings may be copper traces that would conduct electrical current to electrical components that would be mechanically attached to the glass sheet 22 or coated glass sheet 42. An example electrical component would be a capacitive moisture sensing unit on the sheets 22, 42.
Referring to
As shown in
External to the laminated glass solar panel 30, both the metallic tab 14 and the metal foil 24 are shown extending from the glass panel peripheral edge 17. The deposition of the metal foil 24 and the metallic tab 14, as described, causes the two to be in electrical contact with each other, thus providing a measure of redundancy. In addition,
The extension of the spring 35 is a result of a movement of the connection clip 25 within the base setting block 37, wherein the base setting block 37 is formed so as to define at least a widened portion of a block cavity 41. As a result of the aforementioned movement, the laminated glass solar panel assembly 30 and the base setting block 37 abut to form an assembly. Subsequently, the abutment of the laminated glass panel 30 and the base setting block 37 are further abutted to a glazing channel surface 46 that is positioned to define at least a portion of a first glazing channel cavity 48 within a glazing channel base 58.
To further assure that the wiring of the laminated glass solar panels 30 is hidden from the view of the user and to allow moisture to drain out and away from the laminated glass solar panels 30, wiring/drain holes 49 may be provided in the glazing channel base 58, preferably at the time of manufacturing, so as to minimize the need to drill holes in the laminated glass solar panels 30 during installation in a structure or the like.
Unbonded areas (UBAs) may form on the aforementioned assembly, which can result in: (a) moisture entering, (b) glass chipping, (c) glass swelling, and (d) electrical connections being adversely affected. In the present invention, a glazing seal 43 is preferably disposed in assembly voids to minimize the negative effects of UBA.
As illustrated in
As the laminated glass solar panel 30 and the connection clip 25 move into full attachment, the cross sectional view of
c is a perspective view in accordance with
The above discussion on the interconnection of the laminated glass solar panel 30, by way of the metal foil 24, the metallic tab 14, the connection clip 25, and the spring 35, in conjunction with the base setting block 37, applies to heated glass panels as well.
Further,
Subsequently, the metallic tabs 14 mate with the connection clips 25, which are embedded in the first glazing channel 40, as shown in
In combination,
By incorporating the wiring of the laminated glass solar panel 30 into the base setting block 37 and providing the easy and redundant multiple panel wiring 60, the present, invention eliminates the difficulty of making electrical connections by eliminating the hole drilling process into the glass sheet 22 or coated glass sheet 42, prior to lamination, which is typically done to expose the bus bars 12 for connection to the electrical load 26.
Instead, the present invention uses the metallic tabs 14 and metal foil 24, described herein, that are easily incorporated into the integrated connection circuit 11, where the wiring connections between parts of the integrated connection circuit 11 may have flexible boots (not shown) encasing the connections, and conventional glazing sealant (not shown) may be used to attach the flexible boots to the glass panel peripheral edge 17, so as to minimize mechanical wear and accumulation of moisture. The flexible boots, with enclosed wiring, may be dressed through conventional gaskets or sealed with sealant and then terminated in National Electrical Code (NEC) electrical wiring boxes.
Typically, the internal integrated connection circuit 11 will be completed during manufacturing, so as to minimize the need for on-site electricians doing system wiring at the time of field installation. Instead, electricians would need to simply verify correct connection and terminate electrical load wiring at the time of field installation. Whereas, glaziers would be the primary installers of the glass solar panels 15 by glazing the wiring, boots, frames, and panels, which should preserve manufacturing integrity and improve reliability of the glass solar panels 15.
As shown, the laminated glass panel 30, along with various parts of the second glazing channel 40′ are disposed on the channel frame 67. A portion of the laminated glass panel 30 is shown being disposed within the second glazing channel cavity 48′ and abutting the channel frame 67, wherein the metallic tab 14 extends beyond the periphery of the panel 30. Mechanically and electrically disposed on the metallic tab 14 is a spade connector 96, which is mechanically and electrically disposed on an end of a channel conductor 27.
The channel conductor 27 is shown being disposed within the channel conduit 95 that passes through a coupler 91, which secures the channel conduit to the conductor block 93 and prevents moisture and dirt from entering the conductor block 93. Within the conductor block 93 a second end of the channel conductor 27 may be mechanically and electrically disposed on the multiple channel wiring 60 (shown in
Multiple connections, as
In accordance with the provisions of the patent statutes, the principles and mode of operation of this invention have been described and illustrated in its preferred embodiments. However it must be understood that the invention may be practiced otherwise than specifically explained and illustrated without departing from its spirit or scope.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/369,962, filed Apr. 4, 2002, and U.S. patent application Ser. No. 10/256,391, filed Sep. 27, 2002, which applications are incorporated herein in their entirety.
Number | Date | Country | |
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60369962 | Apr 2002 | US |