HIGH-EFFICIENCY PV PANEL WITH CONDUCTIVE BACKSHEET
One embodiment of the invention can provide a solar panel, which can include a cover, a backsheet, and a plurality of solar cell strings. The backsheet can include a first insulation layer, a second insulation layer, and a conductive interlayer positioned between the first insulation layer and the second insulation layer. The solar cell strings can be positioned between the cover and the first insulation layer of the backsheet. The first insulation layer can include a plurality of vias, and the conductive interlayer can be patterned according to locations of the vias, thereby facilitating electrical interconnections among the solar cell strings.
Latest SOLARCITY CORPORATION Patents:
This claims the benefit of U.S. Provisional Patent Application No. 62/088,509, Attorney Docket Number P103-1PUS, entitled “SYSTEM, METHOD, AND APPARATUS FOR AUTOMATIC MANUFACTURING OF SOLAR PANELS,” filed Dec. 5, 2014; and U.S. Provisional Patent Application No. 62/143,694, Attorney Docket Number P103-2PUS, entitled “SYSTEMS AND METHODS FOR PRECISION AUTOMATION OF MANUFACTURING SOLAR PANELS,” filed Apr. 6, 2015; the disclosures of which are incorporated herein by reference in their entirety for all purposes.
This is also related to U.S. patent application Ser. No. 14/563,867, Attorney Docket Number P67-3NUS, entitled “HIGH EFFICIENCY SOLAR PANEL,” filed Dec. 8, 2014; and U.S. patent application Ser. No. 14/510,008, Attorney Docket Number P67-2NUS, entitled “MODULE FABRICATION OF SOLAR CELLS WITH LOW RESISTIVITY ELECTRODES,” filed Oct. 8, 2014; the disclosures of which are incorporated herein by reference in their entirety for all purposes.
FIELD OF THE INVENTIONThis is generally related to solar panels. More specifically, this is related to a solar panel that achieves inter-cell electrical connections via a conductive backsheet.
DEFINITIONS“Solar cell” or “cell” is a photovoltaic structure capable of converting light into electricity. A cell may have any size and any shape, and may be created from a variety of materials. For example, a solar cell may be a photovoltaic structure fabricated on a silicon wafer or one or more thin films on a substrate material (e.g., glass, plastic, or any other material capable of supporting the photovoltaic structure), or a combination thereof.
A “solar cell strip,” “photovoltaic strip,” or “strip” is a portion or segment of a photovoltaic structure, such as a solar cell. A photovoltaic structure may be divided into a number of strips. A strip may have any shape and any size. The width and length of a strip may be the same or different from each other. Strips may be formed by further dividing a previously divided strip.
A “cascade” is a physical arrangement of solar cells or strips that are electrically coupled via electrodes on or near their edges. There are many ways to physically connect adjacent photovoltaic structures. One way is to physically overlap them at or near the edges (e.g., one edge on the positive side and another edge on the negative side) of adjacent structures. This overlapping process is sometimes referred to as “shingling.” Two or more cascading photovoltaic structures or strips can be referred to as a “cascaded string,” or more simply as a string.
“Finger lines,” “finger electrodes,” and “fingers” refer to elongated, electrically conductive (e.g., metallic) electrodes of a photovoltaic structure for collecting carriers.
A “busbar,” “bus line,” or “bus electrode” refers to an elongated, electrically conductive (e.g., metallic) electrode of a photovoltaic structure for aggregating current collected by two or more finger lines. A busbar is usually wider than a finger line, and can be deposited or otherwise positioned anywhere on or within the photovoltaic structure. A single photovoltaic structure may have one or more busbars.
A “photovoltaic structure” can refer to a solar cell, a segment, or solar cell strip. A photovoltaic structure is not limited to a device fabricated by a particular method. For example, a photovoltaic structure can be a crystalline silicon-based solar cell, a thin film solar cell, an amorphous silicon-based solar cell, a poly-crystalline silicon-based solar cell, or a strip thereof.
BACKGROUNDAdvances in photovoltaic technology, which are used to make solar panels, have helped solar energy gain mass appeal among those wishing to reduce their carbon footprint and decrease their monthly energy costs. However, the panels are typically fabricated manually, which is a time-consuming and error-prone process that makes it costly to mass-produce reliable solar panels.
Solar panels typically include one or more strings of complete photovoltaic structures. Adjacent photovoltaic structures in a string may overlap one another in a cascading arrangement. For example, continuous strings of photovoltaic structures that form a solar panel are described in U.S. patent application Ser. No. 14/510,008, filed Oct. 8, 2014 and entitled “Module Fabrication of Solar Cells with Low Resistivity Electrodes,” the disclosure of which is incorporated herein by reference in its entirety. Producing solar panels with a cascaded cell arrangement can reduce the resistance due to inter-connections between the cells, and can increase the number of photovoltaic structures that can fit into a solar panel.
Moreover, it has been shown that solar panels based on strings of strips cascaded in parallel, which are created by dividing complete photovoltaic structures, provide several advantages, including but not limited to: reduced shading, enablement of bifacial operation, and reduced internal resistance. Detailed descriptions of a solar panel based on cascaded strips can be found in U.S. patent application Ser. No. 14/563,867, entitled “HIGH EFFICIENCY SOLAR PANEL,” filed Dec. 8, 2014, the disclosures of which is incorporated herein by reference in its entirety for all purposes. Conventional inter-string connections, including both serial and parallel connections, can involve cumbersome wirings, which often not only complicates the panel manufacturing process but also leads to extra shading.
In addition to interconnecting strings of photovoltaic structures, forming a solar panel also involves connecting each string or portion of the strings to bypass diodes. The bypass diodes can be used to prevent currents flowing from good photovoltaic structures (photovoltaic structures are well-exposed to sunlight and in normal working condition) to bad photovoltaic structures (photovoltaic structures that are burning out or partially shaded) by providing a current path around the bad cells. Ideally, there would be one bypass diode connected to each photovoltaic structure, but electrical connections can be too complicated and expensive. In most cases, one bypass diode can be used to protect a group of serially connected strips, which can be a string or a portion of a string. However, connecting strings or cascaded strips to bypass diodes can be challenging because the strings do not have exposed busbars, except at the very end of the string. In other words, it can be difficult to access a photovoltaic structure that is in the middle of a string.
SUMMARYOne embodiment of the invention can provide a solar panel, which can include a cover, a backsheet, and a plurality of solar cell strings. The backsheet can include a first insulation layer, a second insulation layer, and a conductive interlayer positioned between the first insulation layer and the second insulation layer. The solar cell strings can be positioned between the cover and the first insulation layer of the backsheet. The first insulation layer can include a plurality of vias, and the conductive interlayer can be patterned according to locations of the vias, thereby facilitating electrical interconnections among the solar cell strings.
In a variation on the embodiment, the first insulation layer can include polyethylene terephthalate (PET), fluoropolymer, polyvinyl fluoride (PVF), polyamide, or any combination thereof. The conductive interlayer can include Al, Cu, graphite, conductive polymer, or any combination thereof.
In a variation on the embodiment, a respective via can be filled with conductive paste to facilitate electrical coupling between contact pad located on a corresponding solar cell string and the conductive interlayer and/or mechanical bonding between a contact pad located on a corresponding solar cell string and the conductive interlayer.
In a variation on the embodiment, a respective solar cell string can include a plurality of cascaded photovoltaic structures.
In a variation on the embodiment, the solar panel can further include a plurality of bypass diodes, wherein a respective bypass diode can be coupled to a photovoltaic structure through the conductive interlayer.
In a variation on the embodiment, a conductive path between a first solar cell string and a second solar cell string can include: a first contact pad of the first solar cell string, a first set of vias within the first insulation layer, wherein the first set of vias can be filled with conductive paste and positioned beneath the first contact pad, a second contact pad of the second solar cell string, a second set of vias within the first insulation layer, wherein the second set of vias can be filled with conductive paste and positioned beneath the second contact pad, and a continuous portion of the conductive interlayer that can be in contact with both the first and second sets of vias.
In a variation on the embodiment, the second insulation layer can include a plurality of vias to electrically couple the interconnected solar cell strings to a junction box.
In the figures, like reference numerals refer to the same figure elements.
DETAILED DESCRIPTIONThe following description is presented to enable any person skilled in the art to make and use the embodiments, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present disclosure. Thus, the invention is not limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
OverviewEmbodiments of the invention provide a solar module that includes a conductive backsheet used for inter-cell electrical coupling. More specifically, the conductive backsheet can include a conductive (Cu or Al) middle layer sandwiched between multiple insulating layers. At the cell-facing side of the backsheet, vias can be formed by removing the insulating layers to expose the underneath conductive interlayer at selected locations. Conductive adhesive can fill the vias, thus enabling formations of conductive paths between the photovoltaic structure surface and the backsheet. To achieve inter-string electrical connections and connections to bypass diodes, the conductive middle layer can be patterned according to the solar panel layout design (including how the strings are placed and interconnected and what type of bypass protection strategy is used).
Solar Panel Based on Cascaded StripsAs described in U.S. patent application Ser. No. 14/563,867, a solar panel can have multiple (such as 3) strings, each string including cascaded strips, connected in parallel. Such a multiple-parallel-string panel configuration can provide the same output voltage with a reduced internal resistance. In general, a cell can be divided into a number of (e.g., n) strips, and a panel can contain a number of strings (the number of strings can be the same as or different from number of strips in the cell). If a string has the same number of strips as the number of regular photovoltaic structures in a conventional single-string panel, the string can output approximately the same voltage as a conventional panel. Multiple strings can then be connected in parallel to form a panel. If the number of strings in a panel is the same as the number of strips in the cell, the solar panel can output roughly the same current as a conventional panel. On the other hand, the panel's total internal resistance can be a fraction (e.g., 1/n) of the resistance of a string. Therefore, in general, the greater n is, the lower the total internal resistance of the panel is, and the more power one can extract from the panel. However, a tradeoff is that as n increases, the number of connections required to inter-connect the strings also increases, which increases the amount of contact resistance. Also, the greater n is, the more strips a single cell needs to be divided into, which increases the associated production cost and decreases overall reliability due to the larger number of strips used in a single panel.
Another consideration in determining n is the contact resistance between the electrode and the photovoltaic structure on which the electrode is formed. The greater this contact resistance is, the greater n might need to be to reduce effectively the panel's overall internal resistance. Hence, for a particular type of electrode, different values of n might be needed to attain sufficient benefit in reduced total panel internal resistance to offset the increased production cost and reduced reliability. For example, conventional silver-paste or aluminum based electrode may require n to be greater than 4, because process of screen printing and firing silver paste onto a cell does not produce ideal resistance between the electrode and underlying photovoltaic structure. In some embodiments of the present invention, the electrodes, including both the busbars and finger lines, can be fabricated using a combination of physical vapor deposition (PVD) and electroplating of copper as an electrode material. The resulting copper electrode can exhibit lower resistance than an aluminum or screen-printed-silver-paste electrode. Consequently, a smaller n can be used to attain the benefit of reduced panel internal resistance. In some embodiments, n is selected to be three, which is less than the n value generally needed for cells with silver-paste electrodes or other types of electrodes. Correspondingly, two grooves can be scribed on a single cell to allow the cell to be divided to three strips.
In addition to lower contact resistance, electro-plated copper electrodes can also offer better tolerance to micro cracks, which may occur during a cleaving process. Such micro cracks might adversely impact silver-paste-electrode cells. Plated-copper electrode, on the other hand, can preserve the conductivity across the cell surface even if there are micro cracks in the photovoltaic structure. The copper electrode's higher tolerance for micro cracks allows one to use thinner silicon wafers to manufacture cells. As a result, the grooves to be scribed on a cell can be shallower than the grooves scribed on a thicker wafer, which in turn helps increase the throughput of the scribing process. More details on using copper plating to form a low-resistance electrode on a photovoltaic structure are provided in U.S. patent application Ser. No. 13/220,532, entitled “SOLAR CELL WITH ELECTROPLATED GRID,” filed Aug. 29, 2011, the disclosure of which is incorporated herein by reference in its entirety.
In the examples shown in
To form a cascaded string, cells or strips (e.g., as a result of a scribing-and-cleaving process applied to a regular square-shaped cell) can be cascaded with their edges overlapped.
From
The manufacture of a solar panel typically involves encapsulating photovoltaic structures between two layers of protective material, which are the front and back covers. The light-facing side of the panel often includes a glass cover, and the side facing away from light often includes a non-transparent cover, known as the backsheet. Typical backsheets for solar panels are made of polyvinyl fluoride (PVF) or polyethylene terephthalate (PET) films, which are electrical insulating. Alternatively, a solar panel backsheet may include a conductive interlayer sandwiched between layers of insulating materials. The conductive interlayer can include a conductive interlayer, which can include metallic materials (e.g., Al, Cu, or their alloy) or non-metallic conductive materials (e.g., graphite or conductive polymer).
The usage of a backsheet having a conductive interlayer is originally motivated by the need of a moisture barrier inside a solar panel. However, the existence of a conductive interlayer inside the backsheet can also provide the possibility of establishing electrical paths through the backsheet. More specifically, when two solar strings need to be coupled electrically, one may electrically couple an exposed busbar of one string to a point on the conductive interlayer and couple an exposed busbar of the other string to another point on the conductive interlayer. If a continuous layer of conductive material exists between these two points, these two strings can be electrically coupled. This way, there is no need for additional tabbing wires between the two strings, which not only saves material cost but also simplifies the panel fabrication process.
Electrically coupling between a string and a conductive interlayer of the backsheet requires a way to bypass the insulating PET layer positioned between the string and the conductive interlayer. In some embodiments, vias (or through holes) can be created in the insulating PET layer, and conductive paste can be used to fill these vias to establish a conductive path between the busbar of an edge strip of the string and the conductive interlayer.
Establishing electrical coupling between string 402 and conductive interlayer 414 can involve creating a conductive path between edge busbar 404 and conductive interlayer 414. In the example shown in
Via 418 can be formed by selective etching top insulation layer 412. The conductive material used to fill via 418 can include a conductive paste (or adhesive), which can not only provide conductivity but can also enhance the bonding between string 402 and backsheet 410. The conductive adhesive or paste can have various forms. In one embodiment, the conductive adhesive can include a conductive metallic core surrounded by resin. When the conductive paste fills via 418, the metallic core can establish electrical connections, while the resin that surrounds the metallic core can function as an adhesive. In another embodiment, the conductive paste may be in the form of resin that includes a number of suspended conductive particles, such as Ag or Cu particles. These conductive particles may be coated with a protection layer that evaporates when the paste is thermally cured, thereby resulting in electrical conductivity among the conductive particles suspended inside the resin. The volume fraction of the conductive particles can be approximately between 50 and 90%
Also shown in
In the example shown in
In
On the other hand, when two strings need to be electrically coupled, either in series or in parallel, a continuous portion of the conductive interlayer can serve as a bridge to create a conductive path between busbars of the two strings.
Similar to what is shown in
In certain cases, the strings connected in parallel may be connected to a junction box located on the opposite side (the side facing away from the strings) of backsheet 650 to enable connections to other circuitries outside of the panel. In some embodiments, the electrical coupling between inter-connected strings and the junction box can also be achieved via the conductive interlayer in the backsheet. In the example shown in
In
In the examples shown in
In addition to enabling inter-string connections, the conductive backsheet may also be used to provide electrical access to middle strips of a string. Accessing the middle strips can be important, especially if one wants to provide bypass protections at a higher granularity than an individual string. For example, to provide bypass protections to half of the strips within a string, one may need to connect a bypass diode in parallel to the half string; that is, electrically couple to a strip in the middle of the string. In some embodiments, some of the strips within a string can include specially designed “contact pads” (sometimes also called “landing pads”) to enable electrical access to a strip, even when such a strip is positioned in the middle of a cascaded string, as shown in
In addition to enabling the sub-string level bypass protection, these contact pads can also facilitate mechanical bonding between the string and the backsheet.
To facilitate mechanical bonding between string 810 and backsheet 830, via 842 can be created in top insulation layer 832 underneath additional busbar 812. By filling via 842 with adhesives (which can include conductive paste or other insulating adhesives), one can mechanically bond string 810 to backsheet 830. More specifically, the adhesives bond string 810 to conductive interlayer 834. Since the adhesives most likely include conductive paste (to keep the paste application process consistent), to prevent undesired electrical coupling, portion 844 that is in contact with the conductive paste can be insulated from the rest of conductive interlayer 834 via gaps 846 and 848. As a result, adhesives within via 842 merely serve the purpose of establishing mechanical bonding, and do not provide any electrical coupling.
In the example shown in
In
In the example shown in
One drawback in the solution shown in
Subsequently, conductive paste can be applied to fill the vias within the top insulation layer of the backsheet (operation 1004), and the cascaded strings can be placed on the backsheet (operation 1006). The placement of the strings can be carefully controlled to ensure that the contact pads on the strings are placed above corresponding vias in the backsheet. Once the strings are placed, the system can apply heat to cure the paste to activate electrical conductivity (operation 1008). In some embodiments, a number of heaters can come in contact with photovoltaic structures at locations of the vias to cure the paste filled in the vias. The cured paste can provide mechanical bonding and electrical coupling between the strings and backsheet. Subsequently, the front glass cover can be applied to seal the strings within the glass cover and the backsheet (operation 1010). In some embodiments, the application of the glass cover is performed from beneath, and the backsheet and the strings are flipped over to allow the glass cover to be lifted from below to make soft contact with the strings.
Additional heat and pressure can be applied to laminate the strings between the glass cover and the backsheet (operation 1012), and the laminated module can be placed in a frame (operation 1014). A junction box can then be attached to provide panel output and bypass protection circuitry (operation 1016). In some embodiments, attaching the junction box can involve filling vias within the bottom insulation layer of the backsheet with conductive paste, connecting lead wires to such vias, and curing the paste.
In general, compared to conventional approaches for interconnecting strings and for coupling bypass diodes, embodiments of the invention provide a solution that achieves inter-string electrical coupling through a conductive interlayer within the backsheet of the solar panel, thus eliminating cumbersome wiring via metal wires (or tabs) at the panel surface. Placing all electrical connections within the backsheet can reduce shading, and the elimination of inter-string metal wires (or tabs) can prevent occurrences of thermal and mechanical stresses introduced by the wires. Moreover, having all contacts at one side of the strings can significantly simplify the manufacturing process by eliminating the need to flip over individual photovoltaic structures, as needed in the manufacturing of conventional solar panels. When strings are flipped, they can be flipped as a whole, and the mechanical bonding provided by a number of paste-filled vias situated between the contact pads and the conductive interlayer can ensure that the strings are securely bonded to the backsheet during the flipping process.
The foregoing descriptions of various embodiments have been presented only for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the forms disclosed. Accordingly, many modifications and variations will be apparent to practitioners skilled in the art. Additionally, the above disclosure is not intended to limit the invention.
Claims
1. A solar panel, comprising:
- a cover;
- a backsheet comprising a first insulation layer, a second insulation layer, and a conductive interlayer positioned between the first insulation layer and the second insulation layer; and
- a plurality of solar cell strings positioned between the cover and the first insulation layer of the backsheet;
- wherein the first insulation layer comprises a plurality of vias, and wherein the conductive interlayer is patterned according to locations of the vias, thereby facilitating electrical interconnections among the solar cell strings.
2. The solar panel of claim 1, wherein the first insulation layer comprises polyethylene terephthalate (PET), fluoropolymer, polyvinyl fluoride (PVF), polyamide, or any combination thereof; and wherein the conductive interlayer comprises Al, Cu, graphite, conductive polymer, or any combination thereof.
3. The solar panel of claim 1, wherein a respective via is filled with a conductive paste to facilitate:
- electrical coupling between a contact pad located on a corresponding solar cell string and the conductive interlayer; and/or
- mechanical bonding between a contact pad located on a corresponding solar cell string and the conductive interlayer.
4. The solar panel of claim 1, wherein a respective solar cell string comprises a plurality of cascaded photovoltaic structures.
5. The solar panel of claim 1, further comprising a plurality of bypass diodes, wherein a respective bypass diode is coupled to a photovoltaic structure through the conductive interlayer.
6. The solar panel of claim 1, wherein a conductive path between a first solar cell string and a second solar cell string comprises:
- a first contact pad of the first solar cell string;
- a first set of vias within the first insulation layer, wherein the first set of vias are filled with a conductive paste and are positioned beneath the first contact pad;
- a second contact pad of the second solar cell string;
- a second set of vias within the first insulation layer, wherein the second set of vias are filled with the conductive paste and are positioned beneath the second contact pad; and
- a continuous portion of the conductive interlayer that is in contact with both the first and second sets of vias.
7. The solar panel of claim 1, wherein the second insulation layer comprises a plurality of vias filled with a conductive paste to electrically couple the interconnected solar cell strings to a junction box.
8. A method for manufacturing a solar panel, comprising:
- obtaining a backsheet that comprises a first insulation layer, a second insulation layer, and a conductive interlayer positioned between the first insulation layer and the second insulation layer, wherein the first insulation layer comprises a plurality of vias, and wherein the conductive interlayer is patterned according to locations of the vias;
- overlaying a plurality of solar cell strings on the backsheet, wherein the first insulation layer faces the solar cell strings, and wherein the solar cell strings are overlaid in such a way that selected contact pads of the solar cell strings are positioned above the vias, thereby facilitating electrical interconnections among the solar cell strings; and
- laminating the solar cell strings between the backsheet and a glass cover.
9. The method of claim 8, wherein the first insulation layer comprises polyethylene terephthalate (PET), fluoropolymer, polyvinyl fluoride (PVF), polyamide, or any combination thereof; and wherein the conductive interlayer comprises Al, Cu, graphite, conductive polymer, or any combination thereof.
10. The method of claim 8, further comprising filling the vias with a conductive paste, wherein a respective via filled with the conductive paste is configured to facilitate:
- electrical coupling between a contact pad located on a corresponding solar cell string and the conductive interlayer; and/or
- mechanical bonding between a contact pad located on a corresponding solar cell string and the conductive interlayer.
11. The method of claim 8, wherein a respective solar cell string comprises a plurality of cascaded photovoltaic structures.
12. The method of claim 8, further comprising coupling a plurality of bypass diodes to the interconnected solar cell strings, wherein a respective bypass diode is coupled to a photovoltaic structure through the conductive interlayer.
13. The method of claim 8, further comprising establishing a conductive path between a first solar cell string and a second solar cell string by curing a conductive paste that fills the vias, wherein the conductive path comprises:
- a first contact pad of the first solar cell string;
- a first set of vias within the first insulation layer, wherein the first set of vias are filled with the conductive paste and are positioned beneath the first contact pad;
- a second contact pad of the second solar cell string;
- a second set of vias within the first insulation layer, wherein the second set of vias are filled with the conductive paste and are positioned beneath the second contact pad; and
- a continuous portion of the conductive interlayer that is in contact with both the first and second sets of vias.
14. The method of claim 8, further comprising filling vias included in the second insulation layer with a conductive paste to electrically couple the interconnected solar cell strings to a junction box.
15. A photovoltaic structure encapsulation mechanism, comprising:
- a transparent cover; and
- a non-transparent cover comprising a first insulation layer, a second insulation layer, and a conductive interlayer positioned between the first insulation layer and the second insulation layer;
- wherein the first insulation layer comprises a plurality of through holes, and wherein the conductive interlayer is patterned according to locations of the through holes, thereby facilitating electrical interconnections among solar cell strings sandwiched between the transparent cover and the non-transparent cover.
16. The photovoltaic structure encapsulation mechanism of claim 15, wherein the first insulation layer comprises polyethylene terephthalate (PET), fluoropolymer, polyvinyl fluoride (PVF), polyamide, or any combination thereof; and wherein the conductive interlayer comprises Al, Cu, graphite, conductive polymer, or any combination thereof.
17. The photovoltaic structure encapsulation mechanism of claim 15, wherein a respective through hole is filled with a conductive paste.
18. The photovoltaic structure encapsulation mechanism of claim 17, wherein the conductive paste comprises:
- a conductive metallic core surrounded by a resin; and/or
- a resin comprising a number of suspended conductive particles.
19. The photovoltaic structure encapsulation mechanism of claim 17, wherein the through hole filled with the conductive paste facilitates:
- electrical coupling between a contact pad located on a corresponding solar cell string and the conductive interlayer; and/or
- mechanical bonding between a contact pad located on a corresponding solar cell string and the conductive interlayer.
20. The photovoltaic structure encapsulation mechanism of claim 15, wherein the second insulation layer comprises a plurality of through holes filled with a conductive paste to electrically couple the interconnected solar cell strings to a junction box.
Type: Application
Filed: Oct 27, 2015
Publication Date: Jun 9, 2016
Applicant: SOLARCITY CORPORATION (San Mateo, CA)
Inventors: Bobby Yang (Los Altos Hills, CA), Peter P. Nguyen (San Jose, CA)
Application Number: 14/924,625