U.S. patent application number 15/939655 was filed with the patent office on 2018-11-08 for electrical connectors of building integrable photovoltaic modules.
The applicant listed for this patent is Miasole Hi-Tech Corp.. Invention is credited to Nazir Ahmad, Jason Stephen Corneille, Michael C. Meyers, Adam C. Sherman.
Application Number | 20180323322 15/939655 |
Document ID | / |
Family ID | 53786111 |
Filed Date | 2018-11-08 |
United States Patent
Application |
20180323322 |
Kind Code |
A1 |
Corneille; Jason Stephen ;
et al. |
November 8, 2018 |
ELECTRICAL CONNECTORS OF BUILDING INTEGRABLE PHOTOVOLTAIC
MODULES
Abstract
Provided are novel building integrable photovoltaic (BIP)
modules and methods of fabricating thereof. A module may be
fabricated from an insert having one or more photovoltaic cells by
electrically interconnecting and mechanically integrating one or
more connectors with the insert. Each connector may have one or
more conductive elements, such as metal sockets and/or pins. At
least two of all conductive elements are electrically connected to
the photovoltaic cells using, for example, bus bars. These and
other electrical components are electrically insulated using a
temperature resistant material having a Relative Temperature Index
(RTI) of at least about 115.degree. C. The insulation may be
provided before or during module fabrication by, for example,
providing a prefabricated insulating housing and/or injection
molding the temperature resistant material. The temperature
resistant material and/or other materials may be used for
mechanical integration of the one or more connectors with the
insert.
Inventors: |
Corneille; Jason Stephen;
(San Jose, CA) ; Meyers; Michael C.; (San Jose,
CA) ; Sherman; Adam C.; (Newark, CA) ; Ahmad;
Nazir; (San Jose, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Miasole Hi-Tech Corp. |
Santa Clara |
CA |
US |
|
|
Family ID: |
53786111 |
Appl. No.: |
15/939655 |
Filed: |
March 29, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14806537 |
Jul 22, 2015 |
9935225 |
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15939655 |
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13046461 |
Mar 11, 2011 |
9112080 |
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14806537 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
Y02E 10/50 20130101;
H02S 40/36 20141201; H01L 31/18 20130101; H01L 31/05 20130101; H02S
20/25 20141201; Y02B 10/12 20130101; Y02B 10/10 20130101; H01L
31/0465 20141201; H02S 40/42 20141201; H01L 31/0481 20130101; H02S
20/23 20141201; H01L 31/0504 20130101; H01L 31/052 20130101; H01L
31/186 20130101; H01L 31/02013 20130101 |
International
Class: |
H01L 31/05 20060101
H01L031/05; H02S 40/42 20060101 H02S040/42; H02S 40/36 20060101
H02S040/36; H02S 20/25 20060101 H02S020/25; H02S 20/23 20060101
H02S020/23; H01L 31/02 20060101 H01L031/02; H01L 31/0465 20060101
H01L031/0465; H01L 31/18 20060101 H01L031/18; H01L 31/052 20060101
H01L031/052; H01L 31/048 20060101 H01L031/048 |
Claims
1. (canceled)
2. A photovoltaic module comprising: a front sealing sheet; a back
sealing sheet; a plurality of electrically interconnected
photovoltaic cells sealed in a sealed space between the front
sealing sheet and the back sealing sheet; a first bus bar
electrically connected to the photovoltaic cells and extending
outside the sealed space; a first conductive element outside the
sealed space and electrically connected to the first bus bar; and
an insulating housing that: comprises a temperature resistant
material having a Relative Temperature Index (RTI) of at least
about 115.degree. C., covers the electrical connection between the
first bus bar and the first conductive element, and includes an
extension flap that insulates at least a portion of the first bus
bar that is outside the sealed space.
3. The photovoltaic module of claim 2, wherein the extension flap
comprises a flexible material.
4. The photovoltaic module of claim 3, wherein the flexible
material comprises one or more of a polyethylene, a polypropylene,
a thermoplastic olefin, a thermoplastic rubber, a thermoplastic
elastomer, an ethylene propylene diene, a monomer (EPDM), a
fluoroelastomer or a thermoplastic vulcanizate (TPV), and a
flexible cast thermoset material, such as an urethane or a
silicone.
5. The photovoltaic module of claim 2, wherein the insulating
housing is offset from the front sealing sheet and from the back
sealing sheet.
6. The photovoltaic module of claim 2, the temperature resistant
material has a RTI of at least about 125.degree. C.
7. The photovoltaic module of claim 6, the temperature resistant
material has a RTI of at least about 135.degree. C.
8. The photovoltaic module of claim 2, wherein a section of the
insulating housing is positioned over one of: the front sealing
sheet and the back sealing sheet.
9. The photovoltaic module of claim 2, wherein the insulating
housing is comprises a polyamide.
10. The photovoltaic module of claim 9, wherein the insulating
housing further comprises glass fibers.
11. The photovoltaic module of claim 2, further comprising an outer
portion, wherein the outer portion: comprises a temperature
resistant material having a RTI of at least about 115.degree. C.,
covers the insulating housing, and is positioned over one of: the
front sealing sheet and the back sealing sheet.
12. The photovoltaic module of claim 11, wherein the outer portion
provides mechanical support between the insulating housing, the
front sealing sheet, and the back sealing sheet.
13. The photovoltaic module of claim 11, wherein: a first section
of the outer portion is positioned over the front sealing sheet,
and a first section of the insulating housing is positioned over
front sealing sheet and interposed between the front sealing sheet
and the outer portion.
14. The photovoltaic module of claim 13, wherein a second section
of the outer portion is positioned over the back sealing sheet.
15. The photovoltaic module of claim 11, wherein: a first section
of the outer portion is positioned over the back sealing sheet, and
a first section of the insulating housing is positioned over back
sealing sheet and interposed between the back sealing sheet and the
outer portion.
16. The photovoltaic module of claim 15, wherein a second section
of the outer portion is positioned over the back sealing sheet.
17. The photovoltaic module of claim 11, wherein the outer portion
includes a top section positioned over a first part the front
sealing sheet and a bottom section positioned over a first part of
the back sealing sheet.
18. The photovoltaic module of claim 11, wherein the temperature
resistant material of the outer portion has a RTI of at least about
135.degree. C.
19. The photovoltaic module of claim 11, wherein the outer portion
comprises a polyamide.
20. The photovoltaic module of claim 19, wherein the outer portion
further comprises glass fibers.
21. The photovoltaic module of claim 2, further comprising: a
second bus bar electrically connected to the photovoltaic cells and
extending outside the sealed space; and a second conductive element
outside the sealed space and electrically connected to the second
bus bar, wherein: the insulating housing covers the electrical
connection between the second bus bar and the second conductive
element, and the insulating housing further includes a second
extension flap that insulates at least a portion of the second bus
bar that is outside the sealed space.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of and claims priority to
U.S. patent application Ser. No. 14/806,537, titled "ELECTRICAL
CONNECTORS OF BUILDING INTEGRABLE PHOTOVOLTAIC MODULES," filed Jul.
22, 2015, and now U.S. Pat. No. 9,935,225, which is a continuation
of U.S. patent application Ser. No. 13/046,461, tided "ELECTRICAL
CONNECTORS OF BUILDING INTEGRABLE PHOTOVOLTAIC MODULES," filed Mar.
11, 2011, and now U.S. Pat. No. 9,112,080, all of which are
incorporated herein by reference for all purposes.
BACKGROUND
[0002] Photovoltaic cells are widely used for electricity
generation with one or more photovoltaic cells typically sealed
within and interconnected in a module. Multiple modules may be
arranged into photovoltaic arrays used to convert solar energy into
electricity by the photovoltaic effect. Arrays can be installed on
building rooftops and are used to provide electricity to the
buildings and to the general grid.
SUMMARY
[0003] Provided are novel building integrable photovoltaic (BIP)
modules and methods of fabricating thereof. A module may be
fabricated from an insert having one or more photovoltaic cells by
electrically interconnecting and mechanically integrating one or
more connectors with the insert. Each connector has one or more
conductive elements, such as metal sockets and/or pins. At least
two conductive elements are electrically connected to the
photovoltaic cells using, for example, bus bars. These and other
electrical components are electrically insulated using a
temperature resistant material having a Relative Temperature Index
(RTI) of at least about 115.degree. C. or, at least in some cases
at least about 120.degree. C., 125.degree. C. 130.degree. C.,
135.degree. C. or more. The RTI is the maximum service temperature
at which the critical properties of a material will remain within
acceptable limits over a long period of time. The applicable
standard is UL 746B, incorporated herein by reference. The
insulation may be provided before or during module fabrication by,
for example, providing a prefabricated insulating housing and/or
injection molding the temperature resistant material. The
temperature resistant material and/or other materials may be used
for mechanical integration of the one or more connectors with the
insert.
[0004] In certain embodiments, a method of fabricating a BIP module
involves providing a photovoltaic module insert having one or more
electrically interconnected photovoltaic cells and one or more bus
bars extending away from at least one side of the insert. Two of
the bus bars are electrically connected to the photovoltaic cells.
A connector member having one or more conductive elements is also
provided. The method continues with electrically connecting at
least one conductive element to at least one bus bar. The method
continues with forming a connector body around at least a portion
of the connector member by injection molding a polymeric material,
which may be a temperature resistant material and/or other some
other material. In either case, the resulting BIP module includes a
temperature resistant material that has an RTI of at least about
115.degree. C. which covers at least the conductive element and the
bus bar.
[0005] In certain embodiments, a temperature resistant material
includes one or more of rigid materials. Some examples of rigid
materials include polyethylene terephthalate (e.g., RYNITE.RTM.
available from Du Pont in Wilmington, Del.), polybutylene
terephthalate (e.g., CRASTIN.RTM. also available from Du Pont),
nylon in any of its engineered formulations of Nylon 6 and Nylon
66, polyphenylene sulfide (e.g., RYTON.RTM. available from Chevron
Phillips in The Woodlands, Tex.), polyamide (e.g., ZYTEL.RTM.
available from DuPont), polycarbonate (PC), polyester (PE),
polypropylene (PP), and polyvinyl chloride (PVC) and weather able
engineering thermoplastics such as polyphenylene oxide (PPO),
polymethyl methacrylate, polyphenylene (PPE), styrene-acrylonitrile
(SAN), polystyrene and blends based on those materials.
Furthermore, weatherable thermosetting polymers, such as
unsaturated polyester (UP) and epoxy, may be used. The properties
of these materials listed above may be enhanced with the addition
of fire retardants, color pigments, anti-tracking, and/or ignition
resistant materials. In addition, glass or mineral fibers powders
and/or spheres may be used to enhance the structural integrity,
surface properties, and/or weight reduction. The materials may also
include additives such as anti-oxidants, moisture scavengers,
blowing or foaming agents, mold release additives, or other plastic
additives. One or more of these additives may be also a part of
other non-temperature resistant materials used in forming a
connector body or an overmold covering at least a portion of the
connector body. In more specific embodiments, the material has an
RTI of at least about 125.degree. C. or even an RTI of at least
about 135.degree. C.
[0006] In certain embodiments, a temperature resistant material may
be at least partially enclosed in one or more of flexible
materials. Some examples of flexible materials include
polyethylene, polypropylene, thermoplastic olefins, thermoplastic
rubber, thermoplastic elastomer, ethylene propylene diene, monomer
(EPDM), fluoroelastomers or thermoplastic vulcanizates (TPV), and
flexible cast thermoset materials, such as urethanes or silicones.
In general, various flexible thermoplastic elastomers that have
suitable thermally durable behavior may be used. Some specific
examples include SANTOPRENE.RTM. (Supplied by Exxon Mobil in
Houston, Tex.), HIPEX.RTM. (Supplied by Sivaco in Santa Clara,
Calif.), EFLEX@ (Supplied by E-Polymers Co., Ltd. In Seoul, Korea),
ENFLEX.RTM. (Supplied by Enplast Limited in Longford, Ireland),
EXCELINK.RTM. (Supplied by JSR Corporation in Tokyo, Japan),
SYNOPRENE.RTM. (Supplied by Synoprene Polymers Pvt. Ltd. in Mumbai,
India), Elastron.RTM. (Supplied by Elastron Kimya in Kocaeli,
Turkey). Some additional examples include nitrile butadiene rubber
(e.g., KRYNAC.RTM. (available from Lanxess in Maharashtra, India),
NIPOL.RTM. (available from Zeon Chemicals in Louisville, Ky.) or
NYSYN.RTM. (available from Copolymer Rubber & Chemicals in
Batton Rouge, La.)), hydrogenated nitrile butadiene rubber (e.g.,
THERBAN.RTM. (available from Lanxess in Maharashtra, India),
ZETPOL.RTM. (available from Zeon Chemicals in Louisville, Ky.)),
and tetra-fluoro-ethylene-propylene (e.g., AFLAS.RTM. (Asahi Glass
in Tokyo, Japan) and DYNEON BRF.RTM. (available from 3M in St.
Paul, Minn.) and VITON VTR.RTM. (available from DuPont Performance
Polymers in Wilmington, Del.)).
[0007] Some materials described above and elsewhere in this
document may include engineered polymers, which are specifically
formulated to meet certain requirements specific for photovoltaic
applications. For example, certain hybrid block co-polymers may be
used.
[0008] In more specific embodiments, a provided connector member
includes a prefabricated insulating housing that at least initially
mechanically supports and/or electrically insulates one or more
conductive elements. The housing may be made from or include one or
more temperature resistant materials described above. In even more
specific embodiments, a connector body is formed around the
insulating housing by injection molding one or more of the flexible
materials described above. Other more specific examples are listed
above. This connector body extends over at least a portion of the
photovoltaic module insert to provide mechanical support to the
connector with respect to the insert. In certain embodiments, a
housing includes one or more extension flaps forming an insulating
sleeve around one or more bus bars extending outside the insert and
connected to the one or more conductive elements inside the
insulating housing. In other embodiments, a fabrication process
involves insulating such portions of the bus bars and/or other
electrical components prior to forming the rest of the connector
body. This insulation component may be formed by injection molding
one or more temperature resistant materials.
[0009] In certain embodiments, a connector body is formed using a
temperature resistant material without any additional materials
molded over the connector body. The connector body may extend over
at least a portion of the insert to support the connector body with
respect to the insert. In other embodiments, fabrication of a
module involves forming an additional module overmold over at least
a portion of the connector body made from the temperature
resistance material. The module overmold extends over at least a
portion of the insert. In certain specific embodiments, both the
overmold and the connector body extend over the insert. The
overmold may be made from one or more of the flexible materials
listed above.
[0010] In certain embodiments, a connector body includes a cavity
with a conductive element positioned inside the cavity, e.g.,
forming a conductive socket inside the cavity for receiving a
conductive pin of another connector. The connector body may also
include a seal positioned around the cavity's opening. The seal may
be formed by injection molding of one or more of the flexible
materials listed above. Other more specific examples are listed
above. When two connectors engage with each other, one or two seals
(e.g., one seal on each connector) protect the conductive elements
of the two connectors from contaminations. In some embodiments,
electrically connecting a conductive element of a connector member
to a bus bar of the insert involves aligning the connector member
with respect to the insert. More specifically, the conductive
element is aligned with respect to the bus bar. This alignment may
be substantially maintained during one or more later operations,
for example, during formation of a connector body. Electrically
connecting the conductive element to the bus bar may involve one or
more of the following techniques: resistance welding, ultrasonic
welding, laser welding, and soldering.
[0011] Also provided are examples of BIP modules for use on
building structures, such as rooftops. In certain embodiments, a
BIP module includes an insert having one or more electrically
interconnected photovoltaic cells and one or more bus bars
extending away from the insert. Two of these bus bars are
electrically connected to the cells. The BIP module also includes
one or more connectors including conductive elements. At least two
of these conductive elements electrically connected to the cells
using two or more of the bus bars. One of the connectors may have a
connector body formed around its one or more conductive elements
and portions of the bus bars extending from the inserts and making
electrical connections to the conductive elements. The connector
body may be made from a temperature resistant material having an
RTI of at least about 115.degree. C. or, more particularly, an RTI
of at least about 125.degree. C.
[0012] In certain embodiments, a portion of a connector body or an
overmold over a connector body may be made from one or more of
flexible materials listed above. Other more specific examples are
listed above. In general, these materials may be formed around a
portion of the connector body made from one or more of the
temperature resistant materials or a prefabricated connector
described above. An insert of the BIP module may have one or more
ventilation channels for cooling the module during its operation.
In certain embodiments, an insert has a bus bar that is not
electrically connected to the photovoltaic cells. This bus bar may
extend from one side of the module to another and be used, for
example, for making in-series electrical connections with other
modules. This bus bar may be electrically connected to a separate
conductive element of a connector. Another conductive element of
the same connector may be electrically connected to the
photovoltaic cells.
[0013] These and other aspects of the invention are described
further below with reference to the figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic cross-sectional side view of a
building integrable photovoltaic (BIP) module in accordance with
certain embodiments.
[0015] FIG. 2 is a schematic top view of a BIP module in accordance
with certain embodiments.
[0016] FIG. 3 illustrates a subset of a photovoltaic array that
includes six BIP modules in accordance with certain
embodiments.
[0017] FIG. 4 is a schematic illustration of a photovoltaic array
installed on a rooftop of a building structure in accordance with
certain embodiments.
[0018] FIG. 5 is a schematic representation of a photovoltaic
module having electrically interconnected photovoltaic cells in
accordance with certain embodiments.
[0019] FIG. 6 is a schematic electrical diagram of a photovoltaic
array having three BIP modules interconnected in series in
accordance with certain embodiments.
[0020] FIG. 7 is a schematic electrical diagram of another
photovoltaic array having three BIP modules interconnected in
parallel in accordance with other embodiments.
[0021] FIGS. 8A-8C are schematic cross-sectional views of two
connectors configured for interconnection with each other in
accordance with certain embodiments.
[0022] FIG. 9 is a process flowchart corresponding to a method of
fabricating a BIP module in accordance with certain
embodiments.
[0023] FIG. 10A is a schematic representation of one example a BIP
module having a connector made entirely from a temperature
resistant material in accordance with certain embodiments.
[0024] FIG. 10B is a schematic representation of another example of
a BIP module having a connector made from a prefabricated
insulating housing and an overmold formed around the housing in
accordance with certain embodiments.
[0025] FIG. 10C is a schematic representation of yet another
example of a BIP module having an inner portion of the connector
made from a temperature resistant material and an outer portion of
the connector made from a different material in accordance with
certain embodiments.
[0026] FIG. 11 illustrates a schematic illustration of an alignment
fixture at different stages during the module fabrication process
in accordance with certain embodiments.
[0027] FIG. 12 is a schematic illustration of a connector member
having two flat conductive elements in accordance with certain
embodiments.
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
[0028] In the following description, numerous specific details are
set forth in order to provide a thorough understanding of the
present invention. The present invention may be practiced without
some or all of these specific details. In other instances, well
known process operations have not been described in detail to not
unnecessarily obscure the present invention. While the invention
will be described in conjunction with the specific embodiments, it
will be understood that it is not intended to limit the invention
to the embodiments.
[0029] Building-integrable photovoltaic (BIP) modules are defined
as specially configured photovoltaic modules that are used for
integration into building structures in various parts of buildings,
such as rooftops, skylights, or facades. In certain examples, BIP
modules replace conventional building materials, such as asphalt
shingles. Unlike traditional photovoltaic systems, BIP modules
often do not require separate mounting hardware. As such, installed
BIP modules provide substantial savings over more traditional
systems in terms of building materials and labor costs. For
example, a substantial part of traditional asphalt roof shingles
may be replaced by "photovoltaic shingles." In certain embodiments,
photovoltaic shingles are installed on the same base roof
structures as the asphalt shingles. In fact, a rooftop may be
covered by a combination of the asphalt and photovoltaic shingles.
In certain embodiments, BIP modules are shaped like one or a
collection of asphalt shingles. BIP modules may look and act much
like the asphalt shingles while producing electricity in addition
to protecting the underlying building structures from the
environment. In certain embodiments, BIP modules may be about 14
(e.g., 13.25) inches by about 40 (e.g., 39.375) inches in size and
may be stapled directly to the roof deck through water barrier
roofing cloth, for example. Generally, only a portion of the
photovoltaic shingle is exposed, while the remaining portion is
covered by other shingles. The exposed portion is referred to as
the "shingle exposure", while the covered portion is referred to as
the "flap." For example, the shingle exposure of a 13.25 inch by
39.375 inch shingle may be only about 5 inches wide or, in some
embodiments, about 5.625 inches wide. The length of the shingle
exposure in some of these embodiments may be 36 inches or about
39.375 inches (if side skirts are not used, for example). Other
dimensions of photovoltaic shingles may be used as well.
[0030] BIP modules described herein include designs capable of
withstanding higher operating temperatures typical for rooftops and
other operating environments. Electrical components of connectors
and/or inserts are electrically insulated using a temperature
resistant material having a Relative Temperature Index (RTI) of at
least about 115.degree. C. In certain embodiments, higher RTI rated
materials are used. An RTI is defined as the maximum service
temperature at which certain properties of the material remain
within predetermined limits over a period of time. More
specifically, an RTI may be defined as a maximum service
temperature for a material where a class of critical property will
not be unacceptably compromised through chemical thermal
degradation. This time frame may span over the reasonable life of
an electrical product, relative to a reference material. For
example, a polymer with 115.degree. C. RTI rating may preserve at
least 50% of its dielectric strength, tensile impact strength,
and/or tensile strength for the entire operating period of a BIP
module (e.g., 15 or 20 years). Some examples of rigid materials
that have such RTI ratings are presented above. However, RTI rated
materials may be expensive and often do not provide all needed
properties, such as mechanical support, ductility, conformality,
low cost, UV stability, and other characteristics. Other materials
may also be used to form an overmold to provide additional
mechanical support and/or electrical insulation. In certain
embodiments, polyethylene, polypropylene, and/or thermoplastic
rubber is injection molded over the temperature resistant materials
and at least a portion of the insert.
[0031] Furthermore, embodiments of BIP module designs provided
herein are configured for rapid installation on building
structures, such as building rooftops, providing substantial labor
savings. In certain embodiments, mechanical alignment of two BIP
modules in the same row also results in electrical interconnection
of the two modules. In specific embodiments, connectors are used to
align one BIP module with respect to another.
[0032] For purposes of this document, a BIP module is defined as an
assembled unit ready for installation on a building structure. One
particular example of a BIP module is a photovoltaic shingle for
installation on roof structures. A BIP module may be configured for
direct connection to other BIP modules (i.e., connected only via
BIP-integrated electrical connectors) or indirect connection to
other BIP modules (i.e., connection via a separate connector not
integrated with a BIP module). A BIP module typically is fabricated
using a photovoltaic insert that has two or more integrated
electrical connectors. Other components of BIP modules may include
moisture flaps (e.g., a top flap, which is sometimes referred to as
a "top lap" and/or a side skirt), mechanical support sheets or
components, sealing components, heat transfer features (e.g.,
ventilation channels in a support sheet), and the like.
[0033] A photovoltaic insert is defined as a prefabricated
photovoltaic subassembly that forms part of a BIP module and used
for its fabrication. The insert includes one or more photovoltaic
cells, e.g., multiple electrically interconnected photovoltaic
cells, sealing sheets enclosing the cell or cells, cell-cell
interconnectors (if necessary), electrical contacts extending out
of the sealing sheets for establishing electrical connections with
the photovoltaic cells and other electrical components of the
insert. In certain embodiments, the insert includes one or more bus
bars, or other electrically conductive components configured to
carry current through an insert or BIP module. A bus bar may be
made of a strip of highly conductive material, typically metal, for
example copper, that is configured to carry a rated amount of
current in the context of its operating environment. An insert may
include one or more bus bars that extends from one edge of the
insert to another without having any direct electrical connections
to the photovoltaic cells. An insert may also include one or more
bus bars that are configured for or in direct electrical
communication with one or more photovoltaic cells of the
insert.
[0034] To provide a better understanding of various features of BIP
modules and methods of integrating connectors with photovoltaic
inserts during module fabrication, some examples of BIP modules
will now be briefly described. FIG. 1 is a schematic
cross-sectional end view (line 1-1 in FIG. 2 indicates the position
of this cross-section) of a BIP module 100 in accordance with
certain embodiments. BIP module 100 may have one or more
photovoltaic cells 102 that are electrically interconnected.
Photovoltaic cells 102 may be interconnected in parallel, in
series, or in various combinations of these. Examples of
photovoltaic cells include copper indium gallium selenide (CIGS)
cells, cadmium-telluride (Cd--Te) cells, amorphous silicon (a-Si)
cells, micro-crystalline silicon cells, crystalline silicon (c-Si)
cells, gallium arsenide multi-junction cells, light adsorbing dye
cells, organic polymer cells, and other types of photovoltaic
cells.
[0035] Photovoltaic cell 102 has a photovoltaic layer that
generates a voltage when exposed to sunlight. In certain
embodiments, the photovoltaic layer includes a semiconductor
junction. The photovoltaic layer may be positioned adjacent to a
back conductive layer, which, in certain embodiments, is a thin
layer of molybdenum, niobium, copper, and/or silver. Photovoltaic
cell 102 may also include a conductive substrate, such as stainless
steel foil, titanium foil, copper foil, aluminum foil, or beryllium
foil. Another example includes a conductive oxide or metallic
deposition over a polymer film, such as polyimide. In certain
embodiments, a substrate has a thickness of between about 2 mils
and 50 mils (e.g., about 10 mils), with other thicknesses also
within the scope. Photovoltaic cell 102 may also include a top
conductive layer. This layer typically includes one or more
transparent conductive oxides (TCO), such as zinc oxide,
aluminum-doped zinc oxide (AZO), indium tin oxide (ITO), and
gallium doped zinc oxide. A typical thickness of a top conductive
layer is between about 100 nanometers to 1,000 nanometers (e.g.,
between about 200 nanometers and 800 nanometers), with other
thicknesses within the scope.
[0036] In certain embodiments, photovoltaic cells 102 are
interconnected using one or more current collectors (not shown).
The current collector may be attached and configured to collect
electrical currents from the top conductive layer. The current
collector may also provide electrical connections to adjacent cells
as further described with reference to of FIG. 5, below. The
current collector includes a conductive component (e.g., an
electrical trace or wire) that contacts the top conductive layer
(e.g., a TCO layer). The current collector may further include a
top carrier film and/or a bottom carrier film, which may be made
from transparent insulating materials to prevent electrical shorts
with other elements of the cell and/or module. In certain
embodiments, a bus bar is attached directly to the substrate of a
photovoltaic cell. A bus bar may also be attached directly to the
conductive component of the current collector. For example, a set
of photovoltaic cells may be electrically interconnected in series
with multiple current collectors (or other interconnecting wires).
One bus bar may be connected to a substrate of a cell at one end of
this set, while another bus bar may be connected to a current
collector at another end.
[0037] Photovoltaic cells 102 may be electrically and
environmentally insulated between a front light-incident sealing
sheet 104 and a back sealing sheet 106. Examples of sealing sheets
include glass, polyethylene, polyethylene terephthalate (PET),
polypropylene, polybutylene, polybutylene terephthalate (PBT),
polyphenylene oxide (PPO), polyphenylene sulfide (PPS) polystyrene,
polycarbonates (PC), ethylene-vinyl acetate (EVA), fluoropolymers
(e.g., polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF),
ethylene-terafluoethylene (ETFE), fluorinated ethylene-propylene
(FEP), perfluoroalkoxy (PFA) and polychlorotrifluoroethane
(PCTFE)), acrylics (e.g., poly(methyl methacrylate)), silicones
(e.g., silicone polyesters), and/or polyvinyl chloride (PVC), as
well as multilayer laminates and co-extrusions of these materials.
A typical thickness of a sealing sheet is between about 5 mils and
100 mils or, more specifically, between about 10 mils and 50 mils.
In certain embodiments, a back sealing sheet includes a metallized
layer to improve water permeability characteristics of the sealing
sheet. For example, a metal foil may be positioned in between two
insulating layers to form a composite back sealing sheet. In
certain embodiments, a module has an encapsulant layer positioned
between one or both sealing sheets 104, 106 and photovoltaic cells
102. Examples of encapsulant layer materials include non-olefin
thermoplastic polymers or thermal polymer olefin (TPO), such as
polyethylene (e.g., a linear low density polyethylene,
polypropylene, polybutylene, polyethylene terephthalate (PET),
polybutylene terephthalate (PBT), polystyrene, polycarbonates,
fluoropolymers, acrylics, ionomers, silicones, and combinations
thereof.
[0038] BIP module 100 may also include an edge seal 105 that
surrounds photovoltaic cells 102. Edge seal 105 may be used to
secure front sheet 104 to back sheet 106 and/or to prevent moisture
from penetrating in between these two sheets. Edge seal 105 may be
made from certain organic or inorganic materials that have low
inherent water vapor transmission rates (WVTR), e.g., typically
less than 1-2 g/m.sup.2/day. In certain embodiments, edge seal 105
is configured to absorb moisture from inside the module in addition
to preventing moisture ingression into the module. For example, a
butyl-rubber containing moisture getter or desiccant may be added
to edge seal 105. In certain embodiments, a portion of edge seal
105 that contacts electrical components (e.g., bus bars) of BIP
module 100 is made from a thermally resistant polymeric material.
Various examples of thermally resistant materials and RTI ratings
are further described below.
[0039] BIP module 100 may also have a support sheet 108 attached to
back side sealing sheet 106. The attachment may be provided by a
support edge 109, which, in certain embodiments, is a part of
support sheet 108. Support sheets may be made, for example, from
rigid materials. Some examples of rigid materials include
polyethylene terephthalate (e.g., RYNITE.RTM. available from Du
Pont in Wilmington, Del.), polybutylene terephthalate (e.g.,
CRASTIN.RTM. also available from Du Pont), nylon in any of its
engineered formulations of Nylon 6 and Nylon 66, polyphenylene
sulfide (e.g., RYTON.RTM. available from Chevron Phillips in The
Woodlands, Tex.), polyamide (e.g., ZYTEL.RTM. available from
DuPont), polycarbonate (PC), polyester (PE), polypropylene (PP),
and polyvinyl chloride (PVC) and weather able engineering
thermoplastics such as polyphenylene oxide (PPO), polymethyl
methacrylate, polyphenylene (PPE), styrene-acrylonitrile (SAN),
polystyrene and blends based on those materials. Furthermore,
weatherable thermosetting polymers, such as unsaturated polyester
(UP) and epoxy, may be used. The properties of these materials
listed above may be enhanced with the addition of fire retardants,
color pigments, anti-tracking, and/or ignition resistant materials.
In addition, glass or mineral fibers powders and/or spheres may be
used to enhance the structural integrity, surface properties,
and/or weight reduction. The materials may also include additives
such as anti-oxidants, moisture scavengers, blowing or foaming
agents, mold release additives, or other plastic additives.
[0040] In certain embodiments, support sheet 108 may be attached to
back sheet 106 without a separate support edge or other separate
supporting element. For example, support sheet 108 and back sheet
106 may be laminated together or support sheet 108 may be formed
(e.g., by injection molding) over back sheet 106. In other
embodiments back sealing sheet 106 serves as a support sheet. In
this case, the same element used to seal photovoltaic cells 102 may
be positioned over and contact a roof structure (not shown).
Support sheet 108 may have one or more ventilation channels 110 to
allow for air to flow between BIP module 100 and a building
surface, e.g., a roof-deck or a water resistant
underlayment/membrane on top of the roof deck. Ventilation channels
110 may be used for cooling BIP module during its operation. For
example, it has been found that each 1.degree. C. of heating from
an optimal operating temperature of a typical CIGS cell causes the
efficiency loss of about 0.33% to 0.5%.
[0041] BIP module 100 has one or more electrical connectors 112 for
electrically connecting BIP module 100 to other BIP modules and
array components, such as an inverter and/or a battery pack. In
certain embodiments, BIP module 100 has two electrical connectors
112 positioned on opposite sides (e.g., the short or minor sides of
a rectangular module) of BIP module 100, as for example shown in
FIGS. 1 and 2, for example. Each one of two electrical connectors
112 has at least one conductive element electrically connected to
photovoltaic cells 102. In certain embodiments, electrical
connectors 112 have additional conductive elements, which may or
may not be directly connected to photovoltaic cells 102. For
example, each of two connectors 112 may have two conductive
elements, one of which is electrically connected to photovoltaic
cells 102, while the other is electrically connected to a bus bar
(not shown) passing through BIP module 100. This and other examples
are described in more detail in the context of FIGS. 6 and 7. In
general, regardless of the number of connectors 112 attached to BIP
module 100, at least two conductive elements of these connectors
112 are electrically connected to photovoltaic cells 102.
[0042] FIG. 2 is a schematic top view of BIP module 100 in
accordance with certain embodiments. Support sheet 108 is shown to
have a side skirt 204 and a top flap 206 extending beyond a BIP
module boundary 202. Side skirt 204 is sometimes referred to as a
side flap, while top flap 206 is sometimes referred to as a top
lap. In certain embodiments, BIP module 100 does not include side
flap 204. BIP module boundary 202 is defined as an area of BIP
module 100 that does not extend under other BIP modules or similar
building materials (e.g., roofing shingles) after installation. BIP
module boundary 202 includes photovoltaic cells 102. Generally, it
is desirable to maximize the ratio of the exposed area of
photovoltaic cells 102 to BIP module boundary 202 in order to
maximize the "working area" of BIP module 100. It should be noted
that, after installation, flaps of other BIP modules typically
extend under BIP module boundary 202. In a similar manner, after
installation, side flap 204 of BIP module 100 may extend underneath
another BIP module positioned on the left (in the same row) of BIP
module 100 creating an overlap for moisture sealing. Top flap 206
may extend underneath one or more BIP modules positioned above BIP
module 100. Arrangements of BIP modules in an array will now be
described in more detail with reference to FIGS. 3 and 4.
[0043] FIG. 3 illustrates a photovoltaic array 300 or, more
specifically a portion of a photovoltaic array, which includes six
BIP modules 100a-100f arranged in three different rows extending
along horizontal rooflines in accordance with certain embodiments.
Installation of BIP modules 100a-100f generally starts from a
bottom roofline 302 so that the top flaps of BIP modules 100a-100f
can be overlapped with another row of BIP modules. If a side flap
is used, then the position of the side flap (i.e., a left flap or a
right flap) determines which bottom corner should be the starting
corner for the installation of the array. For example, if a BIP
module has a top flap and a right-side flap, then installation may
start from the bottom left corner of the roof or of the
photovoltaic array. Another BIP module installed later in the same
row and on the right of the initial BIP module will overlap the
side flap of the initial BIP module. Furthermore, one or more BIP
modules installed in a row above will overlap the top flap of the
initial BIP module. This overlap of a BIP module with a flap of
another BIP module creates a moisture barrier.
[0044] FIG. 4 is a schematic illustration of a photovoltaic array
400 installed on a rooftop 402 of a building structure 404 for
protecting building structure 404 from the environment as well as
producing electricity in accordance with certain embodiments.
Multiple BIP modules 100 are shown to fully cover one side of
rooftop 402 (e.g., a south side or the side that receives the most
sun). In other embodiments, multiple sides of rooftop 402 are used
for a photovoltaic array. Furthermore, some portions of rooftop 402
may be covered with conventional roofing materials (e.g., asphalt
shingles). As such, BIP modules 100 may also be used in combination
with other roofing materials (e.g., asphalt shingles) and cover
only a portion of rooftop. Generally, BIP modules 100 may be used
on steep sloped to low slope rooftops. For example, the rooftops
may have a slope of at least about 2.5-to-12 or, in many
embodiments, at least about 3-to-12.
[0045] Multiple BIP modules 100 may be interconnected in series
and/or in parallel with each other. For example, photovoltaic array
400 may have sets of BIP modules 100 interconnected in series with
each other (i.e., electrical connections among multiple
photovoltaic modules within one set), while these sets are
interconnected in parallel with each other (i.e., electrical
connections among multiple sets in one array). Photovoltaic array
400 may be used to supply electricity to building structure 404
and/or to an electrical grid. In certain embodiments, photovoltaic
array 400 includes an inverter 406 and/or a battery pack 408.
Inverter 406 is used for converting a direct current (DC) generated
by BIP modules 100 into an alternating current (AC). Inverter 406
may be also configured to adjust a voltage provided by BIP modules
100 or sets of BIP modules 100 to a level that can be utilized by
building structure 404 or by a power grid. In certain embodiments,
inverter 406 is rated up to 600 volts DC input or even up to 1000
volts DC, and/or up to 10 kW power. Examples of inverters include a
photovoltaic static inverter (e.g., BWT10240-Gridtec 10, available
from Trace Technologies in Livermore, Calif.) and a string inverter
(e.g. Sunny Boy.RTM.2500 available from SMA America in Grass
Valley, Calif.). In certain embodiments, BIP modules may include
integrated inverters, i.e., "on module" inverters. These inverters
may be used in addition to or instead of external inverter 406.
Battery pack 408 is used to balance electric power output and
consumption.
[0046] FIG. 5 is a schematic representation of a photovoltaic
module insert 500 illustrating photovoltaic cells 504 electrically
interconnected in series using current collectors/interconnecting
wires 506 in accordance with certain embodiments. Often individual
cells do not provide an adequate output voltage. For example, a
typical voltage output of an individual CIGS cell is only between
0.4V and 0.7V. To increase voltage output, photovoltaic cells 504
may be electrically interconnected in series for example, shown in
FIG. 5 and/or include "on module" inverters (not shown). Current
collectors/interconnecting wires 506 may also be used to provide
uniform current distribution and collection from one or both
contact layers.
[0047] As shown in FIG. 5, each pair of photovoltaic cells 504 has
one interconnecting wire positioned in between the two cells and
extending over a front side of one cell and over a back side of the
adjacent cell. For example, a top interconnecting wire 506 in FIG.
5 extends over the front light-incident side of cell 504 and under
the back side of the adjacent cell. In the figure, the
interconnecting wires 506 also collect current from the TCO layer
and provide uniform current distribution, and may be referred to
herein as current collectors. In other embodiments, separate
components are used to for current collection and cell-cell
interconnection. End cell 513 has a current collector 514 that is
positioned over the light incident side of cell 513 but does not
connect to another cell. Current collector 514 connects cell 513 to
a bus bar 510. Another bus bar 508 may be connected directly to the
substrate of the cell 504 (i.e., the back side of cell 504). In
another embodiment, a bus bar may be welded to a wire or other
component underlying the substrate. In the configuration shown in
FIG. 5, a voltage between bus bars 508 and 510 equals a sum of all
cell voltages in insert 500. Another bus bar 512 passes through
insert 500 without making direct electrical connections to any
photovoltaic cells 504. This bus bar 512 may be used for
electrically interconnecting this insert in series without other
inserts as further described below with reference to FIG. 6.
Similar current collectors/interconnecting wires may be used to
interconnect individual cells or set of cells in parallel (not
shown).
[0048] BIP modules themselves may be interconnected in series to
increase a voltage of a subset of modules or even an entire array.
FIG. 6 illustrates a schematic electrical diagram of a photovoltaic
array 600 having three BIP modules 602a-602c interconnected in
series using module connectors 605a, 605b, and 606 in accordance
with certain embodiments. A voltage output of this three-module
array 600 is a sum of the voltage outputs of three modules
602a-602c. Each module connector 605a and 605b shown in FIG. 6 may
be a combination of two module connectors of BIP modules 602a-602c.
These embodiments are further described with reference to FIGS.
8A-8C. In other words, there may be no separate components
electrically interconnecting two adjacent BIP modules, with the
connection instead established by engaging two connectors installed
on the two respective modules. In other embodiments, separate
connector components (i.e., not integrated into or installed on BIP
modules) may be used for connecting module connectors of two
adjacent modules.
[0049] Module connector 606 may be a special separate connector
component that is connected to one module only. It may be used to
electrically interconnect two or more conductive elements of the
same module connector.
[0050] Sometimes BIP modules may need to be electrically
interconnected in parallel. FIG. 7 illustrates a schematic
electrical diagram of a photovoltaic array 700 having three BIP
modules 702a-702c interconnected in parallel using module
connectors 705a and 705b in accordance with certain embodiments.
Each module may have two bus bars extending through the module,
i.e., a "top" bus bar 711 and a "bottom" bus bar 713 as shown in
FIG. 7. Top bus bars 711 of each module are connected to right
electrical leads 704a, 704b, and 704c of the modules, while bottom
bus bars 713 are connected to left electrical leads 703a, 703b, and
703c. A voltage between the top bus bars 711 and bottom bus bars
713 is therefore the same along the entire row of BIP modules
702a-702c.
[0051] FIG. 8A is a schematic cross-sectional side view of two
connectors 800 and 815 configured for interconnection with each
other, in accordance with certain embodiments. For simplicity, the
two connectors are referred to as a female connector 800 and a male
connector 815. Each of the two connectors 800 and 815 is shown
attached to its own photovoltaic insert, which includes
photovoltaic cells 802 and one or more sealing sheets 804.
Connectors 800 and 815 include conductive elements 808b and 818b,
respectively, which are shown to be electrically connected to
photovoltaic cells 802 using bus bars 806 and 816,
respectively.
[0052] In certain embodiments, a conductive element of one
connector (e.g., conductive element 808b of female connector 800)
is shaped like a socket/cavity and configured for receiving and
tight fitting a corresponding conductive element of another
connector (e.g., conductive element 818b of male connector 815).
Specifically, conductive element 808b is shown forming a cavity
809b. This tight fitting and contact in turn establishes an
electrical connection between the two conductive elements 808b and
818b. Accordingly, conductive element 818b of male connector 815
may be shaped like a pin (e.g., a round pin or a flat rectangular
pin). A socket and/or a pin may have protrusions (not shown)
extending towards each other (e.g., spring loaded tabs) to further
minimize the electrical contact resistance by increasing the
overall contact area. In addition, the contacts may be fluted to
increase the likelihood of good electrical contact at multiple
points (e.g., the flutes guarantee at least as many hot spot
asperities of current flow as there are flutes).
[0053] In certain embodiments, connectors do not have a cavity-pin
design as shown in FIGS. 8A-8C. Instead, an electrical connection
may be established when two substantially flat surfaces contact
each other. Conductive elements may be substantially flat or have
some topography designed to increase a contact surface over the
same projection boundary and/or to increase contact force at least
in some areas. Examples of such surface topography features include
multiple pin-type or rib-type elevations or recesses.
[0054] In certain embodiments, one or more connectors attached to a
BIP module have a "touch free" design, which means that an
installer can not accidently touch conductive elements or any other
electrical elements of these connectors during handling of the BIP
module. For example, conductive elements may be positioned inside
relatively narrow cavities. The openings of these cavities are too
small for a finger to accidently come in to contact with the
conductive elements inside the cavities. One such example is shown
in FIG. 8A where male connector 815 has a cavity 819b formed by
connector body 820 around its conductive pin 818b. While cavity
819b may be sufficiently small to ensure a "touch free" designed as
explained above, it is still large enough to accommodate a portion
of connector body 810 of female connector 800. In certain
embodiments, connector bodies 810 and 820 have interlocking
features (not shown) that are configured to keep the two connectors
800 and 815 connected and prevent connector body 810 from sliding
outs of cavity 819b. Examples of interlocking features include
latches, threads, and various recess-protrusion combinations.
[0055] FIG. 8B is schematic plan view of female connector 800 and
male connector 815, in accordance with certain embodiments. Each
connector 800, 815 is shown with two conductive elements (i.e.,
conductive sockets 808a and 808b in connector 800 and conductive
pins 818a and 818b in connector 815). One conductive element (e.g.,
socket 808b and pin 818b) of each connector is shown to be
electrically connected to photovoltaic cells 802. Another
conductive element of each connector 800, 815 may be connected to
bus bars (e.g., bus bars 809 and 819) that do not have an immediate
electrical connection to photovoltaic cells 802 of their respective
BIP module (the extended electrical connection may exist by virtue
of a complete electrical circuit).
[0056] As shown, sockets 808a and 808b may have their own
designated inner seals 812a and 812b. Inner seals 812a and 812b are
designed to provide more immediate protection to conductive
elements 808a and 818a after connecting the two connectors 800,
815. As such, inner seals 812a and 812b are positioned near inner
cavities of sockets 808a and 808b. The profile and dimensions of
pins 818a and 818b closely correspond to that of inner seals 812a
and 812b. In the same or other embodiments, connectors 800, 815
have external seals 822a and 822b. External seals 822a and 822b may
be used in addition to or instead of inner seals 812a and 812b.
Various examples of seal materials and fabrication methods are
described below in the context of FIG. 9. FIG. 8C is schematic
front view of female connector 800 and male connector 815, in
accordance with certain embodiments. Connector pins 818a and 818b
are shown to have round profiles. However, other profiles (e.g.,
square, rectangular) may also be used for pins 818a and 818b and
conductive element cavities 808a and 808b.
[0057] Having described some aspects of BIP modules and, more
specifically, some aspects of electrical connectors attached to
photovoltaic inserts, this document will now describe various
examples of a process for fabricating BIP modules. Generally, the
process involves electrically connecting conductive elements of the
connector member and bus wires of the insert and forming a
connector body around at least a portion of the connector member
and insert. FIG. 9 is a process flowchart corresponding to a
process 900 for fabricating BIP modules in accordance with certain
embodiments. Process 900 may start with providing a photovoltaic
module insert and a connector member in operation 902. Various
examples of photovoltaic module inserts are described above, for
example, in the context of FIGS. 1 and 5. In general, an insert
includes one or more electrically interconnected photovoltaic cells
and two or more bus bars extending away from at least one side of
the insert. At least two of these bus bars are electrically
connected to the photovoltaic cells.
[0058] The connector member provided in operation 902 includes at
least one conductive element. In certain embodiments, a connector
member includes two or more conductive elements. The connector
member may be provided with or without a prefabricated insulating
housing. An insulating housing is typically made from one or more
temperature resistant materials. Some examples of rigid materials
with suitable thermal characteristics are provided above. In
specific embodiments, an insulating housing is made from a
temperature resistant material having an RTI of at least about
115.degree. C. or, more particularly, having a RTI of at least
about 125.degree. C. In certain embodiments, an insulating housing
has one or more extension flaps configured to cover and insulate a
portion one or more bus bars extending out of the insert and
connected to conductive elements positioned within the insulating
housing. These extension flaps may be sufficiently flexible to
allow accessing to the conductive elements in order to establish
electrical connections between the bus bars and conductive
elements.
[0059] Process 900 may proceed with establishing one or more
electrical connections between one or more conductive elements of
the connector member and one or more bus bars extending from the
inserts (block 904). The electrical connections may be established
by resistance welding, ultrasonic welding, laser welding,
soldering, crimping, applying conductive adhesive, or any other
suitable connection technique. In certain embodiments, a
photovoltaic insert is aligned with respect to a connector member
prior or during operation 904. This alignment may be maintained
during subsequent operations (e.g., operations 906 and/or 908
further described below) or more generally until the connector is
rigidly or semi-rigidly attached to the insert. An alignment
fixture may be used for this purpose. FIG. 11 illustrates a
schematic illustration of an alignment fixture 1108 in accordance
with certain embodiments. Alignment fixture 1108 is shown at three
stages of BIP module fabrication process 900: during establishing
an initial alignment (1110), during formation of a connector body
(1120), and after removal of the alignment fixture (1130).
[0060] Alignment fixture 1108 may have a reference surface 1108a
for positioning a photovoltaic insert 1102 and a reference fixture
1108b for positioning a conductive element 1106. As shown during
stage 1110, a portion of conductive element 1106 and a portion of
bus bar 1104 may overlap in an overlap area 1112. At this stage
1110, photovoltaic insert 1102 is considered to be aligned with
respect to conductive element 1106. Conductive element 1106 and bus
bar 1104 may be mechanically and/or electrically interconnected
with each other in overlap area 1112 using one or more attachment
techniques described above.
[0061] Once the connection between conductive element 1106 and bus
bar 1104 is formed, a connector body 1122 may be formed around
conductive element 1106 as shown in the next stage 1120. A portion
1124 of connector body 1122 may extend over the connection area
1112 and, in certain embodiments, may extend over at least a
portion of photovoltaic insert 1102. This in turn may result in
connector body 1122 being rigidly or semi-rigidly attached to
insert 1102. In this case, this extended portion 1124 now provides
sufficient alignment between the two components. Alignment fixture
1108 may be removed at this point as shown during stage 1130.
[0062] Process 900 may proceed with forming a connector body in
operation 906. In certain embodiments, a connector body or some
parts of it comes in direct contact with electrical components of
the BIP module (e.g., conductive elements of the connector member
or bus bars extending outside of the insert). In these embodiments,
a connector body may be formed using one or more temperature
resistant materials. Some examples of rigid materials with suitable
thermal characteristics are provided above. In specific
embodiments, a temperature resistant material has an RTI of at
least about 115.degree. C. or, more particularly, an RTI of at
least about 125.degree. C. or even at RTI of at least about
135.degree. C. The temperature resistant material may include one
or more of the following additives: mineral fillers, glass fillers,
and flame retardants.
[0063] In other embodiments, a connector body formed in operation
906 does not directly contact electrical components of the BIP
module and temperature resistant materials may not be needed to
form the connector body. For example, a connector member provided
in operation 902 may include an insulating housing that encloses
all electrical components extending outside of the photovoltaic
insert (e.g., enclosing its own conductive elements and providing
extensions tabs for bus wires extending outside of the insert). In
these embodiments, a connector body may be made from polyethylene,
polypropylene, thermoplastic rubber, thermoplastic elastomer, and
ethylene propylene diene monomer. A connector body is typically
formed using injection molding or other suitable techniques.
[0064] In certain embodiments, a connector body formed in operation
902 may be insufficient to provide electrical insulation and/or
mechanical support. In such situations, process 900 involves
operation 908 during which an overmold is formed over a portion of
the connector body and, in certain embodiments, a portion of the
insert. Operation 908 is optional because a connector body may be
sufficient for the above recited purposed without a separate
overmold. It should be noted that regardless of an overmold, a
connector body may include a temperature resistant materials (e.g.,
provided as a part of prefabricated insulating housing and/or
deposited during operation 904) and, in certain embodiments, other
material (e.g., deposited during operation 904 and/or deposited
during operation 906). Three specific examples are described below
in the context of FIGS. 10A-10C.
[0065] Forming overmold in operation 908 may involve injection
molding or any other technique. Examples of materials that can be
used for an overmold include polyethylene, polypropylene,
thermoplastic rubber, thermoplastic elastomer, ethylene propylene
diene monomer (EPDM), various fluoroelastomers or thermoplastic
vulcanizates (TPV), and flexible cast thermoset materials such as
urethanes. In general, flexible thermoplastic elastomers that have
suitable thermally durable behavior may be used. Some examples are
provided above. An overmold generally extends over at least a
portion of the photovoltaic module insert and a portion of the
connector body.
[0066] Process 900 may continue with forming one or more seals
around various cavities' openings in a connector body in operation
908. Various seal examples are described above in the context of
FIGS. 8A-8C. Seals may be formed by injection molding or other
suitable techniques. In certain embodiments, a seal may be
fabricated in a separate process and inserted into the connector
body during operation 908. For example, a seal may be an O-ring or
more specifically a butyl rubber O-ring or flat ring.
Electrical Connector Examples
[0067] FIG. 10A is a schematic representation of one example of a
BIP module 1000 in accordance with certain embodiments. Some
components of this assembly are similar to an assembly described
above in the context of FIG. 8A. Specifically, BIP module 1000
includes one or more photovoltaic cells 802 sealed by one or more
sealing sheets 804. BIP module 1000 also includes one or more bus
bars 806 extending outside of sealing sheets 804 and making an
electrical connection with connector element 808. The connector
also has a connector body 1002 that electrically insulates and
mechanically supports conductive element 808 with respect to
sealing sheets 804 or more generally, an entire insert 1002. Since
connector body 1002 is in direct contact with conductive element
808 and bus bar 806, it is made from one or more temperature
resistant materials, such as a RTI rated materials listed above.
BIP module 1000 also includes a seal 812 positioned around the
opening of connector body for protecting connector element 808 from
contaminants after establishing a connection with another
connector. As shown in FIG. 10A, there is no additional overmold
positioned around connector body 1002. Connector body 1002 provides
sufficient mechanical support and electrical insulation in this
example.
[0068] However, making a complete connector out of RTI rated
materials may be prohibitively expensive and/or may not provide
certain characteristics, such as UV stability, mechanical support,
and electrical insulation. In certain embodiments, a connector may
include an inner component made from one or more temperature
resistant materials, such as RTI rated materials, and an outer
portion made from some other materials. The inner portion contacts
electrical components of the module (e.g., bus bars and conductive
elements) and may be configured to fully enclose these components
and prevent any contacts with an outer portion of the connector
made from other materials. The inner portion may come as a
prefabricated insulating housing (e.g., with flap extensions) or
formed completely or partially during one or more injection molding
operations during the overall BIP module fabrication process
described above. For example, a prefabricated insulating housing
may only cover some electrical components (e.g., conductive
elements of the connector), while other (e.g., bus bars) may extend
outside of the housing. A separate operation may be used to apply
one or more temperature resistant materials around the remaining
exposed electrical components before forming the remainder of the
connector body from other non-temperature resistant materials.
[0069] FIG. 10B is a schematic representation of another example of
a BIP module 1010 having a connector made from a prefabricated
insulating housing 1012 and an overmold 1016 formed around housing
1012 in accordance with certain embodiments. Insulating housing
1012 is shown with extension flaps 1014 that insulate a portion of
bus bar 806 extending from sealing sheets 804. Insulating housing
1012 may be partially or fully covered with overmold 1016. Overmold
1016 also extends over at least a portion of the insert 1002.
[0070] FIG. 10C is a schematic representation of yet another
example of a BIP module 1020 having an inner portion 1022 of the
connector made from a temperature resistant material and an outer
portion 1026 of the connector made from a different material in
accordance with certain embodiments. Inner portion 1022 may be
configured to insulate both conductive element 808 and bus bar 806.
In certain embodiments, inner portion 1022 may cover a portion of
the photovoltaic insert 1002 as, for example, shown in FIG. 10C.
Inner portion 1022 is made from one or more temperature resistant
materials described above. Outer portion 1026 is made from other
generally less expensive materials that have different functional
characteristics (e.g., high UV stability).
CONCLUSION
[0071] Although the foregoing invention has been described in some
detail for purposes of clarity of understanding, it will be
apparent that certain changes and modifications may be practiced
within the scope of the appended claims. It should be noted that
there are many alternative ways of implementing the processes,
systems and apparatus of the present invention. Accordingly, the
present embodiments are to be considered as illustrative and not
restrictive, and the invention is not to be limited to the details
given herein.
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