U.S. patent application number 11/776272 was filed with the patent office on 2007-12-27 for pv module mounting and support assembly and installation.
This patent application is currently assigned to SunPower Corporation. Invention is credited to Kurt M. Johnson, Carl J. S. Lenox.
Application Number | 20070295391 11/776272 |
Document ID | / |
Family ID | 38475777 |
Filed Date | 2007-12-27 |
United States Patent
Application |
20070295391 |
Kind Code |
A1 |
Lenox; Carl J. S. ; et
al. |
December 27, 2007 |
PV Module Mounting and Support Assembly and Installation
Abstract
In some examples a PV module mounting and support assembly
includes a base mountable to the deck, a deck-penetrating fastener
for securing the base to the deck, and PV module mounting hardware.
The PV module mounting hardware is used to secure an edge of a PV
module on a PV module-support surface of the base with the edge of
the PV module spaced apart from the deck. Flashing may be used
between the lower surface and the deck. In some examples an
internal PV mounting and support assembly is used to engage an
internal lip of the PV module frame.
Inventors: |
Lenox; Carl J. S.; (Oakland,
CA) ; Johnson; Kurt M.; (Richmond, CA) |
Correspondence
Address: |
SunPower Corporation c/o;Haynes Beffel & Wolfeld LLP
P.O. Box 366
Half Moon Bay
CA
94019
US
|
Assignee: |
SunPower Corporation
San Jose
CA
|
Family ID: |
38475777 |
Appl. No.: |
11/776272 |
Filed: |
July 11, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11681972 |
Mar 5, 2007 |
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11776272 |
Jul 11, 2007 |
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60821869 |
Aug 9, 2006 |
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60780819 |
Mar 9, 2006 |
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Current U.S.
Class: |
136/251 |
Current CPC
Class: |
F24S 2025/021 20180501;
Y02E 10/47 20130101; Y02B 10/10 20130101; F24S 25/636 20180501;
Y02E 10/50 20130101; H02S 20/23 20141201; H01R 4/64 20130101; F24S
25/634 20180501; F24S 25/61 20180501; F24S 25/20 20180501; F24S
2025/6008 20180501; Y10T 24/44 20150115 |
Class at
Publication: |
136/251 |
International
Class: |
H02N 6/00 20060101
H02N006/00 |
Goverment Interests
STATE SPONSORED RESEARCH OR DEVELOPMENT
[0002] This invention was made with State of California support
under California Commission Agreement Number 500-04-022. The Energy
Commission has certain rights to this invention.
Claims
1. A PV module mounting and support assembly, for use on a support
structure of the type having a deck on which PV modules are to be
mounted, comprising: a base, having a lower surface, mountable to a
deck; a deck-penetrating fastener engageable with the base and
extendable into the deck so to secure the base to the deck, the
lower surface facing the deck; the base comprising a PV
module-support surface; and PV module mounting hardware securable
to the base, the PV module mounting hardware comprising a retaining
element, whereby an edge of a PV module can be positioned on top of
and be supported by the PV module-support surface with the edge of
the PV module spaced apart from the deck and captured between the
PV module-support surface and the retaining element.
2. The assembly according to claim 1 wherein the elongated fastener
comprises a threaded fastener.
3. The assembly according to claim 1 wherein the deck-penetrating
fastener comprises a self-tapping screw.
4. The assembly according to claim 1 wherein the PV mounting
hardware comprises an upwardly extending, elongated fastener.
5. The assembly according to claim 4 wherein the retaining element
comprises a mounting clip securable to the base with the elongated
fastener.
6. The assembly according to claim 5 wherein the retaining element
is placeable against and separable from an edge of a PV module.
7. The assembly according to claim 4 wherein the base comprises
first and second raised portions on opposite sides of the elongated
fastener, the first and second raised portions engageable with the
same PV module.
8. The assembly according to claim 4 wherein the PV module-support
surface comprises first and second PV module-support surfaces,
whereby adjacent edges of adjacent PV modules can be positioned on
top of and be supported by the first and second PV module-support
surfaces with the elongated fastener extending between said
adjacent edges.
9. The assembly according to claim 1 further comprising a deck hole
sealing element associated with the fastener.
10. The assembly according to claim 9 wherein the deck hole sealing
element comprises a sealing layer between the base and the lower
surface.
11. The assembly according to claim 1 wherein the deck-penetrating
fastener comprises a plurality of screws and the base comprises a
plurality of holes through which the screws pass.
12. The assembly according to claim 1 further comprising flashing
positionable between the lower surface and the deck.
13. A PV module installation comprising: a support structure of the
type having a deck; a PV module having a peripheral edge, the
peripheral edge having upper and lower peripheral edge surfaces; a
plurality of PV mounting and support assemblies positioned along
the peripheral edge and securing the PV module to the deck, each PV
mounting and support assembly comprising: a base having a lower
base surface; a deck-penetrating fastener engaging the base and
extending into the deck so to secure the base to the deck, the
lower base surface facing the deck; the base comprising a PV
module-support surface extending beneath and supporting the lower
peripheral edge surface; the PV module-support surface located a
chosen distance above the lower base surface; and PV module
mounting hardware secured to the base, the PV module mounting
hardware comprising a retaining element contacting the peripheral
edge of the PV module so to secure the PV module to the deck with
the peripheral edge of the PV module spaced apart from the
deck.
14. The installation according to claim 13 wherein the retaining
element contacts the upper peripheral edge surface of the PV
module.
15. The installation according to claim 13 wherein the retaining
element is placeable against and separable from the peripheral
edge.
16. The installation according to claim 13 wherein the support
structure comprises spaced-apart deck support elements beneath the
deck, the positions of the bases being independent of the positions
of the deck support elements.
17. The installation according to claim 13 wherein the PV module
comprises first and second PV modules having adjacent peripheral
edge portions positioned adjacent to one another.
18. The installation according to claim 17 wherein the PV mounting
hardware comprises an upwardly extending, elongated fastener.
19. The installation according to claim 18 wherein the retaining
element comprises a mounting clip secured to the base and biased
against the upper peripheral edge surface by the elongated
fastener.
20. The installation according to claim 18 wherein the PV
module-support surface of at least one of the PV mounting and
support assemblies comprises first and second PV module-support
surfaces located beneath the adjacent peripheral edge portions with
the elongated fastener extending therebetween.
21. The installation according to claim 13 wherein the support
structure comprises upper and lower rows of shingles mounted on the
deck, and further comprising: flashing having upper and lower
flashing surfaces and upper and lower flashing edges, the flashing
supported on the lower row of shingles with the upper flashing edge
positioned beneath the upper row of shingles, and wherein: the base
is mounted on the flashing.
22. The installation according to claim 13 wherein the PV module
comprises a frame along the peripheral edge.
23. The installation according to claim 22 wherein the frame is an
electrically conductive frame and the retaining element makes
electrical contact with the electrically conductive frame.
24. The installation according to claim 13 wherein the PV module is
at least substantially frameless at the peripheral edge and the
retaining element comprises a surface-cushioning member to reduce
localized stresses in the PV module.
25. A PV module installation comprising: a support structure of the
type having a deck; a PV module comprising a PV panel, having a
peripheral edge, and a peripheral frame extending about at least
part of the peripheral edge, the peripheral frame having upper and
lower peripheral surfaces; the PV panel mounted at or towards the
upper peripheral surface; the peripheral frame comprising an
internal lip extending to a position spaced apart from and below
the PV panel; an internal PV mounting and support assembly
positioned along the peripheral edge and securing the PV module to
the deck, the PV mounting and support assembly comprising: a base
having a lower base surface; a deck-penetrating fastener engaging
the base and extending into the deck so to secure the base to the
deck, the lower base surface facing the deck; the base comprising a
PV module-support surface extending beneath and supporting the
lower peripheral edge surface; the PV module-support surface
located a chosen distance above the lower base surface; and PV
module mounting hardware secured to the base, the PV module
mounting hardware comprising a retaining element capturing the
internal lip between the retaining element and the module support
surface so to help secure the PV module to the deck with the
peripheral edge of the PV module spaced apart from the deck.
26. The installation according to claim 25 wherein the retaining
element comprises a mounting clip secured to the base to define a
gap between the mounting clip and the module support surface, the
gap sized to permit the internal lip to slide into and out of the
gap.
Description
CROSS-REFERENCE TO OTHER APPLICATIONS
[0001] This application claims the benefit of provisional patent
application No. 60/821,869 filed 9 Aug. 2006, Attorney Docket
number PWRL 1045-1. This application is also a continuation in part
of U.S. patent application Ser. No. 11/681,972 filed 5 Mar. 2007,
Attorney Docket number PWRL 1044-2, which application claims the
benefit of provisional patent application No. 60/780,819 filed on 9
Mar. 2006, attorney docket number PWRL 1044-1 and provisional
patent application No. 60/821,869 filed on 9 Aug. 2006, attorney
docket number PWRL 1045-1, the disclosures of which are
incorporated by reference. This application is related to U.S.
patent application Ser. No. ______ filed on the same day as this
application, entitled PV Module Mounting Method and Mounting
Assembly, attorney docket PWRL 1045-3.
BACKGROUND OF THE INVENTION
[0003] A typical method of securing PV modules to roofs using a
wood deck is with a rack system including vertical stanchions and
lateral rails. The vertical stanchions are often lag bolted into
joists, which are typically on 24'' (61 cm) centers. Conical
flashings, similar to the type used for ventilation pipes, are used
to waterproof these penetrations. In some cases flashings are not
used and "L" brackets or other mounting hardware is lag bolted
directly through the roofing material, with the penetration caulked
with sealant. Then lateral rails are attached to the stanchions,
typically several inches off the roof to allow clearance for the
flashings. PV modules are then attached to the rails. Reasons for
using the vertical stanchions and a lateral rails approach include:
PV modules are not typically designed in convenient widths relative
to joist spacing, not all PV modules have geometries amenable to
direct-deck mounting, and the racks are designed to accommodate
generally any PV module. In most cases framed PV modules are
mounted in this manner but methods to mount unframed PV modules to
racks do exist.
[0004] In another method for securing PV modules to roofs, the PV
modules are typically lag bolted into blocking members installed
between rafters in the attic; other mounting hardware can also be
used. Relatively large holes must often be pre-drilled through the
roofing material to accommodate the mounting hardware. Because of
the size of these larger holes and the configuration of the module,
it is often difficult to tell if adequate waterproofing has been
achieved. If blocking is used, the process of installing blocking
involves extensive work in the attic which adds significantly to
installation time.
[0005] A further method for securing PV modules to roofs uses a
hold down device that can only be used with specially constructed
PV modules having complementary hold down structure, such as
laterally extending hold down pins.
BRIEF SUMMARY OF THE INVENTION
[0006] An example of a PV module mounting and support assembly, for
use on a support structure of the type having a deck on which PV
modules are to be mounted, includes a base, a deck-penetrating
fastener and PV module mounting hardware. The base has a lower
surface mountable to the deck. The deck-penetrating fastener, such
as a self-tapping screw, is engageable with the base and extendable
into the deck so to secure the base to the deck with the lower
surface facing the deck. The base also comprises a PV
module-support surface. The PV module mounting hardware is
securable to the base. The PV module mounting hardware comprises a
retaining element. An edge of a PV module can be positioned on top
of and be supported by the PV module-support surface with the edge
of the PV module spaced apart from the deck and captured between
the PV module-support surface and the retaining element. In some
examples flashing is used between the lower surface and the
deck.
[0007] A first example of a PV module installation comprises a
support structure of the type having a deck, a PV module and a
plurality of PV mounting and support assemblies. The PV module has
a peripheral edge, the peripheral edge having upper and lower
peripheral edge surfaces. The PV mounting and support assemblies
are positioned along the peripheral edge and secure the PV module
to the deck. Each PV mounting and support assembly comprises a
base, a deck-penetrating fastener and PV module mounting hardware.
The base has a lower base surface. The deck-penetrating fastener
engages the base and extends into the deck so to secure the base to
the deck with the lower base surface facing the deck. The base
comprises a PV module-support surface extending beneath and
supporting the lower peripheral edge surface. The PV module-support
surface is located a chosen distance above the lower base surface.
The PV module mounting hardware is secured to the base and
comprises a retaining element contacting the upper peripheral edge
surface of the PV module so to secure the PV module to the deck
with the peripheral edge of the PV module spaced apart from the
deck. The PV module may comprise first and second PV modules having
adjacent peripheral edge portions positioned adjacent to one
another. In some examples the support structure comprises upper and
lower rows of shingles mounted on the deck, with flashing on the
shingles. The flashing has upper and lower flashing surfaces and
upper and lower flashing edges, the flashing supported on the lower
row of shingles with the upper flashing edge positioned beneath the
upper row of shingles; the base is mounted on the flashing.
[0008] A second example of a PV module installation comprises a
support structure, a PV module, and an internal PV mounting and
support assembly. The support structure comprises a deck. The PV
module comprises a PV panel, having a peripheral edge, and a
peripheral frame extending about at least part around the
peripheral edge. The peripheral frame has upper and lower
peripheral surfaces. The PV panel is mounted at or towards the
upper peripheral surface. The peripheral frame comprises an
internal lip extending to a position spaced apart from and below
the PV panel. The internal PV mounting and support assembly is
positioned along the peripheral edge and secures the PV module to
the deck. The PV mounting and support assembly comprises the
following. A deck-penetrating fastener engages the base and extends
into the deck so to secure the base to the deck with a lower base
surface facing the deck. The base comprises a PV module-support
surface extending beneath and supporting the lower peripheral edge
surface. The PV module-support surface is located a chosen distance
above the lower base surface. PV module mounting hardware is
secured to the base and comprises a retaining element capturing the
internal lip between the retaining element and the module support
surface so to help secure the PV module to the deck with the
peripheral edge of the PV module spaced apart from the deck. In
some examples the retaining element comprises a mounting clip
secured to the base to define a gap between the mounting clip and
the module support surface, the gap sized to permit the internal
lip to slide into and out of the gap.
[0009] An advantage of the invention is that it is suitable for use
with a number of different conventionally designed PV modules. The
PV modules do not need any special hold down or attachment
structures for use with various examples of this invention. In
addition, the size of the modules does not depend on the spacing of
the joists or other structure supporting the deck. Installation
typically does not require access to an attic area for installation
of blocking (which is not needed) or inspections. Some examples of
the invention significantly reduce part count over conventional
mounting systems, for example by eliminating the need for mounting
rails, which reduces cost and installation complexity. In addition,
some examples help to significantly reduce installation time, which
also reduces cost. Additionally, some examples allow very low
profile securement of the PV modules to the roof or other support
structure. In some examples the PV modules can be mounted nearly
flush to the support structure, consistent with proper airflow for
cooling, which improves the aesthetics significantly. The region
beneath the PV module can typically be fluidly coupled to the
region above the module. Wind tunnel tests may be carried out to
determine the parameters that would result in, for example,
pressure equalization between the upper and lower surfaces, thus
providing for reduced loads on the PV modules under different wind
conditions. Wind loading on photovoltaic modules is discussed in
more detail in U.S. patent application Ser. No. 10/922,117 filed
Aug. 19, 2004 and entitled PV Wind Performance Enhancing Methods
and Apparatus, US Patent Publication Number US-2005-0126621-A1
published Jun. 16, 2005. In some examples the mounting structure
can incorporate both a hold down (mounting) function and an
electrical grounding function to substantially eliminate the need
for additional grounding structure. Some examples of the PV
mounting and support assemblies permit adjacent PV modules to be
placed relatively close to one another. This not only improves
aesthetics but also increases the energy output for a given area of
the roof or other support structure. By positioning
deck-penetrating fasteners beneath the PV modules, uplift forces
are essentially tension only; this is in contrast with some
conventional PV module hold down structures in which the
deck-penetrating fasteners are laterally offset from the PV modules
resulting in both tension and bending forces on the fasteners.
[0010] Other features, aspects and advantages of the present
invention can be seen on review of the figures, the detailed
description, and the claims which follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is an exploded isometric view of a PV mounting and
support assembly with only a single deck-penetrating fastener shown
for clarity;
[0012] FIG. 2 is an assembled isometric view of the assembly of
FIG. 1;
[0013] FIG. 3 is an enlarged partial side view of the clip of FIG.
1;
[0014] FIG. 4 is an enlarged cross-sectional view of the assembly
of FIG. 2 shown securing adjacent PV assemblies to the deck of a
support structure;
[0015] FIG. 5 is a simplified overall view of two adjacent PV
assemblies secured to one another using the assembly FIGS. 1-4;
[0016] FIG. 6 is a view similar to that of FIG. 5 shown using
surface-cushioning members engaging frameless PV modules;
[0017] FIG. 7 shows a layout tool used to properly position the
assemblies of FIG. 2 on the support structure;
[0018] FIG. 8 illustrates the layout tool of FIG. 7 positioning two
of the assemblies of FIG. 2 and one of the internal PV mounting and
support assemblies of FIGS. 12-14;
[0019] FIG. 9 is a partially exploded isometric view of flashing
and the assembly of FIGS. 1 and 2 above a shingled support
structure;
[0020] FIG. 10 shows the structure of FIG. 9 with the PV mounting
and support assembly secured to the flashing, the flashing
supported on a lower row of shingles and extending beneath an upper
row shingles;
[0021] FIG. 11 shows the assembly of FIGS. 1 and 2 used at the
periphery of a PV array with a spacer;
[0022] FIGS. 12 and 13 are exploded isometric and isometric views
of an internal PV mounting and support assembly;
[0023] FIG. 14 is a cross-sectional view showing the assembly of
FIG. 13 secured to the internal lip of the frame of a PV
assembly;
[0024] FIG. 15 is an isometric view of an example of a PV mounting
assembly; and
[0025] FIG. 16 is an exploded isometric view of an example of a
peripheral PV mounting assembly using a standoff between the clip
and the base body.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The following description will typically be with reference
to specific structural embodiments and methods. It is to be
understood that there is no intention to limit the invention to the
specifically disclosed embodiments and methods but that the
invention may be practiced using other features, elements, methods
and embodiments. Preferred embodiments are described to illustrate
the present invention, not to limit its scope, which is defined by
the claims. Those of ordinary skill in the art will recognize a
variety of equivalent variations on the description that follows.
Like elements in various embodiments are commonly referred to with
like reference numerals.
[0027] FIG. 1 is an exploded isometric view of one example of a PV
mounting and support assembly 2 made according to the invention.
Assembly 2 includes a clip assembly 10 and a base 14. Clip assembly
10 includes a clip 12 secured to base 14 by a bolt 16. Base 14
includes a base body 18, typically of extruded aluminum or some
other appropriate material, and a sealant 20 secured to the lower
surface 22 of base body 18. Sealant 20 is typically in the form of
a butyl tape about 3 mm thick. Base body 18 has a pair of raised
portions 24 defining a gap 26 therebetween. Gap 26 extends down to
a central region 28 of base body 18, central region 28 having a
threaded hole 30 formed therein for receipt of bolt 16 Central
region 28 may include one or more clearance holes for additional
screws 35. Base body 18 also has a pair of flanges 32 having a
number of mounting holes 34 used to secure base 14 to the deck 31
of a support structure 33, such as a roof, with deck-penetrating
fastener 35. See FIG. 4. Bolt 16 passes through a central opening
36 in clip 12, through a hole 38 formed in a spacer 40, through gap
26, and into a threaded hole 30. Other types and configurations for
base body 18, such as a solid block without a gap 26 or flanges 34,
may also be used.
[0028] FIGS. 4 and 5 show clip assemblies 10 securing adjacent PV
modules 50, also called PV assemblies 50, to base body 18. Clip
assemblies 10 are shown engaging adjacent PV assemblies 50 with
screws 16 in the gap 58 between the PV assemblies. Assemblies 2 are
commonly referred to as interior assemblies when used between
adjacent PV assemblies. PV assemblies 50 include a peripheral frame
52 supporting a PV panel 54. Frame 52 includes a lower peripheral
edge surface 60 which is biased against the PV module support
surface 62 of the base body 18 by virtue of clip 12 pressing
against the upper peripheral edge surface 64 of frame 52. The
distance 65 between support surface 62 and a lower base surface 67
of base 14 is typically chosen by the desired distance between
lower peripheral edge surface 60 and support structure 33. Support
structure 33 typically includes deck 31 covered by a weather
barrier layer 66.
[0029] In one embodiment deck-penetrating fasteners 35 are
typically self tapping screws 35 between the size of #8 and #14
(M4-M6), and of sufficient length to fully engage with deck 31 and
create penetrations or holes 68 therein. Deck 31 is typically
15/32'' (12 mm) thick oriented strand boards (OSB) or 1/2'' (12 mm)
thick plywood or similar materials, on which shingles or other
materials to create weather barrier layer 66 are mounted, formed or
applied. It is preferably that holes 34 be situated on flange 32
such that the head of each screw 35 does not protrude above the top
surface of flanges 32. In one embodiment weatherproofed screws with
sealing washers beneath the head are used in addition to sealant
20. In some embodiments sealant 20 may be eliminated when other
means for sealing the holes in deck 31 are used, such as a liquid
sealant. In some embodiments screw 16 is a 1/4''-20 (M6) stainless
steel screw. A variety of clip or clamp devices, in addition to
those described herein, may be used to secure PV assembly 50 to
base 14.
[0030] PV assembly 50 has a structural frame 52, but may be an
unframed PV laminate, or may be framed in a material that provides
only protection of the edge of the PV laminate without significant
structural function. This material may be nonconductive. An example
of a frameless PV module 50 is shown in FIG. 6. PV mounting and
support assembly 2 of FIG. 6 differs from assembly 2 of FIGS. 1-5
primarily by the use of surface-cushioning members 70 between clips
12 and upper peripheral edge surface 64 of PV assembly 50. Such a
surface-cushioning member could be supplemented by or replaced by a
force-distributing plate or strip which may be secured to clip 12
or PV assembly 50 or simply located between the two.
[0031] Clip 12 is a generally U-shaped structure having a central
portion 42, through which central opening 36 is formed, and a pair
of upstanding arms 44. Arms 44 and central portion 42 define an
access region 45. Access region 45 is accessible from above to
provide clear access to screw 16 thus facilitating the use of clip
assembly 10. Arms 44 include extensions 46 having downwardly
extending teeth 48. As shown in FIG. 3, clip assembly 10 is used
with PV assemblies 50 of the type having electrically conductive
frames 52 surrounding PV panels 54. As can be seen in FIGS. 2 and
3, the head of screw 16 is located completely within access region
45 and is located below the top surface of frame 52 of PV assembly
50. In addition, the generally T-shaped configuration of arms 44
with downwardly facing teeth 48 provide for a low profile
structure. This low profile structure creates a cleaner, less
cluttered appearance and also minimizes shading of PV panel 54.
[0032] Frames 52 have an upper, circumferentially extending edge 56
which are engaged by teeth 48 of clip 12. Frame 52 is typically
anodized aluminum and thus has a non-conductive outer surface.
Frame 52 may also have other types of non-conductive outer
surfaces, such as a painted outer surface. To ensure good
electrical contact between clip 12 and frame 52, teeth 48 act as
surface-disrupting elements. The serrated teeth or other structure
cuts through any nonconductive material on frame 52 thereby
creating a positive electrical connection with clip 12, and via
screw 16, to base 14. This helps to ensure good grounding between
frames 52 of adjacent PV assemblies 50 through clip 12. Other
surface-disrupting methods could also be used, such as causing clip
12 to slide against and score a portion of frame 52 or through the
use of other types of surface-disrupting structures or
procedures.
[0033] In the example of FIGS. 1-5, three teeth 48 are used at each
extension 46 of arms 44. The use of a number of points 44 at each
extension 46 allows some adjustment in the position of clip 12
relative to frame 52, thus facilitating installation. Teeth 48 are
oriented to be generally parallel to a line connecting extensions
46 of each arm 44 and thus generally perpendicular to the adjacent
frame 52.
[0034] Arms 44 are preferably not perpendicular to central portion
42. In the disclosed example, arms 44 extend inwardly over central
portion 42 to define an included angle 53, see FIG. 3. Included
angle 53 is an acute angle and typically ranges from 80-88.degree.,
and is about 83.degree. in the disclosed example. This helps to
strengthen clip 12 because arms 44 will tend to straighten out
under load. Another advantage with the angulation of arms 44 is
that doing so results in more of a point contact by teeth 48 with
frame 52. This can be for two primary reasons. The first reason is
that teeth 48, for practical purposes, do not narrow down to a true
point but rather to a line or edge, the length of which is as long
as clip 12 is thick. Therefore, by angling arms 44, the ends of
teeth 48 first engage frame 52 to provide more of a point contact
than a line contact. The second reason is based upon the fact that
manufacturing constraints limit how sharp of an edge teeth 48 will
exhibit. In some examples, teeth 48 will exhibit a rounded edge so
that if arms 44 were perpendicular to central portion 42, teeth 48
would provide a generally cylindrical surface against frame 52.
[0035] Clip 12 also secures frame 52 to base 14 by capturing the
frame between arms 44 of clip 12 and support surface 62 of raised
portions 24 of base body 18. Spacer 40, as suggested in FIG. 3,
helps to ensure adjacent PV assemblies 50 are located in a proper
distance from one another. Spacer 40 is typically made of rubber or
some other material including, for example, metal or cardboard,
sized to be larger than the width of central portion 42,
illustrated in FIG. 3. The size of spacer 40 is chosen so that when
PV assemblies 50 expand during hot weather, or otherwise, PV
assemblies 50 have room to expand before contacting clip 12. This
helps to prevent damage to PV panels 54, which could occur if PV
assemblies 50 were to press directly against clip 12 during such
thermal expansion. The use of spacer 40 simplifies installation and
by eliminating the need to use a special tool to ensure proper
spacing of PV assemblies during installation. Although the primary
grounding created by clip 12 is from frame 52 of one PV assembly 50
to frame 52 of an adjacent PV assembly, clip assembly 10 can also
be used to provide grounding between PV assembly frames 52 and base
14. Although not presently preferred because it may require a
specially designed frame 52, in some examples clip 12 may be
attached to or an integral portion of frame 52.
[0036] Assemblies 2 are typically secured to deck 31 of support
structure 33 based upon a layout pattern for PV assemblies 50.
After the layout pattern has been chosen, assemblies 2 are located
at selected locations according to the layout pattern so that the
assemblies are properly positioned to engage the edges of one or
more PV assemblies 50. Although this could be carried out using PV
assemblies 50 as a positioning fixture, it is preferably carried
out with the aid of a layout tool, such as layout tool 72 shown in
FIGS. 7 and 8. Layout tool 72 has appropriately located openings 74
size to properly position assemblies 2, see FIG. 8, at appropriate
orientations and spacing. Layout tool 72 helps to accurately
position assemblies 2 in two axes. In some examples layout tools
may be used to locate guide holes or mounting holes for the proper
location of assemblies 2.
[0037] FIGS. 9 and 10 illustrate mounting PV mounting and support
assembly 2 on top of a shingled support structure 76 with flashing
78 between assembly 2 and shingled support structure 76. Flashing
78 has upper and lower edges 79, 80 with upper edge 79 extending
beneath an upper row 81 of shingles and lower edge 80 extending
past the lower edge 83 of a lower row 82 of shingles. Flashing 78
is used to waterproof penetrations 68 into deck 31. The use of
flashing 78 in this manner is advantageous because it provides a
smooth and consistent surface for the typically elastomeric sealing
material of sealant 20 to seal against. Because flashing 78 covers
a relatively large area, 1 square foot (929 cm.sup.2) in one
example, and is fastened tightly to the support structure 33, it
discourages water infiltration to the area of penetrations 68,
especially by wind-driven rain, and facilitates the shedding of
water downwardly. Flashing 78 may be used in conjunction with
liquid-applied roofing sealants to further protect penetrations 68
from any water infiltration. Flashing 78 may not be needed when the
water shedding layer of support structure 33 is of a type, such as
a metal roof, that waterproofing the deck screw penetrations can be
made without the use of flashing. For example, with metal roofs
sealant 20 may provide sufficient waterproofing. With an asphalt or
composition shingle roof, base body 18 may be mounted directly to
the shingled weather barrier layer 66 with penetrations 68 sealed
using an appropriate sealing composition, alone or in combination
with sealant 20, between the base plate and the shingle surface. In
one example flashing 78 is galvanized or Galvalume coated steel.
Flashing 78 may be any suitable sheet metal material or fabricated
from plastic, composite or elastomeric materials. Flashings 78 may
be pre-attached to base 14 rather than field-installed. In some
examples shims, not shown, may be used to correct for undulations
in support structure 33 so that the PV assemblies 50 remain
generally coplanar.
[0038] Clip assembly 10 of FIGS. 1 and 2 can be used at the
periphery by using, for example, a spacer 100 located between the
otherwise unused extensions 46 of clip 12, see FIG. 11, and the
base 14. Spacer 100 is used to ensure that the force exerted by
clip 12 is straight down on PV assembly 50 and to keep clip 12
properly engaged with the PV assembly. Spacer 100 has a periphery
102 configured to accommodate frames 52 having different heights.
Other types of variable-height of spacers, including threaded,
telescoping spacers and spacers consisting of stacks of individual
spacer elements, can also be used.
[0039] FIGS. 12-14 illustrate an internal photovoltaic mounting and
support assembly 104 including an internal clip assembly 106
designed as a modification of clip assembly 10 of FIGS. 1 and 2.
Clip assembly 106 includes a clip 108 and pieces of electrically
insulating adhesive-backed tape 110, 112. Tape 110 is secured to
raised portions 24 of base body 18 to cover support surface 62.
Tape 112 is adhered to clip 108 as shown in FIGS. 12 and 13 to lie
above gap 26. A gap 113 is formed between clip 108 and support
surface 62. Screw 16 is tightened onto base body 18 and then PV
assembly 50 is secured to clip assembly 106 by sliding an internal
lip 116 of frame 52 into gap 113 between clip 108 and base body 18
and between insulating tape 110, 112. This is possible because of
the open region 118 defined by PV panel 54 and peripheral frame 52.
Tape 110, 112 helps to ensure the snug engagement of lip 116
between clip 108 and base body 18 and also helps to reduce marring
of the surface of lip 116. The size of gap 113, the thickness of
internal lip 116, and the thickness and physical characteristics of
tape 110, 112 are chosen to permit the internal lip to slide into
and out of gap 113 while snugly engaging the internal lip.
[0040] In this example internal PV mounting and support assembly
104 acts to secure PV assembly 50 in place but does not necessarily
provide a grounding function. In other examples internal clip
assembly 106 could be configured to provide a grounding function as
well as a mounting function by, for example, causing a spike to
pierce the surface of lip 116 when the lip is inserted between clip
108 and base body 18. Although tape 110, 112 is in this example
electrically insulating, it need not be.
[0041] Internal PV mounting and support assembly 104 may be used in
conjunction with PV mounting and support assembly 2 to secure one
edge of PV assembly 50 to support structure 33 in less time than if
all edges were secured to the support structure using assemblies 2.
The positioning of two assemblies 2 and one assembly 104 is shown
in FIG. 8.
[0042] FIG. 15 illustrates a PV mounting assembly 120 typically
used with the flashing 78 of FIGS. 9 and 10. Assembly 120 includes
a base body 122 that does not have a PV module support surface 62
as do the above-described examples. Rather, separate structure is
used to raise PV assemblies 50 above support structure 33 if it is
desired to do so. An appropriate sealing mechanism, such as sealant
20, is used with or as a part of assembly 120. FIG. 16 illustrates
a peripheral PV mounting assembly 124 similar to that of FIG. 15
but including a peripheral mounting clip 126 having arms 44
extending to one side only. In addition, assembly 120 of FIG. 16
uses a standoff 128 between clip 126 and base body 122 to provide
stability for assembly 121 when clip 126 is secured against a
peripheral edge of a PV assembly 50.
[0043] The size of PV modules 50 that can be supported using PV
support and mounting assemblies 2, 104 and PV mounting assemblies
120, 124 is dependent on the expected wind speed and exposure
conditions as well as the construction of the underlying support
structure. The disclosed examples can typically be used with PV
modules 50 having a plan area of up to, for example, about 18 sq ft
(1.67 m.sup.2) for roofs and other support structures 33
constructed using conventional techniques. PV modules having larger
plan areas may be accommodated but in some cases may require an
adjustment of conventional construction practices and strengthening
of the various mounting components.
[0044] Other contemplated implementations of this invention include
the use screws made from other materials, or fasteners other than
screws to secure base 14 to support structure 33. Countersunk
fasteners can be used to avoid interference between frame 52 and
the fasteners. Instead of a screw 16 engaging threaded hole 30, a
different type of fastening device, such as a threaded stud,
friction based connection, bayonet or twist-lock connection,
push-on connector, ratchet fastener, or other similar device may be
used. Instead of a butyl tape type of sealant 20, other materials
for sealant 20 can be used; examples include an adhered rubber
foot, a mechanically fastened rubber foot, foam tape, spray foam,
butyl tape, cork, liquid adhesive or sealant, and a gasket. Base
body 18 may be made by a variety of methods, including casting,
molding, or machining and may be made from any suitable metal,
plastic, composite, wood, or elastomeric material. In some examples
base 14 may be integrated directly into the PV module 50 so that
the bases and modules ship to site and are installed as a unit. In
some examples base 14 may be integrated such that PV module frame
52 itself acts as the base and is secured directly to the roof
deck. PV modules with bases integrated with the module frame may be
constructed such that the frame design promotes airflow beneath the
module even with the module fastened directly to the roof.
[0045] During installation mounting screw 16 may be torqued such
that the threaded member and the clip are pre-loaded above the
maximum code wind load plus an appropriate safety factor. This
ensures a secure mechanical and electrical connection in all field
conditions and excludes moisture from the ground bond area at teeth
48 by creating a high pressure connection zone around each
point.
[0046] The use of threaded connections has been emphasized.
However, other types of connections, such as a ratchet-type of
connections and connections using spring fingers, may also be
used.
[0047] The above descriptions may have used terms such as above,
below, top, bottom, over, under, et cetera. These terms are used to
aid understanding of the invention are not used in a limiting
sense.
[0048] While the present invention is disclosed by reference to the
preferred embodiments and examples detailed above, it is to be
understood that these examples are intended in an illustrative
rather than in a limiting sense. It is contemplated that
modifications and combinations will occur to those skilled in the
art, which modifications and combinations will be within the spirit
of the invention and the scope of the following claims. Any and all
patents, patent applications and printed publications referred to
above are incorporated by reference.
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