U.S. patent application number 12/318944 was filed with the patent office on 2010-07-15 for flexible roof-mount system and method for solar panels.
This patent application is currently assigned to OPTISOLAR INC.. Invention is credited to Ning Ma, Gianluigi Mascolo, Philip Rettger, David F. Taggart.
Application Number | 20100175337 12/318944 |
Document ID | / |
Family ID | 42318015 |
Filed Date | 2010-07-15 |
United States Patent
Application |
20100175337 |
Kind Code |
A1 |
Mascolo; Gianluigi ; et
al. |
July 15, 2010 |
Flexible roof-mount system and method for solar panels
Abstract
Systems and methods are disclosed for efficiently securing solar
panels on a roof surface that does not require penetration of the
roof membrane. Supports for the solar panels are designed with a
small footprint with sufficient spacing to allow free drainage
between the supports. A simple, low-cost attachment member or clip
can be integrated with each support to attach the panel to the
support, and in some instances the clip (or its mount on the
support) can also be used to lift the support to the roof. The
panels can include one or more rails that can slide through a
loosened clip, but be held securely in place by a tightened clip.
The panels can be installed initially with the clips grasping the
rails loosely and once the supports and rails are in their final
positions, the clips can be fully tightened to form a rigid solar
panel array.
Inventors: |
Mascolo; Gianluigi;
(Emeryville, CA) ; Taggart; David F.; (San Carlos,
CA) ; Ma; Ning; (San Mateo, CA) ; Rettger;
Philip; (Moraga, CA) |
Correspondence
Address: |
THE NATH LAW GROUP
112 South West Street
Alexandria
VA
22314
US
|
Assignee: |
OPTISOLAR INC.
Hayward
CA
|
Family ID: |
42318015 |
Appl. No.: |
12/318944 |
Filed: |
January 13, 2009 |
Current U.S.
Class: |
52/173.3 ;
248/237; 52/745.21 |
Current CPC
Class: |
Y02B 10/10 20130101;
Y02B 10/20 20130101; Y02B 10/12 20130101; F24S 25/11 20180501; F24S
25/61 20180501; F24S 25/617 20180501; F24S 25/33 20180501; F24S
2025/02 20180501; Y02E 10/47 20130101; F24S 25/16 20180501 |
Class at
Publication: |
52/173.3 ;
248/237; 52/745.21 |
International
Class: |
E04B 7/18 20060101
E04B007/18; E04D 13/18 20060101 E04D013/18; E04G 23/00 20060101
E04G023/00 |
Claims
1. A non-invasive, roof-mounting system for flexible configurations
of photo-voltaic (PV) panels having an attachment member,
comprising: a non-slip pad suitable for placement on a roof
surface; a PV-panel support resting on the non-slip pad; and a clip
attached to the support, the clip capable of being tightened to the
attachment member of the PV panel to affix the PV panel above the
roof.
2. The PV roof mounting system of claim 1, wherein the clip
provides an electrical connection to the attachment member of the
PV-panel.
3. The PV roof mounting system of claim 1, wherein the support is
of sufficient weight to hold the non-slip pad to the roof
surface.
4. The PV roof mounting system of claim 1, wherein the support is
of a form factor that permits water and debris to flow around
it.
5. The PV roof mounting system of claim 1, wherein the support is
formed from concrete.
6. The PV roof mounting system of claim 1, wherein the clip is
integral to the support.
7. The PV roof mounting system of claim 1, wherein the clip is
captive, wherein loosening is performed by motioning in one
direction and tightening is performed by motioning in an opposite
direction.
8. The PV roof mounting system of claim 1, wherein the clip is
predominately in the shape of a U.
9. The PV roof mounting system of claim 1, wherein the clip is
attached to the support via a clip mount.
10. The PV roof mounting system of claim 1, wherein the clip is
configured with a shape that accommodates a contour of the
attachment member, whereby the attachment member can be slid
thorugh the clip when the clip is loosely attached to the
attachment member.
11. A non-invasive, roof-mounting system for flexible
configurations of photo-voltaic (PV) panels having an attachment
member, comprising: means for non-slipping suitable for placement
on a roof surface; means for supporting a PV-panel, the supporting
means resting on the means for non-slipping; and means for
attaching the support to the PV-panel, the means for attaching
being attached to a rail of the PV-panel and capable of being
tightened to the rail to affix the PV panel above the roof.
12. The PV roof mounting system of claim 11 wherein the means for
attaching provides an electrical connection to the rail of the
PV-panel.
13. The PV roof mounting system of claim 11, wherein the means for
supporting is of sufficient weight to hold the non-slipping means
to the roof surface.
14. The PV roof mounting system of claim 11, wherein the means for
supporting is of a form factor that permits water and debris to
flow around it.
15. The PV roof mounting system of claim 11, wherein the means for
attachment is integral to the means for supporting.
16. The PV roof mounting system of claim 11, wherein the means for
attachment is attached to the means for supporting via a mounting
means.
17. A method for non-invasive, flexibly configured mounting of
photo-voltaic (PV) panels having an attachment member to a roof,
comprising: placing a non-slip pad on a membrane of the roof;
placing a PV-panel support on the non-slip pad; attaching a clip to
the support; and attaching the clip to the attachment member of the
PV panel, wherein the PV panels are supported above the roof by a
network of the non-slip pads, PV-panel supports and clips.
18. The method of claim 17, wherein the step of attaching includes
loosing the clip to allow the attachment member to be slid through
the clip and tightening the clip to fix the attachment member.
19. A method for non-invasive, flexibly configured mounting of
photo-voltaic (PV) panels having an attachment member to a roof,
comprising: placing a non-slip pad on a membrane of the roof;
attaching a clip to a PV-panel support; lifting the PV-panel
support onto the non-slip pad using a portion of the clip as a
lifting point; and attaching the clip to the attachment member of
the PV panel, wherein the PV panels are supported above the roof by
a network of the non-slip pads, PV-panel supports and clips.
20. The method of claim 19, wherein attaching the clip is performed
by motioning a bolt in a determined direction, and opening the clip
by motioning in an opposite determined direction.
Description
BACKGROUND
[0001] 1. Field
[0002] This disclosure relates to a roof mounting system for solar
panels. More particularly, systems and methods for mounting solar
panels in a manner that is low-cost and non-invasive are
disclosed.
[0003] 2. Background
[0004] Installing photovoltaic (PV) panels onto roof tops requires
careful consideration of the roof structure design and its capacity
to react to loads beyond its own mass (dead loads) and dynamic
loads including wind and rain (live loads). As roofing structures
are primarily designed for environmental protection, they are
typically not well suited for bearing loads or for mounting other
structures without the potential for compromising their shielding
ability. Therefore,--rooftop PV installation should not cause roof
leaks or significantly interfere with drainage (some existing solar
systems have "rails" running directly on the roof membrane and
prevent runoff of rain, especially heavy rain; this design quickly
creates ponding and accumulation of debris, leaves, etc.) Also,
rooftop PV panels--often are installed around existing
roof-components such as chimneys, vents, antennas, stairwells,
skylights, signage, etc., in a way that does not interfere with
their function. Roofs come in different 3-D shapes with differently
arranged slopes. Roofing materials expand and contract as their
temperature changes, and the--interface of PV panels and the
roofing material should not cause additional stress due to their
different thermal expansion rates. Electrical continuity must also
be maintained throughout the entire PV array.
[0005] Due to the wide variety of roof shapes, existing roof
features, roof construction methods, and environmental barriers
used on commercial rooftops, a design approach to install PV panels
has many conflicting considerations. For instance, standard sizes
and positions for rails, frames and other panel mounting features
reduce production costs by enabling easy automation of
manufacturing and economy of scale. However, panel supports cannot
always be spaced regularly on a roof; their positions are
constrained by the locations of underlying load-reacting members,
and other roof features such as pipes, vents, skylights, antennas,
etc.
[0006] As well, installation costs can often be the highest of the
overall system costs. Raising the panels and support structures
onto the roof accounts for one significant fraction of the cost.
Positioning them is also costly, particularly if major disassembly
and starting over results from each discovery of a misalignment.
Ideally, installed panels should be easy to replace during
maintenance, repair, or upgrade operations.
[0007] Therefore, there has been a long-standing need for an
attachment scheme that would address many of the problems stated
above.
SUMMARY
[0008] The foregoing needs are met, to a great extent, by the
present disclosure, wherein systems and methods for the easy and
rapid placement of solar panels on a roofing structure are
provided. In one of various aspects of the disclosure, a
non-invasive, roof-mounting system for flexible configurations of
photo-voltaic (PV) panels having an attachment member is provided,
comprising: a non-slip pad suitable for placement on a roof
surface; a PV-panel support resting on the non-slip pad; and a clip
attached to the support, the clip capable of being tightened to the
attachment member of the PV panel to affix the PV panel above the
roof.
[0009] In one of various aspects of the disclosure, a non-invasive,
roof-mounting system for flexible configurations of photo-voltaic
(PV) panels having an attachment member is provided, comprising:
means for non-slipping suitable for placement on a roof surface;
means for supporting a PV-panel, the supporting means resting on
the means for non-slipping; and means for attaching the support to
the PV-panel, the means for attaching being attached to a rail of
the PV-panel and having the capability to be tightened to the rail
to affix the PV panel above the roof.
[0010] In one of various aspects of the disclosure, a method for
non-invasive, flexibly configured mounting of photo-voltaic (PV)
panels having an attachment member to a roof is provided,
comprising: placing a non-slip pad on a membrane of the roof;
placing a PV-panel support on the non-slip pad; attaching a clip to
the support; and attaching the clip to the attachment member of the
PV panel, wherein the PV panels are supported above the roof by a
network of the non-slip pads, PV-panel supports and clips.
[0011] In another of various aspects of the disclosure, a method
for non-invasive, flexibly configured mounting of photo-voltaic
(PV) panels having n aattachment member to a roof is provided,
comprising: placing a non-slip pad on a membrane of the roof;
attaching a clip to a PV-panel support; lifting the PV-panel
support onto the non-slip pad using a portion of the clip as a
lifting point; and attaching the clip to the attachment member of
the PV panel, wherein the PV panels are supported above the roof by
a network of the non-slip pads, PV-panel supports and clips.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIGS. 1A-B are exploded views of the exemplary mounting
systems.
[0013] FIGS. 2A-2C are side views of example variations of types of
low-cost clips.
[0014] FIG. 3 is an illustration of some examples of clip tips that
form electrical contacts with the rails when the clip is
tightened.
[0015] FIGS. 4A-B are illustrations of possible alternatives for
support lifting schemes.
[0016] FIG. 5 is a side view illustration showing different support
heights can be used to mount the panels at a particular tilt angle
that maximizes the sun exposure.
[0017] FIG. 6A is a partial see-through view of an installed array,
where the panels are mounted in independent rows.
[0018] FIG. 6B is a bottom view of an installed array
DETAILED DESCRIPTION
[0019] Aspects of the disclosed systems and methods are elucidated
in the accompanying figures and following detailed description. In
various embodiments, friction and cushioning providing slip pads
are utilized between low-cost, small-footprint supports and the
roof membrane. The slip pads ensure that the supports stay in place
on the roof without penetrating the roof membrane. The supports are
designed to have a small footprint with sufficient spacing to allow
free drainage between the supports.
[0020] A simple, low-cost attachment "clip" can be integrated with
each support to attach the panel to the support, either flexibly or
rigidly, depending on the amount of tightening applied to the clip.
The clip (or its mount on the support) can also be used in some
embodiments to lift the support to the roof. The panels can include
one or more rails that can slide through a loosened clip, but be
held securely in place by a tightened clip. The panels can be
installed initially with the clips grasping the rails loosely. Any
further fine alignment can be done with no time-consuming
disassembly. Once the supports and rails are in their final
positions, the clips can be fully tightened and the array becomes a
rigid "web" to counter the wind loads that would otherwise tend to
uplift and displace the panels. The clip also is capable of
providing an electrical ground and mechanically secures the panels
in the single, very simple operation of tightening on the rail.
Thus, the PV array configuration is flexible during installation,
but structurally rigid after installation, and is also compatible
with a wide variety of roof designs.
[0021] As made apparent in the following description, the exemplary
clips can be tightened and loosened--. The clip can be spring
loaded and adjusted using a single tool, for example, a socket
wrench, on the tightening bolt. Initially, the clips may only be
partially tightened to the panels so that, if a misalignment is
discovered, the rails can be slid through the clips to refine the
alignment without moving the supports or disassembling any rail
structures. This saves considerable installation time, and thereby
reduces cost.
[0022] When the positioning is satisfactory throughout the array,
the clips are fully tightened, locking the array in place.
Tightening can also function to create an electrical contact
between the clip tips and rails, ensuring electrical continuity of
all the metallic structural members--for grounding. However, the
clips can be re-loosened and re-used if panels ever need to be
replaced.
[0023] FIGS. 1A-B are exploded views 10 and 20 of exemplary
mounting systems. The mounting system contains a clip 11 or 21 that
is positioned above a roof membrane 19. In FIG. 1A, the clip 11 is
mounted onto a clip mount 13 which is coupled to or integrated with
a support 15. The support 15 rests on a slip pad 17, 27 with is
placed above the roof membrane 19. The slip pad 17, 27 may be a
thin underlying sheet as seen in FIG. 1A or a thick stabilizing
base as seen in FIG. 1B, or any variation thereof. Any material
that provides adequate cushioning between the bottom of the support
15, 25 and the top of the roof membrane 19, and is difficult to
slide against either of those surfaces (e.g. EPDM or other
elastomers as one of several possible examples) is suitable for use
as the slip pad 17, 27. The slip pad 17, 27 may be individual
sheets or a roll or any variation thereof, including being attached
to the support 15, 25, according to implementation preference. The
support 15, 25 may be wide as shown in FIG. 1A or narrow as shown
in FIG. 1B. Multiple shapes or versions of the support 15, 25 may
be devised as according to design preference. Accordingly, the
support embodiments shown in FIGS. 1A-B are understood to be
non-limiting examples, whereas variations and modifications in
size, shape, number, orientation and so forth may be made without
departing from the spirit and scope of the disclosure.
[0024] The support 15, 25 may also be placed atop the slip pad 17,
27 and held in place by friction, for example, as in FIG. 1A or
pre-attached or integrated, for example, as shown in FIG. 1B. Any
suitable structural material (for instance, concrete or another
structural composite, or a metal such as aluminum, and so forth)
may be used for the support 15, 25. Both the slip pad 19 and the
support 15, 25 may be any suitable shape; however, they may be
designed and arranged so that no long straight edge impedes any
rainwater, leaves, or other debris from blowing or washing off the
roof.
[0025] More than one clip 11, 21 may be attached to each support
15, 25 and the clips need not be centered. For instance, in some
configurations an off-center clip position may shift the center of
gravity to more efficiently react to dynamic loads such as wind, as
well as for heavier panels that may need a different arrangement of
the clips. It should be noted that the U-shaped clips 11, 21 shown
in FIGS. 1A-B may be replaced with alternative shapes or gripping
mechanisms, examples of some alternatives being shown below. In
various embodiments, the body of the clip 11, 21 may be made of a
conductive material. Also, tips of the clips 11, 21 may be of any
desired shape.
[0026] FIGS. 2A-2C are side views 30, 50, and 60, respectively of
example variations of types of simple clips. The clip body 33, 53,
63 can be made from inexpensive metal, sheet metal, for example, or
any other type of suitable material. The "living" hinges 37 can be
created by bending, and the through-holes 39, 59, 69 by punching,
for example. A mounting nut 48 or fixture can attach the clip to a
threaded bolt integrated into the support (not shown). In various
embodiments, the use of a tightening bolt 42, anti-rotation washer
46 and tightening nut 44 allows the clip to be tightened or
loosened with a single tool. The clip body 33, 53, 63 can be
designed for different rail cross-sections 31, 51, 61.
[0027] As should be readily apparent to one of ordinary skill in
the art, other forms of tightening or loosening may be devised as
there are numerous mechanisms and methods for tightening an object
to another object. For example, a captive fastener, such as a bolt
as a non-limiting example, can be used which tightens or loosens
the exemplary clips 11, 21 by being turned in one direction or
another. Accordingly, variations of the clip types and the methods,
devices for affixing and so forth are understood to be within the
scope of the description provided herein.
[0028] FIG. 3 is an illustration 70 of some examples of clip tips
that can be used to form electrical contacts with the rails when
the clip is tightened. In many cases a plain tip 71 (far left) will
prove to be sufficient for providing gripping as well as electrical
contact as compared to the curved tip 75 (center). Optionally,
teeth can be added to the clip tip as shown in the far-right
example 77. In some embodiments, only a portion of the tip may be
electrically conductive, or there may be an insulative or
protective barrier placed about a portion of the tip to prevent
corrosion. It is envisioned that in these embodiments, a grounding
or conductive cable may be coupled to the clips either through the
described mechanical connection, or using a separate intermediate
connector/cable. Also, in some embodiments, it is contemplated that
a secondary tightening or electrical contact ensuring mechanism may
be utilized, if so desired. That is, electrical contact may be
further facilitated by pressure exerted by a secondary bolt or
screw and so forth, in addition to, or rather than solely by the
tightening bolt 42.
[0029] Installation of the exemplary embodiments can be performed
by positioning the slip pads 17, 27 on the roofing membrane 19. The
slip pads 17, 27 operate to create friction when the supports,
rails, and panels are placed on top of them. Along with the weight
of the array, the friction prevents the array or any of its
components from sliding out of position. The slip pads also cushion
the roof membrane 19 against any scratches or localized pressure
points the bottoms of the supports might otherwise inflict.
[0030] Supports, weighing less than the roof's safe maximum
point-load, can be raised to the roof and positioned on the slip
pads 17, 27. If the support is liftable and the clip is resilient
to mechanical strain, the temporarily tightened clip itself may be
attached to the hoist, allowing the panels to be lifted to the roof
using the clip as the hoist-to-support attachment member.
[0031] FIGS. 4A-B are illustrations 80 and 90 of possible
alternatives for support 86, 96 lifting schemes. The hoist 83, 93
can be attached to the clip mount 82, 92 via arms 85, 95 before
clip attachment as shown, for example, in FIG. 4A. Or the hoist 83,
93 can grip underneath the clip 98 that is already attached (or
where the clip is made as part of the support) as shown in FIG. 4B.
In FIG. 4B, by attaching the clip 98 to the support 96, via the
clip mount nut 94, the hoist 93 can use the clip 98 as the lifting
point for the support/array. Alternatively, as seen in FIG. 4A, the
hoist 83 may be attached to the support 86 via the arm 85 and
secured thereto by the clip mount nut 84, and the lifting force can
be borne by the clip mount 82 rather than by the clip.
[0032] It should be noted that the clip mounts 82, 92 illustrated
in FIGS. 4A-B are not limiting examples. That is, the threaded clip
mounts 82, 92 may be implemented using an alternative mechanical
means. For example, a "snap-in" coupler or other applicable coupler
may be used, according to design preference. Accordingly,
modifications and changes may be made to the clip mounts 82, 92 as
well as to other features of the disclosed embodiments, without
departing from the spirit and scope herein.
[0033] Because the clip 98 shown in FIG. 4B can grasp any point
along the rail's length, the supports 86, 96 (and underlying slip
pads) can be placed over the major structural members of the roof
that can best react to the extra mass of the support--wherever
those members may be--and the clips 98 will still be able to
position and electrically ground the rail. Thus, the disclosed
mounting systems provide an added degree of freedom with respect to
placement on the roof.
[0034] FIG. 5 is a side view illustration 100 showing different
support heights that can be used to mount the panels at a
particular tilt angle that maximizes (or reduces) the sun exposure.
As may be apparent in FIG. 5, if the clips 53 are of sufficient
height and flexibility, they will accommodate "off-plane" or
tilting at the surface of the clip tip and the rail. That is,
accommodation of the tilt angle by the panel can be made without
requiring adjustment or actual bending of the clip. In some
instances, however, it may be necessary to accommodate the tilt
angle, if severe enough, by placing an angle or height modifier
(not shown) at the top of the clips 53. Also, while the exemplary
mounting systems are shown with "square" support structures,
alternative shapes such as round, rectangular, pyramidal, and so
forth may be utilized.
[0035] FIG. 6A is a partial see-through view 110 of an installed
array, where the panels 112 are mounted in independent rows. The
bottom of each PV panel 112 is shown being elevated off the roof
surface. The clips 113 are attached to the rails 119 which are
coupled to the panels 112. Though FIG. 6A illustrates the exemplary
mounting system 115 as being placed in a parallel fashion, it may
be desirable, in some circumstances to stagger the mounting system
115, for example, in a zig-zag pattern. Of course, based on
implementation constraints or other factors, the mounting system
115 may be arranged in varying patterns, as desired. Also, while
only a single clip 113 is attached to the rail 119, per mounting
structure, multiple clips may be utilized as desired.
[0036] FIG. 6B is a bottom view 120 of an installed array where the
rows are mechanically coupled by having the rails 119 of adjacent
panel rows clipped to common supports 121 via the clip supports
125. Here we see that multiple panels or rails 119 can be supported
by a single support 121. Also, FIG. 6B is instructive in showing
that the support 121 does not need to be directly under the panel
to provide the needed support. This configuration is understood to
provide better wind reactance by shifting the centers of gravity to
the points between the rows where an uplifting wind would
enter.
[0037] It should be apparent that as multiple clips from a single
support 121 can be used to support the panels, in some embodiments
it may be desirable to have a single support 121 configured to
bridge two or more slip pads. That is, while the exemplary
embodiments described herein illustrate a one-to-one correspondence
between the supports and the underlying slip pads, it is understood
that a single support resting on several slip pads or several
supports resting on a single slip pad may also be used. Thus,
modifications may be made to the various embodiments herein without
departing from the spirit and scope herein.
[0038] Various advantages can now be realized as demonstrated, for
example:
[0039] Lower-profile objects that are part of the roof (e.g. air
conditioning pipes, conduit, small obstacles) could "disappear"
underneath the array and among the ballasts. They do not interfere
with the array, nor the array with them.
[0040] Because the clips and rails make panel removal and
replacement easy, the roof features under the array can be accessed
for any necessary maintenance.
[0041] Because it is not necessary for the support to physically
touch the roof, and since they make relatively small footprints
with plenty of space between them, any water landing on the roof
easily drains away between the blocks. With this mounting system,
the chain of panels "floats" over the top of the roof independently
of the structural arrangement built into the roof to react live and
dead loads. This allows great flexibility in designing the array
configuration to work around existing roof throughout the array's
operating life, the clip accommodates the daily growth and
shrinkage of metallic components exposed to the wide ambient
temperature ranges seen on large rooftops.
[0042] Further, the ability to re-use or recycle the support
components would reduce both cost and waste.
[0043] Importantly, no modification or penetration of the roof is
necessary for installation. This feature addresses one of the
primary concerns of roof-mounted systems, as it is well known that
most, if not all, roof-mounted systems require some penetration of
the roof membrane or surface, resulting in eventual near or long
term roof failure.
[0044] An exemplary installation would include connecting a chain
of mechanically linked PV panels to supports or support feet such
that the panels were easy to install, that thermal expansion and
contraction could be accommodated without wear and fatigue, that
electrical continuity could be accommodated, and to enable the
array to accommodate the shape of the roof, at very low cost.
[0045] While the above embodiments describe the exemplary
mounting/support system(s) as not requiring any modification of the
roof, it may be desirable in some embodiments to physically link or
couple a portion of the support system to the roof, to
strategically anchor the panel network. That is, various portions
or critical points in the linked PV panels may be directly
connected to the roof or to some support or structural member of
the roof to provide a "hard" mechanical anchor, while other
portions of the linked PV panels may be supported using the
exemplary supporting system(s) described herein. By minimizing the
number of "penetration" points, concern for the roof's integrity
can be minimized. If the anchoring points are situated at locations
that are not part of the roof membrane (e.g, pillar, chimney, and
so forth), then this embodiment will provide the same degree of
roof membrane integrity as the embodiments described above.
[0046] It will be understood that many additional changes in the
details, materials, steps and arrangement of parts, which have been
herein described and illustrated to explain the nature of the
invention, may be made by those skilled in the art within the
principle and scope of the invention as expressed in the appended
claims.
* * * * *