U.S. patent application number 12/914599 was filed with the patent office on 2011-02-17 for solar collector mounting array.
This patent application is currently assigned to ENERGY INNOVATIONS, INC.. Invention is credited to Nathan Allen, Gregg F. Luconi.
Application Number | 20110036342 12/914599 |
Document ID | / |
Family ID | 46326913 |
Filed Date | 2011-02-17 |
United States Patent
Application |
20110036342 |
Kind Code |
A1 |
Allen; Nathan ; et
al. |
February 17, 2011 |
SOLAR COLLECTOR MOUNTING ARRAY
Abstract
A solar collector structural support system that affixes to a
mounting surface without penetrating the mounting surface is
disclosed. The invention in the preferred embodiment includes a
base assembly comprising: a plurality of leg members, a center
junction elements configured to receive (a) the proximal end of
each of the plurality of leg members and (b) a support member
configured to securely uphold at least one of the one or more one
solar collectors, and at least one footing adapted to frictionally
engage the mounting surface. Multiple base assemblies may be
interconnected using peripheral junction elements to form arrays of
solar collectors of arbitrarily large size. The peripheral junction
element is configured to couple the leg members of multiple base
assemblies. When connected with the present invention, a plurality
of solar concentrators form an array with greater structural
integrity and less susceptibility.
Inventors: |
Allen; Nathan; (Pasadena,
CA) ; Luconi; Gregg F.; (Monrovia, CA) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET, FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Assignee: |
ENERGY INNOVATIONS, INC.
Poway
CA
|
Family ID: |
46326913 |
Appl. No.: |
12/914599 |
Filed: |
October 28, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11644643 |
Dec 22, 2006 |
7823583 |
|
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12914599 |
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|
11144995 |
Jun 2, 2005 |
7156088 |
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11644643 |
|
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11042031 |
Jan 24, 2005 |
|
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11144995 |
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60612592 |
Sep 22, 2004 |
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60576770 |
Jun 2, 2004 |
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60557738 |
Mar 30, 2004 |
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Current U.S.
Class: |
126/571 |
Current CPC
Class: |
H01L 31/0547 20141201;
F24S 25/13 20180501; Y02E 10/52 20130101; F24S 30/48 20180501; F24S
2030/131 20180501; F24S 25/634 20180501; F24S 30/422 20180501; F24S
23/77 20180501; F24S 30/452 20180501; F24S 2030/136 20180501; F24S
25/40 20180501; F24S 2025/6007 20180501; F24S 25/65 20180501; F24S
2025/02 20180501; F24S 2030/133 20180501; F24S 2030/115 20180501;
F24S 25/30 20180501; Y02B 10/20 20130101; F24S 25/10 20180501; F24S
40/85 20180501; F24S 25/617 20180501; Y02E 10/47 20130101; F24S
2030/135 20180501 |
Class at
Publication: |
126/571 |
International
Class: |
F24J 2/46 20060101
F24J002/46; F24J 2/52 20060101 F24J002/52 |
Claims
1. A solar collector support system for mounting one or more solar
collectors to a mounting surface, the support system comprising: a
plurality of base assemblies, each base assembly comprising: a
plurality of leg members, each of the plurality of leg members
comprising a proximal end and a distal end; a center junction
element configured to connect to: (a) the proximal end of each of
the plurality of leg members; and (b) a support member configured
to securely uphold at least one of the one or more one solar
collectors; and at least one footing adapted to frictionally engage
the mounting surface; and at least one peripheral junction element
configured to couple distal ends of leg members of two or more base
assemblies; wherein the plurality of base assemblies are rigidly
affix together in an array.
2. The solar collector support system of claim 1, wherein the
plurality of leg members of one or more base assemblies are
rotatably connected to the corresponding center junction
element.
3. The solar collector support system of claim 2, wherein the
plurality of leg members are configured to pivot to a deployed
configuration in which the plurality of leg members project from
the center junction element in a substantially radial pattern.
4. The solar collector support system of claim 3, wherein the
plurality of leg members in the deployed configuration lie in a
substantially common plane at the mounting surface.
5. The solar collector support system of claim 1, wherein the
peripheral junction elements are adapted to support a wind
shield.
6. The solar collector support system of claim 1, wherein the
peripheral junction elements are adapted to support a ballast
element.
7. The solar collector support system of claim 1, wherein the
mounting surface is a roof.
8. The solar collector support system of claim 1, wherein the
distal end of at least one of the plurality of leg members is
configured to securely abut a structure extending from the mounting
surface.
9. The solar collector support system of claim 1, wherein the
distal end of the at least one of the plurality of leg members is
configured to extend beyond and about a mounting surface
boundary.
10. The solar collector support system of claim 1, wherein the
center junction element and support member are rotatably
coupled.
11. The solar collector support system of claim 10, wherein the
center junction element and support member are coupled by rack and
pinion gear.
12. A solar collector support system for mounting one or more solar
collectors to a mounting surface, the support system comprising: a
plurality of base assemblies, each base assembly comprising: a
carousel configured to provide rotation about a substantially
vertical axis; a plurality of leg members connected to the
carousel; at least one footing adapted to frictionally engage the
mounting surface; and at least one peripheral junction element
configured to couple leg members of two or more base assemblies;
wherein the plurality of base assemblies are rigidly affixed
together in an array.
13. The solar collector support system of claim 12, wherein the
plurality of leg members are rotatably affixed to the at least one
footing of the corresponding base assembly.
14. The solar collector support system of claim 13, wherein the
plurality of leg members are configured to rotate between a stowed
configuration and a deployed configuration.
15. The solar collector support system of claim 14, wherein the
plurality of leg members are configured to rotate inward adjacent
to the carousel.
16. The solar collector support system of claim 12, wherein the at
least one peripheral junction element is configured to support a
ballast element.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation application of U.S.
patent application Ser. No. 11/644,642, filed Dec. 22, 2006
entitled "SOLAR COLLECTOR MOUNTING ARRAY, which claims the benefit
of U.S. Provisional App. No. 60/576,770, filed Jun. 2, 2004 and is
a continuation-in-part of U.S. patent application Ser. No.
11/144,995 filed Jun. 2, 2005, now U.S. Pat. No. 7,156,088, which
is a continuation-in-part of U.S. patent application Ser. No.
11/042,031 filed Jan. 24, 2005 entitled "SELFBALASTING SOLAR
COLLECTOR," which claims the benefit of U.S. Provisional Patent
Application No. 60/612,592 filed Sep. 22, 2004, entitled "APPARATUS
FOR REDIRECTING PARALLEL RAYS USING SIMPLE RIGID TRANSLATION," and
of U.S. Provisional Patent Application Ser. No. 60/557,738 filed
Mar. 30, 2004, entitled NON-PENETRATING ROOF-MOUNTED TRACKING SOLAR
COLLECTOR," all of which are hereby incorporated by reference
herein and should be considered a part of this specification.
FIELD OF INVENTION
[0002] The invention generally relates to solar collector support
structures and particularly relates to a system of solar collector
support structures frictionally affixed or affixed with adhesive to
a mounting surface via one or more non-penetrating contacts.
BACKGROUND
[0003] Solar collectors by their nature are, at some time in their
operation, exposed to the outdoor environment. In some systems, the
wind load may produce lateral forces that push the system in a
direction co-parallel to the wind as well lifting forces that can
pull a system upwardly. As such, a solar collector is subjected to
wind forces they may be large enough to cause the solar collector
to move with such motion disrupting the operation of the device. In
order to maintain its location, the support structure for a solar
collector is fixed attached to it mounting surface. If the mounting
surface is at ground level, a firm mounting may be achieved by
attaching the solar collector support structure to concrete
footings that may be placed at or below ground level. If the
mounting surface is the top of a building, roof-penetrating
mounting anchors may be used to secure the solar collector support
structure. With repeated small motions and aging, the mounting
anchor's seals loosen and permit water leakage. In addition,
depending on the roof-penetrating mounting anchors used, it may be
difficult, if not impossible to re-roof or resurface the rooftop
with the solar collector support structure anchors present. There
is therefore a need for a solar collector support structure adapted
to remain fixed on a mounting surface such as roof and, when
deployed with one or more solar collectors, sufficiently wind
resistant without surface-penetrating anchors.
SUMMARY
[0004] The invention in its several embodiments provides one or
more support structures for solar collectors, solar concentrators,
heliostats and wind blinds or articulated wind blinds as part of a
wind management system, that may be mounted on mounting surfaces
such as rooftops or ground surfaces where penetration of the
mounting surface for anchoring purposes is not permitted.
Generally, the system of solar collector support structures
frictionally affixed to a mounting surface via one or more
non-penetrating contacts. The systems are modular in their
preferred embodiments and my additionally laterally supported via
abutting with structures extending from the mounting surface or via
extending below the mounting surfaces at one or more of its edges.
Accordingly, the system of solar collector support structures, when
deployed, provides a frame that includes a plurality of footings
adapted to frictional affix the frame to a roof, for example, so
that one or more solar collecting devices may be detachably secured
to the roof without compromising the integrity of the roof. The
diameter of the carousel is preferably about half the width of a
concentrator assembly 2420, although the diameter may be as small
as one-third of the width of an optical element.
[0005] The solar collector devices may include a directable array
or tracking array of optical elements, or a continuous surface
typically concentrating sunlight on a receiver may be a
photovoltaic cell and the one or more reflectors include an array
of mirrors. The concentrator, including the receiver and mirrors,
may include a heliostat array. The heliostat array includes: (a) a
positioning plate adapted to simultaneously aim each of the
plurality of mirrors--each of which is adapted to rotate about a
first center of rotation--in a direction bisecting the interior
angle between the source and the receiver; and (2) a plurality of
reflector positioning arms for operably coupling the plurality of
reflectors to the positioning plate, each of the positioning arms
being adapted to rotate relative to the positioning plate about a
second center of rotation.
[0006] The mast of a directable or tracking array and the footings
of a heliostat array for example may engage the system of solar
collector support structures to exploit the friction between the
system's surface contact pads and a rooftop, thereby enabling the
solar collecting device to reside on the rooftop without using
fasteners or anchors that might otherwise penetrate the mounting
surface and, in this example, expose the roof to damage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The present invention is illustrated by way of example and
not limitation in the figures of the accompanying drawings in
which:
[0008] FIG. 1 is a close-up view of a junction element having a
support member;
[0009] FIG. 2 is a perspective view of an exemplary deployed base
assembly of the present invention;
[0010] FIG. 3 is a perspective view of an exemplary base assembly
of the present invention in a stow configuration;
[0011] FIG. 4 is a perspective view of a plurality of exemplary
base assemblies as an interconnected array;
[0012] FIG. 5 is a perspective view of the deployment of an
exemplary ballast tank over an exemplary peripheral junction
element;
[0013] FIG. 6 is a perspective view of an exemplary base assembly,
including the ballast tank arrangement of FIG. 5;
[0014] FIG. 7 is a perspective view of an exemplary peripheral
junction element including a foot friction pad;
[0015] FIG. 8 is a perspective view of the base assemblies of FIG.
4, wherein ballast tanks have been positioned over the peripheral
junction elements;
[0016] FIG. 9 is a perspective view of the base assemblies of FIG.
8, wherein the array engages exemplary parapets;
[0017] FIG. 10 is a perspective view of the base assemblies of FIG.
8, wherein the array engages a mounting surface edge;
[0018] FIG. 11 is a perspective view of the base assemblies of FIG.
8, wherein exemplary wind shield are mounted to the array;
[0019] FIG. 12 is a perspective view of the base assemblies of FIG.
8, wherein exemplary wind shields are mounted to the array;
[0020] FIG. 13 is a perspective view of an exemplary embodiment of
a low profile solar collector in a deployed configuration mounted
to an exemplary base assembly;
[0021] FIG. 14 is another perspective view of the solar collector
of FIG. 13;
[0022] FIG. 15 is a side view of a solar collector mounted to the
base assembly of FIGS. 13 and 14, wherein the solar collector is in
a stowed configuration;
[0023] FIG. 16A is a perspective view of another solar collector
embodiment and its actuation;
[0024] FIG. 16B is a perspective view of another solar collector
embodiment and its actuation;
[0025] FIG. 17 is a perspective view of another solar collector
embodiment and its actuation;
[0026] FIG. 18 is a perspective view of another solar collector
embodiment and its actuation;
[0027] FIG. 19 is a perspective illustration of a heliostat that
uses parallel motion of a rigid plate to position the mirrors
simultaneously using simple parallel translation, in accordance
with the preferred embodiment;
[0028] FIG. 20 is a side view of the heliostat, in accordance with
the preferred embodiment;
[0029] FIG. 21A-21B are perspective views of a footing for
frictionally affixing the heliostat to a roof, in accordance with a
first embodiment of the footing;
[0030] FIG. 21C is a cross sectional view of a footing for
frictionally affixing the heliostat to a roof, in accordance with
the first embodiment of the footing;
[0031] FIGS. 22A-22B are perspective views of a footing for
frictionally affixing the heliostat to a roof, in accordance with a
second embodiment of the footing;
[0032] FIG. 23A is perspective view of a footing for frictionally
affixing the heliostat to a roof, in accordance with a third
embodiment of the footing;
[0033] FIG. 23B is a cross sectional view of a footing for
frictionally affixing the heliostat to a roof, in accordance with
the third embodiment of the footing;
[0034] FIG. 24 is a perspective view of a tracking solar
concentrator with a support structure, in accordance with one
embodiment of the present invention;
[0035] FIG. 25 is a side view of a tracking solar concentrator with
a support structure, in accordance with one embodiment of the
present invention;
[0036] FIG. 26 is a perspective view of a base assembly, in
accordance with one embodiment of the present invention;
[0037] FIG. 27 is a perspective view of a base assembly and
concentrator frame, in accordance with one embodiment of the
present invention;
[0038] FIG. 28 is a top view of a base assembly with legs in the
deployed configuration, in accordance with one embodiment of the
present invention;
[0039] FIG. 29 is a top view of a base assembly with legs in the
stowed configuration, in accordance with one embodiment of the
present invention; and
[0040] FIG. 30 is a top view of a plurality of base assemblies
interconnected in an array, in accordance with one embodiment of
the present invention.
DETAILED DESCRIPTION
[0041] The invention in its several embodiments and as a system of
solar collector support structures provides for the mounting of one
or more solar energy collecting devices wherein the mounting may be
made secure to a mounting surface such as a rooftop without
penetrating the surface. The solar collectors, in some embodiments,
include collection surfaces that are broken into smaller elements
so that the collection surface does not present a solid surface to
the wind, but rather a perforated surface that wind can at least
partially blow through. In some embodiments, the collector or
reflecting surface is solid. The solar collectors in some
embodiments may be heliostat arrays.
[0042] The system of solar collector support structures solar
collectors optionally receive integral wind deflector to further
reduce the magnitude of aerodynamic drag and lift forces generated
in high wind conditions on the one or more solar collectors that
may be structurally supported by the system. The wind deflector is
typically configured to reduce the amount of wind to which adjacent
solar collectors may be subjected, and preferable to cause the wind
to exert a downward, stabilizing force on the solar collector,
rather than an upward, lifting force. The system of solar collector
support structures also optionally include leg extensions that can
be adjusted to extend to the edges of the roof, to further reduce
the likelihood that the solar collectors will slide out of position
on the roof. In addition, to further reduce the likelihood that the
solar collectors will slide out of position on the roof, the system
of solar collector support structures for mounting on a first
surface without penetrating the surface may also optionally include
leg extensions that are interposed between a leg of the system and
a second surface extending from the mounting surface, e.g., a
rooftop wall, and optionally placed in compression with a resilient
element.
[0043] Illustrated by example in FIG. 1 is a junction element 112
that has three arms 205, or leg member receptacles, sockets, braces
or mounts, and each arm has a top side and two lateral sides with
each lateral side having a proximal aperture and a distal aperture.
Accordingly, each arm 205 of a junction element 112 forms a trough
for receiving a leg member 110. The proximal aperture 192
preferably receives a fastener, pin or bolt that passes through
both lateral sides of the arm and passes through a leg member 110
and preferably allows for rotation of the leg about the fastener.
The distal aperture 191 of the each arm preferably receives a
removable fastener, pin or bolt that passes through both lateral
sides of the arm and passes through the leg member thereby joining
the leg member rigidly to the arm of the center junction element
112. The junction element 112 preferably has a top aperture 210
adapted to receive and secure a footing or friction pad fastener. A
junction element 112 assembled as a central junction is also
preferably adapted to receive at its top aperture a support riser
or member that may be secured via a washer and nut assembly 190,
for example. For example, the center junction elements 112 may
include a support member or post 107 that may be configured to
receive a solar collector mast or footing thereon or otherwise
provide support for other assemblies and devices. Other embodiments
can include snap-fit and screw-type coupling of the support member
with a device to be mounted.
[0044] FIG. 2 is a perspective view of a base assembly 105 of the
system of solar collector support structures. A central junction
element is preferably rotatably or rigidly joined to three leg
members. Preferably the leg members and junction elements are made
of anodized aluminum or other weight materials resistant to
environmental effects. Other materials suitable for leg member and
junction elements include anodized steel, galvanized steel, alloys,
composites, and resins. A central junction also preferably adapted
to receive at its top aperture a support riser or member that may
be secured via a washer and nut assembly. Relative to the central
junction element, a peripheral junction element 116 secured to the
distal end of a leg member of the base assembly. When only the
proximal fasteners of the central junction element and the proximal
faster of the peripheral junction element are engaged, the distal
ends of the three leg members may rotated about the proximal
fasteners to be proximate to one another, preferably co-parallel,
and the peripheral junction element may be rotated to receive the
distal ends of the leg members of the base assembly. This exemplary
stowed position is illustrated by FIG. 3.
[0045] Returning to the deployed example of FIG. 2, two additional
arms of the peripheral junction element are available to receive
leg members including leg members of other base assemblies. This
allows a plurality of base assemblies 105 to be interconnected, as
illustrated in FIG. 4. The base assemblies can be interconnected
via the peripheral junction elements 116, which optionally include
spring loaded interlocking pins. The peripheral junction elements
116 optionally include foot friction pads 118 configured to support
the base assembly 105 on the roof. In the illustrated exemplary
embodiment, wherein each base assembly includes three legs 110,
interconnection of the base assemblies 105 produces a hexagonal
grid 180. Other grid shapes maybe made with other embodiments of
the multi-armed junction elements, wherein the base assemblies
include other numbers of legs. For example, base assemblies having
a central junction element with four arms and four legs may be used
to create a square grid.
[0046] FIG. 5 illustrates a base assembly 105, having the top side
of its peripheral junction facing toward the mounting surface. A
friction pad is shown attached to the peripheral junction.
Preferably the friction pad is attached to the peripheral junction
by a fastener secured via the top aperture. A ballast tank is shown
above the peripheral junction prior to placement onto the
peripheral junction. The ballast tank 120 includes troughs or slots
122 adapted to receive a leg member or the arm or leg receptacles
of the peripheral junction element allowing the ballast tank to be
placed over the arms or leg receptacles 114 in the peripheral
junction elements 116. The exemplary ballast tank preferably has an
integral handle 181 and a capped orifice 182 to receive ballasting
material. The general shape of the ballast tank is hemispherical to
minimize wind resistance and while maintaining a ballast material
reservoir volume. A ballast tank 120 may be secured to the
peripheral junction elements 116 using friction fits, tabs, snaps,
or other appropriate attachment mechanisms. In an alternative
configuration, a ballast tank 120 can be positioned over the ends
of one or more legs, even without a peripheral junction element
116, by positioning the ends of the legs 110 into the slots 122. As
described above, the weighted ballast tanks 120 assist in securing
the array of base assemblies 105 by weighting the points where legs
of adjoining base assemblies meet. The exemplary deployed base
assembly 105 of FIG. 6 illustrates ballast tank above and prior to
engaging a peripheral junction element. As described above, the
ballast tank 120 may be optionally positioned over a distal end of
one or more leg members 110.
[0047] FIG. 7 illustrates a peripheral junction element 116
including foot friction pad 118. In such embodiments, the foot
friction pad 118 comprises a material or layers of materials such
as molded plastics, neoprene, polyethylene, vinyl, rubber, and
anodized steel, and contact surface finishes such a linear ridges
or an array of protrusions that cause the pad to be resistant to
sliding along the roof, particularly when the weight of the ballast
tank 120 is positioned over the peripheral junction element 116. In
some embodiment, the foot friction pad 118 is selected for use with
particular roof types, such as wood shake roofs and tile roofs. In
place of or in addition to a pad, one or more fasteners may be used
in some embodiments to secure the system to a mounting surface. The
perspective view of the underside of the ballast tank or ballast
element illustrates an example of the ballast tank adapted to
receive via three troughs or slots a peripheral junction element
having three arms. Other embodiments of ballast tanks or elements
may have more or less troughs. For example, an alternative
embodiment of a ballast tank may have four troughs in a cruciform
arrangement to receive a peripheral junction element having four
arms. FIG. 8 illustrates the array of exemplary base assemblies
105, where ballast tanks 120 have been positioned over the
peripheral junction elements 116.
[0048] The system of solar collector support structures described
herein also optionally includes leg extensions that can be adjusted
to extend to the edges of the roof. A schematic configuration of
exemplary leg extensions is provided in FIG. 9. As illustrated,
when deployed the leg extensions reach to and mount against the
edge of the roof, such as against an edge, ledge or parapet. This
allows the array of base assemblies to be held in compression, and
therefore stabilizes the array of base assemblies and reduces the
likelihood of the base assemblies moving or otherwise shifting on
the roof. The leg extensions can be extendable to lock into place
with a pressure fit 196, such as with a screw tightener, or via an
air or coil spring 197. Illustrated in FIG. 10 is an embodiment the
system of solar collector support structures for securing to roofs
without edges, ledges or parapets, the leg extensions 199 can wrap
around the eave of the roof, or hooks or clamps can be coupled to
the legs or leg extensions to wrap around the eave or roof edge and
may be placed in tension 185.
[0049] The system of solar collector support structures described
herein optionally may receive one or more wind deflectors, such as
an integral wind deflector, to further reduce the magnitude of
aerodynamic drag and lift forces generated in high wind conditions
where the wind deflectors may deflect wind over the deployed
receiver arm of a deployed tracking or mast-mounted solar
collector. A schematic configuration of exemplary wind deflectors
171-174 is provided in FIGS. 11 and 12. The wind deflector can be
mounted to the legs 110, the peripheral junction element 116, the
center junction element 112, or another appropriate mounting
location. There may be an equal number of wind deflectors and solar
collectors, or another ratio of wind deflectors to solar collectors
can be used, such as one wind deflector for every three mast
mounted or tracking solar collectors.
[0050] The wind deflectors advantageously reduce the amount of
aerodynamic drag force to which the solar collector 100 is
subjected, and causes the wind to apply a downward force to the
underlying base assembly 105, thereby assisting in the
stabilization of the base assembly on the rooftop. In some
embodiments, the wind deflectors shield only the top portions of a
tracking or mast-mounted solar collector, such as the top third or
half of the solar collector, thereby deflecting wind over the part
of the collector capable of generating the greatest aerodynamic
lift and drag forces.
Mast-Mounted Solar Collector
[0051] FIG. 13 is a perspective view of an exemplary embodiment of
a low profile tracking solar collector 100 in a deployed
configuration. The solar collector 100 is supported by a base
assembly 105, which in the illustrated embodiment includes, among
other components, three legs 110. A solar collector 100 can be
mounted to one or more of the central junction elements 112. The
base assembly 105 can include other quantities of legs in other
embodiments. A ballast tank 120 is optionally positioned over the
end of one or more of the legs 110. Supplemental weight, such as
can be provided by materials such as sand, water or lead shot, can
be added to the ballast tank 120 to provide a precise amount of
weight to aid in the stabilization of the base assembly 105. Other
types of ballasts can be used as well. For example, the base can
include a tray or holder for paving stones which will provide
ballast.
[0052] The solar collector 100 includes a collection surface 130
that comprises an array of optical elements 132. In an exemplary
embodiment, the optical elements 132 are mirrors. In other
embodiments, the optical elements 132 are lenses or other simple or
complex optical elements capable of redirecting light and can
include composites of reflective and refractive elements. The solar
collector 100 also includes a receiver arm 140 having a mounting
bracket 142, to which a collection cell (not illustrated) can be
mounted. FIG. 14 is another perspective view of the solar collector
100 of FIG. 13.
[0053] As illustrated in FIGS. 14 and 15, in this example
embodiment, the solar collector 100 protrudes upward from the
underlying surface only to a relatively small extent, thereby
preventing the generation of tremendous aerodynamic drag and lift
forces, even in high wind conditions. Additionally, the optical
elements 132 are deployed in a relatively flattened array, thereby
providing a significantly lower wind profile, and thereby
significantly lower wind resistance, as compared to a conventional
reflective dish.
[0054] FIG. 15 is a side view of a solar collector 100 mounted to a
base assembly 105, wherein the solar collector 100 is in a stowed
configuration. As illustrated, the exemplary solar collector 100 is
moved between the stowed and deployed configurations by raising and
lowering the receiver arm 140. The solar collector 100 can be put
in the deployed configuration in high wind conditions, and during
storage or transportation. In an exemplary embodiment, an
anemometer detects wind speed and automatically stows the solar
collector when wind speeds exceed a preset velocity.
[0055] The orientation of the collection surface of an exemplary
solar collector may be adjusted in both a horizontal plane (an
"azimuth adjustment") and the vertical plane (an "elevation
adjustment"). In an exemplary embodiment, an azimuth actuator 150
provides the azimuth adjustment, and an elevation actuator 152
provides the elevation adjustment. The azimuth actuator 150 may
include electrical motor with gearing and a belt or chain drive to
rotate the solar collector 100 with respect to the post or
supporting member 107 of the base assembly. For example, the
azimuth actuator 150 may orient the solar collector toward the east
in the morning, and toward the west in the afternoon. The elevation
actuator 152, illustrated by example as an electrically drive worm
screw engaging a pin or tooth fixed attached to a slidable frame of
a mast-mounted solar collector, is accordingly configured to pivot
the solar collector 100 with respect to the base assembly. That is,
an exemplary embodiment may include an elevation actuator 152
includes a motor 151 configured to rotate a screw that causes a
bracket 154 supporting the collection surface 130 to be raised or
lowered. Other configurations for the azimuth actuator 150 and the
elevation actuator can be used in other embodiments. For example,
the elevation actuator 152 may orient the solar collector toward
the horizon during the early and late portion of the day, and
toward the zenith during the midday and effect a stowed position
for wing profile minimization. Other effecting and actuating
devices may be applied in place of or in combination with a stepper
motor. For example, hydraulic, electromagnetic, electromechanical
devices such as solenoids and the like may be used.
[0056] FIGS. 16A and 16B illustrate an exemplary continuous
reflector surface 176 mast-mounted solar collector having a linear
actuator 177 for adjusting elevation and a belt drive or gear box
reduction actuator 178 for adjusting azimuth. FIG. 17 illustrates
an exemplary continuous reflector surface mast-mounted solar
collector where the elevation adjusting linear actuator illustrated
in FIG. 16A has been replaced with a motor driven capstan reeling a
cable attached to a spring-loaded reflector surface. FIG. 18
illustrates an exemplary continuous reflector surface mast-mounted
solar collector where the azimuth adjusting belt drive actuator
illustrated in FIG. 17 has been has been augmented in opposing
torsional force by a spring-loaded collector frame 179.
[0057] Electrical wiring used for collecting electricity from
collection cells, for powering and controlling the azimuth and
elevation actuators, and for other uses can be routed through the
legs 110, which can thereby serve as electrical conduits. The
electrical wiring can be coupled to pins or sockets which mate to
corresponding sockets or pins in an adjacent solar collector. Other
wiring and connection techniques can be used as well.
[0058] The system of solar collector support structures disclosed
herein by example may support other solar energy collection
systems. For example, while the individual optical elements 132
described above are fixed with respect to each other, in other
embodiments other systems having individually adjustable tracking
elements may be mounted at one or more junction elements to the
solar collector support structures.
Heliostat
[0059] A solar collector having more than one point of attachment
to a system of solar collector support structures is illustrated in
FIG. 19 as a solar concentrator or concentrator module in the form
of a heliostat array comprising a plurality of reflectors and a
positioning plate for simultaneously orienting the plurality of
reflectors. The positioning plate is adapted to aim or otherwise
orient each of the plurality of reflectors in a direction bisecting
the interior angle between the source of the radiation and the
receiver of the reflected radiation, thereby mapping between the
parallel rays associated with a distant object and focused rays
associated with the focus. In accordance with the preferred
embodiment of the present invention, the positioning plate is a
rigid plate with a contoured surface adapted to simultaneously
orient each of the plurality of reflections while changing the
direction of the parallel rays, i.e., their angles of incident,
where the distant object is moving, for example. One skilled in the
art will appreciate that the preferred embodiment of the present
invention may be used to transmit radiation from a source to a
distant object or to collect radiation from a distant object then
direct to a common focal point. One skilled in the art will
appreciate that the array may be adapted to reflect radiation from
a wide portion of the electromagnetic spectrum.
[0060] In the preferred embodiment, the array is a linked heliostat
array comprising a plurality of siderostats, a positioning plate
operatively coupled to each of the plurality of siderostats, and a
receiver incorporated into the receiver housing 301. The plurality
of siderostats in cooperation with the positioning plate 305, are
adapted to reflect the incident sunlight to a common focal point
coinciding with a receiver (not shown) independently of the
position of the sun. Each of the plurality of siderostats includes
a combination reflector and a positioning arm rotatably attached to
a heliostat chassis by means of an articulated mounting structure
permitting the reflector to be steered under the control of the
actuated positioning plate. The positioning plate 305 is generally
characterized by a non-planar surface configured to orient each of
the reflectors to reflect the sunlight to the same fixed focal
point as the sun sweeps across the diurnal sky, for example. The
positioning plate 305 is effectively geometrically encoded with the
position of each reflector as a function of the receiver position
and position of the reflector within the array.
[0061] In the exemplary embodiment, the reflectors are mirrors 303
that reflect incident sunlight to the receiver housing 301 and the
receiver therein. The position of the receiver and housing 301 are
preferably fixed relative to the plurality of siderostats by means
of receiver support arms 302. The receiver in the preferred
embodiment includes a photovoltaic plate, associated electronics,
and cooling system, although various other forms of energy
converters may also be employed including thermal absorbing
liquids, for example. In alternative embodiments, the receiver is
selected from a group comprising a heat exchanger, heat engine, and
turbine, for example.
[0062] The plurality of mirrors in the exemplary embodiment are
arrayed two dimensionally in a horizontal or incline plane and the
mirrors adapted to rotated about two orthogonal axes. In other
embodiments, the plurality of mirrors may be arrayed three
dimensionally with suitable modification to the contour of the
positioning plate 305. In the preferred embodiment, each of the
siderostats is rotatably affixed to heliostat chassis which
comprises a support frame 306, a plurality of supports 310 spanning
the width of the chassis, and a plurality of stantions 309 atop the
supports 310 for mounting the mirrors 303.
[0063] Illustrated in FIG. 20 is a side view of the heliostat
array. Each of the plurality of mirrors is oriented so as to bisect
the interior angle between an incident ray I and reflected ray R
directed to receiver 314. To account for diurnal movement of the
source as well as seasonal changes in the declination of the sun,
the heliostat is adapted to continuously track movement of the
source and alter the position of the positioning plate 305
accordingly. The positioning plate 305 is positioned using at least
one, preferably two, actuators that drive the positioning plate 305
to swing relative to the chassis about one, preferably two,
orthogonal axes. Each of the one or more actuators (not shown),
which may include a servo or stepper motor, for example, are
operably coupled to the positioning plate 305 by means of a frame
actuator arm 319, a positioning plate actuator arm 320, and an
articulated joint including joint ball 321 and ball socket 322.
[0064] In some preferred embodiments, the frame of the solar energy
concentrator is made to frictionally adhere to a roof using a
plurality of footings that distribute the weight of the
concentrator and increase the friction inhibiting the concentrator
from sliding across the roof under the force of gravity or wind
loading or combinations thereof. As illustrated in FIGS. 21A-21C,
the heliostat chassis includes a plurality of frame support feet
308, each foot 308 being detachably affixed to a footing that
directly engages the roof. In a first embodiment of the footing,
the footing includes a hollow container 1100 adapted to receive
ballast and means to detachably engage the container 1100 to the
leg 308. The hollow footing includes a bayonet fitting or threaded
mouth 1104 and cap 1105, for example, adapted to receive ballast
1120--preferably water, sand, or gravel-retained within a reservoir
therein. As illustrated in the cross section of the hollow footing
in FIG. 21C, the means to detachably engage the leg 308 includes a
post 1102 fixedly attached to the container 1100. The
smaller-diameter post 1102 slidably engages the larger-diameter leg
308 until pins 1108A, 1108B outwardly biased by spring 1109 engage
corresponding holes 1110 in the leg 308. To detach the footing, the
user merely applies pressure to the two pins 1108A, 1108B while
lifting the chassis. The footing may also be moved conveniently
using the handle 1112 embedded in the container 1100 before of
after emptying its contents.
[0065] In some embodiments, the walls 1130 of the footings outer
facing surfaces are inclined to mitigate the force of wind or to
induce downward pressure on the footings for purposes of increasing
static friction while spreading the point loads into a larger
surface, thus preventing roof damage or deformation. In still other
embodiments, the footing includes a rubber pad or other material
with a high coefficient of static friction to further enhance the
ability of the concentrator to resist lateral movement. In still
other embodiments, the footing may be indirectly attached to the
roof by means of an adhesive, epoxy, mastic, tar, or like bonding
agent. Depending on the weight of the concentrator, the underside
of the footings may be designed with a footprint large enough to
reduce the overall average roof loading to less than 4 pounds per
square foot and the point loading associated with the footing to
less than 34 pounds per square foot.
[0066] As illustrated in FIGS. 22A and 22B, a second embodiment of
a concentrator footing includes a subassembly as a means to
detachably engage the leg 308 and solid ballast. The exemplary
subassembly includes a post 1204 that slidably engages the leg and
a bottom plate 1208 for bearing the weight of the sold ballast
1202. As described above, the post detachably engages heliostat leg
308 by means of pins 1206A, 1206B outwardly biased by a spring
1206C. The ballast may be concrete although various other
materials, preferably durable and having a relatively high density
may also be employed.
[0067] Illustrated in FIGS. 23A and 23B is a third embodiment of a
concentrator footing. Each of the one or more footings 1300 is a
receptacle including a cavity adapted to receive ballast such as an
8 inch cinder block 1310, for example. The footings 1300 are
attached to the concentrator by means of fasteners, e.g., bolts,
that engage the mounting plate 1308 Movement of the concentrator is
inhibited by the cinder block which enhanced the weight and static
friction of the via the inner wall 1304 and bottom plate 1306 made
of rigid material. Preferably, the outer wall 1302 is inclined to
mitigate the force of wind or to induce downward pressure on the
footings for purposes of increasing static friction with the
underlying roof.
[0068] In addition, the several embodiments of the system of solar
collector support structures may be used to secure the heliostat to
a mounting surface. For example, junction elements having three or
four arms or leg receivers may form three-leg or four-leg base
assemblies respectively where these three-leg or four-leg base
assemblies may be joined to from hexagonal, square or rectangular
arrays of central junction elements for receiving the heliostat
footings and peripheral junction elements for receiving ballast
elements.
[0069] Illustrated in FIG. 24 is a perspective view and in FIG. 25
a side view of a low profile tracking solar concentrator with
another embodiment of the solar collector support structure of the
present invention. The solar concentrator 2400 includes a plurality
of concentrator assemblies 2410 adapted to convert sunlight into
electricity. The concentrator assemblies in the preferred
embodiment have a relatively elongated shape and are arrayed
parallel to one another and perpendicular to incoming light. The
concentrator 2400 is configured for installation on a substantially
horizontal surface such as a roof. The orientation of the plurality
of concentrator assemblies 2410 may be periodically adjusted during
the day to track the sun and maximize the energy collected.
[0070] Each solar concentrator assembly includes one or more lenses
for concentrating light onto one or more receivers that capture and
convert the incident energy. In the preferred embodiment, each
concentrator assembly includes at least one Fresnel lens 2420 which
is held perpendicular to the incident light by a tracking
controller. The light from each Fresnel lens 2420 is concentrated
by a factor of up to 500 before impinging on one or more
photovoltaic cells. In the preferred embodiment, each of a
plurality of point-focused Fresnel lenses directs light to one of a
plurality of photovoltaic cells intermittently distributed along
the length of the concentrator assembly 2410, although one skilled
in the art will appreciate that a line-focused Fresnel lens may
also be employed to direct light to a string of photovoltaic cells
arrayed in a line along the length of a concentrator 2410. In other
embodiments, the concentrator assemblies include cylindrical or
parabolic troughs for reflecting light onto at least one receiver
adapted to capture the incoming light.
[0071] The plurality of concentrator assemblies 2410A-2410C are
configured to track the sun over the course of a day by moving
about two degrees of freedom. In particular, the multiple
concentrator assemblies are mounted to a frame 2450 that rotates in
a horizontal plane using a carousel 2454, for example. The base of
the carousel 2454 is then affixed to a mounting surface via a
plurality of legs 2456 and footings 2458. The concentrator
assemblies therefore collectively rotate in unison about a common
vertical axis.
[0072] In addition, each of the individual concentrator assemblies
2410A-2410C is adapted to rotate relative to the frame 2450 about a
unique longitudinal axis. In the preferred embodiment, each
concentrator assembly is pivotally connected to the frame 2450 via
a mounting arm 2452. Depending on the implementation, the elevation
angles of the individual concentrator assemblies may be
independently rotated relative to the associated pair of mounting
arms to aim the assembly toward the incident sunlight 2490. The
concentrator assemblies may include separate actuators or be tilted
in unison with a common actuator and linkages that couple the
concentrator assemblies together.
[0073] Illustrated in FIG. 26 is a perspective view of a base
assembly alone and in FIG. 27 a perspective view of a base assembly
with frame for the concentrator described above. The base assembly
2600 preferably includes a center junction element, a plurality of
leg members 2456A-2456C, and one or more footings 2458A-2458C. The
center junction element in the preferred embodiment includes a
carousel with a weight-bearing rail or ring 2454 centrally disposed
under the concentrator frame 2450 to guide a plurality of casters
or wheels 2710 affixed to the frame 2450 as the concentrator
assemblies 2410A-2410C rotate in a substantially horizontal plane.
A rack and pinion gear system (not shown) integrated with the ring
is used to mechanically drive the concentrator frame 2450 relative
to the base assembly. In the preferred embodiment, the teeth of the
rack are arrayed around the upper-most edge of the ring while the
pinion gear is coupled to a motor attached to the frame. The
carousel may further include a brace 2610 with an axle 2612
configured to holding the frame 2450 to the base assembly while
allowing the frame to rotate. In this exemplary embodiment, the
axle 2612 and/or plurality of wheels 2710 constitute a form of
support member for securely holding the concentrator assemblies in
an upright orientation against the force of wind.
[0074] The footings 2458A-2458C are configured to securely mount to
the underside of the carousel ring 2454 where they contact the
mounting surface via one or more footing pads, for example. In the
preferred embodiment, the footings include a structural member made
of galvanized steel while the pads are made of rubber or other high
friction material adapted to inhibit sliding of the solar
concentrator across the roof or other mounting structure in the
presence of wind.
[0075] As illustrated in the top views of the base assembly in
FIGS. 28 and 29, each of the leg members 2456A-2456C is configured
to conveniently rotate between a deployed configuration and a
stowed configuration. The leg members 2456A-2456C are preferably
rotatably connected to the footings by means of a single rivet 2620
or bolt that serves as a pivot point or hinge. In the deployed
configuration, the leg members extend radially from the central
junction element to uphold the solar concentrator in the presence
of severe winds. In the stowed configuration illustrated in FIG.
29, the leg members 2456A-2456C are swung inward adjacent to the
ring 2454 to reduce the footprint of the assembled concentrator and
therefore reduce the cost of delivery to an installation site.
[0076] The concentrator assemblies 2410A-2410C and frame 2450 are
held upright with one or more base assemblies. As illustrated in
FIG. 26 and the plan view of FIG. 30, the legs members 2456A-2456C
of a base assembly may be coupled to peripheral junction elements
2650. The peripheral junction element 2650 is configured to provide
a point of attachment for solar concentrators when forming an array
of concentrators. In the preferred embodiment, the peripheral
junction element 2650 attaches three concentrators to form a
modular array of concentrators in the form of a hexagon which can
be repeated any number of times. The peripheral junction element
2650 is preferably a 12 inch square of galvanized steel that can
securely hold wind shields or hold ballast to secure the
concentrators in place even in severe wind conditions. The ballast
may include concrete pavers or tanks for holding water or sand, for
example. As one skilled in the art will appreciate, the peripheral
junction elements 2650 are coupling devices that may assume any of
a number of different shapes and sizes that either bolt to or slide
on the leg members.
[0077] The peripheral junction element 2650 described above is a
separate component that is detachably attached to one or more leg
members. In the preferred embodiment, the peripheral junction
element and leg members are connected using one or more bolts,
pins, latches, clasps, or other fasteners. In other embodiments,
however, the peripheral junction element or central junction
element may be integrally attached to one or more leg members to
facilitate easy of assembly of a concentrator array.
SCOPE OF THE INVENTION
[0078] Although the description above contains many specifications,
these should not be construed as limiting the scope of the
invention but as merely providing illustrations of some of the
presently preferred embodiments of this invention. It should be
appreciated that the specific configurations and operations
disclosed can differ from those described above, and that the
systems and methods described herein can be used in contexts other
than solar energy collection. Therefore, the invention has been
disclosed by way of example and not limitation, and reference
should be made to the following claims to determine the scope of
the present invention.
* * * * *