US20100089390A1

US20100089390A1 - Solar array mounting system

Info

Publication number: US20100089390A1
Application number: US12/250,433
Authority: US
Inventors: Robert H.J. Miros; Margaret Birmingham
Original assignee: Sunlink Corp
Current assignee: Sunlink Corp
Priority date: 2008-10-13
Filing date: 2008-10-13
Publication date: 2010-04-15
Also published as: WO2010044830A3; WO2010044830A2

Abstract

A solar array mounting system having unique installation and grounding features, and which is adaptable for mounting solar panels having mounting holes located in different locations. The solar array mounting system includes tilt brackets and longitudinal links forming columns. A tilt bracket includes a tilt arm for supporting an upper spar of one row, and a pivot block for supporting a lower spar of a next row. The spars may be made from extruded aluminum or from steel, wherein the steel spars include an exposed metal channel to provide a common electrical equipment ground. Panel clamps are used to clamp the solar panel frames to the spars, allowing for variations in mounting hole locations.

Description

CROSS REFERENCE TO RELATED APPLICATION

The present application is related to U.S. patent application Ser. No. 11/176,036, entitled SOLAR ARRAY INTEGRATION SYSTEM AND METHODS THEREFOR, filed Jul. 7, 2005, the disclosure of which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates generally to a system for mounting and installing photovoltaic solar panels, and more particularly, to a photovoltaic solar panel mounting support system providing enhanced features.
2. Description of the Related Art
With the continual rise in conventional energy costs, photovoltaic solar panels (“PV panels”) are increasingly becoming cost competitive with other types of energy generation. These PV panel systems are being installed in sites of high energy usage, such as on commercial building rooftops, in industrial open areas, and in proximity to substations tied to the electric grid. These commercial energy systems, or power plants, vary in size but can cover many thousands of square feet on a building rooftop and many acres of land when installed on the ground. Roof mounted systems are particularly attractive in that business owners can elect to offset the energy consumption of their facilities through the use of existing space on the tops of their buildings.
However, such large solar arrays require a sufficiently strong support structure to support not only the weight of the array, but to also provide sufficient resistance to wind forces. Tightly spaced panels effectively form a large surface area, which could result in damage to the panels, the support structure, or both, under strong wind conditions. In addition these systems must accommodate a variety of roof types including built-up roof membranes, monolithic, synthetic membranes, shingled surfaces, and even corrugated metal roofs. In order to respond to a variety of roof deck surfaces the mounting structures must provide flexibility in contact elements and attachment means. These systems must balance the benefits of greater weight, or ballast, to resist wind forces and the load limits of the buildings upon which they are being placed which in many cases were designed to take people walking on them but not the additional load of a large mechanical array
In many installations, the solar panels are mounted in a “tilted” configuration in order to maximize the effective capture of solar radiation, i.e. the solar panels are aligned with the solar angle of incidence. In mounting tilted solar panels, however, the effects of various loads on the mounting surface, such as a roof, must be understood. The loads include standing loads and variable loads, also commonly called dead loads and live loads, respectively.
Standing loads are the result of the combined weight of the solar panels and the mounting system. These standing loads are predictable and are therefore easier to accommodate for during the installation of the solar panels and the mounting system.
Variable loads on the tilted solar panels are mainly caused by environmental conditions, such as wind, rain, snow, hail, etc. Other potential environmental hazards include seismic events, temperature extremes, debris and mold. In order to be able to reliably predict and accommodate variable loads, these environmental problems have to be understood and resolved. The most common and problematic forces are wind-related forces (including hurricanes and tornados), namely lift and drag forces generated by the wind conditions. A variety of mounting systems have been commercially available for mounting solar panels, which have attempted to address and mitigate the wind-induced forces. Most prior mounting systems can be divided into three general categories: non-tilted solar arrays; enclosed tilted solar arrays; and tilted solar panels with wind deflectors attached to every row.
U.S. Pat. No. 5,746,839 (Dinwoodie) and U.S. Pat. No. 6,570,084 (Dinwoodie) are examples of implementations involving non-tilted solar panels. While non-tilted solar panels do present a lower profile with respect to wind forces, they are less efficient at converting solar energy to electrical energy when installed at locations with higher latitudes. Another disadvantage of a non-tilted system is the accumulation of dirt, dust, debris and snow on top of the solar panels, which can further reduce the conversion efficiency of the panels.
U.S. Publication No. 2004/0128923 (Moulder) discloses an example of an enclosed tilted solar panel system. While such a design offers advantages such as improved rigidity, less debris accumulation, and better protection of electrical components, an enclosed solar panel system increase the cost and weight of the system, is likely to increase wind-induced drag forces and also significantly reduces beneficial cooling from natural airflow. The additional heat introduced into the panels by the mounting system results in lower energy output from the photovoltaic panels.
As shown in U.S. Pat. No. 6,063,996 (Takada), U.S. Pat. No. 6,809,251 (Dinwoodie) and U.S. Publication No. 2004/0250491 (Diaz), deflectors are installed on the north-facing back of every panel in order to reduce the wind-induced uplift forces, when installed in the northern hemisphere. Disadvantages of such systems include significantly increased cost and weight of the installed system. These systems also increase the required labor time for installation in that more parts must be assembled in order to complete the array. In addition, reduced cooling of the solar panels can also significantly reduce the solar conversion efficiency of the system.

SUMMARY OF THE INVENTION

In general, the present invention is a solar array mounting system having unique installation and grounding features, and which is adaptable for mounting solar panels having mounting holes located in different locations. The solar array mounting system includes tilt brackets and longitudinal links forming columns. A tilt bracket includes a tilt arm for supporting an upper spar of one row, and a pivot block for supporting a lower spar of a next row. The spars may be made from aluminum or from steel, wherein the steel spars include an exposed metal channel to provide a common electrical equipment ground. Panel clamps are used to clamp the solar panel frames to the spars, allowing for variations in mounting hole locations.
More particularly, according to one embodiment of the present invention, a spar for supporting one or more solar panels comprises a metal body forming a hollow rectangular frame and an extended section aligned with one side of the frame, a top channel in the rectangular frame, a bottom channel in the rectangular frame, and a coating covering the external surfaces of the metal body, except at least a portion of the bottom channel is uncoated metal to form an equipment ground connection surface. The spar may be pre-galvanized before a paint or powder coating is applied to the spar. In another embodiment, the spar can also be formed from extruded aluminum
According to one embodiment, a solar panel mounting clamp comprises a top section having a stud to engage a mounting hole of a solar panel, and a threaded hole, a middle section aligned parallel to and below the top section, and having an opening aligned with the threaded hole in the top section, a hinged joint connecting the top and middle sections, a bottom section extending from the middle section at a right angle at a point between the stud and the threaded hole, and having an angled end formed to attach to a spar channel, and a bolt mounted through the opening in the middle section and into the threaded hole. The panel clamp may be formed from a unitary piece of metal.
According to an alternate embodiment, a solar panel clamp comprises a pawl having a stud to engage a mounting hole on a solar panel, a wire bail to attach to a spar channel, and a hasp connected to the pawl and wire bail, the hasp including a front opening.
A pivot block according to an embodiment of the present invention comprises a metal body, a mounting hole through the metal body, an alignment groove located on a bottom of the body; a tilt-up stop groove located at a rear of the body along a curved bottom edge of the body from the alignment groove, a top groove, and a front spar engagement channel and lip.
A solar panel array system according to the present invention comprises at least one solar panel having a metal frame, an upper spar and a lower spar, each spar comprising a metal body forming a hollow rectangular frame and an extended section aligned with one side of the frame, a top channel in the rectangular frame, a bottom channel in the rectangular frame, and a coating covering the external surfaces of the metal body, except at least a portion of the bottom channel is uncoated metal to form an equipment ground connection surface, at least one solar panel clamp connecting the upper spar to the at least one solar panel frame, wherein the at least one solar panel clamp comprises a stud to engage a mounting hole of a solar panel frame, and a spar engagement member to engage the uncoated metal on the bottom spar channel, at least one solar panel clamp connecting the lower spar to the at least one solar panel frame, wherein the at least one solar panel clamp comprises, a stud to engage a mounting hole of a solar panel frame, and a spar engagement member to engage the uncoated metal on the bottom spar channel, at least two metal tilt brackets, a metal pivot block attached to a front tilt bracket and to the lower spar, the pivot block engaging the uncoated metal on the bottom of the lower spar, a tilt leg connected to a rear tilt bracket and to the upper spar, the tilt leg engaging the uncoated metal on the bottom of the upper spar, and a metal longitudinal link connecting the front and rear tilt brackets; wherein the at least one solar panel frame, the upper and lower spars, the at least two tilt brackets, the pivot block, the tilt leg and the longitudinal link are at a same equipment ground potential.
The system may further comprise a clamp block attached to each solar panel to clamp the solar panel to an upper spar and a wind deflector mounted to the upper spar.
A solar panel array system according to the present invention may comprise at least two solar panel module assemblies, each assembly comprising at least two solar panels having a metal frame, an upper spar and a lower spar, each spar comprising a metal body forming a hollow rectangular frame and an extended section aligned with one side of the frame, a top channel in the rectangular frame, a bottom channel in the rectangular frame; and a coating covering the external surfaces of the metal body, except at least a portion of the bottom channel is uncoated metal to form an equipment ground connection surface, at least one solar panel clamp connecting each solar panel frame to the upper spar, wherein the at least one solar panel clamp comprises a stud to engage a mounting hole of a solar panel frame, and a spar engagement member to engage the uncoated metal on the bottom spar channel, at least one solar panel clamp connecting each solar panel frame to the lower spar, wherein the at least one solar panel clamp comprises a stud to engage a mounting hole of a solar panel frame, and a spar engagement member to engage the uncoated metal on the bottom spar channel, at least two front metal tilt brackets and two rear metal tilt brackets, a metal pivot block attached to each front tilt bracket and to the lower spar, each pivot block engaging the uncoated metal on the bottom of the lower spar, a tilt leg connected to each rear tilt bracket and to the upper spar, each tilt leg engaging the uncoated metal on the bottom of the upper spar, a metal longitudinal link connecting each set of front and rear tilt brackets; wherein the solar panel frames, the upper and lower spars, the at least four tilt brackets, the pivot blocks, the tilt legs and the longitudinal links are at a same equipment ground potential, wherein the at least two module assemblies are connected by a lateral link.
The system may further comprise a clamp block attached to each solar panel to clamp the solar panel to an upper spar, and a wind deflector mounted to the upper spar.
If required to insure a solid metal-to-metal connection between the components the panel clamp, tilt leg and pivot block may include sharp metal protrusions (i.e. teeth) to positively engage the uncoated spar channel and/or panel frame.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:

FIG. 1A is a side view of a solar panel mounting system according to the present invention;

FIG. 1B is a perspective view of the solar panel mounting system of FIG. 1A;

FIG. 1C is a top view of the solar panel mounting system of FIG. 1A;

FIG. 2A is a side view of one embodiment of a spar according to the present invention;

FIG. 2B is a side view of a second embodiment of a spar according to the present invention;

FIG. 2C is a top perspective view of the spar of FIG. 2A;

FIG. 2D is bottom perspective view of the spar of FIG. 2A;

FIG. 3A is a side view of first panel clamp embodiment according to the present invention;

FIG. 3B is a perspective view of the panel clamp of FIG. 3A clamped to a solar panel;

FIG. 3C is a side view showing the panel clamp of FIG. 3A attached to a solar panel and spar;

FIG. 4A is a side view of a second panel clamp embodiment according to the present invention;

FIG. 4B is a perspective view of the panel clamp of FIG. 4A clamped to a solar panel;

FIG. 4C is a side view of the panel clamp of FIG. 4A attached to a solar panel and spar;

FIG. 5A is a perspective view of a pivot block according to an embodiment of the present invention;

FIG. 5B is a side view of the pivot block of FIG. 5A;

FIG. 5C is cross-sectional view of the pivot block of FIG. 5B;

FIG. 6A is a side view of a tilt leg according to an embodiment of the present invention;

FIG. 6B is a perspective view of the tilt leg of FIG. 6A;

FIG. 7 is a perspective view of a tilt bracket according to the present invention;

FIG. 8A is perspective view of a wind deflector according to the present invention;

FIG. 8B is a side view of the wind deflector of FIG. 8A;

FIG. 9A is a side view of top section of a panel clamp block according to an embodiment of the present invention;

FIG. 9B is a side view of a bottom section of a panel clamp block according to an embodiment of the present invention;

FIG. 9C is a side view of the top and bottom sections of the panel clamp attached to a solar panel and a spar;

FIG. 10A is a perspective view of a lateral link according to an embodiment of the present invention;

FIG. 10B is a side view of the lateral link of FIG. 10A installed between spars according to an embodiment of the invention;

FIG. 10C is an enlarged view of lateral link of FIG. 10B;

FIG. 11 is an enlarged side view of the solar panel mounting system;

FIG. 12 shows the panel assembly in the raised position, pivoting on the tilt brackets via the pivot blocks; and

FIG. 13 is an enlarged view of a tilt bracket showing the pivot block in position to receive a panel module.

DETAILED DESCRIPTION OF THE INVENTION

The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor for carrying out the invention. Various modifications, however, will remain readily apparent to those skilled in the art. Any and all such modifications, equivalents and alternatives are intended to fall within the spirit and scope of the present invention.
FIGS. 1A-1C illustrate the basic components of the solar array mounting system according to the present invention. The fundamental design and operation of the basic architecture is described in detail in U.S. application Ser. No. 11/176,036, entitled SOLAR ARRAY INTEGRATION SYSTEM AND METHODS THEREFOR, filed Jul. 7, 2005, the disclosure of which is herein incorporated by reference.
In general, a system may comprise a panel module 12 having one or more photovoltaic solar panels. In a preferred embodiment, three or four panels are used to form the panel module 12. The panels are attached together with an upper support bar 26 and a lower support bar 24 (the support bars are referred to as “spars” herein). Two tilt brackets 14, 16 are connected by a longitudinal link 22. Similarly, two other tilt brackets 18, 20 are connected via another longitudinal link (not shown). The front tilt brackets 14, 18 include a pivot block 28, which attaches to the lower spar 24, and which allows the panel module 12 to be raised and lowered.
The upper spar 26 is connected to a tilt leg 30, which connects to the rear tilt bracket 16. A symmetrically attached tilt leg not shown in the figures is attached to tilt bracket 20 in the same fashion. The length of the tilt leg 30 determines the tilt angle of the panel module. For typical installations, the tilt leg 30 and the hidden tilt leg, and tilt brackets 14, 16, 18 and 20 are sized to provide a tilt angle of 5°, 10°, 15° or 20°. The larger the angle, the greater the potential shading from row to row, so the rows are typically spaced farther apart. To accommodate the longer distances, the tilt brackets, tilt legs, and/or longitudinal links are longer than for lower tilt angles.
In a typical application, many tilt brackets are connected together with longitudinal links to form a column of tilt brackets and links. Parallel columns of tilt brackets and links form the support structure for multiple rows of panel modules.
Generally, on the last row of an array (northern most row in the northern hemisphere), wind deflectors 32, 34 are added to deflect wind from the underside of the array. These wind deflectors have openings 130A, 130B, 130C, 130D to allow for installation of the deflectors over the existing structure of the tilt legs 30 and the tilt brackets 16, 20. Additionally, since the rear tilt brackets on the last row of an array are not needed to support additional rows, these tilt brackets may be shortened to allow service and emergency personnel a wider access way around the perimeter of the array.
FIGS. 2A-2D illustrate the construction of the spars in greater detail. In a preferred embodiment, the spars are roll formed from 1/16″ steel. In an alternate embodiment the spars can be made from extruded aluminum. The length of a spar is determined by the number of solar panels used in an installation for the module assembly, but is typically between 12-24 feet. According to a first embodiment, illustrated in cross-section in FIG. 2A, a spar 40 has a generally rectangular hollow body (illustrated as a generally square cross-section), with a top channel 44 and a bottom channel 46. Along one edge, the metal is folded back on itself to form an extended section 42. The extended section 42 abuts the edges of the solar panel frames. The front edge 48 of the bottom channel is angled at less than 90° from vertical to facilitate the engagement of a clamp (described below). A perspective view of this embodiment is shown in FIG. 2C.
A second embodiment of a spar is shown in FIG. 2B. It has a similar construction as the spar of FIG. 2A, except that its front edge 58 of its bottom channel 56 angles away from the front edge of the spar 50. This edge 58 facilitates the engagement of a second clamp embodiment (described below).
For installed solar array systems, it is important to have a common “equipment ground” i.e. to insure that all the metal surfaces are at a common electrical ground reference. For mounting systems made entirely of aluminum or stainless steel, an equipment ground may be easily obtained since all the surfaces are conductive. As long as each component of the system is securely fastened to the other components, a good equipment ground can be obtained. In addition, most photovoltaic solar panels are manufactured with an aluminum frame around the panel. The frame includes mounting holes on the rear side of the panel for mounting the panel to a support structure. Thus, attaching the aluminum frames to a conductive support structure may provide a good ground for the panel frames.
Manufacturing all solar panel support structures and mounting hardware from either aluminum or stainless steel can be quite expensive. Certain components could be made more cheaply from standard steel. In addition, steel may provide greater strength and increased weight than aluminum, which may be desirable for particular installations. Steel, however, will corrode quickly, so steel components are often coated or painted to protect them. Once the steel components are coated, they are no longer conductive, making it more difficult to insure a good equipment ground.
One prior solution is to cover (i.e. with adhesive tape) fixed spots on the steel during the coating process. Once the coating has been applied, the covering can be removed leaving an exposed metal surface. The metal surface can then be used as a connection point with other components, or a grounding strap could be affixed via the exposed spot. The problem with this approach is that the grounding connection must occur at the exact predesigned location. This greatly reduces the flexibility of the system during installation.
Accordingly, as shown in FIG. 2D, each spar includes an uncoated bottom groove 46 to provide a common ground connection for the various components of the system, and allows the spar to be manufactured from steel, if desired, without sacrificing corrosion resistance of the spars.
In a preferred embodiment, the spars are made from steel and are first “pre-galvanized” to deposit a thin layer of zinc on the spar. This thin layer will provide fair corrosion resistance, but at a much lower cost than fully galvanizing the spars through a hot dipping process. An adhesive strip is then placed on the bottom of the bottom channel 46, 56. The spar can then be either painted or powder coated to provide additional corrosion protection. The adhesive strip is then removed to expose a metal strip along the bottom channel of the spar. Less than the entire channel could be covered by the adhesive strip, for example, only a center section where panels are most likely to be clamped to the spar could be covered, thereby coating some portion of the ends of the channel.
In the case of aluminum spars, not all the enhancements of the present disclosure may be necessary, for example the coating and/or exposed metal channels, etc.
As noted previously, solar panels typically comprise an aluminum frame, which has mounting holes on the back side. Bolts are typically placed through the holes into a support member, and fastened with a threaded nut. This is a very labor intensive process. In addition, the mounting holes would have to be perfectly aligned with corresponding mounting holes on the spars.
Accordingly, the present system utilizes a panel mounting clamp to attach the solar panel frames to the spars. A first embodiment of a suitable clamp is shown in FIGS. 3A-3C. The clamp generally comprises a top section 63, a middle section 65, and a bottom section 67. The clamp is preferably formed from a unitary piece of metal. The top section 63 of the clamp includes a stud 62, such as commercially available PEM® studs from Penn Engineering and Manufacturing, Corp. The stud 62 engages the standard mounting hole on a solar panel frame, as shown in FIGS. 3B and 3C. The top section 63 also includes a threaded hole 64 to receive a tightening bolt 70. The metal is folded back on itself at a hinged joint 66. The hinged joint 66 may be formed by, for example, removing alternate metal sections at the curved joint to form a hinge, as shown in FIG. 3B.
The middle section 65 is aligned generally parallel to and under the top section 63. It has an opening aligned with the threaded hole 64 to allow a tightening bolt 70 to pass through. At location between the stud 62 and threaded hole 64, the middle section 65 is angled at a right angle away from the top section 63. The bottom section 67 is approximately the length of the front side of a spar 40. The end 68 of the bottom section is angled to engage the angled front edge 48 of the spar 40.
To install, the angled end 68 is placed under the spar 40. The stud 62 is then placed into a mounting hole on the solar panel frame. The bolt 70 is tightened to clamp the panel 12 and spar 40 together.
A second embodiment of a panel clamp is illustrated in FIGS. 4A-4C. The panel clamp 70 comprises a pawl 71, a wire bail 76, which are connected with a hasp (buckle) 74. The pawl includes a stud 72, such as a PEM® stud available from Penn Engineering and Manufacturing, Corp. The wire bail 76 is formed with a hooked end to engage the tapered edge of the bottom channel of the second spar embodiment 50. The hasp 74 can be designed to allow for hand operation. In addition, the hasp can be formed with an opening 78, to allow a special tool or a screwdriver, etc. to be used to apply the requisite force on the hasp 74 to close and open the clamp 70, as the closing force may be higher than would be appropriate for an installation technician installing multiple clamps.
Additional “sharp” engagement features may be added to either the first or second panel clamp embodiments to insure a solid metal-to-metal connection to the bottom spar channel. For example, serrated teeth or similar features could be added to the clamp end 68 or wire bail 76. Also, similar sharp features could be added to the panel clamp where it engages the aluminum frame at the mounting hole.
Note that since the panel is not bolted to the spar, either clamp embodiment allows different types of panels, having mounting holes in different locations, to be used with the same spar design. Since the spars include a continuous upper channel, the clamps can be positioned along the channel, regardless of the location of the mounting holes on the panels (i.e. the mounting studs can extend downward into the channel at any point along the channel). This allows for a versatile support system for panels from different manufacturers. In addition, since each clamp contacts the uncoated metal strip on the bottom of the spar (or the aluminum spar), the clamp forms a ground connection between the spar and each panel frame.
For many installations, it is convenient to pre-assemble the solar panels, spars, panel clamps and pivot blocks. For example, these components may be assembled at a convenient location on the ground and then the entire assembly is lifted onto a roof. On the roof, the tilt brackets, longitudinal links, and tilt legs are pre-installed in parallel columns. Therefore, when the panel assembly is lowered into position, it is important to align the pivot blocks into their respective tilt brackets.
An improved pivot block 80 according to the present invention is shown in FIGS. 5A-5C. A pivot block 80 comprises a metal body and has a center mounting hole 84 for attaching the pivot block 80 to a tilt bracket. This also provides a “pivot” point for raising and lowering the panel assembly, if required. A rear section 87 of the pivot block 80 is generally curved. On one end of this curved section 87, at the bottom of the pivot block 80, is an alignment groove 83. This alignment groove aligns with a pre-installed bolt or pin on the tilt bracket. When the panel assembly with the pivot block 80 is lowered into the tilt brackets, the pivot block can slide along the bolt or pin until the alignment groove is positively engaged. As a result, an installer can easily install a mounting bolt through the mounting hole 84, since the pivot block will be properly aligned with holes in the tilt bracket.
The curved section 87 also includes a tilt-up stop groove 82 located at a rear of the body. The tilt-up stop groove will abut against the bolt or pin normally aligned with the alignment groove 83 whenever the panel assembly is raised (pivoting at the mounting hole 84). When the panel assembly is in the raised position, a top groove 81 on the top of the block 80 can be used to lock the entire assembly in the raised position (i.e. by placing a pin or bolt through a corresponding hole in the tilt bracket).
The front of the pivot block 80 attaches to a lower spar. Specifically, a lip 88 engages the bottom channel of a lower spar, and an engagement channel conforms to the shape of the spar. The top of the pivot block lip 88 may have a sharp protrusion that directly engages the metal in the bottom of the spar channel 46, thus forming a continuous ground path through the material. A notch 86 is configured in the front face of the body 80 to hold a threaded nut and tension spring combination. This allows the spar to be bolted to the pivot block 80 by placing a bolt through the spar. With a threaded nut held in place this can be accomplished with one hand, thereby simplifying the installation process.
A tilt leg is shown in detail in FIGS. 6A and 6B. A tilt leg 90 comprises a generally rectangular hollow metal frame. It is simply bolted to a tilt bracket on one end. The end that engages the spar includes a channel 91 to conform to the bottom shape of the spar, and a front edge 92. Specifically, the front edge 92 of top of the tilt leg 90 is designed to insure a solid metal-to-metal connection between the tilt leg 90 and the exposed metal channel on the spar. For example, the front edge 92 may have a sharp protrusion that directly engages the metal in the bottom of the spar channel, thus forming a continuous ground path through the material. The tilt leg 90 is bolted to the spar via top hole 93. Since the front edge 92 engages the bottom channel of the spar, this reduces any “twisting” by the tilt leg 90.
A tilt bracket 100 according to one embodiment of the present invention is illustrated in detail in FIG. 7. The tilt bracket 100 is formed from single metal sheet, and includes two symmetric sides 110A, 110B. Each side includes tabs 111, 112 for installing the tilt bracket 100 onto a support plate (not shown). One end of the tilt bracket 100 supports a tilt leg, which is bolted through holes 101A,101B. The other end is configured to mount a pivot block. Specifically, a pivot block is mounted to the tilt bracket 100 via hole 102 and a corresponding hole (not shown) on side 110A. An alignment pin or bolt is inserted into holes 104A, 104B. A locking pin or bolt is inserted into hole 103 (and it corresponding hole on 110A) to lock the pivot block into a raised position, when desired. To facilitate the installation of the pivot block, the top of the opening between the two sides 110A, 110B includes two tabs 105, 106. The tabs 105, 106 flare out to provide a guide for the pivot block during installation, and helps spread the sides 110A, 110B as the pivot block is inserted.
A wind defector is shown in FIGS. 8A and 8B. Wind deflectors are generally installed on the last, northern most row of a solar array installation. The wind deflectors deflect the wind from the underside of the array, thereby reducing wind uplift forces. The wind deflector 120 is configured as a single sheet of metal, which attaches to an upper spar, and to the last row of tilt brackets in an array. The wind deflector includes two openings 121, 122 to allow tilt legs to be attached to the spars and tilt brackets.
If the solar panel frames and spars are not attached at the top edge, the panel may have a tendency to “roll away” from the spar. To avoid this, clamp blocks are attached from the bottom of the spar to the top of the solar panel and the extended edge of a spar. The clamp blocks are installed between panels and in contact with the spar at the edge of the panel assembly. A clamp block assembly is illustrated in FIGS. 9A-9D. A top section 130 is configured and angled to conform to overlap the top of the solar panel 12 and the extended section of the spar 40. It includes a threaded hole (or affixed threaded nut) 131. A lower section 132 clips on to the spar 40. Specifically, a notched bottom surface 133 of the lower section 132 is configured to engage the top channel of the spar 40. The lower section includes an angled clip 134 to engage the bottom channel of the spar 40. A bolt 135 feeds through the lower section 132 and into the threaded hole or nut 131. As the bolt 135 is tightened, the top section 130 and the lower section 132 are drawn together, thereby tightening the solar panel 12 against the spar 40. In a preferred embodiment, one clamp block assembly is attached between adjacent panels in a module.
As described above, the solar panel mounting system provides an inter-connection between rows of panel modules via the tilt brackets and longitudinal links. It is also desirable to connect the panel modules together along each row by connecting the spars together. The above-described solar panel mounting system is well suited for flat surface installations, such as flat commercial roofs. However, flat commercial roofs can actually be quite uneven. In fact, the ends of the spars will often not be aligned.
To address this problem, the present mounting system includes a lateral link 140, as shown in FIGS. 10A-10B. The lateral link 140 is formed as a generally U-shaped channel 141, with mounting holes on each end. To accommodate the misalignment of the adjacent spars, the lateral link 140 includes a set of elongated mounting holes on at least one end. The holes on the outermost edge 143 may be elongated vertically, and the interior set 142 may be elongated horizontally. The U-shaped channel 141 is inserted over the outside of two adjacent spars, and is then bolted to each spar. Thus, the spars can be connected laterally, forming an inter-connection between the panel modules both laterally and longitudinally. This connection between spars forms a load sharing connection between otherwise independent columns in the solar panel array, thus better distributing the forces acting on the array.
An enlarged side view of the system according to the present invention is shown in FIG. 11. The top view is an enlarged version of FIG. 1A showing the elements in greater detail. The bottom view illustrates the connection between three rows of tilt brackets (two solar panel rows). Note that for tilt brackets in the middle of the array, one end connects to a tilt leg and an upper spar of one row, and the other end of the tilt bracket connects to a lower spar (via a pivot block) to a next row of solar panels.
FIG. 12 illustrates the advantage of using the pivot blocks—the panel assembly can be raised up as a unit, as necessary, to perform system or roof maintenance.
FIG. 13 is an enlarged view of a tilt bracket showing a pivot block mounted in position to receive a spar on the edge of a solar panel module.
Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.

Claims

1. A spar for supporting one or more solar panels, the spar comprising:

a metal body forming a hollow rectangular frame and an extended section aligned with one side of the frame;

a top channel in the rectangular frame;

a bottom channel in the rectangular frame; and

a coating covering the external surfaces of the metal body, except at least a portion of the bottom channel is uncoated metal to form an equipment ground connection surface.

2. The spar of claim 1, wherein the spar comprises a pre-galvanized metal body.

3. The spar of claim 1, wherein the bottom channel includes a front tapered edge.

4. The spar of claim 3, wherein the front tapered edge of the bottom channel is less than 90° from vertical.

5. The spar of claim 3, wherein the front tapered edge of the bottom channel angles away from a front edge of the spar.

6. The spar of claim 1, wherein at least an entire bottom portion of the bottom channel is uncoated.

7. The spar of claim 2, wherein the coating is one of paint and a powder coating.

8. A solar panel mounting clamp comprising:

a top section comprising:

a stud to engage a mounting hole of a solar panel; and

a threaded hole;

a middle section aligned parallel to and below the top section, and having an opening aligned with the threaded hole in the top section;

a hinged joint connecting the top and middle sections;

a bottom section extending from the middle section at a right angle at a point between the stud and the threaded hole, and having an angled end formed to attach to a spar channel; and

a bolt mounted through the opening in the middle section and into the threaded hole.

9. The solar panel mounting clamp of claim 8, wherein the top, middle and bottom sections are formed from a unitary piece of metal, and the hinged joint is formed by removing material at intervals along a joint edge.

10. A solar panel clamp comprising:

a pawl having a stud to engage a mounting hole on a solar panel;

a wire bail to attach to a spar channel; and

a hasp connected to the pawl and wire bail, the hasp including a front opening.

11. The solar panel clamp of claim 10, wherein the clamp is metal and the opening is configured to interface with a fastening and opening tool.

12. A pivot block comprising:

a metal body;

a mounting hole through the metal body;

an alignment groove located on a bottom of the body;

a tilt-up stop groove located at a rear of the body along a curved bottom edge of the body from the alignment groove;

a top groove; and

a front spar engagement channel and lip.

13. The pivot block of claim 12, further comprising a notch in a front surface of the body next to the front spar channel, the notch configured to hold a threaded nut and tension spring.

14. A solar panel array system comprising:

at least one solar panel having a metal frame;

an upper spar and a lower spar, each spar comprising:

a top channel in the rectangular frame;

a bottom channel in the rectangular frame; and

a coating covering the external surfaces of the metal body, except at least a portion of the bottom channel is uncoated metal to form an equipment ground connection surface;

at least one solar panel clamp connecting the upper spar to the at least one solar panel frame, wherein the at least one solar panel clamp comprises:

a stud to engage a mounting hole of a solar panel frame, and

a spar engagement member to engage the uncoated metal on the bottom spar channel;

at least one solar panel clamp connecting the lower spar to the at least one solar panel frame, wherein the at least one solar panel clamp comprises:

a stud to engage a mounting hole of a solar panel frame, and

at least two metal tilt brackets;

a metal pivot block attached to a front tilt bracket and to the lower spar, the pivot block engaging the uncoated metal on the bottom of the lower spar;

a tilt leg connected to a rear tilt bracket and to the upper spar, the tilt leg engaging the uncoated metal on the bottom of the upper spar; and

a metal longitudinal link connecting the front and rear tilt brackets; wherein the at least one solar panel frame, the upper and lower spars, the at least two tilt brackets, the pivot block, the tilt leg and the longitudinal link are at a same equipment ground potential.

15. The solar array system of claim 14, further comprising a clamp block attached to each solar panel to clamp the solar panel to an upper spar.

16. The solar array system of claim 15, further comprising a wind deflector mounted to the upper spar.

17. The solar array system of claim 14, wherein the panel clamp comprises:

a top section comprising:

a stud to engage a mounting hole of a solar panel; and

a threaded hole;

a hinged joint connecting the top and middle sections;

18. The solar array system of claim 17, wherein the top, middle and bottom sections of the panel clamp are formed from a unitary piece of metal, and the hinged joint is formed by removing material at intervals along a joint edge.

19. The solar array system of claim 14, wherein the panel clamp comprises:

a pawl having a stud to engage a mounting hole on a solar panel;

a wire bail to attach to a spar channel; and

a hasp connected to the pawl and wire bail, the hasp including a front opening.

20. The solar array system of claim 14, wherein the pivot block comprises:

a metal body;

a mounting hole through the metal body;

an alignment groove located on a bottom of the body;

a top groove; and

a front spar engagement channel and lip.

21. The solar array system of claim 20, wherein the pivot block further comprises a notch in a front surface of the body next to the front spar channel, the notch configured to hold a threaded nut and tension spring.

22. A solar panel array system comprising:

at least two solar panel module assemblies, each assembly comprising:

at least two solar panels having a metal frame;

an upper spar and a lower spar, each spar comprising:

a top channel in the rectangular frame;

a bottom channel in the rectangular frame; and

at least one solar panel clamp connecting each solar panel frame to the upper spar, wherein the at least one solar panel clamp comprises:

a stud to engage a mounting hole of a solar panel frame, and

at least one solar panel clamp connecting each solar panel frame to the lower spar, wherein the at least one solar panel clamp comprises:

a stud to engage a mounting hole of a solar panel frame, and

at least two front metal tilt brackets and two rear metal tilt brackets;

a metal pivot block attached to each front tilt bracket and to the lower spar, each pivot block engaging the uncoated metal on the bottom of the lower spar;

a tilt leg connected to each rear tilt bracket and to the upper spar, each tilt leg engaging the uncoated metal on the bottom of the upper spar;

a metal longitudinal link connecting each set of front and rear tilt brackets; wherein the solar panel frames, the upper and lower spars, the at least four tilt brackets, the pivot blocks, the tilt legs and the longitudinal links are at a same equipment ground potential;

wherein the at least two module assemblies are connected by a lateral link.

23. The solar array system of claim 22, further comprising a clamp block attached to each solar panel to clamp the solar panel to an upper spar.

24. The solar array system of claim 23, further comprising a wind deflector mounted to the upper spar.

25. The solar array system of claim 22, wherein the panel clamp includes metal protrusions to engage the solar panel frame and the bottom channel of the spar.

26. The solar array system of claim 22, wherein the tilt leg includes metal protrusions to engage the bottom channel of the spar.

27. The solar array system of claim 22, wherein the pivot block includes metal protrusions to engage the bottom channel of the spar.

28. A solar array mounting system comprising:

at least one solar panel having a metal frame;

an upper spar and a lower spar;

at least one solar panel clamp connecting the upper spar to the at least one solar panel frame,

at least two metal tilt brackets;

a metal pivot block attached to a front tilt bracket and to the lower spar, the pivot block engaging the lower spar;

a tilt leg connected to a rear tilt bracket and to the upper spar, the tilt leg engaging the upper spar; and

a metal longitudinal link connecting the front and rear tilt brackets;

wherein the at least one solar panel frame, the upper and lower spars, the at least two tilt brackets, the pivot block, the tilt leg and the longitudinal link are at a same equipment ground potential.

29. A solar panel mounting system comprising:

an upper spar and a lower spar for mounting at least one solar panel frame;

a stud to engage a mounting hole of a solar panel frame, and

a spar engagement member to engage the upper spar;

a stud to engage a mounting hole of a solar panel frame, and

a spar engagement member to engage the lower spar.