PHOTOVOLTAIC MOUNTING SYSTEM FOR SOLAR TRACKER ARRAY

Abstract

Mounting systems are disclosed for attaching photovoltaic modules to torque tubes. Such systems can include saddle brackets that maximize space along a torque tube by sharing torque tube mounting holes between adjacent brackets. The brackets can be positionally stable on the torque tube prior to complete installation to enable a single installer to assemble a complete tracker array.

Claims

1. A photovoltaic (PV) module mounting system for a solar tracker array comprising: a first PV mounting bracket comprising a first saddle portion for supporting a first PV module, the first PV mounting bracket further comprising a first collar portion shaped to fit around a portion of a torque tube, the first collar portion having at least one first mounting hole; and a second PV mounting bracket comprising a second saddle portion for supporting a second PV module, the second PV mounting bracket further comprising a second collar portion shaped to fit around a portion of the torque tube, the second collar portion having at least one second mounting hole aligned with the first mounting hole, the first and second mounting holes for receiving a mechanical fastener to attach the first and second PV mounting brackets to the torque tube.

2. The PV module mounting system of claim 1, wherein each of the first and second saddle portions comprise a plurality of attachment tabs arranged to constrain a top portion of a PV module.

3. The PV module mounting system of claim 2, wherein each of the first and second saddle portions comprise a plurality of ledge portions arranged to constrain a bottom portion of a PV module.

4. The PV module mounting system of claim 1, wherein the first and second collar portions respectively comprise first and second alignment tabs arranged to oppose the first and second mounting holes, each of the first and second alignment tabs fitting into the torque tube.

5. The PV module mounting system of claim 4, wherein the first and second collar portions respectively comprise first and second alignment portions arranged adjacent to the first and second mounting holes, the first and second alignment portions configured to provide leverage points for aligning the first and second mounting holes with a fastener opening of the torque tube.

6. The PV module mounting system of claim 1, wherein each of the first and second PV mounting brackets comprises at least one stiffening rib.

7. The PV module mounting system of claim 1, wherein the first and second collar portions respectively comprise third and fourth mounting holes arranged to oppose the first and second mounting holes, the third and fourth mounting holes being configured to overlap for receiving a second mechanical fastener.

8. A photovoltaic (PV) module mounting bracket for a solar tracker array comprising: a collar portion shaped to mount to at least a portion of a torque tube of a solar tracker array, the collar portion comprising at least one mounting tab having at least one mounting hole, the at least one mounting tab being positioned to overlap with another mounting tab of a second PV mounting bracket to share a fastener for mounting to a torque tube; and a saddle portion having at least one ledge portion configured to support a bottom portion of a PV module and at least one attachment tab configured to resiliently retain an upper portion of the PV module to the at least one ledge portion.

9. The PV module mounting bracket of claim 8, wherein the collar portion comprises an alignment tab configured to insert into an opening of the torque tube.

10. The PV module mounting bracket of claim 9, wherein the alignment tab comprises a folded portion of sheet metal.

11. The PV module mounting bracket of claim 10, wherein the folded portion is attached to a wall portion of the collar portion.

12. The PV module mounting bracket of claim 8, wherein a wall extends between the collar portion and the saddle portion, wherein the wall comprises at least one bumper portion.

13. The PV module mounting bracket of claim 12, wherein the least one ledge portion extends in a first direction and wherein the bumper portion extends in an opposite direction from the first direction to prevent the saddle portion from backing off the PV module.

14. A photovoltaic (PV) mode mounting bracket for a solar tracker array comprising: a wall member; a plurality of saddle supports extending from the wall member, the plurality of saddle supports for supporting one edge of a PV module; a plurality of collar members extending from the wall member, the plurality of collar members arranged to mount onto a torque tube.

15. The PV module mounting bracket of claim 14, wherein the wall portion comprises at least one reinforcement rib extending laterally away from the wall member.

16. The PV module mounting bracket of claim 14, wherein the plurality of saddle supports comprise upper attachment tabs configured to apply compressive force to the one edge of the PV module.

17. The PV module mounting bracket of claim 16, wherein the plurality of saddle supports comprise ledge portions configured to support the one end of the PV module against the compressive force provided by the upper attachment tabs.

18. The PV module mounting bracket of claim 14, further comprising a tab portion extending from the wall member, the tab portion configured to support a mechanical fastener for connection to the torque tube.

19. The PV module mounting bracket of claim 18, further comprising an alignment tab extending from the wall member, the alignment tab configured to extend into an opening of the torque tube.

20. The PV module mounting bracket of claim 14, wherein the plurality of collar members are configured to resiliently bias against the torque tube.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIGS. 1A and 1B show mounting brackets for a solar tracker according to various embodiments of the invention.

[0011] FIGS. 1C through 1G show processes for mounting brackets for a solar tracker according to various embodiments of the invention.

[0012] FIGS. 1H and 1I show mounting brackets for a solar tracker according to various embodiments of the invention.

[0013] FIG. 2 shows a mounting bracket for a solar tracker according to various other embodiments of the invention.

[0014] FIGS. 3A and 3B show a mounting bracket for a solar tracker according to still further embodiments of the invention.

[0015] FIG. 4 shows a mounting bracket for a solar tracker according to additional embodiments of the invention.

[0016] FIGS. 5 through 10C show incremental steps of a process for installing photovoltaic modules on a torque tube with the mounting bracket of FIG. 4 according to various embodiments of the invention.

[0017] FIGS. 11A and 11B show a process for uninstalling a photovoltaic module from a torque tube with the mounting bracket of FIG. 4 according to various embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0018] Referring now to the drawing figures, FIG. 1A illustrates a mounting system for a solar tracker according to various embodiments of the invention. The system can include bracket 100 that can include wall member 101, which can extend along a plane. Various features can extend from wall member 101, including for example, a plurality of ledge portions 105, plurality of attachment tabs 110, and collar portion 115. Such features can be formed from by cutting and bending shapes from wall member 101.

[0019] FIG. 1B shows an alternative arrangement of bracket 100, which shares many of the same features of the bracket shown at FIG. 1A, where wall member can include reinforcement portions 102. Reinforcement portions 102 can extend as ribs along wall member 101 and protrude outwardly or inwardly from a PV module that bracket 100 mounts to. Bumper portions 104 protrude outwardly from a PV module that bracket 100 mounts to. In this manner, bumper portions 104 can act as a spacer and bumper to a directly adjacent PV module and bracket having a similar reinforcement rib facing the opposite direction. This arrangement can help prevent excessive movement between PV modules and brackets, and thus help prevent the PV modules from backing out of the brackets due to wind-induced bracket sway. In addition, gussets 103 can be located at various locations along bracket 100, primarily where bends are located to help strengthen bracket 100.

[0020] With reference to both FIGS. 1A and 1B, ledge portions 105 can extend from one side of wall member 101. Ledge portions 105 can support a bottom surface of a PV module. As shown, ledge portions 105 can extend in a extend in a generally transverse (e.g., 90 degrees) manner from wall member 101, however, ledge portions 105 can also extend from wall member 101 at non-transverse angles (e.g., 70-85 degrees) as well, in order to provide spring bias (i.e., clamping force) against a PV module. Ledge portions 105 are shown extending as tab shaped elements having planer profiles. Here, ledge portions 105 are depicted to be rectangular, however, other shapes are possible as well, such as circular or triangular.

[0021] Attachment tabs 110 can also extend from wall member 101 to help support upper portions of a PV module. Attachment tabs 110 are shown as hook-like protrusions that extend laterally from wall member 101 down towards ledge portions 105. Attachment tabs 110 can extend at angles that intersect planes that extend along ledge portions 105. Attachment tabs 110 and ledge portions 105 cooperate to constrain a PV module, and hence make up portions of a so-called “saddle” for securing one side of a PV module to a torque tube. In some cases, attachment tabs 110 can form an electrical connection with a PV module to serve as a grounding path.

[0022] Collar portion 115 is generally shaped to fit around a torque tube, and is formed about a shape that is complimentary to a torque tube, which here is hexagonal for fitment onto round or hexagonal torque tubes. Other variations are possible too, such as rectangular or rounded shapes. Collar portion 115 is shown as a plurality of petal-like collar members 116 that extend laterally from wall member 101. Three of such collar members 116 are depicted in FIG. 1A-1B, but more or less of collar members 116 can be used. In addition, one or more of collar members 116 can include mounting holes 118 that can serve as attachment locations for additional fasteners or fastening mechanisms such as hooks or clasps.

[0023] Collar portion 115 may include rivet tab 120 with rivet hole 121 for attaching saddle bracket 100 to one side of a torque tube, and alignment tab 125 for attaching bracket 100 to an opposite side of the torque tube. Alignment tab 125 can include a protrusion for fitting into an opening of a torque tube. Alignment tab 125 can be formed from a portion of wall member 101, by folding for example. Alternatively, alignment tab 125 can be formed from additional material, for example a sheet metal portion that is spot welded, riveted, or bonded to wall member as depicted at FIG. 1B.

[0024] Rivet hole 121 and alignment tab 125 can be located on or proximate to the same plane that wall member 101 extends long. This arrangement can help maximize space along a torque tube by allowing sharing of fastener holes between adjacent brackets of directly adjacent first and second PV modules. That is, a first bracket of a first PV module can share the mounting holes on a torque tube with a second bracket of a second PV module. This can be performed by each alignment tab being located within a shared hole within the torque tube while the rivet tabs 120 overlap to such that rivet holes 121 are concentrically located over a shared rivet hole of torque tube. While it is not necessary that rivet hole 121 and alignment tab 125 can be located on the same plane of bracket 100 to achieve these goals, such an arrangement helps maximize space and evenly distribute stress along the array, while providing a uniform arrangement of brackets. It should be appreciated that a rivet is not the only possible means of attachment—a screw, bolt, or other suitable fastener could be used with rivet tabs 120 to attach bracket 100 to the torque tube.

[0025] In various embodiments, a torque tube may be fabricated to include mounting holes and alignment holes along its length so that brackets 100 may be used to attach several photovoltaic modules to the torque tube at the same orientation. As shown at the variation of bracket 100 as shown at FIG. 1B, rivet tab 120 can also include pull hole 122, that can serve as a grabbing location for a tool to leverage rivet hole 121 into location over a matching hole of a torque tube while alignment tab 125 is located within the torque tube. Alternatively, a hook or other shape could be used for this purpose.

[0026] In various embodiments bracket 100 will be made in left-handed and right-handed versions with the significant difference being the orientation of rivet tab 120 and alignment tab 125 is opposite. Alternatively, holes may be formed in the torque tube to allow the same bracket to be used on the left side and right side. In various embodiments, bracket 100 may be formed out of a single piece of sheet metal that is stamped and bent into the appropriate shape. However, it may also be fabricated from roll-formed metal, casting, or some other process.

[0027] FIGS. 1C and 1D depict a sequence for installing photovoltaic modules PVM on a torque tube using bracket 100. Left and right-handed brackets 100 can be installed on each side of photovoltaic module PVM prior to placing photovoltaic module PVM on the torque tube. At FIG. 1C, attachment tabs 110 are secured onto a top portion of photovoltaic module PVM by, for example, hooking ends of attachment tabs 110 onto grooves or ledges of photovoltaic module PVM. In the view shown, bracket 100 can then be rocked or pivoted counter-clockwise or “snapped” to the position shown at FIG. 1D such that ledge portions 105 secure to a bottom portion of photovoltaic module PVM. After snapping into place, the resilient nature of attachment tabs 110 and ledge portions 105 can forcibly hold photovoltaic module PVM in place by applying compressive force to photovoltaic module PVM.

[0028] FIGS. 1E and 1F depict a sequence for positioning photovoltaic module PVM and attached brackets 100 onto torque tube TT. At FIG. 1E, an installer can place one side of photovoltaic module PVM onto torque tube TT and then push photovoltaic module PVM according to the directional arrow to place collar portion 115 onto torque tube TT. As shown, a flat angled portion of bracket 100 may serve as a ramp to guide collar portion 115 onto torque tube TT. At FIG. 1F, after collar portion 115 is over torque tube TT, photovoltaic module PVM can be rotated until alignment tab 125 falls into an opening of torque tube TT. While secured by alignment tab 125, photovoltaic module PVM can be temporarily left hanging in the position shown to allow the installer to install an adjacent photovoltaic module PVM or rivet bracket 100 to torque tube TT.

[0029] In some cases, collar portions 116 can be arranged to resiliently deform when securing bracket 100 to torque tube TT. As such, collar portions 116 can be angled to resist bending and thus provide some spring bias. Such an arrangement can help secure bracket 100 and prevent movement after installation, but also can challenge natural alignment of rivet hole 121 with a corresponding hole within torque tube TT. In cases of brackets 100 having secondary pull holes 122, such as shown at FIG. 1B, pull holes 122 can be used as points to secure wrench W when attaching left and right brackets 100L/R to torque tube TT, as depicted at FIG. 1G. Wrench W can be leveraged about torque tube TT to pull rivet holes 121 of overlapping rivet tabs 120 into position for riveting to torque tube TT.

[0030] The installer can use the torque tube as a pivot to rest the weight of the module on, held in place by collar portion 115 while the assembly (collars and photovoltaic module PVM) are rotated about torque tube TT until orientation tabs 125 on either side of the module rests in its corresponding opening in the torque tube. Bracket 100 may also include an additional rivet hole 126, as shown at FIG. 1A, that allows one bracket 100 to be riveted to an adjacent bracket, further strengthening the attachment of the modules to the torque tube. Using bracket 100, post-installation disconnection of a particular module requires simply cutting or grinding the rivet or removing the other mechanical fastener connecting bracket 100 to the torque tube, and if applicable, to the adjacent saddle bracket.

[0031] FIG. 1H shows an alternative construction of bracket 100 that shares many of the same numbered aspects of the brackets depicted at FIGS. 1A and 1B. However, here, no alignment tab is present, but rather two rivet tabs 120 are provided for double riveting of bracket 100 to a torque tube. In addition, collar portion 115 includes location tab 117 that can insert into a supplementary opening of a torque tube. Location tab 117 serves to help maintain bracket 100 in position while rivets can be secured to rivet tabs 120.

[0032] FIG. 1I shows another alternative construction of bracket 100 that shares many of the same numbered aspects of the brackets depicted at FIGS. 1A and 1B. However, here rivet tab 120 and alignment tab 125 are not coplanar with a plane that wall member 101 extends along. Accordingly, sharing of mounting holes on a common torque tube between adjacent brackets 100 is not intended or needed. Such a bracket 100 can be used at ends of a tracker array, or when an individual set of mounting holes per bracket 100 is desired. In addition, here alignment tab 125 is configured to have a separate body that bolts to a portion of wall member 101 by way of fasteners 127, which can be bolts or rivets for example. Alignment tab 125 can be constructed from a stamped or cast metal body for example, and be configured to use one or more fasteners for attachment to wall member 101.

[0033] Referring now to FIG. 2, this figure shows another photovoltaic mounting system for attaching solar panels to a torque tube. Saddle bracket 200 is similar to saddle bracket 100 with a few notable differences. First, saddle bracket 200 is not handed—in other words, the same bracket may be used for either side of a PV module. Also, as shown, bracket 200 is two-sided, so a single bracket will connect to PV modules on both sides of bracket 200. This can reduce the number of brackets from 2× the number of PV modules to 1× the number of modules +1.

[0034] Similar to bracket 100, bracket 200 can have a collar portion 215 that fits around the torque tube that may include pair of rivet tabs 220 that match up with holes fabricated in the torque tube. It should be appreciated that a rivet is not the only possible means of attachment—a screw, bolt, or other suitable fastener could be used with rivet tabs 220 to attach saddle bracket 200 to the torque tube.

[0035] Bracket 200 can have at least two pairs of opposing ledge portions 205 that support the frame of a PV module from below. Bracket 200 can also have a plurality of attachment tabs 210 that serve to bias the frame of a PV module against the opposing ledge portions 205 on either side of bracket 200.

[0036] During installation, at least one bracket 200 can be installed directly to the torque tube first, before any PV modules are placed. Then, a PV module with an identical bracket pre-attached to other side can be pivoted in at an angle and pressed down to bend back attachment tabs 205 until the module frame rests on one set of ledge portions 205 and the alignment tab returns back to the rest position with the downturned edge of the tab pressing against the top of the module frame. Then the next module can be placed in the same manner, and so on and so forth until all modules have been attached to the torque tube. The modules can have a timing mark or other feature to inform the installer as to the desired position of the module with respect to saddle bracket 200 so that all modules are attached to the brackets at the same place along the module frame, such as, for example, at or near the middle of the module frame. Given its substantially uniform construction, the middle should roughly correspond the center of mass.

[0037] Using saddle bracket 200, disconnection of a particular module may be accomplished using a special tool to push the attachment tabs holding that module down on either side out of the way to release the module from tabs 210.

[0038] Referring now to FIGS. 3A and 3B, these figures shows yet another photovoltaic mounting system for attaching PV modules to a torque tube according to various embodiments of the invention. Bracket 300 can include collar portion 308 with rivet tabs 330 that are used to attach bracket 300 to a torque tube. Like bracket 200, bracket 300 can be first attached to the torque tube using rivets or other suitable mechanical fasteners before any PV modules are attached.

[0039] Bracket 300 can also have a pair of opposing module ledges 305 on either side of vertical spine portion 310. This enables modules to be installed on either side of bracket 300 requiring 1× the number of modules +1 such brackets per torque tube. At one end of spine portion 310, bracket 300 can have several attachment tabs 315 that bias the frames of adjacent PV modules down against ledge 305.

[0040] The other end of vertical spine portion 315 can include rotating cam lock 320 that is used to manually lock down a pair of PV modules after they are placed on either side of bracket 300. In various embodiments lever portion 325 is rotated down to free cam lock 320 to the relaxed position as depicted at FIG. 3A. After two modules are set, lever portion 325 is rotated to effect a corresponding rotation of cam lock 320 so that it covers a portion of the frame of each module instead of covering spine portion 310. Then, lever portion 325 is pressed upwards thereby pulling down on cam lock 320 to bias the module frames against shelf portion 305, as depicted at FIG. 3B. Although in the figure, lever portion 325 is designed for manual adjustment, it is possible that in other embodiments, a tool may be used to facilitate the locking and unlocking process.

[0041] Referring now to FIG. 4, this figure shows a photovoltaic mounting system for attaching PV modules to a torque tube according to further embodiments of the invention. This system includes bracket 400. Bracket 400 is similar to bracket 200 in that it is a two-sided bracket. Bracket 400 can include collar portion 420, which in turn can include torque tube rivet tabs 425 for attaching bracket 400 to a torque tube. Opposing ledge portions 410 can be located at either side of main body 405 to support the frames of two adjacent PV modules. Bracket 400 can also include opposing attachment tabs 415, some of which face one side and others of which face the opposing side.

[0042] One feature that distinguishes bracket 400 from other brackets disclosed herein (e.g., 100, 200, & 300), is that half of attachment tabs 415 have a bolt 416 that enables the tab to be removed from below. With this configuration, every module will have one set of attachment tabs that are removable, making it easier to remove a defective/non-functional module without having to remove the collar. This is discussed in greater detail in the context of FIGS. 11A and 11B. This bolting arrangement is not exclusive to bracket 400, and can be used with any of the brackets disclosed herein.

[0043] Referring now to FIGS. 5-10C, these figures show various steps in the installation of PV modules onto a tracker array using the saddle bracket 400 of FIG. 4. For example, starting with FIG. 5, the first bracket 400 is installed on the torque tube by riveting it or otherwise affixing it through rivet tabs 425. Then, as shown in FIG. 6A, the first module is pivoted down under the detachable attachment tabs 415. As seen in FIG. 6A, in various embodiments, the detachable attachment tabs, that is the ones with bolts 416 may be shaped differently (e.g., 400B) than the other attachment tabs (e.g., 400A) because one bracket is already pre-attached to the torque tube when the module is attached and the other is not.

[0044] As seen at FIG. 7, in various embodiments the next saddle bracket 400 is attached to the PV module off of the torque tube so that when each module is pivoted under the attached bracket 400 it already has a bracket on the other side that can then be riveted to the torque tube. So each time a subsequent module is dropped on the torque tube to be attached to an existing saddle bracket, it will provide another existing open saddle bracket for the next module, and so on, and so forth until all modules have been attached to the torque tube. This sequence is depicted at FIGS. 8A to 8C. At FIG. 8A, module PVM and attached right-most bracket 400 is placed onto torque tube TT, which already has left most located bracket 400 attached. Then, at FIG. 8B the module PVM is slid towards the pre-attached bracket until the configuration of FIG. 8C is achieved.

[0045] FIGS. 9A and 9B show with greater detail how a PV module with an attached saddle bracket is slid into a pre-installed saddle bracket. The upturned lip on the attachment tab 415 allows the module to be slid underneath it without catching. Because the other saddle bracket is attached off of the torque tube, it doesn't require the upturned lip. FIG. 10 shows how the process is repeated with additional modules. A next module with one attached saddle bracket is dropped down on the torque tube so that the collar portion 420 engages the torque tube. Then, it is slid laterally along the torque tube in the direction of the pre-attached saddle bracket until the module clicks under it (as seen in FIG. 9C).

[0046] FIGS. 11A and 11B shows the process for removing a module that is attached using saddle bracket 400, or any bracket using removable holding tabs. This may need to be done, for example, if a module, junction box, or other component fails. The process is accomplished by removing bolt 416 holding tab 415B on to saddle bracket 400. This can be done from underneath the module, as shown at FIG. 11A, making it easier for the technician and eliminating the need to rotate torque tube TT to a particular orientation so that the technician can get above the array. After tabs 415B have been removed, the module can simply be pushed up from the bottom. This will release it from tabs 415A of the opposing saddle bracket. A new module can simply dropped down in and tabs 415B re-attached to lock it in place.

[0047] The various embodiments of the invention have been discussed in the context of a single axis tracker, however, it should be appreciated that the saddle brackets discussed herein may also be usable with a dual-axis tracker or even possibly a stationary ground mounted solar array. Furthermore, the drawings included herewith are exemplary only and are not intended to limit the various embodiments of the invention to a particular geometry, design or materials. Those of ordinary skill in the art will understand and appreciate that various modifications and/or substitutions may be made without departing from the spirit or scope of the invention.