WO2019113650A1

WO2019113650A1 - A solar tracker

Info

Publication number: WO2019113650A1
Application number: PCT/AU2018/051342
Authority: WO
Inventors: Benjamin Thomas Wynn
Original assignee: WYNERGY Pty Ltd
Priority date: 2017-12-16
Filing date: 2018-12-14
Publication date: 2019-06-20

Abstract

The present invention is directed broadly to a solar tracker (10) comprising a first elongate member (12) adapted to support a first solar collector (14), and a second elongate member (16) substantially aligned with the first member (12) and adapted to support a second solar collector (18). The solar tracker (10) also comprises a first support stand (28) arranged support a proximal end of the first member (12), an intermediate support stand (30) arranged to support a distal end of the first member (12) and a proximal end of the second member (16), and a second support stand (32) arranged to support a distal end of the second member (16). The solar tracker (10) also comprises a drive assembly coupled to the first member (12) to effect its rotation. The solar tracker further comprises a coupling assembly coupled between the first member (12) and second member (16) wherein rotation of the first member (12) via the drive assembly effects rotation of the second member (16) together with the first member (12).

Description

A SOLAR TRACKER

Technical Field

[0001 ] The present invention relates broadly to a solar tracker for the collection of solar energy and relates particularly, although not exclusively, to a solar tracker of a modular construction.

Background of Invention

[0002] Conventional solar trackers include spaced apart and large diameter posts interconnected by a single horizontal beam. The posts are ground mounted typically with significant structurally reinforced footings. The horizontal beam includes framework to which an array of solar panels is rail-mounted. The horizontal beam may rotate about its elongate axis to allow the solar panels to “track” the position of the sun to thereby increase the amount of solar energy collected.

Summary of Invention

[0003] According to the present invention there is provided a solar tracker comprising:

a first elongate member adapted to support a first solar collector;

a second elongate member substantially aligned with said first member and adapted to support a second collector;

a first support stand arranged to support a proximal end of the first member;

an intermediate support stand arranged to support a distal end of the first member and a proximal end of the second member;

a second support stand arranged to support a distal end of the second member;

a drive assembly coupled to the first member to effect its rotation;

a coupling assembly coupled between the first member and the second member wherein rotation of the first member via the drive assembly effects rotation of the second member together with the first member. [0004] Preferably the first and the second support stands are of a tripod configuration including a bracing leg aligned with the first and the second members and adapted to be ground anchored to stabilise the solar tracker under end to end shear load. More preferably the bracing leg for each of the first and the second support stands is directed inward of the solar tracker.

[0005] Preferably the coupling assembly is mounted to the intermediate support stand. More preferably the coupling assembly includes an intermediate shaft connected between the first and the second members, the intermediate shaft mounted for rotation within an intermediate bearing mounted to the intermediate support stand.

[0006] Preferably the coupling assembly also includes a pair of intermediate adaptor sub-assemblies mounted to respective of the distal end of the first member and the proximal end of the second member, the intermediate shaft coupled between the pair of intermediate adaptor sub-assemblies to provide rotation of the first and the second members in concert. More preferably the intermediate shaft is of a split configuration including a pair of stub shafts interconnected by a flexible coupling. Even more preferably the intermediate bearing is one of a pair of intermediate bearings mounted to the intermediate support stand either side of the flexible coupling. Still more preferably each of the intermediate adaptor sub- assemblies includes an adaptor housing connected to either the first or the second members and within which a hub assembly is mounted, the hub sub-assembly being rotationally secured to the intermediate shaft for rotation of the first and the second members. Yet even more preferably the hub sub-assembly is one of a pair of hub sub-assemblies mounted within the intermediate adaptor housing. Yet still more preferably the intermediate shaft includes an axially oriented key arranged to engage a corresponding keyway in at least one of the hub sub-assemblies, the key and the keyway cooperating to permit axial movement of the intermediate shaft relative to the hub sub-assemblies whilst preventing relative rotational movement between said shaft and said hub sub-assemblies.

[0007] Preferably the drive assembly includes a motor operatively coupled to the first member via a gearbox for rotation of the first member. More preferably the solar tracker also comprises a first adaptor sub-assembly mounted to the proximal end of the first member, and a first stub shaft rotationally secured to the first adaptor sub-assembly and operatively coupled to the gearbox for rotation of the first member via the motor and the gearbox. More preferably the first adaptor sub- assembly includes a first bearing within which the first stub shaft is mounted for rotation, the first bearing mounted to the first support stand.

[0008] Preferably the solar tracker further comprises a second adaptor sub- assembly mounted to the distal end of the second member, and a second stub shaft rotationally secured to the second adaptor sub-assembly and mounted for rotation within a second bearing mounted to the second support stand.

[0009] Preferably the first or second adaptor sub-assembly includes a first or a second adaptor housing connected to either the first or the second members, and a first or a second pair of hub sub-assemblies mounted within the first or the second adaptor housing and being rotationally secured to the first or the second stub shafts for rotation of the first or the second member, respectively. More preferably the first or the second stub shaft includes an axially oriented key arranged to engage a corresponding keyway in at least one of the first or the second pair of hub sub- assemblies, the key and the keyway cooperating to permit axial movement of the first or the second stub shaft relative to the first or the second hub sub-assembly whilst limiting relative rotational movement between said stub shaft and said hub sub-assembly.

[0010] Preferably the solar tracker also comprises ground anchorages secured to a base of respective of the support stands, each of the ground anchorages including at least one pile member adapted to be driven into the ground. More preferably the ground anchorage also includes a bracket connected to a head of the pile member. Still more preferably the support stand includes a foot member configured for clamping to the bracket. Even more preferably the bracket includes a pair of aligned bracket slots arranged to cooperate with a pair of parallel foot slots includes in the foot member and disposed perpendicular to the bracket slots wherein a pair of clamp fasteners located in respective of one of the pair of the foot and the bracket slots and the other of the pair of the foot and the bracket slots clamp the foot member to the bracket at one of a plurality of horizontal positions depending on the location of the pile member relative to the support stand.

[0011 ] Preferably the solar tracker is of a modular construction wherein the second elongate member and the second support stand is one of a plurality of elongate members and support stands aligned and interconnected with one another.

[0012] Preferably the first and the second elongate members and support stands together with the intermediate stand are repeated on an opposing sides of the drive assembly. More preferably the same drive assembly is operatively coupled to both of the opposing first members and thus arranged for rotation of the opposing first and second elongate members together.

Brief Description of Drawings

[0013] In order to achieve a better understanding of the nature of the present invention a preferred embodiment of a solar tracker will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a perspective view illustrating a solar tracker of a first embodiment;

Figure 2 is a side view illustrating the solar tracker of figure 1 ;

Figure 3 is a top view illustrating the solar tracker of figures 1 and 2;

Figure 4 is a sectional view illustrating the solar tracker at Section 4-4 as illustrated on Figure 3;

Figure 5 is a sectional view illustrating the solar tracker at Section 5-5 as illustrated on figure 3;

Figure 6 is a perspective view illustrating a second embodiment of a solar tracker; Figure 7 is a side view illustrating the second embodiment of the solar tracker; Figure 8 is a top view illustrating the second embodiment of the solar tracker; Figures 9 and 10 are exploded and assembled views of aground anchorage taken from the embodiments of the preceding figures; and

Figure 1 1 is an enlarged view shown in part cutaway of a coupling assembly taken from the embodiments of figures 1 to 8.

Detailed Description

[0014] Referring to Figure 1 to 5, there is shown a first embodiment of a solar tracker 10 according to the invention. The solar tracker 10 is intended for installation in an environment that is suited to agrophotovoltaics (also known as agrovoltaics) where the same land is used for both agricultural purposes and for the generation of solar energy. It will be understood that the invention as broadly described extends to other applications and is not limited to agrophotovoltaics.

[0015] The solar tracker 10 of the first embodiment includes a first horizontal elongate member 12 adapted to support a first solar collector 14, and a second horizontal elongate member 16 adapted to support a second solar collector 18. The first horizontal elongate member 12 includes opposing first (proximal) and second (distal) ends 20 and 22, and the second horizontal elongate member 16 including opposing first (proximal) and second (distal) ends 24 and 26. The first and second members 12 and 16 are substantially aligned with and connected to one another via a coupling arrangement 1 1.

[0016] The solar tracker 10 further includes a first support stand 28 adapted to rotatably support the first end 20 of the first horizontal elongate member 20; an intermediate support stand 30 arranged intermediate the first and second horizontal elongate members 12 and 16 so as to rotatably support the second end 22 of the first horizontal elongate member 12 and the first end 24 of the second horizontal elongate member 16 via the coupling arrangement 1 1 ; and a second support stand 32 adapted to rotatably support the second end 26 of the second horizontal elongate member 16.

[0017] The solar tracker 10 further includes drive assembly including a motor 34 supported by the first support stand 28, the motor 34 being adapted to couple to the first end 20 of the first horizontal elongate member 12 via a gearbox 13 so as to at least partially operatively rotate at least the first horizontal elongate member 12.

[0018] As seen in figure 1 1 , the coupling arrangement 1 1 of this example includes an intermediate shaft 15 in the form of a split shaft having a pair of stub shafts 17 and 19 located either side of a flexible coupling 9. The intermediate bearing is one of a pair of bearings 39 and 41 mounted to the intermediated stand 30 and arranged to locate respective of the stub shafts 17 and 19 to rotatably support the second end 22 of the first horizontal elongate member 12 and the first end 24 of the second horizontal elongate member 16. In this embodiment the first member 12 is connected to the stub shaft 17 via an intermediate adaptor sub- assembly 21 and the second member 16 connected to the other stub shaft 19 via another intermediate adaptor sub-assembly 23. The adaptor sub-assembly 21 associated with the first member 12 includes an adaptor housing 25 which is in a flanged connection mounted axially with the first member 12. The adaptor housing 25 internally houses a pair of hub sub-assemblies 27 and 29 which are rotationally secured to the associated intermediate stub shaft 17. In this example the stub shaft 17 includes a pair of axially oriented keys 31 and 33 arranged to engage a corresponding keyway 35 and 37 in respective of the hub sub-assemblies 27 and 29. The key such as 31 and the keyway 35 cooperate to permit axial movement of the first stub shaft 17 relative to the first hub sub-assemblies 27 and 29 whilst preventing relative rotational movement between the stub shaft 17 and the hub sub- assemblies 27 and 29.

[0019] The other intermediate adaptor sub-assembly 23 is of an identical configuration to the intermediate adaptor sub-assembly 21 associated with the first member 12. It will be understood that the axial movement permitted by each of the adaptor sub-assemblies 21 and 23 is particularly advantageous where:

1. in the course of constructing and erecting the solar tracker 10 variations in spacing between the stands such as 28 and 30 or the length of the first member 12 may be compensated by axial displacement of the stub shaft 17 relative to the intermediate adaptor sub-assembly 21 which is fixed to the associated first member 12; or 2. expansion or contraction of components between the stands 28 and 30 in the course of operating and swiveling the first member 12 may likewise be compensated by the axial displacement permitted by the intermediate adaptor sub-assembly 21.

[0020] Returning to figures 1 to 5, the first and second horizontal elongate members 12 and 16 are coupled at the coupling arrangement 1 1 for likewise rotation. Accordingly, in this example, the motor 34 and gearbox 13 simultaneously drive both the first and second horizontal elongate members 12 and 16 to angle the solar collectors 14 and 18.

[0021 ] The first, intermediate and second support stands 28, 30, 32 each include first, intermediate and second A-frames 46, 48, 50 (see figure 2) associated with the respective bearings 36, 38, 40 located at the apexes 52, 54, 56 thereof.

The solar tracker 10 also comprises a first adaptor sub-assembly 41 mounted to the proximal or first end 20 of the first member 12. The first adaptor sub-assembly 41 is of identical construction to the intermediate adaptor sub-assembly 21 (see figure 1 1 ) being arranged to rotationally secure a first stub shaft 43 operatively coupled to the gearbox 13 for rotation of the first member 12 via the motor 34. The first stub shaft 43 is mounted for rotation within the first bearing 36 which is mounted to the first support stand 28. The first stub-shaft 43 is thus arranged for axial

displacement within the first adaptor sub-assembly 41 as described in more detail in the context of the intermediate stub shaft 17 and adaptor sub-assembly 21. The solar tracker 10 further comprises a second adaptor sub-assembly 47 mounted to the second or distal end 26 of the second member 16.

[0022] The second adaptor sub-assembly 47 is of similar construction to the first adaptor sub-assembly 41 wherein it is arranged to rotationally secure a second stub shaft 49 which is mounted for rotation within the second bearing 40 which is mounted to the second support stand 32. The second adaptor sub-assembly 47 also operates to permit axial movement of the second stub shaft 49 relative to the associated second adaptor sub-assembly 47 and the associated second member 16. [0023] The first and second support stands 28 and 32 are each in the form of a tripod each including respective braces 58 and 60 directed inward of the solar tracker 10 from a location near the apexes 52 and 56 toward the ground below the respective first and second horizontal members 12 and 16. The inward facing arrangement of the braces 58 and 60 provides structural bracing and also clearance so that multiples of the solar trackers 10 may be arrangement end-to-end such as that shown in Figure 6. The solar tracker 10 also comprises ground anchorages 68, 70 and 72 dedicated to respective of the first, intermediate and second support stands 28, 30 and 32.

[0024] As seen in figures 9 and 10, each of the ground anchorages such as 68 includes a pile member 71 adapted to be driven into the ground. The ground anchorage 69 also includes a bracket 73 bolted or otherwise secured to a head of the pile member 71. The bracket 73 includes a horizontal plate 75 configured for clamping to a corresponding foot member 77 secured to the brace 58. The horizontal plate 75 includes a pair of aligned bracket slots such as 79 arranged to cooperate with a pair of parallel foot slots such as 83 in the foot member 77. The bracket slots such as 79 are disposed perpendicular to the foot slots such as 83 wherein they:

1. receive a clamping fastener (not shown) for securing the foot member 77 to the bracket 73 at a required horizontal position;

2. permit sliding transverse movement of the foot member 77 relative to the bracket 73 and the associated pile 71 , said transverse movement being either in the direction of the bracket slots 79 or the foot slots 83.

[0025] The foot member 77 of the solar tracker 10 of this embodiment is shaped circular so as to avoid damage to livestock which may come into contact with the solar tracker 10. This is likely to occur when the solar tracker 10 is erected on farmland or other agricultural environments and the solar tracker 10 of this example is specifically designed for co-existence in these environments. The foot member 77 not only provides a relatively safe perimeter edge for contact with livestock but also shields the underlying ground anchorage 68 from contact with livestock which may otherwise cause harm. [0026] Returning to figures 1 to 5, the first and second horizontal elongate members 12 and 16 support respective frames 62, 64 that in turn support the first and second solar collectors 14 and 18. In this example, the first and second solar collectors 14 and 18 are each photovoltaic solar panels. The overall length of frames 62 and 64 may each be about 12 to 13 meters and the width may be 2.5 to 3 meters. This allows a plurality of solar panels to be carried by each solar tracker 10. For example, up to about twenty-four 24, but not restricted to, solar panels to be affixed to each module of the solar tracker 10. The solar tracker 10 of this embodiment is of a modular construction where the second elongate member 16 and the second support stand 32 may be one of a plurality of elongate members and support stands aligned and interconnected with one another.

[0027] The first and second solar collectors 14 and 18 may be angled relative to one another, and the first and second horizontal elongate members 12 and 16 offset angularly to adjust the relative angle. The motor 34 is supported on a platform 66 that extends from the first support stand 28. The motor 34 may be associated with a control system (not shown) that allows control of the motor 34 such that the motor 34 slowly angles the first and second solar collectors 14, 18 to track the sun throughout the day. In use, the control system is therefore pre-loaded with a time of day and light incident angles. The motor 34 is preferably an electric motor and may include a battery that may be charged by the first and second solar collectors 14,

18. The motor may be a 24v 0.5HP (battery supplied) electric motor, dc charged from its own independent solar panel. The motor may connect to a shaft mounted worm-type gearbox connected to the elongate horizontal member 12.

[0028] Referring now to Figures 6 to 8, there is shown a second embodiment of the solar tracker in which like numerals denote like parts, and all parts are not again described or labelled. In this example, two of the stands 10a, 10b are illustrated in an end-to-end arrangement. In particular, the first support stands 28a, 28b are arranged toward one another with a shared motor platform 66. This allows the motors 34 and gearbox 13 to be associated with a common control system (now shown) and operative parts such as batteries. The end-to-end arrangement allows “modules” of the solar tracker to be added together to form larger arrays for increased solar collection capacity. The solar tracker modules may repeat in equal numbers on opposing sides of the drive assembly. In this example, the drive motor and gearbox of the drive assembly is dedicated to both of the opposing first members 14b and 16a for their rotation in concert. The drive assembly may be sized depending on the number of modules or arrays included in the solar tracker 10.

[0029] The reference in this specification to any known matter or any prior publication is not, and should not be taken to be, an acknowledgment or admission or suggestion that the known matter or prior art publication forms part of the common general knowledge in the field to which this specification relates.

[0030] Now that several embodiment of the solar tracker have been described it will be apparent to those skilled in the art that it has the following advantages:

1. the solar tracker being of a modular construction lends itself to relatively quick assembly and erection;

2. the solar tracker is designed for a reduced“footprint” where in the preferred embodiment the bracing leg is directed inward of the structure;

3. the solar tracker with the preferred bracing arrangement lends itself to end- to-end placement of modules which also means opposing modules can be driven for rotation via a common drive assembly having a predetermined number of balanced solar arrays on either side;

4. the solar tracker is designed for co-existence with agriculture and in

particular livestock where the horizontal members and the associate solar collectors are elevated for increased clearance and the associated supporting structure is designed to minimise harm to livestock.

[0031 ] Those skilled in the art will appreciate that the invention as described herein is susceptible to variations and modifications other than those specifically described. For example, the number and configuration of the solar collectors may vary and still remain within the scope of the invention. The specific drive assembly may also depart from the motor/gearbox arrangement described and remain within the intended scope of the invention. For example, a hydraulically-actuated drive assembly may also be suitable where it provides high torque for relatively slow rotation of the associated members under relatively high loads. The support stands may vary provided they are sufficiently robust with the necessary bracing under typical operational conditions. The ground anchorages may depart from the pile member of the preferred embodiment and take the form of concrete footings upon which the various stands are anchored.

[0032] All such variations and modifications are to be considered within the scope of the present invention the nature of which is to be determined from the forgoing description.

Claims

1. A solar tracker comprising:

a first elongate member adapted to support a first solar collector;

a first support stand arranged to support a proximal end of the first member; an intermediate support stand arranged to support a distal end of the first member and a proximal end of the second member;

a second support stand arranged to support a distal end of the second member;

a drive assembly coupled to the first member to effect its rotation;

a coupling assembly coupled between the first member and the second member wherein rotation of the first member via the drive assembly effects rotation of the second member together with the first member.

2. A solar tracker as claimed in claim 1 wherein the first and the second support stands are of a tripod configuration including a bracing leg aligned with the first and the second members and adapted to be ground anchored to stabilise the solar tracker under end to end shear load.

3. A solar tracker as claimed in claim 2 wherein the bracing leg for each of the first and the second support stands is directed inward of the solar tracker.

4. A solar tracker as claimed in any one of the preceding claims wherein the coupling assembly is mounted to the intermediate support stand.

5. A solar tracker as claimed in claim 4 wherein the coupling assembly includes an intermediate shaft connected between the first and the second members, the intermediate shaft mounted for rotation within an intermediate bearing mounted to the intermediate support stand.

6. A solar tracker as claimed in claim 5 wherein the coupling assembly also includes a pair of intermediate adaptor sub-assemblies mounted to respective of the distal end of the first member and the proximal end of the second member, the intermediate shaft coupled between the pair of intermediate adaptor sub-assemblies to provide rotation of the first and the second members in concert.

7. A solar tracker as claimed in claim 6 wherein the intermediate shaft is of a split configuration including a pair of stub shafts interconnected by a flexible coupling.

8. A solar tracker as claimed in claim 7 wherein the intermediate bearing is one of a pair of intermediate bearings mounted to the intermediate support stand either side of the flexible coupling.

9. A solar tracker as claimed in any one of claims 6 to 8 wherein each of the intermediate adaptor sub-assemblies includes an intermediate adaptor housing connected to either the first or the second members and within which a hub sub- assembly is mounted, the hub sub-assembly being rotationally secured to the intermediate shaft for rotation of the first and the second members.

10. A solar tracker as claimed in claim 9 wherein the hub sub-assembly is one of a pair of hub sub-assemblies mounted within the intermediate adaptor housing.

1 1. A solar tracker as claimed in claim 10 wherein the intermediate shaft includes an axially oriented key arranged to engage a corresponding keyway in at least one of the hub sub-assemblies, the key and keyway cooperating to permit axial movement of the intermediate shaft relative to the hub sub-assemblies whilst preventing relative rotational movement between said shaft and said hub sub- assemblies.

12. A solar tracker as claimed in any one of the preceding claims wherein the drive assembly includes a motor operatively coupled to the first member via a gearbox for rotation of the first member.

13. A solar tracker as claimed in claim 12 also comprising a first adaptor sub- assembly mounted to the proximal end of the first member, and a first stub shaft rotationally secured to the first adaptor sub-assembly and operatively coupled to the gearbox for rotation of the first member via the motor and the gearbox.

14. A solar tracker as claimed in claim 13 wherein the first adaptor sub-assembly includes a first bearing within which the first stub shaft is mounted for rotation, the first bearing mounted to the first support stand.

15. A solar tracker as claimed in any one of the preceding claims further comprising a second adaptor sub-assembly mounted to the distal end of the second member, and a second stub shaft rotationally secured to the second adaptor sub- assembly and mounted for rotation within a second bearing mounted to the second support stand.

16. A solar tracker as claimed in either of claims 14 or 15 wherein the first or second adaptor sub-assembly includes a first or a second adaptor housing connected to either the first or the second members, and a first or a second pair of hub sub-assemblies mounted within the first or the second adaptor housing and being rotationally secured to the first or the second stub shafts for rotation of the first or the second member, respectively.

17. A solar tracker as claimed in claim 16 wherein the first or the second stub shaft includes an axially oriented key arranged to engage a corresponding keyway in at least one of the first or the second pair of hub sub-assemblies, the key and the keyway cooperating to permit axial movement of the first or the second stub shaft relative to the first or the second hub sub-assembly whilst limiting relative rotational movement between said stub shaft and said hub assembly.

18. A solar tracker as claimed in any one of the preceding claims also comprising ground anchorages secured to a base of respective of the support stands, each of the ground anchorages including at least one pile member adapted to be driven into the ground.

19. A solar tracker as claimed in claim 18 wherein the ground anchorage also includes a bracket connected to a head of the pile member.

20. A solar tracker as claimed in claim 19 wherein the support stand includes a foot member configured for clamping to the bracket.

21. A solar tracker as claimed in claim 20 wherein the bracket includes a pair of aligned bracket slots arranged to cooperate with a pair of parallel foot slots includes in the foot member and disposed perpendicular to the bracket slots wherein a pair of clamp fasteners located in respective of one of the pair of the foot and the bracket slots and the other of the pair of the foot and the bracket slots clamp the foot member to the bracket at one of a plurality of horizontal positions depending on the location of the pile member relative to the support stand.

22. A solar tracker as claimed in any one of the preceding claims wherein the solar tracker is of a modular construction wherein the second elongate member and the second support stand is one of a plurality of elongate members and support stands aligned and interconnected with one another.

23. A solar tracker as claimed in any one of the preceding claims wherein the first and the second elongate members and support stands together with the intermediate stand are repeated on an opposing sides of the drive assembly.

24. A solar tracker as claimed in claim 23 wherein the same drive assembly is operatively coupled to both of the opposing first members and thus arranged for rotation of the opposing first and second elongate members together.