WO2013085792A2

WO2013085792A2 - Adjustable tilt angle device for photovoltaic arrays

Info

Publication number: WO2013085792A2
Application number: PCT/US2012/067045
Authority: WO
Inventors: Nagendra Srinivas Cherukupalli; Joseph D. Lobue
Original assignee: Sunedison, Llc
Priority date: 2011-12-08
Filing date: 2012-11-29
Publication date: 2013-06-13
Also published as: WO2013085792A3

Abstract

A support assembly for coupling a photovoltaic (PV) array to a torque rail includes a support member secured to the PV array and a connecting member coupled to the support member. The connecting member is configured to couple to the torque rail. The connecting member is configured to slide along a longitudinal axis of the torque rail between a first position and a second position to vary a tilt angle of the PV array with respect to the torque rail.

Description

ADJUSTABLE TILT ANGLE DEVICE FOR PHOTOVOLTAIC ARRAYS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 61/568,461 filed December 8, 201 1, the entire disclosure of which is hereby incorporated by reference in its entirety.

FIELD

[0002] The field of the present disclosure relates generally to adjustable tilt angle devices for photovoltaic arrays. More specifically, the present disclosure relates to slidably adjustable tilt angle devices for photovoltaic arrays.

BACKGROUND

[0003] Photovoltaic arrays are devices that convert light energy into other forms of useful energy (e.g., electricity or thermal energy). One example of a photovoltaic array is a solar array that converts sunlight into electricity. Typically, solar arrays are fixed above an underlying support structure by a rack. The rack may position the solar array at an angle relative to the support surface to maximize normal incidence between the solar array and the incident sunlight. Normalizing the angle of incidence increases the amount of solar energy gathered by the solar array.

[0004] Racks are typically formed from a plurality of structural members. The structural members are typically assembled into a rack at a factory or other remote site and then transported to an installation location in the assembled configuration or are transported to an installation location and then assembled to form the racks on site. The solar arrays are typically fixed at a set angle of incidence to maximize the normal incidence with respect to the sunlight. However, the angle of incidence of the sunlight with respect to the solar arrays changes by a small amount each day, and over time, the angle of incidence may become significant and reduce the output of the solar array. Thus, a reliable, cost effective system for adjusting a position of the solar arrays and/or the racks is needed.

[0005] This Background section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

SUMMARY

[0006] In one aspect, a support assembly for coupling a photovoltaic (PV) array to a torque rail includes a support member secured to the PV array and a connecting member coupled to the support member. The connecting member is configured to couple to the torque rail. The connecting member is configured to slide along a longitudinal axis of the torque rail between a first position and a second position to vary a tilt angle of the PV array with respect to the torque rail.

[0007] In another aspect, a photovoltaic (PV) assembly includes a PV module, a torque rail for supporting the PV module, a first support assembly coupled to the torque rail and supporting the PV module and a second support assembly coupled to the torque rail and supporting the PV module. The first support assembly is disposed near a first end of the PV module and having a first height. The second support assembly is disposed nearer a second end of the photovoltaic module opposite the first end than the first support assembly. The second support assembly has a second height different than the first height.

[0008] In yet another aspect, a method of adjusting a tilt angle of a photovoltaic (PV) array is described. The photovoltaic array is connected to a torque rail by a first support assembly slidably coupled to the torque rail. The method includes unlocking the first support assembly from the torque rail and sliding the first support assembly along the torque tube from a first location to a second location to adjust a tilt angle of the PV array with respect to the torque rail. The first support assembly is locked in place at the second location to substantially prevent the first support assembly from sliding along the torque rail.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Fig. 1 is a perspective view of an exemplary photovoltaic array of an embodiment. [0010] Fig. 2 is a cross-sectional view of the solar array of Fig. 1 taken along the line A-A of Fig. 1.

[001 1] Fig. 3 is a perspective view of an exemplary photovoltaic assembly in an untilted position.

[0012] Fig. 4 is a perspective view of the photovoltaic assembly of Fig. 3 in a tilted position.

[0013] Fig. 5 is a side view of the exemplary photovoltaic assembly of Fig. 4.

[0014] Fig. 6 is an exploded view of an exemplary support member for a photovoltaic array.

[0015] Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

[0016] Referring to Fig. 1, an embodiment of a photovoltaic array is generally designated 100. In this embodiment, photovoltaic array 100 includes a solar panel 102. Solar panel 102 includes a top surface 106 and a bottom surface 108 (shown in Fig. 2). Edges 110 extend between top surface 106 and bottom surface 108. In one embodiment, solar panel 102 is rectangular shaped. In other embodiments, solar panel 102 may have any shape that allows the photovoltaic array to function as described herein.

[0017] In this embodiment, frame 104 circumscribes and supports solar panel 102. Frame 104 is coupled to solar panel 102, for example as shown in Fig. 2. In one embodiment, frame 104 protects edges 1 10 of solar panel 102. Frame 104 includes an outer surface 130 spaced apart from solar panel 102 and an inner surface 132 adjacent to solar panel 102. In this embodiment, outer surface 130 is spaced apart from, and substantially parallel to, inner surface 132. Frame 104 is made of aluminum, such as 6000 series anodized aluminum, but the frame may be made of any suitable material providing sufficient rigidity including, for example, metal or metal alloys, plastic, fiberglass, carbon fiber and the like.

[0018] Fig. 2 is a cross-sectional view of photovoltaic array 100 taken at line A-A shown in Fig. 1. In this embodiment, solar panel 102 has a laminate structure that includes a plurality of layers 118. Layers 1 18 include, for example, glass layers, non-reflective layers, electrical connection layers, n-type silicon layers, p-type silicon layers, backing layers and combinations thereof. In other embodiments, solar panel 102 may have more or fewer layers 118 than shown in Fig. 2, including only one layer.

[0019] Fig. 3 shows an embodiment of a photovoltaic assembly 134 in an untilted position. Photovoltaic assembly 134 includes one or more photovoltaic arrays 100. Photovoltaic arrays 100 are connected to torque rails 136 via support assemblies 137. Support assemblies 137 include a support member 139, a bracket 141, and a connecting member 138. Support member 139 is configured to support one or more photovoltaic arrays 100. Bracket 139 is coupled to support member 139 and connecting member 138 to couple support member 139 to connecting member 138. Connecting member 138 is connected to support member 139 and torque rails 136. In the embodiment shown in Fig. 3, support members 139 are all substantially a same height H. Accordingly, photovoltaic arrays 100 are disposed substantially parallel to torque rails 136. In one embodiment, torque rails 136 are attached to a support structure 140. In one embodiment, torque rails 136 are removably attached to support structure 140. In some embodiments, support structure 140 includes a post 142, such as an I-beam post, fixedly secured to the ground and supports torque rails 136. In other embodiments, support structure 140 is a ram, pier, foundation, ballast or the like.

[0020] Photovoltaic arrays 100 may be suitably disposed at a nonzero angle relative to torque rails 136. As shown in Fig. 4, each photovoltaic array 100 is set to an angle A with respect to torque rails 136. In this embodiment, angle A is a predetermined angle based upon the seasonal variation in an angle of incidence of sunlight with respect to the photovoltaic array 100, and each photovoltaic array 100 is set to the same angle A. In other embodiments, one or more of photovoltaic arrays 100 are placed at different angles A.

[0021] In some embodiments, angle A is set by adjusting respective heights H of support members 139 coupled to the same one or more photovoltaic arrays 100. When one support member 139 has a height H greater than the other supporting member 139 coupled to a photovoltaic array, the difference in heights H will dispose the coupled photovoltaic array 100 at a nonzero angle A relative to torque rails 136. Supporting members 139 suitably have respective heights H that place photovoltaic array 100 at an angle A within a range of angles of approximately 0 degrees to 25 degrees in a first direction. In other embodiments, supporting members 139 have respective heights H that place photovoltaic array 100 at an angle A within a range of angles of approximately 0 degrees to 25 degrees in second direction opposite the first direction. In other embodiments, one or more of supporting members 139 have an adjustable height.

[0022] Angle A may suitably be adjusted by changing the distance between two different height support members 139 along torque rail 136. In this embodiment, one or more of support assemblies 137 are slidably attached, by connecting members 138, to torque rail 136 to permit the distance between two support members 139 to be varied. In other embodiments, support assemblies 137 may be attached to torque rails 136 by any other suitable attachment that permits the distance between support members 139 to be varied. In the embodiment shown in Fig. 5, the support assemblies 137 are slidably attached such that they may slide along direction D, corresponding to a longitudinal direction of torque rails 136. In this embodiment, one support assembly 137 coupled to a particular photovoltaic assembly 100 is configured to slide along torque rail 136 to adjust angle A, while a second support assembly 137 coupled to that photovoltaic array 100 is locked in place. For example, as the slidable support assembly 137 is moved closer to the fixed support assembly 137, angle A increases, and when the slidable support assembly 137 is moved away from the fixed support assembly 137, angle A decreases. In this embodiment, one or more bump stops 148 are disposed along torque rail 136 to constrain the distance connecting bracket 144 is able to slide along torque rail 136.

[0023] In some embodiments, all support assemblies 137 are configured to be slidable along torque rails 136. In such embodiments, one or both support assemblies coupled to a particular photovoltaic array 100 may be slidably moved. In one method of adjusting the angle A, only one of the support assemblies 137 coupled to a particular photovoltaic array 100 is moved along torque rails 136, while the other support assembly 137 coupled to the photovoltaic array 100 remains locked in position relative to the torque rail. In operation, one of support assemblies 137 is locked in place, for example by a spring-loaded clamp (not shown) or other locking means, such as an adhesive, bolt, screw, peg, lug, pin and the like, at a first position along torque rail 136. The other support assembly 137 coupled to the same photovoltaic array 100 is moved along torque rail 136 until angle A corresponds to a first angle of photovoltaic array 100 with respect to the incident light rays (e.g., sunlight rays), and the relocated support assembly 137 is locked into its new position. To adjust the angle A of photovoltaic array, for example for seasonal variation in incident sunlight angles, a user unlocks (e.g., pulls out the spring-loaded button from the hole) one of the support assemblies 137 and slides the support assembly 137 along torque rail 136 to a second position corresponding to a second angle of photovoltaic array 100 with respect to incident light rays. In this embodiment, to unlock one of the support assemblies 137, a user pulls out a spring-loaded button from a hole in the connecting bracket (e.g. a hole though connecting member 138 that aligns with corresponding hole(s) in torque rails 136). A handle or lever 150 is attached to one or more support assemblies 137 to facilitate sliding of the support assemblies 137 along torque rail 136. In this embodiment, markings are disposed along torque rails 136 corresponding to placement locations for one or more support assemblies 137 to indicate a seasonal adjustment (e.g., summer, spring, fall, winter). In other embodiments, a motor or actuator (not shown) is attached to torque rail 136 or support assemblies 137 to facilitate automatic sliding of support assemblies 137. The motor or actuator may be electronically controlled by a computer controller and programmed to rotate the rotatable member at a predetermined time, for example, seasonally. In the case of automatic sliding, the locking devices are also automatically unlocked by way of a motor, actuator or the like.

[0024] Fig. 6 shows an example embodiment of support assemblies 137. Support member 139 includes a base 152 for disposition adjacent torque rails 136 and an upper portion 154 for attaching to photovoltaic array 100. Upper portion 154 is disposed at a non-zero angle with respect to base 152, such as an angle of approximately 1 degrees to 25 degrees, for example 8 degrees. In other embodiments, upper portion 154 and base 152 are parallel. Support member 139 includes a strengthening member 158 that increases the rigidity of the connecting bracket. In other embodiments, support member 139 may include more or fewer (including none) strengthening members 158 and/or may include differently shaped and/or located strengthening members. Support member 139 is disposed on connecting member 138, which is coupled to torque rails 136 through opening 155 (i.e. torque rail 136 passes through opening 155). Bracket 144 is placed over support member 139 with feet 156 on connecting member 138. Bracket 144 is attached to connecting member 138 via holes 156 by way of bolts, screws, pins or the like. In some embodiments, a height of support members 139 depends on the size of photovoltaic array 100. Larger photovoltaic arrays may require a taller connecting bracket than when the photovoltaic array size is smaller. In one embodiment, the size of the support members 139 is determined during the design of the photovoltaic assembly.

[0025] A plurality of photovoltaic arrays are connected to the torque rail and spaced apart from each other in this embodiment. In another embodiment, the spacing between each photovoltaic array is sized to reduce shading losses. For example, the spacing is mathematically determined by measuring a shadow region around photovoltaic array 100 during a predetermined time period, for example 8:00 am to 3 :00 pm on the Winter solstice day. The spacing between photovoltaic arrays is set to equal a longest shadow point on a mounting plane of photovoltaic array 100.

[0026] The above described systems and methods are suitably electronically or computer controlled. The embodiments described herein are not limited to any particular system controller or processor for performing the processing tasks described herein. The term controller or processor, as used herein, is intended to denote any machine capable of performing the calculations, or computations, necessary to perform the tasks described herein. The terms controller and processor also are intended to denote any machine capable of accepting a structured input and of processing the input in accordance with prescribed rules to produce an output. It should also be noted that the phrase "configured to" as used herein means that the controller/processor is equipped with a combination of hardware and software for performing the tasks of embodiments of the invention, as will be understood by those skilled in the art. The term controller/processor, as used herein, refers to central processing units, microprocessors, microcontrollers, reduced instruction set circuits (RISC), application specific integrated circuits (ASIC), logic circuits, and any other circuit or processor capable of executing the functions described herein.

[0027] The computer implemented embodiments described herein embrace one or more computer readable media, including non-transitory computer readable storage media, wherein each medium may be configured to include or includes thereon data or computer executable instructions for manipulating data. The computer executable instructions include data structures, objects, programs, routines, or other program modules that may be accessed by a processing system, such as one associated with a general-purpose computer capable of performing various different functions or one associated with a special-purpose computer capable of performing a limited number of functions. Aspects of the disclosure transform a general-purpose computer into a special-purpose computing device when configured to execute the instructions described herein. Computer executable instructions cause the processing system to perform a particular function or group of functions and are examples of program code means for implementing steps for methods disclosed herein. Furthermore, a particular sequence of the executable instructions provides an example of corresponding acts that may be used to implement such steps. Examples of computer readable media include random-access memory ("RAM"), read-only memory ("ROM"), programmable read-only memory ("PROM"), erasable programmable read-only memory ("EPROM"), electrically erasable programmable read-only memory ("EEPROM"), compact disk read-only memory ("CD-ROM"), or any other device or component that is capable of providing data or executable instructions that may be accessed by a processing system.

[0028] A computer or computing device such as described herein has one or more processors or processing units, system memory, and some form of computer readable media. By way of example and not limitation, computer readable media comprise computer storage media and communication media. Computer storage media include volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically embody computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism and include any information delivery media. Combinations of any of the above are also included within the scope of computer readable media.

[0029] When introducing elements of the present invention or the embodiment(s) thereof, the articles "a", "an", "the" and "said" are intended to mean that there are one or more of the elements. The terms "comprising", "including" and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

As various changes could be made in the above apparatus and methods without departing from the scope of the disclosure, it is intended that all matter contained in the above description and shown in the accompanying figures shall be interpreted as illustrative and not in a limiting sense.

Claims

WHAT IS CLAIMED IS:

1. A support assembly for coupling a photovoltaic (PV) array to a torque rail, the assembly comprising: a support member secured to the PV array; and a connecting member coupled to the support member and configured to couple to the torque rail, the connecting member configured to slide along a longitudinal axis of the torque rail between a first position and a second position to vary a tilt angle of the PV array with respect to the torque rail.

2. The support assembly according to claim 1, wherein the support member comprises a base portion and a top portion, the base portion configured to be substantially parallel to a plane of the torque rail and the top portion forming an angle with respect to the plane of the torque rail.

3. The support assembly according to any of the preceding claims, further comprising a locking mechanism configured to substantially prevent the connecting member from sliding along the torque rail when locked and to permit the connecting member to slide along the torque rail when unlocked.

4. The support assembly according to any of the preceding claims, further comprising a bracket connecting the support member to the connecting member.

5. The support assembly according to any of the preceding claims, wherein the connecting member defines an opening configured to at least partially surround the torque rail.

6. A photovoltaic (PV) assembly, comprising: a PV module; a torque rail for supporting the PV module; a first support assembly coupled to the torque rail and supporting the PV module, the first support assembly disposed near a first end of the PV module and having a first height; and a second support assembly coupled to the torque rail and supporting the PV module, the second support assembly disposed nearer a second end of the photovoltaic module opposite the first end than the first support assembly, the second support assembly having a second height different than the first height.

7. The PV assembly according to claim 6, wherein at least one of the first support assembly and the second support assembly is slidably coupled to the torque rail.

8. The PV assembly according to claim 7, wherein the slidably attached one of the first and second support assembly is positionable between a first position and a second position along the torque rail.

9. The PV assembly according to claim 8, wherein when the slidably attached support assembly is at the first position the PV array is at a first angle with respect to the torque rail, and when the slidably attached support assembly is at the second position the PV array is at a second angle with respect to the torque rail.

10. The PV assembly according to any of claims 7-9, further comprising a friction reducing material between the torque rail and the slidably attached support assembly.

11. The PV assembly according to any of claims 7-10, wherein both of the first and the second support assemblies are slidably attached to the torque rail.

12. The PV assembly according to any of claims 7-1 1, wherein at least one of the first and second support assemblies further comprises a fixing device configured to selectively lock the support assembly in position relative to the torque rail.

13. The PV assembly according to any of claims 7-11, further comprising one or more bump stops disposed along the torque rail.

14. A method of adjusting a tilt angle of a PV array, the PV array being connected to a torque rail by a first support assembly slidably coupled to the torque rail, the method comprising: unlocking the first support assembly from the torque rail; sliding the first support assembly along the torque tube from a first location to a second location to adjust a tilt angle of the PV array with respect to the torque rail; and locking the first support assembly in place at the second location to substantially prevent the first support assembly sliding along the torque rail.

15. The method according to claim 14, wherein the PV array is further connected to the torque rail by at least a second support assembly disposed apart from the first support assembly, the first support assembly and the second support assembly having different heights.

16. The method according to claim 15, wherein sliding the first support assembly along the torque tube from a first location to a second location to adjust a tilt angle of the PV array with respect to the torque rail comprises at least one of sliding the first support assembly toward the second support assembly to increase the tilt angle of the PV array and sliding the first support assembly away from the second support assembly to reduce the tilt angle.

17. The method according to any of claims 14-16, wherein sliding the first support assembly along the torque tube from a first location to a second location to adjust a tilt angle of the PV array with respect to the torque rail comprises sliding the first support assembly along the torque tube to adjust the tilt angle of the PV array to a predetermined tilt angle based upon a season.

18. The method according to claim 17, further comprising adjusting the tilt angle of the PV array each season.

19. The method according to any of claims 14-18, wherein sliding the first support assembly along the torque tube from a first location to a second location to adjust a tilt angle of the PV array with respect to the torque rail comprises sliding the first support assembly using a lever coupled to the first support assembly.

20. The method according to claim 14, wherein sliding the first support assembly along the torque tube from a first location to a second location to adjust a tilt angle of the PV array with respect to the torque rail comprises sliding the first support assembly using an actuator.