WO2011156833A1

WO2011156833A1 - A solar tracking system

Info

Publication number: WO2011156833A1
Application number: PCT/AU2011/000476
Authority: WO
Inventors: Edwin Foong; Rohan Gillespie
Original assignee: Soleir Ltd
Priority date: 2010-06-16
Filing date: 2011-04-28
Publication date: 2011-12-22

Abstract

The present invention relates broadly to a solar tracking system 10. The solar tracking system 10 comprises a corrugated support structure 12 to which a plurality of solar panels 14 are mounted. The corrugated support structure 12 is coupled to a base structure 16 which permits tilting movement of the solar panels 14. The corrugated support structure 12 includes a plurality of support panels such as 12A each being elongate and having a generally V-shaped cross-section formed by a pair of inclined side flanges such as 13A and 13B interconnected by an intermediate web such as 15A.

Description

A SOLAR TRACKING SYSTEM

Field of the Invention

The present invention relates broadly to a solar tracking system together with a method of constructing a tracking system. Background of the Invention

There exists in Australia and elsewhere solar farms which are designed to convert solar energy into electricity. Such solar farms typically involve an elaborate structure which supports either reflector panels or solar panels where the structure can pivot with the position of the sun so as to maximise solar exposure. As the fuel (in the form of sunlight) for such systems is renewable and essentially free, a challenge for making such systems economically viable, involves the design and construction of low cost pivoting structures to support the solar reflectors, panels, or other solar collectors.

Summary of the Invention According to one aspect of the present invention there is provided a solar tracking system comprising:

a corrugated support structure;

a solar panel mounted to the corrugated support structure;

a base structure coupled to the corrugated support structure to permit movement of the support structure for tilting of the solar panel.

Preferably the corrugated support structure includes a plurality of support panels each roll formed from strip metal and having at least one adjacent ridge and groove with adjacent of the support panels being interconnected. More preferably the plurality of support panels are each elongate having a generally V-shaped cross-section formed by a pair of inclined side flanges interconnected by an intermediate web. Even more preferably the plurality of support panels are held together by interlocking the side flanges of the adjacent support panels. Preferably the solar panel is a solar photovoltaic (PV) panel. More preferably the solar PV panel is flat. Even more preferably the solar PV panel is rolled out in strip form across the corrugated support structure.

Preferably the solar tracking system also comprises a support member to which the corrugated support structure is secured. More preferably the support member includes a support beam. Even more preferably the support beam is substantially flat thereby providing a flat surface for mounting of the flat solar PV panel to the corrugated support structure.

Preferably the base structure comprises a support pedestal coupled to the support member to permit tilting of the solar panel about a single axis. Alternately the support pedestal is coupled to the support member to permit tilting of the solar panel about two axes oriented transverse to one another.

According to another aspect of the present invention there is provided a method of constructing a solar tracking system, said method comprising the steps of:

forming a corrugated support structure;

mounting a solar panel to the corrugated support structure; and

connecting the corrugated support structure to a base structure to permit movement of the support structure for tilting of the solar panel.

Preferably the step of forming a corrugated support structure includes the step of roll forming the support structure from strip metal. More preferably the roll forming step involves cold roll forming a plurality of support panels each being elongate and having a generally V-shaped cross section formed by a pair of inclined side flanges interconnected by an intermediate web.

Preferably the step of forming a corrugated support structure includes the step of interconnecting adjacent of the plurality of support panels. More preferably

interconnection of the support panels is effected by interlocking of the side flanges of the adjacent support panels.

Brief Description of the Drawings

In order to achieve a better understanding of the nature of the present invention a preferred embodiment of a solar tracking system together with a method of constructing such a system will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is an end elevational view of one embodiment of a solar tracking system of the present invention; Figure 2 is a perspective view of the solar tracking system of figure 1 with its associated solar panels tilted;

Figure 3 is a perspective view of the solar tracking system of figure 1 with its associated solar panels directed upwards without any tilting;

Figure 4 is an end sectional view of a solar tracking system according to another embodiment of the invention;

Figure 5 is a perspective view of the alternate solar tracking system of figure 4;

Figure 6 is a perspective view of the alternate solar tracking system of figure 4 but with its associated solar panels tilted;

Figures 7 A and 7B are end elevational views of another embodiment of a solar tracking system of the invention showing its associated solar panels at horizontal and tilted dispositions;

Figure 8 are plan and end views of the other solar tracking system of Figure 7;

Figure 9 is a side elevational view of the solar tracking system of figures 7 and 8;

Figure 10 is a schematic perspective view of the solar tracking system of Figures 7 to 9.

Detailed Description of the Preferred Embodiments

As best shown in figures 1 to 3 there is a solar tracking system 10 comprising a corrugated support structure 12 to which a plurality of solar panels depicted generally as 14 are mounted. The corrugated support structure 12 is coupled to a base structure 16 which permits tilting movement of the solar panels 14. In this

embodiment of the solar tracking system 10 the corrugated support structure is secured to one or more support members such as support beam 18. The corrugated support structure 12 includes a plurality of support panels such as 12A each being elongate and having a generally V-shaped cross-section formed by a pair of inclined side flanges such as 13A and 13B interconnected by an intermediate web such as 15A. Each of the support panels such as 12A is roll formed from strip metal and in this embodiment is otherwise constructed in accordance with Australian patent no. 726159 (by Wade Hylton Blazley) and its foreign counterparts. The disclosure of this Australian patent and its foreign counterparts is to be included herein by way of reference.

The support panel in its preferred form includes a web formed continuous with an opposing pair of flanges which diverge outwardly at an obtuse angle relative to the web. The web includes a series of longitudinally extending stiffening ribs. The flanges may also include a series of transversely extending corrugations which provide additional rigidity to the support panel. Opposing free edge portions of the flanges include C-shaped interlocking ribs. The interlocking ribs have a free edge portion on one of the ribs turned inward whilst the opposing interlocking rib is turned outward of the panel. This facilitates clipping or interlocking of adjacent of the panels.

In this example, adjacent of the plurality of support panels such as 12A and 12B are held together by interlocking their respective side flanges such as 13A and 13B. In this embodiment, there are five of the adjacent support panels 13A to 13E connected to one another and fastened or otherwise secured to the underlying transverse support beam 18. As best shown in figures 2 and 3, the support beam 18 is one of two longitudinally spaced transverse support beams. The support beams 18A and 18B are substantially flat thereby providing a flat upper surface for mounting of the flat solar panels 14 to the corrugated support structure 12. In this example the solar panels are solar photovoltaic (PV) panels which are substantially flat. The specific nature of the mounting of the solar PV panels 14 to the underlying corrugated support structure 12 will depend largely on the type of PV cells used. However, it is envisaged that there may be the following types of mountings:

1 . Direct mounting where the PV panel itself is fastened, adhered (such as glued), clipped or otherwise secured to the panel such as 12A; 2. For relatively thin PV panels, the PV panels are secured to a stiffening panel which is in turn secured to the underlying corrugated support structure 12.

Alternatively, there may be new types of PV technology such as thin-film PV which can be applied directly to the exposed upper surface of the corrugated support structure 12.

The base structure 16 of this example includes a support pedestal 20A coupled to its respective support beam 18A via tilting element 22A. The tilting element 22A of this embodiment permits tilting of the solar panels 14 about a single axis only. The tilting element 22A of this example provides tilting movement about a pivot member 24A which defines the pivot axis.

In Figure 2, the base structures 16A and 16B may be of unequal height to incline the structure relative to the ground level.

In order to provide some indication of the scale of this solar tracking system it is expected that the width of the corrugated support structure such as 12 will be in the order of three metres or greater with a length as long as required or practical to install, ranging from 10 metres up to 200 metres. It should however be appreciated that the solar tracking system is not limited to these indicative dimensions.

Figures 4 to 6 illustrate another embodiment of the solar tracking system 100 which provides tilting movement in two axes oriented transverse to one another. In order to avoid repetition and for ease of reference, like components of this alternate

embodiment are designated with an additional "0". For example, the alternate solar panels are designated as "14" and "140".

In this alternate embodiment it is expected that the length of the corrugated support structure is likely to be more similar to its width or up to one to two times its width.

These dimensions or ratios are not intended in any way to be limiting but rather are of a practical size for installation and operation in permitting tilting about the two axes.

In this example of the solar tracking system 100 the solar PV panels 140 are mounted to five (5) underlying support panels 12A to 12E. The support panels 12A to 12E are in turn secured to a single underlying support beam 180. The solar PV panels 140 are in this embodiment capable of pivoting about two axes defined by:

1 . Pivot axle 240 of the intermediate coupling element 220; and

2. A hinge element (not shown) connected between the support beam 180 and the intermediate coupling element 220 for tilting about a transverse axis.

The general steps involved in constructing a solar tracking system such as 10 or 100 of the previous embodiments are as follows:

1 . The support pedestals such as 16 together with the coupling elements such as 22 and support beams such 18 are fabricated either on-site or off-site to appropriate weights and dimensions depending on the specific application;

2. The support panels such as 12A to 12E are roll-formed on-site from strip metal such as steel or aluminium;

3. The requisite number of solar PV panels such as 14 are prefabricated

either on-site or off-site.

In a preferred embodiment the support pedestals such as 16 are erected on appropriate foundations (not shown) and the support beams such as 18A connected to their respective support pedestal such as 16. The support panels such as 12A to 12E are interlocked alongside one another and then welded, fastened, or otherwise secured to the underlying support beams such as 18A. The solar PV panels are then mounted to an upper surface of the support panels 12 using an adhesive, fastener, bracket, clip or other appropriate means of securement. The solar PV panel may be rolled out on-site in a long strip on top of the corrugated panel structure 12. There may also in the future be some type of PV technology that is deposited directly onto the corrugated panel structure,

It will be understood that the specifics and order of the method of assembling and erecting the solar tracking system 10 or 100 may vary. For example, the solar PV panels 14, support panels 12, and support beams such as 18A may be assembled on the ground and then together elevated for mounting to the support pedestals such as As shown in figures 7 to 10 there is another embodiment of a solar tracking system according to the present invention. In order to avoid repetition and for ease of reference, like components of this other embodiment are designated with an additional "00". For example, the solar panels are in this other embodiment designated as "1400".

The solar tracking system 1000 also comprises a drive assembly 1700 coupled between the support pedestal such as 2000A and the support beam such as 1800A. The drive assembly 1700 includes the titling element 2200, pivot member 2400 and actuator drive 1900. The tilting element 2200 is in the form of a chain guide which is shaped semi-circular and connected to a corresponding support beam such as 1800A. The pivot member 2400 includes a pivot bearing mounted to the support pedestal 2000A and designed to provide tilting about the centre of gravity of the corrugated support structure 1200 and solar panels 1400. The actuator drive 1900 includes a motor and gearbox designed to engage the semi-circular chain guide 2200 for tilting movement of the structure 1200.

The solar tracking system 1000 also comprises a series of spaced apart straps such as 2300 secured transversely across the underlying support structure 1200 including the pair of interlocked support panels 1200A and 1200B. The straps such as 2300 are each connected to a solar panel support member such as 2500. The support members 2500 of this embodiment are each fabricated from angle section to which the solar panels such as 1400 are secured. The angle support members 2500 and solar panels such as 1400 extend beyond the outer edges of the underlying support structure 1200.

As shown in Figure 8, the support structure 1200 and solar panels 1400 are braced by structural bracing depicted generally as 2100. The structural bracing 2100 of this embodiment includes tensioned wires such as 2700 connected at opposing ends to opposite ends of spaced apart of the solar panel support members such as 2500A and 2500G. The tensioned wires such as 2700A and 2700B are formed in a crisscross arrangement and tensioned to brace the matrix of solar panels 1400. As shown in Figures 8 and 9 the solar panels are mounted side by side with six (6) panels dimensioned 1 .2m x 0.6m across the underlying support structure 1200. The system 1000 of this example is around 160 metres in length having 133 panels arranged end to end with a total of 798 panels. The system 1000 is provided with a drive assembly 1700 at every second of the support pedestal 2000. The support structure 1200 is otherwise provided with support pedestals such as 2000 at about 15 metre spacings and around a 5 metre overhand at each end. The support structure 1200 is elevated at around 0.4 times the panel width above ground. In this instance with six (6) times 600mm wide panels, the support structure 1200 is around 0.4 times 3.6 metres which equals around 1 .5 metres above ground. It is estimated that this system will provide a nominal 57kW of power.

Now that alternate embodiments of the invention have been described in some detail it will be apparent to those skilled in the art that the solar tracking system and its preferred method of construction have at least the following advantages:

1 . The preferred construction methodology lends itself to on-site fabrication and reduces the need for transporting finished products with their regular shapes leading to lower transportation costs;

2. Overall construction times are reduced which leads to lower overall costs;

3. The solar tracking system by relying on corrugated support structures

avoids the need for relatively expensive space-frame structures;

4. The interlocked support panels of the solar tracking system span relatively great distances reducing vertical supports and associated structure works contributing to a reduction in overall cost.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. For example, the solar PV panels may be substituted for panels of a non- concentrating variety such as solar fluid panels which capture heat for exchange with a process fluid. The specific trapezoidal-shaped support panel may also be replaced with an alternate panel of a different cross-sectional shape. The dimensions of the solar tracking system may also be altered as required to optimise performance and to suit the particular application. The actuator drive may take the form of a linear actuator instead of the motor, gearbox and chain drive described. 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 foregoing description.

Claims

The claims defining the invention are as follows:

1 . A solar tracking system comprising:

a corrugated support structure;

a solar panel mounted to the corrugated support structure; a base structure coupled to the corrugated support structure to permit movement of the support structure for tilting of the solar panel.

2. A solar tracking system as defined in claim 1 wherein the corrugated support structure includes a plurality of support panels each roll formed from strip metal and having at least one adjacent ridge and groove with adjacent of the support panels being interconnected.

3. A solar tracking system as defined in claim 2 wherein the plurality of support panels are each elongate having a generally V-shaped cross-section formed by a pair of inclined side flanges interconnected by an intermediate web.

4. A solar tracking system as defined in claim 3 wherein the plurality of support panels are held together by interlocking the side flanges of the adjacent support panels.

5. A solar tracking system as defined in any one of all the preceding claims

wherein the solar panel is a solar photovoltaic (PV) panel.

6. A solar tracking system as defined in claim 5 wherein the solar PV panel is flat.

7. A solar tracking system as defined in claim 6 wherein the solar PV panel is rolled out in strip form across the corrugated support structure.

8. A solar tracking system as defined in either of claims 6 or 7 also comprising a support member to which the corrugated support structure is secured.

9. A solar tracking system as defined in claim 8 wherein the support member includes a support beam.

10. A solar tracking system as defined in claim 9 wherein the support beam is

substantially flat thereby providing a flat surface for mounting of the flat solar PV panel to the corrugated support structure.

1 1 . A solar tracking system as defined in any one of claims 8 to 10 wherein the base structure comprises a support pedestal coupled to the support member to permit tilting of the solar panel about a single axis.

12. A solar tracking system as defined in claims 8 to 10 wherein the support

pedestal is coupled to the support member to permit tilting of the solar panel about two axes oriented transverse to one another.

13. A method of constructing a solar tracking system, said method comprising the steps of:

forming a corrugated support structure;

mounting a solar panel to the corrugated support structure; and connecting the corrugated support structure to a base structure to permit movement of the support structure for tilting of the solar panel.

14. A method of constructing a solar tracking system as defined in claim 13

wherein the step of forming a corrugated support structure includes the step of roll forming the support structure from strip metal.

15. A method of constructing a solar tracking system as defined in claim 14

wherein the roll forming step involves cold roll forming a plurality of support panels each being elongate and having a generally V-shaped cross section formed by a pair of inclined side flanges interconnected by an intermediate web.

16. A method of constructing a solar tracking system as defined in claim 15

wherein the step of forming a corrugated support structure includes the step of interconnecting adjacent of the plurality of support panels.

17. A method of constructing a solar tracking system as defined in claim 16

wherein interconnection of the support panels is effected by interlocking of the side flanges of the adjacent support panels.