US20100108113A1

US20100108113A1 - Aeroelastic canopy with solar panels

Info

Publication number: US20100108113A1
Application number: US12/289,725
Authority: US
Inventors: David Taggart; Gianluigi Mascolo; Ning Ma
Original assignee: Optisolar Inc
Current assignee: FOREFRONT INNOVATIVE TECHNOLOGIES Inc
Priority date: 2008-11-03
Filing date: 2008-11-03
Publication date: 2010-05-06

Abstract

An aeroelastic solar-power-generating canopy is described that requires minimal construction efforts. The canopy can be formed over supporting structures such as columns, without requiring an existing roof. The canopy contains a plurality of solar panels arranged substantially adjacent to each other, which are coupled to attachment members. Linking members are coupled to the attachment members, the linking members providing a flexing point for the solar panels. A cable is coupled to the linking members, spanning a substantial portion of the distance covered by the solar panels, providing a restraining force. And, at least one of the attachment members and cable is coupled to a supporting structure, wherein the cable in conjunction with the linking members allows the solar panels to dynamically react to loads, the arranged solar panels operating as a covering and as a source of solar power.

Description

BACKGROUND

1. Field
This disclosure relates to a shading structure that is formed from solar panels. More particularly, systems and methods for coupling solar panels together to form a flexible canopy are disclosed.
2. Background
Solar panels on top of free-standing shade structures such as buildings, pavilions, and pergolas can be an efficient and beneficial use of space. However, the current method of building such structures is to complete the underlying structure first, then install the solar panels on top as a secondary effort. It is an expensive and time-consuming approach, often involving unnecessary duplication of parts, and the result is a rigid structure that requires significant reinforcement to counteract bending moments imposed by wind loads.
Also, many structures in arid or semi-arid climates can benefit from shade, but do not need the exclusion of rain; for example, parking structures, walkways, gazebos, pavilions, band shells, bleachers, outdoor markets, and so forth. Solar panels mounted on top of these structures can provide power for lights, fans, PA systems, refrigerators, surveillance cameras, etc. in and around the structure, feed the power to neighboring buildings or the local power grid, or a combination thereof.
In the above examples, however, if the underlying structure does not already exist, the conventional approach is to build it independently of the solar panels, then add the solar panels afterwards. The result is a relatively expensive, rigid structure that requires extra design effort to shield the solar panels from excessive stress, both from wind loads often found in dry climates and, in some areas, seismic activity.
Therefore, there has been a long-standing need for a solar panel design paradigm that reduces the cost of building these structures, as well as providing the overall structure the necessary resilience against wind and other outside loads.

SUMMARY

The foregoing needs are met, to a great extent, by the present disclosure, wherein systems and methods for the implementation of solar panels as a roofing structure are provided. In one of various aspects of the disclosure, an aeroelastic solar-power-generating canopy is provided, comprising, a plurality of solar panels arranged substantially adjacent to each other; attachment members coupled to at least one portion of a solar panel of the plurality of solar panels; linking members coupled to the attachment members, the linking members providing a flexing point for solar panels of the plurality of solar panels; a cable coupled to the linking members, spanning a substantial portion of a distance covered by the plurality of solar panels, and providing a restraining force; and a plurality of supporting structures, wherein at least one of the attachment members and cable is coupled thereto, wherein the cable in conjunction with the linking members allows the plurality of solar panels to dynamically react to loads, the plurality of solar panels operating as a covering and as a source of solar power.
In another aspect of the disclosure, an aeroelastic solar-power-generating canopy is provided, comprising a plurality of means for generating power from solar energy arranged substantially adjacent to each other; means for attachment coupled to at least one portion of a means of the plurality of the solar means; means for linking coupled to the means for attachment, the linking means providing a flexing point for the means of the plurality of solar means; a tensioning means coupled to the linking means, spanning a substantial portion of a distance covered by the plurality of solar means, and providing a restraining force; and a plurality means for supporting, wherein at least one of the attachment means and tensioning means is coupled thereto, wherein the tensioning means in conjunction with the linking means allows the plurality of the solar means to dynamically react to loads, the plurality of solar means operating as a covering.
In yet another aspect of the disclosure, a method for providing an environmental covering using solar power panels is provided, comprising, arranging a plurality of solar panels substantially adjacent to each other; attaching attachment members to at least one portion of a solar panel of the plurality of solar panels; linking linking members to the attachment members, the linking members providing a flexing point for solar panels of the plurality of solar panels; coupling a cable to the linking members, spanning a substantial portion of a distance covered by the plurality of solar panels to provide a restraining force; and coupling the plurality of solar panels to a plurality of supporting structures, wherein at least one of the attachment members and cable is coupled to a supporting structure of the plurality of supporting structures, wherein the cable in conjunction with the linking members allows the plurality of solar panels to dynamically react to loads.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an illustration of a bottom view of one exemplary embodiment of a single panel section.

FIGS. 2A and 2B are illustrations of end-views of exemplary two- and three-panel roofing sections.

FIG. 3A illustrates an exemplary link which contains a cable supporting member that facilitates connection to the cable.

FIG. 3B provides an illustration of another link, wherein a pulley is configured with the link.

FIG. 4 is an illustration of an exemplary section-end attachment.

FIG. 5 is a perspective view of an exemplary canopy system.

FIG. 6 is an illustration of an exemplary cable spreader system.

FIGS. 7A-B are illustrations of alternate cable terminations.

FIG. 8 is an illustration of a cable termination with an overhanging eave.

DETAILED DESCRIPTION

Aspects of the disclosed systems and methods are elucidated in the accompanying figures and following description. In various embodiments, the solar panels and their structures are configured into a flexible canopy that attach directly to the supports of a structure. For example, this can be accomplished by hinging together the support members of solar panels (forming a “panel section”) and suspending each panel section between the structure's supports. The panel sections can be configured to react to tensile loads, which they do very efficiently. Each link can be connected to a stabilizing element that can apply any one or more of “outward and downward” tension (for example, a guy-wire) to offload the panel section during uplifting wind conditions thus mitigating the compressive loads they experience, while raising the natural resonance of the panel sections to higher frequencies. Panel support members that are used to form the panel sections can also perform “double duty” as canopy structural members, thereby reducing cost and amounts of material used. Pre-assembling and pre-wiring the panel section on the ground on-site, then lifting into place, also significantly reduces installation costs.
Further, the solar panels can be arranged and electrically connected in groups for desired power aggregation, increasing overall installed cost-efficiency. Also, the finished canopy, having the linking structure disclosed herein, can be considered to be sufficiently aeroelastic and seismically resilient for a lower cost than comparable rigid structures which are designed to minimum deflection criteria. As in the embodiments of this disclosure, the design priority is the strength of structural members which are allowed to deflect, thereby costs and amounts of material used are reduced. Therefore, efficiencies in construction and reduction in procured and installed costs are understood to be achievable using the various embodiments disclosed herein.
FIG. 1 is an illustration of a bottom view of one exemplary embodiment of a single panel section 10 formed from a solar panel 2. The single panel section 10 is shown with supporting crossbars 4 and rails 6 attached to one side of the panel section 10 in a structurally efficient manner. As should be apparent, other panel section shapes as well as supporting crossbars/rails styles or shapes or geometries may be utilized according to design preference. For example, two or more rails 6 may extend beyond the two opposing edges of the panel section 10, or the crossbars 4 may be diagonally positioned, and so forth. Or a frame (not shown) or other supporting mechanism or means may be used. Since there are innumerable ways of attaching or supporting or bracing a panel section 10, the enabling embodiment of FIG. 1 is understood to be a non-limiting example. Thus, modifications and changes to the attachment or supporting mechanisms of FIG. 1 may be made without departing from the spirit and scope of this disclosure.
It should also be understood that the panel section 10 may contain one or more solar panels. That is, a plurality of solar panels 2 may be arranged to form a single panel section 10. Thus, the panel section 10 may be larger than a single solar panel 2. Additionally, as stated above, the panel section 10 may be of any arbitrary shape or size, with some panel sections 10 being rectangular, square, polygonal, curved, and so forth. Also, in some embodiments, it may be desirable to attach an intermediate structure between the panel section 10 and the rails 6, in addition to or other than the crossbars 4. Or based on the capabilities and type of rails 6 used, the crossbars 4 may not be necessary. Or based on the capabilities and type of crossbars 4 used, the rails 6 may be supplanted by use of the crossbars 4 as the “rail-like” element.
FIGS. 2A and 2B are illustrations of end-views of exemplary two- and three- panel roofing sections 20 and 25, respectively. The three-panel section 20 of FIG. 2A shows three individual panel sections 10 placed proximal to each other to form a “single” roofing section 20. One or more rails 6 at the ends of the roofing section 20 are attached via a hinge or mount 28 to a support 26 of the underlying structure (e.g. pillar, rafter, girder, ridge beam, and so forth). The hinge or mount 28 can be a bolt, pin, link, or any other type of attaching mechanism that allows the attached panel section 10 to pivot or move in a constrained manner that does not introduce bending into the rail. One or more rails 6 that are interior to the roofing section 20 are joined to a neighboring rail 6 of the adjacent panel section 10 by a link 22. The link 22 may also be of any type of mechanical linkage that allows the panel section 10 to move in a constrained manner. A cable(s) 24 is coupled directly or indirectly to the links 22.
The linked panels 10 of the roofing section 20 are understood to hang down under their weight and their natural shapes, and are held down by the cable pretension, with the linkage points naturally falling along a catenary curve. The linked panels are further pulled downward by the cable pretension. The cable(s) 24 attached to the links 22, being anchored to something solid (e.g., the pillars or rafters, the ground, strong structures, and so forth), apply “outward and downward” tension on the links 22 for stability against random gusts or turbulence.
In some embodiments, it may be desirable to utilize a single cable 24 that traverses all the rails 6 from one side of the structure to the other. Cable spreaders (discussed below) on the supports 26 can be used to control the cable 24 between the sections and maintain the tension on each link 22. If the cable spreader is configured to enable the cable 24 to slide there within, it can distribute the cable's tension wherever it is most needed to react to a given dynamic load. By using such a design, additional parts and labor can be reduced as cable terminations (FIG. 7) are only needed for the outermost links 22 in every row.
When wind pressure is downwards, the rails are in tension; when wind force is upwards, the rails are in compression. Because the compressive load is balanced by the tensile load in the cable 24, the magnitude of the compression experienced by the rails 6 does not overstress them. The tension from the cable(s) 24 also raises the roofing section's 20 natural resonance frequency, thereby minimizing its susceptibility to fatigue. If the individual panel sections 10 are caused to vibrate, they will vibrate at a higher frequency and lower amplitude than they would without the cable(s) 24. This will reduce the dynamic force and in turn the stress of the panel section. This reduces the stress on the individual panel sections 10.
FIG. 2B illustrates a similar approach to that of FIG. 2A except with a two-panel section 25, and should be self-explanatory in view of the foregoing description for FIG. 2A.
Based on the principles described above, structural supports 26 and appropriately configured panel sections 20 or 25 define the main components to build a roof. There is no requirement for purlins, tie beams, collar beams, wind braces, battens, and so forth, which are typically required in a conventional solar panel mounting system. These extra components add considerably to cost, complexity, obstruction of the underlying space, and the energy required to make the superfluous components. Of course, such items may be added to the exemplary approaches described herein, but they are not necessary. Because of the lack of need for these conventional parts, costs associated with their procurement and installation can be eliminated, resulting in a more cost-effective solar panel roofing system.
Based on the above exemplary embodiments, various designs are possible for the links 22. For example, FIG. 3A is an illustration 30 of an exemplary link 29 which contains a cable supporting member 31 that facilitates connection to the cable 24. The cable supporting member 31 may include a lip that the cable 24 rests on or a channel (fully or partially enclosed, etc.) that mechanically couples link 29 to cable 24. Cable 24 may loosen, tighten, or slide lengthwise over the lip or across the channel, depending on the forces on the attached roofing section compared to those on other roofing sections connected to the same cable. The link 29 may be coupled to the panel sections (not shown) via pin/hole combinations 27 which mate to the accompanying rails 6 of the panel sections. It should be understood that the pin/hole combinations 27 may be replaced with any suitable mechanism for coupling that provides some measure of pivoting to the panel sections, as according to design preference.
Also, the cable supporting member 31, though shown as being “below” the link 29 in FIG. 3A may, in some embodiments, be situated above, next to, or on the link 29, and so forth. That is, for example, in some embodiments, it may be desirable to place the cable supporting member 31 above the bottom of the rails 6, possibly on the exterior of the link 29. Also, it is envisioned it may be possible to have the cable supporting member 31 operate as a coupling for securing the link 29 to the rails 6, via the holes 27. Thus, it is apparent that based on the embodiments disclosed herein, several variations and modifications may be made without departing from the spirit and scope of this disclosure.
FIG. 3B provides an illustration 35 of another link 33, wherein a pulley 34 is configured with the link 33, and is instructive for demonstrating possible variations to the link(s) described herein. It should be noted that while FIGS. 3A-B illustrate the rails 6 as having a diagonal edge, allowing the pivoting or flexing of the panel sections ends upward, non-diagonal edging or any other type of contour for the edge of the rails 6 may be used. In some embodiments, it may not be desirable to have a predetermined contour on the edge of the rails 6 as the ends of the rails 6 may be sufficiently spaced from each other to allow movement without contact. In some embodiments, it may be desirable, in fact, to ensure contact of the ends of the rails 6, in order to provide some constraint of the flexing movement, according to design preference.
Also, it should also be noted that while the exemplary embodiments described above show two pin/hole combinations 27 per link, the rails 6 may be configured in such a manner that only one pin/hole combination 27 may be necessary, or several pin/hole combinations 27. That is, in some embodiments, the rails 6 of adjoining panel sections may overlap each other such that a single pin/hole combination 27 may be implementable, thus the link may only require a single pin/hole combination 27 per panel section pair.
FIG. 4 is an illustration 40 of an exemplary section-end attachment, wherein the end(s) of a rail 6 may be attached to a securing mechanism/bracket 45 that is mounted or fixed to a structural member 42. The securing mechanism/bracket 45 is fitted with hole(s) 41 that are mated to hole(s) 41 in the end(s) of the rail 6 by which a pin (not shown) or any suitable securing device or means is used to secure the rail 6 to the structural member 42. In some embodiments, the securing device may be a cotter pin that enables the rail 6 to move laterally, or simply a ring. In some embodiments, a frictioning device such as a washer, collar, and so forth, may also be implemented. It is understood that the frictioning device may also be used to reduce friction (rather than increase friction) or to provide some degree of cushioning to the rail 6 ends during periods of load or movement. By use of the embodiment shown in FIG. 4, the rails 6 may pivot about the hole(s) 41 to enable the supported panel section to flex up or down.
As should be apparent, the embodiment of FIG. 4 is one of several possible ways to secure the rail 6 to a supporting structure. As non-limiting examples, the securing mechanism/bracket 45 may be sleeve or ring that couples to the rail 6. Additionally, the securing mechanism/bracket 45 may be placed on the side or under the structural member 42, for example, as with a rafter. Accordingly, with an understanding of the principles outlined in the exemplary embodiment of FIG. 4, numerous changes and modifications may be made for implementing a rail-to-support connection without departing from the spirit and scope of this disclosure.
FIG. 5 is a perspective view of an exemplary canopy system 50 implementing the systems and methods disclosed herein. Panel sections 10 formed of solar panels flexibly linked together to form a flexible roof that is supported by columns 53. Cabling 24 is attached to strategic points of the panel sections 10 to provide resilience to the canopy system 50. The basic building block of the canopy system 50 is a panel section 10 of at least two or more linked panels.
FIG. 6 is an illustration 60 of an exemplary cable spreader system 55. The cable spreader system 55 contains at one end a sleeve/channel 62 that the cable 24 can be placed in. The sleeve/channel 62 may be enclosed (threading the cable 24 therein) or may be open (laying the cable 24 therein) or of another nature that allows the cable 24 to be situated in the sleeve/channel 62. The sleeve/channel 62 may be displaced a certain distance from a girder 51 that is supported by the support 53. As should be apparent, the cable spreader system 55 may be attached directly to the support 53 in any suitable fashion or manner desired, as according to design preference. Additionally, the cable spreader system 55 may be accommodated with an additional tensioning or spreading mechanism (not shown) that “pushes” the cable 24 downward and/or applies tension to the cable 24, as needed.
The cable spreader system 55 functions to anchor the cable 24 to supporting sections 53 and provides a mechanism to maintain tension on each link in the desired direction. Since the cable 24 can move through the sleeve/channel 62, it can allocate its resilience wherever it is most needed to react to a given dynamic load. Since there may be many other ways to perform the desired control exhibited by the cable spreader system 55, it should be apparent that various modifications or changes may be made to the exemplary cable spreader system 55 without departing from the spirit and scope of this disclosure.
FIG. 7A is an illustration 70 of a cable termination 73. Simply put, the cable termination 73 provides a mechanism to anchor the cable 24 at a termination point. While FIG. 7A shows the cable termination 73 as being displaced from a girder or beam 51 in some embodiments the cable termination 73 may be directly attached to the girder or beam 51. Also, the cable termination 73 may also be directly or indirectly attached to the support 53, depending on design preference. Actual tensioning of the cable 24 may be accomplished by simply pulling the cable 24 to a desired tension and then fixing its end with a plug or restraint 74. The tensioning of the cable 24 may also be facilitated by a turnable termination, for example, as seen in guitar string tuning pegs. Or the cable 24 may be looped through a ring attached to the beam 51. Therefore, it is understood that various changes and modifications can be made without departing from the spirit and scope of this disclosure.
FIG. 7B is a diagram of another cable-termination embodiment. Here, the cable 24 is configures so as not to be attached to or interact with the end support 53. Instead, it passes through a pulley or channel 76, which can be similar to those mounted to the links 29, 31, and may be terminated by a spring 77 that maintains tension in the cable 24 if thermal expansion decreases the cable pretension below its desired lower limit. Many types of simple spring(s) 77 or equivalent devices can be used to control the tension. The spring 77 can be anchored directly to the ground or to a footing 78, as is a compression member 79 that supports the pulley or channel 76. In some embodiments, the pulley 76 may be configured with a spring inside the pulley 76, to provide tension to the cable 24. That is, the end of the cable 24 may be affixed to the pulley 76 and tensioning may be accomplished with the pulley's spring.
Various designs are also possible for the ends of the canopy. For example, the canopy can end just above the outermost major support as in FIG. 7, or an overhanging eave can be added as shown in FIG. 8. In FIG. 8, rail 6 of the eave can be fixed to the support 53 by a fixed member/strut 87. In this example, rather than using a cable 24 to secure the eave, a fixed member/strut 87 is utilized. Since the eave may only consist of a single panel section 2, the ability to flex may not be a concern. However, it should be noted that in some embodiments, it may be desirable to enable the eave to flex and, therefore, the fixed member/strut 87 may be replaced with a cable 24, in a specialized fashion. For example, the end of the eave may be coupled to the cable 24 with the cable 24 “wound” back to be terminated at the support 53. In this instance, the cable termination 73 may be replaced with a cable spreader and the cable 24 terminated at some appropriate place on the support 53.
In various embodiments, it is understood that it may be desirable to attach or secure some form of netting or protection underneath the canopy system 50 to catch any glass or debris from solar panel breakage. In some embodiments, the netting or protection mechanism may be decorative and/or configured with lighting to add to the functionality or aesthetics of the canopy system 50.
Various advantages are realizable using the exemplary methods and systems disclosed herein. For example, rather than attaching solar power panels to an existing roof (requiring complicated attachment mechanisms), the aeroelastic solar-power-generating canopy can be simply built from two or more panel sections with flexibly linked rails and stabilizing cables. This design allows the canopy to be attached to major supports, with no further structure needed. Because of the flexible nature of the canopy, it will react to dynamic loads in any direction. The cables can be configured to be continuous from end to end of the structure, thus reducing the number of junctions. Optional overhanging eaves can be positioned at the ends of the canopy/structure. The canopy is also advantageous in that it is structurally optimized to minimize the use of commodity materials such as steel and concrete, resulting in a more cost effective energy generating solution for open or semi-open structures. Also, installing such a canopy over a building would reduce the thermal energy reaching the building, reducing its cooling requirements and thus its energy usage.
Based on the disclosed embodiments, electrical connections between the panels sections can be arranged to aggregate power in quantities compatible with downstream equipment. Thus, sturdy, resilient, and elegant families of designs can be found for a wide variety of shade providing, power generating structures. The exemplary canopy system, being a solar panel system, is capable of generating power with no noise or smell, which can be a boon in remote recreation areas, as well as being useful in urban and industrial settings.
It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described and illustrated to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.

Claims

1. An aeroelastic solar-power-generating canopy, comprising:

a plurality of solar panels arranged substantially adjacent to each other;

attachment members coupled to at least one portion of a solar panel of the plurality of solar panels;

linking members coupled to the attachment members, the linking members providing a flexing point for solar panels of the plurality of solar panels;

a cable coupled to the linking members, spanning a substantial portion of a distance covered by the plurality of solar panels, and providing a restraining force; and

a plurality of supporting structures, wherein at least one of the attachment members and cable is coupled thereto, wherein the cable in conjunction with the linking members allows the plurality of solar panels to dynamically react to loads, the plurality of solar panels operating as a covering and as a source of solar power.

2. The canopy of claim 1, wherein the attachment members includes a crossbar.

3. The canopy of claim 1, further comprising a termination attachment coupling an end of the cable to a supporting structure of the plurality of supporting structures.

4. The canopy of claim 1, wherein a profile of a portion of the canopy forms a catenary curve.

5. The canopy of claim 1, wherein the linking member includes a pulley mechanism in contact with the cable.

6. The canopy of claim 3, wherein the termination attachment is displaced from the supporting structure.

7. The canopy of claim 1, wherein a cable attached to the supporting structure is attached via a cable spreader.

8. The canopy of claim 8, wherein the cable spreader is capable of allowing the cable to move in an axial direction through the cable spreader.

9. The canopy of claim 1, wherein the cable is terminated to ground.

10. An aeroelastic solar-power-generating canopy, comprising:

a plurality of means for generating power from solar energy arranged substantially adjacent to each other;

means for attachment coupled to at least one portion of a means of the plurality of the solar means;

means for linking coupled to the means for attachment, the linking means providing a flexing point for the means of the plurality of solar means;

a tensioning means coupled to the linking means, spanning a substantial portion of a distance covered by the plurality of solar means, and providing a restraining force; and

a plurality means for supporting, wherein at least one of the attachment means and tensioning means is coupled thereto, wherein the tensioning means in conjunction with the linking means allows the plurality of the solar means to dynamically react to loads, the plurality of solar means operating as a covering.

11. The canopy of claim 10, wherein the attachment means includes a crossbar.

12. The canopy of claim 10, further comprising a means for termination, coupling an end of the tensioning means to a supporting means of the plurality of supporting means.

13. The canopy of claim 10, wherein a profile of a portion of the canopy forms a catenary curve.

14. The canopy of claim 10, wherein the linking means includes a means for rotation in contact with the tensioning means.

15. The canopy of claim 12, wherein the termination means is displaced from the means for supporting of the plurality of supporting mean.

16. The canopy of claim 10, wherein the tensioning means is attached to the supporting means via a means for displacing a cable from a structure.

17. The canopy of claim 10, wherein the displacing means is capable of allowing the tensioning means to move in an axial direction through the displacing means.

18. A method for providing an environmental covering using solar power panels, comprising:

arranging a plurality of solar panels substantially adjacent to each other;

attaching attachment members to at least one portion of a solar panel of the plurality of solar panels;

linking linking members to the attachment members, the linking members providing a flexing point for solar panels of the plurality of solar panels;

coupling a cable to the linking members, spanning a substantial portion of a distance covered by the plurality of solar panels to provide a restraining force; and

coupling the plurality of solar panels to a plurality of supporting structures, wherein at least one of the attachment members and cable is coupled to a supporting structure of the plurality of supporting structures, wherein the cable in conjunction with the linking members allows the plurality of solar panels to dynamically react to loads.

19. The method of claim 18, wherein the attachment members are coupled to a crossbar on the solar panel.

20. The method of claim 18, further comprising, terminating an end of the cable to a supporting structure of the plurality of supporting structures.