Air moving across an array of photovoltaic (PV) assemblies mounted to the roof of a building, or other support surface, creates wind uplift forces on the PV assemblies. Much work has been done in the design and evaluation of arrays of PV assemblies to minimize wind uplift forces. See U.S. Pat. Nos. 5,316,592; 5,505,788; 5,746,839; 6,061,978; 6,148,570; 6,495,750; 6,534,703; 6,501,013 and 6,570,084. Reducing wind uplift forces provides several advantages. First, it reduces the necessary weight per unit area of the array. This reduces or eliminates the need for strengthening the support surface to support the weight of the array, thus making retrofit easier and reducing the cost for both retrofit and new construction. Second, it reduces or eliminates the need for the use of roof membrane- (or other support surface-) penetrating fasteners; this helps to maintain the integrity of the membrane. Third, the cost of transporting and installing the assembly is reduced because of its decreased weight. Fourth, lightweight PV assemblies are easier to install than assemblies that rely on heavy ballast weight to counteract wind uplift forces. Fifth, when appropriately designed, the assembly can serve as a protective layer over the roof membrane or support surface, shielding from temperature extremes and ultraviolet radiation.
PV assemblies can be mounted flat on a roof or other support surface or at an angle to support surface. The rear edge of the PV module (the polar edge, that is the north edge in the northern hemisphere) is commonly supported above the support surface by a rear support. The rear support may be pivotally connected to the PV module. See, for example, U.S. Pat. Nos. 6,046,399; 6,534,703 and 6,809,251.
One example of a collapsible PV assembly comprises a PV module, a front support and a rear support assembly. The PV module comprises front and rear edges on opposite sides thereof, an upper surface and a lower surface. The front support is secured to the PV module at the front edge and has a first support-surface-engaging surface. The rear support assembly comprises a wind deflector assembly having first and second end portions, the wind deflector assembly comprising a wind deflector. The rear support assembly also comprises a connection securing the first end portion to the PV module at the rear edge to permit the wind deflector assembly to be placed in a use orientation, extending downwardly and outwardly away from the rear edge, and a storage orientation, extending along the lower surface of the PV module. The second end portion of the wind deflector assembly comprises a second support-surface-engaging surface. In some embodiments the connection may comprise a pivot connection pivotally securing the first end portion of the wind deflector assembly to the PV module at the rear edge, whereby the one-piece, collapsible PV assembly is a one-piece, folding PV assembly. In some embodiments the front support may be pivotally connected to the PV module for movement between a use orientation, extending outwardly away from the front edge, and a storage orientation, extending along the lower surface of the PV module. In some embodiments the PV module may comprise a peripheral edge, the peripheral edge and the lower surface defining a PV module interior, the rear support assembly being effectively completely within the PV module interior when the wind deflector assembly is placed in the storage orientation. In some embodiments rows of PV assemblies may have side wind deflectors at the ends of the rows.
An example of a method for installing an array of PV assemblies on a support surface comprises receiving a plurality of folded PV assemblies at a worksite in folded, storage orientations and transforming at least one of said PV assemblies from a storage orientation to a use orientation. The PV assemblies each comprise a PV module having a lower surface, a front support and a rear support assembly comprising a wind deflector, the rear support assembly pivotally connected to the PV module and extending along the lower surface of the PV module in the storage orientation. Transformation from the storage orientation to the use orientation includes pivoting the rear support assembly downwardly and outwardly away from the lower surface of the PV module, arranging the front support to extend outwardly away from the PV module, and positioning said at least one PV assembly in the use orientation on the support surface. In some embodiments the receiving step comprises receiving the plurality of one-piece folded PV assemblies with the front support pivotally connected to the PV module and extending along the lower surface in the storage orientation, and the transforming step comprises pivoting the front support downwardly and outwardly away from the PV module. In some embodiments the receiving step is carried out with the PV module having a peripheral edge, the peripheral edge and the lower surface defining a PV module interior, and the rear support assembly is effectively completely within the PV module interior when in the storage orientation.
An example of a method for preparing and installing an array of PV assemblies on a support surface may proceed as follows. A plurality of PV modules is shipped in packaging. The PV modules are removed from the packaging, PV assemblies are repackaged in the packaging in a folded, storage orientation, the PV assemblies each comprising said PV module and a rear support assembly comprising a wind deflector. The rear support assembly is pivotally connected to the PV module and extends along the lower surface of the PV module in the storage orientation. The PV assemblies are transported in the same packaging used for shipping the PV modules. A plurality of the transported PV assemblies is received at a worksite in the folded, storage orientations. The PV assemblies are removed from the packaging. At least one of the PV assemblies is transformed from the folded, storage orientation to an unfolded, use orientation by pivoting the rear support assembly downwardly and outwardly away from the lower surface of the PV module, and arranging a front support to extend outwardly away from the PV module. The at least one PV assembly is positioned in the use orientation on the support surface. In some embodiments a plurality of the PV assemblies may be arranged to form an array of PY assemblies on the support surface. In some embodiments the PV assemblies of the array of PV assemblies are secured to one another using, for example, connector elements. In some embodiments connector means may be used to prevent lateral separation between adjacent PV assemblies while permitting said PV assemblies to follow the contour of an other-than-flat support surface.
An example of a one-piece, nesting PV assembly comprises a PV module comprising front and rear edges on opposite sides thereof, an upper surface and a lower surface. A front support is secured to the PV module at the front edge, the front support having a first support-surface-engaging surface, the front support extending outwardly away from the front edge. A rear support assembly comprises any wind deflector assembly having first and second end portions, the wind deflector assembly comprising a wind defector. The second end portion of the wind deflector assembly comprises a second support-surface-engaging surface. The first end portion is secured to the PV module at the rear edge, the rear support assembly extending downwardly and outwardly away from the rear edge. The PV assembly has complementary nestable top and bottom surface profiles to permit first and second of the PV assemblies to stack in a nesting fashion in a transport mode with the PV module, front support and rear support assembly of the first PV assembly adjacent to the corresponding structure of the second PV assembly thereby maximizing packing density.
One aspect of the present invention is the recognition that there are substantial advantages to be gained from designing a one-piece, collapsible PV assembly that can be shipped to an installation site and mounted directly to a roof or other support surface without the need to assemble the major components, including the rear wind deflector, of the PV assembly, the installation capable of being carried out using simple tools in a straightforward installation process. Another aspect of the present invention is the recognition that there are significant advantages arising from shipping the PV assemblies in a compact folded state, especially where the PV assembly can be shipped in the same shipping container as the PV module.
Various features and advantages of the invention will appear from the following description in which the preferred embodiments have been set forth in detail in conjunction with the accompanying drawings.
The following description of the invention will typically be with reference to specific structural embodiments and methods. It is to be understood that there is no intention to limit the invention to the specifically disclosed embodiments but that the invention may be practiced using other features, elements, methods and embodiments. Preferred embodiments are described to illustrate the present invention, not to limit its scope, which is defined by the claims. Those of ordinary skill in the art will recognize a variety of equivalent variations on the description that follows. Like elements in various embodiments are commonly referred to with like reference numerals.
Each PV assembly 12 preferably includes a rear wind deflector 20 extending downwardly and outwardly away from upper, rear edge 18 PV module 14. A gap 22 is provided between rear edge 18 and the upper edge 24 of rear wind deflector 20. Side wind deflectors 28 are used at the end of each row of PV assemblies 12. A gap 30 is preferably provided between the upper edge 32 of side wind deflector 28 and the outside lateral edge 34 of PV module 14. The use of wind deflectors 20, 28 and the provision of gaps 22, 30 are discussed in more detail in U.S. Pat. No. 6,570,084 and in International patent application PCT/004/27351 published 3 Mar. 2005 as International Publication Number WO 2005/02090, the disclosures of which are incorporated by reference.
PV module 14, in this embodiment, includes a main body 36 surrounded by a peripheral edge 38. Peripheral edge 38 is typically extruded aluminum but may also be made of other metals or appropriate nonmetallic materials as well. Peripheral edge 38 helps to protect main body 36 and also provides structural strength to PV module 14. In addition, front and rear support structures of PY assembly 12, discussed below, are secured to peripheral edge 38 to eliminate the need to secure such support structures directly to main body 36 of PV module 14.
PV assembly 12 also includes a front support 40 secured to and extending from peripheral edge 38 at either end of front edge 16. This is typically accomplished using screws 42, as shown in
PV assembly 12 also comprises a rear support assembly 56 secured to peripheral edge 38 at each end of rear edge 18. Rear support assembly 56 comprises a wind deflector assemble 58, assembly 58 comprising rear wind deflector 20 secured to legs 60. Rear support assembly 56 also includes connections 62 extending from peripheral edge 38. Connections 62 pivotally connect the upper ends 64 of legs 60 to PV assembly 12 for pivotal movement about pivots 66. The lower end 68 of each leg 16 includes a foot 70, see
A connector element 80 is used to secure adjacent PV assemblies 12 to one another at their adjacent corners to help maintain the PV assemblies in place and also to help installation 10 counteract wind uplift forces. The advantages associated with connecting adjacent PV assemblies to one another are discussed in more detail in U.S. Pat. No. 6,570,084 and in International patent application PCT/004/27351 published 3 Mar. 2005 as International Publication Number WO 2005/02090, the disclosures of which are incorporated by reference. Connector element 80 is preferably constructed to prevent lateral separation between the adjacent PV assemblies 12 but is flexible enough to permit the PV assemblies to follow the contour of an other-than-flat support surface.
Rear support assembly 56 of
The embodiments of
While the angle of rear wind deflector 20 could be made to be adjustable, a preferred embodiment uses a fixed angle, the angle typically being chosen according to the inclination, if any, of support surface 48 and the latitude of the site. It is preferred that PV assemblies 12 be mounted without the use of support-surface-penetrating screws, nails, etc. If necessary or desirable, ballast can be used to help counteract wind uplift forces. One way to do so would be to provide the underside of rear wind deflector 20 with L-shaped clips to permit pavers or other ballast to be mounted to and beneath the rear wind deflectors. The weight of PV assemblies 12, including any ballast, is preferably less than 3 pounds per square foot. Depending on various factors, such as expected maximum wind speeds, regulatory requirements and configuration of the roof or other support surface, the weight of PV assemblies 12 in various embodiments may be less than 3 pounds per square foot (144 N per square meter), less than 5 pounds per square foot (239 N per square meter), less than 10 pounds per square foot (479 N per square meter), or less than 15 pounds per square foot (718 N per square meter).
In use, stacks of PV assemblies 12 are preferably delivered to the worksite in a folded condition as one-piece assemblies. After a PV assembly 12 has been removed from its packaging, rear support assembly 56 and front support 40 are moved from their storage orientations to their use orientations. After being properly located on support surface 48, adjacent PV assemblies 12 can be secured to one another using, for example, connector elements 80 and screws 86. Electrical connections are made among PV assemblies 12 and side wind deflectors 28 are installed to complete the installation.
In a further embodiment, shown in
The above descriptions may have used terms such as above, below, top, bottom, over, under, et cetera. These terms are used to aid understanding of the invention are not used in a limiting sense.
Other modification and variation can be made to the disclosed embodiments without departing from the subject of the invention as described above, shown in the accompanying drawing and defined in following claims. For example, in some embodiments it may be desired to secure one or both of rear support assembly 56 and front support 40 to PV module 14 using other than a pivot connection, such as a tool-less clip or a snap in place connection; in such event it would still be preferred that rear support assembly 56 and front support 40 be secured to PV module 14 to lie along lower surface 82 of the PV module, and preferably within interior 98, during shipping and storage. Also, it may be desired to construct an embodiment of PV assembly 12 so that rear wind deflector 20 is attached to the remainder of the assembly in the field. For example, in the embodiment of
Any and all patents, patent applications and printed publications referred to above are incorporated by reference.
This application claims the benefit of provisional patent application No. 60/754,912 filed 29 Dec. 2005 and entitled One Piece, Collapsible PV Assembly.
This invention was made with State of California support under the California Energy Commission Agreement Number 500-00-034. The Energy Commission has certain rights to this invention.
Number | Date | Country | |
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60754912 | Dec 2005 | US |