GB2440430A

GB2440430A - Flexible, inflatable photovoltaic solar roof

Info

Publication number: GB2440430A
Application number: GB0713882A
Authority: GB
Inventors: Benedict George Morris; Daniel Gower Davies
Original assignee: Solar Century Holdings Ltd
Current assignee: Solar Century Holdings Ltd
Priority date: 2006-07-18
Filing date: 2007-07-18
Publication date: 2008-01-30
Also published as: GB0713882D0; GB0614253D0; US20080034684A1; WO2008009916A1; EP2044633A1

Abstract

A building component has a rigid support frame and first and second transparent or translucent flexible sheets 301, 302 attached to the frame to define an inflatable element. At least one region 203 of flexible photo-voltaic laminate material is secured to one of the flexible sheets. The PV may be mounted directly on the outer surface of the roof by adhesive or may be located in pockets formed by an additional, overlying layer of roofing material within which the PV may move. An intermediate transparent sheet 303 may be provided between the first and second sheets and may carry a second PV laminate. A building may be provided comprising the building component with interface devices for receiving cables configured to convey power. A source of compressed air may also be provided which preferably includes an adjustment device for altering the degree of shading provided by the PV laminates. In use, the photo-voltaic material 203 generates electrical energy and provides a degree of shading under conditions of sunlight.

Description

Building Component

Cross Reference to Related Applications

This application claims priority from United Kingdom Patent Application No. 06 14 253.3 filed on July 18, 2006, the whole contents of which are incorporated herein by reference.

Technical Field

The present invention relates to apparatus forming a building component, comprising a substantially rigid support frame, a first substantially transparent or translucent flexible sheet attached to said support frame and a second substantially transparent or translucent flexible sheet attached to said frame to define an inflatable element.

Background of the Invention

Building components constructed from a substantially rigid support frame with a first substantially transparent or translucent flexible sheet attached thereto along with a second substantially transparent or translucent flexible sheet thereto so as to define an inflatable cushion-like element are known. The elements may comprise two or more layers of a plastic foil-like material, such as ETFE (Ethylene Tetra Flouro Ethylene) inflated with relatively low pressure air. The ETFE sheet is restrained in its perimeter frame, the frame usually being manufactured from extruded aluminum, which is turn fixed to a support structure.

As the element is inflated, the ETFE sheet is placed under tension and thereby forms a tight drum-like skin.

ETFE based elements of this type are fixed to a support structure to form a cladding and are used to enclose spaces such as atria or to provide a transparent or translucent roof or façade, often as an alternative to glass.

However, an advantage over using glass structures is that the element-based structures are relatively less expensive, the components have a lower embodied energy and do not require the use of toxic chemicals. The technology has been implemented, for example, by the Eden Project in the United Kingdom.

Brief Summary of the Invention

According to an aspect of the present invention, there is provided an apparatus for forming a building component, comprising a substantially rigid frame; a first substantially transparent or translucent flexible sheet attached to said support frame and a second substantially transparent or translucent flexible sheet attached to said frame to define an inflatable element. In addition, there is provided at least one region of flexible photo-voltaic laminate material positioned over one of said flexible sheets such that when inflated and when constructed said photo-photo-voltaic laminate material generates electrical energy and provides a degree of shading under conditions of sunlight.

Brief Description of the Several Views of the Drawings Figure 1 shows a portion of a building having inflated elements; Figure 2 shows an inflated element of the type shown in Figure 1; Figure 3 shows a cross-section of the element identified in Figure 2; Figure 4 shows a cross-section of the frame forming part of the element identified in Figure 1; Figure 5 shows an alternative embodiment in which a photo-voltaic laminate is secured directly; Figure 6 shows an alternative embodiment in which an additional sheet is provided; Figure 7 shows an alternative embodiment in which the photo-voltaic material is encapsulated within layers of EVA; Figure 8 shows an alternative embodiment in which a third transparent flexible sheet is provided; Figure 9 shows a cross-section of a support frame for the embodiment of Figure 7; Figure 10 shows an alternative embodiment with an intermediate sheet; Figure 11 shows an alternative configuration for the embodiment of Figure 9; and Figure 12 shows an alternative embodiment in which photo-voltaic elements have been incorporated within the cushion material itself.

Description of the Best Mode for Carrying out the Invention Figure 1 A portion of a building is shown in Figure 1 in which a main load bearing structure that includes cross members 101, supports elements 102. Each element 102 has a rigid support frame arranged to support a first substantially transparent or translucent flexible sheet and a second substantially transparent or translucent flexible sheet so as to define an inflatable element.

In a preferred embodiment, most of a building is constructed using inflatable elements. Alternatively, inflatable elements may be used in part of a building, such as for a roof, an atrium or for a façade.

The example of Figure 1 is constructed from rectilinear elements.

However, it should be appreciated that in alternative embodiments it is possible to use cushion-like elements having irregular and sophisticated shapes, possibly defining curves across two planes.

Figure 2 An inflated element 102 is shown in Figure 2, consisting of three rectangular ETFE sheets held within a support frame 201. A space between the sheets is inflated via a compressed air inlet 202, thereby maintaining pressure within the sealed element.

The element is also provided with regions 203 of flexible photo-voltaic laminate material secured to one of the flexible sheets. In this way, when the element has been inflated and the resulting inflated element incorporated within a construction (such as that shown in Figure 1). The photo-voltaic material generates electrical energy and also provides a degree of shading under conditions of sunlight.

The regions 203 of photo-voltaic laminate material are shown connected in parallel by electrical connection wire 204. In order to facilitate the distnbution of cables within the structure as a whole, it is possible for electrical conduction cables, such as cable 204, to pass through flexible sheets via a gland 205, configured such that the sheet itself remains sealed and does not therefore lose pressure.

Figure 3 A cross-section of the element shown in Figure 2 is detailed in Figure 3.

This shows the frame 201 in cross-section, configured to support a first substantially transparent or translucent flexible sheet 301 and a second substantially transparent or translucent flexible sheet 302. Furthermore, in this embodiment, an intermediate transparent or translucent flexible sheet 303 is provided. The provision of intermediate sheet 303 enhances the stability of the element and also affects characteristics of the element, such as its ability to transmit light and its thermal properties.

Within the element itself, a first inflatable region 304 is defined between the first sheet 301 and the intermediate sheet 303. Likewise, a second inflatable region 305 is provided, between the intermediate sheet 303 and the second sheet 302. By making region 304 independently inflatable from region 205 it is possible to apply different degrees of pressure to these regions and thereby control operational attributes of the element itself. The regions receive air under these circumstances via a first inlet 306 (for region 304) and via a second air inlet 307, for the second inflatable region.

Figure 4 A cross-section of support frame 201 is detailed in Figure 4. In a preferred embodiment, the frame is fabricated from aluminum extrusions, taking the form of an upper frame component 401 and a lower frame component 402. At their edges, sheets 301, 302 and 303 are brought together to encapsulate a bead 403. The bead 403 is then held within an extruded edge portion 404, which is itself restrained within the lower frame component 402.

As shown in Figure 4, a similar assembly 405 is restrained on an opposite side.

To complete the assembly of the element, the sheets are firmly held in place by the application of the upper frame component 401.

Figure 5 An embodiment is shown in Figure 5, in which the first sheet 301 has an upper external surface 501 and an internal surface 502. In this embodiment, the photo-voltaic laminate 203 is secured directly to the upper surface 501.

In one embodiment, the photo-voltaic laminate 203 is secured directly to the upper surface 501 by means of an adhesive 503.

Figure 6 An alternative embodiment is shown in Figure 6 in which, again, the laminate 203 is positioned over the upper surface 501 of the first sheet 301.

However, in this embodiment, an additional sheet 601 is provided again being substantially transparent or translucent and in particular allowing the transmission of light at frequencies most applicable for the optimum operation of the photo-voltaic laminate 203. In this embodiment, the additional sheet 601 is larger than the laminate so as to present overhanging edges 602 which are secured to the upper surface 501.

In an embodiment, the additional sheet 601 is secured (by the application of an adhesive for example) to the laminate 202. However, in an alternative embodiment, the sheet is not secured to the laminate and the laminate is held in position in a pocket-like manner, such that the laminate is allowed a degree of movement over the upper surface.

As shown in Figure 2 and as reinforced by Figure 6, the photo-voltaic elements take the form of separate panels that are supported on the upper surface 501 and spaced away from the edge of the elements. This positioning is preferred so as to reduce the degree of flexing to which the photo-voltaic laminate is subjected. Thus, in a preferred embodiment, the photo-voltaic laminate is not applied near to the corners of the element, where the curvature of the transparent sheets is considerable.

Figure 7 An alternative embodiment is shown in Figure 7 in which a factory finished unit 701 includes a conventional photo-voltaic component 702, typically consisting of the photo-voltaic material being encapsulated within layers of EVA. However, in addition, further layers 703 of ETFE are provided to facilitate integration into a top layer 704 by a welding process. Thus, I this way, the photo-voltaic construction 701 may be incorporated within the cushion-like structure itself, either after the fabrication of the cushion or prior to the fabrication of the cushion.

Figure 8 An alternative embodiment is illustrated in Figure 8 in which a third top transparent or translucent flexible sheet 801 has been provided which extends over the first flexible sheet 301. In this embodiment, the element is also provided with a second flexible sheet 302 and an intermediate flexible sheet 303, again defining inflatable regions 304 and 305.

A space is provided between the first flexible sheet 301 and the additional third sheet 801 configured to receive photo-voltaic laminate panels 203.

The embodiment of Figure 8 provides an advantage in that the application, servicing or removal of voltaic laminates 203 is easily facilitated, by the removal or application of the top sheet 801. Thus, the laminates 203 may be secured in position without affecting the integrity of the upper surface of the first sheet 301.

Figure 9 A cross-section of the support frame is shown in Figure 9, substantially similar to the cross-section of Figure 4 but with an additional frame attachment to facilitate assembly of the configuration shown in Figure 8. Frame attachment 901 is secured to the upper frame component 401. The frame attachment 901 provides a first bead-channel 902 and a second bead-channel 903. Each of these bead-channels is configured to receive a beaded edge of a third flexible sheet, such as sheet 801 shown in Figure 8.

Figure 10 An alternative embodiment is shown in Figure 10, in which the first flexible sheet 301 is an outer sheet having an outer upper surface 501 and an inner surface 502. A first photo-voltaic laminate 203 is secured to the outer surface 501, possibly using the techniques described with respect to Figure 5 or with respect to Figure 6. In addition, a second photo-voltaic laminate 1001 is secured to the intermediate sheet 303. When constructed, as illustrated in Figure 10, a degree of shading is provided by both the upper photo-voltaic laminate 203 and the intermediate photo-voltaic laminate 1001. However, in the configuration shown in Figure 10, it is possible for light to pass through the elements (and thereby illuminate the interior of a building) by passing between the photo-voltaic laminate shading components (203, 1001) as illustrated by arrow 1002. However, as previously described with respect to Figure 3, it is possible for a different air pressure to be applied within region 304 compared to the region 305.

Figure 11 The embodiment of Figure 10 is again illustrated in Figure 11. However, in this example, the air pressure within region 305 has been increased relative to the pressure of the air contained within region 304. Consequently, the volume of region 304 has reduced substantially and the volume of region 305 has increased substantially, effectively filling most of the space between the first sheet 501 and the second sheet 502. Under these circumstances, shading laminates 203 are brought into close proximity with shading laminates 901.

The shading regions are interdigitated such that the blank (substantially transparent) regions of the upper layer 501 are covered by the shading regions of the intermediate layer 303. Thus, when the assembly of Figure 10 is modified into the configuration of Figure 11, the overall transparency of the individual elements (and by implication the overall structure) is substantially reduced. Thus, by modifying the relative air pressures within regions 304 and 305, it is possible to adjust the degree of shading provided by the photo-voltaic laminates. Furthermore, it should be appreciated that this modification would not, in a preferred embodiment, substantially reduce the structures ability to generate electrical energy.

Figure 12 An alternative embodiment is shown in Figure 12, that is substantially similar to the embodiment of Figure 10. However, in the embodiment of Figure 12, upper photo-voltaic elements 1201 and intermediate photo-voltaic elements 1202 have been incorporated within the cushion material itself, possibly using the techniques described with respect to Figure 7.

Claims

Claims 1. Apparatus forming a building component, comprising a

substantially rigid support frame; a first substantially transparent or translucent flexible sheet attached to said support frame and a second substantially transparent or translucent flexible sheet attached to said frame to define an inflatable element; and at least one region of flexible photo-voltaic laminate material positioned over one of said flexible sheets such that when inflated and when constructed said photo-voltaic material generates electrical energy and provides a degree of shading under conditions of sunlight.

2. The apparatus of claim 1, wherein said first sheet is an outer sheet having an upper external surface and an internal surface, wherein said photo-voltaic laminate is positioned over said upper surface.

3. The apparatus of claim 2, wherein said photo-voltaic laminate is secured directly to said upper surface.

4. The apparatus of claim 3, wherein said photo-voltaic laminate is secured directly by an adhesive.

5. The apparatus of claim 2, wherein said photo-voltaic laminate is attached to said upper surface by an additional sheet, said additional sheet is larger than the laminate so as to present overhanging edges and said overhanging edges are secured to the upper surface.

6. The apparatus of claim 5, wherein said additional sheet is secured to the laminate.

7. The apparatus of claim 5, wherein the additional sheet is not secured to the laminate and said laminate is held in position in a pocket-like manner, such that said laminate is allowed a degree of movement over the upper surface.

8. The apparatus of claim 2, wherein a third transparent or translucent flexible sheet is positioned over the laminate and said third sheet is attached to said support frame.

9. The apparatus of claim 1, wherein said first flexible sheet is an outer sheet when constructed having an inner surface and an outer surface, wherein a first photo-voltaic laminate is secured to said outer surface; and an intermediate substantially transparent or translucent flexible sheet is attached to said support frame between said first sheet and said second sheet, wherein a second photo-voltaic laminate is secured to said intermediate sheet.

10. The apparatus of claim 1, wherein at least one of said sheets includes a gland to facilitate the passing of electrical cables for carrying power generated by said laminate.

11. A method of constructing a building component, comprising the steps of: defining two or more substantially transparent or translucent flexible sheets; applying at least one region of flexible photo-voltaic laminate to at least one of said sheets; and attaching edges of said sheets to a substantially rigid support frame to form an inflatable element.

12. The method of claim 11, wherein the first sheet is an outer sheet having an upper external surface and an internal surface and the photo-voltaic laminate is positioned over said upper surface.

13. The method of claim 12, wherein the photo-voltaic laminate is attached to said upper surface by an additional sheet, said additional sheet is larger than the laminates so as to present overhanging edges and said overhanging edges are secured to the upper surface.

14. The method of claim 13, wherein the additional sheet is not secured to the laminate and said laminate is held in position in a pocket-like manner1 such that said laminate is allowed a degree of movement over the upper surface.

15. The method of claim 12, wherein a third transparent or translucent flexible sheet is positioned over the laminate and said third sheet is attached to said support frame.

16. The method of claim 11, wherein the first flexible sheet is an outer sheet when constructed having an inner surface and an outer surface, wherein a first photo-voltaic laminate is secured to said outer surface and an intermediate substantially transparent or translucent flexible sheet is attached to said support frame between said first sheet and said second sheet, wherein a second photo-voltaic laminate is secured to said intermediate sheet.

17. A building, atrium or façade, having a main load-bearing structure configured to support a plurality of elements, wherein each of said elements comprises: a substantially rigid support frame; a first substantially transparent or translucent flexible sheet attached to said support frame and a second substantially transparent or translucent flexible sheet attached to said frame to define an inflatable element; and at least one region of flexible photo-voltaic laminate material positioned over one of said flexible sheets such that when inflated and constructed said photo-voltaic material generates electrical energy and provides a degree of shading under conditions of sunlight.

18. A building according to claim 17, wherein said load bearing structure includes interface devices for receiving cables configured to convey power generated by said laminate material.

19. A building according to claim 17, including a source of compressed air for maintaining said elements inflated.

20. A building according to claim 19, wherein said source of compressed air includes an adjustment device for adjusting the degree of shading provided by the photo-voltaic laminates.