AU2016213891B2

AU2016213891B2 - Solar Roof tile

Info

Publication number: AU2016213891B2
Application number: AU2016213891A
Authority: AU
Inventors: Ross Baxter; Sarah Fathinia; Kathy McCormack
Original assignee: BRICKWORKS BUILDING PRODUCTS Pty Ltd
Current assignee: BRICKWORKS BUILDING PRODUCTS Pty Ltd
Priority date: 2016-08-12
Filing date: 2016-08-12
Publication date: 2021-12-16
Anticipated expiration: 2036-08-12
Also published as: AU2016213891A1; NZ733822A

Abstract

A solar roof tile including a generally square or rectangular frame which has a pair of parallel side edges configured for overlapping or underlapping with edges of an adjacent roof tile during side-by-side installation on a rooftop. The solar roof file also includes a generally planar PV component mounted to a mounting face of the frame for generating electric current in an electrical cable connected to the PV component and a cable recess in the mounting face for receiving and mechanically protecting the electrical cable. 1/8 10 12 -)222 ... .. .. .. ............ .... ... .. 2 0.. 14 18 24 \MM' ...FIGURE1... 1 2........... IM52 48...... 34.. 36. 40....44....46.. 46MN ....... 52.......0. ................ .......... MWE ........ 38 FIGURE21

Description

1/8

10

12 -)222 ... .. .............. .... ... .. .. 20.. 14

18 24

\MM' ... FIGURE1...

1 2........... IM52 36. 48...... 40....44....46.. 34. 46MN52.......0. ....... ................

.... .......... MWE .

38

FIGURE21

Title of Invention

SOLAR ROOF TILE

Technical Field

[0001] The present invention relates to roof tiles for cladding a rooftop. In particular the present invention relates to a solar roof tile which includes a photovoltaic (PV) component for generating solar electric current.

Background of Invention

[0002] The following discussion of the background to the invention is intended to facilitate an understanding of the invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge as at the priority date of the application.

[0003] Traditional roof-mounted solar power systems involve relatively large PV panels (each panel including a number of PV'cells') mounted to a rooftop in order to generate solar electricity. Whilst well suited to commercial buildings, these systems are less desirable in domestic applications where a tiled rooftop contributes to the overall aesthetic appeal of the property. In particular, traditional systems involve PV panels being mounted to overlie the rooftop cladding thereby obscuring the view of the roof tiles underneath. Moreover, the PV panels tend to be bulky and protrude outwardly from the rooftop thereby diminishing the aesthetics of the rooftop.

[0004] For this reason, solar roof tiles have been developed to provide a more aesthetic alternative to traditional roof-mounted solar systems. Solar roof tiles are shaped and sized to emulate conventional roof tiles whilst also including a PV component capable of generating solar electricity. Solar roof tiles may be installed adjacent to, and in lieu of, a conventional roof tile thereby allowing for PV componentry to be mounted flush into the rooftop. In this manner, solar roof tiles may be integrated into new or existing tiled rooftops to provide an improved aesthetic as compared to traditional solar panel systems.

[0005] However, solar roof tiles pose a number of technical and design challenges not encountered in traditional roof-mounted solar systems. These challenges stem from solar roof tiles requiring dual functionality both as a roof tile and also as a PV component. For example, it is desirable for solar roof tiles to facilitate water drainage in the manner of a conventional roof tile, be sufficiently strong to support an applied weight and also to allow for mounting to underlying roof battens and/or engagement with adjacent roof tiles during installation. Moreover, unlike conventional roof tiles, solar roof tiles are required to dissipate thermal energy produced by the electric componentry and should facilitate the connection of electrical components during installation as well as adhering to prescribed standards of electrical safety and energy efficiency. By way of example, Australian safety regulations require that electrical cables installed on domestic rooftops be adequately insulated and mechanically protected against impacts which could lead to cable damage.

[0006] Existing solar roof tiles address the above requirements to various degrees of success however no existing device excels in all areas. Some existing devices fail to provide any or adequate water drainage. Others fail to allow for sufficient thermal energy dissipation. Some other devices fail to provide sufficient mechanical protection for electrical cables behind the PV componentry. Other devices fail to provide sufficient safety for installation personnel.

[0007] In view of the above, it is therefore desirable to provide a new solar roof tile which better addresses the above-noted challenges and thereby provides an improved alternative to existing solar roof tiles.

[0008] Before turning to a summary of the invention, it is useful to provide an explanation of some of the terms that will be used to define the spatial relationship of the various parts thereof. In this respect, spatial references throughout this specification will generally be based upon a solar roof tile installed on a pitched rooftop. With this environment as a basis, terms such as "outwardly" and "inwardly" will be generally understood as referring to a direction away from and toward the rooftop respectively. Similarly, terms such as "outside" and "underside" will be understood with reference to the outwardly facing surface of the tile and the inwardly facing surface of the tile respectively. It will also be understood that a roof tile installed on a pitched rooftop will have a pair of opposing edges of different elevation. In this context, these edges will be defined and understood as an "upper edge" that is closer to the apex of the roof and an opposite "lower edge". The terms 'upside' or'downside' will also be understood in the context of a pitched roof with reference to elevation. Moreover, it will be appreciated that roof tiles are typically installed in rows extending the length of the rooftop. In this context, the pair of opposing edges extending between the upper and lower edges may be referred to as 'side edges' and a pair of adjacent tiles in the same row may therefore be referred to as being in a 'side-by-side' installation.

Summary of Invention

[0009] According to the present invention there is provided a solar roof tile including a generally square or rectangular frame having a pair of parallel side edges configured for overlapping or underlapping with edges of an adjacent roof tile during side-by-side installation on a rooftop; a generally planar PV component mounted to a mounting face of the frame for generating electric current in an electrical cable connected to the PV component; and a cable recess in the mounting face for receiving and mechanically protecting the electrical cable and for receiving and protecting a junction box connected to an underside of the PV component containing electrical componentry, the frame including at least one access opening facilitating digital access to an underside of the PV component from an underside of the frame.

[0010] The present invention advantageously provides a cable recess for locating the electrical cables of the PV component and for mechanically protecting the cables against external hazards, for example, sharp surfaces within the rooftop, chewing of the cables by rodents or bending/crushing of the cables during renovation or construction works. In use, a plurality of solar roof tiles can be installed on a rooftop and each solar roof tile is connected in electrical series to an adjacent solar roof tile, the cable recess provides a mechanically protected pocket in which the cables of adjacent tiles can be connected thereby advantageously protecting the connections against forces which could damage or disconnect the cable connections. Furthermore, the cable recess facilitates the mounting of the PV component onto the mounting surface by providing a volume or space into which the electrical cables can extend such that the cables do not obstruct abutment between the mounting face and the underside of the PV component. The cable recess may be formed in a variety of

3a

shapes or configurations and may, for example, be T-shaped or U-shaped. In a particular embodiment of the invention, the cable recess is a channel extending at least partially between the parallel side edges.

[0011] The cable recess can include a base recessed below the mounting face and a cable recess sidewall extending between the mounting face and the base. In this configuration, the cable recess provides a mechanically protected pocket bounded by an underside of the PV component, the base and the cable recess sidewall. The cable recess sidewall can border the base of the cable recess and is therefore defined by the shape of the cable recess and the base. Depending on the shape of the cable recess, the cable recess sidewall can consist of a continuous wall portion (for example an oval shaped cable recess) or can consist of a number of connected wall segments (for example a rectangular cable recess). The cable recess sidewall can therefore include linear wall portions, non-linear wall portions or a combination of linear and non-linear wall portions.

[0012] The cable recess can include at least one cable opening, the cable recess and cable opening cooperatively providing a cable passageway between an underside of the PV component and an underside of the frame. In some forms of the invention, the cable recess may include a pair of cable openings at either end of the cable recess. The cable passageway provided by the cable recess and cable openings provide for convenient installation in that the cables of the PV component of a first solar tile can extend through the passageway to the underside of the tile and then be connected to a cable of a second solar tile installed side-by-side to the first tile. The cable opening can be located, for example, on the cable recess base or on the cable recess sidewall. In some embodiments of the invention, a plurality of cable openings are provided in which case cable openings can be provided, on both the base and on the sidewall. According to a particular embodiment of the invention, the cable recess includes a pair of cable openings located at opposite sides of the cable recess base. The cable openings may be a variety of shapes for example circular, oval or square.

[0013] The PV component is mounted or seated upon a mounting face of the frame which can advantageously provide support against impacts onto the outer side of the PV component. To this extent, the mounting face is generally planar and may include any portion of the frame which abuts an underside of the PV component.

[0014] According to a particular embodiment of the invention, the solar roof tile includes a pair of electrical cables connected to the PV component, the pair of electrical cables including a first cable and a second cable which is longer than the first cable. The second (longer) cable of a first solar roof tile can have a length sufficient to permit feeding of the longer cable through the cable passageway to the underside of the frame and then back through the cable passageway of an adjacent, second solar roof tile to permit connection between the longer cable of the first roof tile with the shorter cable of the second roof tile. In this manner, the cable recess beneath each PV component provides mechanical protection to a cable connection between the shorter cable of that particular roof tile and the longer cable of an adjacent roof tile.

[0015] It will be appreciated that the electronic components of a PV component will generally emit thermal energy. It is desirable (and necessary) for this thermal energy to be dissipated both for fire safety reasons and due to the inverse relationship between PV component temperature and PV efficiency. In some existing solar roof tile devices, PV panels are mounted against a solid backing sheet therefore providing reduced ventilation which may result in inadequate thermal energy dissipation. The cable recess of the present invention advantageously reduces the surface area of the frame in contact with an underside of the PV component and therefore improves thermal energy dissipation from the PV component. To facilitate thermal energy dissipation further, the cable recess can further include ventilation openings. The shape, position and number of ventilation openings can vary. According to a particular embodiment of the invention the ventilation openings are located in the base. In an alternative embodiment, the ventilation openings are located in the cable recess sidewall. In a particular embodiment of the invention, both the base and the sidewall include ventilation openings.

[0016] As noted in the foregoing, most PV panels or PV components include a number of PV'cells'. The PV component of the present invention may include a single PV cell or a plurality of PV cells integrated into the PV component. In a particular form of the invention, the PV component comprises 10 PV cells. It will, of course be appreciated that the number of PV cells in the PV component may vary as can the size of the frame in order to accommodate PV cells or PV components of various size.

[0017] The PV component of the present invention will typically include an outer side configured to face outwardly from the rooftop for exposure to sunlight. The PV component also includes an 'underside' from which electrical wiring may extend. The PV component may further include, on its underside, a junction box to protect and conceal electrical componentry. According to a particular form of the invention, the ventilation openings may be located beneath the junction box. The ventilation openings can be clustered in the general vicinity of the junction box on the base or on the cable recess sidewall (or both) to facilitate dissipation of thermal energy emitted from the electronic componentry within the junction box.

[0018] According to a particular form of the invention, the frame includes a lip overhanging a portion of the mounting face and defining a channel in which an edge of the PV component is received. The provision of a channel provides increased mechanical protection to the edge of the PV component which is received therein. Furthermore, the lip may shelter a section of the interface between the mounting face and the PV component thereby reducing the possibility of rainfall entering the interface and subsequently flowing underneath the PV component. As noted in the foregoing, roof tiles are typically installed on a pitched rooftop such that the edge of the solar roof tile closest to the apex of the roof will constitute an 'upper' edge. According to a particular embodiment of the invention, the lip overhangs an upper side of the mounting face and therefore shelters the upper edge of the PV component and provides a rainfall shield to the interface between the upper edge of the mounting face and the upper edge of the PV component.

[0019] The PV component may be mounted to the frame in a variety of ways, for example using fasteners, liquid adhesives or adhesive tapes. According to a particular embodiment of the invention, the PV component is adhesively mounted to the frame and the mounting face includes an adhesive rebate for receiving the adhesive. The adhesive rebate can consist of a recessed section in the mounting face defining a volume beneath the mounting face in which the adhesive can be located which reduces the possibility of the adhesive spacing apart the underside of the PV component and the mounting face. To this end, the adhesive rebate advantageously facilitates abutment between the underside of the PV component and the mounting face. The adhesive rebate may vary in location and in size however in a particular form of the invention, the adhesive rebate is recessed into the mounting face by approximately 2mm. The adhesive rebate can be located at an edge of the mounting face. In some embodiments of the invention, the adhesive rebate is located at a perimeter of the mounting face.

[0020] In some forms of the invention, the mounting face is recessed below an upper surface of the frame. This configuration can advantageously improve mechanical protection afforded to the edges of the PV component. In some embodiments of the invention, the mounting face is recessed below the upper surface of the frame by at least the thickness of the PV component. The PV component may therefore be flush mounted within the frame such that the upper surface of the frame and the upper surface of the PV component are generally aligned. The mounting face recess may also be greater than the thickness of the PV component such that an outer surface of the PV component is recessed below the upper surface of the frame. Recessing of the mounting face is aesthetically desirable insofar as the PV component appears integrated within the frame, creating a sleek appearance in the rooftop, free of protuberances. Furthermore, a recessed mounting face can improve rainfall drainage along the rooftop. In some forms of the invention, the PV component may be sized to have alength or width less than the length or width of the frame such that the frame defines a border surrounding the perimeter of the PV component. The frame can include wall portions surrounding the recessed mounting face and defining a border around an edge of the PV component. In this manner, the frame can provide mechanical protection to the edge(s) of the PV component thereby further reducing the possibility of damage to PV component.

[0021] According to a particular embodiment of the invention, the frame includes at least one access opening facilitating an underside of the PV component to be digitally accessed from an underside of the frame. An access opening is particularly advantageous during installation of the solar roof tile where an electrician may require access to the underside of the PV component in order to facilitate the wiring procedure. An access opening can also allow for a PV component which is seated upon the mounting face to be conveniently lifted up from the mounting face to allow for the application of adhesive or to make minor adjustments to the position of the PV component after application of the adhesive. It will be appreciated that an access opening to the underside of the PV component may be particularly advantageous when the PV component is flush mounted or recessed below the upper surface of the frame such that the edges of the PV component cannot be readily accessed or grasped by the installer. In some forms of the invention, the frame includes a plurality of access openings.

[0022] A variety of adhesives may be suitable for use with the present invention for example silicone which can advantageously also operate as a sealant to prevent or resist ingress of water beneath the PV component. Of course, it will be appreciated that a number of alternative mounting methods are possible including adhesive tape or fastening elements such as screws, nails, bolts etc. The PV component may, instead, be mounted to the frame using clips or retention tabs extending from the frame and abutting the outward side of the PV component to retain it against the mounting face.

[0023] In an alternative to the installation process discussed above, the solar roof tile of the present invention may be supplied for use with the PV component pre mounted to the frame and each of the cables of the PV component extending through the one or more cable openings. Installation of the pre-assembled solar roof tile may involve a first installer such as a roof tiler installing the solar roof tiles in the normal manner and leaving the cables extending from the underside of the tile frame ready for connection by a second (electrical) tradesperson such as a solar installation electrician. Electrical connection of the pre-assembled solar roof tiles is performed by connecting a cable of a first tile to a cable of a second tile and then feeding the cable connection into a cable recess of the roof tiles of the invention.

[0024] In a particular example of a pre-assembled solar roof tile installation procedure, each pre-assembled solar roof tile is provided with a long cable and a short cable extending from the cable recess (via the cable openings in the cable recess) to an underside of the tile frame. After a pair of first and second adjacent pre assembled solar roof tiles is installed by a roof tiler, a solar installer enters the inside of the roof (beneath the solar roof tiles) to access the underside of the solar tiles. The solar installer connects the short cable of the first solar roof tile to the long cable of the second solar roof tile and then feeds the short cable and the cable connection back within the cable recess of the first solar roof tile such that the connection point of the short and long cables is mechanically protected within the cable recess.

[0025] A pre-assembled solar roof tile may be provided with a 'short' cable of longer length than a PV component intended for use as part of a non pre-assembled solar roof tile, i.e. where the PV component is attached to the tile frame after the frame has been installed on the roof. Whereas installation of non pre-assembled solar roof tiles permits the cable connection to be made within the cable recess, the installation of a pre-assembled solar roof tile requires cable connection to take place outside of the cable recess such that appropriately longer cables may be required to facilitate this procedure. Advantageously, the supply of pre-assembled solar roof tiles eliminates the above-discussed step of mounting the PV component to the frame thereby shortening installation time. Furthermore, the installation procedure of pre assembled solar roof tiles does not require a solar installer to access the top (outside) of the roof which is desirable in terms of safety and facilitates adherence to occupational health and safety requirements.

[0026] According to a particular form of the invention, the frame includes a plurality of struts extending across an open section of the frame. One or more of the struts may define a portion of the mounting face. The plurality of struts extending across the open section can define a plurality of openings extending between the mounting face and the underside of the frame which, advantageously, facilitate thermal energy dissipation from the underside of the PV component whilst retaining a desirable level of frame stiffness. In some forms of the invention, the above-noted one or more access openings may be defined by struts extending across the open section of the frame.

[0027] The frame can include a pair of parallel upper and lower edges extending between the parallel side edges. In a particular embodiment, one of the parallel side edges includes an overlap portion and the opposite side edge includes an underlap portion. It will be appreciated that the overlap portion is configured to overlap the underlap portion of an adjacent roof tile (solar or non-solar) in accordance with typical roof tile installation techniques.

[0028] It will be appreciated that the frame and the PV component may be provided in a variety of shapes however according to a particular embodiment of the invention, the frame and the PV component are each rectangular. In this embodiment, the parallel side edges are therefore shorter in length than the above-noted parallel upper and lower edges which extend between the parallel side edges. It will be appreciated that denoting the upper and lower side edges as the longer side edges implies a 'landscape' orientation of the roof tiles wherein the shorter side edges are pitched in accordance with the pitch of the roof. However, in alternative installations, it may be desirable to install the roof tiles in a 'portrait' orientation whereby the longer edges of the rectangular frame are pitched and wherein the shorter side edges comprise the upper and lower edges.

[0029] The solar roof tile of the present invention can be installed on a rooftop amongst conventional, non-solar roof tiles and can therefore be configured for installation in the same manner as a conventional tile. In this regard, one of the parallel side edges of the solar roof tile may include an overlapping portion for overlapping an underlapping side edge of a first adjacent (solar or non-solar) roof tile and the opposite parallel side edge may include an underlapping portion for underlapping an overlapping side edge of a second adjacent (solar or non-solar) roof tile.

[0030] According to a particular embodiment of the invention, the frame can include a draining opening adjacent to a lower edge of the frame. The drainage advantageously enables rainwater to drain through the frame of a first roof tile to the surface of an adjacent second roof tile installed into the rooftop below the first roof tile. In some forms of the invention, the drainage opening is positioned in the mounting face and therefore facilitates drainage of any water which has flowed behind the PV component. The PV component may substantially overlie the drainage opening. In some forms of the invention, the drainage opening is elongated and has a lengthwise axis generally parallel to the lower edge of the frame. In a particular form of the invention, the drainage opening is a drainage slot.

[0031] The PV component may be formed from a PV laminate or be any other suitable PV device or have any other suitable structure. In a particular form of the invention, the frame is formed from a polymer such as BMC (bulk moulding compound). According to an alternative form of the invention, the frame is formed from SMC (sheet moulding compound). In other forms, the PV component is a laminate including a glass top, an EVA centre containing the PV cells and a TPT (tedlar-polyester-tedlar) backing.

[0032] According to a second aspect of the present invention there is provided a solar roof tile including: a generally square or rectangular frame having a pair of parallel side edges configured for overlapping or underlapping with edges of an adjacent roof tile during side-by-side installation on a rooftop; a generally planar PV component mounted to a mounting face of the frame for generating electric current; and a plurality of ventilation openings in the mounting face beneath the PV component facilitating dissipation of thermal energy emitted from an underside of the PV component.

[0033] As discussed in the foregoing, it is desirable (and necessary) for thermal energy emitted from the PV component to be dissipated both for fire safety reasons and due to the inverse relationship between PV component temperature and PV efficiency. In this regard, the provision of ventilation openings according to the second aspect of the present invention facilitates desirable thermal energy dissipation whilst maintaining the mechanical protection provided to the PV component by the frame.

[0034] The second aspect of the present invention is therefore directed to a solar roof tile having the advantages associated with ventilation openings rather than the cable recess provided in the first aspect of the invention. It is to be appreciated that the second aspect of the invention may also include each of the advantageous features discussed above in relation to the first aspect of the invention, other than those relating to the cable recess. Moreover, the second aspect of the present invention can be combined with the first aspect to form a solar roof tile that has both a cable recess and a plurality of ventilation openings, thus providing all of the advantages associated both of those aspects of the present invention.

[0035] The ventilation openings can be formed in a planar section of the frame that is positioned below the PV component. The section of the frame to either side of the ventilation openings can be substantially solid, or substantially uninterrupted by openings. The section of the frame to either side of the ventilation openings can be planar and can be an extension of the planar section in which the ventilation openings are provided.

[0036] Any number of ventilation openings can be provided and the openings can have any shape and size. For example, there could be 30, 50, 100 or 150 openings.

They can be round, square or rectangular. They can be formed in a grid, array or matrix.

Brief Description of Drawings

[0037] Figure 1 is a perspective view of a solar roof tile comprising a frame and a PV component, according to an embodiment of the present invention.

[0038] Figure 2 is a perspective view of the solar roof tile frame illustrated in Figure 1.

[0039] Figure 3 is a closer perspective of an upper right corner of the solar roof tile frame illustrated in Figure 2

[0040] Figure 4 is an underside view of the solar roof tile frame illustrated in Figures 2 and 3.

[0041] Figure 5 is a side view (looking toward the top edge) of the solar roof tile frame illustrated in Figures 2 to 4

[0042] Figure 6 is an elevated side perspective of the solar roof tile frame illustrated in Figures 2 to 5.

[0043] Figure 7 is a perspective view of the PV component illustrated in Figure 1.

[0044] Figure 8 is an underside view of the PV component illustrated in Figure 7.

[0045] Figure 9 is a view of a number the solar roof tile frames illustrated in Figures 2 to 6, partially installed on a rooftop.

[0046] Figure 10 illustrates a conventional roof tile being secured to a rooftop using a metal clip

[0047] Figure 11 is a view of a number of the solar roof tile frames illustrated in Figures 2 to 6, installed on a rooftop amongst non-solar roof tiles.

[0048] Figures 12 and 13 are views of the PV component illustrated in Figures 7 and 8 being mounted to the solar roof tile frames illustrated in Figures 2 to 6 and 9 to 10.

[0049] Figure 14 is a view of the PV component illustrated in Figures 12 and 13 in a mounted position on a solar roof tile frame, as illustrated in Figures 2 to 5 and 8 to 9.

[0050] Figure 15 illustrates a pre-assembled solar roof tile according to an embodiment of the present invention.

Detailed Description

[0051] Figure 1 is a perspective view of a solar roof tile 10 according to an embodiment of the invention. The solar roof tile 10 includes a rectangular frame 12 and a PV component 14 mounted to frame 12. Frame 12 includes a pair of parallel side edges 18, 20 extending between a pair of parallel lengthwise edges 22, 24. Upon side-by-side installation on a rooftop, side edge 18 is configured to underlap with a side edge of an adjacent roof tile or solar tile frame and side edge 20 is configured to overlap with a side edge of a second adjacent roof tile or solar tile frame. Lengthwise edges 22, 24 include a upper edge 22 and a lower edge 24. Turning briefly to Figure 11, it will be appreciated that solar roof tile frame 12 will typically be installed in a 'landscape' orientation on a pitched rooftop such that side edges 18, 20 will be inclined along the pitch of the rooftop and lengthwise edges 22, 24 will traverse the pitch of the rooftop. The lengthwise edge closer to the apex of the roof therefore defines an upper edge 22 which is elevated higher than the opposing lengthwise edge which therefore defines a lower edge 24.

[0052] Figure 2 illustrates a perspective view of frame 12 without the PV component mounted thereto. Adjacent to the lower edge 24, frame 12 includes a plurality of linear and non-linear struts 26 extending across an open section of frame 12 and defining a plurality of openings. The plurality of openings includes a number of minor openings 28 and a pair of major openings which comprise access openings 30. Minor openings 28 advantageously reducing the overall mass of frame 12 whilst desirable retaining frame stiffness. Access openings 30 advantageously permit an installer to digitally access an underside of the PV component 14 thereby facilitating installation of the solar roof tile 10.

[0053] Frame 12 defines a mounting face 32 for seating PV component 14. The mounting face 32 includes a number of generally rectangular portions 34 as well as the upwardly facing surfaces of struts 26. The mounting face 32 contacts and supports the underside of the PV component 14 upon mounting of the PV component 14 to frame 12. As illustrated in Figure 2, mounting face 32 is recessed into the frame 12, below a frame upper surface 36 such that the PV component 14 can be recessed slightly below the upper surface 36. Mounting face 32 includes a 2mm adhesive rebate 38 at three perimeter edges of the mounting face 32. The operation of rebate 38 will be discussed in greater detail below with reference to Figure 12. As will be discussed in further detail with reference to Figure 9, frame 12 also includes a pair of fastener openings 52 to facilitate fastening of frame 12 to a roof batten.

[0054] Still referring to Figure 2, frame 12 includes a cable recess 40 including a base 42 which is recessed below mounting face 32 and a recess sidewall 44 extending between mounting face 32 and base 42. Cables recess 40 allows cables extending from the PV component to extend beneath the mounting face 32 so as not to obstruct or interfere with the contact between the underside of the PV component 14 and the mounting face 32. Base 42 includes a pair of cable openings 46 at opposite ends of base 42. Cable recess 40 further includes a plurality of ventilation openings on base 42 and on recess sidewall 44. In particular, cable recess 40 includes a plurality of base ventilation openings 48 arranged in an array which is located generally centrally in base 42 and a plurality of discrete ventilation openings located in recess sidewall 44. As illustrated in Figure 2, recess sidewall 44 consists of five straight wall segments and a semi-circular wall segment.

[0055] Figure 3 provides a closer perspective of an upper right corner of frame 12 in which portions of upper edge 22, right side edge 20, frame upper surface 36, mounting face 32, adhesive rebate 38 are illustrated in greater detail. Frame 12 includes a lip 37 which overhangs a portion of mounting face 32 and defines a channel 39 for receiving an upper edge of the PV component.

[0056] Figure 4 is an underside perspective of frame 12 illustrating the undersides of base ventilation openings 48, sidewall ventilation openings 50, fastener openings 52 and cable openings 46. As illustrated in Figures 2 and 4, cable recess 40 and cable openings 46 cooperate to provide a cable passageway extending between the underside of the PV component 14 to the underside of the frame 12. Four batten lugs 53 extend from the underside of frame 12 which, in use, rests upon the upper surface of a roof batten to retain frame 12 in position on the rooftop. The underside of frame 12 includes five cut-outs 54 for reducing the overall mass of frame 12. Figure 4 also illustrates the underside of side edge 20 which includes an overlapping portion 21 for overlapping a side edge of an adjacent solar or non-solar roof tile. Overlapping portion 21 is also illustrated in Figure 5 which provides a side view perspective of frame 12 toward upper edge 22. Also illustrated in Figure 5 is an underlapping portion 19 located at side edge 18. In this regard, the underlapping portion 19 of a first frame 12 can, in use, be overlapped by the overlapping portion 21 of a second frame 12 installed side-by-side to the first frame. Batten lugs 53 and sidewall openings 50 are also illustrated in Figure 5.

[0057] Figure 6 provides an elevated side perspective of frame 12. Frame 12 includes an L-shaped drainage channel 84 extending substantially along the upper edge 22 and along side edge 18. Drainage channel 84 provides a drainage passageway along upper edge 22 (from side edge 20 to side edge 18) and then along side edge 18 (from upper edge 22 to lower edge 24). With brief reference to Figures 9 and 10, it will be appreciated that the upper edges 22 of frames 12 are overlapped by the lower edges 24 of upper frames 12 such that upper edges 22 are generally shielded from rainfall. However winds and flow eddying can direct water underneath the overhanging lower edges 24 such that rainfall may ingress upwards toward the upper edge 22 of the lower, underlapping, frame 12. Referring again to Figure 6, this rainfall is advantageously captured within channel 84 and drained along channel 84 as indicated by drainage flow arrows 86. In this regard channel 86 desirably captures any rainfall which ingresses underneath the lower edge 24 and redirects it downwards along the pitch of the rooftop.

[0058] Figures 7 and 8 illustrate PV component 14 which includes ten PV cells 16 for generating electricity upon exposure to sunlight. In the illustrated form of the invention, the ten cell PV component 14 generates a minimum of 44 Watts when exposed to optimal sunlight PV component 14 comprises a PV laminate formed of a number of layers (not shown). A pair of cables comprising a short cable 54 and a long cable 56 extends from an underside 62 of the PV component 14 to communicate electric current generated therefrom. As illustrated in Figure 8, the pair of cables 54, 56 extend from a junction box 60 connected to an underside 62 of PV component 14. Cables 54, 56 include plugs 58 at their free ends facilitating connection between cables 54, 56 and the cables of an adjacent solar roof tile. Long cable 56 is provided with a high-density flexible conduit 74 surrounding part of the length of long cable 56. Whilst not apparent from Figures 7 and 8, flexible conduit 74 includes circumferential corrugations for strength and flexibility. The function of flexible conduit 74 will be discussed in further detail below with reference to Figure 12.

[0059] Figures 9 to 14 illustrate an installation procedure whereby a plurality of solar roof tiles 10 are installed upon the roof battens 64 of a rooftop 66. With reference to Figure 9, frame 12 is configured such that, in use, the right hand side edge 20 is configured to overlap the left hand edge 18 of an adjacent tile frame and lower edge 24 overlaps the upper edges 22 of two lower frames 12. Figure 11 illustrates a plurality of solar roof tile frames 12 in their installed configuration alongside a number of non-solar roof tiles 70.

[0060] Referring again to Figure 9, the underside of each solar roof tile frame 12 rests upon an outwardly facing surface of a roof batten 64. Batten lugs 53 (illustrated in Figures 4 and 5) rest behind one of the battens 64, i.e. on a surface of batten 64 which faces toward the apex of the rooftop 66. Nails 68 are nailed through fastener openings 52 to fix frame 12 to batten 64. In some installations, each solar roof tile will be nailed to a roof batten. In other installations, only every second or third row or roof tiles will be nailed whilst the remaining rows of tiles are held in place by the batten lug 53 only.

[0061] In some installations, frames 12 may also be clipped in place using a flexible metal clip in accordance with conventional installation procedures for standard roof tiles. As illustrated in Figure 10, conventional installation procedures can involve a resiliently flexible metal clip 88 clipping the edge of a roof tile 90 to the underside of a roof batten 64. The use and/or placement of clips during installation of frames 12 can vary depending on the particular installation however, in a particular example, clips may be used to secure the lower portion of the frames 12 to the roof battens. Clips may be used for every second or third frame in a row. In some installations, clips may be used to secure all frames except for frames in the lowermost row and/or frames at the edge of a row.

[0062] After frames 12 are installed on the rooftop, the next stage of the installation procedure involves PV components 14 being connected together in electrical series. Figure 12 illustrates three PV components 14-1, 14-2 and 14-3 corresponding to respective frames 12-1, 12-2 and 12-3. To facilitate the electrical connection process, the lower edges of the PV components are tilted upwardly to expose the cables extending from respective junction boxes 60-1, 60-2 and 60-3 on the underside of the PV components 14-1, 14-2, 14-3. Beginning from the left of Figure 12, PV component 14-1 includes a junction box 60-1 from which long cable 56 1 extends. As discussed above with respect to Figures 7 and 8, a portion of the length of long cable 56-1 is insulated by a flexible cable conduit 74-1. Long cable 56-1 is fed through the cable opening (not shown) on the right-hand side of frame 12-1 and beneath the side-by-side edges of frames 12-1 and 12-2 and is fed back through the left-hand side cable opening 46-2 of frame 12-2. The plug 58-1 at the end of cable 56 1 is thereby located within the cable recess of frame 12-2 allowing connection of long cable plug 58-1 to the plug 58-2 at the end of short cable 54-2 extending from PV component 14-2. In this manner, first PV component 14-1 is connected in electrical series to the adjacent second PV component 14-2. As shown in Figure 12, cable conduit 74-1 advantageously provides additional electrical insulation and mechanical protection for the portion of long cable 56-1 which extends outside of the mechanical protection afforded by the cable recesses of frames 12-1 and 12-2. As previously discussed, cable conduits 74 include circumferential corrugations (not shown) to improve flexibility, allowing for convenient manipulation of long cable 56 when fed between the cable recess of a first frame to the cable recess of the adjacent frame.

[0063] The process is repeated to connect PV component 14-2 with PV component 14-3. As PV components 14-2 and 14-3 are located at the end of their respective rows, long cable 56-2 is fed from frame 12-2 up the roof to the first frame 12-3 of the next (higher) row of frames 12. As shown in Figure 12, long cable 56-2 is fed into the right-hand side cable opening 46-3 of frame 12-3. Long cable 56-2 is provided with cable conduit 74-2 which insulates long cable 56-2 for at the portion of cable 56-2 that extends beneath frames 12-2 and 12-3. The end of long cable 56-2 is thereby fed into the cable recess of frame 12-3 and is electrically connected to the short cable of PV component 12-3 (not shown) extending from junction box 60-3. The long cable (not shown) extending from junction box 60-3 is then fed through the left hand cable opening of frame 12-3 and into the cable recess of the frame located to the left of frame 12-3 where it is connected to the short cable (not shown) extending from junction box 60-4, and so on. It will therefore be appreciated that the long cables 56 of the lower tile row in Figure 12 will be fed through the right hand cable openings of their respective frames 12 whereas the long cables 56 of the higher row in Figure 12 (i.e. the long cables extending from junction boxes 60-3 and 60-4) will be fed through the left hand cable openings of their respective frames 12. The long and short cables extending from junction boxes 60-3 and 60-4 will therefore cross one another within the cable recess. Advantageously, the cable recesses of frames 12 are sufficiently large to enable the short and long cables to be conveniently crossed over within the cable recess by the electrician, if and when necessary to do so according to the particular installation.

[0064] In particular installations, an extension or linking cable may also be used to connect the long cable 56 of one PV component to the short cable 54 of another PV component. In these instances, a corresponding flexible conduit could also be used to insulate any extension cable extending outside of the mechanical protection provided by the cable recesses in frames 12.

[0065] Turning now to Figure 13, after each of the side-by-side PV components 14 in a row of side-by-side solar roof tiles have been connected in electrical series and appropriate electrical testing has been conducted, each of the PV components 14 are adhered to the mounting face of the respective frame 12. In this procedure, a bead of silicone adhesive 76 is laid along the adhesive rebate on the perimeter of the mounting face using a silicone gun 78. A bead of adhesive 76 is also inserted along the inside of channel 39 (best illustrated in Figure 3). The upper edge 72 of PV component 14 is subsequently inserted into channel 39 and PV component is tilted downward until contact is made with the mounting face and the bead of adhesive 76. In this manner, and as illustrated in Figure 14, PV component 14 is mounted to the mounting face of frame 12 and outer surface 80 of the PV component 14 is recessed slightly below the frame upper surface 36, advantageously providing improved mechanical protection and facilitating drainage of rainfall along the pitch of the rooftop.

[0066] Installation of solar roof tiles 10 may be separated into two procedures performed by separate tradespeople. For example, a tradesperson skilled in roof tiling may first install each of the frames 12. As noted above, the batten lugs 53 of each frame 12 will rest behind a roof batten 64 to retain the frame 12 in place. Frames 12, other than those on the lowermost row or at the edge of a row, are also secured to an underlying batten 64 with a clip. Depending on the type of installation, the roof tiler may opt to also nail each tile (using openings 52) to a batten 64 or, alternatively, to nail only every second or third row of frames 12. Once the desired number of frames 12 has been installed, a second tradesperson (an electrician) will proceed with installation of the PV components 14. As discussed above, this procedure involves positioning the cables of a first solar roof tile 10 within the cable recess 40 of the frame 12 and then feeding the long cable 56 through the cable opening 46 to the underside of the frame 12 and then through the cable opening in the cable recess of an adjacent frame in order to connect to a short cable 54 of the adjacent PV components in electrical series. The process is then repeated on an adjacent, second solar roof tile 10 and the long cable 56 of a second tile 10 may be connected to the short cable 54 of a third tile 10 and so on such that the PV components are connected in electrical series in a snaking pattern from the lowest to the highest row of solar tiles 10. Once the electrical connections have been completed and tested, the PV components 14 are adhered to the frames 12 in the manner discussed above.

[0067] Advantageously, electric current begins to generate only after the PV components 14 are installed by a qualified electrician. This represents a significant safety advantage over a number of existing systems in which the frame and PV components are integral and therefore, during installation of the tile by a roof tiler (and prior to the arrival of an electrician) electricity may begin to be generated by the solar tiles potentially providing an electrocution and/or fire hazard.

[0068] In an alternative to the installation procedure illustrated in Figures 11-14, and as discussed in the foregoing, the solar roof tile of the present invention may be supplied for use in a pre-assembled condition with PV component 14 pre-mounted to frame 12. In this regard, Figure 15 illustrates a pre-assembled solar roof tile 110 including a short cable 154 and a long cable 156 extending from an underside of the tile 110. It will be appreciated that short cable 154 is longer than short cable 54 illustrated in Figures 7 and 8 to enable short cable 154 to extend outside of the cable recess of tile 110.

[0069] An example installation procedure for pre-assembled solar roof tiles 110 involves a roof tiler installing a pair of first and second adjacent pre-assembled tiles 110 on a rooftop with short and long cables 154, 156 left extending from the underside of each tile 110. A solar installer then, from the inside of the roof, connects short cable 154 of the first tile 110 to the long cable 156 of the adjacent second tile 110. The connection is made outside of the cable recess and, subsequently, the installer pushes the short cable and the cable connection point back into the cable recess of the first tile 110 from which the short cable 154 was previously extending. In this manner, the solar installer is not required to access the top of the rooftop providing a desirable improvement in safety. Furthermore, the installation of pre assembled tiles 110 does not require an installer to mount the PV components to the tile frames thereby streamlining the installation procedure.

[0070] The invention described herein is susceptible to variations, modifications and/or additions other than those specifically described and it is to be understood that the invention includes all such variations, modifications and/or additions which fall within the spirit and scope of the above description.

[0071] Throughout the description and claims of this specification the word "comprise" and variations of that word, such as "comprises" and "comprising", are not intended to exclude other additives, components, integers or steps.

Claims

The claims defining the invention are as follows

1. A solar roof tile including: a generally square or rectangular frame having a pair of parallel side edges configured for overlapping or underlapping with edges of an adjacent roof tile during side-by-side installation on a rooftop; a generally planar PV component mounted to a mounting face of the frame for generating electric current in an electrical cable connected to the PV component; and a cable recess in the mounting face for receiving and mechanically protecting the electrical cable and for receiving and protecting a junction box connected to an underside of the PV component containing electrical componentry, the frame including at least one access opening facilitating digital access to an underside of the PV component from an underside of the frame.

2. A solar roof tile according to claim 1, the cable recess including a base spaced from the mounting face and a cable recess sidewall extending between the mounting face and the base.

3. A solar roof tile according to claim 2 the cable recess including at least one cable opening, the cable recess and cable opening cooperatively providing a cable passageway between an underside of the PV component and an underside of the frame.

4. A solar roof tile according to claim 3, the cable opening being located in the base.

5. A solar roof tile according to claim 3, the cable opening being located in the sidewall.

6. A solar roof tile according to any one of claims 2 to 5, the cable recess including a plurality of ventilation openings.

7. A solar roof tile according to claim 6, the ventilation openings being located in the base and/or in the sidewall.

8. A solar roof tile according to claim 6 or 7, at least some of the ventilation openings being located beneath the junction box connected to the underside of the PV component.

9. A solar roof tile according to any one of the preceding claims, including a pair of electrical cables connected to the PV component, the pair of electrical cables including a first cable and a second cable which is longer than the first cable.

10. A solar roof tile according to any one of the preceding claims, the frame including a lip overhanging a portion of the mounting face and defining a channel in which an edge of the PV component is received.

11. A solar roof tile according to any one of the preceding claims, the PV component being adhesively mounted to the frame and the mounting face including an adhesive rebate for receiving the adhesive.

12. A solar roof tile according to claim 11, the adhesive rebate located at a perimeter of the mounting face.

13. A solar roof tile according to claim 11 or 12, the adhesive rebate being recessed into the mounting face by approximately 2mm.

14. A solar roof tile according to any one of the preceding claims, the mounting face being recessed below an upper surface of the frame.

15. A solar roof tile according to claim 14, the mounting face being recessed below the upper surface of the frame by at least the thickness of the PV component.

16. A solar roof tile according to claim 14 or 15, the frame including wall portions surrounding the recessed mounting face and defining a border around an outer edge of the PV component.

17. A solar roof tile according to claim 16, the outer edge of the PV component being in close proximity to or in contact with the border.

18. A solar roof tile according to any one of the preceding claims, the frame including a pair of parallel upper and lower edges extending between the parallel side edges.

19. A solar roof tile according to any one of the preceding claims wherein one of the parallel side edges of the frame includes an overlap portion and the opposite side edge includes an underlap portion.

20. A solar roof tile according to any one of the preceding claims, the frame and PV component each being rectangular.

21. A solar roof tile according to any one of the preceding claims, the PV component being a PV laminate.

22. A solar roof tile according to any one of claims 1 to 5 including: a plurality of ventilation openings in a section of the frame that is positioned beneath the PV component which facilitate dissipation of thermal energy emitted from an underside of the PV component.

23. A solar roof tile according to claim 22, the ventilation openings being formed in a planar surface of the frame that is positioned beneath the PV component.

24. A solar roof tile according to claim 23, the ventilation openings having a grid, array or matrix formation.