GB2531722A

GB2531722A - Solar tile system

Info

Publication number: GB2531722A
Application number: GB1419065.6A
Authority: GB
Inventors: Blackwood Benjamin
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-10-27
Filing date: 2014-10-27
Publication date: 2016-05-04
Also published as: GB201419065D0

Abstract

A solar tile system comprising at least one tile module 2 adhesively fixed to underlying roofing tiles 1 or cladding sheets of an external surface, wherein a photovoltaic (PV) material 2.2 is fixed to the upper side. The adhesive 3 is on the under surface of the module base 2.1 and may be polyurethane. The module may cover a plurality of underlying tiles, e.g. single or multiple rows, and the base may be correspondingly stepped on the upper and lower surface to accommodate the multiple rows. The module may also be shaped to match the underlying surface e.g. corrugated (figure 6) or planar. The tiles may be retrofitted to an existing roof, and may be attached without penetrating the roof. There may be multiple rows of PV cells on each module. The base may be plastic or lightweight sheet metal such as aluminum or thin gauge steel, and may range in thickness between 4mm and 24mm.

Description

SOLAR TILE SYSTEM

Field of the Invention

The present invention concerns improvements in and relating to solar tile systems for mounting to roofs or similar external covering surfaces of buildings or other structures.

Background to the Invention

Solar panels for domestic or grid connected applications are a popular and readily available way of harnessing the energy of the sun to generate renewable electricity but the uptake of solar panels is limited by various factors. Recently, the reduction in financial incentives to install solar panels, has reduced the market considerably. As a result it is necessary to develop more efficient designs to reduce the costs of the installation accordingly. Additionally, in some cases the obtrusive appearance of solar panels atop a dwelling or other building can result in their rejection due to local planning policy or individual dislike. A significant factor in their obtrusiveness is the conspicuous protruding nature of the panels, which can additionally create a hazard in areas susceptible to high winds.

Latterly solar tiles have been brought to market that seek to address the above aesthetic and wind loading concerns. These solar tiles are substantially conventional roofing tiles but which incorporate photovoltaic cells within the tiles and they are designed to replace an area of conventional roof tiles of a roof. Such tiles are primarily limited to use in new-build applications, a small fraction of the overall housing market in the UK, and the installation in new builds can also bring unwanted risks. For the existing roofed buildings the increased cost of installation, due to the invasive nature of their installation via removal of a large number of existing roof tiles to replace the existing roof tiles with the solar tiles has greatly limited their uptake.

It is a general object of the present invention to address these problems of the current solar tile systems to provide a solar tile system that is much more widely suitable for use than the current solar tile systems.

Statement of Invention

According to a first aspect of the present invention, there is provided a solar tile system installed to a roof or other external surface of a structure for harvesting solar energy, the system comprising a plurality of tile modules that cover tiles or other cladding sheet of the roof or other external surface wherein each tile module comprises a tile nodule base with a photovoltaic material fixed to its upper, in use, surface and which tile module base has at its under surface an adhesive fixing it directly onto the top of the roof tiles or other cladding sheet of the roof or other external surface.

According to a second aspect of the present invention, there is provided a method of fitting a solar tile system to a roof or other extemal surface of a structure, the method comprising providing a solar tile system comprising a plurality of tile modules that are configured to cover tiles or other cladding sheet of a roof or other external surface wherein each tile module comprises a tile module base with a photovoltaic material fixed to its upper, in use, surface and which tile module base has an under surface to receive an adhesive for fixing it directly onto the top of the roof tiles or other cladding sheet of the roof or other external surface; applying adhesive to the tile module base under surface; and placing the tile module onto a tile or other cladding sheet of a roof or other external surface that is already in place in the roof, whereby the tile module underside adheres to the tile or other cladding sheet and is thereby fixed in place.

Particularly preferably the extemal surface is a tiled roof and each tile module base is of a surface area covering a plurality of the tiles. Preferably the tile module base is stepped to seat over two or more rows of lapped tiles or other cladding sheets. The expanse of the tile module base enables it to be installed very rapidly and being stepped reduces its profile above the roof and increases its security rendering it relatively invulnerable to dislodgement by high winds. In furtherance of this the adhesive applied preferably is applied to the step wall of the stepped module base to adhere to the tile end, yet further improving security of fixing.

The system is particularly advantageously configured to avoid use of any mechanical means that would require removal of the existing roof tiles/cladding sheet and it is quick and comparatively very cost-effective to install to existing roofed buildings.

The module's base may be formed of a plastics material or light-weight metal with the photovoltaic material on its top surface. The module base for roofs of flat/ planar tiles or other flat/ planar cladding sheets is preferably substantially planar, but for roofs of non-planar tiles or other non-planar cladding is of corresponding/ substantially matching non-planar form.

The tiles/ cladding sheets are suitably supplied in convenient lengths for ease of installation and with profiles to match the profiles of the typical roof tiles. The module is configured to accept adhesive (with a seal around its perimeter if required) to be applied to its bottom surface for bonding onto the top of the existing roof tiles.

The photovoltaic material affixed to the module may suitably be of any proprietary/ commercially available type, and may comprise one or more photovoltaic cells, suitably encapsulated within protective foils. In the installation, a further protective film or sheet may also be applied over the top of the photovoltaic cells as part of the module assembly for further protection from the weather and from impacts during installation.

Preferably the system comprises a set of ten or more modules arranged substantially contiguously in order to achieve the required area of photovoltaic material coverage.

The system yields a number of benefits. Inter alia these include that when used in "retro-fit" situations to an existing roof of a building it: avoids disturbance of the weather-proof layer of the roof; increases speed of installation thus reducing the cost of the installation; increases simplicity of the installation, potentially allowing installation to be achieved via a boom lifting system ("cherry picker") instead of using scaffolding, allowing a significant improvement to safety and reducing costs and disruption still further. Further advantages include that the above cost savings can enable the solar tile system to be used where cost had previously been a prohibiting factor.

When used in a new-build situation the system allows the roofing contractor to maintain responsibility for the waterproofing of the roof and can allow for simplified installation reducing disruption to the progress of the build.

The tile modules are suitably supplied in a range of forms and sizes to suit the diversity of existing roof tiles and cladding sheets. Preferably the tile modules are supplied in a range of thicknesses to suit the thickness of the roofing tiles to which they are mounted. The thickness may be selected as appropriate from a range in 2mm increments between 4mm and 26mm, with some specific variants being favored according to the prevalence of the roof-tile types being used.

In order to increase the speed of installation on repetitive installations with the same roof-tile specification, (such as new build developments) an extra-large module may be provided that incorporates multiple rows of photovoltaic cells.

As noted above, the base of the tile module can be made from a plastic material or a lightweight metal such as Aluminium or narrow gauge steel. Where metal is used as the base of the tile module, this can be used as the ground for the electrical connections of the photovoltaic cells.

The base may incorporate a pattern along its length such as to mirror the pattern used on various types of roofing material, such as that sometimes seen with concrete roof tiles, or metal profiled sheets such as that used on industrial or agricultural buildings. In order for the module to fit certain roof tile designs, the base may in one embodiment be a planar plate accommodating a single row of photovoltaic cells.

Brief Description of the Drawings

Preferred embodiments of the present invention will be now be more particularly described by way of example only, with reference to the following drawings, wherein: Figure 1 is a perspective general overview of a first preferred embodiment of the solar tile system installed to a pitched tiled roof here showing one large double row tile module; Figure 2 is a side elevation view of the tile module prior to adhering to the roof tiles; Figure 3 is a top plan view of the tile module, showing the photovoltaic cells. Figure 4 is a side elevation view of the tile module as fixed to the roof tiles; Figure 5 is a perspective general overview of a larger, five row, embodiment of tile module; Figure 6 is a perspective general overview of a single row embodiment of tile module fixed to a corrugated roofing sheet wherein the module has a corrugated profile that matches the underlying corrugated roofing sheet; and Figure 7 is a perspective general overview of a single row embodiment of tile module that is planar and fixed to planar roofing tiles.

Description of the Preferred Embodiment

Referring to Figures 1 to 4, these show the solar tiling system installed to a roof 1 of a building covering the pre-installed flat roofing tiles of the roof 1. The tiling system shown comprises a tile module 2 having a base 2.1 of plastic or light metal sheet that is rectangular in plan and substantially planar but which has a down-step to enable it to snugly overlie upper and lower adjacent rows of overlapping roof tiles. The illustrated module spans over fourteen underlying roofing tiles including the upper and lower adjacent rows each of seven roofing tiles.

The tile module base 2.1 is bonded directly to the fourteen roofing tiles by a polyurethane (PU) adhesive 3 (may be a foaming PU adhesive for good area coverage) on the flat underside surface of the base 2.1. The end profile of the tile module base 2.1 matches the end profile of the underlying two rows of roofing tiles so that the module 2 not only sits snugly with low profile bit also has a top surface that matches/ mimics the top surface of the two rows of roofing tiles, making the system both visually unobtrusive and at little risk of catching/ disrupting wind-flow over the roof The flat top surface(s) of the tile module 2 carry the one or more Photovoltaic (PV) cells 2.2 to receive the solar energy. In the Figure 1 embodiment the upper plane of the stepped top surface carries an upper row of seven PV cells 2.2 and the lower one carries a lower row of seven Photovoltaic (PV) cells 2.2. The PV cells 2.2 are each suitably a proprietary photovoltaic device incorporating photovoltaic material and are typically connected together in series via bus-bars to form a row. Typically the PV material is encapsulated between protective foils and suitably with an additional protective layer on top.

A boom lift (also known as a mobile access elevated work platform or "cherry picker") can be used for installing the solar tile system to the root Such a lift is not normally used for the installation of solar panels since roof tiling is an intensive job that requires all-round fixed access and thus necessitates use of scaffolding. The ease of installation of the solar module of the present invention allows a boom lift to be used, and as such enables a much quicker, safer and less costly installation than the prior systems that require scaffolding.

The module 2 although illustrated on its own in Figures 1 to 4 can be part of a set of several modules 2 in order to achieve the required overall light receiving surface array area of photovoltaic cells 2.2. on the roof of the building 1. For most domestic pitched roofs an array of up to ten of the fourteen PV module would be sufficient to fully cover the South facing roof aspect.

As noted above, the underside of the base 2.1 of the module 2 is directly bonded by the polyurethane adhesive 3 onto the top surface of the roof tiles. The base 2.1 is shaped to include an upper row portion which is dimensioned to suit the exposed area of an upper row of roofing tiles on the roof 1 for a chosen easily manageable length of module (nominally 900mm). The base 2.1 also comprises a lower row portion similarly dimensioned to the upper row portion to suit the adjacent lower row of tiles on the roof land the base 2.1 includes a step between the upper row and lower row portions, the step being dimensioned to correspond to the thickness of the tiles on the roof 1.

The photovoltaic cells 2.2 are suitably of commercially available type. In the first embodiment they comprise a string of individual photovoltaic cells soldered together at their bus-bars in order to create a continuous connection such that the electrical connections for the string can are made at one end of the module. The photovoltaic cell string is typically encapsulated within and upper and lower foil made from ethylene vinyl acetate or the like to form an assembly of connected photovoltaic cells 2.2. This assembly in turn is affixed during the manufacturing process of the module 2 to the base 2.1 by means of an adhesive or mechanical fastener.

The adhesive 3, is suitably applied to the underside of the base 2.1 just prior to installation by the installer on site. The adhesive 3 is typically of a polyurethane type in order to suit the substrate such as tiles on the roof 1 and accommodate the conditions which may be prevalent atop a dwelling such as moisture, irregular surface quality and impurities.

Turning to Figures 5 to 7, Figure 5 shows a larger, five row, embodiment of tile module that may be used to further speed installations. Figure 6 shows a single row embodiment of tile module fixed to a corrugated roofing sheet where the tile module has a corrugated profile that matches the underlying corrugated roofing sheet. The PV cells 2.2 are on the raised flat surfaces of the module 2 base 2.2. In a further embodiment (not shown) the underside of the module 2 base 2.2 may match the underlying corrugated roofing sheet but the top surface be different/ flatter -especially if the roof is an undulating corrugated roof lacking planar surfaces.

Figure 7 shows a single row embodiment of tile module that is planar and fixed to planar roofing tiles. Single row embodiments give added flexibility for filling in odd rows of roof or for more awkward to access locations.

Claims

CLAIMS1. A solar tile system installed to a roof or other external surface of a structure, the system comprising at least one tile module that cover roofing tiles or other cladding sheets of the roof or other extemal surface wherein the at least one tile module comprises a tile module base with a photovoltaic material fixed to its upper, in use, surface, and which tile module base has at its under surface an adhesive fixing it directly onto the top of the roofing tile or other cladding sheet of the roof or other external surface.
2. A solar tile system according to claim 1 wherein the tile module base is of a surface area covering a plurality of the tiles or other cladding sheets.
3. A solar tile system according to claim 2 wherein the tile module base underside is stepped to seat over two rows of lapped tiles or other cladding sheets.
4. A solar tile system according to claim 2 wherein the tile module base's top surface is also stepped to correspond to the stepped underside.
5. A solar tile system according to claim 1, 2, 3 or 4, wherein, as said photovoltaic material, each tile module base has at least two rows of photovoltaic cells assembled to it.
6. A solar tile system according to claim 1, 2, 3, 4 or 5, wherein the tile module is bonded on top of the roof covering without penetrating or effecting changes to the roof.
7. A solar tile system according to any preceding claim, wherein the base is formed of a plastics material.
8. A solar tile system according to any of claims 1 to 6, wherein the base is formed of a sheet of lightweight metal.
9. A solar tile system according to claim 8, wherein the base is formed of aluminium or of thin gauge steel.
10. A solar tile system according to any preceding claim, wherein the module base is supplied in a range of thicknesses, the thickness being between 4mm and 24mm, to correspond to the differing thicknesses between existing roof tiles.
11. A solar tile system according to any preceding claim, wherein the adhesive is of a polyurethane type.
12. A solar tile system according to any preceding claim wherein the base of the tile module is fitted to a tile or cladding sheet that has a non-planar profile and has a correspondingly non-planar profile to follow the profile of the underlying tile or cladding sheet.
13. A solar tile system according to claim 12 wherein the base of the tile module is fitted to a corrugated tile or corrugated cladding sheet and has a correspondingly corrugated form.
14. A solar tile system according to claim 1 wherein the at least one tile module has a repeat profile shape that is repeated up a number of lapped roofing tiles to accommodate multiple rows of photovoltaic cells.
15. A solar tile system according to claim 1 wherein the at least one tile module incorporates solely a single row of photovoltaic cells.
16. A method of fitting a solar tile system to a roof or other extemal surface of a structure, the method comprising providing a solar tile system comprising at least one tile module that is configured to cover tiles or other cladding sheet of a roof or other external surface wherein each tile module comprises a tile module base with a photovoltaic material fixed to its upper, in use, surface and which tile module base has an under surface to receive an adhesive for fixing it directly onto the top of the roof tiles or other cladding sheet of the roof or other external surface; applying adhesive to the tile module base under surface; and placing the tile module onto a tile or other cladding sheet of a roof or other external surface that is already in place in the roof, whereby the tile module underside adheres to the tile or other cladding sheet and is thereby fixed in place.