GB2555571A

GB2555571A - Solar structural panels

Info

Publication number: GB2555571A
Application number: GB1617670.3A
Authority: GB
Inventors: Pattenden Stephen
Original assignee: Telemetry Associates Ltd
Current assignee: Telemetry Associates Ltd
Priority date: 2016-10-19
Filing date: 2016-10-19
Publication date: 2018-05-09
Also published as: GB201617670D0

Abstract

A structural panel (300, fig 3) comprising a solar thermal collection layer 505 which provides a compression layer in the panel. The solar collection layer comprises channels 430 for thermal energy fluid which collects the solar energy. The solar collection layer preferably comprises a layer of corrugated material 405 to provide the channels and bonded between two further layers 420, 425. The panel preferably also includes a layer of insulation (410, fig 4) arranged in use below the solar thermal collection layer. The panel may also include a photovoltaic layer 100.

Description

(54) Title of the Invention: Solar structural panels

Abstract Title: Structural panel having solar thermal energy collection layer (57) A structural panel (300, fig 3) comprising a solar thermal collection layer 505 which provides a compression layer in the panel. The solar collection layer comprises channels 430 for thermal energy fluid which collects the solar energy. The solar collection layer preferably comprises a layer of corrugated material 405 to provide the channels and bonded between two further layers 420, 425. The panel preferably also includes a layer of insulation (410, fig 4) arranged in use below the solar thermal collection layer. The panel may also include a photovoltaic layer 100.

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SOLAR STRUCTURAL PANELS

The present invention relates to solar structural panels and to apparatus and a method of production for solar structural panels. It finds particular application in roofing.

It is known to produce and use solar photovoltaic (PV) panels and solar thermal energy panels. Structural insulated panels (SIPs) are also known for use in construction. Typically, PV panels and solar thermal energy panels have a solar collection area up to about 2 m and SIPs have significantly larger areas, for example 10 or 20 m².

According to embodiments of the invention in a first aspect, there is provided a structural panel comprising a solar thermal energy collection layer, the solar thermal energy collection layer being configured to provide a compression layer in the structural panel. The structural panel may further have an insulation layer thus providing a SIP.

Known structural panels or SIPs supported at their ends or edges consist of a top layer in compression and a bottom layer in tension with a rigid spacing material between. Known SIPs comprise upper and lower layers with a rigid foam in between, the foam providing the equivalent of the web of an “I” beam, the upper and lower layers acting as flanges. In embodiments of the present invention, the solar thermal energy collection layer can be designed to contribute significant strength in compression, and indeed can provide all the compressive strength required of a structural panel, including those edge-supported.

The compression layer may comprise guided channels for a thermal energy fluid. In an example, the compression layer may be provided as a corrugated sheet of strong but formable material bonded to at least one further sheet. The corrugations together with the further sheet then provide the guided channels. In practice, the corrugated sheet might be bonded between two such further sheets, presenting planar surfaces above and below the corrugations. The compression layer in this form with its flat top surface and flat lower surface thereby provides channels for the flow of the thermal energy fluid of the solar thermal energy collection part of the structure. The lower bonded sheet of the compression layer can also then form an upper layer of an insulated portion of the structural panel.

The formable material might comprise a metal such as aluminium, or an alloy. These may be chosen to have strength and good resistance to corrosion or can be chosen to have a preferred set of characteristics such as plasticity or superplastic forming properties at temperatures that might be used in a forming stage. (“Superplasticity” is a state in which solid crystalline material is deformed well beyond its usual breaking point, usually over about 200% during tensile deformation. Such a state is usually achieved at high homologous temperature.)

The channels may be provided in other ways, for instance by extrusion of a material to form the compression layer in one piece.

Embodiments of the invention take advantage of the structure of the solar thermal energy collection layer, the channels, so as to deliver strength in the structural panel as well as collecting solar thermal energy and offering efficiency in a building process. The resulting structural panel thus has a design which can deliver strength across far greater areas than, for example, the 2 m of a PVT panel mentioned above or the 10 or 20 m of a SIP. For example, a structural panel according to an embodiment of the invention could have a size up to that commonly deliverable by road (approximately 4m by 12m) or beyond if a panel can be constructed on site or perhaps flown in by helicopter.

A structural panel according to an embodiment of the invention may further provide PV capability. Thus a more fully integrated energy producing structural panel may further comprise a PV layer and associated connections for generating electricity from solar radiation. This more fully integrated embodiment, a PVT panel, thus provides both thermal and electrical energy converted from solar radiation while being capable of directly forming part of a building structure such as a roof or canopy, through the strength of the compression layer in the solar thermal energy collection layer. Known PVT panels are, just as known PV and thermal solar panels, add-ons to existing roof structures. Even on flat roofs, there is then a trade-off between holding the panels to the roof by weights and gravity or impairing the integrity of the roof with fixing systems pierced through it. In embodiments of the invention however, a PVT panel can potentially provide combination of the delivery of electrical and thermal energy by solar panels and thermal collectors with the structure of a large scale insulated roofing panel. If the PV layer is constructed with thermal conductivity to the solar thermal energy collection layer, there is an additional advantage in that the collection of thermal energy can act to reduce the temperature of the PV layer which in some circumstances can improve the efficiency of the PV layer.

Where the structural panel has significant length, for example more than 3m long, it is normally necessary to limit the travel of the thermal fluid in use of the panel to no more than two passes along the panel, once in each direction. To connect at least some of the channels for directing fluid flow in use of the panel, the structural panel may further comprise one or more manifolds for delivering fluid from one channel to another. A manifold might also provide entry and exit points for the fluid to/from the panel, as well as delivery between channels, to support the flow of fluid along or across the panel in collecting thermal energy. Importantly, where the structural panel includes a PV layer, the manifold may also support trunking for one or more electrical power takeoffs for the electrical power generated from solar radiation, and for other electrical connections to the PV layer such as control paths for communication and/or optimisation of performance in use.

Alternatively or in addition, the channels might themselves comprise openings for delivering fluid from one to another. Thus a sheet of material for use in making corrugations might have openings pre-constructed in appropriate positions before being formed into corrugations.

According to embodiments of the invention in a second aspect, there is provided a method of making a structural panel, the panel comprising a solar thermal energy collection layer in combination with an insulation layer, the method comprising the steps of constructing a channelled compression layer and mounting it in relation to the insulation layer, the channels providing containment and at least one guided pathway for a thermal fluid collecting solar thermal energy in use of the solar thermal energy collection layer.

The insulation layer may provide a cavity, the method further comprising the step of delivering insulation material into the cavity.

Prior to use, the method will further comprise the step of introducing a thermal energy collecting fluid into the guided pathway(s) provided by the channels.

The method might further comprise the step of attaching one or more manifolds at one or both ends of the channels for delivery of fluid at an appropriate pressure and for delivery of heated fluid back out of the channels. This step may further comprise completing at least one guided pathway by connecting channels one to one another by use of the one or more manifolds.

Embodiments of the invention in its second aspect may be used for making a structural panel according to embodiments of the invention in its first aspect. Where the structural panel includes a PV layer and associated connections, a method of making the panel may further comprise mounting an electrical connection layer and a PV layer for support by the compression layer.

An advantage of a structural panel designed according to an embodiment of the invention is that it can optionally be constructed at the point of use, for example on a building site. An embodiment of the invention in a third aspect therefore comprises apparatus for making a laminated structural panel, the apparatus comprising:

a) insulated panel delivery conveyor;

b) sheet feed and forming rollers, the forming rollers being configured for forming corrugations in metal sheeting;

c) at least one flexible sheet delivery mechanism;

d) at least one cutting unit;

e) adhesive delivery mechanism;

f) binding rollers; and

g) a protective surface applicator.

The apparatus may further provide an insulation delivery mechanism for delivering insulation material into the structural panel. Although the insulation may be delivered as a pre-existing layer during lamination of the structural panel, it may alternatively be constructed during production of the panel, for example by foam injection onto a surface during construction. Thus the insulation delivery mechanism might comprise one or more foam injection nozzles rather than the insulated panel delivery conveyor.

Advantages that are potentially gained, singly or in combination, by using one or more embodiments of the invention include the following:

• it is possible to deliver a large scale structural insulated structural panel with greater load bearing strength than existing roof panels and thus reducing the need for intermediate support and therefore capable of being positioned quickly with little or no additional structure for quite large areas of roof making the panel suitable for medium sized warehouses, agricultural buildings and energy neutral homes • because the thermal solar composite structure can be part of a complete roof structure that can be manufactured cost competitively for the roofing market, the addition of the PV, for example mono/polycrystalline wafers or flexible “building integrated photovoltaic” (BIPV), simply becomes a small marginal cost to the whole structure and the normal mounting and fittings of regular PV array panels can be omitted • as the PV is attached and connected during the manufacturing process of the whole panel, there is no on site construction cost for the PV which further enhances the economics of the whole structure.

The engineering of the overall structure, under all envisaged spans and areas covered, should ensure that it continues as a rigid structure in the same way as if it were a conventional roof structure and therefore with the same forces, loads and stresses that may apply to conventional roof structures. Embodiments of the invention may enable a roof structure without intermediate purlins giving a clean ceiling from wall to pitch.

Embodiments of the invention can provide a level of integration that displays a considerable technological advance and significant economies of cost, simplicity of construction and solar energy generation/harvesting that has not previously been achieved.

A structural panel and method of making it, according to an embodiment of the present invention, will now be described, by way of example only, with reference to the following drawings in which:

Figures 1A and IB show a view from above and from below of a typical PV wafer; Figure 2 shows a partial plan view of a wafer layout for use in the structural panel; Figure 3 shows a perspective view of the completed structural panel;

Figure 4 shows a partial vertical cross section along line A-A shown in Figure 3, viewed in the direction indicated by the arrows;

Figure 5 shows a detail of the cross section of Figure 4 in enlarged scale;

Figure 6 shows the partial plan view of Figure 2 with a spacer layer installed on the wafer layout;

Figure 7 shows the spacer layer of Figure 6;

Figure 8 shows a schematic vertical cross section of a structural panel in the process of production, and the production apparatus;;

Figure 9 shows a perspective view of a containerised manner of production of the structural panel;

Figure 10 shows a perspective view of a building being completed by the addition of a structural panel as a roof element;

Figure 11 shows a perspective view of a compression layer of the structural panel of Figure 3, this including a manifold for delivery of fluid between channels;

Figures 12 A to D show various cross sections through the compression layer of Figure 11;

Figures 13A and B show partial vertical cross sections along the lines E-E and F-F shown in Figure 12A, viewed in the direction indicated by the arrows;

Figure 14 shows a cross section of an extruded form of the compression layer; and Figures 15 and 16 show an exploded view and a cross section of an alternative version of the PV layer shown in Figure 5, Figure 16 showing the PV layer in place on the compression layer of Figure 11.

It should be noted that the figures are schematic only and none of them is drawn to scale. Further, terms indicating orientation, such as “top” and “underside”, are for convenience of description in relation to the drawings only and do not indicate a specific orientation in use or during production unless the context indicates otherwise.

Referring to Figures 1A and IB, a cell 100 of a typical PV wafer has a 12 x 3 array of soldering points 105 on the top for positive contacts and 6x3 array of soldering points 115 on the underside for negative contacts. Referring to Figure 2, in an embodiment of the invention, these cells 100 might be assembled into an array measuring for example 11m by 25m. A structural panel 300 is shown in Figure 3, incorporating such an array.

Referring to Figures 4 to 7, the structural panel 300 has a layered design in which there is a protected PV layer 500 supported on a compression layer 505 made principally of channels for a thermal energy fluid, supported in turn on a structural insulated panel 410, 415.

The protected PV layer 500 consists of the following components (from top as shown in Figures 4 and 5):

a. a transparent weatherproof, heat resistant and tough plastic cover 435;

b. a plastic grid 530 supporting the plastic cover 435 above the PV wafers 100;

c. PV wafers 100 soldered to an underlying copper wire matrix 510 which has been pre-formed, laser cut from a sheet or laid down by a mechatronic system during production, the matrix 510 being set in a layer 515 of slightly flexible (pliable) plastic.

Wafers are typically 156mm x 156 mm and have an average thickness of 180± 30 pm / 200± 30 pm. The wafers 100 are laid out with a small space around each, for instance in the order of 5mm - 10mm, into which a semi rigid plastic grid 530 is placed to space and separate the wafers 100. The grid 530 is high enough to allow clearance between the wafers and the weather proof transparent cover 435. The grid 530 itself might be made of a material such as uPVC, a constraint being that it should cope with high temperatures, and its top and bottom sides are assembled using adhesive. The grid could be a complete structure as shown by 530 or could comprise multiple wafer sized rectangular spacers that fit together during production. The spacer will be typically 6 mm high and 5mm wide - however sections which separate specific areas of wafers 100 may be up to 10mm wide. Spacers may have their vertical sides given a mirror finish in order to increase solar efficiency.

The transparent cover 435 may be formed from ETFE and be around 2mm thick. The thickness of the circuit wiring 510 will be dependent on the area, voltages and current expected. The thickness of the electrical insulation/thermal conducting layer 515 will be in the order of 4mm although for large area panels with high currents and voltages, this could be increased for example to 6mm.

An option for the PV layer 500 is to use a product already incorporating some of the functionality described above, such as PowerFFEX™ modules available from Global Solar Energy Inc. Information is available at:

http://www. global solar.com/produets/fiexihle-modules/ powerfi ex-modules

Referring to Figures 15 and 16, a further option for the PV layer 500 uses standard solar panels which have been stripped of their fixing points and back plates. In this arrangement, glass backing 1505 on which the PV wafers 100 are attached adheres directly to the electrical insulation/thermal conducting layer 515. In this way standard but modified panels could be used.

Referring particularly to Figure 5, the protected PV layer 500 is adhered strongly onto a compression layer 505 which also provides a solar thermal energy collection layer.

This compression layer 505 consists primarily of a corrugated sheet 405 between two further flat sheets 420, 425 so as to provide channels 430 (guided pathways) to circulate a fluid capable of removing heat generated from received solar radiation, and/or from the PV layer, when provided with a circulation means.

The compression layer 505 is made up of a composite of the three sheets 405, 420, 425, these three sheets being bonded together by an epoxy resin adhesive. As mentioned above, the material of the compression layer 505 is preferably strong but formable and might comprise a metal such as aluminium, or an alloy. These have strength and good resistance to corrosion and an alloy can be chosen to have a preferred set of characteristics such as plasticity at temperatures that might be used in a forming stage. The compression layer 505 provides both structural rigidity and good load bearing properties. The characteristics of the sheeting forming the channels 430 will depend on application and panel size/area. If aluminium is used, the thickness might lie between 2mm and 3 mm for the top and bottom sheets 420, 425 and between 1.5mm and 2mm for the central corrugated layer 405. It would be necessary to carry out structural strength calculations to ensure the integrity of this layer under various loadings and especially snow loading. (Note that provided adequate heat energy is stored, the system may apply heat to the panel to melt or cause snow to clear from the panel.) Depending on location, one might expect a roof to have a capability of coping with 30cm of snow or a number of people, say three adults at 12 stone, walking on it. It is certain that as area covered or span increases material thicknesses will also increase. Depending on application, span and area, the distance between the top and bottom, that is the depth of the channels 430, will be between 30mm and 50 mm, and the spacing between the repeat of a channel 430 (one up flow plus one down flow) will be in the order of 60mm and 90 mm. The width of the epoxy adhesive will be between 20mm and 40 mm. It will be spread as thinly as is possible to make a good joint.

There are options with regard to the material(s) and production of the compression layer 505. Many plastics would be unsuitable although some composites such as carbon fibre could be used at a cost, for example as developed for aviation technology. The use of cement reinforced with Cemfil™ fibres, these being alkali resistant glass fibres supplied by Owens Coming, would be possible, this being fire resistant and good at managing high temperatures. However, it takes a while to cure and gain strength so would usually be inappropriate to continuous forming. Alloys and superplastic materials are mentioned above. Superplastic alloys are discussed for example at:

http://www.tota1materia.com/page.asp'x?ID^::::Chec-kArticje&site^::::ktn&NM^:::264)

Such materials might minimise the equipment used in forming the channels 430 but it may be necessary to heat the material and then cool it quite rapidly.

The compression layer 505 is supported by an insulation layer 410 containing a rigid closed cell insulating foam, which in turn is supported on a bottom tension layer 415 made of an aluminium sheet or similar. These three layers 505, 410, 415 are bonded together by the insulating foam 410 to provide a very large scale structural insulated panel (VLSSIP) designed to cover large roof spans. The depth of the rigid foam of the insulation layer 410 is typically 300mm but variants, for instance 200mm or 400mm, can be used depending on application, roof area and span. The thickness of the bottom tension layer 415 will be in the order of 2mm to 3mm, again depending on span, area and application.

An alternative is to use a SIP of known type for the insulation layer 410. In this case, the compression layer 505 might be fixed with adhesive to the top surface of the SIP, whether wood or otherwise.

Again, cement reinforced with Cemfil fibres is an optional material for the bottom tension layer 415 of the insulation layer 410 and also for the bottom layer 425 of the compression layer 505.

The PV wafers 100 and wire matrix 510 must be insulated from the aluminium of the top surface of the compression layer 505. Therefore a sheet 515 of an electrically insulating material is placed between the wire matrix 510 and the compression layer 505. The sheet 515 also has the property of being highly heat conductive, highly heat tolerant and pliable so that it will hold the wafers in place and allow for disparities in thermal expansion between the wafers 100 and the aluminium sheet 420. A plastic material may be used for the sheet 515 with appropriate fillers and plasticisers.

After installation, a fluid will be circulated through the channels 430 in known manner, for the collection of thermal energy. Depending on panel size and other design factors, one channel 430 might provide an “up” channel and its neighbour a “down” channel. In general, it is likely that the fluid needs to stay liquid across a temperature range of about -20 °C to over 100°C, for instance around 130 °C, the first so it doesn't freeze and the second so it will be possible to extract useful work from the low grade heat. There are various thermodynamic cycles such as Organic Rankine Cycle and Trilateral Flash Cycle. Another alternative is to use the heat as the input to an absorption refrigeration cycle for cooling. Fluids known for use in solar thermal energy collectors are water, air and various organic fluids used either on their own or as additives for example to water. Many oil based fluids would have the properties required but it is preferable if the fluid is water with additives such as antifreeze (ethylene glycol) and perhaps a soluble substance to raise the boiling point of the water. It is not necessary to deal with temperatures higher than 80 -90° C but the higher the temperature, the more can be done with the heat energy.

Referring to Figures 11 to 13, in order for thermal fluid to flow through the channels 430, it needs to be delivered and removed and to access adjacent up/down pairs of channels. At one end of the channels 430, it is a relatively simple matter to shape the corrugated sheet 405 of the compression layer 505 so that adjacent pairs of channels 430 have a shortened wall 1205 between them compared with the other walls 1200, thus creating a fluid pathway 1210. At the other end of the channels 430, a manifold 1100 is provided to deliver cool fluid to alternate channels 430 and to receive heated fluid from the other channels 430.

Figure 12A shows a horizontal cross section along the line A-A in Figure 11, viewed from above. Figure 12B shows a vertical cross section along the line B-B in Figure 11, viewed towards a longer wall 1200 of the channels 430. Figure 12C shows a vertical cross section along the line C-C in Figure 11, viewed towards a shorter wall 1205 of the channels 430. Figure 12 D shows a vertical cross section along the line D-D in Figure 11, through two of the channels 430 and viewed towards the manifold

1100. Cross hatched areas shown in Figures 12C and 12D are used to indicate apertures for fluid flow in use of the manifold 1100.

Referring particularly to Figures 11 and 12A, thermal fluid is delivered through a lower duct 1110 in the manifold 1100, flows the length of one of the channels 430 being heated by solar energy, follows a path 1210 round the end of the shortened wall 1205 and returns along a neighbouring channel 430 to the manifold 1100 where it exits into an upper duct 1105. Figures 12B and 12C show the lower and upper ducts 1110, 1105 and the aperture 1215 created by the shortened wall 1205. Figure 12D shows the apertures 1225, 1230 in the lower and upper ducts 1110, 1100 determining the fluid flow path. These apertures 1225, 1230 are spaced along each duct of the manifold 1100, at the position of offset, alternate channels 430. Alternate channels 430 are therefore connected to the upper duct 1105 and different alternate channels 430 are connected to the lower duct 1110. This allows cool thermal fluid to be delivered along the lower duct 1110 of the manifold 1100 to every alternate channel 430, to flow along the relevant channels to their far end, around the shortened walls 1205, back along the adjacent channels and into the upper duct 1105 of the manifold 1100. The upper duct 1105 takes the now heated fluid to a delivery point to leave the structural panel 300 and provide thermal energy as required.

Referring to Figures 13A and B, the manifold 1100 is mounted along an edge of the structural panel 300. Its lower and upper ducts 1110, 1105 for carrying the thermal fluid are in communication with the compression layer 505. An additional channel 1305 carries electrical trunking 1300 connected to the circuit wiring 510. The requirements for electrical trunking 1300 will depend on those of the PV layer 500 but will generally support delivery of electrical power generated by the PV layer 500, and diagnostic and management communications with the PV layer 500.

In production, the manifold 1100 can be made as a casting or be 3D printed. 3D printing has the advantage that the angle of the manifold can vary, for instance to suit specific roofs, and that the size of the ducts can be varied in order to balance the flows equally along the panel. A standard straight manifold could be made by casting but using 3D printing allows for example a curved manifold 1100. The manifold 1100 might be mounted on the roof panel 300 by any appropriate means such as adhesive or mechanical fixings with seals as required. For example, a manifold 1100 might be used that fitted closely to the ducts (channels) 430 of the thermal layer 505, up against the spacers 530 of the PV layer 500 and around the base 415 of the insulation layer 410. Ideally, it should be a snug fit and a two part epoxy adhesive might be used for attachment.

Referring to Figure 8, a method of making the structural panel 300 provides a continuous manufacturing process which starts with the creation of the structural insulated panel 410, 425, 415. This will have as its top and bottom layers 425, 415 a sheet of corrosion resistant material such as aluminium, another metal or alloy, fed from two rolls 855 (one top - one bottom) in between which insulation foam 410 will be blown from injector nozzles 860. The top and bottom layers 425, 415 between them delineate a cavity 885 into which the foam 410 is blown. The foam is of known type, such as isocyanate or polyurethane, and is injected as a mix which foams, expands and solidifies in the cavity 885, adhering to the sheets of metal 425, 415. The sheets 425, 415 are restrained by plates 870 to ensure the correct and uniform thickness of rigid foam 410, and optionally a guide to keep the sheets 425, 415 in the correct lateral position at start up and during production. This process creates a rigid insulation material that is well bonded in position, not flexible or compressible. It may be that the composition of the foam may be graduated to be more dense at the top and bottom and less dense in the middle in order to provide the optimum insulation and strength per amount of material used.

In a possible modification to the above, the foam 410 can be injected to provide a denser and stronger consistency near the edges of the rigid foam 410 and a less dense internal foam because the dense foam 410 close to the containing sheets 425, 415 spreads point load.

On top of the upper sheet 425, another layer of aluminium, alloy or other suitable material is fed from a third roll 880 and formed between corrugation rollers 850 into the channels 430, the channels having flat top and bottom surfaces which are each coated by use of adhesive applicators 845, such as rollers applying fast curing epoxy. A fourth sheet of aluminium, alloy or other suitable material is taken off another roll 875 and this sheet 420, the corrugated sheet 405 and the layer 425 above the foam 410, are pressed together by a binding roller 835 as the adhesive cures. Heat may be applied at this stage. The fourth sheet 420 now offers a flat surface for supporting the PV layer 500.

Referring to Figure 14, an alternative method of production would be to use extruded forms for the compression layer 505 which would generate all three layers in a single operation and one piece. Suitable material for such an extrusion might comprise for example a superplastic alloy.

The wafers 100 of the PV layer 500, including their isolation diodes, need to be connected electrically and set into place. Next the thermally conductive, electrically insulating sheet 515 is applied to the top sheet of the compression layer 505 using a binding roller 835, followed by electrical circuitry 510 laid out either as a pre-cut circuit or as runs of insulated copper wire from a coil 825. The circuitry 510 might be soldered using a laser to the underside of the PV wafers 100, using a wafer handler, and the wafers 100 are then pressed down onto the pliable insulation material 515 leaving wires protruding between the wafers 100 which can be laser soldered to the tops of the wafers 100. All the circuit layout, laser soldering and wafer handling can be done robotically using advanced mechatronics.

This largely completes the electrical connection of a panel of any size and the circuit design must be adaptable for different areas and lengths of panel to ensure current and voltage levels stay within limits. Each row of wafers can be tested for electrical continuity at this stage.

To space the wafers 100 from the weatherproof cover 435 to follow, individual spacer elements are fed from stacks 815, top and bottom being coated with adhesive. The weather proof cover 435 is then fed from a roll 820 and pressed into place under a further binding roller 835.

Once the panel under construction has reached the required length, the whole structure is laser cut, the manifold 1100 attached, the electrical trunking 1300 connected to the circuitry 510 and the structural panel 300 tested. It can be either stored or deployed immediately onto a building.

Referring to Figures 9 and 10, it is possible to produce the panels 300 as described above either on site or elsewhere. Factory manufactured panels could be made to the limit of road transport (approximately 4 metres by 12 metres). Manufacturing on site offers the capability to produce the entire structure in sizes that are too large to transport by road or rail, for example 1 lm by 25m, or in territories where there is little or no local industrialisation. For example, the production process could be housed in multiple containers 900. Containers may be parked in a row sideways and be interconnected - the maximum width of a containerised production system is dictated by the maximum length of a standard container making some allowance to work around the panel production equipment. A 40 foot container limits overall width to around 11 metres. A containerised system could be self-sufficient with its own generator and power sources. Referring to Figure 10, the panel 300 may require additional strength at each comer so it can be slung from a crane for placing onto a building 1000.

Embodiments of the invention can reduce the need for supporting beams and roof members in construction. Onsite installation and fixing of PV or thermal solar is not required since the whole panel is integrated - the cost of the PV is thus marginal and potentially half that of traditional PV panel arrays. Because the thermal layer 505 is a necessary part of the integrated structure, it also only adds the marginal cost of its components and replaces the normal top layer of a traditional roofing SIP. It therefore also has a minimal additional cost for the heat it provides. The integration of the three elements, PV, thermal and SIP, delivers such structural strength that very large spans and areas of roof can be covered by single panels or multiples of single spans where the length of the roof exceeds practical on-site manufacturing widths. Because the entire roof panel is made in one piece (or one span) any weaknesses due to joints are minimised. Because of the structural integrity of the panel, for many building applications the panel will only require support at the external wall of the building.

Both the electrical and fluid connections for a single panel 300 can be routed to a single take off point - further reducing installation time and complexity.

It might be noted that there are many ways to arrive at a suitable thermal channel 5 structure for the compression layer 505. What is important is the principle of delivering a channelled composite structure that is strong in compression.

Importantly, embodiments of the invention can provide edge supported roof structures where the top compression layer is replaced with a thermal solar matrix which also acts as a compressive member.

Claims

1. A structural panel comprising a solar thermal energy collection layer, the solar thermal energy collection layer being configured to provide a compression layer in the structural panel.

2. A structural panel according to claim 1, wherein the compression layer comprises channels for a thermal energy fluid collecting solar thermal energy in use of the panel.

3. A structural panel according to either preceding claim, wherein the channels are provided by corrugations in a layer of material in combination with at least one further layer of material.

4. A structural panel according to any preceding claim, wherein the compression layer comprises a corrugated sheet of material bonded between two further sheets of material, presenting planar outermost surfaces either side of the corrugated sheet.

5. A structural panel according to any preceding claim, further comprising an insulated portion, wherein the compression layer is supported above the insulated portion in use.

6. A structural panel according to claim 5, wherein the insulated portion comprises insulation material between further layers, one of the further layers providing at least part of the compression layer.

7. A structural panel according to any preceding claim, wherein the compression layer comprises a metal or metal alloy material.

8. A structural panel according to any preceding claim, wherein the compression layer comprises an alloy having superplastic forming properties.

9. A structural panel according to claim 6, wherein said one of the further layers comprises a metal, metal alloy or superplastic alloy material.

5

10. A structural panel according to any preceding claim, wherein the compression layer comprises an extrusion, the extrusion providing the channels.

11. A structural panel according to any preceding claim, wherein the panel has an area of at least 15 m2.

12. A structural panel according to any preceding claim, further comprising a PV layer for generating electricity from solar radiation.

13. A structural panel according to any preceding claim, further comprising a 15 manifold for delivering thermal fluid to and from channels of the compression layer.

14. A structural panel according to claims 12 and 13, wherein the manifold comprises:

a first channel having openings for delivering thermal fluid to selected channels of the 20 compression layer;

a second channel having openings for receiving heated thermal fluid from selected channels of the compression layer; and a third channel for receiving and supporting electrical trunking connected to the PV layer.

15. A structural panel according to any preceding claim, supported at its edges, in use.

16. A roof panel for roofing a building construction by mounting onto supporting structures thereof, the roof panel comprising a structural panel according to any preceding claim.

17. A method of making a structural panel, the panel comprising a solar thermal energy collection layer in combination with an insulation layer, the method comprising the steps of constructing a channelled compression layer and mounting it in relation to the insulation layer, the channels providing containment and at least one guided pathway for a thermal fluid collecting solar thermal energy in use of the solar thermal energy collection layer.

18. A method according to claim 17, further comprising the step of delivering insulation material into a cavity to provide the insulation layer.

19. A method according to either of claims 17 or 18, further comprising the step of attaching one or more manifolds at one or both ends of the channels for delivery of fluid at an appropriate pressure and for delivery of heated fluid back out of the channels.

20. A method according to claim 19 wherein the attaching step further comprises completing at least one guided pathway by connecting channels one to another by use of the one or more manifolds.

21. A method according to any one of claims 17 to 20, further comprising the steps of mounting an electrical connection layer and a PV layer for support by the compression layer.

22. Apparatus for making a laminated structural panel, the apparatus comprising:

i) at least one insulation layer delivery mechanism;

ii) channelled layer production equipment for delivering a channelled layer supported by the insulation layer of the structural panel, for use in containing and guiding solar thermal energy fluid for collecting solar thermal energy in use of the panel;

iii) at least one cutting unit;

iv) an adhesive delivery mechanism; and 5 v) binding rollers.

23. Apparatus according to claim 22, wherein the channelled layer production equipment comprises forming rollers and a sheet feed delivery mechanism for delivering formable sheet material to the forming rollers.

24. Apparatus according to claim 22 wherein the channelled layer production equipment comprises extrusion equipment.

Intellectual

Property

Office

Application No: GB1617670.3 Examiner: Mr Colin Walker