WO2009040430A2

WO2009040430A2 - Solar panel

Info

Publication number: WO2009040430A2
Application number: PCT/EP2008/062972
Authority: WO
Inventors: Sean Hoolan
Original assignee: Erin Energy Ltd.
Priority date: 2007-09-26
Filing date: 2008-09-26
Publication date: 2009-04-02
Also published as: IE20070691A1; WO2009040430A3

Abstract

A solar panel (100) comprising a plurality of tubes (102), and a reflector component (104) in thermal communication with the tubes (102), which comprises a substantially thermally insulating base layer (110) and a reflective layer (112) connected to a surface ofthe base layer (110).

Description

SOLAR PANEL

This invention relates to a solar panel.

Currently, solar panels comprising tubes are the most efficient technology available for domestic installation. However, such solar panels are installed externally of the building for which they are used. This reduces their appeal in the domestic market as home buyers often find such solar panels reduce the aesthetic appeal of the building. Additionally, the tubes of current solar panels are usually exposed to the elements.

Existing solar panels usually comprise tubes. The tubes are usually made of glass and are therefore brittle. The current method of construction of a solar panel consisting of a number of tubes is to locate each individual tube in an individual cir-clip or tube tie. This is time consuming and labour intensive, for example, a solar panel comprising fifteen tubes may take upwards of forty five minutes to construct.

In addition to the labour intensive nature of the manufacture of the solar panel, the use of cir-clips can lead to a high rate of breakage of the tubes. This is due to the requirement for a large degree of manual handling of the tubes and also the possible over-tightening of the cir-clips. In an attempt to overcome this problem rubber "socks" have been used to protect the ends of the tubes. However, their installation increases the amount of handling of the tubes that is required, thereby increasing the opportunity for breakage of the tube, and also increases the number of steps in production of the solar panel.

Current tube-based solar panels usually comprise a reflector which is usually made from highly polished metal or coated glass. Such reflectors cause further difficulty as due the nature of the materials of the reflector component, there is an increased risk of fracturing the tubes if they are secured directly to reflectors. To reduce the risk of fracture of the tube the tubes are usually secured at a position above the reflectors so that they do not directly contact the reflectors. The spacing of a tube from a reflector reduces the efficiency of the solar panel, as the intensity of the radiation reflected from the reflectors and therefore absorbed by the tubes decreases with distance according to an inverse square law. A further problem with existing reflectors is that they absorb thermal energy, thereby reducing the amount of thermal energy absorbed into the tubes.

According to a first aspect of the present invention there is provided a solar panel comprising, a plurality of tubes, and a reflector component in thermal communication with the tubes, which comprises a substantially thermally insulating base layer and a reflective layer connected to a surface of the base layer.

A reflector component with a substantially thermally insulating base layer provides a solar panel in which the thermal energy absorbed by the reflector component is minimised. As the thermal energy absorbed by the reflector component is minimised, more thermal energy is available to be absorbed into the tubes, thereby providing a more efficient solar panel.

The plurality of tubes may be a plurality of evacuated tubes.

The base layer of the reflector component may comprise a low density polymer material, for example expanded polystyrene. Alternatively, or additionally, the base layer of the reflector component may comprise a fibrous material, for example woven glass fibres. The use of low density materials in the fabrication of the reflector component allows the fabrication of lightweight solar panels. Furthermore, the use of polymeric or fibrous materials for the reflector component increases the thermal insulation properties of the solar panel when used as part of a roofing construction.

The reflective layer may comprise a reflective film. By reducing the thickness of the reflective layer to a film, the thermal energy absorbed by the reflector component is further reduced. The reflective film may comprise a polymer film coated with a metal. The metal may be, for example, aluminium.

The tubes may be positioned on the reflector component such that the tubes directly contact the reflector component. The tubes may be positioned on the reflective layer of the reflector component such that the tubes directly contact the reflective layer of the reflector component.

The reflector component may comprise a cushioning material. This may provide a cushioning effect for the tubes when placed thereon. The term "cushioning" as used herein, refers to any reflector component material that undergoes elastic deformation when subject to a load.

As the reflector component can provide cushioning for the tubes, these may be seated directly on the reflector component without unduly increasing the risk of fracturing of the tubes as they are so positioned.

This also obviates the necessity for use of rubber "socks" or cir-clips with the tubes, leading to a simpler construction of the solar panel. The use of a cushioning reflector component also improves the efficiency of the solar panel. Using a cushioning reflector component allows the tubes to be placed in direct thermal contact with the reflector component, and radiation reflected from the reflector component will therefore be more readily absorbed by the tubes in comparison to previous solar panel where the tubes are spaced from the reflector. A further advantage of using a cushioning reflector component is that the tubes may be supported along their length by the reflector component, which adds to their stability of location.

The reflector component may comprise a plurality of recessed channels. Each of the plurality of recessed channels may run parallel to one another. Each of the plurality of recessed channels may have a substantially arcuate, for example parabolic, cross-section, such that a part of a tube may be located in a recessed channel. The part of the tube may be contiguous the reflector component. The recessed channels will aid in holding the tubes in position, as they will aid in preventing the tubes from rolling freely on the reflector component.

The solar panel may further comprise at least one holding mechanism, that engages at least some of the tubes to hold them in position with respect to the reflector component. The at least one holding mechanism may comprise a cushioning material. The cushioning material may be, for example, a low density polymer material.

The at least one holding mechanism may comprise an elongate clamping member, that engages at least some of the plurality of tubes to hold them in position with respect to the reflector component. The elongate clamping member may engage each of the plurality of tubes to hold them in position with respect to the reflector component. The elongate clamping member may engage at least some or each of the tubes to hold them in position between the clamping member and the reflector component. The use of such a holding mechanism simplifies construction of the solar panel as a number or, indeed, all of tubes may be held in position by the fixing of a single clamping member, as opposed to arranging a plurality of cir-clips to secure each of the tubes individually. This reduces the solar panel manufacturing time by as much as two minutes per tube.

The clamping member may comprise a bar. The clamping member may have a plurality of recesses formed therein. The recesses may run transversely through the clamping member, substantially parallel to one another. Each recess may be arcuate in cross section, such that a part of a tube may be engage with the recess. The elongate clamping member may comprise a fastening mechanism. The fastening mechanism may retain the clamping member in position with respect to the reflector component.

When the reflector component comprises a plurality of recessed channels, the recessed channels of the reflector component and the recesses of the clamping member may have spacings which are complimentary. Each tube may be positioned in the solar panel, such that a first part of the tube is located in a recessed channel of the reflector component and a second part of the tube engages with a recess of the clamping member.

The at least one holding mechanism may comprise a holding member defining a plurality of substantially cylindrical apertures that engage at least some or all of the plurality of tubes to hold them in position with respect to the reflector component. The apertures may run transversely through the holding member, substantially parallel to one another. Each aperture may be substantially circular in cross-section and dimensioned such that a tube may be frictionally gripped in the aperture. Each aperture may be provided with flexible teeth, which extend radially inwardly towards the centre of the aperture. The flexible teeth may be tapered towards the centre of the aperture. The flexible teeth may frictionally grip a tube. Flexion of the teeth will enable a tube to be easily received into an aperture of the holding member, and will restrict, by friction, removal of the tube from the aperture.

The holding member may comprise a fastening mechanism to attach the holding member to the reflector component.

When the reflector component comprises a plurality of recessed channels, the recessed channels of the reflector component and the apertures of the holding member may have spacings which are complimentary. Each tube may be positioned in the solar panel, such that a first part of the tube is located in a recessed channel of the reflector component and the tube engages with an aperture of the holding member.

A solar panel with such a holding mechanism facilitates easy, fast and reliable, on-site assembly of the tubes and reflector component of the solar panel.

The solar panel may comprise a cover. The cover may comprise a material which is substantially transparent to thermal radiation. The cover may define an enclosure within which the tubes are located. The provision of an enclosure for the tubes, redefines the ambient temperature in which the tubes are located as that within the enclosure, rather than that outside the enclosure. This enhances the performance of the tubes due to the recycling of thermal radiation emitted from the tubes back into the tubes, rather than it being lost if no cover was present. The solar panel may comprise at least one holding recess, within which an edge of the cover may be located. The solar panel may comprise at least one wall portion, which comprises a first flap and a second flap which define the holding recess therebetween. At least one of the first or second flaps may be connected to the cover to form a water-tight seal. The or each of the first or second flaps may be connected to the cover using a sealant.

The holding recess may be provided with additional depth at a portion along the solar panel's length to facilitate the removal of a cover from the solar panel. The increase in the depth of the holding recess will allow a person to extract the cover from the solar panel, thereby permitting access to the tubes of the solar panel which is installed in a roof structure, from the outside of the roof structure. Such an arrangement facilitates the replacement of broken tubes and will also facilitate the replacement of broken or worn covers.

The solar panel may be suitably-sized to be applied onto a roof structure. The solar panel may be suitably-sized to be installed into a roof structure. The solar panel may be suitably-sized to fit between trusses of a roof structure. The solar panel may be suitably-sized to fit between adjacent trusses of a roof structure. This will enable the solar panel to be installed in existing roof structures without having to cut or alter the truss structures in any way. The application of the solar panel into a roof structure is therefore simplified.

The solar panel may be suitably-sized to be substantially flush with an outer surface of a roof structure. This improves the appeal of the solar panel to a purchaser of, for example, a house having such a solar panel. The solar panel will also provide added insulation to the roof structure, due to the substantially insulating base layer of the reflector component of the panel.

The solar panel may comprise a first flange along a first side of the panel to engage with a first truss of a roof structure, and a second flange along a second side of the panel to engage with a second truss of the roof structure. The first and second flanges may extend over the trusses to engage therewith, and the solar panel may be positioned between the trusses.

The flanges further enable the solar panel to tolerate construction variations in the roof structure. Typically the spacing between adjacent trusses of a roof structure is 600mm, however due to inaccuracies in construction this spacing can range between 550mm-650mm. The flanges may be adjustable, for example by cutting, to account for a variation in the spacing between adjacent trusses.

The first flange may further engage with a flange of an adjacent solar panel. The second flange may further engage with a flange of an adjacent solar panel. The provision of flanges on either side of each solar panel will permit a number of solar panels, positioned in parallel along a roof structure, to engage one another. The first flange and the second flange may each comprise a grooved surface, to facilitate engagement of the flanges with flanges of an adjacent solar panel. The engagement of the grooved surfaces of the flanges may provide a water-tight seal. The solar panel may further comprise a self-sealing bolt, which may be used to further secure the attachment of the first and second flanges to flanges of adjacent solar panels. The solar panel may further comprise a docking station, suitable for receiving a manifold. The docking station may comprise retaining members to retain a manifold positioned within the docking station.

The solar panel may be provided with flashing integral to least one of an upper or lower side of the solar panel. Preferably, the solar panel is provided with flashing integral to both the upper and lower sides of the panel. The flashing may allow the solar panel to integrate with roof tiles of a roof structure in a manner that will maintain the roof structure's resistance to water. The flashing on the upper side of the solar panel may extend under a roof tile that lies above an installed solar panel, while the flashing on the lower side of the solar panel may extend over a roof tile that lies below the installed solar panel.

The flashing may be formed of a monomer based material. Such a material will enable the flashing to be easily shaped, to follow the profile of the roof tiles of the roof structure. This enables the solar panel to be integrated into any roof structure, including continental European-style roofs, which use undulating tiles. The flashing may comprise wire. The wire may be integrated within the flashing, for example the wire may be integrated within the monomer based material. The integrated wire will prevent elastic return of the flashing once it has been shaped to the desired shape.

According to a second aspect of the present invention there is provided a solar panel reflector component comprising a substantially thermally insulating base layer and a reflective layer connected to a surface of the base layer. According to a third aspect of the present invention there is provided a tube holding mechanism, for engaging tubes of a solar panel to hold them in position, comprising an elongate clamping member having a plurality of recesses formed therein which are shaped such that a part of a tube may engage with each recess.

According to a fourth aspect of the present invention there is provided a tube holding mechanism, for engaging tubes of a solar panel to hold them in position, the holding mechanism comprising a holding member defining a plurality of substantially cylindrical apertures, substantially circular in cross-section and dimensioned such that a tube may be frictionally gripped in the aperture.

According to a fifth aspect of the present invention a kit of parts is provided, comprising; at least one tube; at least one holding mechanism; a reflector component, wherein the reflector component comprises a substantially insulating base layer with a reflective layer connected thereto.

The parts of the kit may be click-fit together to form a solar panel. This will enable the solar panel to be assembled quickly and easily, on site.

According to a sixth aspect of the present invention there is provided a solar panel unit suitable for installation into a roof structure, comprising a solar panel according to the first aspect of the present invention, a truss configuration arranged to receive the solar panel, and flashing, the flashing being arranged to lie over edges of the solar panel and overlay adjacent roofing materials. According to a seventh aspect of the present invention there is provided a method of installing a solar panel according to the first aspect of the invention in an existing roof structure, comprising the steps of, forming a slot suitable for receiving the solar panel within a truss structure of the roof structure; positioning the solar panel within the slot, and attaching the solar panel to the truss structure.

According to a eighth aspect of the present invention there is provided a method of installing a solar panel according to the first aspect of the invention in an existing roof structure comprising the steps of, sizing the solar panel to fit between adjacent trusses of the roof structure; positioning the solar panel between the adjacent trusses such that a first flange of the solar panel engages with a first truss located on a first side of the solar panel, and a second flange of the solar panel engages with a second truss located on a second side of the solar panel, and attaching the first and second flanges to the first and second trusses.

The method may comprise the step of adjusting the first flange to engage with the first truss. The method may comprise the step of adjusting the second flange to engage with the second truss. Adjusting the flanges may comprise removing a portion of the flange. Either of the flanges may be cut to ensure that they do not extend beyond a truss located on either side of the solar panel.

The method may comprise the step of positioning one or more additional solar panels adjacent to the solar panel and engaging the first flange of the solar panel with a flange of an adjacent solar panel and engaging the second flange of the solar panel with a flange of an adjacent solar panel. This solar panels may be engaged to provide a water-tight abutment between them.

The method may comprise the step of positioning a manifold between the adjacent trusses and connecting the manifold to the solar panel.

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a first embodiment of a solar panel according to the first aspect of the present invention;

Figure 2 is an end view of the solar panel of Figure 1 , showing a holding mechanism in the form of a clamping mechanism;

Figure 3 is a end view of part of an alternative holding mechanism, in the form of a holding member, of the solar panel of Figure 1 ;

Figure 4a is a cross-sectional view of part of the solar panel of Figures 1 to 2 showing a cover, and Figure 4b is a plan view of the part of the solar panel of Figure 4a;

Figure 5 is a perspective view of trusses of a roof structure;

Figure 6 is a cross sectional view of a second embodiment of a solar panel according to first aspect of the invention situated between roof trusses similar to those of Figure 5; Figure 7 is a side view of flanges of the solar panel of Figure 6;

Figure 8 is a perspective view of the solar panel of Figure 6;

Figure 9a is an end view, and Figure 9b is an aerial view, of a manifold suitable for docking in a docking station of the solar panel of Figure 8;

Figure 10 is a perspective view of a truss configuration arranged to receive the solar panel of Figure 1 ;

Figure 11 is a perspective view of part of a roof structure and the solar panel of 1 installed therein;

Figure 12 is a side view of a solar panel of Figures 1 and 6 provided with flashing and installed in a roof structure, and

Figure 13 is a cross-sectional view of the flashing of Figure 12.

Referring to Figure 1 , a first embodiment of a solar panel 100 comprises tubes 102, a reflector component 104. The tubes 102 are standard and their construction and use will be known to those skilled in the art. The reflector component 104 comprises a substantially thermally insulating base layer 110 and a reflective film 112. The film 112 is attached to a surface of the insulating base layer 110, typically by the use of an adhesive or thermal bonding. The substantially thermally insulating base layer 110 is formed from a low density polymer material, for example expanded polystyrene. The reflective film 112 comprises a polymeric, substantially thermally insulating substrate coated with a thin metallic film, for example aluminium. The material of the base layer 100 of the solar panel 100 is a cushioning material, and provides a cushioning effect for the tubes, as described below.

The reflector component 104 comprises a plurality of recessed channels 114. The channels 114 are formed by hot wire cutting of an upper surface 116 of the base layer 110, prior to the adhesion of the reflective film 112. The recessed channels 114 are arranged parallel to one another and are regularly spaced, as shown. The recessed channels 114 have a substantially parabolic cross-section. The tubes 102 are positioned relative to the reflector component 104, such that a first part of each tube 102 is located in a recessed channel 114, as shown. The tubes 102 lie in the channels 114 such that they are supported by the reflector component 104 over substantially all of their length. Each tube 102 is in direct thermal contact with the reflector component 104. As the reflector component 104 provides cushioning for the tubes 102, these may be seated directly on the reflector component 104 without unduly increasing the risk of fracturing of the tubes as they are so positioned.

Figure 2 shows a first holding mechanism, in the form of a first clamping bar 106, of the solar panel 100. The first clamping bar 106 is provided at a first end of the solar panel 100. A second clamping bar, not shown, is provided at a second end of the solar panel 100. The first and second clamping bars are similar in construction, and only the first clamping bar will therefore be described in more detail. The clamping bar 106 is elongate and has an approximately rectangular cross-section. The clamping bar 106 is made from a low density polymeric material, such as expanded polystyrene. The clamping bar 106 comprises recesses 118 passing transversely through the bar, which are formed by hot wire cutting of a substrate forming the clamping bar 106. A steel cross-brace 120 locates on the opposite side of the clamping bar 106 to the recesses 118. The cross-brace 120 gives added rigidity to the clamping bar.

The spacing of the recesses 118 of the clamping bar 106 is complimentary to the spacing of the recessed channels 114 of the reflector component 104. Each recess 118 of the clamping bar 106 is arcuate in cross section, such that a part of a tube 102 may be engage with the recess 118. The clamping bar 106 locates over each of the tubes 102, such that a second part of each tube 102 engages with a recess 118 of the clamping bar 106. The clamping bar 106 comprises a fastening mechanism, in the form of retaining pins 122. The retaining pins 122 pass through the clamping bar 106 into the reflector component 104. Thus, the clamping bar 106 and the reflector component 104 retain the tubes 102 in position.

Figure 3 shows an alternative holding mechanism of the solar panel 100 of Figure 1. The holding mechanism is in the form of a holding member 132, and provides a plurality of substantially cylindrical apertures 134a-134c therein. The apertures 134a-134c are evenly spaced along the holding member 132. The spacing between each of the apertures is complimentary to the spacing between the recessed channels of the reflector component 104. The apertures 134a-134c run transversely through the holding member 132, substantially parallel to one another, as shown. Each aperture is substantially circular in cross-section and dimensioned such that a tube 102 may be inserted into the aperture. Each aperture is provided with flexible teeth 136 , which extend radially inwardly towards the centre of the aperture, and are tapered towards the centre of the aperture. The holding member 132 further comprises a fastening mechanism, not shown to attach the holding member 132 to the reflector component 104. Once the tubes 102 are located in the recessed channels of the reflector component 104, the holding member 132 is used to hold the tubes 102 in position with respect to the reflector component 104. Each of the tubes 102 is inserted into one of the apertures 134a-134c of the holding member 132, and the teeth 136 flex to accommodate the tube 102 being inserted, and then frictionally grip the tube 102, to restrict the movement of the tube back out of the aperture.

Referring now to Figure 4a, a cross-sectional view of part of the solar panel 100 is shown, provided with a cover 124. The cover 124 comprises a material which is substantially transparent to thermal radiation. The cover 124 and walls 126a,b of the solar panel 100 define an internal chamber 128. Within the internal chamber 128, thermal radiation emitted from the tubes 102 is recycled back into them. Furthermore, the temperature within the internal chamber 128 is effectively the ambient temperature in which the tubes 102 operate. This effective ambient temperature will be higher than the external ambient temperature. As will be known to those skilled in the art, the efficiency of tubes is dependent upon the difference between the ambient temperature T_A experienced by the tubes and a temperature T_M of a manifold of the tubes, according to the following relationship:

where: ηo = conversion factor ai and a₂ =loss coefficients G = insolation level x= [(TM- T_A]/G)] Therefore, the closer the ambient temperature is to the manifold temperature, the more efficient the solar panel will be.

The walls 126a, b of the solar panel comprise a first flapi 42 and a second flap 144, which have a gap between them which defines holding recesses 146 on each of the sides 126a,b of the solar panel. The cover 124 is sheet-like in shape, and edges of the cover 124 are held within the holding recesses 146. The first flap142 and the second flap 144 are connected to the edges of the cover 124 using a sealant 152, to form a water-tight seal.

Figure 4b shows a plan view of the solar panel 100 of Figure 4a. The dashed lines 147 indicate the extension of the holding recesses 146 into the side walls 126a,b of the solar panel 100. A holding recess 148 is also provided in an end wall 149 of the solar panel 100, and the dashed line 151 indicates the extension of the holding recess 148 into the end wall . In regions 150, the extension of the holding recesses 146 and 148 is increased relative to the dimensions of the holding recesses in the other regions of the solar panel 100.

In the event it is required to access tubes that lie below the cover 124, or if the cover 124 is to be replaced, the regions 150 of the holding recesses 146 and 148 may be used to facilitate the removal of the cover 124. To remove the cover 124, the sealant 152 is first cut, to release the cover 124 from the first flap 142 and the second flap 144. The cover 124 is then slid along the recesses 146, in direction A (as indicated by the arrow in the Figure 4b). Sliding the cover 124 in direction A will move the cover 124 away from the regions 150, and out of the holding recess 148. The first flap 142 of the side walls 126a,b is then cut in the regions 150, to form access points The cover 124 may then be slid in direction B (as shown by the arrow in Figure 4b), through the access points thereby exposing the tubes that lie beneath. If desired, the cover 124 can be slid in direction B until it has been completely removed from the solar panel 100.

The cover 124 may be slid in direction A, back through the access points, to return it to its original position. The cover 124 is then reconnected to the first 142 and second 144 flap using a suitable sealant to form a watertight seal.

If the cover 124 is to be replaced, a replacement cover is inserted through the access points after the cover 124 has been completely removed. The replacement cover is then connected to the first 142 and second 144 flaps using a suitable sealant to form a water-tight seal.

Figure 5 is a perspective view of a typical truss configuration 1200 of a roof structure. The trusses 1202 are of standard configuration and form part of the roof structure. Standard configuration of the trusses will be known to a person skilled in the art. Each of the trusses 1202 are inclined at an angle α which corresponds to the pitch of the roof structure. In accordance with the standard configuration, the distance 'X' will range from 550mm to 650mm. This standard configuration of the trusses 1202 is suitable for receiving a solar panel that is of the required dimension to fit between adjacent trusses.

Figure 6 is an end view of a second embodiment of a solar panel according to the first aspect of the invention, situated between roof trusses similar to those of Figure 5. The solar panel 600 is of suitable dimension to fit between adjacent trusses 602, 604 of an existing roof structure, without having to break or alter the structure of any of trusses of the roof structure. The solar panel 600 comprises a first flange 606 and a second flange 608, both of which run parallel along the length of the solar panel and extend outward of the solar panel 600. The first flange 606 engages with and is attached to truss 602 while the second flange 608 engages with and is attached to adjacent truss 604.

A plurality of solar panels 600 may be provided between trusses of a roof structure. Each solar panel 600 is attached to one or more adjacent solar panels, using the first and second flanges 606, 608. For the solar panel 600 shown in Figure 6, the first flange 606 engages with a second flange (not shown) of an adjacent solar panel to the left of the solar panel 600, and the second flange 608 engages with a first flange 610 of an adjacent solar panel to the right of the solar panel 600.

The first and second flanges of adjacent solar panels mate to form a water-tight abutment. Figure 7 provides a magnified view of an engagement between a first flange 701 and second flange 702. A surface 704, 706 of each of the flanges 701 ,702 are grooved. The grooves on the first surface 706 are complimentary to the grooves on the second surface 704. As shown in Figure 7, when both the first 701 and second 702 flanges engage to abut adjacent solar panels, the grooves on the surface of each flange, engage one another such that the grooved surface of the first flange 701 meshes with the grooved surface of second flange 702 to prevent the solar panels from moving apart. The abutment of the respective surfaces will provide a water-tight seal.

Figure 8 is a perspective view of the solar panel 600 of Figure 6. The width B of the solar panel 600 is of suitable dimensions to fit between trusses of the truss configuration shown in Figure 5. A series of tubes 1012 have been inserted through apertures 1013 of holding member 1014. The solar panel 600 comprises a docking station 1002 suitable for receiving a manifold. The docking station 1002 is defined by two arms 1008 and 1010 that project from a main body 1006 of the solar panel. A manifold may be positioned within the docking station 1002 such that it will engage with free ends 1004 of the tubes 1012.

Figure 9a shows an end view, and Figure 9b shows an aerial view, of a manifold suitable for docking in the docking station of the solar panel of Figure 8. Referring firstly to Figure 9a, the manifold 11 OOcomprises a heat-exchange compartment 1101 , an inlet 1106 and an outlet 1108. The inlet 1106 and outlet 1108 are orientated at substantially 90^° to the heat- exchange compartment 1101 (as shown in Figure 9b).

The heat-exchange compartment 1101 comprises a first channel 1102 and a second channel 1104. The first channel 1102 is connected to the inlet 1106 at one end of the heat-exchange compartment 1101 and connected to the outlet 1108 at the other, opposing, end of the heat-exchange compartment 1101. Fluid flows through the first channel 1102 from the inlet 1106 to the outlet 1108.

The second channel 1104 is arranged parallel to the first channel 1102. The second channel has a series of sockets 1110a-1110e provided at regular interval along its length. The spacing between each of the sockets 1110a-1110e is complimentary to the spacing between each of the tubes 1012 of solar panel 1000. Each of the sockets 1110a-1110e are of suitable dimension to receive an end portion 1004 of a tube 1012. The first flow channel 1102 and the second flow channel 1104 are separated by a thermal conductive wall 1114. In use, the manifold 1100 is positioned in the docking station 1002 of the solar panel 1000 of Figure 8. The end portion 1004 of each of the tubes 1012 is plugged into the series of sockets 1110a-1110e of the manifold 1100. Heat energy stored in the series of tubes 1012, flows from the tubes, through the series of sockets 1110a-1110e and into the second channel 1104. The heat energy is transferred across the thermal conductive wall 1114, from the second channel 1104 to the fluid flowing in the first channel 1102. The fluid flowing through the outlet 1108 of the manifold is heated fluid. The heated fluid may be used to supply heated water to a water system of a house, for example the heated fluid may be used to supply heated water to an immersion tank of a house. The heated fluid may also be used to supply radiators or an under-floor heating system.

Figure 10 is a perspective view of a truss configuration arranged to receive a solar panel according to Figure 1 , 2, 4a or 4b. Referring to the figure, a roof 400 comprises inclined trusses 402 and a frame 404. One of the trusses 402 is broken and the frame 404 inserted into the gap in the trusses 402. The frame 404 comprises horizontal walls 412a,b, inclined walls 414a,b, and a backing plate 416. The horizontal walls 412a,b attach to the broken truss 402 whilst the inclined walls 414a, b attach to the trusses 402 adjacent the broken truss 402. Thus, the provision of the frame 404 within the roof 400 structure does not significantly weaken the roof 400.

Figure 11 is a perspective partial view of a roof with a solar panel according to Figure 1 , 2, 4a or 4b installed therein. In Figure 11 a roof 400 comprises inclined trusses 402, tiles 406, a solar panel 408 and flashing 410. The trusses may be of the configuration shown in Figure 10. The solar panel 408 fits into the truss configuration such that it is substantially flush with a finished external level of the roof 400. The thermally insulating nature of the panel's reflector component adds insulation to the roof 400 in the region of the solar panel 408. The tiles 406 are laid on the roof 400 and flashing 410 laid over the junction between the tiles 406 and the solar panel 408. This provides a low profile, ideally flush, finish between the tiles 406 and the solar panel 408.

Figure 12 provides a side view of a solar panel 800 of Figure 1 , 2, 4a, 4b, 6 or 8, provided with flashing and installed in a roof structure 802. Upper tile 804, which forms part of the roof structure 802, lies above the installed solar panel 800, while lower tile 806, which also forms part of the roof structure 802, lies below the installed solar panel 800. Flashing 812 is provided on the upper 810 and lower 808 portions of the solar panel 800. The flashing 812 on the upper portion 810 of the solar panel 800 is secured beneath upper tile 804, while the flashing on the lower portion of the solar panel 800 is secured above lower tile 806. The flashing will seal gaps 814 and 816 that exist between the upper 804 and lower 806 tiles and the installed solar panel 800, thereby maintaining the water impermeably properties of the roof structure 802.

It will be appreciated that although described with reference to tiles any suitable roofing material can be used, for example, felt, wood or stones.

Figure 13 provides a cross-sectional view of the flashing referred to in the description of Figure 12. The flashing consists of a monomer based substrate 902. Wire members 904 are integrated at regular intervals, into the substrate 902. Embodiments of the solar panel of the invention have been shown installed into a roof structure. It will be appreciated that the solar panel of the invention may be installed into other structures such as wall structures. It will also be appreciated that the solar panel of the invention may be on a roof structure or other structures such as wall structures.

Various modifications and improvements may be made to the above without departing from the scope of the present invention.

Claims

1. A solar panel comprising a plurality of tubes, and a reflector component in thermal communication with the tubes, which comprises a substantially thermally insulating base layer and a reflective layer connected to a surface of the base layer.

2. The solar panel according to claim 1 , wherein the tubes are positioned on the reflector component such that the tubes directly contact the reflector component.

3. The solar panel according to any preceding claim, wherein the reflector component comprises a cushioning material.

4. The solar panel according to any preceding claim, wherein the reflector component comprises a plurality of recessed channels.

5. The solar panel according to any preceding claim, further comprising at least one holding mechanism, that engages at least some of the tubes to hold them in position with respect to the reflector component.

6. The solar panel according to claim 5, wherein the at least one holding mechanism comprises a cushioning material.

7. The solar panel according to claim 5 or claim 6, wherein the at least one holding mechanism comprises an elongate clamping member, that engages at least some of the plurality of tubes to hold them in position with respect to the reflector component, the clamping member comprising a plurality of recesses formed therein which are shaped such that a part of a tube engages with each recess.

8. The solar panel according to claim 7 as dependent from claim 4, wherein the recessed channels of the reflector component and the recesses of the clamping member have spacings which are complimentary.

9. The solar panel according to claim 5 or claim 6, wherein the at least one holding mechanism comprises a holding member defining a plurality of substantially cylindrical apertures that engage at least some or all of the plurality of tubes to hold them in position with respect to the reflector component.

10. The solar panel according to claim 9, wherein each aperture is provided with flexible teeth, which extend radially inwardly towards the centre of the aperture, such that a tube is frictionally gripped in the aperture.

11. The solar panel according to any preceding claim, comprising at least one holding recess, within which an edge of a cover is located and wherein the holding recess is provided with additional depth at a portion along the solar panel's length, to facilitate the removal of the cover from the solar panel.

12. The solar panel according to any preceding claim, suitably-sized to fit between adjacent trusses of a roof structure.

13. The solar panel according to any preceding claim, further comprising a first flange along a first side of the panel to engage with a first truss of a roof structure, and a second flange along a second side of the panel to engage with a second truss of the roof structure.

14. A solar panel reflector component comprising a substantially thermally insulating base layer and a reflective layer connected to a surface of the base layer.

15. A tube holding mechanism, for engaging tubes of a solar panel to hold them in position, comprising an elongate clamping member having a plurality of recesses formed therein which are shaped such that a part of a tube engages with each recess.

16. A tube holding mechanism, for engaging tubes of a solar panel to hold them in position, the holding mechanism comprising a holding member defining a plurality of substantially cylindrical apertures, substantially circular in cross-section and dimensioned such that a tube is frictionally gripped in the aperture.

17. A kit of parts comprising; at least one tube; at least one holding mechanism; a reflector component, wherein the reflector component comprises a substantially insulating base layer with a reflective layer connected thereto.

18. A solar panel unit suitable for installation into a roof structure, comprising a solar panel according to the first aspect of the present invention, a truss configuration arranged to receive the solar panel, and flashing, the flashing being arranged to lie over edges of the solar panel and overlay adjacent roofing materials.

19. A method of installing a solar panel according to the first aspect of the invention in an existing roof structure, comprising the steps of, forming a slot suitable for receiving the solar panel within a truss structure of the roof structure; positioning the solar panel within the slot, and attaching the solar panel to the truss structure.

20. A method of installing a solar panel according to the first aspect of the invention in an existing roof structure comprising the steps of, sizing the solar panel to fit between adjacent trusses of the roof structure; positioning the solar panel between the adjacent trusses such that a first flange of the solar panel engages with a first truss located on a first side of the solar panel, and a second flange of the solar panel engages with a second truss located on a second side of the solar panel, and attaching the first and second flanges to the first and second trusses.