Field of the Invention

The present invention relates broadly to a solar roof assembly and a method of 6 insulating a roof The invention also relates generally to a method of heating, or cooling a building having roof ciadding.

Background to t e Invention

In a commercial roof structure of a conventional construction, transverse purlins0 extend across a series of parallel beams for a flat roof, or a serios of parallel rafters for a pitched roof. The roof structure Is typically clad In corrugated sheeting to enclose the structure. In order to thermally insulate the corrugated sheeting, sarking is layered across the purlins or rafters prior to fixing of the roof cladding. The roof structure may also be thermally insulated with the addition of insulation between the5 purlins or rafters.

Summary of the invention

According to one aspect of the invention there is provided a solar roof assembly comprising:

0 roof cladding including at least orte channel;

s plurality of solar panels secured directly to the roof cladding to substi-ntia!ly enclose said at least one channel for at least partial coverage of the roof ciadding, each of the solar panels including a rigid panel backing to which a photovoltaic membrane or coating is applied,.

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Preferably the rigid panel backing includes an intermedi te pan located between opposing ridges wherein the panel backing is secured directly to the roof ciadding with said ridges disposed transverse to the channel of the roof cladding thereby cross-bracing, it. More preferably the adjacent solar panels la one- another and are0 both screw fastened to the roof cladding ia a common screw fastener. Still more preferably the PV membrane or coating extends across at lees' substantially all of the pan of the rigid pane! backing. According ro another aspect of the invention there is provided a soter roof assembly comprising:

roof cladding including at least one channel;

a plurality of solar panels secured directly to the roof cladding to substantially enclose said at least one channel for at least partial coverage of the roof cladding; a plurality of seciirement devices each including a hold down fitting configured to engage a perimeter frame of at least one f the solar panels, and a fastening arrangement configured to engage the roof cladding without penetration and op.arativejy coupled to the hold down fitting for clamping of the solar panel directly to the. roof cladding.

Accnrding to a further aspect of the Invention there is provided a method of insulating a roof having roof cladding, said mothod comprising the steps of:

securing & plurality of solar panels "directly to the roof cladding to substantially enclose channels of the roof cladding for at least partial coverage of said roof cladding;

clamping each of the soiar panels directly to the roof cladding via a securement device without penetration of the roof cladding. Preferably the solar panels are each solar photovoltaic (PV) panels having a toughened glass upper layer. More preferably the solar PV panels are. secured to .the roof cladding iry one or more rows located alongside one another and oriented ■ substantially transverse to the channels of the roof cladding. Even more preferably adjacent cows of the solar panels are staggered relative to one another.

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Preferably the solar panel acts as a cross -brace for the cladding panel to which it is secured. More preferably the cross-brace bridges and is oriented transverse to the channel of the roof cladding. Preferably the plurality of solar panels together with the roof cladding define a sttli air gap within said at least one channel. Mere preferably the still air gap has a thermal Insulating effect for the solar root assembly. Preferably' the roof cladding includes a plurality of elongate cladding panels each including said at. least one channel with adjacent of the panels being adjoined to one another. More preferably each of the cladding panels includes a pair of inclined side walls interconnected by an intermediate pan. Even rriore preferably the cladding panels are each in cross-section generally trapezoidal-shaped.

Preferably the cladding panels each include a flange extending from a free edge margin of respective of the side walls. More preferably adjacent of the flanges of adjoining panels are configured to interlock. Even more preferably ope. Qf the interlocked flanges forms a platform on which the solar panel rests.

According to still another of the invention there is provided a securement device for securing a solar panel directly to roof cladding, the securernent device comprising: a hold down fitting adapted to engage a perimeter frame of the solar panel; a fastening arrangement adapted to engage the roof cladding without penetration and operatively coupled to the hold down fitting for clamping the solar panel directly to the roof cladding.

Preferably the fastening arrangement includes a screw threaded bolt arranged at its head to engage the hold down fitting and arranged at its threaded end to screw threadably engage a cleat configured to engage the roof cladding. More preferably the cleat includes a raised flange arranged to engage interlocked flanges of adjoining cladding panels for clamping of the solar panel to sard cladding panels. According to yet another aspect of the invention there is provided a method of heating or cooling a building having roof cladding, said method comprising the steps of:

securing a plurality of solar panels directly to the roof cladding to substantially enclose channels of the roof cladding for at least partial coverage of said roof cladding:

extracting air from at least one of .the enclosed channels of the roof ciadding for heating or cooling of the building. Preferably the method of heating or cooling also comprises the step of diverting the e trac ed air into an enclosed space of the building for heating of the- enclosed space-. More preferably the method further comprises the steps of:

detecting the temperature ^' in the enclosed space of the building;

diverting the e tracted air into either:

(i) the atmosphere in the event that the detected temperature is above a predetermined set point temperature; or

(ii) the enclosed space of the building In the event that the detected temperature is below the set point temperature.

Preferably the roof cladding is fabricated from metal and is in the form of structural roof cladding. Mote preferably said cladding is cold roll formed from strip metal.

Pi ferably the rigid pane! backing is fabricated from metal. More preferably said backing is cold roll formed from strip metal.

Brief Description of the Drawings

In order to achieve a better understanding of the nature of the present invention a preferred embodiment of a solar roof assembly and other aspects of the invention will now be described, by way of example oniy, with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a solar roof assembly according to an embodiment of one as ect of the invention;

Figure 2 is an enlarged side view takeri frorii the solar roof assembly of figure 1 ;

Figures 3A and 3B are perspective views of alternate embodiments of a securement device such as that used in figures 1 and 2 for securing a pair of adjacent solar panels directly to roof cladding according- to another aspect of the invention; and

Figure 4 is a schematic perspective view of another embodiment of a secursment device for securing a solar panel directly to roof cladding according to this other •aspect of the invention; Figure 5 is a perspective view of a solar root- assembly according lo an embodiment of another aspect, of the invention. Detailed Description of the Preferred Embodiments

As best shown in figures 1 and 2 there is a solar roof assembly designated generally as 10 comprising roof cladding 12, and a ^' plurality of solar panels such as 1 A to 14F. The solar roof assembly 0 is in this example installed on a functional roof including purlins, rafters or other structural members. ( iot. shown.) to which the roof cladding. 12 is fixed.

In this embodiment the roof cladding 12. is structural roof cladding wh-ch includes a series of adjacent channels such as 16A to 16C. The solar panels 14A to 1 A F are secured directly to the structural locf cladding 12 to substantially enclose the channels 1.6A to 1 £?C. The solar panels 14A to 14F in this example provide substantially complete coverage of the structural roof cladding 1 2 which ^' it will be appreciated is illustrated in part onl However, the solar panels such as 1 A may also provide only partial coverage of the roof cladding 12 The structural roof cladding 12 of this embodiment includes a plurality of elongate •cladding panels such as 18A to SC each defining the respective channel 16A to i BC Each of the cladding panels such as 18A includes a pair of inclined side walls ^' 2C 20A' interconnected by an intermediate pan 21Ά. The cladding panels such as 8A are in this example in cross-section generally trapezoidal-shaped. The pan 21 A is provided with longitudinally extending strengthening ribs such as 23A. The side walls Such as 20A. are provided with transverse corrugations such as 25A. These ^• design features in combination provide tho cladding panels such as 18A with additional rigidity and effectiveness as structural roof cladding. As best shown in figure 2 the cladding panels such as 16B each include a flange such .as 22B extending from & free edge margin of the side wall such as 2GB, The cladding panel 18B is adjoined with adjacent cladding panels I bA and 16C. This is effected by interlocking of the adjacent flanges such as 22 A' rid 22B. In this example the male flange 22A' of the cladding panel 18A nest within the female flange 22B of the adjacent cladding pane! 18B. The opposite male flange 223' of the cladding panel •1 SB ^' nests within the fomale flange 22C of the cladding pane! 18C.

- The interlocked flanges such as 22AV22B form a platform such' as 24B on which the solar pane! -such as 146 dircoily rests. The solar panel 14S is secured directly to the roof cladding 1 via a securement device; such as 26B or 26C according to another aspect of the ^' invention. The securement device 26B/26C engages the roof cladding 2 without penetration of its cladding panels such as 18Λ to 18C for damping of the solar panel such as 1 B directly to the roof cladding 12..

As shown in figures 3A and 3B the securement device such as 2&E comprises a hold down fitting 6F. and a fastening arrangement 30E operatively ou led to one another for lamping the adjacent solar panels such 14B/14D directly to the roof cladding 2. The hold down fitting 28E is adapted to engage adjacent perimeter frames 32B and 32D of the solar panels 1.4B and 14D respectively, The fastening arrangement 30E is- in Ihis embodiment adapted lb engage the roof cladding 2 without penetration. The hold down fitting 28C is in the embodiment of figure 3A U-shaped in cross-section whereas in the embodiment of figure 3B it is. generally T-shaped in either case the hold down fitting such as 28£ includes a pair of gripping flanges 33E and 33E' extending either side of a fastener-mount 34E.

As shown in figure 4 this alternate securement device designated as 26A is designed to secure a solar panel such as 14A located at cr adjacent the perimeter of the roof ■structure directly to the roof cladding such as 12. For ease of reference and to. avoid repetition, similar components of this securement device 26A have been designed With the same reference numeral as the previous embodiments. The hold down filling 280 is generally Z- shaped in cross- section with its lower flange forming the fastener body 34. The securement devices of figures 3 end 4 each include the fastening arrangement 30 of similar construction. The fastening .arrangement such as 30 includes a threaded bolt 36 arranged at its threaded end to screw threadably engage a cieat 38 configured to engage the roof cladding 12. The cleat 38 includes a raised flange 40 arranged to engage the Interlocked flanges such as 22A' and 22B of adjoining panels 18A and 18B. The cleat 38 includes an adjoining foot 42 threaded for mating engagement w-th ^' the bolt 36. The bolt 36 passes through an aperture 44E formed in the fastener body 34S: of the hold down fitting such as 26E. The head of the bolt 36 bears against the hold clown fitting 26E for clamping of the solar panels 14A and 14D to the roof cladding 12 via thu sccurement device 26E.

Trie plurality of solar panels such as 14A to 14F together with ^' the roof cladding 12 define β stili air gap within at least one of the channels 6Λ to 16C. The still air gap such as 16B has a thermal insulating effect for the solar roof assembly 10. The trapezoidal- shaped cladding panels such as 18A allows a greater volume of air to be enclosed in- the -still air gap or channel such as 16A than, for example, a sinusoidal- shaped cross-sectjori does. This is expe.cted to improve the thermal insulating effect of the solar roof assembly such > 10. At an ambient temperature of around 30" the solar roof assembly 10 is estimated to lower the interior temperature by up to- around 10': In addition to its thermal insulation properties s the solar roof assembly 10 is also expected to provide effective acoustic or noise insulation.

Figure 5 illustrates ^' another aspect of the composite roof 100 where the solar panels such as 140A include a thin film PV membrane 102A applied to a rigid panel backing 104A. The panel backing 0 A of this -example includes an intermediate trough 06A and -adjacent ridges 108A and 1 10A extending parallel to and on either side of the trough Ί 06Α. The trough 106 A is in section shaped trapezoidal with its intermediate pan 1 1 1 A extended relative to the adjacent trapezoidal shaped ridges 108A/1 10A. The panel backing 106A includes- flanges 1 12A/1 14A extending from the respective inclined side walls 1 16A and 13.A of the ridges 108A and 1 iOA. The flanges 12A and -J 14A are designed to be directly screw fastened to the platform 240S of the underlying cladding panels such as 80A to 180C, This penetration such as 122 .does not compromise the waterproofing of the roof cladding such as 180B. It will be understood that the solar pane! 104A is one of a series of adjacent panels arranged adjacent to one another to substantially enclose the underlying structural roof .cladding 20. The flanges such as t12.A.of adjacent paneis such as panels 1.4QA lap one another and are screw fastened into the roof cladding 120 via a common screw fastener (not shown). The rigid panel 104A and its associated thin film PV membrane 102A are oriented with the trough 106A and ridges 108A 110A substantially perpendicular to the channels 160B of the cladding such as 180B. The panel backing 104A Is inherently rigid arid serves to cross brace the roof cladding such as 180B. The profile may also be designed so -thai -shading is minimised to enhance the exposure of the associated thin film PV membrane 102A. The membrane 102A in this embodiment is applied to the intermediate pan 111 A only although it can also ^' extend across substantially all at lhe rigid panel backing 1Q4A. Like components of this other embodiment have been designated with an additional "0" where for example the roof cladding is _. 120.

In the embodiment of ^" Figure 5 the flanges such as -114A anc 112B overlap and are screw fastened to the underlying platform such as 2 QB of the roof cladding 1.20. This means the entire pan such as 11 1A of t e rigid panel backing 104A is available for covering with the thin film P membrane 102A. In an alternative embodiment the ridges such as 11 OA and 10SB may overlap or nast within one another so that the rigid panel backing such as 1 4Α is fastened through its pan 1 11 A to the underlying platform such as 24GB. This means- the nested solar panels such as 14QA and 140B a e more effective in preventing the. ingress of water to the underlying roof cladding 120.

•The rigid panel backing 104A is cold roil formed from strip metal in-silu using a . roll former (not shown). The solar panels may also be assembled in-situ whore t e thin film PV membrane K? A is applied ^" to the rigid panel backing such as 104A. The ^• panel 104A is in this embodiment cold roll formed from strip metal. The PV membrane 102A. may be adhered to the panel 104A downstream of its roll forming arid prior ^" to direct Fosterling of the panel backing 104A to the roof cladding such as 183. Alternatively the panel backing 104A may be screw fastened to tha roof cladding such as 18B and thereafter th.e PV membrane 102.A or coating applied. In another aspect of the invention there is a method of insulating a roof having roof cladding such as that described in the. previous embodiment. In this aspect the method may involve construction of the entire roof structure and the associated building where its roof cladding such as 12 is at least pertly covered in solar panels such as 14A to 14F directly secured to the roof cladding 12 to substantially enclose its channels such as 16A to 16C. In a variation on this aspect of the methodology it is possible that an existing roof structure having stFUGtural roof cladding is at least partly covered with solar panels such as 14A to 14C. In either case this method effectively insulates the roof structure. in a further aspect of the invention there is a method of heating or cooling a building (not illustrated) having roof cladding such as that described in the context of the earlier embodiment The general steps involved in this method comprise:

1. Securing a plurality of solar panels .r.ueh as 14A to. 14F directly to strupturaj roof cladding such as 12 to substantially enclose channels 16A to 16C of the roof cladding 12 for at least partial coverage of the roof cladding 12·;

2. Extracting air from at least one of the enclosed channels such a.s 16A for heating or cooling of the building.

In this embodiment the step of securing the solar panels such as 14A directly to the roof cladding 12 involves securing a perimeter frame 32 A. of the solar panel such as 1£A to the roof cladding without penetrating the cladding 12. The securemervl device such as 26 of the earliar embodiments may be used fo this purpose .

It is expected that the perimeter frame of the solar panels such as 14.A to C will act as a cross -bra ce for the cladding panel suc as 18B to which it is secured. The solar panels such as ' A and 1 £ are staggered in adjacent rows so that a plurality of the solar panels such as 1 A to T4F are laid In a staggered arrangemen t similar to bricks in a well. The means that solar panel 140 effectively cross braces cladding pane! 18B whereas solar pane! 14E from the adjacent row cross braces cladding panel 18A. This staggered arrangement ensures that each of the cladding panels such as 8A and 18B are cross-braced via a solar panel from at least every other (or- alternate) rows of solar panels. That, is, the solar panel such as 14B and its associated perimeter frame 32B bridges the channei such ^■ as 16B of the cladding panel IBB to ^• strengthen it transversely.

The securement devices such as 260 or 26E of this embodiment are designed to locate anywhere along the cladding panels such as 18B wherein the interlocked flanges such as 22A' and 22B operate as a mounting rail.. The securement device such as ^' 26E can also engage the perim ler frame 32B of the solar panel 14B practically anywhere along its length without r&qyiring specific positioning or alignment. This means the solar panels such as 1 A to 14F can be positioned on the Underlying structural roof cladding in a relatively random manner without requiring relative alignment or positioning. The clamping of the eolar panel such as 14A to the roof cladding 12 without penetration also means that the strength or waterproofing of the roof cladding 1 is not compromised.

The method af heating or cooling the building may also comprise the step of diverting the extracted hot air info an enclosed space of the building for heating of the enclosed space ^not shown) _. . The method may also be automated where the temperature in ma enclosed space is measured and the extracted air diverted into either:

1. the atmosphere in the event that the detected temperature is above a predetermined set point temperature, or

2. the enclosed space of the building in. the event that, the detected temperature is below the set point temperature.

This automatic control may be implemented by using a convention thermostat control and valve arrangement. The predetermined set point temperature may vary from between 20 ^* to 30°. The thermal convection within ih e stii! air gap of the channels each ae 16A Of t e solar roof assembly 10 can produce a chimney effect For expelling hot air from the enclosed channels. Alternatively or additional^ the method may Involve one or more extraction fans operativety coupled to the enclosed channels and possibly powered by the solar panels, in any case the relatively large channels such as 15A to 160 of the. roof cladding 12 of this embodiment lend themselves to ^' then'nddynain ^' ic heating dr cooling utilising the still air gap.

The solar roof assembly may, depending on the climati conditions in which it is installed, include sealing strips (not shown). These sealing strips are located between adjacent of the solar panels such as 14A and 14D to substantially seal the gap .between these panels. Instead of sealing adjacent solar panels, with sealing strips they may be arranged in abutment with one another, in this configuration the solar panels are secured directly to the roof cladding from underneath. For example, the solar panels may be screw fastened to the roof cladding such as 12 using for example TE.KS® screws. These screws may for example be self-drilled through interiocked flanges of adjoining panels directly into the perimeteF frame of the solar panel■ In tble installation there is no requirement for a securement device such as that described in the earlier embodiment. Alternatively and typically in temperate Climates, there may be benefit in not completely sealing adjacent soter panels to allow venting of the still air gap.

The solar panels of this embodiment are each solar photovoltaic (PV) panels having a toughened glass upper layer. The PV panels of this construction are sufficiently robust 10 permit pedestrian access across the solar panels without damaging them. In the context' of the solar roof assembly with its substantially- complete coverage this is important because access need not then be provided by walkways, along the roof cladding itself. This means the entire roof cladding can be covered with solar panels to enable maximum eriergy to be harnessed from the solar roof structure.

Now that a preferred embodiment of the present invention has been described in some detail it will be apparent lo those skilled in- the art that trre solar roof assembly at least in its preferred embodiments has the following advantages:

? It provides s composite roof providing both thermal insulation and the ability to generate power or heating via its solar panels;

2. The method of heating or cooling a building utilises the relatively iarge still air ga created by this blanket coverage of the solar panels across the roof cladding;

3. The solar panels can be secured directly to the roof cladding without requiring complicated and expensive mounting structures;

4. The method and its various components allow for location of the solar panel ^' s practically anywhere across the roof cladding which itself provides mounting or hold down rails.

Those skilled in the art will appreciate that the invention described herein is .susceptible to variations, and modifications other than those specifically described. The PV membrane need not be limited to thin film PV but may extend to coatings such as those used in dye solar cell technology. For exarnpie, the securemenl device may vary from tho preferred embodiments where it penetrates interlocked or other portions of the roof cladding without significantly compromising its integrity. All such variations and modifications are to. be considered within the scope of the present invention the nature of which is to be determined from the foregoing description.