Abstract:
There is provided an improved roof solar panel, embodying an array of photovoltaic cells mounted on conventional modular roof sheathing, that can be readily and easily installed onto a conventional sloped roof and integrated into conventional roof shingles. Such panel includes a shingle mounting surface on a perimeter area of the sheathing, a flash strip mounted inside such shingle mounting surface and, when installed on the roof, a retainer trim for securing shingles mounted on said shingle mounting surface, while mounting to the flash strip and sealing to a perimeter of a rigid transparent protective sheet over the array. The retainer trim also serves to provide means for securing the panel onto roof trusses. Integration with the conventional roof shingling provides, inter alia, an attractive low profile with improved water shedding and wind resistance properties. There is also an intermediate roof solar panel, for installation on a roof so as to provide the aforementioned improved roof solar panel. The invention also relates to a kit comprising, inter alia, said intermediate roof solar panel, and to a method of installing said intermediate roof solar panel.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. National Phase filing under 35 U.S.C. §371 of International Application PCT/CA2012/050305, filed May 10, 2012, and published as WO 2012/151700 on Nov. 15, 2012. PCT/CA2012/050305 claimed benefit of priority from Canadian Patent Application No. 2,739,766, filed May 10, 2011. The entire contents of each of the prior applications are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to an improved roof solar panel, embodying photovoltaic cells, that can be readily and easily installed into a conventional sloping roof and that integrates with a conventional shingle finish on the roof so as to provide, inter alia, an attractive low profile with improved water shedding and wind resistance properties. Further, the invention relates to an intermediate roof solar panel, for installation so as to provide the aforementioned improved roof solar panel. The invention also relates to a kit comprising, inter alia, said intermediate roof solar panel, and to a method of installing said intermediate roof solar panel. 
     BACKGROUND 
     Both non-structural and structural roof elements incorporating solar collectors such as an array of photovoltaic cells are well known. However, structural roof panels are generally of specialized and costly configuration and installation, often complex and/or heavy and requiring modification or replacement of existing conventional roof structures. The combination of non-structural substrates and solar panels is also well known as substitutes for roofing materials such as shingles and tiles, but such are also typically costly and requiring specialized installation. Solar panels for installation over existing roof components are also well known, but such pose undesirable profile and aesthetic factors, and challenges for mounting securely on the roof without compromising existing roof components or their function. 
     There is therefore a need for a low cost, easy to install roof solar panel offering highly secure integration into conventional roof structures and consequent functional and aesthetic advantages. 
     SUMMARY OF THE INVENTION 
     In a first aspect, the invention provides a modular roof solar panel installed on a sloping roof, the panel comprising modular roof sheathing having an upper surface and a sheathing perimeter. The sheathing perimeter has an underside mounted on adjacent roof trusses, a topside and a sheathing perimeter edge. There is a (base) flashing strip mounted on the topside of the sheathing perimeter, the flashing strip having inside and outside perimeter edges. The flashing strip is set back from the sheathing perimeter edge to provide a shingle mounting surface. Preferably this set back provides a shingle strip mounting surface around the sides and top of the sheathing perimeter of the panel. There is also an array of photovoltaic cells mounted on the upper surface, the array having an array perimeter inside the flashing strip inside perimeter edge. There is also a rigid, transparent protective sheet over the array, the protective sheet sealingly mounted on the flashing strip proximate to the flashing strip inside perimeter edge. There are a plurality of shingles sealingly secured on the shingle mounting surface and on a topside perimeter area of adjacent roof sheathing to which the shingles extend. There is a retainer trim comprising a mounting base and a retaining lip, the retainer trim mounted at its mounting base on a topside of the shingles over the shingle supporting surface and on a topside of the flashing strip outside where the protective sheet is mounted on the flashing strip. The retaining lip is sealed on a topside perimeter of the protective sheet. 
     Preferably the protective sheet comprises glass, low iron glass, or plexiglass. The protective sheet may be sealingly mounted onto the flashing strip With urethane and the retaining lip may be sealed by a silicone sealer to the topside perimeter of the protective sheet. 
     The retainer trim may further comprise fasteners securing the panel to a roof truss. The roof sheathing preferably comprises 4′×8′ plywood. Preferably, the modular solar panel base is made of a non-flammable substitute (e.g. polypropylene base or covering) for conventional plywood. 
     Such base preferably is sized to span the roof trusses equally, similar to the normal roof sheathing process. Although the solar panel mounted on such base may be smaller in length based on panel sizing requirements. The flashing strip and retainer trim preferably are made of aluminum. Preferably roof shingles over adjacent roof sheathing abut the retainer trim. 
     Most preferably, the plurality of shingles secured on the shingle mounting surface are shingle strips, specifically on the shingle mounting surface that is on the sides and top areas of the sheathing perimeter. The shingle strips are preferably prepared from shingles by removal of part of the showing surface of a shingle. 
     In another aspect the invention provides an intermediate modular roof solar panel for completion upon installation on a sloping roof, the intermediate modular roof solar panel comprising modular roof sheathing having an upper surface and a sheathing perimeter. The sheathing perimeter has an underside mounted on adjacent roof trusses, a topside and a sheathing perimeter edge. A flashing strip is mounted on the topside of the sheathing perimeter, the flashing strip having inside and outside perimeter edges. The flashing strip outside perimeter edge is set back from the sheathing perimeter edge to provide a shingle mounting surface on the topside of the sheathing perimeter. An array of photovoltaic cells is mounted on the upper surface, such array having an array perimeter inside the flashing strip inside perimeter edge. There is also a rigid, transparent protective sheet over the array, the protective sheet sealingly mounted on the flashing strip proximate to the flashing strip inside perimeter edge. 
     In yet a further aspect there is provided a kit of parts for installation as a roof solar panel on a sloping roof, the kit comprising the foregoing intermediate modular roof solar panel and retainer trim for assembly and completion of the panel upon installation on a roof. The retainer trim comprises a mounting base and a retaining lip. The mounting base is adapted for mounting on a topside of a shingle (when said shingle is mounted on said shingle mounting surface during installation of the panel on a roof), and for mounting on a topside of said flashing strip over said flashing strip outside perimeter and outside where the protective sheet is mounted on said flashing strip (also during installation of the panel on a roof). The retaining lip is adapted for sealing on a topside perimeter of the protective sheet. 
     The invention also provides a method of installing the aforementioned intermediate modular roof solar panel onto a sloping roof. The method comprises selecting an area of roof trusses for mounting of the intermediate modular roof solar panel, installing roof sheathing on roof trusses around a perimeter of the area, mounting the intermediate roof solar panel onto the area of roof trusses, securing roof shingles over the shingle supporting surface of the topside of the sheathing perimeter and adjacent roof sheathing, and sealingly mounting a retainer trim, at a mounting base thereof, on the flashing strip outside a perimeter of the protective sheet and on the roof shingles over the shingle mounting surface of the topside of the sheathing perimeter, while sealing a retaining lip of the retainer trim onto a topside perimeter of the protective sheet. 
    
    
     
       SUMMARY OF THE DRAWINGS 
       In drawings which illustrate preferred embodiments of the invention: 
         FIG. 1  is a side perspective view of the roof solar panel according to the invention, installed on a roof; 
         FIG. 1   a  is a front perspective view of a roof solar panel according to the invention, installed on a roof; 
         FIG. 2  is a cross section view from side to side of the inventive roof solar panel installed on a roof; 
         FIG. 2   a  is a close-up, cross section view of the right side of the view of  FIG. 2 ; 
         FIG. 3  is a cross section view through abutting sides of a pair of adjacent roof solar panels according to the invention, installed on a roof; 
         FIG. 4  is a cross section view of a retainer trim component of the invention; 
         FIG. 5  is a cross section view of a base flashing strip component of the invention; 
         FIG. 6  is a cross section view of a rubber connecting strip component of the invention; 
         FIG. 7  is a sequence diagram illustrating steps for installing an intermediate roof solar panel on a roof so as to provide an installed roof solar panel, according to the invention; 
         FIG. 8  is a plan view of a pair of adjacent roof solar panels according to the invention, showing particulars of preferred shingle integration along the lower edge of the roof solar panels before installation of the retainer trim component; and 
         FIG. 8   a  is a cross section view of the bottom (lower) end of one of the roof solar panels of  FIG. 8 , after installation of the retainer trim component. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     There is disclosed herein a prefabricated intermediate roof solar panel that is configured to be installed onto conventional roof trusses, a method of installing such roof solar panel and the resulting finished roof solar panel after such installation. The intermediate roof solar panel is comprised of a substrate which is preferably either conventional (structural) roof sheathing such as 4′×8′ plywood, or a non-flammable substitute. The sheathing supports a conventional photovoltaic cell array sealed onto much of its upper surface and covered by a rigid, transparent protective sheet such as glass, plexiglass, or most preferably low iron glass. Such protective sheet is for protecting the array from the usual physical stresses caused by weather (wind, water, snow etc.) and atmospheric debris, while allowing sunlight to pass through to the surface of the photovoltaic array for conversion into electricity. A flashing strip is mounted around a perimeter area of the sheathing and the protective sheet is mounted at a perimeter of such sheet onto an inner perimeter of the flashing strip. The flashing strip is set back from a perimeter edge of the sheathing, leaving bare a sufficiently sized topside perimeter area adjacent the perimeter edge of the sheathing, i.e. for accommodating shingle integration in the installation process on a roof. 
     During installation on a roof, after the intermediate roof solar panel has been secured to trusses, a preferably single shingle layer (preferably a shingle strip prepared from a shingle by cutting away a show surface of the shingle) is secured around the top and sides of the aforementioned topside perimeter area of the sheathing, i.e. on said topside perimeter area adjacent the perimeter edge of the sheathing. The shingle layer is also sized so that it overlaps onto adjacent regular roof sheathing. Along the lower side of the roof solar panel, shingles are installed so that their upper edges butt up against the outside (i.e. lower) edge of the flashing strip, subject to cutting them preferably so as to avoid overlap of the shingle strips at the sides of the roof solar panel near and at the bottom thereof. Sealer (e.g. silicone) is applied over the shingle strips along the sides and top of the roof solar panel, the upper ends of the regular shingles along the bottom of the roof solar panel, and the flashing strip outside where the protective sheet is mounted, after which the retainer trim is then mounted. The retainer trim has a suitable shape for such mounting and also for sealing onto the topside of the protective sheet (discussed further, below, and as shown in a preferred embodiment in the figures), over where the protective sheet is mounted onto the flashing strip. After installation of the retainer trim, conventional shingling of the roof to points abutting the retainer trim at the sides and top, and under the shingle along the bottom of the roof solar panel is performed. 
     It is noted that the inventive solar roof panel has the advantage of allowing a solar panel to be quickly and easily installed on a conventional existing roof, or on a new roof construction without the usual time consuming aspects of adapting a solar panel for installation over existing conventional roof panels and shingles. Also, use of familiar existing materials requires less training, skill and cost for installation compared to other systems and is less costly to manufacture (particularly as the preferred sheathing is a typical material used for roofing work with the addition of a non-flammable material for the cell array). 
     The present invention further does not require mounting brackets and is integrated with the shingles so as to provide a low profile on the roof (see  FIG. 1 ). Thus, this provides superior water shedding and is less affected by wind compared to higher or more complex profiles. This further provides a more aesthetically pleasing appearance. 
     Further, by using, in the preferred configuration, conventional (non-flammable) roof sheathing as the base for the roof solar panel, significant weight reductions are achieved compared to prior art systems and solar panels, thereby avoiding any need to apply reinforcing structures to the trusses. 
     The preferred use of urethane as an adhesive allows for a more flexible control over expansion and contraction between the construction materials in the roof solar panel. The intermediate roof solar panel, its installation on a roof and the installed roof solar panel will now be described with reference to the Figures. 
       FIG. 1  illustrates the inventive roof solar panel installed on a roof. The perspective view of  FIG. 1  conveys the low profile of the roof solar panel as well as its integration into the surrounding conventional shingles. While this illustrates a single roof solar panel so installed, two or more inventive roof solar panels may be installed on the roof either separated from or, more preferably, abutting each other. 
       FIGS. 2 and 2   a  illustrate the layers and components of the inventive roof solar panel when installed on a roof. Conventional sheathing  8  and the inventive roof solar panel  9  are shown mounted on roof trusses I using adhesive, such as silicone, at locations “A”, Sheathing  2  (e.g. ⅜″ thick plywood with non-flammable coating, or a substitute non-flammable board known in the art) of roof solar panel  9  has photovoltaic cell array  3  (having silicon photovoltaic cells and tag wires) mounted on the upper surface of the sheathing  2 . Preferably, such array is triple sealed to the sheathing using urethane and silicone sealer, Wiring of the array may be led through an opening (not shown) through the sheathing to the area under the roof. Rigid transparent protective sheet  4  (e.g. low iron glass, 3mm (0.118 inches) to 4mm (0.157 inches) thick, depending on the size of the solar panel) is mounted over the array  3  at mounting locations  10 . Flashing strips  7  are mounted on the sheathing  2 , e.g. using silicone sealant and/or fasteners such as screw  11 , at a distance set back from the perimeter edge of the sheathing  2   a , preferably such distance being from about 5 to about 30mm (0.197 to 1.181inches), more preferably from about 5 to about 15 mm (0.197 to 0.591 inches) (such preferences depending on preferred dimensions selected for retainer trim  5  and flashing strip  7 ). The flashing strips  7  provide a base for mounting of said sheet  4  at locations  10 . Mounting adhesive  12  preferably is urethane, and sealant  13  preferably is silicone. Shingle strips  6 , which preferably are cut from conventional shingles, are mounted during installation of the intermediate roof solar panel on the roof, preferably in a single layer on the sides and top of the roof solar panel and over the abutting areas of sheathing  8  and  2 . Regular shingles  16  are shown schematically, butting up to the edge of retainer trim  5 . Along the sides and top of the roof solar panel, retainer trim  5  is mounted (during installation of the intermediate roof solar panel on the roof), on the shingle strips  6  and adjacent flashing strips at mounting base  5   a . Along the bottom area of the roof solar panel, retainer trim  5  is mounted (also during such installation on the roof) on a roof shingle and adjacent flashing strip (see  FIG. 8   a ). Preferably, retainer trim  5  is so mounted using sealing adhesive, preferably silicone. Also preferably, the retainer trim  5  has fastener openings for installing fasteners, preferably screws, through the retainer trim  5 , the underlying flashing strip  7  and sheathing  2  and into the truss  1  (as in  FIG. 2   a ), Preferably sealer (“S”) is applied where shown. 
     In  FIG. 3  there is shown in cross section across abutting sides, a preferred configuration of a pair of adjacent roof solar panels according to the present invention. Thus, instead of a shingle strip  6  covering the joint  14  between the abutting panels (as in  FIGS. 2 and 2   a ), there is a resilient strip  15 , preferably water impermeable and preferably made of rubber, mounted over and along the length of such joint with adhesive sealant. The retainer trim  5  is mounted, when the abutting roof solar panels are being installed on the roof, over such resilient strip  15  (as well as the flashing strip  7  as described above). 
       FIG. 4  shows a preferred configuration of the retainer trim  5  for use in the roof solar panel of the present invention. Preferably such retainer trim  5  is made of aluminum. The retainer trim  5  is shown having retainer lip  20  (e.g. 1.5 mm (0.059 inches) wide), adapted for sealing engagement With a top perimeter area of the protective sheet  4  at position  10  ( FIGS. 2 and 2   a ). The retainer trim  5  also has mounting base  5   a , configured preferably with flange  22  (e.g. 2mm (0.079 inches) wide) for securing engagement with shingle strip  6  or resilient strip  15 . Preferably the mounting base  5 a is about 20 mm (0.787inches) wide of the total preferred width of the retainer trim (30 mm (1.181 inches)), and preferably the retainer trim is 10 mm (0.394 inches) high. 
       FIG. 5  shows a preferred configuration of the flashing strip  7 , which strip is preferably made of aluminum with longitudinal troughs on its underside sheathing-mounting surface and is preferably about 34 mm (1.339 inches) wide and 2 mm (0.079 inches) high. FIG.  6  is a preferred configuration of the resilient strip  6 , preferably of made of rubber and about 15mm (0.591 inches) wide, 2 mm (0.079 inches) high. 
     The inventive method of installation of the subject roof solar panel on a roof is illustrated in  FIG. 7 . While this illustrates the mounting of three abutting roof solar panels, the process for mounting a single roof solar panel is similar, as will be indicated in the following discussion when appropriate. 
     Thus, in step  1 , the planned configuration of three roof solar panels is shown on a roof section in which the vertical lines represent trusses, a peak of the roof is at the top and bottom edge of the roof is at the bottom. The location of the bottom edge of the roof solar panels between the top and bottom of the roof section is preferably at a distance above the bottom edge of the roof section which is approximately a whole multiple of the height (distance from lower to upper edges) of the finished showing surface of a shingle for the roof This is to provide for a full shingle showing surface in the first row of shingles abutting the lower edge of the retainer trim  5  along the bottom of the roof solar panel. In Step  2 , a border for the roof solar panels is marked, as illustrated, on the trusses to ensure correct positioning of the panels to be mounted, In Step  3 , regular roof sheathing is mounted onto the trusses, around the marked opening for the roof solar panels. In Step  4 , preferred application of 4 mm (0.157 inches) × 4 mm (0,157 inches) silicon silicone adhesive bead to tops of trusses that will be under intermediate areas of the first roof solar panel to be installed is shown. in Steps  5  and  6 , mounting of the first solar panel is shown, using regular roof sheathing spacers. Preferably, a screw is installed in each of the four corners of the roof solar panel into the underlying roof trusses, further preferably providing each of such holes with a tapered opening for the screw head, Steps  4 - 6  are repeated to install the other two roof solar panels. In Step  7 , which shows the other two panels also mounted in position, a resilient strip ( 15  in  FIG. 3 ), preferably of rubber, is mounted along the join between abutting roof solar panels. (This is not applicable to when a single roof solar panel is being installed no such resilient strip is needed in the latter ease.) Preferably, the resilient strip  15  is mounted over silicone sealant applied between the respective edges of adjacent roof solar panels, Also preferably, such resilient strip  15  at an upper end extends about from 12 to 30 cm (4.724to 11.81 inches), most preferably 20 cm (7.87 inches) beyond the upper end of the join between the adjacent roof solar panels onto adjacent roof sheathing, and at a lower end is about 8 cm (3.15 inches) shorter than the lower end of such join (for a shingle to butt against such lower end). 
     In Step  10 , regular shingles are shown installed from the bottom edge of the roof up to the bottom edge of the flashing strip  7  (best shown in  FIGS. 8 and 8   a ), with short extensions between the adjoining roof solar panels so as to butt up against the lower edges of the resilient strips  15 . In preparation for installation of the retainer trim  5 , preferably silicone sealant is applied around the perimeter areas of all the solar panels, i.e. over the shingle strips  6 , the flashing strips  7 , the resilient strips  15  and the shingles at the bottom adjacent the flashing strip. Also, preferably roof sealer is applied to all butt joints out 2 inches from the solar panel. In Step  11 , the retainer trim is mounted in position over the flashing trim  7 , shingles and, for multiple solar panel installation, resilient strip  15 . Fasteners, preferably screws and silicone sealer, are then installed through the retainer trim  5 , flashing strip  7  and sheathing  2 , into the underlying truss  1 . Finally, shingling of the roof is performed in which conventional shingles butt up against the retainer strip. 
     In Step  10 , regular shingles are shown installed from the bottom edge of the roof up to the bottom edge of the flashing strip  7  (best shown in  FIGS. 8 and 8   a ), with short extensions between the adjoining roof solar panels so as to butt up against the lower edges of the resilient strips  15 . In preparation for installation of the retainer trim  5 , preferably silicon sealant is applied around the perimeter areas of all the solar panels, i.e. over the shingle strips  6 , the flashing strips  7 , the resilient strips  15  and the shingles at the bottom adjacent the flashing strip. Also, preferably roof sealer is applied to all butt joints out 2 inches from the solar panel. In Step  11 , the retainer trim is mounted in position over the flashing trim  7 , shingles and, for multiple solar panel installation, resilient strip  15 . Fasteners, preferably screws and silicon sealer, are then installed through the retainer trim  5 , flashing strip  7  and sheathing  2 , into the underlying truss  1 . Finally, shingling of the roof is performed in which conventional shingles butt up against the retainer strip. 
       FIG. 8  shows a preferred shingle integration along the lower edge area of a pair of abutting roof solar panels. A normal shingling process is used from the lower edge of the roof  25  upwards to the lower edge of the solar panels  26 , the latter which has been preferably pre-arranged to be located from the former at a distance which is an increment of 6 1/2 ′ from the former. The lower end of the resilient strip  15 , preferably is about 8 mm (0.315 inches) above the lower end  26  of the solar panels. The shingle below said lower end of the resilient strip  15  can be seen between the solar panels where it butts up against said end  15 . In  FIG. 8   a  (Which is a schematic representation, not to scale) the lower area of  FIG. 8  is shown in cross-section but with the retainer trim  5  in position. The top-most, partial shingle strip  30  has been cut to butt against the lower edge of the flashing strip  7 , beneath the retainer trim  5 . The first and second shingles from the roof edge  25  are also shown. 
     In a preferred commercial embodiment of the invention, the roof solar panel is prepared to a pre-installation condition without the retainer strip. This is because, as may be appreciated from the foregoing description of the installation method, the retainer trim can only be installed once the shingle strips  6 , and resilient strips  15  if applicable (i.e. for multiple panel installations) have been installed over the abutting edges of the panel and adjacent sheathing. Thus, such pre-installation condition of the subject roof solar panel comprises an important intermediate product that may be sold as such, preferably in kit form with pieces of retainer trim, for later installation on a roof in combination with the retainer trim. 
     While the foregoing describes most preferred embodiments of the subject invention, a person skilled in the art will appreciate that variations of such embodiments will be feasible and still be within the scope of the teachings herein. Thus, the substitution of different materials (e.g. metals, plastic, adhesives etc.) for those specifically indicated may be expected to occur to such person, and variations in shapes and configurations of the different components involved may be made while sustaining the functions of components actually shown herein, such all being within the intended scope of the present invention.