Abstract:
A photovoltaic shingle having a photovoltaic assembly with a photovoltaic cell or cells. The substrate has an outward face and an inward face and a profile having a plurality of traverse parallel ridges with each ridge separated from the next ridge by a traverse parallel trough. The substrate facilitates vertical and horizontal nesting and alignment. The photovoltaic cell substantially spans the outward face except for a portion thereof that is intended to be overlapped by another similar shingle. The substrate can have two tiers or more, each tier being separated by an integral riser that creates the appearance of two rows or more of shingles. The substrate can be produced from recyclable plastic. The shingles have a translucent color enhancing means for imparting an uniform color and can be produced in many colors and shapes. The shingle is attached directly to a building or roof structure without an intermediary support or framing structure therebetween.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention is directed to the conversion of solar radiation directly into electrical power by photovoltaic methods. 
         [0003]    2. Related Background Art 
         [0004]    In view of the increased cost of petroleum derived fuels and the pollution produced by the combustion of such fuels and other carbon containing fuels, and the incentives provided by governments for clean sources of energy, the direct conversion of solar radiation into electric power is both desirable and needed. 
         [0005]    The industry has recognized that since the roofs of buildings usually receive unobstructed solar radiation that roofs are a good location for installing photovoltaic devices. 
         [0006]    U.S. Pat. No. 6,541,693 discloses a solar cell module having a finished form with a reinforcing sheet that is initially flat but then shaped into a slightly corrugated configuration as shown in  FIGS. 8A and 8B . The reinforcing sheet is worked by bending, without regard to whether or not the photovoltaic device cell block lay there, to form a slightly corrugated configuration having a top flange and a bottom flange. The flanges are apparently for connection to a frame or a support structure. 
         [0007]    Another slightly corrugated roofing material integral type solar cell module is shown in  FIG. 11 . This solar cell module has side flanges that are also apparently for connection to a frame or a support structure. 
         [0008]    Another solar cell module characterized in that it has been bent to form a hill and a valley is shown in  FIGS. 10A and 10B . The solar cell module has a top flange and a bottom flange that are apparently for connection to a frame or a support structure. 
         [0009]    US Pub. No. 2008/0098672 discloses solar panels that substantially conform to curved surfaces, including S-shaped and M-shaped panels. Some of the solar panels are shown to cover only a portion of the roofing tile. Some of the solar panels are shown on only a few of the roofing tiles on the roof. Vinyl and foam modules can be encapsulated in UV stabilized polymers and bonded and stitched to a cushioned backing material. Other curved surface tiles have a solar panel that covers about half of the tile&#39;s convex surface and none of the tile&#39;s concave surfaces are shown in  FIGS. 7-9 . 
         [0010]    U.S. Pub. No. 2008/0135094 discloses a thin film solar cell or photovoltaic roof tile in  FIG. 7  having a curved or Spanish style-like shape with a thin film solar cell on its curved convex surface. Only a portion of the tile surface is covered by the solar cell. The tiles may have a plurality of fins that depend from the underside of the tile that function as a heat sink to remove heat absorbed by the photovoltaic cell that is not converted to electricity. 
         [0011]    U.S. Pat. No. 5,575,861 discloses an arcuate photovoltaic shingle system having a substrate with a series of independent and spaced apart photovoltaic cells separated by gaps and arranged on the lower half of a single strip of roofing material in  FIGS. 8-15 . 
         [0012]    U.S. Pat. No. 4,946,512 discloses a solar energy collector device that simultaneously produces electrical and thermal energy.  FIGS. 6 and 7  show an arcuate or Spanish style-like shaped tile assembly mounted on a roof. Each individual tile  10   a  is produced from metal hot melt and granular or fibrous mix into a block as seen. A solar energy battery rimmed with a plastic heat insulator is affixed to each tile. 
         [0013]    WIPO Pub. No. WO/2007/013115 discloses a tile roof covering system that absorbs and/or converts solar energy striking a shingled roof. A first embodiment shown in  FIGS. 1-4  and  6 , comprises arcuate roofing tiles having a hollow semicircular portion through which is circulated a diathermy or heat transfer fluid. The fluid is circulated to a boiler or heat exchanger which transfer heat to another fluid that is pumped into other means for heating the house below the roof. 
         [0014]    A second embodiment shown in  FIG. 5 , comprises a plurality of spaced apart flat photovoltaic cells arranged on the outer flat surfaces of a semidecagonal tile. 
         [0015]    U.S. Pat. No. 5,651,226 discloses tile modules having more than one tile S-shape unit vertically per shingle as shown in  FIG. 4A , or more than one tile S-shape unit horizontally per shingle as shown in  FIG. 4B . Various designs for interlocking the tiles also are disclosed. The tile modules, together with the underlying surface, form an airspace therebetween such that a plurality of interfitting tiles installed upon the surface will form ducts that can conduct a fluid, such as air, heated by the absorbed solar energy to a location at which it can be dissipated. 
         [0016]    U.S. D396,118 discloses the design of a tile roofing sheet having more than one S-shape portion horizontally per roofing sheet. 
         [0017]    U.S. D374,095 and U.S. D273,233 show designs of arcuate roofing tiles. 
         [0018]    U.S. D285,829 shows a design of a solar tile for heating of a flow through heat transfer fluid. 
         [0019]    U.S. Pat. No. 6,875,914 discloses a photovoltaic roofing system based upon the use of a plurality of pairs of photovoltaic shingle materials that are configured to allow front surface connection and which do not require penetration of a roof deck. 
         [0020]    US Pub. No. 2008/0053519 discloses various thin flexible photovoltaic cells that are integrated with residential structures comprising roofing tiles, a substrate, a back electrical contact layer, a semiconductor p-n junction, and a conductive grid line. The photovoltaic cells are encapsulated, and chemically inert and UV resistant. 
         [0021]    US Pub. No. 2007/0089780 mentions physical vapor deposition (PVD) methods and chemical vapor depositions (CVD) methods and materials in the production of solar cells. 
         [0022]    U.S. Pat. No. 4,359,043 discloses a roofing member for transferring solar energy to a heat-carrying fluid within a M-shaped tile. 
         [0023]    U.S. Pat. No. 4,299,201 discloses a highly efficient solar focusing means for focusing solar rays onto a pipe containing a heat transfer fluid. Focusing means in a semicylindrical or arcuate shape are said to have the appearance of a Spanish-style roof. Instead of a pipe containing a heat transfer fluid, the upper surface of such pipes may have semiconductors converting solar rays to electricity. 
         [0024]    US Pub. No. 2005/0279400 disclose electric tile modules having both a photovoltaic element and a thermovoltaic element for generating electrical power and a diagram for electrically connecting the tile modules. 
         [0025]    US Pub. No. 2006/0225778 discloses a photovoltaic module having two different photovoltaic materials specifically for absorption of two different wavelengths. 
         [0026]    Arcuate roofing tiles designs are disclosed in U.S. design patents D574,493 for a S-shaped roofing tile, and D479,885 and D458,392 for arcuate roofing tiles with cloaked vent. 
       SUMMARY OF THE INVENTION 
       [0027]    While the roofs of industrial buildings have been used for many solar energy devices, it would be desirable for such solar devices to be cheaper to manufacture and install, more efficient in the conversion to electrical energy and the transmission of the electricity, to be more durable, and to be aesthetically pleasing so that such solar devices would be acceptable on residential homes without the need for shielding such devices from view. 
         [0028]    It would also be desirable if such solar devices would be made from, at least in part, recyclable materials. It would be desirable too for a shingle to be made largely of plastic so that it would weigh less thereby allowing a single shingle to be larger and cover more area on a roof. 
         [0029]    The larger shingle can be made to appear to contain more than one row of shingles, and/or more than one column of shingles. Such a shingle would take less time to install than smaller shingles and would reduce installation cost. 
         [0030]    This invention seeks to provide such solar devices with at least some of these desired characteristics that can be produced in a variety of styles, shapes and colors for residential as well as industrial use. 
         [0031]    In this invention, a photovoltaic shingle having a photovoltaic assembly with a photovoltaic cell or cells, is affixed to and conformed to a substrate. The substrate has an outward face and an inward face and a profile having a plurality of traverse parallel ridges with each ridge separated from the next ridge by a traverse parallel trough. The ridges and troughs extend the width of the substrate from the bottom end to the top end thereof. The substrate facilitates vertical and horizontal nesting and alignment. 
         [0032]    In one embodiment of this invention, the photovoltaic cell spans the outward face except for a portion thereof that is intended to be overlapped by another similar shingle, and except for a narrow peripheral band around a peripheral area that is not overlapped by another similar shingle. In a further embodiment the narrow peripheral band is no greater than about one inch (25 mm) in width. In a still further embodiment the narrow peripheral band is about 0.5 inches (13 mm) in width. 
         [0033]    In another embodiment of this invention, the shingles can have a transparent or translucent color enhancing means that imparts an uniform color to substantially the entire exposed portions of the shingles when installed on a roof. 
         [0034]    The traverse parallel ridges and troughs of the substrate can be semicylindrical or semiconical or any other repetitive pattern having ridges and troughs. The traverse parallel ridges and troughs can comprise berms or rims for enabling a snug overlap of the shingles. 
         [0035]    In yet another embodiment of this invention, the substrate can have two tiers or more, each separated by an integral riser that creates the appearance of two rows or more of shingles. 
         [0036]    The substrate can be produced from recyclable plastic to reduce shingle weight or permit larger shingles for a given weight while reducing the amount of discarded plastic material sent to dump sites. 
         [0037]    The shingles of this invention can be produced in many colors and shapes thereby allowing extensive architectural creativity. 
         [0038]    The shingles of this invention can be installed on a building structure or roof structure by merely inserting fasteners, e.g. screws, nails or bolts, through fastener receiving means, e.g. apertures, in the substrate near the top end thereof to attach the shingle directly to a building structure or roof structure without a support or framing structure for spacing the shingle above and away from the roof structure except for an optional intermediate layer comprising a moisture barrier material, or a thermal insulation material, or a thermal insulation/moisture barrier material. 
         [0039]    In one embodiment the substrate is free of means for attaching the photovoltaic shingle to a support or framing structure for spacing the shingle away from the building structure except for an optional intermediate layer comprising a moisture barrier material, or a thermal insulation material, or a thermal insulation/moisture barrier material. 
         [0040]    In one embodiment the optional intermediate layer is no greater than about 0.6 inches (15 mm) and usually will be no greater than about 0.1 inches (3 mm). 
         [0041]    In another embodiment the photovoltaic cell is a thin film photovoltaic cell. In still another embodiment the photovoltaic cell is a cadmium-telluride photovoltaic cell. In yet another embodiment the photovoltaic cell is a thin film cadmium-telluride photovoltaic cell. In a further embodiment the cadmium-telluride photovoltaic cell comprises carbon nanostructures for enhancing electrical conductivity. In still a further embodiment the carbon nanostructures are carbon nanotubes. 
         [0042]    In one embodiment the photovoltaic cell covers at least about 85% of the lower area of the outward face of the substrate that is not intended to be overlapped by a photovoltaic cell of another shingle having the same profile. In a further embodiment the photovoltaic cell covers at least about 90% of the lower area of the outward face of the substrate that is not intended to be overlapped by a photovoltaic cell of another shingle having the same profile. In a still further embodiment the photovoltaic cell covers at least about 95% of the lower area of the outward face of the substrate that is not intended to be overlapped by a photovoltaic cell of another shingle having the same profile. In another embodiment the photovoltaic cell covers approximately all of the lower area of the outward face of the substrate that is not intended to be overlapped by another shingle. 
         [0043]    In one embodiment the lower area of the outward face is at least about 67% of the outward area. In a further embodiment the lower area of the outward face is at least about 75% of the outward area. In a still further embodiment the lower area of the outward face is at least about 85% of the outward area. 
         [0044]    In one embodiment the photovoltaic cell assembly further comprises a plurality of tiered photovoltaic cell assemblies oriented parallel to the bottom end of the substrate, and wherein each tiered photovoltaic cell assembly has a photovoltaic cell. 
         [0045]    In one embodiment the photovoltaic shingle further comprises means for removing electrical energy produced by the photovoltaic cell assembly. 
         [0046]    In one embodiment the photovoltaic cell assembly comprises anode means and cathode means for removing electrical energy from, and produced by, the photovoltaic shingle. In a further embodiment, when the photovoltaic shingle is attached to a structure, the anode means and the cathode means can not be seen from the outside because of the color enhancing layer or layers in the thin film photovoltaic cells and/or the encapsulating layer. In a further embodiment the photovoltaic shingle comprises electrical connectors for connecting to the anode means and cathode means and for transmitting the electrical energy therefrom to an DC-to-AC inverter. 
         [0047]    In another embodiment, when the photovoltaic shingle is attached to a building structure or roof structure, the anode means and the cathode means and the electrical connectors can not be seen from the outside. 
         [0048]    In one embodiment of this invention the photovoltaic shingle the substrate has first interlocking mechanical coupling means proximate the left end of the substrate and second interlocking mechanical coupling means proximate the right end of the substrate. The first interlocking mechanical coupling means can be coupled to second interlocking mechanical coupling means of another substrate having the shape and profile. The second interlocking mechanical coupling means can be coupled to the first interlocking mechanical coupling means of another substrate having the same shape and profile. In a further embodiment the electrical connectors have first electrical coupling means proximate the left end of the substrate and second electrical coupling means proximate the right end of the substrate. The first electrical coupling means can be coupled to second electrical coupling means of another substrate having the same shape and profile, and wherein the second electrical coupling means can be coupled to first electrical coupling means of another substrate having the same shape and profile. 
         [0049]    In a still further embodiment the first electrical coupling means is embedded in the first interlocking mechanical coupling means, and the second electrical coupling means is embedded in the second interlocking mechanical coupling means. 
         [0050]    In one embodiment the photovoltaic cell assembly comprises encapsulating means for sealing the photovoltaic cell on and to the substrate so that, when the photovoltaic shingle is attached to the structure, rain will be prevented from penetrating the photovoltaic cell assembly and damaging the photovoltaic cell. 
         [0051]    In one embodiment the substrate is plastic. In a further embodiment the substrate is formed from a formulation comprising recycled plastic. In another embodiment the substrate is metal. 
         [0052]    In a further embodiment, wherein when the photovoltaic shingle is installed on a surface of a building structure or a roof structure that requires a plurality of rows of the photovoltaic shingle to completely cover the structure, the surface can be at least about 85% covered by the photovoltaic cells of the photovoltaic assemblies except for an area of the surface directly under the upper area of the outward face of the last row of photovoltaic shingles, and the end of the last shingle in each of the rows. 
         [0053]    In another embodiment the substrate comprises an integral riser between a lower tier and an upper tier and the photovoltaic assembly comprises a first photovoltaic cell assembly and a second photovoltaic assembly. 
         [0054]    The first photovoltaic assembly is affixed to, and conformed to, the outward face of the lower tier of the substrate and comprises a first photovoltaic cell that spans at least the lower tier except for a portion thereof that is intended to be overlapped by another shingle, and except for a narrow peripheral band around a periphery of the lower tier of the substrate. 
         [0055]    The second photovoltaic cell assembly is affixed to, and conformed to, the outward face of the upper tier of the substrate and comprises a second photovoltaic cell that spans at least the upper tier except for a portion thereof that is intended to be overlapped by another shingle, and except for a narrow peripheral band around a periphery of the upper tier of the substrate. 
         [0056]    In a further embodiment the narrow peripheral bands in both the lower and upper tiers are no greater than about one inch (25 mm) in width around a periphery of the lower tier of the substrate. In a still further embodiment the narrow peripheral bands are about 0.5 inches (13 mm) in width. 
         [0057]    In a further embodiment the integral riser further comprises offset means for maintaining side-to-side horizontal alignment of the integral risers. 
         [0058]    In one embodiment the substrate has two tiers and two ridges and two troughs. In another embodiment the substrate has at least two tiers, and at least two ridges and at least two troughs. In still another embodiment the substrate has two tiers and about five ridges and about four troughs. In yet another embodiment the substrate has two tiers and about twenty ridges and about nineteen troughs. In another embodiment the substrate has three tiers and about three ridges and about two troughs. Various other shingles featuring other combinations of number of tiers, number of ridges, and number of troughs can be made using the principles of this invention. In this manner shingles as large as about 4 feet (120 cm) by 8 feet (250 cm) can be made. 
         [0059]    This invention also includes a method of producing a photovoltaic shingle from a selection of customized colors. The method comprises producing a substrate having a Spanish tile-like shape with a plurality of ridges and troughs and a repetitive profile from a plastic composition. 
         [0060]    A first metal conductor member is formed on the lower area of the substrate so that the first metal conductor member conforms to and is affixed to the substrate. A first color-imparting member is formed over the first metal conductor member so that the first color-imparting member conforms to and is affixed to the first metal conductor member. 
         [0061]    A first member having a first semiconductor composition is formed over the first color-imparting member so that the first semiconductor composition conforms to and is affixed to the first color-imparting member. 
         [0062]    A second metal conductor member is formed over the first semiconductor composition so that the second metal conductor member conforms to and is affixed to the first semiconductor composition. 
         [0063]    A second member having a second semiconductor composition is formed over the second metal conductor member so that the second semiconductor composition conforms to and is affixed to the second metal conductor member, thereby producing a photovoltaic cell. 
         [0064]    A second member having a second color-imparting composition is formed over the second semiconductor composition so that the second color-imparting composition conforms to and is affixed to the second semiconductor composition. 
         [0065]    The method further comprises forming a translucent encapsulating or sealer member over the second member of a second color-imparting composition so that the sealer member conforms to and is affixed to the second color-imparting composition, thereby producing the photovoltaic shingle of a particular selected customized color. The translucent sealer member being effective for preventing the photovoltaic cell from being damaged by rain. 
         [0066]    In another embodiment the method further comprises preparing a mold for producing the substrate with the Spanish tile-like shape. Then producing the substrate from the plastic composition using the mold, and removing the substrate produced from the mold and using the plastic substrate for producing the photovoltaic shingle. 
         [0067]    In a further embodiment the plastic composition used to produce the substrate is a recycled plastic. 
         [0068]    In one embodiment the first metal conductor member can be in the configuration of a thin grid or a thin film with a thickness between about 4 mils and about 6 mils. 
         [0069]    In one embodiment the first member of color-imparting composition is a thin translucent film with a thickness between about 0.5 mils and about 1.5 mils. 
         [0070]    In one embodiment the first member of semiconductor composition is a film with a thickness between about 50 nm and about 20,000 nm. The unit “nm” means a nanometer. 
         [0071]    In one embodiment the second metal conductor member is a thin grid or a thin with a thickness between about 4 mils and about 6 mils. 
         [0072]    In one embodiment the second member of semiconductor composition is a film with a thickness between about 50 nm and about 20,000 nm 
         [0073]    In one embodiment the second member of a color-imparting composition is a film with a thickness between about 1.5 mils and about 3 mils. 
         [0074]    In one embodiment the translucent sealer member is a film with a thickness between about 15 mils and about 25 mils. 
         [0075]    In one embodiment the composition of the first semiconductor member comprises carbon nanostructures for enhancing electrical conductivity. 
         [0076]    In one embodiment the composition of the second semiconductor member comprises carbon nanostructures for enhancing electrical conductivity. 
         [0077]    In one embodiment the substrate is plastic and has a thickness between about 0.20 inches and about 0.40 inches. 
         [0078]    Plastic forming materials that can be used to produce the plastic substrate by molding processes are molding materials. Examples of molding materials are polypropylenes, polyvinyl chlorides or PVC&#39;s, and acrolonitrile butadiene styrene or ABS. Examples of molding processes useful for the substrate are injection molding, thermoset molding, vacuum molding, pressure molding and stamping. 
         [0079]    Various deposition processes can be used to produce one or more of the layers in the thin film photovoltaic cells including chemical deposition and vapor deposition processes. 
         [0080]    Various compositions of photovoltaic cells that can also be used. For example the following photovoltaic cells can be used in this invention are organic polymers with nano structures, cadmium/telluride, copper, indium, gallium, diselenide or CIGS, amorphorous silicon, and silicon. These products are sold by Konarka, First Solar, Nano Solar and Uni Solar. Konarka&#39;s thin film photovoltaic cell is a polythiaphene-fullerene hetrajunction polymer with an epoxy functionalized fullerene C60 fixer having poly cyclopental dithiaphene alt benzothiadiazole (PCPDTBT) with PCBM pheynel butyric acid me ester fullerene derivative, which are organic polymer photovoltaic cells. The metal conductors are silver. 
         [0081]    The method of producing the photovoltaic shingles of this invention include continuous line operations where the substrates are produced, then conveyed to the photovoltaic cell application operation, then to photovoltaic cell encapsulation operation, then to the electrical completion operation, and then to packaging for shipment to vendors. 
         [0082]    Some manufacturing methods for producing the photovoltaic shingles are (1) injection molding the substrate, laminating the photovoltaic assembly using an adhesive from 3M®, and sealing with a polymer, an acrylic or Teflon® protective layer, (2) embedding the photovoltaic assembly into the injection molded substrate, and (3) injection molding the substrate, direct deposition of the photovoltaic assembly, and sealing with a polymer, an acrylic or Teflon® protective layer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0083]      FIG. 1  is a perspective view of a first embodiment of a single tier substrate with ridges for side to side substrate overlapping. 
           [0084]      FIG. 2  is a plan view of the outward face of the substrate in  FIG. 1 . 
           [0085]      FIG. 3  is a plan view of the inward face of the substrate in  FIG. 1 . 
           [0086]      FIG. 4  is a cross-sectional view of the substrate in the direction of arrows  4  of  FIG. 2 . 
           [0087]      FIG. 5  is a cross-sectional view of the substrate in the direction of arrows  5  of  FIG. 2 . 
           [0088]      FIG. 6  is an end view in the direction of arrows  6  of  FIG. 1 . 
           [0089]      FIG. 7  is a profile of the lower edge of the substrate of  FIG. 1 . 
           [0090]      FIG. 8  is an end view of a second embodiment of a substrate of  FIG. 1  but with integral bird stops. 
           [0091]      FIG. 9  is a perspective view of a first embodiment of a shingle of  FIG. 1  with three ridges having exposed photovoltaic cells. 
           [0092]      FIG. 10  is a plan view of the outward face of the shingle in  FIG. 9 . 
           [0093]      FIG. 11  is a cross-sectional view of the shingle in the direction of arrows  12  in  FIG. 10 . 
           [0094]      FIG. 12  is a cross-sectional view of shingle in the direction of arrows  13  in  FIG. 10 . 
           [0095]      FIG. 13  is an end view of shingle in the direction of arrows  13  in  FIG. 9 . 
           [0096]      FIG. 14  is a profile of the lower edge of the shingle of  FIG. 9 . 
           [0097]      FIG. 15  is an end view of a second embodiment of a shingle with integral bird stops. 
           [0098]      FIG. 16  is a perspective view of a third embodiment of a two tier substrate with ridges for side-to-side substrate overlapping. 
           [0099]      FIG. 17  is a plan view of the outward face of the substrate in  FIG. 16 . 
           [0100]      FIG. 18  is a plan view of the inward face of the substrate in  FIG. 17 . 
           [0101]      FIG. 19  is a cross-sectional view of the substrate in the direction of arrows  19  of  FIG. 17 . 
           [0102]      FIG. 20  is a cross-sectional view of the substrate in the direction of arrows  20  in  FIG. 17 . 
           [0103]      FIG. 21  is an end view of the substrate in the direction of arrows  21  in  FIG. 16 . 
           [0104]      FIG. 22  is a profile of the lower edge of the substrate of  FIG. 17 . 
           [0105]      FIG. 23  is an end view of a fourth embodiment of a substrate with integral bird stops. 
           [0106]      FIG. 24  is a perspective view of a third embodiment of a two tier shingle with three ridges having exposed photovoltaic cells. 
           [0107]      FIG. 25  is a plan view of the outward face of the shingle in  FIG. 25 . 
           [0108]      FIG. 26  is a cross-sectional view of the shingle in the direction of arrows  26  in  FIG. 25 . 
           [0109]      FIG. 27  is a cross-sectional view of the shingle in the direction of arrows  27  in  FIG. 25 . 
           [0110]      FIG. 27A  is an enlarged detail of area  27 A in  FIG. 29 . 
           [0111]      FIG. 27B  is an enlarged detail of area  27 B in  FIG. 29 . 
           [0112]      FIG. 27C  is an enlarged detail of area  27 C in  FIG. 29 . 
           [0113]      FIG. 28  is an end view of shingle in the direction of arrows  28  in  FIG. 24 . 
           [0114]      FIG. 29  is a profile of the lower edge of the shingle of  FIG. 24 . 
           [0115]      FIG. 30  is an end view of a fourth embodiment of a substrate with integral bird stops. 
           [0116]      FIG. 31  is a perspective view of a fifth embodiment of a shingle with two tiers and three ridges having exposed photovoltaic cells. 
           [0117]      FIG. 32  is a perspective view of a sixth embodiment of a single tier shingle with a smaller radius of curvature for its troughs and with three of the four ridges having exposed photovoltaic cells. 
           [0118]      FIG. 33  is a profile of the lower edge of the shingle of  FIG. 32 . 
           [0119]      FIG. 34  is a perspective view of a seventh embodiment of a shingle with flat troughs. 
           [0120]      FIG. 35  is a profile of the lower edge of the shingle of  FIG. 34 . 
           [0121]      FIG. 36  is a perspective view of an eighth embodiment of a shingle with flat troughs and two tiers. 
           [0122]      FIG. 37  is a profile of the lower edge of the shingle of  FIG. 36 . 
           [0123]      FIG. 38  is a detail of side-to-side overlapping substrates. 
           [0124]      FIG. 39  is a detail of side-to-side interlocking substrates. 
           [0125]      FIG. 40  is a prospective detail of the  FIG. 39 . 
           [0126]      FIG. 41  is a photovoltaic assembly layers. 
           [0127]      FIG. 42  is a simple photovoltaic cell with a basic number of layers. 
           [0128]      FIG. 43  is a detail of an electrical jack for photovoltaic shingle. 
           [0129]      FIG. 44  is a schematic for electrical connection of an array of shingles to an electric grid. 
           [0130]      FIG. 45  is an array of the shingles like those of  FIG. 9  on a roof structure. 
           [0131]      FIG. 46  is an array of the shingles having two tiers like those of  FIG. 24  on a roof structure. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0132]    In the several embodiments of this invention that will now be described the last two digits usually refer to elements with a similar function or characteristic, e.g. element nos.  11 ,  111 ,  211 ,  311 ,  411  and  511  are substrates, and element nos.  10 ,  110 ,  210 ,  310 ,  410  and  510  are shingles. Likewise element nos.  27  and  127  represent phantom lines defining areas on the substrates for similar purposes. 
         [0133]    The photovoltaic shingle of this invention comprises a base portion and an energy conversion and power producing portion. The base portion comprises a substrate and the energy and power producing portion comprises a photovoltaic assembly. 
         [0134]      FIGS. 1-7  and  9 - 14  illustrate a first embodiment of a substrate  11  and a shingle  10  of this invention. In particular the base portion of shingle  10  comprises a substrate  11  having a left side  12 , a right side  13 , a length  14 , a bottom end  15 , a top end  16 , a width  17 , an outward face  18  and an inward face  19 . The substrate has an end profile  22  as seen in  FIG. 7  that simulates a Spanish style-like shaped roofing tile with a plurality of parallel ridges  23  that are separated by a plurality of parallel troughs  24 . 
         [0135]    In this embodiment the left side  12  of one substrate  11   a  is designed to nest over the right side  13  and to abut ledge  25  of an adjacent substrate  11   b  of like character as illustrated in  FIG. 38 . 
         [0136]    As seen in  FIG. 2 , the outward face  18  of the substrate has a lower area  28  and an upper area  29  that are separated at and by a phantom line  27  such that the lower area has a width  30  and the upper area has a width  31 . Likewise, as seen in  FIG. 3 , the inward face  19  of the substrate has a lower area  33  and an upper area  34  that are separated at and by a phantom line  32 . 
         [0137]    The substrate is designed so that the lower area  33  of the inward face  19  of the substrate of an upper shingle  10   a  nests and aligns over the upper area  29  of the outward face  18  of the substrate of a lower shingle  10   b  of like character as indicated in  FIG. 45  thereby having the characteristic of Spanish style-like shaped tiles arranged in overlapping rows. 
         [0138]    The low point of each trough  24  in the upper area  29  has apertures  35  for receiving fastener means for securing the substrate  11  and hence the shingle  10  directly to, and abutted against a typically wooden roof structure  900 , often 0.75 inch plywood sheeting, with a layer of moisture/insulating barrier  901 , e.g. roofing felt, therebetween, as shown in the figures. The substrate and hence shingle, is secured to roof structure without an auxiliary support or framing structure for spacing the shingle above and away from the roof structure. The roofing felt is placed between the roof structure and the shingle only as a moisture and/or insulating barrier and not as an auxiliary support or framing structure. The apertures and fasteners are covered by the next row of shingles thereby preventing rain from entering through the apertures to the roof structure. Examples of a fastener means include screws, bolts and nails. 
         [0139]    As seen in  FIG. 38 , the lower right end of each substrate of each shingle has a slot  36  for receiving a clip  37  for securing the shingle directly to and abutted against the wooden roof structure  900  and barrier  901 . One end of the clip can be installed through the slot from outside the shingle and the other end of the clip fastened directly to the roof structure so that the shingle directly abuts the roof structure, except for barrier therebetween. Since the next adjacent shingle in the series will cover the slot  36  and clip  37 , rain is prevented from entering over the clip and through the slot to the roof structure  900 . This feature enables the lower end of each shingle, regardless of the particular row that the shingle is in, to be secured directly to the roof structure  900 . 
         [0140]    The photovoltaic shingle of this invention comprises an energy producing portion on top of the substrate as illustrated in  FIGS. 9-15 . The energy and power producing portion comprises a photovoltaic assembly  40  that comprises a photovoltaic cell  41 . The photovoltaic cell covers the lower area  28  of the outward face  18  of the substrate except for a narrow peripheral band  43  around the bottom end  15  and the left end  12  of the substrate, and except for a portion  42  of the right side of the substrate between the ledge  25  and the right end  13  of the substrate. 
         [0141]    The upper area  29  that is overlapped by at least one other shingle is not covered by the photovoltaic cell. Since the areas of the shingle that are overlapped by another shingle will not receive incident sun light there would be no benefit to having a photovoltaic cell in such overlapped areas. 
         [0142]    Referring also to  FIG. 42 , a photovoltaic cell  41  comprises a first metal conductor member  44  over the outward face  18  of the substrate, a first semiconductor member  45 , a second metal conductor member  46 , and a second semiconductor member  47 . Photovoltaic cell  41  converts solar radiation to electrical energy. Photovoltaic cell  41  is protected by a transparent sealer member  48  that encapsulates and seals the photovoltaic cell  41  to the substrate  11 . Sealer member  48  is effective for preventing the photovoltaic cell, when the shingle is installed on a roof structure, from being damaged by rain. Photovoltaic assembly  40  comprises photovoltaic cell  41  and sealer member  48 . 
         [0143]    Metal conductor members  44  and  46  preferably are configured in a grid pattern and function as anode and cathode conductors for the power produced by the photovoltaic cell. Members  44  and  46  are connected electrically to conductors  49  and  50  (shown only for the uppermost and lowermost members  44  and  46  in  FIGS. 9 and 10 ). Conductors  49  and  50  are connected electrically to electrical jack  51  that is attached to a recess  39  in the substrate. 
         [0144]    Sealer member  48  extends over conductors  49  and  50  into portion  42  of the substrate  11 , and over and above phantom line  27  into upper area  29 . 
         [0145]    The shingle has an end profile  21  as seen in  FIG. 14 . 
         [0146]    The narrow peripheral band  43  is wide enough to seal the photovoltaic cell  41  to the substrate. A width of about 0.5 inches (13 mm) is wide enough to effectively seal the photovoltaic cell to the substrate and protect the photovoltaic cell thereof. 
         [0147]    In one embodiment of this invention the photovoltaic cell is a thin film photovoltaic cell. 
         [0148]    In one embodiment the first metal conductor member  44  is a grid with strips about 3 mm wide, spaced about 15 mm apart and having a thickness between about 4 mils and about 6 mils. 
         [0149]    In one embodiment the first semiconductor member  45  is film having a thickness between about 50 nm to about 20,000 nm. 
         [0150]    In one embodiment the second metal conductor member  46  is a grid with strips about 3 mm wide, spaced about 15 mm apart and having a thickness between about 4 mils and about 6 mils. 
         [0151]    In one embodiment the second semiconductor member  47  is film having a thickness between about 50 nm to about 20,000 nm. 
         [0152]    In one embodiment the transparent sealer member  48  is film having a thickness between about 15 mils to about 25 mils. 
         [0153]    In one embodiment the substrate is plastic and has an average thickness of about 0.25 inches (6 mm). 
         [0154]    In one embodiment the radius of curvature of the ridges  23  is about 4 inches (10 cm) and the troughs  24  is about 2.5 inches (6.4 cm). 
         [0155]    In a second embodiment that is similar to the first embodiment except that the first row, i.e. lowest row of shingles, on a roof structure, has a substrate that includes an integral lower end closures  38 , sometimes referred to as bird stops, as seen in the end views of  FIGS. 8 and 16  instead of the opened end views of  FIGS. 7 and 15 , respectively. All other features of the substrate and shingle are the same as described and shown for the first embodiment of this invention. 
         [0156]    In a third embodiment of this invention the shingle also has a base portion and an energy and power producing portion, and the base portion comprises a substrate that has two tiers separated by an integral riser that has the visual effect of appearing to have two independent rows of shingles. In this embodiment the energy and power producing portion comprises two photovoltaic assemblies, namely a lower and upper photovoltaic assembly separated by the integral riser. 
         [0157]    For example,  FIGS. 16-22  and  24 - 29  illustrate the third embodiment of the substrate  111  and shingle  110  of this invention. In particular the base portion of shingle  110  comprises a substrate  111  having a left side  112 , a right side  113 , a length  114 , a bottom end  115 , a top end  116 , a width  117 , an outward face  118  and an inward face  119 . 
         [0158]    The substrate has an end profile  122  as seen in  FIG. 22  that has a plurality of parallel ridges  123  that are separated by a plurality of parallel troughs  124 . 
         [0159]    In this embodiment the left side  112  of one substrate is designed to nest over the right side  113  and to abut ledge  125  of an adjacent substrate of like character in a manner similar to the first embodiment that was described earlier and illustrated in  FIG. 38 . 
         [0160]    As seen in  FIG. 17 , the outward face  118  of the substrate has a lower area  128  and an upper area  129  that are separated at and by a phantom line  127  such that the lower area has a width  130  and the upper area has a width  131 . Likewise, as seen in  FIG. 18 , the inward face  119  of the substrate has a lower area  133  and an upper area  134  that are separated at and by a phantom line  132 . 
         [0161]    The substrate is designed so that the lower area  133  of the inward face  119  of the substrate of an upper shingle  110   a  nests and aligns over the upper area  129  of the outward face  118  of a substrate of a lower shingle  110   b  of like character as illustrated in  FIG. 46  thereby having the characteristic of two independent rows of Spanish style-like shaped shingles or tiles when there is only one row of the shingles of this embodiment of this invention but with two tiers. 
         [0162]    The low point of each trough  124  in the upper area  129  has apertures  35  for receiving fastener means for securing the substrate  111  and hence the shingle  110  directly to, and abutted against a typical wooden roof structure  900 , often 0.75 inch plywood sheeting, with a layer of barrier  901  therebetween, as shown in the figures, without an auxiliary support or framing structure for spacing the shingle above and away from the roof structure. The barrier  901  is used as a moisture and/or insulating barrier. As in the first embodiment described above, the apertures and fasteners are covered by the next row of shingles thereby preventing rain from entering through the apertures to the roof structure. 
         [0163]    The lower right end of each shingle has a slot for receiving a clip for securing the shingle directly to and abutted against the wooden roof structure  900  and barrier  901  in the same manner as described for the first embodiment with reference to  FIG. 38 . 
         [0164]    The substrate has a lower tier  151  having width  126 A and an upper tier  152  having width  126 B separated by an integral riser  150 . The sum of width  126 A and  126 B equals the width  130  of lower area  128 . In this embodiment widths  126 A and  126 B are equal. 
         [0165]    In this embodiment a portion of riser  150  includes an offset means for maintaining side-to-side alignment of the risers in a row of shingles in an inclined plane  154  perpendicular to the plane of the roof&#39;s sheeting. For example, at ledge  125  riser  150  has an offset  153  that is parallel to the ridges  123  and troughs  124  so that when the shingles are installed side-to-side on a roof structure, the risers will be in alignment with each other in an inclined plane  154  as indicated in  FIG. 46 . 
         [0166]    The photovoltaic shingle also comprises an energy and power producing portion on top of the substrate as illustrated in  FIGS. 24-29 . The energy and power producing portion has the two photovoltaic assemblies  160  and  170  on substrate tiers  151  and  152 , respectively, that comprises photovoltaic cells  161  and  171 , respectively. 
         [0167]    The photovoltaic cells cover the lower area  128  of the outward face  118  of the substrate except for narrow peripheral bands  163  and  173  of photovoltaic assemblies  160  and  170 , respectively, around the bottom end  115  and the left end  112  of the substrate and around the periphery of the riser  150 , and further except for portions  162  and  172  of the right side of the substrate between the ledge  125  and the right end  113  of the substrate. The upper area  129  that is overlapped by at least one other shingle is not covered by the photovoltaic cell since areas that are overlapped will not receive incident sun light. 
         [0168]    The photovoltaic cells  161  and  171  are constructed and function in the same manner as described with regard to the first embodiment of this invention and  FIG. 42 . 
         [0169]    With regard to photovoltaic cells  161  and  171 , metal conductor members  44  and  46  preferably are configured in a grid pattern and function as an anode and cathode conductors for the power produced by the photovoltaic cell. Members  44  and  46  are connected electrically to conductors  49  and  50  (shown only for the uppermost and lowermost members  44  and  46  in  FIGS. 24 and 25 ). Conductors  49  and  50  are in turn connected electrically to electrical jack  51  that is attached to a recess  39  in the substrate. Sealer member  48  extends over conductors  49  and  50  and is also extended above phantom line  127  into upper area  129 . 
         [0170]    The shingle has an end profile  121  as seen in  FIG. 29 . 
         [0171]    In the third embodiment the radius of curvature of the ridges  123  is about 4 inches (10 cm) and the troughs  124  is about 2.5 inches (6.4 cm). 
         [0172]    In a fourth embodiment that is similar to the third embodiment except that the first row, i.e. lowest row of shingles on a roof structure, has a substrate that includes an integral lower end closures  38 , sometimes referred to as bird stops, as seen in the end views of  FIGS. 23 and 30  instead of the opened end views of  FIGS. 22 and 29 , respectively. All other features of the substrate and shingle are the same as described and shown for the third embodiment. 
         [0173]      FIG. 31  is a fifth embodiment of a shingle  210  of this invention similar to the shingle  110  as seen in  FIG. 24 . Shingle  210  comprises substrate  211 , which has a lower tier  251  and an upper tier  252  separated by an integral riser  250 , and three parallel ridges  223  and two parallel troughs  224  that span the integral riser. Shingle  210  also comprises a lower photovoltaic assembly  260  and an upper photovoltaic assembly  270 , which are affixed tiers  251  and  252 , respectively and span two adjacent ridges. 
         [0174]      FIG. 32  is a sixth embodiment of a shingle  310  of this invention similar to the first embodiment of a shingle  10  in  FIG. 9 . Shingle  310  comprises single tier substrate  311  and a photovoltaic assembly  340 . 
         [0175]    Shingle  310  has an end profile  321  as seen in  FIG. 33  that simulates a Spanish style-like shaped roofing tile with a plurality of parallel ridges  323  that are separated by a plurality of parallel troughs  324 . The end profile of  FIG. 33  is different than the end profile of shingle  10  shown in  FIG. 14  in that the radius of curvature of the ridges  323  are about the same as ridges  23 , however, the radius of curvature of troughs  324  is smaller than the radius of curvature of troughs  24 . 
         [0176]    In one embodiment the radius of curvature of the ridges  323  is about 4 inches (10 cm) and the radius of curvature of the troughs  324  is about 1.5 inches (3.8 cm). 
         [0177]      FIG. 34  is a seventh embodiment of a shingle  410  of this invention similar to the third embodiment of a shingle  10  of  FIG. 9 . Shingle  410  comprises a single tier substrate  411  and a photovoltaic assembly  440 . Substrate  411  has four parallel ridges  423  and four parallel troughs  424 , with the photovoltaic assembly  440  affixed to and spanning the ridges and the troughs. 
         [0178]    Shingle  410  has an end profile  421  as seen in  FIG. 35  that simulates another type of Spanish style-like shaped roofing tile with a plurality of parallel ridges that are separated by a plurality of parallel troughs. The profile of shingle  410  as seen in  FIG. 35  is different than the profile of shingles  10  and  310  shown in  FIGS. 22 and 33 , respectively, in that while the radius of curvature of the ridges  23  and  323  are about the same as the ridges  423 , the troughs  424  are flat with small rounded fillets transitioning ridges  423  and the troughs  424 . 
         [0179]    Substrate  411  has four parallel ridges  423  and five parallel troughs  424  with the first and last troughs overlapping and underlapping adjacent troughs of shingles of like character. The photovoltaic assembly  440  is affixed to and span the ridges  423  and troughs  424  of substrate  411 . 
         [0180]    The energy and power produced by the photovoltaic assembly  440  can be transmitted from conductors  44  and  46  to conductors on the inward face  419  of substrate  411  and then to jack  51 . 
         [0181]      FIG. 36  is an eighth embodiment of a shingle  510  of this invention similar to the third embodiment of a shingle  110  in  FIG. 24 . Shingle  510  comprises substrate  511  and two photovoltaic assemblies  560  and  570 . Substrate  511  has a lower tier  551  and an upper tier  552  separated by an integral riser  550 . 
         [0182]    Shingle  510  has an end profile  521  as seen in  FIG. 37  that is similar to the end profile  421  in  FIG. 35  except mainly for the presence of the two tiers  551  and  552  and the integral riser  550 . 
         [0183]    Substrate  511  has four parallel ridges  523  and five parallel troughs  524  with the first and last troughs overlapping and underlapping adjacent troughs of shingles of like character. The photovoltaic assemblies  560  and  570  are affixed to and span the ridges  523  and troughs  524  of tiers  551  and  552 , respectively. 
         [0184]    The energy and power produced by the photovoltaic assemblies  560  and  570  can be transmitted from conductors  44  and  46  to conductors on the inward face  519  of substrate  511  to jack  51 . 
         [0185]      FIG. 39  illustrates a method of interlocking side-to-side adjacent substrates together rather than overlapping the substrates as in  FIG. 38 . The right side of substrate  611   a  contains a snap-in prong  612   a  that snaps into a corresponding socket recess  613   b  in adjacent substrate  611   b  of like character to substrate  611   a . Electrical connection of conductors  44  and  46  are transmitted through conductors on the inward face  619  of substrate  611 , which are then connected to jack  51 . 
         [0186]      FIG. 40  illustrates yet another method of imbedding electrical conductor  649  and  650  in substrates  611   a  and  611   b.    
         [0187]      FIG. 41  illustrates the layers of another photovoltaic assembly  740  affixed to a substrate  11 . Photovoltaic assembly  740  comprises a first metal conductor member  44  over the outward face of the substrate  11 , a first layer of a color-imparting composition  81 , a first semiconductor member  45 , a second metal conductor member  46 , a second semiconductor member  47 , and a second layer of a color-imparting composition  82 . A transparent sealer member  48  encapsulates and seals the photovoltaic cell to the substrate  11 . 
         [0188]      FIG. 43  illustrates an enlarged detail of electrical jack  51  contained in recess  39 . One end of the jack  51  is to electrical conductors  49  and  50 , and the other end of jack  51  is connected to a stringer connecting the photovoltaic cells together in a predetermined arrangement. 
         [0189]      FIG. 44  is a schematic diagram of an electrical circuit for a plurality of photovoltaic shingles  800  of this invention electrically connected by stringers  801  when installed on a roof. Stringers  801  are electrically connected to a second stringer  802  that is electrically connected to a DC/AC invertor  803 . Invertor  803  can be connected to a meter-measuring-recording device  804  to determine the power produced by the photovoltaic shingles before the power is fed to the utility power grid  806 . 
         [0190]    The following examples refer to a structure or roof receiving a plurality of the shingles of this invention that feature overlapped shingles as shown for example in  FIGS. 45 and 46 . Each of the shingles has an overlapped area and an unoverlapped area both of which are projected areas of the structure&#39;s or roof&#39;s flat surface. A large portion of unoverlapped area of each shingle will contain a photovoltaic cell or cells. The examples refer to the unoverlapped area of the shingles. The object is to have a high percentage of the unoverlapped area occupied by a photovoltaic cell or cells. 
       Example 1 
       [0191]    For a shingle having unoverlapped width of about 27.5 inches, and an unoverlapped length of about 42.0 inches and a single tier, the portion of the unoverlapped area covered by the narrow peripheral band (e.g. element  43 ,  FIGS. 9 and 10 ) having a width of about 0.5 inches and without any photovoltaic cells thereunder on both the left boundary and the bottom boundary of the shingle, is about 34.5 square inches. 
         [0192]    The result is an unoverlapped area covered by just the sealer without a photovoltaic cell thereunder of about 3.0% of the total unoverlapped area, and an unoverlapped area covered by a photovoltaic cell of about 97.0% of the total unoverlapped area. 
       Example 2 
       [0193]    For a shingle having unoverlapped width of about 27.5 inches, and an unoverlapped length of about 84.0 inches and a single tier, the portion of the unoverlapped area covered by the narrow peripheral band (e.g. element  43 ,  FIGS. 9 and 10 ) having a width of about 0.5 inches and without any photovoltaic cells thereunder on both the left boundary and the bottom boundary of the shingle, is about 55.5 square inches. 
         [0194]    The result is an unoverlapped area covered by just the sealer without a photovoltaic cell thereunder of about 2.4% of the total unoverlapped area, and an unoverlapped area covered by a photovoltaic cell of about 97.6% of the total unoverlapped area. 
       Example 3 
       [0195]    For a shingle having unoverlapped width of about 27.5 inches, and an unoverlapped length of about 42.0 inches and two tiers separated by a riser, the portion of just the unoverlapped area covered by the narrow peripheral bands (e.g. elements  163  and  173 ,  FIGS. 24 and 25 ) having a width of about 0.5 inches and without any photovoltaic cells thereunder on both the left boundary, the bottom boundary, and on both sides of the riser of the shingle, is about 76.0 square inches. 
         [0196]    The result is an unoverlapped area covered by just the sealer without a photovoltaic cell thereunder of about 6.6% of the total unoverlapped area, and an unoverlapped area covered by a photovoltaic cell of about 93.4% of the total unoverlapped area. 
       Example 4 
       [0197]    For a shingle having unoverlapped width of about 27.5 inches, and an unoverlapped length of about 84.0 inches and two tiers separated by a riser, the portion of just the unoverlapped area covered by the narrow peripheral bands (e.g. elements  163  and  173 ,  FIGS. 24 and 25 ) having a width of about 0.5 inches and without any photovoltaic cells thereunder on both the left boundary, the bottom boundary, and on both sides of the riser of the shingle, is about 139 square inches. 
         [0198]    The result is an unoverlapped area covered by just the sealer without a photovoltaic cell thereunder of about 6.0% of the total unoverlapped area, and an unoverlapped area covered by a photovoltaic cell of about 94.0% of the total unoverlapped area. 
       Example 5 
       [0199]    For a shingle having unoverlapped width of about 55 inches, and an unoverlapped length of about 42.0 inches and two tiers separated by a riser, the portion of just the unoverlapped area covered by the narrow peripheral bands (e.g. elements  163  and  173 ,  FIGS. 24 and 25 ) having a width of about 0.5 inches and without any photovoltaic cells thereunder on both the left boundary, the bottom boundary, and on both sides of the riser of the shingle, is about 89.8 square inches. 
         [0200]    The result is an unoverlapped area covered by just the sealer without a photovoltaic cell thereunder of about 3.9% of the total unoverlapped area, and an unoverlapped area covered by a photovoltaic cell of about 96.1% of the total unoverlapped area. 
       Example 6 
       [0201]    For a shingle having unoverlapped width of about 55 inches, and an unoverlapped length of about 84.0 inches and two tiers separated by a riser, the portion of just the unoverlapped area covered by the narrow peripheral bands (e.g. elements  163  and  173 ,  FIGS. 24 and 25 ) having a width of about 0.5 inches and without any photovoltaic cells thereunder on both the left boundary, the bottom boundary, and on both sides of the riser of the shingle, is about 152.8 square inches. 
         [0202]    The result is an unoverlapped area covered by just the sealer without a photovoltaic cell thereunder of about 3.3% of the total unoverlapped area, and an unoverlapped area covered by a photovoltaic cell of about 96.7% of the total unoverlapped area. 
       Example 7 
       [0203]    For a shingle having unoverlapped width of about 55.5 inches, and an unoverlapped length of about 84.0 inches and a single tier, the portion of the unoverlapped area covered by the narrow peripheral band (e.g. element  43 ,  FIGS. 9 and 10 ) having a width of about 0.5 inches and without any photovoltaic cells thereunder on both the left boundary and the bottom boundary of the shingle, is about 69.3 square inches. 
         [0204]    The result is an unoverlapped area covered by just the sealer without a photovoltaic cell thereunder of about 1.5% of the total unoverlapped area, and an unoverlapped area covered by a photovoltaic cell of about 98.5% of the total unoverlapped area. 
         [0205]    In all of the above examples, since the actual surface area of the shingles of this invention is larger than the unoverlapped area in the above examples due to the curved surfaces of the shingles, the area of photovoltaic cells will be about 15% or more higher than the above calculated percentages, which are projected on a flat area of the structure or roof in the examples. Thus the exposed area of photovoltaic cells receiving incident solar radiation will be in most all cases greater than the total area of the flat surface of the structure or roof on which the shingles of this invention are attached. 
         [0206]    In one embodiment of this invention the color of the shingles is customized by either adjusting the color of the substrate, or the sealer member, or addition of a color adjust layer or layers in the photovoltaic cell or a combination of the above. 
         [0207]    The reflective properties of the photovoltaic assemblies is tailored in one embodiment of this invention so that the entire surface has an uniform appearance. 
         [0208]    An advantage of the embodiments of the shingles of this invention having a thin film photovoltaic cells and a plastic substrate is that the shingles are lightweight and usually do not require reinforcement of the roof structure to accommodate the heavier weight of clay tile shingles or shingles with a metal substrate. 
         [0209]    Another advantage of the various embodiments of the shingles of this invention with a thin film photovoltaic cells and a plastic substrate is that the shingles can be walked on with care without damaging the shingles and the photovoltaic cells thereof. 
         [0210]    While the preferred embodiments of the present invention have been described, various changes, adaptations and modifications may be made thereto without departing from the spirit of the invention and the scope of the appended claims. The present disclosure and embodiments of this invention described herein are for purposes of illustration and example and modifications and improvements may be made thereto without departing from the spirit of the invention or from the scope of the claims. The claims, therefore, are to be accorded a range of equivalents commensurate in scope with the advances made over the art.