Abstract:
A system for mounting photovoltaic cells on a surface and utilizing the energy produced therefrom. Several cells are connected in series to produce DC power. The DC power is converted to AC power suitable for use in utility lines. The cells are pigmented to ensure efficient collection of available radiation.

Description:
FIELD OF THE INVENTION  
       [0001]     The following invention is generally related to instrumentalities and methodologies in photovoltaic cells. More specifically, the instant invention is directed to a method and apparatus for mounting photovoltaic cells on a surface, such as a roof or wall.  
       BACKGROUND OF THE INVENTION  
       [0002]     Photovoltaic (PV) cells are growing in popularity as an alternative energy source as power costs increase. Owners of commercial and residential buildings are installing PV cells to reduce overall dependence on energy provided by a utility company. Owners of residential property are often concerned with curb appeal and generally find current PV systems unattractive. Current systems tend to be more fragile than desired and difficult to install. The number of panels that must be used to provide enough power also creates potential wiring issues with respect to connections that must be made with existing utility systems. The need exists for an integrated, less complicated system that is pleasing to the eye, yet capable of producing power at desired levels.  
         [0003]     The following prior art reflects the state of the art of which applicant is aware and is included herewith to discharge applicant&#39;s acknowledged duty to disclose relevant prior art. It is stipulated, however, that none of these references teach singly nor render obvious when considered in any conceivable combination the nexus of the instant invention as disclosed in greater detail hereinafter and as particularly claimed.  
                                       PAT. NO.   ISSUE DATE   INVENTOR                   6,360,497   Mar. 26, 2002   Nakazima et al.       6,476,314   Nov. 5, 2002   Bauman et al.       2002/0166580   Nov. 14, 2002 (published)   Bauman et al.       WO 01/75377 A1   Oct. 11, 2001 (published)   Erling       WO 02/101839 A1   Dec. 19, 2002 (published)   Mucci       EP 1296382 A1   Mar. 26, 2003 (published)   Gambale Srl                  
 
       SUMMARY OF THE INVENTION  
       [0004]     The present invention is distinguishable over the prior art in that a plurality of photovoltaic cells are oriented together as a panel of cells on a frame, which is then mounted on a surface. The positive and negative connectors from each frame run through a channel on the frame into a combiner box that has one pair of wires as an output. Multiple combiner boxes may be used with a recombiner to ensure that there is only one output, regardless of the number of cells. In addition, the cells themselves may have a coating that maximizes energy production by providing enhanced absorption of available radiation.  
       OBJECTS OF THE INVENTION  
       [0005]     Accordingly, it is a primary object of the present invention to provide a new and novel device and method for efficient capture of available radiation.  
         [0006]     It is a further object of the present invention to provide a device and method as characterized above that is modular in nature and provides for relatively uncomplicated installation.  
         [0007]     It is a further object of the present invention to provide a device and method as characterized above that converts captured radiation into electricity suitable for utilization with conventional utility lines.  
         [0008]     Viewed from a first vantage point, it is an object of the present invention to provide a system for converting actinic radiation to another form of energy, comprising, in combination: a roof; a frame; a panel sensitive to the actinic radiation; means to mount the frame atop the roof; means to mount the panel to the frame, the frame exposed to the actinic radiation; and means to transfer energy from the panel through a chaseway on the frame thence to a power network.  
         [0009]     Viewed from a second vantage point, it is an object of the present invention to provide a method for converting actinic radiation to another form of energy, the steps including: forming a panel by connecting a plurality of photovoltaic cells, the panel of photovoltaic cells having a plurality of electrical tabs exiting the panel, each electrical tab attached to a separate connection wire, each of the connection wires travelling from the panel perpendicular to an edge of the panel and further travelling through a clip that directs the connection wires to separate locations; lodging the panel in a frame, the frame comprising a recess to receive the panel, separate paths for each connection wire, a hood adjacent the recess to receive the clip, and means to receive and direct the connection wires along an edge of the frame, the panel and frame comprising a tile; electrically interconnecting a plurality of tiles; imbricating a plurality of the interconnected tiles on a surface exposed to actinic radiation; combining output from the interconnected tiles; and feeding the combined output into a power network.  
         [0010]     Viewed from a third vantage point, it is an object of the present invention to provide an apparatus for converting actinic radiation to another form of energy, comprising, in combination: a plurality of photovoltaic cells, the photovoltaic cells electrically interconnected with one another and oriented into a panel, wherein output from the panel is directed through a plurality of electrical tabs, the electrical tabs attached to a plurality of connection wires to direct output from the panel, the connection wires routed through a clip; and a frame, the frame comprising, in combination: a recess to receive the panel such that a surface of the panel not contacting the frame is planar with respect to a non-recessed portion of the frame, the recess formed by a plurality of cross pieces, the cross pieces defining windows in the frame; a mounting portion on an edge of the non-recessed portion of the frame, the mounting portion having means to mount a combined frame and panel to a surface; a plurality of separate paths, each path to receive one connection wire from the panel; and a hood to receive the clip from the panel.  
         [0011]     Viewed from a fourth vantage point, it is an object of the present invention to provide an apparatus for converting actinic radiation to another form of energy, comprising, in combination: a plurality of photovoltaic cells oriented in a panel, the panel having means to output current through connection wires; a frame, the frame comprising, in combination: a recess to receive the panel; mounting means to mount the frame on a surface, the mounting means on a separate portion of the frame than the recess; means to separate and direct the connection wires away from the panel; and clip means to selectively attach one frame to another frame.  
         [0012]     These and other objects will be made manifest when considering the following detailed specification when taken in conjunction with the appended drawing figures.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is an exploded view of the laminate structure according to the present invention.  
         [0014]      FIG. 2  is a depiction of the present invention on a conventional roof.  
         [0015]      FIG. 3  is a detail view of the frame interconnection shown in  FIG. 2 .  
         [0016]      FIG. 4  is a front view of a panel having ten photovoltaic cells.  
         [0017]      FIG. 5  is a front view of a panel having twelve photovoltaic cells.  
         [0018]      FIG. 6  is a front view of a panel having twenty-four photovoltaic cells.  
         [0019]      FIG. 7  is a detail view of the frame.  
         [0020]      FIG. 7A  is a cutaway view of a fastener hole in the frame shown in  FIG. 7 .  
         [0021]      FIG. 8  is a perspective view of the attachment of the wind loading clip.  
         [0022]      FIG. 9  is a detail view of the wind loading clip.  
         [0023]      FIGS. 10 and 11  are perspective views of the connection of two frames using the wind loading clips.  
         [0024]      FIG. 12  is a side view of the connection shown in  FIG. 11 .  
         [0025]      FIG. 13  is a representation of the conversion and delivery system used in the present invention.  
     
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0026]     Considering the drawings, wherein like reference numerals denote like parts throughout the various drawing figures, reference numeral  10  as shown in  FIG. 1  is directed to the system according to the present invention.  
         [0027]     In its essence, the system  10  includes a panel  2  of photovoltaic cells  4  mounted in a frame  6 .  
         [0028]     Several cells  4 , preferably twelve, are electrically connected in series to each other. Ten cells  4  are shown in  FIGS. 1 and 2 , and combinations of ten, twelve and twenty-four cells  4  are shown in  FIGS. 4-6 . The panel  2  is the same size in each case; it is the cells  4  that change in size. Each cell  4  has its own set of connection wires  5  to direct current away from the cells  4 . The cells  4  are utilized in a panel  2  that is a laminate support structure. Referring to  FIG. 1 , the support is preferably constructed in layers, with a layer of ethyl-vinyl acetate  14  on either side of and adjacent to the cells  4 , a glass outer sheet  12  adjacent the other side of one ethyl-vinyl layer  14 , and an aluminum heat sink  16  adjacent the side remote from the glass outer sheet. Electrical tabs  17  extend from one edge of the panel  2 . The tabs  17  are soldered onto a pair of electrical cables  18  having male and female connectors  19  and  20  respectively. The electrical cables  18  are directed from the tabs  17  through an elongate U-shaped channel-like clip  11  for direction away from the panel  2 .  
         [0029]     The panel  2  nests within a frame  6  having an recessed portion  22  to accept the panel  2 . The recessed portion  22  also contains several windows  13  separated by spines  15 . Twenty-two windows  13  are illustrated, but any number of windows  13  may be present. The panel  2  is oriented in the frame  6  with the aluminum heat sink  16  contacting the recessed portion  22  of the frame  6 , adjacent the window  13  and spine  15  area.  
         [0030]     The frame  6  includes a hood  23  that frictionally receives clip  11 . Paths  24  receive tabs  17 ; a separator  25  holds the tabs  17  in spaced relation. A chaseway  26  accepts and directs the electrical cables  18  from the panel  2 . The tabs  17  each have a separate path  24 , divided by the separator  25  to prevent contact. The channel-like clip  11  snaps into the hood  23  for precise placement. The electrical cables  18  are further directed through constraining clips  27  for correct orientation. As a unit, the panel  2  and frame  6  form a tile  8 . The tile  8  may be mounted to a surface  50 , preferably a roof, where the cells  4  are exposed to actinic radiation. The tiles  8  are equipped with complementarily formed ends  28 , 29  that allow adjacent tiles  8  to slide together using a groove  46  and tongue  48  method (see  FIG. 3 ).  
         [0031]     Referring to  FIGS. 7 and 7 A, a plurality of circular fastener holes  60 , preferably four, are located on the windowless portion  55  of the frame  6 . Each hole  60  is preferably circumscribed by a plurality of concentric grooved portions  62 , 64  alternating with a ringed portion  68 , with the fastener hole  60  located at the lowest central point therein. The grooved portions  62 , 64  are grooves relative to the plane of the surface of the windowless portion  55  of the frame  6 ; that is, the grooves are recessed into the frame  6 . The hole  60  is first circumscribed by a chamfered edge  66 , when is then circumscribed by a first groove  62 . A ringed portion  68  circumscribes the first groove  62 . The top of the ringed portion  68  is in the same plane as the surface of the windowless portion  55  of the frame  6 . A second groove  64  circumscribes the ringed portion  68 . The second groove  64  is preferably recessed an identical amount as the first groove  62 . The recesses allow tiles  8  to be imbricated such that a lowest R 1  has a portion  55  that underlies a second, higher row R 2 , going up to the roof apex.  
         [0032]     Referring to  FIG. 8 , the holes  60  receive mounting screws  70  and can also secure optional wind loading clips  72 . Anti-rotational ribs  74  are located on the portion  55  of the frame  6  on either side of the wind loading clips  72 , as shown in  FIG. 9 , to help locate the clips on the frame  6 .  
         [0033]     The wind loading clips  72  have a planar, preferably rectangular, bottom portion  76  and a centrally located screwbore  78 . The screwbore is placed directly over the hole  60 , and the bottom portion  76  rests across the circumscribing grooves  62 , 64  and ringed portion  68 , located by the ribs  74 . From the bottom portion  76 , the wind loading clip  72  extends upwardly on either side along the long axis to form teeth  80 . Each of the teeth  80  has endprongs  82  that allow multiple frames  6  to be interlocked with one another (FIGS.  10 , 11 , 12 ). This interlocking produces an offset, overlapping shingle-type array.  
         [0034]     Anti-rotational ribs  74  are formed on either side of each wind loading clip  72  on portion  55 , utilizing the grooves  62 , 64  and ringed portion  68 . The ribs  74  prevent the wind loading clips from moving. Specifically, rotational movement of the wind loading clip  72  about the mounting screw  70  is prevented to ensure a stable structure when frames  6  are joined together and held by the endprongs  82 , as shown in  FIG. 12 .  
         [0035]     The cells  4  can be aesthetically color coordinated with the building and exhibit a range of pigmentation while still capturing as much radiation from the available spectrum of light as possible. Specifically, the cells  4  typically exhibit blue or gray color, using conventional photocells, which has been shown to provide efficient conversion of the full range of radiation. In addition, however, the files  8  may exhibit a red color by using pink colored glass  12 , which maintains efficient conversion of radiation.  
         [0036]     Several tiles  8 , preferably eleven, are connected in series with one another via male and female connectors  19 , 20  to form a string of files  8 . Strings of files  8  are mounted on the surface  50 , preferably a roof. At the edge of the surface  50 , an edge piece  52  is placed, then a string of files  8 . The edge pieces  52  are available in different widths to produce pattern of files  8  that are offset from one another, as shown in  FIG. 2 . The end of the edge piece  52  that engages the tile  8  is equipped with the same type of sliding end  28 , 29  as the tiles  8 . The remote end  53  of the edge piece  52  may end flush with the edge of the surface  50 , or it may exhibit an overhang relative to the edge of the surface  50 . Peaked portions of a surface  50  are covered with cap blocks  54 . The cap blocks  54  are capable of connecting to the frames  8  or to the roof itself.  
         [0037]     As shown in  FIG. 3 , the sliding ends  28 , 29  on each tile  8  allow physical interconnection of the tiles  8  that are electrically connected with one another. Each string of tiles  8  has its own pair of wires that passes through the subroof to the attic below. See  FIG. 13 . This pair of wires terminates in a combiner box  30  that combines the wires from each string of tiles into a single pair of wires  32 , preferably larger copper wires. Several combiner boxes  30  may be used in system  10 . A recombiner  104  is used to join multiple combiner boxes such that a single pair of wires  32  carries the power that originates in the cells  4 .  
         [0038]     For systems  10  connected to a utility power line  40 , synchronous inverters  42  are used to produce AC power in synchronization with the power line. The inverter produces power that is of a quality acceptable to the utility company. In these systems  10 , the utility company serves as the primary energy storage medium. One side of the synchronous inverter  42  is connected to the DC power, and the other is connected through a meter  44  to a circuit breaker box  36  ( FIG. 2 ).  
         [0039]     This connection method allows the utility company to measure the amount of power generated. In systems with only one meter  44 , the meter runs backward as energy is produced and excess power is fed into the utility lines  40 . When the system  10  generates electricity, the inverter  42  supplies power to meet usage. When usage exceeds production of the system  10 , excess power from the utility company is drawn from the utility line  40 .  
         [0040]     Some systems  10  may incorporate a battery  108  for emergency power or for storage of excess power produced. In addition, a stand-alone inverter or an inverter that operates as a stand-alone inverter or a utility-interactive inverter may be utilized in the system.  
         [0041]     The number of cells  4  in the panel  2  determines the output of the tile. A panel of ten 6″-by-6″ cells produces 28 watts at about 5 volts, a panel of twelve 5″-by-5″ cells produces 35 watts at about 7 volts, and a panel of twenty-four 4″-by-4″ cells produces 36 watts at about 12 volts.  
         [0042]     Moreover, having thus described the invention, it should be apparent that numerous structural modifications and adaptations may be resorted to without departing from the scope and fair meaning of the instant invention as set forth hereinabove and as described hereinbelow by the claims.