Abstract:
A roof mount apparatus for mounting on a roof surface includes a first solar panel having a first frame secured to the roof surface, a second solar panel having a second frame secured to the roof surface, the second solar panel spaced from the first solar panel and defining a slot between the first and second frames, and a snow fence secured to the first and second frames. The snow fence includes a bracket positioned adjacent to a top of the first and second frames, the bracket protruding from the first and second frames to inhibit sliding of snow along at least one of the first and second solar panels, and a coupling device including an elongated portion positioned in the slot and extending substantially perpendicular to the roof surface and a wide portion positioned within a channel to couple the bracket to the first and second frames.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of and priority to U.S. Provisional Patent Application No. 61/652,735, filed May 29, 2012, and to U.S. Provisional Patent Application No. 61/707,498, filed Sep. 28, 2012, the entire contents of which are hereby incorporated by reference herein. 
    
    
     BACKGROUND 
     The present invention relates to solar panels and snow fences for solar panels. 
     SUMMARY 
     In some embodiments, the invention provides a roof mounted solar panel assembly having a first solar panel and a second solar panel spaced a distance from the first solar panel. The roof defines a roof plane and the first and second solar panels define a solar panel plane across a top surface of the first and second solar panels. A first mount assembly includes a first portion extending substantially perpendicular to the roof plane between the first and second solar panels and below the solar panel plane. The first mount assembly further includes a second portion extending upward from the solar panel plane at a non-parallel angle with respect to the roof plane. In some embodiments, the second portion extends substantially perpendicularly upward with respect to the roof plane. In some embodiments, the second portion extends upward with respect to the roof plane in a curvilinear and/or arcuate fashion. 
     In some embodiments, the invention provides a snow retention assembly mountable to a solar panel assembly including first and second solar panels positioned on a roof. The snow retention assembly includes a first portion extending between the first solar panel and the second solar panel, and a second portion positioned above the first solar panel and the second solar panel. The first portion extending substantially perpendicular to a plane defined by the roof and the second portion including a substantially perpendicular portion extending away from the roof and a substantially parallel portion extending substantially parallel to the plane defined by the roof. The first portion includes a fastener that couples the snow retention assembly to the first and second solar panels. The second portion is coupled to the first portion and retains at least a portion of snow on the solar panel while permitting flow of fluid along the solar panel. In some embodiments, the first and second solar panels are spaced an adequate distance apart to create a gap to thereby permit fluid to flow along the first solar panel, through the gap and subsequently along the roof surface under the second solar panel. 
     In some embodiments, the invention provides a roof mount apparatus for mounting on a roof surface. The roof mount apparatus includes a first solar panel having a first frame secured to the roof surface, a second solar panel having a second frame secured to the roof surface, the second solar panel spaced from the first solar panel and defining a slot between the first frame and the second frame, and a snow fence secured to the first frame and the second frame. The snow fence includes a bracket positioned adjacent to a top of the first frame and a top of the second frame, the bracket protruding from the first frame and the second frame to inhibit sliding of snow along at least one of the first solar panel and the second solar panel, and a coupling device including an elongated portion positioned in the slot and extending substantially perpendicular to the roof surface and a wide portion positioned within a channel to couple the bracket to the first frame and the second frame. 
     In some embodiments, the invention provides a roof mount apparatus for mounting on a roof surface. The roof mount apparatus includes a first solar panel having a first frame secured to the roof surface, a second solar panel having a second frame secured to the roof surface, the second solar panel spaced from the first solar panel and defining a slot between the first frame and the second frame, and a snow fence secured to the first frame and the second frame. The snow fence includes a bracket positioned adjacent to a top of the first frame and a top of the second frame, the bracket protruding from the first frame and the second frame to inhibit sliding of snow along at least one of the first solar panel and the second solar panel, and a coupling device including an elongated portion positioned in the slot and extending substantially perpendicular to the roof surface and a flange secured to the elongated portion. The flange engages the first frame at a location spaced from the top of the first frame and the second frame at a location spaced from the top of the second frame to secure the bracket to the first frame and the second frame. 
     In some embodiments, the invention provides a roof mount apparatus for mounting on a roof surface. The roof mount apparatus includes a first solar panel having a first frame secured to the roof surface, the first solar panel defining a first top surface, a first bottom surface and a first side surface, a second solar panel having a second frame secured to the roof surface, the second solar panel defining a second top surface, a second bottom surface and a second side surface, the second solar panel spaced from the first solar panel and defining a slot between the first side surface and the second side surface, and a snow fence secured to the first frame and the second frame. The snow fence includes a bracket positioned adjacent to the first top surface and the second top surface, the bracket protruding from the first frame and the second frame to inhibit sliding of snow along at least one of the first solar panel and the second solar panel and a coupling device including an elongated portion positioned in the slot and a flange securable to the elongated portion. The elongated portion extends substantially perpendicular to the roof surface and substantially parallel to the first side surface and the second side surface. 
     In some embodiments, the invention provides a method of retaining snow on a solar panel while permitting rain water and snow melt to flow off of the solar panel. The method further includes extending a first snow retention portion in a direction substantially parallel to a surface of the solar panel and extending a second snow retention portion at a non-parallel angle with respect to the surface of the solar panel. The method further includes retaining snow on the solar panel with at least one of the first and second snow retention portions and permitting rain and snow melt to flow off of the solar panel past at least one of the first and second snow retention portions. 
     In some embodiments, the invention provides a method of increasing resistance to flow of snow across a roof-mounted solar panel by at least one of increasing a coefficient of friction of at least a portion of the solar panel and by providing at least one protrusion extending upward from the solar panel. The method also includes permitting flow of rain and snow melt to flow along the solar panel and through at least one gap between the solar panel and the at least one protrusion. 
     Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a roof with a solar panel array with a plurality of snow fences mounted to the solar panel array. 
         FIG. 2  is a cut away view of the solar panel array and snow fences of  FIG. 1 . 
         FIG. 3  is a top view of the solar panel array and snow fences of  FIG. 1 . 
         FIG. 4  is a right side view of the solar panel array and snow fences of  FIG. 1 . 
         FIG. 5  is a bottom view of the solar panel array and snow fences of  FIG. 1 . 
         FIG. 6  is a close-up view perspective view of one snow fence mounted on adjacent solar panels with a fastener in a first, unlatched position. 
         FIG. 7  is a side view of the snow fence mounted on adjacent solar panels of  FIG. 6 . 
         FIG. 8  is a top view of the snow fence mounted on adjacent solar panels of  FIG. 6 . 
         FIG. 9  is a bottom view of the snow fence mounted on adjacent solar panels of  FIG. 6 . 
         FIG. 10  is an end view of the snow fence mounted on adjacent solar panels of  FIG. 6 . 
         FIG. 11  is a close-up view perspective view of a snow fence according to some embodiments mounted on adjacent solar panels with a fastener in a second, latched position. 
         FIG. 12  is a side view of the snow fence mounted on adjacent solar panels of  FIG. 11 . 
         FIG. 13  is a top view of the snow fence mounted on adjacent solar panels of  FIG. 11 . 
         FIG. 14  is a bottom view of the snow fence mounted on adjacent solar panels of  FIG. 11 . 
         FIG. 15  is an end view of the snow fence mounted on adjacent solar panels of  FIG. 11 . 
         FIG. 16  is a perspective view of a snow fence according to some embodiments of the present invention. 
         FIG. 17  is an exploded view of the snow fence of  FIG. 16 . 
         FIG. 18  is a side view of a snow fence according to some embodiments of the present invention. 
         FIG. 19  is a perspective view of a snow fence according to some embodiments mounted on adjacent solar panels with the fastener in the first, unlatched position. 
         FIG. 20  is a side view of the snow fence of  FIG. 19  with the fastener in the second, latched position. 
         FIG. 21  is side view of a snow fence according to some embodiments of the present invention. 
         FIGS. 22-25  show various diagrams for calculating the geometry of the snow fences. 
         FIG. 26  is a table showing the results of the calculations of  FIGS. 22-25 . 
         FIG. 27  is a compilation of graphs showing the results of the calculations of  FIGS. 22-25 . 
         FIG. 28  is a perspective view of a snow fence according to some embodiments of the present invention. 
         FIG. 29  is an exploded view of the snow fence of  FIG. 28 . 
         FIG. 30  is a side view of the snow fence of  FIGS. 28 and 29 . 
         FIG. 31  is a perspective view of a snow fence according to some embodiments of the present invention. 
         FIGS. 32-35  show various diagrams for calculating the geometry of the snow fences. 
         FIGS. 36-39  are tables showing the results of the calculations of  FIGS. 32-35  during various times of the year. 
         FIG. 40  is a side view of a snow fence according to some embodiments of the present invention. 
         FIG. 41  is a side view of the snow fence of  FIG. 40  when installed on solar panels. 
         FIG. 42  is an exploded view of the snow fence of  FIGS. 40-41 . 
         FIG. 43  is a top perspective view of the snow fence of  FIGS. 40-42 . 
         FIG. 44  is bottom perspective view of the snow fence of  FIGS. 40-43 . 
         FIG. 45  is a side view of a snow fence according to some embodiments of the present invention. 
         FIG. 46  is a perspective view of a snow fence according to some embodiments of the present invention. 
         FIG. 47  is a cross-sectional view of the snow fence of  FIG. 46  taken along lines  47 - 47  of  FIG. 46 . 
         FIG. 48  is an end view of the snow fence of  FIGS. 46 and 47 . 
         FIG. 49  is a side view of the snow fence of  FIGS. 46-48 . 
         FIG. 50  is a perspective view of two snow fences of  FIGS. 46-49  shown installed on a roof. 
         FIG. 51  is a perspective view of a snow fence according to some embodiments of the present invention 
         FIG. 52  is a top view of a snow fence according to some embodiments of the present invention. 
         FIG. 53  is a side view of the snow fence of  FIG. 52 . 
         FIG. 54  is a front view of the snow fence of  FIGS. 52-53 . 
         FIG. 55  is a perspective view of the snow fence of  FIGS. 52-54 . 
         FIG. 56  is a top view of a snow fence according to some embodiments of the present invention. 
         FIG. 57  is a side view of the snow fence of  FIG. 56 . 
         FIG. 58  is a front view of the snow fence of  FIGS. 55-56 . 
         FIGS. 59-67  illustrate various brackets according to some embodiments of the invention. 
         FIGS. 68 and 69  illustrate different bottom portions according to some embodiments of the present invention. 
         FIG. 70  is a perspective view of a snow fence according to some embodiments of the present invention. 
         FIG. 71  illustrates a bracket of the snow fence of  FIG. 70 . 
         FIG. 72  illustrates a mid-panel support of the snow fence of  FIG. 70 . 
         FIG. 73  is a perspective view of a snow fence according to some embodiments of the present invention. 
         FIG. 74  illustrates a bracket of the snow fence of  FIG. 73 . 
         FIGS. 75-79  illustrate various end clamps according to some embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Before any independent embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. 
     Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
     Also, it is to be understood that phraseology and terminology used herein with reference to device or element orientation (such as, for example, terms like “central,” “upper,” “lower,” “front,” “rear,” etc.) are only used to simplify description of embodiments of the present invention and do not alone indicate or imply that the device or element referred to must have a particular orientation. In addition, terms such as “first” and “second” are used herein for purposes of description and are not intended to indicate or imply relative importance or significance. 
       FIGS. 1 and 2  illustrate a roof  10  having a solar panel assembly  12  including a plurality of solar panels  14  mounted to the roof  10 . The solar panels  14  are mounted to the roof  10  by any suitable mounting hardware. A plurality of snow guards or snow fences  16  are mounted to the plurality of solar panels  14  on the roof  10 . The illustrated solar panel assembly  12  includes fifteen solar panels  14  in three rows of five panels each. Other quantities, configurations and arrangements of solar panels  14  are possible and the illustrated solar panel assembly  12  is given by way of example only. 
     With reference to  FIGS. 3-5 , the illustrated solar panels  14  have a substantially rectangular shape having two short sides  18  and two long sides  20 . The solar panels  14  define elongate spaces therebetween. Specifically, first elongate spaces  22  are defined between adjacent short sides  18  and second elongate spaces  24  are defined between adjacent long sides  20 . In the illustrated embodiment, the second elongate spaces  24  are substantially parallel to an apex of the roof  10 . In the illustrated embodiment, the snow fences  16  are positioned in the second elongate spaces  24 . 
     Many of the roof surfaces that the panels are being installed over are asphalt shingles. In regions where snow and ice exist a problem has developed. Prior to installing solar panels on these roofs in snow country, snow would accumulate on the asphalt shingles and slowly melt off due to the fact that the granules on the surface of the shingles created friction that held the snow mass in place. When solar panels are installed over the top of these asphalt shingle surfaces, the smooth and almost frictionless glass panel surface allows the snow mass to dump like an avalanche. This can cause a safety concern and dangerous hazard for the building owner. 
     There is a need for a device that will allow a mechanic to clamp a device to a solar panel without penetrating the panel thus allowing the mechanic to attach a snow retention device or other hardware to the panel frame. The device can allow a mechanic to attach a stanchion to a solar panel, thus providing an attachment means for supplemental devices such as snow retention, mechanical devices, conduit, electrical related cables, etc. 
       FIGS. 6-15  illustrate one of the snow fences  16  coupled to adjacent solar panels  14 . The solar panels  14  each have a solar panel frame  26  around a perimeter of the respective solar panel  14 . The illustrated snow fence  16  includes a coupling device  28  and a bracket  30 . The coupling device  28  couples the bracket  30  to the solar panel frames  26 . The bracket  30  is substantially L-shaped and has a first portion, a second portion, and a third portion. The first portion rests on top of the solar panel frames  26  and extends substantially parallel to the solar panels  14 . The second portion extends upward from the roof and substantially normal with respect to the solar panels  14 . The third portion extends downward toward the roof substantially normal with respect to the solar panels  14 . The third portion abuts the solar panel frame  26  to inhibit movement of the bracket  30  with respect to the solar panel frame  26 . 
     As best shown in  FIG. 7 , the coupling device  28  includes an elongate portion  32  and a rotating portion  34 . The elongate portion  32  has a first end extending through the first and third portions of the bracket  30  and a distal end to which the rotating portion  34  is coupled. The illustrated coupling device  28  is a bolt that extends between adjacent solar panel frames  26 . The rotating portion  34  rotates between an uncoupled position (shown in  FIGS. 6-10 ) and a coupled position (shown in  FIGS. 11-15 ). In some embodiments, the rotating portion  34  can be spring-loaded toward the coupled position, such that, upon insertion of the coupling device  28 , once the rotating portion  34  is clear of the solar panel frame  26 , the spring biases the rotating portion  34  into the coupled position. The snow fence  16  can be inserted either vertically downward into the second elongate space  24  or can slide along the second elongate space  24  in the longitudinal direction. 
     The illustrated elongate portion  32  is of sufficient length to couple the rotating portion  34  to the bracket  30  prior to coupling the snow fence  16  to the solar panel frame  26 . The coupling device  28  can include a nut and a bolt which can be tightened or loosened to thereby couple and uncouple the coupling device  28  from the solar panel frames  26 . The nut and bolt permit a user to adjust the distance between the nut and the rotating portion  34  to account for thickness variations between solar panel frames  26 . 
     In the illustrated embodiment, the portion of the rotating portion  34  that engages the solar panel frames  26  has a roughened surface (see  FIGS. 6 ,  10  and  11 ). The roughened surface engages the solar panel frames  26  and retain the rotating portion  34  in contact with the solar panel frames  26 . In some embodiments, a bottom surface of the bracket  30  may have a textured surface that engages the solar panel frames  26 . In some embodiments, the coupling device  28  includes an actuator that is actuated by the user to move the rotating portion  34  into the coupled position. In some embodiments, the coupling device  28  is replaced with a molly bolt or other similar fastener. 
       FIGS. 16 and 17  illustrate an alternative snow fence  116  including a coupling portion  128  and a bracket  130 . The coupling portion  128  includes a nut  128   a , a bolt  128   b  and a bottom component  128   c . The bracket  130  is similar to the bracket  30  illustrated and described herein. The user can couple the bottom component  128   c  to the bracket  130  by holding the bolt  128   b  and the bottom component  128   c  in place under the solar panel frame, inserting the bolt  128   b  through the bracket  130  and coupling the nut  128   a  to the bolt  128   b . Although no solar panel frame is illustrated in  FIGS. 16 and 17 , the bracket  130  and the bottom component  128   c  are sized to clamp a solar panel frame therebetween. 
       FIG. 18  illustrates a snow fence  216  including a coupling portion  228  and a bracket  230  coupled to solar panel frames  226  of adjacent solar panels  214 . The illustrated coupling portion  228  is similar to the coupling portion  128  and has a nut  228   a , a bolt  228   b  and a bottom component  228   c . The bracket  230  has a substantially J-shape in which a straight portion rests on the solar panel frames  226  and a curved portion extends upward (with respect to a roof surface) from the solar panel frames  226 . The bracket  230  also includes a third portion extending downwardly (with respect to the roof surface) and abuts the solar panel frame  226  to inhibit movement of the bracket  230  with respect to the solar panel frames  226 . 
       FIGS. 19 and 20  illustrate a snow fence  316  including a coupling portion  328  and a bracket  330  coupled to solar panel frames  326  of adjacent solar panels  314 . The coupling portion  328  is similar to the coupling portion  28  illustrated in  FIGS. 6-15  and the bracket  330  is similar to the bracket  230  of  FIG. 18 . Other shapes, configurations and arrangements of brackets are possible and the L-shaped and J-shaped brackets are given by way of example only. Additionally, any suitable fastener or fastener assembly can be utilized to couple the bracket to the solar panel frame and the embodiments described and illustrated herein are given by way of example only. 
       FIG. 21  illustrates a snow fence  416  including a coupling portion  428  and a bracket  430  coupled to solar panel frames  426  of adjacent solar panels  414 . The bracket  430  is similar to the brackets  230  and  330  of  FIGS. 18-20 . The coupling portion  428  includes a nut  428   a , a bolt  428   b  and a bottom plate  428   c . The bolt  428   b  and the bottom plate  428   c  can be integrally formed or can be two separate components joined by threads, press-fit or other suitable joining configuration. The bottom plate  428   c  can be long (extending into the page) and extend between multiple snow fences  416  to thereby couple multiple snow fences  416  to the solar panels  414  with only one bottom plate  428   c.    
     Any of the brackets  30 ,  130 ,  230 ,  330  and  430  illustrated herein can be used to inhibit the movement of water, snow and ice along the respective solar panels. Additionally, or alternatively, the brackets  30 ,  130 ,  230 ,  330  and  430  can be used for attaching conduit to the solar panels. The brackets  30 ,  130 ,  230 ,  330  and  430  can have any suitable height extending above the respective solar panels. In some configurations, the brackets  30 ,  130 ,  230 ,  330  and  430  are of a size that will not allow the sun to cast a substantial shadow over an uppermost point of the brackets  30 ,  130 ,  230 ,  330  and  430  on the solar panels. Shadows cast on solar panels can diminish the efficiency of the solar panels. 
     An example is given herein which outlines the steps taken to determine how much shade is present outside the footprint of our solar panel snow guard or guard during the Summer Solstice and Winter Solstice. This example will show that there is minimal shading of the solar array during the peak operating hours of the solstice. Therefore, there is minimal shading of the peak operating hours during the rest of the year. The Summer Solstice Sun Elevation Angle (SSA) is the peak Angle (in degrees) between the sun and horizon during the Summer Solstice, whereas the Winter Solstice Sun Elevation Angle (WSA) is the Peak Angle (in degrees) between the sun and horizon during the Winter Solstice. The Roof Pitch (RP) is the angle of a given roof (in degrees). “S” stands for the length of the shaded portion of the solar array on the down-slope side of the solar panel snow guard during the Summer Solstice and “W” stands for the length of the shaded portion of the solar array on the up-slope side of the solar panel snow guard during the Winter Solstice 
     If a shadow occurs on the Solar Array during the peak of the Summer Solstice, it will only be present on the down-slope side of the solar panel snow guard. Please note that the calculations in this example may not be accurate examples of solstice angles or roof pitch situations, the numbers are given for explanation purposes only. 
       FIG. 22  shows the geometry that determines the maximum elevation angle the sun can be before casting a shadow on the down-slope side of the solar panel snow guard. (Down-slope S solar panel snow guard Angle—Roof Pitch) is the maximum elevation angle the sun can be before shading occurs. In this case, if sun elevation angle exceeds 70.53 degrees, shading will occur on the down-slope side of the solar panel snow guard. 
       FIG. 23  shows the geometry that determines the sun elevation angle relationship to the roof pitch and solar panel snow guard angle. This angle is the shade angle. The formula is shade angle=180°−(solar panel snow guard angle+roof pitch). The following calculation shows how the 63° shade angle was determined in  FIG. 23 : 63.00°=180°−(100.53°+30.00°). 
     The formula for total shade length (1.712″ is triangle height) is TAN(180.00°−(100.53°+30.00°))=1.712″/Total Shade Length. Therefore, 1.712″/(TAN(63.00°))=Total Shade Length=0.88″. Since the Total Shaded Length includes the portion of the solar panel snow guard that is shaded, the actual Shade Length is calculated using the following formula: Actual Shade Length (S)=Total Shade Length−Shaded Portion of solar panel snow guard. Specifically, the Actual Shade Length (S)=0.88″−0.318″. Therefore, the Actual Shade Length (S)=0.56″. 
     If a shadow occurs on the solar array during the peak of the Winter Solstice, it will likely only be present on the up-slope side of the solar panel snow guard. Please note that the calculations in the following pages may not be accurate examples of solstice angles or roof pitch situations, the numbers are given for explanation purposes only. 
       FIG. 24  shows the geometry that determines the lowest point the sun may be before casting a shadow on the up-slope side of the solar panel snow guard. (Up-Slope Snow Guard Angle—Roof Pitch) is the lowest maximum elevation angle the sun can be before shading occurs. 
       FIG. 25  shows the geometry that determines the Sun Elevation Angle relationship to the Roof Pitch and solar panel snow guard angle. This angle is the shade angle. The formula is Shade Angle=90°−(Sun Elevation Angle+Roof Pitch). The 55.00° shade angle was determined in  FIG. 25  with the calculation of 55.00°=90°−(5.00°+30.00°). The formula for total shade length when 1.712″ is triangle height is TAN(Shade Angle)=Total Shaded Length/1.712″. Therefore, Total Shaded Length=1.712″×TAN(55°)=2.46″. 
     Because the Total Shaded Length includes the portion of the solar panel snow guard that is shaded, the actual Shade Length (w) is calculated using the formula: Actual Shade Length=Total Shade Length—Shaded Portion of solar panel snow guard. Specifically, the Actual Shade Length=2.46″−1.95″. Therefore, the Actual Shade Length (w)=0.51″. 
     The sun elevation angle for the Summer and Winter Solstice is determined using the following formulas: Summer Solstice Sun Elevation Angle=90°−(Latitude(degrees)−23.5°) and Winter Solstice Sun Elevation Angle=90°−(Latitude(degrees)+23.5°. 
       FIG. 26  is a table showing the results of the calculations of  FIGS. 22-25 .  FIG. 27  is a compilation of graphs showing the results of the calculations of  FIGS. 22-25 . 
     In some embodiments, the snow fence can be dark in color. In some embodiments, the snow fence is black to absorb more heat and thereby, encourage any snow on the snow fence to melt. The snow fences described and illustrated herein may be used as small individual components that increase friction to inhibit the movement of snow and ice. The snow fences may also be used in continuous runs for the same purpose or to function as a rain water diverter. 
       FIGS. 28-30  illustrate a snow fence  516  including a coupling portion  528  and a bracket  530  couplable to solar panel frames of adjacent solar panels. The illustrated coupling portion  528  includes an elongate shaft  528   a , a bottom wide portion  528   b , a top wide portion  528   c  and a fastener  528   d . The bracket  530  has a channel  530   a  sized to receive the top wide portion  528   c . The elongate shaft  528   a  is sized to fit between adjacent solar panels and the bottom wide portion  528   b  is sized to engage a bottom side of the solar panels. The bracket  530  rests on top of the solar panels. The elongate shaft  528   a  permits the snow fence  516  to slide along a gap between adjacent solar panels to a desired location. The fastener  528   d  permits the user to move the top wide portion  528   c  vertically in the channel  530   a  (see  FIG. 30 ) to thereby adjust the distance between a bottom of the bracket  530  and the bottom wide portion  528   b . Therefore, the snow fence  516  can fixedly engage the solar panels. 
       FIG. 31  illustrates a snow fence  616  including first and second coupling portions  628 ,  629  and a bracket  630  couplable to solar panel frames of adjacent solar panels. The bracket  630  is substantially identical to the bracket  530  of  FIGS. 28-30 . The first and second coupling portions  628 ,  629  include a fastener  628   a ,  629   a  and an elongate nut  628   b ,  629   b . The bracket  630  has a channel  630   a  sized to receive the fasteners  628   a ,  629   a . The elongate nuts  628   b ,  629   b  are threaded onto the respective fastener  628   a ,  628   b  to adjust a distance between the elongate nuts  628   b ,  629   b  and a bottom of the bracket  630 . The elongate nuts  628   b ,  629   b  can engage a solar panel bottom portion and the bottom of the bracket  630  can engage a solar panel top portion to thereby clamp the snow fence  616  onto the solar panel. 
     Additionally, any suitable fastener or fastener assembly can be utilized to couple the bracket to the solar panel frame and the embodiments described and illustrated herein are given by way of example only. 
     An example given herein outlines the steps taken to determine how much shade is present outside the footprint of our solar panel snow guard or guard during daylight hours in 30 minute increments. This information will show that there is minimal shading of the solar array during the peak operating hours throughout the year for various latitudes. The Sun Elevation Angle (SEA) is the peak Angle (in degrees) between the sun and horizon. The Roof Pitch (RP) is the angle of a given roof (in degrees). “Down” as used in  FIGS. 36-39  is the length of the shaded portion of the solar array on the down-slope side of the guard. “Up” as used in  FIGS. 36-39  is the length of the shaded portion of the solar array on the Up-Slope side of the guard. 
     The following formulas and description show how large the Down-Slope Shaded Length is. Please note that the calculations in the following pages may not be accurate examples of solar elevation angles or roof pitch situations, the numbers are given for explanation purposes only. 
       FIG. 32  shows the geometry that determines the maximum elevation angle the sun can be before casting a shadow on the down-slope side of the guard. (Down-Slope Snow Guard Angle—Roof Pitch) is the maximum elevation angle the sun can be before shading occurs. In this case, if sun elevation angle exceeds 60 degrees, shading will occur on the down-slope side of the Solar Snow Guard. 
       FIG. 33  shows the geometry that determines the Sun Elevation Angle relationship to the Roof Pitch and Snow Guard Angle. This angle is the shade angle. The formula is Shade Angle=180°−(Snow Guard Angle+Roof Pitch). The 63° shade angle was determined in  FIG. 33  with the calculation of 63.00°=180°−(87.00° (SEA)+30.00° (RP)). 
     The Formula For total shade length if 1.375″ is the triangle height, TAN(180.00°−(87.00°+30.00°))=1.375″/Total Shade Length. Therefore, 1.375″/(TAN(63.00°))=Total Shade Length=0.70″. Due to the rounded corners of the part, calculation tolerance is +/−0.015″. 
     The following formulas and description solve for the Solar Snow Guard Up-Slope Shaded Distance if applicable. Please note that the calculations in the following pages may not be accurate examples of solar elevation angles or roof pitch situations, the numbers are given for explanation purposes only. 
       FIG. 34  shows the geometry that determines the lowest point the sun may be before casting a shadow on the up-slope side of the Solar Snow Guard. (Up-Slope Snow Guard Angle—Roof Pitch) is the lowest maximum elevation angle the sun can be before shading occurs. 
       FIG. 35  shows the geometry that determines the Sun Elevation Angle relationship to the Roof Pitch and Snow Guard Angle. This angle is the shade angle. The formula is Shade Angle=90°−(Sun Elevation Angle+Roof Pitch). The 50.00° shade angle was determined with the formula Shade Angle=50.00°=90°−(10.00°+30.00°). 
     The formula for total shade length if 1.375″ is triangle height is TAN(Shade Angle)=Total Shaded Length/1.375″. The Total Shaded Length=1.375″×TAN(50°)=1.64″. Since the Total Shaded Length does not include the portion of the Solar Snow Guard that is shaded when the sun is directly overhead, 0.127″ must be added to the Total Shaded length in the Up-Slope direction only. Therefore, 1.64″+0.127″=Total Shaded Area=1.77″. 
     One important thing to note about this study is that most solar panels do not generate electricity along their outer edges. This means that the shaded length listed in the charts is actually less by the amount of space on the panel edges not generating electricity. The Solar Snow Guard was designed to cause minimal shading during the peak power production hours as seen in  FIGS. 36-39 . 
       FIGS. 40-44  illustrate a snow fence  716  including a coupling portion  728  and a bracket  730  coupled to solar panel frames  726  of adjacent solar panels  714 . The illustrated coupling portion  728  includes an elongate shaft  728   a , a bottom wide portion  728   b , a top wide portion  728   c  and a fastener  728   d . The bracket  730  has a channel  730   a  sized to receive the top wide portion  728   c , and two lateral apertures  730   b ,  730   c  sized to receive pipes  731   b ,  731   c  therethrough. The pipes  731   b ,  731   c  can function as a snow fence to retain snow on the roof surface, as conduit to protect wires electrically coupled to the solar panels  714  and/or to support other structures above the roof surface. The elongate shaft  728   a  is sized to fit between adjacent solar panels  714  and the bottom wide portion  728   b  is sized to engage a bottom side of the solar panel frames  726 . The bracket  730  rests on top of the solar panel frames  726 . The elongate shaft  728   a  permits the snow fence  716  to slide along a gap between adjacent solar panels  714  to a desired location. The fastener  728   d  permits the user to move the top wide portion  728   c  vertically in the channel  730   a  to thereby adjust the distance between a bottom of the bracket  730  and the bottom wide portion  728   b . Therefore, the snow fence  716  can fixedly engage the solar panel frames  726 . 
       FIG. 45  illustrates a snow fence  816  including a coupling portion  828  and a bracket  830  couplable to solar panel frames of adjacent solar panels. The coupling portion  828  includes a fastener  828   a  and an elongate nut  828   b . The bracket  830  has a channel  830   a  sized to receive the fastener  828   a , and two lateral apertures  830   b ,  830   c  sized to receive pipes therethrough or to support other structures. The elongate nut  828   b  is threaded onto the fastener  828   a  to adjust a distance between the elongate nut  828   b  and a bottom of the bracket  830 . The elongate nut  828   b  can engage a solar panel bottom portion and the bottom of the bracket  830  can engage a solar panel top portion to thereby clamp the snow fence  816  onto the solar panel. 
       FIGS. 46-50  illustrate a snow fence  916  including coupling portions  928  and  929  and a bracket  930  couplable to solar panel frames  926  of adjacent solar panels  914 . The coupling portions  928  and  929  each include a fastener  928   a ,  929   a  and an elongate nut  928   b ,  929   b . The fasteners  928   a ,  929   a  are sized to fit between adjacent solar panels  914  to thereby permit the snow fence  916  to slide along a gap between adjacent solar panels  914  to a desired location. The elongate nuts  928   b ,  929   b  are threaded onto the respective fasteners  928   a ,  929   a  to adjust a distance between the elongate nuts  928   b ,  929   b  and a bottom of the bracket  930 . The bracket  930  rests on top of the solar panel frames  926 . The elongate nuts  928   b ,  929   b  engage a bottom of the solar panel frame  926  and a bottom of the bracket  930  engages a top of the solar panel frame  926  to thereby clamp the snow fence  916  onto the solar panel  914 . The bracket  930  has two flanges each of which includes two lateral apertures  930   b ,  930   c  sized to receive pipes  931   b ,  931   c  therethrough. The pipes  931   b ,  931   c  can function as a snow fence to retain snow on the roof surface, as conduit to protect wires electrically coupled to the solar panels  914  and/or to support other structures above the roof surface. 
       FIG. 51  illustrates a snow fence  1016  including a coupling device  1028  and a bracket  1030  that can be coupled to solar panel frames of adjacent solar panels. The coupling portion  1028  includes an elongate portion  1032  and a rotating portion  1034 . The bracket  1030  has a channel  1030   a  sized to receive the elongate portion  1032 , and two lateral apertures  1030   b ,  1030   c  sized to receive pipes therethrough. The rotating portion  1034  is shown in an uncoupled position, but can be rotated to engage the solar panel frames. The rotating portion  1034  has a roughened portion that engages the solar panel frames in the coupled position. The coupling device  1028  is similar to the coupling device  28  shown in  FIGS. 6-15  and described in detail above. Reference is made to the coupling device  28  for a more detailed description of the coupling device  1028 . 
       FIGS. 52-55  illustrate a snow fence  1116  including a coupling portion  1128  and a bracket  1130  that can be coupled to solar panel frames of adjacent solar panels. The illustrated coupling portion  1128  includes an elongate shaft  1128   a , a bottom wide portion  1128   b , a top wide portion  1128   c  and a fastener  1128   d . The bracket  1130  has a channel  1130   a  sized to receive the top wide portion  1128   c , and two lateral apertures  1130   b ,  1130   c  sized to receive pipes therethrough. The pipes can function as a snow fence to retain snow on the roof surface, as conduit to protect wires electrically coupled to the solar panels and/or to support other structures above the roof surface. The elongate shaft  1128   a  is sized to fit between adjacent solar panels and the bottom wide portion  2228   b  is sized to engage a bottom side of the solar panel frames. The bracket  2230  rests on top of the solar panel frames. The elongate shaft  2228   a  permits the snow fence  1116  to slide along a gap between adjacent solar panels to a desired location. The fastener  118   d  permits the user to move the top wide portion  1128   c  vertically in the channel  1130   a  to thereby adjust the distance between a bottom of the bracket  1130  and the bottom wide portion  1128   b . Therefore, the snow fence  1116  can fixedly engage the solar panel frames. 
       FIGS. 56-58  illustrate a snow fence  1216  including a coupling portion  1228  and a bracket  1230  couplable to solar panel frames of adjacent solar panels. The coupling portion  1228  includes a fastener  1228   a  and an elongate nut  1228   b . The bracket  1230  has a channel  1230   a  sized to receive the fastener  1228   a , and two lateral apertures  1230   b ,  1230   c  sized to receive pipes therethrough or to support other structures. The elongate nut  1228   b  is threaded onto the fastener  1228   a  to adjust a distance between the elongate nut  1228   b  and a bottom of the bracket  1230 . The elongate nut  1228   b  can engage a solar panel bottom portion and the bottom of the bracket  1230  can engage a solar panel top portion to thereby clamp the snow fence  1216  onto the solar panel. 
       FIGS. 59-67  illustrate various brackets according to some embodiments of the invention. These brackets include a horizontal portion and a vertical portion. The vertical portions have different shapes and angles designed to retain snow on roof having various angles. These brackets can be interchanged with any of the embodiments illustrated and described herein. 
       FIGS. 68 and 69  illustrate different bottom portions according to some embodiments of the present invention. These bottom portions include an aperture that can be threaded or can be coupled to the bracket with a nut. The bottom portion of  FIG. 68  includes substantially smooth wings, whereas the bottom portion of  FIG. 69  includes rough toothed wings. These bottom portions can be interchanged with any of the embodiments of the bottom portions or elongate nuts illustrated and described herein. 
       FIGS. 70-72  illustrate a snow fence according to some embodiments of the present invention. The snow fence includes a bracket (also shown in  FIG. 71 ) and a mid-panel support (also shown in  FIG. 71 ). Pipes are supported by the bracket and the mid-panel support. The bracket and/or mid-panel support can be utilized with any of the embodiments illustrated and described herein. 
       FIGS. 73 and 74  illustrate a snow fence according to some embodiments of the present invention. The snow fence includes a bracket (also shown in  FIG. 73 ) and a mid-panel support (similar to the mid-panel support shown in  FIG. 71 ). Pipes are supported by the bracket and the mid-panel support. The bracket and/or mid-panel support can be utilized with any of the embodiments illustrated and described herein. 
       FIGS. 75-79  illustrate various end clamps according to some embodiments of the present invention. The end clamps can be utilized at the outer edges of the solar panel array at first and second ends of the pipes. If desired, the end clamps can be utilized in the middle of a run of solar panels if the snow fence does not extend across an entire length of the solar panel array. The end clamps offer support to the pipes and can be coupled to the solar panels in a similar manner as the brackets of the present invention. 
     Any of the brackets illustrated herein can be interchanged with any of the coupling devices or portions illustrated herein to create a snow fence in accordance with the present invention. The illustrated combinations are given by way of example only.