Abstract:
The invention is a new stabilized racking system for solar cell panels on a surface through a novel use of ballast weights and a wind optimized design. The system is further optimized to fit a range of sizes and thicknesses of modules through a combination of self adjusting end clamps, adjustable tilt legs, and unique wind screen design. The system can include an array of individual solar panel systems that are reinforced in both lateral directions to reduce the amount of ballast weight required.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/541,985, filed Sep. 30, 2011 and U.S. Provisional Application No. 61/586,648, filed Feb. 13, 2012, both of which are incorporated by reference herein in their entirety. 
     
    
     BACKGROUND 
       [0002]    Solar cell panels (also referred to as solar cell modules) are an increasingly popular means of generating renewable power, and recently there has been a wide proliferation of solar projects of all sizes, from small residential installations to large utility scale power production. Current solar cell panels are typically composed of photovoltaic solar cells encased in a rigid supporting frame. When installed, these solar cell panels are supported by a racking system, which together comprise a solar panel installation. 
         [0003]    A problem with many current methods of installing solar panels is that the surface supporting the solar panel installation must be penetrated to attach the system. For example, typical solar panel installations are secured to rooftop surfaces by penetrating the roof surface with screws or other means. Adequately securing the solar panel system to the surface is critical to protect the panels and surrounding property from damage caused by wind and/or seismic activity, both of which could cause damage if the solar panel system is not properly secured to the surface. Moreover, securing solar panel systems to a surface often requires that the surface be penetrated numerous times, thereby compromising the surface&#39;s integrity. This is particularly problematic on rooftop installations where the roof surface is sealed to protect against moisture entering the building. 
       SUMMARY 
       [0004]    Various embodiments described herein overcome drawbacks associated with conventional techniques and devices for securing and supporting solar panel systems. Accordingly, the disclosed wind tunnel optimized solar panel systems can include a racking system that may be configured to reduce the lift on a solar panel system caused by wind. In some embodiments, this is accomplished through the use of specifically placed windscreens. Reducing the lift caused from wind reduces the force necessary to keep the solar panels in place. The size and placement of the windscreens have been refined through testing to allow pressure equalization in high lift situations as a result of tight fit to the mounting surface and strategic venting. In some embodiments, the windscreens can also include a rack for holding a number of ballast weights that use the force of gravity to keep the solar panel system in place, even in the face of wind and/or seismic activity. 
         [0005]    Accordingly, there are provided wind tunnel optimized solar panel racking systems that can support and secure solar panels to a surface while reducing the need for the damaging surface penetrations typically required to securely install solar panels. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The above and other objects and advantages of the invention will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying figures, in which like reference characters refer to like parts throughout, and in which: 
           [0007]      FIG. 1  depicts an exemplary embodiment of a wind optimized and ballasted solar panel system; 
           [0008]      FIG. 2  depicts a view of a partially assemble exemplary embodiment of a solar panel system with a mechanical anchor; 
           [0009]      FIG. 3  depicts a detailed cross-section of a solar panel module attached to a rail; 
           [0010]      FIG. 4  depicts a detailed cross-section of a solar panel module attached to a support leg; 
           [0011]      FIG. 5  depicts a view of a partially assemble exemplary embodiment of a solar panel system; 
           [0012]      FIG. 6  depicts an exploded view of a partially assemble exemplary embodiment of a solar panel system; 
           [0013]      FIG. 7  depicts an example embodiment of a wind optimized and ballasted solar panel system with additional wind screens being installed to provide additional ballast trays under the module; 
           [0014]      FIGS. 8A ,  8 B, and  8 C depict example embodiments of wind optimized and ballasted solar panel systems with 1-3 wind screens installed to provide additional ballast trays under the module; 
           [0015]      FIG. 9  depicts an isometric view of a partially assembled multi-unit solar panel system; 
           [0016]      FIGS. 10A and 10B  depict views of a rail splice in accordance with some embodiments; 
           [0017]      FIG. 11  depicts an attachment assembly with a self-adjusting end clamp; 
           [0018]      FIGS. 12A ,  12 B, and  12 C show cross-sectional views of a self-adjusting end clamp in accordance with some embodiments; and 
           [0019]      FIG. 13  is a perspective view of a section of a solar panel system  1300  in accordance with some embodiments. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings. 
         [0021]    Wind tunnel optimized solar panel systems can include solar panel modules mounted to a racking system that includes a number of features designed to reduce uplift caused by environmental factors, such as wind, and increase the amount of downforce on the solar panel system. To this end, a wind tunnel optimized solar panel system can include a number of windscreens, wind grates, and ballast weights, which, together, can achieve those dual objectives. By reducing uplift while increasing downforce, a solar panel system may be installed on a surface without the need for mounting hardware that can penetrate and/or damage the surface. 
         [0022]    The weight required to secure a solar panel system may depend on specific environmental circumstances including, for example, location, altitude, typical local weather patterns, and seismic activity. The weight of the ballast weights can be easily varied to meet the environmental conditions by adding or reducing the number or type of ballast weights, as needed. The combination of a wind optimized design and ballast weights allows a solar panel system to reduce the depth and/or number of penetrations required for installation. In some installations, the need for surface penetrations may be eliminated entirely. In some embodiments, standoff attachments can be incorporated into a solar panel system, which can further help to enhance stability of the system in windy conditions and/or in the event of seismic activity. 
         [0023]    Besides reducing or eliminating the need to penetrate the surface on which the solar panel system is installed, some embodiments may have the added benefit of simplifying the installation process by reducing the number of steps required to install the solar panel systems. The cost of installation may further be reduced by reducing the tools and equipment an installer is required to bring to the job site. 
         [0024]    In some embodiments, modules can be installed in a landscape orientation in which a long side of the solar panel module is parallel to the installation surface (e.g., a roof or the ground). Such an orientation can keep modules close to the installation surface to reduce uplift on the modules caused by the wind. In some embodiments, the solar panel system can be installed on a flat surface with the modules tilted to increase solar exposure. In some further embodiments, the racking system can include shared rails, which can form a more efficient structure that uses less material and assembles more quickly than typical solar panel systems. Tilt legs coupled to flat rails can provide for module tilt and mounting points for windscreens to reduce uplift on the modules. 
         [0025]    Windscreen installation may be accomplished by coupling a windscreen to rear tilt legs on the solar panel system. Self-adjusting end clamps can allow for end-of-row windscreen installation without using requiring additional fasteners. Such self-adjusting end clamps can also permit strategic venting at the ends of a row of modules. Windscreens may also include a tray that can hold ballast. In some embodiments, additional windscreens can be installed under the modules to support additional ballast. In some embodiments, windscreens designed to block or redirect wind can also double as structural members for the solar panel system, providing additional system rigidity. 
         [0026]    The mounting rails can also double as a structural member, providing system rigidity. In some embodiments, the inherent rigidity in the structure allows for distribution of wind loading over the entire system, which may reduce the amount of ballast weight required, thereby reducing the overall system weight and installation cost. 
         [0027]    In some embodiments, standoff attachments may also be incorporated into the system design to provide for seismic or uplift loading as needed to meet local code design and load requirements. As would be appreciated by one skilled in the art, the system can be compatible with a range of module sizes, and may use self-adjusting end clamps to secure modules with a range of module frame thicknesses. 
         [0028]      FIG. 1  is an exemplary embodiment of a wind optimized and ballasted solar panel system  100 . Solar panel system  100  can include feet  101 , rails  102 , support legs  103 , self-adjusting end clamps  104 , a solar panel module  105 , wind grates  106 , a wind screen  107 , a ballast support tray  108 , ballast weights  109 , and side windscreens  110 .  FIG. 1  depicts a single panel system. However, in some embodiments, rails  102  can extend beyond the lengths shown in  FIG. 1 , facilitating the installation of multi-panel systems. Such systems are described in greater detail below with respect to  FIGS. 11 and 12 . 
         [0029]    Feet  101  can each include a flat portion that rests on a surface and a vertical portion extending perpendicularly or obliquely from the flat portion that can connect to a rail  102 . Feet  101  may be designed to snap into the rails  102 . Alternatively, feet  101  can be connected to rails  102  with screws, bolts, or other suitable fasteners. Feet  101  can be constructed of any suitable material (e.g., a metal, such as steel or aluminum, a plastic, or a composite). In some embodiments, the surface area of the flat portion of feet  101  can be determined based on, for example, the characteristics of the surface on which they will rest. 
         [0030]    As depicted in  FIG. 1 , solar panel system  100  can include four feet  101  (one foot is not visible), with one foot at each corner of solar panel system  100 . However, one skilled in the art will appreciate that any suitable number of feet can be included depending on, for example the circumstances (e.g., environmental considerations such as wind and seismic activity) and the composition of the mounting surface. Feet  101  can also serve to lift rails  102  slightly off the mounting surface, which can facilitate drainage of the area underneath solar panel system  100 , for example. In other embodiments, additional feet  101  can be included depending on the circumstances and the composition of the mounting surface. Solar panel systems, according to some embodiments, can be mounted on a number of different relatively level surfaces such as, for example, a roof or the ground. 
         [0031]    Rails  102  can be mounted on feet  101  to form a base for solar panel system  100 . Accordingly, two rails  102  may be placed parallel to one another at a width corresponding, roughly, to the width of solar panel module  105 . Furthermore, rails  102  can have any suitable length. For example, rails  102  can be long enough to provide a stable base for a single solar panel system  100 . In other embodiments, rails  102  can be long enough to support two or more solar panel systems as discussed in more detail below with respect to  FIG. 9 . Rails  102  may be constructed of any suitable material (e.g., for example aluminum, steel, plastic or composite). In some embodiments, feet  101  can be configured to snap into notched surfaces formed in rails  102 . 
         [0032]    Support legs  103  may be used to support the solar panel modules at an angle determined appropriate for the location. For example, the angle may be chosen to optimize solar exposure at the installation location&#39;s latitude. In particular, the length of the support legs  103  and the angle at which they are attached to rails  102  may be varied depending on the desired angle of solar panel module  105 . Support legs  103  may be constructed of any suitable material (e.g., aluminum, steel, plastic or composite). 
         [0033]    In some embodiments, support legs  103  can be secured using either two split lock washers or two internal star washers. Star washers may be especially appropriate as they can provide electrical continuity for grounding solar panel system  100 . However, as would be appreciated by a person of skill in the art, any suitable fasteners may be used to couple support legs  103  to rails  102 . Support legs  103  may also have two holes at the top to allow the inclusion of a WEEB grounding washer or the equivalent. 
         [0034]    Self-adjusting end clamps  104  can be two-piece end clamps used to secure solar panel module  105  to the rest of solar panel system  100 . Self-adjusting end clamps  104  may be secured in place with a bolt that causes the self-adjusting end clamps  104  to automatically adjust to the size of the frame of solar panel module  105 . Although solar panel system  100  includes four self-adjusting end clamps  104  in this example embodiment, more self-adjusting end clamps may be required depending on the environmental conditions where solar panel system  100  is installed. Furthermore, mid clamps may be used to connect multiple solar panel modules arranged in a row. 
         [0035]    In the exemplary embodiment shown in  FIG. 1 , solar panel module  105  may be a photovoltaic solar panel that includes an array of photovoltaic cells. 
         [0036]    Wind grates  106  can be incorporated between the top edges of solar panel module  105  and windscreen  107  to permit airflow and pressure equalization of solar panel system  100 . Wind grates  106  can include openings of any suitable shape (e.g., a rectangular shape). In some embodiments, wind grates  106  can be formed from one contiguous piece with separate openings cut into the piece. In these embodiments, wind grates  106  may be of nesting roll-form steel construction that is cheap to manufacture and easy to ship. Roll-form steel has the additional benefits of being strong and easy to work with. Holes on the top of wind grates  106  can be punched, stamped, or otherwise formed to provide ventilation of solar panel system  100 . Such ventilation can serve to keep solar panel module  105  cool and provide pressure equalization to mitigate uplift from wind forces. Wind grates  106  may be constructed of any suitable material (e.g., aluminum, steel, plastic or composite). 
         [0037]    Windscreen  107  can be coupled to the back of solar panel system  100  to block airflow and at least partially support ballast weights  109 . Windscreen  107  may be constructed of any suitable material (e.g., aluminum, steel, plastic or composite). Windscreen  107  may be attached to support legs  103  with, for example, bolts or screws. In other embodiments, windscreen  107  may be snapped into place on the support legs  103 . 
         [0038]    Ballast support tray  108  can be attached to windscreen  107  to support ballast weights  109 . Accordingly, ballast support tray  108  can extend perpendicularly or obliquely from the outer surface of windscreen  107  to form a ledge. Ballast weights  109  can be placed on the ledge of ballast support tray  108  to provide downforce to solar panel system  100 , which can serve to counter uplift generated by, for example, wind. Ballast support tray  108  may be constructed of any suitable material (e.g., aluminum, steel, plastic or composite). In some embodiments, ballast support tray  108  and windscreen  107  can be formed as a single, contiguous piece. In other embodiments, ballast support tray  108  can be attached to windscreen  107  with bolts, screws and/or other suitable fasteners. 
         [0039]    Ballast weights  109  may be concrete blocks or any other suitable weighted objects used to hold the solar panel system  100  in place and counteract dangerous uplift forces. The number of ballast weights  109  used and their weights may depend on the environmental requirements of the solar panel system  100 . 
         [0040]    In some embodiments, wind grates  106 , windscreen  107  and ballast support tray  108  can be a single contiguous piece of roll form steel. For example, a long strip of sheet metal can be exposed to a roll-forming process that can create a first section for wind grates  106 , a second section for windscreen  107 , and at least a third section for ballast support tray  108 . Openings in wind grates  106  can be formed either before or after the roll-forming process. One skilled in the art will appreciate that some portions (e.g., windscreen  107  and ballast support tray  108 ) can be formed together, and other portions (e.g., wind grates  106 ) can formed and coupled to solar panel system  100  separately. 
         [0041]    Side windscreens  110  can be coupled to one or both sides of solar panel system  100  (e.g., to rails  102 , support legs  103 , and/or solar panel module  105 ) to divert airflow around solar panel system  100 . Side windscreens  110  may be constructed of any suitable material (e.g., aluminum, steel, plastic or composite). 
         [0042]      FIG. 2  depicts an example embodiment of a partially constructed solar panel system  200 . Solar panel system  200  can include feet  201 , rails  202 , support legs  203 , self-adjusting end clamps  204 , solar panel module  205 , mechanical anchor  211 , standoff attachment  212 , standoff bracket  213 , anchor rail  214  and mechanical anchor  250 . . In some embodiments, partially constructed solar panel system  200  depicts a subassembly for constructing a complete solar panel system as depicted in  FIG. 1 . 
         [0043]    Solar panel system  200  can be installed on a relatively flat surface (e.g., a roof or the ground) to provide a stable base for a full solar panel system. In particular, rails  202  can be mounted on feet  201  such that the rails are parallel to each other at a width roughly corresponding to the width of a solar panel module (e.g., solar panel module  105  of  FIG. 1 ) to be mounted to the solar panel system. Rails  202  can be mounted on feet  201  in any suitable manner. For example, rails  202  can include notched surfaces configured to snap onto corresponding features of feet  201 . In other embodiments, rails  202  can be mounted to feet  201  using any suitable hardware (e.g., bolts, screws, and or other fasteners). 
         [0044]    Support legs  203  can be coupled to rails  202  to support the solar panel module. In particular, support legs  203  can be mounted on rails  202  at an angle optimized for the location of the solar panel installation. For example, the angle may be chosen to optimize the angle of a solar panel module to receive maximum sun exposure at a particular latitude. In these and other embodiments, the angle may further be chosen to reduce the effect of uplift caused by wind at the installation site. A windscreen (e.g., windscreen  107  of  FIG. 1 ) can also be mounted to solar panel system  200  at an angle determined by support legs  203 . Support legs  203  can be coupled to rails  202  in any suitable manner. For example, support legs  203  may be configured to snap into rails  202  and/or attach to rails  202  using one or more fasteners. 
         [0045]    According to some embodiments, mechanical anchor  211 , standoff attachment  212 , standoff bracket  213  and anchor rail  214  can serve to secure solar panel system  200  to a surface. Mechanical anchor  211  may be required depending on local regulations and/or conditions at the installation site. Mechanical anchor  211  can used, for example, if tall flashings (e.g., 8″ flashings) are required for the installation surface (e.g., for waterproofing purposes). In particular, to make room for tall flashings, mechanical anchor  211  can be coupled to anchor rail  214  with standoff bracket  213  and a standoff attachment  212 . Standoff bracket  213  can include a riser section coupled to anchor rail  214  with one or more fasteners, a spacer section, which can extend obliquely (e.g., at a 45° angle) in a direction away from both anchor rail  214  and the installation surface, and a standoff section for coupling to standoff attachment  212 . 
         [0046]    Standoff attachment  212  may be configured to position mechanical anchor  211  properly with respect to the tall flashing. 
         [0047]    In embodiments in which a tall flashing is not required, a simpler mechanical anchor  250  can be used to secure solar panel system  200  to the installation surface. In particular, mechanical anchor  250  can simply be coupled to anchor rail  214  with a single bracket, obviating the need for standoff bracket  213 . Mechanical anchor  250  may be appropriate, for example, if a shorter flashing such as, for example, a pour in place curb flashing is used. 
         [0048]    Anchor rail  214  can be configured to perpendicularly span and couple to rails  202  to provide a mounting point for standoff bracket  213 , standoff attachment  212 , and mechanical anchor  211 . In some embodiments, anchor rail  214  can be coupled to a rail  202  with an L-foot  215 . L-foot  215  can have a first portion that attaches to anchor rail  214  and a second portion that attaches to rail  202 , thus coupling anchor rail  214  to rail  202 . In some embodiments, L-foot  215  can be coupled to channel nuts snapped into anchor rail  214  and or rail  202  with a bolt. Aside from providing a mounting surface for mechanical anchor  211  and/or mechanical anchor  250 , anchor rail  214  may provide additional structural support for solar panel system  200 . 
         [0049]      FIG. 3  depicts a detailed cross-sectional view of a portion of solar panel system  200  of  FIG. 2 , including solar panel module  205  coupled to rail  202  with a split leg  220 , a channel nut  221 , and self-adjusting end clamp  204 . Split leg  220  may be a rigid member that is configured to tilt solar panel module  205  at a predetermined angle. In some embodiments, the angle of the short tilt leg used to attach the rail to the module can be varied depending on the desired angle of the module. Accordingly, split leg  220  can include a first section configured to lie flush against the top of rail  202 , a second section bent at the predetermined angle from the first section that is configured to lie flat against the bottom surface of solar panel module  205 , and a vertical section extending from the junction between the first section and the second section that is configured to support a the bottom side surface of solar panel module  205 . 
         [0050]    Split leg  220  can be coupled to rail  202  using any suitable fasteners. However, according to some embodiments, a channel nut  221  can be coupled to a channel of rail  202  (e.g., by snapping channel nut into notches formed in rail  202 ), and a bolt can be threaded hole in split leg  220  and into a threaded hole of channel nut  221 . Furthermore, solar panel module  205  can be coupled to split leg  220  with a clamp. For example, if clamp  204  is at an outer edge of a row of solar panel systems, clamp  204  can be a self-adjusting edge clamp. On the other hand, if clamp  204  is positioned between two solar panel systems in the same row, clamp  204  can be a mid clamp. 
         [0051]      FIG. 4  depicts a detailed cross-sectional view of solar panel system  200  of  FIG. 2 , including solar panel module  205  attached to support leg  203 . In some embodiments, support leg  203  can be formed from a top section  203   a,  a rail section  203   b,  and a base section  203   c.  In such embodiments, solar panel module  205  can be attached to top section  203   a  of support leg  203  with clamp  204  (e.g., a self-adjusting end clamp or a mid clamp), and top section  203   a  can be attached to a rail section  203   b  of support leg  203  with a fastener (e.g., a bolt and washer). Support leg  203  can be attached to rail  202  via a base section  203   c,  which can, in turn, be attached to rail section  203   b  with a fastener (e.g., a bolt and washer). Additionally, base section  203   c  can be attached to rail  202  with suitable hardware, such as a bolt with a split lock washer threaded into channel nut  221 , which can be identical to channel nut  221  of  FIG. 3 . According to other embodiments, support leg  203  could be molded, stamped, or otherwise formed as a single, contiguous piece. 
         [0052]      FIG. 5  depicts an example embodiment of a partially constructed solar panel system  500 . Solar panel system  500  can include feet  501 , rails  502 , support legs  503 , self-adjusting end clamps  504 , solar panel module  505 , wind grates  506 , windscreen  507 , ballast support tray  508 , and anchor rail  514 . Solar panel system  500  can be, for example, a subassembly of solar panel system  100  of  FIG. 1 . 
         [0053]    In some embodiments, windscreen  507 , wind grates  506 , and ballast support tray  508  can be formed together as one contiguous piece. For instance, the three sections can be formed from the three portions of a “ZEE” shaped roll form. The top portion of the ZEE-shaped roll form can form the section for wind grates  506 . Wind grates  506  can include openings to allow ventilation for solar panel system  500  and passive cooling of solar panel module  505 . The openings formed to create wind grates  506  can be any suitable shape and size to promote optimal cooling and ventilation while retaining sufficient structural integrity. 
         [0054]    The main portion of the ZEE-shaped roll form can form the section for windscreen  507 . Windscreen  507  can be configured to block or redirect wind around solar panel system  500  to prevent dangerous uplift forces. 
         [0055]    Windscreen  507  can also include slotted mounting holes  516  to facilitate usage with solar panel modules of varying sizes. Windscreen  507  may be coupled to support legs  503  with any suitable fastener (e.g., flange nuts). 
         [0056]      FIG. 6  depicts a partially constructed solar panel system  600  including an exploded view of a side windscreen  630  and trim pieces  631 ,  632 , and  633 . Solar panel system can include feet  601 , rails  602 , support legs  603 , self-adjusting end clamps  604 , solar panel module  605 , wind grates  606 , rear windscreen  607 , ballast support tray  608  and side windscreens  610 . Solar panel system  600  can be, for example, a subassembly of solar panel system  100  of  FIG. 1 . 
         [0057]    Side windscreen  630  can be coupled to the rest of solar panel system  600  with trim pieces  631 ,  632 , and  633 . Trim piece  631  can include a hook configured to snap onto, or otherwise securely couple to, rail  602 . In some embodiments, the hook can include a flange that engages a notch in a rail  602 . In other embodiments, the hook fits closely against a flange of rail  602 . Trim piece. Similarly, trim piece  632  can snap onto, or otherwise securely engage, a support leg  603 . Trim piece  633 , on the other hand, may be secured to solar panel module  605  with self-adjusting end clamps as discussed in more detail below. Trim pieces  631 ,  632 , and  633  can each include a slot configured to receive and securely retain an edge of side windscreen  630 . 
         [0058]    Side windscreen  630  may be cheaply and easily manufactured from a flat piece of sheet metal or similar material. In some embodiments, side windscreen  630  can be shaped so as to leave a gap between itself and solar panel module  605  to vent solar panel system  600  and passively cool solar panel module  605 . Furthermore, side windscreen  630  can help direct wind around solar panel system  600  to prevent dangerous uplift on solar panel module  605 . 
         [0059]    According to embodiments in which only a single solar panel system is included in the installation, side windscreens  630  can be mounted on each side of solar panel system  600 . However, if solar panel system  600  is part of a row of individual solar panel systems, side windscreen  630  may only be mounted on one side (i.e., the side of solar panel system  600  not directly connected to an adjacent solar panel system in the row). 
         [0060]      FIG. 7  is an exemplary embodiment of a wind optimized and ballasted solar panel system  700 . The solar panel system  700  includes feet  701 , rails  702 , support legs  703 , self-adjusting end clamps  704 , solar panel module  705  and a horizontal ballast support tray  750 .  FIG. 7  shows a single panel system, but in certain embodiments, rails  702  may continue beyond what is shown in  FIG. 7 , allowing for multiple panel systems. Solar panel system  700  can be, for example, a subassembly of solar panel system  100  of  FIG. 1 . 
         [0061]    Horizontal ballast support tray  750  can be attached to rails  702  with any suitable hardware. According to some embodiments, horizontal ballast support tray  750  can include a number of slotted mounting holes configured receive a combination of a bolt, washers and a channel nut for coupling horizontal ballast support tray  750  to rails  702 . In these embodiments, slotted mounting holes formed in horizontal ballast support tray  750  can receive a bolt  751  configured to thread through a first washer  752 , horizontal ballast support tray  750 , a second washer  753 , and finally into a channel nut  754 . Channel nut  754  can be inserted into rail  702  to secure horizontal ballast support tray  750 . Further, in some embodiments, horizontal ballast support tray  750  may be formed in one contiguous piece with one or more side or rear windscreens (not shown in  FIG. 15 ). These embodiments can serve to simplify a solar panel system by allowing one part to serve multiple system functions. 
         [0062]    Horizontal ballast support tray  750  can support ballast weights, which can aid in securing solar panel system  700  to a surface. In particular, because the weight required to properly secure solar panel system  700  to the installation surface may vary based on the environmental conditions at the installation site, additional ballast may be required beyond what can be mounted on, for example, ballast support tray  108  of 
         [0063]      FIG. 1 . Horizontal ballast support tray  750  may be constructed of any suitable material (e.g., aluminum, steel, plastic or composite). 
         [0064]      FIGS. 8A ,  8 B, and  8 C depict example embodiments of wind optimized and ballasted solar panel systems  800   a,    800   b,  and  800   c.  Solar panel system  800  can similar, for example, to solar panel system  700  and can include a single horizontal ballast support tray  850   a  for loading ballast weights. Solar panel systems  800   b  and  800   c  of  FIGS. 8   b  and  8   c  can include two horizontal ballast support trays  850   b  and three horizontal ballast support trays  850   c,  respectively. The additional trays in solar panel systems  800   b  and  800   c  can be used to load more ballast weights on the system as required by environmental reasons. The ballast support trays of  FIGS. 8   a ,  8   b , and  8   c  can be mounted on solar panel systems  800   a,    800   b,  and  800   c  with any suitable hardware, including with a bolt, washers and a channel nut as described above with respect to  FIG. 7 . Any suitable number of ballast support trays can be used to support an appropriate amount of ballast for a solar panel system (e.g., based upon environmental conditions at the installation site). 
         [0065]      FIG. 9  depicts an isometric view of a partially assembled multi-unit solar panel system  900 . Multi-unit solar panel system  900  can include any suitable number of individual solar panel systems (e.g., solar panel system  100  of  FIG. 1 ) arranged in any suitable number of rows and columns. As depicted, multi-unit solar panel system  900  is designed to have four rows and four columns of individual solar panel systems. Each individual solar panel system can include a solar panel module  905  mounted to rails  902  with support legs  903 . Additionally, each individual solar panel system can include ballast weights  909  mounted on a ballast weight tray  908 , which can be integrally formed with, or coupled to, windscreen  907 . 
         [0066]    Side windscreens  930  can be mounted on the outer sides of end-of-row individual solar panel systems. That is, side windscreens  930  may not be mounted on the sides of individual solar panel systems that are adjacent to another individual solar panel system in the same row. According to some embodiments, side windscreens  930  can be mounted on individual solar panel systems with trim pieces (e.g., trim pieces  631 ,  632 , and  633  of  FIG. 6 ) and one or more self-adjusting end clamps  904 . 
         [0067]    Solar panel modules can be coupled to multi-unit solar panel system  900  using self-adjusting end clamps  904  and/or mid clamps. For example, self-adjusting end clamps  904  may couple solar panel modules  905  to an individual solar panel system (e.g., as described with respect to  FIGS. 3 and 4 ) on the sides of end-of-row individual solar panel systems that are not adjacent to any other individual solar panel system. Contrariwise, where a solar panel module  905  is adjacent to another solar panel module  905  in the same row, mid clamps can be used to secure both of the adjacent solar panel modules  905  to each other and/or to multi-unit solar panel system  900 . A mid clamp can be a single clamp that secures two solar panel modules to one or more support legs  903 . 
         [0068]    In order to improve the structural integrity of multi-unit solar panel system  900 , windscreens  907  can be configured to overlap adjacent windscreens  907  in the same row. In some embodiments, a windscreen  907  may be coupled to its own individual solar panel system and/or an adjacent individual solar panel system. For example, an individual solar panel system that is adjacent to two other individual solar panel systems in the same row can have a windscreen  907  that is coupled to support legs  903  of its own individual solar panel system as well as one or both of the adjacent individual solar panel systems. In other embodiments, windscreens  907  can overlap without being physically coupled to support legs  903  of adjacent individual solar panel systems. 
         [0069]    Depending on conditions at the installation site, and/or local regulatory requirements, some or all of the individual solar panel systems can include anchor rail  914 , standoff bracket  913 , standoff attachment  912 , and mechanical anchor  911 . Anchor rail  914 , standoff bracket  913 , standoff attachment  912 , and mechanical anchor  911  may correspond to, for example, anchor rail  214 , standoff bracket  213 , standoff attachment  212 , and mechanical anchor  211  of  FIG. 2 . One skilled in the art will appreciate that the type of mechanical anchor used may also depend on conditions and/or requirements at the installation site and, therefore, a different mechanical anchor (e.g., mechanical anchor  250  of  FIG. 2 ) may be appropriate for a given multi-unit solar panel system. 
         [0070]    Each row in multi-unit solar panel system  900  may share rails  902  with at least one other row. That is, rails  902  can span the entire length of multi-unit solar panel system  900 . In some embodiments, each rail  902  can be formed as a single, contiguous member that can support all of the rows of individual solar panel systems in multi-unit solar panel system  900 . In other embodiments, each rail  902  can include a number of individual rails that are coupled (e.g., spliced) together. Although, these embodiments may require extra hardware, they may be preferable as it can be difficult to manufacture and ship very long rails. Regardless of whether each rail is contiguous or multi-sectioned, rails  902  can be mounted on feet  901  (e.g., as described with respect to  FIG. 1 ) after feet  901  are placed on the installation surface. 
         [0071]      FIG. 10A  depicts an exploded view of a rail splice  1010 . Rail splice  1010  can include rail  1002   a  spliced to rail  1002   b  with rail splice insert  1040 , rails splice top  1041 , bolts  1042 , and split lock washers  1043 . In particular, rail splice insert  1040  can be configured to slide or snap into notches formed in rail  1002   a  and  1002   b.  Rail  1002   a  and  1002   b  may be pushed together (e.g., until they are abutting), and then rail splice top  1041  can be placed above rail splice insert  1040  and clamped into place using bolts  1042  and split lock washers  1043 . 
         [0072]      FIG. 10B  depicts a perspective view of assembled rail splice  910 , including rail  1002   a  spliced to rail  1002   b  with rail splice insert  1040 , rails splice top  1041 , and bolts  1042  (split lock washers  1043  are not visible in  FIG. 10B ). In some embodiments, one or more rail splices  1010  can be used to couple together multiple rails for a solar panel system (e.g., multi-sectioned rails  902  of multi-unit solar panel system  900  of  FIG. 9 ). 
         [0073]      FIG. 11  depicts an attachment assembly  1100  with a self-adjusting end clamp  1110 . Self-adjusting end clamp  1110  may correspond to, for example, self-adjusting end clamp  104  of  FIG. 1 . Accordingly, self-adjusting end clamp  1110  can be configured to attach a solar panel module to an individual solar panel system (e.g., solar panel system  100  of  FIG. 1 ) or at the ends of rows of solar panel systems that form a multi-unit solar panel system (e.g., multi-unit solar panel system  900  of  FIG. 9 ). 
         [0074]    Self-adjusting end clamp  1110  can include a top member  1111  and a bottom member  1112  for attaching a solar panel module  1105  to a support leg  1103  mounted to rail  1102 , which can, in turn, be supported by support foot  1001 . Self-adjusting end clamp  1110  can grip solar panel module  1105  with top member  1111  and bottom member  1112 , which can each include holes for receiving a bolt  1113 . As bolt  1113  is tightened, bolt  1113  can move top member  1111  towards bottom member  1112 , thereby gripping the solar panel module  1105  between top member  1111  and bottom member  1112 . 
         [0075]    Top member  1111  of the self-adjusting end clamp  1110  can be a rectangular-prism shaped member that includes top and sides that include the holes for receiving bolt  1113 . Top member  1111  can also include opposing vertical sides, a first of which can engage solar panel module  1105  while the second can engage a vertical leg of bottom member  1112 . Additionally, top member  1111  can have a lip portion  1111 - 1  extending perpendicularly from the top side of the first vertical side that can engage a top surface of solar panel module  1105 . Lip portion  1111 - 1  can provide a clamping force on solar panel module  1105  when bolt  1113  is tightened. 
         [0076]    Bottom member  1112  can be an L-shaped member with a vertical leg that engages the second vertical side of top member  1111 . As bolt  1113  is tightened, the vertical leg of bottom member  1112  can slide against and relative to the second vertical side of top member  1111 . Additionally, bottom member  1112  can include a horizontal portion  1112 - 1  that can partially slide under the solar panel module  1105 . Horizontal portion  1112 - 1  can include a ridge that prevents solar panel module  1105  from making contact with the bolt  1113 . 
         [0077]    According to some embodiments, bottom member  1112  can also include a clip portion  1112 - 2  for coupling a trim member to the solar panel system. Clip portion  1112 - 2  can extend obliquely from the vertical leg of bottom member  1112  in a direction extending away from solar panel module  1105  and towards support leg  1103 . Clip portion  1112 - 2  can clamp down on a U-shaped portion  1133 - 2  of trim  1133 . For example, clip portion  1112 - 2  can be inserted into a U-shaped portion  1133 - 2  such that trim  1133  is held in place against support leg  1103 . A main section  1133 - 1  of trim snap  1133  can be configured to retain a top edge of a side windscreen  1130 . 
         [0078]    A bottom edge of side windscreen  1130  can be retained within a main section  1131 - 1  of trim  1131 . Furthermore, trim  1131  can be snapped onto a flange of rail  902  with a trim snap  1131 - 2 . In some embodiments, trim  1131  and  1133  can be identical, with trim snap  1133 - 1  of trim  1133  corresponding to U-shaped portion  1133 - 2  of trim  1133  and main section  1131 - 1  corresponding to main section  1133 - 1 . 
         [0079]      FIG. 12A  shows a cross-sectional view of self-adjusting end clamp  1210  in accordance with some embodiments. Self-adjusting end clamp  1210  may be similar to, for example, self-adjusting end clamp  1210 , described above with respect to  FIG. 11  and can include a top member  1211 , a bottom member  1212 , and a bolt  1213 . Self-adjusting end clamp  1210  may be configured to secure a solar panel module  1205   a  as part of a solar panel system (e.g., wind optimized and ballasted solar panel system  100  of  FIG. 1 ). 
         [0080]    The main body section of top member  1211  can include two vertically-aligned holes for receiving bolt  1213 . Bolt  1213  can extend fully through opposing sides of top member  1211  with the head of bolt  1213  abutting one of the opposing sides and the threaded end of bolt  1213  extending through the other opposing side. Top member  1211  can also include a lip  1211 - 1  that extends perpendicularly from the main body section of top member  1111 . As assembled, lip  1211 - 1  can engage the top surface of solar panel module  1205   a  while a side surface of solar panel module  1205   a  abuts a surface of the main body section of top member  1211  that is situated perpendicular to lip  1211 - 1 . 
         [0081]    Bottom member  1212  may be coupled to top member  1211  with bolt  1213 . In particular, a first surface of bottom member  1212  can include a threaded hole that is configured to be vertically aligned with the two vertically-aligned holes of top member  1211 . This first surface of bottom member  1212 , as assembled, can be arranged parallel to lip  1211 - 1  and configured to engage the bottom surface of solar panel module  1205   a.  Tightening bolt  1213  can bring top member  1211  and bottom member  1212  closer together, resulting in a clamping force on solar panel module  1205   a.  Further, bolt  1213  may be configured to couple to system anchor  1221 . System anchor  1221  may be any system component suitable for supporting self-adjusting end clamp  1210 . For example, system anchor  1221  may be a rail insert, such as a channel nut (e.g., channel nut  221  of  FIG. 3 ), or a support leg component (e.g., top section  203   a  of support leg  203  of  FIG. 4 ). 
         [0082]    Bottom member  1212  may also include an integrally formed second surface  1212 - 2 , perpendicular to the first surface and in substantial alignment with bolt  1213 . This second surface  1212 - 2  of bottom member  1212  can abut the main body section of top member  1211  on a side opposing the surface of the main body section of top member  1211  that abuts solar panel module  1205   a  such that top member  1211  is “sandwiched” between solar panel module  1205   a  and second surface  1212 - 2  of bottom member  1212 . As shown, the first surface of bottom member  1212  may include a ridge  1212 - 1  configured to prevent solar panel module  1205   a  from sliding towards bolt  1213 . 
         [0083]      FIGS. 12B and 12C  show further cross-sectional views of self-adjusting end clamp  1210  in accordance with some embodiments. In particular  FIGS. 12B and 12C  depict self-adjusting end clamp  1210  engaging solar panels of various thicknesses. For example, the same self-adjusting end clamp  1210  can be used to effectively clamp solar panel module  1205   a,    1205   b,  and  1205   c,  which have varying thicknesses. Because self-adjusting clamp  1210  can be used for clamping solar panels of various thicknesses, the clamp may be used universally for various wind-optimized and ballasted solar panel system embodiments. 
         [0084]      FIG. 13  is a perspective view of a section of a solar panel system  1300  in accordance with some embodiments. Solar panel system  1300  can include solar panel  1305 , self-adjusting end clamp  1310 , and rail  1302 . Self-adjusting end clamp  1310  may be similar to self-adjusting end clamp  1310  of  FIGS. 12A-C  and can include top member  1311 , bottom member  1312 , and bolt  1313 . 
         [0085]    Rail  1302  can include rail insert  1321 , which may be configured to slide or snap into rail  1302 . Rail insert  1321  can include a threaded hole that is configured to receive the threaded end of bolt  1313  after it passes through top member  1311  and bottom member  1312  of self-adjusting end clamp  1310 . Rail insert  1321  may correspond to, for example, channel nut  221  of  FIG. 3 . 
         [0086]    As assembled, lip  1311 - 1  prevents solar panel  1305  from being lifted out of solar panel system  1300 , and ridge  1312 - 1  prevents solar panel  1305  from sliding towards bolt  1313 . In this configuration, tightening bolt  1313  securely fastens self-adjusting end clamp  1310  to rail  1302  in addition to providing a clamping force to solar panel  1305 . According to some embodiments, self-adjusting end clamp  1310  may be bolted to component of a support leg (e.g., top section  203   a  of support leg  203  of  FIG. 4 ). 
         [0087]    While there have been described wind tunnel optimized solar panel systems, it is to be understood that many changes may be made therein without departing from the spirit and scope of the invention. Insubstantial changes from the claimed subject matter as viewed by a person with ordinary skill in the art, now known or later devised, are expressly contemplated as being equivalently within the scope of the claims. Therefore, obvious substitutions now or later known to one with ordinary skill in the art are defined to be within the scope of the defined elements. 
         [0088]    The described embodiments of the invention are presented for the purpose of illustration and not of limitation.