Abstract:
A system is disclosed that can include an array of solar panels. The array can be arranged into rows of linearly organized modules. The modules can be tilted by a linear actuator attached to a linkage. The tilting can be controlled to maintain a perpendicular orientation between the face of the solar panels (modules) and the direction to the sun.

Description:
BACKGROUND 
       [0001]    1. Field of the Invention 
         [0002]    A system for mounting photovoltaic solar panels and more particularly, to a mounting support system that drives a number of rows of solar panels to track the motion of the sun relative to the earth is disclosed. More particularly, systems are disclosed that are directed to reliability and ease of installation of the tracker arrangement for tilting a group or array of rows of solar panels. The systems can include or be used with solar collectors in which the panels are arrays of photovoltaic cells for generation of electrical power, though the system can also include or be used with arrangements for solar energy concentration, for example. 
         [0003]    2. Description of the Related Art 
         [0004]    Solar photovoltaic (PV) cells convert light directly into electricity. By utilizing the most abundant, renewable energy available on the planet, namely the sun&#39;s rays, PV cells can provide a non-polluting source of electrical energy. As global energy consumption rises the need for clean, renewable sources of power has increased tremendously. This combined with the increased costs of conventional, fossil fuel based energy sources has led to a new era where solar PV systems can generate electricity at market competitive rates on a per kilowatt-hour basis. 
         [0005]    The rapid adoption, development and construction of PV based power plants have led to greater market opportunities for companies producing PV modules. A PV module is an assembly of solar PV cells, typically in a glass laminate which is then packaged in a frame composed of aluminum or other metal. The PV module acts as an electrical component of a system of many such modules. As many as thousands of modules are strung together electrically to form commercial arrays for the generation of many megawatts of power. The greatly expanded market for PV modules combined with federal, state and local government incentive programs as well as huge investments in production capacity has created tremendous competition among PV module manufacturers. The rapid decrease in PV module costs in combination with the desire on the part of electrical utilities to own renewable energy assets has led to a renewed focus on so-called, ‘balance of system component’ costs. These components include DC-AC inverters, electrical connection components, and the mounting systems used to hold the PV modules in place and exposed to the sun&#39;s rays. 
         [0006]    In the case of ground based tracking systems, the mounting structures must orient the modules to the sun at a favorable degree of tilt while maintaining their structural capacity for 20 to 30 years which is the expected energy production lifetime of the PV modules. Typical tracking systems are composed of metal, usually steel or aluminum. The systems have an element that is placed in the ground or attached to large ballast blocks typically of concrete. From this post or pier the system stands in the air supporting the PV modules at a height that is appropriate to prevent ground cover, encroaching weeds, or blown up topsoil from affecting the light exposure of the modules but not so tall as to require excess building materials. The modules are then moved by mechanical linkages attached to the mounting structures that are driven in turn by ground mounted motors or hydraulic rams. The primary structural load on these systems is created by wind forces acting on the PV modules themselves. The tracking systems move the modules in a manner that causes them to catch the wind and transmit the wind forces to the structural frame. Thus great amounts of wind load can be present in a typical tracking PV system. 
         [0007]    As PV tracking systems are deployed for larger ground-based energy plants the need to reduce the costs of the system through better engineering, reduction in total materials required and the innovative use of standardized commercial construction elements rise. The costs and time associated with actual construction of the systems is also the subject of intense scrutiny as commercial building contractors look to be more competitive in the installation and commissioning of commercial and utility based PV power systems. 
         [0008]    The overall ease with which a PV tracking system can be delivered to the construction site, assembled, installed and finally commissioned is referred to in the PV power industry as ‘constructability’. There are many factors that play into good constructability, among them the reduction in labor hours required to assemble the system or the elimination of special trades and skills being required to complete the assembly. The elimination or reductions in special tools or expensive equipment needed are also good steps toward better constructability. Finally the ability to install the tracking systems in many types of terrain and in naturally occurring hazards such as wind, rain or snow can be the key to a suitable design for low cost, high value PV power systems. 
         [0009]    From these requirements for good constructability it can be understood that a PV tracking system which reduces the field labor hours required to build it and that eliminates costly, highly skilled trade workers would be desirable. A tracking system that can be assembled without the use of specialized tools or expensive and difficult to place equipment, such as cranes and hoists, would also be beneficial. Furthermore a system which can be sited on uneven terrain and made level through a series of minor adjustments to both the drive linkage assemblies as well as the PV module support framing, would allow for an assembly sequence with fewer steps. And lastly a PV tracking system that has at its core a utilization of readily available components that can take advantage of already high production quantities in industry would lead to lower costs for structural elements as well as control monitoring equipment and thus be a substantial improvement over specialty componentry produced of expensive materials in small quantities. 
         [0010]    In general terms, these systems have their photovoltaic panels in the form of rows supported on a torsion tube that serves as an axis. A tracker drive system rotates or rocks the rows to keep the panels as square to the sun as possible. Usually, the rows are arranged with their axes disposed in a north-south direction, and the tracking motor and control system gradually rotate the rows of panels throughout the day from an east-facing direction in the morning to a west-facing direction in the afternoon. The rows of panels are bought back to the east-facing orientation for the next day. 
         [0011]    Some systems include an assembly which mounts a series of PV modules to a pivot shaft via U-shaped clamps. Some of these systems can have a reduction in total parts through the multiple uses of various elements and a stable base or support structure by means of triangular supports. However, these systems can also have a pivot shaft defined to be of a relatively small cross section and thus not be able to sustain the large torsional loads that will be present on a much larger array of PV modules loaded by the wind. The U-shaped clamps are also deficient for a larger journalled torsion tube that requires that it be threaded through the bearing assemblies. Conventional bearings in the system, which though satisfactory for a reference design case, would not be durable enough for long term, outdoor, exposed usage where continued motion is required for a span of 20 or more years. 
       SUMMARY OF THE INVENTION 
       [0012]    A solar tracking system that employs a single actuator to control multiple rows of solar panels is disclosed. A system which accommodates field unevenness and changes in pitch within the terrain is disclosed. 
         [0013]    The system can have a solar energy collector and tracker arrangement that can have a tracker associated with at least one row of solar panels. The system can have a generally north-south oriented torque tube that can define a north-south axis of the system. The system can have an array of flat rectangular PV panels that can be attached to the torque tube with the long side of the panels crossing, for example perpendicular to, the tube. The system can have at least one foundation pier. The pier can have a footing supported in the earth. A pivot bearing assembly is affixed to the pier above its footing and the torque tube is journalled in the pivot bearing assembly. This permits the array of solar panels to be rocked on the north-south axis to follow motion of the sun relative to the earth. A torque-arm member is affixed onto the torque tube and extends downward from the height of the torque tube toward the ground. A linear drive actuator has a body portion mounted on a fixed footing of permanent materials. The linear drive actuator is located between at least two rows of PV modules oriented along a north-south axis. A drive line tube extends from both sides of the linear drive actuator in a generally east-west orientation across the PV field array. The drive line assembly is connected on either side of the linear actuator to a mid-segment beam that is attached to the linear actuator arm directly. The drive line tubes are pierced in or near their center by a connecting bolt that attaches the torque arm structure in a hinged fashion. The drive line tubes are coupled at their distal ends via a splice assembly that allows for some undulation in terrain surface. When the linear drive actuator pushes forward on the drive line assembly it is simultaneously pulling on the drive line tubes on the opposite side of the actuator assembly. 
         [0014]    The torque tube can be square in cross section. The torque tube may be formed of two or more sections joined end to end. In such case, the distal ends of the tubes will be spliced together using a cradle and a tube insert of durable materials bolted through to capture both ends of the tube in a fixed manner. This connection splice will transfer the loads in the system effectively while still allowing for expansion in the line due to thermal changes in the material without buckling or deforming the torque tube. 
         [0015]    The bearing assembly, or gimbal, can include a cylindrical ring formed of a durable material and designed to accept two polymer bearing sections which capture either side of a square cross section torque tube. When inserted into the ring the polymer bearings are held in place by a set screw or other mechanical attachment point to prevent shifting of the bearing elements over a long duration of use. The inserts can be formed of a high density polymer material which has lubricious qualities. This arrangement is resistant to weather phenomena, and can withstand the high loads expected with solar panels presented to the wind. This assembly also allows for easy field serviceability as the bearings may be removed laterally without unseating the torque tube from its installed location. 
         [0016]    The linear actuator assembly can drive the multiple rows of PV panels by movement of the drive line assembly. This drive line can be continuous across the array on both sides of the mid-field mounted linear actuator. 
         [0017]    A solar power tracking system is disclosed that can have an actuator, a drive line mechanically attached to the actuator, a first photovoltaic (PV) module, and a second PV module. The drive line can have a first drive line beam, a second drive line beam, and a first splice at least partially between the first drive line beam and the second drive line beam. The first and second PV modules can be rotatably attached to the drive line. The first splice can be positioned between the first PV module and the second PV module. 
         [0018]    The system can have a first pier and a second pier. The piers can be laterally aligned with the respective PV modules. The first splice can be positioned between the first pier and the second pier. 
         [0019]    The system can have a first torque arm and a second torque arm. The bottom ends of the torque arms can be attached to the respective drive line beams. The top end of the torque arms can be attached to the respective PV modules. The first splice can be between the first torque arm and the second torque arm. 
         [0020]    The first drive line beam can be rotatable or rotatably fixed with respect to the second drive line beam about the splice. The drive line beams can move in a linear, longitudinal motion. The drive line beams can move up and down, for example, to accommodate variances during assembly. The drive line beams can be configured within the system so as not to be rotatable. 
         [0021]    The wings of PV modules can each have an elongated structural support member extending along all or part of the length of the wing, such as the torque tube. A panel rail can cross (e.g., extend perpendicularly from) the torque tube and attach to the torque tube and one or two PV modules. The elongated structural support members can be rotatably attached to the tops of piers. 
         [0022]    A solar power tracking system is disclosed that can have a PV module comprising an elongated structural support member, a pier, a housing, and a bearing. The bearing can be rotationally fixed to the elongated structural support member. The bearing can be made from a polymer, such as ultra-high molecular weight polyethylene. The bearing can have a bearing first portion and a bearing second portion. The bearing first portion can be unadhered to the bearing second portion. The bearing can be in the housing. The housing can be attached to the top terminal end of the pier. 
         [0023]    A method of making a solar power tracking system is disclosed. The method includes assembling a drive line, positioning the drive line adjacent to a first PV module and a second PV module, and attaching the drive line to an actuator. Assembling the drive line can include attaching a first drive line beam to a second drive line beam at a splice. The splice can be between the first PV module and the second PV module. 
         [0024]    The method can also include securing a first pier in the ground or in a foundation and attaching a housing to the first pier. The housing can hold a bearing. The method can include rotatably fixing the bearing to the structural support member and removing the bearing from the housing without moving the structural support member with respect to the first pier. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]      FIG. 1   a  is a top view of a variation of the system. 
           [0026]      FIG. 1   b  illustrates a variation of close-up section A-A. 
           [0027]      FIG. 2  is a side view of a variation of the system and the ground. 
           [0028]      FIG. 3  illustrates a variation of drive arm plates attaching the torque arms to the drive line beam. 
           [0029]      FIG. 4   a  is a bottom perspective view of a variation of the torque tube splice. The proximal (first) torque sub-tube is not shown for illustrative purposes. 
           [0030]      FIG. 4   b  is a top side perspective view of a variation of the drive line splice 
           [0031]      FIGS. 5   a  and  5   b  illustrate variations of an assembly for attaching the drive line beam to the torque tube. 
           [0032]      FIGS. 6   a  and  6   c  illustrate variations of the gimbal assembly attached to a pier and a torque tube. 
           [0033]      FIG. 6   b  illustrates the gimbal assembly, pier and torque tube of  FIG. 6   a  with the bearing shown in an exploded view for illustrative purposes. 
           [0034]      FIG. 7  illustrates a variation of the viscous dampener attached to a pier and a torque tube. 
       
    
    
     DETAILED DESCRIPTION 
       [0035]      FIG. 1  illustrates that a photovoltaic (PV) or solar panel array  10  can have one or more PV modules or panels  12 . Each PV module  12  can be a framed power producing PV element, such as a framed collection of solar cells. A number of the PV modules  12 , for example from about 20 to about 50, more narrowly from about 24 to about 44, for example about 24 or 44, can be oriented into rows or lines. The panels  12  can be, for example, all-framed crystalline panels. The array  10  can produce, for example, from about 250 kW to about 50 MW of electrical power from the panels  12 . One array  10  could produce less than 250 kw, but typically 330-500 kW per array, or “block”. 
         [0036]    The array  10  can have a drive motor, such as a linear actuator  14 , for example a ram screw. The linear actuator  14  can be located in the center of the array  10 , as shown, at a terminal end of the array  10 , or elsewhere within the array  10 . The actuator  14  can be, for example, about a 1.5 hp to about a 5 hp, for example 1.5 hp or 5 hp, 480 V three-phase electric motor. The linear actuator  14  can be powered from electricity generated by the array  10 , an external power source or combinations thereof. The linear actuator  14  can push and pull a drive line  18  through from about 24 in to about 84 in, for example about 60 in. of linear distance, for example. 
         [0037]    The linear actuator  14  can be electronically connected to a power source and a controller. The controller can control the position of the actuator  14  dependent on the elevation position of the sun in the sky as estimated by sensors and/or by a data table based on a clock and calendar, for example to maintain the planar faces of the solar panels  12  to be perpendicularly oriented to the elevation of the sun within the limits of rotation of the panels  12 . The controller can have a programmable logic control (PLC) system. The actuator  14  can be a variable frequency drive power actuator (VFD). The controller can communicate with or have a global positioning satellite (GPS) receiver and/or antennae, for example, to receive the location of the array  10  to determine the relative position of the sun in the sky. 
         [0038]    The array  10  can have a drive line  18 . The drive line can extend from or near the linear actuator  14  in one or two directions to or past the most distal module  12  in each direction from the linear actuator  14 . 
         [0039]    The drive line  18  can be made from one or more rigid drive line beams  20 , for example a drive line first beam  20   a  and a drive line second beam  20   b.  One drive line beam can extend across the position of one module and/or torque tube  22 . The drive line beams  20  can transmit the force from the linear actuator  14  to the modules  12  to control the angular orientation of the modules  12 . The drive line  18  can be positioned in the lateral center of the rows of PV modules  12  or at a lateral end of the rows. The drive line  18  can laterally divide the rows of PV modules and attached elements into lateral wings, for example the first, second, third, and fourth west or left wings  24   a,    24   b,    24   c,  and  24   d  and first east or right wing  24   e  as shown in  FIG. 1   a  (the remaining wings are unlabeled for illustrative purposes). The drive line  18  can extend perpendicular to the longitudinal directions of the rows or torque tubes  22  of the rows. 
         [0040]    The drive line  18  can have one or more mid-section beams  20   c  that can pass through the linear actuator  14 . 
         [0041]    The drive line beams  20  can have beam lengths  26 . The beam lengths  26  can be from about 7 feet to about 40 feet, for example about 20 ft. The mid-section beam  20   c  can have a mid-section beam length  26   a.  The mid-section beam length  26   a  can be the same as the other (i.e., not mid-section) beam lengths  26  or a different length from the rest of the drive line beams  20 , for example from about 13 feet to about 52 feet, such as 26 feet. 
         [0042]    The drive line beams  20  can be fixedly attached to adjacent drive line beams at drive line splices  28 . For example, the drive line first beam  20   a  can be attached to the drive line second beam  20   b  at a drive line first splice  28   a.  The drive line splices  28  can be longitudinally adjustable and longitudinally fixable. 
         [0043]    Each module can have or attach to an elongated structural support member, such as a torque tube  22 . For example, first, second, third, and fourth west wings  24   a,    24   b,    24   c,  and  24   d  can be mounted to the first, second, third, and fourth torque tubes,  22   a,    22   b,    22   c,  and  22   d  respectively. The west wings and the corresponding east wings (e.g., the first west wing  24   a  and the first east wing  24   e ) can be mounted to the same torque tube (e.g., the first torque tube  22   a ). The torque tubes  22  can extend perpendicularly away from the drive line  18  in one or both lateral directions. The drive line  18  can intersect the lateral center of the respective torque tube  22  and/or row. 
         [0044]    The torque tubes  22  can have a torque tube length  30  that can be from about 10 feet to about 40 feet, for example about 19 ft 3 in. 
         [0045]      FIG. 1   b  illustrates that a torque tube  22  can be assembled from a number of collinear torque sub-tubes. For example, the torque tube  22  can have a torque first sub-tube  32   a  attached, for example at a torque tube splice  34 , to a torque second sub-tube  32   b.  The torque tube splice  34  can rotationally and translationally fix the adjacent torque sub-tubes  32  to each other. The torque tube splices  34  can be positioned at a consistent frequency along the torque tube  22 , for example from about every 4 PV modules  12  to about every 8 PV modules  12 , such as at every 6.5 PV modules  12 . 
         [0046]    The arrays  10  can have panel rails  36 . The panel rails  36  can cross and extend perpendicularly from the torque tubes  22 . The panel rails  36  can be fixed to the torque tubes  22  and to the PV modules  12 . For example, each panel rail  36  can attach to attach to lateral sides of adjacent PV modules  12 . The tops of the panel rails  36  can attach to the PV modules  12 . The bottoms of the panel rails  36  can attach to the torque tubes  22 . 
         [0047]    The arrays  10  can have rotating joints, such as gimbal assemblies  38 , that can rotationally attach the torque tube  22  to piers  40 . The gimbal assemblies  38  can cross and extend perpendicularly from the torque tubes  22 . The gimbal assemblies  38  can be aligned with the piers  40 . The gimbal assemblies  38  and the piers  40  can be positioned at a consistent frequency along the torque tube  22 , for example from about every 3 PV modules  12  to about every 10 PV modules  12 , such as at every 4.5 PV modules  12 . A pier  40  and gimbal assembly  38  can be positioned at the medial and lateral terminal ends of each wing  24 . 
         [0048]      FIG. 2  illustrates that the array  10  can have piers  40 . The piers  40  can have a square, rectangular, circular, oval, Omega-beam, H-beam, or I-beam cross-section, or variations thereof at different lengths along the pier  40 . The piers  40  can be fixedly attached to or inserted into the ground, or attached to or inserted into concrete foundations that are fixedly attached to or inserted in the ground. The piers  40  can extend vertically above the ground surface  41  at a pier height  42 . The pier height  42  can be from about 2 feet to about 8 feet, for example about 4 feet. The tops of the piers  40  in a single array can be at the same elevation or about the same elevation, for example forming a slope along the terminal top ends of the piers  40  from about 5% (2.4°) to about −5% (−2.4°), for example about 0% (0°). 
         [0049]    The array  10  can have one or more torque arms  44 . For example, each row can have one or more torque arms  44 , for example one torque arm  44  can be adjacent to each gimbal assembly  38 . The torque arms  44  can mechanically link the torque tubes  22  directly and, indirectly, the PV modules  12  to the drive line  18 . For example, the torque arm  44  at a top end can be fixedly attached to the torque tube  22 , and the torque arm  44  at a bottom end can be rotatably attached to a drive line beam  20 . 
         [0050]    The torque arm  44  can have a torque arm length  46  from about 1 feet to about 3 feet, for example about 2 feet. The torque arm length  46  can be measured from the connection with the respective drive line beam  20  (e.g., include part or all of the lengths of the drive arm plates). The torque arm lengths  46  for different torque arms  44  in the same array  10  can be equal to each other. 
         [0051]    The linear actuator  14  can be directly fixedly attached to the ground or fixedly attached to an actuator foundation  16 . The actuator foundation  16  can be fixedly attached to the ground. The actuator foundation  16  can be made from concrete and steel. 
         [0052]    The actuator  14  can have an actuator link  48 , for example extending from the remainder of the actuator  14 , as shown in  FIG. 2 , and/or within the actuator  14 , as shown in  FIG. 1   a.  The actuator link  48  can attach the remainder of the actuator  14  to one or more drive line mid-section beams  20   c.    
         [0053]    The piers  40  can each have a pier longitudinal axis  50 . Each pier longitudinal axis  50  can be parallel with a vertical line with respect to the environment or ground. The pier longitudinal axes  50  can be parallel with each other. 
         [0054]    The length between adjacent piers  40  can be a pier gap, also referred to as row spacing  52 . The pier gap or row spacing  52  can be from about 10 feet to about 50 feet, for example about 25 feet. 
         [0055]    Each module or panel  12  can have a panel longitudinal axis  54 . The panel longitudinal axis  54  can be parallel with the face of the respective panels  12 . 
         [0056]    The panel longitudinal axis  54  can intersect the pier longitudinal axis  50  at a panel-pier angle  56 . The panel-pier angle  56  can be from about −45° to about 45°. When the actuator  14  is turned off or the drive line  18  or torque arm  44  is disconnected from the actuator  14 , the system can be in a relaxed configuration with the panel-pier angle  56  at about 0°. (When the sun is directly above the system, the panel-pier angle can also be at about 0°.) The panel-pier angles  56  for all of the modules  12  can be synchronized with each other. The panel-pier angle  56  can be adjustable and can be changed by the controller causing the linear actuator  14  to alter the position of the drive line  18 . The drive line  18  can translate and push or pull the bottom ends of the torque arms  44 . The torque arms  44  can then rotate the torque tubes  22  and the modules  12 . 
         [0057]    The drive line splices  28  can be located from about 10% to about 90% of the distance from one pier  40  to the adjacent pier  40 , more narrowly from about 30% to about 70%, for example about 50%. The drive line splices  28  can each be positioned between adjacent PV modules  12 . 
         [0058]      FIG. 3  illustrates that the terminal bottom of each torque arm  44  can be attached to a drive arm first plate  58   a  and a drive arm second plate  58   b.  The drive arm plates  58  can be fixedly attached to opposite lateral sides of the torque arm  44 , for example, by two securing bolts  60  through each drive arm plate  58  and the respective lateral wall of the torque arm  44 . The drive arm first plate  58   a  can be not directly attached to the drive arm second plate  58   b.    
         [0059]    The drive line beam  20  can be positioned between the bottom ends of the drive arm first plate  58   a  and the drive arm second plate  58   b.  The drive line beam  20  can be attached to the drive arm plates  58  at a rotatable joint. For example, a pin  62  can be positioned through the drive arm plates  58  and the drive line beam  20 . The drive line beam  20  can rotate about the pin  62  with respect to the drive arm plates  58 . 
         [0060]      FIG. 4   a  illustrates that the torque tube splice  34  can be used to connect adjacent torque sub-tubes  32  (the torque first sub-tube can be positioned in the torque tube splice adjacent to the torque second sub-tube  32   b,  but is not shown for illustrative purposes). The torque tube splice  34  can have a splice housing  64  and a splice body  66 . 
         [0061]    The splice housing  64  can be positioned radially exterior to the splice body  66 . The splice housing  64  can have a larger internal cross-section perimeter than the external cross-section perimeter of the torque sub-tubes  32 . The splice body  66  can have a smaller external cross-section perimeter than the internal cross-section perimeter of the torque sub-tubes  32 . 
         [0062]    The splice housing  64  can be radially external to the torque sub-tubes  32 . The splice body  66  can be radially internal to the torque sub-tubes  32 . 
         [0063]    The torque first sub-tube can terminate in the first end of the splice housing  64 . The torque second sub-tube  32   b  can terminate in the second end of the splice housing  64 . The terminal end of the torque first sub-tube can be spaced apart by a gap within the splice  34  from the adjacent terminal end of the torque second sub-tube  32   b.    
         [0064]    Laterally extending bolts  60  can extend through both lateral walls of the splice housing  64 , respective torque sub-tube  32 , and the splice body  66 . The splice  34  can have two laterally extending bolts  60 , one bolt positioned distal to the other bolt, through each of the respective torque sub-tubes  32  (e.g., 4 lateral bolts total per splice). 
         [0065]    Vertically extending bolts  60  can extend through the top wall of the splice housing  64 , the respective torque sub-tubes  32 , and the splice body  66 . The splice  34  can have one vertically extending bolt  60  through each of the respective torque sub-tubes  32  (e.g., 2 vertical bolts total per splice). 
         [0066]    The bolts  60  can be fastened and attached to the remaining elements of the splice  34  with nuts  68  and washers  70 . 
         [0067]    The torque tube splice  34  can rotatably and linearly fix each respective torque tube beam  32  to the splice housing  64  and splice body  66 . The splice  34  can have at least one bolt  60  that extends laterally or vertically through and linearly fixes each respective torque tube beam  32  to the splice housing  64  and splice body  66 . 
         [0068]      FIG. 4   b  illustrates that the drive line splice  28  can have a splice housing  64 . The drive line splice  28  can have a splice body or be absent of a splice body. The splice housing  64  can have one, two or more splice position adjustment slots  72 . The splice position adjustment slots  72  can extend in the longitudinal direction. The splice adjustment slots  72  can be, for example, from about 1 in. to about 4 in. long, for example about 2 in. long. The splice position adjustment slots  72  can allow the longitudinal translational adjustment of the drive line first beam  20   a  with respect to the splice housing  64 , (and remainder of the) splice  28 , and the drive line second beam  20   b  during manufacture or assembly of the array  10 . 
         [0069]    The drive line splice  28  can have one or more adjustment bolts  60   a  in each adjustment slot  72 . For example,  FIG. 4   b  is shown with a single adjustment bolt  60   a  in a single adjustment slot  72 . The adjustment bolt  60   a  can extend vertically through the drive line first beam  20   a.  The second adjustment bolt can extend through a second splice position adjustment slot (not shown) and through the drive line second beam (e.g., to also adjust the longitudinal position of the drive line second beam with respect to the drive line splice). 
         [0070]    The adjustment bolts  60   a  can each be attached to a washer  70  and nut  68 . During assembly of the array  10 , the adjustment bolts  60   a  can be loose and the drive line beams  20  can be longitudinally adjusted until the drive line beams  20  are at desired positions relative to each other. The adjustment bolts  60   a  and nuts  68  can then be tightened to longitudinally translationally fix respective drive line beams  20  to the drive line splice  28 . 
         [0071]    Lateral securing bolts  60   b  can then be laterally inserted through the splice housing  64  and the drive line first beam  20   a.  For example, ports through the splice housing  64  and the drive line first beam  20   a  for passage of the securing bolts  60   b  can be drilled or otherwise formed after the drive line first beam  20   a  is in a final longitudinal position with respect to the drive line splice  28  and after the adjustment bolt  60   a  is fixed by the respective nut  68  to the drive line first beam  20   a  and the splice housing  64 . 
         [0072]      FIG. 5   a  illustrates that the piers  40  can be laterally spaced in pairs. For example the first pier  40   a  and the second pier  40   b  can be at the same longitudinal location with respect to the drive line  18 , and equally laterally spaced on opposite sides of the drive line  18 . 
         [0073]    The piers  40  can be rotatably attached perpendicularly to the torque tubes  22  at a rotating joint, such as gimbal assemblies  38 . For example, the first gimbal assembly  38   a  can be attached to the top terminal end of the first pier  40   a,  and the second gimbal assembly  38   b  can be attached to the top terminal end of the second pier  40   b.  The gimbal assemblies  38  can rotatably join the torque tube  22  to the first and second piers  40   a  and  40   b.    
         [0074]    The torque arm  44  can be attached to or be integrated with a front torque plate  76   a  and a rear torque plate  76   b.  The front torque plate  76   a  can be fixed at the bottom end to the front of the torque arm  44  and at the top end to the front of the torque tube  22 . The rear torque plate  76   b  can be fixed at the bottom end to the rear of the torque arm  24  and at the top end to the rear of the torque tube  22 . 
         [0075]    The torque plates  76  can be rotatably and translatably fixedly attached to the torque tube  22  by a linear, horizontal row of securing bolts extending through the plates and the torque tube, for example about five bolts. 
         [0076]      FIG. 5   b  illustrates that the torque plates  76  can be rotatably and translatably fixedly attached to the torque tube  22  by welds, adhesives, epoxies, or combinations thereof. 
         [0077]      FIG. 6   a  illustrates that the gimbal assembly  38  can have a gimbal ring  78  or housing. The gimbal ring  78  can be circular. The gimbal ring  78  can be made, for example, from galvanized steel or any other material disclosed herein or combinations thereof. The gimbal ring  78  can rotatably house or attach to a gimbal bearing  80 . The bearing  80  can have a port through the bearing that is shaped (e.g., squarely) to match the torque tube  22 . The torque tube  22  can extend through the port and be rotationally fixed to the bearing  80 . 
         [0078]    The gimbal bearing  80  can have a bearing first portion  80   a  and a bearing second portion  80   b.  The bearing first and second portions  80   a  and  80   b  can each be about half of the bearing  80 . For example, the bearing  80  can be split down the middle of the bearing into the bearing first portion  80   a  and the bearing second portion  80   b.    
         [0079]    The gimbal bearing  80  can be made from a polymer, for example ultra-high molecular weight polyethylene (UHMWPE). The gimbal bearing  80  can be made from a self-lubricating material, for example UHMWPE. The gimbal bearing  80  can have a coefficient of friction from about 0.10 to about 0.18, for example about 0.14. The bearing  80  can be made from an ultraviolet light resistant polymer that is resistant to degradation from solar exposure. 
         [0080]    The gimbal assembly  38  can have gimbal support first and second brackets  82   a  and  82   b.  The gimbal support brackets  82  can be L-brackets. The gimbal assembly  38  can have pier support first and second brackets  84   a  and  84   b.  The pier support brackets  84  can be L-brackets. 
         [0081]    The pier support first and second brackets  84   a  and  84   b  can be fixedly attached to the front and back, respectively of the top end of the pier  40 . The gimbal support first and second bracket  82   a  and  82   b  can be fixedly attached to the top of the pier support first and second brackets  84   a  and  84   b,  respectively, and to the front and rear, respectively, of the gimbal ring  78 . The gimbal ring  78  can be directly attached to the top terminal end of the pier  40 . 
         [0082]    Bolts securing the pier support first and second brackets  84   a  and  84   b  to the pier  40  can extend through vertical slots in the pier support brackets  84 . The pier support brackets  84  can be translated up and down, as needed, to position the gimbal assembly  38  during assembly, before translationally fixing the brackets  84  to the pier  40 . 
         [0083]    The gimbal ring  78  can have allowances in the form of larger than required gaps and generous tolerances in assembly to aid in field adjustment in the pitch and rotation of the torque tube  22  journalled through the gimbal ring  78 . For example, the gimbal ring  78  can accommodate the pier  40  being less than about 10° or less out of plumb (e.g., away from vertical), more narrowly less than about 5° or less out of plumb. 
         [0084]    The torque tube  22  can have a square, rectangular, circular, oval, or I-beam cross-section, or variations thereof at different lengths along the torque tube  22 . 
         [0085]      FIG. 6   b  illustrates that the bearing  80  can be assembled, as shown by arrows, from the bearing first portion  80   a  and the bearing second portion  80   b.  During assembly, the bearing first and second portions  80   a  and  80   b  can be inserted into the gimbal ring  78  after the torque tube  22  in inserted in the gimbal ring  78  and the gimbal ring  78  is attached to the pier  40  (e.g., via the gimbal and pier support brackets  82  and  84 ). 
         [0086]    The bearing first and second portions  80   a  and  80   b  can be adhered or unadhered to or separate from each other. The bearing first and second portions  80   a  and  80   b  can be pressed against each other within the gimbal ring  78  by the compressive forces between the torque tube  22  and the gimbal ring  78 . 
         [0087]    The bearing  80  can have a bearing track  86 , such as an angular track, slot, ridge, or groove that extends circularly around the external perimeter of the bearing  80  that can negatively match tracks, slots, ridges, or grooves in the radially inner surface of the gimbal ring  78 . For example, the matched tracks, slots, ridges, grooves, or combinations thereof, can translationally fix, yet allow rotational motion between the bearing  80  and the gimbal ring  78 . 
         [0088]    The gimbal assembly  38  can have one or more set screws  88 , for example positioned on opposite sides (e.g., front and rear) of the gimbal assembly  38 . The set screws  88  can attach the gimbal support brackets  82  to the gimbal ring  78 . The distal terminal ends of the set screws  88  can extend into the bearing track  86 . The bearing track  86  can be configured to accommodate, seat and slidably rotate against the terminal end of the set screw  88  inside the gimbal ring  78 . 
         [0089]    The gimbal assembly  38  may be disassembled from the torque tube  22  without moving the assembled position of the torque tube  22  in the overall assembly (e.g., relative to the piers  40 , or other elements). For example, the gimbal bearing  38  can be removed from the gimbal ring  78  by removing or otherwise unseating the set screws  88 , if present. The gimbal bearing first and second portions  80   a  and  80   b  can then be dislodged from the ring  78  sequentially or, with sufficient force (e.g., delivered at the seam or split between the portions  80   a  and  80   b ) simultaneously. 
         [0090]    The bearing  80  can then be tapped out to one side of the gimbal ring  78  by striking the bearing  80  from the opposing side with a hammer and cold chisel or other blunt object. Alternately the gimbal and pier support brackets  82  and  84  can be unbolted and removed from the pier  40  allowing for serviceability. 
         [0091]      FIG. 6   c  illustrates that the gimbal support bracket  82  can be a single U-bracket. The pier support bracket  84  can be a single U-bracket. 
         [0092]      FIG. 7  illustrates that a viscous damper or dampener  90 , such as a hydraulic or pneumatic shock, can be fixed at a bottom end to the pier  40 . The viscous dampener  90  can be fixed at a bottom end to the center of a dampener-pier bracket  92 . The dampener-pier bracket  92  can be centered with and attached to the pier  40 . The viscous dampener  90  can be fixed at a top end to an offset position on a dampener-torque tube bracket  94 . The dampener-torque tube bracket  94  can be centered with and attached to the torque tube  22 , The attachment of the top of the viscous dampener  90  to the center of the torque tube  22  when the torque tube is rotated 0° from center (e.g., when the planar faces of the PV modules are horizontal) can be offset by a dampener lever arm  96 . The dampener lever arm  96  can be from about 4 in to about 8 in, for example about 6.25 in. 
         [0093]    The viscous dampener  90  can have a stroke from about 6 in to about 13 in, for example about 12.69 in. The dampener travel length can be equal to the distance traveled by the damper arm. The dampener  90  can have a stroke of about 6 in to about 10 in, for example about 8.1 in. 
         [0094]    Each row can have a viscous dampener  90  attached at one pier  40 , each pier  40 , at the terminal ends of each wing  24 , or combinations thereof. 
         [0095]    Any or all elements of the array other than portions of the panels and power cabling from the panels to a collector can be made from metal, such as from hot-dip galvanized steel and anodized aluminum or combinations thereof, for example, structural steel manufactured to ASTM A36, A500, or A992, and galvanization to ASTM A123. 
         [0096]    Any elements described herein as singular can be pluralized (i.e., anything described as “one” can be more than one). Any species element of a genus element can have the characteristics or elements of any other species element of that genus. The above-described configurations, elements or complete assemblies and methods and their elements for carrying out the invention, and variations of aspects of the invention can be combined and modified with each other in any combination.