Abstract:
A combined PV panel assembly jig and forklift transport pallet is used to assemble PV panels for transport to a field array from a protected manufacturing environment. The panels are assembled to have adhesively applied rails for transport by a robotic drone on a ground-support rack and are pre-wired. The PV panel assembly jig holds, protects, and aligns the PV panels in an upside down position, opposite to their operational position, for ease of wiring in order to decrease the manual labor required in the field. Once the pallet is transported to the load station at the end of a row of solar panel racks in the field array, a robotic loader lifts the upside down PV panels from the combined PV panel assembly jig and forklift transport pallet in an arcing overhead motion that lifts, tilts, and deposits the PV panels in an upright position at the loading station of a railed rack support as ground-mounted in a solar panel field array.

Description:
RELATIONSHIP TO OTHER APPLICATION(S) 
       [0001]    This application is a continuation-in-part of U.S. Ser. No. 13/553,795 filed on Jul. 19, 2012 and claims the benefit of the filing date of US Provisional Patent Application U.S. Ser. No. 61/804,620 filed on Mar. 22, 2013, the disclosure(s) of which are incorporated herein by reference. 
     
    
     GOVERNMENT RIGHTS 
       [0002]    This invention was made under contract awarded by US Department of Energy, Contract Number DE-EE0006378 and DE-SC0009196. The government has certain rights in the invention. 
     
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0003]    This invention relates generally to systems for transporting and installing large photovoltaic modules, and more particularly, to a photovoltaic module handling system that enables substantially automated and rapid replenishment of photovoltaic modules in a solar panel array. 
       Description of the Related Art 
       [0004]    Co-pending patent application U.S. Ser. No. 13/553,795 describes an automated system for photovoltaic (PV) power plant construction. In this system, robotic shuttles deliver large panel assemblies to their mounting positions on a ground-mount rack in the form of an elevated delivery track from load stations at the end of each row of racks in a solar panel array. This system is a marked improvement over manual delivery of large panel assemblies to their final mounting positions. 
         [0005]    A common theme in the utility scale, photovoltaic power plant construction has been to achieve cost reduction by using larger building blocks for construction. One way to do this is to pre-assemble movable PV panels into larger arrays, either at the panel manufacturer, at a local warehouse, or at the construction site. These larger building blocks must then be brought to the field for installation on a support rack systems. Field labor is required to assist in positioning the panels in their final mounting position, to install mounting clamps, and to interconnect electrical wiring. Field labor, particularly if utilizing building trades, is paid at a much higher labor rate than factory labor. 
         [0006]    There is, thus, a need to reduce labor costs per panel by replacing field labor with factory labor. 
         [0007]    Of course the larger building blocks are heavier to handle. Expensive aluminum rails have been used on the panels to reduce weight. There is, therefore, a need to reduce material costs by replacing panel aluminum rails with lower-cost materials, such as galvanized steel, as well as reducing the amount of components, such as clamps, required to complete the installation. 
         [0008]    While larger building blocks can improve overall installation rates, the size and weight of both panel arrays, and large monolithic panels, means that they can no longer be handled by manual labor alone. Therefore, heavy equipment (e.g., cranes, boom trucks, ground-mounted robotic arms) may be required to deploy such panels safely. The use of heavy equipment requires some initial site grading and, frequently, re-grading as heavy equipment can create deep mud tracks and treacherous conditions, especially post-rain and snowfall. It can even bring construction to a halt until the surface is stabilized. Personnel safety is a big issue when heavy equipment is used on the work-site. In addition, special training may be required for use and maintenance of such equipment. There is, therefore, a need for an installation system that does not require the use of heavy equipment to install panel arrays. 
         [0009]    It is therefore, an object of this invention to provide an solar panel installation system that utilizes larger building blocks, such as panel modules, but that does not require the use of large, or heavy, equipment. 
         [0010]    In co-pending application U.S. Ser. No. 13/553,795, small automated PV shuttles, sometimes referred to as drones, support and carry panel assemblies, weighing up to 120 kg, to their final rack-mounted position. No heavy equipment is required to travel between rack rows during installation, and the size of installation crews is reduced. However, while the shuttles utilized can handle pre-panelized framed modules. However, for maximum cost savings, pre-panelization of frameless modules is highly preferred. Frameless modules have the advantage of lower cost (no aluminum frame) and the frames so not have to be grounded, which is a major cost adder. 
         [0011]    However, frameless modules are more fragile at the edges and corners. Therefore, greater care is required when handling frameless modules. There is, thus, a need for a system that can safely utilize frameless modules. 
         [0012]    It is another object of this invention to provide a system that can take full advantage of the economies of scale and the ability to use pre-panelized modules, and particularly, frameless pre-panelized modules. 
       SUMMARY OF THE INVENTION 
       [0013]    These, and other, objects features, and advantages are achieved by the present invention entire solar panel arrays are populated from a single, centralized material handling location by using a specialized assembly jig that serves as a fork lift pallet and pre-positions a stacked-up array of solar panel modules for delivery to a ground-mount rack of a solar array. An advantageous aspect of the present invention is that the manual work in assembling the solar panel modules, including the installation of low-cost, adhesively applied rails that will be used to grip and transport the panels to their final destination, as well pre-wired electrical components, is performed in a weather-protected location on smooth ground and can be located either on-site or off-site. 
         [0014]    In addition to the foregoing, the manual handling risk to the panel is minimized because the frameless solar panel modules are pre-panelized, and most advantageously, pre-panelized in a specialized assembly jig that will be used to transport the pre-panelized solar panel arrays directly to the field array. Field-handling of PV modules is, therefore, limited to one simple loading motion at the end of the array. The rack rail-mounted robotic shuttles then take-over and deliver the PV module to its final position. By minimizing human handling of the modules, particularly at the critical final installation step where module corners are easily struck and damaged, the risks related to frameless modules are minimized and the associated cost savings can be fully realized. 
         [0015]    In a specific embodiment of the invention, a specialized PV assembly jig and fork-lift transport pallet, herein designated “pallet jig,” is provided to support, protect, and align, PV panels stacked in an upside down position, opposite to their operational position. The pallet jig is configured to be transported on the tines of a forklift truck for further transport, or to its final destination at the field array. Once the pallet is transported to the load station at the end of a row of solar panel racks in the field array, a robotic loader lifts the upside down PV panels from the combined PV panel assembly jig and forklift transport pallet in an arcing overhead motion that lifts, tilts, and deposits the PV panels in an upright position at the loading station of a railed rack support as ground-mounted in a solar panel field array. 
         [0016]    In a method embodiment of the invention, panel assembly is accomplished while each panel of the module is uppermost on the pallet jig, and is oriented upside down (or sunny-side-down) for ease of application of the components to the underside of the PV solar panels. The pallet jig holds the individual PV solar panel modules in place in a stacked arrangement, referred to herein as a stack-up, by upright support members attached to the horizontal stringers of the pallet-like jig structure on the external supports on the back side and the shorter, longitudinally-spaced apart sides of the pallet. The upright corner support members on the longitudinally-spaced apart sides of the pallet jig are pivotably, or removably, connected and held in place by a latching mechanism, for example, so that they can be laid out of the way for ease of removing the modules from the stack-up. 
         [0017]    The upright corner support members, as well as the upright support members on the back of the pallet jig, are provided with protrusions, illustratively lugs, for positioning a solar panel module in place relative to a second solar panel module installed on top of the first solar panel module, as series of modules being so stacked to comprise a multi-layer stack-up. The protrusions interengage with rails that are installed on the backside of the solar panels, illustratively, by an adhesive strip. The panels being supported and spaced apart by the lugs so that the height of the applied adhesive strip remains uniform. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0018]    Comprehension of the invention is facilitated by reading the following detailed description, in conjunction with the annexed drawing, in which: 
           [0019]      FIG. 1  is a perspective view of a combined PV panel assembly jig and forklift transport pallet that is prepared in a panelization station, such as shown in  FIG. 12 , for use in the practice of a specific illustrative embodiment of the invention; 
           [0020]      FIG. 2  is a fragmentary perspective view of the PV panel assembly jig and fork lift pallet of  FIG. 1  in an empty condition; 
           [0021]      FIG. 3  is a perspective view of a sub-assembly of a roller-mounted movable support plate with a pivotable jig support channel bar hinge-coupled to the movable plate, and carrying at each end an adjustable draw latch, the sub-assembly is also shown pallet-mounted in  FIG. 2 ; 
           [0022]      FIG. 4  is a fragmentary enlarged perspective view of the details of a slide-out end assembly of the palletjig illustrating the adjustable draw latch and location-establishing pallet jig components as also seen in  FIGS. 2 and 3  on a smaller scale; 
           [0023]      FIG. 5  is a fragmentary perspective sub-assembly view of one of the thin-gauge steel rails (in the form of a hat-style channel) secured by dual beads of a commercially-available adhesive to the underside surface of a PV panel module during the pallet-jig panelization process of the present invention; 
           [0024]      FIG. 6  is a fragmentary perspective view illustrating a portion of a jig locating and lug support strip affixed to and carried by one of the pallet jig upright support posts, the strip having protruding positioning lugs for supporting and positioning respective PV glass panels with their associated support rails as each PV module is being assembled upside down and stacked during pallet loading in the inverted panel stack-up panelization process and that provides the predetermined orientation in the inverted pallet jig stack-up array as shown in  FIG. 1 ; 
           [0025]      FIG. 7  is fragmentary perspective view, with portions shown in cross-section, further illustrating the relationship of a PV panel and associated support rails with the jig lugs of  FIG. 6 ; 
           [0026]      FIG. 8  is a fragmentary perspective view of an uppermost layer in the panelization jig pallet stack-up illustrating installation of wiring and other electrical components to the uppermost inverted panelization layer during the panelization assembly process of  FIG. 11 a    employed in making the pallet jig stack-up of  FIG. 1 ; 
           [0027]      FIG. 9  is a fragmentary perspective view of a support block assembled at a defined position on a support rail which in turn is adhesively affixed to an underlying PV module while the same is upside down and in the uppermost exposed position in the panelization stack-up process; 
           [0028]      FIG. 10  is a fragmentary perspective view of two registered support blocks and associated PV panels, with the blocks being shown in half-section in assembled relationship to one another and associated rails and PV glass panels during the panelization process; 
           [0029]      FIGS. 11 a , 11 b , and 11 c    are perspective semi-schematic views respectively showing successive panelization assembly steps of the bottom PV glass panel utilizing the pallet jig of  FIG. 1 ; 
           [0030]      FIG. 12  is a diagrammatic plan view of a PV solar panel panelization work center in accordance with the invention which illustrates material flow and labor stages in a factory-like environment, preferably located near the ground support rail racks field array installation, and the processing steps involved in preparing the PV solar panel modules oriented inverted and upside-down, or with their shady-side-up, or conversely, sunny-side-down, in the stack-up array of  FIG. 1 ; 
           [0031]      FIG. 13  is a perspective view of an assembled PV solar panel module, shown shady-side-up and by itself; 
           [0032]      FIG. 14  is a perspective view of one system embodiment of solar panel modules having been delivered in a conventional sunny-side-up, non-jigged stack-up to the rack loading station by a forklift truck, and being manually placed on the rack loading station by a two-man crew; 
           [0033]      FIG. 15  is a diagrammatic plan view illustrating an entire rail-rack-supported field array of solar panel PV modules as drone-populated from a central logistics area; 
           [0034]      FIG. 16  is a perspective view of another embodiment of the step of successively individually robotically removing, and inverting to operable, or sunny-side-up, orientation, solar panel modules from two inverted, or sunny-side-down, stack-ups of finished solar panel modules, the stack-up in the foreground shown as being carried in an inverted module stack-up condition by a fork truck and in the forklift pallet jig assembly of  FIG. 1 , and the other stack-up being shown in the background, as having already been transported to, and seated by the fork lift truck, as an entire palletized stack, on a rack-loading entry platform station. At this station, the PV modules are robotically unloaded as, and when, they individually become the uppermost exposed sunny-side-up module on the stack; 
           [0035]      FIG. 17  is a perspective view showing the rack-loading station (shown uppermost in Fig. 16 ) wherein the automated hydraulic robot is shown holding a PV panel slightly beyond midway in the path of its transfer motion as the transfer robot is rotating the lifted panel about its longitudinal axis, and lowering it to bring it into upright orientation for disposition on the associated tilttable drone rack-loading station as shown in  FIG. 16 ; 
           [0036]      FIG. 18  is a perspective view showing a solar panel module supported on an associated operable computerized drone which is in turn movable on the ground-installed rail rack system in an operable embodiment of the invention; 
           [0037]      FIG. 19  is a perspective view of a drone monitoring station constructed to record drone telemetry and provide a watch dog radio signal that, when halted, acts as an emergency stop to all robots operating at the site; 
           [0038]      FIG. 20  is a perspective view of one embodiment of a solar panel array rack in accordance with the system of co-pending U.S. Ser. No. 13/553,795, as ground-installed; 
           [0039]      FIG. 21  is a perspective view of one embodiment of an operable automated drone which is battery-powered and monitored by the drone monitoring station of  FIG. 19 ; 
           [0040]      FIG. 22  is a perspective view of the solar panel transfer robot (as also seen in 
           [0041]      FIGS. 16 and 17 ) illustrating the same entry at the approximate midpoint of the transfer stroke of the pick-up arm of the inverter-rack loader robot as shown in  FIG. 17 , and also showing the tilttable drone loading station; 
           [0042]      FIG. 23  is a perspective view, similar to  FIG. 22 , showing a transfer robot with its panel transfer arm gripping the rails of an inverted PV solar panel assembly supported uppermost on solar panel stack-up  102  of  FIG. 1 , and illustrating a portion of the associated pivotable end support posts unlatched and pivoted down and out of the way during the PV panel transfer operation; 
           [0043]      FIG. 24  is a fragmentary perspective view showing the panel transfer robot carrying a solar panel downwardly in the tilt rack loading portion of its operational cycle, with the robot panel carrier arm having inverted the solar panel to upright orientation and while lowering the same to be supported on top of tilt rails of the robotic drone-loading station. 
           [0044]      FIG. 25  is an isometric view of a stacking block  400  described in conjunction with 
           [0045]      FIGS. 9 and 10 , and referenced as  400   a  and  400   b  therein; 
           [0046]      FIG. 26  is another isometric view of stacking block  400  oriented in a different direction than shown in  FIG. 25 ; 
           [0047]      FIG. 27  is a center cross-section view showing associated rails  312   a  and  312   b  facing the shady-side-surface  316   a  and the sunny-side-surface  316   b  of solar panel  316  as oriented in stack-up  102  of  FIG. 1 ; 
           [0048]      FIGS. 28, 29, 30, 31, 32, 33, 34, and 35  shown in pairs comprising the even-numbered figures and the next consecutive odd-numbered figure, with illustrative spacer block configurations, the space block configuration of  FIGS. 30 and 31  being presently preferred; 
           [0049]      FIGS. 36 and 37  are fragmentary end and isometric views of a four panel stack-up using rails identical to those shown in  FIG. 27  to respectively laterally space apart a vertical stack-up of spacer rails configured in cross-section the same as  FIGS. 30 and 31 ; 
           [0050]      FIGS. 38 and 39  are end elevational and perspective views, respectively, with the solar panels completed and oriented in a stack-up slightly modified from the stack-up of  FIG. 1 ; 
           [0051]      FIG. 40  is perspective assembly view of the robot transfer station having a stationary platform for receiving as input the palletized stack-up  102 , as shown in Fig.  16 , and also having an upright robotic tower provided with the pivotable panel carrier frame duly supported thereon and pivotally-actuated to swing the pick-up box arm through approximately 180° over the top of the robotic tower and to lower the panel, as a stack-up, onto the stationary receiving platform as shown by panel stack-up  102   b  ( FIG. 16 ); 
           [0052]      FIG. 41  is a perspective view of the upright robotic tower equipped with two ram-actuated chain drives, one rigged for pivoting the gripper pick-up arm of the robot, and the other for raising and lowering the pick-up arm and associated carriage, up and down on the robot tower; 
           [0053]      FIG. 42  is a perspective view of the box assembly of the pick-up arm shown in horizontal position by itself; 
           [0054]      FIG. 43  is a semi-exploded perspective view of the hydraulic and chain drive components of the transfer and inverting ram as shown in detail in  FIGS. 40, 41, 42, and 43 ; 
           [0055]      FIGS. 44 and 45  show the pivotal panel pick-up arm mechanism in a perspective assembly view of  FIG. 44  and exploded in the perspective view of  FIG. 45 , that rotates the oppositely extending pair of protruding drive shafts that non-rotatively are affixed to the pivoting arm that carries and pivots the pick-up arm; 
           [0056]      FIG. 46  is a perspective view and  FIG. 47  is partially exploded view of the tilting mechanism and framework for operably supporting the receiving channels  650  and  652 , and also the transfer and tilt station disposed between the upright robot mechanism and the input end of an associated rack row. 
       
    
    
     DETAILED DESCRIPTION 
       [0057]      FIG. 1  is a a perspective representation of a combined PV assembly jig and forklift transport pallet  100 , herein designated “pallet jig,” on which a stack-up  102  of PV modules  104  are individually jigged bottom-first and oriented upside-down relative to their operational orientation when mounted on a support rack in a solar panel array, such as the support rack shown on  FIG. 18 . Components of pallet jig  100  are shown in greater detail in  FIGS. 2, 3, and 4 . Pallet jig  100  is re-usable and serves as both a panelization jig in forming the inverted stack-up  102  of PV modules  104  and a transfer pallet that is removably engageable and supportable on the tines of a suitable forklift truck for transport to rack array panel loading stations in a field-installed solar panel array. 
         [0058]    As best shown in the assembled views of  FIGS. 1 and 2 , pallet jig  100  is made of robust steel pallet frame components, including laterally-spaced and longitudinally extruded box channel members, stringers  106  and  108 , open at their opposite longitudinal ends and designed to slidably receive a pair of fork tines of a commercially available forklift truck. As best seen in  FIG. 2 , a pair of longitudinally spaced apart and parallel box frame members, cross beams  110  and  112 , are made up by a longitudinally-aligned array of open-ended shorter box section channels  114 ,  116 , and  118 , registering with mating openings (not seen) in box beams  106  and likewise as to box beam  108 . The outer front and rear sides of the pallet construction are formed by C-section steel channels, such as front channel  120  seen in  FIG. 2 , and on the opposite side of the pallet by C-section steel channels  122 ,  124 , and  126  ( FIGS. 1, 2, and 4 ). The opposite longitudinal ends of the pallet framework are made up of C-section channels  130 ,  132 , and  134 . C-section channel  130  is welded at its ends to the box section upright corner post  136  and at the other end to the side of stringer  106  adjacent its open end. Likewise C-section channel  132  is welded at its opposite longitudinal ends respectively to stringers  106  and  108  adjacent their open ends, and channel  134  is likewise welded to stringer  108  and upright corner post  140 . 
         [0059]    Stringer beams  106  and  108  provide at each of their opposite longitudinal ends, a pair of rectangular-shaped openings  107 ,  109  for receiving conjointly, respectively, the two conventional tines of a forklift mounted on the upright mast rails of a conventional forklift truck. Likewise, the opposite open ends of cross-beams  110  and  112  are designed to individually receive respective forklift tines of a conventional forklift truck (such as forklift truck  601  in  FIG. 14 ). 
         [0060]    The palletizing panel-locating function of pallet jig  100  is served by a series of upright channel posts disposed along the back of the opposite longitudinal ends of pallet jig  100  and along the rear side of pallet jig  100 . The upright channel posts are also clearly seen and described in connection with  FIGS. 11 a , 11 b   , and  11   c.    
         [0061]    The primary jig post components, as shown in the aforementioned figures, include upright jig support and panel positioning posts arranged in pairs, illustratively, end support uprights  150 ,  152  and  154 ,  157 , one pair being located at each of the longitudinally opposite ends  105  and  115  of pallet jig  100 , along with corner support posts  158   a  and  158   b . Pallet end support uprights  150  and  152 , for example, are both mounted at their bottom ends on a pivoting channel and sliding plate sub-assembly  170  shown separately in  FIG. 3 . Sub-assembly  170  is a pivoting hinge beam that includes an inverted C-channel beam  171 , slide plate  172  and draw latch assemblies  190  and  192 . 
         [0062]    As best seen in  FIGS. 2 and 3 , pivoting channel and sliding plate subassembly comprises an inverted C-channel beam  171  provided with laterally spaced and longitudinally extending rows  174  and  176  of mounting bolt holes. Pivoting hinge beam  170  when upright rests on a centrally located slide plate  172  and is hingedly coupled thereto by a pair of hinges  178  and  180  ( FIGS. 2 and 3 ). Slide plate  172  has a pair of wheels  182  (only one wheel being seen in  FIG. 3 ) rotatably mounted on down-turned side flanges  183  of slide plate  172  and tracking, in assembled condition, in associated wheel track channels  184  and  186 , respectively, affixed to the mutually-facing inner sides of longitudinal pallet channels, or box channel members,  108  and  106  as shown in  FIG. 2 . Pivoting hinge beam  170  is releaseably held to the pallet in a fixed position by a pair of the adjustable draw latch assemblies  190  and  192  to thereby support and restrain associated jig posts  150 ,  152 , and  158  fixed in predetermined upright orientation . 
         [0063]    Draw latch assembly  190  is shown in detail in  FIG. 4 . Referring to  FIG. 4 , a locating and latch block and V-groove receiver sub-assembly  194  comprises an upright mounting plate  196  affixed by bolts  198  and  200  registered by associated mounting holes in the web of channel  120 . Mounting plate  196  has an upper extension  202  which supports mounting bolts  204  and  206  which thread into associated mounting holes in V-groove receiver  194  to securely affix the same to channel  120 . Locating block  194  has a front side facing pallet end channel  130  with a vertically-extending V-groove  210  therein that serves as the locating receiver for a cylindrical pin  212  in the latched position of associated latch  190 . Cylindrical locating pin  212  is welded to the outer face of the vertical flange  214  of pivot channel beam  170  and is drawn into seating engagement with the V-groove  210  of locating block  194  in the fully latched up condition of draw latch assembly  190  shown in  FIG. 4 . 
         [0064]    Each adjustable draw latch  190  and  192 , also comprises a U-shaped bracket member  220  having a pair of upright side flanges  222  and  224  held upright and spaced apart by an integral bottom web (not shown) that is welded to the upper surface of pivoting hinge beam  170  at the associated longitudinal end thereof. Adjustable draw latches  190  and  192  also include an inverted U-shaped latch receiver  226  having its center web welded to the upper face of locating block  194 . Latch receiver  226  serves as a receiver locking catch for cylindrical latch pin  230 . The upper edges of the upright sides of latch receiver  226  are configured to provide sliding support for cylindrical latch pin  230  in the latching and unlatching operating conditions thereof, and also to provide stop latch surfaces of semi-circular configuration to releaseably hold latch pin  230  in securely locked position when drawn thereagainst by swinging pivot handle  240 . Draw latch  190  includes a draw rod  232  that is externally threaded for threadably engaging an internally threaded through hole in latch pin  230  such that latch pin  230 , in unlatched condition, can be threadably adjusted along draw rod  232 . The end of draw rod  232  opposite pin  230  has a cross pin  234  that is pivotably mounted by being received in associated mounting holes in flanges  222  and  224 . Cross pin  234  thus serves as a pivot pin for draw rod  232  as well as a mounting pin for the pivot handle  240  of adjustable draw latch  190 . 
         [0065]    Flanges  222  and  224  of latch assembly  190  have their upper edges configured to provide a draw cam action in cooperation with a cam follower bracket  242  ( FIG. 4 ). Follower bracket  242  has a horizontal cross piece  244  extending between and through associated slots provided in the pair of down-turned flanges of pivot handle  240 . The cam follower edges of cam follower latch bracket  242  are configured to slidably ride on down-sloping and latch-configured camming edges  246  of each mounting bracket  220  as to thereby function as a draw latch arm. 
         [0066]    Draw latch assemblies  190  and  192  are fixedly mounted one each at the opposite longitudinal ends of pivoting hinge beam  170  as shown in  FIGS. 1 to 3 . When latch assemblies  190  and  192  are unlatched by pivotably raising their associated latch operating arms  240  to thereby disengage latching pins  230  from locking brackets  226 . Inverted C-channel beam  171 , along with upright post supports  150 ,  152 , and  158   a  affixed upright thereon, can be pivoted outwardly about the rotational axis of the hinge pin connections  178  and  180  of channel beam  171  to slide plate  172 , thereby removing associated end support channels  150  and  152  as well as corner support post  158  from their upright edge-engagement with the associated panelized modules  104  by allowing the uprights to be pivoted down to rest on the ground. This release action frees up the panelized PV modules  104  and permits the panels to be removed more easily and safely from their position in the palletized stack-up. 
         [0067]    Each of the pallet rear side support uprights and longitudinally opposite pallet end side support uprights, or jig posts,  150 ,  152 ,  158 ,  155 ,  156 ,  158   b ,  154  and  159 , is mounted in a selected position with respect to its associated horizontal support beam member of pallet jig  100  by an associated mounting gusset  260  as seen in  FIG. 2 , only one of which will be described in detail. Gusset  260  comprises a U-shaped plate member having upright flanges  264  and  268  flanking its center web  265 . Gusset center web  265  is seated flat and bolted to an associated horizontal pallet frame member, which in this case is C-channel beam  171  of pivoting hinge beam  170 . Jig post  150  is selectively adjustably located longitudinally of pivoting hinge beam  170  by selecting the appropriate mounting bolt hole registry for a mounting bolt  262  having its head seated on the gusset center web  265  and its threaded shank extending through the selected bolt hole in the row of holes on C-channel beam  170 . The triangularly-shaped upright attachment flanges  264  and  266  of gusset  260  flank the opposite sides of the associated channel flanges of its associated upright jig post  150  and are welded thereto. 
         [0068]    The two rear upright support posts  155  and  156  are likewise mounted to the pallet by associated gussets of like construction to gusset  260  and are likewise bolted in longitudinally adjustable positions by associated mounting bolts that extend one through the center web of the associated gusset. The gusset of each rear support posts  155  and  156  is bolted to the selected bolt hole in a row of bolt holes provided in a mounting channel  157  ( FIG. 2 ) fixedly and non-pivotally carried by associated pallet frame members at the rear side of pallet jig  100 . 
         [0069]    Preferably, the pair of pivotal end support upright posts  150  and  152 , and likewise the pair of pivotal end support upright posts  154  and  157  that are located at the respectively associated opposite longitudinal ends of pallet jig  100  are provided with a pair of associated horizontal spreader bars  151  and  153  ( FIGS. 1, 2 and 11 ). These spreader bars are in the form of C-channels wherein the center web, at opposite longitudinal ends of each spreader bar, are folded in and welded to the associated mutually facing sides of end support upright posts  150  and  152 , and likewise as to a pair of spreader bars  151 ′ and  153 ′ welded to end support upright posts  154  and  157  at the opposite longitudinal ends of pallet jig  100 . 
         [0070]    Referring again to  FIGS. 1 and 2 , and in more detail to  FIGS. 6 and 7 , each of the upright posts  150 ,  152 ,  154 ,  155 ,  156 ,  158   a , and  158   b  is provided with an associated jig strip (best seen in  FIGS. 2 and 11  and fragmentarily in  FIGS. 6 and 7 ). Each of these jig strips is identified by the reference numeral of the associated upright support post as raised by a prime suffix, in  FIGS. 1, 2, 6, and 7 . Preferably, jig strips  150 ′ through  158   b ′ are machined to provide a one-piece finished part that is adhesively, or otherwise, securely affixed with its smooth backside against the inwardly facing surface of its respectively associated upright support post . As seen by way of example in  FIGS. 6 and 7 , the surface of the base of jig strip  150 ′ that faces inwardly toward the panelization zone of pallet jig  100  is provided with protruding support and positioning projections, or lugs,  302   a  and  302   b , arranged in a spaced apart vertical row and designed to position and support an associated PV panel rail in its proper position for the palletization process. Another vertical row of spaced apart lugs  300   a ,  300   b , etc. are each positioned and designed to edge-support an associated PV panel during the panelization process, as described hereinafter, and with the panel edge supported at the desired height to insure uniform adhesive bead thickness. 
         [0071]    The panelization process of the invention is best understood by viewing the assembly sequence shown in  FIGS. 11 a , 11 b , and 11 c   , in conjunction with the panelization work center material flow diagram of  FIG. 12 , all to be read further in conjunction with the details in  FIGS. 5-10 . 
         [0072]    It should be understood that each PV solar panel module build-up starts with constructing a PV solar panel module, such as that shown in  FIG. 13 , while its components are being sequentially supported on pallet jig  100  in an inverted, or upside down, relationship relative to their final operational orientation when later field-mounted on a rack of a solar panel array, illustratively of the type disclosed in co-pending U.S. Ser. No. 13/553,795, published on Jan. 24, 2013 as US-2013-0019925-A1. 
         [0073]    Referring first to  FIG. 13 , each panelized PV solar panel module includes, when completed, two parallel support rails  310  and  312  of identical construction that are adhesively affixed to, and transversely span, the downwardly facing bottom surfaces of two or more panels comprising a panel module. In this specific embodiment, three closely laterally-spaced coplanar PV panels  314 ,  316 , and  318  are employed. PV solar panel module  103  is assembled in inverted condition (bottom-side-up) to form a jig-positioned, stack-up of such panels in forklift compatible pallet jig  100 . 
         [0074]    Referring now to  FIG. 5 , rails  310  and  312  are each preferably a thin gauge steel rail. Although it is to be understood that each rail  310  and  312  can be provided as a single flange or an I-beam section style, the hat section, double brim style channel configuration shown in Fig. 5  is presently preferred inasmuch as it provides better stability and section strength. Each rail  310  and  312  is adhesively affixed to, and spans a laterally-orientated, coplanar array of PV panels  314 ,  316 , and  318  ( FIG. 13 ). Referring to  FIG. 5 , each of the integral rail brim flanges  312   a  and  312   b  carry on their panel-facing sides a single adhesive bead  320   a  and  320   b , respectively. The adhesive beads  320   a  and  320   b  are preferably formed of commercially-available adhesives, such as Dow Corning PV-8303 with the bead size being determined pursuant to the manufacturer&#39;s recommendation, just prior to installation in pallet jig  100 . 
         [0075]    Referring to  FIGS. 11 a , 11 b , 11 c   , and  12 , adhesive beads  320   a  and  320   b  are first applied to the associated rail flanges  312   a  and  312   b  by specifically designed machinery  520  operable in panelization work center  500  as seen in the material flow diagram of  FIG. 12 . By way of example, each adhesive bead  320   a  and  320   b  is preferably 3 mm thick and 9 mm wide in its cross-sectional dimensions as applied by machinery  520 . 
         [0076]    Referring back to  FIGS. 6 and 7 , for example, it is to be understood that the vertical row of rail-support and positioning lugs  302   a ,  302   b , etc. are designed to hold the associated rail  312 , with the applied adhesive beads, with an appropriate contact pressure for the adhesive beads against the jig-oriented, upwardly-facing operable under-surface of the associated PV glass panel. Likewise the vertical row of panel support and positioning lugs  300   a ,  300   b , etc. are vertically spaced apart and oriented to support the associated PV glass panel, resting thereon, at the desired height to assure uniform adhesive bead thickness. 
         [0077]    In the embodiment shown in  FIG. 7 , the rail support and positioning lugs  302   a ,  302   b , etc. are designed to hold the associated rail  312  and  312   a , the appropriate distance above the associated PV glass and are dimensioned to have a relatively small clearance against the associated rail  312  and  312   a  to keep the rail from twisting when assembled thereon in the final jigged position. The distance between rail holding jig lugs  302   a ,  302   b  is just sufficient to allow the next rail to slide in with a slight twisting motion. 
         [0078]    Referring to  FIG. 9 , a single stacking block  400   a  is shown installed on associated rail  312 . Each stacking block can be formed as a one-piece plastic block that is machined or precision injection molded to the configuration shown in  FIGS. 9  and in cross section in  FIG. 10 . All stacking blocks  400 ,  400   a ,  400   b , etc. in contact with a frameless PV glass panel, or module, are preferably made of plastic, illustratively urethane foam, or another relatively soft material, so as to minimize risk of damaging the PV glass of the module array. 
         [0079]      FIG. 10  illustrates two identical stacking blocks, or spacers,  400   a  and  400   b , in cross section, slidably received in vertical registry with one another on the hat section portions of associated rails  312  and  312   a . The stacking blocks are dimensioned so that the weight of the PV module stack-up  102 , as seen in  FIG. 1 , is transmitted though the associated stacking blocks and rails so that no load support stress is placed on a PV glass layer in the panelization jig stack-up  102 . In addition, one or more spacers, suitably located between PV glass layers, may be required to maintain uniform thickness of the adhesive beads across the panel and to preserve the quality of the adhesive beads. 
         [0080]    In  FIG. 10 , two identical stacking blocks  400   a  and  400   b  are shown in assembled condition with associated rail  312  and  312   a , each block being shown in central half section. As shown in assembling step  FIG. 11 c   , four stacking blocks  400   a , etc. are c-rail installed at rail-block position numbered  406 ,  408 ,  410  and  412  per PV module, and as so installed, have a bottom tang portion  402  on their underside to ensure repeatable lateral spacing gaps between adjacent glass panels, such as panels  314  and  316  shown in  FIG. 9 . Such spacing is particularly helpful in preventing damage to adjacent longitudinal solar panel edges as they flex and vibrate during truck lift transport described hereinafter. This is especially beneficial when dealing with “frameless” solar panel modules. each stacking block is provided with a notch  404  ( FIG. 9 ) to provide a gap between the stacking block and adjacent vertical side of the rail to thereby form a suitable passage way for accommodating the DC wiring loads installed in the stack-up assembly step of  FIG. 11   a.    
         [0081]      FIGS. 11 a , 11 b , and 11 c   , diagrammatically and sequentially, illustrate the use of the PV assembly jig and forklift transport pallet  100  of the present invention to construct the stack-up  102  of inverted solar panels PV modules  104  as each is loaded upside-down (i.e., sunny-side-down) as shown in  FIG. 1 . Preferably, the empty pallet jig  100  is provided as starting material for use in the panelization work center  500  shown diagrammatically in  FIG. 12 . Preferably, work center  500  is established at a location spaced away from, but relatively close to, the site where the ground-supported array of solar panel racks is being constructed. 
         [0082]    Panelization work center  500  is preferably a conventional, covered temporary construction-site-installed building (not shown) that provides relatively low cost protection against the weather, such as may be provided by a temporary quonset hut, or circus-tent type structure, so that the solar array construction equipment and materials can be securely, but temporarily stored therein, and solar panel construction labor can also be performed in the weather-protected environment so that such labor is eligible for the applicable factory labor rates which are significantly lower than the field labor rates of the relevant construction trades. Indoor construction conditions also reduce material damage and loss. 
         [0083]    Referring further to diagrammatic  FIGS. 11 a , 11 b , 11 c   , in conjunction with  FIG. 12 , note that, by way of example, panelization work station  500  is arranged with two parallel manual panelization assembly lines  510  and  512  mutually flanking a central rail prep line  516 . Rail prep line  516  preferably provides rail surface prep and adhesive bead application equipment to provide an indoor supply of rails with adhesive applied to the flanges, as described above, for manual installation in the flanking panelization assembly lines  510  and  512 . 
         [0084]    Referring further to  FIGS. 11 a , 11 b , and 11 c   , in that sequence,  FIG. 11 a    shows the initial steps in constructing and pallet-assembling the bottommost solar panel module of a stack of such modules when forming the stack-up array  102  of inverted (i.e., sunny-side-down) modules seen in  FIG. 1 . 
         [0085]    In  FIG. 11 a   , three PV solar panels are shown installed side-by-side and so-oriented upside down and in a laterally-spaced array, ready for transport by fork lift truck, and removably supported in predetermined position by the associated solar panel support jig components of pallet jig  100 . More particularly, PV solar panel  314 , for example, is supported in horizontal orientation, bottom side up, on end support upright posts  150  and  152  by its panel edges resting on their associated jig lugs, such as lug  300   a , more clearly seen in  FIG. 6 , which are provided on end support upright posts  150  and  152 . In this figure, pivoting end support upright posts  150  and  152  are shown locked to their vertical orientation by latches the associated pallet draw latch assemblies  190  and  192 . Likewise, the rear right-hand corner of panel  314 , as viewed in  FIG. 11 a   , is held horizontally-oriented while resting on its associated corner jig lug on upright corner support post  158   b.    
         [0086]    The left-hand longitudinal edge of bottommost panel  314  rests on pallet frame channel sections  114 ,  116 , and  118  ( FIG. 2 ) in lateral closely-spaced relation with the right hand longitudinal pallet edge of center panel  316 . Panel  316  in turn also rests on and is supported by pallet channels  114 ,  116 , and  118 . The left-hand longitudinal edge of center panel  316  is closely spaced from the right-hand longitudinal edge of panel  318 , and those longitudinal edges are both supported on pallet channel  110 . The rear corner of panel  314  rests upon and is horizontally positioned by associated jig lug on upright corner support post  158   a.    
         [0087]    The mutually-facing parallel longitudinal edges of panels  314  and  316  are closely spaced and held parallel to one another by their jig fixturing on pallet jig  100 . Likewise, the closely spaced mutually-facing parallel longitudinal edges of panels  316  and  318  rest on sectional pallet frame channel  110 . Panel  318 , at its rear left-hand corner, rests on on associated jig lugs on rear corner upright post  158 . The left-hand longitudinal edge of panel  318  rests on associated jig lugs on end support upright post  154  and  157 . 
         [0088]    When PV solar panels  314 ,  316 , and  318  are so-assembled and thereby releasably supported in a single layer so as to form the bottommost PV solar panel module  103  in stack-up array  102  ( FIG. 1 ), they are pallet jig oriented as PV module components located at predetermined x, y, and z, datum points, on and relevant to, associated support components of pallet  100 . Thus, the PV solar panel component of the bottommost layer of the pallet stack-up  102  ( FIGS. 1 and 2 ) is positioned at a predetermined x,y,z, location on pallet jig  100 , albeit in an upside down or inverted (sunny-side-down) condition relative to their final operational orientation (sunny-side-up) when finally operationally installed in a PV solar panel field array. 
         [0089]    Referring again to  FIG. 11 a   , following manual installation of module support rails  310  and  312 , the next step in the assembly of pallet stack-up  102  is to install commercially-available panel DC wiring and wire management components, such as electrical components  502   a ,  504   a ,  506   a  and  508   a , as partially shown in  FIG. 8 . The majority of such DC wiring and wire management components are manually installed, with cable ties being used to manually dress the DC wiring, both intra-panel and inter-panel, to the underside surfaces of the three panel array  314 ,  316 , and  31 . The manual labor installation work is greatly facilitated by the upwardly facing inverted orientation of the panels. However, the DC wiring must be restrained prior to the panel module being transported by the automated installation equipment as described hereinafter. 
         [0090]    The next step in the construction of the solar panel module comprising PV panels  314 - 318  is shown in  FIG. 11 b   . Rails  310  and  312  are manually attached. Referring to  FIG. 12 , adhesive beads  320   a  and  320   b  ( FIG. 5 ) are applied to the rails at the central adhesive dispensing station  520  in work center  500 . The panels are likewise oriented upside-down as manually assembled in their predetermined positions and orientation spanning panels  314 ,  316 , and  318 , and with their associated adhesive beads  320   a  and  320   b  contacting the respectively upwardly facing bottom surfaces of inverted PV panels  314 ,  316 , and  318 . Rails  310  and  312  are also inverted as installed and rest at their ends in the associated jig lugs as partially shown in  FIGS. 6 and 7 . 
         [0091]    Referring to  FIG. 11 c   , the next and last step in completing “in jig” the lowermost solar panel module assembly is to install the set of four removable stacking blocks  400  designated in  FIG. 11 c    as stacking blocks  406 ,  408 ,  410 , and  412 . Each of these blocks is identical to one another and to the installed stacking blocks  400   a  and  400   b  as shown in  FIGS. 9 and 10 . Stacking blocks  406  and  410  are assembled on their respective rails  310  and  312  so that their bottom projections  402   a  ( FIG. 9 ) fit in the gap between the mutually facing longitudinal edges of panels  316  and  318 . Likewise, stacking blocks  408  and  412  have their bottom projections  402   a  disposed the gap between the mutually facing longitudinal edges of panels  314  and  316 . Stacking blocks  408  and  412  are removably seated on associated rails  310  and  312  such that their bottom protrusions  402   a  likewise defines the gap between the longitudinally extending and mutually facing edges of panels  316  and  314 . The x, y, z datum in the dimensions of the stacking blocks are predetermined by the associated pallet jig and positioning lug orientations provided for the single bottom layer assembly of  FIG. 11 c   . The stacking blocks also provide a gap to control the vertical distance between the associated rails  310  and  312  and the back of the associated panel, i.e., the thickness of the adhesive beads  320   a  and  320   b , as shown in  FIG. 5 . 
         [0092]    The solar module positioning and assembly steps described above in conjunction with  FIGS. 11 a , 11 b , and 11 c   , complete the bottommost layer of the PV module stack-up  102  of  FIG. 1 . Note that the x,y,z datum points for this module assembly are predetermined relative to the features of the pallet jig  100  as described hereinabove in conjunction with  FIGS. 1-10 . The sequential steps of the assembly cycle of  FIGS. 11 a , 11 b , and 11 c    are repeated with respect to constructing and assembling the next solar assembly module as superimposed sunny side down on top of the bottommost module  103 . These steps further include installing removable and reusable slip-fit stacking blocks  406 ,  418 ,  410 , and  412 , accurately positioned and located on their associated rails  310 ,  312 , for serving their final operative use as damage prevention to the panel stack-up  102  during lift truck delivery to the field array of solar panels. 
         [0093]    Referring specifically to panelization work center  500  shown diagrammatically in the flow diagram of  FIG. 12 . Work center  500  is made large enough to prepare the completed PV assembly jig and forklift transport pallets, shown in  FIG. 1  as pallet jig  110 , and by way of example, may comprise at least two assembly lines  510  and  512  Empty pallet jigs  100  and  100 ′ are returned from their field-emptying cycle and fed as recycling starting input to assembly lines  510  and  512  shown schematically in  FIG. 12 . 
         [0094]    Preferably work center  500  is constructed as a temporary warehouse or portable factory, to provide a weather-protected covered and firm surface work platform, such as a concrete floor pad represented diagrammatically as pad  514  in  FIG. 12 . Hence, the manually-performed assembly steps in the construction of pallet jigged stack-ups  102  of inverted solar panel modules  104  is efficiently completed by manual labor and production equipment that are sheltered in panelization work center  500 . In  FIG. 12 , a series of empty pallet jigs  100  are shown entering assembly line row  510 , and empty pallet jigs  110 ′ are shown entering the duplicate assembly line row  512 . The two assembly lines  510  and  512  are spaced apart to accommodate central processing line  516  for surface preparation and application of adhesive to support rails  310  and  312  for sequential assembly as described herein to each layer of PV modules  104  in the jig pallets  100 ,  100 ′, and so on, as provided to assembly lines  510  and  512 . 
         [0095]    The central rail supply line  516  of workstation  500  includes a rail surface preparatory station  518  and a centrally located adhesive dispensing station  520  that receives the output of panel rails upstream from surface prep station  518  and applies the adhesive beads  320   a  and  320   b  to the rail hat brim flanges  312   a , and  312   b , described in conjunction with  FIG. 5 . In the embodiment shown, central adhesive dispensing station  520  has two sets  520   a  and  520   b  of three duplicate output stages arrayed one set on each of the longitudinal sides of dispensing station  520  to thereby provide the appropriate output of rails from the central station  520  with adhesive beads applied to the rail hat flanges. The rails are manually retrieved from central station output and assembled with and affixedly applied to the upwardly facing bottom surface of inverted PV panels in the manner described in conjunction with  FIG. 11 b   . 
         [0096]    The pallet-jig PV panel assembly stations  520 ,  522 ,  524  and  526 ,  528 ,  530  provided respectively in each of the panelization assembly lines  510  and  512  complete a palletized and jig-oriented respective stack-up  102  ( FIG. 1 ) for fork lift transport. The assembly steps of  FIGS. 11 a , 11 b , and 11 c    are repetitively performed on and in each of the pallet jigs  100 , as shown diagrammatically in  FIG. 12  by the right-angle assembly arrows  519 ,  522 , and  524  of assembly line  512 , and likewise diagrammatically shown by the right angle assembly arrows  526 ,  528 , and  530  and assembly line  510 . These completely assembled PV module stack-ups  102  are then fork lift truck transported from the final stage of assembly lines  510  and  512  to an input queue at a covered adhesive curing station (not shown). Thus, the assemblies are protected from weather, and also if needed, simultaneously heated to assist curing of the adhesive beads and consequent adhesion of the rails to the associated PV module panels. 
         [0097]    Referring to  FIG. 15 , using a system such as that disclosed in co-pending U.S. Ser. No. 13/553,795, entire PV solar panel rail rack arrays  602  and  603  can be populated from a central logistics area. Typically, this area will be a permanent service or fire access road  600  as seen in  FIG. 15  and which is already included in the site plan as shown diagrammatically in the solar panel rail rack arrays  602  and  603 . Aisle breaks  604  and  606  in the arrays  603  and  602 , respectively, can be bridged with temporary rails indicated schematically at  608 , thereby extending the solar panel field area that is reachable from a single logistics area for installation of the PV solar panels by automated drones  902 , as described and shown in the aforementioned co-pending patent application. 
         [0098]      FIG. 14  illustrates a stack-up  610  of PV solar panel modules  611  oriented sunny-side-up and unrestrained while being delivered by fork lift truck  601  and manually off-loaded to provide a ground-supported stack  610  of panels  611  in accordance with the prior art. Also in accordance with the prior art, after having been delivered by a fork lift truck, the individual solar panels  611  are manually off-loaded from the ground-supported stack-up  610  and then individually carried manually, or by specially-equipped rough terrain trucks, between adjacent rack rows until reaching their final individual operational position on the support rack. 
         [0099]      FIG. 14  also illustrates a stack-up  610  of solar panel PV modules oriented right-side up in stack  610  in accordance with the prior art, and to be manually lifted and placed one at a time by a two man installation team on drone-equipped support rails of a system constructed in accordance with the aforementioned co-pending application. This drone-equipped rack array system, in conjunction with the PV assembly jig and forklift transport pallet of the present invention, can save hundreds of hours of service time in constructing solar panel arrays, as well as the time and cost of staging modules around the array field, and the subsequent trash retrieval cost. By using the railed rack arrays and automated robotic drones to carrying and place PV solar panels on the racks to form the solar panel array, a small team of people can install a megawatt (MW) of solar panels per day, approximately 20 times faster than an equivalent number of laborers manually installing PV solar panel modules in accordance with the prior art. The system of the invention can thus eliminate 95% of the automated PV panel carrier labor costs of installing PV solar panels. 
         [0100]      FIG. 16  is a perspective overhead view that shows, by way of two side-by-side parallel field delivery and assembly lines, sequential stages in automated unloading and inverting of upside-down solar panels to a sunny side up orientation from panelization stack assemblies at panel unloading and transfer stations, each feeding PV panels to a given entry location of an associated dual rail rack support made in accordance with the invention. A stack-up load  102   a  of solar panel modules constructed and assembled on a pallet jig  100   a , in the manner described previously herein in conjunction with  FIGS. 1-12 , is shown in  FIG. 16  being carried on fork tines of a forklift truck  103  for deposit of the pallet-jigged load stack-up  102   a  onto the channel-type ground-mounted stationary load-receiving platform  612   a . The accurate predetermined positioning of a pallet jig  100   a  on receiving platform  612   a  is designed to stationarily position stack-up  102   a  at fixed and predetermined x, y, z geographic datum points relative to operational engagement, transfer and release datum points of an associated robotic transfer station mechanism  614  positioned between platform  612   a  and the associated end-loading point of an associated rack rail installation  616 . 
         [0101]      FIG. 16  illustrates a neighboring palletized jig stack-up  102   b , which is provided in a manner similar to stack-up  102   a . Stack-up  102   a  is better seen in  FIG. 17  after the same has been accurately deposited on, and supported by, an associated stationary support rack  612   b  constructed and positioned in the manner of support station  612   a  ( FIG. 16 ). The stack-up  102   b  is also accurately positioned for cooperation with the associated robotic inverter/transfer station  618   a  that in turn is operably positioned relative to the feed-in end of the associated rail rack  620   a  and  620   b.    
         [0102]      FIGS. 22, 23, and 24 , as well as the opposite side view in  FIG. 17 , illustrate the structure and operation of the robotic solar panel load inverter/transfer mechanism of transfer station  618  and of the duplicate mechanism of neighboring transfer station  614  as seen in  FIG. 16 . Transfer stations  618  and  614  each include an automated, hydraulically-actuated robotic carriage tower  622  shown stationarily mounted on channel framework platform  624  that in turn is secured at its entrance end to the associated ground supported loading platform  612   b . Transfer robot tower  622  supports a combined hydraulic and chain-drive, computer controlled drive carriage  626  that is raised and lowered on an interior track of tower  622 . Carriage  626  is located on the side of tower  622  facing oncoming PV solar panel load array stack-up  102   b . Carriage  626  also pivotally supports a transfer carriage pivot arm assembly  628  see, as pivoted almost upright in  FIG. 22 . 
         [0103]    Transfer carriage pivot arm  628  comprises a rectangular hollow beam box frame construction provided, as best shown in Figs. * and *, with two sets of hydraulically-actuated panel rail grippers  529 , located one pair each on the hollow longitudinally extending box frame carriage side member  630  and  632  that are in turn joined at their longitudinally opposite ends by carriage cross frame members  634  and  636  ( FIG. 22 ). A pair of laterally-spaced transfer carriage support arms  640  are affixed at their outer ends to the closet crossbar  636  of carriage arm  628 . Gripper support arms  640  straddle carriage  626  and, at their lower ends, are pivotally supported on carriage  626 . Gripper actuating hydraulic lines  641  are trained from carriage  626  via hollow arms  640  and into the hollow side arms  632  and  634  of gripper  629 . 
         [0104]    Each of the solar panel transfer stations  614  and  618  also includes a tilttable platform station mechanism located between its associated robot transfer tower  622  and the loading/unloading ends of the associated dual rack rails of solar panel support racks. As best seen in  FIGS. 22 and 23 , platform tilt mechanism  624  is made up of a laterally-spaced apart pair of parallel Z-section channel rail platform members  650  and  652 . Tilt platform rails  650  and  652  are carried on the upper ends of a rocker framework *** of generally U-shaped configuration. Rocker platform frame arms *** and *** ( FIGS. 22 and23 ) carry platform rail members  640  and  642 , normally horizontal, mounted to and spanning the upper ends of frame arms  656  and  658 . 
         [0105]    The entire platform framework  650  is rockingly supported by a pair of upright U-shaped stanchion-rocker arm assemblies, located at and supported midpoints of stationary rocker platform  624 . Each stanchion assembly comprises a stationary arm fixed at its lower section frame  624  and rotatably carrying, at its upper end, one end of a pivot rod  662  journalled therethrough. A companion rocker support gusset member  664  is rockingly carried supported faced inwardly of fixed gusset support member  660 . Pivot rod  662 , passes through support member  664 , but is non-rotatively affixed to its upper end. The lower end of the stationary support arm  664  is fixed to the center of the associated rocker U-frame member  652  so as to rockingly carry the same on, and in response to, rotation of pivot rod  662  for rocking travel, through a travel arc angle sufficient to orient the solar panel receiving plane mutually defined by platform rails  650 ,  652 , i.e., tilt platform rails from a horizontal solar panel receiving attitude (shown in  FIGS. 22 and 23 ) to a tilted panel transfer attitude wherein platform rails  650  and  652  are respectively lined up in registry with associated station rack rails  620   a  and  620   b.    
         [0106]    The pivot rocking actuation of rocking carriage  650  is obtained by computer-controlled operation of a hydraulic ram  670  ( FIG. 23 ) pivotally mounted at its lower cylinder end, and thereby affixed, to stationary frame  624 . The piston rod  671  of ram  670  is pivotally connected at its upper end to the swingable crank arm  672 . In turn, crank arm  672  is connected at its upper end to the protruding other end of pivot rod  662  and non-rotatively coupled thereto for actuating pivot rod  662 , and thus swinging support arm  664  through the aforementioned working range of rocker support frame  650  in response to automated hydraulic control. 
         [0107]    In the operation of the respective transfer stations  614  and  618 , the respectively associated transfer carriage receiving platform rails  640  and  642  are automatically controlled and hydraulically actuated to pivot through a working arc starting from a horizontal solar panel pick-up attitude, wherein transfer carriage arm  628  has been lowered to lay flat on the exposed panel rails  310  and  312  affixed to whatever inverted solar panel module is oriented upside down and exposed as the uppermost inverted solar panel such as solar panel module  104  as shown in  FIG. 23 . 
         [0108]    When transfer gripper arm mechanism  628  is so-oriented, the grippers carried by its transport arms  630  and  632  are actuated to cause the grippers to firmly engage the exposed panel rails  310  and  312 . The transfer robot  618  is then actuated, by its computer control system, to first carry the uppermost inverted panel assembly module vertically upwardly as carriage  626  is elevated along tower  622 . The robot  618  thus initially carries the gripped module with a generally horizontal attitude until robot carriage  626  is approaching the upper limit of its vertical travel on tower  622 . The robot then causes carriage  626  to be pivoted upwardly to thereby swing the supported panel  90  to clear over the top of tower  622  while thereby also inverting the panel from its inverted horizontal stack orientation bottom face up to pivoting the panel to fully upright vertical orientation, and thus, completing the first 90° of the load pivoting motion as the carriage  618  travels upright over the upper end of tower  622 . The fully upright vertical orientation of carriage  626  can be seen in  FIG. 22  while traveling empty over tower  622  on its return travel path and where it will complete the second 90° pivoting motion to load-pickup horizontal orientation, as seen in  FIG. 1 , and is then fully inverted to bring the PV module assembly with the glass panels facing upright, as shown in  FIGS. 16 and 17 , as support carriage  628  is traveling down tower  622  with rails of the solar panel load firmly engaged by the grippers of carriage  628 , and having been pivoted to a horizontal attitude as shown in  FIG. 24 . 
         [0109]    In the rail racks panel loading phase of operation of the hydraulically-actuated robot tower  622 , the robot drives carriage arm assembly  628  downwardly to an off-load carriage position where panel rails  310  and  312  extend across and rest upon the uppermost flanges of transfer Z-section channels  640  and  642  of tilt mechanism  618 . Solar panel assembly  104  is oriented horizontally and extends over the ends of transfer channels  640  and  642 , closest to, rails  620   a  and  620   b  that in turn are disposed in an angled plane closely spaced to the ends of rack rails  620   a  and  620   b , as shown In  FIGS. 22 and 23 . As the carriage arm assembly  628  travels through the space between tilt platform rails  640  and  642  of the tilting carriage when disposed in a horizontal plane. The solar panel assembly module rails  130  and  132  engage and rest upon the horizontal flanges of tilt support rails  640  and  642 . The carriage arm assembly  628  then continues its downward travel so as to be clear of tilt platform support channels  650  and  652  until the carriage reaches its lowermost stop position where the carriage components are disposed within the confines of the pivoting frame  650  in non-interfering relation therewith. 
         [0110]    The pivotal panel support mechanism of tilt frame  650  is then actuated to cause the solar panel to bodily pivot about the axis of pivot rod  652  so as to bring the solar panel into the tilted attitude matching the tilt of rack rails  620   a  and  620   b  relative to each other and with the mutually inwardly facing flanges  644  and  646  tilt-aligned with the inwardly extending flanges of rack rails  620   a  and  620   b . This enables the remote-controlled drone  902  with its super-posed panel rail gripping mechanism  910  to be lowered into its lowermost position on the drone, and then the drone  902  to be actuated to travel with its opposite side wheels running on associated flanges  644  and  646  of transfer rails  640  and  642  so that the rails of drone lift mechanism  910  touch the panel assembly module rails  310  and  312  resting on the upper flanges of platform channels  640  and  642 . The lift mechanism of drone  902  is then actuated to elevate and engage the panel assembly module rails  310  and  312  and elevate them upwardly off of transfer platform rails  640  and  642  and carry the tilted panel supported on carriage  910  of drone  902  with the solar panel tilted to match the tilted orientation of the rack rails  620   a  and  620   b  to match their tilt angle for drone-supported travel on the rails to bring the solar panel being carried on the drone  902  in tilted orientation and spaced above the rails  620   a  and  620   b  until the drone-supported solar panel reaches its installation location on the dual rail support rack shown as installed and ground-mounted in  FIG. 20 , as described in the aforementioned co-pending patent application. 
         [0111]    Drone monitoring station  700 , shown in  FIG. 19 , is constructed to record drone telemetry and provide a watch dog radio signal that, when halted, acts as an emergency stop to all robots operating at the site.“Once operation is initiated, both the autoloader and the drones worked autonomously. 
         [0112]    Referring in more detail to  FIGS. 25-47 , and supplementing the photographic views of the structure of operable embodiments of various structural features shown in  FIGS. 13, 14, 16, 18, 19, 21-24 , a successful working embodiments of the system, method, and apparatus of the present invention. 
         [0113]    Referring first to construction and use of the space blocks shown in  FIGS. 25-37 , in conjunction with the perspective drawing views provided in  FIG. 5 through 10  and  FIG. 11 c   , assembly and use of the spacer blocks are shown in  FIGS. 9, 10, and 27 . Referring to  FIGS. 25 and 26 , spacer block  400  is preferably accurately machined, die-cast, or injection-molded, such that its longitudinal bottom projection  402   a  enters into the gap formed between the mating, or opposed longitudinal edges, of an associated pair of solar panels as shown in  FIG. 9 . This helps the accurate positioning of solar panel rails relative to the associated solar panels, and also helps to protect the longitudinal side edges of an adjacent pair of solar panels. 
         [0114]    Spacer blocks  400  have a transverse U-shaped channel of constant cross-sectional configuration extending all the way through and open at the ends of the spacer block. These channels are defined by accurately spaced apart, and parallel, side surfaces  405  and  406 , that are designed to have a close slip fit as the space block is aligned with an associated rail end and slidably pushed down to seated position with the crown and adjacent parallel sides of the rail fitting nicely within groove  403 . 
         [0115]    The slip fit installation and removal characteristic of the spacer blocks relative to the associated solar panel rails helps maintain the rail assembly accurately in the panel jig  100  but does hinder the separation of the spacer blocks from their associated panel rails when the panel is being inverted and installed on the associated field support rack. 
         [0116]    Spacer block  400 , as well as the remaining variations thereof in  FIGS. 28-35 , have basically been described previously in connection with  FIG. 11 c   . 
         [0117]    Referring to the structure, function, and operation, of the “flipper” station for transferring solar panels one at a time from the platform loading station to the rails of the field rack solar panel array, is best seen in  FIGS. 40-47 , and will be described hereinafter with respect to these figures. 
         [0118]    Referring first to the assembly view of  FIG. 40 , the load-receiving platform  612   a , as seen ground-mounted, at the front end of station  618 . The base of robot tower  622  is mounted on a channel framework attached to the rear of platform  612   a . The carriage  626  has upright channel member  700  of channel configuration carrying on each side a pair of vertically-spaced rollers removably supporting the carriage on the cooperative frame walls of tower  622 . A vertically-extending ram has the lower end of its cylinder fixed to the base of the tower and the upper end of its pistons carrying a sprocket on which a carriage-elevating chain is trained with one run extending stationarily down to a fixed point at the base of the train as seen in  FIG. 41 , and the other trained around a sprocket at the upper end of the carriage as seen in  FIG. 43 . 
         [0119]    As seen in  FIG. 44 , the gripper arm pivoting motion is provided by a chain  720  looped over two sprockets  722  and  722 ′ (only one sprocket being shown in the figure), each fixed to a shaft  724  and  724 ′ extending through a pair of bearings  722  and  726 . The inner ends of lift-arm carriage are non-rotatively affixed to the rotary shaft  724 . The chain loop  720  is fixedly coupled to the upper end of the piston of ram  726  that is used to produce the pivoting motion of the grip arm assembly. The ram  726 , through chain  720 , causes the pivot rod  724  to rotate, and thereby causing the pivoting motion of the gripper arms while the same travel up and down with the carriage, the vertical motion being produced by vertical travel of the carriage. Thus, the compound motion of the pivot arms, namely the vertical motion of the carriage carrying the pivot arms bodily up and down. The carriage arms can be independently pivoted by the pivot shaft whose pivoting rotary drive is carried with the carriage as it is being moved vertically by the ram. 
         [0120]    It is also to be noted that the rigging arrangement for the vertical actuation of the carriage is rigged to produce a 2:1 distance. 
         [0121]    The solar panel stack unloading work, wherein each solar panel module is lifted off its uppermost position on the multiple panel stack-up on the pallet jig at the input station to the inverter station is shown in the discussion of  FIGS. 16, 22, 23, 24, 44, and 45 . The tilt station mechanism is best seen in the perspective assembly view of  FIG. 26 , taken in conjunction with the exploded perspective view of  FIG. 47 . This is supplemental to the previous discussion of the tilting and transferring PV panel station comparable for individually-loading drone-mounting solar panels one-at-a-time onto the rail racks described previously. 
         [0122]    From the foregoing description in conjunction with the appended drawings, as well as the description, drawings, and claims of co-pending patent application U.S. Ser. No. 13/553,795 and underlying provisional application U.S. Ser. No. 61/804,620 filed on Mar. 22, 2013, incorporated herein by reference, it will be understood that the system, apparatus, and method of PV power plant construction provides improved results, benefits, and advantages over the prior art apparatus and systems for installing and equipping PV power plant construction. By automating the requisite processes of assembling, transporting and positioning the thousands of PV panels required for large-scale projects, the system of the invention enables megawatt-per-day panel installation rates with just a small construction crew. Moreover, this automation is achieved with no additional installation materials. 
         [0123]    Although the invention has been described in terms of specific embodiments and applications, persons skilled in the art can, in light of this teaching, generate additional embodiments without exceeding the scope or departing from the spirit of the claimed invention. Accordingly, it is to be understood that the drawing and description in this disclosure are proffered to facilitate comprehension of the invention, and should not be construed to limit the scope thereof. Moreover, the technical effects and technical problems in the specification are exemplary and are not limiting. The embodiments described in the specification may have other technical effects and can solve other technical problems.