Patent Publication Number: US-2009229200-A1

Title: Photovoltaic System and Method

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to photovoltaic systems and methods. 
     BACKGROUND OF THE INVENTION 
     Photovoltaic systems have been devised in the past to convert solar energy to electrical energy. Some of these photovoltaic systems are designed to have a lifespan of 40-50 years and be mounted permanently to a ground foundation. A problem with this type of photovoltaic system is that some potential buyers and decision makers of this type of photovoltaic system are afraid to commit to mounting something that was designed to remain in place for 40-50 years. For example potential buyers such as universities and hospitals are not in a position to ensure that new construction would not come along during that period that would require use of the same property where the photovoltaic system(s) are located. Thus, the somewhat permanent nature of a 40-50 year photovoltaic system presents a barrier to buying for potential buyers that are not sure of the eventual use of the property where the photovoltaic system(s) is/are to be located. 
     SUMMARY 
     Accordingly, an aspect of the invention involves the recognition that a need exists for a relocatable photovoltaic system and method that offers potential buyers and decision makers the ability to easily and inexpensively move the photovoltaic system. If the photovoltaic system is relocated to a new location, the user simply builds over (or removes) the old relocatable photovoltaic system ground mount. Thus, the relocatable photovoltaic system is appealing, leaving potential buyers of the relocatable photovoltaic system with options as to future land development. 
     Another aspect of the invention involves a relocatable photovoltaic system including a fixed anchoring system; a relocatable base removably attached to the fixed anchoring system; and a canopy attached to the relocatable base, the canopy including a plurality of energy converting units that convert solar energy into electrical energy. 
     In one or more implementations of the aspect of the invention described immediately above, the fixed anchoring system is located in the ground; the relocatable base includes an elongated vertical member and the fixed anchoring system includes a hole and a sleeve fixed in position in the hole that slidably receives the elongated vertical member of the relocatable base; the sleeve of the fixed anchoring system is vertically disposed within and coaxially located within hole; the anchoring system includes a support structure for fixing the sleeve in position in the hole, the support structure including concrete-reinforced rebar; the hole includes a vertically elongated lower section with a first diameter and a shallow upper section with a second diameter that is greater than the first diameter; the anchoring system includes a top receiver; the top receiver includes a central hole for receiving the elongated vertical member of the relocatable base there through, and threaded holes for receiving threaded bolts for attaching the relocatable base to the fixed anchoring system; a seal is provided for creating a water barrier between the relocatable base and the fixed anchoring system; the relocatable base includes a elongated vertical member with a top configured to attach with the canopy and a bottom configured to be removably attachable to the fixed anchoring system; the relocatable base includes a support structure with concrete-reinforced rebar throughout substantially an entire vertical portion of the relocatable base above the fixed anchoring system when attached to the fixed anchoring system; the relocatable base includes a support structure with concrete-reinforced rebar throughout a lower vertical portion of the relocatable base above the fixed anchoring system when attached to the fixed anchoring system; the anchoring system includes a top receiver having a recess with a geometric configuration and the relocatable base includes a bottom mounting portion with a corresponding geometric configuration that mates within the recess of the top receiver for attaching the relocatable base to the fixed anchoring system; the relocatable base includes an auxiliary power connector for supplying auxiliary power and a grid power connector for supplying grid power; the canopy is separate from, and removably attachable to, the relocatable base; the canopy includes a truss assembly, a panel mounting structure supported by the truss assembly, and one or more solar panels carried by the panel mounting structure, the one or more solar panels include a plurality of energy converting units that convert solar energy into electrical energy; the canopy is a fixed canopy that orients the one or more panels at a fixed angle where the energy converting units capture the most solar energy; and the canopy is a movable canopy that moves the one or more panels to track the relative movement of the sun through the sky so that the energy converting units capture the most solar energy. 
     A further aspect of the invention involves a method of using a relocatable photovoltaic system including a fixed anchoring system, a relocatable base removably attachable to the fixed anchoring system; and a canopy removably attachable to the relocatable base, the canopy including a plurality of energy converting units that convert solar energy into electrical energy. The method includes the steps of providing the fixed anchoring system including providing a hole, vertically positioning a sleeve within the hole so that the sleeve is coaxially located within the hole, connecting rebar to the sleeve, and pouring concrete into the hole to create a concrete-reinforced rebar support structure for fixing the sleeve in position within the hole, the anchoring system including a receiver at a top of the sleeve; removably attaching the relocatable base to the fixed anchoring system by lowering an elongated vertical member of the relocatable base into the sleeve so that the sleeve slidably receives the elongated vertical member, securing a bottom mounting portion of the relocatable base to the receiver; and removably attaching the canopy to the relocatable base by lowering the canopy onto a top of the relocatable base and securing the canopy to the top of the relocatable base. 
     A further implementation includes relocating the relocatable photovoltaic system from a prior location to a new location by providing a new fixed anchoring system at the new location; detaching and removing the canopy from relocatable base at the prior location; detaching and removing the relocatable base from the fixed anchoring system at the prior location; attaching the same relocatable base to the new fixed anchoring system at the new location; and attaching the same canopy to the relocatable base at the new location. 
     In a still further implementation, relocating the relocatable photovoltaic system from the prior location to the new location includes building over the fixed anchoring system at the prior location or removing the fixed anchoring system at the prior location. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The details of the present invention, both as to its structure and operation, may be gleaned in part by study of the accompanying drawings, in which like reference numerals refer to like parts, and in which: 
         FIG. 1  is a cross-sectional view of an embodiment of a relocatable photovoltaic system. 
         FIG. 2  is a cross-sectional view of an embodiment of an anchoring system of the relocatable photovoltaic system. 
         FIG. 3  is an enlarged cross-sectional view of a top portion of the anchoring system in  FIG. 2  taken in area  3  of  FIG. 2 . 
         FIG. 4  is a top plan view of the ground mount in  FIG. 2 . 
         FIG. 5  is a cross-sectional view of another embodiment of a relocatable photovoltaic system. 
         FIG. 6  is a partial cross-sectional view of a further embodiment of a relocatable photovoltaic system. 
         FIG. 7  is a partial cross-sectional view of a further embodiment of a relocatable photovoltaic system. 
     
    
    
     DETAILED DESCRIPTION 
     With reference to  FIG. 1 , an embodiment of a relocatable photovoltaic system  100  and method will be described. After reading this description it will become apparent to one skilled in the art how to implement the invention in various alternative embodiments and alternative applications. However, although various embodiments of the present invention will be described herein, it is understood that these embodiments are presented by way of example only, and not limitation. As such, this detailed description of various alternative embodiments should not be construed to limit the scope or breadth of the present invention as set forth in the appended claims. 
     With reference initially to  FIG. 1 , the relocatable photovoltaic system (“system”)  100  includes a removably attachable canopy  110 , a relocatable base  120 , and a fixed anchoring system  130 . 
     The canopy  110  includes one or more solar panels  140  carried by a panel mounting structure  150 . The one or more solar panels  140  include a plurality of energy converting units. In a preferred embodiment, the energy converting units are photovoltaic cells; however, in alternative embodiments, the energy converting units include, but not are not limited to, thermal-solar cells, concentrating cells, or other units that convert solar energy into electrical energy. The panel mounting structure  150  is supported by a truss assembly  160 . The truss assembly  160  includes a plurality of braces  170  that stabilize the solar panel(s)  140 . In an embodiment the system  100 , the panel(s)  140  is/are oriented at a fixed angle where the panel(s)  140  will capture the most solar energy. Accordingly, the panel(s) may be oriented at an angle orientation other than that shown. In another embodiment, the one or more of the braces  170  of the truss assembly  160  are movable and driven by a driving/tracking mechanism to cause the solar panel(s)  140  to movably track the relative movement/path of the sun in the sky for optimizing the efficiency of the solar panel(s)  140 . An example movable canopy is shown and described in corresponding U.S. patent application Ser. No. 12/025,192, filed Feb. 4, 2008, which is incorporated by reference herein as though set forth in full. The truss assembly  160  is supported by a removably attachable interface  180 . The wires from the solar panel  140  may be routed down through the truss assembly  160  and a central hole of the interface  180 . Alternatively, the wires may terminate at electrical connectors adjacent where the canopy  110  and base  120  interface. 
     In the embodiment shown, the relocatable base  120  has a frusto-pyramidal configuration; however, in alternative embodiments, the relocatable base  120  has alternative configurations such as, but not limited to, frusto-conical, parallelpiped, cubed, and cylindrical. The base  120  has a concrete trunk with an elongated vertical member in the form of a hollow steel pipe  190  longitudinally/vertically disposed in the base  120 . Extending laterally from the hollow steel pipe  190  are first conduit  200  and second conduit  210 . Wires are routed through the steel pipe  190  and out the first conduit  200  and the second conduit  210 . The first conduit  200  terminates in an auxiliary power connector  220  for supplying auxiliary power and the second conduit  210  terminates in a grid power connector  230  for supplying grid power. 
     In an alternative embodiment, the base  120  and/or hollow steel pipe  190  may be pre-wired and pre-configured with the auxiliary power connector  220  and the grid power connector  230 . The base  120  may include connectors near a top of the base that electrically connect to connectors of the canopy  110  adjacent where the canopy  110  and base  120  interface. This may provide a more convenient means for disconnecting/reconnecting electrical connections when the canopy  110  and base  120  are detached/connected. 
     A top  240  of the base  120  is capped by a steel plate or upper mount  250 . A bottom  260  of the base  120  is supported by a steel plate or bottom mount  270 . The bottom mount  270  includes a central hole  280  that the steel pipe  190  extends through and outer holes  290  that receive bolts  300 . Although not shown, in an alternative embodiment, the bottom mount  270  may include downwardly extending pins that mate with holes in the anchoring system  130  to guide the base  120  when lowering and attaching the base  120  onto the anchoring system  130 . 
     With reference additionally to  FIGS. 2-4 , the fixed anchoring system  130  will be described. The anchoring system  130  includes a steel sleeve  310  that slidably receives the steel pipe  190 . The steel sleeve  310  is vertically disposed within and coaxially located within hole  320  in ground  330 . In the embodiment shown, the hole  320  includes a vertically elongated lower section with a first diameter and a shallow upper section with a second diameter that is greater than the first diameter. The steel sleeve  310  is connected to rebar  340  and concrete  350  surrounds steel sleeve  310  and rebar  340 . A receiver  360  is attached (e.g., welded) to a top  370  of the steel sleeve  310 . The receiver  360  includes threaded holes  380  that threadably receive threaded portions of bolts  300  and a central hole  390  that slidably receives the steel pipe  190  there through. The receiver  360  includes a flat plate  400  circumscribed by a concrete vertical wall  410 . In an alternative embodiment, the vertical wall  410  is made of steel or another metal material and is part of or connected to (e.g., welded) to flat plate  400 . Together, the flat plate  400  and vertical wall  410  define a recess  420 . The flat plate  400  includes an upper surface  430  with an annular recess  440  that receives an O-ring seal  450  as shown in  FIGS. 2-4 . 
     In use, the fixed anchoring system  130  is created in the ground  330 . In an alternative embodiment, the fixed anchoring system  130  is created in an above-ground structure such as, but not limited to, an above-ground foundation or wall. A hole  320  having the configuration shown (e.g., vertically elongated lower section with a first diameter and a shallow upper section with a second diameter that is greater than the first diameter) is created in the ground  330 . The steel sleeve  310  is vertically positioned within and coaxially located within the hole  320  and is connected to rebar  340 . Concrete  350  is poured into the hole  320  and surrounds the steel sleeve  310  and rebar  340 . After the concrete  350  hardens, the receiver  360  is attached (e.g., welded) to the top  370  of the steel sleeve  310 . Alternatively, the receiver  360  is already part of (or pre-connected to) the sleeve  310  before the sleeve is introduced into the hole  320 . 
     The relocatable base  120  is then anchored (removably attached) to the fixed anchoring system  130 . The base  120  is moved to a position where the base  120  is vertically aligned and axially aligned with the fixed anchoring system  130 . Depending on the configuration and/or weight of the base  120 , this may involve using a crane or other heavy lifting equipment. The base  120  is lowered downward so that rectangular plate or bottom mount  270  aligns with and mates with the rectangular recess  420  of the receiver  360 , and the steel sleeve  310  slidably receives the steel pipe  190 . With the rectangular plate  270  disposed within the rectangular recess  420 , relative rotation between the base  120  and the anchoring system  130  is prevented. As discussed above, in alternative embodiment, the bottom mount  270  may include downwardly extending pins that mate with holes in the anchoring system  130  to guide the base  120  when lowering and attaching the base  120  onto the anchoring system  130 . The outer holes  290  of the rectangular plate or bottom mount  270  align with the threaded holes  380  of the receiver  260 , and threaded bolts  300  are threadably engaged there through for anchoring the relocatable base  120  to the fixed anchoring system  130 . O-ring  450  provides a seal between a bottom of the rectangular plate or bottom mount  270  and the top  370  of plate  400  of the receiver  360 . 
     In an alternative embodiment, as shown in  FIG. 7 , the O-ring  450  is located on an underside of rectangular plate or bottom mount  270  in addition to (or instead of) being located on the top  370  of plate  400  of the receiver  360 . 
     The canopy  110 , which is preferably a separate assembly from the base  120 , is then attached to the top of the base  120 . The canopy  110  is lowered onto the base  120  (e.g., using a crane) and the interface  180  of the canopy  110  is attached to the upper mount  250  (e.g., via threaded fasteners or other attaching means) to secure the canopy  110  to the base  120 . The wires from the solar panel  140  are routed through the steel pipe  190  and out the first conduit  200  and the second conduit  210 . Auxiliary power connector  220  for supplying auxiliary power and grid power connector  230  for supplying grid power are electrically connected to the wires. 
     In an alternative embodiment, electrical connectors are provided adjacent to where the canopy  110  and base  120  interface so that the electrical connection between the solar panel  140  and the auxiliary power connector  220  and the grid power connector  230  may be connected at a more convenient location when the canopy  110  and base  120  are connected or re-connected. 
     To relocate the relocatable photovoltaic system  100 , a new fixed anchoring system  130  is provided at a new location. Then, the canopy  110  is detached from base  120  (e.g., by removing threaded fasteners securing the interface  180  and the upper mount  250 ) and removed (e.g., lifted) from the base  120 . Before this step, the auxiliary power connector  220  and the grid power connector  230  may be disconnected from the solar panel wires so that the wires can be removed from the hollow steel pipe  190 . 
     In the alternative embodiment described above where the base  120  is pre-wired and electrical connectors are provided adjacent to where the canopy  110  and base  120  interface, the auxiliary power connector  220  and the grid power connector  230  do not need to be disconnected from the solar panel wires and the wires removed from the base  120 . The connectors adjacent to the interface between the canopy  110  and the base  120  are simply disconnected. 
     The base  120  is then detached from the fixed anchoring system  130  (e.g., by removing threaded bolts  300  from the rectangular plate or bottom mount  270  and the receiver  360 ) and removed (e.g., lifted) from the fixed anchoring system  130 . The base  120  is then attached to the new fixed anchoring system  130  at the new location in a manner similar to that described above. Then, the canopy is  110  is re-attached to the top of the base  120  in a manner similar to that described above. With the relocatable photovoltaic system  100  relocated to a new location, the old anchoring system  130  can simply be built over or removed at the old photovoltaic system location. 
     In an alternative embodiment, the canopy  110  and the base  120  are integrated into a single assembly instead of two separate removably attachable assemblies. In such an embodiment, the combined canopy  110  and base  120  form a single assembly that is lowered onto and attached to the anchoring system  130 , and may later be detached/lifted from the anchoring system  130  as a single assembly. 
     Thus, the relocatable photovoltaic system  100  and method offers potential buyers of the photovoltaic system the ability to easily and inexpensively move the photovoltaic system. If the photovoltaic system is relocated to a new location, the user simply builds over (or removes) the old anchoring system  130 . Thus, the relocatable photovoltaic system is appealing to potential buyers because it allows for options as to future land development. 
     With reference to  FIG. 5 , another embodiment of a relocatable photovoltaic system  500  is shown. The relocatable photovoltaic system  500  is similar to the relocatable photovoltaic system  100  described above, except instead of substantially all of the vertical portion of the base  120  being reinforced with concrete, only approximately the bottom ⅓ (e.g., lower 3-4 ft) of the base  520  is reinforced with concrete since this is the area where the stress loads are the greatest on the base  520 . This design also lightens the base  520 , uses less material, and allows the use of faux facades on the outside of the base  520 , especially the upper ⅔ of the base  520 . The faux facades can be used to match the surrounding buildings or to add artistic appeal to the relocatable photovoltaic system  500 . The base  520  in  FIG. 5  would be ideal for applications that call for creative flexibility in the choice of cladding materials, compared to the base  120  in  FIG. 1 , which would be ideal for situations when a uniform concrete finish, as well as the added durability of a monolithic concrete column are desired. 
     With reference to  FIG. 6 , a further embodiment of a relocatable photovoltaic system  600  is shown. The relocatable photovoltaic system  600  is similar to the relocatable photovoltaic systems  100 ,  500  described above, except instead of a concrete base  120 ,  520  with, for example, a frusto-pyramidal configuration, hollow steel pipe  190  forms the base  620 . This design lightens the base and uses less material. The base  620  of  FIG. 6  would be ideal for projects where a pre-engineered concrete base or concrete column are not desired, such as to utilize unique cladding materials or to maintain the aesthetic of an un-clad steel column. 
     With reference to  FIG. 7 , a further embodiment of a relocatable photovoltaic system  700  is shown. The relocatable photovoltaic system  700  is similar to the relocatable photovoltaic systems  100 ,  500 ,  600  described above, except the O-ring  450  is located on an underside of rectangular plate or bottom mount  270  in addition to (or instead of) being located on the top  370  of plate  400  of the receiver  360  of the anchoring system  130 . The relocatable photovoltaic system  700  may include any of the base designs described above or a different base design. 
     The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles described herein can be applied to other embodiments without departing from the spirit or scope of the invention. Thus, it is to be understood that the description and drawings presented herein represent a presently preferred embodiment of the invention and are therefore representative of the subject matter which is broadly contemplated by the present invention. It is further understood that the scope of the present invention fully encompasses other embodiments that may become obvious to those skilled in the art and that the scope of the present invention is accordingly limited by nothing other than the appended claims.