US20070204860A1

US20070204860A1 - Device for supporting, aligning, and cooling a solar panel

Info

Publication number: US20070204860A1
Application number: US11/368,108
Authority: US
Inventors: Andrew Rose
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-03-06
Filing date: 2006-03-06
Publication date: 2007-09-06

Abstract

A device for solar panels and method allows seasonal tilting by human assistance for changes in sun angle above equator, and unassisted daily positioning east to west to east. A primary support member is fixed to the back of a typical solar panel, generally from corner to corner along a line of balance. This support member is elongated and enabled for rotation, with attached panel by rotation sleeves or pivots. Extensions of the rotation sleeves in connection with two posts are positioned on a polar axis. The posts are solidly fixed in the earth or a base. The rotation sleeve covering the longer post, closest to the pole, is manually adjusted and secured to change the angle of the collector with the equator. Stops are provided. A linear actuator is pivotally attached at an edge or corner of the solar panel with the other end attached to a post, which is pivotally attached relative to the ground or base. An electric motor is powered by batteries to drive the linear actuator. Control of the motor is regulated by programmed activation in response to time of day as maintained by an on board clock. The panel tracks the sun and at change of day returns to a preset position. Cooling of the solar panel is provided with subsurface air via infiltration gallery and distribution channels. Air moves by convection or with auxiliary fan.

Description

BACKGROUND OF THE INVENTION

Solar collectors are known to have increased performance (heat or electricity) in cases where they can actively track the sun. Estimates of 30% or more power generation are estimated with active tracking solar devices over that of fixed mounting brackets. Tracking devices have typically taken the configuration of a single mast to support a collector or group of collectors such as U.S. Pat. No. 5,317,145 issued to Corio. Another configuration is shown by U.S. Pat. Nos. 6,253,632 and 6,089,224 issued to Poulek. In some cases adjustments of entire rows or groups of panels are suggested with a long interconnected rigid framework using a number of rods, cables or various mechanisms. See U.S. Pat. No. 6,302,099 to McDermott and U.S. Pat. No. 6,563,040 to Hayden et al. This prior art is generally expensive to manufacture, difficult to install, and inadequate against high winds such as encountered in Wyoming and other Rocky Mountain States. Additional references to solar trackers are found in the technical paper “NEW BIFACIAL SOLAR TRACKERS AND TRACKING CONCENTRATORS” by Poulek and Libra, available at www.solar-trackers.com.
Solar collector (Photovoltaic) performance is often compromised during periods of high temperature, generally mid day to dusk in the summer months of May-September. Solar cell performance and longevity degrades under high heat conditions. It is noted, a tracking solar collector will cast a ground shadow underneath the collector, and at solar noon provides an area where ground temperatures remain significantly cooler then the surrounding areas. Passive convection, fan assist, and shading components are related to this invention.
Additional reference characteristics of photovoltaic performance are described in the paper “The Rating of Photovoltaic Performance” by K. Emery of the National Renewable Energy Lab, Golden, Colo., USA and published October 1999 in Electron Devices, IEEE Transactions: Vol. 46, Issue 10, pages 1928-1931.

SUMMARY OF THE INVENTION

There is discovered a reliable and strong support structure that requires a minimum of electricity to realign panel(s), can withstand excessive winds, provides cooling to the solar panel(s), and contains additional benefits here summarized. The discovery of this invention is based upon the science of biomimicry, specifically the shape and behavior of a leaf. Leaves are often round, ovoid or tapered to a stem. Orientation of a solar panel is presented in which a corner of the panel is closest to the ground and connected to a hollow attachment member or pipe. The solar panel mimics the shape of a leaf when directly viewed. During rotation there is minimum interference of the panel with the ground surface, and greater sweep. Leaves maintain temperature, preventing desiccation, by drawing water upwards through the stem. Analogously, photovoltaic cells diminish in output and degrade under high temperatures. A source of cool air is generally available in the ground beneath a solar panel. Presented is a device to transfer cool ground air to the solar panel with zero or minimal input energy.
Solar panels to generate electricity are increasing in size. Today they are available at 315 Watt capacity, and larger, as a single complete unit. These panels are generally rectangular and approximately 4′2″ wide by 6′2″ long. The corner to corner diagonal length is approximately 7′4″ and weight is approximately 107 lbs. At some point, solar panel units may be of a circular, oval or triangular (isoceles or equilateral) shape in which this invention is equally suited. Most silicon type solar cells are constructed in a solar panel that is rectangular in shape. As silicon shortages affect the industry, various alternative shapes of panels will become available, because other materials are more conducive to different shaped panels. The support for panels is disclosed within this invention at a minimum but effective use of materials to meet structural considerations. The solar panel (or group) is supported along a balance line (polar axis) and a bracket provided at a free hanging corner of the solar panel and attached to a linear actuator. Whereas prior art arrangements provide a solar panel (or group) with the panel edge parallel with the ground or base, my disclosure shows the corner of a panel closest to the ground surface or base. The solar panel achieves the primary support coming from a member attached corner to corner. This provides several advantages. The panel can be positioned closer to the ground allowing rotation east to west with less ground interference at the extreme positions. The panel is less exposed to high winds. A separate frame is not required between the panel and the support member. The tubular support members can provide additional functions of a wire raceway and air conduit for cooling air. Stable third point support is provided with a linear actuator attached at the higher of the two free-hanging corners.
The linear actuator rotates the panel(s) about the balance line or polar axis, in response to a programmed logic control (PLC) device and responsive to a clock time-of-day. The linear actuator contains an electric motor. The motor is driven by batteries mounted on the underside of the panel. The batteries are maintained at charge by electricity from the solar panel.
A cooling function consists of metal raceways or conduits attached to the back of a typical solar panel. These tubes are open at one end and join collectively near the bottom of the solar panel at a manifold. The manifold(s) interconnect with the hollow support member which is internally sealed to prevent air flow to the top of the solar panel. The air passageway is continuous through the lower post and into the ground where it is connected with an air infiltration gallery. The air infiltration gallery extends in the ground area directly beneath the solar panel. The air infiltration gallery includes one (or more) perforated pipe or chambers. To improve air flow capacity and heat capacity underground a zone of crushed rock or pea gravel is placed around the perforated pipe. As the solar panel heats up in summer days, the metal raceways will also heat up through conductive heat flow. This heats the air in the raceways causing a convective flow of air to occur. A vacuum is created drawing cool air from the air infiltration gallery up into the metal raceways and in turn cooling the solar panel. Alternatively a small fan may be installed in the hollow support member and controlled by the PLC. The fan may be activated to improve transfer of cool air to the solar panel during the heat of day. The electrical cost to operate the fan is exceeded by additional electrical generation from the photovoltaic panel at the now lower temperatures. At nighttime the fan may be reversed to pump cool air into the ground pore spaces. An additional feature is a fabric covering or rigid sheet about the support pipe closet to the pole; this provides additional shading to the ground surface under the solar panel in the early morning and late evening hours, as well as blocking wind to minimize wind uplift forces against a solar panel.

DESCRIPTION OF DRAWINGS

FIG. 1 Is a perspective view of the invention.
FIG. 2 is a view of electrical components and wiring.
FIG. 3. is a view of pipe joints and variations.
FIG. 4. is a view of cooling components.
FIG. 5. Is a view of an additional cooling feature.

DESCRIPTION OF PREFERRED EMBODIMENTS

A solar panel support 10 shows embodiments as depicted in FIG. 1. Support members include pipes 12, 14, 16 anchored into concrete footings 18, 20, 22. Concrete footings 18, 20, 22 provide support to download dead and live loads and uplift forces transmitted by pipes 12, 14, 16. Pipe 12 and 16 extend through the concrete 18 and 22, respectively. Pipes 12, 14, 16 are rigidly constrained within concrete 18, 20, 22. Concrete 18, 20, 22 are contained by earth 23. Pipe 12 and Pipe 16 are arranged generally on a polar axis, Pipe 12 being closer to the pole. Pipe 14 includes a pivot linkage 15 providing a range of motion over a cone of approximately 30 degrees along the axis. An extension cover pipe 24 contains a flexible segment 26 and is sized for containment of attachment member 28. Attachment member 28 is generally a hollow pipe, however other shapes are embodied. Pipe 16 contains a flexible segment 36 as shown. Pipe 16 passes through concrete footing 22 and is attached to a buried pipe elbow 38. A collar 40 surrounds attachment member 28 acting as a stop against the end of pipe 16 while permitting rotation of attachment member 28. Attachment member 28 rotates inside extension cover pipe 24 and pipe 16. Attachment member 28, extension cover pipe 24, and pipe 16 may be of various size and material, but in most installations such as shown on FIG. 1, attachment member 28 will be of 1⅝″ outside diameter whilst pipe 16 and extension cover pipe 24 will be 1⅞″ outside diameter and 1¾″ inside diameter.
Extension cover pipe 24 makes a bend of approximately 90 degrees at flexible segment 26, extending and encasing pipe 12. A bolt 42 passes through holes securing extension cover pipe 24 with pipe 12 at preset location.
A solar panel 30 is fastened to attachment member 28 with clamps 44 and 46. In the preferred embodiment solar panel 30 is oriented with attachment member 28 at opposite corners, as shown on FIG. 1. Those skilled in the art will recognize the extension of this device for other shaped panels such as circular, oval, or in clusters. Attachment member 28 is hollow throughout except for a seal 48 and a fan 49. Attachment member 28 is generally inclined at a slope angle related to the latitude of the location of installation. The slope of solar panel 30 and attachment member 28 will range from the latitude minus 15 degrees to latitude plus 15 degrees, depending upon the season.
A linear actuator 50 is pivotally attached to solar panel 30 with pivot connector 52. Linear actuator 50 is rigidly attached to an extension cover pipe 54 with connector 55 as shown on FIG. 1. Extension cover pipe 54 slides axially and encasings pipe 14. A bolt 56 restricts movement of extension cover pipe 54 with pipe 14. Linear actuator 50 is controlled automatically from control circuitry under cover 58. See FIG. 2. PLC 59 is contained within cover 58 on a circuit board 57 along with batteries 61, charge regulator 63, clock 69, and thermoswitch 65. Wires 67 from solar panel 30 enter junction box 62. Leads 60 deliver electricity from solar panel 30 as the sun shines to junction box 62. Lead 60 delivers electricity to charge regulator 63, batteries 61, clock 69, and PLC 59. Lead 73 delivers electricity from PLC 59 to linear actuator 50.
FIG. 3 shows details of extension cover pipe 24 and pipe 12 at area of cooperation. A series of holes 64 are placed perpendicular to the axis and through both walls of pipe 12 at a spacing of approximately six inches. An additional series of holes 66 are placed perpendicular to the axis and through both walls of extension cover pipe 24 at a spacing of approximately six inches. An identical pattern of holes and spacing are utilized on extension cover pipe 54 and pipe 14. Bolt 42 is of slightly smaller diameter then holes 64 and 66. A nut 68 attaches to bolt 42. Sliding and aligning holes 64 with holes 66 enables bolt 42 to be used at a convenient hole location to establish the overall length of pipe 12 coupled to extension cover pipe 24, therefore establishing the slope of solar panel 30. During initial installation or repositioning (for seasonal adjustments) both bolts 42 and 56 are removed. The solar panel 30 is adjusted by sliding extension cover pipe 24 and extension cover pipe 54 positioning relative to pipe 12 and 14. Bolt 42 is secured with nut 68 in appropriate holes 64 and 66. Now, solar panel 30 and fastened attachment member 28 are rotated to place the surface of solar panel 30 directly facing the sun. Linear actuator 50 is manually engaged to extend or retract until holes of pipe 14 are aligned with holes of extension cover pipe 54, then bolt 56 is installed. Adjustments are typically made twice to four times annually and can be easily undertaken by one person. Summer adjustment is made to establish a slope of solar panel 30 to being latitude plus 15 degrees and winter adjustment is made to establish a slope of latitude minus 15 degrees.
Internal clock 69 (FIG. 2) may be settable or wireless calibration to atomic clock sources maintained by National Institute of Standards. Wire conductor lead 70 distributes generated electricity from solar panel 30 through containment within attachment member 28, extension cover pipe 24 and pipe 12 exiting the embodied device below ground surface. (FIG. 1) This provides protection from the elements and vandalism. Lead 70 will continue to a point of use, or connect with other conductors in a solar energy farm. Those familiar with the art will see the advantages in that the invention support members provide an additional feature of wire raceways. Lead 72 is attached to the back of solar panel 30.
The automated operation of daily tracking is now described. All movement (rotation) of solar panel 30 about attachment member 28 is by extension and retraction of linear actuator 50. At sunrise in the preferred embodiment solar panel 30 is facing 45 degrees east from the plane formed by attachment member 28 and pipe 12. For sake of example, at 8:00 am PLC 59 responds to the internal clock 69 and retracts linear actuator 50 for 1.5 inches. On an hourly time interval PLC 59 will continue to engage linear actuator 50 causing rotation of solar panel 30 about attachment member 28, effectively tracking the sun for direct intensity of the suns rays upon the face of solar panel 30. This maximizes electrical generation of solar panel 30. After ten rotations, at 5:00 pm, solar panel 30 faces 45 degrees west from the plane formed by attachment member 28 and pipe 12. At midnight, or change of day, PLC 59 engages linear actuator 50 to extend through reverse polarity application of electricity through lead 73, causing solar panel 30 to return to original position. This embodiment may be varied in scope whereas the sweep of solar panel 30 may be greater or less then 90 degrees, time intervals may be more or less frequent, and linear actuator 50 may have longer or shorter stroke.
Alternative configuration of flexible segments 26 and 36 is shown as FIG. 3B. The joints 69 and 71 include plate sections 75, 77, 79 and 81. Pivot pins 83 and 85 allow rotation as alternative to flexible segments 26 and 36.
A cooling device is embodied and includes several components. FIG. 4 is a side view of the invention with solar panel 30 facing directly away for illustrative purposes. Attached to the back of solar panel 30 are metal raceways 74 which are hollow in crossection, or porous, to permit air flow along the length. Metal raceways 74 are open to the atmosphere at one end 76 and joined to manifolds 78 and 80, as shown. Alternatively, metal raceways 74 may be replaced with a thin envelope or porous conductive mat. Metal raceways 74 are of heat conductive material and responsive to temperature changes of solar panel 30 under changes in temperature, such as caused by direct sunlight.
Manifolds 78 and 80 attach and internally connect with attachment member 28. An airtight seal 48 is contained within attachment member 28 where indicated. As shown on FIG. 4A a fan 49 is contained within attachment member 28, connected with lead 72 passing through an airtight hole 82. The fan 49 is capable of direct or reverse rotation and responsive to PLC.59. A thermoswitch 65 is connected to PLC 59 and settable to threshhold temperature, typically 80 degree Fahrenheit. Attachment member 28 is shown with collar 40 clamped securely. Pipe 16 is viewed in separation. A grease sealant 86 is shown applied to pipe 16. When assembled grease sealant 86 prevents air escape. Alternatively, an O ring may be utilized.
Pipe 16 and flexible segment 36 are completely sealed from the atmosphere. When alternative connection to flexible segment 36 is used as described in FIG. 2B, a bellows 67 is included connecting pipe 36 to itself on either side of the alternative joint 69. The bellows 67 allows connective air passage.
Pipe 16 may be painted a reflective color such as white to discourage heating from the sun, or may be insulated. Pipe 16 extends through concrete 22 attaching to pipe 38. Pipe 38 extends underground connecting with air infiltration gallery 88. See FIG. 4B. Air infiltration gallery 88 includes pipe 90, pipe 92, and pipe 94. Pipes 90, 92, 94 are perforated and substantially large diameter. Typically, pipes 90, 92, 94 may be one foot diameter with perforation holes 96 of 1 inch diameter. Perforation holes 96 may vary in number, particular to onsite conditions. Gravel 98 of 1-2 inch size surrounds pipes 90, 92, 94. Gravel 98 provides maximum pore spaces and air passages are well interconnected to perforation holes 96. Air infiltration gallery 88 is buried and located generally beneath shadow cast from solar panel 30 at noon. Gravel 98 generally surrounds pipes 90, 92, 94 a distance of one foot and may approach ground surface 100 or locate beneath ground surface 100 some distance. In some cases pipes 92 and 94 are excluded.
FIG. 5 shows a cover sheet 102 generally shaped square, being a white or reflective material and highly resistant to weathering. Cover sheet 102 is draped over and supported along pipe 12 and extension cover pipe 24. A tie down hook 104 is anchored in concrete 20 and a second tie down hook 106 is anchored in concrete 108, located symetrically opposite concrete 20 on a line between concrete 18 and concrete 22. Cover sheet 102 provides ground shade during summer months just in early morning and late afternoon, prior to sunset. Cover sheet 102 also prevents uplift winds from reaching the underside of solar panel 30. Cover sheet 102 also diverts rainfall away from air infiltration gallery 88, maintaining air spaces.
The operation of the cooling apparatus is now described. In the preferred embodiment rising temperatures of solar panel 30 create rise in temperature of metal raceways 74. Air within metal raceways 74 heats and begins to rise, drawing air from manifolds 78, 80. Moving air creates a vacuum within attachment member 28 and pipe 16. Cool air within air infiltration gallery 88 is drawn through pipe 38, pipe 16 and attachment member 28 moving upward eventually reaching metal raceways 74. Cool air lowers raceway 74 temperatures and cools solar panel 30 resulting in improved electrical performance.
PLC 59 is used to activate fan 49 if necessary. For example, at a programmed time schedule (10:00 AM, 12:00 AM, 2:00 PM, 4:00 PM, 6:00 PM), PLC 59 will activate fan 49 for a ten minute operation if thermoswitch 65 limit is exceeded. For purpose of example, thermoswitch 65 may be set at 70 degrees fahrenheit. When direct activated, fan 49 enhances air movement from air infiltration gallery 88 to metal raceways 74.
PLC 59 is programmed to reverse activate fan 49 to draw cool nighttime air into metal raceways 74, injecting air into air infiltration gallery 88. Typically, PLC 59 will operate fan 49 for ten minute operation at programmed schedule (4:00 AM, 5:00 AM).
All pipe sections herein described are preferred to be of metal construction, however they may also be composite materials including plastics and carbon fiber. Thus the reader can see the device for supporting, aligning and cooling solar panels is highly reliable, lightweight, and yet an economical device. Significant advantages of electrical generation and ease of manufacture and installation and operation can be realized through the above description. The description should not be construed as limitation on the scope of the invention, but rather as exemplification of one preferred embodiment. Many other variations are possible. For example, multiple rectangular or square solar panels can be combined on one polar axis, with the axis along longest overall dimension, corner to corner of the assemblage.
Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.

Claims

1. An apparatus for the support and movement of a solar panel, said apparatus consisting of:

an attachment member rigidly affixed to said solar panel along a balance line;

a first extension cover pipe acting in cooperation with first end of said attachment member, permitting rotation of said attachment member;

a second pipe acting in cooperation with second end of said attachment member, permitting rotation of said attachment member;

a first support member engaged with said first extension cover pipe providing adjustment axially, corresponding to change in slope of said solar panel;

a hydraulic actuator, first end of said hydraulic actuator pivotally attached to said solar panel, second end of said hydraulic actuator fixed to a third extension member; and,

control means directing movement of said linear actuator in response to time of day, causing rotation of said solar panel about said balance line.

2. The apparatus of claim 1, wherein said attachment member is oriented along a true polar alignment.

3. The apparatus of claim 1, wherein, said balance line is the longest edge to edge distance of said solar panel.

4. The apparatus of claim 3, wherein said solar panel is rectangular.

5. The apparatus of claim 4, wherein said attachment member is fastened corner to diagonal corner of said solar panel.

6. The apparatus of claim 5, including battery power.

7. The apparatus of 6, wherein said battery recharged by said solar panel.

8. A cooling apparatus for a solar panel, said apparatus consisting of:

a series of heat conductive channels connected to the back of said solar panel, said channels open to the atmosphere at first end extension, said channels second end connected with manifolds;

said manifolds second end connected to a pipe;

said pipe extending below ground surface, connected with perforated pipe(s) located spatially directly beneath said solar panel; and,

said perforated pipes in contact with porous rock.

9. The apparatus of claim 8 including an electrically powered fan contained within said pipe.

10. The apparatus of claim 9 including said electrically powered fan with control means, said control means responsive to preset time of day.

11. The apparatus of claim 10 including said electrically powered fan to draw air from said porous rock, transporting said air to atmosphere at said first end extension of said conductive metal channels.

12. The apparatus of claim of 10 including said electrically powered fan to draw air from atmosphere at said first end extension of said conductive metal channels, transporting said air to said porous rock.

13. A solar panel support structure apparatus to reduce uplift wind forces on said solar panel and to improve cooling of underlying ground surfaces, said apparatus consisting of

a sheet;

said sheet supported diagonally along a pipe member, a first end of said pipe member attached to elevated corner of said solar panel, a second end of said pipe member attached to concrete footing;

noncoincident corners of said sheet with said pipe member fastened to tie down hooks anchored in concrete.

14. The apparatus of claim 13 wherein said sheet a weather resistant woven fabric.

15. The apparatus of claim 13 wherein said sheet a square shape.

16. The apparatus of claim 13 wherein said sheet a reflective surface.

17. The apparatus of claim 13 wherein said sheet casts a shadow substantially beneath said solar panel.

18. The apparatus of claim 1 wherein first extension cover pipe bends approximately 90 degrees, to describe a second section, said second section in cooperation with a pipe, said pipe constrained in concrete.

19. The apparatus of claim 18, wherein a bolt restricts movement of said second section of said extension cover pipe with said pipe.

20. The apparatus of claim 19 wherein conductors from said solar panel are enclosed within said attachment member, said extension cover pipe, said pipe; and exiting beneath ground surface.