The invention relates generally to photovoltaic systems, and more specifically to a photovoltaic module support system.
Solar energy produced by the sun can be captured by photovoltaic (PV) modules. Mounting systems for PV modules can be fixed or can track the sun's diurnal motion. Typical single axis tracking systems include a torque tube (roughly five feet above grade) capable of rotating a group of PV modules, which is installed on support posts (driven piles, drilled concrete piles or ballasted foundation). The torque tube supports one or more PV module support structures and PV modules on the support structure (or framed PV modules affixed directly to the torque tube). PV module power plants typically have hundreds or even thousands of rows of PV modules that are fixed in place and must be rotated to track the sun's diurnal motion.
a-1c illustrate one example of a typical single axis tracking system for PV modules. Multiple PV modules 100 are arranged in parallel rows 400, 500, and 600. The rows 400, 500, 600 generally run in the north-south direction, so that PV modules 100 in the rows can be tilted east and west to track the sun's rotation. The PV modules 100 are mounted onto a torque tube 115 elevated above the ground by support posts 104 that may be driven into the ground 110.
At gaps 150 between PV modules 100 in a row 400, 500, 600, a gearbox 101 or other rotation point is affixed to the torque tube 115 on either side of a PV module 100. The gearbox 101 may be driven by independent motors at each support post 104, or more commonly may be connected by an cantilevered lever arm 102 to a linkage 105 that connects all of the assemblies in a column of the PV array, as illustrated in
b and 1c illustrate the rotation of PV modules 100 when the linkage 105 is driven in a horizontal direction (for example, by a motorized screw mounted to a concrete base at one end of a column), the movement of the linkage 105 and the cantilevered lever arms 102 connected to gearboxes 101 causes the PV modules 100 to tilt to track the path of the sun. The PV modules may be tilted east or west in accordance with the movement of the sun. Typically, the rotation point, for example at gearbox 101, is roughly five feet above the ground, and the linkage 105, when employed, is 2-3 feet above the ground.
There are numerous problems with existing mounting systems such as the one illustrated in
a-1c illustrate an example support system for a conventional single axis solar tracker array.
a-2c illustrate top down and side views of a support system for a single axis solar tracker array using a truss and cradle assembly in accordance with an embodiment described herein.
a-3f illustrate top down, side, and perspective views of a support system for a single axis solar tracker array using a truss and butterfly cradle assembly in accordance with another embodiment described herein.
a-4c illustrate top down and side views of a support system for a single axis solar tracker array using a truss and cradle assembly in accordance with another embodiment described herein.
a-5c illustrate top down and side views of a support system for a solar panel array using a truss and cradle assembly in accordance with another embodiment described herein.
a-6c illustrate top down and side views of a support system for a fixed axis solar panel array using a truss and cradle assembly in accordance with another embodiment described herein.
a-7k illustrate top down, side, front, and detail views of a folding truss in accordance with an embodiment described herein.
In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and which illustrate specific embodiments of the invention. These embodiments are described in sufficient detail to enable those of ordinary skill in the art to make and use them. It is also understood that structural, logical, or procedural changes may be made to the specific embodiments discussed herein, without departing from the spirit or scope of the invention.
Described herein is support system for photovoltaic (PV) modules in a solar panel array. The support system utilizing a truss and cradle assembly described herein has beneficial structural properties that enable an increase in the distance between support posts and allows PV modules to be placed directly adjacent one another in a row, resulting in more efficient usage of real estate. The system also enables unobstructed passage between array rows during construction, commissioning, and maintenance. Embodiments of the system described herein enable rotation of multiple rows of PV modules in unison with a low center of gravity rotation point.
a-2c illustrate an embodiment of a PV module support system utilizing a truss and cradle assembly. Photovoltaic (PV) modules 100 are arranged in parallel rows 700, 800, 900 in a photovoltaic array. Photovoltaic modules 100 in a row 700, 800, 900 are affixed to and supported by a truss and cradle assembly 202. The truss and cradle assembly 202 supports a manually installed frame and PV module system, or an automated install (cartridge) module support system such as described in U.S. patent application Ser. No. 12/846,621 entitled “A Mounting System Supporting Slidable Installation of a Plurality of Solar Panels as a Unit” (filed Jul. 29, 2010), U.S. patent application Ser. No. 12/846,365 entitled “Slider Clip and Photovoltaic Structure Mounting System” (filed Jul. 29, 2010), U.S. patent application Ser. No. 12/846,686 entitled “Apparatus Facilitating Mounting of Solar Panels to a Rail Assembly” (filed Jul. 29, 2010), and U.S. patent application Ser. No. 12/957,808 entitled “Method and Apparatus Providing Simplified Installation of a Plurality of Solar Panels” (filed Dec. 1, 2010), which are each incorporated by reference herein in their entirety. The truss and cradle assembly 202 is rotatably fixed by a rotary axis 201 to a foundation support 204, which may be driven piles, drilled concrete piles, ballasted foundation, or other suitable support structure.
The truss and cradle assembly 202 at each row 700, 800, 900 of the array is driven by an electric motor and gearbox or a hydraulic system that is installed on opposite ends of a group of array columns, generally the east and west ends, as described in more detail below. An underground linkage 220 connected to the drive motors facilitates rotating PV modules 100 in multiple rows 700, 800, and 900 in unison to track the sun's diurnal motion. Rotation of the truss and cradle assembly 202 at axis 201 is illustrated in
Comparing the system in
a-3f further illustrate aspects of the embodiment of
c provides a more detailed view of the truss and cradle assembly 202. The PV module 100 is attached to a triangular truss 222 by installation rails 300 which enable a sliding connection with a recess in the PV modules 100 or a carrier for a plurality of modules in the manner illustrated in U.S. patent application Ser. No. 12/846,621. The PV modules 100 of this or any other embodiment described herein can also be attached to the triangular truss 222 using conventional clips, fasteners, screws, glue or any other suitable mechanism for attaching PV modules 100 to the triangular truss 222.
The truss 222 is affixed to a cradle 223, which in this embodiment is a butterfly cradle 222 having movable butterfly drive wings 323 and non-moving (fixed) butterfly drive arms 324. The butterfly drive wings 323 are affixed to and support the truss 222, and can be rotated about the axis 201 in either direction. The axis 201 may be a rotation bearing assembly, a gear drive, or any other suitable rotating connection. The axis 201 may be biased, for example, by a spring 325 inside a rotation bearing of the axis 201, so that, when not acted upon by another force, the axis will return to a position holding the PV module 100 parallel to the ground 110 (the orientation illustrated in
Linkages 205 pass through holes in the non-moving (fixed) butterfly drive arms 324, and are connected to the movable butterfly drive wings 323. Thus, when a linkage 205 is pulled in a downward direction, it will pull down the respective connected movable butterfly drive wing 323 of the cradle 223, which causes the movable butterfly drive wing 323 to rotate about axis 201, thus tilting the PV module 100. Linkages 205 may be a braided metal wire or other moveable connection. A sheath 206 around the linkages 205 allows free movement under ground 110, and can be used to protect the linkages (and as a safety measure) above ground.
In
d-3f provide perspective views of components in the
e illustrates a perspective view of the truss 222. The truss 222 includes top rails 706 connected to side supports 701 and top supports 702. Though shown here as a triangular support structure with rail side supports 701 and open sides, the truss 222 could also have planar side supports 701 that create a continuous side wall on the sides of the truss 222. The truss 222 may be any length suitable for transport and on-site installation. The truss 222 may be a fixed structure or may be a folding truss (described in more detail below). The top rails 706 may be configured with parallel installation rails 300 that enable PV modules 100 to be mounted by sliding multiple PV modules 100 onto the installation rails 300. Alternatively, a cartridge that holds a plurality of PV modules 100 may be slidably mounted onto the installation rails 300 of top rails 706. Though shown here configured with installation rails 300 for mounting PV modules 100, any suitable mounting method may be used to affix PV modules 100 to the top rails 706, as discussed above.
The tilting of multiple rows of PV modules 100 in unison is now described with reference to
To tilt the PV modules 100, the motor and gearbox 225 at one end of the column retracts the linkage 205, for example by winding the connected linkage 205 around a spool 245. When the linkage 205 is retracted, it pulls downward on the movable butterfly drive wing 323 of the connected cradle 202, and this causes the butterfly drive wing 323 to rotate about its axis, tilting the PV modules 100 in one direction. Since all of the cradles 202 in the rows 700, 800, 900, 1000, 1100 are connected by linkages 205, all of the PV modules 100 in the column are tilted in the respective direction by the tension of the linkages 205 between the cradles 222. To tilt the assemblies 202 back in the opposite direction, the motor and gearbox 225 at the other end of the column retracts the connected linkage 205, and the PV modules 100 are tilted back in the opposite direction.
The truss and cradle assemblies 202 may be biased into a neutral position (orienting PV modules parallel to the ground 110) by a spring 325 in a rotation bearing of axis 201, or any other suitable biasing structure. This way, if the electric motors and gearbox 225 fails (due to power outage or other reasons), the system will maintain this neutral position. This avoids damage by winds, and inefficiencies that can be caused by a static tilted position.
Retracting linkages 205 using an electric motor and gearbox 225 is one way to move the rows in unison, but those of skill in the art will recognize that there are other acceptable ways to tilt these assemblies in unison. For example, if the linkage 220 is sufficiently rigid, motors and gearboxes 225 are only necessary on one end of the column, as they could both push and pull the linkages 220 (as opposed to only pulling, as described above). A hydraulic system could also be used at one end of the column to both push and pull the linkages 220 to tilt the PV modules 100.
a-4c illustrate another embodiment of a PV module support system utilizing a truss and cradle assembly. This embodiment uses a similar truss and cradle assembly 302, but the cradle is configured with only one set of drive arms, and instead of being driven by linkages 205 connected to an electric motor and gearbox 225 or hydraulics, it is driven by individual electric actuators 210 located at each foundation support. The electric actuators 210 push or pull one side of the truss and cradle assembly 302 to tilt the PV modules 100 in one direction or another. The electric actuators 210 are connected by an electrical connection 240 such as a shielded electrically conductive wire. The electrical connection 240 is connected, at one end of the PV array, to a power supply 230. As in the other embodiments, the truss and cradle assembly 302 may be biased in a neutral position, so that if there is a failure of the electric actuators 210 or the electrical connection 240, the truss and cradle assembly 202 will return to a neutral position.
c illustrates a detail view of one of the support structures in the
As with the
a-5c illustrate yet another embodiment of a PV module support system utilizing a truss and cradle assembly. The
The
a-6c illustrate another embodiment of a PV module support system utilizing a truss and cradle assembly. In the
The embodiments described herein each include a triangular truss can spans the length of a row in the PV array. The truss 222 may be a fixed truss that is pre-assembled or assembled on-site, or may be a folding truss design.
Various mechanisms may be used to hold the truss 222 in the unfolded state. For example, the bottom box beam 703 may have indents 750 at the point where each side support 701 will come to rest in the unfolded state. This is illustrated in
d-7f illustrate the truss 222 as it is in the process of being folded. The bottom box beam 703 comes forward and up, and will fold in the indicated direction until it meets the top rails 702. The pins 710 on side supports 701 provide a rotation point, and hinges 720 allow necessary articulation for the bottom box beam 703 to move up and forward, towards the top rails 702.
g-7i illustrate the truss 222 in a folded position. Here, the bottom box beam 703 rests against the top rails 702 of the triangular truss structure. The hinges 720 of the side supports 701 have folded to allow articulation of the bottom box beam 703, and the side supports 701 have fully pivoted about rotation points provided by pins 710. The folding truss 222 enables easy transportation and storage of the truss until it is commissioned for use in an installation. The folding truss 222 can be used in fixed PV module arrays or in solar tracker systems.
While embodiments have been described in detail, it should be readily understood that the invention is not limited to the disclosed embodiments. Rather the embodiments can be modified to incorporate any number of variations, alterations, substitutions, or equivalent arrangements not heretofore described without departing from the spirit and scope of the invention.
This application is a divisional of U.S. patent application Ser. No. 13/011,185, filed Jan. 21, 2011, the entirety of which is incorporated herein by reference.
Number | Name | Date | Kind |
---|---|---|---|
1888620 | Clark | May 1927 | A |
4146785 | Neale | Mar 1979 | A |
4184482 | Cohen | Jan 1980 | A |
4249514 | Jones | Feb 1981 | A |
4345582 | Aharon | Aug 1982 | A |
4429178 | Prideaux et al. | Jan 1984 | A |
4476854 | Baer | Oct 1984 | A |
4512117 | Lange | Apr 1985 | A |
4765309 | Legge | Aug 1988 | A |
4832001 | Baer | May 1989 | A |
4995377 | Eiden | Feb 1991 | A |
4999059 | Bagno | Mar 1991 | A |
5169456 | Johnson | Dec 1992 | A |
5228924 | Barker et al. | Jul 1993 | A |
5317145 | Corio | May 1994 | A |
5374317 | Lamb et al. | Dec 1994 | A |
5542409 | Sampayo | Aug 1996 | A |
5660644 | Clemens | Aug 1997 | A |
5730117 | Berger | Mar 1998 | A |
5819492 | Konicek | Oct 1998 | A |
6046399 | Kapner | Apr 2000 | A |
6058930 | Shingleton | May 2000 | A |
6089224 | Poulek | Jul 2000 | A |
6123067 | Warrick | Sep 2000 | A |
6563040 | Hayden et al. | May 2003 | B2 |
6662801 | Hayden et al. | Dec 2003 | B2 |
6870087 | Gallagher | Mar 2005 | B1 |
6959993 | Gross et al. | Nov 2005 | B2 |
7190531 | Dyson et al. | Mar 2007 | B2 |
7192145 | Ealey | Mar 2007 | B2 |
7192146 | Gross et al. | Mar 2007 | B2 |
7240674 | Patterson | Jul 2007 | B2 |
7252083 | Hayden | Aug 2007 | B2 |
D565505 | Shugar et al. | Apr 2008 | S |
7357132 | Hayden | Apr 2008 | B2 |
D586737 | Shugar et al. | Feb 2009 | S |
7531741 | Melton et al. | May 2009 | B1 |
7554030 | Shingleton | Jun 2009 | B2 |
7557292 | Shingleton et al. | Jul 2009 | B2 |
7647924 | Hayden | Jan 2010 | B2 |
7857269 | Plaisted et al. | Dec 2010 | B2 |
7888588 | Shingleton | Feb 2011 | B2 |
20030070705 | Hayden et al. | Apr 2003 | A1 |
20040219039 | Watt | Nov 2004 | A1 |
20040238025 | Shingleton | Dec 2004 | A1 |
20060044511 | Mackamul | Mar 2006 | A1 |
20060054162 | Romeo | Mar 2006 | A1 |
20070012312 | Hayden | Jan 2007 | A1 |
20070019362 | Stevenson et al. | Jan 2007 | A1 |
20070070531 | Lu | Mar 2007 | A1 |
20070215145 | Hayden | Sep 2007 | A1 |
20080000514 | Lin et al. | Jan 2008 | A1 |
20080000515 | Lin et al. | Jan 2008 | A1 |
20080230047 | Shugar et al. | Sep 2008 | A1 |
20080230108 | Keshner et al. | Sep 2008 | A1 |
20080236567 | Hayden | Oct 2008 | A1 |
20080245360 | Almy et al. | Oct 2008 | A1 |
20080245402 | Romeo | Oct 2008 | A1 |
20080251115 | Thompson et al. | Oct 2008 | A1 |
20080264363 | Heusser et al. | Oct 2008 | A1 |
20080264474 | Frauenknecht et al. | Oct 2008 | A1 |
20080283116 | Banin et al. | Nov 2008 | A1 |
20080308091 | Corio | Dec 2008 | A1 |
20090005019 | Patel et al. | Jan 2009 | A1 |
20090007901 | Luconi et al. | Jan 2009 | A1 |
20090031432 | Wakai | Jan 2009 | A1 |
20090032014 | Meydbray | Feb 2009 | A1 |
20090050191 | Young et al. | Feb 2009 | A1 |
20090071154 | Penciu | Mar 2009 | A1 |
20090151769 | Corbin | Jun 2009 | A1 |
20090159075 | Mackamul | Jun 2009 | A1 |
20090188487 | Jones et al. | Jul 2009 | A1 |
20090223142 | Shingleton et al. | Sep 2009 | A1 |
20090223315 | Needham | Sep 2009 | A1 |
20090235975 | Shingleton | Sep 2009 | A1 |
20090260619 | Bailey et al. | Oct 2009 | A1 |
20090283133 | Hebrink et al. | Nov 2009 | A1 |
20100000051 | See | Jan 2010 | A1 |
20100007175 | Mayer et al. | Jan 2010 | A1 |
20100017574 | Takahashi et al. | Jan 2010 | A1 |
20100025203 | Ignasiak et al. | Feb 2010 | A1 |
20100032004 | Baker et al. | Feb 2010 | A1 |
20100039646 | Bourderionnet et al. | Feb 2010 | A1 |
20100051083 | Boyk | Mar 2010 | A1 |
20100051086 | Keshner et al. | Mar 2010 | A1 |
20100071683 | Selig et al. | Mar 2010 | A1 |
20100089433 | Conger | Apr 2010 | A1 |
20100101625 | Kats et al. | Apr 2010 | A1 |
20100101630 | Kats et al. | Apr 2010 | A1 |
20100101632 | Kats et al. | Apr 2010 | A1 |
20100122722 | Halpern | May 2010 | A1 |
20100147286 | Xiang et al. | Jun 2010 | A1 |
20100218806 | Arab et al. | Sep 2010 | A1 |
20100223865 | Gonzalez Moreno | Sep 2010 | A1 |
20100229851 | Reynolds | Sep 2010 | A1 |
20100236601 | Okamoto | Sep 2010 | A1 |
20100258110 | Krabbe et al. | Oct 2010 | A1 |
20110192394 | Brothersen | Aug 2011 | A1 |
Number | Date | Country |
---|---|---|
0 114 240 | Aug 1984 | EP |
1 791 184 | May 2007 | EP |
10-2010-0124386 | Nov 2010 | KR |
WO 2010141740 | Dec 2010 | WO |
Number | Date | Country | |
---|---|---|---|
20130180568 A1 | Jul 2013 | US |
Number | Date | Country | |
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Parent | 13011185 | Jan 2011 | US |
Child | 13784374 | US |