This invention relates to an integrated mounting system for photovoltaic modules for use in solar energy collection. In a more specific aspect, this invention relates to a non-ballasted and non-ground penetrating elongate member integrated photovoltaic mounting system for use with, and supported by, tufted geosynthetics.
In this application, the following terms will be understood to have the indicated definitions:
Photovoltaic solar modules have historically been mounted by use of a rigid racking system over a variety of surfaces such as rooftops, greenfields and brownfields. These rigid racking systems have not been integrated onto the photovoltaic module. Typical systems include racking structures that the photovoltaic module must be placed upon and then mechanically fastened to the racking structure.
Racking structures are placed in spaced-relation and the racking structures enable orienting the photovoltaic module at an energy-generating efficient angle. However, the spacing limits the number of photovoltaic modules that can be installed in an area because the angling causes shadows. An adjacent rack must be spaced sufficiently that the photovoltaic modules are not within a shadow area.
There is a need in the solar industry for an integrated photovoltaic module in which the mounting mechanism is attached to the photovoltaic module which eliminates the need for a rigid racking system. The integration allows for an economical alternative to a traditional rigid racking system and enables the increasing of the density of the photovoltaic modules placed at a solar energy generation site, thereby increasing the potential generation of electrical power while allowing flexibility of installation by using non-traditional racking installers.
While use of solar as a renewable alternative energy source has “clean energy” favorabilities, there are drawback to such installations. Solar energy generation sites typically require large tracts of land. In some location circumstances, wooded lands are cleared or farm lands are re-purposed for use as solar energy generation sites. Other sites are significantly remote from tie-in connections to the power transmission and distribution grid of power generating and supply companies. These remote sites require capital expenditures to install and maintain transmission lines to the electrical grid and such transmission lines occupy additional land. Also, recent changes in power generation capacity has decreased reliance on coal and increased reliance on cleaner combustion fuels such as natural gas and, alternatively, power plants that generate electricity with turbines operated with steam heated by nuclear fuel sources. The coal-fired power plants nevertheless have large areas of ash holding ponds or storage areas. These areas are subject to closing with covers such as geomembranes that restrict environmental waters, such as rain or other precipitation or surface water flow, from passing through the covered site and leaching into the ground or pond.
Accordingly, there is a need in the art for an improved integrated mounting system for securing photovoltaic modules to a surface for generating solar power. It is to such that the present invention is directed.
The present invention meets the need in the art by providing an apparatus for securing a photovoltaic module to a tufted geosynthetic cover overlying a ground surface, with a pair of attaching harnesses each for extending laterally from a pair of supports spaced apart on a respective opposing sides of a photovoltaic module, and a pair of elongate members for disposing between a tufted geosynthetic cover and a geomembrane overlying a ground surface, each of said elongate members on a respective opposing side of the photovoltaic module. A plurality of fasteners each for extending through a respective one of the attaching harnesses and into a respective elongate member, for securing the photovoltaic module to the tufted geosynthetic cover.
In another aspect, the present invention provides a method of securing a photovoltaic module to a tufted geosynthetic cover, comprising the steps of:
(a) connecting an attaching harness to a support of a photovoltaic module;
(b) extending the attaching strip laterally of a side of the photovoltaic module;
(c) inserting an elongate member between a tufted geosynthetic cover and a geomembrane overlying a ground surface along a side of the photovoltaic module; and
(d) driving a fastener through the attaching harnesses and into the elongate member, for securing the photovoltaic module to the tufted geosynthetic cover.
In yet another aspect, the present invention provides an apparatus for securing a photovoltaic module to a tufted geosynthetic cover overlying a ground surface, comprising an attaching harness for extending laterally from the support outwardly of a side of the photovoltaic module, and an elongate member for disposing between a tufted geosynthetic cover and a geomembrane overlying a ground surface. A plurality of fasteners each for extending through the attaching harness and into the elongate member, for securing the photovoltaic module to the tufted geosynthetic cover.
The integrated mounting system of this invention allows for easy installation of a photovoltaic module supported by a tufted geosynthetic on a surface. This combination of the integrated mounting system and tufted geosynthetic results in a lower cost, lower maintenance of the surrounding surface, adaptable for variety of grades from flat to sloping ground and generates more solar power per unit area.
Briefly described, the present invention integrates a photovoltaic module mounting system over tufted geosynthetics on various surfaces (such as a ground cover system, roof, reservoir, pond, etc.). There are two components of this invention that may be used within the integrated photovoltaic module mounting system, in which the integrated mounting system has a flexible attachment connection and an elongate support member. The attachment connection in accordance with the present invention attaches at a first portion to a bottom, top or side of the photovoltaic module and a lateral second portion that overlies and mechanically connects (e.g., screws, bolts, etc.) to the support member disposed below a tufted geosynthetic ground cover. Other means of attaching the attachment connection to the tufted geosynthetic include adhesive means such as glue, tape, etc.
These two components eliminate the need for ballast compared to a traditional photovoltaic racking system which does not have foundation anchoring. The integrated photovoltaic module mounting system supported by a tufted geosynthetic requires no ballast on a surface.
Alternatively, optionally the photovoltaic module mounting system further includes one or more anti-creep strip(s) that enhances interface friction between the photovoltaic module and the tufted geosynthetic, while also reducing shearing forces between the photovoltaic module and its mounting surface, thus preventing or substantially preventing sliding forces from mobilizing the module. If desired, a monitoring device can be used to measure the amount of creep. The mounting system is used alone, or alternatively with the anti-creep strip(s) as an additional factor to increase interface friction and to counter potential shearing and uplift forces which could be caused by high wind gusts.
The result of a non-ballasted integrated photovoltaic module mounting system allows for a lower cost and increased power generation through higher density of module placement at an energy generation site An additional advantage of an integrated photovoltaic module mounting system is that the system does not require grounding. The integrated photovoltaic module mounting system of this invention allows for a higher density (i.e., one or more) of photovoltaic modules in a defined area as compared to traditional systems, and a higher density of modules enables the integrated photovoltaic module mounting system to provide more electrical power per unit area.
Objects, advantages, and features of the present invention will become apparent upon a reading of the detailed description in conjunction with the drawings.
The present invention provides an integrated photovoltaic module mounting system for use with a tufted geosynthetic system on a surface without a racking structure and without ballast for support.
The essential components of this invention are a tufted geosynthetic system, a photovoltaic module, and one or more integrated photovoltaic module mounting systems.
Cover System Examples of tufted geosynthetic systems useful in the integrated photovoltaic module mounting system of this invention are the covers marketed by Watershed Geosynthetics LLC under the registered trademarks ClosureTurf and VersaCap. These covers comprise a composite of at least one geotextile which is tufted with one or more synthetic yarns (i.e., a tufted geosynthetic) and an impermeable geomembrane comprised of a polymeric material.
The synthetic grass of the system may contain an infill material and/or a material for protection of the synthetic grass against ultraviolet rays.
Solar Module
One or more multi-crystalline solar modules can be used in the integrated photovoltaic module mounting system of this invention, such as commercially available polycrystalline silicon solar modules. Examples of effective solar modules are available from BYD (China) under the designation BYD 260P6C-30-DG and from Trina (China) under the designation Solar Duomax TSM-PEG14. Other solar panels may be gainfully used.
Wind Uplift Resistance
The present invention comprises a wind-resistant non-ballasted integrated photovoltaic module mounting system for use on a tufted geosynthetic that preferably includes both an attachment layer (referenced herein as “attaching harness”) and an elongate member disposed between a tufted geosynthetics and a geomembrane, with fasteners securing the attachment layer to the elongate member, and optionally anti-creep strips connected to a support of the photovoltaic module. The system does not rely on weight to resist wind forces, but instead relies on wind-breaking turf blades (i.e., the synthetic grass) and an attachment to the elongate member covered by the turf blades (synthetic grass). The ground cover can be deployed over a large area with very minor ballasting. Wind-breaking elements may also be utilized to break up the airflow over the integrated photovoltaic module to provide wind uplift resistance.
With this invention, the wind velocity becomes turbulent near the surface of the tufted geosynthetic cover, thus greatly reducing the actual wind velocity at the liner surface and decreasing associated uplift. The reaction of the synthetic grass of the tufted geosynthetic to the wind forces can also create a downward force on the tufted geosynthetic cover and the underlying geomembrane. This reaction is caused by the filaments of the synthetic grass applying an opposing force against the wind which is transferred as a downward force on the geomembrane.
The integrated photovoltaic module of this invention can be used with an optional tilting device to raise or lower the module for better energy generation results depending on the location.
Friction
This invention also optionally provides structure and method for a non-ballasted module system utilizing one or more anti-creep strips integrated on the module when mounted over tufted geosynthetics, by increasing the coefficient of friction between the anti-creep strips and the tufted geosynthetic.
The anti-creep strips footing is generally a structured geomembrane.
The anti-creep strips, when used in this invention, comprise a polymeric material such as polyethylene, polypropylene, ethylene propylene diene monomer, rubber, metal, textured metal, polyvinyl chloride, polyurethane, etc. having a field or array of projections, nubs, feet, studs or the like.
When used in this invention, suitable materials for infill are sand, concrete and materials available from Watershed Geosynthetics LLC (Alpharetta, Ga.) under the trademarks HydroBinder and ArmorFill. Infill can be of various colors, sizes and textures.
When used in this invention, examples of suitable materials for anti-creep strips are calendared, textured and structural membranes made by Agru America, Inc. under the trademark SureGripnet.
Referring now to the drawings, in which like numerals represent like elements,
Optionally, wind-breaking elements 219 may also be utilized to break up the airflow over the integrated photovoltaic module to provide further wind uplift resistance. As illustrated in
With this invention, the wind velocity on the impermeable surface (geo-membrane) becomes turbulent near the surface of the cover, thus greatly reducing the actual wind velocity at the liner surface and decreasing associated uplift. The reaction of the synthetic grass of the tufted geosynthetic to the wind forces can also create a downward force on the geomembrane. This reaction is caused by the filaments of the synthetic grass applying an opposing force against the wind which is transferred as a downward force on the geomembrane.
The integrated photovoltaic module of this invention can be used with an optional tilting device to raise or lower the photovoltaic module for better results depending on the location.
Further, the mounting baseplate 2 spaces the solar photovoltaic module 3 from the tufted geosynthetic ground cover 11. The spacing thereby creates a gap between the tufted geosynthetic ground cover and the solar photovoltaic module 3, which gap facilitates air flow therealong for heat dissipation in that heating of the solar photovoltaic module 3 which occurs reduces the solar generation efficiency of the photovoltaic module. In an alternate embodiment, the mounting base plate 2 is sized to provide at least an 18 inch to 24 inch gap under the photovoltaic module 3.
To further enhance solar generation energy capacity, the photovoltaic module 3 is bifacial and the tufted geosynthetic ground cover 11 includes light reflective features, such as reflectants added into the polymeric used the extrusion of the yarn from which the tufts 215 are formed during tufting. As shown in
An alternate embodiment uses the elongated flexible attachment connection or harness strips 4, that extend longitudinally for a distance substantially the length of the solar module 3 or a length of a plurality of the spaced-apart solar modules. Also, the anti-creep strip 5 may be longer to connect to multiple solar panels disposed in spaced-apart relation. Thus, the anti-creep strip 5 may have a length for extending across two or more of the solar modules 3. Such elongated harness strips 4 and/or anti-creep strip 5 thereby further interlock the plurality of solar modules 3 together, which solar modules are disposed in spaced-apart relation as an array of rows of solar modules on a tufted geosynthetic ground cover.
With reference next to
The mounting system 110 comprises a pair of elongated members 120 each positioned between the geomembrane 114 and the geosynthetic cover 116 on respective opposing sides of the photovoltaic solar module 3. The elongated member 120 has a length that is substantially the length of the side of the photovoltaic solar module 3. In an alternate embodiment, the elongated member 120 has a length extending for multiple solar module panels. The opposing distal ends of the elongated member 120 preferably define a bull nose, or curved face, for a purpose discussed below. A plurality of fasteners 122 secure the geosynthetic cover 116 to the elongated member. In the illustrated embodiment, the fasteners 122 are threaded screws. Alternate fasteners (bolts, rivets) may be used. The fastener 122 passes through the geosynthetic cover 116 and a side portion of the weld harness 39, and engages the elongated member 120. The fastener 122 preferably includes a stress distribution plate 124, such as a large washer, that distributes stress at the point of engagement of the fastener 122 with the geosynthetic cover 116 and the attachment harness 4. The fasteners 122 are positioned in spaced-apart relation along the length of the elongated member 120. The fasteners 122 and plates 124 may include a sealant to prevent water infiltration.
The mounting bracket 2 attached to the bottom surface of the photovoltaic solar module 3 engages the attachment harness 1. In the illustrated embodiment, the mounting bracket 2 includes a spacer 130. The spacer 130 is of a selected length. In an alternate embodiment, the spacers at a first end of the photovoltaic solar module 3 are longer than the spacers at the opposing end, whereby the photovoltaic solar module 3 may be oriented at a slight angle relative to the geosynthetics ground cover system 112, for example, for angling the solar module somewhat favorably towards the sun, without creating a shadow that overlies an adjacent solar module and further, for providing a slope for water drainage off of the photovoltaic module.
With continuing reference to
The elongate member 120 is thereby disposed in position relative to the photovolatic panel 3 between the geomembrane 114 and the tufted geosynthetic cover 116. The slit 135 is closed for sealing from water infiltration. The slit 135 may be closed by heat sealing a tufted patch overlying the slit, by a polymeric binder material, or an adhesive. The fasteners 122 each receive one of the stress distribution plates 124. The fasteners 122, driven by a power screw driver through the weld harness 39 and the geosynthetic cover 116, and threadingly engage the elongated member 120. A plurality of fasteners 122 secure the flap of the weld harness 39 to the elongated member, to secure the photovoltaic solar module 3 to the tufted geosynthetics ground cover system 112. The elongated members 120 secure the solar module 3 from movement such as by wind forces over the tufted ground cover system 112 while the solar module 3 generates electrical energy upon exposure to the sun. The fasteners 122 may be sealed, for example, by a gasket or rubber or polymeric material.
A slit similar is formed on the opposing side of the photovoltaic module 3, and receives one of the elongate members 120 as discussed above. The slit is closed, and the opposing side of the photovoltaic module secured with the fasteners 122 to the tufted geosunthetic cover and the elongate member thereunder.
In an alternate embodiment, a pair of aligned slits 135 are made in the tufted geosynthetic cover 116 in spaced-apart relation proximate the solar panel 3. An elongated rod, such as a metal or fiberglass rod, inserts through a first one of the slits 135 between the geomembrane 114 and the tufted geosynthetic cover 116. The rod is pushed longitudinally for exiting of the leading end through the opposing slit. A cord attaches to a distal end of the rod proximate the first slit 135. A free end of the cord attaches to the elongated member 120. The rod is pulled from the passageway formed by the slits in the tufted geosynthetic cover 116. The cord, exiting from the slit, is pulled to move the elongated member 120, and guided by installation personnel at the opposing end, moves into the space between the geomembrane 114 and the tufted geosynthetic cover 116. The slits 135 are closed as described above. The photovoltaic module 3 attaches to the elongated member 120 with the fasteners 122 as discussed above.
Optionally used, the anti-creep strip 44 further prevents relative movement of the photovoltaic module 3 with respect to the tufted geosynthetic.
It should be understood that in these embodiments the attachment harness strip is preferably made of a polyethylene material. Similarly, the yarns of the tufted geosynthetic material are also made of a polyethylene material. With this construction, the melting point of the attachment harness strip is generally that of the yarns of the tufted geosynthetic material, thereby creating a superior hold or weld therebetween. However, it should be understood that other types of polymer materials may also be used for these components without departing from the scope of the invention.
The distinct advantage to the invention described in the embodiments herein is that the solar panels may be positioned or arranged in a manner that provides for a higher density of solar panels per area of land (for example, a series of rows of spaced-apart end-to-end solar modules 3). This higher density allows for the generation of more electricity per land area. Another advantage is the easy of mounting solar panels without the need for a racking system or without the occurrence of panel movement over time.
This invention has been described with particular reference to certain embodiments, but variations and modifications can be made without departing from the spirit and scope of the invention.
The present application claims benefit of U.S. Provisional Patent Application Ser. 62/616,696, filed Jan. 12, 2018.
Number | Date | Country | |
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62616696 | Jan 2018 | US |