[0001]

FIELD OF THE INVENTION

[0002] The present invention relates to a method of enhancing the energy harvesting of solar arrays. More specifically, the invention relates to the use of easy to reversibly install and reversibly remove reflection surfaces for the enhancement of the efficiency of energy harvesting of solar arrays.

[0003]

BACKGROUND OF THE INVENTION

[0004] Solar energy is widely used to generate electricity. The most common way to generate electricity from solar energy involves the use of photo-electric cells, which directly converts sun-light-energy to electricity. The amount of electricity is proportional to the amount of light that is projected on the photo-electric cell.

[0005] In the text, the terms “solar photo-electric cell”, “solar panel” and “solar module” are used interchangeably and refer to a photo-electric device for harvesting sun-energy and converting it to electrical energy.

[0006] Typically, when solar photo-electric modules are used in commercial- scale power-plants, they are arranged in horizontal, parallel to-each-other, configuration. Each row configuration is referred to as “a solar array”.

[0007] In order to generate high amount of energy, the solar modules may be positioned in the most optimal fixed position in relation to sun. In this setting, the modules are in a fixed position throughout the year, and will generate the maximum aggregated annual energy when each of the panels is positioned tilted toward the south in the northern hemisphere and north in the southern hemisphere. The exact tilt angle depends, among other things, on the latitude of the array, on shading from other objects and from other installation constrains. This method of mounting the modules is often referred to as “fixed angle” mounting. See for example patent on a type of a fixed mounting systems: US8, 550,419 (Hausner et al.) [0008] Another method on mounting the solar modules involves dynamic adjustment of the tilt and azimuth of the module, such that the module will all times be kept perpendicular to the sun. This method of mounting the modules is usually referred to as “sun trackers” (also referred to as “sun tracking” modules). Sun trackers may have one or more axis of motion to allow for a more accurate tracking on the sun. See for example, a patent on a type of a tracking mounting systems: US20160218663 (Wemer et al.)

[0009] The optimal pitch (referred to as the distance) between the solar arrays depends, among other things, on the width of the array, the tilt of the array and the latitude of the array.

[0010] The total sum of sun light energy that reaches the solar modules depends, among other factors, on the energy of direct sun light and the energy of the diffused sun light that reaches the cell. Direct sun light refers to light energy that is projected directly from the sun to the solar module. Diffused light is light energy that is projected from other objects to the solar module either by reflectance light process or by diffused light process. For example, some of the sun light may reach the ground and may reflect back from the ground to the module. The sum of light energy of diffused light that reaches the solar array depends on the positioning of reflecting surfaces in relation to the array, and on the reflective coefficient of the reflecting surface i.e. the amount of light energy that is not absorbed by the surface and is being reflected back from the surface to the solar array. The used refractive surfaces for enhancing the efficiency of solar energy harvesting by solar arrays is well known. Typically, the reflective surfaces are connected to the upper “back side” (the opposite side directly facing the sun) of a solar array and to the bottom “front side” (the side directly facing the sun) of the parallel, adjacent solar array. The position of the sun in relation to the solar array changes constantly, thus, the total sum of indirect light energy changes as well. In the context of the present text , the connection of reflective surfaces to the solar arrays is done by the connection to each of the solar modules that construct the solar array in which it is part of. The installing or removal of the connecting reflective surfaces (as later explained) in done by the combined installing or removal actions in at least two parallel solar modules. The reference to the installing or removing of the reflective surfaced to and from the solar arrays in the text refers to the installing and removal of the reflection surfaces to and from the related solar modules. Examples of reflecting surfaces to enhance the sun energy harvesting of solar arrays is given in: DE102012215680 (Rietzler), WO1017157424 (Rietzler) W)2013127791 (Bonomini) and US8528277.

[0011] In order to optimize the sun energy harvesting per given area, in both the mentioned installation methods there is need to install the solar arrays with minimal space between them.

[0012] A major issue in reducing the efficiency of the energy in solar arrays is the dust particles that cover the panels. Dust plays a particular reducing -efficiency role in areas of the world where dust storms are a common event. The removing of the dust from the surface of the solar arrays is in many locations done manually (either as a by-hand work or using mechanical tools). In many cases, especially in large solar energy power plants, vehicles need to maneuver between the solar arrays in order to transport people and equipment for the cleaning operations. In sun harvesting plants, which have an automated panel cleaning devices, the need to reach solar modules in solar arrays for maintenance and mechanical-fixing remains an issue that needs to be addressed.

[0013] Another issue that directly or indirectly effects the reduction in the efficiency of sun energy harvesting by solar arrays in many locations is the vegetation growth between the solar arrays. In the most severe scenario, the growth of vegetation directly shades the solar panels as well as reduces the ease of maneuverability between solar arrays required for dust removal and solar modules maintenance. In less severe cases the vegetation (just) reduces the ease of movement between the solar arrays. The reduction and/or removal of the vegetation between the solar arrays requires periodic maintenance. The maintenance activity is done manually or/and with the aid of vehicles that maneuver between the solar arrays. The reduction and/or removal of the vegetation between the solar arrays is referred to as “vegetation control”.

[0014] The present invention is a method in which highly reflective surfaces are mounted between solar modules of adjacent solar arrays. The reflective surfaces are designed so that they are easily and reversibly installed and easily and reversibly removed, to facilitate the freedom of maneuverability, as needed, of human and/or vehicle between the solar arrays. [0015] The term “’’install” refers in the text to the actions of partially or fully connecting the reflective surfaces to the solar arrays. The term “remove” refer in the text to the actions of partially or fully disconnecting the reflective surfaces from the solar arrays. When completely disconnected, the reflective surfaces can be placed in a location outside the placement of the solar arrays. The term “easily” is defined by the Cambridge dictionary as “with no difficulty or effort”. In the context of the present text, the term “easily” means that a typical person working in the field of cleaning and maintenance of solar arrays will be able to perform the activity of installing and removing of the reflective surfaces without much planning and with little physical efforts.

[0016]

SUMMARY OF THE INVENTION

[0017] The invention is a method for enhancing the harvesting of solar energy by solar arrays by the use of reflective surfaces that are easily mounted and easily removed from the connection between solar modules in parallel positioned solar arrays. The reflective surfaces, when deployed, contribute additional solar energy to the direct energy harvesting of the solar arrays. The position and albedo of the reflective surface determines the amount of energy (sun-light-energy) reflected to the array.

[0018] The reflective surfaces of the invention are typically made of light weight, elastic reflective metalized films and/or reflective elastic fabrics light-weight in order to reduce structural loads and ease of the connecting and disconnecting. The position of the reflecting surfaces should allow for highest obtainable and uniform reflection of diffused light to the solar array.

[0019] The benefit of the ability to easily and reversibly install and reversibly and easily removed the reflective surfaces is to facilitate and simplify the maneuverability, as needed, of human and/or vehicle between the solar arrays.

[0020] The facilitation and simplifying of the maneuverability between the solar arrays makes the cleaning procedure of the solar panels of the solar arrays as well as the maintenance of solar modules within solar arrays, substantially more efficient.

[0021] An additional benefit of simplified freedom of maneuverability between the solar arrays is vegetation control. The saving in the control of the vegetation may substantially reduce the maintenance cost of a power plant. [0022] Another benefit of the proposed invention reduction in wind loads: The reflective surface increases the drag of the array and reduces the wind loads on the array. This can result in reduction in the cost of the solar structure

[0023] Two embodiments of reversibly connecting the reflective surfaces between two solar arrays are disclosed: 1) Support bars connect to each of the solar arrays are reversibly inserted into rings on the edge of the reflective surface causing the refractive surface to stretch between the support bars and, at will, to reversibly and easily slide along the support bars to a compacted configuration. By sliding, the reflective surface can also be easily removed from the connection between the support bars. 2) Rings along the edges of the reflection surface reversibly connect to hooks connected to support bars in the two solar arrays, as previously explained on the “sliding rings” embodiment. The reversible hook-connection stretches the reflective surface between the solar arrays and enables, at will, the easy reversible disconnection between the solar arrays and the reflection surface.

[0024] The reversibly connecting and disconnecting of the reflective surfaces between the solar arrays of the method of the invention is valid for both fix angle and solar tracking solar arrays structures.

[0025] The eversible connecting and disconnecting method of reflective surfaces between solar arrays is not limited to the two embodiments described in the text. Other manners in which the reversible connecting and disconnecting of the reflective surfaces between solar arrays are possible and are within the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to better understand the present invention, and appreciate its practical applications, the following figures are provided and referenced hereafter. It should be noted that the figures are given as examples only and in no way limit the scope of the invention. Like components are denoted by like reference numerals.

[0027] Fig. 1A is an isometric illustration of a fixed angle three solar arrays structure, seen from the side, having two reflection- surfaces between the arrays with the reflection surfaces stretched using side rings inserted into supporting bars. [0028] Fig. IB is an isometric illustration of the fixed angle three arrays structure shown in Fig. 1A, with the two reflection surfaces shown partially slid to compaction over the supporting bars.

[0029] Fig. 2A is an isometric illustration a fixed-angle three arrays structure seen from the side, having two reflection- surfaces reversibly connected and stretched using hooks.

[0030] Fig. 2B is an isometric illustration of fixed angle three arrays of solar panel modules, seen in Fig. 2A with the two reflection surfaces partially disconnected from the supporting bars by releasing the hook connections.

[0031] Fig. 3A, Fig. 3B and Fig. 3C are illustrations of a three sun tracking arrays structure, viewed from the side, having two reflection-surfaces between the arrays, as they change their configuration in the course of a day.

[0032] Fig. 3A illustrates the configuration of sun tracking arrays shown in a tilt-angle in the course of the morning and in movement towards the tilt of mid-day.

[0033] Fig. 3B illustrates the sun tracking arrays of Fig. 3A, in a flat, horizontal configuration, with the sun rays coming from the zenith position in the sky at mid-day and in movement towards the tilt during the afternoon and .

[0034] Fig. 3C illustrates the sun tracking arrays of Fig. 3A, tilted towards the sun rays during the afternoon and evening.

[0035] Fig. 4A is an isometric illustration of the sun tracking arrays configuration in a morning tilting angle, as shown in Fig. 3A.

[0036] Fig. 4B is an isometric illustration of the sun tracking arrays configuration in a horizontal tilting angle, at mid-day, as shown in Fig. 3B.

[0037] Fig. 5A is an isometric illustration of an enlarged section of a reflection surface stretched by side rings inserted into hooks connected to supporting bars, as illustrated in Fig. 2 A and Fig. 2B.

Fig. 5B is an isometric illustration of an enlarged section of a reflection surface stretched by side rings inserted into hooks connected to supporting bars, as illustrated in in Fig. 2A and Fig. 2B.

[0038] DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0039] The invention is a method for enhancing the harvesting of solar energy by modular arrays by the use of a reflective surfaces, typically made of (but not limited to) metalized films and/or elastic fabrics that are easily mount to -and easily removed from - between adjacent solar arrays.

[0040] The use of reflective surfaces between parallel solar arrays for enhancing the solar energy harvesting is well known. The position of the sun in relation to the solar array changes constantly, thus, the total sum of indirect and direct solar energy harvested by solar arrays changes as well.

[0041] Typically, the reflective surfaces are connected to the upper “back side” (the opposite side directly facing the sun) of a solar array and to the bottom “front side” (the side directly facing the sun) of the parallel, adjacent solar array. The connection of the reflective surfaces between parallel, adjacent solar arrays typically makes the maneuvering (either by humans and/or vehicles) between the solar arrays for the purpose of solar-panel surface-cleaning and/or solar-panel maintenance and fixing and/or vegetation-control, difficult and inefficient. The present invention simplifies and substantially increases the efficiency of maneuvering between solar arrays when deploying reflective surfaces between the solar arrays.

[0042] The reflection surfaces of the invention can be mounted on fixed-angle structures or on single-axis sun tracking arrays. Fig. 1A to 2B illustrate fixed-angle structures. Fig. 3A to 4B illustrate sun tracking statures.

[0043] Two embodiments of connecting reflection surfaces between two parallel positioned solar arrays are described:

1) rings in the reflection surfaces are reversibly inserted by support bars that connect to the solar arrays.

2) rings in the reflection surfaces reversibly connect to hooks that are connected to support bars in the solar arrays.

The reflection support bars in both the embodiments are connected to the upper “back side” (the opposite side directly facing the sun) and to the bottom “front side” (the side directly facing the sun) of the parallel, adjacent solar modules and form continuous reflection support bars including the “side neighboring” of each on the solar modules so as to run throughout the length of the solar array. In the present text the references are made to the continous support bars, as seen in the figures. Throughout the figures describing the embodiments of the invention, three categories of sun-rays energy sources, illustrated as rays “hitting” the three solar arrays are presented:

[0044] 1) Rays coming directly from the sun, designated (40), hitting the solar panels.

2) Defused light rays, coming from the surrounding of the arrays that hit the solar panels and the reflection surfaces but are not relevant for energy harvesting by reflection from the surfaces of the reflection surfaces, designated (42). 3) Rays hitting the reflection surfaces and directed by the reflection surfaces to the solar panels, designated (44).

The sun energy sources, designated (40), (42) and (44), in the figures are general schematic illustrations and do not present/relate to a particular angle the rays “hit” the solar panel surfaces and/or the reflection surfaces.

[0045] While the solar panels (12) composing the arrays (11), are constructed as rigid plate structures, the reflective surfaces (14) are typically made of light weight, elastic reflective metalized films and/or reflective elastic fabrics. In the figures the entire sun energy harvesting structure, including the arrays (11) and the reflective surfaces (14) are designated (10) for the fixed angle solar arrays and (20) for the sun tracking solar arrays [0046] Two embodiments of the invention are presently presented and explained in detailed for the fixed angle solar arrays (10). The given explanations are also valid for the sun tracking arrays configuration (20) shown in Fig. 3 A to Fig. 4B.

[0047] The first embodiment is presented in Fig. 1A and IB. The second embodiment of the invention is presented in in Fig. 2A and 2B.

[0048] Fig. 1A is an isometric illustration of three fixed-angle arrays (11) of structure (10). The arrays (11) in the figure have two reflection- surfaces (14) between them. Each reflective surface (14) is connected to two adjacent arrays by two support bars (16). One bar connected to the upper “back side” edge (the opposite side facing the sun) of the solar modules (12) of array (11) and the other support-bar (16) connected to the bottom “front side” edge (the side facing the sun) of the parallel, adjacent modules (12) of array (11). Bars (16) are typically, but not limited to, bars having a tube or a solid-round-bar configuration and are made of a rigid material, such as, but not limited to, metal or plastic, having a smooth surface. The support bars (16) connect to each of the solar modules (12) and form a continuous bar that runs along all the solar modules that construct the solar array (11). The reflection surfaces (14) are stretched between the arrays (11) and are connected to support-bars (16) by sliding-rings (20) inserted into supporting bars (16). The configuration of the connection of the reflection surfaces (14) to the solar modules (12) is explained in detail in Fig. 5A.

[0049] Fig. IB is an isometric illustration of the three fixed-angle arrays (11) of structure (10) shown in Fig. 1A, with the reflection-surfaces (14) shown partially and reversibly slid to compaction over supporting bars (16) between the arrays (11), thus, exposing the ground between the two parallel arrays and enable easy reach to the solar modules (12) of the arrays (11). Exposing the ground also enables (if necessary) with ease the clearing of vegetation that develops between the solar arrays (12). In the illustration the reflection surfaces (14) are shown in a compacted configuration (14A)

[0050] The reflection surfaces (14) can be further slid and compacted (continuing the compaction illustrated in Fig. IB, not shown graphically) so as to be completely removed from being connected to two parallel positioned solar arrays (12). After removal, the reflection surfaces (14) can be reconnected and reinstalled between two parallel positioned solar arrays (12) by sliding sliding-rings (20) over support-bars (16).

[0051] Fig. 2A is an isometric illustration of three fixed angle arrays (11) with stretched reflection surfaces (14) with the arrays (11) connected to the reflection surfaces by hooks (24). The hooks (24) are fixated to support bars (16) that connect to the arrays (11) and the reflection surfaces (14) reversibly connect to the hooks (24) by connection rings (22) that are inserted into holding rings (18) in the margin portion of the reflection surface (14). The configuration of the connection of the reflection surfaces (14) to the solar modules (12) is explained in Fig.5B. The reversible disconnection of the of the reflection surfaces is illustrated in Fig. B2.

[0052] Fig. 2B is an isometric illustration of the three fixed-angle arrays (11) of structure (10) shown in Fig. 2A, with the reflection surfaces (14) shown partially and reversibly disconnected from supporting bars (16) between the arrays (11). Part of the disconnected reflection surfaces (14) is illustrated in a folded configuration (15). The disconnection of the of the reflection surfaces is done by reversibly disconnecting rings (22) from hooks (24). The disconnection of the reflection surfaces (14) can be done by either disconnecting from both supporting bars (16) or from only one of the two bars. The disconnection of the reflection surfaces (14) from the supporting bars (16) enables easy reach to the solar modules (12) of the solar arrays (11) and exposes the ground between the solar arrays (11) thus, enables (if necessary) with ease the clearing of vegetation that develops between the solar arrays (12).

[0053] The reflection surfaces (14) can be further disconnected from the support bars (16) (continuing the disconnection illustrated in Fig. 2B, not shown graphically) so as to be completely removed from being connected to two parallel positioned solar arrays (12). After removal, from one or both support bars (16) the reflection surfaces can be reconnected and installed between two parallel positioned solar arrays (12) by connecting the connection rings (22) to hooks (24) that are connected to support-bars (16).

[0054] Fig. 3A, Fig. 3B and Fig. 3C are illustrations of three sun tracking solar arrays (11) structure (20), viewed from the side, having two reflection- surfaces (14) connected between them , as they change their configuration in the course of a day.

[0055] Fig. 3 A illustrates the configuration of sun tracking solar arrays (11) tilted towards the incoming sun rays (40) during the morning hours. The reflected light rays (44) are shown reflecting from the stretched reflection surfaces (14) and “hitting” the solar panel modules (12). Also shown are the defused sun light energy rays (42) “hitting” the solar modules (12). Arrows (50) indicate the direction of the movement of the sun tracking solar arrays (11) from the morning towards midday.

[0056] Fig. 3B illustrates the sun tracking solar arrays (11) of Fig. 3A, in a flat, horizontal configuration, with the incoming sun rays (40) coming from the zenith position in the sky at mid-day and the defused light rays (42) coming from the surrounding. In the flat, horizontal configuration, the reflection surfaces (14) are in a loose configuration and have no light energy harvesting contribution. Arrows (52) indicate the direction the sun tracking arrays (11) will proceed, tracking the course of the sun, after mid-day hours. [0057] Fig. 3C illustrates the sun tracking arrays (11) of structure (20) tilted towards the incoming sun rays (40) during the after mid-day hours (the sun light hours towards evening). The reflection surfaces (14) are shown in a stretched configuration are contributing to the harvesting of the available solar energy. See arrows (44) indicating the reflection of solar energy obtained by the reflection surfaces (14). [0058] After a full daily cycle of the sun tracking arrays (11), shown in figures 3 A to 3C, when no more light energy is harvested with sun down, the sun tracking arrays (11) are tilted back to the initial morning tilting configuration for another day of sun tracking, as indicated by arrows (54), ilndicate the continuation of the tilting of the sun tracking arrays (11).

[0059] Fig. 4A and Fig. 4B are isometric illustrations of the sun tracking arrays shown in Fig. 3A and 3B, respectively, with Fig. 4A showing the solar arrays in a tilting angle towards the morning hours sun and Fig. 3B showing the solar arrays in an horizontal tilting angle towards noon. The illustrations shows the passage between the sun tracking arrays (11) blocked by the reflection surfaces (14) and the ineffectiveness of the reflection surfaces (14) when folded (relaxed) during the stage when the sun is in or near the zenith position in the sky.

[0060] The reversible connection between the reflection surfaces (14) and the sun tracking arrays (11) of structure (20) is the same reversible connection as was described in detail for the fixed angle arrays (11) of structure (10).

[0061] Presently the two embodiments of connecting reflection surfaces between parallel positioned solar arrays of solar modules is described in detail:

[0062] Fig. 5A is an isometric illustration of an enlarged section of a reflection surface (14) connected to a solar module (12). In the figure the reflection surface is stretched by the use sliding-rings (20) that are inserted into both a supporting bar (16) and into holding- rings (18) located at the edge of the reflection surface (14). The use of sliding-rings (20) inserted into supporting bar (16) is illustrated in Fig. 1A and IB. Rings (20) are typically elongated ring structures made of, but not limited to, metallic, rubber or plastic material. Holding rings (18) are typically round rings made of rigid material, typically but not limited to metal, rubber or plastic material, that are fixated along the longitudinal edges of reflection surface (14). The free space inside holding-rings (18) enable the rings to change their angle relatively to supporting bar (16), thus, facilitating smooth sliding along bar (16). Supporting bar (16) is shown in the figure as having a parallel bar connected to it (designated 16A). Bar (16A) is connected along the edge of the modules (12), designated (12A), and is connected to bar (16) in a manner that enables the free sliding of movement rings (20) along bar (16) so as to facilitate the folding of the reflecting surface, shown in Fig. IB. The connection of bar (16) to bar (16A) is shown without details in Fig, 1A.

[0063] Fig. 5B is an isometric illustration of an enlarged section of a reflection surface (14) connected to a solar module (12) in Fig 2A and 2B. .In the figures the reflection surface (14) is stretched by the use connection rings (22) inserted into holding-rings (18), located at the edge of the reflection surface (14) and connected to hooks (24). Hooks (24) connect to a supporting bar (16) that connect to the edges of modules (12). Connection rings (22) are typically elongated ring structures. The use connection rings (22) inserted into holding-rings (18) and hook (24) connected is illustrated in Fig. 2A and 2B.

[0064] Both sliding-rings (20) and connection rings (22) are typically produced of a strong, resilient, and stretchable materials such as , but not limited to, plastic or rubber that provides improved stretching of the reflection surfaces (14) between the arrays (11). Holding -rings (18) located at the edge of the reflection surfaces is typically produced of, but not limited to, metal or rigid plastic material.

[0065] It should be clear that the description of the embodiments and attached Figures set forth in this specification serves only for a better understanding of the invention, without limiting its scope

[0066] It should also be clear that a person skilled in the art, after reading the present specification could make adjustments or amendments to the attached Figures and above described embodiments that would still be covered by the present invention.