Photovoltaic power generation enhancement

Abstract

Disclosed herein is a photovoltaic (PV) power system, comprising: a) one or more solar panels, and b) one or more dedicated reflectors positioned in irradiated areas near said one or more solar panels, to reflect solar irradiance of said irradiated areas towards the photovoltaic (PV) surface of each of said one or more solar panels, thereby adding reflected irradiance to the direct irradiance received by said one or more solar panels. The dedicated reflectors are configured with predetermined inclination and one or more curvatures, to optimize the receipt of solar irradiance by said one or more reflectors and provide a determined level of homogeneity of the added irradiance across the PV surfaces.

Description

YAELIS-001 PCTPHOTOVOLTAIC POWER GENERATION ENHANCEMENTFIELD OF THE INVENTION

[0001] The present invention relates to photovoltaic (PV) power generation apparatus. More specifically, the invention relates to the yield enhancement of PV power generation systems.BACKGROUND OF THE INVENTION

[0002] The global effort to reduce climate change drives the rapid expansion of exploiting renewable energy sources, specifically solar energy, to produce electricity. However, this industry is far from materializing its vast potential, and there is a continuous need and a global effort to enhance the energy yield production of solar panels.

[0003] Solar panel production capacity and cost-to-production ratio have significantly developed in recent years. Nevertheless, while these parameters are important in designing effective PV power systems (such as solar farms and rooftop PV power systems), an intrinsic energy deficiency of such installations is the unexploited irradiation of empty areas surrounding installed PV panels. These empty areas, particularly between rows of solar panels, are required to avoid mutual shadowing of solar panels and to leave sufficient maintenance space therebetween.

[0004] Exploiting the irradiation of areas near installed PV panels introduces several challenges, such as the dynamic shadowing of installed PV panels of the intermediate area, which changes according to the dynamic sun elevation and azimuth throughout the daytime hours and the months of the year. Another significant challenge is the fact that the intermediate area between installed PV panels is also used as a maintenance space and should be maintained free of obstacles.

[0005] The present invention is directed at providing a suitable solution for the abovementioned and further challenges as described hereinbelow.YAELIS-001 PCTSUMMARY OF THE INVENTION

[0006] In one aspect, the invention relates to a photovoltaic (PV) power system, comprising: a) one or more solar panels, and b) one or more dedicated reflectors positioned in irradiated areas near said one or more solar panels, to reflect solar irradiance of said irradiated areas towards the photovoltaic (PV) surface of each of said one or more solar panels, thereby adding reflected irradiance to the direct irradiance received by said one or more solar panels, wherein said one or more dedicated reflectors are configured with a predetermined inclination and one or more vertical curvatures and optionally one or more horizontal curvatures, to optimize the receipt of solar irradiance by said one or more reflectors and provide a determined level of homogeneity of the added irradiance across the PV surfaces.

[0007] According to an embodiment the invention relates to a photovoltaic (PV) power system, comprising: a) one or more solar panels, and b) one or more dedicated reflectors positioned in irradiated areas near said one or more solar panels, to reflect solar irradiance of said irradiated areas towards the photovoltaic (PV) surface of each of said one or more solar panels, thereby adding reflected irradiance to the direct irradiance received by said one or more solar panels, wherein said one or more dedicated reflectors are configured with a predetermined inclination and two or more vertical and horizontal curvatures, to optimize the receipt of solar irradiance by said one or more reflectors and provide a determined level of homogeneity of the added irradiance across the PV surfaces.

[0008] In one embodiment, the invention relates to a photovoltaic (PV) power system, comprising: a) one or more fixed solar panels arranged in at least a first and second rows, and b) one or more dedicated reflectors comprising at least one set of primary and secondary reflectors positioned between said rows. The primary reflector is configured to reflect solar irradiance towards its corresponding secondary reflector, which in turn reflects the irradiance towards the one or more solar panels in the second row, thereby adding reflected irradiance to the direct irradiance received by said one or more solar panels, wherein said one or more dedicated reflectors are configured with a predetermined inclination and one, two, or more curvatures, to optimize the receipt of solar irradiance by said one or more reflectors and provide a determined level of homogeneity of the added irradiance across the PV surfaces.YAELIS-001 PCT

[0009] In another embodiment, the invention relates to a photovoltaic (PV) power system, comprising: a) one or more bifacial solar panels, and b) one or more dedicated reflectors positioned in irradiated areas near said one or more bifacial solar panels, to reflect solar irradiance of said irradiated areas towards the rearward PV surface(s) of each of said one or more bifacial solar panels, thereby adding reflected irradiance to the direct irradiance received by said one or more solar panels, wherein said one or more dedicated reflectors are configured with a predetermined inclination and one or more curvatures, to optimize the receipt of solar irradiance by said one or more reflectors and provide a determined level of homogeneity of the added irradiance across the PV surfaces.

[0010] In yet another embodiment, the invention relates to a photovoltaic (PV) power system, comprising: a) one or more tiltable bifacial solar panels, and b) at least two opposed dedicated reflectors positioned therebetween in irradiated areas near said one or more solar panels, to reflect solar irradiance of said irradiated areas towards the photovoltaic (PV) surface of each of said one or more solar panels, thereby adding reflected irradiance to the direct irradiance received by said one or more solar panels, wherein said one or more dedicated reflectors are configured with a predetermined inclination and one or more curvatures, to optimize the receipt of solar irradiance and provide a determined level of homogeneity of the added irradiance across the PV surfaces.

[0011] In another embodiment, the invention relates to a photovoltaic (PV) power system, comprising: a) one or more solar panels, and b) one or more dedicated reflectors positioned in irradiated areas near said one or more solar panels, wherein at least one dedicated reflector is installed with an extendable reflector assembly comprising a deployable section that can be shifted between a retracted position and a deployed position. The dedicated reflectors are configured to reflect solar irradiance of said irradiated areas towards the photovoltaic (PV) surface of each of said one or more solar panels, thereby adding reflected irradiance to the direct irradiance received by said one or more solar panels, wherein said one or more dedicated reflectors are configured with a predetermined inclination and one or more curvatures, to optimize the receipt of solar irradiance and provide a determined level of homogeneity of the added irradiance across the PV surfaces.YAELIS-001 PCT

[0012] In another aspect, the invention relates to a method for enhancing the yield of PV power systems, comprising the steps of: a) determining a preliminary configuration of one or more dedicated reflectors, including determining types, number, dimensions, positioning, and orientation of said one or more dedicated reflectors, wherein said preliminary configuration corresponds to the configuration of the PV power system, b) determining a general vertical inclination of said one or more dedicated reflectors, relative to a desired receipt of solar irradiance from determined solar elevation, c) determining an optical design of said one or more dedicated reflectors comprising one or more curvatures of determined curvature radii and shapes, d) determining a target yield enhancement, that derives a desired addition of irradiance and its measure of homogeneity across the PV surfaces of the solar panels of said PV power system, e) evaluating the expected addition of irradiance and homogeneity of said added irradiance provided by the reflectors determined in steps a)-c), in view of said desired yield enhancement of step d), f) revising one or more of the configuration, inclination, and optical design determined in steps a)-c), to improve the expected addition of irradiance and its homogeneity relative to said target yield enhancement of step d), and g) repeating steps e)-f) until reaching the target yield enhancement of step d).

[0013] In another embodiment, the invention relates to a method for enhancing the yield of PV power systems, comprising the steps of: a) determining a preliminary configuration of one or more dedicated reflectors, including determining types, number, dimensions, positioning, and orientation, wherein the types of dedicated reflectors considered include at least one reflector installed with an extendable reflector assembly, b) determining a general vertical inclination of said one or more dedicated reflectors, relative to a desired receipt of solar irradiance from determined solar elevation, c) determining an optical design of said one or more dedicated reflectors comprising one or more curvatures of determined curvature radii and shapes, d) determining a target yield enhancement, e) evaluating the expected addition of irradiance and homogeneity, f) revising one or more of the configuration, inclination, and optical design, and g) repeating steps e)-f) until reaching the target yield enhancement.

[0014] In yet another embodiment, the invention relates to a method for enhancing the yield of PV power systems, comprising the steps of: a) determining a preliminary configuration of one or more dedicated reflectors, b) determining a general vertical inclination of said one orYAELIS-001 PCT more dedicated reflectors, wherein said determination considers irradiation reception from a prioritized solar elevation, c) determining an optical design of said one or more dedicated reflectors comprising one or more vertical or horizontal curvatures, and optionally adding one or more irradiance manipulators, d) determining a target yield enhancement, e) evaluating the expected addition of irradiance and homogeneity, f) revising one or more of the configuration, inclination, and optical design, and g) repeating steps e)-f) until reaching the target yield enhancement.

[0015] In yet another aspect, the invention relates to a photovoltaic (PV) power system wherein at least one dedicated reflector is an extendable reflector assembly, comprising a deployable section forwardly or laterally movable between a retracted position for maintenance and an extended position for enhanced energy harvesting.BRIEF DESCRIPTION OF DRAWINGS

[0016] For a better understanding of the present invention and to show how the same may be carried into effect, example embodiments of the invention are explained in the following detailed description with reference to the accompanying illustrative drawings, in which:

[0017] Fig. 1 illustrates an exemplary layout of an enhanced photovoltaic (PV) power system, according to an embodiment of the present invention;

[0018] Fig. 2A illustrates an exemplary configuration of a PV power system that comprises fixed solar panels with forward-facing photovoltaic surfaces, according to an embodiment of the present invention;

[0019] Fig. 2B illustrates another exemplary configuration of a PV power system that comprises fixed bifacial solar panels, according to an embodiment of the present invention;

[0020] Fig. 2C illustrates an alternative configuration of a PV power system that comprises tiltable bifacial solar panels, according to an embodiment of the present invention;

[0021] Figs. 3A-3C illustrate the prioritization of solar elevation angles, according to an embodiment of the present invention;

[0022] Fig. 4A illustrates the optical path of irradiance in the PV power system of Fig. 2A, according to an embodiment of the present invention;

[0023] Fig. 4B illustrates the optical path of irradiance in the PV power system of Fig. 2B, according to an embodiment of the present invention;YAELIS-001 PCT

[0024] Fig. 4C ill listrates the PV power system of Fig. 2B with reflectors adapted with more than three curvature segments, according to an embodiment of the present invention;

[0025] Fig. 4D illustrates the optical path of irradiance in the PV system of Fig. 2C, according to an embodiment of the present invention;

[0026] Figs. 4E-4F illustrate al tentative configurations of the PV power system of Fig. 4C, according to an embodiment of the present invention;

[0027] Fig. 4G illustrates an exemplary configuration of a PV power system 200b that further comprises an extendable reflector assembly, according to an embodiment of the present invention;

[0028] Fig. 4H shows an optional design of clustered reflectors with an extendable reflector assembly 426, according to an embodiment of the present invention;

[0029] Figs. 5A-5F illustrates optical designs of dedicated reflectors comprising horizontal curvatures respective to the azimuth of incident solar irradiance, according to an embodiment of the present invention;

[0030] Figs. 5G-5I illustrate a top view of optional configurations of a dedicated reflector that utilizes horizontal sub-apertures and differently shaped curvatures to cover multiple solar panels, according to an embodiment of the present invention; and

[0031] Fig. 6 is an exemplary flow chart of a design method for an enhanced PV system, according to an embodiment of the present invention.DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0032] The term “solar”, is interchangeably used herein with the terms “photovoltaic” and its common abbreviation - “PV” and should be understood as referring to means for producing electricity by converting the sun irradiation to electric current, such as solar / photovoltaic / PV panels, installations, and systems. Furthermore, the term “reflector”, as used interchangeably herein with the term “mirror”, refers to an object that comprises one or more reflective surfaces or a single reflective surface having one or more curvatures that reflect incident solar irradiance towards one or more target solar panels. Moreover, the term “target solar panel” used herein refers to a predetermined solar panel, towards which solar irradiance is redirected by one or more dedicated reflectors.YAELIS-001 PCT

[0033] The present invention relates to PV power systems enhancement that utilizes one or more dedicated reflectors, which may be integrated within existing installations of PV power systems (retrofit) or to the design of new PV power systems. The proposed reflectors are configured to reflect direct solar irradiance of empty areas (i.e., near the installed solar panels) towards the photovoltaic (PV) surfaces of one or more target solar panels, thereby increasing the irradiance and, thus, the power production of the solar panels.

[0034] The present invention further discloses a design method that provides a design process whereby the general configuration (number, positioning, orientation, and geometry of proposed dedicated reflectors), is determined considering various parameters, such as the design of existing / planned solar panels, the installation site’s geographic location, etc., as explained in detail hereinbelow.

[0035] The proposed PV power system yield enhancement method and the design of dedicated reflectors thereof, as disclosed herein, are based on the following principles:- maximizing the reception of incident solar irradiance, e.g., by avoiding and / or overcoming obscurement of reflectors’ surface by solar panels and supporting construction thereof, or by other reflectors; by avoiding shadowing solar panels by the reflectors and supporting construction thereof (further explained in Figs. 2A-2C);- diffuse the reflected irradiance to direct the reflected light to determined areas of the photovoltaic (PV) surface(s) of target solar panel(s), thereby improving its homogeneity throughout the PV surface of each target solar panel, and throughout the PV surfaces of a group of target solar panels, by designing the reflectors with reflective surfaces having one or more vertical and / or horizontal curvatures (further explained in Figs. 4A-4F and 5A-5I) so that the reflected irradiance is redirected towards the photovoltaic (PV) surface I la (Fig. 1) of one or more target panel(s) and is diffused to irradiate the target panels in a substantially homogeneous distribution across the photovoltaic surfaces of the solar panels; and- maintaining sufficient operation and maintenance clearance.

[0036] The total irradiance on a given PV surface is the sum of direct irradiance (i.e., incident solar irradiance that directly irradiates the PV surface), and indirect irradiance (such as light reflected from surrounding elements and ground-reflected (Albedo) irradiance). Typically, theYAELIS-001 PCT direct irradiance is the more significant and the most predictable component, whereas the indirect irradiance is lower and is harder to predict since it is significantly affected by local atmospheric conditions that affect the scattering of reflected light, and since the indirect irradiance corresponds to reflectivity and irregularities of the reflective objects and ground.

[0037] The present invention is directed to enhance the power generation capacity of newly planned or existing PV power systems by providing dedicated reflectors, of which orientation, vertical inclination, and general / discrete optical design are determined to optimally receive incident irradiance from predetermined solar elevation angles, that yield maximal irradiance and, thus, PV power generation in terms of annual harvested energy (further explained in Figs.3A-3C)

[0038] Desirably, the redirected collected irradiance is to reach the photovoltaic surface of the target solar panels in (as close as possible to) a normal direction and with a homogenous or at least homogenous-like distribution.

[0039] In the following detailed description, non-limiting exemplary embodiments of the present invention are discussed and illustrated, where references are made to accompanying drawings. These exemplary embodiments and accompanying drawings should be understood as non-limiting examples of implementing the present invention. Furthermore, terms such as “optionally“, “for instance”, “for example”, “exemplary”, “e.g.,”, “may”, etc., refer to optional features being selected in certain embodiments of the invention for the sake of simplicity and clarity of explanation. It should be understood, however, that individual or combinations of optional features mentioned in different embodiments may be used, in conjunction and / or separately, to implement further embodiments of the present invention.

[0040] Fig. 1 illustrates an exemplary layout of an enhanced photovoltaic (PV) power system 100, according to an embodiment of the present invention. Commonly, PV power systems are deployed in rows 12 of solar panels 11, separated by a determined distance. The size and configuration of PV power system 100 (i.e., the total number of solar panels 11, the number of rows 12 and solar panels in each row 12, and the distance 13 between rows 12) are determined according to the following parameters:YAELIS-001 PCT- the size and shape of an allocated area 15 for system 100, and the dimensions of each solar panel 11;- the overall desired power output of system 100, and the power capacity of each of the selected solar panels; and- maintenance clearance requirements (e.g., for monitoring, maintenance, and cleaning of the solar panels).

[0041] Distance 13 defines a corresponding intermediate area, portions of which are shadowed by the installed panels 11, whereas other portions of which are irradiated empty areas 14. These shaded and irradiated areas vary during the day, with the shaded areas being larger during early morning / late afternoon hours, and reducing near midday. According to an embodiment of the present invention, to exploit that irradiation of areas 14, dedicated reflectors 101 and 102 are installed within areas 14 and are configured to receive the solar irradiation of areas 14 (or at least part thereof, for instance, according to considerations explained in Fig. 2A- 2B) and redirect it towards the photovoltaic surface I la of one or more adjacent solar panels 11.

[0042] Along its sunrise-to-sunset path, the sun’s horizontal direction (azimuth) shifts from east to west through the South (in the northern hemisphere of Earth) or through the North (in the southern hemisphere), while the sun’s altitude angle relative to the horizon (also referred herein as “elevation” or “elevation angle”) also changes in a range that varies along the year.

[0043] Commonly, fixed solar panels of PV power systems are directed with their photovoltaic surfaces I la to the South / North (also referred to herein as the “principal direction”) and inclined towards a determined solar elevation that maximizes the accumulated annual energy, hence, the power generation capacity of the PV power system. This considers both the noon hours high irradiance elevation when the solar panels should be minimally inclined so that the incident solar irradiance is normal or near normal to its PV surface, and the wintertime, where the maximal solar elevation is significantly lower than in the summer.

[0044] As further explained in detail hereinafter, reflectors 101 and 102 are essentially oriented in correspondence with the principal direction of solar panels 11 (i.e., North / South)YAELIS-001 PCT and are inclined and optically designed (i.e., with one or more curvatures) to maximize solar irradiance reception and to disperse the irradiation reflected towards panels 11 in homogeneous or near homogeneous manner towards the photovoltaic surface 1 la of panels 11.

[0045] The overall number and size of the dedicated reflectors may vary depending on physical restrictions of specific installation locations of the PV power systems, however, in certain embodiments the footprint of the added dedicated reflectors (i.e., to existing PV power systems, or in the design of new systems) may cover 30% of the area between rows 12.

[0046] Notably, in Fig. 1, each reflector 101 is deployed between two solar panels 11, whereas reflector 102 is deployed between two pairs of solar panels 11. Figs. 5A-5I herein below describe in detail optional configurations of reflector 102 that facilitate irradiation of more than a single solar panel 11 by a single reflector 102.

[0047] Further noted in Fig. 1 is section view A-A that represents a typical section of system 100 to be illustrated in various configurations along the following Figs. 2A-2C. It should be understood that sections A-A illustrated in each of the discussed configurations may be repeated in a desired number along the principal and traverse directions (indicated in Fig. 1) to realize desired embodiments of the present invention.

[0048] Figs. 2A-2C illustrate typical sections A-A (such as section A-A indicated in Fig. 1) of exemplary configurations of PV power systems adapted with dedicated reflectors (i.e., interchangeable with reflectors 101, and 102 of Fig. 1), according to certain embodiments of the present invention. The following description of Figs. 2A-2C explains the preliminary positioning and orientation of the dedicated reflectors. The optical design of the reflectors is explained in detail in Figs. 4A-4F and 5A-5I.

[0049] Fig. 2A illustrates a typical section A-A (indicated in Fig. 1) of an exemplary configuration of a PV power generation system 200a, according to an embodiment of the present invention. System 200a comprises fixed solar panels with forward-facing photovoltaic surfaces I la. Section A-A of system 200a comprises an anterior solar panel 11 and a posteriorYAELIS-001 PCT solar panel 11 ’ (both are interchangeable with solar panels 11 of Fig. 1), which may be identical but are referred to herein with different numerals for the sake of simplicity.

[0050] For the sake of simplicity, the terms “vertical inclination" and “vertical curvature" as used herein, refer to an inclination (for instance, of dedicated reflectors) about the ground and corresponding to solar elevation angles and reflection angles thereof.

[0051] PV system 200a further comprises a primary reflector 210a and a secondary reflector 210b, deployed within area 14, oriented and vertically inclined so that reflector 210a is directly irradiated by the sun and reflects solar irradiance towards reflector 210b, which reflects the irradiance towards the PV surface I la of the posterior solar panel 11’. Correspondingly, reflector 210a is oriented towards the principal direction of solar panels 11 and 11’ (i.e., North / South) and towards reflector 210b, whereas reflector 210b is oriented backward to reflector 210a and towards the posterior solar panel 11’ .

[0052] Reflector 210a is positioned as near as possible to posterior panel 11’, to be distant from the shadow of the anterior panel 11, and to enable a maximal span of reflector 210a and, thus, a maximal receipt of direct solar irradiance of area 14. Nevertheless, the positioning and dimensions of reflector 210a are determined while considering possibly required clearances and other restrictions, such as clearance 201 in front of panel 11’ (e.g., for its routine washing / cleaning) and clearance 201a behind panel 11 (e.g., for accessing electrical apparatus installed thereon). Furthermore, the span and height of reflector 210a are restricted by a virtual line 202 that extends between the rear edge of panel 11 and the front end of panel 11’ to avoid the shadowing of posterior panel 11’.

[0053] Reflector 210b may be positioned below the edge of panel 11 at a maximal height and span to enable maximal irradiance receipt from reflector 210a and maximal reflection aperture towards the PV surface 1 la of target solar panel 11’. Nevertheless, virtual line 202 restricts the maximal span and height of reflector 210b (i.e., to avoid obscuration of reflector 210a and panel H’).YAELIS-001 PCT

[0054] Additional clearances may be considered, for instance, a minimal clearance between reflectors 210a and 210b to avoid shadowing of reflector 210a by reflector 210b or obscurement of panel 11’ from reflector 210b by reflector 210a. Further clearance may be maintained between reflector 210b and the lower surface of the solar panel 11 (indicated as clearance 203 in Fig. 2A) to prevent undesirable impact and to allow sufficient airflow below panel 11 for evacuation of heat therefrom and from the electric apparatus attached thereto.

[0055] Fig. 2B illustrates a typical section A-A (indicated in Fig. 1) of another exemplary configuration of a PV power generation system 200b, according to an embodiment of the present invention. System 200b comprises fixed bifacial solar panels 11 and 11’ having forward photovoltaic surfaces I la and rearward photovoltaic surfaces 211a. System 200b further comprises a dedicated reflector 220 deployed within area 14, oriented and vertically inclined so that reflector 220 is directly irradiated by the sun and reflects solar irradiance towards the rearward photovoltaic surface 211a of the anterior solar panel 11. Correspondingly, reflector 220 is oriented towards the principal direction of solar panels 11 and 11’ (i.e., North / South) and rearward photovoltaic surface 21 la of the anterior solar panel 11.

[0056] Reflector 220 is positioned as near as possible to posterior panel 11’, to be distant from the shadow of the anterior panel 11, and to enable a maximal span of reflector 220 and, thus, a maximal receipt of direct solar irradiance of area 14. Nevertheless, the positioning and dimensions of reflector 220 are determined while considering possibly required clearances and other restrictions, such as clearance 201 in front of panel 11’ (e.g., for its routine washing / cleaning) and clearance 201a behind panel 11 (e.g., for accessing electrical apparatus installed thereon). Furthermore, the span and height of reflector 220 are restricted by a virtual line 202 that extends between the rear edge of panel 11 and the front end of panel 11’ to avoid the shadowing of posterior panel 11’.

[0057] The present invention provides a highly advantageous yield enhancement for PV power generation systems consisting of stationary solar panels with fixed PV surfaces, as previously explained. Nevertheless, in certain embodiments of the present invention, the yield enhancement of the present invention may be provided with adaptations for enhancing PV power generation systems of different configurations, where, for instance, one or moreYAELIS-001 PCT dedicated reflectors are installed in conjunction with dynamically inclined solar panels 11 as discussed in Fig. 2C below.

[0058] Fig. 2C illustrates a typical section of an alternative configuration of a PV power generation system 200c, according to an embodiment of the present invention. System 200c comprises tiltable bifacial solar panels 11 with forward photovoltaic surfaces I la and rearward photovoltaic surfaces 211a. Panels 11 of Fig. 2C are tiltable in a varying principal direction from East to West, corresponding to the solar path. The tilting of panels 11 may be performed by any suitable tilting arrangement (e.g., mechanical or electromechanical arrangements that may allow powered / manual tilting of panels 11) that continuously directs the forward photovoltaic surfaces 1 la of panels 11 towards the sun. The mentioned tilting arrangement may also utilize a tracking device that coordinates the tilting angle to the instant sun position.

[0059] Accordingly, the forward photovoltaic surfaces I la are being tilted to face the sun continuously, whereas the rearward photovoltaic surfaces 211a are irradiated by two opposed dedicated reflectors 230 that reflect solar irradiance thereto. Notably, in the embodiment of Fig. 2C, reflector 230a is more effective at the earlier time of day (such as from sunrise to midday) as it is substantially oriented to the East, whereas reflector 230b is more effective at the later time of day (such as from midday to sunset) as it is substantially oriented West.

[0060] In Fig. 2C, panels 11 are inclined, corresponding to their tilting angle, towards East / West orientation. However, in certain embodiments of the present invention, panels 11 may be further inclined in another direction (for example, towards the North / South direction). In such embodiments, the vertical and / or horizontal inclination and optical design of reflectors 230a and 230b are correspondingly adapted. Such adaptations of reflectors 210a, 210b, and 220 may be applied in combined inclinations of solar panels 11 and / or 11’ in Figs. 2A and 2B.

[0061] In system 200c, reflectors 230a and 230b are positioned amid the empty area between the rows of panels 11, while maintaining the required horizontal clearances from reflectors 11. Furthermore, the span and height of reflectors 230a-230b are restricted by virtual lines 202-1 through 202-6 to avoid mutual shadowing.YAELIS-001 PCT

[0062] Reflectors 210a, 220, and 230a-230b may be supported and affixed to the surface below by similar support construction and attachment means as panels 11, or by other means to be selected by a person skilled in the art according to specific implementations of the present invention.

[0063] While the above discussion covers considerations related to the preliminary positioning and orientation of dedicated reflectors in exemplary configurations of PV power systems, more detailed design considerations and implementation thereof are discussed hereinafter for further optimizing the optical design of the dedicated reflectors and, correspondingly, the yield of PV power systems.

[0064] Fig. 3A illustrates a section view A-A of PV power system 200b, according to an embodiment of the present invention. Reflector 101 is positioned between two solar panels, with its height limited (i.e., illustrated by the virtual line 202 explained in Figs. 2A-2B) to avoid obscuration of direct irradiance of the posterior solar panel 11’. This limitation and the distance of reflector 101 from the anterior solar panel 11 limit the range of elevation angles from which incident solar irradiance is received by reflector 101. For example, in the embodiment of Fig. 3A, the solar path may cross elevation angles ranging between 0° and 70° above the horizon (illustrated by line 301) which may correspond to the day hours of 6 am and 6 pm (i.e., sunrise to sunset), however, the anterior solar panel 11 may obscure reflector 101 (e.g., before / after the solar path crosses elevation angle of 20°, and hence, the elevation angles range of 0°-20° is excluded from the considered range of elevation angles.

[0065] For example, in a specific geographical location, the following scheme of elevation angles might be found:- an elevation angle of 30° is crossed by the solar path throughout the entire year, but with relatively low irradiance levels- an elevation angle of 40° is crossed in 75% of the days, with low-moderate irradiance levels;- an elevation angle of 50° is crossed in 60% of the days, with moderate irradiance levels;- an elevation angle of 60° is crossed in 40% of the days, with high irradiance levels;- an elevation angle of 70° is crossed in 30% of the days, with very high irradiance levels.YAELIS-001 PCT

[0066] As further detailed below, a discrete optical design of reflectors 101 can’t match all of these elevation bands, due to optical restrictions. Therefore, it is necessary to select the band / range (e.g., 10°, 20° wide, or a wider band) that results in the maximum accumulated harvested energy annually. Such a band should be designated with the highest priority regarding the reflector’s design.

[0067] According to an embodiment of the present invention, reflectors 210a-210b, 220, and 230a-230b are preliminarily inclined to face prioritized sun elevation angles that yield the highest annual average irradiance flux at a determined geographic location, thus maximizing the annual accumulated energy by the PV power system. For instance, a normal to the center surface of reflectors 210a-210b, 220, and / or 230a-230b may be directed to the middle of prioritized elevation angles range / band.

[0068] Fig. 3B is a chart that illustrates an exemplary power output of a PV power system during the day. According to the regulations in some regions, PV power systems are limited to supplying the utility grid with a limited power capacity, as illustrated in Fig. 3B. In other cases, the limitation is dictated by the PV system design as a trade-off between output power and inverters’ cost and efficiency. In such cases, when instantaneous power generation exceeds the maximum limitation, commonly in the midday peak solar irradiation hours, the PV system’s circuitry (e.g., DC to AC inverter) clips the PV system’s power output. Accordingly, if the capacity of the PV power system is equally enhanced throughout the day, the increased midday output yield may be clipped and wasted.

[0069] Therefore, in certain embodiments, the orientation, vertical inclination, and / or optical design of reflector 101 are configured to optimally face and receive irradiance from a prioritized range of solar elevation angles (also referred to herein as “elevation band”) which provides maximal accumulated annual energy outside the peak midday hours. For example, reflector 101 may be configured to face an elevation range of between 30° and 60° that may correspond to 8- 10 am and 2-4 pm, as illustrated in Fig. 3C. In this example, the enhancement of reflector 101 during the peak hours is significantly reduced, but its overall yield enhancement to the PV system is optimized while avoiding redundant midday enhancement.YAELIS-001 PCT

[0070] Further factors that may affect the prioritization of elevation angles may be associated inter-alia with the irradiance intensity at different elevation angles and the occurrence frequency of such angles, where, for instance, the annual occurrence of the higher angles might be significantly lower compared to the lower ones. For example, elevation angles of 70°-80° may not occur during winter.

[0071] It will be readily realized by one skilled in the art that different geographic locations (e.g., different latitudes) of the PV power system may derive differently prioritized elevation bands. Additionally, according to the different considerations mentioned above, it should be realized that different systems may require different elevation band prioritization, even at the same geographic location. For example, the current configuration and working conditions (such as clipping) of PV systems being retrofitted with dedicated reflectors may determine systemspecific elevation band prioritization.

[0072] While the abovementioned positioning and vertical inclination of reflectors 210a- 210b, 220, and 230a-230b may significantly enhance the yield of existing or new PV power generation systems, an optimized discrete optical design may be considered to enhance the yield of PV systems further.

[0073] Figs. 4A-4F illustrate the optical design of the proposed dedicated reflectors, according to certain embodiments of the present invention, in which the dedicated reflectors are configured to maximize the irradiation reception from preferred elevation bands and to disperse the irradiance reflected towards the target PV surfaces I la to optimize the added irradiation homogeneity thereat. The optical design disclosed herein is aimed at maximizing the annually aggregated solar energy by adding irradiance to the target PV surfaces at optimal homogeneity. In certain embodiments, the optical design of reflectors may be performed in an iterative process of one or more iterations that utilizes a common Ray Tracing simulation software io evaluate the optical desi n.

[0074] In Figs. 4A-4F received and reflected rays of irradiance are illustrated by solid and dashed lines. For the sake of clarity, only a few individual lines / arrows are illustrated across and at the edges of the reflectors / solar panels. However, these individual lines also representYAELIS-001 PCT the intermediate irradiance rays therebetween. For example, in Fig. 4B, the irradiance reflected by reflector 220 and, in turn, received across PV surface 211a is represented by a few arrows pointed at the edges of PV surface 211a. However, these few arrows also represent the entire irradiance reflected by reflector 220 and received across PV surface 211a.

[0075] Maximal irradiance relates to the Entrance Pupil, which is the image of the solar panel’s PV surface I l a as seen from the sun's direction, and to the Field of View of the reflectors. The irradiance enhancement (added irradiance) over the target PV surface is proportional to the product of the Entrance Pupil by the FOV (Field of View). Considering that this product is constant for each specific optical system, narrowing the FOV enables an increase in the Entrance Pupil, thus the irradiance enhancement. Narrowing the FOV may be implemented by the optical design of the proposed dedicated reflectors. Exemplary narrowing of the FOV is obtained by focusing the narrowed FOV in prioritized elevation bands, as explained in Figs. 3A-3C.

[0076] A minimal threshold level for obtaining homogeneity may be defined (for example, by the designer of the enhanced PV power system) as a state in which the entire area of the target PV surfaces I la receives added irradiance (i.e., reflected by the dedicated reflectors), namely, no predetermined unit area (such as a single PV cell) of the PV surfaces I l a that does not receive added irradiance, whereas ideal homogeneity is obtained when there is no predetermined unit area of the PV surfaces I la that receives less added irradiance than the surrounding portions of PV surfaces I la and, accordingly, the Entrance Pupil shall be located at a certain point and orientation in space wherein all die light rays passing through die Entrance Pupil reach the Exit Pupil, namely, the surface of PV surfaces I la and, hence, pupil imaging is achieved between the Entrance and Exit pupils.

[0077] According to an embodiment of the present invention, to reduce the effort required to achieve homogeneity, the following optional measures may be applied:- Narrowing the dedicated reflectors’ Field of View (FOV), such as by reducing the aperture size of the dedicated reflectors, or by determining a corresponding optical design thereof;YAELIS-001 PCT- Configuring the dedicated reflectors to produce one or more reflections for certain elevation angles, before the irradiance is reflected to the target PV surface;- Configuring the dedicated reflectors with separate sub-apertures of different vertical { Figs. 4A-4F) and horizontal (Figs. 5A-5I) curvatures and inclinations;- .Adding local manipulators, such as one or more manipulators 490.

[0078] Fig. 4A illustrates the optical path of irradiance in PV system 200a (of Fig. 2A), consisting of a solar irradiance section of primary reflector 210a and two consecutive reflected irradiance sections from primary reflector 210a towards secondary reflector 210b and therefrom to P V surface 1 la of the posterior solar panel 11 ’ which is the target panel in system 200a.

[0079] The preliminary configuration (e.g., positioning, dimensions, orientation), general inclination, and optical design (e.g., number and shape of one or more curvatures) of reflectors 210a-210b may be determined by physical considerations discussed in Fig. 2A (e.g., positioning, height, size), prioritized elevations (discussed in Figs. 3A-3C), and further considerations discussed in Figs. 4A-4F and 5A-5I.

[0080] For example, in the embodiment of Fig. 4A, reflector 210b is installed as high as possible, while satisfying the considerations discussed in Fig. 2A (i.e., without crossing line 202 to avoid obscurement of solar panel 11’, and while maintaining clearance 203), so that the reflected irradiance thereby will irradiate the PV surface 1 la of panel 11’ at a closer-to-normal incidence angle. The preliminary configuration of reflector 210a is relative to reflector 210b while considering the desired reception of solar irradiance. In Fig. 4A the inclination angle 401, and aperture size 402 of reflector 210a may be predetermined so that it generally faces an elevation band of 30°-50°, and the curvature radius thereof may be predetermined so that the upper portion of reflector 210a faces lower elevation angles, for instance, 30°-40°, whereas its bottom portion faces higher elevation angles, for instance, 40°-50°.

[0081] Furthermore, when lower solar elevation angles are prioritized, reflector 210a may be installed at a higher position without interfering with the reflection path between reflector 210b and the PV surface of panel 11’. Moreover, when solar irradiance received from higher solarYAELIS-001 PCT elevation angles is desired, the lower portion of panel 210a may be more extended (i.e., while maintaining minimal clearance from the ground) and be correspondingly inclined. In certain embodiments, reflectors 210a and 210b are installed afar (i.e., while maintaining a minimum required clearance from panels 11 and 11’) to provide maximal exposure of reflector 210a to solar elevation angles and to enable higher installation thereof without obscuring the lower portion of panel 11’ from reflector 210b. As explained above, the curvature radii of reflectors 210a and 210b are determined according to the desired solar irradiance reception from prioritized elevation angles, and to the desired dispersion of the reflected irradiance.

[0082] This configuration of two reflectors produces reflection between the dedicated reflectors (201a, 201b), thus adding a degree of freed om / flexibility in the optical design process. For example, during the optical design process, the inclination and curvatures of both 210a and 210b may be modified at each iteration to desirably affect the added irradiance intensity and its uniformity (interchangeable with “homogeneity level”) across the target PV surface, until satisfactory results are accomplished. The system designer may predefine ‘satisfactory results’ as a combination of added irradiance and homogeneity level thresholds.

[0083] It is notable in Fig. 4A that the reflected irradiance of PV surface 1 la (i.e., by reflector 210b) is not normal thereto Additionally, there is non-uniformity of the incidence angle at the target plane as the incidence angle (the angle formed between a normal to surface I la and an incident ray at the point of incidence) increases towards edge 411a, possibly increasing the optical losses related to non-normal incidence. These losses at edge 41 1a affect the whole panel as the solar cells are usually connected in series, so the less productive cell determines the overall result. This emphasizes the importance of homogeneous irradiance distribution across the target panel 11’. While reducing such non-uniformities may be obtained during the abovementioned optical design process, in cases where the iterative process does not converge towards the predetermined thresholds, more specific optical means are proposed as described hereunder.

[0084] Reflectors 210a and 210b are illustrated in Fig. 4A as designed with a single vertical curvature. Nevertheless, in certain embodiments, a discrete optical design of reflectors 210a and 201b comprises several discrete / local vertical curvatures of different angles that diffuse theYAELIS-001 PCT reflected irradiance and, thus, the irradiance towards determined areas of surface 11a can be intensified, for instance, the irradiance reflected towards the edge 411a of surface 1 la, thereby, compensating for the loss of irradiance due to the high incidence angle. In this manner, the homogeneity of the enhanced irradiance onto surface I la is improved. Furthermore, local reflection manipulators 490 may be added in specific locations across reflectors 210a and / or 210b, to manipulate the reflection from specific areas of the reflectors. Manipulators 490 could be fabricated as small craters or a-spheric parabolic surfaces, as irradiance deviators or diffusers, as may be selected for specific implementations of the present invention.

[0085] The discrete optical design is particularly important in cases of significant non-uniform irradiance of solar panels since, beyond the loss of irradiance of higher incidence angles, sharp irradiance differences may induce undesired “hot spots’’ at the PV surface I l a, potentially accelerating solar panel degradation and power generation.

[0086] Fig. 4B illustrates the optical path of irradiance in PV system 200b (of Fig. 2B), according to an embodiment of the present invention. System 200b comprises reflector 220 that has three vertical curvature segments 421-423. The different vertical curvatures of segments 421-42.3 facilitate a unique path of irradiance consisting of a first direct irradiance section of segment 421 of reflector 220 followed by two separate reflection sections, from segment 421 to segments 422 and 423, and subsequently from segments 422 and 423 to PV surface 21 la of the anterior solar panel 1 1 (i.e., the target panel in the configuration of system 200b).

[0087] As already explained regarding discrete / local vertical curvatures of reflector 210a of Fig. 4A, such local vertical curvatures of segments 421-423 may be applied in various combinations to enable maximal receipt of direct solar irradiance, and maximal diffusion of reflected irradiance towards PV surface 211a. The abovementioned segmentation facilitates the utilization of internal reflections between segments of reflector 220, thereby enabling further optimization of the radiance diffusion and, thus, the homogeneous enhanced irradiation of PV surface 21 l a.

[0088] Optionally, reflectors of more than three segments may be used in further embodiments of the present invention, as illustrated in Fig. 4C, in which five reflective sub-YAELIS-001 PCT apertures / segments 421-425 of different vertical curva tures are utilized for enhanced control of the reflected irradiance. The use of such sub-apertures serves as another way to achieve multiple internal reflections and pupil imaging. Furthermore, the multiple curved segments of reflector 220 may be realized by either a single surface of different vertical curvatures or fabricated from separate sub-apertures with gaps or discontinuities therebetween.

[0089] Fig, 4D illustrates the optical path of irradiance in PV system 200c, consisting of reflectors 230a (irradiated through the first half of daytime) and 230b (irradiated through the second half of daytime). The optical design of reflectors 230a and 230b is aimed at achieving maximal irradiance at a desired level of homogeneity, similar to reflectors 210a-210b, and 220 in Figs, 4B, 4C, and 4E.

[0090] While in Figs. 4B, 4C, and 4E, fixed reflectors are utilized to enhance the irradiance across PV surfaces of fixed solar panels. The configuration of system 200c (of Figs. 2C and 4D) comprises tiltable solar panels and fixed reflectors 230a and 230b, and, hence, involves two significant challenges. The first challenge arises during early morning or late afternoon, when the reflectors are shadowed by the tiltable panels, which are tilted towards low elevation angles in the East / West direction correspondingly. This challenge is mitigated by prioritizing elevation angles (described in Figs. 3A-3C) of PV system 200c while excluding elevation angles that correspond to early morning / late afternoon hours, where, in different hours of the day, the reflectors are not obscured by the panels.

[0091] The second challenge is the capability of the fixed reflectors to provide full coverage of the moving target panels. To overcome this challenge, a compromise is made between the added irradiance and the provided PV surface coverage, where a wider reflection coverage is provided (for instance, by configuring reflectors 230a and 230b to reflect irradiance towards a wider span than the actual size of PV surfaces 211a) while producing lower irradiance. The broader reflection produced by reflectors 230a and 230b enables full coverage of PV surfaces 21 la at a broad range of tilting angles of panels 11.

[0092] It should be readily understood that the preliminary and specific design process discussed hereinabove, as well as the inclusive design process and the resulting structure andYAELIS-001 PCT final shape of reflectors 210a-210b, 220, and 230a-230b, may be significantly affected by different conditions (e.g., geographic location, configurations) of specific PV power systems.

[0093] Optionally, the optical design of reflector 220 may comprise separate sub-apertures that directly reflect irradiance towards PV surface 211a, such as illustrated by sub-aperture 461 of Fig. 4E. Furthermore, the above Figs. 4B-4D illustrate substantially concaved sub -apertures, whereas Fig. 4E illustrates a convex sub-aperture 464 that enables dispersion of reflected light towards a broader section of PV surface 211a.

[0094] As explained before, a determined level of homogeneity is achieved by implementing one or more of the following: narrowing the dedicated reflectors’ FOV (e.g., according to prioritized elevation angles and as discussed in reference to Figs. 4A-4E): configuring the dedicated reflectors to produce one or more reflections for certain elevation angles (such as illustrated in Figs. 4B-4E), before the irradiance is reflected towards the target PV surface; configuring the dedicated reflectors with separate sub-apertures of different vertical (Figs. 4A- 4E) and horizontal (Figs. 5A-5I) curvatures and inclinations; and / or adding local manipulators (such as manipulators 490).

[0095] Fig. 4F illustrates an alternative configuration of PV system 200c. It can be noted that similar as in Figs. 4B-4E, each sub-aperture of reflector 220 has a separate FOV. For instance, sub-aperture 481 (Fig. 4F) is designed to receive solar irradiance from low solar elevation angles and to reflect the irradiance towards a broad section of PV surface 211a, whereas subaperture 482 is designed to receive solar irradiance from high solar elevation angles and to reflect the irradiance towards a broad section of PV surface 211a. However, dedicating certain sub-apertures to specific elevation angles / ranges of elevation angles may result in reduced coverage of PV surface 211a when the sun is at different elevation angles. Therefore, reflector 220 of Fig. 4F utilizes a convex sub-aperture 483 to provide sufficient dispersion of irradiance received from those different elevation angles not covered by sub-apertures 481 and 482, thus, facilitating irradiance receipt from a broader range of solar elevation angles along the solar path and dispersing the same across the entire PV surface 21 la in as uniform manner as possible.YAELIS-001 PCT

[0096] While the embodiments described heretofore provide significant yield enhancement, certain applications may benefit from a further expanded or adaptable reflector configuration. Such needs may arise from a desire to achieve exceptionally high energy yields beyond the enhancement of the already described configurations, to overcome specific and stringent site constraints, or to more fully exploit the capabilities of a PV system integrated with energy storage solutions, such as batteries.

[0097] Furthermore, the total irradiance received by a PV system is a sum of direct radiation (i.e., or interchangeably “beam radiation”) and indirect radiation, the latter of which includes diffuse radiation and ground-reflected radiation. The optical designs previously discussed are primarily optimized for capturing direct radiation. However, diffuse radiation, which results from atmospheric scattering and clouds, can constitute a substantial portion of the total available energy, potentially 25% or more, and it characteristically arrives from a much wider range of angles, often with a significant near-vertical component. The previously discussed reflector configurations may need certain types of extensions to capture this indirect irradiation effectively.

[0098] To address these opportunities, certain embodiments of the invention feature at least one dedicated reflector (as disclosed herein above) provided with an extendable reflector assembly. The core principle of this extension concept is to supplement the optically optimized reflective surfaces of the reflectors discussed above (e.g., reflectors 210a-210b, 220, and 230a- 230b) with an additional, extendable surface. This allows PV power systems to, for example, "enjoy both worlds" by retaining an optimized design for a primary range of solar angles (e.g., mid-range elevation angles discussed above), such as implemented by fixed reflector surfaces (e.g., surfaces 421-423 of Fig. 4B, surfaces 421-425 of Fig. 4C, and surfaces 461-464 of Fig. 4D), while adding a dedicated surface to capture energy from other sources, such as very high- angle direct radiation or diffuse radiation.

[0099] A potential challenge with simply enlarging the reflector is the violation of geometric site constraints, such as the required clearance for maintenance access (e.g., clearance 201a in Fig. 2A). The extendable reflector assembly solves this by providing one or more sections, at least one of which is a deployable section. The deployable section may comprise a reflectiveYAELIS-001 PCT surface, similar to the previously discussed dedicated reflector 220, and it may be shifted (i.e., respectively to the corresponding dedicated reflector) from a retracted position, in which it is maintained outside the maintenance clearances (e.g., clearance 201 or 201a), to an extended / deployed position that increases the total optical aperture of the corresponding dedicated reflector to enhance the energy harvesting of a corresponding PV power system. This functionality is illustrated in Figs. 4G and 4H, and explained in detail hereinbelow.

[0100] The deployable section may be movably connected to the corresponding dedicated reflector, or to another section of the extendable reflector assembly via a suitable guiding mechanism, such as a sliding track, a rail, a hinge arrangement, and the like, to facilitate the respective shifting thereof between the retracted and extended / deployed positions.

[0101] Referring now to Fig. 4G, which illustrates an exemplary configuration of a PV power system 200b that further comprises an extendable reflector assembly 426, according to an embodiment of the present invention. Extendable reflector assembly 426 may either be included in the new design of the previously discussed reflector 220 or be an add-on assembly (i.e., retrofit) to an existing reflector 220. As previously explained (e.g., in Fig. 2A), reflector 220 is illustrated positioned in the intermediate area between solar panels 11 and I T, where predetermined maintenance clearance envelopes, such as clearance 201a, define zones that should typically remain free of obstacles to allow for routine access.

[0102] The extendable reflector assembly 426 may comprise one or more sections, for instance, a rotatable section 426a and at least one deployable section 426b (e.g., in a telescopic extractable-retractable arrangement). The rotatable section 426a is rotatably attached to the ground, to a hinge below reflector 220, or to a supporting structure of reflector 220, ensuring the stability and resilience of the entire assembly against environmental factors such as wind. The deployable section 426b is movably (e.g., slidably) connected to the rotatable section 426a, and it can be extracted relative thereto by a guiding mechanism 426c, which may be, for example, a sliding track or a telescopic extendable arm. Mechanism 426c may be maneuvered manually or by a controllable pneumatic, hydraulic, and / or electric driving module. Of course, a person skilled in the art will readily realize and select any of multiple different deploymentYAELIS-001 PCT mechanisms that are suitable for the deployment of one or more deployable sections 426b of the extendable reflector assembly 426.

[0103] Figs. 4G also illustrates assembly 426 in multiple optional deployment states, in at least one of which, deployable section 426b may protrude into the clearance envelope 201a behind the rear end of anterior PV panel 11. In this state, the combined surface area of the fixed segments of reflector 220 and the deployable section(s) 426b constitutes a larger optical aperture, increasing the amount of reflected irradiance directed towards a target solar panel (e.g., rearward surface 211a of anterior panel 11). This state may be the routine operational mode for maximizing energy generation of the corresponding PV power system.

[0104] When maintenance is required, the deployable section(s) 426b can be retracted to a retracted / stowed position, for example, sliding underneath / onto the rotatable section 426a. In this state, the entire assembly 426 does not interfere with the clearance envelope 201a, clearing the way for personnel or equipment. In certain embodiments of the present invention, the rotatable section 426a may be attached or integrated with the front section of an existing dedicated reflector 220, thus simplifying the required deployment assembly and guiding mechanism structure and assembly.

[0105] In certain embodiments, the fixed and deployable sections can be optically designed for different purposes. For example, when the PV system includes battery storage, clipping of midday power is less of a concern. In such a case, the rotatable section 426a may be designed to be optimal for mid-range solar elevation angles, whereas the deployable section 426b is specifically shaped and inclined to efficiently capture irradiance from different solar elevation angles, such as direct irradiance from higher sun elevation angles, or diffused irradiance from clouds.

[0106] Furthermore, while one or more dedicated reflectors installed with an extendable reflector assembly 426 may have a first optical design optimized to reflect direct / diffused solar radiation originating from a first range of solar elevation angles, the deployable section may have a second optical design optimized to reflect direct / diffused radiation from a second range of solar elevation angles. For instance, the first optical design may be optimized for aYAELIS-001 PCT predetermined range of solar elevation angles, whereas the second optical design is optimized for near-vertical solar elevation angles. Moreover, one or more dedicated reflectors may have a first optical design optimized for the receipt and reflection of direct solar irradiance, whereas the deployable section has a second optical design optimized for the receipt and reflection of diffused solar irradiance.

[0107] Fig. 4H shows an optional design of clustered reflectors 220 with an extendable reflector assembly 426, according to an embodiment of the present invention. Fig. 4H shows the extendable reflector assembly 426, where the deployable sections 426b are in retracted, deployment, and fully deployed states.

[0108] The above description is substantially focused on solar elevation angles and on vertical inclination and local vertical curvatures of reflectors 210a-210b, 220, and 230a-230b. In certain embodiments, the optical design of the reflectors further comprises optimized horizontal curvatures respective to the azimuth of incident solar irradiance along the solar sunrise-sunset path and, correspondingly, to optimized reception and homogeneous reflection thereof towards the PV surfaces of solar panels 11, as discussed in the following description referring to Figs.5A-5I

[0109] Fig. 5A is a partial top view of a PV system 500, according to an embodiment of the present invention. System 500 comprises solar panels 511-514 adapted with forward PV surfaces I la and rearward PV surfaces 211a (also shown in Fig. 2B), and reflectors 510a-510d that redirect light (such as from area 14 of Fig. 1) towards panels 511-514 of a single row 12 of solar panels (also shown in Fig. 1). Irradiance lines 501 and 505 are virtual lines representing rays of direct solar irradiance from different solar azimuths (such as, azimuth angles measured respective to the North direction), whereas lines 50 la-50 Id, and 505a represent the corresponding irradiance reflections from reflectors 510a-510d.

[0110] Dashed line 511a represents a section of rearward PV surface 21 la of solar panel 511. Notably, PV rearward surface 211a is not irradiated by reflection 501a and is merely partially irradiated by reflection 505a, whereas section 511a thereof is not irradiated by either of reflections 501a and 505a, significantly reducing the enhanced yield. Hence, proper diffusionYAELIS-001 PCT is required to constitute a homogeneous irradiance across the traverse direction of each of the rearward surfaces 211a across the entire row 12.[OHl] Therefore, reflector 510d is designed with multiple curvatures, for instance, a wavy surface shape of multiple convex and concave sections 520 and 530 of different horizontal curvature radii that enable multiple reflections such as 501b, 501c, and 50 Id of the incident irradiance 501, thereby providing an improved homogeneity of the reflected irradiance in the traverse direction, where the entirety of solar panels 511-514 is irradiated (i.e., by direct irradiance, and by reflections provided by reflector 510d.

[0112] The multiple curvatures design enables optimized horizontal dispersion and, thus, may provide homogeneous irradiance across multiple solar panels. For example, as illustrated in Fig. 5B, panels 511-513 can be irradiated by reflections 501a-501c and 505a-505c from the wavy portion of reflector 510d, which receives direct irradiance from azimuths 501-505 (i.e., throughout the entire solar path).

[0113] Accordingly, a plurality of similarly designed (i.e., wavy) reflectors 510d of smaller spans may also be implemented as add-on reflective surfaces of reflectors 210a, 210b, and 220 of PV systems 200a and 200b, as illustrated in Fig. 5C, and of reflectors 230a-230b (not shown). The effect of a wavy-shaped reflector 510d is further illustrated in enlarged views of Fig- 5D, which illustrates the direct irradiance reflections from different azimuth angles 501, 501’, 502, 505, and correspondingly diffused reflections. For the sake of illustration, respective local normal lines 540 are added in Fig. 5D for reference.

[0114] According to certain embodiments, local reflection manipulators 490 (also illustrated in Fig. 4A) may be added individually or as an array of manipulators 490 to reflectors 510a or any of the reflectors of previous embodiments of the present invention, such as illustrated in Figs. 5E-5F. Manipulators 490 may be added to provide local curvatures in either vertical or horizontal directions.

[0115] Figs. 5G and 5H illustrate a top view of an optional configuration of a dedicated reflector 550 that utilizes five horizontal sub-apertures 551, for instance, may be constructed ofYAELIS-001 PCT five separate sub-reflectors or by a single reflector shaped with local sub -apertures, to disperse the reflected irradiance thereby to cover multiple solar panels 11 (i.e., or any of the solar panels in the above embodiments). Notably, the five horizontal sub-apertures 551 reflect light to six solar panels. However, similar configurations may be implemented in multiple curve dimensions and shapes that may disperse the reflected irradiance across various numbers of solar panels, thus realizing different ratios between the number of solar panels and reflectors.

[0116] In the embodiment of Figs. 5G and 5H different solar azimuth angles are illustrated, which derive different dispersion of the reflected light across panels 11. This configuration of the dedicated reflector 550 enables the balancing between the azimuth range in which full coverage of the solar panels is provided and the intensity of added irradiance thereto.

[0117] While the terms “vertical inclination", “vertical curvature", and “horizontal curvature" are used herein above to explain aspects of optical design implemented in the vertical and horizontal directions, in certain embodiments of the invention, general and / or local inclinations, and curvatures may be applied in substantially or partially vertical and horizontal directions, where the dedicated reflectors and / or portions thereof may be inclined / curved in mixed / di agonal directions respective to the ground.

[0118] Fig. 51 illustrates another optional configuration of a dedicated reflector 550 that utilizes differently shaped curvatures to obtain a broader dispersion of the reflected irradiance, thereby covering thirteen solar panels 11.

[0119] In many cases, solar panels of PV power systems are serially connected to a DC-AC converter in one or more strings. Further to the broader coverage of the entire string of solar panels, the utilization of variously shaped curvatures can provide uniform added irradiance thereto, thus increasing the effectiveness of the added irradiance by preventing irradiance mismatches (i.e., less irradiated PV surface areas / weak points that determine the upper limit of added irradiance) between panels in the string. While the illustrated shapes in Fig. 51 may seem symmetrical, asymmetrical shapes and different numbers of shapes may be utilized according to desired irradiance intensity, homogeneity, and local physical and environmental conditions. This configuration of the dedicated reflector 550 enables the balancing between the azimuthYAELIS-001 PCT range in which full coverage of the solar panels is provided and the intensity of added irradiance thereto, as explained in Figs. 5G and 5H.

[0120] Furthermore, in certain embodiments of the present invention, to increase the total optical aperture of the corresponding dedicated reflectors in the horizontal aspect (i.e., respectively to solar irradiance from different azimuth angles), at least one of reflectors 510a- 510d may be provided with a lateral extendable reflector assembly, similarly to the extendable reflector assembly discussed, in reference to Figs. 4G and 4H. Such an extension can increase the receipt and reflection of direct and diffused irradiance from different azimuth angles, thus the overall energy production of a corresponding PV power system.

[0121] An artisan should readily realize that dedicated reflectors 210a-210b, 220, and 230a- 230b should comprise highly reflective and smooth surface areas. Such reflectors may be manufactured by various suitable manufacturing methods, including, but not limited to, molding, forging, pressing, and additive manufacturing. In certain embodiments, the dedicated reflectors comprise a reflective substrate material. The surface area of the dedicated reflectors may be fine-polished, and, in certain embodiments, a reflective coating material (such as Aluminum) is deposited on top of the polished surface, such as in a vacuum chamber.

[0122] Fig. 6 is a flow chart that illustrates a method for enhancing the yield of PV power systems, according to an embodiment of the present invention. The enhancement method disclosed herein may be adapted to different configurations of PV power systems, such as systems 200a, 200b, or 200c, or to any other configuratio of PV power systems. The proposed method comprises the following steps:- In step 1, a preliminary configuration (e.g., the type and number of reflectors, their dimensions, positioning, and orientation) of the dedicated reflectors is determined, as discussed in Figs. 1 and 2A-2C.- In step 2, a general vertical inclination of the reflectors is determined according to prioritized solar elevation angles, as discussed in detail in reference to Figs. 3A-3C.- In step 3, a specific vertical optical design is determined, as explained in detail in Figs. 4A- 4F, to improve the homogeneity (i.e., over the PV surfaces of the solar panels) of the i rradi an ce enh an ce e t .YAELIS-001 PCT- In step 4, a specific horizontal optical design is determined respectively to the azimuth of incident solar irradiance, as explained in detail in Figs. 5A-5I.- In step 5, the vertical and horizontal optical designs are integrated into a final configuration of reflectors 210a-210b, 220, and 230a-230b.- In step 6, a target yield enhancement, namely, a desired increase in the PV power system’s power production, is determined. Correspondingly target addition of irradiance and its measure of homogeneity are derived. The desired yield enhancement relates to a pre-known yield (i.e., PV power production) of a similarly configured PV power system that does not include dedicated reflectors according to the present invention.- In step 7, a ray tracing optical evaluation and optimization software is used to evaluate the expected addition of irradiance and its homogeneity across the solar panels 11 and 11’ of the PV power system, for which steps 1-5 were executed.- In step 8, one or more of the configuration, inclination, and optical design determined in steps 1 -5 are revised to improve the expected addition of irradiance and its homogeneity relative to said target yield enhancement of step 6.- Steps 7-8 may be repeated until the target yield enhancement determined in step 6 is reached. In certain cases, a certain number of steps 7-8 cycles is predetermined as reasonable for pursuing the target set in step 6, and following the predetermined number of cycles, the final configuration is set, or the target determined in step 6 is reconsidered.

[0123] In certain embodiments, an Al algorithm is implemented in conjunction with steps 1- 7 to continuously improve the convergence towards a final adequate design of the enhanced PV power system. Such an Al algorithm may be taught based on a dataset consisting of prior design processes according to the proposed method of steps 1-8 above.

[0124] In an embodiment, additional reflectors may also be installed at the margins of a PV system rather than between rows 12 thereof. For example, in PV system 200a, rearward-facing reflectors 210a may be installed in front of the most anterior solar panels, namely the frontmost row 12 of solar panels, in the principal direction, to irradiate their PV surface I la. Another example is in PV system 200b, where additional reflectors 210a may be installed behind the rearmost row 12 of solar panels to irradiate their rearward photovoltaic surfaces 211a. In theYAELIS-001 PCT case of PV system 200c, additional reflectors may be added East of the eastern row 12 and / or West of the western row of solar panels.

[0125] Furthermore, while the above embodiments illustrate alternative configurations of PV power systems that are derived from the exemplary layout of Fig. 1, this layout is only an optional layout and is used as a reference illustration for the sake of clarity and brevity. A person skilled in the art will readily recognize multiple different schemes, layouts, and conditions in which the PV power system, the empty irradiated areas are differently positioned and where the exemplary configurations of systems 200a, 200b and 200c, their preliminary positioning and the design of the dedicated reflectors thereof, may be implemented between rows of solar panels, aside solar panels and in various configurations near the solar panels, in which the present invention may be carried out to provide enhanced irradiance and optimal homogeneity thereof, thereby improving the overall annual aggregated energy of such PV power systems.

[0126] Moreover, the above disclosure refers to various dedicated reflectors incorporated in PV power systems. Nevertheless, it should be clear that multiple different configurations of the present invention may be carried out, where the PV power systems may comprise heterogeneous deployments of one or more dedicated reflectors of the present invention in conjunction with one or more reflectors of different types.

Claims

YAELIS-001 PCTCLAIMS1. A photovoltaic (PV) power system, comprising: a) one or more solar panels; and b) one or more dedicated reflectors, at least one of which is affixed in empty irradiated areas near said one or more solar panels and configured with predetermined dimensions that prevent shadowing of said one or more solar panels, said one or more dedicated reflectors are configured to reflect solar irradiance of said empty irradiated areas towards the photovoltaic (PV) surface of each of said one or more solar panels, thereby adding reflected irradiance to the direct irradiance received by said one or more solar panels, wherein said one or more dedicated reflectors are configured with predetermined inclination and two or more vertical and horizontal curvatures, to optimize their receipt of solar irradiance and from a range of incidence angles and to diffuse the reflected irradiance for optimizing the homogeneous receipt of the added irradiance across the PV surfaces of said one or more solar panels.

2. The system of claim 1, wherein the one or more dedicated reflectors comprise at least one set of primary and secondary reflectors positioned between a first and a second rows of solar panels, each row containing one or more solar panels, all solar panels are fixed and inclined in the same principal direction, with the first row preceding the second row in said principal direction, wherein each primary reflector is configured to reflect solar irradiance towards its corresponding secondary reflector, which in turn reflects the irradiance received from said primary reflector towards the one or more solar panels in the second row.

3. The system of claim 1, wherein at least one of the one or more solar panels is a bifacial solar panel, and the one or more dedicated reflectors are configured to reflect solar irradiance towards rearward PV surface(s) of said bifacial solar panels.

4. The system of claim 1, wherein at least one of the one or more solar panels is a fixed solar panel.

5. The system of claim 1, wherein at least one of the one or more solar panels is a tiltable solar panel.YAELIS-001 PCT6. The system of claim 5, wherein at least two of the one or more dedicated reflectors are arranged in one or more pairs of oppositely oriented dedicated reflectors.

7. The system of claim 1, wherein at least one of the one or more dedicated reflectors is configured to maximize the irradiation reception from a prioritized solar elevation.

8. The system of claim 7, wherein the prioritized solar elevation is associated with a prioritized range of solar elevation angles.

9. The system of claim 1, wherein the height of at least one of the one or more dedicated reflectors is restricted by a virtual line between the proximal edges of adjacent solar panels.

10. The system of claim 1, wherein at least one of the one or more dedicated reflectors maintains a predetermined clearance in respect to one or more adjacent solar panels.

11. The system of claim 1, wherein at least one of the one or more dedicated reflectors comprises one or more vertical reflection manipulators.

12. The system of claim 1, wherein said system comprises tiltable bifacial solar panels and two opposed dedicated reflectors therebetween.

13. The system of claim 1, wherein at least one of the one or more dedicated reflectors comprises one or more horizontal reflection manipulators.

14. The system of claim 1, wherein one or more sub-apertures of at least one of the one or more dedicated reflectors directly reflect solar irradiance towards the one or more PV surfaces of the one or more solar panels.

15. The system of claim 1, wherein one or more sub-apertures of at least one of the one or more dedicated reflectors produce one or more reflections before the irradiance is reflected to the one or more PV surfaces of the one or more solar panels.

16. The system of claim 1, wherein at least one of said one or more dedicated reflectors is installed with an extendable reflector assembly comprising one or more sections, at least one of which is a deployable section that can be shifted relative to said at least one of the one or more dedicated reflectors, between a retracted position, and a deployed position, in which it increases the optical aperture of said one or more dedicated reflectors.YAELIS-001 PCT17. The system of claim 16, wherein the deployable section is movably connected to the at least one of said one or more dedicated reflectors, or to another section of the extendable reflector assembly via a guiding mechanism selected from a group consisting of: a sliding track, a rail, a hinge arrangement, and any combination thereof.

18. The system of claim 16, wherein the extendable reflector assembly comprises a rotatable section and a deployable section, movably connected to said rotatable section, wherein said rotatable section is connected to at least one of the one or more dedicated reflectors.

19. The system of claim 16, wherein the at least one of the one or more dedicated reflectors has a first optical design optimized to reflect direct solar radiation originating from a first range of solar elevation and / or azimuth angles, whereas the deployable section has a second optical design optimized to reflect radiation from a second range of solar elevation and / or azimuth angles.

20. The system of claim 16, wherein the at least one of the one or more dedicated reflectors has an optical design optimized to reflect direct solar radiation, whereas the deployable section has an optical design optimized to reflect diffused solar radiation.

21. The system of claim 16, wherein the optical design of the deployable section is optimized to reflect incident radiation arriving at near-vertical angles.

22. A method for enhancing the yield of photovoltaic (PV) power systems, comprising the steps of: a) determining a preliminary configuration of one or more dedicated reflectors, including determining types, number, dimensions, positioning, and orientation of said one or more dedicated reflectors, wherein said preliminary configuration corresponds to the configuration of the PV power system; b) determining a general vertical inclination of said one or more dedicated reflectors, relative to a desired receipt of solar irradiance from determined solar elevation; c) determining an optical design of said one or more dedicated reflectors comprising one or more curvatures of determined curvature radii and shapes; d) determining a target yield enhancement that derives a desired addition of irradiance and its measure of homogeneity across the PV surfaces of the solar panels of said PV power system;YAELIS-001 PCT e) evaluating the expected addition of irradiance and homogeneity of said added irradiance provided by the reflectors determined in steps b)-c), relative to said target yield enhancement of step d); f) revising one or more of the configuration, inclination, and optical design determined in steps a)~c , to improve the expected addition of irradiance and its homogeneity relative to said target yield enhancement of step d); g) repeating steps e)-f) until reaching the target yield enhancement of step d); and h) installing said one or more dedicated reflectors in irradiated areas near one or more solar panels of the PV power system to reflect solar irradiance of said irradiated areas towards the PV surface of each of said one or more solar panels, thereby adding reflected irradiance to the direct irradiance received by said one or more solar panels, wherein said one or more dedicated reflectors are configured with predetermined inclination and one or more curvatures, to optimize the receipt of solar irradiance by said one or more reflectors and provide a determined level of homogeneity of the added irradiance across the PV surfaces.

23. The method of claim 22, wherein step ‘b)’ of determining a general vertical inclination of said one or more dedicated reflectors considers irradiation reception from a prioritized solar elevation.

24. The method of claim 23, wherein the prioritized solar elevation is associated with a prioritized range of solar elevation angles.

25. The method of claim 22, wherein step c) of determining an optical design is executed in the vertical direction.

26. The method of claim 22, wherein step c) of determining an optical design is executed in the horizontal direction.

27. The method of claim 22, wherein step c) of determining an optical design comprises adding one or more irradiance manipulators.

28. The method of claim 22, wherein the types of dedicated reflectors considered in step a) include at least one dedicated reflector installed with an extendable reflector assembly,YAELIS-001 PCT comprising at least one deployable section that can be shifted between retracted and deployed positions.

29. The method of claim 28, wherein the at least one deployable portion is shifted to the retracted position during maintenance activities.

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