WO2011067772A1

WO2011067772A1 - A solar collector apparatus

Info

Publication number: WO2011067772A1
Application number: PCT/IL2010/001029
Authority: WO
Inventors: Ami Dayan
Original assignee: Ami Dayan
Priority date: 2009-12-06
Filing date: 2010-12-06
Publication date: 2011-06-09
Also published as: IL202552A0

Abstract

A solar collector apparatus comprising a basal framework controllably movable and rotatable; an array of controllably tiltable beams connected to the basal framework; sets of collectors, each set mounted on one of the tiltable beams, each collector comprising a photovoltaic panel and a controllably tiltable mirror arranged to reflect solar radiation upon the photovoltaic panel; and at least one controller arranged to control a mirror angle of each controllably tiltable mirror, a beam angle of each controllably tiltable beam and a position and horizontal azimuth angle of the basal framework. The mirror angles, the beam angles and the position and the horizontal azimuth angle are time dependently selected such as to allow maximal production of electricity by the photovoltaic panels during the day without damaging the photovoltaic panels. The basal framework, tiltable beams and collectors are connected such as to allow simple construction and sequential adjustment thereof.

Description

A SOLAR COLLECTOR APPARATUS

BACKGROUND

1. TECHNICAL FIELD

[0001] The present invention relates to the field of solar collectors, and more particularly, to a solar tracking collector array.

2. DISCUSSION OF RELATED ART

[0002] The following patents or patent applications disclose various solar energy collection systems implementing rotatable rigid support frames with movable mirrors permitting height adjustment and rotation about horizontal and vertical axes, carousels mounted on tracks and water-borne tracking systems, as well as various solar tracking devices for illuminating buildings and concentrating solar radiation upon spacecraft solar panels. The following patents and patent documents are incorporated herein by reference in their entirety.

[0003] U.S. Patent No. US4203426 discloses a solar energy collector and converter, carousel mounted rack comprising a plurality of elongated reflectors mounted for arcuate movement on a platform and mounted for further arcuate movement each around a heating tube arranged in the linear focus of the reflectors, the carousel and reflectors each being linked to tracking mechanisms which cause the reflectors to be trained toward the location of the sun so that they receive a maximum amount of solar energy.

[0004] U.S. Patent No. US4109638 discloses a solar energy collector and converter carousel comprising a plurality of elongated reflectors mounted on a platform for arcuate movement and mounted for further movement each around a heating tube arranged in the liner focus of the reflectors, the carousel being linked to a tracking mechanism which causes the reflectors to be trained toward the location of the sun so that they receive a maximum amount of solar energy.

[0005] WrPO Publication No. WO2006000834 discloses a solar energy collection system comprising: a solar energy receiver; and a solar energy directing system to direct sunlight onto said solar energy receiver; wherein said solar energy directing system comprises a set of mirrors, each mirror having a moveable axis and comprising a plurality of facets, and wherein the facets of each mirror are configured to direct incoming sunlight to focus substantially at said receiver when said mirror axis are directed towards said receiver.

[0006] U.S. Patent Publication No. US2008087274 discloses a solar energy collecting device includes a rotation axis to be mounted parallel to the earth's polar axis, a solar energy collector mounted for rotation around the rotation axis at a predetermined rotation speed, the solar energy collector defining a tilt angle with respect to the rotation axis, and a tilt angle adjustment mechanism for automatically and intermittently adjusting the tilt angle. Various configurations of the solar energy collector are possible, and the rotation speed may be one revolution per day or half a revolution per day depending on the solar energy collector configuration. Many drive modes are possible, including rotating continuously throughout a day or rotating during daylight hours and rotating backward or forward at night. The tilt angle adjustment mechanism includes a handle fixed to the solar energy collector and a tilt angle change guide. [0007] U.S. Patent No. US4883340 discloses a solar lighting apparatus for illuminating the interior of a roofed building including a reflector assembly rotatable about a vertical axis for tracking daily movements of the sun.

[0008] U.S. Patent No. US6119986 discloses flexible, lightweight reflective sheets that are positioned to concentrate solar radiation upon spacecraft solar panels.

[0009] U.S. Patent No. US5520747 discloses a low concentration solar array for spacecraft and other uses which has a series of solar panels which can be deployed from a folded stowed configuration to a planar configuration.

[0010] U.S. Patent No. US4296731 discloses a water-borne tracking solar energy collecting and converting system employing booster and multiple mirror concentrator collectors for concentrating sunlight on either photovoltaic cells and/or flat plate collectors.

[0011] U.S. Patent Publication No. US2009032086 discloses a concentrator photovoltaic solar cell array system includes a central support mountable on a surface and a solar cell array including triple junction III-V semiconductor compound solar cell receivers and a support frame coupled to the solar cell array and carried by, and rotatable with respect to, the central support about an axis orthogonal to the central longitudinal axis.

[0012] U.S. Patent No. US4585318 discloses a tracking apparatus mounted on a vertical axis with a tilt to the horizontal axis attained automatically through a directing limb by rotating the vertical axis, this making possible a trustworthy and uncomplicated manufacturable and manageable tracking device that can be easily adjusted to the local circumstances. [0013] Swiss Patent Document No.CH669838 discloses an adjustable supporting frame for solar panel - has elements permitting height adjustment and rotation about horizontal and vertical axes

[0014] WIPO Publication No. WO2008092194 discloses a reflector structure of the heliostat that may be rotated about a first fixed horizontal rotational axis. The reflector structure may be rotated about a second rotational axis that is substantially orthogonal to the first rotational axis. First and second actuators may be employed to effect rotation about the first and second axes, respectively. The reflector structure's motion may be confined to a three-dimensional volume that allows for closer side-to-side packing of the heliostats in a heliostat field.

[0015] U.S. Patent Publication No. US2007227574 discloses a tracking solar power system includes: a solar power substructure and a platform having a first degree of freedom. The solar power substructure is mounted on the platform in a manner such that it has a second degree of freedom relative to the platform. The solar power substructure may include a solar collector and a receiver arranged to receive energy from the solar collector. The receiver may be mounted in a manner that avoids shading of the solar collector during operation. The solar collector may have an area focus at the receiver. The solar power substructure may include a non-concentrating solar power substructure.

[0016] U.S. Patent No. US4147154 discloses a solar heat tracking and collecting apparatus including a frame, means for rotating the frame in altitude and azimuth, a solar heat concentrator mounted on the frame and a solar energy sensing means disposed on the frame and operable to control the frame rotation means. The solar heat concentrator includes a substantially rectangular, flat collector plate and two pair of oppositely disposed light reflective side walls bounding the collector plate, the side walls in a converging relationship to one another. The device may also contain a triphase solar mode sensor which is operable during the full sun phase to enable and disable the solar energy sensing means from automatically controlling the frame rotation. When the sky is overcast the solar energy sensing means become inoperable and the mode sensor then operates a timer which enables the obscured sun to be accurately tracked within very close tolerances. In a third phase, the darkness phase, the mode sensor is operable to reset the frame with its mounted solar heat concentrator to a substantially horizontal, easterly direction.

BRIEF SUMMARY

[0017] Embodiments of the present invention provide a solar collector apparatus comprising: a basal framework controllably movable and rotatable; an array comprising a plurality of controllably tiltable beams connected to the basal framework; a plurality of sets of collectors, each set mounted on one of the tiltable beams, each collector comprising a photovoltaic panel and a controllably tiltable mirror arranged to reflect solar radiation upon the photovoltaic panel; and at least one controller arranged to control a mirror angle of each controllably tiltable mirror, a beam elevation angle of each controllably tiltable beam and a horizontal azimuth angle of the basal framework. The beam elevation angles and the horizontal azimuth angle are time dependently selected such as to allow maximal production of electricity by the photovoltaic panels during the day without damaging the photovoltaic panels. The mirror angle is continuously calculated and controlled providing optimal working conditions without damaging the panel. The basal framework, tiltable beams and collectors are connected such as to allow simple construction thereof and sequential adjustment of the position and tilting angles of the basal framework, the tiltable beams the collectors and the tiltable mirrors.

[0018] Accordingly, according to an aspect of the present invention, there is provided a solar collector apparatus, wherein the basal framework comprises controllable wheels arranged to allow rotation and fixation of the basal framework.

[0019] Accordingly, according to another aspect of the present invention, there is provided a solar collector apparatus, wherein each collector further comprises a sensor arranged to measure at least one characteristic of the photovoltaic panel, and connected to the at least one controller, and wherein the at least one controller is arranged to control the mirror angle of each controllably tiltable mirrors in respect to the measured characteristics of the corresponding photovoltaic panel.

[0020] Accordingly, according to still another aspect of the present invention, there is provided a solar collector apparatus, wherein each collector comprises one of the at least one controller, which is arranged to control the mirror angle of the collector utilizing the measured characteristics of the photovoltaic panel.

[0021] Accordingly, according to yet another aspect of the present invention, there is provided a solar collector apparatus, wherein, the beam elevation angles and the horizontal azimuth angle are time and location dependent selected such as to reflect at least a portion of the solar radiation on the photovoltaic panels, when direct solar radiation as measured by the sensors thereupon is below a specified threshold.

[0022] Embodiments of the present invention provide a method of operating a photovoltaic system, comprising: assembling an array of solar collectors, each comprising a photovoltaic panel and a tiltable mirror arranged to controllably reflect solar radiation on the photovoltaic panel; measuring at least one parameter relating to incident solar radiation; and continuously adjusting a tilt angle of at least one tiltable mirror such as to reflect solar radiation upon at least one of the photovoltaic panels and increase incident solar radiation thereupon. The tilt angles of the tiltable mirrors are selected such as to add reflected solar radiation to direct solar radiation upon the photovoltaic panels in relation to specified operation characteristics allowing a maximal electricity production from the photovoltaic panels.

[0023] Accordingly, according to an aspect of the present invention, there is provided a method, wherein the assembling the array of solar collectors comprises assembling the solar collectors in commonly controlled sets.

[0024] Accordingly, according to another aspect of the present invention, there is provided a method, wherein measuring at least one parameter relating to incident solar radiation and continuously adjusting a tilt angle of at least one tiltable mirror are carried out set-wise, such that the measuring is carried out on at least one photovoltaic panel in the set and the adjusting is carried out in respect to the tilt angles of the tiltable mirrors in each set collectively.

[0025] According to some embodiments of the present invention the mirror length is longer than the panel length ,wherein at certain beam elevation angles, the mirror radiation covers an area on the panel uncovered by the direct radiation. According to some embodiments of the present invention the beam elevation angles are adjusted continuously according to the radiation direction angle preventing shadowing of all panels to ensure equal distribution of light radiation across each panel. [0026] These, additional, and/or other aspects and/or advantages of the present invention are: set forth in the detailed description which follows; possibly inferable from the detailed description; and/or learnable by practice of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be more readily understood from the detailed description of embodiments thereof made in conjunction with the accompanying drawings of which:

Figs. 1A and 1C are high level schematic illustrations of a collector in a solar collector apparatus, according to some embodiments of the invention;

Figs. IB and ID are high level schematic illustrations of a tiltable beam in a solar collector apparatus, according to some embodiments of the invention;

Figs. 2 and 3 are high level schematic illustrations of a solar collector apparatus, according to some embodiments of the invention;

Fig. 4 is a schematic illustration of a wheel in a solar collector apparatus, according to some embodiments of the invention;

Fig. 5 is a high level schematic block diagram of a solar collector apparatus, according to some embodiments of the invention;

Fig. 6 is a high level flowchart illustrating a method of collecting solar radiation by an array of photovoltaic panels, according to some embodiments of the invention; and Figs. 7A and 7B are high level schematic illustrations of a collector in a solar collector apparatus, according to some embodiments of the invention. DETAILED DESCRIPTION

[0028] Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is applicable to other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.

[0029] Fig. 1A is a high level schematic illustration of a collector 150 in a solar collector apparatus 100, according to some embodiments of the invention. Collector 150 comprises a photovoltaic panel 110 and a controllably tiltable mirror 120 (e.g., a substantially planar mirror) arranged to reflect solar radiation upon photovoltaic panel 110. Collector 150 functions as the basic element in solar collector apparatus 100 that may be assembled in a modular manner to form various arrays. As the basic element, collector 150 has a electricity generation unit - photovoltaic panel 110 transforming solar energy to electricity; and a radiation controller in form of tiltable mirror 120 arranged to adjust the level of radiation intensity upon photovoltaic panel 110, by changing the inclination angle of tiltable mirror 120 and so redirecting light (illustrated by the arrows).

[0030] Fig. IB is a high level schematic illustration of a tiltable beam 160 in a solar collector apparatus 100, according to some embodiments of the invention. Tiltable beam 160 comprises several collectors 150 mounted thereon and mechanical positioning means 135B (see Fig. 2) for controlling the movements of tiltable beam 160. Tiltable beam 160 may be arranged to move in either a parallel direction to the movement of collectors 150 (i.e., in the plain of Fig. IB) or perpendicular thereto (outside of the plain of Fig. IB and with beam 160 as an axis). Tiltable beam 160 may be tiltable either in respect to an axis of tiltable beam 160 or in respect to an axis perpendicular to an axis of tiltable beam 160. Tiltable beam 160 and tiltable mirror 120 may be tiltable in the same direction or in perpendicular directions.

[0031] Fig. 1B1 is an enlarged illustration of the mirrors controlling mechanism. The mirror adjusting axis 165A, which is positioned across the beam 160 is connected to all mechanical positioning means 135 A for simultaneously controlling the tilting of all mirrors 120.

[0032] Fig. 1C is a high level schematic illustration of a collector 150 in a solar collector apparatus 100, according to some embodiments of the invention. Fig. 1C illustrates a folded state of collector 150, wherein tiltable mirror 120 is connected to photovoltaic panel 110 by e.g., a pivot 121. Pivot 121 may be arranged to allow folding tiltable mirror 120 upon photovoltaic panel 110 before and during assembling collectors 150 upon tiltable beams 160. Collector 150 may supplied to a site in the folded state, connected, e.g., to tiltable beam 160 by simple means such as screws that are screwed to specified locations on tiltable beam 160, and then only be unfolded (arrow in Fig. 1C) in order to allow operating collector 150. Manufacturing and supplying collector 150 in the folded state may allow simple mounting and maintenance of an array of collectors 150.

[0033] Fig. ID is a high level schematic illustration of a tiltable beam 160 in a solar collector apparatus 100, according to some embodiments of the invention. Fig. ID demonstrates a possibility of pre-installing several collectors 150 in their folded state on tiltable beam 160, and installing whole pre-installed beams 160 at a site, followed by unfolding tiltable mirrors 120 after installation (see arrow).

[0034] Collector 150 may further comprise a controller 130A arranged to control a mirror angle of tiltable mirror 120, and mechanical positioning means 135A for controlling and holding tiltable mirror 120. The mirror angle determines the intensity of solar radiation reflected upon photovoltaic panel 110. Tiltable mirror 120 may be continuously or stepwise moved to reflect any predefined portion of the solar radiation from 100% to 0. Tiltable mirror 120 may be used to increase solar radiation upon photovoltaic panel 110 when direct solar radiation is insufficient for optimal operation of photovoltaic panel 110, e.g., below a specified threshold. Adjusting the mirror angle allows regulation of the radiation intensity on photovoltaic panel 110.

[0035] Collector 150 may also comprise a sensor 140A arranged to measure characteristics of photovoltaic panel 110, for example a thermometer measuring the temperature of photovoltaic panel 110, a current meter measuring the current produced by photovoltaic panel 110, a power meter measuring the power produced by photovoltaic panel 110, a radiation meter measuring solar radiation upon photovoltaic panel 110, and so forth. Sensor 140A may be connected to controller 130A and the measured temperature may be attenuated by moving tiltable mirror 120 to reflect more or less radiation upon photovoltaic panel 110.

[0036] Figs. 2 and 3 are high level schematic illustrations of solar collector apparatus 100, according to some embodiments of the invention. Fig. 4 is a schematic illustration of a wheel 136 in solar collector apparatus 100, according to some embodiments of the invention. Solar collector apparatus 100 comprises a basal framework 101, an array of tillable beams 160 connected to basal framework 101 and sets of collectors 150 on each tiltable beam 160.

[0037] Basal framework 101 is controllably movable and rotatable by mechanical positioning means 135C(See FIG. 5) such as to adjust its position and rotational horizontal azimuth angle to an optimal interception of solar radiation by photovoltaic panels 110, as well as an adaptation to the. terrain. Basal framework 101 may comprise e.g., wheels 136 (Fig. 4) as mechanical positioning means 135C_(See FIG. 5 ). A rotational movement of basal framework 101 allows following the sun in its daily course. Wheels 136 may be controllable and arranged to allow rotation and fixation of basal framework 101. Solar collector apparatus 100 may further comprise a sun tracking sensor (not shown) arranged to track the sun and guide the tilting of tiltable mirrors 120. In some embodiments, , the beam elevation angles , the position and the basal framework horizontal azimuth angle may be selected such as to track the sun according to readings of the sun tracking sensor.

[0038] Tiltable beams 160 are controllable in respect to their elevation tilting angle, and may further comprise mechanical positioning means 135B arranged to tilt tiltable beams 160 to optimize interception of solar radiation by photovoltaic panels 110. Tiltable beams 160 in the array may be correlated in their movements, or may be grouped to groups that move independently from each other. The beam elevation angles are adjusted according to the radiation direction angle preventing shadowing of all panels to ensure equal distribution of light radiation across each panel.

[0039] Collectors 150, comprising photovoltaic panels 110 and controllably tiltable mirrors 120 arranged to reflect solar radiation thereupon, may be mounted in sets upon tiltable beams 160, for example with photovoltaic panels 110 being in a single plain. Alternatively, collectors 150 may be connected to tiltable beams 160 during production.

[0040] Fig. 2A illustrates the structure of the collector according to some embodiments of the present invention. According to this embodiment the mirror length is longer than the panel length, such structure provide more efficient use of the photovoltaic panels 110 ,when the direct radiation cover only part of the panel, the mirror will reflect radian upon the uncovered part of the panel.

[0041] Fig. 5 is a high level schematic block diagram of solar collector apparatus 100, according to some embodiments of the invention. Solar collector apparatus 100 may further comprise controllers 130A, 130B, 130C at the levels of collectors 150, tiltable beams 160, and/or the whole solar collector apparatus 100, respectively. Controllers 130A, 130B, 130C are arranged to control a mirror angle of each controllably tiltable mirror 120, a beam elevation angle of each controllably tiltable beam 160 and a position and horizontal azimuth angle of basal framework 101. Various controller architectures may be used, such as to balance the system complexity with the control effectivity.

[0042] Solar collector apparatus 100 may further comprise sensors 140A, 140B, 140C at the levels of collectors 150, tiltable beams 160, and/or the whole solar collector apparatus 100, respectively. Sensors 140A, 140B, 140C may comprise thermometers, current or power meter and radiation sensors, that are set to measure characteristics of photovoltaic panels 110, sets of photovoltaic panels 110 (e.g...grouped on each tiltable beam 160) or of predefined reference locations on solar collector apparatus 100. Various measurement architectures may be used, such as to balance the system complexity with the control effectivity. Sensors 140A, 140B, 140C may be connected to controllers 130A, 130B, 130C to facilitate an effective control that avoids damage to photovoltaic panels 110 while maximizing their output. For example, sensors 140A may feed measurements to controllers 130A, sensors 140B may feed measurements to controllers 130B, and sensors 140C may feed measurements to controllers 130C, or only one of the levels may be implemented.

[0043] In embodiments, some each collector 150 may comprise sensors 140A arranged to measure characteristics of the corresponding photovoltaic panel 110 and be connected to controller 130A. Controller 130A may control the mirror angle of the corresponding tiltable mirrors 120 in respect to the measured characteristics of the corresponding photovoltaic panel 110. One sensor 140A and one controller 130A may be used for a set of collectors 150 assembled on one tiltable beam 160.

[0044] In embodiments, some each tiltable beam 160 may comprise sensor 140B arranged to measure characteristics of one of the corresponding photovoltaic panels 110 and connected to controller 130B. Controller 130B may control the mirror angle of the corresponding tiltable mirrors 120 in respect to the measured characteristics of the corresponding photovoltaic panel 110. One sensor 140B and controller 130B may control all collectors 150 on tiltable beam 160. One sensor 140B and one controller 130B may be used for a group of tiltable beams 160.

[0045] In embodiments, a single or few sensors 140C and controller 130C may be arranged to measure characteristics of at least one of photovoltaic panels 110 in solar collector apparatus 100, and control the mirror angle of a plurality of controllably tiltable mirrors 120 (respectively) in respect to the measured characteristics of sensors 140C. [0046] Sensors 140A, 140B and/or 140C may comprise a thermometer measuring the temperature of photovoltaic panel 110, a current meter measuring the current produced by photovoltaic panel 110, a power meter measuring the power produced by photovoltaic panel 110, a radiation meter measuring solar radiation upon photovoltaic panel 110, and so forth.

[0047] The beam elevation angle and the position and the horizontal azimuth angle may be time dependently selected such as to allow maximal production of electricity by photovoltaic panels 110 during the day without damaging photovoltaic panels 110. For example, the beam elevation angles and the horizontal azimuth angle may be time dependently selected such as to track the sun and reflect at least a portion of the solar radiation on photovoltaic panels 110. In embodiments, the mirror angle, the beam elevation angle and the horizontal azimuth angle may be selected to reflect a maximally permissible portion of the solar radiation on photovoltaic panels 110. Tiltable mirror 120 may be used to increase solar radiation upon photovoltaic panel 110 when direct solar radiation is insufficient for optimal operation of photovoltaic panel 110. Insufficiency of direct solar radiation may be detected by any of sensors 140A, 140B and/or 140C, e.g., as being below a specified threshold, and tiltable mirrors 120 may be controlled by any of controllers 130A, 130B and/or 130C, according to the configuration of solar collector apparatus 100. Adjusting the mirror angle allows regulation of the radiation intensity on photovoltaic panel 110.

[0048] According to some embodiments of the invention, basal framework 101, tiltable beams 160 and collectors 150 are connected such as to allow simple construction thereof and sequential adjustment of the position and tilting angles of basal framework 101, tiltable beams 160, collectors 150 and tiltable mirrors 120. Basal framework 101, tiltable beams 160, and tiltable mirrors 120 may be arranged to move in orthogonal directions, in respect to each other, allowing the adjustment of each independently of the other, thus easing construction.

[0049] According to some embodiments of the invention, solar collector apparatus 100 may further comprise a sun sensor 102, arranged to measure the position of the sun during the day. Controllers 130A, 130B, 130C may be arranged to control the positions and inclinations of tiltable mirrors 120, tiltable beams 160, and solar collector apparatus 100 in respect to the measured sun position, such as to generate a maximal electric output from photovoltaic panels 110 while avoiding damage to them due to excessive solar radiation.

[0050] Fig. 6 is a high level flowchart illustrating a method of collecting solar radiation by an array of photovoltaic panels, according to some embodiments of the invention. The method comprises the following stages: Assembling an array of solar collectors (stage 200). Each solar collector may comprise a photovoltaic panel and a tiltable mirror arranged to controllably reflect solar radiation on the photovoltaic panel. For example, assembling an array of solar collectors (stage 200) may comprise assembling the photovoltaic panels on a support comprising a basal platform, tiltable beams connected thereto, and sets of collectors, each connected to a tiltable beam, and each comprising at least one of the photovoltaic panels and a tiltable mirror arranged to reflect solar radiation upon the at least one of the photovoltaic panels. The method comprises the following stages: measuring at least one parameter relating to incident solar radiation (stage 210); and continuously adjusting a tilt angle of at least one tiltable mirror (stage 220) such as to reflect solar radiation upon at least one of the photovoltaic panels and increase incident solar radiation thereupon. Each tiltable mirror may be controlled in respect to the measured parameter of the associated photovoltaic panel (stage 210). The tilt angles of the tiltable mirrors are selected such as to add reflected solar radiation to direct solar radiation upon the photovoltaic panels in relation to specified operation characteristics allowing a maximal electricity production from the photovoltaic panels.

[0051] According to some embodiments of the invention, the method may further comprise controlling a positioning angle of the array of solar collectors (stage 230) such as to collectively control solar radiation on the photovoltaic panels.

[0052] According to some embodiments of the invention, assembling the array of solar collectors (stage 200) may comprise assembling the solar collectors in commonly controlled sets, and measuring at least one parameter relating to incident solar radiation (stage 210) and continuously adjusting a tilt angle of at least one tiltable mirror (stage 220) are carried out set-wise, such that measuring (stage 210) is carried out on at least one photovoltaic panel in the set and adjusting (stage 220) is carried out in respect to the tilt angles of the tiltable mirrors in each set collectively.

[0053] According to some embodiments of the invention, measuring at least one parameter relating to incident solar radiation (stage 210) may comprise measuring at least one temperature of at least one of the photovoltaic panels. The method may further comprise tilting the tiltable mirror (stage 225) such as to reduce the solar radiation on the corresponding photovoltaic panels when the measured temperature exceeds a specified threshold temperature. [0054] According to some embodiments of the invention, measuring at least one parameter relating to incident solar radiation (stage 210) may comprise measuring electric output of at least one of the photovoltaic panels. Measuring at least one parameter relating to incident solar radiation (stage 210) may be carried out on a specified position or positions on the array, or be carried out in relation to specified photovoltaic panels.

[0055] According to some embodiments of the invention, assembling the array of solar collectors (stage 200) may comprise assembling the collectors in a folded state, in which the tiltable mirror is folded upon the photovoltaic panel and consequently tilting the tiltable mirror to a specified initial position.

[0056] According to some embodiments of the invention, the method may further comprise connecting the collectors to the tiltable beams pivotly (stage 235), and rotating the collectors such as to regulate solar radiation on the photovoltaic panel (stage 240).

[0057] Figs. 7A and 7B are high level schematic illustrations of a collector 150 in a solar collector apparatus 100, according to some embodiments of the invention. In the illustrated embodiment, collector 150 may be pivotly connected to tiltable beam 160 such that whole collector 150 may be rotated (e.g., in an angle a, Fig. 7B) in respect to the intensity of solar radiation, e.g., as measured by sensors 140A, 140B, 140C. Mirror 120 may be connected at a fixed angle (e.g., angle β), to collector 110, and radiation intensity may be controlled by the tilt angle of collector 150. In embodiments, both the angles (a, β) of collector 150 and of mirror 120 may be changed in relation to the solar radiation. In another embodiment, the azimuth orientation of basal framework 101 or of tiltable beams 160 may be changed such as to control the incident solar radiation. Fig. 8 illustrates, different elevation tilting states of the photovoltaic panels 110. At the upper panels series, the elevation tilt angle is normal to the sun rays direction creates shadowed area 800. The adjustment of the tilting angle based on sun radiation angle, according to the present invention, as seen in the lower panels series, ensure full exposure of the panels to direct radiation providing equal distribution acooss the panel.

[0058] In the above description, an embodiment is an example or implementation of the inventions. The various appearances of "one embodiment," "an embodiment" or "some embodiments" do not necessarily all refer to the same embodiments.

[0059] Although various features of the invention may be described in the context of a single embodiment, the features may also be provided separately or in any suitable combination. Conversely, although the invention may be described herein in the context of separate embodiments for clarity, the invention may also be implemented in a single embodiment.

[0060] Reference in the specification to "some embodiments", "an embodiment", "one embodiment" or "other embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least some embodiments, but not necessarily all embodiments, of the inventions.

[0061] It is to be understood that the phraseology and terminology employed herein is not to be construed as limiting and are for descriptive purpose only.

[0062] The principles and uses of the teachings of the present invention may be better understood with reference to the accompanying description, figures and examples. [0063] It is to be understood that the details set forth herein do not construe a limitation to an application of the invention.

[0064] Furthermore, it is to be understood that the invention can be carried out or practiced in various ways and that the invention can be implemented in embodiments other than the ones outlined in the description above.

[0065] It is to be understood that the terms "including", "comprising", "consisting" and grammatical variants thereof do not preclude the addition of one or more components, features, steps, or integers or groups thereof and that the terms are to be construed as specifying components, features, steps or integers.

[0066] If the specification or claims refer to "an additional" element, that does not preclude there being more than one of the additional element.

[0067] It is to be understood that where the claims or specification refer to "a" or "an" element, such reference is not to be construed that there is only one of that element.

[0068] It is to be understood that where the specification states that a component, feature, structure, or characteristic "may", "might", "can" or "could" be included, that particular component, feature, structure, or characteristic is not required to be included.

[0069] Where applicable, although state diagrams, flow diagrams or both may be used to describe embodiments, the invention is not limited to those diagrams or to the corresponding descriptions. For example, flow need not move through each illustrated box or state, or in exactly the same order as illustrated and described.

[0070] Methods of the present invention may be implemented by performing or completing manually, automatically, or a combination thereof, selected steps or tasks. [0071] The term "method" may refer to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the art to which the invention belongs.

[0072] The descriptions, examples, methods and materials presented in the claims and the specification are not to be construed as limiting but rather as illustrative only.

[0073] Meanings of technical and scientific terms used herein are to be commonly understood as by one of ordinary skill in the art to which the invention belongs, unless otherwise defined.

[0074] The present invention may be implemented in the testing or practice with methods and materials equivalent or similar to those described herein.

[0075] Any publications, including patents, patent applications and articles, referenced or mentioned in this specification are herein incorporated in their entirety into the specification, to the same extent as if each individual publication was specifically and individually indicated to be incorporated herein. In addition, citation or identification of any reference in the description of some embodiments of the invention shall not be construed as an admission that such reference is available as prior art to the present invention.

[0076] While the invention has been described with respect to a limited number of embodiments, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of some of the preferred embodiments. Other possible variations, modifications, and applications are also within the scope of the invention. Accordingly, the scope of the invention should not be limited by what has thus far been described, but by the appended claims and their legal equivalents.

Claims

CLAIMS What is claimed is:

1. A solar collector apparatus comprising:

A basal framework controllably rotatable;

An array comprising a plurality of controllably tiltable beams connected to the basal framework;

a plurality of sets of collectors, each set mounted on one of the tiltable beams, each collector comprising a photovoltaic panel, a controllably tiltable mirror arranged to reflect solar radiation upon the photovoltaic panel and at least one sensor arranged to measure at least one parameter relating to incident solar radiation of the photovoltaic panel; and

at least one controller arranged to control a mirror angle of each controllably tiltable mirror, a beam elevation angle of each controllably tiltable beam and a position and horizontal azimuth angle of the basal framework,

wherein the beam elevation angles and the horizontal azimuth angle of the basal framework are time and location dependent selected such as to allow maximal production of electricity by the photovoltaic panels during the day without damaging the photovoltaic panels, and

wherein the at least one controller is arranged to control the mirror angle of each controllably tiltable mirrors in respect to the measured parameter of the corresponding photovoltaic panel; and wherein the beam elevation angles are adjusted according to the radiation direction angle preventing shadowing of all panels to ensure equal distribution of light radiation across each panel. wherein the basal framework, tiltable beams and collectors are connected such as to allow simple construction thereof and sequential adjustment of the position and tilting angles of the basal framework, the tiltable beams the collectors and the tiltable mirrors.

2. The solar collector apparatus of claim 1, wherein the basal framework comprises controllable wheels arranged to allow rotation and fixation of the basal framework.

3. The solar collector apparatus of claim 1, wherein each collector comprises one of the at least one controller, which is arranged to control the mirror angle of the collector utilizing the measured characteristics of the photovoltaic panel.

4. The solar collector apparatus of claim 1, wherein, the beam elevation angles and the position and the horizontal azimuth angle are time dependently selected such as to reflect at least a portion of the solar radiation on the photovoltaic panels, when direct solar radiation as measured by the sensors thereupon is below a specified threshold.

5. The solar collector apparatus of claim 1, wherein each tiltable beam further comprises a sensor arranged to measure at least one characteristic of one the photovoltaic panels on the beam, and connected to the at least one controller, and wherein the at least one controller is arranged to control the mirror angle of each controllably tiltable mirror on the beam in respect to the measured characteristic by the corresponding sensor.

6. The solar collector apparatus of claim 1, wherein each tiltable beam comprises one of the at least one controller, which is arranged to control the mirror angle of the collectors on the beam utilizing the characteristic measured by the sensor on the beam.

7. The solar collector apparatus of claim 1, wherein the at least one sensor is arranged to measure the temperature on the panel.

8. The solar collector apparatus of claim 1, wherein the tiltable mirrors are substantially planar.

9. The solar collector apparatus of claim 1, wherein in each of the collectors, the tiltable mirror is connected to the photovoltaic panel by a pivot arranged to allow folding the tiltable mirror upon the photovoltaic panel before and during assembling the collectors upon the tiltable beams.

10. The solar collector apparatus of claim 1, wherein the collectors are pivotly connected to the tiltable beams, and arranged to be rotated such as to regulate solar radiation on the photovoltaic panel.

1 1. The solar collector apparatus of claim 1, wherein the mirror length is longer than the panel length ,wherein at certain beam angles, the mirror radiation covers an area on the panel uncovered by the direct radiation.

12. A method of operating a photovoltaic system, comprising:

assembling an array of solar collectors, each comprising a photovoltaic panel and a tiltable mirror and at least one sensor for measuring at least one parameter relating to incident solar radiation arranged to controllably reflect solar radiation on the photovoltaic panel;

measuring at least one parameter relating to incident solar radiation; and continuously adjusting a tilt angle of at least one tiltable mirror based on measured radiation on the panels such as to reflect solar radiation upon at least one of the photovoltaic panels and increase incident solar radiation thereupon,

controlling the adjustment of the beam elevation angles according to the radiation direction angle for preventing shadowing of all panels to ensure equal distribution of light radiation across each panel.

wherein the tilt angles of the tiltable mirrors are selected such as to add reflected solar radiation to direct solar radiation upon the photovoltaic panels in relation to specified operation characteristics allowing a maximal electricity production from the photovoltaic panels.

13. The method of claim 12, further comprising controlling a positioning elevation angle of the array of solar collectors such as to collectively control solar radiation on the photovoltaic panels.

14. The method of claim 12, wherein the assembling the array of solar collectors comprises assembling the solar collectors in commonly controlled sets.

15. The method of claim 12, wherein measuring at least one parameter relating to incident solar radiation and continuously adjusting a tilt angle of at least one tiltable mirror are carried out set-wise, such that the measuring is carried out on at least one photovoltaic panel in the set and the adjusting is carried out in respect to the tilt angles of the tiltable mirrors in each set collectively.

16. The method of claim 12, wherein measuring at least one parameter relating to incident solar radiation comprises measuring at least one temperature of at least one of the photovoltaic panels.

17. The method of claim 16, further comprising tilting the tiltable mirror such as to reduce the solar radiation on the corresponding photovoltaic panels when the measured temperature exceeds a specified threshold temperature.

18. The method of claim 12, wherein each tiltable mirror is controlled in respect to the measured parameter of the associated photovoltaic panel.

19. The method of claim 12, wherein measuring at least one parameter relating to incident solar radiation comprises measuring electric output of at least one of the photovoltaic panels.

20. The method of claim 12, wherein measuring at least one parameter relating to incident solar radiation is carried out in relation to at least one photovoltaic panel.

21. The method of claim 12, wherein assembling the array of solar collectors comprises assembling the collectors in a folded state, in which the tiltable mirror is folded upon the photovoltaic panel, and consequently tilting the tiltable mirror to a specified initial position.

22. The method of claim 12, wherein assembling the array of solar collectors comprises assembling the beams with pre-installed collectors in a folded state, in which the tiltable mirror is folded upon the photovoltaic panel, and consequently tilting the tiltable mirror to a specified initial position.

23. The method of claim 13, further comprising connecting the collectors to the tiltable beams pivotly, and rotating the collectors such as to regulate solar radiation on the photovoltaic panel.