WO2010034038A2

WO2010034038A2 - Systems and methods of collecting solar energy including configuration and/or tracking features

Info

Publication number: WO2010034038A2
Application number: PCT/US2009/065415
Authority: WO
Inventors: Xiaodong Xiang
Original assignee: E-Cube Energy, Inc.
Priority date: 2008-09-22
Filing date: 2009-11-20
Publication date: 2010-03-25
Also published as: WO2010034038A3; WO2010034038A8

Abstract

Systems and methods of collecting solar energy are disclosed. In one exemplary implementation, there is provided a method of collecting solar energy. Moreover, the method may include collecting solar energy with an optical collector panel that comprises an array of optics that redirects solar energy towards one or more receivers/collectors, rotating the panel around a first axis to a first angular position(s) to maintain exposure of the array/optics to a radiation source, and rotating rows of the optics around a plurality of second axes to a second angular position to maintain exposure to the radiation source.

Description

SYSTEMS AND METHODS OF COLLECTING SOLAR ENERGY INCLUDING CONFIGURATION AND/OR TRACKING FEATURES

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

[0001] This application claims priority to United States provisional patent application number 61/192,767 filed 22 September 2008, U.S. provisional patent application number 61/110,752 filed 3 November 2008, and U.S. nonprovisional application No. 12/563,982, filed 21 September 2009, the entire contents of each being hereby incorporated by reference in entirety.

BACKGROUND

Field

[0002] The present inventions relate generally, to solar energy collection, and more specifically to collection and collectors of solar energy including features of compensating for movement of a source of energy.

Description of Related Information:

[0003] Solar power has been viewed by many as a highly desirable energy resource, because it may be readily used to generate thermal and electrical energy. For example, a solar collector (usually formed by mirrors) may collect optical energy from the sun and direct the same to a transducer (receiver), which may convert the optical energy to either thermal energy or electricity. The thermal energy is usually transport out (or between) of transducers to applicator via "heat transfer fluid" (HTF), such as water, oil and the like. By arranging solar collectors in arrays, power plants have been developed that may convert vast amounts of solar energy to energy used for desired applications. [0004] In solar thermal applications, optical energy from the sun is converted to thermal energy for use in other applications, such as generating electrical power employing known implements such as conventional turbine-electric generators or a Sterling Engine, or for cooling or heating. To that end, typically large arrays of individual solar modules (composed of optical collectors and thermal receivers i.e., the device for receiving, absorbing optical energy and converting it to thermal energy) are coupled by fluid pipes and transfer heat, often via a heat transfer fluid. Each module has a fixed power conversion and transfer capacity, i.e., that quantity of solar energy that may be collected and transferred to the thermal transfer fluid.

[0005] In such applications, thermal loss limits the overall conversion efficiency. Thermal loss is dominated by convection loss and "black-body radiation" loss (BRL). While convection loss can be reduced by thermally insulating the thermal receiver and HTF transfer pipes. However, black-body radiation loss of the receiver is difficult to control. Such loss is dependent upon receiver aperture area, temperature, and the material of the absorption surface of the collector. Specifically, BRL is linearly proportional to the receiving/radiating aperture area and to the 4^th power of the temperature of the radiating body. In order to reduce BRL, and consequently, increase the overall conversion efficiency, it is desired to reduce the receiver area. One manner in which to reduce BRL while minimizing the inefficiency of the collector module is to employ a solar collector with a concentrator with a high concentration ratio, i.e., high solar collector area to thermal receiver area ratio.

[0006] Further, to improve the efficiency of solar concentrators, solar trackers may be used. Solar trackers follow the changes in relative position of the sun in order to accomplish the concentration or focusing the sun's radiation onto the thermal receiver aperture. There are two different methods to describe sun's movement with two sets of angular system. One uses azimuth and attitude angles and the other uses "hour angle", and "seasonal angle" or "declination angle." The solar azimuth angle is the angle, measured clockwise on the horizontal plane, from the north-pointing coordinate axis to

the projection of the sun's central ray. The solar altitude angle is defined as the angle between a central ray from the sun and a horizontal plane containing the observer. The hour angle describes the angular position of the sun relative to an earth surface location due to Earth self-rotational daily periodic movement (i.e., Earth spin); while the declination angle describes the angular position of the sun relative to an earth surface location due to the periodic movement of Earth-Sun rotational axis relative to Earth self- spin axis.

[0007] Traditionally, tracking of the movement of the sun is often done by rotating the entire optics-solar collector panel together with a solar receiver assembly in two axes, often called "moving target" tracking system. However, many of these solar concentrators comprise a single optical element per solar receiver resulting in a heavy system that must be rotated. As a result, tracking systems are typically expensive due to mechanics required provide the torque and acceleration desired to provide the desired movement.

[0008] Other solar concentrators comprise an array of optical elements in each solar receiver that individually move to focus the sunbeam on a fixed solar receiver or target, usually referred to as a "heliostat" or "fixed target" system. In such configuration, for each optical element, the concentration ratio is either 1 or slightly higher than 1. However, many such optical elements project the sunlight onto the same solar collector, and therefore resulting very high concentration ratio. Each such optical element has a different relative position and angle relative to the target, collectively forming a "Fresnel reflector", i.e. arrays of small flat (or basically flat) mirrors forming a concave surface on a flat back plate. The optical cosine loss is large in such system (-25%) since the sunbeam is not vertical to the reflecting mirrors in general. A heliostat of MxN optical elements usually require 2xMxN of independent moving axes (and therefore motors) to maintain focus (tracking) on a fixed target as sun moves during the day and seasons, which is very expensive to implement.

[0009] Because of the various drawbacks and inefficiencies of existing techniques, systems and methods having improved techniques for tracking of the sun are desired.

SUMMARY

[0010] Systems and methods consistent with the innovations herein are directed to configuration and/or tracking features associated with solar collectors. [0011] In one exemplary implementation, there is provided a method for collecting energy that may include collecting solar energy with one or more receivers receiving light from a panel that reflects solar energy towards the receiver(s), performing a first (e.g., temporal, etc.) rotation such as rotating the panel around a first axis to a first angle to maintain exposure of an array of optics to a solar source, and performing a second (e.g., seasonal, etc.) rotation such as rotating the rows of optics around a plurality of second axes perpendicular to the first axis to a second angle to maintain exposure of the optics to the source.

[0012] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as described. Further features and/or variations may be provided in addition to those set forth herein. For example, the present invention may be directed to various combinations and subcombinations of the disclosed features and/or combinations and subcombinations of several further features disclosed below in the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 illustrates a block diagram of an exemplary solar collection system, consistent with one or more implementations of the innovations herein.

[0014] Figure 2A is a side view schematic diagram illustrating an exemplary solar collector, consistent with aspects related to the innovations herein.

[0015] Figure 2B is a diagram illustrating initial angle features for a mirror, consistent with aspects related to the innovations herein.

[0016] Figure 3 is a schematic diagram showing a top view of a solar collector, consistent with aspects related to the innovations herein..

[0017] Figure 4 is a table illustrating exemplary focus error, consistent with aspects related to the innovations herein.

[0018] Figure 5 is a flow diagram illustrating an exemplary method of collecting solar energy consistent with aspects related to the innovations herein.

[0019] Figure 6 is a flow diagram illustrating an exemplary method of collecting solar energy consistent with aspects related to the innovations herein.

[0020] Figure 7 is a block diagram of an exemplary computing component operable consistent with aspects related to the innovations herein.

[0021] Figure 8 is a diagram illustrating an exemplary solar collector, consistent with aspects related to the innovations herein.

[0022] Figure 9 is a diagram illustrating an exemplary solar collector, consistent with aspects related to the innovations herein. DETAILED DESCRIPTION OF EXEMPLARY IMPLEMENTATIONS

[0023] Reference will now be made in detail to the invention, examples of which are illustrated in the accompanying drawings. The implementations set forth in the following description do not represent all implementations consistent with the claimed invention. Instead, they are merely some examples consistent with certain aspects related to the invention. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

[0024] FIG. 1 illustrates a block diagram of an exemplary solar collection system 10 in accordance with one or more implementations of the innovations herein. Referring to FIG. 1 , the solar collection system 10 may comprise a solar field 20 including solar collectors 100 and a controller 170 and, optionally, one or more elements of external systems 30. The controller may include one or more computing components, systems and/or environments 180 that perform, facilitate or coordinate control of the collectors. As explained in more detail below, such computing elements may take the form of one or more local computing structures that embody and perform a full implementation of the features and functionality herein or these elements may be distributed with one or more controller(s) 170 serving to coordinate the distributed processing functionality. Further, the controller 170 is not necessarily in close physical proximity to the collectors 100, though is shown in the drawings as being associated with solar field 20. Solar collection system 10 may also include one or more optional external devices or systems 30, which may embody the relevant computing components, systems and/or environments 180 or may simply contain elements of the computing environment that work together with other computing components in distributed arrangements to realize the functionality, methods and/or innovations herein.

[0025] Aspects of the innovations herein are directed to systems and methods of collecting solar energy from a radiation source (e.g., the sun, etc.) and may involve a thermal collection/generation apparatus having a solar collector module including plurality of mirrors (or reflective optics), forming a collection/reflector assembly, to focus the sunlight onto one or more receiving elements, such as a thermal receiver, photovoltaic cells, etc. In one exemplary implementation, a solar collector module includes a panel frame, an array of mirrors (e.g., heliostat, Fresnel reflector, etc.) mounted on the panel frame, and a thermal receiver, also fixed on the panel frame. The panel frame together with all mirrors and thermal receiver is rotated about an axis, which can be oriented South-North direction with a tilt angle equal to the latitude angle at the location, to compensate for sun's hour angle movement during each day via tracking schemes herein. In such implementations, each individual row of mirrors is mounted on a rotation axis, which is approximately perpendicular to a panel rotating axis, and may be, e.g., supported by pivotal supports on the frame. All rows of mirror and their rotation axes rotate by a approximately a same angle relative to the panel frame plane, that is approximately half of the declination angle to compensate for seasonal adjustment of the sun during the year through a "fixed target" scheme. Using this "mixed tracking" scheme, such collectors may track the sun's movement and focus sunlight to the thermal receiver.

[0026] In overcoming one or more drawbacks in existing systems, innovative aspects of systems and methods including a "Modular Heliostat" (MH) are disclosed. In one exemplary implementation, an illustrative modular heliostat may be a 2-dimensional array (MxN) of optical elements and one of multiple solar collectors (receivers) assembled in a modular system defined by a frame and plane. There are M columns of mirrors along Y axis mounted on their rational axis (N number), which is parallel to the X axis of the plane. There are N rows of mirrors and rotational axes along X axis. A thermal (or solar) receiver for each modular system may be located (e.g., fixed on the frame by supporting structure, etc.) at approximately the center above the plane, with a height of H, facing down perpendicularly to the normal of the plane. The optical elements are mounted relative to the plane with initial angles that will allow the sunlight approximately normal to the plane to focus on the solar collector, for example, they may form a 2-D Fresnel reflector array. At each mirror center position of (x, y), the initial angle is made to be approximately α = [V₂) tan-1 ((x²+y²)^1/2/H), and is measured between the plane of the frame and plane of the mirror facing the center point. The center of the mirror should be approximately the rotational center of the rotating axis, i.e. there is preferably no horizontal displacement of the mirror's center position during the mirror rotation. [0027] Here, aspects of both "moving target" and "fixed target" tracking schemes may be modified/integrated within the contexts of the present innovations. For example, the panel may be rotated using aspects of moving target tracking schemes around a "polar axis", which is oriented south-north direction and tilted with a angle relative to the earth horizontal plane equal to the "latitude angle", by the sun's "hour angle" with an angular speed of 15 degree/hour, to align the module. As such, during the day, the sun beam plane (with incoming and reflected beam ray refine the plane) is always normal to the panel (so that cosine loss is kept small) and the sun beam plane is parallel to the y-axis (e.g., perpendicular to the mirror rotation axis). During the seasons, as the sun beam angle changes within this plane by an angle away from the panel normal, all mirror axes supported by pivotal supports fixed on the frame may be rotated at an angle equal to half of, or derived as a function of, a declination angle value to approximately maintain the mirror array (e.g., Fresnel reflector, etc.) focus point on the solar receiver or target. As such, the tracking innovations may entail aspects of "fixed target" tracking schemes. Even though, during this rotation, there could be small de-focus effect among all mirrors, with proper design (e.g. keep the receiver high enough relative to the width (X dimension) of the panel frame and receiver aperture large enough), this effect can kept relatively small to obtain a relatively high value of concentration much higher than that of 1-D system with similar optics (flat mirrors).

[0028] According to implementations herein, optical elements can be selected from variety of optics, such as flat mirror, concave mirror, reflectors, and other devices capable of reflecting the sunlight onto same or focusing the sunlight onto a smaller area of solar cell (or collector). Each optical element may be supported by supporting base with a designed initial angle and fixed on a shaft with bearing support on the plane frame. A 2-dimensional array (MxN) of optical elements is assembled in a modular system defined by a frame and plane. There are M columns along Y-axis with their rational axis parallel to the X-axis of the plane and N rows of mirror along X-axis. In one implementation, a receiver is fixed on the frame (by supporting structure) at the center above the plane (with a height of H) facing down perpendicularly to the normal of the plane. All Fresnel mirrors are fixed relative to the plane with initial angles that will allow the sunlight normal to the plane (at Solar noon on solar equinox, when the sun declination angle is equal to zero) to focus on the center of the receiver, forming 2-D Fresnel reflector array. At each mirror center position of (x, y), the initial angle of the mirror may be:

α = (¹/₂) tan-1 ((x²+y²)^1/2/H)

[0029] and facing the center below the thermal receiver (X and Y, as used herein, denotes the position, along orthogonal axes, of the center of each mirror by its distance from a point p on the plane z, formed by the centers of the mirrors. This point p has the shortest distance among all point on plane z to the solar collector. As such, (X²+y²)^1/2 is the distance between the center of the each mirror to point p). Note that initial angles and mirror rotation axis angles should have a common rotation center. The center of the mirror should not have horizontal displacement during mirror rotation.

[0030] Fig. 2A is a schematic diagram illustrating one exemplary implementation of a solar collector 100 of a thermal generation apparatus (not shown) consistent with aspects related to the innovations herein. In one implementation, the solar collector 100 includes a receiver 125 and a panel frame 150 with an array of mirrors 175. The solar collector 100 can generate thermal energy from exposure to sunlight. The solar collector 100 can be attached, for example, to a base or a rooftop. In one example, multiple solar collectors can be implemented in a system.

[0031] The panel frame 150 may be composed of a rigid material to support the array of mirrors 175 and allow rotation about an axis 102. The rotational axis beam 102 is positioned pointing south-north direction and tilted by a latitude angle (Ly) 108 from the horizontal ground plane. The receiver 125, in one exemplary implementation, may be rigidly attached to the panel frame 150.

[0032] The array of mirrors 175 can be of flat mirrors place, e.g., in a Fresnel lens arrangement. In one implementation, there are M rows (e.g., rows 176) and N columns of flat mirrors that together comprise a large concave aperture. Each mirror in a row is positioned to have approximately an angle (α) 112 relative to the panel frame 150 to allow focus reflected sunlight towards the receiver 125. As a result, successive rows have larger angles as a horizontal distance from the receiver 125 increases. Each row can rotate about an individual axis 106. One example of determining an initial value for angle 112 is illustrated in Fig. 2B. In one implementation, initial angles for individual mirrors can be different.

[0033] In operation, the solar collector 110 may be configured to collect a maximum amount of sunlight in the receiver 125. To receive an optimal amount of incoming sunlight, a plane of the panel frame 150 is positioned approximately normal to a plane of sunlight. The panel frame 150 is rotated about an axis (polar axis, i.e. the rotational axis beam 102 positioned pointing south-north direction and tilted by a latitude angle (Ly) 108 from the horizontal ground plane) to compensate for hour angle adjustments of sunlight (i.e., due to Earth's self-spin)., N rows of mirrors are positioned to focus on a position of the receiver 125. All individual rows of mirrors are rotated about their axes by a half of the declination angle to compensate for seasonal adjustments of sunlight (i.e., due to relative angle movement of Earth self-spin axis and Earth-Sun rotation plane axis). Various combinations of these factors can be implemented for a particular solar collector 100, such as the exemplary combinations described below.

[0034] In one exemplary implementation, tracking scheme is a mixed moving/fixed target tracking scheme. As shown in Fig. 2A, the side-view of Y-axis 102 (in the middle of the panel) of 2-D Fresnel reflector mirror array assembly configuration, the Y-axis 102 of the assembly plane is titled by an angle equal to the latitude angle 108 of the location (e.g., the latitude angle for San Francisco, CA is about 37 degrees). To maintain the incoming and reflected beams of the sunlight and normal line of the assembly plane always in the same plane, i.e. the sun beam plane, which is parallel to Z-Y-plane (perpendicular to the mirror rotation axis), the panel frame 150 is rotated along Y-axis 102 during a day continuously by the sun hour angle at a constant angular speed (e.g., 15 degrees/hour).

[0035] During the year, if the sun at a position so that its beam form a declination angle with the normal plane perpendicular to the Y-axis 102, all M rotational column axes (parallel to X-axis) will be rotated by approximately half of the declination angle (in addition to their initial angles), to maintain an approximate focus on the receiver 125. Although during this rotation, there could be de-focus effect among all mirrors, with proper design (e.g. keeping the receiver 125 high relative to the width (dimension of x) of the panel frame 150, and large receiver aperture), this effect can be kept relatively small to obtain a relatively high value of concentration much higher than that of 1 -D system with similar optics (flat mirrors). As a result, this implementation of the solar collector 100 (a Modular Heliostat) only requires at most 2 moving axes (and motors) to track the sun movement; one motor to track the seasonal declination of the sun (by rotating all mirror axes together through certain mechanical linkage mechanism)), and one motor to track the daily sun hour angle (e.g., at a rate of 15 degrees/hour). Typically, axis 102 and paper plane can be used to define a plane of sunlight on a vernal equinox (i.e., March 22) or autumnal equinox (i.e., September 22).

[0036] Using vector calculation, we may obtain an exemplary formula for the de- focusing effect as following:

[0037] For a mirror at (x, y) position from the center (0, 0) where the target is directly located above the panel plane at height H, if declination angle is δ, the focus errors (deviations from the target center) in x and y directions are:

Nozcos δ/2)]

NozCθs£/2)]

12 + Nozcos δ 12)] J

Where

[0038] Computing components (see below) can include control software to manage automated rotation of the axes 106 and 102, as set forth elsewhere herein.

[0039] Fig. 3 is a schematic diagram illustrating one exemplary implementation showing a top view of a panel 200 including an array of mirrors (e.g., mirrors 201 ) or other reflective elements. The panel 200 has an elongated shape such that a length of a center column (Y-axis) is greater than a width of a center row (X-axis). Furthermore, corners (e.g., corner 205) have been eliminated to remove mirrors that have larger focus errors, as described more fully below. Consequentially, the panel 200 has a higher concentration ratio. Each row of panel 200 is labeled with a common number, while each column is labeled with a common letter. Panel 200 is merely an example implementation as one of ordinary skill in the art would readily recognize variations within the scope of the present invention (e.g., the dimensions and shape). For example, an oval shaped frame and assembly can also be used to achieve high concentration ratio.

[0040] Fig. 4 is a table 300 showing exemplary focus errors calculated for the panel 200 of Fig. 2, consistent with one or more aspects of the innovations herein. More specifically, the number and letter combination for each point on the table 300 maps to an individual mirror of the panel 200 of Fig. 3. Based on the calculations, an exemplary/desired panel may be designed with 300 mirrors each with a dimension of 100mm by 100mm, and a target dimension of x =180mm and y = 150mm. Such an exemplary configuration has a concentration ratio of about 110.

[0041] In one exemplary configuration, the solar collector 100 may include a metal made liquid container as a thermal receiver with incoming (lower) and outgoing (higher) connection pipes. A metal surface is preferably coated with selective coating that will effectively absorb most solar energy, but less effective to emission with infra-red wavelength corresponding to the temperature of the receiver body to reduce the thermal loss. In another implementation, the receiver can be a Sterling Engine. Optical elements are silvered flat glass mirrors with a typical dimension of 10x10cm. To accommodate the panel tracking, a small section of flexible tubing, or a sealed joint, is needed at the end of Y rotational axis. A thermal liquid can be either water or other thermal energy transfer media. A liquid storage tank (not shown) is equipped with capability to maintain the liquid level at the height of middle of the solar container during the seasonal tracking. With the solar heating, the liquid will be heated up and go through the piping to the central heat exchange station to generate high pressure steam for generation of electricity by conventional Turbine-electric generator, or Sterling Engine.

[0042] FIG. 5 is a flow diagram illustrating an exemplary method of collecting solar energy consistent with aspects of the innovations herein. In one exemplary implementation, there is provided a method for collecting energy that may include collecting solar energy 510 with a receiver receiving light from a panel that reflects solar energy towards the receiver, performing a first (e.g., temporal, etc.) rotation 520 such as rotating the panel around a first axis to a first angle to maintain exposure of the array of reflective optics/receiver to a radiation source, and performing a second (e.g., seasonal, etc.) rotation 530 such as rotating the rows of reflective optics around a plurality of second axes perpendicular to the first axis to a second angle to maintain exposure of the array/optics to the radiation source.

[0043] FIG. 6 is a flow diagram illustrating an exemplary method of collecting solar energy consistent with aspects of the innovations herein. As set forth in the illustration of FIG. 6, an exemplary method may include rotating the panel or a frame of the panel at an angle selected as a function of the hourly position of the sun or radiation source 610. For example, the panel may be rotated at a first angle that is approximately equal to an hour angle of the sun. Further, the method may then include rotating rows of the reflective optics as a function of the seasonal position of the sun or radiation source 620. For example, the rows may be rotated along second rotational axes oriented with a rotational angle defined as about zero at the position where sunlight at solar noon (when an hour angle is zero in an equinox day, when declination angle is about zero) is focused by all reflective optics with their initial angle orientation onto the receiver.

[0044] According to one illustrative implementation, a method of collecting thermal energy may comprise collecting solar energy with an optical collector panel that comprises an array of reflective optics that redirects solar energy towards the receiver, rotating the frame of the panel around a first axis to a first angle to maintain exposure of the array of reflective optics and receiver to a radiation source, and rotating the rows of reflective optics around a plurality of second axes perpendicular to the first axis to a second angle to maintain exposure of the array of reflective optics and receiver to the source. Moreover, the method may include using an array of optics having optics that are placed in a Fresnel arrangement. Other exemplary implementations may include a first mechanical driving mechanism that controls rotation of the panel or a frame of the panel and/or second/other mechanical driving mechanism(s) to control rotation of the rows of reflective optics.

[0045] In another exemplary implementation, the first rotational axis may be oriented in a south-north direction with a tilt angle relative to a horizontal plane of the earth equal to a local latitude angle, such that the first rotational axis is oriented parallel to the earth self-rotational axis, the fist rotation angle is defined to be zero at the position where the panel frame plane is normal to sunlight at solar noon when an hour angle is about zero in an equinox day when the declination angle is about zero.

[0046] In further exemplary implementations, the receiver may be approximately centered and above (relative to) the panel, face down perpendicularly, with each mirror in the array being mounted on and configured for rotation at a plurality of second rotational axes that are perpendicular to the first axis. Each mirror may also, for example, be supported by a pivotal support on the panel frame. Further, each mirror may be individually oriented by an initial angle to focus reflected light onto the receiver when their corresponding second rotational axes are oriented with a rotational angle defined as about zero at the position where sunlight at solar noon, when an hour angle is zero in an equinox day when declination angle is about zero, is focused by all reflective optics with their initial angle orientation onto the receiver. Moreover, in exemplary methods, the first angle may be approximately equal to an hour angle of the sun, and/or the second angle may be approximately equal to the half of a declination angle of the sun.

[0047] With regard to additional features of the collectors, the reflective optics may comprise one or more mirrors, such as one or more flat mirrors, one or more parabolic mirrors, one or more concave mirrors. Further, the receiver may be a cavity formed by spiral metal tubing with heat transfer fluid conducting the thermal energy out of the receiver, or the receiver may be a Sterling Engine. Moreover, according to some implementations, the panel may be configured as an oblong shape such that a length of a center column is greater than a width of a center row to increase the concentration ratio of reflected solar energy. Finally, the receiver may be centered relative to the panel and the panel may be formed (e.g., with diagonal corners, etc.) such that a predetermined number of mirrors having the greatest distance from the center are eliminated to increase the concentration ratio of reflected solar energy.

[0048] Turning back to FIG. 1 , the computing component, system or environment 180, computer-readable media, and/or other computer-processing realizations may be implemented in a variety of configurations to realize the methods and/or innovations herein. In this regard, FIG. 7 illustrates one exemplary computing component/system 800 that is configurable consistent with aspects of the present innovations, although this representative diagram is only one example of suitable computing component, and the features, functionality and use of the innovations herein are not limited to any one such representation. With reference to FIG. 7, an exemplary system for implementing the invention includes a computing device, such as computing component 800. In one exemplary implementation, computing component 800 may include one or more processing units 802 and memory 804. Depending on the exact configuration and type of computing device, memory 804 may be volatile (such as RAM), non-volatile (such as ROM, flash memory, etc.) or some combination of the two. Additionally, component 800 may also have additional features/functionality, such as additional storage (removable and/or non-removable) including, but not limited to, the media types set forth below. Such additional storage is illustrated in FIG. 7 by removable data store(s) 808 and nonremovable data store(s) 809. Computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Memory 804, removable storage 808 and non-removable storage 809 are all examples of computer storage media. Exemplary computer storage media is set forth below. Any such computer storage media may be part of component 800. Component 800 may also contain communications connection(s) 112 that allow the component to communicate with other devices.

[0049] Figures 8 and 9 are diagrams illustrating additional exemplary solar collectors, consistent with aspects related to the innovations herein. The solar collectors of FIGs. 8 and 9 show exemplary configurations of photovoltaic (PV) receiver/cell implementations, which may be used in modular heliostat schemes with polar tracking features. For example, the y-axis of the receiver panels 810, 910 may be provided a polar/polaris aim and tilted by a latitude angle 840, 940. Accordingly, during daylight hours, the y-axis may be rotated as a function of hour angle 850, 950, i.e., at a constant angular speed of 15 degree/hour to a position from solar noon, for example, to track the sun movement so that the sunbeam plane is always normal to the panel and parallel to the y-axis. Throughout the year, then, the axes of all the rows 820, 920 of optics (i.e., rows/axes parallel to the x- axis) may be rotated at a solar declination angle 860, 960 away from the position of equinox (e.g., declination angle=0; sunbeam normal to the panel plane), to maintain the sunbeam normal to the optical aperture of all optics 830, 930. In FIG. 8, the exemplary optics 830 may be concentrator optics, in which the focal point is located at the center bottom. Further, photovoltaic cells 835 may be located at the focal points of the optics and metal fins (not shown) may also be attached to the back of the cells for cooling. The exemplary optics 930 illustrated in FIG. 9 are concentrator optics, in which the focal point is located at the center top. Further, photovoltaic cells 935 may be located at the focal points of the optics. Moreover, in some implementations, heat pipes may be arranged supporting and having good thermal contact with each cell, and including option features such as distal ends that are attached with good thermal contact to metal fins (not shown) for cooling, wherein the metal fins may be coupled to/supported by the rotating rows 820, 920. [0050] Implementations of exemplary photovoltaic cell/receiver systems with polar tracking features may be configured using panels of 2-dimensional arrays (MxN) of optical elements, with each optical element being associated with a photovoltaic cell (PV). In these implementations, such distributed configurations of solar PV cells impart innovations related to aspects of the solar cells being more easily cooled, especially as compared against centralized configurations in , e.g., some solar thermal collectors. Structurally, in the exemplary implementations of FIGs. 8 and 9, the panel frames 810, 910 may be supported by two pivotal (e.g., bearing-type) supports, which may be fixed along a y-axis. Further, exemplary implementations may have M rows 820, 920 of optical elements in a panel, wherein each row may be supported by a pivotal (e.g. bearing-type) support, with the pivotal supports being fixed along the y-axis and/or panel frame. As such, innovative implementations are configured such that all rows may be rotated by a same angle and driven by one motor with proper linkage to the axes of all other rows.

[0051] Figure 8 is a diagram illustrating an exemplary solar collector, which may be associated with solar collection and/or energy/thermal generation systems, consistent with aspects related to the innovations herein. FIG. 8 depicts one non-limiting, exemplary configuration in which concentrator optics comprise 2-dimensional compound parabolic concentrator, with the focal point located at the center bottom. Photovoltaic cells are located at the focal points of the optics and metal fins (not shown) may be attached to the back of the cells for cooling.

[0052] Figure 9 is a diagram illustrating an exemplary solar collector, which may be associated with solar collection and/or energy/thermal generation systems consistent with aspects related to the innovations herein. FIG. 9 depicts another non-limiting, exemplary configuration in which concentrator optics comprise 2-dimensional parabolic reflectors (curved mirrors), with the focal point located at the center top. Further, photovoltaic cells may also, optionally, be located at the focal points of the optics. [0053] With regard to computing components and software embodying the inventions herein, such as the tracking and collection methods, the innovations herein may be implemented/operated consistent with numerous general purpose or special purpose computing system environments or configurations. Various exemplary computing systems, environments, and/or configurations that may be suitable for use with the innovations herein may include, but are not limited to, personal computers, servers or server computing devices such as routing/connectivity components, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, smart phones, consumer electronic devices, network PCs, other existing computer platforms, distributed computing environments that include one or more of the above systems or devices, etc.

[0054] The invention may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer, computing component, etc. In general, program modules may include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices.

[0055] Computing component 800 may also include one or more type of computer readable media. Computer readable media can be any available media that is resident on, associable with, or can be accessed by computing component 800. By way of example, and not limitation, computer readable media may comprise computer storage media and communication media. Computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD- ROM, digital versatile disks (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and can accessed by computing component 800. Communication media may comprise computer readable instructions, data structures, program modules or other data embodying the functionality herein. Further, communication media may include wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. Combinations of the any of the above are also included within the scope of computer readable media.

[0056] In the present description, the terms component, module, device, etc. may refer to any type of logical or functional process or blocks that may be implemented in a variety of ways. For example, the functions of various blocks can be combined with one another into any other number of modules. Each module can be implemented as a software program stored on a tangible memory (e.g., random access memory, read only memory, CD-ROM memory, hard disk drive) to be read by a central processing unit to implement the functions of the innovations herein. Or, the modules can comprise programming instructions transmitted to a general purpose computer or to processing/graphics hardware via a transmission carrier wave. Also, the modules can be implemented as hardware logic circuitry implementing the functions encompassed by the innovations herein. Finally, the modules can be implemented using special purpose instructions (SIMD instructions), field programmable logic arrays or any mix thereof which provides the desired level performance and cost.

[0057] As disclosed herein, implementations and features of the invention may be implemented through computer-hardware, software and/or firmware. For example, the systems and methods disclosed herein may be embodied in various forms including, for example, a data processor, such as a computer that also includes a database, digital electronic circuitry, firmware, software, or in combinations of them. Further, while some of the disclosed implementations describe components such as software, systems and methods consistent with the innovations herein may be implemented with any combination of hardware, software and/or firmware. Moreover, the above-noted features and other aspects and principles of the innovations herein may be implemented in various environments. Such environments and related applications may be specially constructed for performing the various processes and operations according to the invention or they may include a general-purpose computer or computing platform selectively activated or reconfigured by code to provide the necessary functionality. The processes disclosed herein are not inherently related to any particular computer, network, architecture, environment, or other apparatus, and may be implemented by a suitable combination of hardware, software, and/or firmware. For example, various general-purpose machines may be used with programs written in accordance with teachings of the invention, or it may be more convenient to construct a specialized apparatus or system to perform the required methods and techniques.

[0058] Aspects of the method and system described herein, such as the logic, may be implemented as functionality programmed into any of a variety of circuitry, including programmable logic devices ("PLDs"), such as field programmable gate arrays ("FPGAs"), programmable array logic ("PAL") devices, electrically programmable logic and memory devices and standard cell-based devices, as well as application specific integrated circuits. Some other possibilities for implementing aspects include: memory devices, microcontrollers with memory (such as EEPROM), embedded microprocessors, firmware, software, etc. Furthermore, aspects may be embodied in microprocessors having software-based circuit emulation, discrete logic (sequential and combinatorial), custom devices, fuzzy (neural) logic, quantum devices, and hybrids of any of the above device types. The underlying device technologies may be provided in a variety of component types, e.g., metal-oxide semiconductor field-effect transistor ("MOSFET") technologies like complementary metal-oxide semiconductor ("CMOS"), bipolar technologies like emitter-coupled logic ("ECL"), polymer technologies (e.g., silicon-conjugated polymer and metal-conjugated polymer-metal structures), mixed analog and digital, and so on.

[0059] It should also be noted that the various logic and/or functions disclosed herein may be enabled using any number of combinations of hardware, firmware, and/or as data and/or instructions embodied in various machine-readable or computer-readable media, in terms of their behavioral, register transfer, logic component, and/or other characteristics. Computer-readable media in which such formatted data and/or instructions may be embodied include, but are not limited to, non-volatile storage media in various forms (e.g., optical, magnetic or semiconductor storage media) and carrier waves that may be used to transfer such formatted data and/or instructions through wireless, optical, or wired signaling media or any combination thereof. Examples of transfers of such formatted data and/or instructions by carrier waves include, but are not limited to, transfers (uploads, downloads, e-mail, etc.) over the Internet and/or other computer networks via one or more data transfer protocols (e.g., HTTP, FTP, SMTP, and so on).

[0060] Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise," "comprising," and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in a sense of "including, but not limited to." Words using the singular or plural number also include the plural or singular number respectively. Additionally, the words "herein," "hereunder," "above," "below," and words of similar import refer to this application as a whole and not to any particular portions of this application. When the word "or" is used in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list and any combination of the items in the list.

[0061] Although certain presently preferred implementations of the invention have been specifically described herein, it will be apparent to those skilled in the art to which the invention pertains that variations and modifications of the various implementations shown and described herein may be made without departing from the spirit and scope of the invention. Accordingly, it is intended that the invention be limited only to the extent required by the appended claims and the applicable rules of law.

Claims

Claims:

1. A method of collecting energy, the method comprising: collecting solar energy with an optical collector panel that comprises an array of optics that redirects solar energy towards at least one receiver/collector; rotating the panel around a first axis to a first angular position(s) to maintain exposure of the array/optics to a radiation source; and rotating rows of the optics around a plurality of second axes to a second angular position(s) to maintain exposure to the radiation source.

2. A method of collecting energy, the method comprising: collecting solar energy with an optical collector panel that comprises an array of reflective optics that redirects solar energy towards a receiver; rotating a frame of the panel around a first axis to a first angle to maintain exposure of the array of reflective optics and receiver to a radiation source, rotating the rows of reflective optics around a plurality of second axes perpendicular to the first axis to a second angle to maintain exposure of the array of reflective optics to the radiation source.

3. The method of claim 2 wherein the array of reflective optics includes a Fresnel arrangement.

4. The method of claim 2, wherein a first mechanical driving mechanism controls rotation of the frame of the panel, and a second mechanical driving mechanism controls rotation of the rows of reflective optics.

5. The method of claim 2, wherein the first rotational axis is oriented south- north direction with a tilt angle relative to a horizontal plane of the earth equal to a local latitude angle, such that the first rotational axis is oriented parallel to the earth self- rotational axis, the fist rotation angle is defined to be zero at the position when the panel frame plane is normal to sunlight at solar noon when an hour angle is about zero in an equinox day when a declination angle is about zero.

6. The method of claim 2, wherein the receiver is centered and above relative to the panel face down perpendicularly, each mirror in the array is mounted on a plurality of second rotational axes that is perpendicular to the first axis and supported by pivotal support on the panel frame, each mirror is individually oriented by an initial angle to focus reflected light on the receiver when their corresponding second rotational axes are oriented with a rotational angle which is defined as approximately zero at the position when sunlight at solar noon when an hour angle is zero in an equinox day when declination angle is approximately zero is focused by all reflective optics with their initial angle orientation onto the receiver.

7. The method of claim 2, wherein the first angle is approximately equal to an hour angle of the sun.

8. The method of claim 2, wherein the second angle is approximately equal to the half of a declination angle of the sun.

9. The method of claim 2, wherein each of the reflective optics comprises a flat mirror.

10. The method of claim 2, wherein each of the reflective optics comprises a parabolic mirror.

11. The method of claim 2, wherein each of the reflective optics comprises a concave mirror.

12. The method of claim 2, wherein each of the reflective optics comprises mirrors.

13. The method of claim 2, wherein the receiver is a cavity formed by spiral metal tubing with heat transfer fluid conducting the thermal energy out of the receiver.

14. The method of claim 2, wherein the receiver is a Sterling Engine.

15. The method of claim 2, wherein the panel forms an oblong shape such that a length of a center column is greater than a width of a center row to increase the concentration ratio of reflected solar energy.

16. The method of claim 2, wherein the receiver is centered relative to the panel and the panel forms diagonal corners such that a predetermined number of mirrors having the greatest distance from and the center are eliminated to increase the concentration ratio of reflected solar energy.

17. A solar collector comprising: a receiver to collect solar energy with by receiving light from a panel that reflects solar energy towards a receiver, the panel comprising an array of reflective optics; wherein the frame of the panel rotates around a first axis to a first angle to maintain exposure of the array of reflective optics and receiver to a radiation source; and wherein rows of reflective optics rotate around a plurality of second axes perpendicular to the first axis to second angular position(s) to maintain exposure of the array of reflective optics and receiver to the radiation source.

18. The solar collector of claim 17, wherein the array of reflective optics comprises optics in a Fresnel arrangement.

19. The solar collector of claim 17, wherein a first mechanical driving mechanism controls rotation of the frame of the panel, and a second mechanical driving mechanism controls rotation of the rows of reflective optics.

20. The solar collector of claim 17, wherein the first rotational axis is oriented south-north direction with a tilt angle relative to a horizontal plane of the earth equal to a local latitude angle, such that the first rotational axis is oriented parallel to the earth self- rotational axis, the fist rotation angle is defined to be zero at the position when the panel frame plane is normal to sunlight at solar noon when an hour angle is zero in an equinox day when a declination angle is approximately zero.

21. The solar collector of claim 17, wherein the receiver is centered and above relative to the panel face down perpendicularly, each mirror in the array is mounted on a plurality of second rotational axes that is perpendicular to the first axis and supported by pivotal support on the panel frame, each mirror is individually oriented by an initial angle to focus reflected light on the receiver when their corresponding second rotational axes are oriented with a rotational angle which is defined as approximately zero at the position when sunlight at solar noon when an hour angle is zero in an equinox day when declination angle is approximately zero is focused by all reflective optics with their initial angle orientation onto the receiver.

22. The solar collector of claim 17, wherein the first angle is approximately equal to an hour angle of the sun.

23. The solar collector of claim 17, wherein the second angle is approximately equal to the half of a declination angle of the sun.

24. The solar collector of claim 17, wherein each of the reflective optics comprises a flat mirror.

25. The solar collector of claim 17, wherein each of the reflective optics comprises a parabolic mirror.

26. The solar collector of claim 17, wherein each of the reflective optics comprises a concave mirror.

27. The solar collector of claim 17, wherein each of the reflective optics comprises mirrors.

28. The solar collector of claim 17, wherein the receiver is a cavity formed by spiral metal tubing with heat transfer fluid conducting the thermal energy out of the receiver.

29. The solar collector of claim 17, wherein the receiver is a Sterling Engine.

30. The solar collector of claim 17, wherein the panel forms an oblong shape such that a length of a center column is greater than a width of a center row to increase the concentration ratio of reflected solar energy.

31. The solar collector of claim 17, wherein the receiver is centered relative to the panel and the panel forms diagonal corners such that a predetermined number of mirrors having the greatest distance from and the center are eliminated to increase the concentration ratio of reflected solar energy.

32. A solar collector comprising: a receiver to collect solar energy with by receiving light from a panel that reflects solar energy towards a receiver, the panel comprising a frame having an array of reflective optics; wherein the frame of the panel is configured to rotate around a first axis to first angular position(s) to maintain exposure of the array of reflective optics/receiver to a radiation source; and wherein rows of reflective optics are configured to rotate around a plurality of second axes perpendicular to the first axis to second angular position(s) to maintain exposure of the array of reflective optics/receiver to the radiation source.

33. A solar collector comprising: a receiver to collect solar energy with by receiving light from a panel that reflects solar energy towards the receiver, the panel comprising a frame having an array of reflective optics; wherein the frame of the panel rotates around a first axis to a first angle to maintain the array of reflective optics and the receiver in a position that provides maximal exposure to a radiation source; and wherein rows of reflective optics rotate around a plurality of second axes perpendicular to the first axis to second angular position(s) to maintain exposure of the array of reflective optics/receiver to the radiation source.

34. The collector of claim 33 wherein the position is normal or about normal to the radiation source.

35. A solar collector comprising: a panel comprising an array of optics arranged in rows of optics that direct solar energy from a radiation source towards one or more receivers/collectors; a first support for the panel having first rotation structure configured to rotate the panel around a first axis to first angular position(s) to maintain exposure of the array of optics the radiation source; and second support for the rows having second rotation structure configured to rotate the rows around a plurality of second axes perpendicular to the first axis to second angular position(s) to maintain exposure of the optics to the radiation source.

36. A solar collector comprising: a panel comprising an array of optics arranged in rows of optics that collect solar energy from a radiation source, wherein the optics comprise parabolic concentrators that direct solar energy towards one or more photovoltaic cells; first support structure for the panel having first rotation structure configured to rotate the panel around a first axis to first angular position(s) to maintain exposure of the optics to the radiation source; and second support structure for the rows having second rotation structure configured to rotate the rows around a plurality of second axes perpendicular to the first axis to second angular position(s) to maintain exposure of the optics to the radiation source.

37. The collector of claim 36 wherein the parabolic concentrators are compound parabolic concentrators.

38. The collector of claim 36 wherein the parabolic concentrators are 2- dimensional parabolic concentrators

39. The collector of claim 36 wherein the parabolic concentrators are 2- dimensional compound parabolic concentrators

40. A solar collector comprising: a panel comprising an array of optics arranged in rows of optics that collect solar energy from a radiation source, wherein the optics comprise parabolic reflectors that direct solar energy towards one or more photovoltaic cells; first support structure for the panel having first rotation structure configured to rotate the panel around a first axis to first angular position(s) to maintain exposure of the optics to the radiation source; and second support structure for the rows having second rotation structure configured to rotate the rows around a plurality of second axes perpendicular to the first axis to second angular position(s) to maintain exposure of the optics to the radiation source.

41. The collector of claim 40 wherein the parabolic reflectors are square shaped parabolic reflectors.

42. A solar collector comprising: a receiver to collect solar energy with by receiving light from a panel that directs solar energy towards one or more collectors, the panel includes an array of optics comprising parabolic concentrators that direct solar energy towards photovoltaic cells; wherein the frame of the panel rotates around a first axis to a first angle to maintain exposure of the array of optics and receiver to a radiation source; and wherein rows of reflective optics rotate around a plurality of second axes perpendicular to the first axis to second angular position(s) to maintain exposure of the optics/receiver to the radiation source.

43. A system comprising: a solar collector, including a panel and an array of optics arranged in rows, according to any of claims 17 through 42; and a computing component configured to process instructions to control movement of the solar collector, wherein the instructions include instructions consistent with one or more features recited in any of claims 1 through 16.

44. At least one computer readable medium containing or configured to execute computer-readable instructions for controlling movement of a solar collector, the computer-readable instructions comprising instructions for: processing information or performing actions consistent with one or more steps or features recited in any of claims 1 through 16.