Patent Application
20190013776
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The present invention generally relates to a solar concentrator. In particular, the present invention relates to a low-cost system that can be dimensioned to supply energy to a household. Being tracked by actuators or sensors, the rays of the sun are redirected by reflectors and collected by a solar panel. The solar light collected by the solar panel is converted into electrical power, which can be used for heating or for supplying electricity to a building or adjacent real estate unit. In the case of relatively small real estate, a self-supplying household may be taken off the electrical supply grid, contributing both to the household finances and to environmental conservation.
With the worldwide population growing steadily, demand for energy scales up. This intensifying demand takes place in a time when traditional sources of energy face particular pressure due to the scarcity of resources as well as stronger calls by customers and households for energy sources that minimize the negative environmental impact. To cope with this conundrum, solar energy constitutes an attractive and reliable alternative based on a readily available energy source—solar light. In this context, there is a need for a better use of solar energy, more specifically for means that provide a more efficient concentration of solar radiation and its conversion at low costs. In addition, by dispensing with distribution costs, means for local concentration and conversion of solar energy reduce overall costs and make solar power more affordable for households and other small units of real estate owners.
Over the years, solar energy research has helped develop systems that have improved efficiency and are more economical. However, a dearth of information, materials, complexity, and manufacturing skills remain an impediment to large-scale production and utilization of this abundantly available energy source for household supply. Due to lack of economic incentives and technical means, access to this technology is particularly difficult in some rural regions of developing countries. One way of overcoming obstacles related to lack of technical knowledge involves reducing the number of complex manipulations or maintenance operations by users.
The typical solar concentrators can be classified according to several aspects. The ones relevant for the purpose of the present description are the kind of focusing employed (point, line or area), positional adjustability of the reflectors involved in the concentration process (fixed or tracking devices) and characteristics of the conversion systems—solar panels, heat absorbers, or both.
Compared to non-concentrating solar energy conversion systems, the sunlight concentrated toward a photovoltaic solar panel is magnified. As a result, on the one hand, solar energy concentrator systems benefit more than non-concentrating solar energy systems from using relatively more performing solar panels. Efficiency improvements are fast in the field of photovoltaic solar cells, and solar energy concentrator systems thus benefit particularly from an easy upgrade to a more efficient solar panel. On the other hand, more heat is gathered at the target area of a concentrator system than in a non-concentrating solar energy system. Heat negatively affects the efficiency of photovoltaic solar panels, entailing that efficient heat transfer or cooling systems have a special importance in solar energy concentrator systems that rely on photovoltaic solar panels as their receivers.
Several examples of solar energy concentrators are found in the prior art. These apparatuses feature several inconveniences, such as complexity and cost. Furthermore, many of those designs do not easily lend themselves to installation in the scale contemplated for supplying a household. For example, the structural weight and design of even a small-sized, movable dish reflector complicates its deployment atop a house roof, in addition to making it vulnerable to wind damage. Sidestepping these problems by reducing the scale of the dish reflector seriously limits the amount of energy this kind of concentrator may yield.
Based on the end application, different types of solar concentrators are employed to achieve optimum results. In the specific scope of the present invention—continual collection of concentrated solar radiation reflected to a focal area in order to generate energy for supplying a standard household or small real estate unit—the performance of state of the art solar concentrators is suboptimal, or the system is too expensive or complex for use by a standard household or in a small real estate unit.
Line focus systems of solar energy concentration, as in U.S. Pat. No. 5,374,317 (Lamb et al.) or U.S. Pat. No. 4,065,053 (Fletcher), typically perform less in concentrating solar radiation than area or point focus. Moreover, line focus systems tend to be bulky. The size and shape of these bulky systems entail higher manufacturing costs (for materials) and require a larger area for their installation. These characteristics make line focus systems rather inadequate for implementation for a standard household or small real estate unit. Conversely, point focus, as in U.S. Patent Publication No. US20110088684 A1 (Tuli) and others, typically requires multiple sets of concentrating reflectors. A substantially high degree of precision is thus required, both in terms of mechanical adjustments of the reflectors and in terms of data analysis and predictions.
For instance, as in U.S. Pat. No. 6,530,369 (Yogev et al.), concentrators comprising a central receiver tower are typically employed in large scale applications for electricity generation. These embodiments require vast real-estate for proper deployment and are thus not economical or convenient for small- and medium-scale applications. Parabolic dish concentrators with continuous surfaces, as in U.S. Pat. No. 7,435,898 (Shifman), entail limitations such as the prohibitive manufacturing costs associated with compound and complex reflector curves as well as expensive mirror substrates.
Most prior art applications of solar energy concentrators involve a primary concentrating reflector that is movable, as can be found in U.S. Pat. No. 8,471,187 (Kinley). In addition to cost issues and physical vulnerabilities inherent to a movable primary concentrating reflector, the moving components need to each be associated with a tracking system and a moving mechanism for the moving feature to improve the system's performance. When integrated to the primary concentrating reflector, these requirements and the associated costs and vulnerabilities are multiplied because primary concentrating reflectors are typically made of numerous parts.
In U.S. Patent Publication No. US20110088684 A1 (Tuli) by the same inventor, a solar energy concentrator is disclosed whereby rays of the sun are reflected and concentrated to a heat absorber by a combination of a fixed primary concentrating reflector and a movable secondary redirecting reflector. The secondary redirecting reflector is ball-pivotally connected to an elongated arm that is itself ball-pivotally connected to a stationary surface. Alternatively, there is no secondary redirecting reflector, and the heat absorber is connected at the distal end of the elongated arm. Unlike in the present invention, this system uses a heat absorber instead of a solar panel. The solar energy concentrator disclosed therein includes several physical components that potentially block the solar radiation reflected by the primary concentrating reflector before it can be collected by the receiver. Moreover, the supporting components are in itself vulnerable to wear and tear, wind and other weather conditions, thus necessitating a suboptimal retraction of the elongated arm to prevent damages to the structural integrity of the elongated arm when wind conditions are threatening. The elongated arm can also be vulnerable when the position of the sun requires the elongated arm to be sharply inclined in order to receive solar radiation redirected by the primary concentrating reflector.
There is accordingly a need for an improved solar concentrating system that overcomes the limitations associated with using complex or suboptimal structures or assemblies that require a high degree of skills. Moreover, there is a need for an improved solar concentrating system wherein the costs associated with manufacture and deployment, which are prohibitive with respect to traditional solar concentrating systems, are minimized so that it is affordable and attractive for use by small- and medium-scale household use.
It is therefore an object of the present invention to disclose a small- or medium-scale, dimensionally-adaptable solar concentrator system featuring high energy conversion efficiency, providing area focus with low building and operational costs.
According to a certain aspect of the present invention, there is disclosed a solar energy concentrator comprising a concentrating reflector, a solar panel, a repositioning mechanism that guides the positioning of the solar panel and a mechanical structure that supports the repositioning mechanism and solar panel. The concentrating reflector is made of multiple reflecting surfaces that are stationary with respect to earth and laid over a two-dimensional flat plane surface, all of said multiple reflecting surfaces cooperating to redirect the incident solar radiation toward a small target area. Since the reflecting surfaces are stationary, the target area continually changes position based on daily and seasonal solar movement. Supported by the apparatus' mechanical structure and guided by the repositioning mechanism, the solar panel is continually positioned near the target area to receive the light redirected by the concentrating reflector, thereby collecting concentrated solar radiation and converting it into electricity.
The repositioning mechanism mainly consists of a lateral arm, to which the solar panel is attached. The solar panel is installed and connected to the lateral arm in a way that allows its rotation. A system of belts and pulleys inside the lateral arm, or a similar mechanism as can be known in the art, can be activated to move the solar panel along the lateral arm. The range of this movement depends on the particular mechanical structure used to support the repositioning mechanism.
In an exemplary embodiment, the mechanical structure consists of a single vertical arm, preferably embedded at the center of the plane surface of the concentrating reflector. The lateral arm is connected to the vertical arm, near the top of the vertical arm. The solar panel is attached to one side of the lateral arm, and a counterweight can be placed on the other side of the lateral arm to keep the lateral arm perpendicular to the vertical arm. The lateral arm is built and installed in a way that allows its rotation around the vertical arm. The solar panel can be moved along the lateral arm in a range that extends from the middle of the lateral arm to the end of the lateral arm that is opposite to the counterweight, if a counterweight is installed. A slot can be cut in the solar panel so that the solar panel slides around the exterior surface of the vertical arm and reaches the middle of the lateral arm to receive solar radiation redirected near the vertical arm. With the rotation of the lateral arm and the movements of the solar panel along the lateral arm, the repositioning mechanism is capable of continually maintaining the solar panel as close as possible to the target area by tracking the locations of the target area while moving the solar panel two-dimensionally.
In a first alternate embodiment, the mechanical structure consists of a single vertical arm similar to the exemplary embodiment preferably embedded at the center of the plane surface of the concentrating reflector. However, a portion of the vertical arm is divided into two side branches forming a squared jaw. The lateral arm is connected to the vertical arm, near the top of the vertical arm. The solar panel is attached to one side of the lateral arm, and a counterweight can be placed on the other side of the lateral arm to keep the lateral arm perpendicular to the vertical arm. The lateral arm is built and installed in a way that allows its rotation around the vertical arm. The solar panel can be moved along the lateral arm in a range that extends from the middle of the lateral arm to the end of the lateral arm that is opposite to the counterweight, if a counterweight is installed. To reach the middle of the lateral arm and receive solar radiation redirected near the vertical arm, the solar panel is simply moved through the gap formed by the side branches. With the rotation of the lateral arm and the movements of the solar panel along the lateral arm, the repositioning mechanism is capable of continually maintaining the solar panel as close as possible to the target area by tracking the locations of the target area while moving the solar panel two-dimensionally.
In a second alternate embodiment, the mechanical structure consists of at least two vertical side beams and one horizontal top beam. When there are only two, the side beams are preferably erected at two opposite corners of the stationary plane of the concentrating reflector. The two side beams support both ends of the top beam, which passes through, or close to, the center vertical axis of the concentrating reflector. Positioned below the top beam, the lateral arm is linked to the middle, or close to the middle, of the top beam by a connecting arm. The solar panel is attached to one side of the lateral arm, and a counterweight can be placed on the other side of the lateral arm to keep the lateral arm perpendicular to the side beams. The lateral arm is built and installed in a way that allows its rotation around the connecting arm. The solar panel can be moved along the lateral arm in a range that extends from the middle of the lateral arm to the end of the lateral arm that is opposite to the counterweight, if a counterweight is installed. With the rotation of the lateral arm and the movements of the solar panel along the lateral arm, the repositioning mechanism is capable of continually maintaining the solar panel as close as possible to the target area by tracking the locations of the target area while moving the solar panel two-dimensionally.
In a third alternate embodiment, a prism structure is erected on the stationary plane of the concentrating reflector. The prism structure is constituted of at least four vertical prism beams. Lateral prism beams connect the vertical prism beams together, preferably at their top ends. The lateral arm is connected to any two lateral prism beams facing each other, and a motorized system inside the two lateral prism beams that are connected to the lateral arm allows the lateral arm to be moved along the entire lengths of those two lateral prism beams. The solar panel is attached to the lateral arm, and it can be moved along the entire length of the lateral arm. With the movements of the lateral arm along the two lateral prism beams to which it is connected and the movements of the solar panel along the lateral arm, the mechanical structure and the repositioning mechanism are capable of continually maintaining the solar panel as close as possible to the target area by tracking the locations of the target area while moving the solar panel two-dimensionally.
To receive solar radiation in a more perpendicular angle, the solar panel can be tilted, and its surface can be mechanically or electronically adjusted to become flat, curved in a concave shape or curved in a convex shape. In addition to those adjustments, the lateral arm can be slightly curved to allow the solar panel to receive solar radiation in a more perpendicular angle. A mirror reflector can be fastened against the solar panel in order to divert toward the solar panel some of the solar radiation, if any, that is redirected from the concentrating reflector and whose trajectory does not meet the space covered by the solar panel. In a preferred embodiment, the solar panel is oval in shape. When in operation, the invention's various mechanisms can be mechanically or electronically controlled by a digital control system, which can be connected to optical sensors. The digital control system can collect feedback data from the sensors and adjust optimally the invention's various mechanisms based on the collected data.
According to an additional embodiment, the solar panel is covered with a filter, such as an optical filter, that does not prevent the passage of parts of solar radiation that can be absorbed by the solar panel, yet reflects parts of solar radiation that would not be absorbed by the solar panel. Relying on the tilting mechanism of the solar panel, on the curvature of the solar panel, or both, the filter reflects this unabsorbed solar radiation toward a central heat absorber positioned on the plane surface of the concentrating reflector, preferably at its center. The central heat absorber in turn collects the heat of the infrared solar radiation diverted upon it, thereby increasing its temperature. The central heat absorber uses this heat as a source of energy, for instance to generate electricity or directly transfer this heat to a useful purpose such as heating water or heating the building on which the solar energy concentrator is installed.
According to an additional embodiment, excessive heat at the solar panel is removed using a heat transfer fluid pipe. A heat pipe is encased into the solar panel, and this heat pipe extends into other components of the solar energy concentrator system, such as the repositioning mechanism, mechanical structure or the concentrating reflector. In the portion of the heat pipe encased in the solar panel, the heat pipe contains a working fluid that lies in a liquid phase under normal ambient temperatures, but transforms into a vaporous phase when in the range of temperatures that the solar panel reaches during operation of the present invention. When heat is gathered at the surface of the solar panel, the materials of the solar panel conduct this heat to the section of the heat pipe that is encased therein. As the temperature increases in the section of the heat pipe encased in the solar panel, the working fluid contained therein is heated, and it eventually transforms into a vaporous phase, its volume thus expanding. This expansion causes pressure into the heat pipe, which results in the vapor being pulled out of the section of the heat pipe that is encased in the solar panel, toward sections of the heat pipe encased in other components of the solar energy concentrator system. In these other sections of the heat pipe, heat is conducted to the colder solid materials of their corresponding components. The consequent temperature drop in those sections of the heat pipe causes the working fluid to transform back into a liquid phase, and the resulting working fluid in a liquid phase is eventually drawn back to the section of the heat pipe encased in the solar panel.
The present invention provides numerous advantages over other solar energy concentrators systems known in the art. Area focusing allows a high solar concentration and small losses attributable to the required size of a solar panel.
The above as well as additional features and advantages of the present invention will become apparent in the following written detailed description.
The invention is described in more detail below with respect to an illustrative embodiment shown in the accompanying drawings in which:
Where used in the various figures of the drawings, the same numerals designate the same or similar parts.
Main Components
The solar concentrator disclosed in the principal embodiments of this invention (
The concentrating reflector 1 is made of an array of reflecting surfaces 3 laid over a two-dimensional, stationary plane surface on which they are themselves stationary. The reflecting surfaces 3 are made of glass, blow-molded plastic or other transparent material, coated with a reflective layer. Alternatively, they can be made of a structurally sound material that is naturally reflective, such as aluminum, stainless steel or a chrome-plated metal.
Reflecting surfaces 3 can be either curved or flat. The concentrated light redirected off flat reflecting surfaces is more homogenous than the concentrated light redirected off curved reflecting surfaces. Depending on the type of solar panel 2 used, homogeneity of the redirected light can be a characteristic affecting the optimal collection and conversion of solar energy. If the solar panel 2 used is more efficient when it receives relatively more homogenous light, flat reflecting surfaces 3 should be preferred.
Whether curved or flat, the reflecting surfaces 3 can be discrete rectangular facets or, as in the principal embodiments illustrated herein, continuous ring facets (see 3 in
When solar rays impinge on the reflecting surfaces 3, each of them redirects the light toward one common small target area, just like in a Fresnel lens, thus focusing solar radiation at this focal area. To achieve this effect as efficiently as possible, each of these multiple reflecting surfaces 3 can have its shape and position optimized in a way that maximizes the amount of incident solar radiation redirected toward the small target area. Typically, the reflecting surfaces 3 whose shapes are determined by these optimizing calculations are slightly curved and concave. Since the reflecting surfaces 3 are stationary, this target area continually changes position based on daily and seasonal solar movement. These position changes occur tri-dimensionally. The optimizing calculations made to initially determine the positions of the reflecting surfaces 3 on the concentrating reflector 1, as well as their shapes, can take these movements into account in various ways, for instance, by ensuring that the target area continuously remains at a height and range that are manageable by this invention's structure and solar panel 2; by maximizing the daily average of solar radiation collection on an annual basis; by maximizing the average of solar radiation collection during peak hours of the day; or any other preferred embodiment to establish with this invention a desired output or efficiency level of solar energy concentration or conversion.
In alternative embodiments for the concentrating reflector 1, illustrated in
Through this invention's mechanical or electronic operations, the position of the solar panel 2 is maintained as near as possible to the target area of the concentrated radiation continually redirected by the concentrating reflector 1, thereby collecting concentrated solar radiation and converting it into heat or electricity. The solar panel 2 has a certain shape, typically square or rectangular when based on prior art apparatuses. In a preferred embodiment of this invention, which can be seen on
As can be seen in
As explained in more details below, the structure that supports the solar panel 2 in this invention is mechanically or electronically activated by a digital control system (not shown), so that the solar panel 2 keeps being continuously positioned as close as possible to the target area. In an exemplary embodiment, this structure is predominantly supported by a vertical arm 4, such as a pole, that is preferably embedded at the center of the plane surface of the concentrating reflector 1 (as can be seen in
In the exemplary embodiment, the solar panel 2 always remains on a specific side of the lateral arm 5. If the structure that supports the solar panel 2 is not sturdy enough for the lateral arm 5 to remain straight—perpendicular to the vertical arm 4—during operation and movements of the solar panel 2, a counterweight 6 can be placed on the other side of the lateral arm 5 to help maintain the lateral arm 5 straight. In a particular embodiment, the counterweight 6 can be slided or moved along its side of the lateral arm 5 to help maintain the lateral arm 5 straight. The weight, size and shape of the counterweight 6 are chosen so that the counterweight 6 does not interfere with movements of the solar panel 2. The solar panel 2 can be attached to the lateral arm 5 in various ways, for instance, in a preferred embodiment, with a connecting bar 7.
In the exemplary embodiment, lower support cables 8 attach the vertical arm 4 is approximately at its mid-height to the sides of the stationary plane of the concentrating reflector 1. This design enhances the stability of the vertical arm 4 and prevents it from bending or toppling over. This precaution is important because of wind and other weather conditions, and, to the same effect, supplementary or alternative stability measures known in the art could be integrated to this invention's structure. In addition to the lower support cables 8, two higher support cables 9, preferably attaching each end-side of the lateral arm 5 to the top of the vertical arm 4, contribute in maintaining the lateral arm 5 in its position and sustain part of the weight of the solar panel 2 (and the counterweight 6, if the latter is implemented). With the reinforcement provided by the higher support cables 9, the lateral arm 5 that is integrated to the structure of the exemplary embodiment does not need to be particularly strong.
In a preferred embodiment of this invention, a mirror reflector 10 is fastened against the solar panel 2, potentially diverting toward the solar panel 2 some of the solar radiation, if any, that is redirected by the concentrating reflector 1 and whose trajectory does not meet the space covered by the solar panel 2. The mirror reflector 10 can be square, rectangular, circular, oval or have any other shape that does not prevent it from effectively diverting redirected solar radiation toward the solar panel 2.
In order for the solar panel 2 to continuously remain as near as possible from the position of the target area despite daily and seasonal solar movements, the lateral arm 5 and the solar panel 2 are built and installed in ways that allow rotation around their respective axes. The lateral arm 5 rotates around the point that connects it to the structure—in the exemplary embodiment, the lateral arm 5 thus rotates around the vertical arm 4 (see
In a preferred embodiment, a motorized system of belts and pulleys inside the lateral arm 5 moves the connecting bar 7 (or whichever apparatus or fastener that links the solar panel 2 to the lateral arm 5) along the lateral arm 5 (see
In the exemplary embodiment, the rotation of the lateral arm 5 and the movements of the connecting bar 7 (or whichever apparatus or fastener that links the solar panel 2 to the lateral arm 5) along the lateral arm 5 allow the structure and the lateral arm 5 to move the solar panel 2 anywhere in the horizontal, circular area defined by the rotation of the lateral arm 5, whose radius is thus equal to half the length of the lateral arm 5. This way, the solar panel 2 can be moved two-dimensionally so that it is continually positioned at or near the target area of concentrated solar radiation redirected by the concentrating reflector 1. By rotating the solar panel 2, the invention's structure further adjusts the orientation of the mirror reflector 10 in order to not block solar radiation incoming from the sun or redirected by the concentrating reflector 1. Moreover, the rotation of the solar panel 2, particularly when it is oval in shape, allows for better receiving the concentrated solar radiation redirected by the concentrating reflector 1.
When redirected solar rays hit the surface of the solar panel 2 perpendicularly, or relatively closer to a right angle, the solar panel 2 collects more solar radiation than if solar rays impinge with a shallow or relatively shallower angle. One of the means, already mentioned, to facilitate the likelihood of this impinging angle is by having the lateral arm 5 slightly curved upward or downward toward its ends. As a result of this slight curvature, the stationary angle by which redirected solar radiation is received by the solar panel 2 is different, and potentially closer to perpendicularity.
In this invention's preferred embodiment, two particular mechanisms improve the amount of solar radiation collected by the solar panel 2 by making it more likely to receive redirected solar radiation perpendicularly. First, a tilting mechanism is implemented at the connecting bar 7 (or whichever apparatus or fastener that links the solar panel 2 to the lateral arm 5), which mechanism tilts the solar panel 2 in comparison with a default position whereby the solar panel 2 is parallel to the lateral arm 5. Alternately, this tilting mechanism can be implemented either at the lateral arm 5 or at the solar panel 2 itself. In one embodiment of the tilting mechanism, the solar panel 2 is fixedly tilted to a particular angle. This angle is determined optimally, based on the structural parameters of the corresponding concentrating reflector 1 and on the sun position calculations for the particular location of the concentrating reflector 1. In another embodiment of the tilting mechanism, a variable tilt angle is implemented, and this variable tilt angle can be controlled by the invention's digital control system or by other means. As illustrated in
As previously mentioned, the mechanisms and systems in this invention's structure, such as the variable tilting mechanism in the connecting bar 7, the motorized system of belts and pulleys in the lateral arm 5, the rotation of the lateral arm 5 around the vertical arm 4, the rotation of the solar panel 2 around the connecting bar 7, and the adaptable curvature of the solar panel 2, can be mechanically or electronically activated by a digital control system. The digital control system is connected to actuators or sensors, for instance, optical sensors (not shown). This system can be located at various locations, including behind the solar panel 2, near the motor that controls the system of belts and pulleys inside the lateral arm 5, or even remotely. By relying on the calculations used in the first place to determine the optimal shapes and positions of the reflecting surfaces 3, on sun track data, on feedback data collected by the optical sensors, and on additional calculations, the digital control system assesses the position, tilt and curvature of the solar panel 2 that are optimal for energy output or conversion. The various systems of the structure can then be mechanically or electronically activated or adjusted by the digital control system to produce this optimal energy output or conversion. These assessment and adjustment processes are repeated continuously.
For example, the optical sensors can provide current output data to the digital control system. Based on this feedback data, the digital control system then estimates output predictions for marginal, or more substantial, changes in the position and variable tilt and curvature of the solar panel 2. If those calculations predict that adjusting one or several of the position, variable tilt or variable curvature of the solar panel 2 can yield a higher energy output, the digital control system adjusts whichever mechanism or system that must be adjusted to produce this higher output. Afterwards, the optical sensors provide updated output data to the digital control system, and further estimations can be calculated.
In another embodiment, when multiple solar concentrators are located in a same area, a single digital control system can operate multiple solar concentrators. This way, feedback data for multiple solar panels is provided to the digital control system. With this additional information, more accurate and efficient output predictions can be made regarding the optimal position, tilt and curvature of each of the solar panels operated by the digital control system.
When, in the exemplary embodiment, the position of the sun in the sky entails that the target area of solar radiation redirected from the concentrating reflector 1 is located near the vertical arm 4, regardless of the height of the target area, this invention's structure requires that the solar panel 2 be moved close to the vertical arm 4 to collect this solar radiation. As mentioned above, the system of belts and pulleys inside the lateral arm 5 can move the connecting bar 7 (or whichever apparatus or fastener that links the solar panel 2 to the lateral arm 5) up to the middle of the lateral arm 5. However, a regular solar panel 2 would physically hit the vertical arm 4 and block against it, thereby preventing the connecting bar 7 from reaching the middle of the lateral arm 5. This issue, illustrated in
The exemplary embodiment of this invention implements the technically simpler of these four solutions. In this embodiment, illustrated in
In a first alternate embodiment, best illustrated with a side perspective as shown in
From the bottom up, the division of the vertical arm 4 into two side branches 15 begins somewhere above the junction of the lower support cables 8 with the vertical arm 4. The side branches 15 are then preferably reunified with the vertical arm 4 at the junction of the lateral arm 5 with the vertical arm 4, although this reunification could structurally take place at any place on the vertical arm 4 that is higher than the lateral arm 5 without affecting this invention's basic operations. The gap formed by the side branches 15 must be wide enough and high enough to allow the unobstructed passage of the solar panel 2, taking into account that the preferably oval-shaped solar panel 2 can be tilted, that its curvature is adjustable, that it is attached to the connecting bar 7 (or whichever apparatus or fastener that links the solar panel 2 to the lateral arm 5), and that a mirror reflector 10 can be fastened to it. To compensate for the loss of stability that can arise with the partial division of the vertical arm 4 into two side branches 15, connectors 16 (as seen in the frontal view of
In a second alternate embodiment, illustrated in
As in the principal embodiment, a motorized system of belts and pulleys inside the lateral arm 5 moves the connecting bar 7 (or whichever apparatus or fastener that links the solar panel 2 to the lateral arm 5) along the lateral arm 5. As there are no obstructing components in this embodiment, the solar panel 2 can be moved up to the middle of the lateral arm 5 to receive solar radiation redirected by the concentrating reflector 1. Since no slot is cut in the solar panel 2, this alternate embodiment is potentially more efficient than the solution described in the principal embodiment because it does not reduce the surface area of the solar panel 2. Since there are no components in this embodiment that can block solar radiation redirected from the concentrating reflector 1 toward the solar panel 2, the present alternate embodiment is potentially more efficient than the first alternate embodiment comprising a vertical arm 4 and side branches 15.
In a third alternate embodiment, illustrated in
In the basic embodiment illustrated in
As in the other embodiments, the lateral arm 5 supports a solar panel 2 that can be attached to the lateral arm in various ways, for instance, a connecting bar 7. Also, a mirror reflector 10 can be fastened against the solar panel 2, with the same functions and characteristics as in the exemplary embodiment. The solar panel 2 is installed in a way that allows its rotation around the connecting bar 7 (or whichever apparatus or fastener that links the solar panel 2 to the lateral arm 5). Unlike in the exemplary embodiment, the lateral arm 5 does not rotate.
A motorized system inside the lateral arm 5 allows the connecting bar 7 (or whichever apparatus or fastener that links the solar panel 2 to the lateral arm 5) to move along the lateral arm 5. Unlike in the exemplary embodiment, these movements can take place through the entire length of the lateral arm 5. The solar panel 2 moves along with the connecting bar 7 (or whichever apparatus or fastener that links the solar panel 2 to the lateral arm 5). In addition, a motorized system inside the two lateral prism beams 24a that support the lateral arm 5 allows the lateral arm 5 to be moved along the entire lengths of the two lateral prism beams 24a to which the lateral arm 5 is connected. With the rotation of the solar panel 2, the movement of the solar panel 2 along the lateral arm 5, and the movement of the lateral arm 5 along the two lateral prism beams 24a to which the lateral arm 5 is connected, the structure is capable of moving the solar panel 2 anywhere in the rectangular or square area 23. This way, the solar panel 2 can be moved two-dimensionally so that it is continually positioned at or near the target area of concentrated solar radiation redirected by the concentrating reflector 1.
In a similar embodiment illustrated in
As in the exemplary embodiment, the motorized systems can be systems of belts and pulleys, and they can be mechanically or electronically activated by a digital control system. Since no slot is cut in the solar panel 2, this alternate embodiment is potentially more efficient than the solution described in the exemplary embodiment because it does not reduce the surface area of the solar panel 2. Since there are no components in this embodiment that can block solar radiation redirected from the concentrating reflector 1 toward the solar panel 2, the present alternate embodiment is potentially more efficient than the first alternate embodiment comprising a vertical arm 4 and side branches 15. As another benefit over the exemplary embodiment and the other alternate embodiments, the present embodiment does not require any counterweight 6.
Two more applications can complement the present invention to increase its efficiency. Although the following embodiments can separately or together be incorporated in the exemplary embodiment of the present invention as well as in all three of the alternate embodiments, they are herein described and drawn only in combination with the exemplary embodiment of the present invention, in which a slot is cut in the solar panel 2. Their respective implementations to the three alternate embodiments of this invention do not require substantial or technically challenging adaptations in comparison with their implementation in the exemplary embodiment of the present invention.
Most types of solar panels are not able to collect and convert into electricity all of the infrared light incoming from the sun or redirected by reflectors. Instead, substantial parts of solar radiation whose wavelengths are associated with infrared light are typically wasted as they turn into mere heat upon hitting a solar panel. The present embodiment discloses means for efficiently collecting and using this heat in this invention's solar energy concentrator.
In the present embodiment graphically represented in
Solar radiation impinging on the solar panel 2 increases its temperature, and excessive heat needs to be removed from the solar panel 2 in order to prevent structural damage to the solar panel 2. The present embodiment discloses a particular method to efficiently achieve this removal of excessive heat from the solar panel 2 in the context of this invention's structure: a heat pipe. Henceforth is disclosed one embodiment of a heat transfer fluid pipe in this invention's solar energy concentrator, illustrated in
When heat is gathered at the surface of the solar panel 2, the materials of the solar panel 2 conduct it toward the section of the heat pipe 28 that is encased in the solar panel 2, and the temperature of the working fluid in that limited section of the heat pipe increases. As heat is accumulated therein, the working fluid then in a liquid phase eventually transforms into vapor, its volume thus expanding. This expansion causes pressure into the heat pipe 28, whereby the hotter working fluid now in a vaporous phase is pulled out of the section of the heat pipe 28 that is encased in the solar panel 2, toward the section of the heat pipe 28 that is inside the connecting bar 7 (or whichever apparatus or fastener that links the solar panel 2 to the lateral arm 5). This vapor potentially expands into further sections of the heat pipe 28 that extend inside the other components of the present invention, such as the lateral arm 5, the mechanical structure that supports the lateral arm 5, or into the concentrating reflector 1. In the sections of the heat pipe 28 that are not encased in the solar panel 2, the heat of the vaporous working fluid is conducted to the colder solid materials that constitute these components. Since the structure and the concentrating reflector 1 are relatively large and typically made of metal, they have a great capacity to expel heat. The consequent temperature drop in those sections of the heat pipe 28 causes the working fluid to transform back into a liquid phase, and the resulting working fluid in a liquid phase is drawn back to the section of the heat pipe 28 that is encased in the solar panel 2. With these thermal reactions, which reoccur in continual loops, excessive heat keeps circulating from the solar panel 2 to the other components of this invention, to which the solar panel 2 is connected directly or indirectly through the heat pipe 28.
As an alternative to the heat pipe 28, the solar panel 2 can comprise a heat sink component, such as a layer of a metallic material with excellent thermal conductivity. This layer is physically in touch, directly or indirectly, with the present invention's other components, such as the connecting bar 7 (or whichever apparatus or fastener that links the solar panel 2 to the lateral arm 5), the lateral arm 5, the mechanical structure that supports the lateral arm 5, or the concentrating reflector 1. With this heat sink, heat is conducted from the solar panel 2 to the other components of the present invention. Since the structure and the concentrating reflector 1 are relatively large and typically made of metal, they have a great capacity to expel heat.
The present embodiment allows the invention to dispense with external and potentially wasteful or cumbersome means to remove excessive heat at the solar panel 2. In addition, when this invention is installed at a location that faces cold or snowy climate conditions, this integrated transfer of heat from the solar panel 2 to the concentrating reflector 1 or to the structure as a whole efficiently reduces the need for costly climate-related upkeep operations such as heating or snow removal.
The present invention offers several particular advantages. Being a small-scale, dimensionally-adaptable solar concentrator system featuring high energy conversion efficiency, it requires low building and operation costs. Moreover, except for the third alternate embodiment with the prism structure, the configurations of the other embodiments of the present invention provide a particular advantage: in those embodiments, all moving components are located in the lateral arm 5 or in the connecting bar 7 (or whichever apparatus or fastener that links the solar panel 2 to the lateral arm 5). These configurations allow for an easy and simple replacement of the system's moving components or of the solar panel 2 without having to change, replace or manipulate any stationary component. Those stationary components, such as the concentrating reflector 1 or the mechanical structure, tend to be very durable. In the context of locally-distributed solar energy concentrators as in the present invention, this feature allows repairs to be made or technology upgrades—for instance, more efficient solar panels—to be implemented without having to make any change or adjustment in those stationary components. Considering the fast improvement rate in the technological development of PV solar panels and the particular importance of a solar panel's conversion ratio when used in a concentrating system, significant performance benefits can stem from being able to upgrade the system easily.
While this invention has been particularly shown and described with reference to an exemplary embodiment and alternate and additional embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. The invention in its broadest, and more specific aspects, is further described and defined in the claims which now follow
