US20100024805A1

US20100024805A1 - Solar panels for concentrating, capturing, and transmitting solar energy in conversion systems

Info

Publication number: US20100024805A1
Application number: US12/182,023
Authority: US
Inventors: Mark A. Raymond; Howard G. Lange
Original assignee: Genie Lens Technologies LLC
Current assignee: Genie Lens Technologies LLC
Priority date: 2008-07-29
Filing date: 2008-07-29
Publication date: 2010-02-04
Also published as: WO2010014372A1

Abstract

A panel for concentrating and collecting solar energy. The panel includes light collector assemblies that are positioned side-by-side. Each collector assembly includes a receiver element with an elongate body and a light receiving surface on a first side of the body that has a curved cross section. A concentrating lens extends along the length of the receiver body, and the lens is a flat or arched Fresnel lens adapted to focus incident light onto a long, thin strip along the length of the light receiving surface. A plurality of light transmission sheets or wafers extend along the receiver element body with a first edge of the sheet abutting (e.g., to provide optical coupling) a surface opposite the light receiving surface. Light is captured by the transmission sheets at angles that allow total internal reflectance to transmit the light to a master light sheet for transmission through the panel.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates, in general, to devices and systems for concentrating and collecting solar energy, and, more particularly, to a solar energy concentrator and transmission panel configured to focus light or rays from the Sun onto smaller or select portions of light receiving surfaces and to then to capture or trap the concentrated, received light (or photons) and transmit it efficiently through one or more panels in a solar array to a solar energy collector (e.g., a solar thermal collector, a photovoltaic collector, or other collector) for use by a load such as a thermal load to heat a house or water or such as an electrical load after conversion of the solar energy to electricity.
2. Relevant Background
There is a rapidly growing interest in using solar energy to replace or supplement conventional energy sources such as coal and oil. Governments and industries are experiencing shortages in conventional energy due to reduced supply from their sources and increased demand for the limited output. Conventional energy sources have also become increasingly expensive due to increased demand from developing countries and other users. Many of these energy sources such as oil and coal are criticized because their use may cause harm to or degrade the local or global environment. In contrast, solar energy is freely available over the entire Earth's surface, is renewable, and is generally considered environmentally friendly. One of the main remaining challenges facing researchers is how to more effectively and efficiently collect and use the Sun's light or energy.
There are many different types of solar energy systems that convert solar energy into a useful form of energy. Solar energy systems may include a solar collector that captures light or solar energy and converts the energy into heat that is supplied to a demand for thermal energy or a thermal load such as residential heating or heating of a fluid such as water for residential or industrial uses. In other solar energy systems, the demand for energy or the load may include an electrical storage device or a system or appliance using electricity. In such solar energy systems, the solar collector assembly may include a photovoltaic collector to convert the solar energy directly into electricity or the solar collector assembly may include a thermal collector and a power cycle to convert heat in a fluid, such as water, into electricity. The electricity is then fed to an electrical transmission grid, to electrical storage, or to the end-use system or device.
A limiting factor in effective utilization of solar energy is the cost and inefficiency of the solar collector assembly. The solar collector assembly acts to intercept incoming light or rays from the Sun (e.g., solar energy, photons, or the like) and changes it to a useable form of energy for a particular load or demand. One form of solar collector assembly is called a flat-plate thermal solar collector, and these collector assemblies include a large plate of blackened material that is oriented on a roof or other location to receive a significant amount of solar energy (e.g., on a portion of a residential roof with southern exposure in the northern hemisphere). Tubes or ducting are provided adjacent this array or plate of absorbing material to remove heat from the plate by transferring it to gas, water, or other fluid in the tubes or ducting, and the heated fluid carries the collected energy to a thermal load. Flat plate collectors typically are stationary and do not track the Sun, with their fixed mounting chosen to provide an appropriate tilt to minimize the angle between the Sun's rays and the surface at a peak collection time such as noon. Flat plate thermal collectors do not require significant maintenance and are relatively inexpensive to install, but these collectors are not able to achieve high temperatures in the collector fluids and are generally not very efficient in collecting the available solar energy.
Flat-plate photovoltaic collector assemblies are also in common use and include an array or panel of photovoltaic cells that are encapsulated within a sandwich structure with a front or upper surface made of glass or plastic. These assemblies are also often positioned at an angle and direction that is optimum for a particular time of day and time of year to receive solar energy striking the front surface and to convert a portion of this energy into electricity. In some cases, flat plate photovoltaic panels are mounted on mechanisms that track the Sun about a tilted axis to increase the daily output of the panels. Such collector assemblies are often inefficient in converting the received power into electricity and may require large surface areas to support an electrical load of any size, which increases the overall cost.
Concentrators are often included in solar collector assemblies to more effectively capture solar energy such as when higher temperatures are required for a thermal load or to more efficiently utilize a photovoltaic (PV) collector. In typical concentrator configurations, a large reflective surface is directed or adapted to reflect onto a smaller area for conversion of the solar energy into a useful form of energy. Most concentrating collectors must follow or track the Sun's path across the sky as they can only concentrate parallel rays or light from the Sun's disk. For example, a parabolic trough collector assembly may provide a parabolic concentrator with a reflective surface that reflects on a receiver within the trough. A central receiver-type collector assembly may include a number of planar or arcuate reflective surfaces that are directed toward a centrally located receiver or collector. A parabolic dish-type collector assembly uses a parabolic concentrator to reflect received light onto a receiver or collector. In some photovoltaic collector assemblies, panels of non-imaging Fresnel lenses or lens materials (e.g., arched or convex shaped Fresnel lenses) are used to concentrate light striking the lens array onto a single absorber or PV collector surface. In these assemblies, tracking is typically performed in an extremely accurate manner to focus the received light from the Sun onto a receiver or fixed portion of the collector surface. Tracking is required because even a small misalignment can result in a substantial decrease in the amount of solar energy collected as the concentrated light often fails to strike the receiver or collector. In addition to the need for tracking, existing solar concentrators are generally very large and complex, which causes collector assemblies to be expensive to build and install and also expensive to maintain.
Hence, there remains a need for improved solar conversion systems that more effectively collect or capture solar energy. Preferably, such conversion systems would include concentrators or solar panels that concentrate received light, with these concentrator mechanisms being relatively inexpensive to manufacture and maintain. In some cases, such concentrator designs will be smaller than conventional or existing concentrator assemblies such as with less surface area and/or smaller profiles (e.g., thicknesses) being required to achieve similar or higher energy outputs to the collector. Further, it may be preferable that such concentrator assemblies provide significantly more efficiency in capturing and concentrating received light or solar energy, with some such assemblies or panels not requiring tracking of the Sun's daily path to achieve enhanced solar energy concentration that is then provided to a solar collector.

SUMMARY OF THE INVENTION

The present invention addresses the above problems by providing solar panels or modules that can be used individually or combined to form a solar array to provide concentrated energy to a collector within a solar energy conversion system. The solar panels of the present invention are unique, in part, because they include one, two, and more typically a plurality of light concentrator assemblies that are arranged in a side-by-side manner to combine the light or energy each captures to provide concentrated solar energy output. Each of the light concentrator assemblies may include an elongate trough or basket (e.g., a light receiving element) to provide an arcuate (e.g., parabolic), light receiving surface that extends the length of the panel. A concentrating lens such as a flat or arched Fresnel lens is provided that extends above the light receiving surface and acts to focus Sun light onto the light receiving surface, and the lens is spaced apart from much or all of the receiving surface.
The concentrating lens may function to focus the Sun's rays or solar energy over a large range of incidence angles onto the light receiving surface of the trough or basket, and this focused light may be significantly concentrated (e.g., up to a 30 to 50 times or more concentration of received or incident light) and typically is focused on the light receiving surface as a thin strip or a long bead of light that extends along the length of the trough. For example, the solar panel may be positioned within a stationary solar array on a roof or in a solar collection field/plot, and the position of the concentrated strip of light may move from higher up on one side of the arcuate light receiving surface to a center point of the surface (e.g., at about noon) to higher up on the other side of the arcuate light receiving surface.
To capture this concentrated light or solar energy, the solar trough or light receiving element is formed of material that is light transmissive and, more typically, transparent or nearly so such as a clear plastic, glass, or ceramic material. Each of the concentrator assemblies includes a plurality of thin wafers or sheets that are in optical contact with the back or opposite side of the light receiving surface and extend the length of the trough. These wafers or sheets act as initial light transmission sheets or pipes that accept or capture the light or energy concentrated or focused upon the light receiving elements at various positions along the trough and at a proper acceptance angle to enter the wafer (e.g., less than about 42 degrees to provide total internal reflection (TIR) within the wafer or sheet). The light receiving surface may have its cross sectional shape and position relative to the concentrating lens defined by, at least in part or based on, the focal points of the lens at various angles of incidence of the Sun's rays. As the light is focused from the Sun or other source onto the light receiving surface, one to three or more of the thin wafers or sheets acts to capture and then transmit the received light (e.g., a subset of the initial light transmission sheets or pipes captures and transmits the light any particular incidence angle or time of day).
The physical configuration of the light receiving element and the initial light transmission sheets may generally be understood by bending a book or magazine backwards to cause the spline to become arched, and in this position the book spline is similar to the light receiving element and the pages are similar to the light transmission sheets. The initial light transmission sheets may be positioned to capture light focused on substantially all of the light receiving surface, e.g., with little or no spacing between adjacent sheets at or near the optical contact connection between the back surface of the light receiving element or trough and the receiving/capturing end of the initial light transmission sheets. The sheets may be kept spaced apart by texturing their surfaces, by providing a lenticular-lens type raised surface, and/or with other optical spacer mechanisms that function to limit light being transmitted from one transmission sheet or pipe to a neighboring sheet/pipe. The dimensions of such a solar array may vary widely to practice the invention, but some embodiments may provide a relatively small solar panel or module that is up to 1 to 12 inches or more in width, up to 12 to 36 inches or more in length, and about 3 to 8 inches or less in thickness (e.g., each light concentrator assembly may have a cross section that is less than about 3 square inches in some embodiments where it is desirable to provide a low or flat profile such as roof-top applications). These relatively small panels or modules may be combined to form an array of any desired size and solar energy capacity or output level.
The captured or received light is transmitted in the initial light transmission pipes or sheets to a main or master light sheet or pipe that may be a planar sheet of plastic, glass, ceramic, or the like extending below the light concentrator assemblies. In some embodiments, intermediate light transmission sheets or pipes may be provided to facilitate transmission of the received light or energy from the initial light transmission sheets or pipes to the main or master light sheet. The light or energy captured from each of the light receiving elements is transmitted to the main or master light sheet of the solar panel or module and is then transmitted, again via TIR, to an outlet edge of the panel or module, which may in turn be connected to another solar panel or module to form a solar array or may be positioned so as to direct the concentrated, captured, and transmitted light onto a solar collector (e.g., a photovoltaic (PV), solar thermal, or other collector of a solar energy conversion system or other solar energy use system).
More particularly, a panel or module is provided for concentrating and collecting solar energy such as a panel or module that may be combined with other such panels or modules to form a collector array for a solar energy conversion system. The panel includes two or more light collector assemblies that are positioned side-by-side (e.g., such that they are parallel to each other). Each of the light collector assemblies includes a number of similar components including a light receiver element (sometimes labeled a trough or basket for receiving the concentrated light from the lens) with an elongate body and a light receiving surface on a first side of the body that has a curved or arcuate cross sectional shape. Each collector assembly also includes a concentrating lens that extends over and along the length of the receiver element body, and lens may be a flat or arched Fresnel lens adapted to focus incident light (e.g., the Sun's rays striking the lens) onto a long, thin strip or focusing region along the length of the light receiving surface. Each of the collector assemblies also includes a plurality of light transmission sheets or wafers that are positioned so as to extend along the receiver element body with a first edge of the sheet abutting (e.g., to provide optical coupling/contact) a surface opposite the light receiving surface.
During use, a set of one or more of the light transmission sheets receives or captures the concentrated light and then transmits at least a portion of the light focused into the strip on the light receiving surface. The panel also includes a master light transmission sheet formed of a light transmissive material, and this sheet is positioned in the panel “below” or spaced apart from the receiver elements. Each of the light transmission sheets may have a second edge or side in abutting contact (e.g., to provide a second optical coupling/contact) with a surface of the master sheet such that the light received or captured by the light transmission sheets from the light receiving surface are injected or provided to the master sheet for transmission (e.g., using TIR) through the panel, e.g., for output to a collector provided adjacent the panel or adjacent an array of such panels.
Significantly, the panel may be used in non-tracking applications as the focusing area or strip will move through a number of differing positions on the light receiving surface corresponding to the incidence angles of the light striking the concentrating lens. In this regard, the set of the light transmission sheets receiving/capturing the concentrated light will change (or differ) for these differing positions. In other words, a single receiver is not used that requires a reflective surface to be carefully moved to maintain its focus on the receiver, but, instead, numerous light transmission sheets (e.g., 10 or more) are provided on the opposite side of the light receiver element to capture the concentrated light. The receiver body and the light transmission sheets are formed from a light transmissive material (or, more typically, a transparent or at least substantially transparent material) such as a plastic, a glass, and/or a ceramic material. The Fresnel lens will have a plurality of focal points for the received light over a range of angles of incidence, and to better capture the concentrated light, the curved shape of the light receiving surface may be configured such that at least portions of it are proximate (or even partially or substantially coincident/overlapping) to a set of focal points for the concentrating lens at a number of incidence angles (e.g., the acceptance angle or range for the panel such as −35 to +35 degrees or −50 to +50 degrees with 0 degrees being normal or an orthogonal ray striking the lens). Also, the light is receive or captured at the edge of the light transmission sheets at one or more angles so as to create a state of total internal reflection (TIR) within the sheets (e.g., at an acceptance angle of less than about 42 degrees) such that the captured light is transmitted through the sheets to the master or main light transmission sheet, wafer, or pipe. Intermediate light transmission sheets may be positioned between these initial transmission sheets and the master sheet to facilitate manufacturing and/or maintenance of the TIR in the transmission sheets. The light transmission sheets are typically relatively thin such as less than about 1 to 100 more in thickness (but may, of course, be thicker than 100 mils such as up to 300 mils or more) and chosen/configured to capture much of the light striking and exiting the light receiver body. The sheets are spaced apart at the receiving ends by only a small amount such as between about 0.5 mils to 100 mils separation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a functional block illustration of a solar energy conversion system of an embodiment of the invention showing in perspective a solar array or module that may be formed of one or more solar panels that are described in detail herein (i.e., the light or solar energy capture, concentration, and transmission panels of various embodiments of the invention);

FIG. 2 is a perspective view of a solar panel that may be used independently or as part of a solar panel or module as shown in the solar energy conversion system of FIG. 1, with the solar panel being illustrated with an open or exposed end to show components of light concentrator assemblies used to more effectively capture or trap light as the light is focused on an elongate light-receiving element or basket (or trough) having an arcuate cross section (e.g., a parabolic or near parabolic cross section) that may be defined, in part, by a plurality of focal points of an arched or curved concentrating lens that extends along/over the light-receiving element or basket;

FIG. 3 illustrates a perspective view of a subassembly of an embodiment of a light concentrator assembly including a concentrating lens in the form of an arched Fresnel lens combined with an elongate, arcuate (or generally parabolic) shaped light-receiving element or trough, which during use would receive light (e.g., the Sun's rays) focused upon a light-receiving or inner surface by the Fresnel lens (e.g., light is concentrated onto a thin strip or rectangle along the length of the light-receiving element);

FIG. 4 illustrates a sectional view of an exemplary light concentrator assembly shown to include an arched Fresnel lens with an elongate, light receiving element and a light capture and transmission assembly of an embodiment of the invention that has a plurality of thin, elongate wafers or sheets (e.g., initial light transmission pipes or sheets) in optical-transmission contact with the light receiving element for transferring light received or captured/trapped along the length of the light receiving element or trough to a main or master light transmission element (or sheet or pipe) via a number of intermediate light transmission wafers, sheets, or pipes positioned between the initial light transmission sheets and the main or master light transmission element or sheet;

FIG. 5 illustrates an end view of another exemplary light concentrator assembly that may be used in a solar panel of the invention, with the light concentrator assembly including a planar or flat Fresnel lens for its concentrating lens, including a smaller number of initial light emission sheets in optical contact with the receiving element, such as may be used in a panel in a non-stationary or tracking panel arrangement (e.g., illustrating the concept that the initial light transmission sheets or wafers do not have to extend about entire surface of receiving element), and further including textured surfaces on the sheets or wafers to space adjacent sheets/wafers apart to limit optical contact;

FIG. 6 illustrates a representation of a single concentrating lens and light-receiving element pair of a concentrator assembly showing the effectiveness of a concentrator assembly in concentrating incoming light (or energy from the Sun or other source) onto a small surface, which can then be captured or trapped by a light wafer or pipe (or small set of such wafers/pipes) in optical transmission contact with an opposite side of a light receiving element or trough;

FIG. 7 is an end view of another solar panel of an embodiment of the invention that includes three light concentration and transmission assemblies with each including a plurality of thin, flexible light wafers, sheets, or pipes (e.g., initial and intermediate transmission pipes combined) that are placed in optical contact or connection with the light receiving element and then arranged with a cross-sectional shape as needed to attach to the main or master light pipe, sheet, or wafer with a desired acceptance angle (e.g., less than about 42 degrees such that light is transmitted through the master light pipe or sheet due to total internal reflection or TIR);

FIG. 8 is a detailed view taken from FIG. 7 showing light combination of multiple light wafers or pipes into the master light pipe, sheet, or wafer so as to maintain total internal reflection or only a small amount of variance and loss;

FIG. 9 illustrates a detailed view taken from FIG. 7 showing light receiving or trapping by a subset of the light wafers or pipes having optical contact with a portion of the light-receiving element (e.g., adjacent or proximate to light (or Sun's energy) concentration/receiving area on the light-receiving surface of the receiver element or trough);

FIGS. 10-12 illustrate ray tracing diagrams for an exemplary arched Fresnel lens that may be used for a collecting or concentrating lens of an embodiment of a light concentrating and transmitting assembly of the invention with the ray tracing being used for defining or selecting a cross sectional shape for a light-receiving surface of a receiver or trap element or trough (e.g., showing focal points/areas for the Fresnel lens at a number of incidence angles for a light source such as the Sun with an ideal receiver element having rays being focused on or near the receiving surface over a range of incidence angles unless tracking/positioning is used with the concentrator assembly or a panel containing such assembly); and

FIGS. 13 and 14 illustrate an exploded end view of a solar array showing assembly of modular solar panels of an embodiment of the invention and an end view of an assembled solar array further optically linked to a solar collector (e.g., a solar thermal collector).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Generally, the present invention is directed to solar panels or modules that can readily be assembled into larger solar arrays and to solar energy conversion systems that include such solar arrays such as to supply thermal energy to a thermal load and/or to supply electricity to an electrical load. The following description explains in detail solar concentrator assemblies that are configured to focus or concentrate solar energy or the Sun's rays incident upon the solar panel such as by using arched Fresnel lenses. The solar energy is concentrated in strips or long beads upon an upper surface of an arcuate light receiving element or trough, with the location of the strip on the upper surface varying with the time of day or incidence angle of the received light. One or more light transmission sheets or pipes are in optical contact with the lower surface of the light receiving element, which itself is transparent or at least significantly transmissive of light, to capture the concentrated light or solar energy and to transmit it to a main or master light sheet or pipe in optical contact with each of the light receiving elements. In this manner, solar energy can be concentrated upon the light receiving surface at varying points along its surface, the concentrated light can be captured by one or more light transmission sheets or pipes, and the captured light can be provided to a master or main light sheet or pipe for transmittal to a solar panel outlet (e.g., to another panel or to a solar collector for conversion to a more useful form of energy). This occurs for each solar concentrator assembly in the solar panel or module such that the concentrated solar energy is also combined to provide a desired quantity or magnitude of solar energy to a collector. The following description provides additional background on the need for enhanced solar energy concentrators and transmission and then provides a detailed discussion of embodiments of the invention with reference to the attached figures.
The demand for effective collection of solar energy for the generation of heat with thermal collectors and of electricity with PV collectors is not a recent development, but rising oil prices, demands for less fossil fuel dependency, and increased interests in renewable energy have combined to significantly increase the interest in solar energy. Many believe solar energy could be used to meet a large portion of the world's energy demands. Recently, there has been increased investments in solar energy research, and there has even been widespread land speculation regarding where large solar power facilities will be built. Clearly, there is a need for solar energy to meet expanding energy demands worldwide.
Unfortunately, there are a number of problems with utilizing solar energy. One problem with using solar energy is that after collection and conversion to another form of energy it is a relatively expensive per unit of useful energy or power. Additionally, the Sun's energy is readily available across most of the globe's surface, but energy conversion systems are often very inefficient in producing useful energy from the received energy or light. For example, most PV-based conversion systems are only able to convert about 20 percent or less of the solar energy to electricity. Many PV-based systems generate very little net power per area (e.g., per square meter), with some systems providing net power outputs of less than about 20 to 30 Watts per square meter (with 70 Watts per square meter sometimes considered an upper maximum at perfect alignment of the PV arrays with the Sun). This results in a large cost for the produced electricity, with some residential PV-based systems being designed to recoup initial expenditures in over 20 years (even, in some cases, with governmental tax relief on the purchase/installation costs). A great amount of research is expended attempting to provide PV collectors or panels that provide slightly better (e.g., up to a few percent) efficiencies, and PV material is often expensive to manufacture and involves sophisticated designs adapted to capture various wavelengths of the Sun's rays. Presently, electricity from PV-based conversion systems is expensive with utilities buying electricity from such systems at up to 25 times or more the cost of electricity generated from fossil fuels such as coal, e.g., to comply with regulations regarding purchasing electricity from renewable energy-based generation systems or facilities.
In some solar energy conversion systems, the thermal portion of the solar energy is collected and used to heat water or other fluid, with the water being used directly or being used to generate electricity (e.g., steam used to operate a turbine or the like). Thermal-based conversion systems often are more efficient than PV-based conversion systems in capturing energy from the Sun's rays or received solar energy and, often, in converting the captured energy to electricity. Most of the industrial power plants that use solar energy use parabolic troughs or mirrors that focus reflected rays from the Sun onto a single, central tower or receiver so as to heat a collector or fluid in such a collector. The captured thermal energy is then converted to electricity or mechanical power with a turbine, Sterling engine, or other power cycle. While being more efficient, thermal-based systems also have problems or issues that have limited their implementation as an alternative to fossil fuel systems. For example, thermal-based systems generate up to a few hundred Watts of energy per square meter of receiving panel but the costs of the system are typically relatively high. Additionally, these systems often require extremely accurate tracking of the Sun with the troughs and/or mirrors being moved by complex operation and/or control systems to maintain a desired angular relationship with the Sun's rays. Thermal-based systems in the past have had high maintenance costs including keeping the reflective surfaces clean and properly aligned within the positioning equipment While these systems have been implemented in some industrial settings, residential systems have not been widely developed or implemented by consumers.
FIG. 1 is a functional block or schematic view of a solar energy conversion system 100 of an embodiment of the invention. As shown, a light or energy source 104 such as the Sun transmits energy, rays, or light 108 (generally termed “solar energy” and typically considered to be made up of parallel light rays due to the distance to the source 104). The system 100 includes a solar array 110 that is used concentrate this energy 108 and provide a concentrated output 124 at an outlet or end/side 120. The system 100 includes a solar collector 130 that acts to convert the solar energy 124 into another form of energy for use by a load. For example, the collector 130 may be a solar thermal collector that converts the solar energy 124 into heat or thermal energy. The thermal energy may then be stored in thermal storage 134 or 144 and/or it may be supplied to a thermal-based system 132 to supply a thermal load 138 (e.g., used to heat water, to provide residential or industrial levels of heat, and hot fluids/heat used in other residential or industrial applications) or supplied to a PV/thermal-based system via a power cycle 146 (e.g., a power plan, an engine, or the like) that converts the thermal energy into electricity that is then supplied to a power grid, standalone, or other electrical load 150. The conversion system 100 may also include auxiliary source 136, 142, 152 of energy so that demand may be met when the system 100 cannot meet demands with received solar energy 108 such as during long periods with no sunshine and after the storage 134, 144, 154 is depleted. In other cases, the collector 130 may include one or more photovoltaic or PV collectors that convert a portion of the output solar energy 124 into electricity that is provided to storage 154 and to electrical load 150.
One goal of the present invention is to create a low profile device or solar array that does not require tracking of the Sun's position. Another goal of some embodiments is to try to more efficiently use more of the received solar energy 108 (e.g., more of the available PV and thermal energy provided by the Sun 104). Another feature or goal of some embodiments is to provide an array or collector device that is relatively inexpensive to make and use/maintain and that is safe for home and other uses. Yet another goal is to provide concentrator technology that is modular and, in some cases, readily scalable to suit varying collectors 130 and/or converter and load subsystems 132, 140.
With these goals in mind, the system 100 includes a low-profile solar array 110 that is formed by combining or mating together a plurality of solar panels or modules 112 (with 8 panels 112 being shown in this non-limiting exemplary array 110). Each panel 112 includes two or more light or energy concentrator assemblies 118 that are arranged parallel to each other within the panel 112 and generally extend the length, L_panel, of the panel 112, and, as explained below in detail, the concentrator assemblies 118 each act to concentrate and capture solar energy 108 that strikes the upper surface 116 of the panels 112 or array 110. The concentrated and captured light 122 is then transmitted transverse (e.g., orthogonal) to the receiving surface 116 through each of the panels or modules 116 (e.g., the connection mechanism 114 used between abutting pairs of the panels 112 is configured to join the panels 112 while also allowing the light or energy 122 to be transmitted through the solar array 110 such as within a main or master light sheet or planar pipe provided at the bottom or in another location within each panel 112) to be provided to the collector via outlet or output edge/side 120 of the array 110 to collector 130. The length, L_panel, and width, W_panel, may be varied to practice the invention such as from a few inches to several feet or more. For example, an array 110 that is 6 feet by 12 feet may be desired for a residential application, and this may be readily achieved by fitting panels/modules 112 (e.g., 36 panels that are 2 feet long and 1 foot wide arranged in a 3 by 12 array and so on). The height, H_panelmay also vary from less than an inch up to about 3 inches or more and likely will vary with the materials utilized, the particular application (e.g., industrial versus residential and so on), with lower profile arrays 110 in some residential cases and other applications where a low profile array may be desirable the panel 112 may have heights, H_panel, of less than about 5 inches and more typically less than about 3 inches and even less than about 1 inch.
The concentrator assemblies 112 are believed to be unique when compared with prior concentrator technologies in part because nearly all of the rays or solar energy 108 can be collected and transmitted within the array 110 without tracking. This is achieved in part by “trapping” the photons or rays 108 inside each assembly 112 by focusing the energy 108 with a concentrating lens (e.g., an arched or flat Fresnel lens) that extends the length, L_panel, of the panel 112. The energy or rays 108 is focused on a strip, bead, or thin line on an upper surface of a light receiving element (e.g., a curved or parabolic surface spaced apart from the lens with the surface coinciding generally with the focal points of the lens at a plurality of incidence angles for the rays 108 from the Sun). Coinciding with this light receiving surface, a plurality of fiber optic wavers or light transmission sheets are placed in optical contact with the opposite side of the light receiving element, which is transparent or substantially so. In this manner, the incoming rays 108 are focused into these light transmission sheets or wafers and are then transmitted or directed into a master or main wafer or light transmission sheet, the concentrated/trapped rays 122 can then be directed into the next panel 112 for combination with its captured rays 122 for eventual output 124 of the array 110. Computer modeling has shown that rays 108 over a large range of incidence angles can be received on surface 116 with up to and over 90 percent of the incoming rays 108 being trapped or captured in the panes 112 and then transmitted (with some small transmission losses) as output 124 for use by collector 130.
As shown in FIG. 1, the panels 112 are adapted to be modular and are designed to “panel” together. As discussed above, the collector 124 may use just the portions or wavelengths of concentrated energy 124 for PV conversion to electricity, but in other cases the collector 130 is adapted to convert other portions or wavelengths of the energy 124 into thermal energy or heat for use by power cycle 146, thermal load 138, and/or storage 134, 144. As shown in the embodiment of FIG. 1, the panels 112 move the captured photons or energy 122 laterally, and generally this is performed without losses in the light transmission sheets or pipes (e.g., initial, intermediate, and/or main/master fiber optic sheets, pipes, or wafers) as the captured energy 122 is moved toward the collector 130. In the assemblies 112 and even with nonplanar arrays 110 or panels 112, the energy 122 can be caused to move around corners/bends, up and down, or in a variety of paths to be supplied to the collector 130 (or other end use/load).
The captured and transmitted energy 122 can be transmitted with minimal transmission losses and with little or no thermal/heat loss. In other words, it is not expected that the panels 112 will become excessively hot due to losses regardless of the quantity or magnitude of the energy 122 or energy 124. As a result, the panels 112 can be made of a wide variety of materials such as readily available plastics that are transmissive to light 108, 122 or glass or certain ceramics that are transparent or at least highly transmissive. When formed of plastic, the panels 112 of the invention may be fabricated using conventional and well-known methods for producing plastics, with the particular technique chosen not being limiting of the invention, and the panels 112 including the light receiving element, the concentrating lenses, and light transmission sheets may be formed using a variety of materials. The materials used for forming the lens arrays may be glass, nearly any type of clear (i.e., transparent to translucent/less transmissive) plastic including but not limited to PET, propylene, OPP, PVC, APET, acrylic, or any clear plastic, and/or a ceramic. In many embodiments, the preferred base material is a plastic, and the plastic may be extruded, calendared, cast, or molded with the tools formed as described above to provide the functional structure described herein.
In some embodiments, no tracking is utilized and the panels 112 are able to collect incoming rays 108 at over 70 percent acceptance within the “photon traps” or concentrator assemblies 112. The array 110 is designed to work without use of mirrors/reflective surfaces, without motors and control systems, and without moving parts. The panels 112 may be thought of as “self correcting” because they allow nearly any incoming angle (sometimes called incidence angle or acceptance angle) of rays 108 to enter directly into the concentrator assemblies through the panel's main or master light sheet or wafer as shown at 122 to the collector 130 as shown at 124. The array 110 may be configured to generate with a solar thermal collector 130 fluid at several 1000° C. while a more useful or optimum level may be around 1000° F. at about 600 suns. The array 110 and the individual panels or modules 112 are self-contained or sealed, which facilitates maintenance (e.g., simply clean and/or dust external surfaces periodically and the like) and when combined with the lack of moving parts provides a very long service life (e.g., up to 30 to 50 years or more) depending on the materials (e.g., polymers) used for the panel components (e.g., the Fresnel or other concentrating lenses). The panels 112 are also inexpensive to manufacture, and due to the high amounts of concentration provided (higher efficiency in concentration and capture of energy 108) the cost of the collector 130 (e.g., the amount of PV material required) is also lower.
There is a potential that the configuration of the panels 112 and the concentrator assemblies 118 may make many existing thermal-based solar energy conversion systems at least partially obsolete. Unlike traditional units, the panels 112 and array 110 are generally unaffected by wind or harsh weather as they are non-tracking (except for some embodiments) and have a much lower profile that more tolerant of high winds. The panels 112 are highly effective at concentrating the Sun's energy 108 onto thin lines or strips on a light receiving surface from which it is captured or received by one or more light transmission sheets, wafers, or pipes for transmission to a main or master light transmission sheet, wafer, or pipe with relatively low vertical height and associated mass and without tracking. PV-based systems are also enhanced and the collector 130 may be a PV collector/converter as the energy or light 124 is significantly more concentrated, which improves the efficiency of typical PV material thus reducing the amount and/or quality of the PV material required to achieve a particular output or supply a particular load 150. The array 110 may be configured with a number and size of panel 112 such that the array can run a small turbine or Sterling engine 146 for home use 150 and is also practical for use in commercial buildings and industrial power plant settings. It is highly likely that the costs associated with fabricating, installing, and operating the power conversion system 100 of FIG. 1 are comparable to energy costs per kW in capital cost associated with producing electricity with coal and less than existing thermal and PV-based solar energy conversion systems.
FIG. 2 illustrates a perspective end view of a solar panel 210 of an embodiment of the invention such as may be used for the panels 112 in a solar array 110. In some embodiments, the end of the panel 210 would be covered but in the illustrated embodiment an end cap/cover is not provided, which facilitates explanation of one arrangement of light or energy concentrator assemblies as their components are visible at the end of the panel 210. As shown, the panel 210 includes a set of two or more concentrator assemblies 220 with five being shown in this implementation. The concentrator assemblies 220 are arranged in a side-by-side or parallel manner. The panel 210 includes an upper or receiving surface formed of the concentrating lenses 212 and optional separating shoulders/spacers 214 of each concentrator assembly 220. The panel 210 also includes two end or side walls 214, 215 that may be formed of clear or opaque material and that are typically spaced apart from the end concentrator assemblies 220 (e.g., not in optical contact to avoid transmitting any captured light from the initial or intermediate light transmission wafers or sheets). A lower or bottom surface 216 further defines the panel 210, and this surface 216 may be planar and, in some embodiments, may be a portion of a main or master light transmission sheet or pipe 238 that is used to combine and transmit light or solar energy concentrated and captured by each concentrator assembly 220 parallel to the surface 216 (e.g., transverse to rays or light received on the upper surface of panel 210 in either or both (concurrently in each direction in a symmetric concentrator assembly embodiment not shown in FIG. 2) the right and left directions when the panel 210 is viewed at the end as shown).
Now, it may be useful to explain the configuration of one embodiment of the concentrator assemblies 220 of the invention. As shown, each concentrator assembly 220 includes a light receiving element 222 that may be thought of as an elongate trough or basket for receiving light or solar energy that strikes the panel 210. The light receiving element 222 typically extends along the length of the panel 210 (but may be somewhat shorter in length than the panel 210) and is fabricated from a material such as plastic, glass, or ceramic that is substantially transparent (or at least highly light transmissive), e.g., an elongate sheet of plastic bent or formed into an arcuate, parabolic, or other useful cross sectional shape. An upper surface of the element 222 is the light receiving surface while the opposite or lower surface of the element 222 may be thought of as the light capture and/or transmission surface.
The particular shape of the cross section of the element 222 (or its upper, light-receiving surface) is, in some cases, chosen to match or at least approximate a pattern defined by focal points of a concentrating lens 212 at a range or set of incidence or acceptance angles for the Sun's rays or solar energy received by the concentrator assembly 220. The concentrating lens 212 may take many forms to practice the invention such as a simple arched, transparent body. More typically, though, the concentrating lens 212 is provided as a flat Fresnel lens or, as shown, an arched Fresnel lens, with Fresnel lenses being well known in the optical arts and within the solar energy industry. In the past, Fresnel lenses were used to concentrate solar energy upon a single receiver at a particular acceptance angle (e.g., 0 to 50 degrees or the like with 0 degrees being about noon or when rays strike the module 210 orthogonally), and the panel with the Fresnel lenses was moved to carefully track the Sun's movements to focus on the receiver. In contrast, the concentrating lens 212, which may be a flat or arched Fresnel or other lens configuration, is used to focus or concentrate the light or energy that strikes its upper surface onto a receiving/concentrating portion of the receiving surface of element 222. The receiving portion typically is relatively thin and extends the length of the panel 210 or element 222, e.g., may take the shape of a relatively thin strip or rectangle or, in some cases, may approach a line on the element 222 when light is accurately focused on the upper surface of element 222. During operation, then, this causes solar energy to be focused upon a plurality of such light receiving portions over the surface of the light receiving element 222, and it may appear to be a thin strip or rectangle of light that slowly moves during the day from an upper side portion of the element 222 down to the bottom or lower portion of the trough formed by element 222 and then back up to the other upper side portion later in the day. A void space 218 is formed between the concentrating lens 212 and the light receiving element 222, and this is typically only filled with air or gas to limit diffusion or interference with the light concentrated by the lens 212 from being directed to the receiving element 222.
To capture the concentrated light or energy, the concentrator assembly 220 includes a light capture and transmission assembly 230. This assembly 230 includes in this embodiment a plurality or set of initial light transmission wafers or sheets 232. These wafers or sheets 232 function similar to light pipes in that light is transferred along their lengths via TIR, and the sheets 232 are attached to the lower or transmission surface of the light receiving element 222 to provide an optical coupling (e.g., in optical transmission contact). In this manner, the light that is concentrated by the lens 212 in a thin strip along the length of light receiving element 222 is received or captured, after it is transmitted through the body of the element 222, by an optically coupled end of one or more of the light transmission sheets 232. To this end, a thickness of each of the sheets 232 may be about or somewhat greater than a width of the focused light strip on the element 222 and/or the sheets 232 may be provided in an adequate quantity and positioned close together (or even abutting) at the coupled end near element 222 such that 2 or more of the sheets 232 may be used to capture light from the lens 212. In the first example, light focused by the lens 212 onto the element 222 may be captured by a single one of the sheets 232 at a particular angle of incidence of solar energy and then two may act to capture the light/energy as the Sun moves to a next position in which the adjacent sheet 232 captures the light/energy (e.g., a set of one or two sheets 232 typically captures or receives the majority of the concentrated light). In the latter example, a set of two or more sheets 232 work in conjunction to capture light striking and passing through the light receiving element 222 as each sheet 232 is generally thinner than the strip of concentrated light passing through the element 222. The sets of initial light transmission sheets 232 used to capture the photons or solar energy changes over the day as the Sun moves on its path when the panel 210 is stationary while some embodiments may include tracking such that a single or smaller set of the sheets 232 is used to capture the light from lens 212.
Another aspect of the panel 210 is that the solar energy or light captured by each assembly 220 is combined and/or transmitted from the panel 210 to an end or side 215 (or 214 in some cases not shown) for use by a collector or other load of solar energy (or to an adjacent panel 210 that is coupled for receiving the collected solar energy). To this end, the captured light traveling via TIR in the sheets 232 is transmitted or supplied to a master or main light transmission sheet, wafer, or pipe 238. This may be achieved with a direct coupling of the sheets 232 to the master light transmission sheet 238 such as with an optic coupling at an acceptance or entry angle to maintain TIR such as less than about 42 degrees (as measured from a plane orthogonal to the sheet 238). As shown, though, it may be desirable to provide a plurality of intermediate light transmission sheets 234 within the assembly 230 to connect the sheets 232 with the master sheet or pipe 238. For example, a set of intermediate light transmission sheets 234 that are typically much smaller in number than the initial sheets 232 is coupled to ends (or at another location) of the initial sheets 232 to accept the concentrated light and transmit the light/energy, again via TIR, to the master sheet 238.
Both the initial sheets 232 and the intermediate sheets 234 are elongate members generally extending the length of the panel 210 and are called sheets because they typically may be formed of thin, light transmissive or substantially transparent material such as a plastic, ceramic, or glass material. As explained earlier, the combination of the trough 222 and the initial light transmission elements 232 is similar to a book that is opened to the point where the spline becomes arched and the pages spread outward about the arched spline in a spaced-apart manner, and in this visualization the spline is the element 222 and the pages are the sheets 232. As in this example, the sheets 232 are typically spaced apart as shown by air or spacing gaps 236 showing that optical contact is avoided or minimized between the sheets 232 (and sheets 234). The number of sheets 232 may be varied to practice the invention with some assemblies 220 containing only a few sheets 232 (such as when tracking is used or the sheets 232 are thicker) to tens to hundreds or more. Again, it is typically preferred that most or nearly all of the lower or transmission surface of the trough or receiving element 222 is in optical contact with the sheets 232 such that a large percentage (e.g., up to 90 percent or more) of the light passing through the lens 212 is captured by the transmission assembly 230.
The intermediate sheets 234 are provided to facilitate transmission of the captured light to the master pipe or sheet 238, e.g., to maintain TIR in the initial sheets 232 by reducing risks of overly sharp bends and corners in the pipes or sheets 232. The master pipe or sheet 238 is typically a planar sheet of light transmissive or transparent material such as plastic, glass, or ceramic that is provided over the lower surface of the assemblies 220 (and, in some embodiments, nearly over the entire lower surface 216). The master sheet 238 receives the concentrated light from each of the assemblies 220 via the intermediate light transmission sheets 234, which are optically connected to the initial sheets 232 and to the master sheet 238. The master sheet 238 may have a wall that provides the lower surface 216 of the panel 210 or may be spaced apart from the surface 216 in some embodiments to limit loss of captured and concentrated solar energy or light.
FIG. 3 illustrates a perspective view of a subassembly 300 of an embodiment of a light concentrator assembly (such as an assembly 112, 220 of FIGS. 1 and 2). The subassembly 300 includes a concentrating lens 310 extending a length, L_panel, of a solar panel (not shown in FIG. 3). In the assembly 300, the lens 310 is attached at its sides to a light receiving element, trough, or basket 320. The lens 310 is in the form of an arched Fresnel lens with an outer, flat surface 312 for receiving incident light from the Sun or another source and an inner, rough surface 314 that projects the received incident light onto element 320. The Fresnel lens may be an imaging lens or, more typically, is a non-imaging Fresnel lens with a plurality of prisms or facets 316 that act to focus rays striking the outer, upper surface 312 onto a light receiving or upper surface 324 of the element 320. The lens 310 may be flat in some embodiments or arched as shown, and it is typically configured with numerous prisms 316 to focus the substantially parallel rays from the Sun or other source onto a thin strip or line extending along the length, L_panel, of the assembly 300 (e.g., a focusing area that is a thin strip or line running parallel to a longitudinal axis of the assembly 300). The shape and depth of the surface 324 is selected based on the lens 310 configuration such as to have the Fresnel lens prisms 316 focus incident rays onto a strip or elongate area that is on or proximate to the surface 324. Hence, the surface 324 may be arcuate (e.g., parabolic or the like) such that tracking is not required over a range of incidence for solar rays (e.g., over a range of 50 to −50 degrees or the like the focal points/lines of the prisms 316 are coincident (or within an acceptable tolerance/range of) the surface 324). The lens 310 may be formed of plastic or other material such as glass or ceramic to transmit received light through its body. Likewise, the light receiving element 320 is typically formed of a transparent (or substantially so) material such as a plastic, ceramic, or glass such that light or energy focused on its upper or receiving surface 324 is transmitted through to a lower or transmission side 322, where it is captured or received by one or more light pipe, wafer, or sheet (not shown in FIG. 3).
FIG. 4 illustrates a cross sectional view of an embodiment of a light concentrator assembly 400 that may be used in the solar panels of the invention such as for the assemblies 118 in panels 112 of array 110 in FIG. 1. In other words, the concentrator assembly 400 may be used alone to concentrate light or energy, but, more typically, the assembly 400 is one of a set of such assemblies provided within a solar panel or module, which in turn may be used independently to provide concentrated energy or light or be part of a modular solar array (as discussed with reference to FIG. 1). The assembly 400 includes a concentrating lens 410, an enclosure or housing 420, and a light transmission subassembly 440.
The housing 420 includes a top wall or spacer surface separating the lens 410 from adjacent lenses and also providing space for the transmission subassembly 440. The housing 420 further includes sidewalls 424 that extend the length of the assembly 400 and generally enclose the transmission subassembly 440 and, again, reduce risk of optical contact with adjacent assemblies 400 and loss of captured light. The walls 422, 424 may be formed of the same material as the lens 410 and transmission assembly 440 components but this is not required as the walls 422, 424 provide physical support and protection/enclosure functions and do not capture or transmit light or solar energy.
The assembly 400 includes a concentrating lens 410 in the form of an arched Fresnel lens that extends the length of the assembly 400 (or at least the length of the receiver or receiving element 430). The lens 410 is arranged with a smooth receiving side or surface 412 facing outward, which facilitates cleaning of the assembly 400. An inner focusing or transmission surface 414 includes a plurality of prisms or facets that function to focus light incident upon the surface 412 across a void space onto a portion of the light receiving surface 423 of element 430. For example, parallel rays or solar energy from the Sun may strike the lens 410 at an incidence angle of about 20 degrees from perpendicular or normal and be reflected onto an elongate region or strip on the surface extending into the paper in FIG. 4 (e.g., a strip with a width of less than a mil to several mils or much more depending upon the lens 410 configuration). The lens 410 has a width, W_lens, that will vary upon the implementation (along with its amount of curvature or arch), and, in one embodiment, the width, W_lens, is selected to from the range of about 0.5 to about 6 inches while in other cases a smaller or larger lens may be used (e.g., a non-residential application may use widths, W_lens, of 6 to 12 or more inches).
The receiver or receiving element 430 extends below the lens 410 and has a thickness, t_receiver, that is chosen to be relatively thin (such as less than 0.25 inches and more typically several mils or less) and of a clear or substantially transparent material so as to pass light focused on the surface 432 by lens 410 to an opposite or transmission side 434 with little diffraction and/or loss. Typically, the thickness, t_receiver, is constant throughout the element 430 but this is not a required limitation. Also, both surfaces 432, 434 are typically smooth to enhance light acceptance and transmission. The receiver surface 432 is typically arcuate with the particular shape being variable to practice the invention. In some embodiments, performance of the assembly 400 is significantly enhanced by mapping or plotting focal points for the shape and design of the particular concentrating lens 410 for a desired range of incidence angles for light or Sun's rays striking the surface 412 of lens 410. Then, with this focal point pattern, the element 430 can be fabricated to match or substantially match this pattern with its surface 432. In other cases, though, the shape of surface 432 is select based on this pattern but is not forced to match it too closely as the assembly 400 is adapted to capture solar energy (but potentially at lower efficiency) even when the focal points are not perfectly aligned. In general, the shape of surface 432 is chosen such that a large percentage of the light or its rays focused by the facets or prisms 416 strike the surface 432 at an angle that is less than about 42 degrees as measured from normal with the surface 432 such that the light can be readily captured and then transmitted as it passes through the element 430 and exits via transmission surface 434. The receiver 430 has a depth, d_receiver, that is, in some embodiments, less than the width, W_lens, of the lens 410, which presents a lower height to width ratio and a smaller overall profile or height, H_panel, of the panel 400 (e.g., the width, W_lens, may be 1 to 2 inches while the depth, d_receiver, of the receiver 430 is about 0.75 to 1.5 inches over this same range for a panel profile, H_panel, less than 3 inches and, in some cases, less than about 1 to 1.5 inches).
To capture the concentrated light or solar energy, the transmission subassembly 440 includes a plurality of initial light transmission sheets or wafers 442. These are called sheets because they each may be an elongate, thin rectangular or other shaped member formed to act as a light pipe. A relatively small number of fairly thick sheets or wafers 442 are shown (e.g., to ease the difficulty of illustration), but in some embodiments many wafers 442 are provided such as up to 100, 200, 300 or more such as when the perimeter about the surface 434 is relatively large and/or the sheets 442 are relatively thin such as less than about 10 mils and in some cases less than 3 mils. In this regard, each sheet or light transmission element 442 is coupled to the transmission surface 434 of the light receiver 430 at a first end 444 and then extends outward from this surface to a second or distal end 446. The sheets 442 are formed of a plastic or other material and typically will be relatively thin such as a thickness, t_wafer, less than 200 mils but more typically about 3 to 100 mils in thickness, t_wafer. The optically coupled first or capture end 444 receives or accepts photons or rays of light that strikes the opposite portion of the receiver element 430, and when the photons or light rays enter the end 444 at an angle of less than about 42 degrees the light is captured by the sheet 442 and transmitted within the sheet 442 away from the receiver 430 via TIR. In the illustrated embodiment, wafers or sheets 442 are coupled at their receiving or capture ends 444 along the entire transmission surface 434 of the receiver 430 (and opposite the entire receiving surface 432) to capture concentrated solar energy regardless of where it is focused by the lens 410. The ends 444 of adjacent sheets 442 may be spaced apart a distance, t_spacing, but typically this spacing, t_spacing, is minimal or nonexistent to allow most of the solar energy transmitted through the lens 410 and receiver 430 to be captured. As with the receiver 430, the thickness, t_wafer, of the sheets 442 may be constant from end 444 to end 446 but in some embodiments the receiving or capturing end 444 may be wider than the body and end 446 to facilitate greater photon trapping (e.g., up to twice or more the thickness, t_wafer, at the end 444). As discussed above, there will typically be a set of 1, 2, 3, or more sheets 442 that will be active in the sense that they are being used to concurrently capture concentrated light from lens 410 (e.g., the thickness or width of the focusing area or strip of light upon the surface 432 will be wider than 1 or 2 or 3 etc of the sheets 442 in addition to any spacing such that more a set of the sheets 442 is needed to capture the photons as they strike the surface 432 and pass through the element 430 to the sheets 442).
To facilitate transmission of the captured light, the transmission subassembly 440 includes a plurality of intermediate light transmission wafers, sheets, or pipes 450 that generally are thin sheets of light-transmissive material such as plastic that extend the length of the receiver 430 (or panel 400), e.g., extend into the plane of the paper upon which FIG. 4 is drawn. The intermediate sheets 450 have a first side 452 and second side 454 and are arranged to be in optical contact with the second or distal ends 446 of the initial sheets 442 to receive or accept concentrated light transmitted through the sheets 442. To maintain TIR within the intermediate sheets 450, it is preferred that the initial sheets 442 abut the surface 452 at a proper coupling or acceptance angle, α, e.g., less than about 42 degrees. The light from the sheets 442 is than transmitted in the intermediate light transmission sheets 450 with TIR minimizing losses until the light reaches the output end 456 of the sheets 450 that are optically coupled with an upper surface 462 of a main or master light transmission sheet or light pipe 460. Again, the connection preferably maintains TIR within the main pipe 460 and, hence, coupling or acceptance angle, β, is typically less than about 42 degrees. The master pipe 460 typically extends into the paper the length of the receiver 430 (or assembly 400) and also the width, W_receiverassembly, of the assembly 400, with the width, W_{receiver assembly,}typically being somewhat larger than the width, W_lens, of the lens 410 to provide spacing for the transmission subassembly 440 such as up to twice the width, W_lens, or more). The main sheet or pipe 460 is formed of a layer of optically transmissive material such as a transparent, or substantially so, plastic, glass, or ceramic with a thickness, t_{Main Pipe}, that may be the same thickness as other elements or somewhat thicker (e.g., a range of a few mils to up to 1 inch or more) to provide structural rigidness or strength to the assembly 400 and panels with such assemblies 400. Although not shown, the pipe 460 may be isolated from other optic materials to avoid or limit losses of light transmitted into and then through the pipe 460. Also, as discussed above, the assembly 400 may be used alone or, more typically, will be part of a larger solar panel or module and the edge or end one of the assemblies 400 in such a module is typically adapted for optical coupling to another assembly/panel (e.g., with an optical coupler provided at both ends of the main pipe 460 or the like).
FIG. 5 illustrates another embodiment of a light concentrator assembly 500 of the present invention. The concentrator assembly 500 is shown in use with solar energy (or photons, light, Sun's rays, or the like) 506 striking a housing 508 on an upper surface 512, which includes an upper surface of a concentrating lens 510. For example, the rays 506 may represent sunlight striking the assembly 500 orthogonally, which may coincide with noontime or another time of the day depending upon the positioning of the assembly 500 on a roof or other installation. The assembly 500 includes a housing 508 with top and sidewalls to support the lens 510 and other components (and, in some cases, to position a main or master pipe 560 apart from the lower or outer surface 562). The view of FIG. 5 is an end view (with an optional end cap or wall removed to expose the internal components of assembly 500) and the assembly 500 generally would extend into the paper a length (e.g., a panel or assembly length that is typically up to a few inches long and more typically 9 to 18 inches or more with length often established to facilitate manufacturing, shipping, and other design parameters) and the various components of the assembly 500 typically extend the length of the assembly 500 (or panel).
The assembly 500 differs from assembly 400 in part because it utilizes a concentrating lens 510 that is configured as an elongate, flat Fresnel lens with its flat surface 512 facing outward to receive the solar energy 506. An inner or transmission surface 514 faces inward and includes a set of prisms or facets 516. The prisms 516 act to focus the received light 506 as shown at 520 onto a relatively narrow and elongate area (or strip, line, or the like) 536 upon a light receiving element 530. The light receiving element 530 is attached at its ends to the upper wall of the housing (or to the edges of the lens 510) and extends downward to define an arcuate (e.g., parabolic or other curved shape) cross sectional shape with its upper or receiving surface 534 (e.g., a concave surface facing the prisms 516). As discussed above, the shape of the surface 534 is typically selected based on (e.g., to coincide with) the focal points of the prisms 516 of lens 510 at various incidence angles for the light 506. For example, during the operating condition shown in FIG. 5, the incidence angle is about 0 degrees and the prisms 516 act to focus 520 the light 506 upon a thin strip (that extends into the paper along the length of the trough or basket-shaped element 530) 536 on surface 534. The light receiving element 530 typically is formed of material that transmits light (e.g., is clear or substantially transparent to the light 520) through to a back or transmission surface 532.
The assembly 500 also differs from the assembly 400 in that the assembly 500 is only adapted for gathering light over a smaller range of incidence angles such as −25 to 25 degrees relative to normal (or an orthogonal ray as measured from planar lens 510). This may be useful for collecting an acceptable portion of solar energy during the day (such as a period of time about noon or the like) or the assembly 500 may be used in a panel and array that is moved to track the Sun's movements. Such tracking would not have to be as accurate as existing tracking systems because the assembly 500 is adapted to effectively collect the concentrated rays over a range of incidence angles rather than only at a particular or single angle (or very tight band).
As shown, the assembly 500 includes a light capture and transmission subassembly 540. This subassembly 540 includes a set of initial light transmission sheets or wafers 542. Each of these sheets 542 is optically coupled to the transmission side 532 of the receiver 530 bottom of the trough or valley of the element 530. The light sheets 542 also include a roughened surface (or surface with raised elements such as lenticules or the like) that acts to provide a plurality of spacers to separate adjacent or neighboring sheets 542 to limit optical transmission or loss between the sheets 542. Numerous other spacers or separating elements may be used to provide some spacing between the sheets 542. At the coupling end, there may be little or no spacing to better capture all the rays 520 as they are focused upon the concentration area or strip 536 and are transmitted through the receiver layer 530.
In the assembly 500, a single intermediate light transmission sheet or wafer 550 is provided that is coupled to all of the wafers 542 upon an upper or inlet surface 554. The coupling is preferably accomplished at a desirable acceptable angle, β, such that rays or energy 546 within the intermediate pipe or sheet 550 remain within its walls due to TIR (e.g., an angle of less than about 42 degrees). The second surface 552 of the intermediate sheet is typically not in contact with any sheets 542 but may optionally be supported by structural elements (not shown). An end or edge 558 of the sheet or wafer 550 is typically optically connected to a main or master light transmission sheet, wafer, or pipe 560 such as via upper surface 564. Again, the connection of end 558 is such that discharged light 570 travels within the sheet 560 with no or minimal losses (e.g., TIR results in the light remaining in the sheet 560 similar to light pipe functionality). The concentrated light 580 is then output to the end or edge of the master or main sheet 560 such as to a collector when the assembly 500 is used as a standalone device or when the assembly 500 is on the end of a panel or array while in other cases the light 580 is injected into an adjacent assembly (with the configuration shown for assembly 500 or another configuration described herein).
FIG. 6 illustrates a concentrator subassembly 600 as may be used in the light concentrator assemblies of the invention to provide a desired level of concentration on a receiver element with a trough or other shape. As shown, the subassembly 600 includes a concentrating lens 520 in the form of an arched Fresnel lens with a smooth, upward/outward facing surface 622 and a downward/inward facing transmission surface 624. The surface 624 is rough or textured with a plurality of facets or prisms 626 configured to focus incoming rays (usually substantially parallel rays) at varying incidence angles upon focal points (or strips/lines) that are tightly grouped (as is common for Fresnel imaging and nonimaging lenses). As shown, the subassembly 600 also includes a receiver element or trough 640 with an arcuate (e.g., parabolic) cross sectional shape. Both the lens 620 and the element 640 have elongate bodies (extending into the plane of the paper in this view), and the lens 620 is positioned relative to the receiver element 640 such that the lens 620 covers most or all of the open end of the trough 640. In other words, a longitudinal axis of the arched lens 620 is parallel (or substantially so) to a longitudinal axis of the receiver element 640. The receiver element 640 (as well as the lens 620) is formed of a light-transmissive to transparent material such as plastic, glass, ceramic, or the like. The receiver element 650 includes a body or wall 652 with an inner facing, receiving surface 644 and an outer facing, transmission surface 646 (e.g., the surface to which a plurality of light wafers or pipes are attached in light concentrator assemblies to capture photons).
During operation as shown, a plurality of light rays 610 such as solar energy strikes the exposed, outer surface 622 of the concentrating lens 620 such as at about an incidence angle of about zero degrees. The rays 610 have a width, w_x, of 50 units of measure as they enter/exit the lens 620. The Fresnel prisms 626 are configured in this example, though, to focus the concentrated rays 630 onto a concentrated or receiving area or region 650 upon the surface 644 of the receiver 640 that is significantly smaller such as a width, w_y, of about 1 unit of measure (with the length of the concentrated or receiving area or region 650 typically being the length of the lens 620 and element 640 such as a few inches up to several feet or more but generally not varying due to the concentrating effect of lens 620). For example, concentration may concentrate rays with a width, w_x, of 500 mils down to a strip or line at 650 with a width, w_y, of 10 mils (or 50 mils down to 1 mil and so on), and such concentration may be thought of as capturing 50 suns at the region 650.
The receiver element 640 may be designed such that the cross sectional shape of surface 644 matches, approximates, or is within an acceptable range or proximity from the focal points such as points 650 at a range of incidence angles (e.g., the desired acceptance or capture range of the subassembly 600 to reduce or eliminate the need for tracking of the Sun's movements). Generally, for an arched Fresnel lens embodiment of the concentrating lens 620, this will result in the surface 644 being arcuate or parabolic in nature. The width, w_y, of the concentrated light region or area 650 then determines along with the size of the wafers/sheets used, the number of light transmission sheets or wafers are “active” at any time in capturing the concentrated light or energy 630 (e.g., if the width, w_y, is 5 mils and each wafer is about 1 mil in thickness, 5 wafers would be in the active set to collect or capture and then transmit the rays 630). As discussed, the active set of such wafers will change as the angle of the incoming rays 610 changes typically with one a small subset of a few of the wafers or sheets being utilized at any particular time/incidence angle to capture and transmit concentrated light.
In some embodiments, it may be desirable to simplify the light transmission assembly such as by eliminating intermediate light transmission sheets. FIG. 7 illustrates an exposed end view (e.g., a view without an optional end cap/cover) of a solar panel or module 700 with no intermediate transmission sheets or wafers. As shown, the panel 700 includes 3 light concentrator assemblies 710, 712, 714 that are similarly configured and are enclosed or supported by end or sidewalls. The assemblies 710, 712, 714 each concentrate light that strikes an upper surface and transmit the concentrated and captured light or solar energy to a master or main light transmission sheet or pipe 728 (e.g., a thin layer or sheet of plastic or the like that extends over most or all of the bottom of the assembly 700). In this manner, the light from the assemblies 710, 712, 714 is added or combined together and then may be output or discharged an end as concentrated light 718 to a collector or adjacent (and optically linked) solar module or panel (with the panels forming a solar array). Additionally, another panel (not shown) may be positioned “upstream” of the panel 700 and optically linked so as to inject light 716 from the adjacent panel in an array from its main/master sheet to the master light transmission sheet or wafer 728 for transmission to collector or other panel as shown at 718.
As shown with reference to assembly 710, the collector assemblies include a light concentrating lens 720 such as an arched Fresnel lens that extends along the length of and over a light receiving trough element 724. A plurality of thin sheets or wafers 726 of light transmissive material are positioned to be in optical contact with a back surface of the element 724. These sheets 726 may be formed, for example but not a limitation, of a flexible thin sheets or rectangles/strips of plastic such that they can more readily be arranged within the assembly 700 to contact the backside of element 724 and to then be snaked around (without losing TIR qualities) to an optical contact or coupling with an upper surface of the master or main light transmission sheet 728.
The panel 700 is shown during operation at 3 different incidence angles for received light or solar energy (e.g., 3 positions of the Sun relative to the panel 700). For example, in earlier morning hours, light may be incident upon the lens 720 such that light 730 is concentrated upon a strip or elongate region 732 of the light receiving surface of the element 724 (e.g., an incidence angle of 10 to 50 degrees measured clockwise from normal or the like). During such operations, a first set of one or more of the sheets or wafers 726 functions to capture or accept the concentrated light 730 and then transmit the light to the main sheet or pipe 728 for later discharge as combined, concentrated light 718. FIG. 8 illustrates in more detail at 800 such transmission of light to the main or master pipe 728 from the set of active light transmission sheets 726. As shown, captured light 805 is retained within the light pipes or sheets 726 by TIR. The sheets 726 are then coupled with the upper surface of the master or main light transmission sheet or pipe 728 at an angle, β, such that the light 810 is also retained in the master sheet 728 by TIR such that it can be transmitted within the assembly 700 and light from each assembly 710, 712, 714 can be injected into the pipe or sheet 728.
Nearer noon or other times, the Sun may be positioned more directly over the panel 700, and in such a position, light 740 is concentrated by the lens 720 upon a region 742 (e.g., again a thin strip or elongate, rectangular region) extending the length of the lens 720 and receiver 724. The region 742 is spaced apart from the first region 732 such as near the bottom of the trough of element 724. At this different position for light 740, a differing set of the sheets 726 become the active or utilized set of sheets or wafers and act to capture or accept the light 740 as it is transmitted through the element 724 to a back or transmission surface to which the sheets 726 are in contact or otherwise positioned for accepting the light 740. The captured photons or light is then transmitted in these sheets 726 to the main or master pipe 728. Then, later in the day or afternoon/evening (when the incidence angle may be 10 to 50 degrees as measured counterclockwise from normal or the like) light 750 is concentrated by the lens 720 onto yet another region or area 752 of the light receiving surface of the element 724. Again, this light concentration region 752 generally will appear to be a relatively thin strip of light on the element 724 with its width depending upon the configuration of the lens 720 and how closely the surface of element 724 is designed to match the focal points of the lens 720 (as well as other factors). Due to the new position of the region 752 upon the surface of element 724, another set of the sheets 726 becomes the active or utilized set that acts to capture the concentrated energy 750 and transmit it to the main pipe 728 for discharge from the panel 700 as light or energy 718.
FIG. 9 illustrates in view 900 a close up or detailed view of the light concentration or receiving region 752 for concentrated light 750. As shown, a quantity of the concentrated light 920 enters and travels through the element 724 where it is captured by the light wafers or sheets 726. These sheets 726 are attached (or optically coupled) at ends 910 to the back or transmission surface of the light receiving element 724. The sheets or wafers 726 have a thickness, t_wafer, that may vary to practice the invention with relatively thin sheets being useful in some low profile panels (e.g., the wafer thickness, t_wafer, may be less than a few mils and often less than a mil such as 0.5 mils). The captured light 930 travels within the sheets 726 along its length to the main pipe, and to this end the light is thought of as “captured” when it enters the sheets or pipes 726 at an angle that facilitates TIR such as less than about 42 degrees. Some spacing, t_spacing, is provided between the sheets 726 to reduce transfer of light between the sheets 726 that may result in losses of captured light 930 but generally this spacing, t_spacing, is minimized at the point of coupling or contact at end 910 such that a larger percentage of the light 920 traveling through the receiver 724 and exiting the backside is captured by the sheets 726. Again, spacing between adjacent sheets 726 may be provided by a surface texturing on the sheets 726 (such as by providing lenticules or similar protruding members on a side of each of the sheets 726) or by other techniques.
With the above description of exemplary embodiments of light concentrator assemblies in mind, it may now be useful to discuss some modeling of such assemblies that has been performed by the inventors with computer modeling techniques including ray tracing. The following discussion also provides advantages for embodiments of the invention, various aspects and configurations that may provide useful in implementing embodiments of the invention, and materials/ranges for design parameters for use in fabricating and using embodiments of the invention.
FIG. 10 illustrates a representation 1000 of a ray tracing that was performed with computer modeling software for one embodiment of an arched Fresnel lens 1020. In some of the light concentrator assemblies described herein, rays 1010 are first collected or received by a curved Fresnel lens 1020 used for the concentrating lens. The acceptance angle (or range of incidence angles) for the lens 1020 in the modeling was about 50 degrees (as measured in either direction from a normal or 0 degree ray). The received rays 1010 are focused with lens 1020 to concentrated rays 1030 at the focal points of facets of the Fresnel lens 1010 at a small concentration region 1014 with a particular width, w_{focus area}, which may provide a large concentration ratio such as 30:1 up to 70:1 or larger. The light source 1005 such as the Sun is shown in a position to provide an incidence angle of about 0 degrees in FIG. 10.
As discussed above, a light receiving element can be designed by mapping out the various focal points or focus areas for the concentrating lens 1020 over a range of incidence angles. With that in mind, FIG. 11 illustrates a modeling or ray tracing of the concentrating lens 1020 at a second, different incidence angle of about 30 degrees (e.g., light source 1105 is positioned to provide light rays 1110 at an angle of about 30 degrees to the lens 1020). Note, the position of the lens 1020 is held constant (e.g., no tracking in this embodiment), and the ray tracing shows that the lens 1020 concentrates the received light 1110 as shown at 1130 to a plurality of focal points or focusing/concentrating region or strip 1140. An effective or useful cross sectional shape for a light receiving surface (or trough element) can be achieved by plotting a number of these focusing regions or points and passing a line through or near these plotted focal point sets. The light receiving surface can then be shaped to coincide with or at least be within an acceptable range or offset distance from such a plotted focal point pattern for the lens 1020 over a number of incidence angles (e.g., the combination of the receiving surface and optically connection initial light transmission sheets is effective in capturing a significant portion of concentrated light even when the receiving surface is not perfectly aligned with the focal point pattern of the lens (or the approximation of the primary focal points) as long as a significant number of the rays/photons are striking the surface at a desirable incoming angle for the sheets to obtain TIR).
FIG. 12 illustrates a schematic end view of a collector or photon trap subassembly 1200 in which the lens 1020 has been modeled with ray tracing software or computer-based modeling tools to identify a desirable and effective light receiving element or trough 1210 for use with the lens 1020. The element 1210 has been provided a cross sectional shape that is substantially aligned or coinciding with a mapping or pattern of the primary focal points of the lens 1020 (or its facets/prisms) over a range of acceptance or incidence angles (e.g., −35 to 0 to +35 degrees). The plotting in one case was performed in part by creating ray tracings for the lens 1020 over the range of selected incidence angles at 2 degree increments (but, of course, other smaller or larger increments may be used) and the plotted focal points were used to construct a receiving surface shape for element 1210 that passed through or near many of these focal points.
As shown, for example, a first portion 1219 of the element 1210 is located to coincide or be proximate to focal points of the lens 1020 when light rays are focused from an incidence angle of about −35 degrees. A second portion 1217 is positioned to coincide or be near focal points associated with an incidence angle of −30 degrees. This technique is continued with portion 1215 coinciding with incidence of about −14 degrees, portion 1212 with a 0 degree incidence, portion 1214 with a +14 degree incidence angle, portion 1216 with a +30 degree incidence angle, and portion 1218 with a +35 degree incidence angle. In practice, the active set of initial light transmission sheets for any particular incidence angle or range of such angles is then the sheets positioned behind the portion of the light receiving element 1210 associated with that incoming light angle. Again, the subassembly 1200 would be formed by providing a Fresnel lens with the prism or facet design matching (or being within an acceptable range or variation from) the configuration used in the modeling or ray tracing program and providing a light receiving element with a receiving surface having or approximating the cross sectional shape of element 1210. The lens 1020 and the element 1210 would also be positioned in the subassembly 1200 with the spacing shown or modeled and to be parallel (or longitudinal axes of each component substantially parallel along the length of the two components).
In addition to the modeling of a light receiving element, the inventors have also performed ray tracing or optical modeling of a light collector assembly formed according to embodiments of the invention. This modeling has shown that an active set of about 3 to 6 light sheets can be used to capture light focused from an elongate, arched, nonimaging Fresnel lens upon a light receiving surface, and the modeling showed that such focused light is directed into the light sheets to obtain TIR (e.g., to allow the captured light to remain in the sheets formed of light transmissive to transparent material).
In use in a solar array, the light concentrating assemblies function to efficiently capture received solar energy. The Sun's rays are first collected by a concentrating lens such as a curved Fresnel lens extending over a light receiving trough or arcuate/curved element. The concentrating or Fresnel lens may be thought of as having a focus corresponding with a sweep angle generated by the azimuth of the Sun moving across the sky from morning to evening (e.g., east to west across the sky above the in-place solar array) when the lens is placed substantially perpendicular to the arc of the Sun (e.g., with its body or a longitudinal axis extending along a north to south line). The array, however, may also be positioned in an east-to-west arrangement (e.g., with its axes parallel to the Sun's travel path) so that the sweep angle generated by the arched Fresnel concentrating lens in each concentrate assembly is defined by the change in seasons as to the height of the Sun in the sky.
The received rays or solar energy/photons are then concentrated upon the light receiving surface (or a region/area thereon such as a thin strip), and the concentrated rays are captured or collected by the photon trap such as by passing through the light receiving element into adjacent, proximate light transmission sheets. In other words, the “photon trap” is made up in part by a series of fiber optic wafers or sheets that are angled as part of their optic coupling to the back or transmission side of the light receiving element so as to collect the pre-focused rays (or concentrated rays from the concentrating lens) via a set of active wafers or sheets. The wafers or sheets are angled in such a way that the acceptance angles match the incoming ray angles, whereby the collected rays are controlled or retained with little or no ray escape or loss. For example, the focused rays enter the ends of the sheets or wafers at angles not exceeding 42 degrees as measured as the angle between normal and a tracing of the ray as it contacts a sidewall or exterior surface of the sheet or wafer.
The light collection assembly or photon trap, with its individual fiber optic wafers or sheets, is designed to collect incoming rays from the concentrating lens over the sweep angle provided by the arched Fresnel or other concentrating lens. Then, the captured light is bent and/or moved along the sheets or wafers (or “active set”) toward the master fiber optic wafer or sheet by working with the specific angles created by the concentrating lens (or Fresnel lens in some cases) as a result of the Sun or other light source and the ray angles created by the lens. The rays are focused or directed through the sheets or wafers to the master light wafer or sheet at angles that allow the captured, concentrated light to enter the master light wafer or sheet at acceptable angles (e.g., angles that provide TIR within the master light wafer) to provide light transmission in the master light wafer to a collector or to an adjacent and optically linked solar panel.
In many embodiments, regardless of the sweep angle created by the curved Fresnel lens or other concentrating lens (and the position of the Sun or light source), the concentrated rays are directed into the trap or receiving element and to the individual wafers or sheets at acceptance angles to the approximate focal points of the Fresnel lens, which coincide or approximate the location of the light receiving surface and light transmission sheets or wafers. The captured rays are then gently curved in the selected or active light wafers or sheets (e.g., the set or portion of the trap or concentrator assembly utilized based on the azimuth of the Sun and the incoming angle) toward the master light transmission wafer or sheet. In some embodiments, a significant concentration ratio is provided from the lens to the capture location or concentrating/focus region on the light receiving surface such as up to about 30 to about 50 times or more, with only a subset of the light transmission sheets or wafers being used or active at any particular time/incidence angle (but, rather than a single receiver requiring tracking a plurality of available light transmission sheets are provided such that, in some embodiments, the concentrated light is effectively captured regardless of where it strikes the light receiving surface).
The thickness or height of the light collector assemblies and panels containing the assemblies may vary widely to practice the invention such as from less than 0.5 inches to over 3 feet. Some embodiments intended for residential building roof mounting and other lower profile applications are about 3 inches in thickness or height, which takes into account anticipated difficulties or issues with tooling of Fresnel lenses for the concentrating lens and the light transmission subassembly with the numerous, thin light transmission sheets or wafers attached to the light receiving element.
Although the invention has been described and illustrated with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example, and that numerous changes in the combination and arrangement of parts can be resorted to by those skilled in the art without departing from the spirit and scope of the invention, as hereinafter claimed. For example, while much of the above discussion highlighted use of a flat or arched Fresnel lens, the concentrating lens may take other forms to practice the invention, which may be useful when it is acceptable to have lower efficiencies and potentially less forgiving acceptance angles resulting in more cosine fall off than devices with Fresnel lenses used for the concentrating lenses. For example, non-Fresnel designs may not be as efficient because of the lack of focused rays provided directly into the sheets or wafers, and such designs may be less effective at self-correction/tracking but perform relatively well within particular ranges of incoming angles.
One aspect of the invention is the use of fiber optic technology and the leap into creating fiber optic wafers, which provides substantial energy transfer ability. After the light enters the wafer, the concentrated and captured light can bounce around thousands of time without real loss while light channels made with mirrored surfaces lose 4% at every reflection against the mirror such that a light chamber loses most of its energy by bouncing the energy off the walls of the mirrors, but this is not the case with the light concentrator assemblies and solar panels of the invention in which losses of less than about 10 percent (as measured from the total light/energy contacting the concentrating lenses). Another benefit of the present embodiments of the invention is that since no or little energy is lost, there is no or little thermal temperature rise in the light wafer. The inventors believe that this invention is truly revolutionary in part because the design of the light capture and transmission features allows the light sheets, concentrator assemblies, and solar panels to “link” to each other even if they are tilted individually, thereby allowing the combination any number of Suns or amounts of solar energy, which can then be provided to a collector or a load. Such scalability and modularity is not provided by devices using mirrors or traditional technology. This invention also facilitates low maintenance scaling of the units potentially to create any desired temperature up to the theoretical temperature of the surface of the Sun at the collector, and embodiments of the invention may be used to obsolete/replace or supplement light trough collectors, light towers, mirror towers and other thermal devices, while allowing nearly 100% of the PV rays to be collected and used as well.
At a desired point adjacent a master or main sheet or wafer of a panel, a collector may be placed at the end of the device (e.g., a solar thermal collector with an appropriately matched/selected diameter). The collector could be strictly PV material but would collect virtually all of the wavelengths available if it were used for the collection of thermal rays as well. The collector design may follow a more traditional parabolic design with the collector diameter determined by the width of the device. In order to “scale” the device, one way to manufacture the device may be to create solar “panels” or modules much the way traditional PV panels are sized and created. The difference in this device is that a target amount of energy to drive a Sterling engine or turbine may be targeted for designing a modular or scalable array of panels or modules with light concentrator assemblies as described herein. The devices or panels may be put together in both directions and cover any desired surface into a larger solar array, with the panels often mounting or connecting/linking together in both directions to allow light to be transmitted from the master or main sheets or wafers of each to an adjoining panel or module. The target energy or number of Suns output to the collector may be calculated by the following formula: length times width of collection area of the solar array as compared to the collector length times Pi. In order to generate steam and use the full energy created by the device, a computation allowing about 600 to 1000 Suns can achieve those goals and also allow PV materials to operate at higher efficiencies. The device also has such a wide acceptance angle (over 70 degrees) that it is several times more efficient than traditional PV collectors (e.g., conventional flat and non-tracking devices). Other advantages of the panels and arrays are that the light concentrator assemblies are sealed, the concentrator assemblies and panels (and arrays with the panels) have no moving parts and may be “snapped on” wherever the device ends (in some embodiments). Every unit may be designed to be modular and identical, and either may “snap” together with the next unit or have the collector unit “snap” into place. The panels and arrays of such panels are designed to have a long service life (e.g., to last virtually forever—sealed (e.g., with end covers and the like) with lasting materials (metal, glass, acrylic, steel, aluminum, recycled tires, and/or the like). As technology improves for collectors (including PV materials), the collector of conversions systems itself may be easily and inexpensively replaced. The panels and arrays of such panels may essentially be maintenance free, with cleaning and/or dusting performed occasionally to enhance effectiveness. It is anticipated based on modeling efforts of the inventors that on average with a 600 Sun target, an array of solar panels as described herein will be able to generate an average of about 100 Watts to about 450 Watts from thermal energy after converting the energy in a Sterling engine or turbine of a conversion system. The total of about 450 Watts is from a total available 1000 Watts per square meter at sea level, making the device by a highly efficient energy generation/conversion in the renewable energy market or industry.
As discussed with regard to FIG. 1, the solar array 110 may be configured to be modular such that each panel 112 may be optically fit together with or linked to adjacent ones of the panels 112 (and, particularly, to those along their output edges for the collected light). Such modularity and linking of the panels may be performed in numerous ways to practice the invention. FIG. 13 provides one useful example showing an exploded end view of a pair of solar panels 112 of an array. Each solar module or panel 110 includes a light collector assembly as discussed throughout this description and these function to collect and transmit light into a master or main light transmission sheet or wafer 1310 (with the collected light shown at 122 traveling transversely or laterally within the panel 112). The panel 112 may further include a bottom layer or base 1320 such that the master wafer or sheet 1310 is sandwiched between the base 1320 and the body of the panel 112 (or additional portions of the light collector assemblies).
On each end or side 114 of the panel 112, a connection groove or recess 1312, 1314 is provided, and this recessed surface 1312, 1314 extends the length of the panel 112 and has a depth, d_recess, chosen to support mechanical coupling and a height, H_recess, that typically substantially matches the thickness of the master or main wafer or sheet 1310. To fit 2 of the panels, a connector 1330 may be provided that includes a body 1332 as well as an optical connector or planar member 1334. The connector 1330 preferably has a length matching the length of the panels 112 and the optical connector 1334 extends the length of the body 1332 with two protruding members 1336, 1337 for mating with grooves or recesses 1312, 1314 of two adjacent panels 112 (e.g., with a height or thickness that is selected to provide a tight or even interference fit with the recesses 1312, 1314 and a depth of at least about the depth, d_recess, of the recess 1312, 1314). When fit together as shown by arrows 1351, 1352, an optical link is provided such that the collected light 122 from a first panel 112 is able to travel through the connector 1334 to a next panel 112. Additional couplings (not shown) may be provided on the sides or ends of the panels 112 that are not used to pass collected light (such as on the short ends of the panels 112 or sides transverse to the longitudinal axes of the light receiving elements and arched Fresnel lenses), and these couplings may also tongue and groove (male/female) type fittings but no optical connection is required at these edges/sides of the panels as the light travels out of the panels via the other two sides.
A similar connection may be provided between the “last” or ends panels 112 of the array 110 and the collector 130. One exemplary connection technique is shown in FIG. 14. As shown, a pair of solar panels 112 are connected together via a connector 1330 such that a planar main light sheet or wafer is provided for the collected light 122 via the master wafers 1330 of each panel 112 combined with the optical connector 1334. Instead of an additional panel 112, a solar collector 130 is optically coupled to the panel 112 at its recess or coupling groove 1314. This may be achieved by providing a collector with a housing or body 1410 that includes an optical coupling member 1412 that is sized for receipt or insertion into the groove or recess 1314 of the panels 112 and is fabricated of optically transmissive materials (e.g., plastic, glass, ceramic, or the like with the coupler 1412 often formed of the same material as the master wafers or sheets 1330 of panels 112). The solar collector 1410 may include piping or tubing 1414 (which may also be formed of a material that transmits light to allow at least thermal energy to reach the internal cavities of the pipe 1414) for routing or pumping a fluid such as glycol or water 1418 through the body 1410 to be exposed to the collected solar energy 122 via optical coupling 1412 that abuts the piping or tubing sidewall 1414 (or otherwise directs light 122 so as to convert thermal energy to the fluid 1418). In some cases, the collector 130 may also include PV material on the outer surface of the pipe 1414 such as at the edge of the optical coupling 1412 or PV material may be used solely with no fluid 1418 being utilized in the collector 130 (e.g., a PV collector rather than a combination thermal/PV collector). Again, additional coupling devices may be provided to increase the rigidity and physical robustness of the combination of the array 110 and the collector 130, and, in some cases, the array 110 is mounted onto tracking mechanisms that act to pivot or move the array 110 to track the movement of the Sun, which may require additional coupling or mounting components to attach the array 110 to the tracking equipment.
It may be useful at this point to provide specific examples of one modeled, light collector assembly providing the dimensions used in the modeling. These dimensions are not intended to be limiting but to provide values that fall within useful ranges for a concentrator assembly such as the assembly 400 of FIG. 4. In one modeling exercise (e.g., the ray tracing and light receiving surface defining of FIGS. 10-12), a plastic curved Fresnel lens was used for the concentrating lens and had a width of 2 inches and a thickness of 0.125 inches. The distance from the top of the curved Fresnel lens to the bottom of the basket or trough element (e.g., the light receiving surface at the bottom of the valley as the light receiving element is thin such as less that about 100 mils and, in some cases, less than 10 mils) was about 2.5 inches, and the total assembly thickness (or height of a panel with such assemblies) was about 3.5 inches including the wafers or sheets from the top of the lens to the bottom of the casing for the assembly or panel. The receiver or light receiving element had a “diameter” of about 0.25 inches and a length (e.g., panel length) of about 36 inches.
The first or initial light transmission sheets or wafers each had a thickness of 10 mils while the intermediate or second light transmission sheets or wafers each had a thickness of 100 mils. The main or master light transmission sheet or wafer was provided with a thickness of 0.25 inches. Hence, the actual focus of the wafer may be thought of as 0.25 inches times 36 inches or 9 square inches in this example (e.g., representative of a line on the cylindrical collector element equal to the width of the master wafer). The total length of the surface area of the light receiving surface of the trough or light receiving element (e.g., when laid flat or measured from edge to edge transverse to a longitudinal axis of the element) was 4.625 inches, and, with the given thickness of the initial light transmission sheets and with little or no separation at their optical coupling point on the back side of the light receiving surface, the total number of wafers or sheets used to cover this surface area is about (or some number less than to account for some separation) is about 462. During operation, the first or initial light transmission sheets or wafers channel the light into intermediate wafers, which may have a total of about 6 inches of area/width available for optical connectivity (e.g., width of intermediate wafers in some embodiments). The total width of the intermediate wafers less the total length of the basket or trough light receiving element equals a total area available for the gaps or spaces in the photon trap to limit optical contact between wafers/sheets (e.g., 6 minus 4.625 or 1.3175 inches in this modeled example). The number of gaps or spaces, of course, equals the number of initial or first light transmission sheets or wafers divided by 2 or, in this example, 462 divided by 2 or 231 gaps or spaces in the concentrator assembly. The width or thickness of these gaps is then determined by the available space divided by this number or 1.3175 inches divided by 231 or 0.0059 inches (or about 5.9 mils).
Again, these are only exemplary values that may be used in one implementation of a collector assembly of the invention with relatively large variations being acceptable—and sometimes preferred or more useful—in other implementations of the invention. For example, a Fresnel lens with a smaller or larger width and thickness may be utilized to implement a collector or concentrator (e.g., a width of several mils up to 12 inches or more and a thickness of several mils up to several inches or more). The specific configuration of the Fresnel or concentrating lens will dictate or define the separation of the top of the lens to the bottom of the light receiving surface as well as the shape of this light receiving surface. The thickness and number of the light transmission sheets or wafers may, of course, also be varied such as using first or initial light transmission wafers or sheets of less than 1 mil up to 100 mils or more (with 10 mils being just one example in this range), using second or intermediate light transmission wafers of several mils up to 300 mils or more (again, with 100 mils just being one example within such a useful range), and using a master wafer or sheet of less than about 0.125 inches up to 1 inch or more (with 0.25 inches being one useful value in this range). Once the configuration of the light receiving surface (or trough/basket element) and thicknesses of the wafers are selected, the number can be chosen to provide desired collection and transmission of the concentrated light landing on the trough surface (e.g., with little or no separation at the light coupling end of the initial light transmission sheets).
A solar array such as array 110 may be modeled or formed with solar panels containing the light collector assemblies defined or modeled in the preceding discussion. For example, the solar array may be a modular array with 30 of the solar panels or modules that each contain a set of light collector assemblies. The panel or module size may be set at 36 inches in length and width at 24 inches, with the Fresnel lens direction being in the length direction (e.g., the longitudinal axes of the lenses and the panel being parallel). Each panel or module would then have a surface area of 864 square inches such that the overall surface area of the 30-panel solar array would be 25,920 square inches or 180 square feet or 59.4 square meters (i.e., 30 panels times 864 square inches per panel). During use for power generation, the maximum wattage available from the Sun at sea level may be taken to be about 1000 watts (or 1 KW).
All or a significant portion of the code or pseudocode used by the inventors in modeling and/or designing the concentrator or collector assemblies of the invention is provided in a program listing after this detailed description, and it is believed that this code/program listing will be useful to those skilled in the art in selecting a concentrating lens configuration, creating a light receiving surface, and choosing arrangements of light transmission wafers as well as modeling the particular concentrator assemblies to verify light concentration, collection, and transmission in such assemblies. In the computer modeling of the light concentration or collector assemblies, the inventors have been determined that up to about 92 percent of the Sun's rays that are received on the surface of the panels (or surface of the Fresnel lenses) are captured and transmitted through the transmission sheets or wafers to the panel's or the solar array's outlet (e.g., to the collector for conversion to another useful form of energy). Hence, it is believed to be reasonable to assume up to about 90 percent efficiencies at peak hours (which minimizes cosine fall off) for a solar array fabricated with solar panels or modules of an embodiment of the invention. During use, then, a solar array with receiving surface area of about 59.4 square meters will be able to produce about 53.460 KW at the collector from the concentrated and captured solar energy (i.e., 59.4 square meters multiplied by 1 KW multiplied by 0.9 to take into account efficiencies).
Power conversions can be estimated for a solar conversion system such as shown in FIG. 1, but it should be remembered that such estimates will vary widely depending on the underlying assumptions regarding the conversion efficiencies of the various components (with such efficiencies not being limiting of the invention and an important factor simply being the large improvement in the amount of solar energy that can be effectively delivered to the solar collector for conversion). It is anticipated that up to about 25 percent of the concentrated, captured, and transmitted solar energy can be converted to direct current (DC) electrical power using a PV-based collector or converter (e.g., 53.460 KW multiplied by 0.25 or 13.36 KW of DC power, which may be further converted to AC power using an inverter or the like). In a combination PV/thermal collector system, the remaining solar energy (53.460-13.36 or 40.10 KW) may be used by a thermal collector directly as heat for buildings or a heat exchanger by using this energy to heat a fluid such as water or the thermal energy may be further converted by a Sterling engine or the like into electricity (e.g., up to about 45 percent or more of the thermal energy may be converted to AC power by a Sterling engine or process).
Other parameters that may be considered in evaluating the usefulness or effectiveness of a solar panel with the described concentrator assemblies is that the number of suns for fluid dynamics calculations is determined by the following equation/calculation: the total surface area of 25,920 square inches divided by the collector surface area of 28.6 square inches multiplied by the efficiency of 90 percent for a result of about 816 suns. The actual focus of the master wafer or sheet is typically considered as being against the collector surface and limited to one side of the “cylinder.” Hence, the actual surface area for this example may be taken as equal to 0.25 inches multiplied by 36 inches or about 9 square inches, and the number of suns can then be determined by first dividing 25,920 square inches by 9 square inches and then multiplying this result of 2,880 by 0.9 (or 90 percent) to produce the result of 2,592 suns.
It may also be useful to provide a general operational flow description of an implementation of solar array such as array 110 in a conversion system such as system 100 of the invention so as to provide further understanding to the usefulness and advantages of the concentrator technologies described herein. Sunlight comes into the Fresnel or other concentrating lens in each concentrator assembly and is focused straight down at noon (or near this time of day or overhead position of the Sun) with proper positioning of the solar array. The sunlight is focused by the lens into the first or initial light transmission wafers or sheets (or, more accurately, a small subset of such sheets at their optically coupled ends that may be about 10 mils thick). The captured, concentrated light is then transferred into the intermediate light transmission sheets or wafers (which may be about 100 mils thick) via an upper surface optically coupled to the initial light transmission sheets or wafers at acceptance angles of less than about 42 degrees. The light then moves into the master or main light transmission wafer or sheet (which may be about 0.25 inches thick) again at an acceptance angle of less than about 42 degrees such that light transmission physics including TIR continues to apply to the concentrated and captured sunlight. The sunlight is then joined or combined with the concentrated and captured from an adjacent or next concentrating lens and light receiving element or photon trap (e.g., the next concentrating assembly of the panel) as the light is moved or transmitted from one end to the other end of the panel for discharge at an end or edge of the master sheet or wafer (or out both ends concurrently in embodiments where the transmission sheets are arranged symmetrically or in other arrangements to transfer collected sunlight in opposite directions to the master or main sheet or wafer).
In some embodiments of the solar panels, there are 12 concentrator assemblies (e.g., 12 Fresnel lens and photon trap pairs) in each panel or module with each being about 2 inches wide (e.g., the panel has a width of 24 inches). The light moving through the master or main sheet or wafer continues in a transverse direction (e.g., transverse to a longitudinal axis of the light receiving element) to the next panel and son such that the solar panels (e.g., 30 panels) are optically linked together in the solar array, with each panel or module in one embodiment being 24 inches wide and 36 inches long. The light and energy continues to build in magnitude or accumulate in energy amounts as it approaches an end or edge of the solar array where a subset of the 30 panels or modules abuts or is proximate to a collector unit (that itself may be modular and/or connected in a detachable manner to the array). The collector unit may include a collector tube (e.g., a high temperature glass tube or the like) filled with a liquid such as glycol, water, or other fluid. The outside of the collector tube may be coated with high temperature resistant PV material to absorb the PV rays or rays falling in a particular range of wavelengths convertible or absorbed by PV material. Fluid is circulated through the collector at an appropriate volumetric rate to generate steam for a turbine or Sterling engine (or to heat the fluid as desired for use as a heated fluid in a thermal load). The PV-generated DC power may be fed to an inverter to conversion to AC power while the AC power from the Sterling engine may be fed to a home, business, power plant, and/or provided to a power grid or other end use/load.
Program Listing or Subroutine for Light Concentrator Assembly with Light Transmission Wafers or Sheets

Sub Generate_Wafers( ) ‘This subroutine generates wafers that feed into intermediate wafers. Wafers are generated from the locus of focal points from a Fresnel “basket” parallel to focal lines and then into a circle that is tangent to the walls of the intermediate collector.’
Dim intlineflag As Boolean
Dim i, j, k, n, ntype As Integer
Dim angle, anglestart, anglestop, de1, del1, del2, anglestep, radiusbasket, xcenterbasket, ycenterbasket As Double
Dim e1x, e1y, e2x, e2y, e3x, e3y, x1, y1, x2, y2, phi, xx, yy As Double
Dim s1, s2, s3, s4, tol1 As Double
tol1=0.01′ gap to box bottom
‘Use top of Fresnel as radius center and focal length of radius of basket.
‘The starting point of the straight portion of wafer is at the radius and is parallel to basket radius.
‘Pick the first arched fresnel that is in use.
For i=1 To NumberArchedFresnelLenses

If UseArchedFresnel(i)=True Then

- xcenterbasket=XArchedFresnelCenter(i)
- ycenterbasket=YArchedFresnelCenter(i)′−ArchedFresnelConjugateFacet(i)
- radiusbasket =BasketRadius(i)

End If

Next i
‘anglestep=−10#*DegToRadian
i=1
‘angle measured between vertical axis and basket surface
If radiusbasket=0 Then

MsgBox (“Wafer selected has basket radius of zero”)
Exit Sub

End If
anglestep=−2#*Atn((ThicknessWafer(i)+SpaceWafer(i))/(2#*radiusbasket))‘thickness+space of wafers
del1=anglestep*SpaceWafer(i)/(ThicknessWafer(i)+SpaceWafer(i)) ‘gives the space between wafers
del2=anglestep−del1‘get the step needed to produce the desired thickness
n=0
For angle=55#*DegToRadian To 25#*DegToRadian Step anglestep ‘adjust range for section of basket
For ntype=1 To 2 ‘(upper and lower part of wafer

If ntype=1 Then

- de1=0#
- n=n+1
- RWafer(ntype, i)=RWafer(3, i) ‘adjust, if necessary, by thickness for concentric circles

End If
If ntype=2 Then

- de1=del2
- RWafer(ntype, i)=RWafer(3, i)

End If
XWaferStart(ntype, i, n)=xcenterbasket+radiusbasket*Sin(angle+de1)
YWaferStart(ntype, i, n)=ycenterbasket−radiusbasket*Cos(angle+de1)
x1=XWaferStart(ntype, i, n)
y1=YWaferStart(ntype, i, n)
e1x=Sin(angle+de1) ‘direction cosines of wafer
e1y=−Cos(angle+de1)
‘Starting point of intermediate wafer for right side intermediate intersection
x2=XCenterWaferIntermediate(11)−ThicknessWaferIntermediate(11)/2#
y2=YBottomWaferIntermediate(11)
e2x=0# ‘direction cosines of intermediate wafer with tilted possibility in some other embodiments
e2y=1#
‘intersection point of wafer and intermediate wafer
Call intlines(x1, y1, x2, y2, e1x, e1y, e2x, e2y, xx, yy, intlineflag)
If intlineflag=False Then

- MsgBox (“No intersection of wafer and intermediate RIGHT wafer in Generate_Wafers”)

End If
‘Angle between wafer and intermediate wafer
s1=(e1x*e2x+e1y*e2y)
phi=Pi+Atn(Sqr(1#−s1̂2)/s1) ‘inverse cosine of dot product but larger than 90 degrees
s2=RWafer(ntype, i)/Tan(phi/2#) ‘+Pi/2# ‘distance of circle tangent points from intersection of wafer and intermediate wafer
XCircleStart(ntype, i, n)=xx−e1x*s2
YCircleStart(ntype, i, n)=yy−e1y*s2
XWaferEnd(ntype, i, n)=XCircleStart(ntype, i, n)
YWaferEnd(ntype, i, n)=YCircleStart(ntype, i, n)
XCircleEnd(ntype, i, n)=xx−e2x*s2
YCircleEnd(ntype, i, n)=yy−e2y*s2
‘Circle center
e3x=e1y
e3y=−e1x
XCircleCenterWaferR(ntype, i, n)=XCircleStart(ntype, i, n)+RWafer(ntype, i)*e3x
YCircleCenterWaferR(ntype, i, n)=YCircleStart(ntype, i, n)+RWafer(ntype, i)*e3y
‘- - - - - -
‘Circle start and stop angles
s1=XCircleStart(ntype, i, n)−XCircleCenterWaferR(ntype, i, n)
s2=YCircleStart(ntype, i, n)−YCircleCenterWaferR(ntype, i, n)
If s1=0 Then

- anglestart=Pi/2#

Else

- anglestart=Atn(s2/s1)

End If
s1=XCircleEnd(ntype, i, n)−XCircleCenterWaferR(ntype, i, n)
s2=YCircleEnd(ntype, i, n)−YCircleCenterWaferR(ntype, i, n)
If s1=0 Then

- anglestop=Pi/2#

Else

- anglestop=Atn(s2/s1)

End If
‘Calculate the straight line segments of the circles

- Call Calculate_Circle_Wafer_Segments(ntype, anglestart, anglestop, i, n)

Next ntype
NumberWafers(i)=n
NumberWaferArcs(i)=n

Next angle
‘Now calculate the intermediate wafer pieces between the openings (all the segments together for tracing and plotting).
i=11
k=1
XWaferStart(1, i, k)=XCenterWaferIntermediate(i)−ThicknessWaferIntermediate(i)/2#
YWaferStart(1, i, k)=YTopWaferIntermediate(i)
XWaferEnd(1, i, k)=XCenterWaferIntermediate(i)−ThicknessWaferIntermediate(i)/2#
YWaferEnd(1, i, k)=YCircleEnd(1, 1, 1)
For j=1 To (n−1)

k=k+1
XWaferStart(1, i, k)=XCenterWaferIntermediate(i)−ThicknessWaferIntermediate(i)/2#
YWaferStart(1, i, k)=YCircleEnd(2, 1, j)
XWaferEnd(1, i, k)=XCenterWaferIntermediate(i)−ThicknessWaferIntermediate(i)/2#
YWaferEnd(1, i, k)=YCircleEnd(1, 1, (j+1))

Next j
NumberWafers(i)=k
‘* * * * * * *
‘Bottom of intermediate wafer and circle connection to horizontal main wafer make a simple right angle turn of the desired radius.
‘First make the radii concentric
‘Note index 3 used for saved radii (may save some variables by including this calculation in the below calculation).
RWafer(1, i)=RWafer(3, i)−ThicknessWaferIntermediate(i)/2#
RWafer(2, i)=RWafer(3, i)+ThicknessWaferIntermediate(i)/2#
‘The center of the radii are
‘Note, index 1 is for smaller radius, 2 for larger radius
XCircleCenterWaferIntermediate(1,i)=XCenterWaferIntermediate(i)+ThicknessWaferIntermediate (i)+RWafer(1, i)
YCircleCenterWaferIntermediate(1, i)=2#*ThicknessWaferIntermediate(i)+RWafer(1, i)+tol1 ‘Wafer is assumed to lie on bottom of box
XCircleCenterWaferIntermediate(2,i)=XCenterWaferIntermediate(i)+ThicknessWaferIntermediate (i)+RWafer(2, i)
YCircleCenterWaferIntermediate(2, i)=2#*ThicknessWaferIntermediate(i)+RWafer(2, i)+tol1 ‘Wafer is assumed to lie on bottom of box
‘Get intersections of circles with intermediate wafers
n=0
For ntype=1 To 2 ‘Here ntype refers to small or large radii or one side vs. the other side of the intermediate wafer

If ntype=1 Then

- n=n+1
- x1=XCenterWaferIntermediate(i)+ThicknessWaferIntermediate(i)/2#
- y1=YTopWaferIntermediate(i)
- e1x=0# ‘for perpendicular intermediate wafer
- e1y=1#
- x2=HorizontalPositionWaferIntermediate(i)
- y2=ThicknessWaferIntermediate(i)+tol1
- e2x=1#
- e2y=0#
- RWafer(ntype, i)=RWafer(3, i)−ThicknessWaferIntermediate(i)

Else

- x1=XCenterWaferIntermediate(i)−ThicknessWaferIntermediate(i)/2#
- y1=YTopWaferIntermediate(i)
- e1x=0# ‘for perpendicular intermediate wafer
- e1y=1#
- x2=HorizontalPositionWaferIntermediate(12)
- y2=tol1 ‘Just off the floor of the box
- e2x=1#
- e2y=0#
- RWafer(ntype, i)=RWafer(3, i)+ThicknessWaferIntermediate(i)

End If
‘Intersection point of intermediate wafers
Call intlines(x1, y1, x2, y2, e1x, e1y, e2x, e2y, xx, yy, intlineflag)
If intlineflag=False Then

- MsgBox (“No intersection of intermediate wafers in Generate_Wafers”)

End If
‘Agle between intermediate wafers
s1=(e1x*e2x+e1y*e2y)

- If s1=0 Then
- phi=Pi/2#

Else

- phi=Pi+Atn(Sqr(1#−s1̂2)/s1)’ inverse cosine of dot product but larger than 90 degrees

End If
s2=RWafer(ntype, i)/Tan(phi/2#)+Pi/2# ‘distance of circle tangent points from intersection of wafer and intermediate wafer
XCircleStart(ntype, i, n)=xx−e1x*s2
YCircleStart(ntype, i, n)=yy+e1y*s2 ‘watch for sign to determine direction of circle center.
‘XWaferEnd(ntype, i, n)=XCircleStart(ntype, i, n)
‘YWaferEnd(ntype, i, n)=YCircleStart(ntype, i, n)
XCircleEnd(ntype, i, n)=xx+e2x*s2
YCircleEnd(ntype, i, n)=yy−e2y*s2
e3x=e1y
e3y=−e1x
XCircleCenterWaferR(ntype, i, n)=XCircleStart(ntype, i, n)+RWafer(ntype, i)*e3x
YCircleCenterWaferR(ntype, i, n)=YCircleStart(ntype, i, n)+RWafer(ntype, i)*e3y
‘- - - - - -
‘Circle start and stop angles
s1=XCircleStart(ntype, i, n)−XCircleCenterWaferR(ntype, i, n)
s2=YCircleStart(ntype, i, n)−YCircleCenterWaferR(ntype, i, n)
‘s1=inversesine(0.8)
s3=Sin(s1)
s3=Sqr(s1̂2+s2̂2)
s4=s2/s3 ‘This is the sine of the angle
anglestart=inversesine(s4)
If s0<0# Then

- anglestart=anglestart−Pi

End If
‘If s1=0 Then
‘anglestart=Pi/2#
‘Else
‘anglestart=Atn(s2/s1)
‘End If
s1=XCircleEnd(ntype, i, n)−XCircleCenterWaferR(ntype, i, n)
s2=YCircleEnd(ntype, i, n)−YCircleCenterWaferR(ntype, i, n)
s3=Sqr(s1̂2+s2̂2)
s4=s2/s3
anglestop=inversesine(s4)
If s1<0# Then

- anglestart=anglestart−Pi/2#

End If
‘If s1=0 Then
‘anglestop=Pi/2#
‘Else
‘anglestop=Atn(s2/s1)
‘End If
‘Calculate the straight line segments
Call Calculate_Circle_Wafer_Segments(ntype, anglestart, anglestop, i, n)
‘Define intermediate vertical wafer
‘If ntype=1 Then
‘XWaferStart(ntype, i, n)=x1
‘YWaferStart(ntype, i, n)=y1
‘XWaferEnd(ntype, i, n)=x1
‘YWaferEnd(ntype, i, n)=YCircleStart(ntype, i, n)
‘End If
‘If ntype=2 Then
‘XWaferStart(ntype, i, n)=x2
‘YWaferStart(ntype, i, n)=y2
‘For j =1 ToNumberWafers(1)
‘n=n+1
‘XWaferEnd(ntype, i, n)=XCircleEnd(ntype, 1, n)
‘Next j
‘End If
‘n=n+1
‘Define intermediate horizontal wafer
‘XWaferStart(ntype, i, n)=XCircleEnd(ntype, i, n)
‘YWaferStart(ntype, i, n)=YCircleEnd(ntype, i, n)
‘XWaferEnd(ntype, i, n)=HorizontalPositionWaferIntermediate(i)
‘YWaferEnd(ntype, i, n)=y2
‘NumberWafers(i)=n
NumberWaferArcs(i)=n

Next ntype

DesignWafers=True

End Sub

Claims

1. A panel for concentrating and collecting solar energy, comprising:

a plurality of light collector assemblies positioned side-by-side;

each of the light collector assemblies comprising:

a receiver element with an elongate body and a light receiving surface with a curved cross sectional shape;

an elongate concentrating lens extending over the receiver element body focusing incident light onto the light receiving surface in a strip extending along a length of the light receiving surface; and

a plurality of light transmission sheets extending along the receiver element body with an edge optically connected to the receiver element body on a surface opposite the light receiving surface, wherein a set of one or more of the light transmission sheets receives and transmits at least a portion of the light focused in the strip by the concentrating lens.

2. The panel of claim 1, wherein the strip of the focused light has a plurality of differing positions on the light receiving surface corresponding to a plurality of incidence angles for the incident light.

3. The panel of claim 2, wherein the set of one or more of the light transmission sheets receiving and transmitting the focused light includes differing ones of the light transmission sheets at least for at least some of the differing positions for the strip of the focused light.

4. The panel of claim 2, wherein concentrating lens comprises an arched Fresnel lens.

5. The panel of claim 4, wherein the curved shape of the light receiving surface is configured such that at least portions of the light receiving surface are proximate to a set of focal points for the Fresnel lens at differing angles of incidence for the incident light.

6. The panel of claim 5, wherein the curved shape of the light receiving surface is substantially coincident with locations of the set of focal points for the Fresnel lens.

7. The panel of claim 1, wherein the receiver element and the light transmission sheets comprise a material that transmits light, the material selected from the group consisting of a plastic, a glass, and a ceramic.

8. The panel of claim 7, wherein the portion of light received by the set of light transmission sheets is received at angles to cause total internal reflection within the light transmission sheets of the set, whereby the portion of light received is transmitted along the set of light transmission sheets.

9. The panel of claim 8, further comprising a master light transmission sheet formed of a light transmissive material spaced apart from the receiver elements of the light collector assemblies, wherein in each light collector assembly a second edge of the light transmission sheets opposite the edge optically connected to the receiver element body is optically connected to a surface of the master light transmission sheet, whereby the portion of the light focused in the strip by the concentrating lens of each of the light collector assemblies is provided to the master light transmission sheet for transmission through the panel.

10. The panel of claim 9, further comprising, in each light collector assembly, a plurality of intermediate light transmission sheets formed of light transmissive material positioned in optical contact with the second edges of the light transmission sheets and with the surface of the master light transmission sheet to transmit the at least a portion of the light focused in the strip by the concentrating lens between the light transmission sheets and the master light transmission sheet via total internal reflection.

11. The panel of claim 1, wherein the light transmission sheets have a thickness in the range of about 0.5 mils to about 2 inches and the edges connected to the receiver element body are spaced apart by at least about 0.5 mils from adjacent ones of the edges.

12. The panel of claim 11, wherein the thickness of the light transmission sheets is less than about I mil and wherein each of the light collector assemblies includes at least about 10 of the light transmission sheets positioned along a portion of the receiver element body.

13. A light concentrator assembly, comprising:

a light receiving element formed of a substantially transparent material and having a concave light receiving surface extending a length of the light receiving element;

a lens extending over the light receiving surface, the lens receiving light from a light source at a plurality of angles of incidence and, in response, focusing the received light onto the light receiving surface in strips associated with each of the angles of incidence, the strips being substantially parallel to a longitudinal axis of the light receiving element and differing in position based on the angles of incidence; and

a light collection and transmission subassembly configured to collect at least a portion of the received light concentrated into the strips and to transmit the collected portion of the received light to an outlet of the light concentrator assembly.

14. The assembly of claim 13, wherein the lens comprises an elongate, arched Fresnel lens.

15. The assembly of claim 14, wherein the light receiving surface has a cross sectional shape at least partially coinciding with a pattern of focal points of the Fresnel lens for light striking the Fresnel lens at a set of the angles of incidence.

16. The assembly of claim 13, wherein the light collection and transmission subassembly comprises a plurality of initial light transmission wafers each extending along the light receiving element with an edge positioned to provide optical contact with a back surface of the light receiving element opposite the light receiving surface.

17. The assembly of claim 16, wherein the wafers comprise light transmissive material and wherein the assembly comprises at least about 10 of the wafers positioned about at least a portion of a periphery of the light receiving element.

18. The assembly of claim 17, wherein at least a portion of the light in the strips is directed into a set of the edges of the initial light transmission wafers at an angle of less than about 42 degrees, whereby the received portion of the light is transmitted through the wafers associated with the set of the edges.

19. The assembly of claim 17, wherein the light collection and transmission subassembly further comprises a planar, master light transmission wafer extending adjacent the light receiving element and formed of a light transmissive material and wherein the light collection and transmission subassembly further comprises a plurality of intermediate light transmission wafers optically coupled to a second edge of the initial light transmission wafers to receive the transmitted and collected portion of the received light and to a surface of the master light transmission wafer, whereby the transmitted and collected portions of the received light input to the master light transmission wafer for transmission out of the light concentrator assembly.

20. The assembly of claim 16, wherein the edges of the initial light transmission wafers are arranged to be parallel with a longitudinal axis of the lens, wherein the strips of concentrated, received light each have a width that is greater than a width of each of the edges of the wafers, and wherein a set of two or more of the initial light transmission wafers receives the collected portion of the concentrated, received light transmitted through the back surface of the light receiving element.

21. A solar energy conversion system, comprising:

a solar array comprising a plurality of solar modules, each of the solar modules comprising:

a concentrating lens with an elongate body operable to focus light incident upon the lens into a strip-like pattern along its length;

a plurality of light concentrators having a light receiving trough formed of light transmissive material with a curved light receiving surface and light transmitting surface opposite the light receiving surface, wherein the light receiving surface has a cross sectional shape and position relative to the lens such that the light receiving surface is at least proximate to positions of the light focused into the strip-like pattern at a set of incidence angles; and

a plurality of light transmission sheets each with an edge optically coupled to the light transmitting surface and extending substantially parallel to a longitudinal axis of the light receiving trough, wherein a set of the light transmission sheets receives at least a portion of the incident light focused into the strip-like pattern via the edges;

wherein each of the solar module further comprises a master light transmission sheet extending adjacent and spaced apart from the light receiving trough, the master light transmission sheet being linked optically to the plurality of light transmission sheets in the light concentrators to receive the portion of the incident light from the set of the light transmission sheets; and

wherein the solar modules are arranged in the solar array with the master light transmission sheets optically coupled, whereby the incident light received by master light transmission sheets of the solar modules is combined and transmitted to a light outlet for the solar array.

22. The system of claim 21, wherein the light transmission sheets are coupled to the light transmitting surface such that the light focused into the strip-like pattern enters the set of the light transmission sheets at an acceptance angle of less than about 42 degrees, whereby the entering light is transmitted within the set of the light transmission sheet by total internal reflection.

23. The system of claim 21, further comprising a collector positioned to receive the combined and transmitted light at the light outlet of the solar array.

24. The system of claim 23, further comprising means for converting the light received at the collector into thermal energy or electricity.