US20110061718A1 - Passively Cooled Solar Concentrating Photovoltaic Device - Google Patents

Passively Cooled Solar Concentrating Photovoltaic Device Download PDF

Info

Publication number
US20110061718A1
US20110061718A1 US12/950,918 US95091810A US2011061718A1 US 20110061718 A1 US20110061718 A1 US 20110061718A1 US 95091810 A US95091810 A US 95091810A US 2011061718 A1 US2011061718 A1 US 2011061718A1
Authority
US
United States
Prior art keywords
optical element
heat spreader
central portion
heat
thermal resistance
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US12/950,918
Inventor
David K. Fork
Stephen J. Horne
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Palo Alto Research Center Inc
Solfocus Inc
Original Assignee
Palo Alto Research Center Inc
Solfocus Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Palo Alto Research Center Inc, Solfocus Inc filed Critical Palo Alto Research Center Inc
Priority to US12/950,918 priority Critical patent/US20110061718A1/en
Publication of US20110061718A1 publication Critical patent/US20110061718A1/en
Assigned to CPV SOLAR LLC C/O HARPER CONSTRUCTION COMPANY, INC. reassignment CPV SOLAR LLC C/O HARPER CONSTRUCTION COMPANY, INC. SECURITY AGREEMENT Assignors: SOLFOCUS, INC.
Abandoned legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/052Cooling means directly associated or integrated with the PV cell, e.g. integrated Peltier elements for active cooling or heat sinks directly associated with the PV cells
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/054Optical elements directly associated or integrated with the PV cell, e.g. light-reflecting means or light-concentrating means
    • H01L31/0547Optical elements directly associated or integrated with the PV cell, e.g. light-reflecting means or light-concentrating means comprising light concentrating means of the reflecting type, e.g. parabolic mirrors, concentrators using total internal reflection
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00Energy generation through renewable energy sources
    • Y02E10/50Photovoltaic [PV] energy
    • Y02E10/52PV systems with concentrators

Definitions

  • This invention relates to solar power generators, more particularly to managing the heat generated at and around the photovoltaic (PV) cell in solid dielectric solar concentrator photovoltaic (CPV) devices.
  • PV photovoltaic
  • CPV solid dielectric solar concentrator photovoltaic
  • Photovoltaic solar energy collection devices used to generate electric power generally include flat-panel collectors and concentrating solar collectors.
  • Flat collectors generally include PV cell arrays and associated electronics formed on semiconductor (e.g., monocrystalline silicon or polycrystalline silicon) substrates, and the electrical energy output from flat collectors is a direct function of the area of the array, thereby requiring large, expensive semiconductor substrates.
  • Concentrating solar collectors reduce the need for large semiconductor substrates by concentrating light beams (i.e., sun rays) using, e.g., a parabolic reflectors or lenses that focus the beams, creating a more intense beam of solar energy that is directed onto a small PV cell.
  • concentrating solar collectors have an advantage over flat-panel collectors in that they utilize substantially smaller amounts of semiconductor.
  • Another advantage that concentrating solar collectors have over flat-panel collectors is that they are more efficient at generating electrical energy.
  • a problem with conventional concentrating solar collectors is that they are expensive to operate and maintain.
  • the reflectors and/or lenses used in conventional collectors to focus the light beams are produced separately, and must be painstakingly assembled to provide the proper alignment between the focused beam and the PV cell. Further, over time, the reflectors and/or lenses can become misaligned due to thermal cycling or vibration, and become dirty due to exposure to the environment. Maintenance in the form of cleaning and adjusting the reflectors/lenses can be significant, particularly when the reflectors/lenses are produced with uneven shapes that are difficult to clean.
  • concentrating solar collectors produce flux densities of 300 to over 1000 suns at the PV cell, with typically less than half of the energy is converted into electricity and the remainder occurring as heat, producing PV cell temperatures that can reach well above 100° C.
  • a conventional approach to reducing peak PV cell temperatures in concentrating solar collectors includes using a forced liquid cooling system to cool the PV cell, but such forced liquid cooling systems are expensive to produce and maintain, thus significantly increasing the overall production and operating costs of such concentrating solar collectors.
  • CPV concentrator PV
  • the present invention is directed to a Cassegrain-type CPV device that induces the efficient radiation of heat out the front of the concentrator by utilizing a heat spreader to evenly distribute heat from the centrally located PV cell over the backside surface of a solid optical element, and by utilizing the solid optical element to transfer the heat from the heat spreader to a front aperture surface, from which the heat is radiated into space.
  • This arrangement facilitates the radiation of more than 30% of the generated heat through the front aperture surface, thus improving passive cooling performance by approximately a factor of two over hollow concentrator systems that radiate heat out the back surface.
  • the solid optical element facilitates the direct formation of primary and secondary mirrors thereon, thus automatically and permanently aligning the concentrator optics and maintaining optimal optical operation while minimizing maintenance costs.
  • a lateral thermal resistance of the heat spreader is less than a transverse thermal resistance of the solid optical element, thereby optimizing radiant heat transfer by maximizing the heat distribution to maintain the optical element and, hence, the aperture surface at a substantially uniform temperature.
  • the solid optical element includes a low-iron glass structure having a thickness in the range of 5 to 12 mm and a diameter of approximately 28 mm
  • the heat spreader includes copper heat-distributing layer having a nominal thickness of approximately 70 microns. At this thickness, a lateral thermal resistance of thermal resistance of the copper heat-distributing layer is greater than the transverse thermal resistance of the optical element, thereby producing the desired uniform heating and radiation from the front aperture surface.
  • the heat spreader includes a thermal conductive layer (e.g., copper) formed on a flexible substrate (e.g., a polyimide film such as Kapton® produced by DuPont Electronics), and the PV cell is mounted on the heat spreader prior to assembly onto the solid optical element, thereby greatly simplifying the assembly process.
  • a flexible substrate e.g., a polyimide film such as Kapton® produced by DuPont Electronics
  • the PV cell is mounted on the heat spreader prior to assembly onto the solid optical element, thereby greatly simplifying the assembly process.
  • the flexible substrate is cut or otherwise separated into a plurality of radial arms that extend from a central support region, which facilitates close contact to curved lower surface of the solid optical element during assembly.
  • the wiring layers of the heat spreader are optionally used to help direct heat to the optical element.
  • the primary mirror includes a thin silver reflective layer, a copper anti-migration layer disposed on the silver layer, and a barrier paint layer disposed on the anti-migration layer.
  • the heat spreader is then secured to the barrier paint layer by way of a suitable adhesive (e.g., EVA), and a protective shell (e.g., Tedlar) is secured to the backside of the flexible substrate using the same adhesive.
  • a suitable adhesive e.g., EVA
  • Tedlar e.g., Tedlar
  • FIG. 1 is an exploded perspective view showing a CPV device according to an embodiment of the present invention
  • FIG. 2 is a cross-sectional side view showing the CPV device of FIG. 1 during operation
  • FIG. 3 is an exploded perspective view showing a CPV device according to another embodiment of the present invention.
  • FIG. 4 is a cross-sectional side view showing CPV device of FIG. 3 in additional detail
  • FIG. 5 is a perspective view showing a heat spreader substrate utilized in the CPV device of FIG. 3 ;
  • FIG. 6 is an assembled perspective view showing the CPV device of FIG. 3 .
  • the present invention relates to managing the heat generated at and around the PV cell in a solid dielectric solar concentrator, such as that disclosed in co-owned and co-pending U.S. patent application Ser. No. 11/110,611 entitled “CONCENTRATING SOLAR COLLECTOR WITH SOLID OPTICAL ELEMENT”, which is incorporated herein by reference in its entirety.
  • the present invention relates to a passive heat management system that avoids the production and maintenance costs of conductive and fluid cooled systems by facilitating the radiation of more than 30% of the generated heat from the front aperture surface of the solid optical element.
  • the blackbody temperature of the sky is typically on the order of ⁇ 40 degrees Celsius ( ⁇ 40° C.).
  • the blackbody temperature of the ground is typically about 4° C. above the ambient temperature. It is therefore desirable to provide a thermal path to the front surface of the device so it can radiate heat skyward.
  • the net radiation flux per unit area from the front surface of the concentrator can be expressed as:
  • ⁇ f is the emissivity of the front surface (typically 0.85 for low iron glass)
  • is the Stefan-Boltzmann constant (5.67 ⁇ 10 ⁇ 8 Watts/m 2 Kelvin 4 )
  • T f is the absolute temperature of the front surface
  • R f is the reflectivity of the front surface (typically about 8%)
  • T s is the blackbody temperature of the sky (about ⁇ 40 Celsius).
  • the radiation out the back of the concentrator can be expressed similarly as:
  • ⁇ b is the emissivity of the back surface (typically 0.9 for plastic laminated Tedlar)
  • T b is the absolute temperature of the concentrator's back surface
  • R b is the reflectivity of the concentrator's back surface (typically about 10% for Tedlar in the infrared)
  • T g is the blackbody temperature of the ground or rooftop (typically about 4 degrees Celsius above ambient).
  • Equations 1 and 2 What is apparent from Equations 1 and 2 is that the front surface radiates into a much colder bath than the back surface. In flat plate PV systems, more than twice as much heat is typically lost out the front of the panel than out the rear. It is a useful aspect of this invention to create a concentrating PV system that mimics this advantageous heat loss mechanism.
  • FIG. 1 is an exploded perspective view showing an internal mirror, Cassegrain-type concentrator photovoltaic (CPV) device 100 according to a simplified embodiment of the present invention.
  • Concentrating solar collector 100 generally includes an optical element 110 , a photovoltaic (PV) cell 120 , a primary mirror 130 , a secondary mirror 140 , and a heat spreader 150 .
  • PV photovoltaic
  • Optical element 110 is a solid, disk-like, light-transparent structure including an upper layer 111 , a relatively large convex surface 112 protruding from a lower side of upper layer 111 , a substantially flat aperture surface 115 disposed on an upper side of upper layer 111 , and a relatively small concave (curved) surface (depression) 117 defined in aperture surface 115 (i.e., extending into upper layer 111 ).
  • upper layer 111 may be vanishingly small.
  • optical element 110 is molded using a low-iron glass (e.g., Optiwhite glass produced by Pilkington PLC, UK) structure according to known glass molding methods.
  • optical element 110 may be machined and polished to form single-piece optical element 110 , or separate pieces by be glued or otherwise secured to form optical element 110 .
  • optical element 110 is 5 to 12 mm thick and 20 to 40 mm wide. This thickness helps to ensure that the heat conduction path from the backside convex surface 112 to aperture surface 115 does not become too resistive as it would be if optical element 110 were either thicker or hollow.
  • PV cell 120 is located in a central first side (cavity) region 113 that is defined in the center of convex surface 112 .
  • PV cell 120 is connected by way of suitable conductors 122 and 124 (indicated in FIG. 2 ), for example, to the PV cells of adjacent CPV devices (not shown) using known techniques.
  • suitable photovoltaic (concentrator solar) cells are produced, for example, by Spectrolab, Inc. of Sylmar, Calif., USA.
  • Primary mirror 130 and secondary mirror 140 are respectively disposed on convex surface 112 and concave surface 117 .
  • Primary mirror 130 and secondary mirror 140 are shaped and arranged such that, as shown in FIG. 2 , light beams LB traveling in a predetermined direction (e.g., perpendicular to aperture surface 115 ) that enters optical element 110 through a specific region of aperture surface 115 is reflected by a corresponding region of primary mirror 130 to an associated region of secondary mirror 140 , and from the associated region of secondary mirror 140 to PV cell 120 (e.g., directly from secondary mirror 140 to PV cell 120 , or by way of a reflective or refractive surface positioned between secondary mirror and PV cell 120 ).
  • a predetermined direction e.g., perpendicular to aperture surface 115
  • PV cell 120 e.g., directly from secondary mirror 140 to PV cell 120 , or by way of a reflective or refractive surface positioned between secondary mirror and PV cell 120 .
  • primary mirror 130 and secondary mirror 140 are fabricated by sputtering or otherwise depositing a reflective mirror material (e.g., silver (Ag) or aluminum (Al)) directly onto convex surface 112 and concave surface 117 , thereby minimizing manufacturing costs and providing superior optical characteristics.
  • a reflective mirror material e.g., silver (Ag) or aluminum (Al)
  • primary mirror 130 substantially takes the shape of convex surface 112
  • secondary mirror 140 substantially takes the shape of concave surface 117 .
  • optical element 110 is molded or otherwise fabricated such that convex surface 112 and concave surface 117 are arranged and shaped to produce the desired mirror shapes. Note that, by forming convex surface 112 and concave surface 117 with the desired mirror shape and position, primary mirror 130 and secondary mirror 140 are effectively self-forming and self-aligning, thus eliminating expensive assembly and alignment costs associated with conventional concentrating solar collectors.
  • primary mirror 130 and secondary mirror 140 remain affixed to optical element 110 , their relative position is permanently set, thereby eliminating the need for adjustment or realignment that may be needed in conventional multiple-part arrangements.
  • primary mirror 130 and secondary mirror 140 are formed simultaneously using the same (identical) material or materials (e.g., plated Ag), thereby minimizing fabrication costs.
  • the surfaces of optical element 110 to fabricate the mirrors, once light enters into optical element 110 through aperture surface 115 , the light is only reflected by primary mirror 130 /convex surface 112 and secondary mirror 140 /concave surface 117 before reaching PV cell 120 .
  • the light is subjected to only one air/glass interface (i.e., aperture surface 115 ), thereby minimizing losses that are otherwise experienced by conventional multi-part concentrating solar collectors.
  • the single air/glass interface loss can be further lowered using an antireflection coating on aperture surface 115 .
  • this production method would greatly increase manufacturing costs and may reduce the superior optical characteristics provided by forming mirror films directly onto convex surface 112 and concave surface 117 .
  • Heat spreader 150 includes a central portion 151 and a curved peripheral portion 152 extending outward from central portion 151 .
  • Heat spreader 150 includes a material having relatively high thermal conductivity, and includes a thickness selected such that a lateral thermal resistance TR 1 of heat spreader 150 (i.e., measured in a radial direction from central portion 151 to the outer edge of peripheral portions 152 ) is less than a transverse thermal resistance TR 2 of optical element 110 (i.e., measured from the convex surface 112 to the aperture surface 115 ).
  • many small CPV devices 100 are arrayed together in order to keep the volume of glass from becoming excessively large, and to keep the amount of power per PV cell manageable without active cooling.
  • heat spreader 150 includes a copper heat-distributing layer having a thickness of 70 microns (i.e., two ounce copper), which provides a thermal resistance TR 1 that is greater than a thermal resistance TR 2 of optical element 110 .
  • a lateral thermal resistance of the copper heat-distributing layer is greater than the transverse thermal resistance of the optical element.
  • central portion 151 of heat spreader 150 is disposed over cavity 113 , and curved peripheral portion 152 is formed on or otherwise secured to the back (non-reflecting) surface of primary mirror 130 .
  • PV cell 120 is mounted on an inside surface of central portion 151 such that PV cell 120 is disposed inside cavity 113 .
  • a gap filling transparent adhesive 128 such as silicone (e.g., polydiphenylsiloxane or polymethylphenylsiloxane), is also disposed inside cavity 113 over PV cell 120 , and serves to minimize the disruptive break in the refractive indicies between the outside surface of cavity 113 and PV cell 120 .
  • a central opening 131 is defined in primary mirror 130 to facilitate the passage of light through cavity 113 to PV cell 120 .
  • PV cell 120 is mounted onto central region 151 by way of a heat slug 127 .
  • one or more openings are formed in central region 151 and heat slug 127 to facilitate the passage of current from PV cell 120 , e.g., by way of conductors 122 and 124 .
  • current is transmitted to and from PV cell 120 by way of heat spreader 150 or primary mirror 130 in a manner similar to that disclosed in co-owned and co-pending U.S. patent application Ser. No. 11/110,611 (cited above).
  • a single layer may be formed on convex surface 112 that serves the functions of both primary mirror 130 and heat spreader 150 . That is, mirror surfaces are typically formed using a thin 500 Angstrom Ag layer and one or more protective layers that may include a thin 1000 Angstrom Cu anti-migration layer and/or a barrier paint layer. Such conventional mirror surfaces exhibit a relatively high lateral thermal resistance that is insufficient for adequately distributing heat from PV cell 120 such that optical element 110 achieves uniform heat distribution. Hence, a relatively thick layer of a material (e.g., copper) exhibiting high thermal conductivity is formed over the backside of the mirror surface to provide the needed heat distribution.
  • a material e.g., copper
  • FIG. 2 is a side view showing concentrating solar collector 100 during operation. Similar to conventional concentrating solar collectors, a collector positioning system (not shown; for example, the tracking system used in the MegaModuleTM system produced by Amonix, Incorporated of Torrance, Calif., USA) is utilized to position concentrating solar collector 100 such that light beams LB (e.g., solar rays) are directed into aperture surface 115 in a desired direction (e.g., perpendicular to aperture surface 115 .
  • PV cell 120 is disposed substantially in a concentrating region F, which designates the region at which light beams LB are concentrated by primary mirror 130 , secondary mirror 140 and any intervening optical structures (e.g., a dielectric flux concentrator).
  • convex surface 112 , primary mirror 130 , concave surface 117 , and secondary mirror 140 are centered on and substantially symmetrical about an optical axis X that extends substantially perpendicular to aperture surface 115 (i.e., the curved portions of convex surface 112 and concave surface 117 are defined by an arc rotated around optical axis X).
  • waste heat generated at focal point F i.e., heat generated by solar energy that is not converted to electricity by PV cell 120
  • central portion 151 by way of heat slug 127 , when present
  • peripheral portion 152 is transmitted via central portion 151 (by way of heat slug 127 , when present) by conductive heat transfer to peripheral portion 152 , as indicated by dashed line arrows CH 1 in FIG. 2 .
  • focal point refers both to concentration by imaging and non-imaging elements.
  • the heat transferred to peripheral portions 152 in this manner is passed into optical element 110 via primary mirror 130 and convex surface 112 , and are transmitted by conductive heat transfer to aperture surface 115 , as indicated by dashed line arrows CH 2 in FIG. 2 . From aperture surface 115 , the heat is radiated into space, as indicated by the wavy dashed line arrows RH.
  • FIG. 3 is a top-side exploded perspective view showing a CPV device 200 according to another embodiment of the present invention. Similar to concentrating solar collector 100 , concentrating solar collector 200 includes an optical element 210 , a photovoltaic cell 220 , a primary mirror 230 formed on a convex surface 212 of optical element 210 , a secondary mirror 240 formed on a concave surface 217 of optical element, and a heat spreader 250 .
  • optical element 210 includes six contiguous facets 219 located around a peripheral edge of aperture surface 215 .
  • This six-sided arrangement facilitates the formation of large arrays of concentrating solar collectors 200 in a highly space-efficient manner, as discussed in additional detail in co-owned and co-pending U.S. patent application Ser. No. 11/110,611 (cited above).
  • less space-efficient concentrating solar collector arrays may be produced using concentrators having other peripheral shapes (e.g., the circular peripheral shape of concentrator 100 , described above).
  • a central region (cavity) 213 is defined in (e.g., molded into) convex surface 212 for receiving PV cell 220 .
  • FIG. 4 is a simplified, partially exploded cross-sectional side view showing the various components of CPV device 200 in additional detail.
  • a fabrication process for producing CPV device 200 begins by forming primary mirror 230 and secondary mirror 240 on optical element 210 .
  • First, highly reflective (mirror) material layers 232 and 242 e.g., silver
  • the silver can be applied by various techniques including liquid silvering which is commonly used to produce mirrors on glass for architectural applications.
  • the silver can also be applied by known sputtering techniques such as DC magnetron sputtering.
  • anti-migration layers 234 and 244 are deposited over highly reflective material layers 232 and 242 , respectively.
  • this process typically uses an electroless Cu process.
  • metals such as titanium or inconel are used to cap and protect the silver from tarnishing.
  • optional barrier paint layers 236 and 246 are formed over anti-migration layers 234 and 244 respectively. The barrier paint is typically applied by a spray coating process and then baked to both dry and harden the paint layer.
  • an inner adhesive layer 260 (e.g., EVA adhesive produced by Dupont) is deposited onto barrier layer 236 , and a transparent adhesive 228 is deposited into cavity 213 .
  • the cavity 213 can be filled with the adhesive in its uncured state prior to the lamination process. Care should be exercised when applying inner adhesive 260 to ensure none of it enters cavity 213 .
  • adhesive 260 is adhered to heat spreader 250 instead of optical element 210 .
  • Adhesive layer 260 has a nominal thickness of approximately 100 microns. Additional details regarding lamination of the various layers of CPV device 200 are disclosed in co-owned and co-pending U.S. patent application Ser. No.
  • Heat spreader 250 is produced and assembled with PV cell 220 prior to being mounted onto adhesive layer 260 .
  • heat spreader 250 is a multilayered substrate (referred to in the industry as “flex”) including one or more layers of a conductive layer 250 B (e.g., copper or other metal) faulted on a flexible substrate 250 A (e.g., a polyimide film such as Kapton® produced by DuPont Electronics, 0.5 mm thickness).
  • Kapton flex that is suitable for the production of heat spreader 250 is available from 3M Corporation (St. Paul, Minn., USA). As shown in FIG.
  • heat spreader (flex) 250 is cut or otherwise patterned from a flat sheet to include a central portion 251 and multiple peripheral portions (radial arms) 252 that extend radially from central portion 251 and are separated by slits 254 .
  • PV cell 220 will typically have a top (illuminated side) electrical contact and a bottom electrical contact.
  • PV cell 220 which is mounted on and in mechanical and electrical contact with heat spreader 250 , may have its top electrical contact electrically connected to a heat slug which is in turn electrically connected to one electrical portion of the flex.
  • the bottom electrical contact is electrically connected to a second electrical portion of the flex.
  • both the base and emitter contacts of PV cell 220 are electrically connected to thermal conductive layer 250 B.
  • a portion of conductor layer 250 B may be used to carry current from PV cells 220 using series or parallel connections.
  • the connections between PV cell 220 and thermal conductive layer 250 B may either be direct, or through an intermediate package or heat slug.
  • the copper conductive layer may be replaced with another metal or alloy (e.g., Alloy 42 (Fe—Ni alloy) exhibits a better CTE match to optical element 210 , but is not as good of an electrical or thermal conductor.
  • a further improvement is to form the heat spreader out of a bonded stack of metals, for example copper and Alloy 42.
  • Such a structure has superior thermal expansion characteristics compared to copper without compromising electrical conductivity.
  • heat spreader 250 is conformally attached to primary mirror 230 by way of adhesive layer 260 such that thermal conductive layer 250 B is in good mechanical and thermal contact with optical element 210 .
  • flex is processed in sheet or roll form, so it is inherently flat.
  • peripheral portions 252 A and 252 B of heat spreader 250 are patterning in the manner shown in FIG. 5 , both flexible substrate 250 A and thermal conductive layer 250 B conform to curved convex surface 212 when heat spreader 250 is mounted onto inner adhesive layer 260 , as illustrated in FIGS. 3 and 6 , thereby facilitating contouring of heat spreader 250 to provide close thermal contact between thermal conductive layer 250 B and optical element 210 .
  • Holes may be punched through peripheral portions 252 to facilitate the communication between adhesive layers 260 and 275 .
  • heat spreader 250 may be implemented using stamped metal shim stock that is utilized to perform both heat transfer and electrical conduction functions.
  • stamped or formed part that includes the heat slug, spreader, and wiring, and has the emitter and base leads tied together outside the array so they can be trimmed and separated after lamination.
  • the PV cells could slip into a “sandwich” which nests the cell from the front and makes contact to the back in a structure which goes through one solder reflow step to make both contacts.
  • this arrangement might act like a guillotine and break cells when pressure is applied.
  • An alternative embodiment is to form the heat slug, spreader and one side of the parallel wiring of an array of cells within the concentrator from a single stamped or formed metal part.
  • the other side of the parallel wiring could be provided for example with a piece of flex. Additional details regarding the use of a heat slug and other packaging features are disclosed in co-owned and co-pending U.S. patent application Ser. No. ______, entitled “SOLAR CONCENTRATING PHOTOVOLTAIC DEVICE WITH RESILIENT CELL PACKAGE ASSEMBLY” [Atty Docket No. 20060466-US-NP (XCP-070)], which is co-filed with the present application and incorporated herewith by reference in its entirety.
  • a double-sided heat spreader arrangement that includes copper on both sides of Kapton substrate. This would make the structure more complex, but would eliminate a Kapton/EVA interface.
  • a protective plastic shell layer 270 (e.g., Tedlar® produced by DuPont with 150 micron thickness) is then secured onto the exposed surface of flexible substrate 250 A using an outer (e.g., EVA) adhesive layer 275 .
  • EVA outer (e.g., EVA) adhesive layer 275 .
  • Kapton is an inert material
  • suitable adherence to EVA may require surface preparation.
  • the surface may be prepared using a plasma treatment of the Kapton surface or a silane coupling agent applied to the Kapton prior to assembly.
  • the flex substrate may have a layer of EVA applied directly after this surface treatment before the components of the stack are assembled together for lamination.
  • CPV device 200 exploits the discovery that the thermal resistance of the flex conductive (e.g., copper) in the lateral direction is comparable to the thermal resistance of the optical element glass in the vertical direction.
  • the thermal resistance of the flex conductive e.g., copper
  • the proposed concentrator that has a glass thickness of 5 to 12 mm and a copper layer of 70 microns, neither part of the structure becomes a severe bottleneck for heat transfer from aperture surface 215 .
  • Adequate heat spreading ensures that radiative and convective cooling occurs over wide surface areas on the front and back of CPV device 200 . This results in a more uniform surface temperature and a colder junction temperature for the PV cell.
  • a thermal model of CPV device 200 during regular operating conditions for a cell with 35% electrical conversion efficiency in a 300° K ambient indicates the junction temperature rises less than 30° C. above ambient.
  • the junction temperature of the cell rises only about 5° C. higher above the ambient than a conventional flat plate module collecting sunlight without any concentration.
  • the heat flow calculations predict that 67% or about two-thirds of the heat flowing out of the concentrator passes through the top surface.
  • the primary and secondary mirrors may be preformed and then mounted to the optical element using a suitable adhesive, but this approach may substantially increase production costs.
  • the curved surface utilized to form the secondary mirror may be convex instead of concave, thus being in the form of a classical Gregorian type system.
  • the curved surfaces utilized to form the primary and secondary mirrors may be elliptical, ellipsoidal, spherical, or other curved shape.

Abstract

A Cassegrain-type concentrating solar collector cell includes primary and secondary mirrors disposed on opposing convex and concave surfaces of a light-transparent (e.g., glass) optical element. Light enters an aperture surface surrounding the secondary mirror, and is reflected by the primary mirror toward the secondary mirror, which re-reflects the light onto a photovoltaic cell. The photovoltaic cell is mounted on a central portion of heat spreader that extends over the primary mirror. The heat spreader transmits waste heat from the photovoltaic cell in a manner that evenly distributes the heat over the optical element, thereby maximizing the radiation of heat from the aperture surface into space. The heat spreader includes a thick copper layer formed on a flexible substrate (e.g., polyimide film) that is patterned with radial arms that facilitate mounting onto the convex surface of the optical element.

Description

    RELATED APPLICATIONS
  • This application is a continuation of U.S. patent application Ser. No. 11/381,999, entitled “Passively Cooled Solar Concentrating Photovoltaic Device” filed May 5, 2006.
  • FIELD OF THE INVENTION
  • This invention relates to solar power generators, more particularly to managing the heat generated at and around the photovoltaic (PV) cell in solid dielectric solar concentrator photovoltaic (CPV) devices.
  • BACKGROUND OF THE INVENTION
  • Photovoltaic solar energy collection devices used to generate electric power generally include flat-panel collectors and concentrating solar collectors. Flat collectors generally include PV cell arrays and associated electronics formed on semiconductor (e.g., monocrystalline silicon or polycrystalline silicon) substrates, and the electrical energy output from flat collectors is a direct function of the area of the array, thereby requiring large, expensive semiconductor substrates. Concentrating solar collectors reduce the need for large semiconductor substrates by concentrating light beams (i.e., sun rays) using, e.g., a parabolic reflectors or lenses that focus the beams, creating a more intense beam of solar energy that is directed onto a small PV cell. Thus, concentrating solar collectors have an advantage over flat-panel collectors in that they utilize substantially smaller amounts of semiconductor. Another advantage that concentrating solar collectors have over flat-panel collectors is that they are more efficient at generating electrical energy.
  • A problem with conventional concentrating solar collectors is that they are expensive to operate and maintain. The reflectors and/or lenses used in conventional collectors to focus the light beams are produced separately, and must be painstakingly assembled to provide the proper alignment between the focused beam and the PV cell. Further, over time, the reflectors and/or lenses can become misaligned due to thermal cycling or vibration, and become dirty due to exposure to the environment. Maintenance in the form of cleaning and adjusting the reflectors/lenses can be significant, particularly when the reflectors/lenses are produced with uneven shapes that are difficult to clean.
  • Another problem associated with conventional concentrating solar collectors is damage to the PV cell and mirror structure due to the excessive temperatures generated by the focused light. For reliable operation it is essential to keep the PV cell and its surrounding packaging within safe limits, which is typically well under 100 degrees Celsius (100° C.). Because flat plate photovoltaic modules are exposed to direct (i.e., unfocused) solar light, the temperature rise of most flat plate photovoltaic modules under peak isolation is about 25° C. above ambient in zero wind, which produces a maximum PV cell temperature of about 70° C. (i.e., assuming an ambient temperature of 45° C.). In contrast, concentrating solar collectors produce flux densities of 300 to over 1000 suns at the PV cell, with typically less than half of the energy is converted into electricity and the remainder occurring as heat, producing PV cell temperatures that can reach well above 100° C. A conventional approach to reducing peak PV cell temperatures in concentrating solar collectors includes using a forced liquid cooling system to cool the PV cell, but such forced liquid cooling systems are expensive to produce and maintain, thus significantly increasing the overall production and operating costs of such concentrating solar collectors.
  • What is needed is a concentrator PV (CPV) device that avoids the expensive assembly and maintenance costs associated with conventional concentrator-type PV cells, and also maintains the CPV device within reliable operating temperatures in a cost effective and reliable manner.
  • SUMMARY OF THE INVENTION
  • The present invention is directed to a Cassegrain-type CPV device that induces the efficient radiation of heat out the front of the concentrator by utilizing a heat spreader to evenly distribute heat from the centrally located PV cell over the backside surface of a solid optical element, and by utilizing the solid optical element to transfer the heat from the heat spreader to a front aperture surface, from which the heat is radiated into space. This arrangement facilitates the radiation of more than 30% of the generated heat through the front aperture surface, thus improving passive cooling performance by approximately a factor of two over hollow concentrator systems that radiate heat out the back surface. In addition, the solid optical element facilitates the direct formation of primary and secondary mirrors thereon, thus automatically and permanently aligning the concentrator optics and maintaining optimal optical operation while minimizing maintenance costs.
  • In accordance with an aspect of the invention, a lateral thermal resistance of the heat spreader is less than a transverse thermal resistance of the solid optical element, thereby optimizing radiant heat transfer by maximizing the heat distribution to maintain the optical element and, hence, the aperture surface at a substantially uniform temperature. In one embodiment, the solid optical element includes a low-iron glass structure having a thickness in the range of 5 to 12 mm and a diameter of approximately 28 mm, and the heat spreader includes copper heat-distributing layer having a nominal thickness of approximately 70 microns. At this thickness, a lateral thermal resistance of thermal resistance of the copper heat-distributing layer is greater than the transverse thermal resistance of the optical element, thereby producing the desired uniform heating and radiation from the front aperture surface.
  • In accordance with an embodiment of the present invention, the heat spreader includes a thermal conductive layer (e.g., copper) formed on a flexible substrate (e.g., a polyimide film such as Kapton® produced by DuPont Electronics), and the PV cell is mounted on the heat spreader prior to assembly onto the solid optical element, thereby greatly simplifying the assembly process. In one embodiment the flexible substrate is cut or otherwise separated into a plurality of radial arms that extend from a central support region, which facilitates close contact to curved lower surface of the solid optical element during assembly. The wiring layers of the heat spreader are optionally used to help direct heat to the optical element. In one embodiment, the primary mirror includes a thin silver reflective layer, a copper anti-migration layer disposed on the silver layer, and a barrier paint layer disposed on the anti-migration layer. The heat spreader is then secured to the barrier paint layer by way of a suitable adhesive (e.g., EVA), and a protective shell (e.g., Tedlar) is secured to the backside of the flexible substrate using the same adhesive.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • These and other features, aspects and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings, where:
  • FIG. 1 is an exploded perspective view showing a CPV device according to an embodiment of the present invention;
  • FIG. 2 is a cross-sectional side view showing the CPV device of FIG. 1 during operation;
  • FIG. 3 is an exploded perspective view showing a CPV device according to another embodiment of the present invention;
  • FIG. 4 is a cross-sectional side view showing CPV device of FIG. 3 in additional detail;
  • FIG. 5 is a perspective view showing a heat spreader substrate utilized in the CPV device of FIG. 3;
  • FIG. 6 is an assembled perspective view showing the CPV device of FIG. 3.
  • DETAILED DESCRIPTION OF THE DRAWINGS
  • The present invention relates to managing the heat generated at and around the PV cell in a solid dielectric solar concentrator, such as that disclosed in co-owned and co-pending U.S. patent application Ser. No. 11/110,611 entitled “CONCENTRATING SOLAR COLLECTOR WITH SOLID OPTICAL ELEMENT”, which is incorporated herein by reference in its entirety. In particular, the present invention relates to a passive heat management system that avoids the production and maintenance costs of conductive and fluid cooled systems by facilitating the radiation of more than 30% of the generated heat from the front aperture surface of the solid optical element.
  • In considering the radiation balance of the CPV device, it is important to recognize that the blackbody temperature of the sky is typically on the order of −40 degrees Celsius (−40° C.). The blackbody temperature of the ground is typically about 4° C. above the ambient temperature. It is therefore desirable to provide a thermal path to the front surface of the device so it can radiate heat skyward.
  • Quantitatively, the net radiation flux per unit area from the front surface of the concentrator can be expressed as:

  • Q ff σT f 4−(1−R fT s 4  Equation 1
  • where εf is the emissivity of the front surface (typically 0.85 for low iron glass), σ is the Stefan-Boltzmann constant (5.67×10−8 Watts/m2 Kelvin4), Tf is the absolute temperature of the front surface, Rf is the reflectivity of the front surface (typically about 8%) and Ts is the blackbody temperature of the sky (about −40 Celsius).
  • The radiation out the back of the concentrator can be expressed similarly as:

  • Q bb σT b 4−(1−R bT g 4  Equation 2
  • where εb is the emissivity of the back surface (typically 0.9 for plastic laminated Tedlar), Tb is the absolute temperature of the concentrator's back surface, Rb is the reflectivity of the concentrator's back surface (typically about 10% for Tedlar in the infrared) and Tg is the blackbody temperature of the ground or rooftop (typically about 4 degrees Celsius above ambient).
  • What is apparent from Equations 1 and 2 is that the front surface radiates into a much colder bath than the back surface. In flat plate PV systems, more than twice as much heat is typically lost out the front of the panel than out the rear. It is a useful aspect of this invention to create a concentrating PV system that mimics this advantageous heat loss mechanism.
  • FIG. 1 is an exploded perspective view showing an internal mirror, Cassegrain-type concentrator photovoltaic (CPV) device 100 according to a simplified embodiment of the present invention. Concentrating solar collector 100 generally includes an optical element 110, a photovoltaic (PV) cell 120, a primary mirror 130, a secondary mirror 140, and a heat spreader 150.
  • Optical element 110 is a solid, disk-like, light-transparent structure including an upper layer 111, a relatively large convex surface 112 protruding from a lower side of upper layer 111, a substantially flat aperture surface 115 disposed on an upper side of upper layer 111, and a relatively small concave (curved) surface (depression) 117 defined in aperture surface 115 (i.e., extending into upper layer 111). In order to minimize material, weight, thickness and optical adsorption, upper layer 111 may be vanishingly small. In one embodiment, optical element 110 is molded using a low-iron glass (e.g., Optiwhite glass produced by Pilkington PLC, UK) structure according to known glass molding methods. Alternatively, clear plastic may be machined and polished to form single-piece optical element 110, or separate pieces by be glued or otherwise secured to form optical element 110. In a preferred embodiment, optical element 110 is 5 to 12 mm thick and 20 to 40 mm wide. This thickness helps to ensure that the heat conduction path from the backside convex surface 112 to aperture surface 115 does not become too resistive as it would be if optical element 110 were either thicker or hollow.
  • PV cell 120 is located in a central first side (cavity) region 113 that is defined in the center of convex surface 112. PV cell 120 is connected by way of suitable conductors 122 and 124 (indicated in FIG. 2), for example, to the PV cells of adjacent CPV devices (not shown) using known techniques. Suitable photovoltaic (concentrator solar) cells are produced, for example, by Spectrolab, Inc. of Sylmar, Calif., USA.
  • Primary mirror 130 and secondary mirror 140 are respectively disposed on convex surface 112 and concave surface 117. Primary mirror 130 and secondary mirror 140 are shaped and arranged such that, as shown in FIG. 2, light beams LB traveling in a predetermined direction (e.g., perpendicular to aperture surface 115) that enters optical element 110 through a specific region of aperture surface 115 is reflected by a corresponding region of primary mirror 130 to an associated region of secondary mirror 140, and from the associated region of secondary mirror 140 to PV cell 120 (e.g., directly from secondary mirror 140 to PV cell 120, or by way of a reflective or refractive surface positioned between secondary mirror and PV cell 120). As used herein, directional terms such as “upper”, “lower”, “above” and “below” are intended to provide relative positions for purposes of description, and are not intended to designate an absolute frame of reference. In one embodiment, primary mirror 130 and secondary mirror 140 are fabricated by sputtering or otherwise depositing a reflective mirror material (e.g., silver (Ag) or aluminum (Al)) directly onto convex surface 112 and concave surface 117, thereby minimizing manufacturing costs and providing superior optical characteristics. By sputtering or otherwise forming a mirror film on convex surface 112 and concave surface 117 using a known mirror fabrication technique, primary mirror 130 substantially takes the shape of convex surface 112, and secondary mirror 140 substantially takes the shape of concave surface 117. As such, optical element 110 is molded or otherwise fabricated such that convex surface 112 and concave surface 117 are arranged and shaped to produce the desired mirror shapes. Note that, by forming convex surface 112 and concave surface 117 with the desired mirror shape and position, primary mirror 130 and secondary mirror 140 are effectively self-forming and self-aligning, thus eliminating expensive assembly and alignment costs associated with conventional concentrating solar collectors. Further, because primary mirror 130 and secondary mirror 140 remain affixed to optical element 110, their relative position is permanently set, thereby eliminating the need for adjustment or realignment that may be needed in conventional multiple-part arrangements. In one embodiment, primary mirror 130 and secondary mirror 140 are formed simultaneously using the same (identical) material or materials (e.g., plated Ag), thereby minimizing fabrication costs. Further, by utilizing the surfaces of optical element 110 to fabricate the mirrors, once light enters into optical element 110 through aperture surface 115, the light is only reflected by primary mirror 130/convex surface 112 and secondary mirror 140/concave surface 117 before reaching PV cell 120. As such, the light is subjected to only one air/glass interface (i.e., aperture surface 115), thereby minimizing losses that are otherwise experienced by conventional multi-part concentrating solar collectors. The single air/glass interface loss can be further lowered using an antireflection coating on aperture surface 115. Although it is also possible to separately form primary mirror 130 and secondary mirror 140 and then attach the mirrors to convex surface 112 and concave surface 117, respectively, this production method would greatly increase manufacturing costs and may reduce the superior optical characteristics provided by forming mirror films directly onto convex surface 112 and concave surface 117.
  • Heat spreader 150 includes a central portion 151 and a curved peripheral portion 152 extending outward from central portion 151. Heat spreader 150 includes a material having relatively high thermal conductivity, and includes a thickness selected such that a lateral thermal resistance TR1 of heat spreader 150 (i.e., measured in a radial direction from central portion 151 to the outer edge of peripheral portions 152) is less than a transverse thermal resistance TR2 of optical element 110 (i.e., measured from the convex surface 112 to the aperture surface 115). In one practical embodiment, many small CPV devices 100 are arrayed together in order to keep the volume of glass from becoming excessively large, and to keep the amount of power per PV cell manageable without active cooling. In the preferred embodiment, low-iron glass having a thickness of 5 to 12 mm is used for optical element 110, and heat spreader 150 includes a copper heat-distributing layer having a thickness of 70 microns (i.e., two ounce copper), which provides a thermal resistance TR1 that is greater than a thermal resistance TR2 of optical element 110. At this thickness, a lateral thermal resistance of the copper heat-distributing layer is greater than the transverse thermal resistance of the optical element.
  • As indicate in FIG. 2, central portion 151 of heat spreader 150 is disposed over cavity 113, and curved peripheral portion 152 is formed on or otherwise secured to the back (non-reflecting) surface of primary mirror 130. PV cell 120 is mounted on an inside surface of central portion 151 such that PV cell 120 is disposed inside cavity 113. A gap filling transparent adhesive 128, such as silicone (e.g., polydiphenylsiloxane or polymethylphenylsiloxane), is also disposed inside cavity 113 over PV cell 120, and serves to minimize the disruptive break in the refractive indicies between the outside surface of cavity 113 and PV cell 120. Note that a central opening 131 is defined in primary mirror 130 to facilitate the passage of light through cavity 113 to PV cell 120. In one embodiment, PV cell 120 is mounted onto central region 151 by way of a heat slug 127. In another embodiment, one or more openings are formed in central region 151 and heat slug 127 to facilitate the passage of current from PV cell 120, e.g., by way of conductors 122 and 124. In another embodiment, current is transmitted to and from PV cell 120 by way of heat spreader 150 or primary mirror 130 in a manner similar to that disclosed in co-owned and co-pending U.S. patent application Ser. No. 11/110,611 (cited above).
  • Although primary mirror 130 and heat spreader 150 are illustrated as separate layers in FIGS. 1 and 2, in one embodiment a single layer may be formed on convex surface 112 that serves the functions of both primary mirror 130 and heat spreader 150. That is, mirror surfaces are typically formed using a thin 500 Angstrom Ag layer and one or more protective layers that may include a thin 1000 Angstrom Cu anti-migration layer and/or a barrier paint layer. Such conventional mirror surfaces exhibit a relatively high lateral thermal resistance that is insufficient for adequately distributing heat from PV cell 120 such that optical element 110 achieves uniform heat distribution. Hence, a relatively thick layer of a material (e.g., copper) exhibiting high thermal conductivity is formed over the backside of the mirror surface to provide the needed heat distribution. While these two separate layers are needed to provide both an optimal reflective surface and adequate heat transfer, it may be possible to utilize a single (e.g., silver or copper) layer to perform both the reflective and heat transfer functions. However, at this time, forming silver to the thickness needed to facilitate sufficient heat transfer is economically infeasible, and depositing copper using known techniques is considered to form an inadequate mirror surface.
  • FIG. 2 is a side view showing concentrating solar collector 100 during operation. Similar to conventional concentrating solar collectors, a collector positioning system (not shown; for example, the tracking system used in the MegaModule™ system produced by Amonix, Incorporated of Torrance, Calif., USA) is utilized to position concentrating solar collector 100 such that light beams LB (e.g., solar rays) are directed into aperture surface 115 in a desired direction (e.g., perpendicular to aperture surface 115. PV cell 120 is disposed substantially in a concentrating region F, which designates the region at which light beams LB are concentrated by primary mirror 130, secondary mirror 140 and any intervening optical structures (e.g., a dielectric flux concentrator). To facilitate the positioning of concentrating region F in central region 113, convex surface 112, primary mirror 130, concave surface 117, and secondary mirror 140 are centered on and substantially symmetrical about an optical axis X that extends substantially perpendicular to aperture surface 115 (i.e., the curved portions of convex surface 112 and concave surface 117 are defined by an arc rotated around optical axis X).
  • In accordance with the present invention, waste heat generated at focal point F (i.e., heat generated by solar energy that is not converted to electricity by PV cell 120) is transmitted via central portion 151 (by way of heat slug 127, when present) by conductive heat transfer to peripheral portion 152, as indicated by dashed line arrows CH1 in FIG. 2. For the purposes of this invention, the use of the term focal point refers both to concentration by imaging and non-imaging elements. The heat transferred to peripheral portions 152 in this manner is passed into optical element 110 via primary mirror 130 and convex surface 112, and are transmitted by conductive heat transfer to aperture surface 115, as indicated by dashed line arrows CH2 in FIG. 2. From aperture surface 115, the heat is radiated into space, as indicated by the wavy dashed line arrows RH.
  • FIG. 3 is a top-side exploded perspective view showing a CPV device 200 according to another embodiment of the present invention. Similar to concentrating solar collector 100, concentrating solar collector 200 includes an optical element 210, a photovoltaic cell 220, a primary mirror 230 formed on a convex surface 212 of optical element 210, a secondary mirror 240 formed on a concave surface 217 of optical element, and a heat spreader 250.
  • As indicated in FIG. 3, optical element 210 includes six contiguous facets 219 located around a peripheral edge of aperture surface 215. This six-sided arrangement facilitates the formation of large arrays of concentrating solar collectors 200 in a highly space-efficient manner, as discussed in additional detail in co-owned and co-pending U.S. patent application Ser. No. 11/110,611 (cited above). In other embodiments, less space-efficient concentrating solar collector arrays may be produced using concentrators having other peripheral shapes (e.g., the circular peripheral shape of concentrator 100, described above). A central region (cavity) 213 is defined in (e.g., molded into) convex surface 212 for receiving PV cell 220.
  • FIG. 4 is a simplified, partially exploded cross-sectional side view showing the various components of CPV device 200 in additional detail.
  • In one embodiment, a fabrication process for producing CPV device 200 begins by forming primary mirror 230 and secondary mirror 240 on optical element 210. First, highly reflective (mirror) material layers 232 and 242 (e.g., silver) are deposited on convex surface 212 and concave surface 217, respectively. The silver can be applied by various techniques including liquid silvering which is commonly used to produce mirrors on glass for architectural applications. The silver can also be applied by known sputtering techniques such as DC magnetron sputtering.
  • Next, anti-migration layers 234 and 244 (e.g., copper) are deposited over highly reflective material layers 232 and 242, respectively. In liquid immersion or spray techniques, this process typically uses an electroless Cu process. In a sputter process, metals such as titanium or inconel are used to cap and protect the silver from tarnishing. Next, optional barrier paint layers 236 and 246 are formed over anti-migration layers 234 and 244 respectively. The barrier paint is typically applied by a spray coating process and then baked to both dry and harden the paint layer.
  • Next, an inner adhesive layer 260 (e.g., EVA adhesive produced by Dupont) is deposited onto barrier layer 236, and a transparent adhesive 228 is deposited into cavity 213. For example, the cavity 213 can be filled with the adhesive in its uncured state prior to the lamination process. Care should be exercised when applying inner adhesive 260 to ensure none of it enters cavity 213. In an alternative embodiment, adhesive 260 is adhered to heat spreader 250 instead of optical element 210. Adhesive layer 260 has a nominal thickness of approximately 100 microns. Additional details regarding lamination of the various layers of CPV device 200 are disclosed in co-owned and co-pending U.S. patent application Ser. No. ______, entitled “LAMINATED SOLAR CONCENTRATING PHOTOVOLTAIC DEVICE” [Atty Docket No. 20060351-US-NP (XCP-071)], which is co-filed with the present application and incorporated herewith by reference in its entirety.
  • Heat spreader 250 is produced and assembled with PV cell 220 prior to being mounted onto adhesive layer 260. In accordance with another aspect of the present invention, heat spreader 250 is a multilayered substrate (referred to in the industry as “flex”) including one or more layers of a conductive layer 250B (e.g., copper or other metal) faulted on a flexible substrate 250A (e.g., a polyimide film such as Kapton® produced by DuPont Electronics, 0.5 mm thickness). Kapton flex that is suitable for the production of heat spreader 250 is available from 3M Corporation (St. Paul, Minn., USA). As shown in FIG. 5, heat spreader (flex) 250 is cut or otherwise patterned from a flat sheet to include a central portion 251 and multiple peripheral portions (radial arms) 252 that extend radially from central portion 251 and are separated by slits 254. PV cell 220 will typically have a top (illuminated side) electrical contact and a bottom electrical contact. PV cell 220, which is mounted on and in mechanical and electrical contact with heat spreader 250, may have its top electrical contact electrically connected to a heat slug which is in turn electrically connected to one electrical portion of the flex. The bottom electrical contact is electrically connected to a second electrical portion of the flex. In one embodiment, where there are multiple electrical paths in the thermal conductive layer 250B, both the base and emitter contacts of PV cell 220 are electrically connected to thermal conductive layer 250B. In an array of power units, a portion of conductor layer 250B may be used to carry current from PV cells 220 using series or parallel connections. The connections between PV cell 220 and thermal conductive layer 250B may either be direct, or through an intermediate package or heat slug. In an alternative embodiment, the copper conductive layer may be replaced with another metal or alloy (e.g., Alloy 42 (Fe—Ni alloy) exhibits a better CTE match to optical element 210, but is not as good of an electrical or thermal conductor. A further improvement is to form the heat spreader out of a bonded stack of metals, for example copper and Alloy 42. Such a structure has superior thermal expansion characteristics compared to copper without compromising electrical conductivity.
  • In accordance with another aspect of the present invention, heat spreader 250 is conformally attached to primary mirror 230 by way of adhesive layer 260 such that thermal conductive layer 250B is in good mechanical and thermal contact with optical element 210. Ordinarily, as indicated in FIG. 5, flex is processed in sheet or roll form, so it is inherently flat. By patterning peripheral portions 252A and 252B of heat spreader 250 in the manner shown in FIG. 5, both flexible substrate 250A and thermal conductive layer 250B conform to curved convex surface 212 when heat spreader 250 is mounted onto inner adhesive layer 260, as illustrated in FIGS. 3 and 6, thereby facilitating contouring of heat spreader 250 to provide close thermal contact between thermal conductive layer 250B and optical element 210. Holes may be punched through peripheral portions 252 to facilitate the communication between adhesive layers 260 and 275.
  • In alternative embodiments, heat spreader 250 may be implemented using stamped metal shim stock that is utilized to perform both heat transfer and electrical conduction functions. When multiple CPV devices of an array are parallel-wired, it may be feasible to make a stamped or formed part that includes the heat slug, spreader, and wiring, and has the emitter and base leads tied together outside the array so they can be trimmed and separated after lamination. The PV cells could slip into a “sandwich” which nests the cell from the front and makes contact to the back in a structure which goes through one solder reflow step to make both contacts. However, this arrangement might act like a guillotine and break cells when pressure is applied. An alternative embodiment is to form the heat slug, spreader and one side of the parallel wiring of an array of cells within the concentrator from a single stamped or formed metal part. The other side of the parallel wiring could be provided for example with a piece of flex. Additional details regarding the use of a heat slug and other packaging features are disclosed in co-owned and co-pending U.S. patent application Ser. No. ______, entitled “SOLAR CONCENTRATING PHOTOVOLTAIC DEVICE WITH RESILIENT CELL PACKAGE ASSEMBLY” [Atty Docket No. 20060466-US-NP (XCP-070)], which is co-filed with the present application and incorporated herewith by reference in its entirety.
  • In another alternative embodiment, a double-sided heat spreader arrangement that includes copper on both sides of Kapton substrate. This would make the structure more complex, but would eliminate a Kapton/EVA interface.
  • A protective plastic shell layer 270 (e.g., Tedlar® produced by DuPont with 150 micron thickness) is then secured onto the exposed surface of flexible substrate 250A using an outer (e.g., EVA) adhesive layer 275. Because Kapton is an inert material, suitable adherence to EVA may require surface preparation. For example, the surface may be prepared using a plasma treatment of the Kapton surface or a silane coupling agent applied to the Kapton prior to assembly. In one embodiment, the flex substrate may have a layer of EVA applied directly after this surface treatment before the components of the stack are assembled together for lamination.
  • CPV device 200 exploits the discovery that the thermal resistance of the flex conductive (e.g., copper) in the lateral direction is comparable to the thermal resistance of the optical element glass in the vertical direction. As a result of this for the proposed concentrator that has a glass thickness of 5 to 12 mm and a copper layer of 70 microns, neither part of the structure becomes a severe bottleneck for heat transfer from aperture surface 215. Adequate heat spreading ensures that radiative and convective cooling occurs over wide surface areas on the front and back of CPV device 200. This results in a more uniform surface temperature and a colder junction temperature for the PV cell. A thermal model of CPV device 200 during regular operating conditions for a cell with 35% electrical conversion efficiency in a 300° K ambient indicates the junction temperature rises less than 30° C. above ambient. In spite of the fact that this device concentrates the sun several hundred times and uses only passive cooling, the junction temperature of the cell rises only about 5° C. higher above the ambient than a conventional flat plate module collecting sunlight without any concentration. For the invention described herein, during normal operating conditions, the heat flow calculations predict that 67% or about two-thirds of the heat flowing out of the concentrator passes through the top surface.
  • Although the present invention has been described with respect to certain specific embodiments, it will be clear to those skilled in the art that the inventive features of the present invention are applicable to other embodiments as well, all of which are intended to fall within the scope of the present invention. For example, the primary and secondary mirrors may be preformed and then mounted to the optical element using a suitable adhesive, but this approach may substantially increase production costs. In yet another alternative embodiment, the curved surface utilized to form the secondary mirror may be convex instead of concave, thus being in the form of a classical Gregorian type system. In yet another alternative embodiment, the curved surfaces utilized to form the primary and secondary mirrors may be elliptical, ellipsoidal, spherical, or other curved shape.

Claims (8)

1. A concentrating photovoltaic (CPV) device comprising:
a solid, light-transparent optical element having a relatively large convex surface defining a central first side region, and an opposing aperture surface and a relatively small curved surface defined in a central portion of the aperture surface;
a heat spreader comprising a thermally conductive material and including a central portion disposed over the central first side region of the optical element, and a plurality of radial arms extending from the central portion such that the radial arms are conformally disposed over and in thermal contact with the convex surface; and
a photovoltaic (PV) cell disposed on the central portion of the heat spreader and being electrically connected to at least one of the plurality of radial arms.
2. The CPV device according to claim 1, wherein the heat spreader comprises a laminate structure including one or more non-conductive layers and one or more metallization layers.
3. The CPV device according to claim 1,
wherein the one or more non-conductive layers comprise a polyimide film, and
wherein the one or more metallization layers comprise one of copper and Fe—Ni alloy.
4. The CPV device according to claim 1,
wherein the heat spreader has a lateral thermal resistance extending from the central portion to the peripheral portions,
wherein the optical element has a transverse thermal resistance extending from the convex surface to the aperture surface, and
wherein the transverse thermal resistance is greater than the lateral thermal resistance.
5. A concentrating photovoltaic (CPV) device comprising:
a solid, light-transparent optical element having a relatively large convex surface defining a central first side region, and an opposing aperture surface and a relatively small curved surface defined in a central portion of the aperture surface;
a heat spreader including a central portion disposed over the central first side region of the optical element, and a plurality of radial arms extending from the central portion; and
a photovoltaic (PV) cell disposed on the central portion of the heat spreader and being electrically connected to at least one of the plurality of radial arms,
wherein the heat spreader comprise a thermally conductive material and the plurality of radial arms are in thermal contact with and conformally disposed over the convex surface such that heat generated at the focal region is passively transmitted from the central portion to the plurality of radial arms, and from the plurality of radial arms through the optical element for radiation from the substantially flat aperture surface.
6. The CPV device according to claim 5, wherein the heat spreader comprises a laminate structure including one or more non-conductive layers and one or more metallization layers.
7. The CPV device according to claim 5,
wherein the one or more non-conductive layers comprise a polyimide film, and
wherein the one or more metallization layers comprise one of copper and Fe—Ni alloy.
8. The CPV device according to claim 5,
wherein the heat spreader has a lateral thermal resistance extending from the central portion to the peripheral portions,
wherein the optical element has a transverse thermal resistance extending from the convex surface to the aperture surface, and
wherein the transverse thermal resistance is greater than the lateral thermal resistance.
US12/950,918 2006-05-05 2010-11-19 Passively Cooled Solar Concentrating Photovoltaic Device Abandoned US20110061718A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US12/950,918 US20110061718A1 (en) 2006-05-05 2010-11-19 Passively Cooled Solar Concentrating Photovoltaic Device

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US11/381,999 US7851693B2 (en) 2006-05-05 2006-05-05 Passively cooled solar concentrating photovoltaic device
US12/950,918 US20110061718A1 (en) 2006-05-05 2010-11-19 Passively Cooled Solar Concentrating Photovoltaic Device

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US11/381,999 Continuation US7851693B2 (en) 2006-05-05 2006-05-05 Passively cooled solar concentrating photovoltaic device

Publications (1)

Publication Number Publication Date
US20110061718A1 true US20110061718A1 (en) 2011-03-17

Family

ID=38197762

Family Applications (2)

Application Number Title Priority Date Filing Date
US11/381,999 Active 2027-04-08 US7851693B2 (en) 2006-05-05 2006-05-05 Passively cooled solar concentrating photovoltaic device
US12/950,918 Abandoned US20110061718A1 (en) 2006-05-05 2010-11-19 Passively Cooled Solar Concentrating Photovoltaic Device

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US11/381,999 Active 2027-04-08 US7851693B2 (en) 2006-05-05 2006-05-05 Passively cooled solar concentrating photovoltaic device

Country Status (5)

Country Link
US (2) US7851693B2 (en)
EP (1) EP1852919B1 (en)
CN (1) CN100544036C (en)
AU (1) AU2007248262B2 (en)
WO (1) WO2007130794A2 (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140090692A1 (en) * 2011-05-20 2014-04-03 Sharp Kabushiki Kaisha Concentrated solar cell and manufacturing method for the same
US20150140263A1 (en) * 2013-11-20 2015-05-21 Kabushiki Kaisha Toshiba Optical element and optical device
WO2015187739A1 (en) * 2014-06-02 2015-12-10 California Institute Of Technology Large-scale space-based solar power station: efficient power generation tiles
US20160376037A1 (en) 2014-05-14 2016-12-29 California Institute Of Technology Large-Scale Space-Based Solar Power Station: Packaging, Deployment and Stabilization of Lightweight Structures
WO2017015605A1 (en) * 2015-07-22 2017-01-26 California Institute Of Technology Mirrors transparent to specific regions of the electromagnetic spectrum
WO2017027629A1 (en) * 2015-08-10 2017-02-16 California Institute Of Technology Lightweight structures for enhancing the thermal emissivity of surfaces
US10454565B2 (en) * 2015-08-10 2019-10-22 California Institute Of Technology Systems and methods for performing shape estimation using sun sensors in large-scale space-based solar power stations
US10696428B2 (en) 2015-07-22 2020-06-30 California Institute Of Technology Large-area structures for compact packaging
US10992253B2 (en) 2015-08-10 2021-04-27 California Institute Of Technology Compactable power generation arrays
US11128179B2 (en) 2014-05-14 2021-09-21 California Institute Of Technology Large-scale space-based solar power station: power transmission using steerable beams
US11634240B2 (en) 2018-07-17 2023-04-25 California Institute Of Technology Coilable thin-walled longerons and coilable structures implementing longerons and methods for their manufacture and coiling
US11772826B2 (en) 2018-10-31 2023-10-03 California Institute Of Technology Actively controlled spacecraft deployment mechanism

Families Citing this family (49)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2518162C (en) 2003-03-11 2014-02-25 Carroll Hospital Group Inc. Steerable ultra-low patient bed
ITAQ20070009A1 (en) 2007-05-17 2007-08-16 Giovanni Lanzara SOLAR ENERGY CONCENTRATION SYSTEM FOR PHOTOVOLTAIC AND / OR THERMAL USE WITH HEAT RECOVERY THROUGH FLUID-EXCHANGERS IN SERIES
US8631787B2 (en) * 2005-07-28 2014-01-21 Light Prescriptions Innovators, Llc Multi-junction solar cells with a homogenizer system and coupled non-imaging light concentrator
US20090114265A1 (en) * 2007-11-03 2009-05-07 Solfocus, Inc. Solar Concentrator
US8088994B2 (en) * 2007-12-21 2012-01-03 Solergy, Inc. Light concentrating modules, systems and methods
US20090283144A1 (en) * 2008-05-14 2009-11-19 3M Innovative Properties Company Solar concentrating mirror
US20090283133A1 (en) * 2008-05-14 2009-11-19 3M Innovative Properties Company Solar concentrating mirror
US9086227B2 (en) * 2008-09-26 2015-07-21 Industrial Technology Research Institute Method and system for light collection and light energy converting apparatus
DE102008060599A1 (en) 2008-12-06 2010-06-10 Rainer Merdonig Solar cell unit has solar cell, which has photovoltaic active sandwich and lens assembly, which partly covers solar cell
US20100139768A1 (en) * 2008-12-10 2010-06-10 Solfocus, Inc. Heat spreading shield
US20100154788A1 (en) * 2008-12-19 2010-06-24 Skyline Solar, Inc. Solar receiver
WO2010078105A1 (en) 2008-12-30 2010-07-08 3M Innovative Properties Company Broadband reflectors, concentrated solar power systems, and methods of using the same
CN101872796A (en) * 2009-04-24 2010-10-27 云南师范大学 High-efficiency low-condensation photovoltaic assembly
US20120042949A1 (en) * 2009-05-14 2012-02-23 Aerosun Technologies Ag. Solar concentrator
JP4878382B2 (en) * 2009-05-14 2012-02-15 独立行政法人 宇宙航空研究開発機構 Solar thermal collector in solar combined power generation system and solar thermal power generation module using the solar thermal collector
DE102009033771A1 (en) 2009-07-17 2011-04-07 Schünemann, Gerhard Solar reflector for installation on e.g. flat saddle or monopitch roofs of building, has reflector surface reflecting sunlight on photovoltaic panels of photovoltaic systems, where reflector surface is designed as strewing reflector surface
US9231142B2 (en) * 2009-10-06 2016-01-05 Brightleaf Technologies Inc. Non-parabolic solar concentration to an area of controlled flux density conversion system and method
WO2011044278A2 (en) * 2009-10-06 2011-04-14 Brightleaf Technologies, Inc. Solar collector and conversion array
US9337360B1 (en) 2009-11-16 2016-05-10 Solar Junction Corporation Non-alloyed contacts for III-V based solar cells
US20110146754A1 (en) * 2009-12-22 2011-06-23 Brightleaf Technologies, Inc. Solar conversion system having solar collector for forming a transposed image
WO2011127572A1 (en) * 2010-04-13 2011-10-20 John Robert Mumford Solar concentrators, solar collectors and methods of making same
US9214586B2 (en) 2010-04-30 2015-12-15 Solar Junction Corporation Semiconductor solar cell package
WO2012093327A1 (en) * 2011-01-04 2012-07-12 Siu Chung Tam A photovoltaic device
US8962989B2 (en) 2011-02-03 2015-02-24 Solar Junction Corporation Flexible hermetic semiconductor solar cell package with non-hermetic option
US8859892B2 (en) 2011-02-03 2014-10-14 Solar Junction Corporation Integrated semiconductor solar cell package
ITRM20110361A1 (en) * 2011-07-11 2013-01-12 Matteo Repetto PHOTOVOLTAIC DEVICE.
CN102306674B (en) * 2011-09-21 2012-12-26 福鼎市一雄光学仪器有限公司 High-efficient solar photovoltaic battery condensation device
CN102684558A (en) * 2011-12-12 2012-09-19 苏州科雷芯电子科技有限公司 Device for improving solar power generation efficiency
IL217059A (en) * 2011-12-18 2015-07-30 Or Hama Energy Ltd Lightweight system and method for dynamic solar energy utilization
TWI456154B (en) * 2012-01-31 2014-10-11 Au Optronics Corp Solar panel module
US9353974B2 (en) 2012-04-30 2016-05-31 Daniel Demers Solar collecting device
US8878050B2 (en) 2012-11-20 2014-11-04 Boris Gilman Composite photovoltaic device with parabolic collector and different solar cells
ITMI20130317A1 (en) * 2013-03-04 2014-09-05 Er En OPTICAL CONCENTRATOR
US9960303B2 (en) 2013-03-15 2018-05-01 Morgan Solar Inc. Sunlight concentrating and harvesting device
US9714756B2 (en) 2013-03-15 2017-07-25 Morgan Solar Inc. Illumination device
US9595627B2 (en) 2013-03-15 2017-03-14 John Paul Morgan Photovoltaic panel
CA2906109A1 (en) 2013-03-15 2014-09-18 Morgan Solar Inc. Light panel, optical assembly with improved interface and light panel with improved manufacturing tolerances
KR101479567B1 (en) * 2013-10-15 2015-01-07 전자부품연구원 solar cell module
US10418932B2 (en) 2014-07-09 2019-09-17 Eustratios N. Carabateas Mirror system for considerably increasing the productivity of photovoltaic power plants
CN104393065B (en) * 2014-11-26 2017-06-06 天津三安光电有限公司 Solar battery chip, use the solar cell module of the chip with and preparation method thereof
CN106160657B (en) * 2015-04-02 2018-12-14 中海阳能源集团股份有限公司 A kind of condensation photovoltaic integrated power generation system
CN105099359B (en) * 2015-08-11 2017-11-10 中国科学技术大学先进技术研究院 A kind of solar energy composite of distributed optically focused light splitting utilizes system
TWM521266U (en) * 2015-12-10 2016-05-01 Bee Space Co Ltd Assembled type solar power generation device
US10090420B2 (en) 2016-01-22 2018-10-02 Solar Junction Corporation Via etch method for back contact multijunction solar cells
US9680035B1 (en) 2016-05-27 2017-06-13 Solar Junction Corporation Surface mount solar cell with integrated coverglass
JP6259140B1 (en) * 2017-04-03 2018-01-10 株式会社Daylight energy Photovoltaic generator
CN107525283B (en) * 2017-09-01 2019-04-19 广东五星太阳能股份有限公司 A kind of portable non-tracking wide-angle Photospot solar device
US10490682B2 (en) 2018-03-14 2019-11-26 National Mechanical Group Corp. Frame-less encapsulated photo-voltaic solar panel supporting solar cell modules encapsulated within multiple layers of optically-transparent epoxy-resin materials
CN109284566B (en) * 2018-10-09 2023-06-27 顺德中山大学太阳能研究院 Photovoltaic module heat flow calculation method and device

Citations (95)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US49421A (en) * 1865-08-15 Improvement in sewing-machines
US49658A (en) * 1865-08-29 Improved process for treating ores
US200496A (en) * 1878-02-19 Improvement in strainers for faucets and water-pipes
US209724A (en) * 1878-11-05 Improvement in fire-extinguishers
US1715260A (en) * 1927-03-23 1929-05-28 Weber Peter Adjustable stand
US1854637A (en) * 1926-04-12 1932-04-19 Prep Ind Combustibles Trough-shaped belt conveyer
US1973528A (en) * 1933-11-01 1934-09-11 Sperry Prod Inc Flaw detector mechanism
US2097724A (en) * 1934-12-31 1937-11-02 Cal A Forney Collapsible ironing table
US2606309A (en) * 1950-06-15 1952-08-05 Bell Telephone Labor Inc Glow discharge device
US3923381A (en) * 1973-12-28 1975-12-02 Univ Chicago Radiant energy collection
US3988166A (en) * 1975-01-07 1976-10-26 Beam Engineering, Inc. Apparatus for enhancing the output of photovoltaic solar cells
US4021267A (en) * 1975-09-08 1977-05-03 United Technologies Corporation High efficiency converter of solar energy to electricity
US4045246A (en) * 1975-08-11 1977-08-30 Mobil Tyco Solar Energy Corporation Solar cells with concentrators
US4053327A (en) * 1975-09-24 1977-10-11 Communications Satellite Corporation Light concentrating solar cell cover
US4084985A (en) * 1977-04-25 1978-04-18 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Method for producing solar energy panels by automation
US4086485A (en) * 1976-05-26 1978-04-25 Massachusetts Institute Of Technology Solar-radiation collection apparatus with tracking circuitry
US4095997A (en) * 1976-10-07 1978-06-20 Griffiths Kenneth F Combined solar cell and hot air collector apparatus
US4114596A (en) * 1976-03-16 1978-09-19 Chang Wei Yi Method and apparatus for tracking the sun for use in a solar collector with linear focusing means
US4148301A (en) * 1977-09-26 1979-04-10 Cluff C Brent Water-borne rotating solar collecting and storage systems
US4221468A (en) * 1979-02-26 1980-09-09 Macken John A Multi-cavity laser mirror
US4224081A (en) * 1974-11-27 1980-09-23 Sharp Kabushiki Kaisha Solar cell sealed by glass laminations
US4234351A (en) * 1978-07-14 1980-11-18 The Boeing Company Process for fabricating glass-encapsulated solar cell arrays and the product produced thereby
US4296731A (en) * 1977-09-26 1981-10-27 Cluff C Brent Tracking booster and multiple mirror concentrator floating collector
US4320251A (en) * 1980-07-28 1982-03-16 Solamat Inc. Ohmic contacts for solar cells by arc plasma spraying
US4331703A (en) * 1979-03-28 1982-05-25 Solarex Corporation Method of forming solar cell having contacts and antireflective coating
US4337758A (en) * 1978-06-21 1982-07-06 Meinel Aden B Solar energy collector and converter
US4683348A (en) * 1985-04-26 1987-07-28 The Marconi Company Limited Solar cell arrays
US4746370A (en) * 1987-04-29 1988-05-24 Ga Technologies Inc. Photothermophotovoltaic converter
US4771764A (en) * 1984-04-06 1988-09-20 Cluff C Brent Water-borne azimuth-altitude tracking solar concentrators
US4841946A (en) * 1984-02-17 1989-06-27 Marks Alvin M Solar collector, transmitter and heater
US4847349A (en) * 1985-08-27 1989-07-11 Mitsui Toatsu Chemicals, Inc. Polyimide and high-temperature adhesive of polyimide from meta substituted phenoxy diamines
US4849028A (en) * 1986-07-03 1989-07-18 Hughes Aircraft Company Solar cell with integrated interconnect device and process for fabrication thereof
US4855884A (en) * 1987-12-02 1989-08-08 Morpheus Lights, Inc. Variable beamwidth stage light
US4947825A (en) * 1989-09-11 1990-08-14 Rockwell International Corporation Solar concentrator - radiator assembly
US4952026A (en) * 1988-10-14 1990-08-28 Corning Incorporated Integral optical element and method
US5004319A (en) * 1988-12-29 1991-04-02 The United States Of America As Represented By The Department Of Energy Crystal diffraction lens with variable focal length
US5062899A (en) * 1990-03-30 1991-11-05 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Wide acceptance angle, high concentration ratio, optical collector
US5089055A (en) * 1989-12-12 1992-02-18 Takashi Nakamura Survivable solar power-generating systems for use with spacecraft
US5180441A (en) * 1991-06-14 1993-01-19 General Dynamics Corporation/Space Systems Division Solar concentrator array
US5216543A (en) * 1987-03-04 1993-06-01 Minnesota Mining And Manufacturing Company Apparatus and method for patterning a film
US5344496A (en) * 1992-11-16 1994-09-06 General Dynamics Corporation, Space Systems Division Lightweight solar concentrator cell array
US5389159A (en) * 1992-09-01 1995-02-14 Canon Kabushiki Kaisha Solar cell module and method for producing the same
US5404869A (en) * 1992-04-16 1995-04-11 Tir Technologies, Inc. Faceted totally internally reflecting lens with individually curved faces on facets
US5501743A (en) * 1994-08-11 1996-03-26 Cherney; Matthew Fiber optic power-generating system
US5529054A (en) * 1994-06-20 1996-06-25 Shoen; Neil C. Solar energy concentrator and collector system and associated method
US5540216A (en) * 1994-11-21 1996-07-30 Rasmusson; James K. Apparatus and method for concentrating radiant energy emanated by a moving energy source
US5552820A (en) * 1993-05-21 1996-09-03 Xerox Corporation Fly's eye optics for a raster output scanner in an electrophotographic printer
US5559677A (en) * 1994-04-29 1996-09-24 Motorola, Inc. Method of forming a device by selectively thermal spraying a metallic conductive material thereon
US6011307A (en) * 1997-08-12 2000-01-04 Micron Technology, Inc. Anisotropic conductive interconnect material for electronic devices, method of use and resulting product
US6020554A (en) * 1999-03-19 2000-02-01 Photovoltaics International, Llc Tracking solar energy conversion unit adapted for field assembly
US6091017A (en) * 1999-08-23 2000-07-18 Composite Optics Incorporated Solar concentrator array
US6094273A (en) * 1996-11-06 2000-07-25 University Of Pittsburgh Of The Commonwealth System Of Higher Education Crystalline colloidal array compositions
US6118067A (en) * 1998-11-20 2000-09-12 Swales Aerospace Method and apparatus for improved solar concentration arrays
US6130465A (en) * 1997-10-29 2000-10-10 Light Point Systems Inc. Micro-solar assembly
US6131565A (en) * 1996-12-20 2000-10-17 Stanwell Corporation Limited Solar energy collector system
US6140570A (en) * 1997-10-29 2000-10-31 Canon Kabushiki Kaisha Photovoltaic element having a back side transparent and electrically conductive layer with a light incident side surface region having a specific cross section and a module comprising said photovolatic element
US6239353B1 (en) * 1998-10-14 2001-05-29 Christopher M. Hall Solar tracker
US6274508B1 (en) * 1999-02-05 2001-08-14 Alien Technology Corporation Apparatuses and methods used in forming assemblies
US6278054B1 (en) * 1998-05-28 2001-08-21 Tecstar Power Systems, Inc. Solar cell having an integral monolithically grown bypass diode
US6379521B1 (en) * 1998-01-06 2002-04-30 Canon Kabushiki Kaisha Method of producing zinc oxide film, method of producing photovoltaic element, and method of producing semiconductor element substrate
US20020056473A1 (en) * 2000-11-16 2002-05-16 Mohan Chandra Making and connecting bus bars on solar cells
US6407329B1 (en) * 1999-04-07 2002-06-18 Bridgestone Corporation Backside covering member for solar battery, sealing film and solar battery
US6410644B2 (en) * 1996-12-31 2002-06-25 Kimberly-Clark Worldwide, Inc. Temperature sensitive polymers and water-dispersible products containing the polymers
US6420266B1 (en) * 1999-11-02 2002-07-16 Alien Technology Corporation Methods for creating elements of predetermined shape and apparatuses using these elements
US20020148497A1 (en) * 2001-03-23 2002-10-17 Makoto Sasaoka Concentrating photovoltaic module and concentrating photovoltaic power generating system
US20020149107A1 (en) * 2001-02-02 2002-10-17 Avery Dennison Corporation Method of making a flexible substrate containing self-assembling microstructures
US6479395B1 (en) * 1999-11-02 2002-11-12 Alien Technology Corporation Methods for forming openings in a substrate and apparatuses with these openings and methods for creating assemblies with openings
US6527964B1 (en) * 1999-11-02 2003-03-04 Alien Technology Corporation Methods and apparatuses for improved flow in performing fluidic self assembly
US6531653B1 (en) * 2001-09-11 2003-03-11 The Boeing Company Low cost high solar flux photovoltaic concentrator receiver
US20030051750A1 (en) * 2001-05-29 2003-03-20 Paul Lawheed Conversion of solar energy
US6568863B2 (en) * 2000-04-07 2003-05-27 Seiko Epson Corporation Platform and optical module, method of manufacture thereof, and optical transmission device
US6590235B2 (en) * 1998-11-06 2003-07-08 Lumileds Lighting, U.S., Llc High stability optical encapsulation and packaging for light-emitting diodes in the green, blue, and near UV range
US6597510B2 (en) * 2001-11-02 2003-07-22 Corning Incorporated Methods and apparatus for making optical devices including microlens arrays
US6623579B1 (en) * 1999-11-02 2003-09-23 Alien Technology Corporation Methods and apparatus for fluidic self assembly
US20040031517A1 (en) * 2002-08-13 2004-02-19 Bareis Bernard F. Concentrating solar energy receiver
US20040070855A1 (en) * 2002-10-11 2004-04-15 Light Prescriptions Innovators, Llc, A Delaware Limited Liability Company Compact folded-optics illumination lens
US20040084077A1 (en) * 2001-09-11 2004-05-06 Eric Aylaian Solar collector having an array of photovoltaic cells oriented to receive reflected light
US20040151014A1 (en) * 1997-10-14 2004-08-05 Speakman Stuart Philip Method of forming an electronic device
US20040191422A1 (en) * 2003-03-24 2004-09-30 Canon Kabushiki Kaisha Method for manufacturing solar cell module having a sealing resin layer formed on a metal oxide layer
US20040211460A1 (en) * 2003-04-22 2004-10-28 Simburger Edward J. Thin film solar cell thermal radiator
US20050029236A1 (en) * 2002-08-05 2005-02-10 Richard Gambino System and method for manufacturing embedded conformal electronics
US20050034751A1 (en) * 2003-07-10 2005-02-17 William Gross Solar concentrator array with individually adjustable elements
US20050046977A1 (en) * 2003-09-02 2005-03-03 Eli Shifman Solar energy utilization unit and solar energy utilization system
US20050081908A1 (en) * 2003-03-19 2005-04-21 Stewart Roger G. Method and apparatus for generation of electrical power from solar energy
US6958868B1 (en) * 2004-03-29 2005-10-25 John George Pender Motion-free tracking solar concentrator
US7045794B1 (en) * 2004-06-18 2006-05-16 Novelx, Inc. Stacked lens structure and method of use thereof for preventing electrical breakdown
US7104028B2 (en) * 2002-05-31 2006-09-12 Tetra Laval Holdings & Finance S.A. Forming jaw for producing a succession of sealed packages from a tube of sheet packaging material
US20060207650A1 (en) * 2005-03-21 2006-09-21 The Regents Of The University Of California Multi-junction solar cells with an aplanatic imaging system and coupled non-imaging light concentrator
US20060231133A1 (en) * 2005-04-19 2006-10-19 Palo Alto Research Center Incorporated Concentrating solar collector with solid optical element
US7160522B2 (en) * 1999-12-02 2007-01-09 Light Prescriptions Innovators-Europe, S.L. Device for concentrating or collimating radiant energy
US20070137691A1 (en) * 2005-12-19 2007-06-21 Cobb Joshua M Light collector and concentrator
US20080047605A1 (en) * 2005-07-28 2008-02-28 Regents Of The University Of California Multi-junction solar cells with a homogenizer system and coupled non-imaging light concentrator
US20080186593A1 (en) * 2007-02-02 2008-08-07 Sol Focus, Inc. Metal trace fabrication for optical element
US20090056789A1 (en) * 2007-08-30 2009-03-05 Vladimir Draganov Solar concentrator and solar concentrator array
US20090084374A1 (en) * 2007-06-13 2009-04-02 Mills David R Solar energy receiver having optically inclined aperture

Family Cites Families (120)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US535648A (en) * 1895-03-12 Half to charles a
US2031387A (en) 1934-08-22 1936-02-18 Schwarz Arthur Nozzle
US2789731A (en) 1955-06-06 1957-04-23 Leonard L Marraffino Striping dispenser
US3032008A (en) 1956-05-07 1962-05-01 Polaroid Corp Apparatus for manufacturing photographic films
US3159313A (en) 1961-05-16 1964-12-01 Dow Chemical Co Multi-component proportioning meter system
US3602193A (en) 1969-04-10 1971-08-31 John R Adams Apparatus for preparing coatings with extrusions
US3973994A (en) 1974-03-11 1976-08-10 Rca Corporation Solar cell with grooved surface
AT349415B (en) 1975-07-28 1979-04-10 Zimmer Peter Ag INJECTION PRESSURE DEVICE FOR SAMPLING OF A GOODS
US4018367A (en) 1976-03-02 1977-04-19 Fedco Inc. Manifold dispensing apparatus having releasable subassembly
GB1578018A (en) 1976-03-11 1980-10-29 Schmermund A Glue applications
US4131485A (en) 1977-08-08 1978-12-26 Motorola, Inc. Solar energy collector and concentrator
US4177083A (en) 1977-09-06 1979-12-04 Acurex Corporation Photovoltaic concentrator
US4153476A (en) 1978-03-29 1979-05-08 Nasa Double-sided solar cell package
US4254894A (en) 1979-08-23 1981-03-10 The Continental Group, Inc. Apparatus for dispensing a striped product and method of producing the striped product
DE8033450U1 (en) 1980-12-17 1982-07-22 Colgate-Palmolive Co., 10022 New York, N.Y. Long container for a donor for pastoeses good
US4355196A (en) 1981-03-11 1982-10-19 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Solar cell having improved back surface reflector
JPS58180262A (en) 1982-04-16 1983-10-21 Fuji Photo Film Co Ltd Coating method
US4476165A (en) 1982-06-07 1984-10-09 Acumeter Laboratories, Inc. Method of and apparatus for multi-layer viscous fluid deposition such as for the application of adhesives and the like
US4521457A (en) 1982-09-21 1985-06-04 Xerox Corporation Simultaneous formation and deposition of multiple ribbon-like streams
DE3308269A1 (en) 1983-03-09 1984-09-13 Licentia Patent-Verwaltungs-Gmbh SOLAR CELL
JPS6082680A (en) 1983-10-07 1985-05-10 Fuji Photo Film Co Ltd Surface treating device for metallic web
US4602120A (en) 1983-11-25 1986-07-22 Atlantic Richfield Company Solar cell manufacture
EP0257157A1 (en) 1986-08-29 1988-03-02 General Systems Research Inc. Optical apparatus for scanning radiation over a surface
US4638110A (en) * 1985-06-13 1987-01-20 Illuminated Data, Inc. Methods and apparatus relating to photovoltaic semiconductor devices
US4796038A (en) 1985-07-24 1989-01-03 Ateq Corporation Laser pattern generation apparatus
JPS63175667A (en) 1987-01-14 1988-07-20 Matsushita Electric Ind Co Ltd Multilineal simultaneous coating method
US4747517A (en) 1987-03-23 1988-05-31 Minnesota Mining And Manufacturing Company Dispenser for metering proportionate increments of polymerizable materials
US4826777A (en) 1987-04-17 1989-05-02 The Standard Oil Company Making a photoresponsive array
US4792685A (en) 1987-04-29 1988-12-20 Masami Yamakawa Photoelectric sensor
US4938994A (en) 1987-11-23 1990-07-03 Epicor Technology, Inc. Method and apparatus for patch coating printed circuit boards
US5075281A (en) 1989-01-03 1991-12-24 Testardi Louis R Methods of making a high dielectric constant, resistive phase of YBA2 CU3 OX and methods of using the same
US5011565A (en) 1989-12-06 1991-04-30 Mobil Solar Energy Corporation Dotted contact solar cell and method of making same
DK170189B1 (en) 1990-05-30 1995-06-06 Yakov Safir Process for the manufacture of semiconductor components, as well as solar cells made therefrom
JPH04124645A (en) 1990-09-14 1992-04-24 Fuji Photo Film Co Ltd Photographic base and production thereof
US5213628A (en) 1990-09-20 1993-05-25 Sanyo Electric Co., Ltd. Photovoltaic device
US5254388A (en) 1990-12-21 1993-10-19 Minnesota Mining And Manufacturing Company Light control film with reduced ghost images
US5151377A (en) 1991-03-07 1992-09-29 Mobil Solar Energy Corporation Method for forming contacts
US5167724A (en) * 1991-05-16 1992-12-01 The United States Of America As Represented By The United States Department Of Energy Planar photovoltaic solar concentrator module
US5356488A (en) 1991-12-27 1994-10-18 Rudolf Hezel Solar cell and method for its manufacture
CZ196794A3 (en) 1992-02-25 1994-12-15 Cambridge Consultants Liquid feeding device
US5353813A (en) 1992-08-19 1994-10-11 Philip Morris Incorporated Reinforced carbon heater with discrete heating zones
EP0632507A3 (en) 1993-05-12 1995-11-22 Optical Coating Laboratory Inc UV/IR reflecting solar cell cover.
WO1994028361A1 (en) 1993-06-02 1994-12-08 Stirbl Robert C Method for changing solar energy distribution
JPH0768208A (en) 1993-09-06 1995-03-14 Matsushita Electric Ind Co Ltd Intermittent coating device
US5543333A (en) 1993-09-30 1996-08-06 Siemens Solar Gmbh Method for manufacturing a solar cell having combined metallization
US5700325A (en) 1994-08-03 1997-12-23 Matsushita Electric Industrial Co., Ltd. Coating device and a method of coating
US5553747A (en) 1994-12-07 1996-09-10 Smithkline Beecham Corporation Container for multisegmental toothpaste
US5981902A (en) 1994-12-15 1999-11-09 Mitsubishi Chemical Corporation Texturing apparatus for magnetic recording medium and magnetic recording medium process thereby
US5569399A (en) 1995-01-20 1996-10-29 General Electric Company Lasing medium surface modification
ES2122721T3 (en) 1995-02-02 1998-12-16 Minnesota Mining & Mfg METHOD AND APPARATUS FOR APPLYING THIN STRIPS OF LIQUID COATING.
US5538563A (en) 1995-02-03 1996-07-23 Finkl; Anthony W. Solar energy concentrator apparatus for bifacial photovoltaic cells
EP0729189A1 (en) 1995-02-21 1996-08-28 Interuniversitair Micro-Elektronica Centrum Vzw Method of preparing solar cells and products obtained thereof
GB9507572D0 (en) 1995-04-12 1995-05-31 Smithkline Beecham Plc Dispenser
US5929530A (en) 1995-08-18 1999-07-27 Mcdonnell Douglas Corporation Advanced solar controller
FR2741194B1 (en) 1995-11-13 1998-01-30 Photowatt Int SOLAR CELL COMPRISING MULTICRYSTALLINE SILICON AND METHOD FOR TEXTURIZING THE SURFACE OF P-TYPE MULTICRYSTALLINE SILICON
ATE226114T1 (en) 1996-01-31 2002-11-15 Airspray Int Bv SPRAY DEVICE FOR DISPENSING MULTI-COMPONENT MATERIAL
US5990413A (en) 1996-06-19 1999-11-23 Ortabasi; Ugur Bifacial lightweight array for solar power
US6047926A (en) 1996-06-28 2000-04-11 Alliedsignal Inc. Hybrid deicing system and method of operation
US6476343B2 (en) 1996-07-08 2002-11-05 Sandia Corporation Energy-beam-driven rapid fabrication system
US5902540A (en) 1996-10-08 1999-05-11 Illinois Tool Works Inc. Meltblowing method and apparatus
US5873495A (en) 1996-11-21 1999-02-23 Saint-Germain; Jean G. Device for dispensing multi-components from a container
EP0851511A1 (en) 1996-12-24 1998-07-01 IMEC vzw Semiconductor device with two selectively diffused regions
US6354791B1 (en) 1997-04-11 2002-03-12 Applied Materials, Inc. Water lift mechanism with electrostatic pickup and method for transferring a workpiece
WO1999001342A1 (en) 1997-07-01 1999-01-14 Smithkline Beecham Corporation Apparatus for inserting plural materials into containers
DE19735281A1 (en) 1997-08-14 1999-02-18 Rolf Hoericht Energy generating arrangement using solar radiation
US6008449A (en) 1997-08-19 1999-12-28 Cole; Eric D. Reflective concentrating solar cell assembly
JP4003273B2 (en) 1998-01-19 2007-11-07 セイコーエプソン株式会社 Pattern forming method and substrate manufacturing apparatus
US6185030B1 (en) 1998-03-20 2001-02-06 James W. Overbeck Wide field of view and high speed scanning microscopy
US6032997A (en) 1998-04-16 2000-03-07 Excimer Laser Systems Vacuum chuck
AUPP437598A0 (en) 1998-06-29 1998-07-23 Unisearch Limited A self aligning method for forming a selective emitter and metallization in a solar cell
JP3259692B2 (en) 1998-09-18 2002-02-25 株式会社日立製作所 Concentrating photovoltaic module, method of manufacturing the same, and concentrating photovoltaic system
US6380729B1 (en) 1999-02-16 2002-04-30 Alien Technology Corporation Testing integrated circuit dice
US6291896B1 (en) 1999-02-16 2001-09-18 Alien Technology Corporation Functionally symmetric integrated circuit die
US6257450B1 (en) 1999-04-21 2001-07-10 Pechiney Plastic Packaging, Inc. Dual dispense container having cloverleaf orifice
US6164633A (en) 1999-05-18 2000-12-26 International Business Machines Corporation Multiple size wafer vacuum chuck
US6203621B1 (en) 1999-05-24 2001-03-20 Trw Inc. Vacuum chuck for holding thin sheet material
US6924493B1 (en) 1999-08-17 2005-08-02 The Regents Of The University Of California Ion beam lithography system
FI115295B (en) 1999-09-01 2005-04-15 Metso Paper Inc Curtain coating device and curtain coating method
JP2001110659A (en) 1999-10-05 2001-04-20 Toyota Autom Loom Works Ltd Receptacle for electrical charge for charging
JP2001148500A (en) 1999-11-22 2001-05-29 Sanyo Electric Co Ltd Solar cell module
JP4774146B2 (en) 1999-12-23 2011-09-14 パナソニック株式会社 Method and apparatus for drilling holes with a pitch smaller than the wavelength using a laser
JP2001291881A (en) 2000-01-31 2001-10-19 Sanyo Electric Co Ltd Solar battery module
US6310281B1 (en) 2000-03-16 2001-10-30 Global Solar Energy, Inc. Thin-film, flexible photovoltaic module
US6433303B1 (en) 2000-03-31 2002-08-13 Matsushita Electric Industrial Co., Ltd. Method and apparatus using laser pulses to make an array of microcavity holes
US6423565B1 (en) 2000-05-30 2002-07-23 Kurt L. Barth Apparatus and processes for the massproduction of photovotaic modules
US6232217B1 (en) 2000-06-05 2001-05-15 Chartered Semiconductor Manufacturing Ltd. Post treatment of via opening by N-containing plasma or H-containing plasma for elimination of fluorine species in the FSG near the surfaces of the via opening
US6423140B1 (en) 2000-06-08 2002-07-23 Formosa Advanced Coating Technologies, Inc. Die set for preparing ABCABC multiple-stripe coating
JP2002111035A (en) 2000-09-27 2002-04-12 Sanyo Electric Co Ltd Double-side generation type solar battery module
US6398370B1 (en) 2000-11-15 2002-06-04 3M Innovative Properties Company Light control device
KR100378016B1 (en) 2001-01-03 2003-03-29 삼성에스디아이 주식회사 Method of texturing semiconductor substrate for solar cell
JP3848168B2 (en) 2001-03-29 2006-11-22 三菱製紙株式会社 Curtain coating device
US7186102B2 (en) 2001-04-26 2007-03-06 Strandex Corporation Apparatus and method for low-density cellular wood plastic composites
US6606247B2 (en) 2001-05-31 2003-08-12 Alien Technology Corporation Multi-feature-size electronic structures
US7449070B2 (en) 2001-06-01 2008-11-11 Ulvac, Inc. Waveform generator for microdeposition control system
DE60223196T2 (en) 2001-06-15 2008-02-07 Fujifilm Corp. Process for producing a cellulose ester film
CN2606309Y (en) 2001-06-22 2004-03-10 高增世 Solar mirror double grooved single-way light conducting energy-collecting board
US6555739B2 (en) 2001-09-10 2003-04-29 Ekla-Tek, Llc Photovoltaic array and method of manufacturing same
US6697096B2 (en) 2001-11-16 2004-02-24 Applied Materials, Inc. Laser beam pattern generator having rotating scanner compensator and method
DE60225332T2 (en) 2001-12-13 2009-02-19 Dow Global Technologies, Inc., Midland METHOD AND DEVICE FOR CURTAINING
AU2003223213A1 (en) 2002-02-28 2003-09-16 Scimed Life Systems, Inc. Ultrasonic assisted apparatus and process
EP1345026B1 (en) 2002-03-15 2010-05-05 Affymetrix, Inc. System and method for scanning of biological materials
JP3889644B2 (en) 2002-03-25 2007-03-07 三洋電機株式会社 Solar cell module
US7270528B2 (en) 2002-05-07 2007-09-18 3D Systems, Inc. Flash curing in selective deposition modeling
JP2004266023A (en) 2003-02-28 2004-09-24 Sharp Corp Solar battery and method of manufacturing the same
US7388147B2 (en) 2003-04-10 2008-06-17 Sunpower Corporation Metal contact structure for solar cell and method of manufacture
US7964789B2 (en) 2003-05-07 2011-06-21 Imec Germanium solar cell and method for the production thereof
JP4748955B2 (en) 2003-06-30 2011-08-17 株式会社半導体エネルギー研究所 Pattern fabrication method
JP4121928B2 (en) 2003-10-08 2008-07-23 シャープ株式会社 Manufacturing method of solar cell
JP4232597B2 (en) 2003-10-10 2009-03-04 株式会社日立製作所 Silicon solar cell and manufacturing method thereof
EP1703801B1 (en) 2004-01-15 2011-08-17 Kellogg Company Nozzle assembly for imprinting patterns on an extruded product
JP2005347628A (en) 2004-06-04 2005-12-15 Sharp Corp Electrode forming method, electrode, and solar cell
US7169228B2 (en) 2004-04-29 2007-01-30 The Procter & Gamble Company Extrusion applicator having linear motion operability
US7097710B2 (en) 2004-04-29 2006-08-29 The Procter & Gamble Company Extrusion applicator having rotational operability
JP4459086B2 (en) * 2005-02-28 2010-04-28 三洋電機株式会社 Laminated photovoltaic device and manufacturing method thereof
EP1763086A1 (en) 2005-09-09 2007-03-14 Interuniversitair Micro-Elektronica Centrum Photovoltaic cell with thick silicon oxide and silicon nitride passivation and fabrication method
US7444934B2 (en) 2005-05-24 2008-11-04 Micron Technology, Inc. Supercritical fluid-assisted direct write for printing integrated circuits
US7394016B2 (en) 2005-10-11 2008-07-01 Solyndra, Inc. Bifacial elongated solar cell devices with internal reflectors
US20070169806A1 (en) 2006-01-20 2007-07-26 Palo Alto Research Center Incorporated Solar cell production using non-contact patterning and direct-write metallization
US7799371B2 (en) 2005-11-17 2010-09-21 Palo Alto Research Center Incorporated Extruding/dispensing multiple materials to form high-aspect ratio extruded structures
US7928015B2 (en) 2006-12-12 2011-04-19 Palo Alto Research Center Incorporated Solar cell fabrication using extruded dopant-bearing materials

Patent Citations (99)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US49421A (en) * 1865-08-15 Improvement in sewing-machines
US49658A (en) * 1865-08-29 Improved process for treating ores
US200496A (en) * 1878-02-19 Improvement in strainers for faucets and water-pipes
US209724A (en) * 1878-11-05 Improvement in fire-extinguishers
US1854637A (en) * 1926-04-12 1932-04-19 Prep Ind Combustibles Trough-shaped belt conveyer
US1715260A (en) * 1927-03-23 1929-05-28 Weber Peter Adjustable stand
US1973528A (en) * 1933-11-01 1934-09-11 Sperry Prod Inc Flaw detector mechanism
US2097724A (en) * 1934-12-31 1937-11-02 Cal A Forney Collapsible ironing table
US2606309A (en) * 1950-06-15 1952-08-05 Bell Telephone Labor Inc Glow discharge device
US3923381A (en) * 1973-12-28 1975-12-02 Univ Chicago Radiant energy collection
US4224081A (en) * 1974-11-27 1980-09-23 Sharp Kabushiki Kaisha Solar cell sealed by glass laminations
US3988166A (en) * 1975-01-07 1976-10-26 Beam Engineering, Inc. Apparatus for enhancing the output of photovoltaic solar cells
US4045246A (en) * 1975-08-11 1977-08-30 Mobil Tyco Solar Energy Corporation Solar cells with concentrators
US4021267A (en) * 1975-09-08 1977-05-03 United Technologies Corporation High efficiency converter of solar energy to electricity
US4053327A (en) * 1975-09-24 1977-10-11 Communications Satellite Corporation Light concentrating solar cell cover
US4114596A (en) * 1976-03-16 1978-09-19 Chang Wei Yi Method and apparatus for tracking the sun for use in a solar collector with linear focusing means
US4086485A (en) * 1976-05-26 1978-04-25 Massachusetts Institute Of Technology Solar-radiation collection apparatus with tracking circuitry
US4095997A (en) * 1976-10-07 1978-06-20 Griffiths Kenneth F Combined solar cell and hot air collector apparatus
US4084985A (en) * 1977-04-25 1978-04-18 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Method for producing solar energy panels by automation
US4148301A (en) * 1977-09-26 1979-04-10 Cluff C Brent Water-borne rotating solar collecting and storage systems
US4296731A (en) * 1977-09-26 1981-10-27 Cluff C Brent Tracking booster and multiple mirror concentrator floating collector
US4337758A (en) * 1978-06-21 1982-07-06 Meinel Aden B Solar energy collector and converter
US4234351A (en) * 1978-07-14 1980-11-18 The Boeing Company Process for fabricating glass-encapsulated solar cell arrays and the product produced thereby
US4221468A (en) * 1979-02-26 1980-09-09 Macken John A Multi-cavity laser mirror
US4331703A (en) * 1979-03-28 1982-05-25 Solarex Corporation Method of forming solar cell having contacts and antireflective coating
US4320251A (en) * 1980-07-28 1982-03-16 Solamat Inc. Ohmic contacts for solar cells by arc plasma spraying
US4841946A (en) * 1984-02-17 1989-06-27 Marks Alvin M Solar collector, transmitter and heater
US4771764A (en) * 1984-04-06 1988-09-20 Cluff C Brent Water-borne azimuth-altitude tracking solar concentrators
US4683348A (en) * 1985-04-26 1987-07-28 The Marconi Company Limited Solar cell arrays
US4847349A (en) * 1985-08-27 1989-07-11 Mitsui Toatsu Chemicals, Inc. Polyimide and high-temperature adhesive of polyimide from meta substituted phenoxy diamines
US4849028A (en) * 1986-07-03 1989-07-18 Hughes Aircraft Company Solar cell with integrated interconnect device and process for fabrication thereof
US5216543A (en) * 1987-03-04 1993-06-01 Minnesota Mining And Manufacturing Company Apparatus and method for patterning a film
US4746370A (en) * 1987-04-29 1988-05-24 Ga Technologies Inc. Photothermophotovoltaic converter
US4855884A (en) * 1987-12-02 1989-08-08 Morpheus Lights, Inc. Variable beamwidth stage light
US4952026A (en) * 1988-10-14 1990-08-28 Corning Incorporated Integral optical element and method
US5004319A (en) * 1988-12-29 1991-04-02 The United States Of America As Represented By The Department Of Energy Crystal diffraction lens with variable focal length
US4947825A (en) * 1989-09-11 1990-08-14 Rockwell International Corporation Solar concentrator - radiator assembly
US5089055A (en) * 1989-12-12 1992-02-18 Takashi Nakamura Survivable solar power-generating systems for use with spacecraft
US5062899A (en) * 1990-03-30 1991-11-05 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Wide acceptance angle, high concentration ratio, optical collector
US5180441A (en) * 1991-06-14 1993-01-19 General Dynamics Corporation/Space Systems Division Solar concentrator array
US5404869A (en) * 1992-04-16 1995-04-11 Tir Technologies, Inc. Faceted totally internally reflecting lens with individually curved faces on facets
US5389159A (en) * 1992-09-01 1995-02-14 Canon Kabushiki Kaisha Solar cell module and method for producing the same
US5344496A (en) * 1992-11-16 1994-09-06 General Dynamics Corporation, Space Systems Division Lightweight solar concentrator cell array
US5552820A (en) * 1993-05-21 1996-09-03 Xerox Corporation Fly's eye optics for a raster output scanner in an electrophotographic printer
US5559677A (en) * 1994-04-29 1996-09-24 Motorola, Inc. Method of forming a device by selectively thermal spraying a metallic conductive material thereon
US5529054A (en) * 1994-06-20 1996-06-25 Shoen; Neil C. Solar energy concentrator and collector system and associated method
US5501743A (en) * 1994-08-11 1996-03-26 Cherney; Matthew Fiber optic power-generating system
US5540216A (en) * 1994-11-21 1996-07-30 Rasmusson; James K. Apparatus and method for concentrating radiant energy emanated by a moving energy source
US6094273A (en) * 1996-11-06 2000-07-25 University Of Pittsburgh Of The Commonwealth System Of Higher Education Crystalline colloidal array compositions
US6097530A (en) * 1996-11-06 2000-08-01 University Of Pittsburgh Of The Commonwealth System Of Higher Education Method of using thermally switchable optical devices
US6131565A (en) * 1996-12-20 2000-10-17 Stanwell Corporation Limited Solar energy collector system
US6451429B2 (en) * 1996-12-31 2002-09-17 Kimberly-Clark Worldwide, Inc. Temperature sensitive polymers and water-dispersible products containing the polymers
US6410644B2 (en) * 1996-12-31 2002-06-25 Kimberly-Clark Worldwide, Inc. Temperature sensitive polymers and water-dispersible products containing the polymers
US6011307A (en) * 1997-08-12 2000-01-04 Micron Technology, Inc. Anisotropic conductive interconnect material for electronic devices, method of use and resulting product
US20040151014A1 (en) * 1997-10-14 2004-08-05 Speakman Stuart Philip Method of forming an electronic device
US6140570A (en) * 1997-10-29 2000-10-31 Canon Kabushiki Kaisha Photovoltaic element having a back side transparent and electrically conductive layer with a light incident side surface region having a specific cross section and a module comprising said photovolatic element
US6130465A (en) * 1997-10-29 2000-10-10 Light Point Systems Inc. Micro-solar assembly
US6379521B1 (en) * 1998-01-06 2002-04-30 Canon Kabushiki Kaisha Method of producing zinc oxide film, method of producing photovoltaic element, and method of producing semiconductor element substrate
US6278054B1 (en) * 1998-05-28 2001-08-21 Tecstar Power Systems, Inc. Solar cell having an integral monolithically grown bypass diode
US6239353B1 (en) * 1998-10-14 2001-05-29 Christopher M. Hall Solar tracker
US6590235B2 (en) * 1998-11-06 2003-07-08 Lumileds Lighting, U.S., Llc High stability optical encapsulation and packaging for light-emitting diodes in the green, blue, and near UV range
US6118067A (en) * 1998-11-20 2000-09-12 Swales Aerospace Method and apparatus for improved solar concentration arrays
US6274508B1 (en) * 1999-02-05 2001-08-14 Alien Technology Corporation Apparatuses and methods used in forming assemblies
US6020554A (en) * 1999-03-19 2000-02-01 Photovoltaics International, Llc Tracking solar energy conversion unit adapted for field assembly
US6407329B1 (en) * 1999-04-07 2002-06-18 Bridgestone Corporation Backside covering member for solar battery, sealing film and solar battery
US6091017A (en) * 1999-08-23 2000-07-18 Composite Optics Incorporated Solar concentrator array
US6420266B1 (en) * 1999-11-02 2002-07-16 Alien Technology Corporation Methods for creating elements of predetermined shape and apparatuses using these elements
US6479395B1 (en) * 1999-11-02 2002-11-12 Alien Technology Corporation Methods for forming openings in a substrate and apparatuses with these openings and methods for creating assemblies with openings
US6527964B1 (en) * 1999-11-02 2003-03-04 Alien Technology Corporation Methods and apparatuses for improved flow in performing fluidic self assembly
US6623579B1 (en) * 1999-11-02 2003-09-23 Alien Technology Corporation Methods and apparatus for fluidic self assembly
US7160522B2 (en) * 1999-12-02 2007-01-09 Light Prescriptions Innovators-Europe, S.L. Device for concentrating or collimating radiant energy
US6568863B2 (en) * 2000-04-07 2003-05-27 Seiko Epson Corporation Platform and optical module, method of manufacture thereof, and optical transmission device
US20020056473A1 (en) * 2000-11-16 2002-05-16 Mohan Chandra Making and connecting bus bars on solar cells
US20020149107A1 (en) * 2001-02-02 2002-10-17 Avery Dennison Corporation Method of making a flexible substrate containing self-assembling microstructures
US20020148497A1 (en) * 2001-03-23 2002-10-17 Makoto Sasaoka Concentrating photovoltaic module and concentrating photovoltaic power generating system
US20030051750A1 (en) * 2001-05-29 2003-03-20 Paul Lawheed Conversion of solar energy
US6531653B1 (en) * 2001-09-11 2003-03-11 The Boeing Company Low cost high solar flux photovoltaic concentrator receiver
US20040084077A1 (en) * 2001-09-11 2004-05-06 Eric Aylaian Solar collector having an array of photovoltaic cells oriented to receive reflected light
US6597510B2 (en) * 2001-11-02 2003-07-22 Corning Incorporated Methods and apparatus for making optical devices including microlens arrays
US7104028B2 (en) * 2002-05-31 2006-09-12 Tetra Laval Holdings & Finance S.A. Forming jaw for producing a succession of sealed packages from a tube of sheet packaging material
US20050029236A1 (en) * 2002-08-05 2005-02-10 Richard Gambino System and method for manufacturing embedded conformal electronics
US20040031517A1 (en) * 2002-08-13 2004-02-19 Bareis Bernard F. Concentrating solar energy receiver
US20040070855A1 (en) * 2002-10-11 2004-04-15 Light Prescriptions Innovators, Llc, A Delaware Limited Liability Company Compact folded-optics illumination lens
US6896381B2 (en) * 2002-10-11 2005-05-24 Light Prescriptions Innovators, Llc Compact folded-optics illumination lens
US7181378B2 (en) * 2002-10-11 2007-02-20 Light Prescriptions Innovators, Llc Compact folded-optics illumination lens
US20050081908A1 (en) * 2003-03-19 2005-04-21 Stewart Roger G. Method and apparatus for generation of electrical power from solar energy
US20040191422A1 (en) * 2003-03-24 2004-09-30 Canon Kabushiki Kaisha Method for manufacturing solar cell module having a sealing resin layer formed on a metal oxide layer
US20040211460A1 (en) * 2003-04-22 2004-10-28 Simburger Edward J. Thin film solar cell thermal radiator
US20050034751A1 (en) * 2003-07-10 2005-02-17 William Gross Solar concentrator array with individually adjustable elements
US20050046977A1 (en) * 2003-09-02 2005-03-03 Eli Shifman Solar energy utilization unit and solar energy utilization system
US6958868B1 (en) * 2004-03-29 2005-10-25 John George Pender Motion-free tracking solar concentrator
US7045794B1 (en) * 2004-06-18 2006-05-16 Novelx, Inc. Stacked lens structure and method of use thereof for preventing electrical breakdown
US20060207650A1 (en) * 2005-03-21 2006-09-21 The Regents Of The University Of California Multi-junction solar cells with an aplanatic imaging system and coupled non-imaging light concentrator
US20060231133A1 (en) * 2005-04-19 2006-10-19 Palo Alto Research Center Incorporated Concentrating solar collector with solid optical element
US20080047605A1 (en) * 2005-07-28 2008-02-28 Regents Of The University Of California Multi-junction solar cells with a homogenizer system and coupled non-imaging light concentrator
US20070137691A1 (en) * 2005-12-19 2007-06-21 Cobb Joshua M Light collector and concentrator
US20080186593A1 (en) * 2007-02-02 2008-08-07 Sol Focus, Inc. Metal trace fabrication for optical element
US20090084374A1 (en) * 2007-06-13 2009-04-02 Mills David R Solar energy receiver having optically inclined aperture
US20090056789A1 (en) * 2007-08-30 2009-03-05 Vladimir Draganov Solar concentrator and solar concentrator array

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140090692A1 (en) * 2011-05-20 2014-04-03 Sharp Kabushiki Kaisha Concentrated solar cell and manufacturing method for the same
US20150140263A1 (en) * 2013-11-20 2015-05-21 Kabushiki Kaisha Toshiba Optical element and optical device
US9864111B2 (en) * 2013-11-20 2018-01-09 Kabushiki Kaisha Toshiba Optical element and optical device
US11128179B2 (en) 2014-05-14 2021-09-21 California Institute Of Technology Large-scale space-based solar power station: power transmission using steerable beams
US20160376037A1 (en) 2014-05-14 2016-12-29 California Institute Of Technology Large-Scale Space-Based Solar Power Station: Packaging, Deployment and Stabilization of Lightweight Structures
US10144533B2 (en) 2014-05-14 2018-12-04 California Institute Of Technology Large-scale space-based solar power station: multi-scale modular space power
US10340698B2 (en) 2014-05-14 2019-07-02 California Institute Of Technology Large-scale space-based solar power station: packaging, deployment and stabilization of lightweight structures
WO2015187739A1 (en) * 2014-06-02 2015-12-10 California Institute Of Technology Large-scale space-based solar power station: efficient power generation tiles
US11362228B2 (en) 2014-06-02 2022-06-14 California Institute Of Technology Large-scale space-based solar power station: efficient power generation tiles
WO2017015605A1 (en) * 2015-07-22 2017-01-26 California Institute Of Technology Mirrors transparent to specific regions of the electromagnetic spectrum
US10696428B2 (en) 2015-07-22 2020-06-30 California Institute Of Technology Large-area structures for compact packaging
US10749593B2 (en) 2015-08-10 2020-08-18 California Institute Of Technology Systems and methods for controlling supply voltages of stacked power amplifiers
US10992253B2 (en) 2015-08-10 2021-04-27 California Institute Of Technology Compactable power generation arrays
US10454565B2 (en) * 2015-08-10 2019-10-22 California Institute Of Technology Systems and methods for performing shape estimation using sun sensors in large-scale space-based solar power stations
WO2017027629A1 (en) * 2015-08-10 2017-02-16 California Institute Of Technology Lightweight structures for enhancing the thermal emissivity of surfaces
US11634240B2 (en) 2018-07-17 2023-04-25 California Institute Of Technology Coilable thin-walled longerons and coilable structures implementing longerons and methods for their manufacture and coiling
US11772826B2 (en) 2018-10-31 2023-10-03 California Institute Of Technology Actively controlled spacecraft deployment mechanism

Also Published As

Publication number Publication date
US7851693B2 (en) 2010-12-14
EP1852919A2 (en) 2007-11-07
CN101075646A (en) 2007-11-21
WO2007130794A3 (en) 2008-10-16
EP1852919A3 (en) 2009-02-25
AU2007248262B2 (en) 2011-04-28
WO2007130794A2 (en) 2007-11-15
US20070256724A1 (en) 2007-11-08
EP1852919B1 (en) 2014-07-16
CN100544036C (en) 2009-09-23
AU2007248262A1 (en) 2007-11-15

Similar Documents

Publication Publication Date Title
US7851693B2 (en) Passively cooled solar concentrating photovoltaic device
US7638708B2 (en) Laminated solar concentrating photovoltaic device
US7906722B2 (en) Concentrating solar collector with solid optical element
US20070256725A1 (en) Solar Concentrating Photovoltaic Device With Resilient Cell Package Assembly
JP5281154B2 (en) Photovoltaic generator with spherical imaging lens for use with parabolic solar reflector
US20100012171A1 (en) High efficiency concentrating photovoltaic module with reflective optics
US20110197880A1 (en) Solar Concentration and Cooling Devices, Arrangements and Methods
MX2011008352A (en) Concentrator-type photovoltaic (cpv) modules, receivers and sub-receivers and methods of forming same.
US20100288332A1 (en) Solar photovoltaic concentrator panel
US20140020733A1 (en) Photovoltaic device for a closely packed array
US20110203638A1 (en) Concentrating linear photovoltaic receiver and method for manufacturing same
JP4898145B2 (en) Concentrating solar cell module
WO2009149504A1 (en) A substrate for photovoltaic devices
CN102270690A (en) Solar energy utilization device

Legal Events

Date Code Title Description
STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION

AS Assignment

Owner name: CPV SOLAR LLC C/O HARPER CONSTRUCTION COMPANY, INC

Free format text: SECURITY AGREEMENT;ASSIGNOR:SOLFOCUS, INC.;REEL/FRAME:029733/0583

Effective date: 20130201