SYSTEM AND METHOD FOR SOLAR ENERGY CAPTURE AND RELATED METHOD OF MANUFACTURING

• US 20110226332A1
• Filed: 09/18/2009
• Published: 09/22/2011
• Est. Priority Date: 09/19/2008
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Tremblay, Eric, Hallas, Justin Matthew, Karp, Jason Harris, Ford, Joseph E.
• Granted Patent: US 9,274,266 B2
• Time in Patent Office: Days
• US Class Current: 136/259
• CPC Class Codes: B29D 11/00009 Production of simple or compound lenses
• CPC Class Codes: B29D 11/00865 Applying coatings; tinting; colouring printing, marking or copying processes B41M; identification in general G09F3/00; producing decorative effects in general B44C; positioning or marking of lenses B24B13/0055
• CPC Class Codes: F24S 23/12 Light guides
• CPC Class Codes: F24S 23/31 having discontinuous faces, e.g. Fresnel lenses
• CPC Class Codes: G01S 3/7861 Solar tracking systems
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0042 for use with direct solar radiation
• CPC Class Codes: G02B 3/0037 characterized by the distribution or form of lenses
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0078 Side-by-side arrangements, e.g. for large area displays
• CPC Class Codes: G02B 6/26 Optical coupling means G02B6/36, G02B6/42 take precedence
• CPC Class Codes: G02B 7/005 Motorised alignment
• CPC Class Codes: H01L 31/0543 comprising light concentrating means of the refractive type, e.g. lenses
• CPC Class Codes: H01L 31/0547 comprising light concentrating means of the reflecting type, e.g. parabolic mirrors, concentrators using total internal reflection
• CPC Class Codes: H01L 31/055 where light is absorbed and re-emitted at a different wavelength by the optical element directly associated or integrated with the PV cell, e.g. by using luminescent material, fluorescent concentrators or up-conversion arrangements
• CPC Class Codes: Y02B 10/10 Photovoltaic [PV]
• CPC Class Codes: Y02B 10/20 Solar thermal
• CPC Class Codes: Y02E 10/40 Solar thermal energy, e.g. solar towers
• CPC Class Codes: Y02E 10/47 : Mountings or tracking
• CPC Class Codes: Y02E 10/52 : PV systems with concentrators

Abstract

A system and method of capturing solar energy, and related method of manufacturing, are disclosed. In at least one embodiment, the system includes a first lens array having a plurality of lenses, and a first waveguide component adjacent to the lens array, where the waveguide component receives light, and where the waveguide component includes an array of prism/mirrored facets arranged along at least one surface of the waveguide component. The system further includes at least one photovoltaic cell positioned so as to receive at least a portion of the light that is directed out of the waveguide. A least some of the light passing into the waveguide component is restricted from leaving the waveguide component upon being reflected by at least one of the prism/mirrored facets, hereby the at least some light restricted from leaving the waveguide component is directed by the waveguide toward the at least one photovoltaic cell.

Claims

1. A system for capturing solar energy, the system comprising:

a first lens array having a plurality of lenses;

a first waveguide component adjacent to the lens array, wherein the waveguide component receives light, and wherein the waveguide component includes an array of prism or mirrored facets arranged along at least one surface of the waveguide component; and

at least one photovoltaic cell positioned so as to receive at least a portion of the light that is directed out of the waveguide;

wherein at least some of the light passing into the waveguide component is restricted from leaving the waveguide component upon being reflected by at least one of the prism or mirrored facets, and

whereby the at least some light restricted from leaving the waveguide component is directed by the waveguide toward the at least one photovoltaic cell.

2. The system of claim 1, wherein the at least some light is substantially trapped within the waveguide by total internal reflection due to operation of the prism or mirrored facets.

3. The system of claim 1, wherein each of the prism or mirrored facets is aligned with a respective one of the lenses of the lens array

4. The system of claim 1, wherein the lens array includes an outer surface upon which the light received by the waveguide is initially incident prior to being received by the waveguide, and an inner surface opposed to the outer surface, the inner surface extending alongside the waveguide component.

5. The system of claim 4, wherein the lenses of the lens array serve to focus the light toward the prism or mirrored facets of the waveguide component.

6. The system of claim 4, wherein the waveguide component includes a first surface, a second surface and an intermediate light conductive structure in between the first and second surfaces, wherein a cladding layer forms the first surface and the cladding layer is in contact with the inner surface of the lens array.

7. The system of claim 6, wherein the prism or mirrored facets are formed along the second surface.

8. The system of claim 7, wherein the prism or mirrored facets are formed at least in part by directing light toward photosensitive material arranged along the second surface, and wherein the second surface additionally serves as an additional cladding layer.

9. The system of claim 1, wherein the prism or mirrored facets are formed at least in part by a photosensitive material that is capable of repeatedly responding to changes in the light, such that characteristics of the prism or mirrored facets change over time as the light received by the waveguide component varies in direction.

10. The system of claim 9, wherein the photosensitive material operates to repeatedly sense and respond to changes in electric fields of portions of the light, by drawing in high dielectric index particles so as to achieve optical trapping.

11. The system of claim 10, wherein the photosensitive material includes both the high dielectric index particles, wherein the high dielectric index particles are nanoscale particles of Titanium dioxide, and wherein the photosensitive material further includes dense but low index of refraction fluoropolymer material in which the high dielectric index particles are contained.

12. The system of claim 1, wherein at least two portions of the system are capable of being shifted relative to one another so that incident light first arriving at the system is ultimately received by the prism or mirrored facets even though the incident light varies with time in terms of an angle of incidence.

13. The system of claim 12, further comprising a plurality of additional lens arrays, wherein at least one of the additional lens arrays is capable of being shifted relative to at least one other of the lens arrays.

14. The system of claim 1, wherein the waveguide component is laterally shiftable relative to the lens array.

15. The system of claim 1, wherein the waveguide component receives the light from the lens array after the light has previously arrived at the lens array.

16. The system of claim 15, wherein the light arrives at the lens array from an external location.

17. The system of claim 15, wherein the light arrives at the lens array after first passing through the waveguide component.

18. The system of claim 17, wherein the lens array includes a mirrored surface for reflecting the light arriving at the lens array back toward the waveguide component.

19. The system of claim 18, wherein the mirrored surface is a dichroic surface by which at least a portion of additional light arriving at the lens array is able to proceed to either a diffuse light receiver or another waveguide component.

20. The system of claim 1, further comprising a second lens array, wherein the waveguide component is positioned in between the first lens array and the second lens array.

21. The system of claim 1, wherein the light received by the waveguide component is received after having first passed through the first lens array and having additionally been reflected by the second lens array back toward the waveguide component.

22. The system of claim 20, wherein the waveguide component is laterally shiftable relative to the first and second lens arrays.

23. The system of claim 1, wherein a first of the at least one photovoltaic cell is positioned along a longitudinal edge of the waveguide component.

24. The system of claim 1, further comprising one or more of a folding prism, a curved mirror, and a reflector positioned along at least one longitudinal edge of the waveguide component.

25. The system of claim 24, wherein the at least some of the light directed toward the at least one photovoltaic cell proceeds to the at least one photovoltaic cell only after being redirected by one or more of the folding prism, the curved mirror, and the reflector.

26. The system of claim 25, wherein a first of the at least one photovoltaic cell also receives additional light from another adjacent waveguide component.

27. A planar array solar energy system including the system of claim 25 and further including a plurality of additional systems each including a respective waveguide component and a respective lens array.

28. The system of claim 1, wherein a first portion of the at least some light restricted from leaving the waveguide component is directed by the waveguide component to and through a first edge surface of the waveguide component and thereby coupled into a first of the at least one photovoltaic cell.

29. The system of claim 28, wherein the first edge surface includes a first dichroic minor allowing for transmission of the first portion of the at least some light corresponding to a first light spectrum portion to pass out of the waveguide component for receipt by the first photovoltaic cell.

30. The system of claim 29, wherein the waveguide component includes a second edge surface having a second dichroic mirror allowing for transmission of a second portion of the at least some light corresponding to a second light spectrum portion to pass out of the waveguide component for receipt by a second of the at least one photovoltaic cell.

31. The system of claim 1,

wherein the first waveguide component includes first and second longitudinal surfaces that are substantially opposed to one another, wherein the first longitudinal surface extends alongside the lens array,

wherein the waveguide component further includes first and second side edge surfaces each extending between the first and second longitudinal surfaces and further extending away from the lens array, and

wherein the waveguide component further includes first and second end edge surfaces each extending between the longitudinal surfaces and also between the side edge surfaces.

32. The system of claim 31, wherein a first dichroic mirror is formed on the first end edge surface and a second dichroic mirror is formed on the second end edge surface, wherein the first dichroic minor allows a first portion of the at least some light to pass out of the waveguide component for receipt by a first of the at least one photovoltaic cell but precludes a second portion of the at least some light to pass out of the waveguide component, and wherein the second dichroic minor allows the second portion to pass out of the waveguide component for receipt by a second of the at least one photovoltaic cell but precludes the first portion to pass out of the waveguide component.

33. The system of claim 31, further comprising a second waveguide component extending alongside either the first longitudinal surface or the second longitudinal surface of the first waveguide component, and wherein a dichroic mirror is formed between the first and second waveguide components.

34. The system of claim 33, wherein the dichroic minor is formed upon the lenses of the lens array, the lens array being positioned between the first and second waveguide components.

35. The system of claim 34, wherein the lenses of the lens array serve to direct a first light component to the prism or mirrored facets of the first waveguide component and further serve to allow a second light component to pass to additional prism or mirrored facets of the second waveguide component.

36. The system of claim 33, further comprising at least one of a folding prism, a reflector, and a curved mirror that redirects at least one light component exiting the waveguide component by way of one of the edge surfaces.

37. The system of claim 31, further comprising at least one of a folding prism, a reflector, and a curved minor that redirects at least one light component exiting the waveguide component by way of one of the edge surfaces, and also at least one external dichroic minor that differentiates the at least one light component into first and second light components.

38. The system of claim 31, wherein a first of the at least one photovoltaic cell is positioned along the first end edge surface, wherein the first photovoltaic cell covers only a first portion of the first end edge surface, and wherein a remainder portion of the first end edge surface other than the first portion is configured to reflect light incident thereon.

39. The system of claim 38, wherein the end edge surfaces are either parallel to one another or skewed relative to one another.

40. The system of claim 38, wherein at least one of a minor, a Fresnel reflector, a retroreflector and an additional photovoltaic cell is provided along or as the second end edge surface.

41. The system of claim 1, wherein each of the prism or mirrored facets is configured to direct at least a portion of the light in a respective direction within the waveguide component.

42. The system of claim 41, wherein the prism or mirrored facets are respectively configured to direct the at least some light toward the at least one photovoltaic cell.

43. The system of claim 42, wherein the prism or mirrored facets are respectively configured to direct that least some light in a radial manner toward the at least one photovoltaic cell, and wherein the at least one photovoltaic cell is positioned at a location other than an edge surface of the waveguide.

44. The system of claim 43, wherein the waveguide component is either cylindrical or hexagonal.

45. A method of manufacturing the system of claim 1, wherein the waveguide component includes first and second surfaces, and wherein the method comprises:

providing at least one photosensitive material upon the second surface of the waveguide component; and

forming the prism or mirrored facets by exposing the at least one photosensitive material to at least some light.

46. A method of manufacturing a solar energy collection system, the method comprising:

providing a waveguide layer;

providing a lens array in combination with the waveguide layer; and

forming prism or mirrored facets on the waveguide layer by exposing the waveguide layer and at least one additional layer to light.

47. The method of claim 46, further comprising:

(a) applying a superstrate and a cladding layer upon a first surface of the waveguide layer;

(b) performing embossing to form lenses of the lens array in the superstrate;

(c) applying an ultraviolet-curable molding film upon a second surface of the waveguide layer, the second surface being opposite the first surface;

(d) performing stamping to provide prism facet formations in the molding film;

(e) exposing the molding film to ultraviolet light, whereby the prism or mirrored facets are formed; and

(f) performing a solvent bath operation to remove uncured facet material.

48. The method of claim 47, further comprising:

(g) attaching at least one photovoltaic cell to at least one edge surface of the waveguide layer.

49. The method of claim 46, further comprising:

(a) providing a photopolymer coating on the waveguide layer;

(b) applying a mold to the waveguide layer with the photopolymer coating;

(c) baking the mold, waveguide layer, and photopolymer coating in combination;

(d) removing the mold prior to performing the providing of the lens array, wherein the lens array is provided adjacent a surface of the waveguide layer opposite the photopolymer coating;

(e) exposing the photopolymer coating to ultraviolet light;

(f) depositing a reflective coating onto the photopolymer coating; and

(g) further heating the photopolymer coating, wherein the prism or mirrored facets are formed by at least a portion of the photopolymer coating.

50. A method of capturing solar energy, the method comprising:

receiving light at a waveguide component;

reflecting at least a portion of the received light at a plurality of prism or mirrored facets formed along a surface of the waveguide component, wherein substantially all of the reflected light experiences total internal reflection within the waveguide component subsequent to being reflected by the prism or mirrored facets;

communicating the reflected light within the waveguide component toward an edge surface of the waveguide layer; and

receiving the communicated reflected light at a photovoltaic cell upon the communicated reflected light being transmitted through the edge surface.

51. The method of claim 50, wherein the photovoltaic cell extends substantially between the first and second surfaces of the waveguide layer.

52. The method of claim 50, wherein the light is first provided to a plurality of microlenses and then subsequently transmitted to a cladding layer of the waveguide component by which the light is received by the waveguide component, the received light then proceeding through a waveguide layer of the waveguide component.

53. The method of claim 50, wherein either the prism or mirrored facets, or at least one optical path to the prism facets, is modified in at least one characteristic over time as changes in the light occur.

55. A modular concentrated solar photovoltaic system comprising the system of claim 53, wherein the photovoltaic system allows the at least one photovoltaic cell to be attached and detached from a large-area waveguide-based optical concentrator, where the attachment acts to strip guided light into the aperture of the photovoltaic cell.

54. A system for capturing solar energy, the system comprising:

an optical waveguide layer, having an upper and lower cladding layer;

a lens array having a plurality of lenses, disposed above the upper cladding layer, and upon which sunlight is incident;

an array of injection features formed on the optical waveguide layer and arranged so that each injection feature is located at or near the focus of a respective one of the lenses, wherein each of the injection features is oriented so that light focused from the lens onto the respective injection feature is coupled into the optical waveguide layer; and

at least one photovoltaic cell positioned along at least one edge surface of the optical waveguide, wherein the light coupled into the optical waveguide layer is guided by the waveguide toward and absorbed by the at least one photovoltaic cell.

56. A solar photovoltaic system comprising:

a solar concentrator that collects direct sunlight into a small-area PV cell, overlapping in light collection area with a non-concentrated solar panel that collects indirect sunlight into a large-area PV or solar-thermal panel.