Light concentrator photovoltaic module method of manufacturing same and light concentrator photovoltaic system

• US 6,323,415 B1
• Filed: 09/17/1999
• Issued: 11/27/2001
• Est. Priority Date: 09/18/1998
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yazawa, Yoshiaki, Ohtsuka, Hiroyuki, Warabisako, Terunori, Muramatsu, Shin-ichi, Tsutsui, Ken, Miyamura, Yoshinori, Uematsu, Tsuyoshi, Minemura, Junko
• Primary Examiner(s): CHAPMAN, MARK A
• Application Number:
  US09/398,043
• Time in Patent Office: 802 Days
• Field of Search: 136/246
• US Class Current: 136/246
• CPC Class Codes: B32B 17/10018 comprising only one glass sheet
• CPC Class Codes: B32B 17/10788 containing ethylene vinylacetate
• CPC Class Codes: H01L 31/048 Encapsulation of modules
• 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: H02S 20/32 specially adapted for solar tracking
• CPC Class Codes: H02S 30/20 Collapsible or foldable PV modules
• CPC Class Codes: Y02E 10/52 PV systems with concentrators

Abstract

A light concentrator photovoltaic module includes a medium having a light receiving plane, a plurality of photovoltaic elements arranged in a spaced relationship with the light receiving plane, and a light reflecting plane for conducting light incident upon the light receiving plane but is not directly received by the photovoltaic elements to the photovoltaic elements. The light reflecting plane has a structure as viewed on a cross section in a plane transverse to the module light receiving plane and traversing adjacent two photovoltaic elements and a light reflecting member therebetween such that the light reflecting plane includes, at least two first inclined planes and at least two second inclined planes, the first inclined planes being rightwardly ascending while the second inclined planes are leftwardly ascending, respectively, at least two first inclined planes being arranged on a right side of a middle point of a distance between the adjacent two photovoltaic elements while at least two second inclined planes being arranged on a left side of the middle point.

Claims

1. A light concentrator photovoltaic module comprising a flat module light receiving plane upon which sunlight is incident, a plurality photovoltaic elements, a light reflecting member, and a medium for transmitting the sunlight to said photovoltaic elements and said light reflecting member,

wherein said module light receiving plane is formed by a surface of said medium upon which the sunlight is incident, and said medium and said light reflecting member are joined with each other so that their interface forms a light reflecting plane;

wherein, with said module light receiving plane and said photovoltaic elements being located at a relatively upper level and at a relatively lower level, respectively, said light reflecting plane includes, between adjacent two photovoltaic elements, at least two first inclined planes and at least two second inclined planes, said first inclined planes being rightwardly ascending while said second inclined planes are leftwardly ascending, respectively, as viewed on a cross section taken on a line on which the adjacent two photovoltaic elements lie, at least two first inclined planes being arranged on a right side of a middle point of a distance between said adjacent two photovoltaic elements while at least two second inclined planes being arranged on a left side of said middle point; and

wherein a portion of said light reflecting plane including said first and second inclined planes between said adjacent two photovoltaic elements is arranged relative to one of said two adjacent photovoltaic elements which is on a right side in such a manner that said one photovoltaic element has a light receiving plane at least partly positioned within a parallelogramic area, as viewed on said cross section, consisting of first to fourth sides,

the first side defined by a first reflection light beam produced by a sunlight beam entering a left edge of a most leftwardly located one of said second inclined planes of said portion of said light reflecting plane and undergoing total internal reflection on said module light receiving plane,

the second side defined by a second reflection light beam produced by said sunlight beam entering a most rightwardly located one of said second inclined planes of said portion of said light reflecting plane and arriving at and undergoing total internal reflection on said module light receiving plane without impinging on an opposed one of said first inclined planes,

the third side defined by a line on which points of said total internal reflection of said first and second reflection light beams on said module light receiving plane lie, and

the fourth side defined by a line farther from said module light receiving plane than a plane containing the uppermost portions of said first and second inclined planes of said portion of said light receiving plane,

wherein adjacent first and second inclined planes of said light reflecting plane are in contact to each other on an individual one side to form a groove so that said light reflecting plane provides a groove-formed reflection sheet, and a width between adjacent grooves as viewed in a direction parallel to the light receiving plane on said cross section is no less than 1 mm.

2. A light concentrator photovoltaic module comprising a flat module light receiving plane upon which sunlight is incident, a plurality photovoltaic elements, a light reflecting member, and a medium for transmitting the sunlight to said photovoltaic elements and said light reflecting member,

wherein said module light receiving plane is formed by a surface of said medium upon which the sunlight is incident, and said medium and said light reflecting member are joined with each other so that their interface forms a light reflecting plane;

wherein, with said module light receiving plane and said photovoltaic elements being located at a relatively upper level and at a relatively lower level, respectively, said light reflecting plane includes, between adjacent two photovoltaic elements, at least two first inclined planes and at least two second inclined planes, said first inclined planes being rightwardly ascending while said second inclined planes are leftwardly ascending, respectively, as viewed on a cross section taken on a line on which the adjacent two photovoltaic elements lie, at least two first inclined planes being arranged on a right side of a middle point of a distance between said adjacent two photovoltaic elements while at least two second inclined planes being arranged on a left side of said middle point; and

wherein a portion of said light reflecting plane including said first and second inclined planes between said adjacent two photovoltaic elements is arranged relative to one of said two adjacent photovoltaic elements which is on a right side in such a manner that said one photovoltaic element has a light receiving plane at least partly positioned within a parallelogramic area, as viewed on said cross section, consisting of first to fourth sides,

the first side defined by a first reflection light beam produced by a sunlight beam entering a left edge of a most leftwardly located one of said second inclined planes of said portion of said light reflecting plane and undergoing total internal reflection on said module light receiving plane,

the second side defined by a second reflection light beam produced by said sunlight beam entering a most rightwardly located one of said second inclined planes of said portion of said light reflecting plane and arriving at and undergoing total internal reflection on said module light receiving plane without impinging on an opposed one of said first inclined planes,

the third side defined by a line on which points of said total internal reflection of said first and second reflection light beams on said module light receiving plane lie, and

the fourth side defined by a line farther from said module light receiving plane than a plane containing the uppermost portions of said first and second inclined planes of said portion of said light receiving plane,

wherein said module light receiving plane includes first and second module light reception planes forming opposite surfaces of said medium, said first module light reception plane being located at said relatively upper level, each of said photovoltaic elements having first and second element light receiving planes, said first element light receiving plane being provided on a first side of the photovoltaic element on which said first module light reception plane exists, said second element light receiving plane being provided on a second side of the photovoltaic element on which said second module light reception plane exists, and said light reflecting plane enables light reflection on both sides thereof.

3. A light concentrator photovoltaic module according to claim 2, wherein said plurality of photovoltaic elements are flat elements.

4. A light concentrator photovoltaic module according to claim 2, wherein adjacent first and second inclined planes of said light reflecting plane are in contact to each other on individual one side to form a groove, a plurality of grooves being provided by said first and second inclined planes in contact to each other.

5. A light concentrator photovoltaic module according to claim 2, wherein adjacent first and second inclined planes of said light reflecting plane are in contact to each other on individual one side to form a groove, said groove having an angle of 120°

±

10°

.

6. A light concentrator photovoltaic module according to claim 2, wherein a portion of said light reflecting plane including said first and second inclined planes between said adjacent two photovoltaic elements is arranged, as viewed on said cross section, relative to one of said two adjacent photovoltaic elements which is on a right side in such a manner that a part of said second inclined planes leftwardly ascending in said portion of said light reflecting plane have inclination angles with respect to module light receiving plane are gradually decreasing as locations of the second inclined planes approach nearer to said photovoltaic element.

7. A light concentrator photovoltaic module according to claim 2, wherein said light reflecting plane is provided in the form of said inclined planes continuously extending to a side opposite to a module light receiving plane side of said plurality of photovoltaic elements.

8. A light concentrator photovoltaic module according to claim 2, wherein said light reflecting plane is provided to continuously extend between said plurality of photovoltaic elements on a side opposite to a module light receiving plane side of said plurality of photovoltaic elements, a part of said light reflecting plane, on which the photovoltaic element is projected, having a shape of a curved line or a broken line similar to said curved line as viewed on a cross section taken along a line on which projections of adjacent two photovoltaic elements lie.

9. A light concentrator photovoltaic module according to claim 2, wherein said light reflecting plane is discontinuous in a direction of a line on which said plurality of photovoltaic elements lie.

10. A light concentrator photovoltaic module according to claim 2, wherein said adjacent first and second inclined planes of said light reflecting plane are in contact to each other on individual one side to form a said groove having an angle of 120°

±

10°

.

11. A light concentrator photovoltaic module according to claim 2, wherein said adjacent first and second inclined planes of said light reflecting plane are in contact to each other on individual one side to form a groove, said light reflecting plane including an array of a plurality of quadrangular pyramids with recesses and projections in a direction of the length of said groove.

12. A light concentrator photovoltaic module according to claim 2, wherein said adjacent first and second inclined planes of said light reflecting plane are in contact to each other on individual one side to form a groove, with recesses and projections additionally formed in a direction of the length of said groove.

13. A light concentrator photovoltaic module according to claim 2, wherein said module is being capable of being folded or rolled up.

14. A light concentrator photovoltaic module according to claim 2, wherein said light reflecting plane is formed on a resin substrate, a metal substrate or a metal oxide substrate.

15. A light concentrator photovoltaic module according to claim 14, wherein said resin substrate is made of a material selected from a group consisting of acrylic resin, PET, polycarbonate and a fluoric resin, said metal substrate is made of a material selected from a group consisting of aluminum, an aluminum alloy, copper, a stainless alloy and kovar, and said metal oxide substrate is made of a material selected from a group consisting of alumina and surface oxidized-aluminum.

16. A light concentrator photovoltaic module according to claim 14, wherein said metal substrate is an aluminum substrate, said light reflecting plane is made from said aluminum substrate itself or from said aluminum substrate and an aluminum film formed on said aluminum substrate, and an interference film is further formed on said light reflecting plane to enhance a reflectance of said light reflecting plane.

17. A light concentrator photovoltaic system comprising the photovoltaic module defined in claim 2, and an angle varying means for varying an inclination angle of said photovoltaic module with respect to a horizontal plane.

18. A light concentrator photovoltaic system comprising an artificial satellite, and the photovoltaic module defined in claim 2, said photovoltaic module being mounted on said artificial satellite.

19. A light concentrator photovoltaic system comprising a two-axis tracking apparatus, and the photovoltaic module defined in claim 2.

20. A light concentrator photovoltaic system comprising a single axis tracking apparatus, the photovoltaic module defined in claim 2 installed in said single axis tracking apparatus, and control means for controlling said photovoltaic module in such a manner that the sun is located in a virtual plane perpendicular to said module light receiving plane and parallel with a direction of the length of a groove formed by adjacent first and second inclined planes in contact with each other on individual one side.

21. A method of manufacturing the photovoltaic module as defined in claim 2, comprising preparing separately at least a part of said medium and said light reflecting plane, and said medium and said light reflecting plane with each other.