Solar module

• US 5,977,478 A
• Filed: 12/04/1997
• Issued: 11/02/1999
• Est. Priority Date: 12/05/1996
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Hasegawa, Hiroshi, Hibino, Kouetsu
• Primary Examiner(s): DIAMOND, ALAN D
• Application Number:
  US08/985,260
• Time in Patent Office: 698 Days
• Field of Search: 136/246, 136/259, 126/684, 126/685, 126/698, 250/216, 250/225, 257/432, 257/436, 359/831, 359/834, 359/837, 359/742, 359/485, 359/494, 359/496, 359/497
• US Class Current: 136/259
• CPC Class Codes: F24S 23/00 Arrangements for concentrating solar-rays for solar heat collectors
• CPC Class Codes: F24S 23/10 Prisms
• CPC Class Codes: F24S 23/31 having discontinuous faces, e.g. Fresnel 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: Y02E 10/44 Heat exchange systems
• CPC Class Codes: Y02E 10/46 Conversion of thermal power into mechanical power, e.g. Rankine, Stirling or solar thermal engines
• CPC Class Codes: Y02E 10/52 PV systems with concentrators

Abstract

For the purpose of providing a solar module which has a fixed type solar concentrator of high converging magnification, a solar cell 12 is installed on the bottom face of an extension 30 which is extended further from the apex of a V shape formed by a pair of prisms having a refractive index larger than that of air, and a mirror surface 18 is formed on the back side of an incident surface 20 on which sunlight 10 falls. The mirror surface 18 and the incident surface 20 are formed in such a manner that their distance widens toward the apex of the V shape. The sunlight 10 incident on the prisms 16 performs reflection on the mirror surface 18 and total internal reflection on the incident surface 20, respectively. After repeating such reflection, the sunlight 10 reaches the bottom of the extension 30, where it emerges as outgoing light 22 to the solar cell 12.

Claims

1. A solar module comprising:

a solar concentrator having a pair of prisms for converging sunlight by utilizing reflection and total internal reflection, each of said prisms being a member having a refractive index larger than that of air and having a triangular section,

wherein said prisms form a V shape having an apex and an extension having a bottom spaced from the apex, and a solar cell is arranged on the bottom of the extension.

2. The solar module according to claim 1, wherein a V groove is formed at the apex of said V shape and extending in the longitudinal direction thereof.

3. The solar module according to claim 1, wherein said extension has a refractive index larger than the refractive indices of said prisms.

4. The solar module according to claim 3, wherein the interface of said extension and said prisms is convex on the side of said prisms.

5. The solar module according to claim 1, wherein a mirror surface is formed on a back side of each of said prisms, the back side being opposite from the side facing the other prism, and wherein said mirror surfaces face in the direction of the side facing the other prism.

6. The solar module according to claim 1, wherein a layer of adhesive is provided between said solar cell and said extension.

7. The solar module according to claim 1, wherein a triangular cavity is provided in each of said prisms, the triangular cavity being an upside-down image of sections of said prisms.

8. The solar module according to claim 7, wherein a substance having a refractive index smaller than the refractive indices of said prisms is filled in said cavity.

9. The solar module according to claim 1, wherein a convex cavity is provided in a prism portion of the interface between said prism and said solar cell and is the prism side of a part corresponding to an electrode position of said solar cell.

10. A solar module comprising:

a solar concentrator prism comprising a transparent material with a refractive index larger than that of air, the prism having a triangular section, and performs convergence by utilizing reflection and total internal reflection,

wherein said prism has a Fresnel lens for polarizing incident sunlight to a direction in which the incident angle of sunlight to said prism is increased.

11. The solar module according to claim 10, wherein the Fresnel lens has an incident surface and a bottom face, and wherein a surface sandwiched between the incident surface and the bottom face of said Fresnel lens is tilted toward an incident surface of said prism by an angle.

12. The solar module according claim 10, wherein said prism is arranged so that the incident surface of said prism is horizontal.

13. The solar module according to claim 10, wherein the Fresnel lens has an incident surface and a bottom face, and wherein a perpendicular surface sandwiched between the incident surface and the bottom face of said Fresnel lens is a reflection surface.

14. The solar module according to claim 10, wherein a solar cell is arranged on one side of the prism, and a convex cavity is provided in a prism portion of the interface between said prism and said solar cell and is the prism side of a part corresponding to an electrode position of said solar cell.