The present disclosure relates to photovoltaic systems, and more particularly to a photovoltaic module with light concentration.
Photovoltaic modules may concentrate sunlight onto photovoltaic surfaces to generate electrical energy. Such a photovoltaic module uses a number of solar cells to turn the sunlight into electrical energy, and use a primary optical element to focus light onto the solar cells. The solar cells are electrically interconnected by gold wires, which utilizes a large amount of gold.
Implementations of the present technology will now be described, by way of example only, with reference to the attached figures.
It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts have been exaggerated to better illustrate details and features of the present disclosure.
Several definitions that apply throughout this disclosure will now be presented.
The term “coupled” is defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The connection can be such that the objects are permanently connected or releasably connected. The term “substantially” is defined to be essentially conforming to the particular dimension, shape or other word that substantially modifies, such that the component need not be exact. For example, substantially cylindrical means that the object resembles a cylinder, but can have one or more deviations from a true cylinder.
The following disclosure is described in relation to a light-concentrating photovoltaic module 100.
The solar cells 40 are electrically mounted on the circuit 31. The solar cells 40 are electrically connected with each other by the circuit 31. The solar cell 40 has a top surface facing the secondary optical element 50, and a bottom surface facing the substrate. Each of solar cells 40 includes a light receiving surface 43, a first conductive region 42 and second conductive region 41. The solar cell 40 may be a multi junction solar cell 40 containing semiconductor layers, and the first and the second conductive regions 41, 42 may be semiconductor regions of opposite conductivity types (e.g., N-type and P-type). In the embodiment, the light receiving surface 43 is arranged on the top surface; the first and the second conductive regions 41, 42 are formed on the top and the bottom surface of the solar cell 40 respectively.
The secondary optical element 50 includes a secondary optical body 51, which is made of polymer material and substantially cuboid. The secondary optical body 51 defines a light hole 511 for allowing light to pass through to the light receiving surface 43. The secondary optical body 51 has a sloped sidewall 513 forming the light hole 511. The sloped sidewall 513 is coated with a reflective layer 53, the reflective layer 53 reflects light received from the primary optical element 20. The reflective layer 53 reduces solar energy losses. A diameter of the light hole 511 gradually decreases from a top end of the light hole 511 adjacent to the primary optical element 20 towards a bottom end of the light hole 511 adjacent to the solar cells 40, and a central vertical line of the top opening 5111 aligns with a central vertical line of the bottom opening 5113. In other embodiments, the shape of the top end 5111 and the bottom end 5113 may be square, hexagonal or octagonal.
A plurality of support protrusions 57 are arranged on corners of bottom surface 515. The support protrusions 57 support the secondary optical element 50 on the substrate 30. Each of the support protrusions 57 protrudes downwardly from the bottom surface 515, a bottom surface of the support protrusion 57 is square, and the area of the bottom surface gradually decreases in a direction away from the bottom surface 515. In other embodiments, the bottom surface of the support protrusion 57 may be round or triangular. The structure of the support protrusion 57 described gives some strength to the support protrusion 57 preventing fractures due to mishandling during assembly.
A conductive film 59 is provided on the secondary optical element 50. The conductive film 59 is coated on the bottom surface 515 and outer surfaces of the support protrusions 57. In assembly, the solar cell 40 is mounted on the bottom surface 515 with the light receiving surface 43 aligned to light hole 511, the first conductive region 42 electrically connects to the conductive film 59. When the secondary optical element 50 is supported on the substrate 30, the conductive film 59 coated on the bottom surface of the support protrusion 57 electrically connects to the circuit 31, so the first conductive region 42 is electrically connected to the circuit 31. At the same time, the second conductive region 41 electrically connects to the circuit 31 directly. Because the solar cell 40 is directly bonded to the secondary optical body 51 with no gap, the structure reduces losses from light leakage, and improves light conversion performance.
A plurality of limiting protrusions 55 are arranged around the bottom end 5113. The limiting protrusions 55 cooperatively define an assembling space for limiting a location of the solar cell 40, which improves the precise alignment between the light hole 511 and the light receiving surface 43. A ring-shaped protrusion 52 protrudes outwardly from an outer periphery of the secondary optical body 51, and the ring-shaped protrusion 52 is adjacent to the bottom surface 515. With the ring-shaped protrusion 52 in place, the secondary optical body 51 can be easily mounted on the substrate 30.
The primary optical element 20 comprises a glass plate 21. A bottom surface 215 of the glass plate 21 opposite to the substrate 30 is arranged with an array of lenses 23. In the embodiment, the lenses 23 connect with each other. In other embodiments, the lenses 23 are spaced from each other. Each of the lenses 23 can concentrate the light received from the glass plate 21 and form the light beam L, and then the secondary optical element 50 focuses the light beam L onto the light receiving surfaces 43. The array of lenses 23 faces the array of solar cells 40, with each focus C of the lenses 23 aligned to each center of a solar cell 40.
In assembly, the array of solar cells 40 is connected to the bottom surface 515, with the second conductive region 41 electrically coupled with the conductive film 59, and the light receiving surface 43 aligned with the light hole 511. The secondary optical bodies 51 are electrically and mechanically coupled with the circuit 31 via the support protrusions 57 and the conductive film 59, with the first conductive region 42 electrically coupled with the circuit 31. The array of solar cells 40 is thus electrically interconnected in serial or parallel via the circuit 31 and the secondary optical element 50 has no wires of gold or other conductive metal thereby improving manufacturing and cost efficiency. The substrate 30 with the array of solar cells 40 and the secondary optical elements 50 is supported on the second opening 15, and the primary optical element 20 is supported on the first opening 13. With the focus C of each lens, the light hole 511 is aligned to the light receiving surface 43. In the embodiment, the focus C is located under a plane P defined by an end of the secondary optical body 51 adjacent to the primary optical element. In other embodiments, the focus C is located upon the plane P defined by an end of the secondary optical body 51 adjacent to the primary optical element.
In use, the light passes through the glass plate 21 and is concentrated by the lens 23 to form light beam L, the light beam L is concentrated and focused onto the light receiving surface 43 of the solar cell 40, aided by the reflection of the reflective layer 53.
Many details are often found in the art such as the other features of a shielding plate. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, especially in matters of shape, size and arrangement of the parts within the principles of the present disclosure up to, and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the embodiments described above may be modified within the scope of the claims.
Number | Date | Country | Kind |
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201410009913.X | Jan 2014 | CN | national |