The present application claims priority to Chinese Patent Application No. 202310458880.6, filed on Apr. 24, 2023, the content of which is incorporated herein by reference in its entirety.
The present disclosure relates to the technical field of photovoltaic manufacturing, and in particular, to a back-contact photovoltaic module and a manufacturing method thereof.
PN junctions and electrodes of a back-contact solar cell are located on a back surface of the cell. In other words, electrodes in emitter and base regions of the back-contact solar cell are all on the back surface, and a front surface is not shielded by gate lines, which can significantly improve photoelectric conversion performance of the solar cell and bring high cell efficiency and great development potential. Since the front surface of the back-contact solar cell is not shielded by the gate lines, a front film layer is directly in contact with a transfer table, which easily causes scratches during the transfer of the back-contact solar cell and affects an appearance of the solar cell.
The present disclosure provides a back-contact photovoltaic module and a manufacturing method thereof, so as to protect the front surface of the back-contact solar cell and reduce a risk of scratches to the back-contact photovoltaic module.
In a first aspect of the present disclosure, a back-contact photovoltaic module is provided, including a glass substrate, an upper adhesive film layer, a solar cell layer, a lower adhesive film layer, and a back sheet arranged in sequence from top to bottom; and
the solar cell layer includes back-contact solar cells, and a front surface of each of the back-contact solar cells is provided with a transparent support layer, the transparent support layer protruding from a surface of the back-contact solar cell, and the transparent support layer covering a partial region of the front surface.
In some embodiments, an area ratio of the transparent support layer to the front surface ranges from 1% to 80%.
In some embodiments, the transparent support layer includes transparent bumps.
In some embodiments, the transparent bumps are evenly distributed on the surface of the back-contact solar cell.
In some embodiments, a number of the transparent bumps is equal to or more than 9; or an interval between adjacent transparent bumps is equal to or less than 7 cm.
In some embodiments, a projected area of the transparent bumps on the surface of the back-contact solar cell is less than 10 mm2.
In some embodiments, a height of each of the transparent bumps is less than 0.5 mm.
In some embodiments, a gap is provided between each of the transparent bumps and an edge of each of the back-contact solar cells.
In some embodiments, the transparent support layer is made of any one of an insulating adhesive, a hot melt adhesive, polyethylene terephthalate (PET), ethyl vinyl acetate (EVA), and polyolefin elastomer (POE).
In some embodiments, a side of the upper adhesive film layer facing the back-contact solar cell is provided with a groove, the groove fitting the transparent support layer.
In a second aspect of the present disclosure, a method for manufacturing a back-contact photovoltaic module is provided, wherein the back-contact photovoltaic module includes a glass substrate, an upper adhesive film layer, a solar cell layer, a lower adhesive film layer, and a back sheet arranged in sequence from top to bottom; and
the solar cell layer includes back-contact solar cells, and a front surface of each of the back-contact solar cells is provided with a transparent support layer, the transparent support layer protruding from a surface of the back-contact solar cell, and the transparent support layer covering a partial region of the front surface; and the manufacturing method includes:
making the front surface of the back-contact solar cell face upwards, and manufacturing the transparent support layer on the front surface of the back-contact solar cell; curing the transparent support layer; turning the back-contact solar cell over for transfer; and packaging the back-contact solar cells to form the back-contact photovoltaic module.
It should be understood that the general description above and the detailed description in the following are merely exemplary, and cannot limit the present disclosure.
The accompanying drawings herein, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the specification, serve to explain principles of the present disclosure.
In order to make the objectives, technical solutions, and advantages of the present disclosure clearer, the present disclosure is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that specific embodiments described herein are intended only to interpret the present disclosure and not intended to limit the present disclosure.
In the description of the present disclosure, unless otherwise clearly stated and limited, the terms “first” and “second” are used for descriptive purposes only, which cannot be construed as indicating or implying a relative importance. Unless otherwise specified or stated, the term “a plurality of” means two or more. The terms “connection” and “fixing” should be understood in a broad sense. For example, “connection” may be a fixed connection, a detachable connection, or an integral connection; or an electrical connection; or a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the foregoing terms in the present disclosure can be understood on a case-by-case basis.
In the description of the present disclosure, it is to be understood that orientation terms such as “up” and “down” described in the embodiments of the present disclosure are described from the perspective shown in the accompanying drawings, and should not be construed as limiting the embodiments of the present disclosure. Besides, in this context, it is to be further understood that one element described as being connected “on” or “under” another element not only means that the element may be directly connected “on” or “under” another element, but also means that the element may be indirectly connected “on” or “under” the another element through an intermediate element.
As shown in
In an embodiment, the solar cell layer 3 includes back-contact solar cells 31. Each back-contact solar cell 31 includes a front surface and a back surface arranged oppositely. The back surface refers to a side of the back-contact solar cell 31 provided with a gate line, and the front surface refers to a side of the back-contact solar cell 31 provided with no gate line.
For example, referring to
Referring to
In an embodiment, the transparent support layer 7 is made of a transparent material, so that the incident light can pass therethrough smoothly. The transparent support layer 7 protrudes from the surface of the front surface of the back-contact solar cell 31. When the front surface of the back-contact solar cell 31 is transferred downwards, the transparent support layer 7 separates the back-contact solar cell 31 from a transfer table, the transparent support layer 7 is in contact with the transfer table, and a gap is formed between the front surface of the back-contact solar cell 31 and the transfer table, so that the transparent support layer 7 protects the front surface of the back-contact solar cell 31, which prevents direct contact of the surface of the back-contact solar cell 31 with the transfer table, thereby reducing a risk of scratches to the back-contact photovoltaic module.
In an embodiment, the transparent support layer 7 covers a partial region of the front surface. That is, the transparent support layer 7 does not completely cover the front surface of the back-contact solar cell 31. For example, the transparent support layer 7 accounts for no more than 95% of an area of the front surface, which further reduces absorption of the incident light by the transparent support layer 7, thereby improving conversion efficiency of solar energy.
Preferably, the transparent support layer 7 accounts for 1% to 80% of the area of the front surface. For example, the transparent support layer accounts for 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80% of the area of the front surface, which can effectively protect the front surface of the back-contact solar cell 31 and can also ensure that the front surface of the back-contact solar cell 31 has sufficiently high transmittance, thereby improving the conversion efficiency of the solar energy. When the transparent support layer 7 accounts for less than 1% of the area of the front surface, the area of the transparent support layer 7 is excessively small. Due to influences of factors such as unevenness of the transfer table, possible bending of the back-contact solar cell 31, and vibration or shaking generated during the transfer, the transparent support layer 7 cannot effectively protect the front surface of the back-contact solar cell 31, and the partial region of the front surface of the back-contact solar cell 31 may still be in contact with the transfer table. When the transparent support layer 7 accounts for more than 80% of the area of the front surface, the area of the transparent support layer 7 is excessively large, so that great losses are generated when light passes through the transparent support layer 7, resulting in low transmittance.
More preferably, the transparent support layer 7 accounts for 2% to 30% of the area of the front surface. For example, the transparent support layer 7 accounts for 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 15%, 18%, 20%, 23%, 25%, 28%, or 30% of the area of the front surface. Within the range, the front surface of the back-contact solar cell 31 can be reliably protected, and the front surface of the back-contact solar cell 31 can be guaranteed to have higher transmittance as much as possible, thereby improving the conversion efficiency of the solar energy.
The transparent support layer 7 may be arranged as a continuous structure or a discrete structure.
When the transparent support layer 7 is arranged as the continuous structure, the transparent support layer 7 may be arranged in any suitable shape such as a rectangle, a circle, a ring, a zigzag, a curve or an irregular shape. Preferably, the transparent support layer 7 is arranged as a rectangular structure (refer to
When the transparent support layer 7 is arranged as the discrete structure, the transparent support layer 7 may include support portions spaced apart from each other. Each support portion protrudes from the surface of the back-contact solar cell 31, and the plurality of support portions jointly form the transparent support layer 7. The plurality of support portions may be evenly distributed on the surface of the back-contact solar cell 31 in a rectangular array or an annular array, and the plurality of support portions may alternatively be unevenly distributed on the surface of the back-contact solar cell 31 in a random manner. It may be understood that each support portion may be arranged in any suitable shape such as a rectangle, a circle, a ring, a zigzag, a curve or an irregular shape.
Referring to
In an embodiment, the transparent bumps 71 are evenly distributed on the surface of the back-contact solar cell 31. On the one hand, the evenly distributed transparent bumps 71 can form uniform shields on the front surface of the back-contact solar cell 31, so that the incident light is uniformly distributed on the front surface of the back-contact solar cell 31. On the other hand, the evenly distributed transparent bumps 71 can form uniform support points on the front surface of the back-contact solar cell 31, so that each transparent bump 71 can bear a load evenly, which prevents local damages caused by an uneven force on the back-contact solar cell 31. It may be understood that the transparent bumps 71 may alternatively be unevenly distributed on the surface of the back-contact solar cell 31. For example, the plurality of transparent bumps 71 may be unevenly distributed on the surface of the back-contact solar cell 31 in a random manner.
In some embodiments, referring to
When the plurality of transparent bumps 71 are unevenly distributed according to the rectangular array, a number of the transparent bumps 71 is no less than 9. Taking 9 transparent bumps 71 as an example for detailed illustration, the 9 transparent bumps 71 are distributed in a 3×3 rectangular array. That is, three transparent bumps 71 are arranged on each side of the back-contact solar cell 31, and one transparent bump 71 is arranged in the center, so as to form support for edge and central parts of the back-contact solar cell 31, which effectively prevent possible contact of the partial region of the back-contact solar cell 31 with the transfer table.
In some other embodiments, referring to
In an embodiment, a projected area of the transparent bumps 71 on the surface of the back-contact solar cell 31 is less than 10 mm2. For example, the projected area of the transparent bumps 71 on the surface of the back-contact solar cell 31 may be 10 mm2, 9.5 mm2, 9 mm2, 8.5 mm2, 8 mm2, 7.5 mm2, 7 mm2, 6.5 mm2, 6 mm2, 5.5 mm2, 5 mm2, 4.5 mm2, 4 mm2, 3.5 mm2, 3 mm2, 2.5 mm2, 2 mm2, 1.5 mm2, 1 mm2, 0.5 mm2, or the like, which reduces absorption of the incident light by the transparent bumps 71 as much as possible and improves the conversion efficiency of the solar energy.
In an embodiment, a height of each of the transparent bumps 71 is less than 0.5 mm. For example, the height of the transparent bump 71 may be 0.5 mm, 0.45 mm, 0.4 mm, 0.35 mm, mm, 0.25 mm, 0.2 mm, 0.15 mm, 0.1 mm, 0.05 mm, or the like. On the one hand, the transparent bump 71 maintains high structural strength, thereby providing stable support for the back-contact solar cell 31. On the other hand, an influence of formation of pressure points inside the photovoltaic module by the transparent bumps 71 on an overall load capacity of the photovoltaic module is prevented.
In an embodiment, referring to
In an embodiment, the transparent support layer is made of any one of an insulating adhesive (any one of silicone, epoxy, and acrylic systems), a hot melt adhesive, polyethylene terephthalate (PET), ethyl vinyl acetate (EVA), and/or polyolefin elastomer (POE), which can form better adhesion on the surface of the back-contact solar cell 31 and prevent damages such as delamination during lamination of the back-contact photovoltaic module, can have good light transmission, and produce no optical gain effect. That is, the transparent support layer is only light-transmitting and does not produce any optical gain effect, and the light passes through the transparent support layer and irradiates the surface of the back-contact solar cell 31, which is not significantly different from direct irradiation on the surface of the back-contact solar cell 31. Therefore, an influence of the transparent support layer on the incident light can be reduced as much as possible, and uniformity of distribution of the incident light on the surface of the back-contact solar cell 31 can be maintained. It may be understood that the transparent support layer may alternatively be made of a material with an optical gain effect such as PVB, EPE, or EP, as long as the selected material has high adhesion and high transparency.
In an embodiment, referring to
As shown in
The front surface of the back-contact solar cell 31 is provided with the transparent support layer, and the transparent support layer is made of a transparent material, so that incident light can pass therethrough smoothly. The transparent support layer protrudes from the surface of the back-contact solar cell 31, so that the transparent support layer can protect the front surface of the back-contact solar cell 31 and prevent direct contact of the surface of the back-contact solar cell 31 with the transfer table, thereby reducing a risk of scratches to the back-contact photovoltaic module. The transparent support layer covers the partial region of the front surface. That is, the transparent support layer does not completely cover the front surface of the back-contact solar cell 31, which further reduces absorption of the incident light by the transparent support layer, thereby improving the conversion efficiency of the solar energy.
In an embodiment, the transparent support layer may be manufactured on the front surface of the back-contact solar cell 31 by glue printing. The transparent support layer may be cured by thermosetting or photo-curing, or both.
In an embodiment, the packaging the back-contact solar cells 31 to form the back-contact photovoltaic module may include: printing and curing an insulating material on a back surface of the back-contact solar cell 31; printing and curing a conductive layer on the back surface of the back-contact solar cell 31; scribing; series welding; layout; and lamination. The frame 6 and the junction box may be further mounted after the lamination.
The printing and curing of the insulating material on the back surface of the back-contact solar cell 31 realizes insulation between positive and negative electrodes and prevents a short circuit caused by contact of solder strips during soldering. The printing and curing of the conductive layer on the back surface of the back-contact solar cell 31 realizes interconnection of the back-contact solar cells 31. Scribing means reducing on-chip current transfer losses in the module by cutting the whole cell into small pieces.
The above descriptions are only preferred embodiments of the present disclosure, and are not intended to limit the present disclosure. For those skilled in the art, various modifications and changes may be made to the present disclosure. Any modifications, equivalent replacements, improvements, and the like made within the spirit and the principle of the present disclosure shall fall within the protection scope of the present disclosure.
Number | Date | Country | Kind |
---|---|---|---|
202310458880.6 | Apr 2023 | CN | national |