SOLAR CELL ARRAY, SOLAR CELL MODULE AND MANUFACTURING METHOD THEREOF
A solar cell array comprises a plurality of cells. Each cell has a front surface on which light is incident when the cell is in operation and a back surface opposite to the front surface. The solar cell array also comprises a plurality of conductive wires. Adjacent cells are connected by the plurality of conductive wires. The solar cell array further comprises secondary grid lines disposed on the front surface of the respective cell. The secondary grid lines comprise middle secondary grid lines disposed in the middle of the respective cell and intersecting with the conductive wires, and edge secondary grid lines disposed on the edges of the respective cell and non-intersecting with the conductive wires. The solar cell array also comprises short grid lines disposed on the front surface of the cell. The short grid lines connect the edge secondary grid lines with the conductive wires or with at least one middle secondary grid line.
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The present application claims priority to the following 41 Chinese applications, the entireties of all of which are hereby incorporated by reference.
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The present application is relevant to the following 10 U.S. applications, filed concurrently with the present application, the entireties of which are hereby incorporated by reference.
U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-23), entitled “Solar Cell Module And Manufacturing Method Thereof,” filed ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-26), entitled “Solar Cell Array, Solar Cell Module And Manufacturing Method Thereof,” filed ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-28), entitled “Solar Cell Module And Manufacturing Method Thereof,” filed ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-29), entitled “Solar Cell Array, Solar Cell Module And Manufacturing Method Thereof,” filed ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-32), entitled “Solar Cell Unit, Solar Cell Array, Solar Cell Module And Manufacturing Method Thereof,” filed ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-33), entitled “Solar Cell Unit, Solar Cell Array, Solar Cell Module And Manufacturing Method Thereof,” filed ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-34), entitled “Solar Cell Unit, Solar Cell Array, Solar Cell Module And Manufacturing Method Thereof,” filed ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-35), entitled “Solar Cell Unit, Solar Cell Array, Solar Cell Module And Manufacturing Method Thereof,” filed ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-36), entitled “Solar Cell Unit, Solar Cell Array, Solar Cell Module And Manufacturing Method Thereof,” filed ______; and
U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-44), entitled “Method For Manufacturing Solar Cell Module,” filed ______.
FIELDThe present disclosure relates to the field of solar cells, and more particularly, to solar cell arrays, solar cell modules and manufacturing methods thereof.
BACKGROUNDA solar cell module is one of the most important components of a solar power generation device. Sunlight irradiates to a cell from its front surface and is converted to electricity within the cell. Primary grid lines and secondary grid lines are disposed on the front surface and cover part of the front surface of the cell. As such, the part of sunlight irradiating to the primary grid lines and the secondary grid lines are blocked by the grid lines and cannot be converted into electric energy within the cell. Thus, the primary grid lines and the secondary grid lines need to be as fine as possible in order for the solar cell module to receive more sunlight. However, the primary grid lines and the secondary grid lines serve to conduct current, and in terms of resistivity, the finer the primary grid lines and the secondary grid lines are, the smaller the cross section areas thereof are, which causes greater loss of electricity due to increased resistivity. Therefore, the primary grid lines and the secondary grid lines must be designed to achieve a balance between light blocking and electrical conduction, and to take the cost into consideration.
SUMMARYIn one aspect, a solar cell array comprises a plurality of cells. Each cell has a front surface on which light is incident when the cell is in operation and a back surface opposite to the front surface. The solar cell array also comprises a plurality of conductive wires. Adjacent cells are connected by the plurality of conductive wires. The solar cell array further comprises secondary grid lines disposed on the front surface of the respective cell. The secondary grid lines comprise middle secondary grid lines disposed in the middle of the respective cell and intersecting with the conductive wires, and edge secondary grid lines disposed on the edges of the respective cell and non-intersecting with the conductive wires. The solar cell array also comprises short grid lines disposed on the front surface of the cell. The short grid lines connect the edge secondary grid lines with the conductive wires or with at least one middle secondary grid line.
In another aspect, a method for manufacturing a solar cell module comprises forming a cell array with a plurality of cells. The call array comprises a secondary grid line and a short grid line disposed on a front surface of the cell on which light is incident when the cell is in operation. The secondary grid line includes a middle secondary grid line disposed in the middle of the respective cell and intersected with a conductive wire. The secondary grid line also includes an edge secondary grid line disposed on the edge of the respective cell and non-intersected with the conductive wire. The short grid line connects the edge secondary grid line with the conductive wire or with at least one middle secondary grid line. The method further comprises superposing an upper cover plate, a front adhesive layer, the cell array, a back adhesive layer and a back plate in sequence. The front surface of the cell faces the front adhesive layer, and a back surface thereof facing the back adhesive layer. The method also comprises laminating the superposed layers to obtain the solar cell module.
- 100 cell module
- 10 upper cover plate
- 20 front adhesive layer
- 30 cell array
- 31 cell
- 31A first cell
- 31B second cell
- 311 cell substrate
- 312 secondary grid line
- 312A front secondary grid line
- 312B back secondary grid line
- 3121 edge secondary grid line
- 3122 middle secondary grid line
- 313 back electric field
- 314 back electrode
- 32 conductive wire
- 32A front conductive wire
- 32B back conductive wire
- 321 metal wire body
- 322 connection material layer
- 33 short grid line
- 40 back adhesive layer
- 50 lower cover plate
Embodiments of the present disclosure will be described in detail and examples of the embodiments will be illustrated in the drawings, where same or similar reference numerals are used to indicate same or similar members or members with same or similar functions. The embodiments described herein with reference to the drawings are explanatory, which are used to illustrate the present disclosure, but shall not be construed to limit the present disclosure.
In prior art, primary grid lines and secondary grid lines of solar cells are made of expensive silver paste, which requires a complicated and costly manufacturing process of the primary grid lines and the secondary grid lines. When the cells are connected into a module, the primary grid lines on the front surface of a cell are welded to the back electrodes of an adjacent cell by a solder strip. Consequently, the welding of the primary grid lines is complicated, and the manufacturing cost of the cells is high.
In prior art, two primary grid lines are usually disposed on the front surface of a cell, and formed by applying silver paste to the front surface of the cell. The primary grid lines have a great width (for example, up to over 2 mm), which consumes a large amount of silver, and makes the cost high.
In prior art, a solar cell with three primary grid lines is provided, which still consumes a large amount of silver, and has a high cost. Moreover, three primary grid lines increase the shaded area, which lowers the photoelectric conversion efficiency.
In addition, the number of the primary grid lines is limited by the solder strip. The larger the number of the primary grid lines is, the finer a single primary grid line is, and hence the solder strip needs to be narrower. Therefore, it is more difficult to weld the primary grid lines with the narrower solder strip and to produce the narrower solder strip, and thus the cost of the welding rises.
Consequently, from the perspective of lowering the cost and reducing the shaded area, the silver primary grid lines printed on the cell are replaced with metal wires, for example, copper wires. The copper wires are welded with the secondary grid lines to output the current. Since the silver primary grid lines are no longer used, the cost can be reduced considerably. The copper wire has a smaller diameter to reduce the shaded area, so the number of the copper wires can be raised up to 10. This kind of cell may be called a cell without primary grid lines, in which the metal wire replaces the silver primary grid lines and solder strips in the traditional solar cells.
The present disclosure provides a solar cell without primary grid lines, which needs neither primary grid line nor sold strip disposed on the cells, and thus lowers the cost. The solar cell without primary grid lines can be commercialized for mass production, is easy to manufacture with simple equipment, especially at low cost, and moreover has high photoelectric conversion efficiency.
However, in the field of solar cells, although the structure of the solar cell is relatively uncomplicated, each component is relatively crucial. The production of the primary grid lines takes various aspects into consideration, such as shaded area, electric conductivity, equipment, process, cost, etc., and hence becomes a difficult and crucial issue in the solar cell technology. In the market, solar cells with two primary grid lines were replaced with solar cells with three primary grid lines in 2007 through huge efforts of those skilled in the art. A few manufacturers launched solar cells with four primary grid lines around 2014. The concept of multiple primary grid lines is put forward in the recent years, but there is no relatively mature product.
Particularly, the metal wires are relatively fine and in a large number. Moreover, the metal wires are connected afterwards and have free ends. Due to the problem concerning the sophistication of the manufacturing equipment, it cannot be guaranteed that the fine and many metal wires are connected with the cells in accurate positions, especially the accuracy of the positions of the ends. In order to avoid short circuits caused by the metal wire extending beyond the cells, the conductive wires are generally formed in the cells, in which case part of the secondary grid lines at the edges of the cells cannot be connected with the conductive wires well, thereby resulting in current loss.
The present disclosure seeks to solve at least one of the problems existing in the related art to at least some extent.
Thus, the present disclosure provides a solar cell array that is easy to manufacture at low cost, and improves the photoelectric conversion efficiency.
The present disclosure further provides a solar cell module having the above solar cell array. The solar cell module is easy to manufacture in low cost, and improves the photoelectric conversion efficiency.
The present disclosure further provides a method for manufacturing the solar cell module.
According to a first aspect of embodiments of the present disclosure, a solar cell array includes a plurality of cells and conductive wires, adjacent cells being connected by the conductive wires, secondary grid lines and short grid lines being disposed on a front surface of the cell. The secondary grid lines comprise middle secondary grid lines intersected with the conductive wires and edge secondary grid lines non-intersected with the conductive wires, the short grid lines being connected with the edge secondary grid lines, and being connected with the conductive wires or at least one middle secondary grid line.
In the solar cell array according to embodiments of the present disclosure, particularly regarding the solar cell without primary grid lines, the short grid lines are disposed on the front surface of the cell, so as to electrically connect the edge secondary grid lines non-intersected with the conductive wires at the edge of the cell with the conductive wires, thereby reducing current loss. The short grid lines can be formed by screen printing silver, which is easy to realize and to control with high accuracy. The electric connection of all the fine grid lines and the conductive wires can be guaranteed, which lowers the sophistication and difficulty of the process, and improves the photoelectric conversion efficiency of the cell considerably.
The present disclosure further gives preference to connection of adjacent cells by the plurality of conductive wires. The conductive wires are constituted by the metal wire. At least one metal wire extends reciprocally between a surface of a first cell and a surface of a second cell adjacent to the first cell, so as to form at least two conductive wires.
It is particularly concerned with the solar cell without primary grid lines, in which the conductive wires are formed by extending reciprocally.
The conductive wires are constituted by the metal wire which extends reciprocally. The metal wire extends reciprocally between the two adjacent cells in a winding way to form a folded shape. The conductive wires of this structure are easy to manufacture in low cost, and can improve the photoelectric conversion efficiency of the solar cell array. Moreover, the conductive wires are arranged in a winding way to avoid problems due to cutting of the conductive wires. However, as for this kind of cells, the edges of the cells cannot be reached in the manner of wire winding. In view of the problem concerning the sophistication of the manufacturing process of the cell, the inventors of the present disclosure finds preferable embodiments after a long-term research, i.e. regarding the solar cell whose conductive wires are formed by wire winding. The short grid lines are disposed on part of the secondary grid lines at the edges of the front surface of the cell, so as to avoid partial current loss because the conductive wires arranged in the winding way cannot reach the secondary grid lines at the edges of the cell, to further improve the photoelectric conversion efficiency of the solar cell module.
According to a second aspect of embodiments of the present disclosure, the solar cell module includes an upper cover plate, a front adhesive layer, a cell array, a back adhesive layer and a back plate superposed in sequence, the cell array being a solar cell array according to the above embodiments.
According to a third aspect of embodiments of the present disclosure, a method for manufacturing a solar cell module includes: forming a cell array with a plurality of cells, in which secondary grid lines and short grid lines are disposed on a front surface of the cell; the secondary grid lines include middle secondary grid lines intersected with the conductive wires and edge secondary grid lines non-intersected with the conductive wires, the short grid lines being connected with the edge secondary grid lines, and being connected with the conductive wires or at least one middle secondary grid line; superposing an upper cover plate, a front adhesive layer, the cell array, a back adhesive layer and a back plate in sequence, in which a front surface of the cell faces the front adhesive layer, a back surface thereof facing the back adhesive layer, and laminating them to obtain the solar cell module.
The present disclosure relates to the solar cells connected by the metal wires. The short grid lines are disposed on the front surface of the cells to solve the accuracy problem of connection between the metal wire and the cell, to avoid current loss. The process is simple and easy to realize, and can lower the cost considerably.
Part of technical terms in the present disclosure will be elaborated herein for clarity and convenience of description.
According to one embodiment of the present disclosure, referring to
The cell substrate 311 can be an intermediate product obtained by subjecting, for example, a silicon chip to processes of felting, diffusing, edge etching and silicon nitride layer depositing. However, it shall be understood that the cell substrate 311 in the present disclosure is not limited to be formed by the silicon chip.
In other words, the cell 31 comprises a silicon chip, some processing layers on a surface of the silicon chip, secondary grid lines on a front surface, and a back electric field 313 and back electrodes 314 on a back surface, or includes other equivalent solar cells of other types without any front electrode.
A cell unit includes a cell 31 and conductive wires 32 constituted by a metal wire S.
A solar cell array 30 includes a plurality of cells 31 and conductive wires 32 which connect adjacent cells 31 and are constituted by the metal wire S. In other words, the solar cell array 30 is formed of a plurality of cells 31 connected by the conductive wires 32.
In the solar cell array 30, the metal wire S constitutes the conductive wires 32 of the cell unit, and extends between surfaces of the adjacent cells 31, which shall be understood in a broad sense that the metal wire S may extend between front surfaces of the adjacent cells 31, or may extend between a front surface of a first cell 31 and a back surface of a second cell 31 adjacent to the first cell 31. When the metal wire S extends between the front surface of the first cell 31 and the back surface of the second cell 31 adjacent to the first cell 31, the conductive wires 32 may include front conductive wires 32A extending on the front surface of the cell 31 and electrically connected with the secondary grid lines 312 of the cell 31, and back conductive wires 32B extending on the back surface of the cell 31 and electrically connected with the back electrodes 314 of the cell 31. Part of the metal wire S between the adjacent cells 31 can be called connection conductive wires.
In the present disclosure, descriptive terms, such as the cell substrate 311, the cell 31, the cell unit, the cell array 30 and the solar cell module, are used only for the convenience of description, and shall not be construed to limit the scope of the present disclosure.
All the ranges disclosed in the present disclosure include endpoints, and can be individual or combined. It shall be understood that the endpoints and any value of the ranges are not limited to an accurate range or value, but also include values proximate the ranges or values.
In the present disclosure, orientation terms such as “upper” and “lower” usually refer to the orientation “upper” or “lower” as shown in the drawings under discussion, unless specified otherwise; “front surface” refers to a surface of the solar cell module facing the light when the module is in operation, i.e. a surface on which light is incident, while “back surface” refers to a surface of the solar cell module back to the light when the module is in operation.
In the following, the solar cell array 30 will be described according to the embodiments of the present disclosure with respect to the drawings.
As shown in
The present disclosure relates to the solar cells connected by the conductive wires 32. The short grid lines 33 are disposed on the front surface of the cell 31 to solve the accuracy problem of connection between the conductive wires 32 and the cell 31, to avoid current loss. The process is simple and easy to realize, and can lower the cost considerably.
In the solar cell array 30 according to the embodiments of the present disclosure, adjacent cells 31 are connected by the plurality of conductive wires 32. The conductive wires 32 are constituted by the metal wire S. At least one metal wire S extends reciprocally between a surface of a first cell 31 and a surface of a second cell 31 adjacent to the first cell 31, so as to form at least two conductive wires 32.
The present disclosure is not limited to that all the conductive wires are formed by winding the metal wire—the conductive wires can be partially or completely formed by winding the metal wire. The reciprocal extension can be back and forth once. There is no limit to the termination point of the reciprocal extension—the starting point and the termination point can be at the same cell or at different cells, as long as the metal wire is winded.
In other words, the solar cell array 30 in the present disclosure comprises at least two cells 31, each of which comprises a cell substrate 311, secondary grid lines 312 and short lines 33 disposed on a front surface of the cell substrate 311, and back electrodes 314 disposed on a back surface of the cell substrate 311. Adjacent cells 31 are connected by a plurality of conductive wires 32 constituted by a metal wire S which extends reciprocally between the adjacent cells 31.
The secondary grid lines 312 located at a side surface of the cell substrate 311 comprises two parts—one part of the secondary grid lines 312 intersected with the conductive wires 32 and located in a middle position of the cell substrate 311 to form middle secondary grid lines 3122; the other part of the secondary grid lines 312 non-intersected with the conductive wires 32 and located at an edge of one side away from the conductive wires 32 to form edge secondary grid lines 3121.
The edge secondary grid lines 3121 are provided with short grid lines 33 connected with the conductive wires 32 or at least one middle secondary grid line 3122. In specific embodiments, the short grid lines 33 are located at the edges of the cell 31 where the conductive wires 32 cannot reach when being winded, so as to avoid current loss.
Thus, in the solar cell array 30 according to the embodiments of the present disclosure, the conductive wires 32 are constituted by the metal wire which extends reciprocally. The conductive wires 32 of this structure extend reciprocally between two adjacent cells in a winding way to form a folded shape, which is easy to manufacture in low cost, and can improve the photoelectric conversion efficiency of the solar cell array 30. The conductive wires 32 are arranged in a winding way, such that problems caused by cutting of the conductive wires 32 can be avoided. Moreover, the short grid lines 33 are disposed on the secondary grid lines 312 at the edge of the front surface of the cell 31, such that the current will not be wasted because the conductive wires 32 cannot reach the secondary grid lines 312 at the edge of the cell 31, so as to further improve the photoelectric conversion efficiency of the solar cell module.
The cell unit is formed by the cell 31 and the conductive wires 32 constituted by the metal wire S which extends on the surface of the cell 31. In other words, the solar cell array 30 according to the embodiments of the present disclosure are formed with a plurality of cell units; the conductive wires 32 of the plurality of cells are formed by the metal wire S which extends reciprocally between the surfaces of the cells 31.
It shall be understood that the term “extending reciprocally” in this disclosure can be called “winding” which means that the metal wire S extends between the surfaces of the cells 31. For example, referring to
In addition, when the cells 31 are connected in parallel by the metal wire S, the metal wire S can extend on front surfaces of the cells, such that the metal wire S constitutes a front conductive wire 32A. Alternatively, a first metal wire S extends reciprocally between the front surfaces of the cells, and a second metal wire S extends reciprocally between the back surfaces of the cells, such that the first metal wire S constitutes a front conductive wire 32A, and the second metal wire S constitutes a back conductive wire 32B.
When the cells 31 are connected in series by the metal wire S, the metal wire S can extend reciprocally between a front surface of a first cell 31 and a back surface of a second cell 31 adjacent to the first cell 31, such that part of the metal wire S which extends on the front surface of the first cell 31 constitutes a front conductive wire 32A, and part thereof which extends on the back surface of the second cell 31 constitutes a back conductive wire 32B. In the present disclosure, unless specified otherwise, the conductive wire 32 can be understood as the front conductive wire 32A, the back conductive wire 32B, or the combination thereof.
The term “extending reciprocally” can be understood as that the metal wire S extends reciprocally once to form two conductive wires 32 which are formed by winding a metal wire S. For example, two adjacent conductive wires form a U-shape structure or a V-shape structure, yet the present disclosure is not limited to the above.
In the solar cell array 30 according to the embodiments of the present disclosure, a plurality of conductive wires 32 of the cells are constituted by the metal wire S which extends reciprocally; and the adjacent cells 31 are connected by the conductive wires 32. Hence, the conductive wires 32 of the cells are not necessarily made of expensive silver paste, and can be manufactured in a simple manner without using a solder strip to connect the cells. It is easy and convenient to connect the metal wire S with the secondary grid line and the back electrode, so that the cost of the cells is reduced considerably.
Moreover, since the conductive wires 32 are constituted by the metal wire S which extends reciprocally, the width of the conductive wires 32 (i.e. the width of projection of the metal wire on the cell) may be decreased, thereby decreasing the shaded area of the conductive wires 32. Further, the number of the conductive wires 32 can be adjusted easily, and thus the resistance of the conductive wires 32 is reduced, compared with the conductive wires made of the silver paste, and the efficiency of photoelectric conversion is improved. Since the metal wire S extends reciprocally to form the conductive wires, when the cell array 30 is used to manufacture the solar cell module 100, the metal wire S will not tend to shift, i.e. the metal wire is not easy to “drift”, which will not affect but further improve the photoelectric conversion efficiency.
In the following, the solar cell array 30 according to specific embodiments of the present disclosure will be described with reference to the drawings.
The solar cell array 30 according to a specific embodiment of the present disclosure is illustrated with reference to
In the embodiment shown in
It can be understood that the cell 31 comprises a cell substrate 311, a secondary grid line 312 (a front secondary grid line 312A) disposed on a front surface of the cell substrate 311, a back electric field 313 disposed on a back surface of the cell substrate 311, and a back electrode 314 disposed on the back electric field 313. In the present disclosure, it can be understood that the back electrode 314 may be a back electrode of a traditional cell, for example, printed by the silver paste, or may be a back secondary grid line 312B similar to the secondary grid line on the front surface of the cell substrate, or may be multiple discrete welding portions, unless specified otherwise. The secondary grid line refers to the secondary grid line 312 on the front surface of the cell substrate 311, unless specified otherwise.
As shown in
In some embodiments, the metal wire extends reciprocally between the first cell 31A and the second cell 31B for 10 to 60 times. Preferably, as shown in
More preferably, as shown in
It shall be noted that in the present disclosure, the metal wire S refers to a metal wire for extending reciprocally on the cells 31 to form the conductive wires 32; and the conductive wires 32 include a metal wire body 321 and a welding layer 322 coating the metal wire body 321, i.e. the metal wire S comprises the metal wire body 321 and the welding layer 322 coating the metal wire body 321. In the embodiments of the present disclosure, unless specified otherwise, the metal wire represents the metal wire S which extends reciprocally on the cells to form the conductive wires 32.
In some embodiments, preferably, the metal wire body 321 is a copper wire. Of course, the metal wire S can be a copper wire, too. In other words, the metal wire does not include the welding layer 322, but the present disclosure does not limited thereto. For example, the metal wire body 321 can be an aluminum wire. Preferably, the metal wire S has a circular cross section, such that more sunlight can reach the cell substrate to further improve the photoelectric conversion efficiency.
In some embodiments, preferably, before the metal wire contact the cells, the metal wire extends under a strain, i.e. straightening the metal wire. After the metal wire is connected with the secondary grid lines and the back electrodes of the cell, the strain of the metal wire can be released, so as to further avoid the drifting of the conductive wires when the solar cell module is manufactured, and to guarantee the photoelectric conversion efficiency.
According to an embodiment of the present disclosure, the adjacent cells 31 are connected by a plurality of conductive wires 32 constituted by the metal wire which extends between a surface of a first cell 31 and a surface of a second cell 31 adjacent to the first cell 31.
Alternatively, the metal wire breaks off at a turn after being connected with the cells 31.
Preferably, the short grid lines 33 are connected with the edge secondary grid line 3121 closest to the middle secondary grid lines 3122 as shown in
In some other specific embodiments of the present disclosure, the short grid lines 33 are connected with the conductive wires 32. Preferably, the short grid lines 33 and the metal wire at the front surface of the cell 31 are connected at a turn formed by reciprocal extension. An extra welding point can be added to decrease the probability of breaking the welding portion at the edges, and to further enhance the binding force of the metal wire and the cell. The connection at the turn herein can be understood that the short grid lines 33 have intersection points with the turns, i.e. the short grid lines 33 do not terminate at the turns.
According to an embodiment of the present disclosure, the short grid lines 33 are perpendicular to the secondary grid lines 312. The short grid lines 33 are, preferably, electrically connected with bended parts (ends proximate to the edges) of the conductive wires 32 on the front surface of the cell 31. More preferably, at least one short grid line 33 is disposed corresponding with each bended part.
Since the distance between the bended parts of the conductive wires 32 and the edges of the cell 31 is usually short, the short grid lines 33 have a length of 1 to 10 mm, preferably 2.4 to 7 mm, a width of 0.05 to 0.5 mm, and a thickness of 0.01 to 0.02 mm. There are 3 to 40, preferably 6 to 20 short grid lines.
The short grid lines 33 can be disposed in the same manner as the secondary grid lines 312 on the front surface of the cell 31. For example, the short grid lines 33 can be printed along with the secondary grid lines 312 by silk-screen printing at the same screen plate (which can be made of silver paste) as the front secondary grid lines 3121.
In some preferable embodiments of the present disclosure, the secondary grid lines 312 have a width of 40 to 80 μm and a thickness of 5 to 20 μm; there are 50 to 120 secondary grid lines, a distance between adjacent secondary grid lines ranging from 0.5 to 3 mm.
Alternatively, the metal wire breaks off at a turn after being connected with the cell 31. The metal wire breaks off at the turn after being welded with the cell 31 to form multiple independent conductive wires 32.
The metal wire breaks off at the turn after being welded with the cell 31 to separate the multiple conductive wires 32, which can decrease the stress between the cells and peeling strength at the joints of the metal wire and the cell, and further improve the photoelectric conversion efficiency of the solar cell array 30.
In some specific embodiments of the present disclosure, referring to
Alternatively, in two adjacent rows of cells 31, the metal wire extends reciprocally between a surface of a cell 31 at an end of the ath row and a surface of a cell 31 at an end of the (a+1)th row, the end of the ath row and the end of the (a+1)th row located at the same side of the matrix form.
Preferably, in the same row of cells 31, the metal wire extends reciprocally between a front surface of a first cell 31 and a back surface of a second cell 31 adjacent to the first cell 31. In two adjacent rows of cells 31, the metal wire extends reciprocally between a front surface of a cell 31 at an end of the ath row and a back surface of a cell 31 at an end of the (a+1)th row, to connect the two adjacent rows of cells 31 in series.
In other words, the solar cell array 30 according to the embodiment of the present disclosure is arranged in an n×m matrix form by a plurality of cells 31. Specifically, in the solar cell array 30, there are multiple cells 31, and the cells are arranged in the n×m matrix form. In a row of cells, the conductive wire 32 extends from a surface of a first cell 31, and is electrically connected with a surface of a second cell 31 adjacent to the first cell 31, to connect the cells 31 in the same row; in two adjacent rows of cells, the conductive wire 32 extends from a surface of a cell 31 in a ath row and is electrically connected with a surface of a cell in a (a+1)th row, to connect the two adjacent rows of cells 31, in which n represents a column, m represents a row, and m−1≧a≧1.
N can range from 2 to 30, m ranging from 2 to 18. Preferably, multiple cells 31 are arranged in a 12×6 or 10×6 matrix form, i.e. 10 or 12 cells in a row, six rows in total. According to the preferable embodiment, the cells 31 in two adjacent rows are directly connected by the conductive wires without using the bus bars, which decreases the number of the bus bars, shortens the connection distance, and reduces the resistance, so as to obtain higher electricity generation performance of the solar cell module.
Preferably, in the two adjacent rows of cells 31, the conductive wire extends from a surface of a cell 31 at an end of a ath row and is electrically connected with a surface of a cell at an end of a (a+1)th row.
The solar cell array 30 according to another embodiment of the present disclosure is illustrated with reference to
The solar cell array 30 according to the embodiment of the present disclosure comprises n×m cells 31. In other words, a plurality of cells 31 are arranged in an n×m matrix form, n representing a column, and m representing a row. More specifically, in the embodiment, 36 cells 31 are arranges into six columns and six rows, i.e. n=m=6. It can be understood that the present disclosure is not limited thereto. For example, the column number and the row number can be different. For convenience of description, in
In a row of the cells 31, the metal wire extends reciprocally between a surface of a first cell 31 and a surface of a second cell 31 adjacent to the first cell 31; in two adjacent rows of cells 31, the metal wire extends reciprocally between a surface of a cell 31 in a ath row and a surface of a cell in a (a+1)th row, and m−1≧a≧1.
As shown in
More preferably, in the two adjacent rows of cells 31, the metal wire extends reciprocally between the surface of the cell 31 at an end of the ath row and the surface of the cell 31 at an end of the (a+1)th row, the end of the ath row and the end of the (a+1)th row located at the same side of the matrix form, as shown in
More specifically, in the embodiment as shown in
A sixth metal wire extends reciprocally between a front surface of the sixth cell 31 in the first row and a back surface of a sixth cell 31 in the second row, such that the first row and the second row are connected in series. A seventh metal wire extends reciprocally between a front surface of the sixth cell 31 in the second row and a back surface of a fifth cell 31 in the second row; a eighth metal wire extends reciprocally between a front surface of the fifth cell 31 in the second row and a back surface of a fourth cell 31 in the second row, until a eleventh metal wire extends reciprocally between a front surface of a second cell 31 in the second row and a back surface of a first cell 31 in the second row, and then a twelfth metal wire extends reciprocally between a front surface of the first cell 31 in the second row and a back surface of a first cell 31 in the third row, such that the second row and the third row are connected in series. Sequentially, the third row and the fourth row are connected in series, the fourth row and the fifth row connected in series, the fifth row and the sixth row connected in series, such that the cell array 30 is manufacture. In this embodiment, a bus bar is disposed at the left side of the first cell 31 in the first row and the left side of the first cell 31 in the sixth row respectively; a first bus bar is connected with a conductive wire extending from the left side of the first cell 31 in the first row, and a second bus bar is connected with a conductive wire extending from the left side of the first cell 31 in the sixth row.
As said above, the cells in the embodiments of the present disclosure are connected in series by the conductive wires—the first row, the second row, the third row, the fourth row, the fifth row and the sixth row are connected in series by the conductive wires. As shown in the figures, alternatively, the second and third row, and the fourth and fifth rows can be connected in parallel with a diode respectively to avoid light spot effect. The diode can be connected in a manner commonly known to those skilled in the art, for example, by a bus bar.
However, the present disclosure is not limited to the above. For example, the first and second rows can be connected in series, the third and fourth rows connected in series, the fifth and sixth rows connected in series, and meanwhile the second and third rows are connected in parallel, the fourth and fifth connected in parallel. In such a case, a bus bar can be disposed at the left or right side of corresponding rows respectively.
Alternatively, the cells 31 in the same row can be connected in parallel. For example, a metal wire extends reciprocally from a front surface of a first cell 31 in a first row through the front surfaces of the cells 31 in the second row to the sixth row.
In some specific embodiments of the present disclosure, a binding force between the metal wire and the cells 31 ranges from 0.1 N to 0.8 N. That's to say, the binding force between the conductive wires 32 and the cells 31 ranges from 0.1 N to 0.8 N. Preferably, the binding force between the metal wire and the cells ranges from 0.2 N to 0.6 N, so as to secure the welding between the cells and the metal wire, to avoid sealing-off of the cells in the operation and the transferring process and performance degradation due to poor connection, and to lower the cost.
The solar cell module 100 according to embodiments of the present disclosure is illustrated with reference to
As shown in
The front adhesive layer 20 and the back adhesive layer 40 are adhesive layers commonly used in the art. Preferably, the front adhesive layer 20 and the back adhesive layer 40 are polyethylene-octene elastomer (POE) and/or ethylene-vinyl acetate copolymer (EVA). In the present disclosure, polyethylene-octene elastomer (POE) and/or ethylene-vinyl acetate copolymer (EVA) are conventional products in the art, or can be obtained in a method known to those skilled in the art.
In the embodiments of the present disclosure, the upper cover plate 10 and the back plate 50 can be selected and determined by conventional technical means in the art. Preferably, the upper cover plate 10 and the back plate 50 are transparent plates respectively, for example, glass plates.
In the process of manufacturing the solar cell module 100, the conductive wire can be first bounded or welded with the secondary grid lines and the back electrodes of the cell 31, and then superposed and laminated.
Other components of the solar cell module 100 according to the present disclosure are known in the art, which will be not described in detail herein.
Specifically, the solar module 100 includes an upper cover plate 10, a front adhesive layer 20, the cell array 30, a back adhesive layer 40 and a back plate 50. The cell array 30 includes a plurality of cells 31, and adjacent cells 31 are connected by the plurality of conductive wires 32. The conductive wires 32 are constituted by the metal wire S. At least one metal wire S extends reciprocally between a surface of a first cell 31 and a surface of a second cell 31 adjacent to the first cell 31, so as to form at least two conductive wires 32. The front adhesive layer 20 contacts with the conductive wires 32 directly and fills between the adjacent conductive wires 32.
That's to say, the solar cell module 100 according to the present disclosure includes an upper cover plate 10, a front adhesive layer 20, the cell array 30, a back adhesive layer 40 and a back plate 50 superposed sequentially along a direction from up to down. The cell array 30 includes a plurality of cells 31 and conductive wires 32 for connecting the plurality of cells 31. The conductive wires are constituted by the metal wire S which extends reciprocally between surfaces of two adjacent cells 31.
The conductive wires 32 are electrically connected with the cells 31, in which the front adhesive layer 20 on the cells 31 contacts with the conductive wires 32 directly and fills between the adjacent conductive wires 32, such that the front adhesive layer 20 can fix the conductive wires 32, and separate the conductive wires 32 from air and moisture from the outside world, so as to prevent the conductive wires 32 from oxidation and to guarantee the photoelectric conversion efficiency.
Thus, in the solar cell module 100 according to embodiments of the present disclosure, the conductive wires 32 constituted by the metal wire S which extends reciprocally replace traditional primary grid lines and solder strips, so as to reduce the cost. The metal wire S extends reciprocally to decrease the number of free ends of the metal wire S and to save the space for arranging the metal wire S, i.e. without being limited by the space. The number of the conductive wires 32 constituted by the metal wire which extends reciprocally may be increased considerably, which is easy to manufacture, and thus is suitable for mass production. The front adhesive layer 20 contacts with the conductive wires 32 directly and fills between the adjacent conductive wires 32, which can effectively isolate the conductive wires from air and moisture to prevent the conductive wires 32 from oxidation to guarantee the photoelectric conversion efficiency.
In some specific embodiments of the present disclosure, the metal wire S extends reciprocally between a front surface of a first cell and a back surface of a second cell adjacent to the first cell; the front adhesive layer 20 contacts with the conductive wires on the front surface of the first cell 31 directly and fills between the adjacent conductive wires 32 on the front surface of the first cell 31; the back adhesive layer 40 contacts with the conductive wires 32 on the back surface of the second cell 31 directly and fills between the adjacent conductive wires 32 on the back surface of the second cell 31.
In other words, in the present disclosure, the two adjacent cells 31 are connected by the metal wire S. In the two adjacent cells 31, the front surface of the first cell 31 is connected with the metal wire S, and the back surface of the second cell 31 is connected with the metal wire S.
The front adhesive layer 20 on the first cell 31 whose front surface is connected with the metal wire S is in direct contact with the metal wire S on the front surface of the first cell 31 and fills between the adjacent conductive wires 32. The back adhesive layer 40 on the second cell 31 whose back surface is connected with the metal wire S is in direct contact with the metal wire S on the back surface of the second cell 31 and fills between the adjacent conductive wires 32 (as shown in
Consequently, in the solar cell module 100 according to the present disclosure, not only the front adhesive layer 20 can separate the conductive wires 32 on the front surfaces of part of the cells 31 from the outside world, but also the back adhesive layer 40 can separate the conductive wires 32 on the back surfaces of part of the cells 31 from the outside world, so as to further guarantee the photoelectric conversion efficiency of the solar cell module 100.
In some specific embodiments of the present disclosure, for a typical cell with a dimension of 156 mm×156 mm, the solar cell module has a series resistance of 380 to 440 mΩ per 60 cells. The present disclosure is not limited to 60 cells, and there may be 30 cells, 72 cells, etc. When there are 72 cells, the series resistance of the solar cell module is 456 to 528 mΩ, and the electrical performance of the cells is better.
In some specific embodiments of the present disclosure, for a typical cell with a dimension of 156 mm×156 mm, the solar cell module has an open-circuit voltage of 37.5-38.5 V per 60 cells. The present disclosure is not limited to 60 cells, and there may be 30 cells, 72 cells, etc. The short-circuit current is 8.9 to 9.4 A, and is not related to the number of the cells.
In some specific embodiments of the present disclosure, the solar cell module has a fill factor of 0.79 to 0.82, which is independent from the dimension and number of the cells, and can affect the electrical performance of the cells.
In some specific embodiments of the present disclosure, for a typical cell with a dimension of 156 mm×156 mm, the solar cell module has a working voltage of 31.5-32 V per 60 cells. The present disclosure is not limited to 60 cells, and there may be 30 cells, 72 cells, etc. The working current is 8.4 to 8.6 A, and is not related to the number of the cells.
In some specific embodiments of the present disclosure, for a typical cell with a dimension of 156 mm×156 mm, the solar cell module has a conversion efficiency of 16.5-17.4%, and a power of 265-280 W per 60 cells.
A method for manufacturing the solar cell module 100 according to the embodiments of the present disclosure will be illustrated with respect to
Specifically, the method according to the embodiments of the present disclosure includes the following steps:
Forming a cell array 30 with a plurality of cells 31, in which secondary grid lines 312 and short grid lines 33 are disposed on a front surface of the cell 31; the secondary grid lines 312 includes middle secondary grid line 3122 intersected with conductive wires 32 and edge secondary grid lines 3121 non-intersected with the conductive wires 32, the short grid lines 33 being connected with the edge secondary grid lines 3121, and being connected with the conductive wires 32 or at least one middle secondary grid line 3122, in which specifically, the short grid lines 33 can be manufactured in the same way as the secondary grid lines 312 on the front surface of the cell 31, for example, screen printed in conjunction with the secondary grid lines and with the help of the same screen printing plate as the front secondary gird lines 3121, and the short grid lines 33 may be made of silver paste.
Superposing the upper cover plate 10, the front adhesive layer 20, the cell array 30, the back adhesive layer 40 and the back plate 50 in sequence, in which the front surface of the cell 31 faces the front adhesive layer 20, and the back surface thereof faces the back adhesive layer 40, and laminating them to obtain the solar cell module 100.
In the specific embodiments of the present disclosure, the solar cell array 30 comprises at least two cells 31, each of which comprises a cell substrate 311, secondary grid lines 312 and short grid lines 33 disposed on a front surface of the cell substrate 311, and back electrodes 314 disposed on a back surface of the cell substrate 311. Adjacent cells 31 are connected by a plurality of conductive wires 32 constituted by a metal wire S which extends reciprocally between the adjacent cells 31.
The secondary grid lines 312 located at a side surface of the cell substrate 311 comprises two parts—one part of the secondary grid lines 312 intersected with the conductive wires 32 and located in a middle position of the cell substrate 311 to form middle secondary grid lines 3122; the other part of the secondary grid lines 312 non-intersected with the conductive wires 32 and located at an edge of one side away from the conductive wires 32 to form edge secondary grid lines 3121.
The edge secondary grid lines 3121 are provided with short grid lines 33 connected with the conductive wires 32 or at least one middle secondary grid line 3122. The short grid lines 33 are located at the edges of the cell 31 where the conductive wires 32 cannot reach when being winded, so as to avoid current loss.
In the solar cell array 30 according to the embodiments of the present disclosure, the conductive wires 32 are constituted by the metal wire which extends reciprocally. The conductive wires 32 are constituted by the metal wire which extends reciprocally. The conductive wires 32 of this structure extend reciprocally between two adjacent cells in a winding way to form a folded shape, which is easy to manufacture in low cost, and can improve the photoelectric conversion efficiency of the solar cell array 30. Moreover, the conductive wires 32 are arranged in a winding way, such that problems caused by breaking off the conductive wires 32 can be avoided. Moreover, the short grid lines 33 are disposed on the secondary grid lines 312 at the edge of the front surface of the cell 31, such that the current will not be wasted because the conductive wires 32 cannot reach the secondary grid lines 312 at the edge of the cell 31, so as to further improve the photoelectric conversion efficiency of the solar cell module.
The method includes the steps of preparing a solar array 30, superposing the upper cover plate 10, the front adhesive layer 20, the cell array 30, the back adhesive layer 40 and the back plate 50 in sequence, and laminating them to obtain the solar cell module 100. It can be understood that the method further includes other steps, for example, sealing the gap between the upper cover plate 10 and the back plate 50 by a sealant, and fixing the above components together by a U-shape frame, which are known to those skilled in the art, and thus will be not described in detail herein.
The method includes a step of forming a plurality of conductive wires by a metal wire which extends reciprocally surfaces of cells 31 and is electrically connected with the surfaces of cells 31, such that the adjacent cells 31 are connected by the plurality of conductive wires to constitute a cell array 30.
Specifically, as shown in
In the embodiment shown in
The cell array 30 obtained is superposed with the upper cover plate 10, the front adhesive layer 20, the back adhesive layer 40 and the back plate 50 in sequence, in which a front surface of the cell 31 faces the front adhesive layer 20, a back surface thereof facing the back adhesive layer 40, and laminating them to obtain the solar cell module 100. It can be understood that the metal wire can be bounded or welded with the cell 31 when or before they are laminated.
The front adhesive layer 20 is disposed in direct contact with the conductive wires 32. In the process of laminating, the front adhesive layer 20 melts and fills the gaps between adjacent conductive wires 32. The back adhesive layer 40 is disposed in direct contact with the conductive wires 32. In the process of laminating, the back adhesive layer 40 melts and fills the gaps between adjacent conductive wires 32.
Example 1Example 1 is used to illustrate the solar cell module 100 according to the present disclosure and the manufacturing method thereof.
(1) Manufacturing a Metal Wire S
An alloy layer of Sn40%-Bi55%-Pb5% (melting point: 125° C.) is attached to a surface of a copper wire, in which the copper wire has a cross section of 0.04 mm2, and the alloy layer has a thickness of 16 μm. Hence, the metal wire S is obtained.
(2) Manufacturing a Solar Cell Module 100
A POE adhesive layer in 1630×980×0.5 mm is provided (melting point: 65° C.), and a glass plate in 1633×985×3 mm and a polycrystalline silicon cell 31 in 156×156×0.21 mm are provided correspondingly. The cell 31 has 91 secondary grid lines (silver, 60 μm in width, 9 μm in thickness) on its front surface, each of which substantially runs through the cell 31 in a longitudinal direction, and the distance between the adjacent secondary grid lines is 1.7 mm.
The short grid lines are printed at an edge of a side of the front surface of the cell by a secondary grid mesh at the same time of printing the secondary grid lines. The short grid lines are perpendicular to the secondary grid lines, and connected with the outermost secondary grid line at the edge. The short grid line printed has a length of 5.1 mm and a width of 0.2 mm. There are eight short grid lines.
The cell 31 has five back electrodes (tin, 1.5 mm in width, 10 μm in thickness) on its back surface. Each back electrode substantially runs through the cell 31 in a longitudinal direction, and the distance between the adjacent back electrodes is 31 mm.
60 cells 31 are arranged in a matrix form (six rows and ten columns). In two adjacent cells 31 in a row, a metal wire extends reciprocally between a front surface of a first cell 31 and a back surface of a second cell 31 under strain. The metal wire extends reciprocally under strain from two clips at two ends thereof, and is intersected with the short gird lines at the turns formed by reciprocal extension, so as to form 15 parallel conductive wires. The secondary grid lines of the first cell 31 are welded with the conductive wires and the back electrodes of the second cell 31 are welded with the conductive wires. The distance between parallel adjacent conductive wires is 9.9 mm. 10 cells are connected in series into a row, and six rows of the cells of such kind are connected in series into a cell array via the bus bar. Then, an upper glass plate, an upper POE adhesive layer, multiple cells arranged in a matrix form and welded with the metal wire, a lower POE adhesive layer and a lower glass plate are superposed sequentially from up to down, in which the front surface of the cell 31 faces the front adhesive layer 20, such that the front adhesive layer 20 contacts with the conductive wires 32 directly; and the back surface of the cell 31 faces the back adhesive layer 40, and finally they are laminated in a laminator, in which the front adhesive layer 20 fills between adjacent conductive wires 32. In such way, a solar cell module A1 is obtained.
Comparison Example 1The difference of Comparison example 1 and Example 1 lies in that a conventional grid mesh is employed, and the short grid lines are not printed at the same time of printing the secondary grid lines. In such a way, a solar cell module D1 as shown in
The differences between Comparison example 2 and Comparison example 1 lie in that the cells are arranged in a matrix form; 15 metal wires connected in series are pasted at a transparent adhesive layer, and the metal wires are attached to the solar cells. In two adjacent cells, the metal wire connects a front surface of a first cell and a back surface of a second cell. Then, an upper glass plate, an upper POE adhesive layer, and a first transparent adhesive layer, multiple cells arranged in a matrix form and welded with the metal wire, a second transparent adhesive layer, a lower POE adhesive layer and a lower glass plate are superposed sequentially from up to down. Thus, a solar cell module D2 is obtained.
Example 2Example 2 is used to illustrate the solar cell module 100 according to the present disclosure and the manufacturing method thereof.
(1) Manufacturing a Metal Wire S
An alloy layer of Sn40%-Bi55%-Pb5% (melting point: 125° C.) is attached to a surface of a copper wire, in which the copper wire has a cross section of 0.03 mm2, and the alloy layer has a thickness of 10 μm. Hence, the metal wire S is obtained.
(2) Manufacturing a Solar Cell Module
A EVA adhesive layer in 1630×980×0.5 mm is provided (melting point: 60° C.), and a glass plate in 1650×1000×3 mm and a polycrystalline silicon cell 31 in 156×156×0.21 mm are provided correspondingly. The cell 31 has 91 secondary grid lines (silver, 60 μm in width, 9 in thickness) at its front surface, each of which substantially runs through the cell 31 in a longitudinal direction, and the distance between the two adjacent secondary grid lines is 1.7 mm. The cell 31 has five back electrodes (tin, 1.5 mm in width, 10 μm in thickness) on its back surface. Each back electrode substantially runs through the cell 31 in the longitudinal direction, and the distance between the two adjacent back electrodes is 31 mm.
The short grid lines are printed at an edge of a side of the front surface of the cell by a newly designed secondary grid mesh at the same time of printing the secondary grid lines. The short grid lines are perpendicular to the secondary grid lines, and connected with the outermost secondary grid line at the edge. The short grid line printed has a length of 3.4 mm and a width of 0.1 mm. There are ten short grid lines.
60 cells 31 are arranged in a matrix form (six rows and six columns). In two adjacent cells 31 in a row, a metal wire extends reciprocally between a front surface of a first cell 31 and a back surface of a second cell 31 under strain. The metal wire extends reciprocally under strain from two clips at two ends thereof, and is intersected with the short gird lines at the turns formed by reciprocal extension, so as to form 20 parallel conductive wires. The secondary grid lines of the first cell 31 are welded with the conductive wires and the back electrodes of the second cell 31 are welded with the conductive wires. The distance between parallel adjacent conductive wires is 7 mm. 10 cells are connected in series into a row, and six rows of the cells of such kind are connected in series into a cell array via the bus bar. Then, an upper glass plate, an upper POE adhesive layer, multiple cells arranged in a matrix form and welded with the metal wire, a lower POE adhesive layer and a lower glass plate are superposed sequentially from up to down, in which the front surface of the cell 31 faces the front adhesive layer 20, such that the front adhesive layer 20 contacts with the conductive wires 32 directly; and the back surface of the cell 31 faces the back adhesive layer 40, and finally they are laminated in a laminator, in which the front adhesive layer 20 fills between adjacent conductive wires 32. In such way, a solar cell module A2 is obtained.
Example 3The solar cell module is manufactured according to the method in Example 2, but the difference compared with Example 2 lies in that the short grid lines are printed at an edge of a side of the front surface of the cell by a secondary grid mesh at the same time of printing the secondary grid lines. The short grid lines are perpendicular to the secondary grid lines, and connected with the outermost secondary grid line at the edge. The short grid line printed has a length of 5.1 mm and a width of 0.15 mm. There are ten short grid lines. The turn formed by reciprocal extension is located between the second and the third short grid lines. The short grid lines are intersected with the third secondary grid line. In such a way, a solar cell module A3 is obtained.
Example 4The solar cell module is manufactured according to the method in Example 2, but the difference compared with Example 2 lies in that after being welded the secondary grid lines, the metal wire cuts the arc segments at the turns to form separate and parallel 20 metal wires. The distance between adjacent parallel primary grid lines is 7 mm. In such a way, a solar cell module A4 is obtained.
Example 5The solar cell module is manufactured according to the method in Example 3, but the difference compared with Example 3 lies in that the cell array is connected in such a manner that in two adjacent rows of cells, the conductive wires extend from a front surface of a cell at an end of the ath row (a≧1) to form electrical connection with a back surface of a cell 31 at an adjacent end of the (a+1)th row, so as to connect the two adjacent rows of cells. The conductive wires for connecting the two adjacent rows of cells 31 are arranged in perpendicular to the conductive wires for connecting the adjacent cells 31 in the two rows. In such a way, a solar cell module A4 is obtained.
Testing Example 1(1) Whether the metal wire in the solar cell module drifts is observed with the naked eyes;
(2) According to the method disclosed in IEC904-1, the solar cell modules manufactured in the above examples and the comparison example are tested with a single flash simulator under standard test conditions (STC): 1000 W/m2 of light intensity, AM1.5 spectrum, and 25° C. The photoelectric conversion efficiency of each cell is recorded. The testing result is shown in Table 1.
The fill factor refers to a ratio of the power at the maximum power point of the solar cell module and the maximum power theoretically at zero resistance, and represents the proximity of the actual power with respect to the theoretic maximum power, in which the greater the value is, the higher the photoelectric conversion efficiency is. Generally, the series resistance is small, so the fill factor is great. The photoelectric conversion efficiency refers to a ratio of converting the optical energy into electric energy by the module under a standard lighting condition (1000 W/m2 of light intensity). The series resistance is equivalent to the internal resistance of the solar module, in which the greater the value is, the poorer the performance of the module is. The fill factor represents a ratio of the actual maximum power and the theoretical maximum power of the module, in which the greater the value is, the better the performance of the module is. The open-circuit voltage refers to the voltage of the module in an open circuit under a standard lighting condition. The short-circuit current refers to the current of the module in a short circuit under a standard lighting condition. The working voltage is the output voltage of the module working with the largest power under a standard lighting condition. The working current is the output current of the module working with the largest power under a standard lighting condition. The power is the maximum power which the module can reach under a standard lighting condition.
It can be indicated from Table 1 that for the solar cell module according to the embodiments of the present disclosure, the metal wire does not drift, and higher photoelectric conversion efficiency can be obtained.
Testing Example 2(1) Welding a metal wire onto a surface of a cell, the metal wire being in perpendicular to secondary grid lines of the cell;
(2) Placing the cell horizontally at a testing position of a tensile tester, and pressing blocks on the cell, in which the pressing blocks are disposed at two sides of the metal wire, such that the cell will not be pulled up during the test;
(3) Clamping the metal wire at a pull ring of a tension meter that forms an angle of 45° with the cell;
(4) Actuating the tension meter, such that the tension meter moves uniformly along a vertical direction, pulls up the metal wire from the surface of the cell and records the pull data tested, in which the data is averaged to obtain the pull data of the metal wire. The testing result is shown in Table 2.
It can be indicated from Table 2 that for the solar cell module according to the embodiments of the present disclosure, greater tensile force is needed to pull the metal wire away from the upper gall of the cell, which proves stronger stability of connection between the metal wire and the cell in the solar cell module.
In the specification, it is to be understood that terms such as “central,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” and “counterclockwise” should be construed to refer to the orientation as then described or as shown in the drawings under discussion. These relative terms are for convenience of description and do not require that the present disclosure be constructed or operated in a particular orientation.
In addition, terms such as “first” and “second” are used herein for purposes of description and are not intended to indicate or imply relative importance or significance or to imply the number of indicated technical features. Thus, the feature defined with “first” and “second” may comprise one or more of this feature. In the description of the present disclosure, “a plurality of” means two or more than two, unless specified otherwise.
In the present disclosure, unless specified or limited otherwise, a structure in which a first feature is “on” or “below” a second feature may include an embodiment in which the first feature is in direct contact with the second feature, and may also include an embodiment in which the first feature and the second feature are not in direct contact with each other, but are contacted via an additional feature formed therebetween. Furthermore, a first feature “on,” “above,” or “on top of” a second feature may include an embodiment in which the first feature is right or obliquely “on,” “above,” or “on top of” the second feature, or just means that the first feature is at a height higher than that of the second feature; while a first feature “below,” “under,” or “on bottom of” a second feature may include an embodiment in which the first feature is right or obliquely “below,” “under,” or “on bottom of” the second feature, or just means that the first feature is at a height lower than that of the second feature.
Reference throughout this specification to “an embodiment,” “some embodiments,” or “some examples” means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. Thus, these terms throughout this specification do not necessarily refer to the same embodiment or example of the present disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.
Although embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes, modifications, alternatives and variations can be made in the embodiments without departing from the scope of the present disclosure.
Claims
1. A solar cell array, comprising:
- a plurality of cells, each cell having a front surface on which light is incident when the cell is in operation and a back surface opposite to the front surface;
- a plurality of conductive wires, adjacent cells connected by the plurality of conductive wires;
- secondary grid lines disposed on the front surface of the respective cell, the secondary grid lines comprising middle secondary grid lines disposed in the middle of the respective cell and intersecting with the conductive wires, and edge secondary grid lines disposed on the edges of the respective cell and non-intersecting with the conductive wires; and
- short grid lines disposed on the front surface of the cell, the short grid lines connecting the edge secondary grid lines with the conductive wires or with at least one middle secondary grid line.
2. The solar cell array according to claim 1, wherein the adjacent cells are connected by the plurality of conductive wires comprising a metal wire; the metal wire extends reciprocally between a surface of a first cell and a surface of a second cell adjacent to the first cell, so as to form at least two conductive wires.
3. The solar cell array according to claim 2, wherein the metal wire breaks off at a turn formed by reciprocal extension after being connected with the first and second cells.
4. The solar cell array according to claim 2, wherein the short grid lines are connected with the middle secondary grid lines closest to the edge secondary grid lines.
5. The solar cell array according to claim 2, wherein the short grid lines are connected with the conductive wires.
6. The solar cell array according to claim 5, wherein the short grid line and the metal wire at the front surface of the respective cell are connected at a turn formed by reciprocal extension.
7. The solar cell array according to claim 1, wherein the short grid line is perpendicular to the secondary grid line.
8. The solar cell array according to claim 1, wherein the short grid line has a width of 0.05 to 0.5 mm.
9. The solar cell array according to claim 1, wherein the short grid line has a length of 1 to 10 mm.
10. (canceled)
11. The solar cell array according to claim 1, wherein there are 3 to 40 short grid lines.
12. The solar cell array according to claim 1, wherein the conductive wires are welded with the secondary grid lines.
13. The solar cell array according to claim 2, wherein the metal wire extends reciprocally between a front surface of the first cell and a back surface of the second cell.
14-21. (canceled)
22. The solar cell array according to claim 2, wherein the metal wire is a copper wire.
23. (canceled)
24. The solar cell array according to claim 2, wherein the metal wire extends reciprocally under strain, before being connected with the cells.
25-27. (canceled)
28. A solar cell module, comprising an upper cover plate, a front adhesive layer, a solar cell array of claim 1, a back adhesive layer and a back plate superposed in sequence.
29. The solar cell module according to claim 28, wherein adjacent cells are connected by the plurality of conductive wires comprising a metal wire; the metal wire extends reciprocally between a surface of a first cell and a surface of a second cell adjacent to the first cell, so as to form at least two conductive wires; the front adhesive layer contacts with the conductive wires directly and is disposed between the adjacent conductive wires.
30-35. (canceled)
36. A method for manufacturing a solar cell module, comprising:
- forming a cell array with a plurality of cells, the call array comprising a secondary grid line and a short grid line disposed on a front surface of the cell on which light is incident when the cell is in operation, the secondary grid line including a middle secondary grid line disposed in the middle of the respective cell and intersected with a conductive wire, and an edge secondary grid line disposed on the edge of the respective cell and non-intersected with the conductive wire, the short grid line connecting the edge secondary grid line with the conductive wire or with at least one middle secondary grid line;
- superposing an upper cover plate, a front adhesive layer, the cell array, a back adhesive layer and a back plate in sequence, in which the front surface of the cell faces the front adhesive layer, a back surface thereof facing the back adhesive layer; and
- laminating the superposed layers to obtain the solar cell module.
37. The method according to claim 36, further comprising: forming a plurality of the conductive wires by extending a metal wire reciprocally that extends between a surface of a first cell and a surface of a second cell adjacent to the first cell, such that adjacent cells are connected by the plurality of conductive wires to form the cell array.
38. The method according to claim 37, wherein the metal wire extends reciprocally under a strain.
39. The method according to claim 37, further comprising breaking the metal wire at a turn after the metal wire is connected with the cells.
40-46. (canceled)
Type: Application
Filed: Jun 12, 2015
Publication Date: May 5, 2016
Applicant: BYD COMPANY LIMITED (Shenzhen)
Inventors: Zhiqiang ZHAO (Shenzhen), Meiling TENG (Shenzhen), Nan WANG (Shenzhen), Zhanfeng JIANG (Shenzhen), Long HE (Shenzhen)
Application Number: 14/738,322
