KR20230036764A - Shingled Module For High Efficiency Bifacial Generating Power And Method For Producing The Same - Google Patents

Abstract

According to the present invention, for a high-output shingled module for high-efficiency bifacial power generation, a double-sided light-receiving solar cell substrate with electrode members including finger electrodes, busbar electrodes, and back electrodes are divided into a plurality of split cells. A string is formed in a shingled array structure using a conductive adhesive. A first encapsulating material, the string, and second encapsulating material are sequentially stacked between a front cover and a rear cover. A lamination process is performed using lamination equipment to produce a shingled module. The front cover is formed of tempered glass located on the front of the module. The back cover is formed by a back sheet made of a light-transmitting resin material, located on the back of the module. Therefore, the high-output shingled module can generate high output on the back as well as the front.

Description

High-output shingled module for high-efficiency double-sided power generation and its manufacturing method {Shingled Module For High Efficiency Bifacial Generating Power And Method For Producing The Same}

The present invention reduces the overall weight of a double-sided light-receiving solar cell module and has excellent constructability, supports module design in various forms by changing the connection structure of the string connecting the split cells according to the installation environment of the module, and supports module design from the front as well as the rear It relates to a high-output shingled module for high-efficiency double-sided power generation capable of generating high output and a manufacturing method thereof.

Due to the global warming problem caused by the use of fossil fuels and the depletion of fossil fuels themselves, interest in environmentally friendly renewable energy sources that can replace them has increased. In the future, the proportion of new and renewable energy generation is expected to increase further. Among them, solar power generation has the advantage of using pollution-free and infinite solar energy sources, so solar power generation facilities are in the limelight as a new alternative energy source in the future, and solar cells Among various application fields, it is currently being used to obtain power generation for solar power plants, building-integrated photovoltaics (BIPV), barriers, agricultural power generation facilities, and automobiles.

Due to the recent decline in the price of single-crystal silicon modules, which have strengths in efficiency, the global photovoltaic market is rapidly reorganizing, and bifacial solar cells generate additional photogeneration using reflected light, Demand is increasing in the market because it increases the conversion efficiency of the battery.

Existing photovoltaic modules are manufactured by connecting solar cells with a metal ribbon, and when a string is manufactured by connecting a plurality of cells, a space is required for electrical insulation between the cells. This space is an empty space that cannot generate current and causes cell-to-module (CTM) losses. In addition, since busbars exist on the front surface of the cell, photocurrent cannot be generated in the area covered by the busbars, causing additional power loss.

Korean Registered Patent Publication No. 10-1911845 (registered on October 19, 2018) Korean Registered Patent Publication No. 10-2138744 (registered on July 22, 2020)

doesn't exist

In contrast, shingled solar modules are manufactured by applying conductive adhesive (ECA) to the front bus bar of a divided cell and bonding it to the back side of another divided cell. Since the string is manufactured in a busbar-less structure while being connected, optical loss due to the busbar can be greatly reduced. In addition, unlike existing solar modules, there is no space to electrically separate cells, and since many cells can be integrated in the same area, a high-power and high-density module can be manufactured. However, since the output and efficiency of the string of the shingled module are affected by the characteristics of the split cells to be joined, in order to manufacture a high-output string, the type, shape, and electrode structure of the split cell (bus bar thickness, finger opening, etc.) It is required to optimize the bonding characteristics according to

The present invention reduces the overall weight of a double-sided light-receiving solar cell module and has excellent constructability, supports module design in various forms by changing the connection structure of the string connecting the split cells according to the installation environment of the module, and supports module design from the front as well as the rear It is to provide a high-output shingled module for high-efficiency double-sided power generation capable of generating high output and a manufacturing method thereof.

In order to achieve the above object, a method for manufacturing a high-output shingled module for high-efficiency double-sided power generation according to the present invention includes (a) a double-sided light-receiving solar cell substrate on which electrode members including finger electrodes, bus bar electrodes, and rear electrodes are formed; preparing; (b) dividing the double-sided light-receiving solar cell substrate into a plurality of unit cells by cutting along the cutting line using laser scribing; (c) forming a string of a shingled array structure by partially overlapping the divided unit cells and using a conductive adhesive; (d) manufacturing a shingled module by sequentially stacking a first encapsulant, a string, and a second encapsulant between the front cover and the rear cover, and performing a limination process using lamination equipment; , The front cover is formed of tempered glass located on the front surface of the module, and the rear cover is formed of a back sheet made of a translucent resin material located on the rear surface of the module.

In addition, in the step (b), a finger electrode and a bus bar electrode are formed as front electrodes on the front surface of the double-sided light-receiving solar cell substrate, and a rear electrode is formed on the rear surface, and the finger electrode is parallel to the short side of the divided unit cell. A plurality of them are disposed along a first direction, and the bus bar electrode extends in a second direction parallel to the long side of the divided unit cell, and a collection electrode line connecting the ends of the plurality of finger electrodes, electrically connected to other unit cells to be joined It is characterized in that a connection electrode line branching from the end of the collection electrode line and extending along the first direction is formed in order to connect to.

In addition, in the step (d), the lamination process is performed at a low temperature of 140 to 160 ° C. for 10 to 15 minutes.

In order to achieve the above object, the high-output shingled module for high-efficiency double-sided power generation according to the present invention sequentially laminates a first encapsulant, a string, and a second encapsulant between the front cover and the rear cover and proceeds with a lamination process. As a high-power shingled module manufactured by integrating, the front cover is formed of tempered glass as a transparent material located on the front of the module, the rear cover is formed of a back sheet made of a light-transmitting resin material of the module, and the string is a finger electrode It is characterized by forming a shingled array structure in which a double-sided light-receiving solar cell substrate including an electrode member composed of and a bus bar electrode and a rear electrode is divided into a plurality of cells, and the divided cells are partially overlapped and bonded with a conductive adhesive.

In addition, a plurality of the finger electrodes are disposed along a first direction parallel to the short side of the divided unit cell, and the bus bar electrode extends in a second direction parallel to the long side of the divided unit cell to form a plurality of finger electrodes. It is characterized in that a collection electrode line connecting the ends and a connection electrode line extending along the first direction branching from the end of the collection electrode line are formed to electrically connect to another unit cell to be bonded.

According to the present invention, the back cover of the double-sided light-receiving solar cell module is replaced with a rear back sheet made of a light-transmitting resin material, and the construction work is easy through the weight reduction of the entire module, and the number of cells bonded in a shingled array structure and the connection structure to support various types of module design, and generate high output from the front as well as the rear of the module, enabling high-output shingled modules that can realize high-efficiency double-sided power generation.

1 is a view showing the cross-sectional structure of a high-power shingled module for high-efficiency double-sided power generation according to an embodiment of the present invention;
2 is a diagram for explaining a connection structure of a string according to an embodiment of the present invention;
3 is a view showing the front surface of a solar cell substrate according to an embodiment of the present invention;
4 is a view showing the rear surface of a solar cell substrate according to an embodiment of the present invention;
5 is a view for explaining an operation of bonding divided unit cells to manufacture a string according to an embodiment of the present invention.
Figure 6 is a cross-sectional view along line AA of Figure 5;
7 is a prototype image of a high-output shingled module for high-efficiency double-sided power generation according to an embodiment of the present invention;
8 is prototype EL analysis data of a high-power shingled module for high-efficiency double-sided power generation according to an embodiment of the present invention;
9 is a prototype performance test graph of a high-power shingled module for high-efficiency double-sided power generation according to an embodiment of the present invention;
10 is a flowchart illustrating a method of manufacturing a high-output shingled module for high-efficiency double-sided power generation according to an embodiment.

Hereinafter, the present invention will be described by describing an embodiment of the present invention with reference to the accompanying drawings. Like reference numerals in each figure indicate like members. In addition, in describing the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, when a certain component is said to "include", this means that it may further include other components without excluding other components unless otherwise stated.

As shown in FIG. 1, the high-output shingled module 1 for high-efficiency double-sided power generation according to an embodiment of the present invention includes a first encapsulant 4 positioned between a front cover 2 and a rear cover 3 , A string 10, and a second encapsulant 5 may be included.

The first encapsulant 4 and the front cover 2 are laminated on the upper part of the string 10, the second encapsulant 5 and the rear cover 3 are laminated on the lower part of the string 10, and then the lamination equipment Lamination is performed to integrate all sequentially stacked module components (front cover, first encapsulant, string, second encapsulant, rear cover) sequentially using. The lamination process may be performed at a low temperature of 140 to 160° C. for 10 to 15 minutes.

The front cover 2 may include a transparent material positioned on the front surface of the module to protect the solar cell. For example, the front cover 2 may be formed of tempered glass that has high transmittance and is resistant to external impact to prevent breakage.

The rear cover 3 may be formed of a translucent material to receive light to the rear surface of the module, and may be formed of a rear back sheet containing a resin material that is lighter than glass material to reduce the weight of the module. For example, PET-type transparent synthetic resin may be used, and functions such as waterproofing, insulation, and UV protection may be used.

A protective film may be formed on one side of the front cover 2 and the rear cover 3, respectively. As the protective film, a UV blocking film or the like can be used, and it can help extend the lifespan of the solar cell by blocking ultraviolet rays transmitted to the solar cell.

The first and second encapsulants (4) (5) are materials for maintaining the life of the solar cell module for a long time and are located on the front and rear surfaces of the string (10) to act as a buffer to prevent damage to the cell and to cover the front cover (2) and The rear cover 3 is bonded and sealed, and EVA, POE, Ionomer, etc. may be used as a material for the encapsulant.

The string 10 is formed in a shingled array by dividing double-sided light-receiving solar cells into a plurality of cells and partially overlapping the divided cells. A plurality of divided single cells are bonded with conductive adhesive 7 (ECA) to form the string 10.

The conductive adhesive 7 is an electrically conductive adhesive used for bonding wires of electrical and electronic products or circuits, and is made by mixing silver particles with epoxy resin. The principle that such a conductive adhesive exhibits conductivity is that the conductive filler dispersed in the adhesive is in contact with the filler in a curing or solidifying step to develop conductivity. In addition, the conductive adhesive is applied using a micro dispenser, and the discharge amount from the needle must be constant and not run down. Metal powders such as gold, platinum, silver, copper, and nickel, carbon fibers, graphite, and composite powders may be used as the conductive filler.

A frame (not shown) is positioned to surround the outer portion of the module, and internal components may be protected from external impact by the frame. The frame may be formed of a rigid material such as reinforced plastic or stainless steel.

In order to design the shape of the module in various ways, as shown in FIG. 2, it may be formed into string arrays 10A, 10B, and 10C having various sizes and shapes. The string array 10A is configured in a square shape by serially connecting 20 cells to one side of three shingled-joined strings with a string connecting member 8. Another string array (10B) is configured in a rectangular shape by connecting 14 cells in series with a string connecting member (8) to one side of two strings shingled-bonded, and another string array (10C) has 20 cells shingled-bonded One side and the other side of the three strings can be configured in a square by connecting them in parallel with a string connection member (8).

In this way, solar cells may be configured in various forms through series, parallel, and series-parallel connection of strings. In addition, it is possible to secure the diversity of solar module design by adjusting the length and width of the string by varying the horizontal and vertical widths of the divided unit cells.

As shown in FIG. 3 , the solar cell substrate 100 on which electrode members including bus bar electrodes 20 and finger electrodes 40 are formed may be divided into a plurality of cells along a cutting line Ct. The size of the solar cell substrate 100 is 156.75 mm X 156.75 mm. Considering the output characteristics of the solar cell, it can be divided into 3 to 12 unit cells, and the short side of the divided unit cell 10-1 can be manufactured to be 13.3 to 66.6 mm. As illustrated, the solar cell substrate 100 is divided into four unit cells 10-1, which can be divided into equal sizes along the cutting line Ct using laser scribing. An electrode member composed of bus bar electrodes 20 and finger electrodes 40 may be formed on the front surface of the solar cell to correspond to the number of divided cells. That is, the divided unit cells 10-1 may have the same size and shape and form the same electrode pattern.

A plurality of finger electrodes 40 are disposed along a first direction parallel to the short sides of the divided unit cells 10-1, and serve to collect photoelectrically converted carriers. The line width of the finger electrode 40 is 0.08 to 0.12 mm.

The bus bar electrode 20 serves to transfer carriers collected by the finger electrode 40 to an external storage battery or the like. The bus bar electrode 20 is composed of a collection electrode line 21 for connecting the ends of the plurality of finger electrodes 40 and a connection electrode line 22 for electrical connection with other unit cells. The collection electrode line 21 extends along a second direction parallel to the long side of the divided unit cell 10-1, and the connection electrode line 22 diverges from the end of the collection electrode line 21 in the first direction. extends along The collection electrode line 21 and the connection electrode line 22 may be disposed along the edge of the divided unit cell 10-1, and the collection electrode line 21 is the cut of the dividing unit cell 10-1. It is disposed adjacent to the line Ct, and the connection electrode line 22 is disposed adjacent to the short side of the dividing unit cell 10-1. In a form in which the connection electrode line 22 is vertically bent at the end of the collection electrode line 21, the collection electrode line 21 and the connection electrode line 22 may form an L shape as a whole. The line width of the bus bar electrode 20 is 0.8 to 1.2 mm.

Referring to FIG. 4 , rear electrodes 30 may be formed on the rear surface of the unit cell 10 - 1 to be divided to correspond to the number of divided cells. The rear electrode 30 may be formed in the same electrode pattern as the electrode pattern of the bus bar electrode 20 formed on the front surface. The rear electrode 30 is electrically and physically connected to a connection electrode line 22 formed on the front surface of another unit cell 10-1 when forming a shingled array to be described later.

As shown in FIGS. 5 and 6 , unit cells 10 - 1 divided to form a module having a shingled array structure may be bonded through a heat treatment process through a conductive adhesive 7 . For example, a string array structure can be formed by partially overlapping the short side of one unit cell 10-1 and the short side of another unit cell 10-1. Two unit cells are formed by disposing the conductive adhesive 7 between the connection electrode lines 22 of the bus bar electrodes 20 of the unit cell 10-1 where the electrode 30 is positioned below and bonding them through a heat treatment process. At the same time that (10-1) is integrated, an electrical path through which the current collected by the finger electrode 40 moves is provided.

A prototype and performance test results of a high-power shingled module for high-efficiency double-sided power generation according to an embodiment of the present invention will be described.

In FIG. 7 (a) (b), tempered glass is mounted on the front of the module of the prototype, and a light-transmitting back sheet is mounted on the rear of the module of the prototype, and then, as shown in FIG. 8, electroluminescence for the front and rear surfaces of the module EL) properties were tested. In addition, as a result of the performance test on this prototype, the output characteristics of the front of the module of the prototype are as shown in Fig. A factor (FF) of 0.740 was obtained. In addition, as for the output characteristics of the rear side of the module of the prototype, as shown in FIG. As such, 313.49W of power output from the rear of the module was able to secure 72.9% of the front output of the module, confirming that not only the front but also the rear output of the module appeared excellent.

Hereinafter, a manufacturing method of a high-output shingled module for high-efficiency double-sided power generation according to an embodiment will be described with reference to FIG. 10 .

First, a double-sided light-receiving solar cell substrate 100 having finger electrodes 40 and bus bar electrodes 20 formed as front electrodes on the front surface of the module and rear electrodes 30 formed on the rear surface is prepared (S10). Here, a plurality of finger electrodes 40 are disposed along a first direction parallel to the short side of the divided unit cell, and the bus bar electrode 20 extends in a second direction parallel to the long side of the divided unit cell to form a plurality of A collection electrode line 21 connecting the ends of the finger electrodes and a connection electrode line 22 branched off from the end of the collection electrode line 21 and extending along the first direction in order to electrically connect to another unit cell to be joined. can include

The plurality of bus bar electrodes 20 and finger electrodes 40 are made of nickel (Ni), copper (Cu), silver (Ag), aluminum (Al), tin (Sn), zinc (Zn), indium (In), It is made of at least one selected from the group consisting of titanium (Ti), gold (Au), and combinations thereof, and in the present invention, a configuration made of silver (Ag) is applied to the bus bar electrode 20 and the finger electrode 40.

The rear electrode 30 is made of a conductive material, may be formed integrally with a plurality of passivation films and the rear surface of the semiconductor substrate, and may include nickel (Ni), copper (Cu), silver (Ag), aluminum (Al), tin ( Sn), zinc (Zn), indium (In), titanium (Ti), gold (Au), and at least one selected from the group consisting of combinations thereof. is formed of aluminum (Al).

Next, the double-sided light-receiving solar cell substrate 100 prepared in step S10 is cut and divided into a plurality of unit cells 10-1 (S20). The cutting process in step S20 may be performed by, for example, a nanosecond laser (532 nm, 20 ns, 30-100 KHz from coherent). That is, it can be executed by setting an average power of 10W, a frequency of 50 KHz, and a scan speed of 1,300 mm/s in a 20 ns laser using a 532 nm wavelength.

Subsequently, a shingled array is formed by partially overlapping the divided cells. The single cells divided into a plurality are bonded with the conductive adhesive 7 (ECA) to form the string 10. That is, the short side of the upper unit cell 10-1 prepared in step S20 and the lower side of the other unit cell ( A conductive adhesive 7 is applied to one of the short sides of 10-1) and joined in a shingled array to form a string 10 (S30).

The conductive adhesive 7 is a product with high conductivity and suitable viscosity suitable for the present invention among conductive adhesives on the market, for example, SKC Panacol's EL-3012, EL-3556, EL-3653, EL-3655 and Henkel of CE3103WLV, CA3556HF can be applied. In addition, the conductive filler in the conductive adhesive may include at least one material selected from Au, Pt, Pd, Ag, Cu, Ni, and carbon. The above-described application of the conductive adhesive is the connection electrode line 22 of the short-side rear electrode 30 of any one unit cell 10-1 above and the short-side bus bar electrode 20 of another unit cell 10-1 below. ) can be executed for either one or both. The positioning of such application may be determined according to the characteristics and discharge amount of the conductive adhesive.

The first encapsulant 4 and the front cover 2 are laminated on top of the string 10 to which the conductive adhesive is applied and joined in a shingled array, and the second encapsulant 5 and the back cover are laminated on the lower part of the string 10 (3) is laminated. Here, the front cover 2 is a transparent material positioned on the front surface of the module to protect the solar cell, and may be formed of tempered glass that has high transmittance and is strong against external impact to prevent breakage. The rear cover 3 may be formed of a translucent material to receive light to the rear surface of the module, and may be formed of a rear back sheet containing a resin material that is lighter than glass material to reduce the weight of the module. For example, PET-type transparent synthetic resin may be used, and functions such as waterproofing, insulation, and UV protection may be used. In addition, protective films may be formed on one side of the front cover 2 and the rear cover 3, respectively. As the protective film, a UV-blocking film or the like may be used. The first and second encapsulants (4) (5) are materials for maintaining the life of the solar cell module for a long time and are located on the front and rear surfaces of the string (10) to act as a buffer to prevent damage to the cell and to cover the front cover (2) and The rear cover 3 is bonded and sealed, and EVA, POE, Ionomer, etc. may be used as a material for the encapsulant.

Then, lamination is performed to integrate all sequentially stacked module components (front cover, first encapsulant, string, second encapsulant, and rear cover) using lamination equipment to manufacture a high-power shingled module. The lamination process may be performed at a low temperature of 140 to 160° C. for 10 to 15 minutes (S40).

In this way, since the power generation efficiency of the front and rear surfaces of the high-power shingled module to which the double-sided light-receiving solar cell is applied is high, it can be suitably used for building-integrated photovoltaic power generation (BIPV), barriers, greenhouse structures, agricultural power generation facilities, etc. In addition, it is possible to secure the diversity of module design by breaking away from the uniform design of solar cell modules and applying a shingled array that partially bonds the divided cells by varying the length and width of the divided cells on the solar cell substrate. It is possible to manufacture a module in response to small-scale power generation, and the construction work is easy by using a lightweight light-transmitting back sheet replacing the tempered glass on the back of the module.

The above description of the present invention is for illustrative purposes, and those skilled in the art can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be.

1: High power shingled module
2 : front cover
3 : Back Cover
4,5: first and second encapsulants
10 : string

Claims (5)

(a) preparing a double-sided light-receiving solar cell substrate on which an electrode member including a finger electrode, a bus bar electrode, and a rear electrode is formed;
(b) dividing the double-sided light-receiving solar cell substrate into a plurality of unit cells by cutting along the cutting line using laser scribing;
(c) forming a string of a shingled array structure by partially overlapping the divided unit cells and using a conductive adhesive;
(d) manufacturing a shingled module by sequentially stacking a first encapsulant, a string, and a second encapsulant between the front cover and the rear cover, and performing a limination process using lamination equipment; ,
The front cover is formed of tempered glass located on the front surface of the module,
The method of manufacturing a high-output shingled module for high-efficiency double-sided power generation, characterized in that the rear cover is formed of a rear back sheet made of a light-transmitting resin material located on the rear surface of the module. According to claim 1,
In step (b), finger electrodes and bus bar electrodes are formed as front electrodes on the front surface of the double-sided light-receiving solar cell substrate, and rear electrodes are formed on the rear surface,
A plurality of finger electrodes are disposed along a first direction parallel to the short side of the divided unit cells, and the bus bar electrode extends in a second direction parallel to the long side of the divided unit cells to form ends of the plurality of finger electrodes. A high-power shingled module for high-efficiency double-sided power generation, characterized in that a connection electrode line branched from the end of the collection electrode line and extending along the first direction is formed to electrically connect to the connecting collection electrode line and other unit cells to be joined. manufacturing method. According to claim 1,
In step (d), the lamination process is performed at a low temperature of 140 to 160 ° C. for 10 to 15 minutes. A high-output shingled module manufactured by sequentially stacking a first encapsulant, a string, and a second encapsulant between the front cover and the rear cover and integrating them through a lamination process,
The front cover is formed of tempered glass as a transparent material located on the front surface of the module,
The rear cover is formed of a rear back sheet of a light-transmitting resin material of the module,
The string is a shingled array structure in which a double-sided light-receiving solar cell substrate including an electrode member composed of a finger electrode, a bus bar electrode, and a rear electrode is divided into a plurality of cells, and the divided cells are partially overlapped and bonded with a conductive adhesive. High-power shingled module for high-efficiency double-sided power generation, characterized in that. According to claim 4,
The plurality of finger electrodes are disposed along a first direction parallel to the short side of the divided unit cell,
The bus bar electrode extends in a second direction parallel to the long side of the divided unit cell to connect the ends of a plurality of finger electrodes, the collection electrode line, and the end of the collection electrode line to electrically connect to another unit cell to be joined A high-power shingled module for high-efficiency double-sided power generation, characterized in that a connection electrode line branched from and extending along the first direction is formed.

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