Lightweight photovoltaic module and preparation method thereof

Abstract

The invention discloses a light photovoltaic module and a preparation method thereof, the light photovoltaic module comprises a glass cover plate, a first packaging adhesive film, a battery piece layer, a second packaging adhesive film and a back plate which are sequentially stacked from top to bottom, the battery piece layer comprises a left half battery, a right half battery and a junction box, the junction box comprises a cathode connector, a base, a cable and an anode connector which are connected in sequence, and a left half battery and a right half battery are respectively mounted on the left side and the right side of the junction box by taking the junction box as a boundary; and the front cover plate is made of ultrathin coated glass with the thickness of 1.0-1.8 mm. The preparation method of the light photovoltaic module comprises the steps of glass and adhesive film laying, series welding, series arrangement, stitch welding, bus bar leading-out head bending, EL detection, adhesive film and backboard laying, lamination, trimming, junction box installation, EL and IV testing, cleaning and boxing. The flexible photovoltaic module is simple in structure and convenient to manufacture, and the problems that hail, heavy objects and the like are prone to falling on the surface of an existing flexible photovoltaic module, so that battery pieces are damaged, ultraviolet resistance and weather resistance are poor, and dust accumulation is prone to occurring are solved.

Description

Technical Field

[0001] The invention relates to the technical field of photovoltaic assembly production and manufacturing, in particular to a lightweight photovoltaic assembly and a preparation method thereof. Background Art

[0002] With the rapid development of human society, energy demand and environmental protection are becoming two major problems facing mankind. Efficient, green and renewable energy is becoming a key for human society to solve the current predicament. As the main force of green renewable energy, solar energy accounts for an increasingly large proportion of global energy. In recent years, the country has vigorously promoted the deep integration and development of solar energy and buildings. Improve the photovoltaic building integrated application technology system, and encourage public institutions to install photovoltaic or solar thermal utilization facilities in existing buildings. At present, the mainstream photovoltaic modules are crystalline silicon solar modules, including polycrystalline and monocrystalline, accounting for more than 95% of the current photovoltaic modules. The conventional packaging method is glass / encapsulation film / battery / encapsulation film / backplane packaging, and a metal aluminum frame is used as the frame to support and fix it. The weight is about 12kg / m 2 . With the gradual rise of distributed power generation, conventional components cannot be used in some distributed projects due to their load-bearing reasons, such as some color steel tile roof projects. Lightweight photovoltaic components are a new type of components that are lighter, thinner and have a certain degree of flexibility. They can be directly pasted on low-load and curved roofs without the need for brackets. Compared with conventional photovoltaic components, lightweight components have significant characteristics such as "light", "thin", "bendable", and "rainwater self-cleaning". Therefore, it can not only be used in distributed power station scenes such as industrial and commercial color steel tile roofs, flat roofs, and residential tile houses, but also in photovoltaic mobile buses, convenient mobile power supplies, and outdoor activities. It can be easily combined with various innovative solutions, infinitely expanding the imagination of the application of photovoltaic technology.

[0003] At present, there are some technical solutions that attempt to solve the problem of lightweight photovoltaic modules by changing the packaging materials, that is, using high-transmittance films, transparent backplanes, etc. to replace tempered glass, that is, flexible module products. However, in actual application, since these high-transmittance films and transparent backplanes are mostly made of polymer materials, the light transmittance of the front panel is low, the conversion rate of the module is low, the surface flatness is poor, it is easy to absorb dust, and there are problems such as hot spots. The performance is also insufficient in terms of impact resistance, fire resistance, and weather resistance. In addition, the material cost and manufacturing cost of flexible modules are high, resulting in a long project payback period.

[0004] A Chinese patent with publication number CN108376717A discloses a method for preparing a laminated structure of a photovoltaic module, a laminated structure, and a photovoltaic module, which are prepared by a lamination process, wherein the lamination process includes a first heating stage, a second heating stage, and a third pressurized cooling stage. The heating temperature range of the first stage is 110-130°C, and the heating time range is 100-600 seconds; the heating temperature range of the second stage is 131-200°C, and the heating time range is 100-1200 seconds; the cooling temperature range of the third stage is 25-60°C, and the applied pressure range is 0.05-0.25Mpa. The present invention realizes a lamination process in a low temperature environment, reduces energy consumption, and at the same time ensures the flatness of the laminated structure of the photovoltaic module, further facilitating the installation and application of the photovoltaic module. This patent discloses a method of making a front panel by soaking fiber cloth in super weather-resistant coating and a method of making components using the same. Although this method solves the problems of heavy weight and insufficient weather resistance of the component front panel, the front panel manufacturing process is complicated, the cost is high, and there are problems such as water vapor permeability, low surface flatness, and low light transmittance, which is not conducive to the application and promotion of photovoltaic components.

[0005] Therefore, there is an urgent need to seek new solutions to solve the problems of heavy packaging materials, high costs and poor lamination effects of existing photovoltaic modules for low-load roof applications. At the same time, the new module products must meet the requirements of photovoltaic industry technical standards such as UV resistance, aging resistance, impact resistance, fire resistance and insulation resistance. Summary of the invention

[0006] The problem addressed by the present invention is that current flexible photovoltaic modules have no frame, which easily leads to water vapor entering in harsh outdoor environments. Using ETFE and PET as the front panel easily leads to hail, heavy objects, etc. falling on the surface and causing damage to the battery cells; the front panel has low light transmittance, which reduces the power of the module; the front panel has poor UV resistance and weather resistance; the junction box and cables block the battery, causing a decrease in module power and hot spot phenomenon; the module production cost is high and the rate of return is low.

[0007] In order to solve the above technical problems, the present application provides a lightweight photovoltaic module, including a glass cover plate, a first POE encapsulation film layer, a battery cell layer, a second POE encapsulation film layer and a back plate stacked in sequence, the battery cell layer includes a left half-cell battery, a right half-cell battery and a junction box, the junction box includes a negative connector, a base, a cable and a positive connector connected in sequence, with the junction box as the boundary, the left half-cell battery is installed on the left side of the junction box, and the right half-cell battery is installed on the right side of the junction box; wherein, the front cover plate is 1.0-1.8mm ultra-thin coated glass.

[0008] According to an embodiment of the present application, the base includes a first base, a second base and a third base connected in series, the negative electrode connector is installed on the first base, and the positive electrode connector is connected to the third base through a cable.

[0009] According to an embodiment of the present application, the positive electrode connector, the base and the negative electrode connector are all located on the front side of the battery layer.

[0010] According to an embodiment of the present application, a black pad is provided around the battery layer.

[0011] According to an embodiment of the present application, the interval between the left half cell and the right half cell is 30-52 mm.

[0012] According to an embodiment of the present application, the left half cell and the right half cell are made of crystalline silicon cells.

[0013] According to an embodiment of the present application, the backplane adopts a CPC backplane.

[0014] Another aspect of the present application provides a method for preparing a lightweight photovoltaic module, comprising the following steps:

[0015] (1) Lay the front cover plate and the first POE packaging film on the stage in sequence, and after stringing the cells, stringing, and stacking, lead out the bus bar, bend the bus bar lead wire, and pass it through the glass hole;

[0016] (2) Conduct EL testing on the above components, lay a second POE encapsulation film layer and a backplane on qualified components, and send them to a laminator for lamination;

[0017] (3) Chamfering the laminated components and then turning the components over to install the junction box;

[0018] (4) After installing the junction box on the front, test IV and EL online;

[0019] (5) Cleaning and packing.

[0020] According to an embodiment of the present application, when a string welding machine is used to weld the battery cells in step (1), the length of the string welding wire is 18-29 mm, and the spacing between the battery cells is 30-52 mm.

[0021] According to the embodiments of the present application, the photovoltaic module is of frameless design, and the packaging box used for packaging is a multi-layer high-weight high-quality corrugated material packaging box.

[0022] The beneficial effects of the technical solution of the present invention compared with the prior art are:

[0023] 1. The present invention adopts ultra-thin glass as the front plate of lightweight photovoltaic modules, with a light transmittance of about 93.8%, which is greater than 85% of flexible photovoltaic modules, and is light in weight, thin in thickness, and strong in weather resistance; the surface coating increases light transmittance, has low dust absorption capacity, high impact strength, good heat dissipation performance, reduces module power loss and hot spot phenomenon, and solves the problem of damage to battery cells caused by hail, heavy objects, etc. falling on the surface of existing flexible modules, as well as poor UV resistance and weather resistance.

[0024] 2. The present invention adopts POE film packaging material, which can prevent the entry of water vapor into the frameless lightweight components, ensure the long-term outdoor use of the components, and improve the outdoor reliability and insulation of the photovoltaic components.

[0025] 3. The present invention adopts a frameless design, which reduces the weight of the component by 10%, has the ability of self-cleaning in rainwater, and reduces the subsequent maintenance cost;

[0026] 4. The present invention adopts a new type of junction box, in which the negative connector is integrated with the base, which is convenient for cable connection after component installation, reduces cable length and saves costs.

[0027] 5. The half-cell structure process used in the present invention reduces the current, reduces the power generation loss caused by the increase in the working temperature of the photovoltaic module, and improves the conversion efficiency of the module.

[0028] 6. When preparing lightweight photovoltaic modules, because the junction box is installed on the front, in order not to block the solar cells, the middle spacing of the conventional modules is adjusted to optimize the module size, reduce the blocking of the junction box, and ensure outdoor reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the structure of a lightweight photovoltaic module in an example of the present invention;

[0030] Figure 2 It is a schematic diagram of the structure of the battery sheet layer in the example of the present invention;

[0031] Figure 3 Schematic diagram of the structure of the junction box in the example of the present invention.

[0032] The following are the descriptions of the reference numerals:

[0033] 1. Backplane, 2. Second POE encapsulation film layer, 3. Battery cell layer, 4. First POE encapsulation film layer 4, 5. Glass cover, 6. Black pad, 7. Junction box, 71. Negative connector, 72. Positive connector, 73. First base, 74. Second base, 75. Third base. Specific implementation method:

[0034] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. The following embodiments are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0035] See also Figures 1 to 3As shown, the present invention shows a lightweight photovoltaic module, a lightweight photovoltaic module, comprising a glass cover plate 5, a first POE encapsulation film layer 4, a cell layer 3, a second POE encapsulation film layer 2 and a back plate 1 stacked in sequence. Compared with the current flexible photovoltaic module, the lightweight photovoltaic module of the present application is a new type of module with lighter weight, thinner thickness and certain flexibility. It can be directly pasted on low-load and curved roofs without the need for a bracket, while avoiding the problems of existing flexible modules such as damage to the cell due to hail, heavy objects, etc. falling on the surface, as well as poor UV resistance and weather resistance.

[0036] Specifically, according to the direction of sunlight, in the structure of the lightweight photovoltaic module, the first layer is the front cover 1, the second layer is the POE encapsulation film layer, the third layer is the battery cell layer 3, the fourth layer is the POE encapsulation film layer, and the fifth layer is the back panel 5, a total of five layers. The lightweight photovoltaic module has fewer layers, and the production process is simpler than that of photovoltaic modules with more layers.

[0037] In this embodiment, Figure 2 As shown, the cell layer 3 includes a left half cell, a right half cell and a junction box 7. The junction box 7 includes a negative connector 71, a base, a cable and a positive connector 72 connected in sequence. The left half cell is installed on the left side of the junction box 7 and the right half cell is installed on the right side of the junction box 7. The cell layer 3 uses a half cell structure process to reduce the current, reduce the power generation loss caused by the increase in the working temperature of the photovoltaic module, and improve the conversion efficiency of the module.

[0038] Furthermore, if Figure 3 As shown, the base includes a first base, a second base 74 and a third base 75 connected in series, the negative connector 71 is installed on the first base, and the positive connector 72 is connected to the third base 75 through a cable. The positive connector 72, the base and the negative connector 71 are all located on the front of the battery layer 3. Using this new type of junction box 7, the front assembly is performed, and the negative connector 71 is integrated with the base, which is convenient for cable connection after the assembly is installed.

[0039] Furthermore, the interval between the left half cell and the right half cell is preferably 30-52 mm, which optimizes the design and size of the component and avoids the junction box 7 and cables blocking the cell.

[0040] Furthermore, a black cushion strip 6 is provided around the battery cell layer 3 .

[0041] Furthermore, the left half cell and the right half cell are made of crystalline silicon cells, and the cell thickness is 100-200 μm.

[0042] In this embodiment, the front cover plate 1 is preferably 1.0-1.8 mm ultra-thin coated glass. In the actual operation example, 1.6 mm ultra-thin coated glass is used as the front plate. The coating on the surface of ultra-thin coated glass increases light transmission, has high impact strength, has certain flexibility, and the light transmittance reaches 93.8%, which greatly reduces the weight of the component, thereby solving the problem that the use of PET and ETFE in flexible components easily causes hail, heavy objects, etc. to fall on the surface and cause damage to the battery cell.

[0043] Furthermore, the back plate 5 is a CPC back plate 5 with a thickness of 0.35-0.5 mm.

[0044] The present embodiment also provides a method for preparing a lightweight photovoltaic module, comprising the following steps: (1) laying a glass cover plate 5 and a first POE packaging film 4 on a stage in sequence, and after stringing the cells, stringing, and stacking, leading out the bus bar, bending the bus bar lead wire and passing it through the glass hole; (2) performing EL testing on the above-mentioned modules, laying a second POE packaging film layer 2 and a back plate 1 on qualified components, and sending them to a laminator for lamination; (3) chamfering the laminated components, and then flipping the components to install the junction box 7; (4) after installing the junction box 7 on the front, online testing of IV and EL; (5) cleaning and packaging.

[0045] Furthermore, in step (1), when a string welding machine is used to weld the battery cells, the length of the string welding wire is 18-29 mm, and the spacing between the battery cells is 30-52 mm, preferably 51 mm. The optimized design size allows for convenient and quick cable insertion, avoiding the junction box 7 and the cable blocking the battery cells.

[0046] Furthermore, the photovoltaic modules are designed without frames, which require special packaging boxes. Therefore, the packaging boxes used in the packing step are multi-layer high-weight high-quality corrugated packaging boxes. The bursting strength is not less than 2500KPa, and the edge compression strength is not less than 15.5KN / m.

[0047] In summary, the lightweight photovoltaic module of the present invention has the following beneficial effects:

[0048] 1. The present invention adopts 1.0-1.8mm ultra-thin glass as the front plate of lightweight photovoltaic modules, with a light transmittance of about 93.8%, which is greater than 85% of flexible photovoltaic modules, and is light in weight, thin in thickness, and strong in weather resistance; the surface coating increases light transmittance, has low dust absorption capacity, high impact strength, good heat dissipation performance, reduces module power loss and hot spot phenomenon, and solves the problem of damage to the battery cells of existing flexible modules due to hail, heavy objects, etc. falling on the surface, as well as poor UV resistance and weather resistance.

[0049] 2. The present invention adopts POE film packaging material, which can prevent the entry of water vapor into the frameless lightweight components, ensure the long-term outdoor use of the components, and improve the outdoor reliability and insulation of the photovoltaic components.

[0050] 3. The present invention adopts a frameless design, which reduces the weight of the component by 10%, has the ability of self-cleaning in rainwater, and reduces the subsequent maintenance costs.

[0051] 4. The present invention adopts a new type of junction box, and the negative electrode connector is integrated with the base, which is convenient for cable connection after the assembly is installed, reduces the cable length, and can conveniently and quickly plug in the cables, avoiding the junction box 7 and the cable blocking the battery cells, while reducing the power loss and hot spot problems of the assembly.

[0052] 5. The half-cell structure process used in the present invention reduces the current, reduces the power generation loss caused by the increase in the working temperature of the photovoltaic module, and improves the conversion efficiency of the module.

[0053] 6. When preparing lightweight photovoltaic modules, because the junction box is installed on the front, in order not to block the solar cells, the middle spacing of the photovoltaic modules is adjusted to optimize the module size, reduce the blocking of the junction box, and ensure outdoor reliability.

[0054] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A lightweight photovoltaic module, characterized in that: It includes a glass cover plate, a first POE encapsulation film layer, a battery layer, a second POE encapsulation film layer and a back plate which are stacked in sequence. The battery layer includes a left half battery, a right half battery and a junction box, the junction box includes a negative electrode connector, a base, a cable and a positive electrode connector connected in sequence, with the junction box as the boundary, the left half battery is installed on the left side of the junction box, and the right half battery is installed on the right side of the junction box; Wherein, the glass cover plate is 1.0-1.8 mm ultra-thin coated glass.

2. A lightweight photovoltaic module according to claim 1, characterized in that: The base comprises a first base, a second base and a third base connected in series, the negative electrode connector is installed on the first base, and the positive electrode connector is connected to the third base through the cable.

3. A lightweight photovoltaic module according to claim 2, characterized in that: The positive electrode connector, the base and the negative electrode connector are all located on the front side of the battery sheet layer.

4. A lightweight photovoltaic module according to claim 1, characterized in that: A black pad is arranged around the battery layer.

5. A lightweight photovoltaic module according to claim 1, characterized in that: The interval between the left half battery and the right half battery is 30-52 mm.

6. A lightweight photovoltaic module according to claim 1, characterized in that: The left half cell and the right half cell are made of crystalline silicon cells.

7. A lightweight photovoltaic module according to claim 1, characterized in that: The back plate adopts a CPC back plate.

8. A method for preparing a lightweight photovoltaic module, characterized in that: The following steps are involved: (1) Lay the front cover plate and the first POE packaging film on the stage in sequence, and after stringing the cells, stringing, and stacking, lead out the bus bar, bend the bus bar lead wire, and pass it through the glass hole; (2) Conduct EL testing on the above components, lay a second POE encapsulation film layer and a backplane on qualified components, and send them to a laminator for lamination; (3) Chamfering the laminated components and then turning the components over to install the junction box; (4) After installing the junction box on the front, test IV and EL online; (5) Cleaning and packing.

9. A method for preparing a lightweight photovoltaic module according to claim 8, characterized in that: When the battery cells are welded by a string welding machine in step (1), the length of the string welding wire is 18-29 mm, and the spacing between the battery cells is 30-52 mm.

10. A method for preparing a lightweight photovoltaic module according to claim 8, characterized in that: The photovoltaic module is designed to be frameless, and the packaging box used for packaging is a multi-layer, high-weight, high-quality corrugated material packaging box.

Images