A bifacial photovoltaic cell module and a cell module arrangement, manufacturing process

Abstract

This invention discloses a bifacial photovoltaic cell module, its arrangement structure, and manufacturing process. The module includes a light-transmitting first panel, a photovoltaic cell module, and a light-transmitting second panel. The first panel, the photovoltaic cell module, and the second panel are stacked sequentially. Each photovoltaic cell module comprises multiple photovoltaic cells arranged side-by-side and connected in series to form at least a portion of the power generation circuit. In the photovoltaic cell module, at least one photovoltaic cell's positive electrode surface and at least one photovoltaic cell's negative electrode surface are located on a first light-receiving surface near the first panel. Furthermore, at least one photovoltaic cell's positive electrode surface and at least one photovoltaic cell's negative electrode surface are located on a second light-receiving surface near the second panel, enabling the module to receive light from more directions and improving the economic efficiency of electricity sales.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic equipment technology, and in particular to a bifacial photovoltaic cell module, its arrangement structure, and its manufacturing process. Background Technology

[0002] Due to the inherent photoelectric conversion characteristics of photovoltaic cells, designing both the front and back sides of a photovoltaic module to be structurally similar light-receiving surfaces would actually lead to a decrease in photoelectric conversion efficiency. Therefore, existing photovoltaic modules typically have significant structural differences between their front and back sides: the front side has higher light transmittance to facilitate the reception of more incident light; the back side has lower light transmittance to complement the front side and achieve higher photoelectric conversion efficiency.

[0003] In practical applications, workers typically position photovoltaic (PV) modules horizontally based on the actual sunlight conditions of a given area, with the side with higher light transmittance tilted at an angle of 15° to 50° towards the sunniest direction. Most PV modules in this area are fixed with the same orientation. However, the sun's position in the sky changes constantly over time, and the angle at which it shines on the PV modules also changes, leading to the following problems: During certain periods, the angle of sunlight and the tilt angle of the photovoltaic modules are well matched, allowing each module to receive sufficient sunlight and achieve high photoelectric conversion efficiency. This results in a large influx of electricity into the grid, creating peak load periods. However, the grid typically offers lower electricity prices during these peak periods, leading to poor economic returns for the power supplier.

[0004] During other times, the angle of sunlight and the fixed tilt angle of the modules are difficult to match, resulting in insufficient sunlight reaching the light-receiving surface of the photovoltaic modules and low photoelectric conversion efficiency. This period often coincides with periods of higher grid electricity prices, leading to underutilization of solar resources and economic losses. Summary of the Invention

[0005] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a bifacial photovoltaic cell module that receives sunlight from more directions, thereby improving the economic efficiency of electricity sales.

[0006] A bifacial photovoltaic cell module according to a first aspect of the present invention includes: a light-transmitting first panel; a photovoltaic cell module; and a light-transmitting second panel, wherein the first panel, the photovoltaic cell module, and the second panel are stacked sequentially, wherein the photovoltaic cell module includes multiple photovoltaic cells arranged side by side and connected in series to form at least a partial power generation branch, wherein at least one photovoltaic cell's positive electrode surface and at least one photovoltaic cell's negative electrode surface are located on a first light-receiving surface near the first panel, and at least one photovoltaic cell's positive electrode surface and at least one photovoltaic cell's negative electrode surface are located on a second light-receiving surface near the second panel.

[0007] A bifacial photovoltaic cell module according to an embodiment of the present invention has at least the following beneficial effects: The bifacial photovoltaic (PV) module of this invention, whether on the first light-receiving surface near the first panel or the second light-receiving surface near the second panel, is composed of at least one positive electrode surface and at least one negative electrode surface of a PV module. Multiple PV cells are connected in series to form at least a portion of the power generation circuit. In use, the bifacial PV module is placed vertically. During periods of low electricity prices, sunlight can illuminate the first light-receiving surface. Although the first light-receiving surface, composed of part of the positive electrode surface and part of the negative electrode surface of the PV module, has a lower power generation compared to a PV module whose entire light-receiving surface is composed of the same electrode surface, it is still compatible with the angle of solar illumination during this period, meeting power generation requirements. As the sun moves, during periods of higher electricity prices, sunlight can illuminate the second light-receiving surface. At this time, the bifacial PV module of this invention demonstrates its advantages. After receiving sunlight, the PV module converts the light into electrical energy and supplies it to the grid. The bifacial PV module of this invention can receive sunlight from more directions, improving the economic efficiency of electricity sales.

[0008] According to some embodiments of the present invention, on the first light-receiving surface or the second light-receiving surface, the positive and negative electrode surfaces of two adjacent photovoltaic cells are alternately arranged; in the power generation branch, two adjacent photovoltaic cells are electrically connected by a straight guide bar, wherein the first end of the guide bar is connected to the positive electrode surface of one of the photovoltaic cells, and the tail end of the guide bar is connected to the negative electrode surface of the other photovoltaic cell.

[0009] According to some embodiments of the present invention, the photovoltaic cell includes a cell unit, the cell unit includes multiple photovoltaic cell blocks arranged side by side along the length direction of the guide strip, the positive or negative electrode surfaces of the photovoltaic cell blocks are located on the same side, and in the same cell unit, the guide strip is connected to multiple photovoltaic cell blocks.

[0010] According to some embodiments of the present invention, there are multiple battery cells, multiple flow guides, and multiple flow guides are arranged side by side at intervals perpendicular to the length direction. Multiple battery cells are arranged along the side-by-side direction of the flow guides, and each battery cell is correspondingly connected to at least one of the flow guides.

[0011] According to some embodiments of the present invention, the bifacial photovoltaic cell module further includes a first contact element and a second contact element. The positive electrode surface of the photovoltaic cell at the first end of the photovoltaic cell module is connected to at least one first busbar, and the negative electrode surface of the photovoltaic cell at the rear end of the photovoltaic cell module is connected to at least one second busbar. The first contact element is connected to the first busbar, and the second contact element is connected to the second busbar. The first contact element and the second contact element are used to connect to power transmission equipment.

[0012] According to some embodiments of the present invention, both the positive and negative surfaces of the photovoltaic cell are textured surfaces, and the textured surfaces of the positive and negative surfaces have the same structure so that the surface reflectivity is approximately the same.

[0013] According to a second aspect of the present invention, a battery module arrangement structure includes a base and a bifacial photovoltaic cell module disclosed in any of the above embodiments, wherein the base is used to fix the bifacial photovoltaic cell module so that the bifacial photovoltaic cell module is placed vertically.

[0014] The battery assembly arrangement structure according to embodiments of the present invention has at least the following beneficial effects: The battery module arrangement structure of this invention, with bifacial photovoltaic modules placed vertically, can receive sunlight from more directions, thereby improving the economic benefits of electricity sales.

[0015] According to some embodiments of the present invention, the angle between the vertical orientation of the bifacial photovoltaic cell module and the horizontal plane in which it is placed ranges from 70° to 110°.

[0016] According to a manufacturing process of a third aspect of the present invention, for manufacturing a bifacial photovoltaic cell module disclosed in any of the above embodiments, the manufacturing process includes: texturing the positive and negative surfaces of a photovoltaic cell block using an etching solution, wherein the etching solution concentration and etching time are the same for the positive and negative surfaces of the photovoltaic cell block; depositing a crystalline silicon layer of the same thickness on both the positive and negative surfaces of the photovoltaic cell block; arranging the photovoltaic cell blocks side by side to form multiple photovoltaic cells; electrically connecting the multiple photovoltaic cells using multiple guide strips to form at least a partial photovoltaic cell module; and sequentially stacking and laminating a light-transmitting first panel, a photovoltaic cell module, and a light-transmitting second panel to form at least a partial bifacial photovoltaic cell module.

[0017] The manufacturing process according to embodiments of the present invention has at least the following beneficial effects: The bifacial photovoltaic cell module manufactured using the process of this invention can receive sunlight from more directions, thereby improving the economic benefits of electricity sales.

[0018] According to some embodiments of the present invention, before arranging photovoltaic cell blocks side by side to form multiple photovoltaic cells, a power generation electrical performance test step is included on the positive and negative electrode surfaces of each photovoltaic cell block. This power generation electrical performance test step includes: detecting the power generation current on the positive and negative electrode surfaces of the photovoltaic cell block; calculating the current deviation between the power generation current on the positive and negative electrode surfaces of the photovoltaic cell block; if the current deviation is less than a deviation threshold, the photovoltaic cell block meets the usage conditions; classifying the photovoltaic cell blocks that meet the usage conditions into different battery packs according to multiple current ranges based on the power generation current of each photovoltaic cell block; and obtaining photovoltaic cell blocks from the same battery pack for the step of arranging the photovoltaic cell blocks side by side to form multiple photovoltaic cells.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a side view of a traditional photovoltaic cell module. Figure 2 This is a top view of one embodiment of the photovoltaic cell module of the present invention; Figure 3 for Figure 2 An enlarged schematic diagram of part A of one embodiment of the photovoltaic cell module of the present invention; Figure 4 This is a cross-sectional view of one embodiment of the photovoltaic cell module of the present invention; Figure 5 This is a vertical cross-sectional view of one embodiment of the battery assembly arrangement structure of the present invention; Figure 6 This is a flowchart illustrating one embodiment of the manufacturing process of the present invention.

[0021] Figure label: <Existing Technology> Photovoltaic cell 230; flow guide bar 400.

[0022] <Invention> First panel 100; photovoltaic cell module 200; first light-receiving surface 210; second light-receiving surface 220; photovoltaic cell 230; cell unit 240; photovoltaic cell block 250; second panel 300; guide bar 400; first busbar 410; second busbar 420; base 500. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0024] In the description of this invention, it should be understood that the orientation descriptions, such as the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer", indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0025] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] like Figures 1 to 5As shown, a bifacial photovoltaic cell module according to a first aspect embodiment of the present invention includes a light-transmitting first panel 100, a photovoltaic cell module 200, and a light-transmitting second panel 300. The first panel 100, the photovoltaic cell module 200, and the second panel 300 are stacked sequentially. The photovoltaic cell module 200 includes multiple photovoltaic cells 230, which are arranged side by side and connected in series to form at least a partial power generation branch. In the photovoltaic cell module 200, at least one photovoltaic cell 230 has its positive electrode surface and at least one photovoltaic cell 230 has its negative electrode surface located on a first light-receiving surface 210 near the first panel 100. Furthermore, at least one photovoltaic cell 230 has its positive electrode surface and at least one photovoltaic cell 230 has its negative electrode surface located on a second light-receiving surface 220 near the second panel 300.

[0028] The first panel 100 and the second panel 300 can be made of tempered glass, and the same specifications and batches can be used to ensure that the light transmittance is roughly the same. PVC film can be used to bond the first panel 100 and the photovoltaic cell module 200, as well as the second panel 300 and the photovoltaic cell module 200.

[0029] The bifacial photovoltaic module of the present invention, whether it is the first light-receiving surface 210 near the first panel 100 or the second light-receiving surface 220 near the second panel 300, is composed of at least one positive electrode surface of a photovoltaic cell module 200 and at least one negative electrode surface of a photovoltaic cell module 200. Multiple photovoltaic cells 230 are connected in series to form at least a portion of the power generation branch. In use, the bifacial photovoltaic module is placed vertically. During periods of low electricity prices, sunlight can illuminate the first light-receiving surface 210. Although the first light-receiving surface 210 is composed of the positive electrode surface of a portion of the photovoltaic cell module 200 and the negative electrode surface of a portion of the photovoltaic cell module 200... The negative electrode surface of the first light-receiving surface 210 has a lower power generation compared to a photovoltaic module 200 whose entire light-receiving surface is composed of the same electrode surface. However, the first light-receiving surface 210 is compatible with the angle of solar irradiation during this period and meets the power generation requirements. As the sun moves, during periods when the electricity purchase price is higher, sunlight can shine on the second light-receiving surface 220. At this time, the bifacial photovoltaic module of the present invention shows its advantages. After receiving light, the second light-receiving surface 220 is converted into electrical energy by the photovoltaic module 200 and supplied to the grid. The bifacial photovoltaic module of the present invention can receive sunlight from more directions and improve the economic benefits of electricity sales.

[0030] In some embodiments of the present invention, such as Figure 2 , 3As shown, on the first light-receiving surface 210 or the second light-receiving surface 220, the positive and negative surfaces of two adjacent photovoltaic cells 230 are alternately arranged.

[0031] Specifically, multiple photovoltaic cells 230 can be arranged along the length of the photovoltaic module. For two adjacent photovoltaic cells 230, the positive electrode surface of one photovoltaic cell 230 is located on the first light-receiving surface 210, and the negative electrode surface of the other photovoltaic cell 230 is located on the first light-receiving surface 210. This ensures that the positive and negative electrode surfaces of the first light-receiving surface 210 or the second light-receiving surface 220 are evenly distributed on the photovoltaic module, so that sunlight can be received well at different times.

[0032] And such Figure 1 As shown, in traditional photovoltaic modules, the positive electrode surfaces of multiple photovoltaic cells 230 are all on the same side, while the negative electrode surfaces are on the opposite side. These multiple photovoltaic cells 230 need to be connected in series. Therefore, the current guide strip 400 connecting adjacent photovoltaic cells 230 previously needed to be set in a "Z" shape. The first end of the current guide strip 400 is connected to the positive electrode of one of the photovoltaic cells 230, and the last end of the current guide strip 400 is connected to the negative electrode of another photovoltaic cell 230. It can be seen that the "Z" shaped current guide strip 400 needs to be bent during the processing, which is prone to material loss during processing and may break during use, increasing production and maintenance costs.

[0033] In the photovoltaic cell module of the present invention, since the positive and negative electrode surfaces of two adjacent photovoltaic cells 230 are alternately arranged, such as Figure 4 As shown, multiple photovoltaic cells 230 are connected in series. In the power generation branch, two adjacent photovoltaic cells 230 are electrically connected by a straight guide strip 400. The first end of the guide strip 400 is connected to the positive electrode surface of one of the photovoltaic cells 230, and the last end of the guide strip 400 is connected to the negative electrode surface of the other photovoltaic cell 230. The guide strip 400 does not need to be bent, making production and processing simpler and less prone to damage in the later stages of use. Production and maintenance costs are significantly reduced. In addition, the spacing between two adjacent photovoltaic cells 230 can be narrowed, or even approached zero spacing, resulting in a compact structure, beautiful appearance, and improved conversion efficiency.

[0034] In some embodiments of the present invention, such as Figure 2 , 3As shown, the photovoltaic cell 230 includes a cell unit 240, and the cell unit 240 includes multiple photovoltaic cell blocks 250 arranged side by side along the length direction of the guide bar 400. The positive or negative electrode surfaces of the photovoltaic cell blocks 250 are located on the same side. In the same cell unit 240, the guide bar 400 is connected to multiple photovoltaic cell blocks 250.

[0035] In the same photovoltaic cell 230, the positive or negative electrode surfaces of each photovoltaic cell block 250 are located on the same side. The end of the guide bar 400 usually extends on the first light-receiving surface 210 and the second light-receiving surface 220. Multiple photovoltaic cell blocks 250 are arranged side by side along the length of the guide bar 400. Thus, multiple photovoltaic cell blocks 250 can be welded to different positions of the guide bar 400 through the positive or negative electrode surfaces to output electrical energy.

[0036] In some embodiments of the present invention, such as Figure 2 , 3 As shown, there are multiple battery cells 240 and multiple flow guides 400 arranged in a row at intervals perpendicular to the length direction. The multiple battery cells 240 are arranged along the parallel direction of the flow guides 400, and each battery cell 240 is connected to at least one flow guide 400.

[0037] Two adjacent battery cells 240 can be connected by the same guide bar 400. In traditional photovoltaic cell modules, due to the difficulty in processing the "Z"-shaped guide bar 400, the photovoltaic cell blocks 250 in the same battery cell 240 need to be connected by fine grid bars first, and then the fine grid bars of each battery cell 240 converge into the guide bar 400. The structure is complex, the internal resistance is large, and the power loss is large. However, in the photovoltaic cell module of the present invention, the guide bar 400 can be in the form of an "I" shape, and multiple guide bars 400 can be designed side by side with intervals. The structure is simple, the internal resistance is reduced, and the transmission efficiency is high.

[0038] In some embodiments of the present invention, the bifacial photovoltaic cell module further includes a first contact element and a second contact element. The positive electrode surface of the photovoltaic cell 230 at the first end of the photovoltaic cell module 200 is connected to at least one first busbar 410, and the negative electrode surface of the photovoltaic cell 230 at the rear end of the photovoltaic cell module 200 is connected to at least one second busbar 420. The first contact element is connected to the first busbar 410, and the second contact element is connected to the second busbar 420. The first contact element and the second contact element are used to connect to power transmission equipment.

[0039] Both the first and second electrical connectors can use conventional electrical terminals. The electrical terminals can be connected to power transmission equipment via power transmission lines. Specifically, the power transmission equipment can include power transmission boxes, distribution boxes, etc., that connect to the power grid or electrical appliances. Both the first busbar 410 and the second busbar 420 can be made of the same material as the guide bar 400. However, the first busbar 410 and the second busbar 420 are only connected to the photovoltaic cells 230 at the end of the photovoltaic cell module 200.

[0040] In some embodiments of the present invention, the positive and negative surfaces of the photovoltaic cell 230 are both textured surfaces, and the textured surfaces of the positive and negative surfaces have the same structure so that the surface reflectivity is approximately the same.

[0041] Traditional photovoltaic cells 230 have one side textured (positive or negative) and the other polished. The textured side primarily receives sunlight to ensure photoelectric conversion efficiency. In contrast, the photovoltaic module of this invention has textured surfaces on both the positive and negative sides of the photovoltaic cell 230. Both sides can receive sunlight and convert it into electrical energy. Furthermore, the textured surfaces of the positive and negative sides have identical structures, resulting in approximately the same surface reflectivity. This ensures that the power generation current among the series-connected photovoltaic cells 230 is roughly the same, leading to a relatively stable lifespan for the photovoltaic cell 230. Although the textured surface and identical structure of the photovoltaic cell 230 slightly sacrifices power conversion efficiency, the decrease is minimal. It also enables power generation from multiple sunlight directions and at different times of day. Providing power during periods of higher electricity prices significantly increases economic efficiency, completely compensating for the reduced power conversion efficiency.

[0042] According to a second aspect embodiment of the present invention, the battery assembly arrangement structure is as follows: Figure 5 As shown, the device includes a base 500 and a bifacial photovoltaic cell module disclosed in any of the above embodiments. The base 500 is used to fix the bifacial photovoltaic cell module so that the bifacial photovoltaic cell module is placed vertically.

[0043] The battery module arrangement structure of this invention, with bifacial photovoltaic modules placed vertically, can receive sunlight from more directions, thereby improving the economic benefits of electricity sales.

[0044] The base 500 can be provided with mounting holes, and mounting nails can be inserted through the mounting holes and the wall or ground to fix the base 500 to the wall or ground. The base 500 can be clamped to the two side walls at the bottom of the bifacial photovoltaic module, so that the bifacial photovoltaic module can be placed vertically. Specifically, the first light-receiving surface 210 of the bifacial photovoltaic module can face east, while the second light-receiving surface 220 of the bifacial photovoltaic module can face west, which can make greater use of the light at different times of the day. Of course, the staff can also change the orientation of the bifacial photovoltaic module according to the actual situation.

[0045] In some embodiments of the present invention, the angle between the vertical orientation of the bifacial photovoltaic cell module and the horizontal plane is in the range of 70-110°. The operator can adjust the tilt angle between the vertical orientation of the bifacial photovoltaic cell module and the horizontal plane according to the actual situation. For example, the tilt angle of the first light-receiving surface 210 relative to the horizontal plane is 105°, and the tilt angle of the second light-receiving surface 220 relative to the horizontal plane is 75°. The first light-receiving surface 210 can face the direction with stronger all-day illumination, while the second light-receiving surface 220 can face the direction with relatively weaker all-day illumination, but can still receive light.

[0046] According to the manufacturing process of the third aspect of the present invention, a bifacial photovoltaic cell module disclosed in any of the above embodiments is used to manufacture the module. Figure 6 As shown, the manufacturing process includes: S610. Texturing treatment is performed on the positive and negative surfaces of the photovoltaic cell block 250 using an etching solution, wherein the concentration of the etching solution and the etching time are the same for the positive and negative surfaces of the photovoltaic cell block 250. S620, a crystalline silicon layer of the same thickness is deposited on both the positive and negative surfaces of the photovoltaic cell block 250; S630, photovoltaic cell blocks 250 are arranged side by side to form multiple photovoltaic cells 230; S640: Multiple photovoltaic cells 230 are electrically connected by multiple guide strips 400 to form at least a portion of a photovoltaic cell module 200. S650, The light-transmitting first panel 100, the photovoltaic cell module 200 and the light-transmitting second panel 300 are sequentially stacked and pressed together to form at least a partial bifacial photovoltaic cell module.

[0047] The bifacial photovoltaic cell module manufactured using the process of this invention can receive sunlight from more directions, thereby improving the economic benefits of electricity sales.

[0048] In some embodiments of the present invention, the bifacial photovoltaic cell module can be a heterojunction photovoltaic cell module (HJT). A KOH solution can be used to anisotropically etch the silicon wafer to form a pyramidal textured surface to enhance light absorption. The textured surface height is 3–5 μm, and the surface reflectivity is less than 10%. Then, an intrinsic amorphous silicon layer and a doped microcrystalline silicon layer with a total thickness of 20–30 nm are deposited on both the front and back sides of the silicon wafer. Furthermore, a 90–100 nm TCO layer with a sheet resistance of 30–50 Ω / nm and a refractive index of 1.9–2.1 is deposited on both sides of the silicon wafer where the crystalline silicon layer is deposited. Silver or silver-clad copper metal grid lines are printed on both sides of the silicon wafer.

[0049] In some embodiments of the present invention, the bifacial photovoltaic cell module can be a tunnel oxide passivated contact cell. Anisotropic etching of the silicon wafer using KOH solution can be used to form a pyramidal textured surface to enhance light absorption. The texture height is 3–5 μm, and the surface reflectivity is less than 10%. Boron is diffused at high temperature on the front side of the N-type silicon wafer to construct a PN junction. The P-layer BSG wrapped around the back side is etched using an HF / HNO3 mixture, preserving the front side structure. A 1.5–1.7 nm SiO2 layer is grown on the back side, followed by the deposition of 100–120 nm polycrystalline silicon. The non-contact area is thinned to 20–30 nm using laser. Phosphorus is diffused on the back side to form an electron collecting layer, with the front-side BSG acting as a mask to prevent contamination. Residual PSG / BPSG is removed to ensure surface cleanliness. AlOx (3–5 nm) and SiNx (70–80 nm, refractive index 2.0–2.2) are deposited sequentially on the front side. A SiNx thin film is deposited on the polycrystalline silicon surface on the back side to protect and optimize optical performance, with the film thickness controlled at 70–80 nm. nm, refractive index 2.0–2.2; silver paste is printed on both sides of the formed photovoltaic cell block 250 and sintered at high temperature to form ohmic contacts for welding with the guide bar 400.

[0050] In some embodiments of the present invention, before arranging the photovoltaic cell blocks 250 side by side to form multiple photovoltaic cells 230, a power generation electrical performance test step is included on the positive and negative electrode surfaces of each photovoltaic cell block 250. The power generation electrical performance test step includes: The power generation current of the positive and negative electrodes of the photovoltaic cell block 250 is measured. Calculate the current deviation between the power generation current of the positive electrode surface and the power generation current of the negative electrode surface of the photovoltaic cell block 250. If the current deviation is less than the deviation threshold, the photovoltaic cell block 250 meets the usage conditions. Based on the power generation current of each photovoltaic cell 250, the photovoltaic cell 250 that meet the usage conditions are classified into various battery packs according to multiple current ranges. The photovoltaic cell blocks 250 are obtained from the same battery pack and arranged side by side to form multiple photovoltaic cells 230.

[0051] Since the power generation current of the interconnected photovoltaic cells 230 needs to be approximately the same, it is necessary to test parameters such as power generation current and power generation efficiency on the positive and negative surfaces of the photovoltaic cell block 250 under basically the same light intensity. Taking power generation current as an example, under basically the same light intensity, the current deviation between the power generation current of the positive and negative surfaces of the photovoltaic cell block 250 needs to be less than a deviation threshold. The deviation threshold can be set by the staff according to the different specifications of the photovoltaic cells 230. If this condition is met, it is also necessary to classify each photovoltaic cell block 250 according to multiple current ranges. For example, classify them in 100 mA intervals, with the first battery group being 800-900 mA, the second battery group being 900-1000 mA, etc. Then, photovoltaic cell blocks 250 are taken from the same battery group and arranged side by side to form a power generation branch. In the power generation branch, the power generation current of each photovoltaic cell block 250 is approximately the same, which improves the service life.

[0052] In addition, during the manufacturing process, the photovoltaic cells 250 in the same battery pack can be further classified according to their surface color, so that the color of the same light-receiving surface of the photovoltaic cell module is roughly the same and there will be no large color difference.

[0053] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0054] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A bifacial photovoltaic cell module, characterized in that, include: The first panel that allows light to pass through; Photovoltaic cell modules; The second panel is transparent to light. The first panel, the photovoltaic cell module, and the second panel are stacked in sequence. The photovoltaic cell module includes multiple photovoltaic cells. The multiple photovoltaic cells are arranged side by side and connected in series to form at least a partial power generation branch. In the photovoltaic cell module, the positive electrode surface of at least one photovoltaic cell and the negative electrode surface of at least one photovoltaic cell are located on a first light-receiving surface near the first panel. In addition, the positive electrode surface of at least one photovoltaic cell and the negative electrode surface of at least one photovoltaic cell are located on a second light-receiving surface near the second panel.

2. A bifacial photovoltaic cell module according to claim 1, characterized in that: On the first light-receiving surface or the second light-receiving surface, the positive and negative electrode surfaces of two adjacent photovoltaic cells are alternately arranged; in the power generation branch, two adjacent photovoltaic cells are electrically connected by a straight guide bar, wherein the first end of the guide bar is connected to the positive electrode surface of one of the photovoltaic cells, and the tail end of the guide bar is connected to the negative electrode surface of the other photovoltaic cell.

3. A bifacial photovoltaic cell module according to claim 2, characterized in that: The photovoltaic cell includes a cell unit, and the cell unit includes multiple photovoltaic cell blocks arranged side by side along the length of the guide strip. The positive or negative electrode surfaces of the photovoltaic cell blocks are located on the same side. In the same cell unit, the guide strip is connected to multiple photovoltaic cell blocks.

4. A bifacial photovoltaic cell module according to claim 3, characterized in that: There are multiple battery cells and multiple flow guides arranged in parallel at intervals perpendicular to the length direction. The multiple battery cells are arranged along the parallel direction of the flow guides, and each battery cell is connected to at least one of the flow guides.

5. A bifacial photovoltaic cell module according to claim 4, characterized in that, It also includes a first power connector and a second power connector. The positive electrode surface of the photovoltaic cell at the first end of the photovoltaic cell module is connected to at least one first busbar, and the negative electrode surface of the photovoltaic cell at the rear end of the photovoltaic cell module is connected to at least one second busbar. The first power connector is connected to the first busbar, and the second power connector is connected to the second busbar. The first power connector and the second power connector are used to connect to power transmission equipment.

6. A bifacial photovoltaic cell module according to claim 2, characterized in that: Both the positive and negative surfaces of the photovoltaic cell are textured surfaces, and the textured surfaces of the positive and negative surfaces have the same structure so that the surface reflectivity is approximately the same.

7. A battery assembly arrangement structure, characterized in that, The device includes a base and a bifacial photovoltaic cell module as described in any one of claims 1 to 6, wherein the base is used to fix the bifacial photovoltaic cell module so that the bifacial photovoltaic cell module is placed vertically.

8. The battery assembly arrangement structure according to claim 7, characterized in that: The angle between the vertical orientation of the bifacial photovoltaic cell module and the horizontal plane is in the range of 70-110°.

9. A manufacturing process for producing a bifacial photovoltaic module as described in any one of claims 1 to 6, characterized in that, The manufacturing process includes: The positive and negative surfaces of the photovoltaic cell block were texturized using an etching solution, with the same etching solution concentration and etching time for both the positive and negative surfaces. A crystalline silicon layer of the same thickness is deposited on both the positive and negative surfaces of the photovoltaic cell block; Photovoltaic cells are arranged side by side to form multiple photovoltaic cells; Multiple photovoltaic cells are electrically connected using multiple guide strips to form at least a partial photovoltaic cell module; The light-transmitting first panel, the photovoltaic cell module, and the light-transmitting second panel are sequentially stacked and pressed together to form at least a partial bifacial photovoltaic cell module.

10. The manufacturing process according to claim 9, characterized in that: Before arranging the photovoltaic cell blocks side by side to form multiple photovoltaic cells, a power generation and electrical performance test is performed on the positive and negative electrode surfaces of each photovoltaic cell block. This power generation and electrical performance test includes: Detect the power generation current on the positive and negative surfaces of the photovoltaic cell block; Calculate the current deviation between the power generation current on the positive electrode and the power generation current on the negative electrode of the photovoltaic cell block. If the current deviation is less than the deviation threshold, the photovoltaic cell block meets the usage conditions. Based on the power generation current of each photovoltaic cell, the photovoltaic cells that meet the usage conditions are classified into various battery packs according to multiple current ranges. The photovoltaic cell blocks are obtained from the same battery pack and arranged side by side to form multiple photovoltaic cells.

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