Method for retarding visual color difference and improving light utilization rate of photovoltaic cell module

Abstract

The invention provides a method for relieving visual chromatic aberration and improving light utilization rate of a photovoltaic cell. The photovoltaic assembly (1) comprises packaging glass (2) located at the top, and the lower portion of the photovoltaic assembly (1) is connected with a photovoltaic cell (3) through an interface (4). Supporting fasteners (5) are arranged on the two sides of each photovoltaic cell (3), the lower ends of the photovoltaic cells (3) are inserted into the base body (7) through interfaces (6), and photovoltaic cells (8) are arranged on the upper surface of the base body (7). And the plurality of photovoltaic cells (3) are arranged in a crossed manner and form a light-gathering cavity (8) together with the packaging glass (2) and the upper surface of the base. The method for slowing down the visual chromatic aberration is based on optical and topology principles, and the visual chromatic aberration is slowed down by weakening and mixing chromatic aberration light, reducing the visual brightness of the chromatic aberration light and reducing the visual resolution of the light color of the chromatic aberration light. By weakening and mixing chromatic aberration light, the visual chromatic aberration is slowed down; the three-dimensional design of the inner wall of the light gathering cavity (9) is utilized to obtain a three-dimensional photovoltaic module structure, and the light utilization rate is improved.

Description

Technical Field

[0001] The invention relates to a method for constructing a photovoltaic assembly, in particular to a method for reducing visual color difference and improving light utilization rate of a photovoltaic cell assembly. Background Art

[0002] With the continuous progress of photovoltaic power generation technology, the optimization of energy structure and the acceleration of green energy transformation have injected new vitality into the sustainable development of society. At present, this technology has become one of the frontiers of scientific and technological development. Thanks to the breakthrough in photovoltaic-grade silicon manufacturing technology, the reduction of silicon raw material costs, and the significant improvement in photovoltaic cell efficiency, silicon-based TOPCon and BC battery technologies have achieved battery efficiencies close to or even exceeding the theoretical power generation efficiency of traditional silicon-based batteries, significantly reducing the cost of photovoltaic power generation. At present, the price of photovoltaic power generation is even lower than that of thermal power generation, which has led to the transformation of photovoltaic power generation technology from manufacturing technology to application technology. Silicon-based photovoltaic cells have developed rapidly due to their high power generation efficiency and green and environmentally friendly main material silicon. They have become the backbone of the "rooftop plan" and centralized photovoltaic power stations, played an important role in the modernization of rural areas and towns, and are gradually expanding to the field of urban photovoltaics. However, in the process of photovoltaic power generation developing into cities, new challenges have been encountered. There are two main problems: First, silicon-based photovoltaic cells are prone to color difference during long-term use, including color difference between panels and color difference within panels. Although color difference has little effect on power generation efficiency, it affects visual perception and limits its application in urban wall curtain walls; second, the preciousness of urban land resources puts higher requirements on the power generation efficiency per unit area of ​​photovoltaic cells. In response to these challenges, cadmium telluride photovoltaic cells, perovskite photovoltaic cells and gallium arsenide photovoltaic cells have been developed. Among them, cadmium telluride photovoltaic cells have a lower probability of color difference and have been used in photovoltaic curtain walls and semi-transparent photovoltaic roofs; gallium arsenide photovoltaic cells have been used in satellites, space stations and radars due to their extremely high power generation efficiency; perovskite photovoltaic cells have become a hot spot in current photovoltaic power generation research due to their potential high power generation efficiency, although they have not yet been widely used. Although these batteries have their own characteristics, their common defect is that they contain toxic ingredients and do not meet environmental protection requirements, making it difficult for them to become mainstream products for urban photovoltaics. Therefore, there is an urgent need for a photovoltaic cell assembly that is environmentally friendly, has no visual color difference, and has a high power generation efficiency per unit building area to meet the needs of application scenarios such as urban walls, high-speed railways, highways, and bridges. Based on the principles of optics and topology, the present invention proposes a method for photovoltaic cells to reduce visual color difference and improve light utilization. The method innovatively designs the topological structure of the photovoltaic cell assembly without changing the internal structure of the photovoltaic cell, achieves the effects of environmental protection, no visual color difference, and high light utilization, improves the power generation efficiency of the assembly per unit illumination area, and meets the use requirements of photovoltaic assemblies within the visual area. Summary of the invention

[0003] In order to achieve the purpose of the present invention, the present invention proposes a method for reducing visual chromatic aberration of photovoltaic cells and improving light utilization, characterized in that the photovoltaic module (1) includes an encapsulation glass (2) located at the top, which is connected to the photovoltaic cell (3) through an interface (4) below, and each photovoltaic cell (3) is provided with supporting fasteners (5) on both sides, and the lower end of the photovoltaic cell (3) is inserted into the substrate (7) through the interface (6), and the upper surface of the substrate (7) is provided with a photovoltaic cell (8). A plurality of photovoltaic cells (3) are arranged crosswise, and together with the encapsulation glass (2) and the cells (8) on the upper surface of the base, form a focusing cavity (9). The method for reducing visual chromatic aberration is based on optical and topological principles, and reduces its visual brightness and the visual resolution of the light color by weakening and mixing chromatic aberration light, thereby reducing its visual chromatic aberration. Specifically, it includes: 1) Reduce chromatic aberration light: On the inner wall of the light trap, there are usually two parts of photovoltaic cells, one of which produces chromatic aberration and the other does not. Light irradiated on the surface of these cells will be reflected, and the reflected light with color is chromatic aberration light; while the light reflected by the cells without chromatic aberration is non-chromatic aberration light. The closed space of the focusing cavity (9) is used to form a light trap. Through the "light trapping" function of the light trap, most of the sunlight entering from the encapsulating glass (2) is trapped in the light trap, significantly reducing the intensity of the reflected light that passes through the encapsulating glass (2) and returns to the outside of the cavity, reducing the visual clarity of the situation inside the cavity when observing from outside the cavity, thereby reducing visual chromatic aberration; 2) Mixed chromatic aberration light: According to the propagation theory of light waves, lights of different colors will mix with each other due to diffusion, scattering and interference when they propagate together. When the incident sunlight propagates in the closed space of the focusing cavity (9), the reflected light that is not absorbed by the wall of the focusing cavity will be reflected multiple times on the inner surface of the cavity. This process not only prolongs the propagation path of the light, but also increases the number of interface reflections, thereby significantly improving the degree of mixing between the reflected light with and without chromatic aberration. The chromatic aberration lights can also be effectively mixed, so that the light can be fully mixed. Therefore, even if a small amount of mixed light escapes from the focusing cavity (9), since they have been mixed, the color difference is almost imperceptible visually, thereby achieving the effect of reducing visual chromatic aberration. Even if all the photovoltaic cells on the inner wall of the focusing cavity (9) have chromatic aberration and the reflected light is all chromatic aberration light, effective light mixing can be achieved in this way.

[0004] The method for improving the utilization rate of light energy is to obtain a three-dimensional photovoltaic cell structure by utilizing the three-dimensional design of the inner wall of the focusing cavity (9), and its structural shape can be changed according to the actual use occasion. Compared with the planar structure of the traditional flat-plate photovoltaic cell, the three-dimensional structure has a larger inner surface area. This design significantly increases the area of ​​the photovoltaic cell irradiated by the incident sunlight per unit area, thereby improving the efficiency of the cell in utilizing sunlight. The device involved in the method for reducing visual chromatic aberration and improving light utilization is a focusing cavity (9), whose three-dimensional topological structure realizes the "light trapping" effect of reducing visual chromatic aberration and increases the light receiving area. These improvements do not affect the internal structure of the photovoltaic cell (3) on the wall of the focusing cavity (9) and the photovoltaic cell (8) on the substrate surface. The beneficial effects brought about by these improvements include: Improve the "light trapping" performance of photovoltaic modules. The present invention forms a light trap by using a focusing cavity with a three-dimensional inner surface, so that the number of reflections of the incident sunlight on the inner surface of the cavity increases, thereby increasing the incident frequency of light on the inner surface of the cavity, and enhancing the penetration of light into the photovoltaic cells on the inner wall of the cavity, thereby achieving the "light trapping" effect and reducing the intensity of light escaping from the focusing cavity light trap. Compared with the current photovoltaic cell technology that uses suede surfaces to achieve the "light trapping" effect, the shape of the focusing cavity of the present invention is controllable, and the focusing effect can be optimized by adjusting the shape and structure of the focusing cavity. In contrast, the "light trapping" structure of the suede surface is difficult to accurately control, and the parameters such as the shape, size, density and depth of the porous silicon inside it cannot be accurately set. There is a lack of quantitative description methods, and it is difficult to accurately quantify the suede effect and the "light trapping" effect. The shape, size, density, depth, aspect ratio and other parameters of the focusing cavity provided by the present invention can be quantified, and a quantitative relationship can be established with the "light trapping" effect of the component, matching the light resources in the application scenario, and improving the utilization efficiency of the unit component area receiving sunlight. By optimizing the packaging glass structure, the "light trapping" performance can be further enhanced. This includes constructing a polymer of optical components, such as creating a concave mirror array with a focusing function, or a convex mirror array with enhanced reflection capability, and forming a grating with stronger reflection characteristics. These improvements can improve the ability of the packaging glass to reflect the light escaping the light trap back to the light trap, thereby enhancing the "light trapping" effect of the light trap. In addition, combining the shape of the light trap with the characteristics of the light resources in the application scenario can increase the light intensity entering the light trap, while reducing the light intensity escaping from the light trap, thereby effectively improving the light trapping effect. Improve the solar light utilization efficiency per unit area of ​​components. This effect mainly comes from two aspects: In the design of the three-dimensional focusing cavity, the surface area of ​​the battery significantly exceeds the surface area of ​​the battery of the traditional flat photovoltaic module. Figure 1Taking the rectangular light-collecting cavity structure shown in the figure as an example, five of its six inner surfaces are equipped with photovoltaic cells. Assuming that the area of ​​each surface is equal and the influence of the wall thickness of the light-collecting cavity is not considered, the surface area of ​​the photovoltaic cell will increase five times. This expansion of the surface area increases the light-receiving area of ​​the cell, allowing more sunlight to penetrate and be absorbed by the cell. In addition, the three-dimensional cell structure also means a larger power generation volume. Since the surface layer of the cell has been doped, the three-dimensional surface causes the internal doping layer to also present a three-dimensional distribution, and its volume is several times that of the traditional planar doping layer. The increase in doping volume helps to improve the power generation capacity of the cell, thereby improving the power generation efficiency per unit area of ​​the component. Compared with the BC cell technology of Longi Green Energy, this three-dimensional design method avoids complex surface treatment by increasing the light-receiving area and doping volume of the cell, and solves the problem that the surface of the BC cell is too complex to weld the electrode. In this design, the electrode can be conveniently welded on the front side of the cell instead of the back side, simplifying the process flow and facilitating large-scale production. By improving the "light trapping" performance of the focusing cavity, the utilization efficiency of sunlight in photovoltaic power generation can be significantly enhanced, the intensity of light reflected back to the outside of the battery assembly can be reduced, and the utilization rate of sunlight can be improved. This improved "light trapping" performance not only surpasses the light trapping effect of the traditional battery velvet, but is also independent of the refractive index and structure of the battery surface. Therefore, the battery surface using this method does not need to be velvet-treated, which simplifies the manufacturing process of the battery, reduces the production cost, and avoids the phenomenon that the surface structure of the battery is destroyed by the velvet-treated battery surface of the conventional battery. Since the reflected light on the surface of the battery can enter the battery again for power generation after multiple re-reflections on the three-dimensional cavity surface, the "light trapping" of this system can effectively reduce the light loss caused by reflection. When welding electrodes, the light loss caused by the front electrode will be greatly reduced due to the "light trapping" effect. This allows the system to adopt a front electrode battery structure without welding the electrode on the back of the battery, simplifying the process, avoiding the electrical loss caused by the back electrode, and reducing the light loss disadvantage of the front electrode, which helps to improve the power generation efficiency of the battery. In addition, this effect of significantly reducing the reflected light loss on the cell surface can even make it possible to consider omitting the anti-reflection layer on the cell surface. Normally, the surface of a silicon-based cell is covered with a silicon nitride anti-reflection layer to reduce reflectivity, but this silicon nitride anti-reflection layer will have light absorption loss, and plating this silicon nitride film will increase the cell manufacturing process. In the system of the present invention, the cell can consider not using an anti-reflection layer, and use the optimized "light trapping" ability to effectively reduce the light loss caused by reflection, reduce the light loss of the system, improve the utilization rate of sunlight, and simplify the cell manufacturing process to reduce costs. Alleviate visual chromatic aberration. Although the present invention cannot completely avoid the generation of battery chromatic aberration, by applying optical and topological theories, the topological structure of the battery assembly is innovatively designed, and the excellent "light trapping" ability of the focusing cavity is used to effectively weaken the intensity of the chromatic aberration light reflected by the chromatic aberration battery, and mix it with other light, significantly reducing the resolution of this part of the chromatic aberration light, thereby achieving the effect of reducing the visual chromatic aberration of the photovoltaic assembly. This effect of alleviating visual chromatic aberration is also related to the fact that the surface of the photovoltaic cell of this system does not need to be suede-treated. In order to achieve the "light trapping" effect on the surface, traditional silicon-based photovoltaic cells are usually suede-treated to reduce the surface light reflection loss. However, suede treatment will destroy the integrity of the surface structure, increase the surface resistance, and reduce the generation and transmission efficiency of the surface photocurrent. What is more serious is that during the long-term use of the battery, the suede surface may become unstable due to reasons such as material aging, resulting in the collapse of some pores and micro-protrusions, changing the angle and direction of reflected sunlight, causing the color of this part of the battery surface to change, and becoming an important factor in the generation of chromatic aberration. The system of the present invention adopts a more advanced three-dimensional topological structure to achieve light trapping, and there is no need to perform velvet treatment on the surface of the battery, so the probability of battery color difference can be reduced. In addition, this effect of alleviating visual color difference is produced by the combined action of the topological structure and optical behavior, and has nothing to do with the structure of the battery itself. Therefore, it is suitable for silicon-based batteries that are prone to color difference. Compared with the cadmium telluride batteries that are currently widely used to avoid color difference, when the system of the present invention adopts silicon-based batteries, the manufacturing process is more mature and the main materials are environmentally friendly. The power generation efficiency of the current mainstream silicon-based batteries is comparable to that of cadmium telluride batteries, and the photovoltaic power generation efficiency per unit area of ​​the photovoltaic modules of this system is higher. Optimized mechanical structure design. The fasteners on both sides of the cell can be made of aluminum with excellent mechanical strength and conductivity. The aluminum strips not only have high mechanical strength, but also can effectively support the encapsulation glass while fixing the cell. In addition, the substrate at the bottom of the battery module can also be made of aluminum plate to provide solid support and enhance the compressive resistance of the battery module. The excellent conductivity of aluminum strips makes it the electrode material of choice for photovoltaic cell modules, which helps to reduce power loss during current transmission. The part of the aluminum strip exposed to the air will form a dense alumina ceramic film, which has a passivation effect similar to the alumina film on the back of the PERC cell, which is heat-insulating and prevents leakage, thereby reducing power loss, reducing the risk of static electricity accumulation, and improving the safety of battery modules. In summary, the innovative topological structure design of the photovoltaic module proposed in the present invention can effectively alleviate the visual color difference problem of the photovoltaic module and significantly improve the utilization efficiency of sunlight. This not only improves the power generation efficiency per unit area of ​​the photovoltaic module, but also simplifies the manufacturing process of the battery. Although the number of photovoltaic cells used in the module has increased, the cost increase caused by the increase in the number of cells can be effectively offset by simplifying the manufacturing process and improving the photovoltaic power generation efficiency. In addition, the design can also bring the dual effects of alleviating visual color difference and increasing photovoltaic power generation to the module, which is particularly beneficial for urban photovoltaic applications. Urban photovoltaic power generation is not particularly sensitive to the price of photovoltaic modules, but has high requirements for the neatness of the appearance of photovoltaic cells and the total power generation of photovoltaic modules. The photovoltaic module of the present invention can just meet these needs.

[0005] The photovoltaic module design of the present invention achieves higher photoelectric conversion efficiency by optimizing the battery arrangement and circuit connection method. Its innovation lies in that it not only takes into account the performance improvement of the module, but also takes into account the aesthetics and environmental adaptability. In urban environments, photovoltaic modules often need to be integrated with architectural aesthetics, and the module design of the present invention can better integrate into the urban landscape while maintaining efficient power output. In addition, the design also takes into account long-term reliability and maintenance convenience, ensuring the long-term stable operation of the photovoltaic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Attached Figure 1 This is a structural diagram of the focusing cavity involved in the present invention, which shows a photovoltaic module composed of a focusing cavity arranged in a row of rectangular parallelepipeds and a substrate and packaging glass, wherein 1 is a photovoltaic module, 2 is the packaging glass located at the top, 3 is a photovoltaic cell on the side of the focusing cavity, 4 is an interface between the packaging glass and the side photovoltaic cell, 5 is a supporting fastener of the side photovoltaic cell, 6 is an interface between the side photovoltaic cell and the substrate, 7 is the substrate, 8 is a photovoltaic cell on the substrate, which is also the bottom photovoltaic cell of the focusing cavity, and 9 is the focusing cavity. DETAILED DESCRIPTION

[0007] The specific embodiments of the present invention can be illustrated by the following examples.

[0008] Embodiment: A high-efficiency single-crystal silicon photovoltaic module with no color difference in appearance On an aluminum plate measuring 2.5×2×0.01 meters, 10 horizontal and 10 vertical cross-arranged grooves are precisely engraved. In these grooves, Tiger Neo 3.0 Topcon photovoltaic cells produced by Jinko are installed. Three identical photovoltaic cells are arranged side by side in a vertical column and fixed on both sides with aluminum strips to form a cell. Then, these cells are embedded in the grooves on the substrate, and the aluminum strip fasteners on both sides are welded to the substrate. A layer of encapsulation glass is covered on the top of the cell group, and the cell is embedded in the pre-prepared grooves on the encapsulation glass. Finally, the upper end of the aluminum strip fastener on the side is welded to the encapsulation glass. Through this series of steps, a photovoltaic module with a width-to-depth ratio of 1:3 is constructed, in which the focusing cavity is in the shape of a rectangular parallelepiped. The depth of the module is three times the width. This design not only enhances the "light trapping" effect, but also ensures high efficiency of photovoltaic power generation per unit area.

[0009] In order to further improve the performance of photovoltaic modules, advanced packaging technology is used to ensure the sealing and durability of the modules. The surface of the packaging glass is specially treated to reduce reflection and increase light absorption.

[0010] This photovoltaic module is not only innovative in technology but also cost-effective. It provides an efficient and economical solution for large-scale solar power plants, helping to promote the popularization of renewable energy and environmental protection.

[0011] The above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A method for reducing visual color difference and improving light utilization of a photovoltaic cell assembly, characterized in that The photovoltaic module (1) comprises a packaging glass (2) located at the top of the photovoltaic module and connected to the photovoltaic cell (3) via an interface (4) below, each photovoltaic cell (3) has supporting fasteners (5) on both sides, the lower end of the photovoltaic cell (3) is inserted into a base (7) via an interface (6), and the upper surface of the base (7) has a photovoltaic cell (8); a plurality of cross-arranged photovoltaic cells (3) and the photovoltaic cell packaging glass (2) and the photovoltaic cells (8) on the upper surface of the base form a focusing cavity (9).

2. A method for reducing visual color difference and improving light utilization of a photovoltaic cell assembly according to claim 1, characterized in that The method for reducing visual chromatic aberration is based on the principles of optics and topology. By weakening and mixing chromatic aberration light, the visual brightness is reduced, the visual resolution of the light color is reduced, and the visual chromatic aberration is reduced. The specific method includes: 1) Reduce chromatic aberration: On the inner wall of the light trap, there are two parts of photovoltaic cells, one part has chromatic aberration and the other part does not. Light irradiated on the surface of these cells will be reflected, and those reflected lights with colors are chromatic aberration lights; while the light reflected by the cells without chromatic aberration is non-chromatic aberration light. The cavity of the focusing cavity (9) is used to enclose the space to form a light trap. Through the "light trapping" function of the light trap, most of the sunlight entering from the encapsulation glass (2) is trapped in the light trap, significantly weakening the intensity of the reflected light that passes through the encapsulation glass (2) and returns to the outside of the cavity, reducing the visual clarity of the situation inside the cavity when observing from outside the cavity, and reducing visual chromatic aberration; 2) Mixed chromatic aberration light: According to the propagation theory of light waves, lights of different colors will mix with each other due to diffusion, scattering and interference when they propagate together. When the incident sunlight propagates in the closed space of the focusing cavity (9), the reflected light that is not absorbed by the wall of the focusing cavity will be reflected multiple times on the inner surface of the cavity. This process not only prolongs the propagation path of the light, but also increases the number of interface reflections, thereby significantly improving the degree of mixing between the reflected light with and without chromatic aberration. The chromatic aberration lights can also be effectively mixed, so that the light can be fully mixed. Therefore, even if a small amount of mixed light escapes from the focusing cavity (9), since they have been mixed, the color difference is almost imperceptible visually, thereby achieving the effect of reducing visual chromatic aberration. Even if all the photovoltaic cells on the inner wall of the focusing cavity (9) have chromatic aberration and the reflected light is all chromatic aberration light, effective light mixing can be achieved in this way.

3. A method for reducing visual color difference and improving light utilization rate of a photovoltaic cell assembly according to claim 1, characterized in that The method for improving the utilization rate of light energy is to obtain a three-dimensional photovoltaic cell structure by utilizing the three-dimensional design of the inner wall of the focusing cavity (9). Compared with the planar structure of a traditional flat-plate photovoltaic cell, the three-dimensional structure has a larger inner surface area. This design significantly increases the area of ​​the photovoltaic cell irradiated by incident sunlight per unit area, thereby improving the utilization efficiency of sunlight.

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