Composite glass for photovoltaic modules and photovoltaic module

Abstract

The present disclosure relates to a composite glass for a photovoltaic module and the photovoltaic module, the composite glass comprising a glass substrate and at least one layer of high-reflection material layer coated on the glass substrate; the side surface of the composite glass coated with the high-reflection material layer has a convexity. The composite glass of the present disclosure can realize directional reflection of light, and improve the power and light utilization rate of the photovoltaic module.

Description

Technical Field

[0001] This application relates to the field of solar cells, and more specifically, to a composite glass for photovoltaic modules and a photovoltaic module. Background Technology

[0002] The development trend of photovoltaic modules is towards bifacial photovoltaic modules. Currently, most mainstream bifacial photovoltaic modules are made by laminating materials such as front glass, top encapsulation film, bifacial cell strings, bottom encapsulation film, and transparent backsheet or backsheet glass. To reduce light loss caused by cell string spacing and string edges, white grid glass, white grid backsheets, or transparent backsheets or backsheets with directional reflective film are often used. These reflect light transmitted through the front of the module to the upper glass, and then the glass reflects the light back onto the cells, improving light utilization.

[0003] Currently, grid backsheets or grid backglass on the market often utilize light in a disordered manner. There are also solutions that involve gap-applying films to transparent backglass or transparent backsheets. While this can also effectively utilize light, it requires additional equipment, increasing costs. Furthermore, the film application process adds three steps (backglass flipping - film application - backglass flipping), significantly reducing production efficiency. Additionally, after lamination, the reflective film on the directional reflective film may shift, leading to light leakage risks and making it difficult to guarantee product yield. Utility Model Content

[0004] The purpose of this disclosure is to provide a composite glass for photovoltaic modules and a photovoltaic module. The composite glass of this disclosure can achieve directional light reflection, thereby improving the power and light utilization rate of the photovoltaic module.

[0005] To achieve the above objectives, a first aspect of this disclosure provides a composite glass for photovoltaic modules, the composite glass comprising a glass substrate and at least one layer of highly reflective material coated on the glass substrate; the side surface of the composite glass coated with the highly reflective material layer has a protrusion.

[0006] Optionally, the shape of the cross section along the height direction of the protrusion is one or more of the following: triangle, quadrilateral, circular arc, and hexagon.

[0007] Optionally, the ratio of the height of the protruding cross section to the length of the bottom side is 1:(1-10).

[0008] Optionally, the ratio of the height of the protruding cross section to the length of the bottom side is 1:(2-6).

[0009] Optionally, the shape of the protruding cross section is an isosceles triangle, the degree of the vertex angle of the isosceles triangle is 30-140°, the height is 10-40μm, and the distance between adjacent vertices of the isosceles triangle is 50-300μm.

[0010] Optionally, the number of high-reflectivity material layers is 2-20, and the refractive index of the high-reflectivity material layers alternates between high and low along the direction away from the glass substrate. The refractive index of the high-reflectivity material layer in contact with the glass substrate is higher than the refractive index of the glass substrate.

[0011] Optionally, the thickness of the high-reflectivity material layer is 0-30 μm, and the thickness of the glass substrate is 0-6 mm.

[0012] The second aspect of this disclosure provides a solar photovoltaic module, the solar photovoltaic module comprising the composite glass provided in the first aspect of this disclosure.

[0013] Optionally, the photovoltaic module includes a front glass panel, a top encapsulating film, a double-sided cell string, a bottom encapsulating film, and the composite glass stacked sequentially.

[0014] Optionally, the solar cell is selected from HJT, TOPCon, PERC or BC.

[0015] Through the above technical solution, the composite glass disclosed herein includes a raised high-reflectivity material layer, which enables the composite glass to reflect incident light in a directional manner, and the high-reflectivity material layer can reflect light to the back of the solar cell, avoiding light energy loss, thereby improving light utilization, increasing the power generation on the back of the solar cell, and improving the power of the photovoltaic module.

[0016] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a structural schematic diagram of one specific embodiment of the photovoltaic module disclosed herein.

[0018] Figure 2 This is a cross-sectional view of one specific embodiment of the photovoltaic module disclosed herein.

[0019] Explanation of reference numerals in the attached figures Detailed Implementation

[0020] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0021] like Figure 1As shown, the first aspect of this disclosure provides a composite glass for photovoltaic modules, the composite glass including a glass substrate 101 and at least one high-reflectivity material layer 102 covering the glass substrate 101; the side surface of the composite glass covered by the high-reflectivity material layer 102 has a protrusion.

[0022] In this disclosure, the protrusions of the high-reflectivity material layer are used to directionally reflect light incident upon it. The outer surface of the outermost high-reflectivity material layer 102, away from the glass substrate 101, refers to the side of the outermost high-reflectivity material layer that is not in contact with the glass substrate or other high-reflectivity material layers.

[0023] The composite glass disclosed herein has a specific high-reflectivity material layer. The protrusions in this high-reflectivity material layer enable directional reflection of light onto the solar cell, thereby improving light utilization and resulting in a more significant power gain. Simultaneously, the high-reflectivity material layer can reflect light that is transmissible to the solar cell back to it, contributing to improved photoelectric conversion efficiency of the photovoltaic module.

[0024] In this disclosure, the high-reflectivity material layer of the composite glass can be a continuous layer, or it can be set as a discontinuous layer according to the spacing of different components and different types of solar cells, so as to reduce the amount of high-reflectivity material used. For example Figure 2 As shown, in one embodiment, a high-reflectivity material layer is disposed below the gap between the two solar cells.

[0025] According to this disclosure, the shape of the protruding cross-section on the high-reflectivity material layer 102 is not specifically limited, as long as it can achieve directional light reflection. In one specific embodiment of this disclosure, the shape of the cross-section along the height direction of the protrusion is one or more of a triangle, quadrilateral, arc, and hexagon, preferably a triangle. In this disclosure, the cross-section of the protrusion refers to the surface obtained by cutting along the vertical direction of the protrusion.

[0026] In one specific embodiment of this disclosure, the shape of the protruding cross-section is an isosceles triangle. The ratio of the height to the base length of the isosceles triangle cross-section can vary within a wide range, preferably 1:(1-10), more preferably 1:(2-6). In one embodiment, the vertex angle of the isosceles triangle is 30-140°, the height is 10-40 μm, and the distance between the vertices of adjacent isosceles triangles is 50-300 μm. In this disclosure, adjacent isosceles triangles refer to isosceles triangles formed by adjacent protruding cross-sections. Excessive protrusion height on the composite glass surface may lead to stress concentration points, making it prone to breakage after lamination when used in photovoltaic module fabrication; while insufficient protrusion may result in poor directional light reflection. In this embodiment, the ratio of the height to the base length of the protrusion on the composite glass surface is appropriate, resulting in better directional light reflection and structural stability of the composite glass.

[0027] According to this disclosure, the high-reflectivity material layer 102 can be a single layer, or multiple high-reflectivity material layers with different refractive indices can be provided as needed. In one specific embodiment of this disclosure, the number of high-reflectivity material layers 102 is 2-20 layers, for example, 2, 4, 6, 8, 10, 12, 14, 16, 18, or 20 layers. Along the direction away from the glass substrate 101, the refractive indices of the multiple high-reflectivity material layers alternate, and the refractive index of the high-reflectivity material layer 102 in contact with the glass substrate is higher than the refractive index of the glass substrate 101.

[0028] In one embodiment, along a direction away from the glass substrate 101, the high-reflectivity material layer includes at least one set of alternating first high-reflectivity material layers and second high-reflectivity material layers, wherein the refractive index of any one of the first high-reflectivity material layers is lower than the refractive index of the adjacent second high-reflectivity material layer, and the refractive index of the first high-reflectivity material layer is higher than the refractive index of the glass substrate 101.

[0029] In another embodiment, along a direction away from the glass substrate 101, the high-reflectivity material layer includes at least one set of alternately arranged first and second high-reflectivity material layers. The refractive index of any one of the first high-reflectivity material layers is higher than that of the adjacent second high-reflectivity material layer, and the refractive index of the first high-reflectivity material layer is higher than that of the glass substrate 101. By combining high-reflectivity material layers with different refractive indices, composite glass with specific light reflection effects can be prepared as needed. Preferably, the thickness of each high-reflectivity material layer is designed to be one-quarter of the desired gain wavelength, so that light of a specific wavelength is reflected at each layer interface. After multiple reflections, the reflected light is enhanced.

[0030] According to this disclosure, the thickness of the high-reflectivity material layer and the thickness of the glass substrate can vary within a wide range. In one specific embodiment, the thickness of the high-reflectivity material layer is 0.1-30 μm, preferably 0.1 μm-20 μm, and the thickness of the glass substrate is 1-6 mm, preferably 1-3 mm. In this disclosure, the thickness of the high-reflectivity material layer refers to the distance from the highest point of the protrusion to the surface in contact with the glass substrate.

[0031] According to this disclosure, the material of the high reflectivity layer 102 can be a material with reflective properties, such as silicon dioxide, titanium dioxide, silver nanoparticles, zirconium dioxide or hafnium dioxide. The above materials have the advantages of good acid and alkali resistance, good wear resistance, strong adhesion and not easy to fall off.

[0032] According to this disclosure, the material of the glass substrate 101 is well known to those skilled in the art. In one embodiment, the material of the glass substrate 101 is selected from quartz glass, silicate glass, soda-lime glass or fluoride glass, preferably silicate glass.

[0033] In one specific embodiment of this disclosure, the composite glass is prepared by a method comprising the following steps: coating a high-reflectivity material slurry onto a glass substrate, followed by rolling, curing, tempering, and cooling using an embossing roller. In this embodiment, composite glass with directional reflectivity can be prepared using an embossing roller with a specific embossing pattern in the glass production process, without the need for additional equipment or process steps, thus improving module production efficiency. Furthermore, because the high-reflectivity material is coated onto the glass substrate, it has strong adhesion and will not shift after lamination, significantly improving the yield of photovoltaic modules.

[0034] In one specific embodiment of this disclosure, the rolling conditions include a pressure of 10-30 MPa and a temperature of 500-700°C. In this embodiment, a more structurally stable composite glass can be prepared.

[0035] According to this disclosure, curing, tempering and cooling are processes well known to those skilled in the art, and specific process conditions can be selected according to actual needs, which will not be elaborated here. A second aspect of this disclosure provides a solar photovoltaic module, which includes the composite glass provided in the first aspect of this disclosure. This photovoltaic module has a high photoelectric conversion power.

[0036] According to this disclosure, the solar photovoltaic module can be a bifacial solar module well known to those skilled in the art. In one specific embodiment, such as... Figure 2 As shown, the photovoltaic module includes a front glass panel 201, a top encapsulating film 202, a solar cell 203, a bottom encapsulating film 204, and the composite glass 205 stacked in sequence.

[0037] According to this disclosure, the solar cell 203 can be any cell used in a photovoltaic module, such as HJT, TOPCon, PERC or BC.

[0038] According to this disclosure, the front panel glass and the encapsulating film can be those well known to those skilled in the art. For example, the front panel glass can be quartz glass, silicate glass, soda-lime glass, fluoride glass, etc., and the encapsulating film can be EVA, POE, EPE, PVB, etc.

[0039] The present disclosure will be further illustrated by the following examples, but the present disclosure is not limited thereto.

[0040] Unless otherwise specified, all materials used in the following examples and comparative examples were commercially available. The glass substrates used in the following examples and comparative examples were made of silicate glass.

[0041] Example 1 The glass substrate (2mm thick) is rolled using an embossing roller at 600℃ and 15MPa. Glass powder and titanium dioxide are mixed in a weight ratio of 1:2 to obtain a high-reflectivity material slurry. The high-reflectivity material slurry is then coated onto the rolled glass substrate using a screen printing method. After curing, tempering, and cooling, composite glass is obtained.

[0042] The composite glass has a high reflectivity material layer with a thickness of 20 μm. The shape of the raised cross section of the high reflectivity material layer is an isosceles triangle with a height of 20 μm, a base length of 69.3 μm, a vertex angle of 120°, and a distance of 69.3 μm between adjacent raised vertices.

[0043] Example 2 Composite glass was prepared using the same method as in Example 1, except that the embossing roller was replaced so that the composite glass obtained by rolling had a different shape of protrusions than that in Example 1.

[0044] The thickness of the high-reflectivity material layer in the prepared composite glass is 20 μm. The shape of the protruding cross section of the high-reflectivity material layer of the composite glass is quadrilateral, with a height of 20 μm, a base length of 50 μm, and a distance of 69.3 μm between adjacent vertices of adjacent protrusions.

[0045] Example 3 Composite glass was prepared using the same method as in Example 1, except that the embossing roller was replaced so that the composite glass obtained by rolling had a different shape of protrusions than that in Example 1.

[0046] The thickness of the high-reflectivity material layer in the prepared composite glass is 20 μm. The shape of the protruding cross section of the high-reflectivity material layer of the composite glass is semi-circular, with a height of 25 μm, a base length of 50 μm, and a distance of 50 μm between adjacent vertices of adjacent protrusions.

[0047] Example 4 Composite glass was prepared using the same method as in Example 1, except that the embossing roller was replaced so that the composite glass obtained by roller pressing had a different shape of protrusions than that in Example 1.

[0048] The composite glass has a high reflectivity material layer with a thickness of 20 μm. The shape of the raised cross section of the high reflectivity material layer is an isosceles triangle with a height of 50 μm, a base length of 94.6 μm, a vertex angle of 150°, and a distance of 189.2 μm between adjacent raised vertices.

[0049] Example 5 A multilayer of highly reflective material is formed by alternating deposition of high-refractive-index TiO2 and low-refractive-index SiO2. The thickness of each highly reflective material layer is designed to be one-quarter of the required gain wavelength.

[0050] An embossing roller is used to press a glass substrate (2 mm thick) at 600°C and 15 MPa. Glass powder and titanium dioxide are mixed in a weight ratio of 1:2 to obtain a first slurry of high reflectivity material. The first slurry is then screen-printed onto the pressed glass substrate. Glass powder and silicon dioxide are then mixed in a weight ratio of 1:2 to obtain a second slurry of high reflectivity material. The second slurry is then screen-printed onto the first high reflectivity material layer. After curing, tempering, and cooling, composite glass is obtained.

[0051] The thickness of the first high reflective material layer in the composite glass is 0.1 μm, the thickness of the second high reflective material layer is 0.11 μm, the shape of the raised cross section on the surface of the composite glass is an isosceles triangle with a height of 20 μm, a base length of 69.3 μm, a vertex angle of 120°, and a distance of 69.3 μm between adjacent raised vertices.

[0052] Comparative Example 1 A high-reflectivity material was prepared by screen printing on a glass substrate (2 mm thick) to obtain a composite glass. The surface of the composite glass has no directional protrusions and no directional reflection effect.

[0053] Test case A photovoltaic module was fabricated using a lamination process, comprising a front glass panel, a top encapsulating film, solar cells, a bottom encapsulating adhesive, and the composite glass prepared in the examples and comparative examples. TOPCon cells were used, with a cell size of 182.2*183.75mm, an efficiency of 25.5%, and a quantity of 144 cells. The power generation of the photovoltaic module was tested using a solar simulator, and the test results are shown in Table 1.

[0054] Table 1

[0055] As can be seen from the above, the composite glass disclosed herein can achieve directional light reflection, thereby improving the power and light utilization rate of photovoltaic modules.

[0056] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0057] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0058] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A composite glass for photovoltaic modules, characterized in that, The composite glass includes a glass substrate (101) and at least one highly reflective material layer (102) covering the glass substrate (101); the surface of the composite glass covered with the highly reflective material layer (102) has a protrusion; the highly reflective material layer can reflect light that can pass through the solar cell back to the solar cell; the ratio of the height of the protrusion cross section to the length of the base is 1:(2-6); the shape of the protrusion cross section is an isosceles triangle, the degree of the vertex angle of the isosceles triangle is 30-140°, the height is 10-40μm, and the distance between adjacent vertices of the isosceles triangle is 50-300μm.

2. The composite glass according to claim 1, wherein, The number of layers of the high reflectivity material layer (102) is 2-20. The refractive index of the high reflectivity material layer alternates between high and low along the direction away from the glass substrate (101). The refractive index of the high reflectivity material layer (102) in contact with the glass substrate is higher than that of the glass substrate (101).

3. The composite glass according to claim 1, wherein, The thickness of the high-reflectivity material layer is 0.1-30 μm, and the thickness of the glass substrate is 1-6 mm.

4. A solar photovoltaic module, characterized in that, The solar photovoltaic module includes the composite glass described in any one of claims 1-3.

5. The photovoltaic module according to claim 4, wherein, The photovoltaic module includes a front glass panel (201), a top encapsulating film (202), a solar cell (203), a bottom encapsulating film (204), and the composite glass (205) stacked in sequence.

6. The photovoltaic module according to claim 4, wherein, The solar cells are selected from HJT, TOPCon, PERC or BC.

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