Hollow photovoltaic module and photovoltaic roof
By setting up multiple light scattering structures in the photovoltaic module, the incident light rays are diffused multiple times, and the problems of poor light transmission and uneven light rays in traditional photovoltaic modules are solved, achieving a softer and even indoor lighting effect.
Patent Information
- Application Number
- CN202423118562.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-17
- Publication Date
- 2025-03-21
- Estimated Expiration
- 2034-12-17
AI Technical Summary
Traditional crystalline silicon photovoltaic modules have poor light transmission due to dense cell string arrangement, which easily produces blocky black spots in the sun, affecting the uniform distribution of indoor light and limiting their application value in the roof parts that require light transmission.
A hollow photovoltaic module is designed, including a layered first panel, a battery string and a second back panel, and a plurality of light scattering structures arranged on the back and back sides of the second back panel. By increasing the exit angle of light rays through primary and secondary diffusion, the dispersion of light sources and uniformity of light distribution is achieved.
Through the multiple diffusion of light, the generation of light spots is avoided, making the light softer, improving the comfort of indoor lighting, and achieving a more efficient and uniform indoor lighting effect.
Smart Images
Figure CN222655670U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of building photovoltaic integration, and more specifically, to a hollow photovoltaic module and a photovoltaic roof. Background Art
[0002] The hollow roof BIPV (Building Integrated Photovoltaics) module is an application form of photovoltaic building integration. It combines photovoltaic power generation technology with the building roof structure. It not only has the function of power generation, but also can serve as a part of the building roof to provide functions of traditional building materials such as insulation and waterproofing.
[0003] In the field of building integrated photovoltaics (BIPV), the demand for natural light in buildings is increasing, which places higher demands on the light transmission performance of photovoltaic modules. Traditional crystalline silicon photovoltaic modules have poor light transmission due to the dense arrangement of battery strings, which easily produces blocky black spots in the sun, affecting the uniform distribution of indoor light. Even if the photovoltaic modules are installed at intervals, the problem of uneven light transmission cannot be completely solved, which limits the application value of crystalline silicon photovoltaic modules in roof parts that need light transmission. Utility Model Content
[0004] The purpose of the present application is to provide a hollow photovoltaic module and a photovoltaic roof, wherein the hollow photovoltaic module can scatter the incident light multiple times, reduce the shadows created by the battery strings, and make the light softer, thereby improving the comfort of indoor lighting and achieving a more efficient and uniform indoor lighting effect.
[0005] In a first aspect, the present application provides a hollow photovoltaic module, which is installed above a roof and includes at least a first panel, a battery string, and a second back plate that are stacked and assembled, and each layer of structural members has a front side and a back side along a first direction, and also includes:
[0006] A first light scattering structure is disposed on the back of the second back plate, and is used to diffuse the incident light once to increase the incident angle of the incident light;
[0007] A second light scattering structure is disposed on the back side of the second back plate and has a certain distance from the second back plate to form a hollow layer, the second light scattering structure is a plate structure with a plano-concave cylindrical lens, and the concave surface of the second light scattering structure faces the hollow layer to perform secondary diffusion on the incident light;
[0008] The first direction is an assembly direction from the first panel to the second back panel.
[0009] In an implementable solution, the first light scattering structure is a polygonal prism structure, and a plurality of the polygonal prism structures are arranged in an array on the back side of the second back plate.
[0010] In an implementable solution, the first light scattering structure is an equilateral triangular prism structure, and a plurality of the equilateral triangular prism structures are arranged in a tight array along the second direction or the third direction on the back side of the second back plate;
[0011] The second direction is the length direction of the battery string, the third direction is the arrangement direction of each group of the battery strings, the second direction and the third direction are perpendicular to each other, and the first direction is perpendicular to the plane where the second direction and the third direction are located.
[0012] In an implementable solution, the first light scattering structures are arranged in an array with equal spacing on the back side of the second back plate, and the spacing between adjacent first light scattering structures is between 0 mm and 5 mm.
[0013] In an implementable scheme, the first light scattering structure has a top surface in contact with the second back plate, and two side surfaces for scattering incident light; the junction where the side surfaces extend away from the top surface is a bottom edge; the distance between the bottom edge and the top surface is d, and d is between 1mm and 2mm.
[0014] In an implementable solution, along the array direction of the first light scattering structures, the top surface has a width L, and L is between 2 mm and 5 mm.
[0015] In an implementable solution, the first light scattering structure and the second back plate are an integrated structure.
[0016] In an implementable solution, the second light scattering structure is a plate structure having plano-concave cylindrical lenses, and a plurality of the plano-concave cylindrical lenses are arranged in a spaced array along a third direction on the front side of the second light scattering structure; the third direction is the arrangement direction of each group of the battery strings.
[0017] In an implementable solution, the second light scattering structure includes a recess and a connecting portion between adjacent recesses, wherein the cylindrical extension direction of the recess coincides with the second direction for secondary diffusion of incident light; the second direction is perpendicular to the third direction.
[0018] In an implementable solution, in the first direction, projections of adjacent recesses of the second light scattering structure and projection areas of the battery string are sequentially spaced and distributed.
[0019] In an implementable solution, the concave portion of the second light scattering structure has a depth H, and H is between 4 mm and 8 mm;
[0020] The concave portion of the second light scattering structure has a curvature radius R, and R is between 70 mm and 80 mm.
[0021] In an implementable solution, the hollow layer has a hollow thickness, which is the distance between the back surface of the second back plate and the front surface of the second light scattering structure, and the hollow thickness is between 6 mm and 15 mm.
[0022] In an implementable solution, the concave portion of the second light scattering structure has a central thickness and an edge thickness, wherein the central thickness is between 2 mm and 5 mm, and the edge thickness is between 6 mm and 12 mm.
[0023] In an implementable solution, a roughened film layer is disposed on the front side of the second light scattering structure, and the roughness of the roughened film layer is greater than the roughness of the front side of the second light scattering structure; the roughened film layer is located on at least a portion of the surface of the plano-concave cylindrical lens.
[0024] In a second aspect, the present application provides a photovoltaic roof, on which a hollow photovoltaic assembly as described in the above technical solution is installed, wherein the first panel is located on a side away from the indoor room; and the second back panel is located on a side close to the indoor room.
[0025] Compared with the prior art, the beneficial effects of the present application include at least the following:
[0026] The hollow photovoltaic module provided by the technical solution of the present application adds multiple light adjustment structures on the basis of traditional photovoltaic modules: a first light scattering structure arranged on the back side of the second back plate, and a second light scattering structure arranged on the back side of the second back plate and at a certain distance from the second back plate, which diffuse the incident light to increase the exit angle of the light, realize the dispersion of the light source, and improve the uniformity of the light distribution, thereby making the light softer, avoiding the generation of light spots, and achieving a more efficient and uniform indoor lighting effect. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.
[0028] Figure 1 It is a schematic diagram of the assembly structure of a photovoltaic module in the prior art.
[0029] Figure 2 It is a schematic diagram of the arrangement of battery strings of photovoltaic modules in the prior art.
[0030] Figure 3 It is a schematic diagram of the assembly structure of a photovoltaic module according to an embodiment of the present application.
[0031] Figure 4 Schematic diagram of the arrangement of cell strings of a photovoltaic module according to an embodiment of the present application.
[0032] Figure 5 A schematic diagram of the light transmission path of a photovoltaic module shown in an embodiment of the present application.
[0033] Figure 6 for Figure 5 A partial enlarged schematic diagram of .
[0034] Figure 7 for Figure 6 A partial enlarged schematic diagram of .
[0035] Figure 8 A schematic structural diagram of a second light scattering structure provided in an embodiment of the present application.
[0036] Fig. 9 A schematic diagram of the structure of a photovoltaic roof provided in an embodiment of the present application.
[0037] In the figure:
[0038] 10. Photovoltaic module; 11. First panel; 12. First film layer; 13. Battery string; 14. Second film layer; 15. Second back plate; 151. First light scattering structure; 16. Hollow layer; 17. Second light scattering structure; 171. Concave portion; 172. Connecting portion; 18. Roughened film layer. DETAILED DESCRIPTION
[0039] like Figure 1 and Figure 2 As shown, the photovoltaic modules in the prior art usually include at least a first panel 11, a first film layer 12, a battery string 13, a second film layer 14 and a second backplane 15, etc. The battery string 13 is the core part of the photovoltaic product, responsible for converting light energy into electrical energy. The photovoltaic modules are connected to the circuit systems of different application scenarios to meet the power demand. The existing crystalline silicon photovoltaic modules have poor light transmittance due to the dense arrangement of the battery strings 13, which easily produces blocky black spots under the sun, affecting the uniform distribution of indoor light. Even if the photovoltaic modules are installed at intervals, the problem of uneven light transmittance cannot be completely solved, which limits the application value of crystalline silicon photovoltaic modules in roof parts that need light transmission. In view of this, the present application provides a technical solution to improve the problems of low light transmittance and light transmittance uniformity of crystalline silicon photovoltaic modules.
[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.
[0041] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.
[0042] For the convenience of description, the first direction is defined as the assembly direction from the first panel 11 to the second back panel 15, the second direction is defined as the length direction of the battery string 13, and the third direction is defined as the arrangement direction of each group of battery strings 13. The second direction is perpendicular to the third direction, and the first direction is perpendicular to the plane where the second direction and the third direction are located.
[0043] The present application provides a hollow photovoltaic module installed above a roof, such as Figures 3 to 8 As shown, the hollow photovoltaic module includes a first panel 11, a first film layer 12, a battery string 13, a second film layer 14, a second back sheet 15, a first light scattering structure 151 and a second light scattering structure 17 that are stacked and assembled. It can be understood that each layer of the structural member has a front side and a back side along the first direction. For example, the front side of the second back sheet 15 is the side facing the battery string 13, and the back side of the second back sheet 15 is the side facing the second light scattering structure 17.
[0044] Among them, the first light scattering structure 151 is arranged on the back side of the second back plate 15, and is used to diffuse the incident light once to increase the exit angle of the incident light; the second light scattering structure 17 is arranged on the back side of the second back plate 15, and has a certain distance between it and the second back plate 15 to form a hollow layer 16, which is used to diffuse the incident light for a second time.
[0045] Among them, Figure 4 As shown, the technical solution provided by the present application is based on a photovoltaic module with a size of 1200mm*1200mm, which has five battery strings 13 arranged in sequence, and the spacing between adjacent battery strings 13 is between 40mm and 60mm, preferably 48mm. It can be understood that photovoltaic modules of any other size can be designed or improved based on the principle analogy of the technical solution of the present application.
[0046] In one embodiment, the first panel 11 and the second back panel 15 are both glass panels and have the same thickness, such as 6mm, 8mm or 10mm, etc., preferably a 6mm thick glass panel, which can better protect the internal battery string and packaging materials and prevent physical damage and erosion by moisture, dust, etc. The front and back of the battery string 13 are respectively attached with the first film layer 12 and the second film layer 14. The first film layer 12 and the second film layer 14 can be a PVB (polyvinyl butyral) film of a certain thickness. While maintaining good light transmittance, it is used to bond the first panel 11 and the second back panel 15 of the battery string 13 together to form a double-layer laminated structure, increase the mechanical strength and impact resistance of the photovoltaic module, and further improve the safety and durability of the photovoltaic module together with the first panel 11 and the second back panel 15.
[0047] In one embodiment, the cell string 13 is a crystalline silicon cell. It is understandable that in the field of BIPV, although cadmium telluride photovoltaic modules have high light transmittance, their power generation efficiency in BIPV applications is generally lower than that of crystalline silicon modules. Although crystalline silicon modules have excellent power generation efficiency, their light transmittance and light transmission effect are difficult to reach the level of cadmium telluride photovoltaics. The photovoltaic module provided in this embodiment is particularly suitable for crystalline silicon cells. By optimizing the crystalline silicon cells and adding optical structures to the modules, it can achieve a light transmission effect comparable to that of existing cadmium telluride cells, while ensuring that the softness of the light transmission effect meets the requirements of architectural aesthetics.
[0048] In one embodiment, if Figures 5 to 7 As shown, the first light scattering structure 151 is a prism structure, and a plurality of prism structures are arranged in an array on the back of the second back plate 15. After the light passes through the prism structure, the propagation direction of the light is changed, so that the shadow position originally generated by the battery string 13 is covered by the light, which can improve the effect of black spots to a certain extent and make the light more evenly distributed in the room.
[0049] In one embodiment, if Figures 5 to 7 As shown, the first light scattering structure 151 is an equilateral prism structure, and a plurality of equilateral prism structures are arranged in a tight array along the second direction or the third direction on the back of the second back plate 15. This structure enables the prism to simultaneously achieve the maximum light dispersion effect and the minimum reflection loss during the light transmission process, while reducing the number of reflections of light inside the prism, thereby reducing light loss. In a relatively preferred embodiment, each equilateral prism structure extends along the second direction and is arranged in a tight array along the third direction on the back of the second back plate 15 to achieve the maximum utilization of the area of the second back plate 15, ensuring that each beam of light can be dispersed into evenly distributed light through the first light scattering structure 151, thereby reducing the shadows produced by the battery string 13 and improving the uniformity of indoor lighting.
[0050] In one embodiment, the first light scattering structures 151 are arranged in an array with equal spacing on the back of the second back plate 15, and the spacing between adjacent first light scattering structures 151 is between 0 mm and 5 mm. In this embodiment, the first light scattering structures 151 can be prism structures, and the length of each prism is adapted to the length of each battery string 13, and they are distributed on the back of the second back plate 15 in sequence and at equal spacing along the width direction. It can be understood that even if it is a material with high light transmittance, the light will still lose some brightness when it is reflected inside the first light scattering structure 151. Therefore, under the premise of satisfying the basic light uniformity, a spacing is set between adjacent first light scattering structures 151 to reduce unnecessary light loss and optimize the production cost of photovoltaic modules. Further, the spacing between adjacent first light scattering structures 151 is between 0 mm and 2 mm, for example, 0.5 mm, 1.0 mm or 1.5 mm.
[0051] In one embodiment, if Figure 7 As shown, the first light scattering structure 151 has a top surface in contact with the second back plate 15, and two side surfaces for scattering incident light; the junction where the side surfaces extend away from the top surface is the bottom edge; the distance between the bottom edge and the top surface is d, and d is between 1mm and 2mm. It can be understood that the distance d is also the height value of the first light scattering structure 151. Under the condition that the thickness of the hollow layer 16 allows, the height of the first light scattering structure 151 can only consider its divergence effect on light. Further, d is between 1.2mm and 1.5mm, for example, 1.3mm or 1.4mm.
[0052] In one embodiment, along the array direction of the first light scattering structure 151, the top surface has a width L, and L is between 2 mm and 5 mm. The top surface width L and the widths of the two side surfaces can be the same or different. When the top surface width is the same as the widths of the two side surfaces, the first light scattering structure 151 is an equilateral prism; when the widths of the two side surfaces are equal but not equal to the top surface width L, the first light scattering structure 151 is an isosceles prism. The widths of the two side surfaces are both smaller than the top surface width L. Further, L is between 3.0 mm and 4.0 mm, for example, 3.4 mm, 3.6 mm or 3.8 mm.
[0053] In one embodiment, the first light scattering structure 151 and the second back plate 15 are an integrated structure. In the actual processing technology, the second back plate 15 is surface treated to form an integrated glass panel with a prism structure, which optimizes the production efficiency of the photovoltaic module and can avoid the reflection of light at the connection between the first light scattering structure 151 and the second back plate 15, thereby reducing the brightness loss.
[0054] In one embodiment, if Figures 5 to 8As shown, the second light scattering structure 17 is a plate structure with a plano-concave cylindrical lens, and a plurality of plano-concave cylindrical lenses are arranged in a spaced array along the third direction on the front side of the second light scattering structure 17. That is, the second light scattering structure 17 is an integrated glass panel with a plano-concave cylindrical lens. After the light is dispersed by the first light scattering structure 151, it propagates a certain distance through the hollow layer 16 and reaches the front side of the second light scattering structure 17, and is further scattered by the plano-concave cylindrical lens. This structure not only enhances the uniformity of the light source, but also makes the light softer through the divergence of the plano-concave cylindrical lens, thereby improving the comfort of indoor lighting, effectively improving the limitations of the traditional component back panel glass in light source processing, and achieving a more efficient and uniform indoor lighting effect.
[0055] In one embodiment, if Figure 7 and Figure 8 As shown, the second light scattering structure 17 includes a concave portion 171 and a connecting portion 172 located between adjacent concave portions 171 . The cylindrical extension direction of the concave portion 171 coincides with the second direction, so as to perform secondary diffusion on the incident light.
[0056] In one embodiment, if Figure 4 As shown, in the first direction, the projections of the adjacent recesses 171 of the second light scattering structure 17 are spaced apart from the projection areas of the battery string 13 in sequence. The technical solution provided in the present application is based on a photovoltaic module with a size of 1200mm*1200mm, which has five battery strings 13 spaced apart in sequence, and the spacing distance between adjacent battery strings 13 is 48mm. Therefore, the spacing between adjacent recesses 171 is also 48mm. The spacing area of the battery string 13 is the light source transmission area, and only setting the recess 171 in the transmission area can save the manufacturing cost to the greatest extent. It can be understood that for photovoltaic modules of any other size, they can be designed or improved based on the principle analogy of the technical solution of the present application.
[0057] In one embodiment, if Figure 7As shown, the concave portion 171 of the second light scattering structure 17 has a depth H, H is between 4mm and 8mm, for example, the depth H can be 4.5mm, 5.0mm, 5.5mm, 6.0mm, 6.5mm or 7.0mm. The depth matches the radius of curvature R of the concave portion 171 of the second light scattering structure 17, and the radius of curvature R is between 70mm and 80mm, for example, the radius of curvature R can be 72mm, 74mm, 76mm, 78mm or 80mm. It can be understood that the main part of the light source that is transmitted is a battery string spacing of 48mm, and the depth H and radius of curvature R of the second light scattering structure 17 are matched by this spacing value. Further, the depth H of the concave portion 171 is specifically 6mm, the radius of curvature R is specifically 74mm, and the spacing between adjacent concave portions 171 is also 48mm. The second light scattering structure 17 with this structural parameter can achieve a relatively uniform dispersion effect on the light.
[0058] In one embodiment, if Figure 7 As shown, the hollow layer 16 has a hollow thickness, which is the distance between the back of the second back plate 15 and the front of the second light scattering structure 17. Under the sealing of the photovoltaic module frame structure, the second back plate 15 and the second light scattering structure 17 are vacuum treated, and the hollow thickness is between 6mm and 15mm. The setting of the hollow layer 16 can improve the thermal insulation performance of the photovoltaic module and reduce the transfer of heat, thereby reducing the operating temperature of the photovoltaic cell to a certain extent and improving the power generation efficiency. Since the hollow layer 16 can affect the propagation state of light inside the module, thereby affecting the absorption and reflection of light, the thickness of the hollow layer 16 should not be too large or too small. Further, the thickness of the hollow layer 16 can be 6mm, 9mm, 12mm or 15mm.
[0059] In one embodiment, if Figure 7 As shown, the concave portion 171 of the second light scattering structure 17 has a center thickness and an edge thickness, the center thickness is between 2mm and 5mm; the edge thickness is between 6mm and 12mm. It can be understood that the center thickness is the thickness of the second light scattering structure 17 minus the depth H of the concave portion 171, and the edge thickness is the average thickness of the connecting portion 172. If the center thickness is too small, the structural strength of the second light scattering structure 17 may be affected, and cracks may be easily caused in the concave portion 171; however, if the center thickness is too large, the brightness may be lost, and the light may be dissipated by multiple refractions and reflections inside the glass panel of the second light scattering structure 17, affecting the power generation efficiency of the photovoltaic module.
[0060] In one embodiment, see Figure 7A roughened film layer 18 is disposed on the front side of the second light scattering structure 17, and the roughness of the roughened film layer 18 is greater than the roughness of the front side of the second light scattering structure 17, so as to further soften the light; the roughened film layer 18 is located on at least part of the surface of the plano-concave cylindrical lens.
[0061] The present application also provides a photovoltaic roof, such as Fig. 9 As shown, the hollow photovoltaic assembly provided in the above embodiment is installed on the photovoltaic roof, wherein the first panel 11 is located on the side away from the indoors; the second back panel 15 is located on the side close to the indoors. The first light scattering structure arranged on the second back panel 15 and the second light scattering structure 17 arranged below the second back panel 15 diffuse the incident light to increase the light emission angle, achieve the dispersion of the light source, and improve the uniformity of light distribution, so that the light is softer, the generation of light spots is avoided, and a more efficient and uniform lighting effect is achieved indoors.
[0062] The above description is only a partial embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A hollow photovoltaic module installed on a roof, comprising at least a first panel (11), a battery string (13) and a second back panel (15) which are stacked and assembled, and each layer of structural members has a front side and a back side along a first direction, characterized in that: Also includes: A first light scattering structure (151) is arranged on the back side of the second back plate (15) and is used to diffuse incident light once to increase the incident light's exit angle; A second light scattering structure (17) is arranged on the back side of the second back plate (15) and has a certain distance from the second back plate (15) to form a hollow layer (16); the second light scattering structure (17) is a plate structure having a plano-concave cylindrical lens, and the concave surface of the second light scattering structure (17) faces the hollow layer (16) to perform secondary diffusion on incident light; The first direction is an assembly direction from the first panel (11) to the second back panel (15).
2. The hollow photovoltaic module according to claim 1, characterized in that: The first light scattering structure (151) is a polygonal prism structure, and a plurality of the polygonal prism structures are arranged in an array on the back side of the second back plate (15).
3. The hollow photovoltaic module according to claim 2, characterized in that: The first light scattering structure (151) is an equilateral triangular prism structure, and a plurality of the equilateral triangular prism structures are arranged in a tight array along the second direction or the third direction on the back side of the second back plate (15); The second direction is the length direction of the battery string (13), the third direction is the arrangement direction of each group of the battery strings (13), the second direction and the third direction are perpendicular to each other, and the first direction is perpendicular to the plane where the second direction and the third direction are located.
4. The hollow photovoltaic module according to claim 2, characterized in that: The first light scattering structures (151) are arranged in an array with equal spacing on the back side of the second back plate (15), and the spacing between adjacent first light scattering structures (151) is between 0 mm and 5 mm.
5. The hollow photovoltaic module according to claim 2 or 3, characterized in that: The first light scattering structure (151) has a top surface in contact with the second back plate (15), and two side surfaces for scattering incident light; the junction where the side surfaces extend away from the top surface is a bottom edge; the distance between the bottom edge and the top surface is d, and d is between 1 mm and 2 mm.
6. The hollow photovoltaic module according to claim 5, characterized in that: Along the array direction of the first light scattering structures (151), the top surface has a width L, and L is between 2 mm and 5 mm.
7. The hollow photovoltaic module according to claim 1, characterized in that: The first light scattering structure (151) and the second back plate (15) are an integrated structure.
8. The hollow photovoltaic module according to claim 1, characterized in that: The second light scattering structure (17) is a plate structure having plano-concave cylindrical lenses, and a plurality of the plano-concave cylindrical lenses are arranged in a spaced array along a third direction on the front side of the second light scattering structure (17); the third direction is the arrangement direction of each group of battery strings (13).
9. The hollow photovoltaic module according to claim 8, characterized in that: The second direction is defined as the length direction of the battery string (13), the second direction being perpendicular to the third direction; The second light scattering structure (17) comprises a concave portion (171) and a connecting portion (172) located between adjacent concave portions (171); the cylindrical extension direction of the concave portion (171) coincides with the second direction, so as to perform secondary diffusion on the incident light.
10. The hollow photovoltaic module according to claim 9, characterized in that: In the first direction, the projections of the adjacent recesses (171) of the second light scattering structure (17) and the projection areas of the battery strings (13) are sequentially spaced apart.
11. The hollow photovoltaic module according to claim 9, characterized in that: The concave portion (171) of the second light scattering structure (17) has a depth H, where H is between 4 mm and 8 mm; The concave portion (171) of the second light scattering structure (17) has a curvature radius R, and R is between 70 mm and 80 mm.
12. The hollow photovoltaic module according to claim 11, characterized in that: The hollow layer (16) has a hollow thickness, the hollow thickness being the distance between the back surface of the second back plate (15) and the front surface of the second light scattering structure (17), and the hollow thickness being between 6 mm and 15 mm.
13. The hollow photovoltaic module according to claim 11, characterized in that: The concave portion (171) of the second light scattering structure (17) has a central thickness and an edge thickness, the central thickness being between 2 mm and 5 mm; and the edge thickness being between 6 mm and 12 mm.
14. The hollow photovoltaic module according to claim 8, characterized in that: A roughened film layer (18) is arranged on the front surface of the second light scattering structure (17), and the roughness of the roughened film layer (18) is greater than the roughness of the front surface of the second light scattering structure (17); the roughened film layer (18) is located on at least a portion of the surface of the plano-concave cylindrical lens.
15. A photovoltaic roof, characterized in that: The photovoltaic roof is installed with a hollow photovoltaic assembly as claimed in any one of claims 1 to 14, wherein the first panel (11) is located on a side away from the indoor space, and the second back panel (15) is located on a side close to the indoor space.