Double-sided color bifacial solar module with edge sealing structure

Abstract

The present invention relates to a double-sided light-receiving double-sided color type solar module having an edge sealing structure that can secure long-life reliability of the solar module by applying a novel edge sealing method in realizing a solar module capable of double-sided light-receiving and double-sided color, and a method for manufacturing the same. The double-sided light-receiving double-sided color type solar module having an edge sealing structure according to the present invention is characterized in that a first substrate and a second substrate are each divided into an encapsulating area in which an encapsulating material is provided and a module edge sealing area outside thereof, a solar cell and a cell edge sealing material are interposed between the first substrate and the second substrate, and based on the edge of the solar cell, the cell edge sealing material is arranged to include a certain area inside the edge and a certain area outside the edge, and both the first substrate and the second substrate are made of colored glass, the solar cell is a double-sided light-receiving type solar cell, and the cell edge sealing material has a dark background color on both sides.

Description

Technology Field

[0001] The present invention relates to a double-sided light-receiving double-sided color solar module having an edge sealing structure and a method for manufacturing the same. More specifically, the invention relates to a double-sided light-receiving double-sided color solar module having an edge sealing structure and a method for manufacturing the same, wherein a novel edge sealing method is applied to realize a solar module capable of double-sided light reception and double-sided color, thereby ensuring long-life reliability of the solar module. Background Technology

[0002] Long-life reliability is required for the sustainable growth of Building Integrated Photovoltaic (BIPV) systems.

[0003] Characteristics directly related to the long-life reliability of BIPV modules include wet leakage characteristics, insulation resistance, and maximum output degradation characteristics after long-term operation. In other words, wet leakage and insulation resistance characteristics must be excellent after long-term operation, and the degradation of the photovoltaic module's maximum output must be minimized.

[0004] The inventor of the present invention (Park Seong-cheol) disclosed in Korean Registered Patent Publication No. 2741286 (Patent Document 1) that polyolefin elastomer (POE) has excellent moisture resistance and electrical insulation properties compared to ethylene vinyl acetate copolymer (EVA), and presented a photovoltaic module using POE as an encapsulant. In addition, the applicant achieved an insulation resistance of 33.6 GΩ with a photovoltaic module using POE as an encapsulant (see Table 1 in the 'Description of the Invention'), which is a value significantly exceeding the 50 MΩ required by KS.

[0005] The reason for adopting POE as a replacement for EVA as a sealing material is clear. This is because POE has significantly superior moisture penetration resistance compared to EVA, and the applicant believes that applying POE as a sealing material is essential for realizing BIPV modules with long-life reliability. However, since approximately 1.8 times more volatile gases are generated compared to EVA during the crosslinking of POE, complete removal of bubbles is a key issue.

[0006] If the moisture penetration resistance of the encapsulant is poor, moisture penetrates into the solar module, causing corrosion and a decrease in the efficiency of the solar cell (see Fig. 9). Since EVA encapsulant has lower moisture penetration resistance compared to POE, in the case of solar modules using EVA encapsulant, a frame-shaped frame is applied to the edges of the solar module as a means to suppress moisture penetration (see Fig. 10). Most power generation solar modules apply the aforementioned frame to suppress moisture penetration.

[0007] However, when solar modules are applied for BIPV, appearance is also an important consideration, and picture-frame-shaped frames detract from the aesthetics. Consequently, some installation sites are utilizing frameless solar modules with removed frames as BIPV modules; however, due to the poor moisture resistance of the EVA encapsulant, reliability regarding long-term lifespan is inevitably compromised.

[0008] Meanwhile, a technology applying a double-sided light-receiving solar cell to a BIPV module has been presented (see Patent Document 7). A BIPV module with a double-sided light-receiving solar cell can be applied to environments where double-sided light reception is possible, such as sound barriers and windows. Recently, colored glass of various colors is being applied to BIPV modules for aesthetic purposes. Although such double-sided light-receiving solar modules must also ensure long-life reliability, they adopt a structure with a frame and mostly use EVA as the encapsulant, similar to the conventional solar modules mentioned above. Prior art literature

[0009] Korean Registered Patent Publication No. 2741286 (Published Dec. 11, 2024) Korean Published Patent Publication No. 2019-0000520 (Published Jan. 3, 2019) Korean Published Patent Publication No. 2014-0031259 (Published Mar. 12, 2014) International Patent Application Publication WO2024-182603 (Published Sep. 6, 2024) Korean Published Patent Publication No. 2017-0130770 (Published Nov. 29, 2017) Japanese Patent Publication No. 7579431 (Registered Oct. 29, 2024) Korean Published Patent Publication No. 2023-0041880 (Published Mar. 27, 2023)

[0010] PIB Edge Sealant, 'Designing New Materials for Photovoltaics: Opportunities for Lowering Cost and Increasing Performance through Advanced Material Innovations', Report IEA-PVPS T13-13:2021. The problem to be solved

[0011] As described in the 'Technical Background of the Invention,' the long-life reliability of a photovoltaic module can be secured to a certain extent by applying POE as a sealing material (see Patent Document 1). Furthermore, the applicant focused on the possibility of further improving long-life reliability by applying edge sealing and conducted research, and also conducted research on incorporating the edge sealing structure of the present invention into a double-sided light-receiving double-sided color photovoltaic module, and the present invention is the result of such research.

[0012] It is a well-known fact that edge sealing is applied to photovoltaic modules. Polyisobutylene (PIB), polyurethane, silicone, and polysulfide have been proposed as edge sealing materials for photovoltaic modules, and among these, PIB is known to have the best moisture resistance. Korean Patent Publication No. 2019-0000520 (Patent Document 2) also presents a technology for applying PIB, etc. as an edge sealing material (sealing member).

[0013] However, although PIB has the advantages of excellent moisture resistance and good bonding properties with other components, as a thermoplastic resin, it has the disadvantage that its strength decreases as the temperature increases and has the problem of reduced durability when exposed to continuous moisture such as rain. Due to these problems with PIB, there is a need to apply silicone as an edge sealing material to replace PIB, or to apply additional secondary edge sealing materials such as silicone, polyurethane, or polysulfide when using PIB (see Non-Patent Literature 1).

[0014] However, when silicone is used as an edge sealant to replace PIB or in combination with PIB, bubble removal during lamination must be considered. While PIB has excellent gas diffusion properties, silicone has low viscosity and high airtightness, so bubble removal during lamination is not easy when silicone is used as an edge sealant. For this reason, silicone is used as an edge sealant in environments where bubble removal is not required or after lamination is completed.

[0015] For example, Korean Patent Publication No. 2014-0031259 (Patent Document 3) presents a technique for laminating a sealing member (7) made of silicone rubber, placed on the upper and lower parts of a spacer member (6) respectively, in an environment where lamination of the sealing member is not required by applying an elastomer instead of a sealing member, and a butyl rubber (PIB) is placed on the outer periphery of a solar module. International Patent Application Publication WO2024-182603 (Patent Document 4) also presents an edge sealing composed of a PIB layer (154)(156) and a silicone layer (152), but this case also corresponds to a case where lamination of the sealing member is not required.

[0016] The poor laminating properties of silicon are also disclosed in Non-Patent Literature 2 (see p. 18). For this reason, when silicon is to be applied as an edge sealing material, a method is adopted in which silicon is filled between the upper glass and the lower glass along the edge of the photovoltaic module after the laminating process is completed.

[0017] However, in the manufacturing of conventional solar modules, lamination is performed with a lower encapsulant, a solar cell, and an upper encapsulant stacked between the upper and lower substrates (see Patent Document 5). After lamination is completed, the space between the upper and lower substrates is very narrow, making it difficult to fill that space with silicon. Consequently, a very small amount of silicon is filled into the space between the upper and lower substrates, and most of the silicon is applied in the form of a coating on the outer surface of the solar module. Applying silicon in this manner not only degrades the moisture resistance characteristics of silicon but is also aesthetically unpleasing. The reason this method is adopted is that, as mentioned in the 'Technology forming the background of the invention,' the area where silicon is applied can be concealed as a picture frame is mounted on the outer surface of the solar module.

[0018] In addition, when PIB is applied alone as an edge sealing material, for example, when the technology disclosed in Patent Document 2 is implemented, the problem of PIB being released outside the module and flowing down during lamination inevitably occurs due to the high viscosity of PIB. Japanese Patent Publication No. 7579431 (Patent Document 6) discloses a technology in which lamination is performed while a spacer (15) is installed on the outside of the module to prevent the sealing material from protruding outside during lamination. Even if the spacer (15) of Patent Document 6 is incorporated into Patent Document 2 to prevent the phenomenon of PIB being released outside the module, the complexity of the process follows.

[0019] The present invention was devised to solve the above-mentioned problems, and aims to provide a double-sided light-receiving double-sided color solar module equipped with an edge sealing structure that can secure long-life reliability of the solar module by applying a novel edge sealing method in realizing a solar module capable of double-sided light reception and double-sided color, and a method for manufacturing the same. means of solving the problem

[0020] A double-sided light-receiving double-sided color solar module having an edge-sealing structure according to the present invention for achieving the above objective is characterized in that a first substrate and a second substrate are each divided into an encapsulating area in which an encapsulating material is provided and a module edge-sealing area outside thereof, a solar cell and a cell edge-sealing material are interposed between the first substrate and the second substrate, and based on the edge of the solar cell, the cell edge-sealing material is arranged to include a certain area inside the edge and a certain area outside the edge, and both the first substrate and the second substrate are made of color glass, the solar cell is a double-sided light-receiving solar cell, and the cell edge-sealing material has a dark background color on both sides.

[0021] A lower encapsulator and a solar cell are sequentially stacked on an encapsulator area of ​​a first substrate, and a cell edge sealing material is provided on the solar cell, wherein the cell edge sealing material is arranged to include a certain area on the inner edge of the solar cell and a certain area on the outer edge of the solar cell, and an upper encapsulator is provided on the cell edge sealing material, wherein the edge of the cell edge sealing material is exposed by the upper encapsulator, and a module edge sealing material is provided in a module edge sealing area of ​​the first substrate, wherein a part of the module edge sealing material is located in the exposed edge area of ​​the cell edge sealing material and another part is located on the first substrate, and a second substrate is provided to cover both the upper encapsulator and the module edge sealing material.

[0022] The stacking position of the cell edge sealing material is fixed by the module edge sealing material.

[0023] The cell edge sealing material consists of a substrate and a sealing material coated on at least one surface of the substrate.

[0024] The substrate is made of PI (Polyimide) or PET (Polyethylene Terephthalate).

[0025] The bagging material consists of an upper bagging material and a lower bagging material, and the bagging material and the sealing material are made of different materials.

[0026] The packaging material is made of POE (polyolefin elastomer), and the sealing material is made of EVA (ethylene vinyl acetate).

[0027] The module edge sealing material is made of PIB (polyisobutylene).

[0028] A method for manufacturing a double-sided light-receiving double-sided color solar module having an edge-sealing structure according to the present invention comprises the steps of: dividing a first substrate and a second substrate into an encapsulation area where an encapsulation material is provided and a module edge-sealing area outside the encapsulation area; sequentially stacking a lower encapsulation material and a solar cell on the encapsulation area of ​​the first substrate, sequentially stacking a cell edge-sealing material and an upper encapsulation material on the solar cell, and stacking a module edge-sealing material on the module edge-sealing area of ​​the first substrate; stacking a second substrate to cover both the upper encapsulation material and the module edge-sealing material; and performing lamination.

[0029] The edge of the cell edge sealing material is exposed by the upper encapsulation material, and a part of the module edge sealing material is located in the exposed edge area of ​​the cell edge sealing material, and another part is located on the first substrate.

[0030] During lamination, the stacking position of the cell edge sealing material is fixed by the module edge sealing material. Effects of the invention

[0031] The double-sided light-receiving double-sided color solar module having an edge sealing structure according to the present invention and the method for manufacturing the same have the following effects.

[0032] By applying POE as an encapsulant, wetting leakage characteristics can be improved, and in addition, by applying cell edge sealing material and module edge sealing material, long-life reliability of the photovoltaic module can be secured. Furthermore, as the cell edge sealing material acts as a brightness control structure and provides a dark background color, it becomes possible to implement double-sided light reception and double-sided color. Along with this, since long-life reliability is secured through edge sealing, the use of a frame as in the past is not required. Brief explanation of the drawing

[0033] FIG. 1 is a schematic diagram showing the cross-sectional structure of a double-sided light-receiving double-sided color solar module having an edge sealing structure according to one embodiment of the present invention. FIG. 2 is a schematic diagram showing the planar structure of a double-sided light-receiving double-sided color solar module having an edge sealing structure according to one embodiment of the present invention. Figure 3 is a plan view of a cell edge sealing material. FIG. 4 is an exploded perspective view of a double-sided light-receiving double-sided color solar module having an edge sealing structure according to one embodiment of the present invention. Specific details for implementing the invention

[0034] The present invention provides a solar module capable of double-sided light reception and double-sided color implementation, and also presents a technology that can secure long-life reliability by applying a novel edge sealing structure.

[0035] In this specification, 'double-sided light reception' means producing electricity by receiving light through one side of a solar module and the other side opposite it, and 'double-sided color' means that color can be realized through one side of a solar module and the other side opposite it.

[0036] The novel edge sealing structure according to the present invention includes cell edge sealing and module edge sealing. Cell edge sealing means directly sealing the edge area of ​​a solar cell, and module edge sealing means indirectly sealing the solar cell in the area between the edge of the solar cell and the edge of the photovoltaic module.

[0037] Accordingly, in the present invention, the solar cell has a structure in which it is primarily sealed by an encapsulating material, secondarily sealed indirectly by module edge sealing, and thirdly sealed directly by cell edge sealing.

[0038] Meanwhile, in order for both double-sided light reception and double-sided color to be possible in solar modules, it is essential to first apply double-sided light-receiving solar cells. To achieve double-sided color, both sides of the solar cell must be exposed, and a brightness control structure must be applied.

[0039] Color implementation in solar modules can be achieved by applying a polymer film of a specific color or colored glass that exhibits a specific color, as described in Patent Document 7; however, a dark background color must be applied so that the color of the polymer film or colored glass is visible as is. For example, in a single-sided color solar module, a back sheet having a dark color acts as a dark background color, so that the color of the colored glass on the front is perceived by people.

[0040] Therefore, in order to implement double-sided color, a dark background color must be applied to both sides of the solar module, and in the present invention, this is referred to as a 'brightness control structure'. In the present invention, 'dark background color' refers to black or a color with a brightness close to black.

[0041] Hereinafter, a double-sided light-receiving double-sided color solar module having an edge sealing structure according to an embodiment of the present invention and a method for manufacturing the same will be described in detail with reference to the drawings.

[0042] Referring to FIGS. 1 to 4, a double-sided light-receiving double-sided color solar module having an edge sealing structure according to one embodiment of the present invention has a structure in which a solar cell (130) is interposed between a first substrate (110) and a second substrate (160). Both the first substrate (110) and the second substrate (160) are made of colored glass, and the color of the colored glass can be applied arbitrarily.

[0043] In describing the structure of a photovoltaic module according to one embodiment of the present invention, the first substrate (110) may be divided into an encapsulation area and a module edge sealing area. The encapsulation area is an area where an encapsulation material (lower encapsulation material (121) and upper encapsulation material (122)) is provided, and the module edge sealing area is an area where a module edge sealing material (150) is provided. The module edge sealing area is provided on the outer side of the encapsulation area, and the encapsulation area and the module edge sealing area are in contact with each other. The second substrate (160) also has an area defined in the same way as the first substrate (110).

[0044] The size of the solar cell (130) is smaller than the encapsulation area, and the cell edge sealing material (140) provided on the solar cell (130) has its entire edge located between the encapsulation area and the module edge sealing area (see FIG. 1 and FIG. 2). This is explained in detail as follows.

[0045] A lower encapsulation material (121) is laminated on the encapsulation material region of the first substrate (110), and a solar cell (130) is provided on the lower encapsulation material (121). As described above, the region where the solar cell (130) is provided is smaller than the encapsulation material region, so the solar cell (130) is placed within the encapsulation material region. In addition, in the present invention, the solar cell (130) is a double-sided light-receiving solar cell and refers to a plurality of unit solar cells connected by a ribbon or string.

[0046] A cell edge sealing material (140) is laminated onto a solar cell (130). The area where the cell edge sealing material (140) is provided includes the edge area of ​​the solar cell (130) and a portion of the area outside the solar cell (130). Specifically, the cell edge sealing material (140) is arranged to include a certain area inside the edge and a certain area outside the edge, based on the edge of the solar cell (130).

[0047] As shown in FIG. 3, the cell edge sealing material (140) forms a grid-shaped square band and is arranged to wrap around the edges of all unit solar cells constituting the solar cell (130). That is, a certain area on the inner edge and a certain area on the outer edge of each unit solar cell constituting the solar cell (130) are covered by the cell edge sealing material (140). In another aspect, most of the light-receiving area of ​​the solar cell (130) can be exposed by the cell edge sealing material (140). Here, the entire edge of the cell edge sealing material (140) is located between the encapsulation area and the module edge sealing area as described above.

[0048] The cell edge sealing material (140) serves to directly seal the solar cell (130) by contacting it, and also serves to provide a dark background color on both sides of the solar module.

[0049] The cell edge sealing material (140) consists of a substrate made of a polymer material and a sealing material coated on at least one surface of the substrate. The substrate is a polymer material having transparency, durability, and flexibility, and in one embodiment, it may be made of PI (Polyimide) or PET (Polyethylene Terephthalate). The sealing material cross-links during lamination to seal the edge area of ​​the solar cell (130) and may be made of EVA or POE. Here, the sealing material may be coated on the substrate with a thickness of less than 200 μm.

[0050] It is preferable that the sealing material and the encapsulating material (upper encapsulating material (122) and lower encapsulating material (121)) be made of different materials, and one may be made of EVA and the other may be made of POE. In one embodiment, when the encapsulating material is made of POE, it is preferable that the sealing material of the cell edge sealing material (140) be made of EVA. Conversely, when the encapsulating material is made of EVA, it is preferable that the sealing material of the cell edge sealing material (140) be made of POE. Of course, it is also possible to apply both the encapsulating material and the sealing material as EVA or POE.

[0051] In one embodiment of the present invention, the most preferred combination is that the encapsulant is composed of POE and the sealing material is applied as EVA. Through this combination, excellent wet leakage characteristics and long-life reliability can be secured, which can be confirmed through the experimental results of Experimental Examples 1 to 3 described below.

[0052] It is presumed that the long-life reliability of the solar module is secured in the combination of encapsulating material POE and sealing material EVA, which is obtained by doubling the bonding strength through the crosslinking of POE and EVA during lamination. That is, during lamination, the encapsulating material POE is crosslinked to primarily encapsulate the solar cell (130), and in the edge region of the solar cell (130), the crosslinking reaction between the EVA coated on the cell edge sealing material (140) and the encapsulating material POE proceeds to seal, thereby doubling the encapsulating and sealing effects of the solar cell (130).

[0053] Meanwhile, the cell edge sealing material (140) has a dark background color, for example, black or a color with a brightness close to black. As the solar cell (130) is exposed by the cell edge sealing material (140) and both sides of the cell edge sealing material (140) have a dark background color, color recognition on both sides of the solar module becomes possible when the first substrate (110) and the second substrate (160) are applied. That is, the cell edge sealing material (140) acts as a brightness control structure for realizing double-sided color.

[0054] An upper sealing material (122) is provided on the cell edge sealing material (140), and the size and position of the upper sealing material (122) are the same as that of the lower sealing material (121). At this time, as described above, the entire edge of the cell edge sealing material (140) is located between the sealing material area and the module edge sealing area, so the edge of the cell edge sealing material (140) is exposed when the upper sealing material (122) is stacked.

[0055] In this state, a module edge sealing material (150) is laminated in the module edge sealing area. The edge of the module edge sealing material (150) coincides with the edge of the first substrate (110) and the second substrate (160), and a part of the module edge sealing material (150) is located in the edge area of ​​the exposed cell edge sealing material (140) and another part is located on the first substrate (110).

[0056] The module edge sealing material (150) is provided in the outer region of the solar cell (130) and performs the role of indirectly sealing the solar cell (130) and also performs the role of fixing the cell edge sealing material (140) during the laminating process.

[0057] Laminating is performed by applying pressure to the second substrate (160) while the lower encapsulation material (121), solar cell (130), cell edge sealing material (140), upper encapsulation material (122), module edge sealing material (150), and second substrate (160) are stacked on the first substrate (110). Since the contact friction between the solar cell (130) and the cell edge sealing material (140) is small, the cell edge sealing material (140) can easily slide and deviate from the stacked position during laminating. Therefore, it is necessary to maintain the cell edge sealing material (140) in an accurate position during lamination, and as the module edge sealing material (150) is provided on the edge of the cell edge sealing material (140), the cell edge sealing material (140) is fixed by the module edge sealing material (150), so that the stacking position of the cell edge sealing material (140) can be accurately maintained.

[0058] The module edge sealing material (150) is made of a material with excellent moisture penetration resistance, and while the material is not particularly limited, PIB is given priority consideration. It is also possible to use known edge sealing materials other than PIB. The reason PIB is given priority consideration as the module edge sealing material (150) is that it has superior gas diffusion properties compared to other edge sealing materials, such as silicone.

[0059] The reason why gas diffusivity as well as moisture penetration resistance must be considered when selecting the material of the module edge sealing material (150) is that bubbles generated by the cross-linking reaction of the encapsulant during the laminating process must be smoothly discharged. In particular, when POE is applied as the encapsulant, more than 1.8 times the amount of bubbles are generated compared to the EVA encapsulant, and the time for bubble generation is also longer. For reference, the applicant conducted a heating test (150°C, 20 minutes) on the EVA encapsulant and the POE encapsulant and performed GC / MS analysis on the volatile gas characteristics (see FIG. 11). As a result, it was confirmed that POE generates more than 1.8 times the amount of volatile gas than EVA, and the time for volatile gas generation is also longer for POE (26.2 minutes) than for EVA (17.5 minutes).

[0060] With the above-described stacked structure in place, that is, with a lower encapsulating material (121), a solar cell (130), a cell edge sealing material (140), and an upper encapsulating material (122) stacked on the encapsulating material area of ​​the first substrate (110), a module edge sealing material (150) stacked on the module edge sealing area of ​​the first substrate (110), and a second substrate (160) stacked to cover both the upper encapsulating material (122) and the module edge sealing material (150), a laminating process is performed under reduced pressure and high temperature conditions.

[0061] Through the laminating process, crosslinking between the encapsulating materials, crosslinking between the sealing material (EVA) and the encapsulating material (POE), and curing of the module edge sealing material (150) (PIB) are carried out, thereby encapsulating and sealing the solar cell (130). Although the lower surface of the module edge sealing material (150) and the upper surface of the first substrate (110) are shown as being separated in FIG. 1, when the laminating process is completed, the lower surface of the module edge sealing material (150) and the upper surface of the first substrate (110) come into contact.

[0062] Above, a double-sided light-receiving double-sided color solar module having an edge sealing structure according to one embodiment of the present invention and a method for manufacturing the same have been described. Below, the present invention will be explained in more detail through experimental examples.

[0063] Experimental Example 1: Wet Leakage Current Test

[0064] Photovoltaic modules of Comparative Examples 1 to 3 and Examples 1 to 2 were fabricated, and a wet leakage current test was performed on each photovoltaic module. Comparative Examples 1 to 3 and Examples 1 to 2 are all photovoltaic modules with a G(glass) to G(glass) structure, and POE is applied as the encapsulant.

[0065] In addition, Comparative Example 1 is one in which no cell edge sealing material is applied, Comparative Examples 2 and 3 are one in which a PET substrate without a sealing material EVA coating is applied as a cell edge sealing material, and Examples 1 and 2 are one in which a sealing material EVA is coated on both sides of a PET substrate as a cell edge sealing material. In all Comparative Examples 1 to 3 and Examples 1 to 2, the solar modules were manufactured with a size of 1000 mm x 1350 mm.

[0066] The wet leakage current test of Experimental Example 1 was conducted at the Korea Institute of Construction & Living Environment Testing, and the test conditions were maintained at 1500V for 2 minutes.

[0067] Sample Insulation resistance (GΩ) Comparative Example 1 - 33.6 Comparative Example 2 PET 53.9 Comparative Example 3 PET 48.7 Example 1 PET / EVA 99.9 Example 2 PET / EVA 99.9

[0068] As shown in Table 1, the experimental results indicate that Comparative Example 1, in which only POE was applied as the encapsulant without the application of a cell edge sealing material, exhibited an insulation resistance characteristic of 33.6 GΩ. This value significantly exceeds the 50 MΩ required by the KS standard, and implies that a substantial level of wet leakage characteristics can be secured even by applying only the POE encapsulant without the application of a cell edge sealing material.

[0069] In Comparative Examples 2 and 3, where only the PET substrate was applied, the insulation resistance was found to be 53.9 GΩ and 48.7 GΩ, respectively, confirming that the insulation resistance characteristics were improved by applying the PET substrate compared to Comparative Example 1. In Examples 1 and 2, where the PET / EVA cell edge sealing material was applied, the insulation resistance was measured to be 99.9 GΩ, confirming that no current leakage occurred at all.

[0070] Through Experimental Example 1 above, it can be seen that the wet leakage characteristics of a photovoltaic module can be dramatically improved by applying POE as a packaging material along with a PET / EVA structured cell edge sealing material.

[0071] Based on these experimental results, the applicant additionally conducted a 2,000-hour high temperature and high humidity test and an extreme temperature cycle test, which will be explained in detail in Experimental Examples 2 and 3 below.

[0072] Experimental Example 2: Long-term High Temperature and High Humidity Test

[0073] Through Experimental Example 1, it was confirmed that a photovoltaic module with a cell edge sealing material (PET / EVA) secured excellent insulation resistance characteristics of 99.9 GΩ.

[0074] Experimental Example 2 was conducted to determine the long-life reliability of a photovoltaic module with a cell edge sealing material (PET / EVA) and a photovoltaic module with both a cell edge sealing material (PET / EVA) and a module edge sealing material (PIB). The test conditions for Experimental Example 2 complied with the KS standard KS C 8561:2020 and were conducted for 2,000 hours (November 4, 2024 – February 3, 2025) under conditions of a temperature of 85±2 ℃ and a relative humidity (RH) of 85±5 %. This long-term high-temperature and high-humidity test was conducted by the Korea Institute of Construction & Living Environment Testing.

[0075] Photovoltaic modules of Comparative Examples 4-5 and Examples 3-4 were fabricated for a long-term high temperature and high humidity test. Comparative Examples 4-5 and Examples 3-4 are all photovoltaic modules with a G to G structure, and POE is applied as the encapsulant.

[0076] In addition, Comparative Example 4 is one in which neither the cell edge sealing material nor the module edge sealing material is applied, Comparative Example 5 is one in which the module edge sealing material (PIB) is applied, Example 3 is one in which the cell edge sealing material (PET / EVA) is applied, and Example 4 is one in which both the cell edge sealing material (PET / EVA) and the module edge sealing material (PIB) are applied. For all Comparative Examples 4–5 and Examples 3–4, the solar modules were manufactured with a size of 782 mm x 1568 mm. FIG. 6 is a photograph of the solar module according to Example 3 manufactured for Experimental Example 2.

[0077] Table 2 below shows the maximum output reduction rate after long-term high temperature and high humidity tests of Comparative Examples 4–5 and Examples 3–4, and Table 3 shows the characteristics such as photoelectric conversion efficiency after long-term high temperature and high humidity tests of Comparative Examples 4–5 and Examples 3–4.

[0078] Sample Pre-test output Output after test Maximum output reduction rate Comparative Example 4 - 238.81 W 236.38 W 1.46 % Comparative Example 5 PIB 236.58 W 236.25 W 0.57 % Example 3 PET / EVA 236.54 W 237.20 W - 0.56 % Example 4 PET / EVA + PIB 236.82 W 236.93 W 0.38 %

[0079] Sample V OC (V) I SC (A) V MP (V) I MP (A) Efficiency (%) Comparative Example 4 Before the exam 20.68 14.78 16.58 14.41 19.50 After the exam 20.67 14.71 16.50 14.26 19.22 Comparative Example 5 Before the exam 20.68 14.54 16.62 14.24 19.32 After the exam 20.68 14.46 16.65 14.13 19.21 Example 3 Before the exam 20.67 14.75 16.59 14.27 19.48 After the exam 20.71 14.71 16.62 14.27 19.37 Example 4 Before the exam 20.62 14.59 16.59 14.27 19.34 After the exam 20.64 14.52 16.65 14.24 19.27

[0080] Referring to Table 2, the maximum output reduction rate after the long-term high temperature and high humidity test of Comparative Example 4, in which neither cell edge sealing material nor module edge sealing material was applied, was found to be -1.46%. This figure sufficiently satisfies the maximum output reduction of less than 5% required by the KS standard, indicating that long-life reliability is secured even by applying POE as a sealing material.

[0081] In the case of Comparative Example 5, where a module edge sealing material (PIB) was applied, the maximum output reduction rate was -0.57%, and in the case of Example 3, where a cell edge sealing material (PET / EVA) was applied, the maximum output reduction rate was -0.56%, showing similar characteristics. These figures demonstrate that the maximum output reduction characteristics can be further improved by applying a cell edge sealing material (PET / EVA) while POE is used as the encapsulant. Furthermore, it can be seen that excellent maximum output reduction characteristics can be secured by applying a module edge sealing material (PIB) while POE is used as the encapsulant.

[0082] Finally, in the case of Example 4, in which both cell edge sealing material (PET / EVA) and module edge sealing material (PIB) were applied, the maximum output reduction rate was -0.38%, showing the best characteristics. Through these results, it can be seen that the maximum output reduction characteristics can be further improved by applying the edge sealing structure according to the present invention.

[0083] Referring to Table 3, it can be confirmed that Comparative Examples 4 and 5 and Examples 3 and 4 all exhibit good characteristics, such as photoelectric conversion efficiency, after a long-term high temperature and high humidity test.

[0084] For reference, FIGS. 5a and 5b are test reports issued by the Korea Institute of Construction and Living Environment Testing for the long-term high temperature and high humidity test of Experimental Example 2 of this study, and in FIG. 5b, Sample No. (1) corresponds to Comparative Example 4, Sample No. (2) corresponds to Example 3, Sample No. (3) corresponds to Example 4, and Sample No. (4) corresponds to Comparative Example 5.

[0085] Experimental Example 3: Temperature Cycle Test

[0086] A temperature cycle test was conducted to further verify long-life reliability. The test conditions of Experimental Example 3 complied with the KS standard KS C 8561:2020, and the temperature cycle was repeated 400 times from 85±2℃ to -40±2℃. This temperature cycle test was conducted by the Korea Institute of Construction & Living Environment Testing, and the test period was from November 4, 2024 to February 3, 2025.

[0087] Photovoltaic modules of Comparative Examples 6–7 and Examples 5–6 were fabricated for a temperature cycle test. Comparative Examples 6–7 and Examples 5–6 are all photovoltaic modules with a G to G structure, and POE is applied as the encapsulant.

[0088] In addition, Comparative Example 5 is one in which neither the cell edge sealing material nor the module edge sealing material is applied, Comparative Example 6 is one in which the module edge sealing material (PIB) is applied, Example 5 is one in which the cell edge sealing material (PET / EVA) is applied, and Example 6 is one in which both the cell edge sealing material (PET / EVA) and the module edge sealing material (PIB) are applied. For Comparative Examples 6–7 and Examples 5–6, the solar modules were manufactured with a size of 782 mm x 1566 mm. FIG. 8 is a photograph of the solar module according to Example 6 manufactured for Experimental Example 3.

[0089] Table 4 below shows the maximum output reduction rate after 400 temperature cycle tests of Comparative Examples 6–7 and Examples 5–6, and Table 5 shows the characteristics such as photoelectric conversion efficiency after 400 temperature cycle tests of Comparative Examples 6–7 and Examples 5–6.

[0090] Sample Pre-test output Output after test Maximum output reduction rate Comparative Example 6 - 237.39 W 235.92 W 1.92 % Comparative Example 7 PIB 236.37 W 233.87 W 1.07 % Example 5 PET / EVA 236.77 W 234.26 W - 1.07 % Example 6 PET / EVA + PIB 237.90 W 235.55 W 1.00 %

[0091] Sample V OC (V) I SC (A) V MP (V) I MP (A) Efficiency (%) Comparative Example 6 Before the exam 20.69 14.57 16.67 14.24 19.38 After the exam 20.63 14.51 16.48 14.13 19.02 Comparative Example 7 Before the exam 20.63 14.58 16.60 14.24 19.30 After the exam 20.65 14.52 16.51 14.17 19.10 Example 5 Before the exam 20.64 14.55 16.64 14.23 19.33 After the exam 20.64 14.51 16.62 14.10 19.13 Example 6 Before the exam 20.63 14.66 16.63 14.30 19.43 After the exam 20.66 14.55 16.60 14.19 19.23

[0092] Referring to Table 4, it can be seen that the trend of the temperature cycle test results is consistent with the long-term high temperature and high humidity test results.

[0093] Specifically, the maximum output degradation rate after the temperature cycle test of Comparative Example 6, in which neither the cell edge sealing material nor the module edge sealing material was applied, was found to be -1.92%. This figure sufficiently satisfies the maximum output degradation of less than 5% required by the KS standard, indicating that long-life reliability is secured even by applying POE as a sealing material.

[0094] In addition, the maximum output reduction rate of Comparative Example 7, in which a module edge sealing material (PIB) was applied, and the maximum output reduction rate of Example 5, in which a cell edge sealing material (PET / EVA) was applied, were both -1.07%, indicating that the maximum output reduction characteristics can be improved by additionally applying a cell edge sealing material (PET / EVA) and a module edge sealing material (PIB) while the POE encapsulant is applied.

[0095] In the case of Example 6, in which both cell edge sealing material (PET / EVA) and module edge sealing material (PIB) were applied, the maximum output reduction rate was -1.00%, showing the best characteristics. Through these results, it can be seen that the maximum output reduction characteristics can be further improved by applying the edge sealing structure according to the present invention.

[0096] Referring to Table 5, it can be confirmed that Comparative Examples 6 and 7 and Examples 5 and 6 all have good characteristics, such as photoelectric conversion efficiency, after 400 temperature cycle tests.

[0097] For reference, FIGS. 7a and 7b are test reports issued by the Korea Institute of Construction and Living Environment Testing for the temperature cycle test of Experimental Example 3, and in FIG. 7b, Sample No. (1) corresponds to Example 6, Sample No. (2) corresponds to Example 5, Sample No. (3) corresponds to Comparative Example 7, and Sample No. (4) corresponds to Comparative Example 6. Explanation of the symbols

[0098] 110: First substrate 121: Lower encapsulating material 122 : Top encapsulating material 130 : Solar cell 140 : Cell edge sealing material 150 : Module edge sealing material 160 : Second substrate

Claims

Claim 1 The first substrate and the second substrate are each divided into an encapsulation area where an encapsulation material is provided and a module edge sealing area on the outside thereof, a solar cell and a cell edge sealing material are interposed between the first substrate and the second substrate, and based on the edge of the solar cell, the cell edge sealing material is arranged to include a certain area inside the edge and a certain area outside the edge, both the first substrate and the second substrate are made of colored glass, the solar cell is a double-sided light-receiving solar cell, and the cell edge sealing material has a dark background color on both sides, a lower encapsulation material and a solar cell are sequentially stacked on the encapsulation area of ​​the first substrate, a cell edge sealing material is provided on the solar cell, the cell edge sealing material is arranged to include a certain area inside the edge of the solar cell and a certain area outside the edge of the solar cell, an upper encapsulation material is provided on the cell edge sealing material, and on the upper encapsulation material A double-sided light-receiving double-sided color solar module having an edge-sealing structure, characterized in that the edge of the cell edge-sealing material is exposed, the module edge-sealing material is provided in the module edge-sealing area of ​​the first substrate, a part of the module edge-sealing material is located in the exposed edge area of ​​the cell edge-sealing material and another part is located on the first substrate, and a second substrate is provided to cover both the upper encapsulant and the module edge-sealing material. Claim 2 delete Claim 3 A double-sided light-receiving double-sided color solar module having an edge sealing structure, characterized in that, in claim 1, the stacking position of the cell edge sealing material is fixed by the module edge sealing material. Claim 4 A double-sided light-receiving double-sided color solar module having an edge sealing structure, wherein, in claim 1, the cell edge sealing material is composed of a substrate and a sealing material coated on at least one surface of the substrate. Claim 5 A double-sided light-receiving double-sided color solar module having an edge-sealing structure, characterized in that, in claim 4, the substrate is made of PI (Polyimide) or PET (Polyethylene Terephthalate). Claim 6 A double-sided light-receiving double-sided color solar module having an edge sealing structure, characterized in that, in claim 4, the encapsulating material is an upper encapsulating material and a lower encapsulating material, and the encapsulating material and the sealing material are made of different materials. Claim 7 A double-sided light-receiving double-sided color solar module having an edge-sealing structure, characterized in that, in claim 6, the encapsulating material is made of POE (polyolefin elastomer) and the sealing material is made of EVA (ethylene vinyl acetate). Claim 8 A double-sided light-receiving double-sided color solar module having an edge sealing structure, characterized in that, in claim 1, the module edge sealing material is made of PIB (polyisobutylene). Claim 9 A method for manufacturing a double-sided light-receiving double-sided color solar module having an edge-sealing structure, wherein a first substrate and a second substrate are each divided into an encapsulation area where an encapsulation material is provided and a module edge-sealing area outside the same, and a lower encapsulation material and a solar cell are sequentially stacked on the encapsulation area of ​​the first substrate, and a cell edge-sealing material and an upper encapsulation material are sequentially stacked on the solar cell, and a module edge-sealing material is stacked on the module edge-sealing area of ​​the first substrate; a step of stacking a second substrate to cover both the upper encapsulation material and the module edge-sealing material; and a step of performing lamination; wherein the edge of the cell edge-sealing material is exposed by the upper encapsulation material, and a part of the module edge-sealing material is located in the exposed edge area of ​​the cell edge-sealing material, and another part is located on the first substrate. Claim 10 delete Claim 11 A method for manufacturing a double-sided light-receiving double-sided color type solar module having an edge sealing structure, characterized in that, in claim 9, the stacking position of the cell edge sealing material is fixed by the module edge sealing material during lamination. Claim 12 A method for manufacturing a double-sided light-receiving double-sided color type photovoltaic module having an edge sealing structure, wherein, in claim 9, the cell edge sealing material comprises a substrate and a sealing material coated on at least one surface of the substrate. Claim 13 A method for manufacturing a double-sided light-receiving double-sided color solar module having an edge-sealing structure, characterized in that, in claim 12, the substrate is made of PI (Polyimide) or PET (Polyethylene Terephthalate). Claim 14 A method for manufacturing a double-sided light-receiving double-sided color solar module having an edge sealing structure, characterized in that, in claim 12, the encapsulating material is an upper encapsulating material and a lower encapsulating material, and the encapsulating material and the sealing material are made of different materials. Claim 15 A method for manufacturing a double-sided light-receiving double-sided color solar module having an edge sealing structure, characterized in that, in claim 14, the encapsulating material is made of POE (polyolefin elastomer) and the sealing material is made of EVA (ethylene vinyl acetate). Claim 16 A method for manufacturing a double-sided light-receiving double-sided color solar module having an edge sealing structure, characterized in that, in claim 9, the module edge sealing material is made of PIB (polyisobutylene).

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