Photovoltaic power generator

Abstract

The purpose of the present invention is to provide a photovoltaic power generator having high durability even in a case of being fixed by a method of opening a hole in the photovoltaic power generator. This photovoltaic power generator (1) comprises: a power generation unit (11); a sealing layer (12) which seals the entirety of the power generation unit (11); a front sheet (13) which is laminated on the surface of the sealing layer (12) on the light-receiving surface side; a back sheet (14) which is laminated on the surface of the sealing layer (12) on the reverse side of the light-receiving surface; through-holes (3) which are provided along at least one side of the front sheet (13) to penetrate a plurality of sites on the front sheet (13); and fixing members (4) that pass through the through-holes (3). The photovoltaic power generator (1) is characterized in that: the power generation unit (11) and the sealing layer (12) are laminated on the inner side of the peripheral edge of the front sheet (13); the front sheet (13) covers the surface on the light-receiving surface side and the entire side surface of the sealing layer (12); and the through-holes (3) are not in contact with the sealing layer (12).

Description

Solar power generation equipment

[0001] This invention relates to a solar power generation device.

[0002] Traditionally, rigid solar panels made of silicon semiconductors have been widely used as solar cells. However, conventional solar panels have a certain weight, making them unsuitable for installation on some structures with low load-bearing capacity, or they cannot be installed on areas with low load-bearing capacity even on suitable installation surfaces, thus hindering the effective utilization of the installation surface area. Therefore, in recent years, flexible solar cells based on heat-resistant polymer materials such as polyimide and polyester, or metal foil, have been attracting attention. Flexible solar cells have advantages such as ease of transport and installation due to their thinness and lightness, and resistance to impact, making them suitable for installation on corrugated metal roofs and other structures where installation was previously difficult due to load-bearing capacity issues. Although a method for installing solar power generation sheets using flexible solar cells has not yet been established, Patent Document 1 discloses a solar cell sheet that is fixed by sewing it with thread-like material as a method for fixing the sheet.

[0003] Japanese Patent Publication No. 2011-181566

[0004] However, fixing flexible solar cells using thread-like materials as described in Patent Document 1, or by making holes with a tacker or stapler, had the problem of reducing the durability of the flexible solar cells.

[0005] The present invention aims to provide a highly durable solar power generation device, even when fixed by drilling holes in the device.

[0006] The present invention includes the following disclosures 1 to 8. The present invention will be described in detail below. [Disclosure 1] A photovoltaic power generation device comprising: a power generation unit; a sealing layer that seals the entire power generation unit; a front sheet laminated on the light-receiving surface side of the sealing layer; a back sheet laminated on the surface of the sealing layer opposite to the light-receiving surface; through holes provided along at least one side of the front sheet and penetrating multiple locations of the front sheet; and a fixing member passing through the through holes, wherein the power generation unit and the sealing layer are laminated inward from the peripheral edge of the front sheet; the front sheet covers the entire light-receiving surface and side of the sealing layer; and the through holes do not come into contact with the sealing layer. [Disclosure 2] The photovoltaic power generation device according to disclosure 1, further comprising a frame member disposed on the front sheet so as to surround the portion of the front sheet that comes into contact with the side of the sealing layer. [Disclosure 3] The photovoltaic power generation device according to disclosure 1 or 2, further comprising a frame member disposed on the front sheet so as to surround the portion of the front sheet that comes into contact with the side of the sealing layer. [Disclosure 4] The photovoltaic power generation device according to Disclosure 1 or 2, characterized in that the minimum distance between the power generation unit and the through-hole is 5 mm or more. [Disclosure 5] The photovoltaic power generation device according to any one of Disclosures 1 to 4, characterized in that the front sheet and the back sheet have a sheet-like member on the side opposite to the light-receiving surface, and the through-hole penetrates the front sheet and the sheet-like member. [Disclosure 6] The photovoltaic power generation device according to any one of Disclosures 1 to 5, characterized in that the power generation unit and the sealing layer are laminated inward from the peripheral edge of the back sheet, the light-receiving surface side of the back sheet and the surface opposite to the light-receiving surface side of the front sheet are in contact, and the through-hole penetrates the front sheet and the back sheet. [Disclosure 7] The photovoltaic power generation device according to any one of Disclosures 1 to 6, characterized in that the diameter of the through-hole is 0.3 mm or more and 3.0 mm or less. [Disclosure 8] The photovoltaic power generation device according to any one of Disclosures 1 to 7, characterized in that the pitch of the through-hole is 1.0 mm or more and 15.0 mm or less.

[0007] According to the present invention, it is possible to provide a highly durable solar power generation device even when it is fixed by drilling holes in the solar power generation device.

[0008] This is a schematic cross-sectional view of an example of the photovoltaic power generation device of the present invention. This is a schematic top view of an example of the photovoltaic power generation device of the present invention. This is a schematic cross-sectional view of yet another example of the photovoltaic power generation device of the present invention. This is a schematic cross-sectional view of yet another example of the photovoltaic power generation device of the present invention.

[0009] The present invention will be described in more detail below with reference to specific embodiments, but the present invention is not limited to these embodiments.

[0010] (Embodiment 1) Figure 1 shows a schematic cross-sectional view of an example of the photovoltaic power generation device of the present invention, and Figure 2 shows a schematic top view of an example of the photovoltaic power generation device of the present invention. The photovoltaic power generation device 1 of Embodiment 1 has a power generation unit 11, a sealing layer 12 that seals the entire power generation unit 11, a front sheet 13 laminated on the light-receiving surface side of the sealing layer 12, and a back sheet 14 laminated on the side of the sealing layer 12 opposite to the light-receiving surface. Furthermore, the sealing layer 12, the power generation unit 11, and the back sheet 14 are laminated inward from the peripheral edge of the front sheet 13; that is, the peripheral edge of the front sheet 13 is located outside the peripheral edges of the sealing layer 12, the power generation unit 11, and the back sheet 14. The front sheet 13 covers the entire light-receiving surface and side of the sealing layer 12 and the side of the back sheet 14, and has multiple through holes 3 along at least one side. The through-hole 3 also penetrates the sheet-like member 2, which is positioned on the side of the front sheet 13 and back sheet 14 opposite to the light-receiving surface. The fixing member 4 secures the solar power generation device 1 to the sheet-like member 2 through the through-hole 3. Furthermore, the through-hole 3 is positioned so as not to come into contact with the sealing layer 12. Here, the light-receiving surface refers to the side onto which light enters when the solar power generation device is installed.

[0011] The inventors investigated the cause of reduced durability when conventional flexible solar cells are fixed by sewing, and found that the cause is the passage of through-holes created during fixing through the encapsulating layer. In flexible solar cells, the adhesion between the encapsulating layer and the layer in contact with it is important, and in many cases, some compromise must be made regarding water vapor barrier performance. When through-holes are formed through such a encapsulating layer with low water vapor barrier performance, moisture penetrates through the encapsulating layer in contact with the through-hole and reaches the power generation section, degrading the power generation section. To address this problem, one might consider pre-creating through-holes and reinforcing them with eyelets. However, while reinforcement with eyelets is effective when the number of through-holes is small and the diameter of the through-holes is large, when the solar cells are fixed by sewing, the spacing between the stitching holes becomes narrow, making it difficult to pre-reinforce through-holes with eyelets. On the other hand, if the spacing between stitching holes is wide, the flexible solar cell cannot be sufficiently fixed, which can cause it to fall off. In this invention, by preventing the through-holes from contacting the sealing layer, that is, by not providing a sealing layer at the fixed parts of the photovoltaic power generation device, the intrusion of moisture from the through-holes can be suppressed, thereby improving durability. Furthermore, since the front sheet covers the entire light-receiving surface and sides of the sealing layer, the sealing layer is not exposed to the outside, further enhancing durability.

[0012] The above-mentioned power generation unit is the part that converts sunlight into electricity, and is composed of a substrate, electrodes, counter electrodes, a photoelectric conversion layer, an electron transport layer, a hole transport layer, etc., and has at least electrodes, a photoelectric conversion layer, and counter electrodes. In this specification, "layer" means not only layers with clear boundaries, but also layers with a concentration gradient in which the contained elements change gradually. Elemental analysis of a layer can be performed, for example, by FE-TEM / EDS line analysis of a cross-section of the solar cell to confirm the elemental distribution of specific elements. Furthermore, in this specification, "layer" means not only flat, thin-film layers, but also layers that can form a complex, interwoven structure together with other layers.

[0013] Examples of the above-mentioned substrates include resin films made of polyimide or polyester-based heat-resistant polymers, metal foils, and thin glass sheets. Among these, PET resin films are preferred from the viewpoint of cost and heat resistance.

[0014] The materials for the electrodes and counter electrodes are not particularly limited and include, for example, FTO (fluorine-doped tin oxide), ITO (tin-doped indium oxide), AZO (aluminum zinc oxide), IZO (indium zinc oxide), GZO (gallium zinc oxide), sodium, sodium-potassium alloy, lithium, magnesium, aluminum, magnesium-silver mixture, magnesium-indium mixture, aluminum-lithium alloy, Al / Al ２ O ３ Examples include mixtures, Al / LiF mixtures, etc. Also, gold, silver, titanium, molybdenum, tantalum, tungsten, carbon, nickel, chromium, etc. These materials may be used individually or in combination of two or more.

[0015] The thickness of the electrode and counter electrode is not particularly limited, but a preferred lower limit is 10 nm and a preferred upper limit is 1000 nm. If the thickness is 10 nm or more, the electrode can function while suppressing resistance. If the thickness is 1000 nm or less, the light transmittance can be further improved. A more preferred lower limit for the thickness of the electrode and counter electrode is 50 nm and a more preferred upper limit is 500 nm.

[0016] The above-mentioned photoelectric conversion layer preferably contains an organic-inorganic perovskite compound. The organic-inorganic perovskite compound is a compound represented by the general formula AMX (where A is an organic base compound and / or alkali metal, M is a lead or tin atom, and X is a halogen atom), and a solar cell containing such an organic-inorganic perovskite compound is also called an organic-inorganic hybrid solar cell. By using the above-mentioned organic-inorganic perovskite compound in the photoelectric conversion layer of the power generation section, the photoelectric conversion efficiency of the solar power generation device can be further improved.

[0017] The above A is an organic base compound and / or alkali metal. Specifically, the above organic base compounds include, for example, methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, ethylmethylamine, methylpropylamine, butylmethylamine, methylpentylamine, hexylmethylamine, ethylpropylamine, ethylbutylamine, formamidine, acetamidine, guanidine, imidazole, azole, pyrrole, aziridine, azirine, azetidine, azeto, azole, imidazoline, carbazole and their ions (for example, methylammonium (CH4) ３ NH ３ Examples include ) and phenethylammonium. Among these, methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, formamidine, acetamidine and their ions and phenethylammonium are preferred, and methylamine, ethylamine, propylamine, formamidine and their ions are more preferred. Examples of the alkali metals mentioned above include lithium, sodium, potassium, rubidium, cesium, etc.

[0018] The above M is a metal atom, which is either a lead or tin atom. These metal atoms may be used individually or in combination of two or more types.

[0019] The above X is a halogen atom, and examples of halogen atoms include chlorine, bromine, iodine, sulfur, and selenium. These halogen atoms may be used individually or in combination of two or more. By including a halogen in the structure, the above organic-inorganic perovskite compound becomes soluble in organic solvents, making it possible to apply it to inexpensive printing methods and the like. In particular, X is preferably iodine because it narrows the energy band gap of the above organic-inorganic perovskite compound.

[0020] The above organic-inorganic perovskite compound preferably has a cubic crystal structure in which a metal atom M is located at the body center, an organic base compound or alkali metal A is located at each vertex, and a halogen atom X is located at the face center. Although the details are not clear, it is presumed that having the above structure allows the orientation of the octahedra in the crystal lattice to change easily, thereby increasing the electron mobility in the organic-inorganic perovskite compound and improving the photoelectric conversion efficiency of the solar cell.

[0021] The above organic-inorganic perovskite compound is preferably a crystalline semiconductor. A crystalline semiconductor is a semiconductor in which the X-ray scattering intensity distribution can be measured and a scattering peak can be detected. The crystalline nature of the organic-inorganic perovskite compound increases the electron mobility within it, thereby improving the photoelectric conversion efficiency of the solar power generation device.

[0022] Furthermore, the degree of crystallinity can also be evaluated as an indicator of crystallization. The degree of crystallinity can be determined by separating the scattering peaks originating from the crystalline portion and the halos originating from the amorphous portion, detected by X-ray scattering intensity distribution measurement, by fitting them together, calculating the integral of each intensity, and then calculating the ratio of the crystalline portion to the whole. The preferred lower limit for the degree of crystallinity of the above organic-inorganic perovskite compound is 30%. When the degree of crystallinity is 30% or higher, the electron mobility in the above organic-inorganic perovskite compound increases, improving the photoelectric conversion efficiency of the solar cell. A more preferred lower limit for the degree of crystallinity is 50%, and an even more preferred lower limit is 70%. In addition, methods for increasing the degree of crystallinity of the above organic-inorganic perovskite compound include, for example, thermal annealing, irradiation with high-intensity light such as lasers, and plasma irradiation.

[0023] Said photoelectric conversion layer may further contain an organic semiconductor or an inorganic semiconductor in addition to said organic-inorganic perovskite compound, as long as the effects of the present invention are not impaired. The organic semiconductor or inorganic semiconductor mentioned herein may function as a hole transport layer or an electron transport layer. Examples of said organic semiconductors include compounds having a thiophene skeleton such as poly(3-alkylthiophene). Other examples include conductive polymers having a polyparaphenylene vinylene skeleton, a polyvinylcarbazole skeleton, a polyaniline skeleton, a polyacetylene skeleton, and the like. Further examples include compounds having a porphyrin skeleton such as a phthalocyanine skeleton, a naphthalocyanine skeleton, a pentacene skeleton, a benzoporphyrin skeleton, a spirobifluorene skeleton, etc., and carbon-containing materials such as optionally surface-modified carbon nanotubes, graphene, and fullerenes.

[0024] Examples of said inorganic semiconductors include titanium oxide, zinc oxide, indium oxide, tin oxide, gallium oxide, tin sulfide, indium sulfide, zinc sulfide, CuSCN, Cu ２ O, CuI, MoO ３ , V ２ O ５ , WO ３ , MoS ２ , MoSe ２ , Cu ２ S, and the like.

[0025] When said photoelectric conversion layer contains said organic-inorganic perovskite compound and said organic semiconductor or said inorganic semiconductor, it may be a laminate obtained by laminating a thin-film organic semiconductor or inorganic semiconductor portion and a thin-film organic-inorganic perovskite compound portion, or may be a composite film obtained by compositing an organic semiconductor or inorganic semiconductor portion and an organic-inorganic perovskite compound portion. A laminate is preferable from the viewpoint of simple production process, and a composite film is preferable from the viewpoint that charge separation efficiency in said organic semiconductor or said inorganic semiconductor can be improved.

[0026] The thickness of the thin film-like organic-inorganic perovskite compound portion described above has a preferred lower limit of 5 nm and a preferred upper limit of 5000 nm. If the thickness is 5 nm or more, sufficient light absorption becomes possible, and the photoelectric conversion efficiency increases. If the thickness is 5000 nm or less, the occurrence of regions where charge separation is not possible can be suppressed, leading to an improvement in photoelectric conversion efficiency. A more preferred lower limit for the thickness is 10 nm, a more preferred upper limit is 1000 nm, an even more preferred lower limit is 20 nm, and an even more preferred upper limit is 500 nm.

[0027] When the photoelectric conversion layer is a composite film formed by combining an organic semiconductor or inorganic semiconductor portion with an organic-inorganic perovskite compound portion, the preferred lower limit of the thickness of the composite film is 30 nm, and the preferred upper limit is 3000 nm. If the thickness is 30 nm or more, sufficient light can be absorbed, and the photoelectric conversion efficiency will be high. If the thickness is 3000 nm or less, the charge can reach the electrodes more easily, and the photoelectric conversion efficiency will be high. A more preferred lower limit of the thickness is 40 nm, a more preferred upper limit is 2000 nm, an even more preferred lower limit is 50 nm, and an even more preferred upper limit is 1000 nm.

[0028] The method for forming the above-mentioned photoelectric conversion layer is not particularly limited and includes methods such as vacuum deposition, sputtering, vapor deposition (CVD), electrochemical deposition, and printing. In particular, by employing the printing method, solar cells that can exhibit high photoelectric conversion efficiency can be easily formed over a large area. Examples of printing methods include spin coating and casting, and methods using the printing method include roll-to-roll.

[0029] The above-mentioned power generation unit may have an electron transport layer between the electrode acting as the cathode or the counter electrode and the photoelectric conversion layer. The material of the electron transport layer is not particularly limited and includes, for example, N-type conductive polymers, N-type low molecular weight organic semiconductors, N-type metal oxides, N-type metal sulfides, alkali metal halides, alkali metals, surfactants, etc. Specifically, examples include cyano group-containing polyphenylene vinylene, boron-containing polymers, vasocuproin, vasophenanthrene, hydroxyquinolinatoaluminum, oxadiazole compounds, benzimidazole compounds, naphthalenetetracarboxylic acid compounds, perylene derivatives, phosphine oxide compounds, phosphine sulfide compounds, fluoro group-containing phthalocyanines, titanium dioxide, zinc oxide, indium oxide, tin oxide, gallium oxide, tin sulfide, indium sulfide, zinc sulfide, etc.

[0030] The electron transport layer described above may consist only of a thin-film electron transport layer, but it is preferable to include a porous electron transport layer. In particular, when the photoelectric conversion layer is a composite film formed by combining an organic semiconductor or inorganic semiconductor portion with an organic-inorganic perovskite compound portion, a more complex composite film (a more intricately interwoven structure) can be obtained, and the photoelectric conversion efficiency is higher, so it is preferable that the composite film is fabricated on a porous electron transport layer.

[0031] The preferred lower limit for the thickness of the electron transport layer is 1 nm, and the preferred upper limit is 2000 nm. If the thickness is 1 nm or more, holes can be sufficiently blocked. If the thickness is 2000 nm or less, it will not be a resistance during electron transport, and the photoelectric conversion efficiency will be high. A more preferred lower limit for the thickness of the electron transport layer is 3 nm, a more preferred upper limit is 1000 nm, an even more preferred lower limit is 5 nm, and an even more preferred upper limit is 500 nm.

[0032] The above-mentioned power generation unit may have a hole transport layer between the electrodes or counter electrodes that make up the anode and cathode and the photoelectric conversion layer. The material of the hole transport layer is not particularly limited, and the hole transport layer may be made of an organic material. Examples of materials for the hole transport layer include P-type conductive polymers, P-type low molecular weight organic semiconductors, P-type metal oxides, P-type metal sulfides, surfactants, etc. Specifically, examples include compounds having a thiophene skeleton such as poly(3-alkylthiophene). Also, examples include conductive polymers having a triphenylamine skeleton, poly(p-phenylenevinylene) skeleton, polyvinylcarbazole skeleton, polyaniline skeleton, polyacetylene skeleton, etc. Furthermore, examples include compounds having phthalocyanine skeletons, naphthalocyanine skeletons, pentacene skeletons, porphyrin skeletons such as benzoporphyrin skeletons, spirobifluorene skeletons, molybdenum sulfide, tungsten sulfide, copper sulfide, tin sulfide, fluoro group-containing phosphonic acids, carbonyl group-containing phosphonic acids, copper compounds such as CuSCN and CuI, etc.

[0033] The above-mentioned power generation unit may be formed on a substrate. Examples of the substrate include resin films made of polyimide or polyester-based heat-resistant polymers, metal foils, thin glass sheets, etc. In particular, from the viewpoint of flexibility and transparency, the substrate is preferably made of polyethylene terephthalate, polyethylene, polypropylene, polyethylene naphthalate, polymethyl methacrylate, polystyrene, or polycarbonate.

[0034] The above-mentioned substrate is preferably 30 μm or more and 200 μm or less in thickness. A substrate thickness within this range can further enhance handling and flexibility. A substrate thickness of 50 μm or more is more preferable, and 70 μm or more is even more preferable. From the viewpoint of further enhancing flexibility, a substrate thickness of 150 μm or less is more preferable, and 100 μm or less is even more preferable.

[0035] The sealing material that forms the main component of the sealing layer described above only needs to be able to seal the power generation unit. Specific examples of the sealing material include thermosetting resins, thermoplastic resins, or inorganic materials. Examples of thermosetting resins or thermoplastic resins include epoxy resins, acrylic resins, silicone resins, phenolic resins, melamine resins, and urea resins. Other examples include butyl rubber, polyester, polyurethane, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl alcohol, polyvinyl acetate, ABS resin, polybutadiene, polyamide, polycarbonate, polyimide, polyisobutylene, and polyisoprene. In particular, when the power generation unit contains an organic-inorganic perovskite compound in the photoelectric conversion layer, the durability of the power generation unit over time can be further enhanced, therefore, polybutadiene, polyisobutylene, polyisoprene, and butyl rubber, which are resins having at least one skeleton selected from the group consisting of polybutadiene, polyisobutylene, and polyisoprene, are preferred.

[0036] The thickness of the sealing layer is preferably 10 μm or more, more preferably 50 μm or more, more preferably 1000 μm or less, and more preferably 700 μm or less, from the viewpoint of balancing the protective performance and flexibility of the power generation section. Here, the thickness of the sealing layer refers to the maximum thickness of the portion consisting only of the sealing layer.

[0037] The front sheet described above is placed on the outermost surface of the upper side of the flexible solar cell and plays a role in suppressing light reflection and improving the drainage performance of the flexible solar cell surface by forming patterns such as irregularities and arcs on its surface. The material of the front sheet is not particularly limited as long as it is transparent, and examples include fluorine-containing resins, vinyl chloride resins, polyethylene resins, and polycarbonate resins. Specifically, examples include polycarbonate, polyvinyl chloride, tetrafluoroethylene resin, polyvinylidene fluoride, and polychlorotrifluoroethylene. Among these, fluorine-containing resins are preferred because they have excellent weather resistance.

[0038] The thickness of the front sheet is not particularly limited, but from the viewpoint of the balance between light transmittance and the functionality of the front sheet, it is preferably 25 µm or more, more preferably 50 µm or more, preferably 1000 µm or less, and more preferably 300 µm or less.

[0039] The back sheet functions to prevent the intrusion of substances that cannot be completely blocked only by the sealing layer, thereby improving the weather resistance of the flexible solar cell. In particular, in perovskite solar cells, the options for the sealing layer in contact with the power generation unit are limited due to compatibility issues with the power generation unit, and a generally used resin material having excellent water vapor transmittance cannot be used. In addition, moisture is likely to accumulate on the installation surface side of the photovoltaic power generation device, and deterioration due to moisture is more likely to occur. Therefore, when an organic-inorganic perovskite compound is used for the power generation unit, the back sheet is preferably made of a material with low water vapor transmittance. Examples of the material for the back sheet include polyethylene terephthalate and the like.

[0040] The thickness of the back sheet is not particularly limited, but from the viewpoint of the balance between flexibility and the functionality of the back sheet, it is preferably 50 µm or more, more preferably 100 µm or more, preferably 1000 µm or less, and more preferably 500 µm or less.

[0041] The fixing member only needs to be able to penetrate the front sheet and fix the photovoltaic power generation device to an installation surface such as a sheet-like member, and examples thereof include thread-like members, tucker needles, stapler needles, and staples. Among these, a thread-like member is preferable because it is easily elastically deformed and thus the fixing strength can be easily adjusted by tension. In particular, photovoltaic power generation devices and sheet-like members are often laminates obtained by laminating various materials, and often include both a hard layer and a soft layer. Therefore, it is necessary to adjust the fixing strength as appropriate, so that balanced fixing can be achieved by adjusting the tension when sewing the thread-like member. Examples of the material for the thread-like member include synthetic fibers, metal fibers, glass fibers, carbon fibers and the like. The thread-like member may be either a monofilament or a multifilament.

[0042] Preferably, the filamentous member has weather resistance. Examples of materials having weather resistance include weather-resistant nylon, PTFE, and polyester. Since the filamentous member has weather resistance, the fixing force can be maintained for a long time even when the filamentous member is installed in an outdoor exposed state.

[0043] Preferably, the filamentous member is covered with a cover member. By covering the filamentous member with the cover member, even when the filamentous member itself does not have weather resistance, the fixing force can be maintained outdoors for a long time, and the influence of water can be suppressed. Examples of the cover member include a tape material, a filler and the like, and it is particularly preferable that the cover member has weather resistance.

[0044] Preferably, the cover member is opaque. Since the cover member is opaque, light is less likely to hit the filamentous member, so deterioration of the filamentous member caused by light can be suppressed.

[0045] Preferably, the thickness of the filamentous member is equivalent to or greater than No. 20 in yarn count conversion. When the thickness of the filamentous member is equivalent to or greater than No. 20 in yarn count conversion, when water comes into contact with the filamentous member, water-caused spaces are formed between the filaments constituting the filamentous member, so that the filamentous member expands. Therefore, the gap between the through hole and the filamentous member is reduced, and the progression of water can be suppressed. More preferably, the thickness of the filamentous member is equivalent to or greater than No. 10 in yarn count conversion, and still more preferably equivalent to or greater than No. 8 in yarn count conversion.

[0046] Preferably, when the diameter of the filamentous member in a dry state is defined as 1, the diameter after immersion in water is 1.05 times or more. When the expansion rate of the diameter of the filamentous member is equal to or higher than the above lower limit, when water comes into contact with the filamentous member, water-caused spaces are formed between the filaments constituting the filamentous member to cause expansion, thereby suppressing the progression of water. More preferably, the expansion rate of the diameter of the filamentous member is 1.1 times or more, and still more preferably 1.15 times or more. In addition, from the viewpoint of suppressing damage to the front sheet and the sheet-like member through which the filamentous member passes, the expansion rate of the diameter of the filamentous member is preferably 2 times or less, more preferably 1.7 times or less, and still more preferably 1.5 times or less.

[0047] The sheet-like member described above corresponds to the installation site of the photovoltaic power generation device of the present invention. Examples of the sheet-like member include resin sheets, fiber-reinforced sheets, metal thin-film laminated sheets, and fiber sheets. Among these, fiber sheets are preferred because they have good drainage of water such as rain, and it is more preferable that they contain inorganic fibers from the viewpoint of improving strength. On the other hand, since fiber sheets are permeable to water vapor, if the sheet-like member is a fiber sheet, it is preferable to use a back sheet with low water vapor permeability.

[0048] The sheet-like member may be bonded to the back sheet and the front sheet. Bonding the sheet-like member to the front sheet and the back sheet can further enhance the fixing strength.

[0049] When the sheet-like member is sewn on by the thread-like member, it has through-holes that are continuous with the through-holes of the front sheet. However, when it is fixed by a stapler or the like, the stapler's needles do not need to penetrate the sheet-like member as long as the solar power generation device can be fixed in place, so the sheet-like member does not necessarily need to have through-holes. Furthermore, when the solar power generation device is fixed by a stapler or the like, the mounting member and installation location of the solar power generation device are not limited to a sheet-like form.

[0050] The thickness of the sheet-like member described above is not particularly limited, but from the viewpoint of ensuring strength, it is preferably 0.2 mm or more, more preferably 0.5 mm or more, and even more preferably 1 mm or more. Furthermore, from the viewpoint of ensuring flexibility, it is preferably 5 mm or less, more preferably 4 mm or less, and even more preferably 3 mm or less.

[0051] The above-mentioned through-holes are created by the passage of the fixing member. Furthermore, the diameter of the through-holes is approximately the same as the diameter of the fixing member, and the fixing member is in contact with the through-holes. Since the through-holes created by the passage of the fixing member have a diameter approximately the same as the fixing member and are in contact with the fixing member, it is possible to suppress the intrusion of moisture into the through-holes from the outside. In addition, from the viewpoint of facilitating the passage of the fixing member, the front sheet and the sheet-like member may have holes smaller than the diameter of the fixing member at the positions through which the fixing member passes. By providing holes smaller than the diameter of the fixing member in advance in the parts through which the fixing member passes, the formed through-holes compress the fixing member, reducing the gap between the fixing member and the through-holes, thereby further suppressing the intrusion of moisture.

[0052] The through-hole is preferably 0.3 mm or larger and 3.0 mm or smaller in diameter. When the diameter of the through-hole is 0.3 mm or larger, that is, when the diameter of the fixing member is 0.3 mm or larger, the strength of the fixing member is increased, which suppresses the breakage of the fixing member and can further increase the fixing strength. Also, when the diameter of the through-hole is 3.0 mm or smaller, the damage to the installation surface of the sheet-like member, etc. is reduced, which can further suppress damage to the installation surface. The diameter of the through-hole is more preferably 1.0 mm or larger, even more preferably 1.5 mm or larger, even more preferably 2.5 mm or smaller, and even more preferably 2.0 mm or smaller.

[0053] The pitch of the through holes is preferably 1.0 mm or more and 15.0 mm or less. Here, pitch refers to the distance between adjacent through holes. When the pitch of the through holes is 1.0 mm or more, the frictional heat generated when forming the through holes per unit area is reduced, thus further suppressing delamination due to frictional heat. Also, when the pitch of the through holes is 15.0 mm or less, the force applied to the fixing member is reduced, thus further suppressing damage to the fixing member and further increasing the fixing strength. The pitch of the through holes is more preferably 3.0 mm or more, even more preferably 5.0 mm or more, even more preferably 13.0 mm or less, and even more preferably 10.0 mm or less.

[0054] In the photovoltaic power generation device of the present invention, it is preferable that the minimum distance between the sealing layer and the through-hole is 1 mm or more. When the minimum distance between the sealing layer and the through-hole is greater than or equal to the lower limit, moisture is less likely to penetrate the sealing layer, thereby further improving durability. It is more preferable that the minimum distance between the sealing layer and the through-hole is 2 mm or more, and even more preferable that it is 3 mm or more. There is no particular upper limit to the minimum distance between the sealing layer and the through-hole, but it is preferable that it is 10 mm or less from the viewpoint of further improving the area efficiency of power generation.

[0055] In the photovoltaic power generation device of the present invention, it is preferable that the minimum distance between the power generation section and the through-hole is 5 mm or more. A minimum distance of 10 mm or more between the power generation section and the through-hole is more preferable than the lower limit, as this makes it more difficult for moisture to penetrate the sealing layer, thereby increasing durability. The minimum distance between the power generation section and the through-hole is more preferably 10 mm or more, and even more preferably 20 mm or more. While there is no particular upper limit to the minimum distance between the power generation section and the through-hole, it is preferable to have a minimum distance of 100 mm or less from the viewpoint of further increasing the area efficiency of power generation.

[0056] The solar power generation device of the present invention may have the fixing member and the through-hole covered with tape. By covering the fixing member and the through-hole with tape, the intrusion of moisture into the through-hole can be further suppressed, and durability can be further improved.

[0057] The photovoltaic power generation device of the present invention may have the through-holes filled with a filler material. By filling the gaps in the through-holes with a filler material, the intrusion of moisture into the through-holes can be further suppressed, and durability can be further enhanced. The filler material is not particularly limited as long as it has high waterproofing properties, and examples include sealants.

[0058] The method for manufacturing the power generation section, sealing layer, front sheet, and back sheet of the photovoltaic power generation device of the present invention is not particularly limited, but a preferred method is to laminate the power generation section between the sealing layers of a sheet (sheet A) in which the sealing layer is laminated inward from the edge of the front sheet and a sheet (sheet B) in which the sealing layer is laminated on the back sheet, as this method facilitates manufacturing over a large area.

[0059] One example of a method for laminating sheet A, the power generation unit, and sheet B is the roll-to-roll method. By using the roll-to-roll method, large-area solar cells can be manufactured continuously.

[0060] (Embodiment 2) Figure 3 shows a schematic cross-sectional view illustrating another example of the photovoltaic power generation device of the present invention. The photovoltaic power generation device of Embodiment 2 has, in addition to the photovoltaic power generation device of Embodiment 1, a frame member 5 that is placed on the front sheet 13 so as to surround the portion where the front sheet 13 and the side surface of the sealing layer 12 are in contact. By surrounding the side surface of the sealing layer 12 with the front sheet 13 and the frame member 5, the area around the power generation unit 11 can be reinforced, and the intrusion of moisture from the side surface of the sealing layer 12 can be further suppressed, thereby increasing durability. Details of the power generation unit 11, sealing layer 12, front sheet 13, back sheet 14, sheet-like member 2 and fixing member 4 in the photovoltaic power generation device of Embodiment 2 are the same as those of the photovoltaic power generation device of Embodiment 1.

[0061] The material of the frame member described above is not particularly limited as long as it has a certain degree of strength and excellent water vapor barrier performance. Examples include inorganic materials such as metals, tape materials, fillers, and caulking materials. Among these, tape materials or caulking materials that can follow deformation are preferred because the sheet-like member is flexible.

[0062] The thickness of the frame member described above is not particularly limited, but from the viewpoint of balancing reinforcing performance, water vapor barrier performance and flexibility, it is preferably 200 μm or more, more preferably 300 μm or more, preferably 10,000 μm or less, and even more preferably 5,000 μm or less.

[0063] (Embodiment 3) Figure 4 shows a schematic cross-sectional view illustrating another example of the photovoltaic power generation device of the present invention. In the photovoltaic power generation device of Embodiment 3, the power generation unit 11 and the sealing layer 12 are laminated inward from the peripheral edge of the backsheet 14, and the light-receiving surface of the backsheet 14 is in contact with the surface of the frontsheet 13 that is opposite to the light-receiving surface. The through hole 3 penetrates the frontsheet 13, the backsheet 14, and the sheet-like member 2. Similar to the frontsheet 13, the peripheral edge of the backsheet 14 is also positioned outside the peripheral edges of the power generation unit 11 and the sealing layer 12, that is, the end of the backsheet 14 protrudes from the end of the power generation unit 11 and the sealing layer 12. As a result, the power generation unit 11 and the sealing layer 12 are wrapped by the frontsheet 13 and the backsheet 14, making it more difficult for moisture to penetrate the sealing layer and further increasing durability. The details of the power generation unit 11, sealing layer 12, front sheet 13, back sheet 14, sheet-like member 2, and fixing member 4 in the solar power generation device of Embodiment 3 are the same as those of the solar power generation device of Embodiment 1.

[0064] (Embodiment 4) Figure 5 shows a schematic cross-sectional view illustrating another example of the photovoltaic power generation device of the present invention. In the photovoltaic power generation device of Embodiment 4, the end of the front sheet 13 of Embodiment 1 wraps around to the side of the sheet-like member 2 opposite to the light-receiving surface. By arranging the front sheet 13 in this way, even if moisture penetrates from the interface between the front sheet 13 and the sheet-like member 2, the path to the sealing layer is extended, thus further improving durability.

[0065] The wrap-around width of the front sheet, that is, the distance between the edge of the front sheet and the edge of the sheet-like member, is preferably 5 mm or more and 100 mm or less. Having the wrap-around width of the front sheet within this range can further enhance durability. From the viewpoint of reducing costs while further improving durability, the wrap-around width of the front sheet is more preferably 10 mm or more, even more preferably 15 mm or more, even more preferably 50 mm or less, and even more preferably 30 mm or less.

[0066] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0067] (Example 1) A PET film measuring 3000 mm in length, 1500 mm in width, and 50 μm in thickness was prepared as the front sheet. Next, sheet A was obtained by applying polyisobutylene as a sealant to a thickness of 100 μm in a 2800 mm x 1300 mm area in the center of the front sheet. On the other hand, an aluminum-reinforced back sheet (FAPL, manufactured by Toyo Aluminum Co., Ltd.) measuring 2800 mm in length, 1300 mm in width, and 360 μm in thickness was prepared as the back sheet, and sheet B was obtained by applying a sealant made of polyisobutylene to a thickness of 100 μm. Subsequently, a perovskite solar cell was prepared as the power generation section, and a solar cell module was obtained by laminating sheet A, the perovskite solar cell, and sheet B so that the sealant-coated area of ​​sheet A and the sealant of sheet B coincided, and the perovskite solar cell was positioned between the sealants of sheet A and sheet B. A photovoltaic power generation device was obtained by placing the obtained solar cell module on a sheet-like member made of polyvinyl chloride-impregnated glass fiber (HIT 100FM, manufactured by Izumi Co., Ltd.) and sewing the ends of the solar cell module to the sheet-like member using a thread-like member made of weather-resistant yarn (TENARA, manufactured by Gore-Tex Japan). In this case, the sewing position (position of the through-hole) was set to 50 mm from the edge of the front sheet, the thread diameter of the thread-like member (through-hole diameter) was set to 1 mm, and the pitch of the through-holes was set to 5 mm.

[0068] (Examples 2-9) A photovoltaic power generation device was obtained in the same manner as in Example 1, except that the through-hole diameter and through-hole pitch were as shown in Table 1.

[0069] (Comparative Example 1) A solar cell module was obtained in the same manner as in Example 1. A photovoltaic power generation device was obtained by bonding and fixing the entire back surface of the obtained solar cell module and a sheet-like member with a silicone adhesive (ESCO Corporation, EA935N-42A).

[0070] <Evaluation> The photovoltaic power generation systems obtained in the examples and comparative examples were evaluated as follows. The results are shown in Table 1.

[0071] (Evaluation of fixing strength) Tensile tests were conducted using a wind pressure resistance testing device to peel the solar cell module from the sheet-like member under a pressure of 2400 Pa. The fixing strength was evaluated as follows: "○" if the solar cell module and the sheet-like member did not peel off, "△" if they partially peeled off but not completely, and "×" if they peeled off completely.

[0072]

[0073] 1. Solar power generation device 11. Power generation unit 12. Sealing layer 13. Front sheet 14. Back sheet 2. Sheet-like member 3. Through hole 4. Fixing member 5. Frame member

Claims

1. A photovoltaic power generation device comprising: a power generation unit; a sealing layer that seals the entire power generation unit; a front sheet laminated on the light-receiving surface side of the sealing layer; a back sheet laminated on the surface of the sealing layer opposite to the light-receiving surface; through holes provided along at least one side of the front sheet and penetrating multiple locations in the front sheet; and a fixing member passing through the through holes, wherein the power generation unit and the sealing layer are laminated inward from the peripheral edge of the front sheet; the front sheet covers the entire light-receiving surface and side of the sealing layer; and the through holes do not come into contact with the sealing layer.

2. The photovoltaic power generation apparatus according to claim 1, characterized in that it has a frame member disposed on the front sheet so as to surround the portion where the front sheet and the side surface of the sealing layer are in contact.

3. The photovoltaic power generation apparatus according to claim 1 or 2, characterized in that the minimum distance between the sealing layer and the through hole is 1 mm or more.

4. The photovoltaic power generation device according to claim 1 or 2, characterized in that the minimum distance between the power generation unit and the through hole is 5 mm or more.

5. The photovoltaic power generation device according to any one of claims 1 to 4, wherein the front sheet and the back sheet have a sheet-like member on the side opposite to the light-receiving surface, and the through hole penetrates the front sheet and the sheet-like member.

6. The photovoltaic power generation device according to any one of claims 1 to 5, wherein the power generation unit and the sealing layer are laminated inward from the peripheral edge of the back sheet, the surface of the back sheet on the light-receiving side and the surface of the front sheet opposite to the light-receiving side are in contact, and the through hole penetrates the front sheet and the back sheet.

7. The photovoltaic power generation device according to any one of claims 1 to 6, wherein the diameter of the through hole is 0.3 mm or more and 3.0 mm or less.

8. The photovoltaic power generation device according to any one of claims 1 to 7, wherein the pitch of the through holes is 1.0 mm or more and 15.0 mm or less.

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