Solar cell unit

Abstract

A solar cell unit according to one embodiment of the present invention has a solar cell film, an infrared reflective film, and an area adjustment mechanism. The solar cell film has a perovskite-based compound as a photoelectric conversion layer and is disposed on the indoor side of a window pane. The infrared reflective film is disposed between the window pane and the solar cell film. The area adjustment mechanism is capable of adjusting the overlapping area of the infrared reflective film and the solar cell film when viewed from the normal direction of the solar cell film.

Description

Solar cell unit

[0001] Embodiments of the present invention relate to a solar cell unit.

[0002] When solar panels are installed outdoors, their lifespan may be shortened, and repair and replacement may become difficult. On the other hand, when solar panels are installed indoors, they generate electricity from sunlight that enters the room through window glass. In this case, it becomes difficult to regulate the indoor temperature, and the amount of electrical energy consumed for heating and cooling increases.

[0003] Japanese Patent Publication No. 2017-85750

[0004] The problem that this invention aims to solve is to provide a solar cell unit that can regulate the temperature of a room.

[0005] The solar cell unit of Embodiment 1 comprises a solar cell film, an infrared reflective film, and an area adjustment mechanism. The solar cell film has a perovskite compound as a photoelectric conversion layer and is placed on the indoor side of the window glass. The infrared reflective film is placed between the window glass and the solar cell film. The area adjustment mechanism can adjust the overlapping area of ​​the infrared reflective film and the solar cell film when viewed from the normal direction of the solar cell film.

[0006] Embodiment 2 is based on the solar cell unit described in Embodiment 1. The area adjustment mechanism includes an outer winding section for winding up the infrared reflective film.

[0007] Embodiment 3 is based on the solar cell unit described in Embodiment 1 or 2. The area adjustment mechanism includes an inner winding section for winding the solar cell film.

[0008] Embodiment 4 is based on the solar cell unit described in any one of Embodiments 1 to 3. The solar cell film can generate electricity from light incident from the window glass side and light incident from the indoor side.

[0009] Embodiment 5 is based on the solar cell unit described in any one of Embodiments 1 to 4. The infrared reflectance of the infrared reflective film is 10% or more.

[0010] Embodiment 6 is based on the solar cell unit described in any one of Embodiments 1 to 5. The visible light transmittance of the solar cell film is 10% or more and 30% or less.

[0011] Embodiment 7 is based on the solar cell unit described in any one of embodiments 1 to 6. It has a water reservoir above the solar cell film that can release water vapor.

[0012] Embodiment 8 is based on the solar cell unit described in any one of embodiments 1 to 7. The solar cell unit has a heat insulating layer between the window glass and the infrared reflective film, and between the infrared reflective film and the solar cell film, at least one of these.

[0013] Side view of the solar cell unit in the first embodiment. Explanatory diagram of the area adjustment mechanism in the second embodiment. Side view of the solar cell unit in the third embodiment.

[0014] The solar cell unit of the embodiment will be described below with reference to the drawings. (First Embodiment) Figure 1 is a side view of the solar cell unit 10 in the first embodiment. The solar cell unit 10 is placed inside a room 5 which is the inside of a wall 1 of a structure. The structure is a building, automobile, train, aircraft, etc. The solar cell unit 10 is placed along a window glass 3 installed in the wall 1. The solar cell unit 10 has a solar cell film 11, an infrared reflective film 12, and an area adjustment mechanism 15.

[0015] In this application, the Z, X, and Y directions of the Cartesian coordinate system are defined as follows: The X direction is the normal direction of the solar cell film 11. The -X side is the window glass 3 side of the solar cell film 11, and the +X side is the interior 5 side of the solar cell film 11. The Y direction is the direction parallel to the surface of the solar cell film 11 and is horizontal. The Z direction is the direction parallel to the surface of the solar cell film 11 and is perpendicular to the X and Y directions. In the following embodiment, as an example, the case in which the Z direction is vertical and the +Z side is the upper side is shown.

[0016] The solar cell film 11 is disposed on the indoor 5 side of the window glass 3. The solar cell film 11 is a film-shaped perovskite solar cell. The perovskite solar cell has a material with a perovskite structure (perovskite-based compound) as a photoelectric conversion layer. Preferably, it is a perovskite-based compound having a halogen element. The perovskite solar cell has a structure in which a perovskite layer is sandwiched between an intermediate layer and a charge transport layer, and further sandwiched between two electrodes. At least the electrode on the window glass 3 side of the two electrodes is a transparent electrode. In order to make it film-shaped, it is preferable to form an electrode on a resin film or a thin film glass film, and form a layer including a perovskite layer thereon.

[0017] The perovskite structure consists of, for example, ions A1, ions A2, and ions X, and can be represented as A1A2X. ３ There may be a case where the perovskite structure is present when ion A2 is smaller than ion A1. The perovskite structure has, for example, a cubic unit cell. Ion A1 is arranged at each vertex of the cube, and ion A2 is arranged at the body center. Ion X is arranged at each face center of the cube with the body-centered ion A2 as the center.

[0018] A2X ６ The orientation of the octahedron is likely to be distorted by the interaction with ion A1. Due to the decrease in symmetry, a Mott transition occurs, and the valence electrons localized on ion A2 can spread as a band. Ion A1 is preferably CH. ３ NH ３ ＋ Ion A2 is preferably at least one of Pb. ２＋ And Sn. ２＋ Ion X is preferably at least one of Cl. － Br. － And I. － Ion A1, ion A2, and each of the materials constituting ion X may be a single material or a mixed material. The thickness of the perovskite layer is, for example, 200 nm to 800 nm.

[0019] When forming solar cells, it is preferable to use a coating method in which the material is dissolved in a solvent and applied to the electrode (or intermediate layer). Examples of solvents that can be used include unsaturated hydrocarbon solvents, halogenated aromatic hydrocarbon solvents, halogenated saturated hydrocarbon solvents, and ethers. Examples of unsaturated hydrocarbon solvents include toluene, xylene, tetralin, decalin, mesitylene, n-butylbenzene, sec-butylbenzene, and tert-butylbenzene. Examples of halogenated aromatic hydrocarbon solvents include chlorobenzene, dichlorobenzene, and trichlorobenzene. Examples of halogenated saturated hydrocarbon solvents include carbon tetrachloride, chloroform, dichloromethane, dichloroethane, chlorobutane, bromobutane, chloropentane, chlorohexane, bromohexane, and chlorocyclohexane. Examples of ethers include tetrahydrofuran and tetrahydropyran. It is more preferable to use halogenated aromatic solvents. Furthermore, DMF (N,N-dimethylformamide), DMSO (dimethyl sulfoxide), 2-propanol, and γ-butyrolactone can also be used. These solvents can be used individually or in combination. There are no particular restrictions as long as the solvent can dissolve the material.

[0020] Methods for applying a solution to form a photoelectric conversion layer include spin coating, dip coating, casting, bar coating, roll coating, wire bar coating, spray coating, screen printing, gravure printing, flexographic printing, offset printing, gravure-offset printing, dispenser coating, nozzle coating, capillary coating, inkjet coating, and meniscus coating. These coating methods can be used individually or in combination.

[0021] The perovskite solar cell film 11 is extremely thin, flexible, and lightweight. Perovskite solar cell films 11 often have poor weather resistance. However, by installing the solar cell film 11 indoors 5, the lifespan of the solar cell film 11 is extended, and repair and replacement become easier.

[0022] The weight of the solar cell film 11 is 2 kg / m２ The following can be done. This makes it easier to install and replace the solar cell film 11. 2 kg / m ２ If the solar cell film 11 is heavier, the mounting hardware used to install it will become heavier, and the time required to replace the solar cell film 11 will increase.

[0023] Generally, silicon solar cells generate electricity using infrared light. In contrast, the perovskite solar cell film 11 can generate electricity mainly using visible light (wavelength 400-800 nm). Also, the energy conversion efficiency of silicon solar cells decreases as the solar radiation intensity decreases. In contrast, the energy conversion efficiency of the perovskite solar cell film 11 tends to increase as the solar radiation intensity decreases. The normal direction of solar cells placed on the interior side 5 of the window glass 3 tends to be horizontal. The angle of incidence of sunlight with respect to the normal direction of the solar cell becomes large, and the solar radiation intensity decreases. By using the perovskite solar cell film 11 as the solar cell placed in the interior 5, high energy conversion efficiency can be obtained.

[0024] The visible light transmittance of the solar cell film 11 can be set to 10-30%. This makes it easier to see the view outside the window glass 3 from inside the room 5 by passing light through the solar cell film 11. The visible light transmittance of the solar cell film 11 can be increased by using transparent electrodes or metal wire electrodes on the electrodes on the room 5 side of the solar cell film 11.

[0025] By using transparent electrodes on both sides of the solar cell film 11, it becomes possible to generate electricity from light coming from both sides of the solar cell film 11. This allows for power generation not only from the light incident from the window glass 3 but also from the lighting in the room 5, thereby increasing the amount of power generated.

[0026] The infrared reflective film 12 is placed between the window glass 3 and the solar cell film 11. The infrared reflective film 12 is a film that increases the reflectivity of infrared light while maximizing the transmittance of visible light. Infrared light accounts for about 50% of the energy of sunlight, and near-infrared light in particular has a large thermal effect. It is preferable to form the infrared reflective film 12 by placing a near-infrared reflective film on a transparent film.

[0027] The infrared reflective film 12 absorbs ultraviolet light, just like all other materials. Therefore, the degradation of the solar cell film 11 due to ultraviolet light is suppressed, and the temperature rise in the room 5 due to ultraviolet light is also suppressed.

[0028] The infrared reflective film 12 transmits visible light necessary for power generation by the perovskite solar cell film 11. The infrared reflective film 12 reflects infrared light that raises the temperature of the room 5 and emits it outside the window glass 3. The infrared light reflectance of the infrared reflective film 12 can be set to 10% or more. If the reflectance is less than 10%, the effect of suppressing the temperature rise of the room 5 will be small. A preferred reflectance is 30 to 70%. If the reflectance is greater than 70%, the transmittance of visible light tends to decrease.

[0029] The area adjustment mechanism 15 can adjust the overlapping area of ​​the infrared reflective film 12 and the solar cell film 11 when viewed from the X direction. The area adjustment mechanism 15 of the first embodiment includes an outer winding section 17 and an inner winding section 16. The outer winding section 17 is located at the upper end of the infrared reflective film 12 and winds and unwinds the infrared reflective film 12. The inner winding section 16 is located at the upper end of the solar cell film 11 and winds and unwinds the solar cell film 11.

[0030] A weight rod 13 may be attached to the lower end of the infrared reflective film 12. This suppresses the bending of the infrared reflective film 12. Similarly, a weight rod (not shown) may be attached to the lower end of the solar cell film 11.

[0031] The outer winding section 17 is positioned on the outside (window glass 3 side) of the solar cell film 11 together with the infrared reflective film 12. The outer winding section 17 winds the infrared reflective film 12 on the outside of the infrared reflective film 12. The inner winding section 16 is positioned on the inside (indoor 5 side) of the infrared reflective film 12 together with the solar cell film 11. The inner winding section 16 winds the solar cell film 11 on the inside of the solar cell film 11. This allows the infrared reflective film 12 and the solar cell film 11 to be positioned close together.

[0032] As the outer winding section 17 winds up the infrared reflective film 12, the area of ​​the infrared reflective film 12 decreases. As the outer winding section 17 unwinds up the infrared reflective film 12, the area of ​​the infrared reflective film 12 increases. As the inner winding section 16 winds up the solar cell film 11, the area of ​​the solar cell film 11 decreases. As the inner winding section 16 unwinds up the solar cell film 11, the area of ​​the solar cell film 11 increases. As a result, the area adjustment mechanism 15 can adjust the overlapping area of ​​the infrared reflective film 12 and the solar cell film 11 when viewed from the X direction.

[0033] It is desirable to unwind the solar cell film 11 from the inner winding section 16 to increase the area of ​​the solar cell film 11 and thereby increase the amount of power generated. As the amount of sunlight entering the room 5 through the window glass 3 increases, the amount of power generated by the solar cell film 11 increases, and the temperature rise in the room 5 also increases.

[0034] During the hot months from May to October, it is desirable to extend the infrared reflective film 12 to increase its overlapping area with the solar cell film 11. As the infrared reflective film 12 reflects infrared rays, the amount of power generated by the solar cell film 11 decreases, but the rise in temperature inside the room 5 is suppressed. This reduces the amount of electricity used for cooling inside the room 5, resulting in an overall advantage in the power balance.

[0035] In the cold period from November to April of the following year, it is desirable to wind up the infrared reflection film 12 to reduce the overlapping area with the solar cell film 11. The infrared reflection film 12 becomes less likely to reflect infrared rays, and the amount of infrared rays incident on the solar cell film 11 increases. As a result, the power generation amount of the solar cell film 11 increases, and the temperature rise in the room 5 becomes larger. Since the amount of electric power used for heating in the room 5 decreases, there is a great merit in the total power balance.

[0036] The solar cell film 11 generates electricity by the illumination light in the room 5 at night. The infrared reflection film 12 reflects the infrared rays (heat rays) in the room 5 and does not release them to the outside of the window glass 3.

[0037] At night in the cold period, it is desirable to unwind the infrared reflection film 12 to increase the area of the infrared reflection film 12. By reflecting the infrared rays in the room 5 by the infrared reflection film 12, the temperature drop in the room 5 is suppressed, and the amount of electric power used for heating in the room 5 decreases.

[0038] At night in the hot period, it is desirable to wind up the infrared reflection film 12 to reduce the area of the infrared reflection film 12. The infrared rays in the room 5 are more likely to be released to the outside of the window glass 3 without being reflected by the infrared reflection film 12. As a result, the temperature rise in the room 5 is suppressed, and the amount of electric power used for cooling in the room 5 decreases.

[0039] When power generation of the solar cell film 11 is not required, the solar cell film 11 may be wound up. When temperature adjustment of the room 5 is not required, the infrared reflection film 12 may be wound up. Thereby, a view from the room 5 to the outside of the window glass 3 can be obtained. Also, cleaning and repair of the window glass 3 become easier.

[0040] The outer winding portion 17 and the inner winding portion 16 are manually operated. On the other hand, the outer winding portion 17 and the inner winding portion 16 may be driven by an electric motor such as a motor. Further, the outer winding portion 17 and the inner winding portion 16 may be automatically driven according to the time and time by a program stored in a control unit (not shown).

[0041] As described in detail above, the solar cell unit 10 of the first embodiment includes a solar cell film 11, an infrared reflection film 12, and an area adjustment mechanism 15. The solar cell film 11 has a perovskite-based compound as a photoelectric conversion layer and is disposed on the indoor 5 side of the window glass 3. The infrared reflection film 12 is disposed between the window glass 3 and the solar cell film 11. The area adjustment mechanism 15 can adjust the area where the infrared reflection film 12 and the solar cell film 11 overlap when viewed from the normal direction of the solar cell film 11.

[0042] The area adjustment mechanism 15 can increase the area where the infrared reflection film 12 and the solar cell film 11 overlap. Thereby, the infrared reflection film 12 reflects infrared rays, suppressing the temperature rise in the room 5. The area adjustment mechanism 15 can decrease the area where the infrared reflection film 12 and the solar cell film 11 overlap. Thereby, the amount of infrared light incident on the room 5 increases, and the temperature rise in the room 5 becomes larger. Therefore, the solar cell unit 10 can adjust the temperature of the room 5.

[0043] The area adjustment mechanism 15 includes an outer winding portion 17 that winds up the infrared reflection film 12. Thereby, the area adjustment mechanism 15 can adjust the area of the infrared reflection film 12.

[0044] The area adjustment mechanism 15 includes an inner winding portion 16 that winds up the solar cell film 11. Thereby, the area adjustment mechanism 15 can adjust the area of the solar cell film 11.

[0045] The solar cell film 11 can generate electricity by the incident light from the window glass 3 side and the incident light from the indoor 5 side. Thereby, the power generation amount of the solar cell film 11 increases.

[0046] The infrared reflectance of the infrared reflection film 12 is 10% or more. Thereby, the effect of suppressing the temperature rise in the room 5 becomes larger.

[0047] The visible light transmittance of the solar cell film 11 is between 10% and 30%. This makes it easier to see the view outside the window glass 3 even when the solar cell film 11 is deployed.

[0048] (Second Embodiment) Figure 2 is an explanatory diagram of the area adjustment mechanism 30 in the second embodiment. The area adjustment mechanism 30 in the second embodiment adjusts the area of ​​the solar cell film 11 by attaching and detaching small pieces 11p of the solar cell film 11 to the fixing jig 31. Descriptions of the second embodiment that are the same as the first embodiment may be omitted.

[0049] The solar cell film 11 is divided into a plurality of small pieces 11p. The plurality of small pieces 11p are obtained by dividing the solar cell film 11 in the Z direction. The plurality of small pieces 11p are electrically connected in parallel.

[0050] The fixing jig 31 is a columnar member extending in the Z direction. A pair of fixing jigs 31 are arranged parallel to each other and spaced apart in the Y direction. Multiple small pieces 11p of the solar cell film 11 are attached to the fixing jig 31 by mounting mechanisms such as bolts or hooks. By operating the mounting mechanism, the multiple small pieces 11p can be detached from the fixing jig 31. In other words, the multiple small pieces 11p are detachable from the fixing jig 31.

[0051] As shown on the left side of Figure 2, the area of ​​the solar cell film 11 can be increased by arranging multiple small pieces 11p in the Z direction. As shown on the right side of Figure 2, the area of ​​the solar cell film 11 can be decreased by overlapping all or some of the small pieces 11p in the X direction. It is also possible to remove all of the small pieces 11p from the fixing jig 31. In this way, the area adjustment mechanism 30 can adjust the area of ​​the solar cell film 11. This allows the area adjustment mechanism 30 to adjust the overlapping area between the infrared reflective film 12 (see Figure 1) and the solar cell film 11.

[0052] The area adjustment mechanism 30 adjusts the area of ​​the solar cell film 11 by attaching and detaching small pieces 11p of the solar cell film 11 to the fixing jig 31. Similarly, the area adjustment mechanism 30 can also adjust the area of ​​the infrared reflective film 12 by attaching and detaching small pieces of the infrared reflective film 12 to the fixing jig. In this way, the area adjustment mechanism 30 can freely adjust the overlapping area of ​​the infrared reflective film 12 and the solar cell film 11.

[0053] The area adjustment mechanism is not limited to the area adjustment mechanism 15 of the first embodiment and the area adjustment mechanism 30 of the second embodiment. Possible area adjustment mechanisms include folding the film, a blind curtain structure, and fixing and peeling the film with an adhesive that can be peeled off and re-adhered.

[0054] (Third Embodiment) Figure 3 is a side view of the solar cell unit 10 in the third embodiment. The solar cell unit 10 of the third embodiment has a water reservoir 25. Descriptions of the third embodiment that are the same as the first embodiment may be omitted.

[0055] The water storage section 25 is a container capable of holding water. Since the top of the water storage section 25 is open, water vapor can be released. A humectant may be contained inside the water storage section 25 along with the water. The humectant may be made of a material such as polyvinyl alcohol or silica gel. The water storage section 25 is positioned above the solar cell film 11 and the infrared reflective film 12.

[0056] The solar cell film 11 generates electricity using a portion of the visible light, but most of the visible light is converted into heat. Updrafts tend to form around the solar cell film 11 and the infrared reflective film 12. The water contained in the water reservoir 25 vaporizes by absorbing the heat of vaporization from the updrafts. This suppresses the rise in temperature inside the room 5.

[0057] During the daytime in hot weather, water is released from the humidifying material in the water storage section 25 and evaporates. At night in hot weather, the humidifying material absorbs moisture from the surroundings. This suppresses the humidity inside the room 5.

[0058] A first thermal insulation layer 21 is formed between the solar cell film 11 and the infrared reflective film 12. A second thermal insulation layer 22 is formed between the infrared reflective film 12 and the window glass 3. The thermal insulation layers 21 and 22 are composed of air, vacuum, transparent foam material, etc. Spacers 23 may be placed to ensure the thickness of the thermal insulation layers 21 and 22 in the X direction. Only one of the first thermal insulation layer 21 and the second thermal insulation layer 22 may be formed.

[0059] The water storage section 25 is positioned above the solar cell film 11, the first insulation layer 21, the infrared reflective film 12, and the second insulation layer 22. These provide stable support to the bottom of the water storage section 25. Heat tends to accumulate in the insulation layers 21 and 22 adjacent to the solar cell film 11 and the infrared reflective film 12. The rising airflow through the insulation layers 21 and 22, and the heat transfer from the insulation layers 21 and 22, promote the evaporation of water in the water storage section 25.

[0060] As detailed above, the solar cell unit 10 of the third embodiment has a water reservoir 25 above the solar cell film 11 that can release water vapor. Most of the sunlight entering through the window glass 3 is converted into heat. Updrafts tend to occur around the solar cell film 11 and the infrared reflective film 12. The water reservoir 25 can absorb the heat of vaporization from the updraft and release water vapor. This suppresses the rise in temperature inside the room 5.

[0061] The solar cell unit 10 has heat insulating layers 21 and 22 in at least one of the following locations: between the window glass 3 and the infrared reflective film 12, and between the infrared reflective film 12 and the solar cell film 11. Heat tends to accumulate in the heat insulating layers 21 and 22 adjacent to the solar cell film 11 and the infrared reflective film 12. The rising airflow through the heat insulating layers 21 and 22 and the heat transfer from the heat insulating layers 21 and 22 promote the evaporation of water in the water storage section 25.

[0062] (Example 1) As shown in Figure 1, an infrared reflective film 12 and a solar cell film 11 are placed on the interior side 5 of the window glass 3. The solar cell film 11 is a perovskite solar cell film 11. The solar cell film 11 is a single-sided power generation type and generates electricity only from light irradiation from the window glass 3 side. The solar cell film 11 has an energy conversion efficiency of 14% per sun. The solar cell film 11 has dimensions of 30 x 40 cm, a thickness of 2 mm, and a weight of 1.9 kg / m. ２ The infrared reflective film 12 is a highly transparent heat-shielding film X-3 manufactured by AGC Inc., with dimensions of 30 x 40 cm and a thickness of 100 μm. The window glass 3 has dimensions of 30 x 60 cm and a thickness of 3 mm. The first insulation layer 21 and the second insulation layer 22 are air layers with a thickness of 10 mm.

[0063] Simulated sunlight is shone from the window glass 3 side. The energy conversion efficiency of the solar cell film 11 is 9%, and the ratio of energy converted into heat through transmission and absorption is 60%. When the energy of the irradiated light is reduced to 1 / 4, the power generation efficiency is 11%. The energy conversion efficiency of the perovskite solar cell film 11 tends to increase as the solar radiation intensity decreases.

[0064] The entire solar cell film 11 is wound up by the inner winding section 16, and with only the infrared reflective film 12 present, simulated sunlight is irradiated. The power generation energy conversion efficiency is 0%, and the ratio of energy converted into heat through transmission and absorption is 69%.

[0065] The entire infrared reflective film 12 is wound up by the outer winding section 17, and simulated sunlight is irradiated with only the solar cell film 11 present. The power generation energy conversion efficiency is 12%, and the ratio of energy converted into heat through transmission and absorption is 85%. Subtracting the power generation energy conversion efficiency from the ratio of energy converted into heat gives 73%. Even when cooling is performed using the generated energy, 73% of the heat energy remains. This is greater than the ratio of energy converted into heat, which is 69%, when only the infrared reflective film 12 is present. Therefore, during hot periods, it is desirable to unwind the infrared reflective film 12 to increase the overlapping area with the solar cell film 11. On the other hand, during cold periods, it is desirable to wind up the infrared reflective film 12 to decrease the overlapping area with the solar cell film 11.

[0066] (Comparative Example) Instead of the perovskite solar cell film 11 of Example 1, a silicon solar cell film is used. The silicon solar cell film has an energy conversion efficiency of 14% per sun. The entire infrared reflective film 12 is wound up, and simulated sunlight is irradiated with only the silicon solar cell film present. Similar to Example 1, the power generation energy conversion efficiency is 12%, and the ratio of energy converted into heat through transmission and absorption is 85%. However, when the irradiated light energy is reduced to 1 / 4, the power generation efficiency decreases to 4%.

[0067] (Example 2) The window glass 3, infrared reflective film 12, and solar cell film 11 from Example 1 are attached with a silicone-based transparent adhesive. This forms an integrated solar cell unit 10 without the presence of heat insulating layers 21 and 22. When irradiated with simulated sunlight, the energy conversion efficiency is 10%, and the ratio of energy converted into heat through transmission and absorption is 62%.

[0068] (Example 3) Instead of the single-sided solar cell film 11 of Example 2, a double-sided solar cell film 11 is used. The solar cell film 11 has an energy conversion efficiency of 13% on the -X side and an energy conversion efficiency of 10% on the +X side at 1 sun. When simulated sunlight is irradiated from the window glass 3 side, the power generation energy conversion efficiency is 9%. When illumination light at 1 / 100 sun is irradiated from the indoor side 5, the power generation energy efficiency is 40%.

[0069] (Example 4) Instead of the solar cell film 11 with a visible light transmittance of 0% in Example 3, a solar cell film 11 with a visible light transmittance of 30% is used. The solar cell film 11 uses transparent electrodes on both sides and has a thin perovskite layer. When irradiated with simulated sunlight, the power generation energy conversion efficiency is 5%. However, the view outside the window glass 3 is still visible.

[0070] (Example 5) As shown in Figure 3, a solar cell unit 10 having a water reservoir 25 at the top is created. A water-containing polymer humectant is placed inside the water reservoir 25. When irradiated with simulated sunlight for one hour, the weight of the water reservoir 25 decreases by 20 g. When not irradiated with simulated sunlight, the decrease is 3 g. The heat generated by the irradiation of simulated sunlight is converted into the heat of vaporization of the water in the water reservoir 25.

[0071] According to at least one embodiment described above, there is an area adjustment mechanism that allows adjustment of the overlapping area between the infrared reflective film 12 and the solar cell film 11. This makes it possible to adjust the temperature of the room 5.

[0072] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

[0073] 3...Window glass, 5...Interior, 10...Solar cell unit, 11...Solar cell film, 12...Infrared reflective film, 15...Area adjustment mechanism, 16...Inner winding section, 17...Outer winding section, 21...First insulation layer (insulation layer), 22...Second insulation layer (insulation layer), 25...Water reservoir section, 30...Area adjustment mechanism.

Claims

1. A solar cell unit comprising: a solar cell film having a perovskite compound as a photoelectric conversion layer and disposed on the interior side of a windowpane; an infrared reflective film disposed between the windowpane and the solar cell film; and an area adjustment mechanism capable of adjusting the area in which the infrared reflective film and the solar cell film overlap when viewed from the normal direction of the solar cell film.

2. The solar cell unit according to claim 1, wherein the area adjustment mechanism includes an outer winding section for winding the infrared reflective film.

3. The solar cell unit according to claim 1 or 2, wherein the area adjustment mechanism includes an inner winding section for winding the solar cell film.

4. The solar cell unit according to claim 1 or 2, wherein the solar cell film is capable of generating electricity from incident light from the window glass side and incident light from the indoor side.

5. The solar cell unit according to claim 1 or 2, wherein the infrared reflectance of the infrared reflective film is 10% or more.

6. The solar cell unit according to claim 1 or 2, wherein the visible light transmittance of the solar cell film is 10% or more and 30% or less.

7. The solar cell unit according to claim 1 or 2, further comprising a water reservoir capable of releasing water vapor above the solar cell film.

8. The solar cell unit according to claim 7, wherein at least one of the following is provided: a heat insulating layer between the window glass and the infrared reflective film, and between the infrared reflective film and the solar cell film.

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