JP5762564B2 - Solar cell module - Google Patents

Description

  The present invention relates to a solar cell module and a method for manufacturing the solar cell module, and more particularly to a solar cell module having excellent cleaning properties and a method for manufacturing the solar cell module.

  The surface of the solar cell module is protected by tempered glass or the like that is a protective member having translucency. The transmittance of the tempered glass is an important characteristic that affects the power generation efficiency of the solar cell module. Since the solar cell module is installed in a place where it is exposed to outdoor wind and rain, dust such as yellow sand, volcanic ash, car dust, and soot is attached to the tempered glass on the surface. When the light transmittance of the tempered glass is reduced due to such dust adhesion, the amount of light incident on the solar battery cell is reduced, so that the power generation efficiency of the solar battery module is reduced.

  Usually, most of these dusts are washed away by rain, and the light transmittance of the tempered glass is restored. However, when there is little rainfall or when dust adheres, there is a problem that the washing of dust does not occur sufficiently and the light transmittance of the tempered glass does not recover.

  Various techniques have been developed as techniques for maintaining the cleanliness of the glass surface. For example, in Patent Document 1, a surface layer containing a photocatalytic oxide and an amorphous oxide is formed on the surface of the substrate, and the adhering dirt is caused by rainfall due to the hydrophilicity of the photocatalytic oxide caused by sunlight hitting the surface layer. Techniques have been proposed that make it easy to drop. Further, for example, in Patent Document 2, a technique for improving antifouling property and water droplet releasability by fusing a water repellent / oil repellent / antifouling antireflection film containing transparent fine particles of water / oil repellent / antifouling on the glass surface. Has been proposed.

Japanese Patent No. 3613085 International Publication No. 2008/120782

  However, the method of hydrophilizing the photocatalytic oxide and facilitating washing away dirt as in Patent Document 1 is effective when washed away with a large amount of water, but in the case of a small amount of rainfall, water droplets on the surface The force that spreads on the surface of the layer and carries away the dirt does not work. Furthermore, there is a possibility that the dirt that could not be carried away is fixed to the surface layer.

  Moreover, in the method of making the surface of a base material water-repellent and improving water droplet peelability like patent document 2, there exists a possibility that the suppression of the force which carries away the stain | pollution | contamination of a water droplet like patent document 1, and the adhering of dust may generate | occur | produce. Absent. However, since the water droplets cannot collect the dust efficiently, the dust may not be sufficiently removed in the case of a small amount of rain.

  The present invention has been made in view of the above, and an object of the present invention is to obtain a solar cell module excellent in detergency and a method for manufacturing the solar cell module that can efficiently remove dust and the like adhering to the surface even with a small amount of rainfall. And

In order to solve the above-described problems and achieve the object, a solar cell module according to the present invention has a translucent protective member fixed to the light-receiving surface side of the solar cell, and a plurality of solar cells are arranged at predetermined intervals. A plurality of first regions and second regions having different hydrophilicity on the light-receiving surface side of the protective member, and the second solar cell modules sandwiched between adjacent first regions. direction in which the first region sandwiched between a direction or adjacent the second region area successive consecutive, Ri predetermined direction der to induce water droplets on the protective member, the predetermined direction, the A surface area of the protective member corresponding to a boundary portion where the solar battery cell and the solar battery cell are adjacent to each other, and directed to a region along the direction in which the water droplet flows by gravity, and the direction in which the water droplet flows by gravity It is a direction that intersects at an acute angle alpha, wherein the.

  Advantageous Effects of Invention According to the present invention, there is an effect that a solar cell module with excellent cleaning properties that can efficiently remove dust and the like attached to the surface even with a small amount of rainfall or the like can be obtained.

1-1 is sectional drawing which shows typically schematic structure of the solar cell module concerning embodiment of this invention. FIGS. 1-2 is principal part sectional drawing which shows typically the structure of the solar cell array concerning embodiment of this invention. FIGS. FIGS. 1-3 is a principal part top view which shows typically the state which looked at the solar cell module concerning embodiment of this invention from the light-receiving surface side. FIG. 2 is a diagram schematically showing a state in which a resin layer is formed on the surface module glass of the solar cell module according to the embodiment of the present invention, and a plurality of dotted resins have a predetermined directionality. It is a figure which shows the state arrange | positioned distributed. FIG. 3 is a diagram schematically showing a state in which a resin layer is formed on the surface module glass of the solar cell module according to the embodiment of the present invention, and a plurality of elliptical resins have a predetermined directionality. It is a figure which shows the state arrange | positioned distributed. FIG. 4 is a schematic diagram showing the arrangement direction of the resin layers and the direction in which the water droplets move. FIG. 5 is a schematic view showing a method of attaching a resin to the surface of the surface module glass.

  Embodiments of a solar cell module and a method for manufacturing the same according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited to the following description, In the range which does not deviate from the summary of this invention, it can change suitably. In the drawings shown below, the scale of each member may be different from the actual scale for easy understanding. The same applies between the drawings. Further, even a plan view may be hatched to make the drawing easy to see.

Embodiment 1 FIG.
As a result of diligent research to solve the above problems, the present inventors have found that the above problems can be solved by controlling the movement of water droplets by partially attaching a resin to the surface of the solar cell module. . That is, in the present invention, the surface (exposed surface) of the protective member and the resin surface are mixed on the light receiving side surface of the solar cell module, the hydrophilicity of the surface of the protective member and the resin surface is different, and the protective member The movement of water droplets on the surface of the solar cell module is controlled by increasing the distance in which the surface or the resin surface continues in one direction.

  1-1 is sectional drawing which shows typically schematic structure of the solar cell module concerning embodiment of this invention. A solar cell module 1 (hereinafter referred to as module 1) according to the present embodiment has a solar cell array 10 (hereinafter referred to as array 10). FIG. 1-2 is a main part cross-sectional view schematically showing the configuration of the array 10 according to the present exemplary embodiment. The array 10 according to the present embodiment is configured by electrically connecting a plurality of solar battery cells 100 (hereinafter referred to as cells 100). FIGS. 1-3 is a principal part top view which shows typically the state which looked at the module 1 concerning embodiment of this invention from the light-receiving surface side.

  First, the configuration of the module 1 will be described with reference to FIG. The module 1 includes a front surface module glass 2 that is a front surface side protective member disposed on the front surface side (light incident side) of the module 1 and a back surface side protective member disposed on the rear surface side (opposite side of the light incident side) of the module 1. A filler (sealing material) 3 is sandwiched between the back surface protection sheet 4 and the back surface protection sheet 4. An array 10 is sealed in the filler (sealing material) 3.

  The surface module glass 2 protects the array 10 sealed with the filler (sealing material) 3. The surface of the surface module glass 2 is exposed to sunlight and exposed to wind and rain. Here, the surface module glass 2 is used as the surface-side protection member, but a resin plate or the like may be used as long as the material has translucency. The surface module glass 2 is fixed to the outer surface of the filler 3 located on the light receiving surface side of the module 1. A resin layer 20 is partially formed on the surface of the surface module glass 2. Details of the resin layer 20 will be described later.

  For the filler (sealing material) 3, for example, a resin having translucency such as ethylene-vinyl acetate copolymer (EVA) is used.

  The back surface protection sheet 4 protects the array 10 sealed with the filler (sealing material) 3. The back surface protection sheet 4 is fixed to the outer surface of the filler 3 located on the installation surface side of the module 1.

  Next, the configuration of the array 10 will be described with reference to FIGS. 1-2 and 1-3. In the array 10, a plurality of cells 100 are packaged at a predetermined distance in the in-plane direction of the module 1. Adjacent cells 100 are electrically connected by an inter-element connection line 101. For example, a conductive wire is used as the inter-element connection line 101. In addition, in FIG. 1-3, description of the connection line 101 between elements is abbreviate | omitted.

  As the cell 100, for example, a known solar cell such as a crystal system can be used. Examples of the crystalline solar battery cell include, but are not limited to, a single crystal silicon solar battery cell and a polycrystalline silicon solar battery cell using a semiconductor wafer.

  Next, the resin layer 20 according to the present embodiment will be described in detail. The resin layer 20 according to the present embodiment is partially formed on the surface of the surface module glass 2. The resin layer 20 does not cover the entire surface of the surface module glass 2, and a resin is formed by arranging a plurality of dot-like resins or arranging a plurality of resins such as a linear shape or an elliptical shape in a uniform direction. This arrangement has directionality in a predetermined direction. That is, the resin layer 20 has a direction in which the resin layer 20 sandwiched between adjacent glass exposed surfaces continues or a direction in which the glass exposed surface sandwiched between adjacent resin layers 20 continues on the surface module glass 2. It is provided so as to be in a predetermined direction for inducing water droplets. Further, the resin layer 20 may be in a state where the resin forms a film on the surface module glass 2 and the glass surface is exposed from a dot-like or linear hole provided in the film. In the present invention, the resin arranged in this way is called a resin layer 20.

  As described above, the resin layer 20 adheres to the surface of the surface module glass 2, and the glass exposed surface and the resin surface on the surface of the surface module glass 2 become intertwined, and the glass exposed surface or the resin layer 20 is continuous. The distance to do is longer in one direction. In the present invention, the distance where the glass exposed surface or the resin layer 20 continues is a line segment connecting any two points on the boundary line between the glass exposed surface and the resin layer 20, and the straight line does not intersect the boundary line. It's about length. About the length of this arbitrary line segment, the average value for every direction is not equal in all directions, but becomes a big value in a fixed direction. Water drops tend to flow in the direction in which the average value for each direction becomes a large value. That is, by providing the resin layer 20 with the resin adhered to the surface of the surface module glass 2, water droplets can easily move on the surface of the module 1, and the direction of movement is also preferable. Can do. Thereby, the washing | cleaning property of the surface of the surface module glass 2 at the time of rain can be improved.

  By using a hydrophobic resin such as a fluororesin as the resin constituting the resin layer 20, the exposed glass surface of the surface module glass 2 becomes more hydrophilic than the surface of the resin layer 20. In this case, water droplets mainly flow on the glass exposed surface of the surface module glass 2. In addition, by using a highly hydrophilic resin or a resin that has been improved in hydrophilicity by mixing a hydrophilic additive as the resin constituting the resin layer 20, the surface of the resin layer 20 is made of the surface module glass 2. It can be in a state of higher hydrophilicity than the exposed glass surface. In this case, water droplets mainly flow on the resin layer 20. In any of these cases, since the surface composition and surface roughness of the glass surface of the surface module glass 2 and the surface of the resin layer 20 are different, the glass exposed surface of the surface module glass 2 and the surface of the resin layer 20 Do not show the same hydrophilicity.

  FIG. 2 is a view schematically showing a state in which the resin layer 20 is formed on the surface module glass 2, and a plurality of dotted resin layers 20 are arranged in a dispersed manner with a predetermined direction. Indicates the state. FIG. 3 is a diagram schematically showing a state in which the resin layer 20 is formed on the surface module glass 2, and a plurality of elliptical resin layers 20 are dispersed and arranged with a predetermined direction. Indicates the state. In any state shown in FIG. 2 and FIG. 3, the distance over which the glass exposed surface or the resin layer 20 continues is long in the horizontal direction in the figure, and the water droplets easily move in the horizontal direction in the figure.

  That is, when the surface state of the surface module glass 2 has a surface state as shown in FIG. 2 and FIG. 3, when the water droplets adhering to the surface of the surface module glass 2 move by an external force, a dotted resin layer Water droplets easily move along the arrangement direction in which 20 is arranged and the long axis direction of the elliptical resin layer 20. In addition, when a plurality of linear resin layers 20 are arranged on the surface of the surface module glass 2 so that the extending directions are aligned, water droplets easily move along the extending direction of the linear resin layer 20. Become. Moreover, when the surface state of the surface module glass 2 is a surface state as shown in FIG. 2 and FIG. 3, the entire surface side of the surface module glass 2 has the same hydrophilicity, Compared with the case where there is no directionality that is easy to move, the height of the water droplet increases and the movement speed due to gravity increases because the water droplet hardly spreads laterally with respect to the moving direction.

  As described above, by applying the resin layer 20 with a predetermined direction on the surface of the surface module glass 2, the direction in which water droplets such as rainwater flow on the surface of the surface module glass 2 is adjusted. The moving speed can be increased. Hereinafter, the direction in which the water droplets easily move is referred to as the arrangement direction of the resin layers 20. 2 and 3 are merely examples, and the resin layer 20 in the present invention is not necessarily arranged as shown in these drawings. For example, even if the resin layers 20 are arranged in a mesh pattern. Similar effects can be obtained.

  The arrangement direction of the resin layers 20 is preferably close to the direction in which water droplets move due to gravity (hereinafter sometimes referred to as the gravity movement direction). Here, the gravitational movement direction assumes a case where the module 1 is arranged in a predetermined arrangement direction. Thereby, it comes to flow along the sequence direction of the resin layer 20, and the moving speed of a water droplet can be improved. Then, by causing the water droplets to flow in the direction of gravity movement, the water droplets can be moved from the surface of the module 1 by being moved by the shortest distance. Moreover, when a wind blows etc., it can suppress that a water droplet flows into a horizontal direction. The horizontal direction here is a horizontal direction with respect to the direction of gravity movement in the plane of the surface module glass 2.

  If the amount of rainfall is small and a large number of water droplets do not flow repeatedly on the surface of the module 1, the water droplets that collect and flow will evaporate in the plane of the surface module glass 2 to fix the dust. There is a risk that. However, by adjusting the arrangement direction of the resin layer 20 to the direction of gravity movement, the movement speed of the water droplets can be improved, and by moving the resin layer 20 by the shortest distance, the probability of evaporation of the water droplets during the movement can be reduced. The removal of attached dust can be improved.

  Further, the arrangement direction of the resin layer 20 is set to a direction that intersects the direction of the component force along the surface of the gravitational surface module glass 2 at an acute angle α, so that water droplets and dirt from the surface of the surface module glass 2 can be obtained. The removability can be improved. For example, as shown in FIGS. 1-3 and 4, the arrangement direction of the resin layer 20 is set to a direction 32 that forms an obtuse angle with respect to the gravitational movement direction, thereby removing water droplets and dirt from the surface of the surface module glass 2. Can be improved. In the module 1 shown in FIG. 1-3, the virtual line 31 extending in the gravitational movement direction and the direction that forms an acute angle α with the upper part of the virtual line 31 in the plane of the surface module glass 2, that is, the gravitational movement direction. The resin layer 20 is formed along the direction 32 that forms an obtuse angle. In addition, in FIG. 1-3, description of the resin layer 20 is abbreviate | omitted on the relationship of illustration. FIG. 4 is a schematic diagram illustrating the arrangement direction of the resin layers 20 and the direction in which the water droplets move.

  In the module 1, as shown in FIGS. 1 to 3 and FIG. 4, a virtual line 31 extending in the gravitational movement direction is set, and the arrangement direction of the resin layers 20 is in the gravitational movement direction in the plane of the surface module glass 2. On the other hand, the direction is an obtuse angle 32, that is, an oblique direction with respect to the direction of gravity movement. 1-3 and FIG. 4, the imaginary line 31 is indicated by a dotted line, and the gravitational movement direction is indicated by an arrow at one end of the imaginary line 31.

  When the resin layer 20 has such an arrangement direction, the water drops descend in a direction 32 that forms an obtuse angle with respect to the direction of gravity movement along the arrangement direction of the resin layer 20, and collect on the virtual line 31. The collected water droplets merge to form large water droplets that quickly fall in the direction of gravity. Thereby, the removability of the water droplet and dirt from the surface of the surface module glass 2 can be improved. The arrangement direction of the resin layers 20 may be bidirectional between the gravity movement direction and the oblique direction described above.

  Further, as shown in FIG. 1C, it is preferable to set a virtual line 31 in which water droplets gather and coalesce and fall in a gap region between the cells 100 in the array 10. As described above, the water droplets adhering to the surface module glass 2 gather on the virtual line 31 along the arrangement direction of the resin layers 20 and fall. Therefore, as shown in FIG. 1C, by setting the imaginary line 31 in the gap region between the cells 100 in the array 10, the water droplets are between the adjacent cells 100 from the region on the cell 100 on the surface of the surface module glass 2. Therefore, the dirt can be efficiently removed from the surface module glass 2.

  When the arrangement direction of the resin layers 20 is not provided in the oblique direction described above, most of the water droplets move on the surface of the surface module glass 2 on the cell 100 in the direction of gravity movement. That is, most of the water droplets move from the region on the cell 100 arranged in the upper part in the vertical direction to the region on the cell 100 arranged in the lower part on the surface of the surface module glass 2. Since the water droplets are not removed from the surface module glass 2 unless they move to the lowermost part of the module 1, the dust cannot be removed if the water droplets are dried on the way, and the dust is on the cell 100 on the surface of the surface module glass 2. Remain in the area. For this reason, the sunlight incident on the module 1 is scattered by the remaining dust, the sunlight incident on the cell 100 is reduced, and the power generation efficiency is lowered.

  On the other hand, as shown in FIG. 1-3, when the virtual line 31 in which water droplets gather and fall together is set in the gap region between adjacent cells 100 in the array 10, the water droplets are on the surface of the surface module glass 2. If it moves to the area | region on the clearance gap between the cells 100 and it dries, dust will remain on the surface module glass 2 similarly to the above. However, in this case, dust remains in a region on the gap between adjacent cells 100 on the surface of the surface module glass 2. Therefore, a decrease in power generation efficiency due to dust remaining in the region on the cell 100 on the surface of the surface module glass 2 is prevented. Furthermore, the sunlight that does not originally enter the cell 100 and is incident on the region on the gap between the cells 100 due to scattering of sunlight due to dust remaining in the region on the gap between the cells 100 on the surface of the surface module glass 2 It can enter into the cell 100 and the improvement effect of power generation efficiency is acquired.

  Resin used for the resin layer 20 is not specifically limited, A well-known thing can be used. For example, fluororesin, polyethylene, polypropylene, polystyrene, AS (acrylonitrile / styrene copolymer compound) resin, ABS (acrylonitrile / butadiene / styrene copolymer) resin, polyphenylene ether, polyacrylonitrile, polymethacrylstyrene, methacrylic resin, nylon, polyethylene Terephthalate, polycarbonate, polyvinyl acetate, polyvinyl alcohol, polyacetal, polybutylene terephthalate, polybutylene terephthalate, polyallylsulfone, polyarylate, hydroxybenzoic acid polyester, polyetherimide, polycyclohexylenedimethylene terephthalate, polyethylene naphthalate, polyester Such as carbonate, polylactic acid, polyvinyl chloride, and polyvinylidene chloride Thermoplastic resins, phenol resins, epoxy resins, melamine resins, urea resins, unsaturated polyester resins, alkyd resins, polyurethanes, and the particles formed like a thermosetting resin such as a thermosetting polyimides. Moreover, those containing these mixtures, ionomers, and various additives can also be used.

  Among the above resins, excellent characteristics are often obtained by using a fluororesin. The fluororesin has high water repellency. For this reason, by using a fluororesin as the resin layer 20, the difference in water repellency between the exposed glass surface of the surface module glass 2 having a small water repellency and the resin layer 20 becomes large, and the direction in which water drops flow is easily determined. In addition, since the fluororesin has high durability against ultraviolet rays and rain, durability as a solar cell can be ensured for a long period of time. Examples of the fluororesin include PTFE (polytetrafluoroethylene), FEP (tetrafluoroethylene / hexafluoropropylene copolymer), PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer), and FEVE- (fluoroethylene vinyl ether copolymer). Polymer), ETFE (ethylene-tetrafluoroethylene copolymer), ECTFE (ethylene-chlorotrifluoroethylene copolymer), PVDF (polyvinylidene fluoride), PCTFE (polychlorotrifluoroethylene), PVF (polyvinyl fluoride) ), Copolymers and mixtures thereof, or those obtained by mixing other resins with these fluororesins. In addition, the resin constituting the resin layer 20 is preferably a resin having excellent translucency in order to ensure the amount of light incident on the surface module glass.

  Further, the resin layer 20 can contain other components for imparting desired characteristics. Other components are not particularly limited. For example, surfactants for improving the adhesion to the surface of the surface module glass 2 and the stability of the coating liquid for attaching the resin, fungi, Examples thereof include antibacterial agents and antifungal agents for suppressing mold generation, inorganic particles for adjusting the hydrophilicity and hydrophobicity of resins, and fluorine-based additives.

  As described above, by forming the resin layer 20 on the surface module glass 2, it is possible to adjust the direction in which the raindrops flow, to increase the movement speed of the waterdrops, The removal property of dirt can be improved, and it contributes to the improvement of power generation efficiency.

  Next, a method for manufacturing the module 1 will be described. First, a plurality of cells 100 are manufactured by a known method. Next, the array 10 is produced using the cells 100. The array 10 is produced by arranging a plurality of cells 100 at a predetermined distance and electrically connecting adjacent cells 100 with inter-element connection lines 101. Next, after the filler 3 made of EVA resin or the like, the array 10, the filler 3, and the back surface protective sheet 4 are stacked in this order on the surface module glass 2, they are heated and pressed in, for example, a vacuum. Thereby, the surface module glass 2 to the back surface protection sheet 4 are integrated by the filler 3.

  Next, resin is adhered to the surface of the surface module glass 2 in a predetermined arrangement direction to form the resin layer 20. Thereby, the glass exposed surface where the surface module glass 2 is exposed and the resin surface of the surface of the resin layer 20 are mixed on the surface side of the surface module glass 2.

  There is a method of attaching the resin to the surface of the surface module glass 2 by rubbing the above resin powder. For example, there are a method in which the resin powder is rubbed with a metal or plastic squeegee while being in contact with the surface of the surface module glass 2, and a method in which the resin powder is rubbed against the surface of the surface module glass 2 in a nonwoven fabric or steel wool. The direction in which the resin powder is rubbed is the arrangement direction of the resin layers 20 and the direction in which the water droplets are easily moved. Moreover, it is preferable to raise the temperature of the surface module glass 2 at the time of or after rubbing the resin powder to improve the adhesion efficiency and adhesion.

  The average particle size of the resin powder is preferably 0.1 μm or more and 500 μm or less, more preferably 0.5 μm or more and 100 μm or less. When the average particle diameter of the resin particles is less than 0.1 μm, the adhesion portion to the surface of the surface module glass 2 becomes too small, and the desired effect of creating the direction of water droplet movement cannot be obtained. On the other hand, when the particle diameter exceeds 500 μm, the adhesion part to the surface of the surface module glass 2 becomes too large, and it is difficult to obtain the effect of water droplet movement, and there is a possibility that the adverse effect that dirt easily adheres to the resin part may occur. .

  As a method of attaching the resin to the surface of the surface module glass 2, a method of applying a solution (resin solution) in which the resin is dissolved in a solvent as a coating agent may be used. The resin solution can be applied by spraying, for example, with a spray. As a method of spraying and applying the resin solution by spraying, for example, a method of spraying the sprayed air flow obliquely with respect to the surface of the surface module glass 2 to attach the deformed droplets, a method of spraying the resin solution to another air flow And a method of deforming the resin by spraying a resin solution on the surface of the surface module glass 2 and then rubbing in a predetermined direction. Moreover, it is preferable to heat the surface module glass 2 after the application of the resin solution to ensure the drying and adhesion of the resin solution.

  A method of using a coating agent in an emulsion state in which the resin solution is dispersed in water or the like instead of the resin solution as the coating agent for attaching the resin is also suitable as a method for attaching the resin to the surface of the surface module glass 2. When the resin solution is applied directly to the surface of the surface module glass 2, it is necessary to control the application so that the amount of application is very small and the unevenness of application is as small as possible. On the other hand, when the coating agent is an emulsion, even if a liquid film is formed on the surface of the surface module glass 2, desired resin adhesion can be obtained by phase separation of the resin solution and water. As the coating method in this case, in addition to the method of spraying at the same time as the coating of the resin solution coating agent, a method of forming a thin liquid film with a roller or brush can be used. is there. Examples of a method for imparting a predetermined direction to the resin attached to the surface of the surface module glass 2 include a method of blowing an air flow before drying the resin solution, a method of performing a rubbing treatment before and after drying.

  In the rubbing treatment, it is preferable to move the member for rubbing treatment in a zigzag manner in addition to the method of moving the member for rubbing treatment linearly. For example, as shown in FIG. 5, a rubbing process (friction process) is performed in a zigzag rubbing direction (friction direction) 33 in accordance with the position of the cell 100 from one side of the surface module glass 2 toward the other side. Thus, the resin can be easily attached in the direction 32 that forms an obtuse angle with respect to the direction of gravity movement shown in FIG. FIG. 5 is a schematic diagram showing a method of attaching a resin to the surface of the surface module glass 2, and is a diagram showing an example of the rubbing direction (friction direction). The zigzag rubbing direction (friction direction) 33 is a combination of rubbing processing (friction processing) in a direction 32 that forms an obtuse angle with respect to the gravitational movement direction. The same applies when the resin powder is rubbed against the surface of the surface module glass 2.

  In addition, as a coating agent for adhering the resin, a solution in which a droplet of water is dispersed in a solution in which the resin is dissolved in an organic solvent (organic resin solution), or the organic solvent or resin in the organic resin solution. There is also a method of using a liquid in which droplets of other organic solvents that are not dissolved are dispersed. In this case, as in the case of using the coating agent in an emulsion state, even if a liquid film of the coating liquid is formed on the surface module glass 2, directional resin adhesion occurs in a state where the resin film has a hole. realizable. The coating method can be the same as the case of using the coating agent in the emulsion state.

  Further, the coating liquid may be applied in the state of a glass plate before assembling the module 1, or may be applied after assembling as the module 1. If it is the method of apply | coating after formation of the module 1, it can apply also to the solar cell module which has been installed and is operating.

  By forming the resin layer 20 by the method described above, the module 1 according to the present embodiment is completed.

  As described above, according to the present embodiment, a glass exposed surface and a resin surface having different hydrophilicity are mixed on the light receiving surface side surface of the surface module glass 2 by providing the resin layer 20 having a predetermined direction. Adjusting the direction in which the water droplets flow on the surface module glass 2 by increasing the distance in which the glass exposed surface or resin surface continues in a predetermined direction, increasing the moving speed of the water droplets, surface module Removability of water droplets and dirt from the glass 2 can be improved.

  Therefore, according to this Embodiment, the solar cell module excellent in the washability which can remove dust etc. adhering to the surface efficiently even with a small amount of rain is obtained.

  In the above description, the module 1 configured using the array 10 configured by electrically connecting a plurality of cells 100 has been described. However, the module 1 is applied to a module configured using only one large cell, for example. It is also possible to do.

Embodiment 2. FIG.
In the module 1 according to the first embodiment, the surface of the surface module glass 2 is coated with metal oxide fine particles to form a hydrophilic and translucent thin film, and the resin layer 20 is formed on the thin film. Thus, the movement of the water droplets can be made more efficient, and the stability of the effect obtained by the resin layer 20 described above can be improved. This is because the thin film formed by applying fine particles is more hydrophilic than the glass surface, and when a hydrophobic resin is adhered to the glass surface, the difference between hydrophilicity and hydrophobicity is observed. This is because it can be made larger than the case. In addition, on the surface of the metal oxide film, the adhesive force of the resin becomes larger than that of the glass surface, and there is an effect that the long-term reliability of the performance of the resin layer 20 is increased.

  The metal oxide is not particularly limited as long as it can form a film. For example, oxidation of metal of an element such as silicon, magnesium, aluminum, titanium, cerium, tin, zinc, germanium, indium, antimony, etc. Things. The metal oxide thin film can be formed by applying a coating liquid containing these metal oxide fine particles to the surface of the surface module glass 2. This method is preferable because the resulting thin film is porous and has a low density, so that the effect of increasing the antifouling property and the effect of suppressing light reflection on the surface of the thin film are obtained.

  The metal oxide may be modified with various substances for hydrophilization. These fine particles can be used alone or in combination. To form a film, sols of metal oxides such as silica and alumina, various silicates such as sodium silicate and lithium silicate, metal alkylates, and general binders such as aluminum phosphate and ρ-alumina are added to the coating composition. May be. In addition, if the binder contains inorganic fine particles, the binder can be used alone.

  The average particle size of the metal oxide fine particles is not particularly limited, but the average particle size is preferably 3 nm to 0.5 μm, more preferably 5 nm to 0.2 μm. If the average particle size is less than 3 nm, it is difficult to form a coating solution, a dense thin film is obtained, and there is little difference from the properties of the glass surface, and it is difficult to obtain the effect of forming a metal oxide thin film. When the average particle size exceeds 0.5 μm, the unevenness of the thin film becomes too large, and light scattering is likely to occur, which may deteriorate the performance of the solar cell.

  Moreover, the thickness of the thin film made of inorganic fine particles is preferably 0.05 μm or more and 1.0 μm or less, more preferably 0.1 μm or more and 0.5 μm or less. When the thickness of the thin film is less than 0.05 μm, the hydrophilicity of the film surface cannot be obtained sufficiently. When the thickness of the thin film exceeds 1.0 μm, cracks and fine holes are likely to occur in the inorganic thin film, and the performance of the solar cell may be deteriorated by light scattering.

  As described above, according to the second embodiment, a thin film made of metal oxide fine particles and having a higher hydrophilicity than the glass surface is formed on the surface of the surface module glass 2, and the resin layer 20 is formed on the thin film. Thereby, the movement of water droplets can be made more efficient, and the stability of the effect obtained by the resin layer 20 described above can be improved. Therefore, according to Embodiment 2, it is possible to obtain a solar cell module with better cleaning properties that can more efficiently remove dust and the like adhering to the surface even with a small amount of rainfall.

(Example)
EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not limited to a following example, unless the meaning is exceeded.

<Example 1>
FEVE (Lumiflon manufactured by Asahi Glass Co., Ltd.), which is a fluororesin, was made into a 40% xylene solution, 50 times the amount of water and an equal amount of propyl alcohol were added thereto, and the mixture was stirred with a homogenizer to prepare an emulsion coating solution.

  The coating liquid is prepared by the above-mentioned known method and applied to the surface module glass 2 of the module having the light receiving surface size of 1657 mm × 858 mm by spraying, and then dried for 30 minutes to form the resin thin film on the surface module glass. 2 (coating treatment).

Next, a 2 mm thick polyester nonwoven fabric was wrapped around a square member having a length of 2000 mm and a cross section of 20 mm × 120 mm to prepare a rubbing member. Then, while pressing the surface of the rubbing member with a width of 20 mm against the surface of the surface module glass 2 on which the resin thin film is formed, the pressure is set to be 50 g weight / cm ^2, and as shown in FIG. A rubbing process (friction process) of rubbing in a zigzag rubbing direction (friction direction) 33 in accordance with the position of the cell 100 from one side to the other side was repeated three times. The module produced as described above was used as the module of Example 1.

  As a result, a very small amount of FEVE resin was linearly rubbed on the glass surface of the surface module glass 2. The FEVE resin is in a state of faint cloudiness when visually observed. When the surface of the surface module glass 2 was confirmed with a microscope, it was confirmed that the linear resin was lined up. Therefore, the direction of water droplet movement is given to the surface of the surface module glass 2. The resin not rubbed on the glass surface of the surface module glass 2 was removed by air blowing.

<Example 2>
The same coating liquid as in Example 1 was included in the rubbing member used in Example 1, and the coating agent was applied by applying to the surface module glass 2 heated to 50 ° C. As in the case of Example 1, the rubbing member at the time of applying the coating liquid is a zigzag rubbing direction (friction direction) in accordance with the position of the cell 100 from one side in the plane of the thin film to the other as shown in FIG. ) Moved to 33. A module was produced in the same manner as in Example 1 except for the method of attaching the resin to the surface of the surface module glass 2 to obtain a module of Example 2.

  As a result, a very small amount of FEVE resin was linearly rubbed on the glass surface of the surface module glass 2. The FEVE resin is in a state of faint cloudiness when visually observed. When the surface of the surface module glass 2 was confirmed with a microscope, it was confirmed that the linear resin was lined up. Therefore, the direction of water droplet movement is given to the surface of the surface module glass 2.

<Example 3>
By applying a mixture of 90% silica having an average particle diameter of 15 nm and 10% titanium oxide having an average particle diameter of 25 nm to the surface of the surface module glass 2 and heating at 150 ° C., the surface of the surface module glass 2 is more hydrophilic than the glass surface. A thin film having high properties was formed with a film thickness of 0.11 μm. The surface of the surface module glass 2 was coated with a fluororesin and rubbed in the same manner as in Example 1. Other than this, a module was produced in the same manner as in Example 1, and the module of Example 3 was obtained. Therefore, the direction of water droplet movement is given to the surface of the thin film on the surface module glass 2.

<Comparative Example 1>
A module produced by a known method in the same manner as in Example 1 and not subjected to fluororesin coating and rubbing treatment was used as a module of Comparative Example 1. That is, no streak-like resin is attached on the surface module glass 2 of the module of Comparative Example 1.

<Comparative Example 2>
A module in which a resin thin film was formed on the surface module glass 2 in the same manner as in Example 1 was used as the module of Comparative Example 2. That is, although the resin thin film is formed on the surface module glass 2 of the module of Comparative Example 2, the rubbing process (friction process) for rubbing the resin is not performed, so that the direction of water droplet movement is given. Not.

  Next, the modules of Example 1, Example 2, Example 3, Comparative Example 1, and Comparative Example 2 produced as described above were installed at an angle of 45 ° from the horizontal in the test chamber. And after washing | cleaning the surface of a module, the Kanto loam dust was swirled up and left to stand for one day, and the dust was made to adhere to the surface of a module. This state was assumed to be a dust contamination state. Thereafter, water corresponding to a rainfall of 0.5 mm was sprayed and sprayed on the surface of the module, and this state was assumed to be after 0.5 mm of rain. Furthermore, water equivalent to 2.5 mm of rain was sprayed on the surface of the module and sprayed, and this state was assumed to be after 3.0 mm of rain. And the change of the electric power generation amount of the module in each state of the dust contamination state immediately after module manufacture (initial value), the state after 0.5 mm rain, and the state after 3.0 mm rain was measured. Table 1 summarizes the fluctuations of the power generation from the initial value.

  The surface of the module after adhering dust appeared to be colored yellow. In this dust contamination state, the power generation amount of all modules decreased due to light scattering by dust.

  With a small amount of spray equivalent to 0.5 mm (0.5 mm after rain), the dust on the surface of the module was mottled. This decrease in the amount of power generation after the 0.5 mm rain is caused by the modules of Comparative Example 1 in which the coating process is not performed and Comparative Example 2 in which the resin thin film is coated but the resin is not oriented. Both are big. The module of the comparative example 2 which performed the coating process of the resin thin film has the result of a slightly smaller recovery amount than the comparative example 1. This is presumably because the water repellency of the module surface was increased by the coating treatment.

  On the other hand, in the state after 0.5 mm rain, the modules of Example 1, Example 2 and Example 3 in which streaked resin was rubbed onto the surface module glass 2 to give the direction of water droplet movement to the surface of the module The amount of power generation has recovered greatly. The amount of recovery of the module of Example 2 is slightly smaller than that of Example 1 and Example 3. This is presumably because the amount of deformation (direction) in one direction of the resin adhering to the surface of the surface module glass 2 is small.

  In the state after the 3.0 mm rain, all of the modules of Example 1, Example 2 and Example 3 recovered the initial power generation amount. On the other hand, the modules of Comparative Example 1 and Comparative Example 2 remain affected by dirt, resulting in a small recovery amount. Thereby, it turns out that this invention has the effect of the dust removability improvement.

  Water droplet traces remain on the glass surface as dust adheres to them, but a large amount of colored water droplet traces remain in the module of Comparative Example 1, whereas a small amount of dark water droplet traces remain in the module of Comparative Example 2 Met. Moreover, in the modules of Example 1, Example 2, and Example 3, the water droplet traces were thin and linear and remained sparsely. In the module of Example 2, the width of the linear water droplet trace was slightly wide. In any of the modules, only a few traces of water drops remain in the region corresponding to the cell 100 on the surface module glass 2, and the area corresponding to the space between the cells 100 on the surface module glass 2 is dotted. What remained in the shape was observed.

  The above shows that according to the present invention, the movement of the water droplets on the surface of the module, that is, the removal of the dust by the water droplets, is efficiently performed, and the influence of the dust on the power generation amount can be efficiently suppressed even with a small amount of rainfall. .

  As described above, the solar cell module according to the present invention is useful for realizing a solar cell module with excellent detergency that can efficiently remove dust and the like adhering to the surface even with a small amount of rainfall.

  DESCRIPTION OF SYMBOLS 1 Solar cell module (module), 2 Surface module glass, 3 Filler, 4 Back surface protection sheet, 10 Solar cell array (array), 20 Resin layer, 31 Virtual line extended in gravity movement direction, 32 In gravity movement direction The direction which makes an obtuse angle with respect to 100, 100 photovoltaic cell (cell), 101 Interelement connection line.

Claims (5)

A solar cell module in which a translucent protective member is fixed to the light receiving surface side of the solar cell, and a plurality of solar cells are connected at a predetermined interval,
A plurality of first regions and second regions having different hydrophilicity on the light receiving surface side of the protective member are mixed,
The direction in which the second regions sandwiched between the adjacent first regions continue or the direction in which the first regions sandwiched between the adjacent second regions induce water droplets on the protective member. In a given direction,
The predetermined direction is a surface region of the protective member corresponding to a boundary portion where the solar cells and the solar cells are adjacent to each other, and is directed to a region along the direction in which the water droplet flows by gravity, and the water droplet Is a direction that intersects with the direction of gravity by an acute angle α,
A solar cell module characterized by. Either one of the first region and the second region is hydrophilic and the other is hydrophobic.
The solar cell module according to claim 1. The first region is an exposed surface of the protective member;
The second region is a surface of a resin layer formed on the protective member;
The solar cell module according to claim 1 or 2. The first region is a surface of a hydrophilic film formed on the protective member and having a higher hydrophilicity than the surface of the protective member;
The second region is a surface of a hydrophobic resin layer formed on the protective member;
The solar cell module according to any one of claims 1 to 3. The hydrophilic film is made of metal oxide fine particles;
The solar cell module according to claim 4.

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