Solar cell module

Abstract

Even when solar cell modules are installed at an angle close to horizontal, dust, dirt, and other debris that adhere to the light-receiving surface and block sunlight from reaching the power generation area can be easily removed by rainwater, making it easier to maintain the power generation efficiency of the solar cell modules. [Solution] The solar cell module 10 comprises a sheet-like barrier material 11 with a light-receiving surface 12, a power generation region 15, a first region 121a provided on the light-receiving surface 12 and located in a position overlapping with the power generation region 15, and a second region 122 located in a position not overlapping with the power generation region 15. The average value of the water contact angle within a small area of ​​the first region 121a gradually decreases as it approaches the boundary line with the second region 122, and the water contact angle near the boundary line between the second region 121a and the first region 122 is less than or equal to the average value of the water contact angle within a small area near the boundary line between the second region 122 and the first region 121a.

Description

Technical Field

[0001] The present invention relates to a solar cell module.

Background Art

[0002] Conventionally, when dust, sand, etc. adhere to the light-receiving surface of a solar cell module, sunlight is blocked by this, and there is a problem that the power generation efficiency of the solar cell decreases. In contrast, a structure has been proposed that makes it easier to remove dust, sand, etc. adhering to the light-receiving surface by rainwater. For example, Patent Document 1 discloses a structure in which a pattern of a hydrophilic region is provided on the light-receiving surface of a solar cell module to induce the movement of water droplets by rainwater and make it easier to remove adhering dust, sand, etc.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the case where the solar cell module is installed at an angle close to horizontal, etc., there is a possibility that it is difficult to remove dust, sand, etc. that adhere to the light-receiving surface and block the sunlight irradiating the power generation region by rainwater. An object of the present invention is to provide a solar cell module that can easily remove dust, sand, etc. that adhere to the light-receiving surface and block the sunlight irradiating the power generation region by rainwater or the like, and can easily maintain the power generation efficiency, even when the solar cell module is installed at an angle close to horizontal.

Means for Solving the Problems

[0005] The present invention comprises a sheet-like barrier material having a light-receiving surface; a plurality of power generation regions arranged at predetermined intervals parallel to the in-plane direction of the barrier material near the surface of the barrier material opposite to the light-receiving surface; a first region provided on the light-receiving surface, at least a portion of which overlaps with the power generation regions when viewed from a direction perpendicular to the in-plane direction of the barrier material; and a second region provided on the light-receiving surface, at least a portion of which does not overlap with the power generation regions when viewed from a direction perpendicular to the in-plane direction of the barrier material, and having a boundary line with the first region in a first direction when viewed from the first region, wherein the average value of the water contact angle in a predetermined sub-region within the first region gradually decreases in at least a portion as it approaches the boundary line with the second region, and the water contact angle in the second region near the boundary line with the first region is at least a portion less than or equal to the average value of the water contact angle in a predetermined sub-region near the boundary line with the second region within the first region. [Effects of the Invention]

[0006] According to an embodiment of the present invention, even when a solar cell module is installed at an angle close to horizontal, dust, sand, and other debris that adhere to the light-receiving surface and block sunlight from irradiating the power generation area can be easily removed by rainwater, making it easier to maintain the power generation efficiency of the solar cell module. [Brief explanation of the drawing]

[0007] [Figure 1] This is a plan view showing the overall structure of the solar cell module according to the first embodiment. [Figure 2] This is a cross-sectional view (front view) showing the overall structure of the solar cell module according to the first embodiment. [Figure 3] This is a cross-sectional view (plan view) showing the overall structure of the solar cell module according to the first embodiment. [Figure 4] This is a plan view showing the structure of the light-receiving surface of the first embodiment. [Figure 5] These are a plan view and a front view showing the structure of the light-receiving surface and the mechanism of water droplet movement on the light-receiving surface of the first embodiment. [Figure 6]This is a plan view showing the overall structure of the solar cell module according to the second embodiment. [Figure 7] This is a cross-sectional view (front view) showing the overall structure of the solar cell module according to the second embodiment. [Figure 8] This is a plan view showing the structure of the light-receiving surface of the third embodiment. [Figure 9] This is a plan view showing the structure of the light-receiving surface of the fourth embodiment. [Modes for carrying out the invention]

[0008] [First Embodiment] The solar cell module according to the first embodiment of the present invention will be described below with reference to Figures 1 to 5.

[0009] Figure 1 is a plan view showing the overall structure of the solar cell module 10. As shown in Figure 1, the solar cell module 10 includes a sheet-like barrier material 11. The barrier material 11 is a sheet-like, light-transmitting member made of resin materials such as polycarbonate, polyethylene terephthalate, polyimide, polyethylene, polypropylene, and polyvinyl chloride, or glass materials. The barrier material 11 includes a light-receiving surface 12.

[0010] The light-receiving surface 12 comprises a first region 121a (hatched region), a first region 121b (hatched region), a second region 122 (non-hatched region) having a boundary line with the first region 121a and the first region 121b, and a third region 123 (hatched region) having a boundary line with the first region 121a and the first region 121b. The second region 122, the first region 121b, the third region 123, the first region 121a, and the second region 122 are arranged in this order along direction X, which is the in-plane direction of the barrier material 11. Multiple such arrangements are arranged continuously along direction X. Each region extends along direction Y, which is the in-plane direction of the barrier material 11 and intersects direction X.

[0011] The barrier material 11 is provided with a drainage groove 14 in a second region 122 on the side of the light-receiving surface 12. The drainage groove 14 extends along direction Y from the central region to the outer peripheral region of the barrier material 11, and has a drainage groove end 141 in the outer peripheral region. In addition, multiple drainage grooves 14 and drainage groove ends 141 are arranged along direction X at predetermined intervals.

[0012] Figure 2 is a cross-sectional view (front view) of cross-section AA (Figure 1) showing the overall structure of the solar cell module 10. As shown in Figure 2, the solar cell module 10 comprises a power generation region 15, a non-power generation region 16, and a substrate 17. The power generation region 15 is the part that contains the photoelectric conversion layer of a power generation element such as a perovskite solar cell, a dye-sensitized solar cell, or an organic thin-film solar cell, and converts the irradiated sunlight into electrical energy. Multiple such regions are arranged at predetermined intervals along direction X near the surface of the barrier material 11 opposite to the light-receiving surface 12. The non-power generation region 16 is the part that does not directly participate in converting the irradiated sunlight into electrical energy. The substrate 17 is a sheet-like member and is located on the opposite side of the power generation region 15 and the non-power generation region 16 from the side where the barrier material 11 is located.

[0013] Figure 3 is a cross-sectional view (plan view) of cross-section BB (Figure 2) showing the overall structure of the solar cell module 10. As shown in Figures 1 and 3, when the light-receiving surface 12 is viewed from the Z direction (perpendicular to the plane of the paper), which is perpendicular to the in-plane direction of the barrier material 11, the first region 121a, the first region 121b, and the third region 123 are located in positions that overlap with the power generation region 15, while the second region 122 is located in a position that does not overlap with the power generation region 15. However, it is sufficient that at least a portion of the first region 121a, the first region 121b, and the third region 123 overlap with the power generation region 15, and that at least a portion of the second region 122 does not overlap with the power generation region 15.

[0014] Figure 4 is a plan view showing the structure of the light-receiving surface 12, and is an enlarged view of region C in Figure 1. As shown in FIG. 4, the light-receiving surface 12 includes a first surface 131 (hatched area) and a second surface 132 (area without hatching) having a smaller water contact angle than the first surface 131. In the first region 121a and the first region 121b, a boundary line between the first surface 131 and the second surface 132 is located, and both the first surface 131 and the second surface 132 are distributed.

[0015] The boundary line between the first surface 131 and the second surface 132 may include a line in which two line segments inclined with respect to the direction X are alternately continuous. Further, the boundary line may include a curve.

[0016] In the vicinity of the boundary line with the third region 123 in the first region 121a, the ratio of the area of the first surface 131 to the second surface 132 is large, and along the direction X (the first direction), the ratio of the area of the second surface 132 gradually increases, and the ratio of the area of the first surface 131 gradually decreases. In the vicinity of the boundary line with the second region 122 in the first region 121a, the ratio of the area of the second surface 132 to the first surface 131 is large. Also, in the vicinity of the boundary line with the third region 123 in the first region 121b, the ratio of the area of the first surface 131 to the second surface 132 is large, and along the opposite direction of the direction X (the second direction), the ratio of the area of the second surface 132 gradually increases, and the ratio of the area of the first surface 131 gradually decreases. In the vicinity of the boundary line with the second region 122 in the first region 121b, the ratio of the area of the second surface 132 to the first surface 131 is large.

[0017] The entire third region 123 may be the first surface 131. Also, the entire second region 122 may be the second surface 132.

[0018] The second surface 132 may be the surface of the barrier material 11. The first surface 131 may be a thin layer of a translucent material, such as a fluororesin or silicone resin, formed on the surface of the barrier material 11, with a water contact angle greater than that of the surface of the barrier material 11. In these cases, the thin layer may be formed on both the first surface 131 and the second surface 132 of the light-receiving surface 12 of the barrier material 11 by a coating method or vacuum deposition method, and the thin layer on the second surface 132 may be removed by laser processing or the like. Furthermore, the first surface 131 may have a fine uneven structure that exhibits water repellency, formed on the surface of the barrier material 11. In this case, the fine uneven structure that exhibits water repellency may be formed on the portion of the first surface 131 of the light-receiving surface 12 of the barrier material 11 by laser processing or the like.

[0019] Figure 5 shows the structure of the light-receiving surface 12 and the mechanism of water droplet movement on the light-receiving surface 12. Figure 5(a) is an enlarged plan view of region D (Figure 4), and Figure 5(b) is a front view corresponding to Figure 5(a). As shown in Figure 5, within the first region 121a, three subregions are defined: subregion P, which is close to the boundary with the third region 123; subregion Q, which is equal in distance to the second region 122 and to the third region 123; and subregion R, which is close to the boundary with the second region 122. The average water contact angle in each sub-region can be calculated using the following formula. [Average water contact angle in a small area (degrees)] = [Water contact angle of the first surface 131 (degrees)] × [Percentage of the area of ​​the first surface 131 in the small area] + [Water contact angle of the second surface 132 (degrees)] × [Percentage of the area of ​​the second surface 132 in the small area]

[0020] As an example, let the water contact angle of the first surface 131 be 110 degrees and the water contact angle of the second surface 132 be 50 degrees. The proportions of the area occupied by the first surface 131 in sub-regions P, Q, and R are 92%, 50%, and 8%, respectively, and the proportions of the area occupied by the second surface 132 in sub-regions P, Q, and R are 8%, 50%, and 92%, respectively. In this case, the average value of the water contact angle in each sub-region can be calculated as follows. Small area P [105 (degrees)] = [110 (degrees)] × [0.92] + [50 (degrees)] × [0.08] Small area Q [80 (degrees)] = [110 (degrees)] × [0.50] + [50 (degrees)] × [0.50] Small area R [55 (degrees)] = [110 (degrees)] × [0.08] + [50 (degrees)] × [0.92]

[0021] The average water contact angle in a small area can be determined by the method described above, or by attaching tiny water droplets to multiple locations within the small area, measuring the water contact angle of each droplet, and averaging the water contact angles.

[0022] The water contact angle of the third region 123 may be the same as the water contact angle of the first surface 131, which is 110 degrees. Also, the water contact angle of the second region 122 may be the same as the water contact angle of the second surface 132, which is 50 degrees.

[0023] A water droplet 191 attached to the light-receiving surface 12, spanning both the third region 123 and the small region P, moves in direction X because the water contact angle on the small region P side is smaller than the water contact angle on the third region 123 side. A water droplet 192 attached to the light-receiving surface 12 between small regions P and Q moves in direction X because the water contact angle on the side of small region Q is smaller than the water contact angle on the side of small region P. A water droplet 193 attached to the light-receiving surface 12 between small regions Q and R moves in direction X because the water contact angle on the side of small region R is smaller than the water contact angle on the side of small region Q. Some of the water droplets 194 that have moved to the second region 122 are pushed towards the drain 14 and move into the drain 14 by capillary force, etc. When a large number of water droplets fill the inside of the drain 14, the water droplets are discharged to the outside of the solar cell module 10 from the drain end 141 (Figure 1).

[0024] Although not shown in the diagram, water droplets adhering to the first region 121b move in the opposite direction to direction X by the same structure and mechanism as described above, and move into the drain channel 14. When a large number of water droplets fill the drain channel 14, the water droplets are discharged from the drain channel end 141 (Figure 1) to the outside of the solar cell module 10.

[0025] The average value of the water contact angle in a predetermined sub-region within the first region 121a should, at least in part, gradually decrease as it approaches the boundary line with the second region 122. Also, the water contact angle near the boundary line between the second region 122 and the first region 121a should, at least in part, be less than or equal to the average value of the water contact angle in a predetermined sub-region near the boundary line between the first region 121a and the second region 122. The water contact angle near the boundary line between the third region 123 and the first region 121a should, at least in part, be greater than or equal to the average value of the water contact angle in a predetermined sub-region near the boundary line between the first region 121a and the third region 123. The first region 121b, the second region 122, and the third region 123 may also have the same structure as described above.

[0026] The above structure and mechanism allow water droplets adhering to the first region 121a, the first region 121b, and the third region 123 to be moved into the second region 122 and the drainage channel 14, even in the absence of gravity. This movement of water droplets makes it easier to move dust, sand, and other debris adhering to the first region 121a, the first region 121b, and the third region 123, which obstruct sunlight from reaching the power generation region 15, into the second region 122 and the drainage channel 14. Even when the solar cell module 10 is installed at an angle close to horizontal, dust, sand, and other debris adhering to the light-receiving surface 12, which obstruct sunlight from reaching the power generation region 15, can be easily removed by rainwater, making it easier to maintain the power generation efficiency of the solar cell module 10.

[0027] [Second Embodiment] Hereinafter, a solar cell module according to a second embodiment of the present invention will be described with reference to Figures 6 and 7. However, components having the same configuration as those in the first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0028] Figure 6 is a plan view showing the overall structure of the solar cell module 20. As shown in Figure 6, the solar cell module 20 includes a sheet-like barrier material 21. The barrier material 21 is a sheet-like, light-transmitting member made of resin materials such as polycarbonate, polyethylene terephthalate, polyimide, polyethylene, polypropylene, and polyvinyl chloride, or glass materials. The barrier material 21 includes a light-receiving surface 22.

[0029] The light-receiving surface 22 comprises a first region 121a (hatched region), a first region 121b (hatched region), a second region 122 (non-hatched region) having a boundary line with the first region 121a and the first region 121b, and a third region 123 (hatched region) having a boundary line with the first region 121a and the first region 121b. The second region 122, the first region 121b, the third region 123, the first region 121a, and the second region 122 are arranged in this order along direction X, which is the in-plane direction of the barrier material 21. Multiple such arrangements are arranged continuously along direction X. Each region extends along direction Y, which is the in-plane direction of the barrier material 21 and intersects direction X.

[0030] The second region 122 extends along direction Y from the central region to the outer peripheral region of the light-receiving surface 22, and the outer peripheral region includes an end portion 241 of the second region. In addition, multiple end portions 241 of the second region are arranged at predetermined intervals along direction X.

[0031] Figure 7 is a cross-sectional view (front view) of the solar cell module 20 at cross-section EE (Figure 6), showing the overall structure. The mechanism of water droplet movement on the light-receiving surface 22 is the same as in the first embodiment described above. However, as shown in Figures 6 and 7, the solar cell module 20 does not have the drainage channel 14 and drainage channel end 141 that the solar cell module 10 has. In the solar cell module 20, water droplets that have moved to the second region 122 become wet and spread within the second region 122, and are discharged to the outside of the solar cell module 20 from the end 241 (Figure 6), etc., of the second region.

[0032] The above structure and mechanism allow water droplets adhering to the first region 121a, the first region 121b, and the third region 123 to be moved to the second region 122, even in the absence of gravity. This movement of water droplets makes it easier to move dust, sand, and other debris adhering to the first region 121a, the first region 121b, and the third region 123, which obstruct sunlight irradiating the power generation region 15, to the second region 122. Even when the solar cell module 20 is installed at an angle close to horizontal, dust, sand, and other debris adhering to the light-receiving surface 12, which obstruct sunlight irradiating the power generation region 15, can be easily removed by rainwater, making it easier to maintain the power generation efficiency of the solar cell module 20.

[0033] [Third Embodiment] Hereinafter, a solar cell module according to a third embodiment of the present invention will be described with reference to Figure 8. However, components having the same configuration as those of the first embodiment described above will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0034] Figure 8 is a plan view showing the structure of the light-receiving surface 32 of the solar cell module 30. (This corresponds to Figure 5(a) of the first embodiment.) As shown in Figure 8, the light-receiving surface 32 comprises a first surface 331 (hatched area) and a second surface 332 (unhatched area) having a smaller water contact angle than the first surface 331. The boundary line between the first surface 331 and the second surface 332 is located in the first region 121a, and both the first surface 331 and the second surface 332 are distributed within it.

[0035] The boundary line between the first surface 331 and the second surface 332 may include a number of closed lines, such as circular shapes. The area inside the closed lines may be the first surface 331 and the area outside the closed lines may be the second surface 332, or the area inside the closed lines may be the second surface 332 and the area outside the closed lines may be the first surface 331. The density of the closed lines and the size of the closed lines will differ depending on their location within the first region 121a.

[0036] Near the boundary line between the first region 121a and the third region 123, the area ratio of the first surface 331 is large compared to the area of ​​the second surface 332, and along direction X, the area ratio of the second surface 332 gradually increases and the area ratio of the first surface 331 gradually decreases. Near the boundary line between the first region 121a and the second region 122, the area ratio of the second surface 332 is large compared to the area of ​​the first surface 331.

[0037] The third region 123 may be entirely the first surface 331. Similarly, the second region 122 may be entirely the second surface 332.

[0038] This embodiment, using a mechanism similar to that of the first embodiment, can move water droplets adhering to the first region 121a and the third region 123 into the second region 122 and the inside of the drain 14. Thus, this embodiment has the same advantages as the first embodiment.

[0039] [Fourth Embodiment] Hereinafter, a solar cell module according to a fourth embodiment of the present invention will be described with reference to Figure 9. However, components having the same configuration as those of the first embodiment described above will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0040] Figure 9 is a plan view showing the structure of the light-receiving surface 42 of the solar cell module 40. (This corresponds to Figure 5(a) of the first embodiment.) As shown in Figure 9, the first region 121a of the light-receiving surface 42 includes a third surface 433 (hatched region) with a smaller water contact angle than the first surface 431, a fourth surface 434 (hatched region) with a smaller water contact angle than the third surface 433, a fifth surface 435 (hatched region) with a smaller water contact angle than the fourth surface 434, and a sixth surface 436 (hatched region) with a smaller water contact angle than the fifth surface 435. The water contact angle of the sixth surface 436 is greater than the water contact angle of the second surface 432 (region without hatching).

[0041] A third surface 433 is positioned at the boundary line between the first region 121a and the third region 123, and a fourth surface 434, a fifth surface 435, and a sixth surface 436 are positioned in order along direction X, with the sixth surface 436 located at the boundary line between the first region 121a and the second region 122.

[0042] The third region 123 may be entirely the first surface 431. Similarly, the second region 122 may be entirely the second surface 432.

[0043] This embodiment, using a mechanism similar to that of the first embodiment, can move water droplets adhering to the first region 121a and the third region 123 into the second region 122 and the inside of the drain 14. Thus, this embodiment has the same advantages as the first embodiment.

[0044] [Variation] Next, modified examples of each of the above embodiments will be described.

[0045] The direction in which the boundary line between the first region 121b and the second region 122 is located, as viewed from the first region 121b (the second direction), does not need to be a direction different from direction X (the first direction), and may be a direction that intersects direction X (the first direction).

[0046] The first region 121a and the first region 121b may be in contact. The first region 121b is optional. The third area 123 is optional.

[0047] The first region 121a and the drainage channel 14 may be in contact. In this case, the average value of the water contact angle in a predetermined sub-region within the first region 121a should gradually decrease as it approaches the boundary line with the drainage channel 14, at least in part. Furthermore, the water contact angle in the drainage channel 14 near the boundary line with the first region 121a should be less than or equal to the average value of the water contact angle in a predetermined sub-region near the boundary line with the drainage channel 14 within the first region 121a, at least in part. The first region 121b and the drainage channel 14 may be in contact and have a structure similar to that described above.

[0048] The solar cell module 10 may be installed in an environment where water droplets other than rainwater, such as splashes, adhere to the light-receiving surface 12, such as above or near the water surface. The same advantages apply to water droplets other than rainwater. The same applies to solar cell modules 20, 30, and 40.

[0049] The present invention is not limited to the embodiments and modifications described above, and various modifications are possible. [Explanation of Symbols]

[0050] 10 solar modules 11 Barrier materials 12 Photosensitive surface 14 Drainage 15 Power Generation Area 121a First area 121b First area 122 Second Domain 123 The Third Domain 131 First surface 132 Second surface P small area Q small area R small area X direction (first direction)

Claims

1. A sheet-like barrier material having a light-receiving surface, A plurality of power generation regions are arranged at predetermined intervals parallel to the in-plane direction of the barrier material near the surface of the barrier material opposite to the light-receiving surface, A first region is provided on the light-receiving surface, and when viewed from a direction perpendicular to the in-plane direction of the barrier material, at least a portion of which overlaps with the power generation region. Provided on the light-receiving surface, and when viewed from a direction perpendicular to the in-plane direction of the barrier material, at least a portion of it is located in a position that does not overlap with the power generation region, and a second region having a boundary line with the first region in a first direction when viewed from the first region, Equipped with, The average value of the water contact angle in a predetermined sub-region within the first region gradually decreases in at least a portion of the region as it approaches the boundary line with the second region. A solar cell module in which the water contact angle near the boundary line between the second region and the first region is, at least in part, less than or equal to the average value of the water contact angle in a predetermined sub-region near the boundary line between the first region and the second region.

2. The solar cell module according to claim 1, wherein the second region has a boundary line with the first region in a second direction different from the first direction when viewed from the first region.

3. The solar cell module according to claim 2, wherein the second direction is opposite to the first direction.

4. Furthermore, a third region is provided on the light-receiving surface, and when viewed from a direction perpendicular to the in-plane direction of the barrier material, at least a portion of which overlaps with the power generation region and has a boundary line with the first region. Equipped with, The solar cell module according to claim 1, wherein the water contact angle near the boundary line between the third region and the first region is, in at least a portion of the case, greater than or equal to the average value of the water contact angle in a predetermined sub-region near the boundary line between the first region and the third region.

5. The solar cell module according to claim 1, wherein the first region comprises a first surface and a second surface having a smaller water contact angle than the first surface, and the ratio of the areas of the first surface and the second surface changes depending on the location, thereby causing the average value of the water contact angle in a small region within the first region to change depending on the location.

6. The solar cell module according to claim 5, wherein the boundary line between the first surface and the second surface includes a line in which two line segments, which are inclined with respect to the first direction, are alternately continuous.

7. The solar cell module according to claim 5, wherein the boundary line between the first surface and the second surface includes a number of closed lines.

8. The solar cell module according to claim 5, wherein the second surface is the surface of the barrier material, and the first surface is a thin layer of a translucent material formed on the surface of the barrier material, the water contact angle being higher than that of the surface of the barrier material.

9. The solar cell module according to claim 5, wherein the entire area of ​​the second region is the second surface.

10. The solar cell module according to claim 1, wherein the second region extends from the central region to the outer peripheral region of the barrier material.

11. The solar cell module according to claim 1, wherein the barrier material is provided with a drainage channel in the second region.

12. The solar cell module according to claim 11, wherein the drainage channel extends from the central region to the outer peripheral region of the barrier material.

13. The solar cell module according to claim 12, wherein the drainage channel is in contact with the first region.

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