The present disclosure relates to a solar cell module.
There are solar cell modules in which an extraction electrode to extract charges generated in a solar cell extends to an outside via a through hole of a substrate that is for protection of one surface of the solar cell (e.g., refer to description of Japanese Patent Application Laid-Open No. 2013-89751).
A solar cell module is disclosed.
One aspect of a solar cell module includes a first plate part, a second plate part, a solar cell section, a wiring material, a first sealing material, and a second sealing material. The second plate part is positioned in a state of facing the first plate part. The solar cell section is positioned in a gap between the first plate part and the second plate part. The wiring material is electrically connected to the solar cell section and is positioned from an inside of the gap to an outside of the gap via a through hole that is present in the first plate part. The first sealing material is positioned in a region covering the solar cell section in the gap. The second sealing material is in a state of being filled in an annular region that is closer to the through hole than the first sealing material in the gap and surrounds the entire periphery of the through hole in plan perspective view, and has a higher water barrier property than the first sealing material. At least one of the first plate part and the second plate part has a light-transmitting property for light having a wavelength in a specific range.
There are solar cell modules in which one surface of a solar cell is joined with a protective substrate such as glass for protection of the solar cell. Such a solar cell module is produced, for example, by forming a photoelectric conversion body on one surface of a substrate, disposing a collector electrode on this photoelectric conversion body, disposing an extraction electrode having a first end part connected to the collector electrode on this photoelectric conversion body, covering the photoelectric conversion body with a seal member, and disposing a protective substrate on this sealing member. At this time, for example, it is conceivable to position a second end part of the extraction electrode in a state of extending to a side opposite to a region where the photoelectric conversion body is present, through an opening present in the protection substrate, and to position the sealing member so as to close the opening. Here, for example, polyisobutylene resin or butyl resin can be used as the sealing member. Further, as the sealing member, for example, an ethylene-vinyl acetate copolymer (EVA) or the like can be used.
Meanwhile, with regard to solar cell modules, life extension in which a stable output is maintained for a long period of time is pursued. Therefore, the present inventors have created a technique that can enhance long-term reliability of the solar cell module.
Regarding this, each embodiment will be described with reference to the drawings below. In the drawings, the same reference numerals are given to portions having similar configurations and functions, and redundant explanations are omitted in the following description. Further, the drawings are schematically shown. In
A configuration of a solar cell module 100 according to a first embodiment will be described with reference to
For example, the first plate part 1 can protect the protected part 3. A shape of the first plate part 1 is, for example, a flat plate shape. Specifically, for example, a flat plate having a board surface with a rectangular shape such as an oblong may be adopted as the first plate part 1. For example, the first plate part 1 may have a light-transmitting property for light having a wavelength in a specific range, or may not have a light-transmitting property for light having a wavelength in a specific range.
For example, when glass or a resin such as acrylic or polycarbonate having a thickness of about 1 mm or more and 5 mm or less is adopted as a material of the first plate part 1, the first plate part 1 having a water barrier property is realized. This may reduce entry of moisture from the outside of the solar cell module 100 to the protected part 3. At this time, for example, the first plate part 1 having a light-transmitting property for light having a wavelength in a specific range may also be realized. This allows, for example, light irradiated to the back surface 100bs and transmitted through the first plate part 1 to be incident on the protected part 3, and to be used for photoelectric conversion in a solar cell section 3pv in the protected part 3. As a result, for example, an output in the solar cell module 100 may be improved. Light to be incident on the back surface 100bs may be generated, for example, by reflection of sunlight on the ground or the like. Further, as a material of the first plate part 1, for example, ceramics or the like not having a light-transmitting property for light having a wavelength in a specific range may be adopted. As a wavelength in a specific range in this specification, for example, there is adopted a wavelength in a range of light that may be photoelectrically converted by the solar cell section 3pv in the protected part 3. When a wavelength of light having a high irradiation intensity constituting sunlight is included in the wavelength in the specific range, photoelectric conversion efficiency in the solar cell section 3pv may be improved.
In the first plate part 1, there is a through hole 1h. This through hole 1h is for outputting electric charges obtained by photoelectric conversion in the solar cell section 3pv to the outside of the solar cell module 100. The through hole 1h penetrates, for example, the first plate part 1 in a thickness direction of this first plate part 1. For example, the through hole 1h is present at a position close to one end face 1Es of the first plate part 1, such as a position apart from this one end face 1Es by about 10 mm or more and 40 mm or less. The through hole 1h may be formed in the first plate part 1 by a drill for boring, a jet water stream, or the like.
In the first embodiment, for example, there are the through hole 1h for a positive electrode and the through hole 1h for a negative electrode. Then, a cross section perpendicular to a direction (also referred to as a penetration direction) penetrating through the first plate part 1 in the through hole 1h is a substantially perfect circle. In the example of
The second plate part 2 is, for example, positioned in a state of facing the first plate part 1. Then, the protected part 3 is positioned in a gap 3g between the first plate part 1 and the second plate part 2. Therefore, the second plate part 2 can protect the protected part 3 together with the first plate part 1. A distance that the first plate part 1 and the second plate part 2 are separated from each other with the gap 3g interposed in between is, for example, about 0.5 mm or more and 5 mm or less. A shape of the second plate part 2 is, for example, a flat plate shape similar to that of the first plate part 1. Specifically, for example, a flat plate having a board surface of a rectangular shape such as an oblong may be adopted as the second plate part 2. In the first embodiment, the second plate part 2 has the same outer shape as the first plate part 1.
Further, the second plate part 2 has a light-transmitting property for light having a wavelength in a specific range. Therefore, for example, light irradiated on the front surface 100fs and transmitted through the second plate part 2 may be incident on the protected part 3, and may be used for photoelectric conversion in the solar cell section 3pv included in the protected part 3.
For example, when glass or resin such as acrylic or polycarbonate is adopted as a material of the second plate part 2, it is possible to realize the second plate part 2 having a water barrier property capable of reducing entry of moisture from the outside of the solar cell module 100 to the protected part 3. At this time, for example, the second plate part 2 having a light-transmitting property for light having a wavelength in a specific range may also be realized. As the glass, for example, a material with high light transmittance, such as white plate glass, tempered glass, and heat ray reflecting glass having a thickness of about 1 mm or more and 5 mm or less may be adopted.
The protected part 3 includes the solar cell section 3pv, a wiring material 3t, a first sealing material 3fi, and a second sealing material 3se. Therefore, the solar cell section 3pv is positioned in the gap 3g between the first plate part 1 and the second plate part 2. For example, the solar cell section 3pv may be formed on the second plate part 2 or the first plate part 1, or may be positioned so as to be sandwiched between the first plate part 1 and the second plate part 2.
The solar cell section 3pv includes N pieces of (N is an integer of 1 or more) solar cell element capable of converting incident sunlight into electricity, for example. As the solar cell element, for example, a crystalline solar cell element or a thin film solar cell element may be adopted. As the crystalline solar cell element, for example, there may be adopted a silicon solar cell element such as single crystal silicon, polycrystalline silicon, or a heterojunction type, or a compound solar cell element such as III-V group.
Further, as the thin film solar cell element, for example, a silicon solar cell element, a compound solar cell element, or other type of solar cell element may be adopted. The silicon solar cell element in the thin film system may include, for example, a solar cell element using amorphous silicon and thin-film polycrystalline silicon. The compound solar cell element in the thin film system may include, for example, a solar cell element using a compound semiconductor such as a CIS semiconductor, a CIGS semiconductor, a cadmium telluride (CdTe) semiconductor, or a compound having a perovskite structure. The CIS semiconductor is a compound semiconductor containing cadmium (Cd), indium (In), and selenium (Se). The CIGS semiconductor is a compound semiconductor containing cadmium (Cd), indium (In), gallium (Ga), and selenium (Se). Other types of solar cell elements in thin film system may include, for example, a solar cell element of a type such as an organic thin film or dye sensitization. Here, for example, in a case where N pieces of solar cell element are electrically connected in series, an output of the solar cell module 100 may be larger as N is larger. In the first embodiment, the solar cell section 3pv including a plurality of thin film solar cell elements is formed on the second plate part 2.
The wiring material 3t is electrically connected to the solar cell section 3pv. This wiring material 3t is positioned in a state of extending from inside the gap 3g between the first plate part 1 and the second plate part 2 to outside the gap 3g, via the through hole 1h that is present in the first plate part 1. In other words, a first end part 3t1 (see
The first sealing material 3fi is positioned in a second region A2 covering at least the solar cell section 3pv, in the gap 3g between the first plate part 1 and the second plate part 2. As the second region A2, for example, there may be adopted such a region that covers the entire surface of the first plate part 1 side (the −Z direction side) of the solar cell section 3pv positioned on the second plate part 2. The first sealing material 3fi can seal the solar cell section 3pv by covering this solar cell section 3pv. Further, by filling the gap 3g with the first sealing material 3fi over a wide range of the gap 3g, moisture and the like are unlikely to enter the solar cell section 3pv. As a material of the first sealing material 3fi, for example, there may be adopted an ethylene-vinyl acetate copolymer (EVA), triacetyl cellulose (TAC), a polyester resin such as polyethylene naphthalate, or the like, having an excellent light-transmitting property for light having a wavelength in a specific range. For example, the first sealing material 3fi may be made of two or more kinds of sealing materials.
The second sealing material 3se is in a state of being filled in a third region A3 that is closer to the through hole 1h than the first sealing material 3fi in the gap 3g between the first plate part 1 and the second plate part 2. As shown in
Here, for example, as shown in
In addition, here, for example, in the gap 3g between the first plate part 1 and the second plate part 2, an area of the first opening Op1 that opens toward the fourth region A4 between the through hole 1h and the second plate part 2 is defined as S1. Further, here, for example, an area of the second opening Op2 that opens toward a side opposite to the second plate part 2 in the through hole 1h is defined as S2. In this case, for example, when the area S1 is smaller than the area S2, for example, in a path leading to the solar cell section 3pv from the second opening Op2 of the through hole 1h, the narrowed first opening Op1 may be sealed with the second sealing material 3se having a high water barrier property. This may reduce entry of moisture or the like from the outside of the solar cell module 100 via the through hole 1h of the first plate part 1 toward the solar cell section 3pv. As a result, long-term reliability of the solar cell module 100 can be enhanced. In the first embodiment, for example, a distance L1 between the first plate part 1 and the second plate part 2 is about 1 mm, and a diameter D1 of the through hole 1h is about 5 mm. At this time, the area S1 (=5π mm2=5 mm×π×1 mm) is smaller than the area S2 (6.25π mm2=π×2.5 mm×2.5 mm).
The terminal box 4 is positioned on the back surface 100bs as a surface opposite to the second plate part 2 in the first plate part 1. The terminal box 4 is what is called a so-called junction box. The wiring material 3t is present in a state of extending into the terminal box 4 via an opening (also referred to as a third opening) Op3 of the terminal box 4. Then, the second end part 3t2 of the wiring material 3t is connected to a terminal, for example, in a fifth region A5 in the terminal box 4. The terminal box 4 is fixed to the back surface 100bs. The terminal box 4 may be fixed to the back surface 100bs with use of resin such as silicon sealant, for example. Here, the terminal box 4 is positioned so as to cover the through hole 1h from the back surface 100bs side. At this time, for example, when the terminal box 4 includes a resin casing 4b with a high water barrier property, and resin or the like is closing between this casing and the back surface 100bs, passage of moisture and the like from the outside of the solar cell module 100 toward the through hole 1h may be reduced.
Here, as shown in
The output wiring 5 can output electricity obtained through the solar cell module 100 to the outside. Here, the output wiring 5 is electrically connected to the wiring material 3t in the fifth region A5 in the terminal box 4. Then, the output wiring 5 is present in a state of extending from the fifth region A5 in the terminal box 4 to the outside of the terminal box 4.
Four end faces Es1, Es2, Es3, and Es4 of the solar cell module 100 may be mounted with, for example, a frame made of aluminum or the like. At this time, when a resin having an excellent water barrier property, such as a butyl resin, is filled between the frame and the end faces Es1, Es2, Es3, and Es4, entry of moisture and the like from the end faces Es1, Es2, Es3, and Es4 of the solar cell module 100 toward the solar cell section 3pv may be reduced. As a result, long-term reliability of the solar cell module 100 may be enhanced.
One example of a method for manufacturing the solar cell module 100 will be described with reference to
In step ST1, the first process of preparing the second plate part 2 is performed. Here, for example, as shown in
Next, in step ST2, the second process of arranging the solar cell section 3pv is performed. Here, for example, as shown in
Next, in step ST3, the third process of arranging the wiring material 3t is performed. Here, for example, as shown in
Next, in step ST4, the fourth process of arranging a sheet to be a sealing material is performed. Here, for example, as shown in
Next, in step ST5, the fifth process of arranging the first plate part 1 is performed. Here, for example, as shown in
Next, in step ST6, the sixth process of performing lamination processing for the laminate SL1 is performed. Here, a laminating apparatus (laminator) is used to integrate the laminate SL1. For example, in the laminator, the laminate SL1 is placed on a heater board in a chamber, and the laminate SL1 is heated to about 100° C. to 200° C. while the inside of the chamber is decompressed to about 50 Pa to 150 Pa. At this time, the first sheet St1 and the second sheet St2 are brought into a state of being flowable by heating. In this state, the laminate SL1 is pressed by a diaphragm sheet or the like in the chamber, so that the laminate SL1 is brought into a state of being integrated. This causes a state where the solar cell section 3pv is covered with the first sealing material 3fi, and the second sealing material 3se is filled in the annular third region A3 closer to the through hole 1h than the first sealing material 3fi. In this lamination processing, for example, integration of the laminate SL1 is performed under vacuum. Therefore, for example, air bubbles are unlikely to enter each of the first sheet St1 and the second sheet St2 in the molten state. As a result, pressing of the first sheet St1 and the second sheet St2 in the molten state allows the first sealing material 3fi and the second sealing material 3se to be in a dense state with few vacancies. As a result, for example, a water barrier property by the first sealing material 3fi and the second sealing material 3se may be improved.
Next, in step ST7, the seventh process of mounting the terminal box 4 is performed. Here, for example, as shown in
Next, in step ST8, the eighth process of mounting a frame 7 to the solar cell module 100 is performed. Here, for example, as shown in
In the solar cell module 100 according to the first embodiment, for example, in the gap 3g between the first plate part 1 and the second plate part 2, the second sealing material 3se is filled in the annular third region A3 including the first opening Op1, and the periphery thereof, that opens to the fourth region A4 between the through hole 1h and the second plate part 2. As a result, for example, in a path leading to the solar cell section 3pv from the second opening Op2 that opens toward a side opposite to the second plate part 2 in the through hole 1h, the narrowed first opening Op1 may be sealed with the second sealing material 3se having a high water barrier property. Therefore, entry of moisture or the like from the outside of the solar cell module 100 via the through hole 1h of the first plate part 1 toward the solar cell section 3pv may be reduced. Therefore, long-term reliability of the solar cell module 100 may be enhanced.
The present disclosure is not limited to the above-described first embodiment, and various modifications and improvements are possible without departing from the subject matter of the present disclosure.
In the first embodiment above, for example, the second sealing material 3se may be filled not only in the third region A3 as the annular region, but also in the fourth region A4. Specifically, for example, as shown in
In each of the embodiments above, for example, as shown in
In each of the embodiments above, for example, there may be one through hole 1h in the first plate part 1, and two wiring materials 3t may be positioned in a state of extending from the inside of the gap 3g to the outside of the gap 3g via this one through hole 1h. At this time, a diameter of the one through hole 1h may simply be increased in order not to cause a short circuit due to contact of the two wiring materials 3t.
In each of the embodiments above, for example, in the gap 3g, the first sealing material 3fi may be present not only between the first plate part 1 and the solar cell section 3pv, but also between the second plate part 2 and the solar cell section 3pv. In this case, in manufacturing the solar cell module, for example, a first one of first sheets St1, the solar cell section 3pv, and a second one of the first sheets St1 may simply be stacked in this described order on the second plate part 2.
In each of the embodiments above, for example, in a region other than the region where the second sealing material 3se is present in the gap 3g, the solar cell section 3pv may be appropriately positioned as long as it is within a range that can be covered with the first sealing material 3fi. For example, in a case where the solar cell section 3pv includes a plurality of solar cell elements, it suffices that the plurality of solar cell elements are positioned avoiding a position of the second sealing material 3se.
Needless to say that all or part constituting each of the embodiments and the various modified examples can be combined as appropriate in a range not inconsistent.
Number | Date | Country | Kind |
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2016-193659 | Sep 2016 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2017/035550 | 9/29/2017 | WO | 00 |