JP7047720B2 - Solar cell module with snow melting function - Google Patents

Description

The present invention relates to a solar cell module with a snow melting function. More specifically, the present invention relates to a solar cell module having a snow melting function capable of melting snow adhering to the surface of the solar cell module on the light receiving surface side.

In recent years, due to growing awareness of environmental issues, solar cells as a clean energy source have been attracting attention. Currently, various forms of solar cell modules have been developed and proposed. Generally, in the solar cell module, the transparent front substrate, the sealing material sheet on the light receiving side, the solar cell element, the sealing material sheet on the non-light receiving surface side, and the back surface protective sheet are in this order from the light receiving surface side. It is a structure that is laminated with.

By the way, when such a solar cell module is installed in an area where the amount of snowfall is large, if snow continues to adhere to the surface of the solar cell module on the light receiving surface side, the power generation efficiency is significantly reduced. Therefore, the development of a solar cell module with a snow melting function capable of removing snow adhering to the module surface is in progress.

For example, a solar cell module with a snow melting function (Patent Documents 1 and 2) in which an electric heating member for snow melting is arranged directly above or below a transparent front substrate on the light receiving surface side of the solar cell module, or a solar cell module. A solar cell module with a snow melting function (Patent Document 3) in which a heater for melting snow is arranged between a solar cell element and a back surface protective sheet is disclosed.

In the solar cell module disclosed in Patent Documents 1 and 2, an electric heating member for melting snow is placed near the surface of the solar cell module on the light receiving surface side and above the light receiving surface side of the solar cell element. The arrangement of the electric heating member at such a position may block or attenuate a part of the incident light to the solar cell element, which may cause a decrease in the power generation efficiency of the solar cell module. In addition, it was not always the best arrangement in terms of safety, such as the risk of failure of the electric heating member due to the load or impact caused by a large amount of snow. Alternatively, since the metal circuit constituting the electric heating member is visibly exposed from the outside on the light receiving surface side, there is a request for improvement in the deterioration of the design of the solar cell module due to this.

If the electric heating member is arranged on the non-light receiving surface side of the solar cell element as in the solar cell module disclosed in Patent Document 3, the above-mentioned problems related to power generation efficiency, safety, and design can be solved. be able to. However, on the other hand, in this case, since the electric heating member is arranged at a position farther from the surface of the module to be heated, the heat conduction efficiency to the surface of the solar cell module on the light receiving surface side is maintained above a certain level. At the same time, it was necessary to reliably insulate between the electric heating member and the solar cell element. In fact, it was not easy to meet these contradictory requirements in the solar cell module with snowmelt function installed in cold regions.

Japanese Unexamined Patent Publication No. 2017-153195 Japanese Unexamined Patent Publication No. 2017-153196 Japanese Unexamined Patent Publication No. 2001-250973

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to simultaneously avoid the risk of deterioration of power generation efficiency, safety and design due to the presence of the electric heating member arranged in the solar cell module, and the solar cell module from the electric heating member. It is a solar cell module with a snow melting function that can achieve both the heat conduction efficiency up to the snow surface on the surface and the insulation between the electric heating member and the solar cell element at a high level, and is in an inclined state. It is an object of the present invention to provide a solar cell module having a snow melting function capable of efficiently promoting snow fall from the surface of the solar cell module arranged in.

The present inventors arrange a heat-generating sheet in which the heat-generating circuit is formed on the resin base material on the non-light receiving surface side of the solar cell element, and at this time, the metal heat-generating circuit is not on the solar cell element side. We have found that the above problems can be solved by arranging the sheets so as to face the back surface protective sheet side, and have completed the present invention.

(1) A heat-generating sheet for a solar cell module including a resin base material and a heat-generating circuit, wherein the resin base material has a volume resistance of 1.0 × 10 ¹⁶ Ω · m or more according to JIS C2151. The heat generation circuit has a thickness of 50 μm or more and 300 μm or less, and the heat generation circuit is formed of metal on one side of the resin substrate, and at least one of the heat generation circuits is included in the outer region including the outer edge of the formation region of the heat generation circuit. A heat-generating sheet in which the circuit pattern on the end side of the heat-generating circuit is a circuit pattern in which the abundance density of the metal is relatively larger than that of the circuit pattern in the inner region including the central portion of the heat-generating circuit forming region.

(2) The transparent front substrate, the sealing material sheet on the light receiving surface side, the solar cell element, the sealing material sheet on the non-light receiving surface side, the heat generating sheet, the adhesive layer, and the back surface protective sheet according to (1) are the same. The heat-generating sheet is a solar cell module with a snow-melting function, which is laminated in order and is arranged so that the surface on the side where the heat-generating circuit is formed faces the adhesive layer.

(3) A method of arranging the solar cell module, wherein the solar cell module according to (2) is arranged in an inclined state.

According to the present invention, it is possible to simultaneously avoid the risks of power generation efficiency, safety and deterioration of design due to the presence of the electric heating member arranged in the solar cell module, and the electric heating member can be used as the sun. It is possible to provide a solar cell module with a snow melting function that can achieve both the heat conduction efficiency up to the snow-covered surface on the surface of the battery module and the insulation between the electric heating member and the solar cell element at a high level.

It is sectional drawing which shows typically the layer structure of the solar cell module with a snow melting function of this invention. It is a top view which shows typically the plane structure of the heat generation sheet for the solar cell module of this invention, the resin base material which comprises this, and the heat generation circuit.

Hereinafter, each embodiment of the solar cell module with the snowmelt function of the present invention will be described. The present invention is not limited to the following embodiments, and can be carried out with appropriate modifications within the scope of the object of the present invention.

<Solar cell module with snowmelt function>
First, the overall configuration of the solar cell module with the snowmelt function of the present invention will be described. As shown in FIG. 1, the solar cell module 10 with a snow melting function of the present invention (hereinafter, simply referred to as a solar cell module 10) has a transparent front substrate 2 and a sealing material sheet 3 on the light receiving surface side from the light receiving surface side. , The solar cell element 4, the sealing material sheet 5 on the non-light receiving surface side, the heat generating sheet 1, the adhesive layer 6, and the back surface protective sheet 7 are laminated in this order.

[overall structure]
The solar cell module 10 is provided with a heat generating sheet 1 which is a heat source for exerting a snow melting function for removing snow adhering to the surface of the module on the light receiving surface side. The heat-generating sheet 1 is an electric heating member in which a metal heat-generating circuit 12 is formed on one side of a resin base material 11. As shown in FIG. 1, the heat generating sheet 1 is arranged below the non-light receiving surface side of the solar cell element 4 in the solar cell module 10. Therefore, the arrangement of the heat generating sheet 1 does not hinder the entrance of light to the light receiving surface side of the solar cell element 4. Further, when the solar cell module 10 is viewed mainly from the side of the transparent front substrate 2, the heat generating circuit is almost invisible, so that it is easy to maintain a preferable design.

Further, in the heat generating sheet 1, the surface on the side on which the heat generating circuit 12 is formed is arranged so as to face the adhesive layer 6. As exemplified in Patent Documents 2 and 3, in a heat generating sheet in which a heat generating circuit is usually formed on a resin substrate, the side of the heat generating circuit is naturally heated on either side of the heat generating sheet, that is, a solar cell module. It is arranged toward the surface on the light receiving surface side of the. However, in the solar cell module 10, the heat generating sheet 1 is not arranged so that the heat generating circuit 12 faces the surface of the solar cell module 10 on the light receiving surface side, but faces the adhesive layer 6, that is, the non-light receiving surface side. It is said that it is arranged toward the surface of the.

[Transparent front board]
As the transparent front substrate 2 constituting the solar cell module 10, a transparent glass plate is usually used. Further, the transparent front substrate 2 may be a transparent resin sheet having other weather resistance. This resin sheet may be a resin sheet having flexibility that can form a flexible type module. In the solar cell module 10, since the heat generating sheet 1 is arranged on the non-light receiving surface side of the solar cell element 4, for example, a resin sheet having inferior impact resistance as compared with a glass plate or the like is used as the transparent front substrate 2. Even if there is, the risk of failure of the heat generating sheet due to the impact due to snowfall or the load can be sufficiently suppressed.

[Encapsulant sheet]
The encapsulant sheet 3 on the light receiving surface side and the encapsulant sheet 5 on the non-light receiving surface side (hereinafter, collectively referred to as simply “encapsulating material sheet”) are made of ethylene as in the conventionally known solar cell module. -A resin sheet using a vinyl acetate copolymer resin (EVA), an olefin resin such as polyethylene, or a polyvinyl alcohol resin (PVA) as a base resin is used. The thickness of the encapsulant sheet is not particularly limited, but is preferably 300 μm or more and 600 μm or less.

In the solar cell module 10, the three layers consisting of the sealing material sheet 3 on the light receiving surface side, the sealing material sheet 5 on the non-light receiving surface side, and the adhesive layer 6 are all based on the same type of resin. It can be made of a resin sheet or the like as a resin. Specifically, it is based on the same type of resin as the resin selected as the base resin for the encapsulant sheet from the above-mentioned ethylene-vinyl acetate copolymer resin (EVA), polyethylene, or polyvinyl alcohol resin (PVA). The adhesive layer 6 can be formed as a resin. By forming all of the above three layers with the same type of resin as described above, it is possible to increase the availability of materials in the entire manufacturing of the solar cell module and reduce the procurement cost.

Further, for example, when all of the above three layers are formed using the EVA resin as the base resin, the volume resistance of the EVA resin according to JIS C2151 is about 1.5 × ¹⁰⁸ , but in the solar cell module 10. Is arranged in such a manner that the surface of the heat-generating sheet 1 on the side of the resin base material 11 on which the heat-generating circuit 12 is not formed faces the solar cell element 4, and therefore the encapsulant on the non-light-receiving surface side of the solar cell element 4. Even if the insulation of the EVA forming the sheet is at the above level, it is possible to maintain sufficiently high reliability of the insulation between the solar cell element 4 and the heat generating circuit 12.

[Adhesive layer]
The adhesive layer 6 is arranged between the surface of the heat generating sheet 1 on which the heat generating circuit 12 is formed and the back surface protective sheet 7, and is a layer whose main purpose is to bond the two with sufficient strength. The material for forming such an adhesive layer 6 is a thermoplastic resin such as EVA, ionomer, polyvinyl butyral (PVB), or a polyethylene resin, a phenol resin, a urea resin, a melamine resin, an epoxy resin, an unsaturated polyester, or a silicon resin. , Polyurethane, etc., or a resin in which a cross-linking agent or the like is contained in a thermoplastic resin is preferable. However, as described above, the above-mentioned effect can be enjoyed by using the same resin as the encapsulant sheet as the base resin. Therefore, for example, when the encapsulant sheet uses EVA as the base resin. Similarly, for the adhesive layer 6, it is preferable to use EVA resin as a base resin.

The encapsulant sheet may be a single-layer sheet or a multilayer sheet. When the encapsulant sheet is a multilayer sheet, the outermost layer is a layer containing a silane-modified polyethylene-based resin having an effect of improving adhesion in order to improve the adhesion of the heat-generating sheet 1 to the resin base material 11. Is preferable.

The thickness of the adhesive layer 6 is not particularly limited, but is preferably 300 μm or more and 600 μm or less from the viewpoint of following the unevenness of the heat generating circuit 12 and maintaining sufficient adhesiveness and adhesive durability.

[Back side protection sheet]
As the back surface protective sheet 7, a PET film, a fluororesin film, or the like is used as in the conventionally known solar cell module. As the PET film, a transparent polyethylene terephthalate (PET) film, a white PET film, a hydrolysis-resistant polyethylene terephthalate (HR-PET) film and the like are selected as necessary. Among these, hydrolysis-resistant polyethylene terephthalate (for example, Shine Beam manufactured by Toyobo Co., Ltd. (hydrolysis-resistant polyester film), etc.)) is preferable. Fluorine-based resin films include PCTFE (polychlorotrifluoroethylene), PFA (tetrafluoroethylene perfluoroalkyl vinyl ester copolymer), PTFE (polytetrafluoroethylene), and ETFE (tetrafluoroethylene / ethylene co-weight). Combined), PVDF (polychlorotrifluoroethylene) and the like are used. The thickness of the back surface protective sheet 7 is not particularly limited, but is preferably 50 μm or more and 600 μm or less.

[Solar cell element]
As the solar cell element 4 according to the present embodiment, various conventionally known thin-film solar cell elements using an amorphous silicon type solar cell element, a crystalline silicon type solar cell element, a calcopyrite-based compound, or the like are used. It is used without any particular limitation.

[Fever sheet]
As shown in FIGS. 1 and 2, the heat generating sheet 1 is an electric heating member in which a metal heat generating circuit 12 is formed on one side of a resin base material 11. The heat generating circuit 12 is formed directly on the surface of the resin base material 11 or via an adhesive layer. Further, as shown in FIG. 2, the heat generation circuit 12 (12A, 12B) of the heat generation sheet 1 is connected to the power supply 121 (121A, 121B), and is required for heat generation from the power supply 121 to the heat generation circuit 12. Electricity is supplied.

(Resin base material)
The resin base material 11 constituting the heat generating sheet 1 is preferably a resin film having a predetermined volume resistivity and thickness. Regarding the volume resistivity of the resin base material 11, the volume resistivity according to JIS C2151 is preferably 1.0 × 10 ¹⁶ Ω · m or more, and more preferably 1.0 × 10 ¹⁷ Ω · m or more. .. Further, the thickness of the resin base material 11 is preferably 50 μm or more and 300 μm or less, and more preferably 125 μm or more and 200 μm or less, while satisfying the requirements for such insulating properties. The volume resistivity (Ω · m) in the present specification means the value of the volume resistivity according to JIS C2151.

When the volume resistivity of the resin base material 11 is 1.0 × 10 ¹⁶ Ω · m or more and the thickness is 150 μm or more, the insulating property required for the solar cell module 10 can be ensured. .. Further, by maintaining the thickness of the resin base material 11 to 200 μm or less, the heat conduction efficiency to the surface of the solar cell module can be maintained at a preferable level. The thickness of the resin base material 11 is preferably within the above range from the viewpoint of maintaining good productivity in the case of manufacturing by the roll-to-roll method.

Polyethylene terephthalate (PET) is preferable as the resin that satisfies the requirements relating to the volume resistivity and forms the resin base material 11. As an example, the volume resistivity of a PET film (“Lumina (trade name)” manufactured by Toray Industries, Inc.) is 1.0 × 10 ¹⁷ Ω · m (product catalog value). On the other hand, as disclosed in Patent Documents 1 and 2, a polyethylene naphthalate (PEN) -based resin film, which has been widely used as a resin substrate for a heat generating circuit, usually has a volume resistivity of 1. It is less than 0 × 10 ¹⁶ Ω ・ m. For reference, the volume resistivity of "Theonex (registered trademark): biaxially stretched polyethylene naphthalate" is 1.8 × 10 ¹⁵ . Therefore, as long as it is essential to enjoy the maximum effect of the solar cell module 10, the PEN film is inferior in suitability as the resin base material 11 of the heat generating sheet 1, and the PET film is more preferable. Become.

The thermal conductivity of the resin base material 11 is preferably 0.1 W / m · K or more and 0.5 W / m · K or less, and 0.15 W / m · K or more and 0.3 W / m · K or less. Is more preferable. By setting the thermal conductivity of the resin base material 11 to 0.1 W / m · K or more, the heat generated from the heat generating circuit 12 can be efficiently transferred to the surface of the solar cell module 10 on the light receiving surface side. By setting the thermal conductivity of the resin base material 11 to 0.5 W / m · K or less, the heat generated from the heat generating circuit 12 can be transferred to the light receiving surface side of the solar cell module without escaping to the outside. The thermal conductivity in the present specification refers to the thermal conductivity at 25 ° C. measured by the laser flash method, such as a laser flash method thermal constant measuring device (“TC-7000” manufactured by Vacuum Riko Co., Ltd.) and the like. It refers to a value that can be measured by using. The thermal conductivity of general PET is in the range of 0.20 to 0.33 W / m · K.

Here, as described above, the solar cell module 10 of the present invention has the heat conduction efficiency from the electric heating member, that is, the snow-covered surface on the surface of the solar cell module 10, that is, the transparent front substrate 2, and the electric heating member. It is a technical issue to achieve a high level of insulation between the (heat generating sheet 1) and the solar cell element 4. Therefore, in the solar cell module 10, the heat generating sheet 1 is laminated so that the forming surface of the heat generating circuit 12 is intentionally oriented in the direction opposite to the direction in which heat should be transferred (the side of the transparent front substrate 2). It is supposed to be placed. According to this unique arrangement mode of the heat generation sheet 1, as usual, if the forming surface of the heat generation circuit 12 of the heat generation sheet 1 is directed in the direction in which heat should be transferred, the arrangement of other insulating base materials that are separately required is required. The above-mentioned problems can be surely solved without any problem.

When the heat-generating sheet 1 is arranged as described above, it is preferable that the volume resistivity of the resin base material 11 constituting the heat-generating sheet 1 is within a predetermined range, which is a unique physical property value for each material resin. After guaranteeing that, in each module, the effect of the present invention can be enjoyed without undue trial and error by going through the process of determining the sheet thickness according to the required insulation and heat conduction efficiency. be able to. As described above, although the solar cell module 10 of the present invention has a simpler layer structure than the conventional one, the above-mentioned problems that have been difficult to solve in the past have been solved by the original device of the arrangement mode of the heat generating sheet 1. The point is the first technical feature. As an example of the most preferable selection of the resin base material 11, a polyethylene terephthalate film having a volume resistivity of 1.0 × 10 ¹⁷ and a thickness of 150 μm according to JIS C2151 can be mentioned.

(Heat generation circuit)
The heat generation circuit 12 is an electric heating circuit that generates heat for melting the snow adhering to the light receiving surface side of the solar cell module 10 when energized. Copper, aluminum, and gold are used as the metals constituting the heat generation circuit 12. , Silver, etc. can be mentioned as preferred metals.
Above all, it is preferable to use copper from the viewpoint of electrical conductivity and thermal conductivity. Hereinafter, the details will be described assuming that the heat generating circuit 12 is made of copper.

FIG. 2 is a diagram schematically showing the planar configuration of the heat generating circuit 12, but the planar configuration of the heat generating circuit 12, that is, the circuit pattern is not limited thereto. The circuit pattern of the heating circuit 12 may be a continuous pattern of folded back as shown in FIG. 2, a comb-shaped pattern in which a plurality of comb-shaped plates arranged side by side or facing each other are continuous, a simple grid pattern, or a pattern. , Voronoi shape pattern may be used. Regardless of which circuit pattern is used, any circuit pattern may be used as long as the risk of short circuit between the patterns is sufficiently suppressed and sufficient heat is generated.

Here, in the solar cell module 10, the heat generating sheet 1 that is supposed to be arranged on the non-light receiving surface side of the solar cell element 4 is a case where the heat generating sheet is arranged on the light receiving surface side of the solar cell element 4 (for example). , The snow melting mechanism disclosed in Patent Documents 1 and 2) is not required to have light transmission. For example, in the heat generating sheet (snow melting mechanism) disclosed in Patent Documents 1 and 2, the metal coverage ratio, which is the ratio of the area of the heat generating circuit to the area of the resin base material, is 0.2% or more and 5.0% or less. Although it is described that it is preferable to do so, in the heat generating sheet 1 freed from such restrictions, the degree of freedom in the circuit design of the heat generating circuit 12 is greatly increased.

In the heat-generating sheet 1, the metal coverage of the resin base material 11 in the formation region of the heat-generating circuit 12 of the resin base material 11 is preferably more than 10% and 25% or less. If the metal coverage of the resin base material 11 is less than 10%, it becomes difficult to transfer sufficient heat required for snowmelt to the module surface in the layer structure of the solar cell module 10. When this metal coverage exceeds 25%, the area of the resin surface exposed on the surface is reduced, so that the adhesiveness with the facing member may be lowered to a level below the lower limit of the required adhesive strength, which is preferable. not. The uniformity of heat generation can be improved by increasing the metal coverage as much as possible within the range of the above upper limit value or less.

Here, the "metal coverage of the resin base material" refers to the metal foil forming the heat generation circuit with respect to the total area of the heat generation circuit formation region on the surface on which the heat generation circuit is formed on both surfaces of the resin base material. Alternatively, it refers to the ratio (%) of the area of the portion covered with the resin base material by the metal wire. As a specific example, in the case of the heat generation circuit 12 shown in FIG. 2, the metal foil constituting the heat generation circuit 12 (black in FIG. 2) with respect to the area (xxy) of the entire region where the heat generation circuit 12 is formed. It refers to the ratio (%) of the total area of the pattern part (the pattern part filled with).

Further, the heat generating sheet 1 virtually divides the forming region of the heating circuit 12 into an inner region including the central portion of the region and an outer region surrounding the inner region and including the outer edge of the forming region of the heating circuit 12. It is more preferable that the circuit pattern is configured such that the metal coverage in the outer region is larger than the metal coverage in the inner region.

As described above, in the outer region of the formation region of the heat generation circuit 12, the circuit pattern in which the abundance density of the metal as the heat generation source is relatively large is adopted, for example, by adjusting the current for each parallel circuit. As in the case where only the power density (W / m ² ) of a specific region of the heating circuit is increased by some other means, only the calorific value in the outer region is easily increased independently of the other regions. Can be made to. As a result, on the surface of the solar cell module 10 on the light receiving surface side, more heat can be supplied to the vicinity of the outer edge portion than to the central portion. Since the solar cell module 10 is usually set in an inclined state, for example, on a gabled house roof, for example, according to the above circuit configuration, the solar cell module 10 installed on the inclined surface is closer to the lower side. When more heat reaches the end of the roof, the snow adhering to that part is preferentially melted to efficiently promote the snow fall from the surface of the solar cell module 10 arranged in an inclined state. can. That is, by making the circuit pattern of the heating circuit 12 a pattern in which more heating sources are unevenly distributed in the outer region, it is possible to efficiently remove snow on the entire surface of the solar cell module with a smaller amount of heat, that is, electricity consumption. .. In FIG. 2, the boundary line of the heat generation circuit formation region is described by the alternate long and short dash line, but the boundary line is not actually formed and the boundary line is a virtual line. As described above, the heat generating sheet 1 has the effect of "promoting snowfall efficiently" by "delivering more heat to the lower end of the solar cell module 10 installed on the inclined surface". It is characterized by being a thing. Therefore, as a matter of course, the above-mentioned "circuit pattern in which the abundance density of the metal is relatively large" may be formed at least in a part including the end of any one of the above-mentioned outer regions, and is not always required. It is not necessary to have a similar high density circuit pattern over the entire outer region.

The method of energizing the heat generating circuit 12 is not particularly limited, but a method of energizing from an external power supply 121 via a control unit can be exemplified. For example, when it snows or when snow accretion occurs on the surface of the solar cell module with a snowmelt function on the light receiving surface side, the heat generating circuit 12 is energized from an external power source to control the temperature of the surface of the transparent snow melting mechanism on the light receiving surface side. By providing the unit, the power consumption required for the snow melting function of the solar cell module with the snow melting function can be minimized.

The line width of the heat generating circuit 12 is preferably 5 μm or more and 50 μm or less, and more preferably 10 μm or more and 30 μm or less. Since the heat generation circuit 12 is a copper circuit having a line width of 5 μm or more, the risk of disconnection that may occur in the heat generation circuit 12 can be reduced, and the heat generation circuit 12 can be made with good durability. When the heat generation circuit 12 has a line width of 50 μm or less, it is possible to increase the electric resistance value to the extent that heat generation of the heat generation circuit 12 becomes easy. Therefore, heat can be generated in the heat generating circuit 12 with smaller power consumption.

The thickness of the heat generating circuit 12 is preferably 4 μm or more and 75 μm or less, and more preferably 9 μm or more and 18 μm or less, although it depends on the line width. When the thickness of the heat generation circuit 12 is 10 μm or more, the risk of disconnection that may occur in the heat generation circuit 12 can be reduced, and the heat generation circuit 12 can be made to have good durability. When the thickness of the heat generating circuit 12 is 75 μm or less, the electric resistance value can be increased to the extent that heat generation of the heat generating circuit 12 becomes easy. Further, the heat generating sheet 1 in which the heat generating circuit 12 is formed on the resin base material 11 can maintain sufficient flexibility, and the deterioration of handleability due to the increase in weight can be prevented.

As a method for forming the heat generating circuit 12 on the surface of the resin base material 11, a conventionally known circuit forming method can be used. For example, a method of forming a heat generating circuit 12 by masking and etching after adhering a copper foil to the surface of a PET film is typical.

As described above, in the solar cell module 10, the circuit pattern of the heat generation circuit 12 of the heat generation sheet 1 is freed from the restrictions for ensuring the light transmittance, and the metal coating for obtaining the required heat generation amount is obtained. The rate setting can be set flexibly. Further, the energy efficiency of snowmelt can be further improved by adopting a circuit pattern in which the power density in the outer region of the heat generating circuit 12 is relatively large. As described above, the solar cell module 10 of the present invention is a solar cell in which the heat generating sheet 1 as a heat source is arranged on the non-light receiving surface side of the solar cell element 4 by an original device of the circuit pattern of the heat generating circuit 12 of the heat generating sheet 1. The second technical feature is that although it is a module, it can exhibit a snow melting function comparable to that of a conventional solar cell module in which a heat source is arranged on the light receiving surface side of the solar cell element.

[Manufacturing method of solar cell module]
(Laminating process)
In the manufacture of the solar cell module 10, first, the heat generating sheet 1 and each component described in detail above are provided with a transparent front substrate 2, a sealing material sheet 3 on the light receiving surface side, a solar cell element 4, and non-light receiving. A laminating step is performed in which the sealing material sheet 5 on the front surface side, the heat generating sheet 1, the adhesive layer 6, and the back surface protective sheet 7 are laminated in this order. In this laminating step, the heat-generating sheet 1 is arranged so that the surface on the side where the heat-generating circuit 12 is formed faces the adhesive layer 6, unlike the general mounting mode.

(Integration process)
Next, in the laminating step, the laminated bodies laminated in the above order are heat-bonded by a thermal lamination treatment such as vacuum thermal laminating to integrate them. The heating temperature at the time of heat crimping is preferably in the range of 110 ° C. or higher and 190 ° C. or lower, and more preferably 130 ° C. or higher. The heating time is preferably in the range of 5 to 60 minutes. This vacuum heat laminating process is performed in such a manner that the back surface protective sheet 7 and the forming surface of the heat generating circuit 12 of the heat generating sheet 1 are heat-bonded via the adhesive layer 6. For example, when the base resin of the adhesive layer 6 is EVA, this makes it possible to sufficiently exhibit the high adhesiveness of the adhesive layer 6 interposed between the back surface protective sheet 7 and the heat generating sheet 1.

As described above, the solar cell module 10 with the snow melting function of the present invention simultaneously avoids the risks of power generation efficiency, safety, and deterioration in design due to the presence of the electric heating member arranged in the solar cell module. In addition, it is a solar cell module that can achieve both the heat conduction efficiency from the electric heating member to the snow surface on the surface of the solar cell module and the insulation between the electric heating member and the solar cell element at a high level. be.

1 Heat-generating sheet 11 Resin base material layer 12 Heat-generating circuit 121 Power supply 2 Transparent front substrate 3 Sealing material sheet on the light-receiving surface side 4 Solar cell element 5 Sealing material sheet on the non-light-receiving surface side 6 Adhesive layer 7 Backside protective sheet 10 Snow melting function Solar cell module with

Claims (3)

A heat-generating sheet for solar cell modules with a snowmelt function.
With a resin base material
Equipped with a heating circuit,
The resin substrate has a volume resistivity of 1.0 × 10 ¹⁶ Ω · m or more and a thickness of 50 μm or more and 300 μm or less according to JIS C2151.
The heat generation circuit is formed of metal on one side of the resin base material.
Within the outer region including the outer edge of the heat generation circuit forming region, only the circuit pattern on one end side is a circuit pattern in which the abundance density of the metal is relatively larger than the circuit pattern of the other portion. By being present, the calorific value is larger in the outer region than in the other regions.
Heat generation sheet. It is an installation structure of a solar cell module with a snowmelt function, in which a solar cell module with a snowmelt function is installed on an inclined surface.
The solar cell module with a snow melting function includes a transparent front substrate, a sealing material sheet on the light receiving surface side, a solar cell element, a sealing material sheet on the non-light receiving surface side, a heat generating sheet, an adhesive layer, and a back surface protective sheet. They are stacked in this order,
The heat-generating sheet includes a resin base material and a heat-generating circuit, and the surface on the side on which the heat-generating circuit is formed is arranged so as to face the adhesive layer.
The resin substrate has a volume resistivity of 1.0 × 10 ¹⁶ Ω · m or more and a thickness of 50 μm or more and 300 μm or less according to JIS C2151.
The heat generation circuit is formed of metal on one side of the resin base material, and the circuit pattern on the lower end side of the inclined surface is formed in the outer region including the outer edge of the formation region of the heat generation circuit. The circuit pattern has a relatively higher metal abundance density than the circuit pattern in the inner region including the central portion of the heat generation circuit forming region, so that the other region is on the lower end side of the inclined surface. The calorific value is larger than
Installation structure of solar cell module with snow melting function. Only the circuit pattern on the lower end side of the inclined surface is a circuit pattern in which the abundance density of the metal is relatively higher than that of the circuit patterns of the other parts.
The installation structure of the solar cell module with the snowmelt function according to claim 2.

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