Solar cell attached to cover glass with conductive coating and its mounting method

Abstract

To enable contact storage such as winding in a flexible solar cell array.SOLUTION: Provided is a solar cell on which cover glass with a conductive coating is stuck. The solar cell includes: a flexible insulating sheet 1; a photovoltaic power generation element 2 bonded onto the face of the insulating sheet 1: cover glass 3 bonded onto the photovoltaic power generation element 2; a transparent conductive film 4 covering the surface of the cover glass 3, the transparent conductive film having a conductive coating that transmits sunlight; an electrode pad 5 placed on the surface of the transparent conductive film 4; a connecting metal fitting 6, one end side of which is joined to the electrode pad 5, the connecting metal fitting conducting electricity; a vacancy 10 provided in the insulating sheet 1 and capable of passing through the connecting metal fitting 6; and a back contact bar 7 placed on the rear face of the insulating sheet 1 and electrically connected to the other end side of the connecting metal fitting 6 through the vacancy 10.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a solar power module for a flexible solar cell array, a solar cell in the module, and a method for mounting the solar cell. [Background technology]

[0002] In recent years, flexible solar cell arrays, in which solar cells are mounted on non-rigid insulating sheets such as polyimide sheets, have been attracting attention as a primary power source equipped on artificial satellites and probes, in response to demands for weight reduction and space saving, as opposed to the conventional structure in which solar cells are mounted on rigid panels.

[0003] When solar cells are used in space, they are covered with a cover glass to reduce heat control and radiation exposure to the solar cells. This cover glass becomes charged by plasma in space. During exploration missions, if micro-sized dust particles on the surface of a planet, such as the moon, are charged, the dust particles will adhere to the charged cover glass, blocking sunlight from reaching the solar cell and reducing the power generation.

[0004] In order to suppress the accumulation of dust during exploration missions, a structure using conductive cover glass has been proposed.

[0005] A method for suppressing dust accumulation on probes and the like has been proposed, as shown in Non-Patent Document 1, in which a cover glass patterned with a conductive indium tin oxide layer is mounted on a solar cell. An AC power source is connected to this cover glass, and by applying a traveling wave created by superimposing sine waves, it is possible to remove the dust adhering to the shield of the probe and the like. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] CI Calle, et al., J. Electrostat. 67, (2009) 89. Summary of the Invention [Problem to be solved by the invention]

[0007] The structure proposed in Non-Patent Document 1 mentioned above is a prototype in the research stage, and the control circuit for applying a control signal from the AC power supply to the cover glass is directly connected to the test wire. In flexible solar cell arrays that use contact storage, the test wire acts as a barrier, making it impossible to store the module, which is an issue.

[0008] The present disclosure has been made to solve the problems described above, and aims to provide a solar cell attached to a cover glass with a conductive coating that provides a path to connect to control circuitry necessary to suppress dust accumulation, even in a flexible solar cell array that uses contact storage, and a method for mounting such a solar cell. [Means for solving the problem]

[0009] In order to solve the above problems, the present disclosure provides a solar cell with a cover glass attached and having a conductive coating, comprising: an insulating sheet that blocks heat and insulates electricity; a photovoltaic element that generates electricity from sunlight and is adhered to the surface of the insulating sheet; a cover glass that reduces radiation exposure to the solar cell and is adhered to the photovoltaic element; a transparent conductive film that covers the surface of the cover glass and has a conductive coating that transmits sunlight while being conductive like a metal material; electrode pads that are placed on the surface of the transparent conductive film and conduct electricity; connecting fittings that are joined at one end to the electrode pads and conduct electricity; holes that are provided in the insulating sheet and allow the connecting fittings to pass through; and a back contact bar that is placed on the surface of the insulating sheet opposite the photovoltaic element and is electrically connected to the other end of the connecting fitting through the hole. Effect of the Invention

[0010] The solar cells with conductively coated cover glass of the present disclosure allow for contact storage, such as rolling up, in flexible solar cell arrays that use contact storage, while maintaining a path to connect to the control circuitry necessary to suppress dust accumulation. [Brief description of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view showing a solar cell according to a first embodiment. [Diagram 2] 1 is a top view of a solar cell according to a first embodiment. [Diagram 3] FIG. 2 is a perspective view showing a state in which the solar cell according to the first embodiment is stored in contact with one another. [Figure 4] 1 is a perspective view showing a part of a flexible solar cell array on which solar cells according to a first embodiment are mounted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals. Duplicate descriptions will be appropriately simplified or omitted. Note that the present disclosure is not limited to the embodiments described below.

[0013] Embodiment 1 A solar cell according to a first embodiment of the present disclosure will be described with reference to Fig. 1 to Fig. 4. Fig. 1 is a cross-sectional view showing a solar cell according to the first embodiment. Fig. 2 is a top view according to the first embodiment. Fig. 3 is a perspective view showing a state of contact storage in which the solar cell according to the first embodiment is mounted. Fig. 4 is a perspective view showing a part of a flexible solar cell array in which the solar cell according to the first embodiment is mounted.

[0014] The solar cell 100 has a flexible insulating sheet 1, a photovoltaic power generation element 2, a cover glass 3, a transparent conductive film 4, an electrode pad 5, a connecting metal fitting 6, a back contact bar 7, a photovoltaic power generation element adhesive 8, a transparent adhesive 9, holes 10, and a back contact bar adhesive 11. The insulating sheet may be a heat-resistant and electrically insulating polyide film or the like, but the material is not limited to these. The photovoltaic power generation element adhesive 8 and the back contact bar adhesive 11 may be a silicone-based adhesive or the like, but the material is not limited to these.

[0015] A photovoltaic power generation element 2 is adhered onto an insulating sheet 1 with a photovoltaic power generation element adhesive 8. A cover glass 3 is adhered onto the photovoltaic power generation element 2 with a transparent adhesive 9. The surface of the cover glass 3 is covered with a transparent conductive film 4. The transparent conductive film 4 is electrically connected to a back contact bar 7 through holes 10 provided in the insulating sheet 1 by connecting metal fittings 6 joined to electrode pads 5 provided on the surface of the transparent conductive film 4. The back contact bar 7 is adhered with a back contact bar adhesive 11 to the side of the insulating sheet 1 opposite to the side on which the photovoltaic power generation element 2 is adhered.

[0016] In FIG. 2, 5a, 5b, and 5c are electrode pads, 6a, 6b, and 6c are connecting fittings, and 7a, 7b, and 7c are back contact bars.

[0017] As shown in Fig. 2, the solar cell 100 has a structure having a corner crop in the longitudinal direction of the solar cell. The corner crop is a cutout at the corner of the solar cell, and corresponds to region A and region B in Fig. 2. Here, the shape of the corner crop may be a triangular cutout as in region A in Fig. 2, or a circular arc cutout as in region B, and is not limited to these shapes.

[0018] 2, an electrode pad 5a is provided on a transparent conductive film 4 on a cover glass 3 near a corner crop A of a solar cell 100. The electrode pad 5a is connected to a back contact bar 7a by a connecting metal fitting 6a through a hole 10a provided in the corner crop. This connection structure makes it possible to improve the mounting efficiency when mounting solar cells 100 in parallel, compared to a case in which no corner crops are provided.

[0019] 3, in a flexible solar cell array 110 in which a plurality of solar cells 100 are arranged, the solar cells 100 are stored in contact with each other by rolling up the contact sheet 1. In the flexible solar cell array 110 as well, it is possible to provide an electrical path.

[0020] 2, the solar cell 100 according to the present disclosure has two corner crops, and three electrode pads 5 are connected near the corner crops to the transparent conductive film 4 on the cover glass 3. Therefore, by providing three holes 10 in the two corner crops, three parallel back contact bars 7a, 7b, 7c can be connected to the connecting fittings 6a, 6b, 6c for one parallel solar cell 100.

[0021] In the configuration of Fig. 2, three electrode pads 5a, 5b, and 5c are connected on the transparent conductive film 4 on the cover glass 3. As shown in Fig. 4, the electrode pads 5a, 5b, and 5c are connected to different back contact bars 7a, 7b, and 7c, respectively, so that it is possible to provide an electrical path for connecting a three-phase AC power supply to the cover glass 3 by, for example, applying patterning to the cover glass 3. The solar cell 100 of the present disclosure provides an electrical path for connecting a three-phase AC power source, so that a three-phase AC signal can be applied to the patterned transparent conductive film 4 to generate a traveling wave electric field, and dust adhering to the transparent conductive film 4 on the cover glass 3 can be removed.

[0022] In Figure 4, the corner crops in region B and region D allow the connecting fittings 6c in region C to face downward, allowing many solar cells 100 to be mounted vertically, improving mounting efficiency. Although the connecting fittings 6c in Figure 4 face downward, the connecting fittings can also face sideways, allowing many solar cells 100 to be mounted in parallel.

[0023] According to the solar cells 100 in the embodiment 1 described above, by connecting the electrode pads 5 provided near the corner crops with connecting fittings 6 through holes 10 provided in the corner crop portion to the back contact bar 7, it is possible to store a flexible solar cell array 110 having a plurality of solar cells 100 mounted on a contact sheet 1 by rolling up the insulating sheet 1 so that the solar cells 100 are in contact with the back surface of the insulating sheet 1, and it is also possible to improve the mounting efficiency when mounting the solar cells 100 in parallel and in series. [Explanation of symbols]

[0024] 1 Insulating sheet 2. Photovoltaic element 3 Coverslip 4. Transparent conductive film 5 Electrode pads 5a Electrode pad 5b Electrode pad 5c Electrode pads 6 Connection fittings 6a Connection fittings 6b Connection fitting 6c Connection fittings 7 Back Contact Bar 7a Back Contact Bar 7b Back contact bar 7c Back Contact Bar 8. Photovoltaic element adhesive 9 Transparent adhesive 10 Vacancies 10a hole 10b Hole 10c hole 11 Back Contact Bar Adhesive 100 Solar Cells 110 Flexible solar cell array Area A B area C area D area

Claims

1. A flexible insulating sheet; a photovoltaic power generation element bonded onto a front surface of the insulating sheet; A cover glass adhered onto the photovoltaic element; A transparent conductive film that covers the surface of the cover glass and has a conductive coating that transmits sunlight; an electrode pad disposed on a surface of the transparent conductive film; A connecting fitting, one end of which is joined to the electrode pad and which conducts electricity; a hole provided in the insulating sheet, through which the connecting fitting can pass; a back contact bar that is disposed on a back surface of the insulating sheet and is electrically connected to the other end of the connecting fitting through the hole; A solar cell attached to a cover glass with a conductive coating.

2. A corner crop, which is a cutout, is formed in the cover glass; The corner crop is provided with the electrode pad and the connection metal fitting, and the insulating sheet is provided with the hole around the corner crop, the hole leading to the surface of the back contact bar.

2. The solar cell according to claim 1, wherein the solar cell is attached to a cover glass having a conductive coating.

3. 3. The solar cell having a cover glass attached thereto and a conductive coating according to claim 1, further comprising an insulating sheet for insulating electricity and blocking heat.

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