JP2013149858A - Solar battery module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar battery module with high reliability which prevents an output decline or a hot spot phenomenon in a specific solar battery cell installed and used in an environment where the cell is in the shade of an obstacle and incident sunlight thereon is blocked.SOLUTION: A solar battery module 10 comprises a laminate 12 composed of a first electrode layer 13, a power generation layer 14 and a second electrode layer 15 which are stacked in order on a substrate 11, where the power generation layer 14 and the second electrode layer 15 are divided by scribe lines into a plurality of solar battery cells 21, with the solar battery cells 21 located at adjacent positions connected together in series. Among the solar battery cells 21 constituting the solar battery module 10 and connected in series, specific solar battery cells 21 located in end regions on one or both sides are installed and used in an environment in which they are in the shade of an obstacle and incident sunlight thereon is blocked. The specific solar battery cells 21 have a structure for short-circuiting between the first electrode layer 13 and the second electrode layer 15.

Description

  The present invention relates to a solar cell module capable of avoiding the influence even when a shaded portion exists.

  In recent years, solar cells are becoming more and more widely used from the viewpoint of efficient use of energy. In particular, a solar cell using a silicon single crystal is excellent in energy conversion efficiency per unit area. However, on the other hand, since a solar cell using a silicon single crystal uses a silicon wafer obtained by slicing a silicon single crystal ingot, a large amount of energy is consumed for manufacturing the ingot, and the manufacturing cost is high. In particular, if a large-area solar cell installed outdoors or the like is to be realized using a silicon single crystal, the current cost is considerably high. Therefore, solar cells using amorphous (amorphous) silicon thin films that can be manufactured at lower cost are widely used as low-cost solar cells.

  An amorphous silicon solar cell uses an amorphous silicon film (i-type) that generates electrons and holes when receiving light, and a semiconductor film having a layer structure called a pin junction sandwiched between p-type and n-type silicon films. Electrodes are formed on both sides of the film. Electrons and holes generated by sunlight move actively due to the potential difference between the p-type and n-type semiconductors, and generate electricity by repeating this continuously.

  As a specific configuration of such an amorphous silicon solar cell, for example, as shown in FIG. 7, a transparent electrode such as TCO is formed as a positive electrode (also referred to as a surface electrode) 113 on a glass substrate 111 on the light receiving surface side. A semiconductor film 114 made of amorphous silicon, an Ag thin film that becomes a negative electrode (also referred to as a back electrode) 115, and the like are formed thereon. The amorphous silicon solar cell 110 including the photoelectric conversion body 112 composed of the upper and lower electrodes 113 and 115 and the semiconductor film 114 has a problem of a resistance value only by forming each layer uniformly over a wide area on the substrate. For example, the photovoltaic cell 121 which divided the photoelectric conversion body 112 for every predetermined size is formed, and the mutually adjacent photovoltaic cells 121 are connected. Specifically, a plurality of strip-shaped solar cells 121 are formed by forming grooves called scribe lines (scribe lines) 120 with a laser beam or the like in the photoelectric converter 112 formed over a large area on the substrate 111. The solar battery cells 121 are connected in series.

  Such a solar cell module 100 is used by being installed on the roof of a building such as a house. However, the solar cell module is almost inclined.

  Therefore, when taking measures against snow on a solar cell module, there is usually a technology for fixing a plate-like snow stop member to the frame on the eaves side of a rectangular solar cell module so as to be orthogonal to the surface of the solar cell module It has been proposed (see, for example, Patent Document 1). Specifically, this will be described with reference to FIG. 8. First, the supporting means 150 for supporting the solar cell module 100 is fixed to the base plate 120 constituting the roof 110 and the pier 130 thereon. Then, by fixing the eaves side frame 161 of the solar cell module 100 to the support means 150, the rectangular solar cell module 100 is fixed on the base plate 120.

  In this way, a plurality of solar cell modules 100 are arranged on the building, and all or a part of the roof 110 is covered with the solar cell module 100, and then the snow stopper 170 is applied to the roof. The snow stopper 170 has a plate-like portion 171 that can be fitted into a fitting groove 161 a provided in the eaves-end side frame 161, and the width direction of the plate-like portion 171 is the surface 100 a of the solar cell module 100. By directly fitting in the fitting groove 161a so as to be perpendicular to each other, the plate-like portion 171 has a function of preventing the snow 180 that has fallen on the solar cell module 100 from slipping.

  However, when the snow stopper 170 is attached to the roof on which the solar cell module is laid, as shown in FIG. 7, a shadow of the snow stopper 170 (particularly, the plate-like portion 171) is formed on the solar cell module 100, thereby Incidence of light is hindered, resulting in a problem that power generation efficiency of some solar cells is lowered.

  As described above, when the snow stopper 170 forms a shadow on the light incident surface and the output of some of the solar cells 121 is lowered, the output of the entire thin film silicon solar cell module 100 having a series structure is significantly lowered. Further, the solar cell 121 whose output is reduced becomes a resistance on the circuit, and a voltage (bias voltage) is applied in the opposite direction to both ends of the solar cell, causing a phenomenon of local heating (hot spot phenomenon). Was a problem. In particular, when a hot spot phenomenon occurs at the edge of the substrate, the substrate may break, causing a decrease in reliability.

JP 2004-27734 A

  The present invention has been devised in view of such a conventional situation, and the output of a specific solar battery cell that is installed and used in an environment that becomes a shadow of an obstacle and prevents the incidence of sunlight is used. An object of the present invention is to provide a solar cell module excellent in reliability by preventing a decrease and a significant output decrease and hot spot phenomenon due to the decrease.

The solar cell module according to claim 1 of the present invention includes a laminate in which a first electrode layer, a power generation layer, and a second electrode layer are sequentially stacked on a substrate, and the power generation layer and the electrode layer are formed by a scribe line. It is a solar cell module that is a partitioned solar cell and is formed by connecting the solar cells in adjacent positions in series, constituting the solar cell module, and the solar cells connected in series Among these, the specific solar cell located in one or both of the end regions is used by being installed in an environment where it becomes a shadow of an obstacle and obstructs the incidence of sunlight. The battery cell has a structure that short-circuits between the first electrode layer and the second electrode layer.
The solar cell module according to claim 2 of the present invention includes a laminate in which a first electrode layer, a power generation layer, and a second electrode layer are sequentially stacked on a substrate, and the power generation layer and the electrode layer are formed by a scribe line. It is a solar cell module that is a partitioned solar cell and is formed by connecting the solar cells in adjacent positions in series, constituting the solar cell module, and the solar cells connected in series Among these, the specific solar cell located in one or both of the end regions is used by being installed in an environment where it becomes a shadow of an obstacle and obstructs the incidence of sunlight. Between the battery cells, the scribe line is not provided and the second electrode layer is connected.
The solar cell module according to claim 3 of the present invention is characterized in that, in claim 1 or 2, the obstacle is a snow stopper that is separated from the solar cell module.

In the solar cell module of the present invention, among the solar cells connected in series, it is located in one or both end regions, and is installed in an environment in which the incidence of sunlight is obstructed as a shadow of an obstacle. Since the specific solar cell used has a structure that short-circuits between the first electrode layer and the second electrode layer, no power is generated in the specific solar cell. Accordingly, it is possible to provide a solar cell module with excellent reliability by preventing a decrease in output in a specific solar cell that is a shadow of an obstacle, and a decrease in output and hot spot phenomenon of the entire module due to the decrease. .
Further, in the solar cell module of the present invention, the solar cells connected in series are located in one or both end regions, and are installed in an environment in which the incidence of sunlight becomes a shadow of an obstacle and is blocked. Since the specific solar battery cell used has a structure in which the second electrode layer is connected without providing the scribe line between the specific solar battery cells, the specific solar battery cell No power is generated in the solar battery cell. As a result, the solar cell module of the present invention is a highly reliable solar cell that prevents a decrease in output in a specific solar cell that is a shadow of an obstacle, as well as a decrease in output of the entire module and a hot spot phenomenon resulting therefrom. Modules can be provided.
Further, since the laser pattern is simply added or deleted, it is possible to easily take countermeasures, and the appearance is the same as that of the module without countermeasures. Although measures can be taken by changing the size of the module, it is not practical because a significant change in the production line is required.

The perspective view which shows an example of the solar cell module of this invention. Sectional drawing in the X1-X2 line | wire in FIG. Sectional drawing which shows the manufacturing process of the solar cell module shown in FIG. The perspective view which shows another example of the solar cell module of this invention. Sectional drawing in the X3-X4 line | wire in FIG. Sectional drawing which shows the manufacturing process of the solar cell module shown in a figure. Sectional drawing which shows the principal part of the conventional solar cell module. Sectional drawing which shows the state by which the snow stopper was attached to the solar cell module.

Hereinafter, the best mode of a solar cell module according to the present invention will be described with reference to the drawings. The present embodiment is specifically described for better understanding of the gist of the invention, and does not limit the invention unless otherwise specified. In addition, in the drawings used in the following description, in order to make the features of the present invention easier to understand, there is a case where a main part is shown in an enlarged manner for convenience, and the dimensional ratio of each component is the same as the actual one. Not necessarily.
Further, in the present embodiment, the case of a snow stopper installed on the roof of a building such as a house will be described as an example of an obstacle that hinders the incidence of sunlight on the solar cell module. The present invention is not limited to this, and any object other than the snow stopper can be applied as long as it forms a shadow and obstructs the incidence of sunlight.

FIG. 1 is a perspective view showing an example of an amorphous silicon solar cell module 10A (10) of the present invention. 2 is a cross-sectional view showing the main part of the solar cell module 10A (10) of FIG. 1, and is a cross-sectional view taken along line X1-X2 in FIG.
The solar cell module 10A (10) of the present invention includes a laminate 12 in which a first electrode layer 13, a power generation layer 14, a buffer layer 15, and a second electrode layer 15 are sequentially stacked on one surface 11a of a substrate 11 to generate power. The layer 14 and the second electrode layer 15 are partitioned by a scribe line 20 to form a plurality of solar cells (partition elements) 21, 21..., And the solar cells 21, 21. Configured.

  The substrate 11 is made of an insulating material that is excellent in sunlight transmittance and durable, such as glass and transparent resin. In the solar cell module 10, sunlight S is incident from the other surface 11 b side of the substrate 11.

The laminate 12 is formed by laminating a first electrode layer (lower electrode) 13, a power generation layer (semiconductor layer) 14, and a second electrode layer (upper electrode) 15 in order from the substrate 11 side.
The first electrode layer (lower electrode) 13 may be formed of a transparent conductive material, for example, a light-transmitting metal oxide such as TCO or ITO.

  The power generation layer (semiconductor layer) 14 has, for example, a pin junction structure in which an i-type amorphous silicon film 14i is sandwiched between a p-type amorphous silicon film 14p and an n-type amorphous silicon film 14n, as shown in the upper part of FIG. Make it. When sunlight is incident on the power generation layer 14, electrons and holes are generated, which are actively moved by the potential difference between the p-type amorphous silicon film 14p and the n-type amorphous silicon film 14n, and this is repeated continuously. Electric power is generated between the one electrode layer 13 and the second electrode layer 15 (photoelectric conversion).

A buffer layer (not shown) may be disposed between the power generation layer 14 and the second electrode layer 15 disposed on the power generation layer 14.
By disposing the buffer layer between the power generation layer 14 and the second electrode layer 15, the diffusion and reaction of silicon in the power generation layer 14 into the second electrode layer 15 can be suppressed. Such a buffer layer is made of, for example, ZnO.

  The second electrode layer 15 may be composed of a conductive light reflecting film such as Ag (silver) or Al (aluminum). The second electrode layer 15 can be formed, for example, by sputtering.

  In such a laminate 12, the power generation layer 14 and the second electrode layer 15 are divided by a scribe line 20 (scribe line) 20 into a large number of solar cells 21, 21. The solar cells 21α, 21β,... Are connected in series between the adjacent solar cells 21. Thereby, the laminated body 12 becomes the form which connected all the photovoltaic cell 21 (alpha), 21 (beta) ... in series, and can take out the electric current of a high electrical potential difference. The scribe line 20 may be formed, for example, by forming the laminated body 12 uniformly on one surface of the substrate 11 and then forming grooves in the power generation layer 14 and the second electrode layer 15 at a predetermined interval by a laser beam or the like.

Here, when taking measures against snow on the solar cell module, as shown in FIG. 1, by arranging a snow stop (plate-like portion) 70 so that the width direction is perpendicular to the surface of the solar cell module 10. The snow stopper 70 is allowed to exhibit a function of preventing the snow that has fallen on the solar cell module 10 from slipping. Such a snow stop 70 is separate from the solar cell module 10.
However, as shown in FIG. 1, among the solar cells 21 connected in series, specific solar cells 21 located in one or both end regions (here, two specific solar cells from the end portions). In the case of the battery cells 21α and 21β, the power generation efficiency is reduced in the specific solar cells 21α and 21β when the incident of sunlight is blocked by the snow stopper 70. Not only that, the output of the entire module is significantly reduced and the hot spot phenomenon occurs.

  When such a shadow of the snow stopper 70 is formed, the output of the entire solar cell module having a series structure is remarkably reduced. Further, the solar cells 21α and 21β whose outputs are reduced become resistances on the circuit, and a voltage (bias voltage) is applied in the opposite direction to both ends of the solar cells 21α and 21β to cause local heating (hot). Spot phenomenon) occurs.

  Therefore, in the solar cell module 10A (10) of the present invention, the solar cell module 10 is configured and used in an environment where it becomes a shadow of an obstacle (for example, snow stopper 70) and the incidence of sunlight is obstructed. The specific solar cells 21α and 21β have a structure in which the first electrode layer 13 and the second electrode layer 15 are short-circuited.

As shown in FIG. 2, in the solar cell module 10 </ b> A (10) of this embodiment, the solar cells 21 connected in series are located in one or both end regions, and are obstructions (snow stoppers). 70), in the specific solar cells 21α and 21β that are installed and used in an environment where the incidence of sunlight is obstructed, the second electrode layer 15 and the second electrode layer 15 are formed through the openings 14a provided in the power generation layer 14. The first electrode layer 13 is short-circuited. Thereby, no power is generated in the specific solar battery cell 21. In other words, in these specific solar cells 21α and 21β, even if the incident sunlight is blocked by the shadow of the obstacle (snow stopper 70), it is not affected.
As a result, the solar cell module 10A (10) of the present invention prevents a decrease in output in the specific solar cells 21α and 21β, which is a shadow of an obstacle, and a decrease in output of the entire module and a hot spot phenomenon due to the decrease. It will be reliable.
In addition, it is preferable to apply the countermeasure of this invention also about the photovoltaic cell 21 which becomes a shadow of an obstruction only in a part of cell, or only a part of time slot | zone.

Next, a manufacturing method for manufacturing the solar cell module 10A (10) configured as described above will be described in the order of steps.
FIG. 3 is a cross-sectional view sequentially illustrating manufacturing steps of the solar cell module 10A (10) of the present embodiment.
First, as shown in FIG. 3A, an insulating transparent substrate 11 on which a transparent conductive film is formed as a first electrode layer 13 is prepared.

Next, as shown in FIG. 3B, a p-type amorphous silicon film 14p, an i-type amorphous silicon film 14i, and an n-type amorphous silicon film 14n of the power generation layer 14 are separately provided on the first electrode layer 13, respectively. It is formed in a plasma CVD reaction chamber.
At this time, the specific solar cells 21α and 21β that are located in one or both end regions and are used by being installed in an environment that is a shadow of an obstacle (snow stopper 70) and that is impeded by sunlight. The opening 14a is formed in the power generation layer 14 by patterning at a portion to be formed.

Next, as shown in FIG. 3C, a buffer layer (not shown) and the second electrode layer 15 are formed in order on the power generation layer 14.
The buffer layer and the second electrode layer 15 are continuously formed (film formation) in the same apparatus using, for example, an inline type sputtering apparatus.

  At this time, in the specific solar cells 21α and 21β which are located in one or both end regions and used in an environment where they are shadowed by an obstacle (snow stopper 70) and are impeded by sunlight. The second electrode layer 15 and the first electrode layer 13 are short-circuited through the scribe line 14a provided in the power generation layer 14, and no power is generated in the specific solar cells 21α and 21β.

Next, as shown in FIG. 3 (d), for example, a laser beam is irradiated toward the power generation layer 14 and the second electrode layer 15 to form a scribe line 20 (scribe line) 20. Thereby, the laminated body 12 is divided | segmented into many strip-shaped photovoltaic cell 21 (alpha), 21 (beta) .... The solar cells 21α, 21β,... Are connected in series between the adjacent solar cells 21.
Finally, a protective layer (not shown) may be formed on the second electrode layer 15 by sputtering, for example.

  Thereby, solar cell module 10A (10) as shown in FIG.1 and FIG.2 is obtained. In this way, the output of the specific solar cells 21α and 21β that are the shadow of the obstacle, and the output reduction and hot spot phenomenon of the entire module due to the output are prevented, and the solar cell module 10A having excellent reliability is achieved. (10) can be easily produced.

<Second embodiment>
Next, a second embodiment of the solar cell module and the manufacturing method thereof of the present invention will be described. In the following description, parts different from those of the first embodiment described above will be mainly described, and description of parts similar to those of the first embodiment will be omitted.

FIG. 4 is a perspective view showing an example of the solar cell module 10B (10) of the present embodiment. 5 is a cross-sectional view showing a main part of the solar cell module 10B (10) of FIG. 4, and is a cross-sectional view taken along line X3-X4 in FIG.
The solar cell module 10B (10) of the present embodiment constitutes a solar cell module, and among the solar cells 21 connected in series, specific solar cells 21α, located in one or both end regions. 21β is used by being installed in an environment where the incident of sunlight becomes a shadow of an obstacle (for example, snow stopper 70) and is impeded, and between the specific solar cells 21α and 21β. The scribe line 20 is not provided, and the second electrode layer 15 is connected.

As shown in FIG. 5, in the solar cell module of the present embodiment, the solar cells 21 connected in series are located in one or both end regions, and are shaded by an obstacle (snow stopper 70). In the specific solar cell 21 installed and used in an environment where the incidence of sunlight is obstructed, the scribe line 20 is not provided between the specific solar cells 21α and 21β. The second electrode layer 15 is connected. As a result, no power is generated in the specific solar cells 21α and 21β.
As a result, the solar cell module 10B (10) of the present invention is excellent in reliability by preventing a decrease in output of the entire module and a hot spot phenomenon.

Such a solar cell module 10B (10) of this embodiment can be manufactured in substantially the same manner as the solar cell module 10A (10) of the first embodiment described above.
FIG. 6 is a cross-sectional view sequentially illustrating manufacturing steps of the solar cell module 10B (10) of the present embodiment.
First, as shown in FIG. 6A, an insulating transparent substrate 11 having a transparent conductive film formed as a first electrode layer 13 is prepared.

Next, as shown in FIG. 6B, a p-type amorphous silicon film 14p, an i-type amorphous silicon film 14i, and an n-type amorphous silicon film 14n of the power generation layer 14 are separately formed on the first electrode layer 13, respectively. It is formed in a plasma CVD reaction chamber.
Next, as shown in FIG. 6C, a buffer layer (not shown) and the second electrode layer 15 are formed in order on the power generation layer 14.

Next, as shown in FIG. 6D, the first electrode layer 13 and the power generation layer 14 are irradiated with, for example, a laser beam to form a scribe line 20 (scribe line) 20 and connected in series. It is divided into a large number of solar cells 21, 21.
At this time, the solar cell 21 connected in series is located in one or both of the end regions, and is used by being installed in an environment where it becomes a shadow of an obstacle and obstructs the incidence of sunlight. The scribe line 20 is not provided between the solar cells 21α and 21β. Thus, the second electrode layer 15 is connected between the specific solar cells 21α and 21β, and no power is generated in the specific solar cells 21α and 21β.
Finally, a protective layer (not shown) may be formed on the second electrode layer 15 by sputtering, for example.

  Thereby, solar cell module 10B (10) as shown in FIG.3 and FIG.4 is obtained. In this way, it is possible to easily manufacture the solar cell module 10B (10) having excellent reliability by preventing a decrease in output of the entire module and a hot spot phenomenon.

The solar cell module of the present invention has been described above, but the present invention is not limited to this and can be appropriately changed without departing from the spirit of the invention.
For example, the solar cell module of the present invention is not limited to those illustrated in the drawings, and a part of the configuration may be appropriately changed within a range not impairing the effects of the present invention.

Although the present invention has been described in detail with respect to an example applied to an amorphous silicon type (using thin film silicon) solar cell module, the essence of the present invention is “in a specific solar cell, it becomes a shadow of an obstacle and the sun. “Equipped with a structure that is not affected by generation of light even if light incidence is hindered (no power generation is performed)” is not limited to amorphous silicon solar cells (cells).
A solar cell module to which the present invention is applied is a laminate in which a first electrode layer, a power generation layer, and a second electrode layer are sequentially stacked on a substrate, and a cell is formed by laser scribing. Any type of solar cell can be used.
That is, even when the solar cell (cell) is a thin film silicon type, it may be microcrystalline silicon or multi-junction type in addition to amorphous silicon. Moreover, the gist of the present invention is effective even when the solar cell (cell) is replaced with a silicon-based compound-based (III-V group multijunction, CIGS, CdTe, etc.) or an organic system (dye sensitization, organic semiconductor). is there.

  10A, 10B (10) Solar cell module, 11 substrate, 12 laminate, 13 first electrode layer, 14 power generation layer, 14a opening, 15 second electrode layer, 20 scribe line, 21 solar cell, 70 snow stopper ( Obstacle).

Claims (3)

A laminated body in which a first electrode layer, a power generation layer, and a second electrode layer are sequentially stacked on a substrate, and the power generation layer and the second electrode layer are partitioned by a scribe line to form a plurality of solar cells, adjacent to each other A solar cell module formed by connecting the solar cells in a position to each other in series,
Among the solar cells connected in series that constitute the solar cell module, specific solar cells located in one or both end regions serve as shadows of obstacles and impede sunlight. It is installed and used in the environment,
The specific solar battery cell has a structure in which the first electrode layer and the second electrode layer are short-circuited. A laminated body in which a first electrode layer, a power generation layer, and a second electrode layer are sequentially stacked on a substrate, and the power generation layer and the second electrode layer are partitioned by a scribe line to form a plurality of solar cells, adjacent to each other A solar cell module formed by connecting the solar cells in a position to each other in series,
Among the solar cells connected in series that constitute the solar cell module, specific solar cells located in one or both end regions serve as shadows of obstacles and impede sunlight. It is installed and used in the environment,
Between the specific solar cells, the solar cell module has a structure in which the second electrode layer is connected without providing the scribe line.   The solar cell module according to claim 1 or 2, wherein the obstacle is a snow stopper that is integrated with or separate from the solar cell module.

Images