JP2001111087A - Solar cell module - Google Patents

Abstract

(57) [Problem] To provide a solar cell module capable of maintaining a power generation amount even if the solar cell module is blocked from sunlight by another solar cell module or a peripheral member such as a frame. A plurality of solar cell elements in which a first electrode, a semiconductor layer, and a second electrode are stacked in this order are provided on an insulating substrate, and these solar cell elements are electrically connected in series. When the solar cell module 13 is mounted, the solar cell element 13a which becomes a shadow of sunlight when the solar cell module 13 is mounted is made wider than the other solar cell elements 13 and the solar cell element 13a
Is substantially equal to or lower than the series resistance of the other solar cell elements 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell module used, for example, as a roofing material for a building.

[0002]

2. Description of the Related Art A solar cell system has been put to practical use in which a plurality of solar cell modules are laid on a roof of a house or the like to convert solar energy into electric energy, thereby supplementing the original power consumption and saving power consumption. .

In the solar cell module, for example, a transparent electrode layer (first electrode), a solar cell element made of amorphous silicon, and a back electrode layer (second electrode) are formed on a single glass substrate.
In general, a horizontally long rectangular thin panel structure in which a steel plate is integrally provided on the back surface via a heat insulating material.

FIG. 8 shows a conventional solar cell module 1, in which a plurality of solar cell elements 3 are arranged on a back surface of a glass substrate 2 in a plurality of stages in a vertical direction with its longitudinal direction being a horizontal direction. . Further, a frame 4 made of an extruded aluminum product is fixed to the outer peripheral edge of the solar cell module 1. In the solar cell module 1, a plurality of solar cell elements 3 are electrically connected in series so that the output voltage is increased and the output current is decreased to increase the power generation efficiency.

Therefore, if the output of any one of the plurality of solar cell modules 3 decreases, the solar cell module 1 becomes a resistor connected in series, and the output of the entire solar cell module 1 decreases. There is a problem.

For example, as shown in FIGS. 9 and 10, when a plurality of solar cell modules 1 are tiled (stacked) on each of a south slope 6 and a north slope 7 of a roof 5 of a house, The solar cell module 1 is constructed so that the upper edge 1a of the solar cell module 1 overlaps the lower edge 1b of the upper solar cell module 1. Each of the solar cell modules 1 receives the sunlight L on the entire surface.

However, the solar cell module 1 laid on the south slope 6 of the roof 5 has no problem, but the solar cell module 1 laid on the north slope 7 has a solar cell module 1 due to the presence of the upper solar cell module 1. The light beam L is blocked, and a shadow a (shown by oblique lines) is formed on the upper edge 1a of the lower solar cell module 1. The shadow “a” spreads as the incident angle of the sunlight L decreases as in winter. In addition, since the solar cell module 1 has the solar cell elements 3 arranged from the uppermost stage to the lowermost stage so as to be able to receive the sunlight L over a slightly larger area, the upper stage 1
Since the two solar cell elements 3 do not receive the sunlight L, the output of the solar cell element 3 decreases, and as a result,
The output of the entire solar cell module 1 is reduced.

[0008] Such a phenomenon is not limited to the case where the solar cell module 1 is tiled, but as shown in FIG. 11, the solar cell modules 1 are connected to each other by a frame 8 so that the solar cell module 1 is planarized. Even in the case of construction, since the frame 8 protrudes from the upper surface of the solar cell module 1, a shadow a due to the frame 8 is formed,
There is a similar problem.

Therefore, for example, in Japanese Patent Application Laid-Open No. 8-228017, the solar cell to the solar cell panel is blocked by the surrounding frame, and the solar cell element in the shadowed portion is made a dummy element, Output reduction is prevented. This dummy element was manufactured in the same manner in the process of manufacturing the solar cell element, and was electrically short-circuited in the electrode forming step. is there.

Further, as disclosed in Japanese Patent Application Laid-Open No. 6-13637, a resistance component at a connection portion for electrically connecting a plurality of solar cell elements provided on an insulating substrate in series is reduced to improve photoelectric conversion efficiency. There is known a solar cell module designed to increase power.

Further, as shown in Japanese Patent Application Laid-Open No. 57-173982, metal strips are arranged in a direction in which a photocurrent flows on a transparent electrode forming one electrode of a solar cell element to reduce the surface resistance of the transparent electrode. There is also known a solar cell module in which the photoelectric conversion efficiency is increased.

[0012]

However, according to the above-mentioned Japanese Patent Application Laid-Open No. 8-228017, it is possible to prevent the output of the solar cell panel from being reduced due to shadows. In the same process, the manufacturing cost increases. In addition, since the solar cell panel is formed so as not to generate power even when receiving solar rays, in the case of solar cell panels of the same size, the area of the solar cell element is reduced, so that there is a problem that the amount of power generation is reduced.

JP-A-6-13637 and JP-A-57-173982 are intended to reduce the resistance component and increase the photoelectric conversion efficiency. If the solar light is partially blocked by peripheral members such as the solar cell module and the frame, the output of the entire solar cell module is reduced.

In order to solve the above-mentioned problem, the present applicant has proposed a solar cell in which a part of the solar cell element where light incident on the solar cell module is blocked by peripheral members is wider than other solar cell elements. Battery module, Japanese Patent Application Hei 1
A patent application has already been filed as 1-159412.

As described above, when the width of a specific solar cell element is increased, the influence of the shadow as a solar cell module is reduced, but the series resistance of the solar cell element having the increased width is increased, and the solar cell element has a larger resistance. Fill factor worsens. As a result, there is a problem that the characteristics are poor even in the case where no shadow is generated as compared with a solar cell module in which the widths of all the solar cell elements are equal.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a solar cell module in which sunlight is blocked by other solar cell modules and peripheral members such as a frame to form a shadow. Even so, an object of the present invention is to provide a highly reliable solar cell module which is less affected by the influence and can maintain a desired power generation amount.

[0017]

In order to achieve the above object, the present invention is directed to a solar cell in which a first electrode, a semiconductor layer and a second electrode are laminated in this order on an insulating substrate. A plurality of battery elements are provided, and in a solar cell module in which these solar cell elements are electrically connected in series, when the solar cell module is mounted, the solar cell element that becomes a shadow of sunlight is another. The solar cell element is wider than the solar cell element, and the series resistance of the wider solar cell element is substantially equal to or lower than the series resistance of other solar cell elements.

A second aspect of the present invention is characterized in that the wide solar cell element of the first aspect and another adjacent solar cell element are connected in series also inside the wide solar cell element.

According to a third aspect of the present invention, the wide solar cell element according to the first or second aspect is configured such that a series connection with an adjacent solar cell element forms a groove reaching the second electrode by the solar cell element. And a part of the second electrode of the solar cell element adjacent to the groove is extended and connected to the first electrode.

According to a fourth aspect of the present invention, the first electrode, the first electrode,
A plurality of solar cell elements in which a semiconductor layer and a second electrode are stacked in this order are provided, and when the solar cell module is mounted on a solar cell module in which these solar cell elements are electrically connected in series, Making the solar cell element which is shaded by the sun's rays wider than other solar cell elements, and lowering the resistance of the first electrode on the insulating substrate, corresponding to the width of the wider solar cell element. It is characterized in that a conductive film is provided.

According to the constructions of the first to third aspects, even if the solar cell module is shielded from sunlight by another solar cell module or a peripheral member such as a frame, the solar cell element is wide. Does not become a shadow, and the resistance value of the solar cell element does not increase. Also, by making the series resistance of the wide solar cell element substantially equal to or lower than the series resistance of the other solar cell elements, the photoelectric conversion efficiency is increased, and the characteristics of the wide solar cell element increase the area. Only demonstrate. The amount of power generated by each solar cell element can be maintained.

According to the configuration of the fourth aspect, the resistance value of the first electrode is reduced by the conductive film formed on the insulating substrate, and the photoelectric conversion efficiency of the wide solar cell element is increased.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 5 show a first embodiment, and FIG.
2 is a perspective view of the solar cell module, FIG. 2 is a plan view of the solar cell module, FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2, and FIG. 4 is tiled on a 4.5-dimension roof. FIG. 5 is an enlarged longitudinal side view of a portion B in FIG.

As shown in FIG. 1, the solar cell module 1
1 is an insulating substrate 12 such as a horizontally long rectangular glass substrate.
A plurality of solar cell elements 13 are arranged in a plurality of stages in the vertical direction with the longitudinal direction being the horizontal direction. Further, a frame 14 made of an extruded aluminum product is fixed to the outer peripheral edge of the solar cell module 11. In the solar cell module 11, the plurality of solar cell elements 13 are electrically connected in series so that the output voltage is increased and the output current is decreased to increase the power generation efficiency.

As shown in FIG.
As shown in the figure, when the roof 15 of a house or the like is tiled,
The width W ₁ of the solar cell element 13 a on the upper edge side of the solar cell module 11, which becomes the ridge side 16,
Wider than the width W ₂ of, in this embodiment are formed at two times the width.

Further, as shown in FIGS. 2 and 3, the wide solar cell element 13a has a first electrode 2 made of a transparent electrode on the insulating substrate 12, like the other solar cell elements 13.
1. Amorphous semiconductor layer 22, second electrode as back electrode
An electrode 23 is provided.

A plurality of grooves 24 are formed at the connection portion of the wide solar cell element 13a with another solar cell element 13 with respect to the amorphous semiconductor layer 22 and the second electrode 23 so that the first electrode 21 is exposed. I have. Furthermore, the solar cell element 13 adjacent to the wide solar cell element 13a is
The contact grid 25 formed from a part of the second electrode 23 is provided in a finger-like manner so as not to directly contact the second electrode 23 of the solar cell element 13a. Is connected to the first electrode 21.

That is, the solar cell element 13 adjacent to the wide solar cell element 13a is also connected in series inside the solar cell element 13a, the contact area is increased, the resistance component at the connection is reduced, and the photoelectric conversion is performed. Improving efficiency.

The groove 24 can be formed by partially etching the amorphous semiconductor layer 22 by, for example, an active ion etching method, or by burning it off with a laser by a laser scribe method.

The contact grid 25 not only increases the connection area of the wide solar cell element 13a, but also makes the first electrode 2
1 that the contact grid 25 has a parallel resistance component and operates as a current collecting grid of a crystalline solar cell as a collecting electrode for carriers generated in the solar cell element 13a. It also functions to reduce the series resistance component of one electrode 21.

FIG. 4 shows a state in which a plurality of solar cell modules 11 are tiled on each of the south slope 17 and the north slope 18 of the roof 15, and 19 is a roof tile. The lower edge 11b of the upper solar cell module 11 is constructed so as to overlap the upper edge 11a of the lower solar cell module 11 of the tiled roof. And each solar cell module 1
Numeral 1 is fixed to the field plate 28 by a roof fixing nail (not shown).

According to the solar cell module roof constructed as described above, when solar light L enters each solar cell module 11, the solar cell elements 13 and 13a constituting the solar cell module 11 convert the solar energy into electricity. It can be converted into energy and extracted as electrical energy.

At this time, the solar cell module 11 laid on the south inclined surface 17 of the roof 15 has no problem, but the solar cell module 11 laid on the north inclined surface 18 has a ridge tile 19 as a peripheral member or an upper stage. The sunlight rays L are blocked by the presence of the solar cell module 11, and a shadow a (shown by oblique lines) is formed on the upper edge portion 11a of the lower solar cell module 11. The shadow “a” spreads as the incident angle of the sunlight L decreases as in winter.

However, as shown in FIG. 5, when each solar cell module 11 is tiled on the roof 15,
Becomes 6, the width _{W 1} of the upper edge 11a side of the solar cell element 13a of the solar cell module 11, the different solar cell element 13
It is formed wider than the width W _2. Therefore, even if the incident angle of the solar ray L is small, the entire solar cell element 13a does not become a shadow, and solar energy can be converted into electric energy as in the other solar cell elements 13, Power generation can be maintained without being affected by shadows.

Further, even if the angle of incidence of the solar light L becomes small and the entire solar cell element 13a becomes a shadow a, since the solar cell element 13a is wide, the power generation amount can be maintained by scattered light and the like, and As a result, it is possible to reduce a decrease in the amount of power generation.

The solar cell element 13 adjacent to the wide solar cell element 13a is also connected in series inside the solar cell element 13a, and the contact area can be increased to reduce the resistance component at the connection. Therefore, the characteristics of the wide solar cell element 13a exhibit only the effect of increasing the area.

FIG. 6 shows a second embodiment. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. FIG. 6 is a vertical sectional side view showing a state in which the solar cell module 11 is laid flat on the roof 15. The solar cell module 11 is the same as that of the first embodiment. The width W ₁ of the solar cell element 13a on the upper edge side of the solar cell module 11 which becomes the ridge side 16 when the roof 15 is tiled on the roof 15 is twice the width W ₂ of the other solar cell elements 13. Is formed.

Further, the solar cell element 13 adjacent to the wide solar cell element 13a is also connected in series inside the solar cell element 13a as in the first embodiment, and the connection area is increased by increasing the contact area. Is reduced.

A plurality of solar cell modules 11 are connected to each of the south slope 17 and the north slope 18 of the roof 15 by a frame 31. The frame 31 is inserted between the adjacent solar cell modules 11, and the frame 31 includes a lower frame 32 and an upper frame 33.

The lower frame 32 is fixed to the base plate 28 by nails 34, and the lower frame 32 is
The upper frame 33 holds and fixes the outer peripheral edge of the solar cell module 11.

According to the solar cell module roof constructed as described above, when solar rays L enter each solar cell module 11, the solar cell elements 13 and 13a constituting the solar cell module 11 convert solar energy into electricity. It can be converted into energy and extracted as electrical energy.

At this time, the solar cell module 11 laid on the south inclined surface 17 of the roof 15 has no problem, but the solar cell module 11 laid on the north inclined surface 18 has the upper frame 31 (peripheral member). , The sunlight L is blocked, and a shadow a (shown by oblique lines) is formed on the upper edge 11a of the solar cell module 11. The shadow “a” spreads as the incident angle of the sunlight L decreases as in winter.

However, when each solar cell module 11 is tiled on the roof 15, the solar cell element 13 a on the upper edge 11 a side of the solar cell module 11 becomes the ridge side 16.
Width W ₁ of is formed wider than the width W ₂ of the other solar cell element 13. Therefore, even if the incident angle of the solar ray L is small, the entire solar cell element 13a does not become a shadow, and solar energy can be converted into electric energy as in the other solar cell elements 13, Power generation can be maintained without being affected by shadows.

FIG. 7 shows a third embodiment. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. As shown in FIGS. 7A and 7B, a conductive film 35 is deposited on the insulating substrate 12 corresponding to the width W1 of the wide solar cell element 13a. The conductive film 35 is, for example, a light-transmitting conductive film, and may be formed over the entire width W1 of the wide solar cell element 13a. May be partially applied. On the upper surface of the conductive film 35, like the other solar cell elements 13, the first electrode 21 formed of a transparent electrode and the amorphous semiconductor layer 2 are formed.
2. A second electrode 23 is provided as a back electrode, and a solar cell element 13a is formed.

As described above, by providing the conductive film 35 on the insulating substrate 12 and forming the first electrode 21 on the upper surface thereof,
The resistance value of the first electrode 21 in the width W1 portion decreases, and the photoelectric conversion efficiency improves. Therefore, even if the incident angle of the solar ray L becomes small and the entire solar cell element 13a becomes a shadow a, since the solar cell element 13a is wide, the power generation amount can be maintained by scattered light and the like. The resistance value at the element 13a is reduced, and the decrease in the power generation amount as a whole can be reduced.

In each of the above embodiments, the solar cell element 13 on the upper edge 11a side of the solar cell module 11 is used.
The width _{W 1} of a, was twice as wide _{W 2} of the other solar cell element 13, may be 2-3 times. Further, although the frame 14 is fixed around the solar cell module 11, the present invention can be applied to a solar cell module without a frame.

Furthermore, the case where the solar cell module is laid on the sloped roof of the house has been described. However, a sloped solar cell module installation tower is constructed on a vacant lot, a rooftop, or the like, and the solar cell module is installed on the slope of the installation tower. It is also applicable when laying modules.

[0049]

As described above, according to the present invention, even if the solar cell module is blocked by other solar cell modules or a peripheral member such as a frame, the solar cell element in a shadowed portion is removed. Since the width is widened, the whole does not become a shadow, and the resistance value of the solar cell element does not increase.

Further, by making the series resistance of the wide solar cell element substantially equal to or lower than the series resistance of the other solar cell elements, the photoelectric conversion efficiency increases, and the characteristics of the wide solar cell element reduce the area. Exhibits only the widened effect. Therefore, there is an effect that the power generation amount of each solar cell module can be maintained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a solar cell module according to a first embodiment of the present invention.

FIG. 2 is a schematic plan view of the solar cell module of the embodiment.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a vertical cross-sectional side view of the solar cell module of the embodiment, which is tiled on a 4.5-dimension roof.

FIG. 5 is an enlarged longitudinal side view of a portion B in FIG. 4;

FIG. 6 is a longitudinal sectional side view showing a state in which the solar cell module according to the second embodiment of the present invention is laid flat on a 4.5-dimensional gradient roof;

FIGS. 7A and 7B show a third embodiment of the present invention, wherein FIG. 7A is a perspective view of a solar cell module, and FIG. 7B is a cross-sectional view taken along line CC.

FIG. 8 is a perspective view of a conventional solar cell module.

FIG. 9 is a vertical sectional side view of a state where a conventional solar cell module is tiled on a 4.5-dimension roof.

FIG. 10 is an enlarged vertical sectional side view of a portion D in FIG. 9;

FIG. 11 is a longitudinal sectional side view of a state where a conventional solar cell module is laid flat on a 4.5-dimensional sloped roof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Solar cell module 13 ... Solar cell element 13a ... Wide solar cell element 21 ... 1st electrode 22 ... Semiconductor layer 23 ... 2nd electrode 24 ... Groove 25 ... Contact grid

Claims (4)

[Claims] 1. A plurality of solar cell elements in which a first electrode, a semiconductor layer, and a second electrode are stacked in this order on an insulating substrate, and these solar cell elements are electrically connected in series. In the solar cell module, when the solar cell module is mounted, the solar cell element, which becomes a shadow of sunlight, is made wider than other solar cell elements, and the series resistance of this wide solar cell element is substantially reduced. A solar cell module characterized by having a series resistance equal to or lower than the series resistance of another solar cell element. 2. The solar cell module according to claim 1, wherein the wide solar cell element and another adjacent solar cell element are connected in series also inside the wide solar cell element. . 3. The wide solar cell element, wherein a series connection with an adjacent solar cell element forms a groove portion reaching the second electrode inside the solar cell element, and the solar cell element adjacent to the groove portion has a groove. 3. The battery device according to claim 1, wherein a part of the second electrode of the battery element is extended and connected to the first electrode.
The solar cell module as described. 4. A plurality of solar cell elements in which a first electrode, a semiconductor layer, and a second electrode are laminated in this order on an insulating substrate, and these solar cell elements are electrically connected in series. In the solar cell module, when the solar cell module is mounted, the solar cell element, which becomes a shadow of sunlight, is made wider than other solar cell elements, and the wide solar cell is provided on the insulating substrate. A solar cell module comprising a conductive film corresponding to the width of an element and lowering the resistance of the first electrode.