JPH03124070A - Roof-mounted type solar cell - Google Patents

Abstract

PURPOSE:To prevent a strain or the like of a stand by a thermal stress caused between a plurality of solar cell modules and the stand by a method wherein the modules are attached to the stand so as to be capable of being moved a little. CONSTITUTION:Z-shaped installation metal fittings 15 are attached to outer frames of individual modules 10; the installation metal fittings 15 are hooked to wires 12 of a stand 11; the modules are attached by forming a prescribed gap 17 at one side between the adjacent modules 10, 10. Consequently, the individual modules 10 are fixed so as to be capable of being moved a little by elasticity of the wires 12. Even when a temperature on the surface of a solar cell is raised in midsummer or the like and the stand 11 is expanded, its expansion is absorbed between the modules 10 and the stand 11 and it is possible to prevent a strain or the like by a thermal stress from being caused.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a roof-mounted solar cell, and more particularly to a solar cell that can be installed on an existing roof of a general residence.

(b) Conventional technology Solar cells, which directly convert light energy into electrical energy, are in the spotlight as the depletion of energy resources becomes a problem because they use inexhaustible sunlight as their main energy source. When using this solar cell as a household power source, a light-receiving area of 30 m2 is sufficient for normal household power consumption, assuming that the conversion efficiency of the solar cell is 10%.

The light-receiving area of this solar cell is enough to cover the roof of a normal house.

Therefore, a tile-shaped solar cell device has been proposed, as disclosed in Japanese Patent Application Laid-Open No. 60-31259. This tile-shaped solar cell device can be simply installed in place of the existing roof tiles.
It has 1 point.

However, if the above-mentioned tile-shaped solar cell device is to be installed on an existing roof, the roof tiles that have already been laid must be removed, and then the tile-shaped solar cell device must be installed. .

Therefore, the installation work was very time-consuming and was not suitable for existing roofs.

Furthermore, since a glass substrate that is curved in the shape of a tile is used as the substrate for solar cells, it is difficult to manufacture, increasing costs, and due to the curved shape, it is undeniable that the photovoltaic force varies depending on the beam angle. .

On the other hand, attempts are being made to install flat solar panels developed for electric power on rooftops. The conventional installation method for this flat type solar cell panel was to directly fix the solar cell panel to the roof material with bolts or the like.

(c) Problems to be solved by the invention Tile-shaped solar cell devices can be installed simply by laying them in place of roof tiles, but as mentioned above, installing them on an existing roof is time-consuming and costly. I also don't like how bulky it is.

Furthermore, flat solar cell panels have the advantage that they can be manufactured at a lower cost than tiled solar cells. As mentioned above, in the conventional system, the roof is directly fixed to the roof material using bolts or the like.

By the way, the surface temperature of a solar panel installed on a roof rises to about 70° C. on a sunny day in midsummer. Further, at this time, the temperature of the roof located under the panel is approximately 40°C. This temperature increase causes the solar panel to expand. In particular, aluminum is generally used for the frame that fixes the panel, and the linear expansion coefficient of this aluminum is different from that of the solar cell itself and the linear expansion coefficient of the roofing material. There is a high possibility that thermal stress will occur, causing the aluminum frame to warp and the roof components to crack. Moreover, since the panels are firmly fixed to prevent them from being blown away by winds such as typhoons, distortion caused by thermal stress has a negative effect not only on the frame but also on the solar cells themselves.

Furthermore, in order to be used as a power source for a house, it is desired to have a service life of 15 years or more, and the above-mentioned installation method also has problems with durability.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems.The object of the present invention is to provide a roof-mounted solar cell that can be easily installed on an existing roof, does not damage the roof, and has excellent durability. shall be.

(D) Means for Solving the Problems The present invention provides a pedestal mounted on a roofing material, and a solar cell module of multiple R9 incorporated in this pedestal.

A plurality of solar cell modules are movably attached to a mount.

Further, a plurality of solar cell modules may be attached to a pedestal so as to provide a predetermined gap between them.

(E) Function Since the multiple solar cell modules are movably attached to the stand, even if the temperature of the surface of the solar cells rises and the stand expands, such as in the middle of summer, the solar cell modules and the stand will not move. The expansion is absorbed between the two, and distortion due to thermal stress does not occur.

Furthermore, since wind passes through the gaps between the solar cell modules, heat dissipation from the solar cells is improved, deterioration of characteristics can be prevented, and wind pressure from typhoons and the like can be alleviated.

Furthermore, since vibrations caused by earthquakes and the like are mutually dissipated between the solar cell module and the mount, earthquake resistance is also improved.

(f) Examples Examples of the present invention will now be described with reference to FIGS. 1 to 9.

First, an example of a solar cell module used in the present invention will be explained with reference to FIG.

(1) is a substrate made of a transparent and insulating material such as tempered glass, and (2) (2)... are charging conversion regions directly attached at regular intervals to the surface of the substrate (1). . The above-mentioned photoelectric conversion regions (2) (2)... are made of a transparent conductive film (such as tin oxide or indium tin oxide) (
3) (3)... and a semiconductor film made of amorphous silicon with a semiconductor junction inside it (4) (4)...
・and a back electrode film (5) (S) made of aluminum or the like that makes ohmic contact with the semiconductor film (4) (4)...
It takes the form of a film on the order of microns, which is formed by sequentially laminating layers.

Each semiconductor film (4) (4)... has a thickness of 5 mm from the light-receiving surface side in order to form a PIN junction parallel to the film surface inside.
A P-type layer of about 0 to 250 A, an I (intrinsic) layer of about 4000 to 7000 A, and an N-type layer of about 300 to 600 A are sequentially deposited, thus forming a substrate (1) and a transparent conductive film (3). (3) When light is incident upon passing through..., free-state electrons and holes are generated in the PIN layer, and these electrons and holes are attracted by the PIN junction electric field formed by each layer. Each transparent conductive film (3) (3)... and back electrode film (
5)(5)...- and the adjacent photoelectric conversion area (
2) The electrically added power is extracted by which transparent conductive film (3) (3)... and the back electrode film (5) (5)... of (2) (2)... overlap.

(6) is an outer frame made of aluminum or the like, and (7) is a resin layer that covers the photoelectric conversion regions (2) (2).

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing the device of the present invention installed on an existing roof, FIG. 2 is a perspective view of the same main part, and FIG. 3 is a side view showing different attachment modes. FIG. 4 is a perspective view showing a manner of attachment to an under-eaves member, and FIG. 5 is a perspective view showing an example of a frame used in the present invention. FIG. 6 shows how the solar cell module is assembled into the mount, FIG. 6(a) is an exploded perspective view, and FIG. 6(b) and FIG. 6(c) are side views. 7th
1 is a perspective view showing an example of electrical connections between modules.

The pedestal used in this embodiment will be explained according to Section 5.

The pedestal (11) is made of aluminum or the like, and has a required number of wires (12) for attaching the module inside. A plurality of fixed legs (13) are provided at the bottom of this pedestal (11).
(13)... is provided, and this fixed leg (13)... is provided.
) A spacer member (14) made of fluorine rubber, wood, etc. is provided at the end of the &

The structure of this frame (11) may be one made by bending an aluminum vibrator or a stainless steel vibrator, as shown in Figure 5 (a), or an aluminum plate as shown in Figure 5 (b). Some are formed by the body.

In both of these embodiments, the distance between the roofing material and the module is the total length of both the fixed leg (13) and the spacer member (14).

A plurality of solar cell modules (10) shown in FIG. 8 are incorporated into the above-mentioned pedestal (11). When the solar cell module (10) assembled on the mount (11) is placed on the roof material, the distance between the solar cell module (10) and the roof material is the length of the fixed leg (13) and the spacer (14). A void is created by the amount. This gap creates a solar cell module (10
) can be dissipated.

In this embodiment, nine modules (10) are incorporated into one pedestal (11). To assemble the frame (11) and the module (lO), for example, as shown in FIG. ) wire (12)
The installation fittings (15) are hooked onto each of the adjacent modules (10), and a predetermined gap (17) is provided on one side between the adjacent modules (10). That is, module (10) (10
) A gap (17) is provided as a space for ventilation. This gap (17) is provided on at least one side of the module (10), but may be provided on all four sides of the module (10).
), the wire (12) is fixed so that it can be moved due to the elasticity of the wire (12). Therefore, due to vibrations, wind, etc., the module (10)
moves and plays the role of relieving that stress.

Electrical connections between each module (to) (10) are made by winding an electric wire around the wire (12) or by making the wire (12) itself a conductive wire, as shown in Figure 7. Connection can be made to the electric wire using a crimp terminal (16). The solar panel (20) thus formed is attached to the existing roof using wires. Installation of the solar panel (20) on the roof will be explained with reference to FIGS. 1 to 4.

In these figures, (21) is the roof (22) of an existing house.
) are roof tiles, and (23) are empty tiles.

Roof tiles (22) on the roof (21) facing south (22)
)...The solar panel (10) is placed on top of the spacer (13)
). The mount (11) of this solar panel (20) and under-eave members (24) such as the purlin, nose purlin, eaves, and gassho of the roof (21) are attached with multiple wires (25)... Ru. In this example,
As shown in Fig. 4, a clamp member (26) is fixed to the main building (24) under the eaves with bolts (27), etc., and a wire (
25) is attached via a turnbuckle (28).

On the other hand, as shown in Figures 2 and 3, the direction of inclination of the roof (21) is determined by fixing the clamp member (26) to the rafters under the eaves with bolts, etc., beyond the gutter (30). The wire (2) attached to the clamp member (26) and the pedestal (11)
5) Attach and.

Note that (31) is a cushion member.

In addition, the mount (11) above the solar panel (20)
As shown in Fig. 3 (B), a fixing metal fitting (32) is provided on the blank tile (23), and a wire (
25).

By the way, as mentioned above, when using a solar battery device as a household power source, the conversion efficiency is currently around 11% for a 3kW system, so the required area is 30m2.
It is. Therefore, the overall size of the solar cell panel (20) described above is 3 m on the short side and 10 m on the long side.

FIG. 9 is a diagram showing changes in the amount of solar radiation and temperature of the solar cell depending on time. As can be seen from FIG. 9, during clear weather in midsummer, the temperature of the solar cell surface can rise to as much as 70°C. On the other hand, the temperature of the surface of the roof tile (22) rises to about 40°C. This temperature rise causes differences in the linear expansion coefficients of each member, that is, the glass substrate (1) of the solar cell module (10), the aluminum of the pedestal (11), and the roof tiles (22), such as slate tiles. The amount of thermal expansion differs depending on the difference.

For example, in the longitudinal direction of Ion, glass 7 mm, aluminum 16 mm, and slate roof tiles expand by about 14 mm (when considered as a whole) compared to when the temperature is 0°C.

Here, each linear expansion coefficient α is α (aluminum) = 23X 10-' (1/℃
) α (glass) = IOX 10-' (1/
"C) α (slate) = tax to-'
It was calculated as (1/'C).

As mentioned above, there is a difference of about 12 mm between the aluminum frame (II) and the slate tile roof. Therefore, the frame (1
1) and the roof tile (22) are directly fixed, the roof tile (2)
2) Misalignment may occur or thermal stress may occur between the two. As a result, the frame (11) may become distorted, or the roof tile (22) may become distorted.
) may be damaged, and the durability is not good. However, in this embodiment, the roof tile (22) and the solar panel (20) are placed movably, so even if the pedestal (11) is extended, stress is applied to the roof tile (22). There is no risk of damage to the roof tiles (22).

On the other hand, the frame (11) and the roof (21) are wired (25)
Since the linear expansion coefficient of the wire (25) is very close to that of the aluminum frame (11),
This wire (25) also extends to absorb the expansion of the pedestal (11). Furthermore, the wires (25) are attached to prevent the solar panel (20) from falling during a typhoon, earthquake, or the like. Therefore, attachment using wires (25) has a certain degree of freedom compared to directly fixing to the roof with bolts. Therefore, the elongation due to thermal expansion of the pedestal (11) can be sufficiently absorbed, no thermal stress is applied to the pedestal (11), no distortion occurs, and the durability is excellent.

Now, 1. In the present invention, a solar cell module (lO)
As mentioned above, the installation of the pedestal (11) and the pedestal (11)
It is movably attached. That is, in this embodiment, a certain degree of freedom is provided between the wires provided on the pedestal (11). Therefore, the difference in elongation between the glass and the pedestal can be absorbed by the portion where both are attached, and deterioration due to thermal stress or the like can be prevented.

Further, a predetermined gap (17) is provided between the modules (10) (10). Therefore, this gap (I
Since the wind passes through the solar cell module (1)
0) allows good heat dissipation. Furthermore, as mentioned above,
Since the solar cell panels (20) are installed on the roof (21) with a certain degree of freedom, vibrations such as earthquakes and winds such as typhoons are released from each other, thereby improving durability.

Further, in this embodiment, a frame is used separately from the outer frame of the solar cell module, but this outer frame can also be used as the frame.

(G) As described in detail, according to the present invention, the solar cell module is movably attached to the pedestal, so even if the mount expands due to a rise in midsummer temperature, This expansion is absorbed between the solar cell module and the mount, preventing distortion due to thermal stress, etc., and improving durability.

Furthermore, since wind passes through the gaps between the solar cell modules, the heat dissipation of the solar cells is improved, deterioration of characteristics can be prevented, and wind pressure from typhoons and the like can be alleviated. In addition, vibrations such as those caused by earthquakes can be dissipated between the solar cell module and the pedestal, improving earthquake resistance.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the device of the present invention installed on an existing roof, FIG. 2 is a perspective view of the same main part, and FIG. 3 is a side view showing different attachment modes. FIG. 4 is a perspective view showing a manner of attachment to an under-eaves member, and FIG. 5 is a perspective view showing an example of a frame used in the present invention. FIG. 6 shows a mode of assembling the solar cell module into the mount, FIG. 6(a) is an exploded perspective view, and FIG. 6(b) and FIG. 6(c) are side views. 7th
The figure is a perspective view showing an example of electrical connections between modules. FIG. 8 is a cross-sectional view showing the solar cell module, and FIG. 9 is a diagram showing changes in the amount of solar radiation and temperature of the solar cell over time. 10... Solar cell module, 11... Frame, 13
... Fixed leg, 14... Spacer, 17... Gap,
20...Solar panel, 21...Roof, 22...
- Roof tile, 23...Muna tile, 24...Eave member, 2
5...Wire.

Claims (2)

[Claims] (1) A roof comprising a pedestal placed on a roof material and a plurality of solar cell modules incorporated into the pedestal, the plurality of solar cell modules being attached to the pedestal so as to be slightly movable. Installed solar cells. (2) The roof-mounted solar cell according to claim 1, wherein the solar cell module adjacent to another solar cell module is attached to the mount with a predetermined gap provided between at least one side of the solar cell module.