Batteries: thermoelectric and photoelectric – Photoelectric – Panel or array
Reexamination Certificate
1999-09-23
2001-04-17
Diamond, Alan (Department: 1753)
Batteries: thermoelectric and photoelectric
Photoelectric
Panel or array
C136S244000, C136S256000, C136S293000, C257S433000, C257S443000, C257S459000
Reexamination Certificate
active
06218606
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a solar cell module and more particularly relates to a solar cell module having front and rear surface members that are transmissive and which can let in light from both front and rear surfaces.
2. Description of the Prior Art
A solar cell can directly convert photo-energy from the sun that provides clean energy without depletion. Solar cell technology is expected to replace fossil fuel such as petroleum and coal. Since solar energy has been predicted to be the new energy source, a lot of effort has been made to commercialize solar cell technology. When using a solar cell as an energy source in practical general circumstances, a plurality of solar cells are connected electrically in serial or in parallel to increase output.
A description of a conventional solar cell module will be made by referring to
FIGS. 13-16
.
FIG. 13
is a front view,
FIG. 14
is a cross-sectional view at the A-A′ line indicated in
FIG. 13
, and
FIG. 15
is a rear elevation schematically illustrating a rear surface member which will be described later.
FIG. 16
is an explanatory view illustrating an enlarged structure of an inside portion of a terminal box.
As shown in these figures, the solar cell module comprise of a front surface member
1
containing transmissive material such as glass and plastic, a rear surface member
2
, and solar cells
3
. . . Generally a rear surface member
2
has a three-layered structure sandwiching an aluminum foil between resin films.
The solar cell
3
is, for example, one that contains crystalline Si substrate having p-n junction inside. Seventy-two units of solar cells
3
. . . are disposed in an 8×9 matrix shape and are connected electrically in serial with connection members
4
. . . containing a metal thin plate such as a copper thin plate. The solar cells
3
. . . are sealed between the front surface member
1
and the rear surface member
2
with sealing member
5
, such as ethylene vinyl acetate (EVA), which is transmissive and insulated. A frame
6
formed by processible metal such as aluminum-is mounted around the sealing member.
Electricity generated in the solar cells
3
. . . is drawn to terminal boxes
50
,
50
provided on a rear surface of the rear surface member
2
through electricity drawing wires
11
,
11
. Then, the electricity is output from the terminal boxes
50
,
50
through an electric cable (not shown) to the outside.
In the above system which operates a plurality of solar cells connected in serial, the sunlight is sometimes prevented from being incident to a part of solar cells because of shade created from a building or snow drifts. In this case, a total voltage generated by the solar cells, which are normally operating, is applied to the above part of the solar cells as reverse voltage. If the reverse voltage reaches beyond a capacity voltage of the solar cells, the solar cells are broken. Otherwise, the above part of the solar cells generates heat, causing such problems as discoloration or foaming in the EVA sealing member or breakage of solar cells.
Thus, in order to overcome this problem, a common solar cell module has solar cells divided into several groups of a plurality of solar cells, and has means for preventing reverse voltage from being applied, which is connected to these solar cell groups in parallel.
For example, in the above solar cell module, 72 units of solar cells are divided into four groups of eighteen solar cells
3
. . . A diode
21
, as means for preventing reverse voltage from being applied, is connected to these solar cell groups electrically in parallel and in reverse via connection wire
12
. The diode
21
, as shown in
FIG. 16
, is located in a terminal box
50
, thus increasing the size of terminal box
50
.
I the interim, a solar cell, which can generate energy from light which is incident not only from a front surface but from a rear surface, has been developed. A solar cell module, which employs such a solar cell that can take light from both front and rear surfaces, has a structure in which light can be incident to a rear surface of a solar cell through a rear surface member consisting of transmissive material such as glass rather than conventional material which is not transmissive.
However, in the solar cell module of the above structure, light which is incident from the rear surface is blocked by the terminal boxes
50
,
50
, the electricity drawing wires
11
,
11
, and the connection wires
12
. . . Because of the present configuration of the solar cell module light can not be incident to some parts of the rear surfaces of the solar cells. As a result, the solar cells of those parts generate electric current only by light which is incident from the front surface, and an electric current value of those parts becomes lower than others. Since a plurality of solar cells are connected electrically in serial, an output electric current value of the whole module becomes is lower for solar cells having the above configuration where light is not incident to the rear surface. Accordingly, light which is incident from the rear surface can not be utilized fully.
in addition to the above solar cell which can let in light from both front and rear surfaces, a solar cell module of sophisticated-design using a conventional solar cell, of which rear surface member is made of transmissive material and can transmit a part of light to the rear surface, has been provided. However, the terminal boxes
50
,
50
, electricity drawing wires
11
,
11
, and connection wires
12
. . . in such a solar cell module also reduce light transmitting through the rear surface, degrading an effect of the transmissive rear surface.
SUMMARY OF THE INVENTION
One object of the present invention is to solve the problems described above, and to provide a solar cell module which can let in light from both front and rear surfaces. Further, the solar cell module of the present invention has an increased area where light can be incident to improve power generating efficiency.
The solar cell module of the present invention comprises a plurality of solar cell groups connected each other electrically in serial, and a plurality of means for preventing reverse voltage from being applied connected to each solar cell group electrically in parallel. The plurality of means for preventing reverse voltage from being applied are sealed between transmissive front surface member and rear surface member together with the plurality of solar cell groups.
The solar cell module of the present invention does not need a conventional terminal box which blocks light which is incident from a rear surface. As a result, light which is incident from a rear surface can contribute fully to generating electricity. Further, the present invention can provide a solar cell module which can be manufactured at a low cost, and which is one of sophisticated design.
The solar cell group comprises a plurality of solar cells electrically connected each other, and a pair of open ends in the solar cell group is arranged on the same side, the plurality of solar cell groups are arranged so that each pair of open ends of the solar cell group is positioned on the same side, and means for preventing reverse voltage from being applied is disposed in an outer periphery of a side where the open ends are arranged.
The means for preventing reverse voltage from being applied, which is connected with the solar cell group electrically in parallel can be connected between a pair of open ends arranged on the same side of the solar cell group, to shorten a length of electric wire for connecting the means for preventing reverse voltage from being applied.
The solar cell group comprises of the plurality of solar cells arranged in even-number lines, and the plurality of solar cell groups are arranged in a vertical direction.
The means for preventing reverse voltage from being applied and conductor for electrically connecting the plurality of solar cell groups each other are arranged in a straight
Morizane Masashi
Murata Kenji
Nishi Nobuyuki
Yagiura Toshio
Yasuda Takayoshi
Arent Fox Kintner & Plotkin & Kahn, PLLC
Diamond Alan
Sanyo Electric Co,. Ltd.
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