JPH09261980A - Solar battery and photovoltaic power generation system using the battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently effectively use solar light, by a method, when a solar battery module constituting a solar battery is cut off, power generation amount proportional to the area of the module can be obtained. SOLUTION: This system is provided with a solar battery module M constituted by arranging a plurality of solar battery cells C1 -C8 . The solar battery module M is connected in the following configuration of wiring; when the module is cut off, the power generation current of each of the units U1 -U4 , which is obtained when a plurality of the solar battery cells C1 -C8 contained in a cut part are combined and the units U1 -U4 are constituted, becomes equal or almost equal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell provided with a solar cell module formed by assembling a large number of solar cells, and a solar power generation system using the solar cell.

[0002]

2. Description of the Related Art As shown in FIG.
When installing the solar cell module on the roof of a house, the solar cell module M ′ as shown in FIGS. 8 and 9 is manufactured in advance in consideration of durability, workability at the time of installation, and the like. A plurality of M'is arranged vertically and horizontally on the roof R, and the modules M'are connected in parallel or in series to form a solar cell array so that a required power generation output can be obtained.

Then, the above-mentioned solar cell module M '
Includes a large number (four in this example) of solar cells C _{1 to} C ₄ sequentially arranged in parallel, and each of the solar cells C _{1 to} C _{4 is} arranged.
Are electrically connected in series and integrated with a glass or plastic sealing material G.

[0004]

The conventional solar cell module M'has an overall shape of, for example, 100 cm-
A square with 120 cm square, or (100 cm to 120 c
A rectangular shape of (m) × (30 cm to 40 cm) is used. Therefore, for example, when a large number of solar cell modules M ′ are installed on the roof R of the house as shown in FIG. 7, the installation place is limited.

That is, the corner portion of the roof R of the house (see FIG.
If the solar cell module M ′ is installed at a position (indicated by a diagonal line), the solar cell module M ′ will protrude from the roof R, which is unfavorable in appearance and unstable in strength. When the installation range of the solar cell module M ′ is limited in this way, sunlight cannot be effectively used, and a desired generated power cannot be obtained.

In order to remedy this inconvenience, this solar cell module M'is obliquely cut, for example, as shown in FIG. 10, and the solar cell module M'c after cutting is indicated by the shaded area in FIG. It may be possible to install it in.

However, when the solar cell module M'shown in FIGS. 8 and 9 is simply cut obliquely, the following problems occur.

Generally, the generated current of each solar cell C ₁ -C ₄ is proportional to the cell area. Here, when the solar cell module M′c after cutting has the shape shown in FIG. 10, the cell area becomes maximum when the solar cell C is at the top.
_When the cell area is ₁ , the cell area is the smallest at the bottom solar cell C ₄ . Moreover, since the respective solar cells C _{1 to} C ₄ are connected in series, the generated current of the entire solar cell module M′c after disconnection is the lowest solar cell C having the smallest cell area. Limited by the generated current of ₄ . The generated voltage of the entire solar cell module M′c is determined by the number of solar cells C _{1 to} C ₄ in series, so there is no problem even if the cells are cut diagonally.

For example, as a result of cutting as shown in FIG. 10, the total area of the solar cell module M'c after cutting is
Assuming that the total area of the original solar cell module M'has become half, the current that can be expected to be generated from the solar cell module M'c in that case is 1 of the generated current of the original solar cell module M '. It should be / 2. However, as described above, in reality, the solar cell module M'c after cutting is
The total generated current is limited by the generated current of the bottom solar cell C ₄ with the smallest cell area. And
If the cell area of the bottom solar cell C ₄ is 1/20 of the cell area before cutting, the power generation current of the solar cell module M′c is 1/10 (= 1/20 of the expected power generation current). ÷ 1
/ 2) can only generate electricity.

Since such a decrease in the generated current leads to a decrease in the generated power of the solar cell module M'c, the power generation efficiency of the solar cell module M'c after disconnection becomes extremely poor.

The present invention has been made in order to solve the above-mentioned problems. Even when the solar cell module is cut, the amount of power generation proportional to the area of the module can be obtained so that the sunlight is sufficiently supplied. Solar cells that can be effectively used for
Another object is to provide a solar power generation system using the solar cell.

[0012]

The present invention employs the following structure to solve the above-mentioned problems.

That is, the solar cell according to the invention of claim 1 is provided with a solar cell module in which a plurality of solar cells are arranged, and the solar cell module is cut when it is cut. The units are connected in a wiring form such that the generated electric currents obtained when a plurality of solar cells included in a part are combined to form a unit are equal or substantially equal to each unit.

According to a second aspect of the present invention, in the solar cell of the first aspect, the solar cells included in each unit are connected in parallel with each other, and the units are connected in series with each other. Is configured.

According to a third aspect of the present invention, in the solar cell according to the first or second aspect, the sum of the cell areas of the solar cells included in each unit is Each solar cell is obliquely cut so as to be equal or substantially equal to each unit.

According to a fourth aspect of the present invention, in the solar cell module according to the third aspect, the same wiring form is used for each portion obtained when the solar cell module is cut diagonally. .

A solar power generation system according to a fifth aspect of the present invention includes the solar cell according to any one of the first to fourth aspects.

[0018]

1 is a plan view of a solar cell according to an embodiment of the present invention, showing a solar cell module constituting the solar cell, and FIG. 2 is a plan view showing the solar cell module of FIG. It is explanatory drawing which shows the wiring connection state of a photovoltaic cell.

The solar cell module M of this embodiment is
A large number (eight in this example) of solar cells C _{1 to} C ₈ are sequentially arranged in parallel, and the respective solar cells C _{1 to} C ₈ are integrated by a sealing material G such as glass or plastic. There is.

In the present example, each of the solar cells C _{1 to} C ₈ is a so-called amorphous solar cell formed by vapor-depositing silicon on a substrate such as glass or stainless steel in an amorphous state. solar cell C ₁ -C ₈ are connected in a state as shown in FIG.

That is, in this solar cell module M, each unit U is formed by combining a pair of solar cells indicated by the symbols C ₁ and C ₈ , C ₂ and C ₇ , C ₃ and C ₆ , and C ₄ and C _{5. 1} when the ~U _4, the solar cell C ₁ and C ₈ included in each unit U ₁ ~U _4, C ₂ and C _7, C ₃ and C _6, C ₄ and C ₅
They are connected in parallel with each other and each unit U
_{1 to} U ₄ are connected to each other in series.

With such a wiring configuration, as shown in FIG. 3, even when each of the solar cells C _{1 to} C ₈ of this solar cell module M is cut diagonally, The power generation current obtained by the solar cell module Mc has the same value for each of the units U _{1 to} U ₄ .

The reason will be described below with reference to FIG.

Now, as shown in FIG. 4, the lower left corner of the bottom solar cell C ₈ is the origin o, and the length l ₈ from this origin o.
It is assumed that the solar cell module M is cut at a predetermined inclination (angle θ) from a position distant from the position. Further, the array pitch of the respective solar cells C _{1 to} C ₈ is d. At this time,
If the cell length of the solar cell at the n-th position counting from the bottom solar cell C ₈ is ln, the cell length ln is
It is given by the following equation.

[0025] _{ln = l 8 + (8-} n) · d / tanθ (1) for each unit U ₁ ~U _4, the solar cell C ₁ included in each unit U ₁ ~U ₄ and C _8, C ₂ and C ₇ , C ₃ and C ₆ , C ₄
When the sum of the cell lengths of C ₅ and C ₅ is calculated, from the relationship of equation (1), l ₁ + l ₈ = l ₂ + l ₇ = l ₃ + l ₆ = l ₄ + l ₅ = 2 · l ₈ + 7 · d / tan θ ( 2) That is, in the equation (2), [2 · l on the last right side
₈ + 7 · d / tan θ] has a constant value, so each unit U ₁
The sum of the cell length per ~U ₄ is equal to all the units U ₁ ~U _4.

[0026] Then, because the cell area is proportional to the cell length, the cell area of each unit U ₁ ~U ₄ is all equal for each unit U ₁ ~U _4. Moreover, as shown in FIG. 2, the solar cells C ₁ and C ₈ , C ₂ and C ₇ , C ₃ and C ₆ , and C ₄ and C ₅ included in each unit U _{1 to} U ₄ are parallel to each other. Since the cells are connected and the power generation current of each cell is proportional to the cell area as described above, the power generation current obtained by the solar cell module Mc after disconnection is eventually different for each unit U _{1 to} U ₄ . It becomes the same value.

Further, since the units U _{1 to} U ₄ are connected in series with each other, the power generation currents of the units U _{1 to} U ₄ are summed up. As a result, the solar cell module Mc after the disconnection has a conventional structure. Smallest area solar cell like
The power generation amount according to the solar cell module Mc can be obtained without being limited to the power generation current (here, C ₈ ).

The solar cell module M shown in FIG.
Is intended to be cut into a shape as shown in FIG. 3 in order to install it in a corner portion of a roof R of a house as shown in FIG. 7 (a place shown by diagonal lines in FIG. 7). Therefore, the solar cell module M ′ having the conventional configuration shown in FIG. 8 and FIG. 9 can be used as it is for those that are to be installed on the roof without cutting. Also,
If the wiring form shown in FIG. 3 is also provided in the right side portion of FIG. 1, both of the divided solar cell modules Mc and Mc can be used together when the solar cell module M is cut. , You can eliminate waste.

[0029] In the above embodiments, the solar battery module M is eight amorphous solar cell C ₁ -C ₈
However, the number of cells may be smaller or larger than that in this example.
The present invention is also applicable to a solar cell module having a thin film polycrystalline solar cell or a single crystal solar cell, instead of the amorphous solar cell as in this embodiment. Especially for single crystal solar cells,
Since the size of the cell that can be manufactured is limited, in this case, as shown in FIG. 5, each solar cell C ₁₁ ,
If C ₁₂ , ... Are connected in series for each horizontal row in advance and the wiring form shown in FIG. 2 is adopted, the same measure can be taken.

Further, in the above embodiment, only the case where the solar cell module M is cut along one side to form the solar cell module Mc having the shape shown in FIG. 3 has been described, but the solar cell module M is cut along multiple sides. Even in this case, the wiring configuration may be such that the generated current obtained when a plurality of solar cells included in the remaining portion are combined into a unit is the same for each unit.

For example, when cutting over two sides, the total cell area of the solar cells included in each unit is the same for each unit, and the solar cells included in each unit are connected in parallel with each other. In addition, the units may be connected in series with each other.

Next, a solar cell module Mc cut into a shape as shown in FIG. 3 and a conventional solar cell module M'shown in FIGS. 8 and 9 are used in combination, for example, as shown in FIG. FIG. 6 shows an example in which a solar cell B is installed on the roof R of the house as shown in FIG.

In this solar power generation system, a solar battery B is connected to a load L via an inverter I along with a commercial power system D.
When the power from the solar cell B is insufficient for the load L of the so-called system interconnection system connected to the power system D, the shortage is supplied from the power system D, When surplus power is generated in the solar cell B, it can be sent to the power system D side.

Even in this case, by using the cut solar cell module Mc, the entire roof R is covered and the solar cell B is covered.
Since it can be installed, it becomes possible to use sunlight more effectively than before.

Further, the cut solar cell module Mc
If they are connected in parallel, the area is almost the same as that of the conventional solar cell module M'and the generated current is almost the same.
A series connection with the conventional solar cell module M ′ is also possible.

[0036]

According to the present invention, the following effects can be obtained.

(1) According to the invention described in claims 1 to 3, even when the solar cell module is cut, the amount of power generation can be obtained in proportion to the area of the module. It is possible to obtain a solar cell that makes full use of sunlight, such as effective power generation.

In particular, in the case of an amorphous solar battery cell, the size of the cell is less restricted than that of a single crystal solar battery cell, so that it is possible to generate power even when the solar battery module is cut, which is a great effect. can get.

(2) According to the invention described in claim 4, when the solar cell module is cut obliquely and divided, each of the divided solar cell modules can be utilized, so that waste is eliminated. be able to.

(3) According to the invention described in claim 5, it is possible to obtain a solar power generation system having the above effects.

[Brief description of drawings]

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

FIG. 2 is an explanatory diagram showing a wiring connection state of each solar battery cell that constitutes the solar battery module of FIG.

FIG. 3 is a plan view showing a state in which the solar cell module of FIG. 1 is obliquely cut.

FIG. 4 is a diagram showing the relationship between the distance along the arrangement direction of each solar battery cell and the cell length of each solar battery cell.

FIG. 5 is a plan view of a solar cell module showing another embodiment of the present invention.

FIG. 6 is a configuration diagram of a photovoltaic power generation system using the solar cell of the present invention.

FIG. 7 is an explanatory diagram showing a state in which a large number of solar cell modules are arranged on a roof of a house.

FIG. 8 is a plan view schematically showing a solar cell module that constitutes a conventional solar cell.

FIG. 9 is a side view schematically showing a conventional solar cell module.

10 is a plan view showing a state in which the conventional solar cell module shown in FIG. 8 is obliquely cut.

[Explanation of symbols]

B ... solar cells, M, Mc ... solar cell module, C ₁ ~C
₈ ... solar cell, U ₁ ~U ₄ ... units, G ... sealing material,
I ... Inverter, L ... Load, D ... Electric power system.

Claims (5)

[Claims] 1. A solar battery module comprising a plurality of solar battery cells arranged, and when the solar battery module is cut, the solar battery module includes a plurality of solar battery cells included in the cut part. A solar cell, wherein the solar cells are connected in a wiring form such that the generated currents obtained when combined into a unit are equal or substantially equal to each other. 2. The solar cell according to claim 1, wherein the solar cells included in each unit are connected in parallel with each other, and the respective units are connected in series with each other. Solar cells to do. 3. The solar cell according to claim 1 or 2, wherein the sum of the cell areas of the solar cells included in each unit of the solar cell module is equal or substantially equal to each unit. The solar cell is characterized in that each solar cell is cut diagonally across. 4. The solar cell according to claim 3, wherein the solar cell module has the same wiring pattern for each portion obtained when the solar cell module is cut diagonally. 5. A solar power generation system comprising the solar cell according to claim 1.