JP2006080568A - Solar power generation equipment and method of installing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the cost of a solar power generation equipment without decreasing an amount of insolation. <P>SOLUTION: A double-sided acceptance type solar battery is connected a plurality of double-sided acceptance solar cells in series through lead wires, in which an n<SP>+</SP>layer in which phosphorous diffusion is performed is formed in a surface of a p type silicon substrate, p<SP>+</SP>layer in which boron diffusion is performed is formed in a reverse side, a passivation oxide film and an antireflection film are formed on diffusion layers of both sides, and an emitter electrode is formed in the n<SP>+</SP>layer and a collector electrode is formed in the p<SP>+</SP>layer. An acceptance side of the double-sided acceptance type solar battery is installed in a direction displaced from north and south, while turned perpendicular to installation side. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a photovoltaic power generation apparatus and an installation method thereof.

  A conventional general solar power generation device is a solar cell array in which a plurality of solar cell modules in which a plurality of single-sided light-receiving solar cells are arranged are provided. In the case of the non-tracking type, the solar cell array faces the zenith angle at the time of spring equinox and autumn equinox, taking into account the latitude of the installation location so that the solar cell light receiving surface faces south and receives the maximum amount of solar radiation for the year. Install at an inclined angle. Moreover, in buildings, such as a building, a solar cell module is installed in the wall surface of a building.

  In [Patent Document 1], a plate-like solar generator 7 of a solar cell facility is vertically installed, and the solar generator 7 installed at the upper end of the wall has a photosensitive thickness of 0.1 mm on both sides. The solar cell 13 (for example, a MIS solar cell whose both surfaces are photosensitive) is used and installed on two supporting glass plates 14 whose edges are reinforced by a frame 15.

Japanese National Patent Publication No. 10-50712

  The conventional solar cell array is installed on a solar cell module installation base where the light receiving surface of the solar cell is facing south, as described above, with a zenith angle inclination at the time of equinox / autumn, or on a base mounted on the south roof of a house. Installed. Therefore, the solar cell module needs a large installation area on a plane parallel to the ground surface.

  Since the conventional solar cell array is constructed and installed as described above, it is designed to withstand a prescribed wind pressure, and is a rigid structure, which increases the construction cost accordingly.

  In a conventional pedestal installation type solar cell array, snowfall occurs on the light receiving surface of the solar cell module during snowfall, and power generation becomes impossible. In addition, it is necessary to design a solar cell module installation height that allows for the amount of snowfall in the year and a solar cell module and a stand that can withstand the weight of snowfall, which increases construction costs.

  In a conventional solar cell array, the amount of solar radiation received by the light receiving surface has a cosine-like distribution with a peak at noon or in the vicinity thereof. That is, power generation is not performed at a power generation output equal to or lower than a low level threshold (generally 5% of the maximum output) of the solar power generation apparatus. Therefore, early morning and evening power generation cannot be expected. Furthermore, since the operation is performed at a low output point relative to the rated value of the power conditioner, the conversion loss is large.

  In the prior art, as described above, the solar radiation array is installed facing south, but the average amount of solar radiation received by the solar cell array throughout the year has a distribution having a peak near noon. Therefore, since the electrical equipment such as a power conditioner and a power cable attached to the solar cell array is designed with the output of the solar cell array at the time of receiving the peak irradiation amount as a design condition, the construction cost is expensive.

  In addition, the conventional technique described in [Patent Document 1] only describes that both sides use photosensitive MIS (abbreviation of metal insulated) solar cells, and both exposure surfaces have the same efficiency. Is assumed to have an annual gain of 106% as the sum of both contributions, and in fact, the efficiency of the back side is usually considerably worse. In addition, if the efficiency of the back surface is poor, the power generation output due to the amount of solar radiation on the light receiving surface does not become flat, and thus there is a problem that the average operating point of the power conditioner cannot be increased.

  The present invention has been made in consideration of the above-described problems, and provides a solar power generation apparatus and a method for installing the solar power generation apparatus that can reduce the cost while ensuring the amount of solar radiation.

  The solar power generation device according to the present invention includes a double-sided light receiving solar cell. One and the other light receiving surfaces of the double-sided light-receiving solar cell are substantially perpendicular to the installation surface of the solar power generation device. In this solar power generation device, since the light receiving surface of the solar cell is substantially perpendicular to the installation surface, the installation area of the device can be reduced. On the other hand, although the solar radiation amount per one side of the solar cell is reduced, since the double-sided light receiving solar cell in which power generation operation is performed on both light receiving surfaces is used, the effective solar radiation amount as a whole solar power generation device can be secured. Therefore, it is possible to reduce the cost of the solar power generation apparatus or the solar power generation equipment including the present apparatus while securing the amount of solar radiation. In addition, the light receiving surface is perpendicular means that a direction along the plane of the light receiving surface or a direction parallel to the direction is perpendicular to the installation surface.

  In another solar power generation device according to the present invention, the direction of one and the other light receiving surface of the double-sided light receiving solar cell is displaced from the north-south direction. For this reason, the magnitude | size of the peak value of the solar radiation amount in a light-receiving surface reduces rather than the case where a light-receiving surface faces south. Therefore, since the design conditions such as current and voltage of the incidental electrical facilities are relaxed, the cost of the entire solar power generation facility including the solar power generation device is reduced. On the other hand, although the peak value of the amount of solar radiation is reduced, since the double-sided light-receiving solar cell is used, the effective solar radiation amount as the whole solar power generation device can be secured. The direction of the light receiving surface means a direction perpendicular to the plane of the light receiving surface, a direction of a virtual normal on the light receiving surface, or a direction parallel to these directions.

  In yet another photovoltaic power generation apparatus according to the present invention, the time at which the amount of solar radiation on one and the other light receiving surfaces of the double-sided light receiving solar cell reaches a peak value in one day is different from each other. Thereby, since the magnitude | size of the peak value of the solar radiation amount which match | combined both light-receiving surfaces of a double-sided light reception type solar cell reduces, the cost of the whole photovoltaic power generation equipment provided with a photovoltaic power generation device reduces. On the other hand, although the peak value of the amount of solar radiation is reduced, since the double-sided light-receiving solar cell is used, the effective solar radiation amount as the whole solar power generation device can be secured.

  In addition, in each said solar power generation device, it is preferable that the direction of the light-receiving surface of a double-sided light reception type solar cell is a substantial east-west direction. Thereby, the peak value of the solar radiation amount is reduced and the solar radiation amount is flattened. Furthermore, the effective solar radiation amount at least equivalent to the past can be ensured. Therefore, even in the case of vertical installation, the effective solar radiation amount is not impaired.

  In addition, the method for installing the solar power generation device as described above includes, as a first step, a double-sided light-receiving solar cell or a double-sided light-receiving solar cell module, a double-sided light-receiving solar cell or a double-sided light-receiving solar cell module. A structure or a support to be attached is prepared, and as a second step, one and the other light receiving surfaces of the double-sided light receiving solar cell or the double-sided light receiving solar cell module are substantially perpendicular to the installation surface of the photovoltaic power generation device. Install to be. As a 2nd step, you may install so that a light-receiving surface may become the direction displaced from the north-south direction so that it may become substantially perpendicular | vertical with respect to the installation surface of a solar power generation device.

  According to the present invention, the effective power generation time can be extended from early morning to evening without impairing the amount of solar radiation, and the peak value of the generated electrical output can be reduced, so that the rated value of electrical equipment such as a power conditioner can be designed low, The cost of the photovoltaic device can be reduced.

Examples of the present invention will be described below. FIG. 1 shows a typical cell structure of a double-sided light receiving solar cell applied to the present invention. In this cell, an n ⁺ layer 2 subjected to phosphorus diffusion is formed on the surface of a p-type silicon substrate 1, and a p ⁺ layer 3 subjected to boron diffusion is formed on the back side, and the diffusion layers on both sides are formed. A passivation oxide film 4 and an antireflection film 5 are formed. An emitter electrode 6 and a collector electrode 7 are formed on the n ⁺ layer 2 and the p ⁺ layer 3, respectively. In this cell, an electrical output can be obtained by both irradiation light from the front surface and irradiation light from the back surface.

  FIG. 2 shows a configuration example of a double-sided light receiving solar cell module to which the double-sided light receiving cell is applied. The double-sided light receiving solar cells 8 are arranged vertically and horizontally and connected in series with lead wires 9 as shown in the figure. This connected cell group is sealed with a sealing material 11 in two transparent protective materials 10 as shown in a cross-sectional view. The double-sided light receiving solar cell module 13 is obtained by attaching a frame 12 and a terminal box to this assembly.

  3, 4 and 5 are diagrams showing examples of solar cell arrays to which the present invention is applied. FIG. 3 shows an example of an array in which a plurality of double-sided light receiving modules 13 are installed on one columnar structure (pole). This array will be described below. The columnar structure 14 is built on a foundation 15 built on the ground. A horizontal support structure 16 is connected to the columnar structure 14 by a fixed hardware 17. The horizontal support structure 16 extends horizontally on both sides of the columnar structure 14 along the direction parallel to the installation surface with the columnar structure 14 as the center. The double-sided light receiving solar cell module 13 is fixed to the upper joint 18 while being suspended from the horizontal support structure, and the lower portion of the module 13 is fixed to the lower joint. In this way, a plurality of solar cell modules are arranged symmetrically about the columnar structure. The upper joint employs a structure that can rotate around the length direction of the horizontal support structure 16, and the lower joint 19 has a spring structure. In this case, when the double-sided light receiving solar cell module 13 receives wind pressure, the module has a flexible structure that allows rotational displacement within a specified range about the length direction of the horizontal support structure and absorbs wind pressure. Yes.

  In the prior art, the array installation base needs to have a rigid structural design in order to have design resistance against wind pressure or the like, which increases the cost. According to this embodiment, the solar cell module is a pair of horizontal Since the flexible structure can be attached to the support structure, the construction cost can be reduced.

  FIG. 4 is a diagram illustrating a case where the present invention is applied to a fence-like structure. The structure is composed of a combination of a vertical structure 20 and a cross beam 21 and is fixed on the foundation 15. The double-sided light receiving solar cell module is attached in the same manner as the columnar structure array described with reference to FIG.

  FIG. 5 is a partial modification of the method described with reference to FIG. 3, and is an example in which a small double-sided light receiving module is attached to a pole such as a utility pole. In this modification, a solar cell module is attached to one side of the columnar structure around the columnar structure 14.

  In each of the above-described embodiments, the light receiving surface of the double-sided light receiving solar cell module, that is, the light receiving surface of the double-sided light receiving solar cell is oriented in a direction perpendicular to the installation surface of the solar power generation device. For this reason, a plurality of solar cell modules can be installed in the height direction. Actually, a double-sided light-receiving solar cell module, that is, a double-sided light-receiving solar cell is arranged in the height direction of a structure such as a columnar shape or a fence shape for mounting the solar cell module as shown in each embodiment. Therefore, the installation area of the photovoltaic power generator is reduced. In addition, restrictions on the installation location are eased. When the light receiving surface of the solar cell module is made perpendicular to the installation surface, as will be described later, the peak value of the amount of solar radiation received by one or the other light receiving surface in one day is reduced. However, since a double-sided light-receiving solar cell is used, the effective solar radiation received on both light-receiving surfaces can be at least equivalent to the conventional amount. Therefore, the output power amount of the photovoltaic power generator is not impaired. Depending on the location conditions of the photovoltaic power generation device, the light receiving surface may be inclined in a direction slightly deviated from the vertical direction within a range where the installation area does not increase much compared to the vertical installation.

Further, in each of the above-described embodiments, the double-sided light-receiving solar cell module is installed with the light-receiving both sides facing in the east-west direction. FIG. 6 is an explanatory diagram comparing the received solar radiation amount of the double-sided light receiving solar cell array of the example with that of the solar cell array of the prior art. The solar radiation data shown in this figure is based on actual data at a specific point in the north Kanto. The amount of solar radiation received per year (1) of the conventional single-sided solar cell array with a slope on the south surface is a distribution having a peak at noon as shown in the figure. On the other hand, the amount of solar radiation received on the east vertical surface and the amount of solar radiation received on the west vertical surface are 9 am on the east side and 15 pm on the west side as shown by curves (2) and (3), respectively. The distribution shows a peak around the time. In the embodiment, the solar cell module to be applied is a double-sided light receiving type, and the solar radiation of (2) and (3) is received simultaneously, and the amount of received light has a distribution shown in the curve (4). . That is, the effective amount of received solar radiation in the single-sided light receiving solar cell array in the prior art is an integral value of the curve (1), and in the double-sided solar cell array in the embodiment, the integral value of the curve (4) is obtained. Are almost the same value. Further, the peak value becomes low, and a high level of solar radiation can be received on average from early morning to evening. Even if the light receiving surface does not accurately face the east-west direction, the peak value can be reduced if the light-receiving surface is displaced from the north-south direction. The light receiving surface may be slightly deviated from the east-west direction within a range that does not impair the effective solar radiation amount.

  According to each embodiment, since the solar cell module is installed vertically, snow during snowfall does not accumulate on the module, and power generation can be continued. Furthermore, in the A prior art, it is necessary to use a solar cell module and an installation stand that allow for the snow cover weight of the solar cell array, which increases the construction cost. However, according to each embodiment, no snow is generated on the array. It can be an economical facility. Furthermore, the solar cell array needs to be designed in consideration of the amount of snow in advance. In the prior art, the mount for installing the module requires that much height, and the construction cost is high. Only the height of the columnar structure is simply increased, and an economical facility design can be achieved.

  According to each embodiment, since the light-receiving surface of the double-sided light-receiving solar cell module is installed vertically in the east and west, these solar radiations can be received with high efficiency in snowy areas where the sunlight is strongly reflected on the ground or near the coast. Compared with the conventional solar cell array with a slope on the south surface, it is possible to generate a large amount of annual power generation with the same module area.

  According to each example, with a solar cell module having the same area, compared to the conventional technology, the annual total power generation amount is ensured to be equal to or higher, and the effective power generation time is expanded from early morning to evening. In addition, it is possible to provide a solar power generation facility that flattens the distribution of the daily generated electrical output. Therefore, since the peak value of the generated electrical output can be greatly reduced, the rated value of the electrical equipment such as the power conditioner can be designed to be low accordingly, and the construction cost can be reduced. Furthermore, since the daily generated electrical output has a flat distribution, the average operating point of the power conditioner becomes high, and the power conditioner can be operated with high conversion efficiency.

  Another embodiment of the present invention will be described below with reference to FIGS. FIG. 7 shows that the second solar cell module 22 is further installed on the above-described columnar structure type solar cell array with a south surface inclination, and both array outputs are connected in parallel to obtain the total electric output of both. It is what I did. FIG. 8 shows the daily time distribution of the amount of solar radiation in the year when this embodiment is applied. Curve (4) in the figure shows the total east-west vertical plane of the double-sided solar cell module described in FIG. On the other hand, the curve (5) indicates the amount of solar radiation received by the second solar cell module 20 installed at the uppermost part of the columnar structure with a slope on the south surface. It has a solar radiation distribution shape corresponding to the curve (1). Accordingly, by appropriately selecting the light receiving area of the second solar cell module 20, it is possible to obtain an amount of solar radiation that flattens the concave portion at the center of the curve (4). In other words, it is possible to provide a solar power generation system that can generate power over a long period of time from early morning to evening with a flat power generation output based on the amount of received sunlight.

It is a figure explaining the basic structure of the double-sided light reception type photovoltaic cell used with the solar power generation device by this invention. It is a figure explaining the basic structure of the double-sided light reception type solar cell module used with the solar power generation device by this invention. It is a figure explaining the Example which applied this invention to the columnar structure. It is a figure explaining the Example which applied this invention to the fence-like structure. It is a figure explaining the Example which applied this invention to the utility pole. It is a figure explaining the daily distribution of the amount of annual solar radiation which a solar cell array receives. It is a figure explaining the other Example of this invention. It is a figure explaining the daily distribution of the annual solar radiation amount which the solar cell array in the case of the Example of FIG. 7 light-receives.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... p-type silicon substrate of a double-sided light reception photovoltaic cell, 2 ... n ⁺ layer of a double-sided light reception cell, 3 ... p ⁺ layer of a double-sided light reception cell, 4 ... Passivation oxide film of a double-sided light reception cell, 5 ... Reflection of a double-sided light reception cell Prevention film, 6 ... Emitter electrode of double-sided light receiving cell, 7 ... Collector electrode of double-sided light receiving cell, 8 ... Double-sided light receiving cell, 9 ... Lead wire, 10 ... Transparent protective material, 11 ... Sealing material, 12 ... Frame,
DESCRIPTION OF SYMBOLS 13 ... Double-sided light reception type solar cell module, 14 ... Columnar structure, 15 ... Base, 16 ... Horizontal support structure, 17 ... Fixing metal fitting, 18 ... Upper joint, 19 ... Lower joint, 20 ... Vertical structure material, 21 ... Cross beam , 22 ... Installation solar cell module with a south surface inclination.

Claims (4)

An n ⁺ layer with phosphorus diffusion is formed on the surface of a p-type silicon substrate, a p ⁺ layer with boron diffusion is formed on the back side, and a passivation oxide film and an antireflection film are formed on both diffusion layers. The light-receiving surface of a double-sided solar cell in which a plurality of double-sided solar cells with an emitter electrode in the n ⁺ layer and a collector electrode in the p ⁺ layer are connected in series with lead wires is perpendicular to the installation surface. The second solar cell module formed by the light-receiving surface cells with a south surface inclination, and the array output of the double-sided light-receiving solar cell and the second sun A solar power generation device that outputs the total power by connecting the array outputs of battery modules in parallel. An n ⁺ layer with phosphorus diffusion is formed on the surface of a p-type silicon substrate, a p ⁺ layer with boron diffusion is formed on the back side, and a passivation oxide film and an antireflection film are formed on both diffusion layers. A double-sided light-receiving solar cell formed by connecting a plurality of double-sided light-receiving solar cells formed with an emitter electrode in an n ⁺ layer and a collector electrode in a p ⁺ layer in series with a lead wire, The solar power generator installed with its light receiving surface oriented in a direction perpendicular to the installation surface and with the light receiving surface displaced from the north-south direction.   The solar power generation device according to claim 2, wherein the double-sided light receiving solar cell is sealed with a sealing material in two transparent protective materials. An n ⁺ layer with phosphorus diffusion is formed on the surface of the p-type silicon substrate by the upper joint and lower joint, which are horizontal support structures connected to the columnar structure provided in the vertical direction, and boron is formed on the back side. Forming a diffused p ⁺ layer, forming a passivation oxide film and an antireflection film on the diffused layers on both sides, and forming multiple emitters on the n ⁺ layer and a collector electrode on the p ⁺ layer A solar power generation apparatus installation method in which a double-sided light-receiving solar cell in which solar cells are connected in series with lead wires is fixed, and a light-receiving surface of the double-sided light-receiving solar cell is installed in a direction displaced from the north-south direction.

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