JP2013229359A - Solar battery panel, solar battery module and photovoltaic power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar battery module capable of suppressing output reduction.SOLUTION: In a solar battery module 2, a plurality of solar battery cells 20 are formed of an n-type silicon substrate 21, and a first solar battery cell (for example, solar battery cell 20b) and a second solar battery cell (for example, solar battery cell 20a) having a higher potential than the first solar battery cell are included. Between the first solar battery cell and the second solar battery cell, and between the second solar battery cell and a holding member 11, a high potential electrode 31c is provided which has a higher potential than the n-type silicon substrate 21 of the second solar battery cell.

Description

  The present invention relates to a solar battery panel, a solar battery module, and a solar power generation system, and more particularly to a solar battery panel, a solar battery module, and a solar power generation system including a plurality of solar battery cells.

  In recent years, solar cell modules including so-called back electrode type solar cells in which an n electrode and a p electrode are formed on the back surface side of a silicon substrate have been developed. For example, a conventional solar cell module 1001 includes a solar cell panel 1002 and a conductive holding member 1003 that holds an edge of the solar cell panel 1002, as shown in FIG.

  The solar battery panel 1002 includes a plurality of back electrode solar cells 1010 (hereinafter simply referred to as solar cells 1010), a wiring substrate 1020 that electrically connects adjacent solar cells 1010, and solar cells 1010. And a sealing material 1031 that covers the wiring substrate 1020, a translucent substrate 1032 that sandwiches the solar cell 1010, the wiring substrate 1020, and the sealing material 1031 in the vertical direction, and a back surface protection sheet 1033. As shown in FIG. 10, the solar cell 1010 includes an n-type silicon substrate (semiconductor substrate) 1011 provided with an n-type current collecting layer 1011a and a p-type current collecting layer 1011b on the back surface side, and an upper surface ( A passivation film 1012 provided on the (light receiving surface) side, and an n electrode 1013 and a p-type current collection layer 1011b provided on the back side of the silicon substrate 1011 and electrically connected to the n-type current collection layer 1011a. Connected p-electrode 1014.

  When the solar cell module 1001 is irradiated with sunlight, electron-hole pairs are generated in the silicon substrate 1011, and the electrons and holes are attracted to the n-type current collection layer 1011 a and the p-type current collection layer 1011 b, respectively. Thereby, a predetermined output (electric power) is taken out. In this solar cell 1010, since no electrode is formed on the light receiving surface side of the silicon substrate 1011, there is no shadow loss due to the electrode (loss of light due to the shadow of the electrode).

  In addition, the solar cell module provided with the solar cell panel containing a several photovoltaic cell and the holding member holding the edge part of a solar cell panel is disclosed by patent document 1, for example.

JP 2010-16074 A

  However, the present inventor has a problem that when the solar cell module 1001 is irradiated with sunlight to generate power, the output of the solar cell module 1001 may be reduced (power generation efficiency may be reduced). I found. Specifically, as a result of various studies on the solar cell module 1001, the present inventor has found that the potential of the power generation circuit in the solar cell module 1001 and the surroundings (adjacent solar cell 1010b (see FIG. 11), holding member 1003, etc.) It has been found that the output is more likely to decrease as the potential difference between the first and second potentials is larger, and that the output is likely to decrease when a water film is formed on the light-receiving surface of the solar cell module 1001 due to rain or the like. .

  From these results, the inventor estimated that the output of the solar cell module 1001 is reduced by the following mechanism.

  First, the potential of the solar battery cell 1010a (see FIG. 11) is the surrounding (adjacent solar battery cell 1010b (see FIG. 11), holding member 1003, rainwater 1040 collected on the solar battery panel 1002 (see FIG. 11). 11), the electric field E in the direction shown in FIG. 11 is generated on the light receiving surface side of the solar battery cell 1010a due to the potential difference. Note that the potential of the rainwater 1040 accumulated on the solar cell panel 1002 is equal to the potential of the holding member 1003. Then, as shown in FIG. 12, electrons contained in the sealing material 1031 are collected on the passivation film 1012 by the electric field E.

  Secondly, holes should be collected in the direction of the light receiving surface of the silicon substrate 1011, that is, the side where the passivation film 1012 is formed, so as to form a pair with the electrons collected on the light receiving surface of the passivation film 1012. Force is generated.

  Thirdly, when the pn junction of the solar battery cell 1010 is irradiated with light, an electron / hole pair is generated. Then, due to the force to collect the holes, the probability that the generated holes are directed toward the passivation film 1012 is increased, and the generated holes are generated in the p-type current collecting layer 1011b provided on the back surface of the silicon substrate 1011. The rate of arrival decreases. When the silicon substrate 1011 is n-type, holes become minority carriers, so that the rate at which the generated holes reach the p-type current collecting layer 1011b decreases that the output current of the solar battery cell 1010 decreases. It is. That is, the output of the solar cell module 1001 decreases (power generation efficiency decreases).

  This invention is made | formed in order to solve said subject, The objective of this invention is providing the solar cell panel which can suppress an output fall, a solar cell module, and a solar power generation system. is there.

  In order to achieve the above object, a solar panel of the present invention includes a plurality of solar cells, a translucent substrate disposed on the light receiving surface side of the solar cells, and the solar cells and the translucent substrate. A plurality of solar cells including a first solar cell and a second solar cell having a potential higher than that of the first solar cell; When the battery cell is formed of an n-type semiconductor substrate, at least one between the first solar cell and the second solar cell and between the second solar cell and the end face of the translucent substrate. Is provided with a high potential electrode having a higher potential than the n-type semiconductor substrate of the second solar cell, and when the solar cell is formed of a p-type semiconductor substrate, Between the two solar cells and with the first solar cell At least one of between the end surface of the optical substrate, the low potential electrode is provided with a lower potential than the p-type semiconductor substrate of the first solar cell.

  In the present specification and claims, a light-transmitting substrate refers to a substrate that is transparent to sunlight (having light-transmitting properties).

  In the solar cell panel of the present invention, as described above, the plurality of solar cells include the first solar cell and the second solar cell having a higher potential than the potential of the first solar cell. And when the photovoltaic cell is formed of an n-type semiconductor substrate, between the first photovoltaic cell and the second photovoltaic cell, and between the second photovoltaic cell and the end face of the translucent substrate. At least one of these is provided with a high potential electrode having a higher potential than the n-type semiconductor substrate of the second solar battery cell. Thereby, the electric potential of a 1st photovoltaic cell and the electric potential of a 2nd photovoltaic cell become lower than the electric potential of a high potential electrode. For this reason, it can suppress that the electrons in a sealing material gather on the passivation film side. That is, the density of electrons on the passivation film side in the sealing material can be reduced. Thereby, the force which is going to collect the hole which generate | occur | produced in the semiconductor substrate to the passivation film side can be suppressed. As a result, it is possible to suppress a decrease in the output of the solar cell module (a decrease in power generation efficiency).

  Or when the photovoltaic cell is formed of the p-type semiconductor substrate, between the 1st photovoltaic cell and the 2nd photovoltaic cell, and between the 1st photovoltaic cell and the end surface of a translucent board | substrate. At least one of these is provided with a low potential electrode having a lower potential than the p-type semiconductor substrate of the first solar cell. Thereby, the electric potential of a 1st photovoltaic cell and the electric potential of a 2nd photovoltaic cell become higher than the electric potential of a low potential electrode. For this reason, it can suppress that the hole in a sealing material collects on the passivation film side. That is, the density of holes on the passivation film side in the sealing material can be reduced. As a result, it is possible to suppress the force of collecting electrons generated in the semiconductor substrate to the passivation film side. As a result, it is possible to suppress a decrease in the output of the solar cell module (a decrease in power generation efficiency).

  In the solar battery panel, preferably, the solar battery cell is formed of an n-type semiconductor substrate, and is between the first solar battery cell and the second solar battery cell, and the second solar battery cell and the light transmitting material. A high-potential electrode having a higher potential than the n-type semiconductor substrate of the second solar battery cell is provided on at least one of the end surfaces of the substrate.

  In the solar battery panel in which the solar battery cell is formed of an n-type semiconductor substrate, preferably, the solar battery cell includes a wiring board for electrically connecting a plurality of solar battery cells, and the high potential electrode is formed on the wiring board. . If comprised in this way, a high potential electrode can be formed easily.

  In the solar battery panel in which the solar battery cell is formed of an n-type semiconductor substrate, the plurality of solar battery cells are preferably a third solar battery cell having the highest potential among the solar battery panels, and a solar battery. The fourth solar cell having the lowest potential in the panel, and the high potential electrode has a higher potential than the n-type semiconductor substrate of the third solar cell. If comprised in this way, the electric potential of all the photovoltaic cells contained in a solar cell panel will become lower than the electric potential of a high potential electrode. Further, the potential difference between the solar battery cell and the high potential electrode can be increased. As a result, it is possible to effectively suppress a decrease in the output of the solar cell panel (a decrease in power generation efficiency).

  In the solar cell panel in which the solar cell is formed of an n-type semiconductor substrate, preferably, the plurality of solar cells constitute a plurality of cell rows in which adjacent solar cells are connected in series with each other, and have a high potential. The electrodes are provided so as to extend along the cell rows between adjacent cell rows and at least one between the cell rows and the end face of the translucent substrate. With this configuration, the high potential electrode can be provided without intersecting the cell row, and therefore the wiring of the high potential electrode is facilitated.

  The solar cell module of this invention is equipped with the solar cell panel of said structure, and the holding member holding the edge part of a solar cell panel. If comprised in this way, the solar cell module which can suppress an output fall can be obtained. Moreover, the intensity | strength of a solar cell module can be improved by providing the holding member which hold | maintains the edge part of a solar cell panel.

  The solar power generation system of this invention is equipped with the said photovoltaic cell or the said photovoltaic module. If comprised in this way, the solar energy power generation system which can suppress an output fall can be obtained.

  In the solar power generation system, preferably, a plurality of solar battery panels or solar battery modules are provided, and the plurality of solar battery cells are the fifth solar battery cell having the highest potential in the solar power generation system, and sunlight. The sixth solar cell having the lowest potential in the power generation system, the solar cell is formed of an n-type semiconductor substrate, and the high-potential electrode is formed from the n-type semiconductor substrate of the fifth solar cell. Also has a high potential. If comprised in this way, the electric potential of all the photovoltaic cells contained in a photovoltaic power generation system will become lower than the electric potential of a high potential electrode. Further, the potential difference between the solar battery cell and the high potential electrode can be further increased. As a result, it is possible to effectively suppress a decrease in the output of the solar power generation system (a decrease in power generation efficiency).

  As described above, according to the present invention, it is possible to easily obtain a solar cell panel, a solar cell module, and a solar power generation system that can suppress a decrease in output.

It is the figure which showed roughly the structure of the solar energy power generation system by one Embodiment of this invention. It is the top view which showed the structure of the solar cell module of one Embodiment of this invention shown in FIG. It is the rear view which showed the structure of the solar cell module of one Embodiment of this invention shown in FIG. It is sectional drawing which showed the structure of the solar cell module of one Embodiment of this invention shown in FIG. It is sectional drawing which showed the structure of the back surface electrode type solar cell of the solar cell module of one Embodiment of this invention shown in FIG. It is sectional drawing which showed the electric field which generate | occur | produces in the solar cell module of one Embodiment of this invention shown in FIG. It is sectional drawing which showed the motion of the electron and the hole which generate | occur | produced in the back electrode type photovoltaic cell of the solar cell module of one Embodiment of this invention shown in FIG. It is the top view which showed the structure of the solar cell module by the modification of this invention. It is sectional drawing which showed the structure of the solar cell module by an example of the past. It is sectional drawing which showed the structure of the back electrode type photovoltaic cell of the conventional solar cell module shown in FIG. It is sectional drawing which showed the electric field which generate | occur | produces in the conventional solar cell module shown in FIG. It is sectional drawing which showed the motion of the electron and the hole which generate | occur | produced in the back electrode type photovoltaic cell of the conventional solar cell module shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In order to facilitate understanding, even a cross-sectional view may not be hatched.

  With reference to FIGS. 1-7, the structure of the solar power generation system 1 by one Embodiment of this invention is demonstrated. As shown in FIG. 1, the solar power generation system 1 includes a plurality of solar cell modules 2, a power conditioner 3, and cables 4 a and 4 b that electrically connect them.

  As shown in FIGS. 2 and 3, the solar cell module 2 is disposed on the solar cell panel 10, the conductive holding member 11 that holds the edge of the solar cell panel 10, and the back side of the solar cell panel 10. Terminal box 12.

  As shown in FIG. 4, the solar cell panel 10 includes a plurality of back electrode type solar cells 20 (hereinafter simply referred to as solar cells 20), and a wiring substrate 31 that electrically connects the plurality of solar cells 20. The sealing material 32 that covers the light-receiving surface side and the back surface side of the solar battery cell 20, the translucent substrate 33 and the back surface protection sheet 34 that sandwich the solar battery cell 20, the wiring substrate 31, and the sealing material 32 in the vertical direction. Contains.

  As shown in FIG. 5, the solar cell 20 includes a silicon substrate 21 (semiconductor substrate), an insulating passivation film 22 made of a silicon nitride film formed on the upper surface (light-receiving surface) of the silicon substrate 21, and a passivation film. An insulating antireflection film (not shown) made of a silicon nitride film formed on 22, an insulating film 23 provided on the back surface of the silicon substrate 21, and through the through hole of the insulating film 23, A protruding n electrode 24 and p electrode 25 are included. An n-type silicon substrate was used as the silicon substrate 21.

A texture structure (uneven structure) is formed on the upper surface of the silicon substrate 21. The silicon substrate 21 includes an n-type region 21a, an n ⁺ -type layer 21b (n-type diffusion region) provided on the light receiving surface side of the silicon substrate 21 and having an n-type impurity at a concentration higher than that of the n-type region 21a. An n-type current collecting layer 21c having n-type impurities at a higher concentration than the n-type region 21a is provided on the back side of the silicon substrate 21, and a p-type impurity having p-type impurities provided on the back side of the silicon substrate 21. 21 d of type | mold current collection layers. When solar cell 20 is irradiated with sunlight, electron-hole pairs are generated, electrons are attracted to n-type current collecting layer 21c, and holes are attracted to p-type current collecting layer 21d.

  The n-type current collection layer 21c and the p-type current collection layer 21d are in ohmic contact with the n-electrode 24 and the p-electrode 25, respectively. The n electrode 24 and the p electrode 25 are mounted on a wiring layer 31b (see FIG. 4) described later of the wiring substrate 31 via a solder layer or the like (not shown). And the n electrode 24 and the p electrode 25 of the adjacent photovoltaic cell 20 are electrically connected by the wiring layer 31b of the wiring board 31, and the several photovoltaic cell 20 is connected in series.

  The passivation film 22 preferably has a higher refractive index than the antireflection film (not shown). The passivation film 22 may be formed of a silicon compound film such as a silicon oxide film or a silicon carbide film instead of the silicon nitride film. The passivation film 22 may be formed of a dielectric film having a passivation effect that suppresses surface recombination of carriers (electrons and holes). The antireflection film (not shown) can be formed of various oxide films such as a silicon oxide film and a titanium oxide film instead of the silicon nitride film. Further, the antireflection film (not shown) can be formed of another film having an antireflection effect in combination with the passivation film 22.

  As shown in FIG. 2, the plurality of solar battery cells 20 constitutes a plurality of (for example, four) cell rows L. In each cell row L, adjacent solar cells 20 are connected to each other in series by a wiring layer 31b described later of the wiring board 31. A plurality of (for example, four) cell rows L are connected to each other in series by the wiring layer 31 b of the wiring substrate 31. When the solar cell 20 operates, a potential difference is generated between the n electrode 24 and the p electrode 25 of the solar cell 20. The potential of the n-type silicon substrate 21 is substantially equal to the potential of the n electrode 24. In other words, when the solar cells 20 are connected in series, a potential difference is generated between the n-type silicon substrates 21 of the solar cells 20. For this reason, when attention is paid to the solar cells 20a to 20d shown in FIG. 2, for example, the solar cells 20a, 20b, 20c, and 20d have higher potentials in this order. In each solar battery module 2, the p-electrode 25 of the solar battery cell 20a has the highest potential, and the n-type silicon substrate 21 of the solar battery cell 20d has the lowest potential.

  In the relationship between the solar battery cell 20a and the solar battery cell 20b, the solar battery cell 20a corresponds to the “second solar battery cell” of the present invention, and the solar battery cell 20b corresponds to the “first solar battery cell” of the present invention. Corresponding to Moreover, in the relationship between the solar battery cell 20b and the solar battery cell 20c, the solar battery cell 20b corresponds to the “second solar battery cell” of the present invention, and the solar battery cell 20c is the “first solar battery cell” of the present invention. Corresponding to Moreover, in the relationship between the solar battery cell 20c and the solar battery cell 20d, the solar battery cell 20c corresponds to the “second solar battery cell” of the present invention, and the solar battery cell 20d is the “first solar battery cell” of the present invention. Corresponding to The solar battery cell 20a corresponds to the “third solar battery cell” of the present invention, and the solar battery cell 20d corresponds to the “fourth solar battery cell” of the present invention.

  As shown in FIG. 4, the wiring substrate 31 is formed on the insulating base 31a, the main surface of the base 31a, the wiring layer 31b for electrically connecting the solar cells 20 to each other, and the main surface of the base 31a. High potential electrode 31c. The wiring layer 31b and the high potential electrode 31c may be formed by etching the same conductive layer provided on the main surface of the base 31a.

  As shown in FIG. 2, a plurality of high potential electrodes 31 c are provided, and extend along the cell rows L between the adjacent cell rows L and between the cell rows L and the holding member 11. It is provided as follows. That is, the high potential electrode 31 c is provided between the solar cells 20 and between the solar cells 20 and the holding member 11. In FIG. 2, the high potential electrode 31 c is indicated by a bold line so that the wiring layer 31 b and the high potential electrode 31 c can be easily distinguished. In this embodiment, since the solar cell module 2 having the holding member 11 is described, the case where the high potential electrode 31c is provided between the cell row L and the holding member 11 is described. In the case of the solar cell module 2 that does not have the holding member 11, the high potential electrode 31 c may be provided between the cell row L and the end face of the translucent substrate 33. Here, the end surface of the translucent substrate 33 refers to a surface that is substantially on the extension line of the surface perpendicular to the light receiving surface of the translucent substrate 33, and the end surface of the sealing material 32 and the end surface of the back surface protection sheet 34 are also included. included.

  The wiring layer 31b is electrically connected to the plus terminal 12a and the minus terminal 12b (see FIG. 3) of the terminal box 12 through a through hole or a wiring (not shown). The p electrode 25 of the solar cell 20a having the highest potential in the solar cell module 2 is connected to the plus terminal 12a of the terminal box 12, and the n electrode 24 of the solar cell 20d having the lowest potential is the terminal box. 12 negative terminals 12b. The high potential electrode 31c is electrically connected to a plurality of high potential terminals 12c (see FIG. 3) of the terminal box 12 through through holes or wirings not shown. The plurality of high potential terminals 12c are electrically connected to each other. For this reason, the potentials of all the high potential electrodes 31c are substantially equal. The potential of the high potential electrode 31 c is substantially equal to the potential of the p electrode 25 of the solar battery cell 20 a having the highest potential in the solar battery module 2. More specifically, the potential of the high-potential electrode 31c is slightly lower than the potential of the p-electrode 25 of the solar battery cell 20a due to the resistance of the wiring layer 31b, but the n-type silicon substrate 21 of the solar battery cell 20a. The potential is higher than the potential of. A cable 4a is connected to the plus terminal 12a and the minus terminal 12b of the terminal box 12, and a cable 4b is connected to the high potential terminal 12c as necessary. Connectors are provided at the ends of the cables 4a and 4b as necessary.

  As shown in FIG. 4, the sealing material 32 is formed using an insulating resin (ethylene vinyl acetate resin or the like) that is transparent to sunlight. The sealing material 32 is disposed between the solar cell 20 and the translucent substrate 33 and between the wiring substrate 31 and the translucent substrate 33, and the solar cell 20 and the translucent substrate 33. And the wiring substrate 31 and the translucent substrate 33 are bonded. Further, the sealing material 32 is disposed between the wiring substrate 31 and the back surface protection sheet 34 and adheres the wiring substrate 31 and the back surface protection sheet 34. Moreover, the part arrange | positioned above the photovoltaic cell 20 and the wiring board 31 of the sealing material 32 and the part arrange | positioned below are formed of the same resin. In addition, the part arrange | positioned above the photovoltaic cell 20 and the wiring board 31 and the part arrange | positioned below may be formed with different resin.

  Although the translucent board | substrate 33 is formed using a glass substrate, PC (polycarbonate resin), etc., if it is transparent with respect to sunlight, it will not specifically limit.

  As the back surface protection sheet 34, for example, a sheet material made of a weather resistant film conventionally used can be used. As a sheet material made of a weather resistant film, for example, an insulating film such as a PET (polyethylene terephthalate) film can be used. For example, a glass substrate may be used instead of the back surface protection sheet 34. By using the glass substrate, the moisture resistance of the solar cell module 2 can be improved.

  The holding member 11 holds the entire periphery of the edge of the solar cell panel 10 via an insulating panel end surface sealing member (not shown). The holding member 11 is made of a metal such as aluminum and has conductivity. Further, the holding member 11 is grounded via a wiring or the like (not shown) in order to ensure safety against electric shock or the like.

  In the solar power generation system 1, as shown in FIG. 1, a plurality of solar cell modules 2 are connected in series with each other by a cable 4a. For this reason, all the photovoltaic cells 20 included in the solar power generation system 1 are connected to each other in series. The solar cell 20 a of the solar cell module 2 a on the highest potential side has the highest potential among all the solar cells 20 included in the solar power generation system 1. The solar cell 20d of the solar cell module 2b on the lowest potential side has the lowest potential among all the solar cells 20 included in the solar power generation system 1. The solar battery cell 20a of the solar battery module 2a corresponds to the “fifth solar battery cell” of the present invention, and the solar battery cell 20d of the solar battery module 2b corresponds to the “sixth solar battery cell” of the present invention. doing.

  Moreover, the cables 4b of the adjacent solar cell modules 2 are electrically connected, and the potentials of all the high potential electrodes 31c included in the solar power generation system 1 are equal. The cable 4b of the solar cell module 2a on the highest potential side is connected to the cable 4a connected to the plus terminal 12a of the solar cell module 2a. That is, the high potential electrode 31c of the solar cell module 2a is electrically connected to the p electrode 25 of the solar cell 20a of the solar cell module 2a. Thereby, the electric potential of all the high potential electrodes 31c included in the solar power generation system 1 is that of the solar battery cell 20 (solar battery cell 20a of the solar battery module 2a) having the highest potential in the solar power generation system 1. It is higher than the potential of the n-type silicon substrate 21. For this reason, the potential of the high potential electrode 31c is higher than the potentials of all the solar cells 20 of the solar cell module 2a.

  In other words, in the solar cell module 2a, between the first solar cell and the second solar cell and between the second solar cell and the holding member 11 (second solar cell and translucent substrate 33). It can be said that the high potential electrode 31c having a potential higher than the potential of the n-type silicon substrate 21 of the second solar battery cell is provided on both of the first and second end surfaces. Moreover, in each of the solar cell modules 2, between the 1st photovoltaic cell and the 2nd photovoltaic cell, and between the 2nd photovoltaic cell and the holding member 11 (2nd photovoltaic cell and translucent board | substrate) It can be said that the high potential electrode 31c having a potential higher than the potential of the n-type silicon substrate 21 of the second solar battery cell is provided on both of the first and second end surfaces 33).

  In the solar power generation system 1 of this embodiment, it connected with the transformerless inverter (power conditioner 3). When connected to a transformerless inverter, the potential of the solar cell module 2 corresponding to the center (center) of the photovoltaic power generation system 1 connected to the plurality of solar cell modules 2 is 0 V due to the internal configuration of the inverter, and is grounded. Correspond. Therefore, the potential of the solar cell 20 between the solar cell module 2 at the center and the solar cell module 2 on the higher potential side than the solar cell module 2 is equal to or higher than the ground potential. In the case of a transformer-less inverter, there is an advantage that the conversion efficiency from direct current to alternating current is higher than that of an inverter having a transformer.

  In this solar power generation system 1, the potential of the n-type silicon substrate 21 of all the solar cells 20 of the solar cell module 2a is lower than the potential of the high potential electrode 31c. For this reason, the electric field E of the direction shown in FIG. 6 generate | occur | produces around the photovoltaic cell 20 and the high potential electrode 31c. Note that the potential of the rainwater 40 accumulated on the solar cell panel 10 is equal to the potential of the holding member 11.

  Due to the electric field E, electrons contained in the sealing material 32 move to the high potential electrode 31c side. That is, the electric field E can suppress the electrons in the sealing material 32 from being collected on the passivation film 22 side of the solar battery cell 20. Therefore, the holes generated in the silicon substrate 21 are suppressed from collecting on the passivation film 22 side, and the holes in the silicon substrate 21 move toward the p-type current collecting layer 21d as shown in FIG.

  In the present embodiment, as described above, between the first solar cell (for example, the solar cell 20b) and the second solar cell (for example, the solar cell 20a), and the second solar cell (for example, the solar cell). A high potential electrode 31c having a potential higher than the potential of the n-type silicon substrate 21 of the second solar battery cell is provided between both the cell 20a) and the holding member 11. As a result, the potential of the n-type silicon substrate 21 of the first solar cell and the potential of the n-type silicon substrate 21 of the second solar cell are lower than the potential of the high potential electrode 31c. For this reason, it is possible to suppress the electrons in the sealing material 32 from collecting on the passivation film 22 side. That is, the density of electrons on the passivation film 22 side in the sealing material 32 can be reduced. Thereby, the force which is going to collect the hole which generate | occur | produced in the silicon substrate 21 to the passivation film 22 side can be suppressed. As a result, it is possible to suppress the output of the solar cell module 2 from being reduced (power generation efficiency is reduced).

  Further, as described above, the high potential electrode 31 c is formed on the wiring substrate 31. Thereby, the high potential electrode 31c can be easily formed.

  Moreover, as described above, the solar battery cell 20 is a back electrode type solar battery cell. The potential of the n-type silicon substrate 21 of the solar battery cell 20 is higher than the potential of the surroundings (the holding member 11 that holds the solar battery panel 10, rainwater 40 accumulated on the solar battery panel 10, the outside of the solar battery module 2, etc.). When the n-type silicon substrate 21 is used for the so-called back electrode type solar battery cell 20, the output of the solar battery module 2 is likely to decrease. Therefore, the present invention is particularly effective when the n-type silicon substrate 21 is used for the so-called back electrode type solar battery cell 20.

  In addition, as described above, the plurality of solar cells 20 constitute a plurality of cell rows L in which the adjacent solar cells 20 are connected in series, and the high potential electrode 31c is between the adjacent cell rows L. In addition, both the cell row L and the holding member 11 are provided so as to extend along the cell row L. Thereby, between the photovoltaic cells 20 and between the photovoltaic cells 20 and the holding member 11, the high potential electrode 31 c can be easily provided. Further, the potentials of all the high potential electrodes 31c can be easily made equal.

  Moreover, the strength of the solar cell module 2 can be improved by providing the holding member 11 as described above.

  Further, as described above, the high potential electrode 31c has a potential substantially equal to the potential of the p electrode 25 of the solar battery cell 20 (solar battery cell 20a of the solar battery module 2a) having the highest potential in the photovoltaic power generation system 1. Have Thereby, the potential of the n-type silicon substrate 21 of all the solar cells 20 of the solar cell module 2a is lower than the potential of the high potential electrode 31c. Further, the potential difference between the solar battery cell 20 and the high potential electrode 31c can be increased. As a result, it is possible to effectively suppress a decrease in the output of the solar power generation system 1 (a decrease in power generation efficiency).

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

In the above embodiment, an n-type silicon substrate is used and an n-type diffusion region made of an n ⁺ -type layer having an n-type impurity having a higher concentration than the n-type region is formed on the light-receiving surface side. A p-type silicon substrate may be used to form a p-type diffusion region on the light receiving surface side.

  When it is set as the structure of the photovoltaic cell which has a p-type spreading | diffusion area | region in the light-receiving surface side of a p-type silicon substrate, it is between a 1st photovoltaic cell and the 2nd photovoltaic cell which has a higher electric potential than a 1st photovoltaic cell. Or a potential lower than the potential of the p-type silicon substrate of the first solar cell between the first solar cell and the holding member (between the first solar cell and the end face of the translucent substrate). If the low potential electrode which has is provided, it can suppress that the output of a solar cell module falls. When a p-type silicon substrate is used, the output of the solar cell module is reduced when the potential of the p-type silicon substrate of the solar cell is lower than the surrounding potential (such as the holding member or the outside of the solar cell module). Is likely to occur.

  In the above embodiment, an example in which a silicon substrate is used as a semiconductor substrate has been described. However, the present invention is not limited to this, and a semiconductor substrate other than a silicon substrate may be used.

  Moreover, although the said embodiment demonstrated the case where the photovoltaic cell was a back surface electrode type, this invention is not limited to this. Even when using solar cells in which electrodes are provided on each of the light receiving surface and the back surface, the output of the solar cell module may decrease, so electrodes are provided on each of the light receiving surface and the back surface. It is also effective to apply the present invention to a solar cell module using solar cells.

  Moreover, although the said embodiment demonstrated the solar cell module which has a holding member, this invention is not limited to this. It is effective even when applied to a solar cell module having no holding member.

  Moreover, in the said embodiment, although the solar power generation system showed about the example containing the several solar cell module, the solar power generation system may contain only one solar cell module.

  Moreover, in the said embodiment, adjacent solar cell modules are connected with the cable 4b, and the electric potential of all the high potential electrodes is made into the 5th photovoltaic cell (solar cell which has the highest electric potential in a photovoltaic power generation system). ), The potential of the p electrode is almost equal to the potential of the p electrode. However, the present invention is not limited to this. For example, the solar cell modules may not be connected to each other by the cable 4b, and the potential of the high potential electrode may be substantially equal to the potential of the p electrode of the solar cell having the highest potential among the solar cell modules. If comprised in this way, since an electrical connection of a high potential electrode can be performed on a wiring board, without using the cable 4b, a manufacturing process can be simplified.

  Further, in each solar cell module, the potentials of all high potential electrodes need not be higher than the potential of the semiconductor substrate of the solar cell having the highest potential. For example, you may comprise like the solar cell module 102 by the modification of this invention shown in FIG. Specifically, between a 1st photovoltaic cell (for example, photovoltaic cell 20d) and a 2nd photovoltaic cell (for example, photovoltaic cell 20c), a 2nd photovoltaic cell (for example, photovoltaic cell 20c), and a holding member. 11 may be provided with a high-potential electrode 31c electrically connected to the second solar battery cell. In this modification, the high potential electrode 31c is formed to extend from the wiring layer 31b.

  In the above-described embodiment, an example in which the potential of the high potential electrode is equal to the potential of the p electrode of the fifth solar cell (solar cell having the highest potential in the photovoltaic power generation system) is shown. The invention is not limited to this. The potential of the high potential electrode may be higher than the potential of the p electrode of the fifth solar battery cell. In this case, a high potential electrode may be connected to the booster circuit of the power conditioner 3. If comprised in this way, since the electrical potential difference of the semiconductor substrate of a photovoltaic cell and a high potential electrode can be enlarged more, it is more effective.

  Moreover, in the said embodiment, although it showed about the example which provided the high electric potential electrode between both photovoltaic cells and between the photovoltaic cell and the holding member, between the photovoltaic cells and the sun A high potential electrode may be provided on one side between the battery cell and the holding member (between the solar battery cell and the end face of the light-transmitting substrate).

  Moreover, although the example which provided the high potential electrode in all the solar cell modules was shown in the said embodiment, this invention is not limited to this. For example, the high potential electrode may be provided only on the high potential side solar cell module without providing the high potential electrode on the low potential side solar cell module.

  In the above embodiment, an example in which the high potential electrode is provided on the wiring board has been described. However, the present invention is not limited to this. The high potential electrode may be provided separately from the wiring board.

  Moreover, in the said embodiment, although the example which a holding member has electroconductivity was shown, the holding member may be formed with the insulating member, for example. The holding member may be formed of a conductive member (metal) and an insulating member.

  Moreover, although the example which provided the antireflection film on the passivation film was shown in the said embodiment, this invention is not limited to this, An antireflection film may not be provided.

  In the above embodiment, an example in which the high potential electrode has a higher potential than the silicon substrate of the third solar cell when the silicon substrate is formed of an n-type silicon substrate has been described. Not limited to this. When the silicon substrate is formed of a p-type silicon substrate, the low potential electrode may be configured to have a lower potential than the silicon substrate of the fourth solar battery cell. If comprised in this way, the electric potential of all the photovoltaic cells contained in a solar cell panel will become higher than the electric potential of a low potential electrode. In addition, the potential difference between the solar battery cell and the low potential electrode can be increased. As a result, it is possible to effectively suppress a decrease in the output of the solar cell module (a decrease in power generation efficiency).

  Moreover, in the said embodiment, when the silicon substrate was formed with the n-type silicon substrate, it showed about the example in which a high electric potential electrode has a higher electric potential than the silicon substrate of a 5th photovoltaic cell. Not limited to this. When the silicon substrate is formed of a p-type silicon substrate, the low potential electrode may be configured to have a lower potential than the silicon substrate of the sixth solar battery cell. If comprised in this way, the electric potential of all the photovoltaic cells contained in a photovoltaic power generation system will become higher than the electric potential of a low electric potential electrode. Further, the potential difference between the solar battery cell and the low potential electrode can be further increased. As a result, it is possible to effectively suppress a decrease in the output of the solar power generation system (a decrease in power generation efficiency).

DESCRIPTION OF SYMBOLS 1 Photovoltaic power generation system 2,102 Solar cell module 10 Solar cell panel 11 Holding member 20 Solar cell 20a Solar cell (2nd solar cell, 3rd solar cell, 5th solar cell)
20b, 20c Solar cell (first solar cell, second solar cell)
20d solar cell (first solar cell, fourth solar cell, sixth solar cell)
21 Silicon substrate (semiconductor substrate)
21b n ⁺ -type layer (n-type diffusion region)
22 Passivation film 24 N electrode 25 P electrode 31 Wiring substrate 31c High potential electrode 32 Sealing material 33 Translucent substrate L Cell array

Claims (8)

A plurality of solar cells, a translucent substrate disposed on the light receiving surface side of the solar cells, and a sealing material disposed between the solar cells and the translucent substrate,
The plurality of solar cells include a first solar cell and a second solar cell having a higher potential than the potential of the first solar cell,
When the solar cell is formed of an n-type semiconductor substrate, between the first solar cell and the second solar cell, and between the second solar cell and the translucent substrate. A high potential electrode having a higher potential than the n-type semiconductor substrate of the second solar battery cell is provided on at least one of the end faces,
When the solar cell is formed of a p-type semiconductor substrate, between the first solar cell and the second solar cell, and between the first solar cell and the translucent substrate. A solar cell panel, wherein a low potential electrode having a lower potential than the p-type semiconductor substrate of the first solar cell is provided on at least one of the end surfaces. The solar cell is formed of an n-type semiconductor substrate;
The n of the second solar cells is provided between at least one of the first solar cells and the second solar cells and between the second solar cells and an end face of the light-transmitting substrate. The solar cell panel according to claim 1, wherein a high potential electrode having a higher potential than that of the type semiconductor substrate is provided. A wiring board for electrically connecting the plurality of solar cells,
The solar cell panel according to claim 2, wherein the high potential electrode is formed on the wiring board. The plurality of solar cells include a third solar cell having the highest potential among the solar panels, and a fourth solar cell having the lowest potential among the solar panels,
4. The solar cell panel according to claim 2, wherein the high potential electrode has a higher potential than the n-type semiconductor substrate of the third solar cell. 5. The plurality of solar cells constitute a plurality of cell rows in which the adjacent solar cells are connected in series with each other,
The high-potential electrode is provided so as to extend along the cell row between the adjacent cell rows and at least one of the cell row and an end surface of the light-transmitting substrate. The solar cell panel according to any one of claims 2 to 4, wherein: The solar cell panel according to any one of claims 1 to 5,
A solar cell module comprising: a holding member that holds an edge of the solar cell panel.   A solar power generation system comprising the solar cell panel according to any one of claims 1 to 5 or the solar cell module according to claim 6. A plurality of the solar cell panels or the solar cell modules are provided,
The plurality of solar cells include a fifth solar cell having the highest potential in the solar power generation system and a sixth solar cell having the lowest potential in the solar power generation system,
The solar cell is formed of an n-type semiconductor substrate;
The solar power generation system according to claim 7, wherein the high potential electrode has a higher potential than the n-type semiconductor substrate of the fifth solar cell.

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