Abstract:
A solar battery module includes a plurality of solar cells connected to one another and a plurality of spaces each provided between adjacent solar cells, the plurality of spaces including at least one repair space which is larger than other spaces. A replacement solar cell includes an electrode and an interconnector electrically connected to the electrode, the interconnector including a connecting portion, which is positioned with respect to a connecting portion of an interconnector electrically connected to an electrode of an existing solar cell adjacent to the repair space so that the connection by the interconnectors is performed in the repair space. A method of replacing a solar cell includes the steps of simultaneously removing a plurality of existing solar cells arranged between at least two repair spaces, and simultaneously mounting a plurality of replacement solar cells to the region from which the plurality of existing solar cells are removed.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a solar battery module, a replacement solar cell, and a method of replacing a solar cell. 
     2. Description of the Background Art 
     A solar battery module is used, for example, as a power-supply for an artificial satellite, and various shapes thereof have been provided in accordance with the shape of the satellite or the power required. Moreover, the solar battery module has a plurality of solar cells, and a light-receiving side of each solar cell is provided with a cover glass for reducing exposure to radiation and for blocking ultraviolet rays in the universe. The plurality of solar cells are connected in series to form a string, and a plurality of strings are connected in parallel and in series to form the solar battery module. The solar cells are connected to one another via an interconnector. A three-dimensional or two-dimensional stress relief is formed at the interconnector to absorb and alleviate displacement and stress between solar cells. 
     Incidentally, when a solar cell of the solar battery module is failed or damaged, it must be replaced with a new solar cell. 
     However, in the conventional solar battery module, as solar cells are arranged close to each other within a string, it has been very difficult to perform such a series of work that only a failed or damaged solar cell is removed and a new solar cell is mounted and connected to existing solar cells adjacent to the failed cell. Thus, even if one solar cell is failed or damaged, the entire string including that cell must be replaced. Therefore, other normal solar cells included in the string are also replaced at the same time, incurring enormous waste. 
     Moreover, when a failed or damaged solar cell is removed, other normal solar cells adjacent thereto may also be destroyed, causing not only troublesome work but also waste of normal solar cells. 
     SUMMARY OF THE INVENTION 
     Therefore, the prevent invention was made in view of the above, and is directed to provide a solar battery module, a replacement solar cell, and a method of replacing a solar cell, that can suppress waste of solar cells to be minimum when a solar cell is replaced. 
     According to one aspect of the present invention, a solar battery module includes a plurality of solar cells connected to one another, and a plurality of spaces each provided between adjacent ones of the plurality of solar cells. The plurality of spaces includes at least one repair space. The repair space is larger than the other spaces. 
     According to another aspect of the present invention, in a solar battery module including a plurality of existing solar cells connected to one another and a plurality of spaces each provided between adjacent ones of the plurality of solar cells, the plurality of spaces including at least one repair space, the repair space being larger than other ones of the spaces; a replacement solar cell replacing the existing solar cell includes an electrode and an interconnector electrically connected to the electrode. The interconnector includes a connecting portion. The connecting portion of the interconnector is positioned with respect to a connecting portion of an interconnector electrically connected to an electrode of the existing solar cell adjacent to the repair space, such that connection of the interconnector for the replacement solar cell to the interconnector for the existing solar cell is performed in the repair space. 
     According to a further aspect of the present invention, in a solar battery module including a plurality of existing solar cells connected to one another, a replacement solar cell includes an electrode of a first conductivity type, an electrode of a second conductivity type opposite to the first conductivity type, a first interconnector electrically connected to the electrode of the first conductivity type, and a second interconnector electrically connected to the electrode of the second conductivity type. The first and second interconnectors include connecting portions respectively. The connecting portion of the first interconnector and the connecting portion of the second interconnector are arranged at one end of the replacement solar cell. 
     In the replacement solar cell, preferably, the electrode of the first conductivity type is arranged at one end of the replacement solar cell, the electrode of the second conductivity type is arranged at the other end of the replacement solar cell, and the second interconnector extends from the other end to the one end of the replacement solar cell so that the connecting portion of the second interconnector is arranged at the one end of the replacement solar cell. 
     In the replacement solar cell, preferably, the electrode of the first conductivity type and the electrode of the second conductivity type are arranged at one end of the replacement solar cell. 
     According to another aspect of the present invention, in a solar battery module including a plurality of existing solar cells connected to one another and a plurality of spaces each provided between adjacent ones of the plurality of solar cells, the plurality of spaces including at least two repair spaces, the repair space being larger than other ones of the spaces; a method of replacing a solar cell includes the steps of simultaneously removing the plurality of existing solar cells arranged between at least two of the repair spaces, and simultaneously mounting a plurality of replacement solar cells into a region from which the plurality of existing solar cells are removed. 
     In the method of replacing a solar cell, preferably, the step of mounting includes the step of connecting the replacement solar cell to the existing solar cell adjacent to the replacement solar cell, within the repair space. 
     According to a yet another aspect of the present invention, in a solar battery module including a plurality of existing solar cells connected to one another, a method of replacing a solar cell includes the steps of removing the existing solar cell, and mounting a replacement solar cell smaller than the existing solar cell into a region from which the existing solar cell is removed. A repair space is provided between the replacement solar cell and the existing solar cell adjacent to the replacement solar cell. 
     In the method of replacing a solar cell, preferably, the replacement solar cell has a power output approximately equal to the existing solar cell. 
     In the method of replacing a solar cell, preferably, the step of mounting includes the step of connecting the replacement solar cell to the existing solar cell adjacent to the replacement solar cell, within the repair space. Here, the existing solar cell adjacent to the replacement solar cell preferably includes an electrode, and the replacement solar cell includes an electrode and a first interconnector electrically connected to the electrode. The step of mounting preferably includes the steps of connecting the electrode of the existing solar cell adjacent to the replacement solar cell to one connecting portion of a second interconnector and extending the other connecting portion of the second interconnector into the repair space, and connecting a connecting portion of the first interconnector and the other connecting portion of the second interconnector. 
     Specifically, the solar battery module according to the present invention includes a plurality of solar cells connected to one another, and at least one of spaces between adjacent solar cells is used as a repair space, which is made larger than other spaces. 
     According to the present invention with such a structure, the repair space between solar cells is made larger. This facilitates connecting work of solar cells performed in the repair space. Moreover, adhesive for fixing the solar cells can easily be processed in the large repair space, so that processing may be started in this repair space and proceeded to the periphery of a solar cell, to allow detachment of the solar cell. 
     Moreover, the replacement solar cell according to the present invention is to replace a solar cell of the solar battery module described above, and a connecting portion of an interconnector electrically connected to an electrode of the replacement solar cell and a connecting portion of an interconnector electrically connected to an electrode of an existing solar cell adjacent to the replacement solar cell are positioned such that connection of the interconnector for the replacement solar cell to the interconnector for the existing solar cell is performed in the repair space. 
     Here, the position of the connecting portion of the interconnector electrically connected to the electrode of the replacement solar cell is set in accordance with the position of the repair space, such that connection by the interconnector is performed in the repair space. 
     Moreover, the replacement solar cell according to the present invention is for a solar battery module including a plurality of solar cells connected to one another, and includes interconnectors used for connection to an existing solar cell adjacent to the replacement solar cell. A connecting portion of an interconnector electrically connected to an N-electrode of the replacement solar cell and a connecting portion of an interconnector electrically connected to a P-electrode of the replacement solar cell are both arranged on one side of the replacement solar cell. 
     Here, the replacement solar cell may be mounted with a side thereof adapted to the repair space, to allow connection by each interconnector to be performed in the repair space. 
     Furthermore, in the replacement solar cell according to the present invention, one of the connecting portions of the interconnector electrically connected to the N-electrode and of the interconnector electrically connected to the P-electrode extends to one side of the replacement solar cell on which the other one of the connecting portions is arranged. 
     By thus extending one of the connecting portions of the interconnectors to one side of the replacement solar cell on which the other one of the connecting portions is arranged, the connecting portions of both interconnectors can be arranged together on one side of the replacement solar cell, even if the electrodes are spaced apart. 
     The replacement method according to the present invention is to replace a solar cell of the solar battery module, in which a plurality of solar cells arranged between repair spaces are simultaneously replaced. 
     If, for example, three solar cells are arranged between two repair spaces, all of the three solar cells are simultaneously replaced. As described earlier, connection of solar cells to each other and processing of an adhesion may easily be performed in the repair space. Therefore, replacement of solar cells between the repair spaces may be facilitated. 
     Furthermore, in the replacement method according to the present invention, the replacement solar cell used for replacement and an existing solar cell adjacent to the replacement solar cell are connected in the repair space. 
     Accordingly, connecting work may easily be performed in the repair space. 
     In addition, the replacement method according to the present invention is for replacing a solar cell of a solar battery module including a plurality of solar cells connected to one another, in which an existing solar cell is replaced with a smaller replacement solar cell so that a repair space is formed. 
     When such a small replacement solar cell is mounted, a large repair space is formed adjacent to the replacement solar cell. Thus, connection of the replacement solar cell to the existing solar cell can easily be performed in the large repair space. 
     Moreover, in the replacement method according to the present invention, the smaller solar cell has a power output approximately equal to the existing solar cell. 
     This prevents lowering of the power output of the solar battery module even after the smaller replacement solar cell is mounted. 
     Moreover, in the replacement method according to the present invention, the replacement solar cell after replacement and the existing solar cell adjacent to the replacement solar cell are connected in the repair space. 
     The connection work is facilitated because of the large size of the repair space. 
     Furthermore, in the replacement method of the present invention, an electrode of an existing solar cell adjacent to the replacement solar cell is connected to an interconnector, and a connecting portion of the interconnector is arranged to extend to the repair space and is connected to a connecting portion of an interconnector electrically connected to an electrode of the replacement solar cell. 
     Here, the electrode of the existing solar cell is connected to the interconnector and the connecting portion of this interconnector extends to the repair space to be connected to the connecting portion of the interconnector for the replacement solar cell. Thus, the interconnector for the existing solar cell can be connected to the interconnector for the replacement solar cell, even if the electrode of the existing solar cell is spaced from the repair space. 
     The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view showing a string according to the first embodiment of a solar battery module of the present invention; 
     FIG. 2 is a plan view showing the string in FIG. 1 from which three solar cells have been removed; 
     FIG. 3 is a plan view showing three replacement solar cells; 
     FIG. 4 is a plan view showing the string in FIG. 2 to which the replacement solar cells shown in FIG. 3 are mounted; 
     FIG. 5 is a plan view showing a replacement solar cell according to the second embodiment of the solar battery module of the present invention; 
     FIG. 6 is a plan view showing an ordinary solar cell; 
     FIG. 7 is a plan view showing a string from which one failed solar cell has been removed; 
     FIG. 8 is a plan view showing the string in FIG. 7 to which extension lines are connected; 
     FIG. 9 is a plan view showing the string in FIG. 8 to which the replacement solar cell in FIG. 5 is mounted; 
     FIG. 10 is a plan view showing a replacement solar cell according to the third embodiment of the solar battery module of the present invention; 
     FIG. 11 is a plan view showing a string from which one failed solar cell has been removed; 
     FIG. 12 is a plan view showing the string in FIG. 11 to which extension lines are connected; and 
     FIG. 13 is a plan view showing the string in FIG. 12 to which the solar cell in FIG. 10 is mounted. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention will be described below in detail with reference to the drawings. 
     FIG. 1 shows a string according to the first embodiment of a solar battery module of the present invention. The solar battery module according to the present embodiment finds application in, for example, a power-supply of an artificial satellite. 
     As shown in FIG. 1, a string  1  of the solar battery module is formed by nine solar cells  2  that are connected in series and adhered on an insulated substrate (not shown). Solar cells  2  in string  1  are divided into three groups A, B and C, and repair spaces  3  are provided between groups A and B, and between groups B and C, respectively. Moreover, separation spaces  4  separating one string from another are provided at the upper side of group A and at the lower side of group C, respectively. 
     Each solar cell  2  has a dimension of 40 mm×60 mm in vertical and horizontal lengths respectively. Each repair space  3  and each separation space  4  have a width of 2 mm, whereas a regular space  5  has a width of 1 mm. Therefore, the total length of string  1  is 378 mm. 
     In addition, each solar cell  2  has N-electrode pads  6  at the lower edge thereof and P-electrode pads  7  at the upper edge thereof. N-electrode pads  6  in one of two adjacent solar cells  2  are electrically connected to P-electrode pads  7  in the other one of the adjacent solar cells  2  via interconnectors  9 , respectively. 
     Now, in string  1  having such a structure, when any one of solar cells  2  in e.g. group B is failed, three solar cells  2  in group B are removed and three new replacement solar cells are mounted by the procedure as described below. 
     First, interconnectors  9  in repair space  3  between groups A and B are cut, while interconnectors  9  in repair space  3  between groups B and C are also cut. Then, for example, piano wire or the like having a diameter of approximately 0.1 mm is introduced into repair space  3 , and is moved between solar cells  2  in group B and the insulated substrate, to cut adhesive between solar cells  2  and the insulated substrate so that solar cells  2  are removed. As a result, string  1  comes to a state as shown in FIG.  2 . In addition, a cutter or the like is used in the space of group B to remove remaining adhesive on the insulated substrate. 
     Subsequently, a set of three replacement solar cells  11  as shown in FIG. 3 is adhered to the space of group B shown in FIG. 2 by an adhesive. As the adhesive, for example, RTV-S691 (trade name) from Wacker-Chemie GmbH is applied. Then, as shown in FIGS. 2 to  4 , in repair space  3  between groups B and C, interconnectors  13  electrically connected to respective N-electrode pads  12  of replacement solar cell  11  at the lower side are connected to interconnectors  9  electrically connected to P-electrode pads  7  of existing solar cell  2  adjacent to replacement solar cell  11 , respectively, by soldering or the like. Likewise, in repair space  3  between groups A and B, interconnectors  13  electrically connected to respective P-electrode pads  14  of replacement solar cell  11  at an upper side are connected to interconnectors  9  electrically connected to respective N-electrode pads  6  of existing solar cell  2  adjacent to replacement solar cell  11 , respectively, by soldering or the like. 
     As such, replacement of three solar cells  2  by three replacement solar cells  11  is completed. 
     Thus, according to the present embodiment, if any one of solar cells  2  in string  1  is failed, replacement thereof is performed per group including three solar cells  2 , eliminating the need for replacing the other two groups including six normal solar cells  2 . This greatly cuts down on waste compared to the conventional example in which the entire string was replaced. 
     Moreover, because the large repair space  3  is provided per group of three solar cells, piano wire can easily be introduced into repair space  3  to cut adhesive to remove solar cells  2 , and also replacement solar cells  11  and existing solar cells  2  can easily be connected in this repair space  3 . 
     It is noted that the width of each repair space  3  and the number of repair spaces  3  in string  1  may appropriately be increased or reduced. As the width and number of spare spaces  3  increases, the number of solar cells to be replaced when failed is reduced, facilitating removal of solar cells or work of connecting. However, this reduces the area occupied by each solar cell, lowering power generation efficiency of the solar battery module. Therefore, the width or number of repair spaces  3  is increased when the solar battery module has an output sufficient for the power required by an artificial satellite, whereas the number of repair spaces is reduced when the output of the solar battery module is insufficient, to increase the output of the solar battery module. Even with only one repair space  3  provided in string  1 , solar cells  2  in string  1  are divided into two groups, so that the number of solar cells to be replaced at failure is reduced to half compared to the conventional example in which the entire string was replaced, greatly cutting down on waste. 
     FIG. 5 shows a replacement solar cell according to the second embodiment of the solar battery module of the present invention. 
     A replacement solar cell  21  according to the present embodiment is formed as follows: an ordinary solar cell  22  shown in FIG. 6 is cut (diced) along a dotted line  23 , interconnectors  25   n  are connected to N-electrode pads  24  respectively while interconnectors  25   p  are connected to P-electrode pads  26  respectively, and connecting portions of respective interconnectors  25   p  are arranged to extend to the side on which connecting portions of respective interconnectors  25   n  are arranged. 
     Replacement solar cell  21  is formed by cutting ordinary solar cell  22  shown in FIG. 6, so that its vertical length is shorter than that of ordinary solar cell  22 . Thus, when replacement solar cell  21  is used for replacement instead of ordinary solar cell  22 , a wide space for repairing is formed adjacent to replacement solar cell  21 . 
     FIG. 7 shows a string  28  of the solar battery module according to the present embodiment, from which one failed solar cell has already been removed. The procedure of mounting replacement solar cell  21  to string  28  will be described below. 
     First, as shown in FIG. 8, N-electrode pads  32  of existing solar cell  22  adjacent to replacement solar cell  21  are connected to respective repair interconnectors  29 , and connecting portions of the respective repair interconnectors  29  are arranged to extend to a section which is to be a repair space  31 . 
     Subsequently, as shown in FIG. 9, replacement solar cell  21  is placed and adhered. Here, repair space  31  is provided at a lower side of replacement solar cell  21 . Then, in repair space  31 , interconnectors  25   n  electrically connected to respective N-electrode pads  24  of replacement solar cell  21  are connected to interconnectors  30  electrically connected to respective P-electrode pads  33  of the adjacent solar cell  22  on the lower side, respectively, by soldering or the like. In addition, interconnectors  25   p  electrically connected to respective P-electrode pads  26  of replacement solar cell  21  are connected to repair interconnectors  29  electrically connected to respective N-electrode pads  32  of the adjacent solar cell  22  on the upper side, respectively, by soldering or the like. As a result, replacement solar cell  21  is serially connected to existing solar cells  22 . 
     As such, according to the present embodiment, a failed ordinary solar cell  22  is replaced with replacement solar cell  21  having a shorter vertical length, so that wide repair space  31  is formed in which replacement solar cell  21  is connected to existing solar cells  22 , facilitating the connection work. 
     Moreover, the connecting portions of interconnectors  25   p ,  29  are arranged to extend to repair space  31  such that P-electrode pads  26  of replacement solar cell  21  can be connected to N-electrode pads  32  of the adjacent solar cell  22  on the upper side, respectively, in repair space  31 , so that only one repair space is required. This can prevent enlargement of the repair space and thus prevent reduction of the area occupied by each solar cell and lowering of power generation efficiency of the solar battery module. 
     Furthermore, replacement solar cell  21  can easily be fabricated, since it is formed by cutting ordinary solar cell  22 . 
     FIG. 10 shows a replacement solar cell according to the third embodiment of the solar battery module of the present invention. 
     Replacement solar cell  41  according to the present embodiment includes N-electrode pads  42  and P-electrode pads  43  provided together at a lower side thereof, in which N-electrode pads  42  are connected to respective interconnectors  44   n  while P-electrode pads  43  are connected to respective interconnectors  44   p.    
     Replacement solar cell  41  also has a vertical length shorter than that of an ordinary solar cell  46  in a string  45  shown in FIG.  11 . Thus, when replacement solar cell  41  is used for replacement instead of ordinary solar cell  46 , a repair space is formed adjacent to replacement solar cell  41 . 
     In order to mount replacement solar cell  41  to string  45  from which one failed solar cell  46  has already been removed as shown in FIG. 11, first, as shown in FIG. 12, N-electrode pads  51  of existing solar cell  46  adjacent to replacement solar cell  41  are connected to respective repair interconnectors  47 , and connecting portions of these interconnectors  47  are arranged to extend to a section which is to be a repair space  48 . 
     Subsequently, as shown in FIG. 13, replacement solar cell  41  is placed and adhered, and repair space  48  is provided at a lower side of replacement solar cell  41 . Thereafter, in repair space  48 , interconnectors  44   n  electrically connected to respective N-electrode pads  42  of replacement solar cell  41  are connected to interconnectors  49  electrically connected to respective electrode pads  52  of the adjacent solar cell  46  on the lower side, respectively, by soldering or the like. In addition, interconnectors  44   p  electrically connected to respective electrode pads  43  of replacement solar cell  41  are connected to repair interconnectors  47  electrically connected to respective N-electrode pads  51  of the adjacent solar cell  46  on the upper side, respectively, by soldering or the like. As a result, replacement solar cell  41  is serially connected to existing solar cells  46 . 
     In the present embodiment also, a failed ordinary solar cell  46  is replaced with replacement solar cell  41  having a shorter vertical length, so that wide repair space  48  is formed, facilitating connection work between replacement solar cell  42  and existing solar cells  46 . Moreover, only one repair space is provided, so that enlargement of the repair space is suppressed, preventing reduction of the area occupied by each solar cell and lowering of power generation efficiency of the solar battery module. 
     Furthermore, replacement solar cell  41  includes N-electrode pads  42  and P-electrode pads  43  provided together on one side thereof, so that the length of repair interconnectors for one of N-electrode pads  42  or P-electrode pads  43  can be shortened. 
     In the second and third embodiments, the vertical length of a replacement solar cell is shorter than that of an existing solar cell, resulting in a small light-receiving area. Thus, the replacement solar cell preferably has a high power generation efficiency per unit area and a total output approximately equal to that of the existing solar cell. For example, assuming that the dimension of the existing solar cell is 40 mm×60 mm in vertical and horizontal lengths and that of the replacement solar cell is 39 mm×60 mm, the light-receiving area for the replacement solar cell is reduced by 2.5%. In such a case, the replacement solar cell preferably has a power generation efficiency per unit area that is approximately 2.5% higher. 
     It is noted that the present invention is not limited to the embodiments described above, and may be modified in various manners; For example, the present invention may apply to any type or size of a solar cell. Moreover, either side of one solar cell may be provided with a repair space. 
     Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.