JP2006278758A - Solar cell module and solar cell array - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a single power source with good workability by sharing the output wiring of a solar cell module or a series system of solar cell modules with the wiring of a resistance heating element for snow melting in a photovoltaic power generation system with a snow melting function using a resistance heating element To provide an efficient and efficient snow melting system.
A solar cell module in which a solar cell module having a frame attached to an end of a solar cell panel having a solar cell element string composed of a plurality of solar cell elements is installed at an inclination. A heating resistor is attached to a lower frame body, a diode is connected in parallel to the heating resistor, and wiring of the solar cell element strings is connected in series to the heating resistor.
[Selection] Figure 1

Description

  The present invention relates to a solar cell module and a solar cell array that generate power using solar energy, and more particularly to a solar cell module and a solar cell array to which a snow melting function is added in a snowy area.

  In recent years, solar power generation systems using solar energy have been installed and spread on the roofs of buildings such as houses. Among them, in the snowy area, sunlight is blocked by snow on the roof during the winter period, so the annual power generation is less than in other areas, and this is a factor that delays the spread.

  Therefore, various types of solar power generation systems with a snow melting function have been proposed in order to promote the widespread use of solar power generation systems in snowy areas. As a specific example, there is a method of melting the snow on the module by generating heat on the back surface of the solar cell module as shown in FIG. The solar cell module 20 has a structure in which the solar cell element 1 is filled and fixed with a laminate material 14 or silicon resin between a light-transmitting substrate such as a plate glass 13 and a weather-resistant film 18 to improve strength. Therefore, the plate glass 13 and the weather resistant film 18 are sandwiched between the metal frame frames 6. And the heating part which passes warm water like the heat pipe 17 is affixed on the back surface of the solar cell module 20, ie, the back surface of the weather-resistant film 18, and the plate glass 13 is thermally conductive by flowing warm water through the heat pipe 17 during snowfall. It warms and the snow on the solar cell module 20 can be melted. The hot water heating type, in which hot water passes through the pipe or the frame of the solar cell module and melts the snow on the surface of the solar cell by heating with hot water, is usually used for kitchens and baths. It can be used as hot water.

  As another snow melting method, although not particularly shown, there is a power application type that uses a phenomenon in which heat is generated by the internal resistance of the solar cell element when electricity is reversely supplied to the heater or the solar cell element, and the snow is melted by the heat. .

  In recent years, the grid-connected solar power generation system that sells the power generated by solar cells to power companies has become the mainstream, so when snow melts, power for snow melting is purchased from the power companies, and after snow melting The power application type that returns the power used for melting snow by increasing the power consumption at home and selling electricity at power companies is increasing. In addition, the power application type does not require hot water piping like the hot water type or external devices for hot water overheating, the system is lightweight and compact, and the amount of power used for melting snow cannot be returned by the amount of generated power. There is also an effect of reducing the load on the roof by eliminating snow on the roof, and can prevent the collapse of the house and extend the life.

  As a specific example of the power application type method of melting the snow on the solar cell module by causing the solar cell module to generate heat as described above, a heating element is incorporated into the glass surface or the back surface of the solar cell module to energize the solar cell. There is a method of melting snow on a battery module (see, for example, Patent Document 1).

Further, in a snow melting system using solar cells, as a specific example of a hot water heating type that prevents remelting of melted snow in the metal frame of the solar cell module, a solar cell element on the metal frame of the solar cell module, Alternatively, there is a method of easily conducting heat from the heating element on the module surface, or a method of incorporating the heating element itself into the frame (see, for example, Patent Document 2).
JP-A-8-250756 JP 2001-81918 A

  However, in the snow melting system using the hot water as described above, a boiler for heating the hot water is required, and the installation of water pipes is also required.

  In addition, in the method of heating the solar cell element by applying a heater or reverse voltage, the heat generation efficiency at the center of the solar cell module surface is good, but heat is not easily transmitted to the metal frame part at the end of the solar cell module, and snow in the center of the solar cell module is Even if it melts, snow will remain in the edges and frame part, so if you want to melt the snow completely until the end, you must continue to generate heat including the part that does not need snow melting in the center, There is a problem that it becomes an inefficient snow melting system in terms of energy.

  Many residential photovoltaic systems are installed on an inclined roof, so when the solar cell module generates heat, the snow is reduced in frictional resistance due to a layer of water generated between the glass surface of the solar cell module. However, although it tends to slide down, a phenomenon in which it becomes more difficult to melt by freezing again at a low temperature portion near the frame at the lower part of the solar cell module and collecting on the lower side of the module is likely to occur.

  Further, Patent Document 2 has been proposed from the viewpoint of preventing re-freezing in the metal frame of the solar cell module, but is not proposed as an active and efficient snow melting method. In other words, there is no mention of which installation is most efficient on which of the four side metal frames of a module that is generally rectangular.

  Each proposal is a system that is simply a combination of a photovoltaic power generation system and an electric heater. The wiring for power generation of the solar cell module and the wiring for energizing the electric heater of the module or metal frame are performed separately. On the construction side, both the solar cell wiring connection and the electric heater electric wiring connection have to be performed, and there is a problem that the construction is complicated and the number of work steps is increased.

  Furthermore, the power supply and control circuit for energizing the solar cell module and electric heater are simply installed separately when the system is combined, but it is shared from the viewpoint of efficiency, workability, and ease of use of the entire system. It is desirable to make it.

  In order to solve the above problems, a solar cell module according to the present invention is provided by inclining a solar cell module having a frame attached to an end of a solar cell panel having a solar cell element string composed of a plurality of solar cell elements. In the solar cell module, a heating resistor is attached to a frame located below the solar cell module, a diode is connected in parallel to the heating resistor, and wiring of the solar cell element string is connected to the heating resistor. It is characterized by being connected in series.

  Further, another solar cell module of the present invention is installed by inclining a solar cell module having a frame attached to an end of a solar cell panel having a solar cell element string composed of a plurality of solar cell elements. In the solar cell module, a heating resistor is attached to a lower frame of the solar cell module, the heating resistor is connected in parallel to the wiring of the solar cell element string, and the resistance heating in series with the heating resistor. A switch for cutting off the current flowing through the body is provided.

  Further, the solar cell array of the present invention is a solar cell array in which a solar cell module string in which a plurality of solar cell modules are connected in series is installed on a rail-shaped frame, and a resistance for melting snow on the frame A heating element is attached, a diode is connected in parallel to the resistance heating element, and wiring of the solar cell module strings is connected in series to the resistance heating element.

  Furthermore, another solar cell array of the present invention is a solar cell array in which a solar cell module string in which a plurality of solar cell modules are connected in series is installed on a rail-like gantry for melting snow on the gantry. The resistance heating element is attached, the resistance heating element is connected in parallel to the wiring of the solar cell module strings, and a switch for cutting off the current flowing through the resistance heating element is provided in series with the resistance heating element. Features.

  According to the solar cell module of the present invention, at the time of melting snow, the snow on the surface of the solar cell module is melted, and the snow is slid to the vicinity of the lower snow stop fitting, and the snow stop fitting portion is locally covered by the resistance heating element. Since accumulated snow can be melted, it is possible to efficiently melt snow on the roof surface. Moreover, although it is a complex system, it is possible to perform construction by wiring work similar to that of a normal solar power generation system, and workability is improved. Furthermore, since the output wiring can be shared, the power supply and the control circuit can be shared.

  Moreover, according to the solar cell array of this invention, the same effect as the above is acquired.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a solar power generation system with a snow melting function of the present invention will be described in detail based on the drawings schematically shown.

(Example 1)
FIG. 1 is a schematic circuit configuration diagram schematically illustrating a first embodiment of a solar cell module according to the present invention.

  The solar cell module 7 is formed by sandwiching solar cell element strings in which a plurality of solar cell elements 1 are connected in series with a wiring material such as a copper foil wire between a plate glass and a weather resistant film, and filling or laminating with a transparent resin. In this structure, the end face is protected and reinforced by a metal frame 6 made of aluminum or the like. Moreover, the joint box 4 for taking out the output wiring of a solar cell element string is provided in the back surface. Note that the laminated structure of the solar cell element portion is the same as that of the general solar cell module described in FIG.

  On the other hand, the metal frame 6 has a structure in which a snow stopper described later can be integrated or easily attached to one side arranged below (in the case of a house roof) at the time of installation. A resistance heating element 2 such as a heating wire for melting snow is provided. In this example, the resistance heating element 2 has a structure in which a heating wire or the like is passed through the frame of the metal frame 6, but the planar heating element may be attached and fixed to the back surface or the surface of the metal frame 6.

  Further, as an electrical connection, a diode 3 is connected in parallel to the resistance heating element 2, and a wiring is connected so as to form a series circuit with the strings of solar cell elements. By doing so, it becomes possible to share the output wiring of the solar cell module for power generation and snow melting, and, like a normal solar cell module, it is possible to use two wires on the plus side and the minus side. It is possible to secure both power transmission and power reception paths. The diode 3 may be molded with a filler together with the solar cell element, but may be housed in the joint box 4 described above.

  The actual current flow will be described below.

  During normal power generation, electricity generated by the solar cell element 1 is output from the plus side. When a plurality of solar cell modules 7 are connected in series, the positive side of the solar cell module adjacent to the negative output terminal of the solar cell module 7 is connected, so that the current input from the negative terminal is positive. Current flows toward the side output terminal. At this time, since the internal resistance in the forward direction of the diode 3 connected in parallel is sufficiently smaller than that of the resistance heating element 2, the current flows to the diode 3 side, and no current flows to the resistance heating element 2.

  On the other hand, when snow is melted, when a voltage is applied to the positive output terminal of the solar cell module 7 from the outside and a reverse current is applied, the solar cell element 1 generates heat due to internal resistance and acts as an electric heater for melting snow.

Next, the action during actual snowfall will be described using the schematic structural cross-sectional view of FIG.

  When the snow melt is energized, both the solar cell element 1 and the resistance heating element 2 act as heating elements. When the solar cell element 1 generates heat, the plate glass 13 is warmed, the bottom surface of the snow piled on the plate glass 13 is melted to reduce the frictional resistance, and the snow cover 15 is slid to the snow stop fitting 6c of the lower metal frame frame 6a. Make it. A resistance heating element 2 is installed on the lower metal frame 6a so as to melt the snow 15 locally. At this time, since the frame frame other than the lower frame is in contact with the lower metal frame frame 6b and the glass panel, it is possible to prevent re-freezing of the molten water by heat conduction. Due to the frozen snow cover, it is possible to prevent the snow cover 15 from becoming an obstacle to the operation of dropping the snow cover 15 to the snow stopper position. Note that the amount of heat generated by the solar cell element 1 at this time may be set smaller than the amount of heat generated by the resistance heating element 2. This is because, when the solar cell element 1 is heated, slippage occurs on the glass surface due to the inclination of the roof surface, and most of the snow 15 falls immediately near the lower stage of the solar cell module. This is because, even if the heat generation amount is set to be large and the snow melting is performed, the snow is slipped down before the snow melting and the portion where there is no snow is heated, so that the energy efficiency of the snow melting is deteriorated. Therefore, heat generation of the solar cell element 1 is reduced, and power consumption can be reduced if only the snowfall effect on the glass surface is aimed. On the other hand, the heat generation amount of the resistance heating element 2 is set to be large, and the snow is locally melted in a place where the snow cover that has slipped off from the solar cell module is accumulated.

(Example 2)
FIG. 2 is a schematic circuit diagram schematically illustrating a second embodiment of the solar cell module according to the present invention.

  The structure of the solar cell module 77 is substantially the same as that of the first embodiment described above, except that the circuit connection method and the switching circuit 8 are used instead of the diode 3.

  The resistance heating element 2 is connected via the switching circuit 8a so as to form a parallel circuit with the strings of the solar cell elements 1. By doing so, the output wiring of the solar cell module can be shared between power generation and snow melting, and can be configured with two plus and minus lines as in the case of a normal solar cell module. This switching circuit 8 a is assumed to be housed in the joint box 4. In this example, the switching circuit 8b is also provided in the output wiring of the solar cell element. However, this is not necessarily required to achieve this object.

  Here, an actual current flow will be described.

  During normal power generation, electricity generated by the solar cell is output from the positive side. When the solar cell modules 77 are connected in series, a current flows from the negative output terminal toward the positive output terminal inside the solar cell module 77. At this time, the switching circuit 8a of the resistance heating element 2 may be turned off, and the output wiring switching circuit 8b of the solar cell element may be turned on.

  Next, when the snow melts, a voltage is applied to the positive output terminal of the solar cell module 77 so that a reverse current flows. At this time, if the switching circuit 8a of the resistance heating element 2 is turned on and the switching circuit 8b of the output wiring of the solar cell element is also turned on, the solar cell element 1 generates heat as a resistance due to the reverse current, and the resistance heating element 2 also Current flows and acts as an electric heater for melting snow.

  Next, the action during actual snowfall will be described. Although it becomes the description similar to Example 1, it differs from Example 1 by the point which can perform more efficient snow melting.

  As shown in FIG. 5, in Example 1, the heat generation degree of the solar cell module surface and the lower metal frame 6 could not be controlled, but in this example, as described in FIG. It can be controlled by changing the ON / OFF time ratio of the switching circuit 8a of the resistance heating element 2 and the switching circuit 8b of the output wiring of the solar cell element. For example, when snow is accumulated on the entire surface of the module, the ON time ratio of the output circuit switching circuit 8b of the solar cell element is increased, and when the snow is biased to the snow stopper 6c of the lower metal frame due to snow slide, the resistance heating element 2 This is a method of increasing the ON time ratio of the switching circuit 8a. These circuits may be separate from the solar cell module, or may be housed in a waterproof case or the like and integrated with the solar cell module, and the location is not particularly limited.

  Next, the embodiment of the solar power generation system with a snow melting function of the present invention will be described with respect to the fact that the same effect can be obtained even if it is developed from a solar cell module structure to a solar cell system.

(Example 3)
FIG. 3 is a schematic circuit diagram schematically illustrating a third embodiment of the solar cell system according to the present invention.

  The resistance heating element built-in solar cell mount system 12 is a solar cell module string 9 in which a plurality of solar cell modules are connected in series with a connection cable (a solar cell module string is a plurality of solar cell modules connected in series or in parallel. Is installed on the roof surface of the house using the solar cell mounting rail 10, and the output wiring of the solar cell strings relays or connects the output wiring of the solar cell strings, or boosts the output wiring of the solar cell module strings. It is assumed that the connection box 11 is connected. The solar cell mounting rail 10 is a module fixing rail member that is in a horizontal direction at the time of installation, and has a structure in which a snow stop fitting is integrated or can be easily mounted, and resistance heating such as a heating wire for melting snow. Body 2 is installed in the rail. In this example, the resistance heating element 2 has a structure in which a heating wire or the like is provided in the rail of the solar cell mounting rail 10 and between the main body and the cover, but a planar heating element may be attached and fixed to the mounting rail 10.

  A diode 3 is connected in parallel to the resistance heating element 2, and a cable is connected so as to form a series circuit with the strings 9 of the solar cell module. The diode 3 is placed in the connection box 11. In this way, although the number of connecting cables to the resistance heating element 2 is increased by one, the output wiring work of the strings 9 of the solar cell module can be constituted by two plus and minus lines as in the case of a normal solar cell module. The wiring after the connection box 11 can be shared for power generation and snow melting.

  Here, an actual current flow will be described.

  During normal power generation, electricity generated by the solar cell is output from the positive side. In the solar cell mount system 12, a current flows from the negative output terminal of the connection box 11 toward the positive output terminal. At this time, since the resistance heating element 2 forms a forward circuit of the diode 3 in parallel, no current flows.

  Next, when the snow melts, a voltage is applied to the positive output terminal of the connection box 11 so that a reverse current flows. At this time, the strings 9 of the solar cell module generate heat as a resistor due to the reverse current. Further, since the diode blocks the current, a current also flows through the resistance heating element 2 and acts as an electric heater for melting snow.

  Next, the action during actual snowfall will be described with reference to the schematic cross-sectional view of FIG.

  When the snow melt is energized, both the solar cell element 1 and the resistance heating element 2 act as a heating element, and the solar cell element 1 generates heat to warm the plate glass 13, so that the snow 15 can reach the snow stopper 10 c of the lower solar cell mounting rail. Slide. The solar cell mounting rail 10 is configured such that the solar cell module is sandwiched and fixed to the main body 10b using the rail cover fixing screw 16 in the cover 10a, and the resistance heating element 2 is interposed between the solar cell mounting rail main body 10b and the cover 10a. The snow can be melted locally.

(Example 4)
FIG. 4 is a schematic circuit diagram schematically illustrating a fourth embodiment of the solar cell module according to the present invention.

  The structure of the resistance heating element built-in solar cell mounting system 22 is substantially the same as that of the above-described third embodiment, except that the circuit connection method and the switching circuit 8 are used instead of the diode 3.

  The resistance heating element 2 is connected via the switching circuit 8a so as to form a parallel circuit with the strings 9 of the solar cell module. In this way, although the number of connecting cables to the resistance heating element 2 is increased by one, the output wiring work of the strings 9 of the solar cell module can be constituted by two plus and minus lines as in the case of a normal solar cell module. The wiring after the connection box 11 can be shared for power generation and snow melting. This switching circuit 8 a is assumed to be housed in the connection box 11. In this example, the switching circuit 8b is also provided in the output wiring of the strings 9 of the solar cell module, but this is not necessarily required to achieve this object.

  Here, an actual current flow will be described.

  During normal power generation, electricity generated by the solar cell is output from the positive side. In the solar cell system 12, a current flows from the minus output terminal of the connection box 11 toward the plus output terminal. At this time, the switching circuit 8a of the resistance heating element 2 may be turned off, and the switching circuit 8b of the output wiring of the strings 9 of the solar cell module may be turned on.

  Next, when the snow melts, a voltage is applied to the positive output terminal of the connection box 11 so that a reverse current flows. At this time, if the switching circuit 8a of the resistance heating element 2 is turned on and the switching circuit 8b of the output wiring of the strings 9 of the solar cell module is also turned on, the strings 9 of the solar cell module generate heat as a resistor due to the reverse current, and the resistance A current also flows through the heating element 2 and acts as an electric heater for melting snow.

The actual operation during snowfall will be explained in the same way as in the third embodiment by using the schematic structural cross-sectional view of FIG. 6, and the ON / OFF time of the switching circuit 8 in the second embodiment in that more efficient snow melting can be performed. This is the same as the control for changing the ratio.

It is a schematic circuit block diagram which illustrates typically the 1st Example of the solar cell module which concerns on this invention. It is a schematic circuit block diagram which illustrates typically the 2nd Example of the solar cell module which concerns on this invention. It is a schematic circuit block diagram which illustrates typically the 3rd Example of the solar cell system which concerns on this invention. It is a schematic circuit block diagram which illustrates typically the 4th Example of the solar cell system which concerns on this invention. It is a schematic structure sectional view for explaining typically the 1st and 2nd examples of the solar cell module concerning the present invention. It is a schematic structure sectional view for explaining typically the 3rd and 4th example of the solar cell module concerning the present invention. It is sectional drawing which illustrates typically the snow melting structure of the conventional solar cell module.

Explanation of symbols

1: Solar cell element 2: Resistance heating element 3: Diode 4: Joint box 5: Solar cell module 6: Metal frame frame 6a: Metal frame frame (lower stage)
6b: Metal frame (upper)
6c: Metal frame (snow stopper)
7, 77: Resistance heating element built-in solar cell module 8a: Resistance heating element wiring switching circuit 8b: Solar cell wiring switching circuit 9: Solar cell module string 10: Solar cell mounting rail 10a: Solar cell mounting rail (cover)
10b: Solar cell mounting rail (main body)
10c: Solar cell mounting rail (snow stopper)
11: Connection boxes 12, 22: Resistive heating element built-in solar cell mount system 13: Sheet glass 14: Laminate material 15: Snow cover 16: Rail cover fixing screw 17: Heat pipe 18: Weather resistant film 20: Solar cell module

Claims (4)

In a solar cell module in which a solar cell module having a frame attached to an end of a solar cell panel having a solar cell element string made of a plurality of solar cell elements is inclined and positioned below the solar cell module A solar cell module, wherein a heating resistor is attached to a frame, a diode is connected in parallel to the heating resistor, and wiring of the solar cell element string is connected in series to the heating resistor. A solar cell module in which a solar cell module having a frame attached to an end of a solar cell panel having a solar cell element string composed of a plurality of solar cell elements is installed at an angle, below the solar cell module A heating resistor is attached to the frame body, and the heating resistor is connected in parallel to the wiring of the solar cell element string, and a switch for cutting off the current flowing through the resistance heating element in series with the heating resistor is provided. A solar cell module characterized by that. A solar cell array in which a solar cell module string in which a plurality of solar cell modules are connected in series is installed on a rail-shaped frame, and a heating resistor is attached to the frame, and a diode is connected in parallel to the heating resistor In addition, a solar cell array, wherein the wiring of the solar cell module strings is connected in series to the heating resistor. A solar cell array in which solar cell module strings in which a plurality of solar cell modules are connected in series are installed on a rail-shaped frame, wherein a heating resistor is attached to the frame, and the heating resistor is connected to the solar cell module strings. And a switch for interrupting a current flowing through the heating resistor in series with the heating resistor.

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