JP2013158094A - Electric power selling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow inexpensive power, which has charged a storage battery during the night (purchased power), to be sold to a commercial power supply system in the next morning.SOLUTION: Power is generated from a solar cell panel 11 receiving sunlight in daytime, and the power from a commercial power supply system 19 is stored in a storage battery 17 during midnight power contract time (during a set time). The power stored in a storage battery 12 is fed, together with the power generated from the solar cell panel 11, to the commercial power supply system 19 during a time zone other than the midnight power contract time.

Description

  The present invention relates to a power selling system that uses a solar battery panel and a storage battery in combination, and sells the stored power stored in the storage battery at night to a commercial power supply system in the daytime when the power utilization rate is high.

  Today, for the purpose of preventing air pollution and preventing global warming, power generation systems using clean energy using natural energy, particularly sunlight, instead of fossil fuels have become common. However, the energy obtained by this power generation system is unstable, and in the clear daytime when the sun is out, you can expect enough power generation more than the power consumed by the load. There is little generated power or almost no power generation can be expected.

  For this reason, until now, when the amount of power generated by a power generation system using sunlight or the like exceeds the amount of demand in the load, the surplus power corresponding to the amount of power generated is stored in a storage battery, while the amount of power generated by the power generation system Discloses a technique for discharging the power stored in the storage battery to the load when the demand amount in the load falls below, and leveling the power supply to the load (for example, see Patent Document 1). Furthermore, a grid-connected power selling system that sells this surplus power to a power plant of an electric power company when the amount of power generated in the daytime is larger than the capacity of the storage battery is also known.

JP 2011-151959 A

  However, in such a conventional power storage system, it is possible to supply or sell DC power generated in the solar cell panel during the daytime when sufficient solar energy is obtained to a load during the daytime when the power utilization is high. However, there is a difficulty in always stably selling (supplying) electric power to the commercial power supply system because there is a variation in time when solar energy is always sufficiently obtained depending on weather conditions.

  The present invention has been made in view of such conventional problems, and an object of the present invention is to generate electric power generated by a solar cell panel in the daytime from stored electric power taken in from a commercial power supply system and stored in a storage battery. At the same time, by converting to AC power and supplying it to the commercial power supply system, low-cost power charged to the storage battery (purchasing power) at night is supplied to the commercial power supply system (power sales), so that the consumer side uses the power. The object is to provide a charging system capable of reducing charges.

  In order to achieve the above-described object, a power selling system according to the present invention includes a solar cell that generates power by receiving sunlight in the daytime, and power from a commercial power system within a midnight power contract time (within a set time). And a controller that enables the power generated by the solar battery panel and the power stored in the storage battery to be supplied to the commercial power supply system in a time zone other than the midnight power contract time. Features.

  With this configuration, cheap power from the commercial power supply system is stored in the storage battery at the midnight power contract time, and the stored power of the storage battery stored at low cost is consumed by the load out of the power generated by the solar panel in the daytime. The power can be supplied to the commercial power system along with the power exceeding the generated power, and the power can be sold to the commercial power system while continuing to supply power to the load.

  Moreover, the power sale system according to the present invention is characterized in that a storage battery for midnight power dedicated to storage of midnight power is additionally provided in the storage battery.

  With this configuration, even when the DC power generated by the solar cell panel is insufficient or the stored power of the storage battery is insufficient at the start of power supply to the load, together with the power generated by the solar cell panel It becomes possible to sell the electric power discharged from the midnight power storage battery to the commercial power supply system while continuing to supply the load as necessary. The amount of power sold in this way increases with an increase in the number of late-night power storage batteries installed, thereby increasing the amount of electricity stored and the amount of power sold.

  According to the present invention, midnight power purchased at low cost at night and power generated by a solar panel can be sold at high cost to a commercial power system during the daytime when the load power utilization rate is high, and commercial power can be supplied from the commercial power system. Customers who receive the supply can benefit from reduced electricity consumption and reduced electricity bills.

  The present invention has been briefly described above. Further, the best mode for carrying out the invention described below will be described in detail with reference to the accompanying drawings.

It is a block connection diagram showing a power selling system according to an embodiment of the present invention. It is a circuit diagram which shows another embodiment of the electrical storage device in FIG.

  Hereinafter, a power selling system according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  The power selling system of this embodiment generates power in a solar cell that receives sunlight in the daytime, and causes the midnight power storage battery to store the power from the commercial power supply system within the midnight power contract time (within the set time), The controller is configured to feed the power stored in the storage battery to the commercial power supply system at midnight together with the power generated by the solar cell panel in a time zone other than the midnight power contract time.

  As a result, cheap power is stored from the commercial power supply system at the midnight power contract time, and the stored power of the storage battery stored at low cost can be supplied to the commercial power supply system together with the power generated by the solar panel in the daytime. Thus, it is possible to sell power to the commercial power system while continuing to supply power to the load.

  As shown in FIG. 1, the power selling system according to this embodiment includes a solar cell panel 11, a capacitor 12, a power converter 13, a switch 14, a controller 15, and a timer signal output device for midnight power. 16. Among these, the solar cell panel 11 is configured so that a plurality of solar cells (cells) are connected in series and parallel to obtain a predetermined voltage and current. For example, a plurality of solar cell panels 11 are installed on the roof of a customer's building or the roof of the house.

  The storage battery 12 includes one or more storage batteries 17 and functions to store and discharge the power generated by the solar battery panel 11 and the power supplied from the outside (commercial power supply system) to the storage battery 17. When the power generation amount of the solar battery panel 11 is larger than the power consumption of the load 18, the storage battery 17 stores excess power exceeding the power generation amount, and the generated power amount of the solar battery panel 11 is the power consumption of the load. When the amount is smaller than the amount, the stored power can be supplied to the load.

  Further, in this embodiment, the storage battery 17 functions to store midnight power, and functions to supply power to the commercial power supply system 19 in addition to replenishing power that has decreased in amount due to additional power supply in the daytime. To do. Therefore, it is desirable that the storage battery 17 used here has a sufficiently large charging power capacity. Further, a rechargeable ion battery or a rechargeable ion polymer that has a high voltage, a high energy density, can be rapidly charged, and can obtain a high output. The use of batteries is advantageous. However, not only the lithium ion battery or the lithium ion polymer battery but also a nickel cadmium battery or a nickel metal hydride battery can be used as necessary.

  The power converter 13 is a bidirectional DC / AC converter, which synchronizes the DC power generated by the solar battery panel 11 and the DC power discharged by the battery 12 with the AC power phase of the commercial power supply system 19. On the other hand, the AC power from the commercial power supply system 19 is converted into DC power so that the storage battery 17 can be charged. The power converter 13 may be connected to the solar panel 11 side with a DC / DC converter for direct current power amplification.

  The switcher 14 switches the AC power obtained by converting the DC power from the solar battery panel 11 or the capacitor 12 by the power converter 13 to the commercial power supply system 19 or the load 18, or the AC power supplied from the commercial power supply system 19. It functions to switch and supply electric power to the storage battery 17 or the load 18 via the power converter 13.

  Based on the output value of the DC power generated by the solar battery panel 11, the power consumption value of the load 18, and the output value of the timer signal output device 16, the controller 15 charges and discharges the storage battery 17 and the power of the power converter 13. It functions to control the conversion operation and the switching operation of the switch 14. A backflow prevention diode 20 for protecting the solar cell is connected between the solar cell panel 11, the power converter 13, and the storage battery 17. In addition, by connecting a display 21 to the controller 15, various remaining messages are displayed on the display 21 in addition to the remaining amount of power stored in the storage battery 17, the amount of power sold, and the amount corresponding to the amount of power. Can be made.

  In the power selling system having such a configuration, the solar battery panel 11 receives sunlight in the daytime and generates a predetermined value of DC power. This direct current power is supplied to the battery 12 through the backflow prevention diode 20 and charges the battery 17. At this time, the DC power exceeding the capacity of the storage battery 17 is converted into AC power synchronized with the phase of AC power of the commercial power supply system 19 by the power converter 13 and input to the switch 14.

  The switcher 14 supplies this AC power to either one or both of the load 18 and the commercial power supply system 19. Further, the switch 14 feeds the DC power converted from AC power by the power converter 13 from the commercial power system 19 through the power converter 13 to the storage battery 17, together with or supplied to the storage battery 17. Separately, the AC power from the commercial power supply system 19 is switched to be supplied to the load 18.

  The controller 15 receives the generated power value of the solar battery panel 11 and the power consumption value of the load 18 as inputs, and controls the operation of the battery 12, the power converter 13 and the switch 14, and turns on / off the timer signal output device 16. Based on the OFF signal, the switching operation of the switch 14 is controlled.

  The commercial power supply system 19 enables supply of AC power to the load 18 on the consumer side via the switching device 14, and when the amount of power output from the solar cell panel 11 or the storage battery 17 is small or absent, The AC power of the commercial power supply system 19 is stably supplied to the load 18 via the switch 14. In this case, when the generated power of the solar cell panel 11 is sufficient, the controller 15 compares the consumed power amount of the load 18 with the DC power amount generated by the solar cell panel 11, and the generated DC power amount. Is larger than the power consumption of the load 18, the surplus power exceeding the power consumption is stored in the storage battery 17, and the surplus power after charging is supplied to the commercial power supply system 19 and the load 18 through the switch 14. . At this time, power supply from the commercial power supply system 19 to the load 18 is temporarily interrupted, and at this time, there is no power purchase from the commercial power supply system 19.

  On the other hand, when the amount of DC power generated by the solar battery panel 11 is smaller than the amount of power consumed by the load 18, the stored power of the stored storage battery 17 is supplied to the load 18. When the storage power of the storage battery 17 is reduced, AC power is supplied from the commercial power supply system 19 to the load 18 via the switching device 14, and the AC power is converted into DC power by the power converter 13. This is stored in the storage battery 17. For this reason, the load 18 receives AC power from the commercial power supply system 19 and continues its operation or operation.

  Further, when the power consumption amount of the load 18 is larger than the power supply amount of the commercial power supply system 19, the power amount of the commercial power supply system may be reduced, and the operation of the load 18 may become unstable. If sunlight is sufficiently obtained at this time, the solar panel 11 stores high-level DC power in the storage battery 17 and supplies the surplus power after the storage to the commercial power system 19 via the switch 14. Can do. As a result, power can be sold from the consumer to the commercial power supply system 19.

  Moreover, in the power sale system of this embodiment, late-night power is used. This midnight power is power supplied from night time (for example, 11:00 pm) to the next morning (for example, 7:00 am) where power consumption by the load 18 connected to the commercial power supply system 19 is low. The usage fee is significantly cheaper than in the daytime, for example, 1/3 to 1/4 of the normal (daytime) power rate.

  Therefore, midnight (alternating current) power obtained from the commercial power supply system is received from the commercial power supply system 19 via the switching device 14 and the power converter 13 in the middle of the night even when the solar cell panel 11 does not generate power (purchased power). The DC power converted by the power converter 13 is stored in the storage battery 17 of the battery 12. This power storage is performed in the predetermined midnight time zone regardless of whether or not power is supplied from the commercial power supply system 19 to the load 18. For this reason, the storage battery 17 that has been no longer in the charged state until now is fully charged with the DC power.

  On the other hand, in the next morning, when the solar cell panel 11 receives sunlight and generates electric power at a level that can be supplied to the load 18, the controller 15 charges the DC power generated by the solar cell panel 11 at night. The DC power obtained by adding the DC power discharged from the storage battery 17 is applied to the power converter 13 and converted into AC power. This AC power is a high level of power obtained from both the solar cell panel 11 and the battery 12.

  Therefore, surplus power exceeding the power consumption of the load 18 connected to the commercial power supply system 19 among the high-level AC power is supplied to the commercial power supply system 19. As a result, by returning the power obtained from the storage of inexpensive nighttime power to the commercial power supply system 19 side, the amount of power used from the commercial power supply system 19 to the consumer side can be reduced and the power usage fee can be reduced. You can save money. In addition, the amount of electricity stored in the battery 12, the amount of power sold to the commercial power supply system 19, the power sale price, and the like are displayed on the display 21. Further, the controller 15 executes such charging / discharging of the battery 12, the power conversion operation by the power converter 13, and the switching operation of the switch 14 according to a predetermined program.

  FIG. 2 shows another embodiment of the battery 12. The battery 12 is formed by connecting one or a plurality of midnight power storage batteries 23 in parallel to the storage battery 17 via a timer switch 22. Here, the timer switch 22 is controlled to be opened / closed by an on / off signal output from the timer signal output unit 16 or by a separately set timing signal. For example, the timer switch 22 is turned on during the supply time of midnight power, whereby AC power supplied from the commercial power supply system 19 is input to the power converter 13 via the switch 14, and the power converter 13 The converted DC power is stored in the late-night power storage battery 23. Then, the time switch 22 is turned off at the timing when all the midnight power storage batteries 23 become full.

  Then, the timer switch 22 is turned on at the timing when the solar cell panel 11 generates a sufficient level of DC power at the set time of the next morning (7 o'clock). As a result, the DC power discharged from the midnight power storage battery 23 and the DC power generated from the solar battery panel 11 are input to the power converter 13, and the AC power converted by the power converter 13 is switched to the switch 14. To the commercial power supply system 19. In this way, late-night power can be sold to the commercial power supply system 19 at a time when the demand for power in the daytime is high, and as a result, the consumer side benefits from the reduction of the power charge.

  As described above, in the present embodiment, power is generated in the solar cell panel 11 that receives sunlight in the daytime, and the power from the commercial power supply system 19 is stored in the storage battery within the midnight power contract time (within the set time). In the time zone other than the midnight power contract time, the controller 15 supplies the power stored in the storage battery to the commercial power supply system 19 together with the power generated by the solar cell panel 11, so that Low-cost electric power is stored from the power supply system 19, and the stored electric power of the storage battery 17 stored at low cost is the electric power generated by the solar battery panel 11 in the daytime, together with electric power that exceeds the electric power consumed by the load 18, The power can be supplied to the commercial power supply system 19 and the power can be sold to the commercial power supply system 19 while the power supply to the load 18 is continued.

  The power selling system of the present invention can supply inexpensive late-night power stored in the middle of the night to the commercial power system together with the power generated by the solar panel in the daytime. It is useful for a power selling system or the like that uses a solar battery panel and a storage battery in combination, and supplies the stored power stored in the storage battery at night to a commercial power supply system during the daytime when the power utilization rate is high.

DESCRIPTION OF SYMBOLS 11 Solar cell panel 12 Electric power storage device 13 Power converter 14 Switcher 15 Controller 16 Timer signal output device 17 Storage battery 18 Load 19 Commercial power supply system 21 Indicator 22 Timer switch 23 Power storage area for midnight power

Claims (2)

A solar cell panel that generates power by receiving sunlight in the daytime;
A storage battery that stores power from the commercial power system within the midnight power contract time (within the set time);
A controller for controlling the power stored in the storage battery together with the power generated by the solar cell panel in a time zone other than the midnight power contract time so as to be able to supply power to the commercial power supply system;
A power selling system characterized by comprising:   The power storage system according to claim 1, wherein the storage battery is additionally provided with a storage battery for late-night power used exclusively for storage of late-night power.

Images