JPH04200245A - Solar cell system - Google Patents

Abstract

PURPOSE:To eliminate the shortage of the power supply when the weather is cloudy or rainy by assuming the quantity of solar radiation of the next day from the received weather forecast, and performing the operation to determine the charge level of the storage battery for the next day from this quantity of radiation, and charging the storage battery with the night power. CONSTITUTION:This is composed of a solar cell 1, a storage battery 2, a weather forecast receiving means 3, an operating means 4, a measuring means 5, a charge means 6. The quantity of solar radiation of the next day is assumed, receiving the forecast and considering this weather forecast, season, etc. By this quantity of solar radiation, the quantity of power required for supplementing the shortage of the power supply by the solar cell 1 of the next day is determined, and the charge level of the storage battery 2 is determined so that it can supply this quantity of power. And it is charged at night until the charge level of the storage battery 2 reaches the decided value. The quantity of power which is assumed to run short the next day can be charged in the storage battery 2, and also charging the storage battery excessively the energy loss due to can be reduced.

Description

[Detailed Description of the Invention] [Field of Industrial Application] ゛The present invention relates to a solar cell system for supplying power to buildings such as houses, and in particular, to a system for resolving power shortages in solar cells due to bad weather. This relates to a solar battery system that supplements electricity with the previous night's electricity based on weather forecasts.

[Prior Art] Conventionally, there have been houses called solar houses designed to effectively take in sunlight and use it for lighting, etc.

In addition, in recent years, active solar houses have been developed, which actively utilize solar energy by equipping them with concentrators, heat collectors, etc., in order to utilize sunlight not only for lighting but also for hot water supply, air conditioning, and other energy sources. Something called is appearing.

Furthermore, in order to use solar energy effectively, there is a method of using solar cells that convert sunlight into electricity, which is a highly versatile energy source. Capital investment for installation and
There was an economic problem when considering the price of electricity supplied by the electric power company.

However, as the price of solar cells has decreased and the electromotive force per area and amount of solar radiation has increased due to recent technological innovations, solar houses using solar cells have entered the stage of practical use.

Furthermore, while household electricity consumption is increasing due to the spread of air conditioners and other electrical appliances in the home and the increasing size of electrical appliances, when considering the global environment,
The global warming phenomenon associated with the increase in carbon dioxide in the atmosphere due to the consumption of fossil fuels during thermal power generation, the fatal environmental destruction in the event of an accident at a nuclear power plant, and the Consider the issue of radioactive waste, etc.
There are problems with increasing the amount of electricity supplied by increasing the number of power generation facilities any further.

Therefore, there has been a desire for a solar power system that can use clean solar energy as electricity for household use.

``Problems to be solved by the invention'' By the way, when power is supplied by solar cells,
Naturally, the amount of power generated varies depending on the amount of light that hits the solar cells, and there is a problem in that the amount of power that can be used is drastically reduced due to fluctuations in the amount of solar radiation due to weather, seasons, etc.

In addition, solar cells rarely generate power at night when there is no sunlight, and at night or on days when the weather is inclement, they either receive power from the power company or increase the power generation capacity of the solar cells in advance. Therefore, it was necessary to charge a storage battery with surplus electricity during the day when the weather was good, and use the electricity from this storage battery.

However, when increasing the power generation capacity of solar cells, the area and equipment investment for the solar cells becomes large.
Further, even if the power generation capacity is large, there is a problem in that it is difficult to cover the power consumption at night if the weather continues for a long time.

In addition, when receiving electricity from a power company, it is better to receive electricity under a night power contract than under a regular contract, since power is mainly supplied at night. However, the cost is low, and power generation equipment can be used effectively by using nighttime power, which consumes less power. However, the problem with nighttime electricity is that it is impossible to receive electricity during the day when the weather is unseasonable.

The present invention has been made in view of the above circumstances, and its purpose is to supply electricity consumed by houses etc. using solar cells, and also to solve the problem when the electricity supply by solar cells is insufficient during inclement weather. An object of the present invention is to provide a solar cell system that can effectively utilize nighttime power in certain cases.

[Means for Solving the Problems] In order to achieve the above object, the solar cell system of the present invention includes a solar cell that supplies power to a house, etc., a storage battery that makes up for the shortage of power supply by the solar cell, a weather forecast receiving means; a calculating means for estimating the next day's solar radiation from the received weather forecast and determining the next day's charge level of the storage battery from this solar radiation; a measuring means for measuring the charge level of the storage battery; and charging means for charging the storage battery with nighttime power until the charge level measured by the calculation means reaches the charge level determined by the calculation means.

[Operations] According to the above configuration, first, a weather forecast is received, and the amount of solar radiation for the next day is statistically estimated in consideration of the weather forecast and the season. Based on this amount of solar radiation, the amount of power required to make up for the shortfall in the power supply from the solar cells the next day is determined, and the charge level of the storage battery is determined so that this amount of power can be supplied. Then, nighttime power is charged until the charge level of the storage battery reaches a predetermined value. Therefore, it is possible to charge the storage battery with the amount of power that is predicted to be insufficient the next day, and it is also possible to reduce energy loss that occurs due to charging the storage battery with excess power.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a drawing showing an outline of an embodiment of the present invention, and the solar cell system of this embodiment includes a solar cell 1 that supplies power to a house A, etc., and a solar cell 1 that supplies power to a house A and the like. A storage battery 2 to make up for the shortage, a weather forecast receiving means 3, a calculating means 4 for estimating the next day's solar radiation from the received weather forecast and determining the next day's charge level of the storage battery from this solar radiation, and a calculation means 4 for determining the next day's charge level of the storage battery. and the charging level measured by the measuring means 5 is calculated by the calculating means 4.
the storage battery 2 until it reaches a charge level determined by
and a charging means 6 for charging electricity during the night.

Next, the solar cell system of this example will be explained in detail.

The solar cell I is installed on the upper surface of the roof on the south side of house A, and its area is set so that it has a power generation capacity of about 2kV to 4kw, which can cover the power consumption of a normal house during the day. Within the range of 2 (in” to 40m!
degree. Note that the area of the solar cell I is determined by taking into consideration the power consumption of the house A in which it is installed, the position of the house A, the slope of the roof, the amount of solar radiation, etc.

The storage battery 2 is a lead storage battery, and its capacity is approximately twice the power supplied by the solar cell 1 in one day.

The weather forecast receiving means 3 consists of a telephone line modem 3a for computer communication and a personal computer 4a, and receives the weather forecast in advance from the host computer 7 via the telephone line 7a to the solar cell of this embodiment. The information is sent to each house A equipped with the system.

When transmitting the weather information, it is divided into four categories: clear, sunny, cloudy, and rainy.

The calculation means 4 is composed of a personal computer 48 or the like, and calculates the received value of solar radiation on clear, sunny, cloudy, and rainy days by 1.0 and 7.5 from the statistical value of the electromotive force of the solar cell depending on the weather.・
0.5 and 0.2, and the charging level is determined based on these values.

Note that this value depends on the capacity of the solar cells, the slope of the roof,
It changes depending on the direction of the top surface of the roof, etc., and is determined by taking these into consideration.

In addition, in the personal computer 4a, the difference in the sunshine hours depending on the season, the difference in the power consumption of the house A depending on the season, etc. are converted into coefficients in advance to the above-mentioned value, and the correction is made by multiplying the coefficient by the value of the above-mentioned amount of solar radiation.

The measuring means 5 measures the charge level of the lead-acid battery 2. The charge level of the lead-acid battery 2 can be known by measuring the specific gravity of the electrolyte. By installing a well-known hydrometer capable of outputting a signal, the charge level can be input from the hydrometer to the personal computer 4a serving as the calculation means 4 via an AD converter.

Therefore, the personal computer 4a sets the value of the specific gravity at which supplementary charging is required due to discharge of the storage battery 2 to be a charging level 0, and sets the charging level when the electrolyte returns to the original specific gravity of sulfuric acid by charging to be 100. It has become. Since the capacity of the storage battery I is approximately twice the power generation capacity of the solar cell I, the charge levels from 0 to 50 are used as reserve power in case the weather forecast is incorrect. Therefore,
When the amount of solar radiation is 1, the charge level of storage battery 1 is set to 50 so that the power is provided by solar cell 1 without using the power of the storage battery, and when the amount of solar radiation is 0, solar cell 1 cannot be used. , the charge level is set to 100 so that the storage battery 2 supplies all the power.

That is, when the charge level is L and the value of the amount of solar radiation is S, the charge level L is expressed by the following equation (2).

■・・・・・・L=50(2-S) Note that this formula (■) is an example and may be changed depending on changes in the reserve charging level or increase/decrease in the power consumption of house A. I don't mind.

The charging means 6 converts alternating current into direct current and charges the storage battery 2, and in this embodiment, the solar battery 1, the storage battery 2, and the nighttime power are used to charge the solar battery 1, the storage battery 2, and the nighttime power to the house according to the amount of power generated by the solar battery 1. A power distribution board 6a is controlled by a personal computer 4a to supply power to A.

Charging of the storage battery 2 is continued from the start of night power transmission until the value of the specific gravity of the electrolyte of the lead storage battery 2 sent from the hydrometer 5a reaches the value determined by the calculation means.

When the solar battery system of this embodiment is used to supply power to house A, first, the next day's weather forecast is sent via the telephone line 7a to the personal computer 4a that controls the solar battery system. Then, the personal computer 4a, as the calculation means 4, estimates the amount of solar radiation for the next day from the results of the weather forecast. Then, the charge level of the storage battery 2 is determined so as to be able to supplement the amount of power that will be consumed in the house A the next day and is expected to be insufficient in the power supply from the solar battery. At this time, this charge level also includes reserve power in case the weather forecast is incorrect. Then, when the supply of electricity at night starts, charging of the storage battery 2 is started, and the hydrometer 5
When the charge level measured by step a reaches a predetermined charge level, charging is stopped. Note that when charging starts, if the charge level of the storage battery 2 is already equal to or higher than the charge level determined by the personal computer, charging will not be performed.

Then, power is supplied to the house from the switchboard 6a, mainly using the power from the solar cell 1, with supplementary power from the storage battery 2 and nighttime power. Further, the power of the solar cell 1 that is not consumed is charged to the storage battery 2.

Therefore, if the weather is as per the weather forecast, during the day, the storage battery 2, excluding the power from the solar battery 1 and the reserve power charged the previous day.
The power consumption of house A is covered by the electricity of
and nighttime electricity.

Additionally, if the weather forecast turns out to be incorrect and the weather improves, the charged power will be left over and carried over for the next day.

If the weather forecast is incorrect and the weather worsens, the power stored in the storage battery 2 as a reserve is used.

As explained above, according to the solar cell system of this embodiment, the solar cell 1 and the storage battery 2, which is charged with nighttime electricity based on the weather forecast, can efficiently supply the power consumed by a house or the like.

By supplying household electricity with the solar cell 1 and nighttime electricity, which costs less than general electricity, it is possible to reduce the cost of electricity for the house.

In addition, in the solar cell system of this embodiment, the power required for the next day is charged the day before based on the weather forecast, so there is no power loss during charging and discharging, or power loss due to self-discharge. can reduce running costs.

Furthermore, the daytime power consumption of the house can be covered by the solar battery 1 and nighttime power, so when the electric power company's power supply reaches its peak, such as on a hot summer day,
A house equipped with the solar cell system of this embodiment does not need to consume electricity from an electric power company, and the peak value of electricity supply can be reduced. Therefore, since it is difficult to store electricity, it is possible to reduce or suppress the increase in power generation facilities that are constructed to coincide with the peak of power supply, and also to reduce the amount of carbon dioxide and nuclear energy generated by the consumption of fossil fuels from power generation facilities. It is possible to reduce or suppress the increase in radioactive waste generated by power generation, thereby suppressing the progress of environmental destruction.

In this embodiment, the weather forecast receiving means 3 communicates with a personal computer through the telephone line 7a, but the weather forecast is transmitted by a communication satellite to houses equipped with solar battery systems in the wide area. The forecast may be received at a branch office in each region, and the received weather forecast may be transmitted via data communication such as personal computer communication via the telephone line 7a, and then received by the computer. Furthermore, instead of transmitting the weather forecast for the solar battery system, the weather forecast may be read in the form of teletext telecast into the personal computer using a well-known image analysis method.

The method of estimating the amount of solar radiation from the weather forecast is to divide the weather into four parts, but it also divides the weather into smaller parts like an actual weather forecast, and also includes changes in the weather over time for the next day. It's good as well.

In addition, the solar cell system of this example does not necessarily cover the entire power of house A during the daytime, but considering the amount of electricity consumed in the house, the capital investment amount for the solar cell system, the area of the roof, etc. For example, it may be possible to supply only electricity related to air conditioning.

[Effects of the Invention] As described above in detail, the solar cell system of the present invention can provide the following excellent effects.

(a) The power consumption of houses, etc. can be efficiently supplied by solar cells and storage batteries charged based on weather forecasts.

(b) The cost of electricity for the house can be reduced by providing electricity for the house using solar cells and nighttime electricity.

(C) Based on the weather forecast, the electricity required for the next day is charged the day before, which reduces power loss during charging and discharging, as well as power loss due to self-discharge, and allows storage batteries to run smoothly. Costs can be lowered.

(d) Furthermore, since the daytime power consumption of a house can be covered by solar cells and nighttime electricity, when the electric power company's power supply reaches its peak, such as on a hot summer day, the electric power company can It is possible to reduce the peak value of power supply. Therefore, since it is difficult to store electricity, it is possible to reduce or suppress the increase in power generation facilities that are constructed to coincide with the peak of power supply, and also to reduce the amount of carbon dioxide and nuclear energy generated by the consumption of fossil fuels from power generation facilities. It is possible to reduce or suppress the increase in radioactive waste generated by power generation, thereby suppressing the progress of environmental destruction.

[Brief explanation of the drawing]

FIG. 1 shows one embodiment of the present invention, and is a schematic diagram of a solar cell system. ■...Solar cell, 2...Storage battery, 3...Weather forecast receiving means, 4...Calculating means, 5...Measuring means , 6... Charging means.

Claims (1)

[Claims] A solar battery that supplies electricity to houses, etc., a storage battery that makes up for the lack of electricity supplied by the solar battery, a weather forecast receiving means, and a means for estimating the next day's solar radiation from the received weather forecast. a calculation means for determining the charge level of the storage battery; a measurement means for measuring the charge level of the storage battery; and a calculation means for supplying nighttime power to the storage battery until the charge level measured by the measurement means reaches the charge level determined by the calculation means. A solar battery system consisting of a charging means for charging.