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How to simply measure the installed photovoltaic capacity of your home?
Friends often ask about how much capacity photovoltaic power plants should be installed in their homes. In fact, many friends outside the photovoltaic industry have fallen into a misunderstanding: thinking that the size of photovoltaic power plants is related to household appliances.
In fact, to put it simply, the photovoltaic power station will not only supply power to a certain electrical appliance, but will supply power to the entire family. The photovoltaic power and the electricity of the national grid will supply power to the family together!
Schematic diagram of grid-connected photovoltaic power generation system
The above picture is a schematic diagram of a typical grid-connected photovoltaic power generation system. It can be seen that the photovoltaic power generation is used by the load first. If the photovoltaic power generation > the load power consumption, the electricity can be sold to the upper power grid. If the photovoltaic power generation < the load power consumption , the grid power and photovoltaic power supply power to the load together, so your photovoltaic power station is equivalent to a small tributary of the large power grid, and it is merged into the large power grid together. How many electrical appliances do you have at home, and the question of whether the photovoltaic power station installed by yourself is enough to generate enough electricity!
So how do you know how much photovoltaic power generation system you should install in your home?
There are three main determining factors: grid company requirements, electricity consumption in the home, and available installation area.
According to the requirements of Shaanxi local power grid company, 8kW and below can be connected to 220V; 8kW to 400kW can be connected to 380V; 400kW to 6000kW can be connected to 10kV. Therefore, if the home is 220 volts, the maximum can only be connected to 8 kilowatts. At present, the State Grid and the South Grid have not clearly issued a document requiring the relationship between the grid connection level and the installed capacity!
The home photovoltaic power generation system generally adopts the mode of "spontaneous use of surplus electricity to connect to the Internet". The more electricity is used, the better the income and the more obvious the economic benefits! Therefore, the installed photovoltaic capacity should match the power consumption of the home as much as possible!
On the other hand, if the roof area is large, you can try to lay the installed photovoltaic capacity according to the capacity of the roof area. After all, the income of photovoltaic is still good!
Simple calculation method:
Taking the commonly used monocrystalline silicon photovoltaic modules as an example, a photovoltaic module has a length of 1644 mm, a width of 992 mm, and a nominal power of 280 watts. The calculation shows that each kilowatt photovoltaic power generation system requires an installation area of about 6 square meters.
Each kilowatt photovoltaic power generation system can generate 1200 kWh of electricity throughout the year. (China has a vast territory and a huge area, and the power generation volume varies greatly from place to place. Only the power generation volume in the surrounding areas of Beijing is taken as an example)
for example:
Lao Wang's house uses 5,000 kWh of electricity every year, and the roof can be installed on an area of 50 square meters.
According to the calculation method, Lao Wang's house can install a 3KW photovoltaic power generation system, which can generate 3600 kWh of electricity annually. Because the family uses more electricity at night, 3600 kWh can basically meet all the electricity consumption during the day! The 3KW photovoltaic power generation system requires a roof area of about 20 square meters, which also meets the conditions!
If Lao Wang wants to make full use of the roof of his home, he can install up to 8KW photovoltaic power generation system, which can not only meet the electricity consumption of the home, but also upload excess electricity to the national grid to make money by selling electricity.
The installable area is related to factors such as the type of house, roof area, and orientation. It can only be determined after a professional visit. After the installable area is determined, the size of the photovoltaic power station that can be installed in the home can be determined.