In recent years, the state has vigorously supported the development of the photovoltaic industry, especially in favor of distributed photovoltaics. Many forward-thinking individuals have taken advantage of national policies to install photovoltaics on their roofs. So, what are the benefits of installing photovoltaic power plants? A comprehensive investigation found that, first of all, the photovoltaic power station is installed on the roof, which has good heat insulation effect, reduces the use of air conditioners in summer, and can achieve energy saving and emission reduction effects. Every 1 kilowatt-hour of photovoltaic electricity generated by photovoltaics is equivalent to reducing the burning of 0.4KG standard coal, reducing carbon emissions by nearly 1KG, and reducing dust by 0.27KG. It cannot be underestimated to improve our living environment, and the home photovoltaic power station is a one-time investment, and the return cycle Long-term, the income is as long as 25 years, and there is also the saying of "photovoltaic pension". Its annual yield is higher than 14%, far exceeding bank deposit interest rates. With the Chinese government's vigorous promotion of distributed photovoltaics and the reduction of construction and installation costs, in the future, photovoltaic power stations will be "roof banks" that can be seen everywhere, not only for investment and financial management, but also for retirement.
The household energy storage photovoltaic power generation system is very suitable for installation and use in villas, self-built houses in the suburbs, and single-family shops. Not only can it supply power to all the electrical appliances needed for daily use, but it can also avoid the adverse effects caused by power outages and save electricity bills at the same time. However, the solar power generation system is not a standardized product, and the same configuration may not be suitable for all users. It needs to be designed and configured according to the user's own situation, and many users know little about it. So for users who intend to purchase solar power generation systems, what considerations should they make before purchasing?
Usually, individuals applying for grid-connection of solar photovoltaic power stations do not need much qualifications except for clarifying the right to use the roof. But apart from policy regulations, some objective factors need to be considered before installing solar photovoltaic power stations. It is recommended to consider the installation location and installation area of photovoltaic modules. Generally speaking, south roofs or east-west facing roofs are more suitable for installation. In addition, families with yards or balconies can also consider installing sun sheds, carports or sunshades. In general, we estimate how much photovoltaic system can be installed on our roof, which can be calculated according to the following formula:
Cement flat roof: installed capacity = 100 watts/square meter × roof area;
Color steel or tile roof: installed capacity = 150 watts/square meter × roof area;
Use elevated columns to install in the courtyard to achieve active tracking: installed capacity = 110 watts/square meter × (length from east to west of the courtyard × 5 meters).
The State Grid adopts an encouraging and cooperative attitude towards distributed photovoltaic power generation, allowing owners of photovoltaic power stations to adopt a settlement model in which surplus power generated for self-use or all electricity consumed is connected to the grid. Which of the two grid-connected models has more revenue? According to industry estimates, if the power consumption is not too large and the electricity price does not exceed the first gear, the full-scale grid-connected model is more appropriate in terms of current revenue. If the power consumption is particularly large and reaches the third-grade electricity price standard, it is recommended to use the self-generated and self-used surplus power grid mode, which is more appropriate. From the perspective of the national strategy, it is natural to encourage home users to adopt the model of spontaneous self-use surplus electricity to go online, which is also in line with the characteristics of distribution.
1) Bracket
There are two types of fixed brackets and tracking brackets on the market. It is generally recommended to choose fixed brackets, because fixed brackets have low maintenance costs and a large market share, while tracking brackets require the brackets to be like sunflowers, with flowers (solar module front) following them. The sun moves, but the tracking bracket technology is not mature enough, and the stability and reliability are not high. Fixed brackets generally use hot-dip galvanized C-shaped steel or aluminum brackets in the market. Pay attention to avoid on-site welding and other methods when installing the brackets. If welding is necessary due to factors such as the orientation of the room, rust prevention must be done and regular inspections must be made. With anti-rust treatment, the service life of the general bracket is basically the same as the service life of the components. Each region has an optimal angle of inclination, and power generation will be affected if it is greater or less than this angle, so it is necessary to choose a professional installer to measure the optimal angle.
2)Cable
The durability of photovoltaic cables is very important. It is necessary to choose cables with weather resistance, UV resistance and ozone erosion resistance. The most important thing is to withstand changes in temperature differences. Therefore, it is best to use special cables for solar applications. The quality of the cables directly affects the entire system. service life. If the 5KW household power station is used as the standard, I suggest to choose the cable diameter of 4mm2 or 6mm2.
3)Solar panels
Solar cells currently on the market are divided into amorphous silicon and crystalline silicon. Among them, crystalline silicon can be divided into polycrystalline silicon and single crystal silicon. The photoelectric conversion efficiency of amorphous silicon is about 10%, and it is not stable enough. With the extension of time, its conversion efficiency decays. The average photoelectric conversion efficiency of monocrystalline silicon solar cells is about 17%. Crystalline silicon solar cells are similar, and their photoelectric conversion efficiency is generally lower than 17%. From the perspective of the photoelectric conversion efficiency of the three materials, it is suitable to use monocrystalline silicon or polycrystalline silicon solar cell materials, and considering the price of monocrystalline silicon materials Expensive, so polysilicon material is generally used.
4) Photovoltaic inverter
Inverters are the heart of photovoltaic power generation. Inverters are generally divided into three types: centralized inverters, string inverters, and distributed inverters. The inverter must be selected for easy management, good stability, easy maintenance, high power quality, complete protection functions, and high safety. Generally, the inverter corresponding to the power segment is configured according to the requirements of the system. The power of the selected inverter It should match the maximum power of the photovoltaic cell array. Generally, the rated output power of the photovoltaic inverter is selected to be close to the total input power, which can save costs.
5) Controller
The controller works uninterruptedly for 24 hours. If its own power consumption is large, it will consume part of the power, so you should choose a controller with low power consumption, preferably a controller with power consumption below 1 mA. It is also necessary to choose a controller with high charging efficiency. The controller with MCT charging mode can automatically track the maximum current of the battery panel. Especially in winter or when there is insufficient light, the efficiency of MCT charging mode is about 20% higher than that of others.
It is not easy to choose a photovoltaic power generation system that suits your family. Non-professionals suggest that you directly choose a professional installer to customize the installation plan to improve safety and reduce unnecessary troubles. After installing a photovoltaic power generation system at home, scientific daily maintenance is essential. In the process of daily operation and maintenance, it is necessary to pay attention to the cleaning of photovoltaic modules, and to clean up dust and foreign objects in time. As long as scientific maintenance is performed, the service life will generally reach 25 There are some well-maintained photovoltaic power stations that can even be used for more than 40 years.
