When it comes to the core part of photovoltaic power plants, you may think of photovoltaic modules and inverters. When it comes to the revenue of photovoltaic power plants, you may have to mention the quality of photovoltaic modules. So, what are such important photovoltaic modules?
Photovoltaic modules refer to the smallest and indivisible photovoltaic cell combination device with packaging and internal connection, which can provide DC output alone, and different specifications of solar cell combination cut by solar cells or by laser cutting machine or steel wire cutting machine.
1. The composition of photovoltaic modules and the functions of each part.
1)Tempered Glass
Its function is to protect the main body of power generation (such as the battery), and the selection of light transmission is required. The light transmittance must be high (generally more than 91%); Ultra-white tempering treatment
2)EVA
It is used to bond and fix the tempered glass and the main body of power generation (such as batteries). The quality of the transparent EVA material directly affects the life of the module.
The EVA exposed to the air is easy to age and turn yellow, which affects the light transmittance of the module, thereby affecting the in addition to the quality of the EVA itself, the power generation quality of the module is also greatly affected by the lamination process of the module manufacturer.
For example, the adhesiveness of the EVA is not up to standard, and the bonding strength of the EVA to the tempered glass and the backplane is not enough, which will cause the EVA to age prematurely, affecting the component life.
3)Battery Slices
The main function is to generate electricity. The mainstream in the power generation market is crystalline silicon solar cells and thin-film solar cells, both of which have their own advantages and disadvantages.
The equipment cost is relatively low, but the consumption and cell costs are high. However, the photoelectric conversion efficiency is also high. It is more suitable for thin-film solar cells to generate electricity in outdoor sunlight.
The relative equipment cost is high, but the consumption and battery cost are very low. However, the photoelectric conversion efficiency is more than half that of crystalline silicon cells, but the weak light effect is very low. Well, it can also generate electricity under ordinary lights, like the solar cells on a calculator.
4)Backplane
The function is to seal, insulate, and be waterproof. Generally, TPT, TPE, and other materials must be resistant to aging. Most component manufacturers have a 25-year warranty. Tempered glass and aluminum alloy are generally no problem. The key is whether the backplane and silicone can be used.
5)Aluminum Alloy
It protects the laminate, and plays a certain sealing and supporting role.
6) Junction Box
The junction box protects the entire power generation system and acts as a current transfer station. If the module is short-circuited, the junction box automatically disconnects the short-circuit battery string to prevent the whole system from being burned.
The most critical thing in the junction box is the selection of diodes, according to the battery in the module. Different types of the corresponding diodes are also different.
7)Silicone
The sealing function is used to seal the junction between the component and the aluminum alloy frame, the component, and the junction box. Some companies use double-sided tape and foam to replace the silica gel. The silica gel is widely used in China. The process is simple, convenient, easy to operate, and the cost is very low.
2. The power calculation of PV module
Take 100W output power and use it for 6 hours a day as an example, and the calculation method:
1) Firstly, calculate the watt-hour consumption per day (including the loss of the inverter):
If the conversion efficiency of the inverter is 90%, then when the output power is 100W, the actual required input power should be 100W/90% =111W; if it is used for 5 hours a day, the power consumption is 111W*5 hours = 555Wh.
2) Calculation of photovoltaic modules:
Calculated according to the daily effective sunshine time of 6 hours, and then considering the charging efficiency and the loss during the charging process, the output power of the photovoltaic modules should be 555Wh/6h/70%=130W.
70% of which is the actual power used by the photovoltaic modules during the charging process.
In conclusion, these are the composition, function and calculation of PV module, if you have any questions or any ideas want to share with us, welcome to comment here, thank you.
