What are the eight main materials of PV modules? — Read it so you can understand in seconds!

Preface

The photovoltaic module is the smallest PV cell assembly device with a package and internal connection, which can provide DC power individually and cannot be divided. It is the core component of a photovoltaic power generation system, composed of eight core materials. Then today let’s go into the ambitious photovoltaic, together to understand the module eight main materials of science and technology knowledge!

1. Cell

The cell is the most central component of the module. It is mainly used to convert light energy into electricity. After the cells are connected in series and parallel to reach a certain rated output power and voltage, and the PV module is formed. PV modules are combined to form a PV array. Connected with the controller, battery pack, inverter, and other components to form a photovoltaic power generation system.

Solar cells are divided into monocrystalline silicon, polycrystalline silicon, and amorphous silicon solar cells according to raw materials. At the same time, crystalline silicon cell technology is based on the silicon wafer as the substrate, based on PN junction for photogenerated carrier separation for power generation. According to the difference in raw materials and cell preparation technology, crystalline silicon cells are divided into P-type cells and N-type cells. p-type silicon wafers are made by doping boron elements in silicon materials. P-type cell preparation technology has the traditional AL-BSF (aluminum backfield) and PERC technology. And N-type silicon wafers are made by doping phosphorus elements in silicon material. In other words, N-type cell preparation technologies are more numerous, including PERC, TOPCon, IBC, and HJT.

2. Tempered Glass

Photovoltaic glass is a soda lime silicate glass, mainly used for the encapsulation of photovoltaic modules. PV glass will directly affect the power generation efficiency and service life of PV modules.

And photovoltaic glass is generally low-iron tempered glass or semi-tempered glass, which has the following characteristics:

Firstly, good permeability. Light transmission is a key factor affecting the conversion efficiency of photovoltaic cells. In the meanwhile, the photovoltaic glass needs to have high light transmission and high reflectivity of 1200nm infrared light.

Secondly, high mechanical strength. Impact resistance, which can withstand 2400Pa wind pressure and 5400Pa snow pressure. Also, it plays a supporting and protective role.

Thirdly, good durability. Affected by climate and geographical location, the components need to operate in the open air and in an environment with a large temperature difference between day and night and need to have corrosion resistance and weather resistance qualities.

3. Adhesive film

Photovoltaic encapsulation film is an important part of the PV module, located on the upper and lower sides of the cell. The primary role of the film is to bond the cell to the glass and back sheet. Secondly, the film can play a protective role to protect the cell circuit from external environmental interference and prolong the service life of the module. In addition, the encapsulation film can enhance the light transmittance of the PV module, which in turn can improve the module’s power generation efficiency. Finally, the film also serves as structural support and positions the cell during module production, storage, installation, and use.

According to the material, the mainstream adhesive films are EVA, POE, EPE, and PVB. EVA adhesive film is the mainstream PV encapsulation adhesive film, with good light transmission, good processing performance, stable supply, and low cost. POE film has a low water vapor transmission rate, good PID resistance, and is suitable for double-glass modules and N-type modules, but has poor processing properties and high cost.

4. Back Sheet

The photovoltaic back sheet is an encapsulation material used for backside protection and is generally used for single glass modules. And the photovoltaic back sheet is divided into a fluorine back sheet and a non-fluorine back sheet. Of course, fluorine back sheets include TPT, TPE, TPC, CPC, and non-fluorine back sheets include PET, PA/PO, etc.

The photovoltaic back sheet is mainly used to resist the erosion of cells, adhesive film, and other materials by humidity and heat, and plays the role of corrosion resistance, weather resistance, anti-oxidation, and insulation protection, in the meanwhile, it can effectively extend the service life of the module. In addition, the white back sheet has high reflectivity, which can improve the conversion efficiency of the module. Also, the high infrared reflectivity facilitates the reduction of the module’s operating temperature.

5. Frame Kit

The photovoltaic bezel is the bezel installed on the glass epitaxy. And it is mainly used to fix and seal solar modules. It facilitates the transportation and installation of PV modules. The installation of the frame is conducive to protecting the edge of the glass and strengthening the sealing performance of the PV module. At the same time, the frame is the link carrier to carry the module and the bracket. In addition, the use of a bezel can improve the overall mechanical strength and load resistance of the module, thus extending the module’s life.

6. PV Ribbon

PV ribbon is also called tinned copper tape, mainly divided into PV tabbing wire and PV bus bar. The PV tabbing wire is mainly used in the connection between PV module cells. And PV busbar is mainly used for the connection between the cell strings of the module. At the same time, it will collect the current generated by the solar cells into the junction box.

7. Silicone

Silicone is mainly used for bonding and sealing laminated glass PV modules, bonding bezel and glass, junction box, and back sheet (or glass), playing a sealing and connecting role.

According to the use of different positions, silicone is divided into the sealant and potting adhesive. Sealant is used in the frame slot and the bottom of the junction box and the back panel. Potting glue is generally used inside the junction box, the main role is to protect the internal circuit of the junction box.

8. Junction Box

The main role of the junction box is to connect the power generated by the solar cell to the external wiring. Usually it can play the role of sealing, waterproof,ing and dustproof the PV module lead wires. In the meanwhile, the junction box also protects the PV module system operation safety role. In additon, if a short circuit occurs in the module, the junction box will automatically disconnect the short-circuiting battery string to prevent the entire system from being burned.