Understand the role of photovoltaic thin film materials together
Not long ago, China Petrochemical Group Capital Corporation (Sinopec capital) announced to invest in Changzhou baijiashi film science and Technology Co., Ltd. to comprehensively layout the field of new materials for photovoltaic power generation. The news aroused great concern Photovoltaic film Attention of material industry.
Qualified PV modules are required to maintain the maximum output power of 80% of the initial value after 25 years of outdoor work and effectively resist the impact of external forces. Therefore, in order to prolong the service life of photovoltaic modules, packaging materials are added for packaging protection.
Typical photovoltaic modules are composed of solar cells, backplane, photovoltaic glass, junction box, frame, packaging materials, etc. The packaging film material is located between the optical glass and the solar cell. It can bond the solar cell, copper tin welding belt, back plate and optical glass. It is an important part of the optical module. The ethylene vinyl acetate copolymer (EVA) packaging film in photovoltaic cells is a thermosetting and viscous film. Experts from Changzhou Trina Solar energy company said that EVA film has special advantages in adhesion, durability and optical properties, so it is widely used in photovoltaic modules and various optical products.
The back plate is a single glass photovoltaic module with plastic and glass on the front. EVA packaging film is mainly used. Because it has no viscosity at room temperature, it is melt bonded and cross-linked cured under certain conditions. It is completely transparent. After bonding with glass, it can improve the light transmittance of glass and play the role of penetration.
Both sides are glass double glass photovoltaic modules, and POE (ethylene octyl polymer) film is a commonly used packaging material in the market. Compared with EVA film, Poe film has better safety and aging resistance. However, this material is 30% - 50% higher than EVA film.
The thickness of double glass photovoltaic module glass is now reduced from 2.5mm to 2.0mm and is expected to decrease to 1.6mm in the future. Ou Junfei said that with the decrease of glass thickness of dual glass photovoltaic modules, EVA film can also seal the frame of dual glass modules, and EVA film will be widely used in dual glass modules in the future.
Ou Junfei said in an interview that the content of EVA raw material (vinyl acetate) for the production of photovoltaic packaging film is more than 28%. At present, it is mainly produced by kettle method. With the rapid development of China's photovoltaic market, EVA film market is also growing rapidly. By 2013, EVA film was monopolized overseas. Now, domestic enterprises account for more than 90% in the field of domestic film, realizing domestic substitution.
According to the analysis of relevant experts, there is a certain gap between the raw materials of EVA film produced in China and the international advanced level. In the next few years, the raw materials of EVA film will be imported from Singapore, South Korea and other neighboring countries to meet the needs of the photovoltaic market.
