What is the new photovoltaic material invested by Sinopec?
Not long ago, Sinopec Group Capital Co., Ltd. (hereinafter referred to as Sinopec Capital) announced that it will invest in Changzhou Baijias Thin Film Technology Co., Ltd. to fully deploy new photovoltaic power generation materials.
This news has caused great concern in the photovoltaic film material industry.
What are the main uses of photovoltaic film materials in the photovoltaic industry and how is the localization situation?
With these questions, reporters from Science and Technology Daily visited relevant industry experts.
"Qualified photovoltaic modules are required to maintain 80% of the maximum output power of the initial value after 25 years of outdoor work, and they must also be able to effectively resist the impact of external forces. Therefore, in order to prolong the service life of photovoltaic modules, add Encapsulation materials protect it." said Ou Junfei, a professor at the School of Materials Engineering, Jiangsu Institute of Technology.
A typical photovoltaic module is composed of solar cells, backplanes, photovoltaic glass, junction boxes, frames, packaging materials, etc.
The encapsulation film material is located between the photovoltaic glass and the solar cell. It can bond the solar cell, copper-tin ribbon, backplane and photovoltaic glass together, and is a key component of the photovoltaic module.
"The ethylene-vinyl acetate copolymer (EVA) encapsulating film in photovoltaic cells is a thermosetting and adhesive film." According to relevant experts from Changzhou Trina Solar Co., Ltd., due to the adhesive force of EVA film It has special advantages in terms of, durability, optical properties, etc., so it is widely used in photovoltaic modules and various optical products.
The single-glass photovoltaic module with the back sheet of plastic and the front face of glass mainly uses EVA encapsulating film. Because of its non-tackiness at room temperature, it can be melt-bonded and cross-linked and solidified under certain conditions and become completely transparent. After bonding with glass, the light transmittance of the glass can be increased, and it plays a role of anti-reflection.
For dual-glass photovoltaic modules with glass on both sides, POE (an ethylene-octene copolymer) film is currently a commonly used packaging material on the market.
Compared with EVA film, POE film has better safety and aging resistance.
But this material is 30%-50% more expensive than EVA film.
"The thickness of the double-glass photovoltaic module glass has now been reduced from 2.5 mm to 2.0 mm, and it is estimated to drop to 1.6 mm in the future." Ou Junfei said that as the thickness of the double-glass photovoltaic module glass decreases, EVA film can also be used for double-glass modules. The frame is sealed, and the EVA film will also be widely used in double-glass photovoltaic modules in the future.
Ou Junfei told reporters that the EVA raw material used to produce photovoltaic encapsulation film requires a VAc (vinyl acetate) content of more than 28%, which is currently mainly produced by the kettle method.
With the rapid development of China's photovoltaic market, the EVA film market has also seen rapid growth.
Prior to 2013, EVA film has been monopolized by foreign countries. Now domestic companies have a market share of over 90% in the domestic film field, achieving domestic substitution.
The reporter learned that at present, domestic EVA film produced by the kettle-style process such as Beijing Organic Chemical Factory, Huamei Polymer, Levima, Ningbo Formosa Plastics, Shanghai Petrochemical, and Yangzi Petrochemical all occupy a place.
Jiangsu Sierbang is the only domestic enterprise that can produce EVA film by the tube method. The products produced have been recognized by the market since its launch in September 2019.
According to relevant experts, there is still a certain gap between the raw materials for EVA film production in my country and the international advanced level. In the next few years, EVA film materials will be imported from neighboring countries such as Singapore and South Korea to supplement the photovoltaic market demand.