In July 2021, Tongwei Solar uses PERC mass production equipment and through battery process innovation, the conversion efficiency of M6 large-size full-area (Area=274.50cm2) battery can reach 23.47%, and it has been approved by the ISO/IEC 17025 third-party international authority. The certification has created a world record for the efficiency of M6 large-size and full-area industrialized PERC cells.
Improving battery conversion efficiency is the primary indicator for improving the long-term competitiveness of the company’s products. The record-breaking solar cell is currently Tongwei Solar’s leading product: P-type single crystal double-sided PERC solar cell. With the continuous increase in the size of silicon wafers in the past two years, the process difficulty and complexity of large-area PERC cells have further increased. Through the optimal integration of mass production technologies such as grid pattern, light trapping structure, diffusion and passivation technology, the technical team has greatly improved the IV parameters of the M6 PERC battery, thereby creating a 166 full-area battery World record for conversion efficiency.
Liu Hanyuan, member of the Standing Committee of the 11th CPPCC National People’s Congress, and chairman of Tongwei Group’s board of directors, said that Tongwei has always adhered to the development direction of taking a professional path and providing customers with efficient and reliable solar cell products; the company’s PERC products have been maintained. With the industry’s leading level, the research and development of post-PERC technology is also increasing investment, hoping to take the lead in substantial mass production.
Tongwei Solar, a subsidiary of Tongwei, is deeply involved in the R&D, manufacturing and promotion of core solar power products, and is the world’s leading crystalline silicon cell manufacturer. The company now has four bases in Hefei, Shuangliu, Meishan and Jintang, with an existing production capacity of 35GW. The market share of crystalline silicon cells and the scale of production capacity have been the largest in the world for many years, setting a new record in the photovoltaic industry. It is estimated that in 2023, Tongwei Solar will have a production capacity of 80-100GW, with an output value of more than 80 billion yuan.
Tongwei Solar has formed a number of technical achievements with independent intellectual property rights in core technology fields such as atomic layer deposition back passivation, selective emitter technology, double-sided cells, multi-bus grids, HJT cells, and high-efficiency components. On the one hand, the company focuses on the current mainstream PERC technology and upgrades and optimizes it by superimposing other process technologies to improve conversion efficiency and reduce production costs. On the other hand, the company continues to increase its investment in tracking and R&D of new battery technologies. The company’s HJT battery R&D production line was officially put into operation in June 2019. After continuous R&D and improvement, the current maximum conversion efficiency of HJT batteries has reached 25.18%. At the same time, the company will build a 1GW HJT pilot line to further improve equipment selection, optimize process technology, and improve product cost-effectiveness on the basis of research and development production lines. Tongwei has also made a major breakthrough in TOPCon technology. Using 210-size PECVD tunneling oxidation/polysilicon deposition equipment and process, the average cell efficiency of the R&D line has reached 24.10%, and the 1GW TOPCon pilot line is also under construction.
To date, Tongwei Solar has obtained a total of 382 valid authorized patents, and won a total of national “green factories”, national “green supply chain management demonstration enterprises”, national “green supply chain management demonstration enterprises”, and the Ministry of Industry and Information Technology in 2018. There are more than 400 important awards such as Pilot Enterprise for the Implementation of the Standardization of the Integrated Management System of Industrialization and Industrialization, the National Intellectual Property System Implementation Standard, the National Five-star Site, and the National High-Tech Enterprise