With the rapid development of its green economy, Chengdu has grown into a city of strategic importance in the global PV sector. As an important county in Chengdu, Jintang is accelerating the building of a 100-billion yuan crystalline silicon PV industry cluster and a 100-billion-yuan new lithium cell industry cluster. Today, we are going to visit TW Solar's Jintang Base, the first 5G application base in the PV sector.

Walking through the double gate, we see flat roads, standardized arrangements, and a beige and black-colored factory building, which houses Tongwei's GW-class intelligent manufacturing production line for solar cells.

This is a world-leading 5G industrial application park jointly built by Tongwei, China Telecom and Huawei.

TW Solar's Jintang Base

According to the law of competition in the PV sector, eligible enterprises will spare no effort to catch up with any technology that may help them find some competitive edge over their opponents. Up to now, Tongwei has achieved an annual production capacity of over 140 GW in high-efficiency cells and 85 GW in high-efficiency modules, securing its leading position in the sector.

According to Li Jingxiang, Deputy Manager of the Information Department of TW Solar's Jintang Base, every dust-free workshop in Jintang Base is as big as a soccer field, where there are several over-300-meter-long fully automatic intelligent manufacturing production lines and hundreds of smart trolleys, some of which are even equipped with environmental monitoring equipment to monitor temperature, humidity, particle concentration, etc. and even the entire workshop environment in real time.

Manufacturing capability lays a foundation for PV enterprises to compete in the industry, while competition in the manufacturing industry actually occurs among manufacturing plants. Taking Jintang Base as a sample, Tongwei has revealed to visitors the secret about why China boasts a world-leading PV industry chain.

1. Subtraction after addition

In fact, the secret of achieving the leading position in the manufacturing industry is very simple, that is, making more valuable goods at the lowest possible cost and developing sufficient production capacity to meet the market demand. In the past few years, the market demand has been met by the manufacturing capacity and the rapidly increasing market size has been aligned with the increasing capacity in the PV sector. Then, all this changed with the introduction of cross-industry businesses. At that time, a PV business could be started with a few devices and just one production line after applying for a trademark. Due to the low threshold of starting a business in the industry, PV manufacturing capacity has moved from moderate to flooding, resulting in excess capacity, beyond the demand. A part of the production capacity could be cut only by economic laws, but enterprises could neither predict the future nor stay in the present forever. Consequently, how to work out a solution to the dilemma has become an unavoidable question for PV enterprises. Undoubtedly, intelligent manufacturing is one of the answers. As the first 5G application base in the global PV sector, TW Solar's Jintang Base has upgraded its plants in full accordance with the 5G+ intelligent manufacturing scheme. Leveraging core technologies such as unmanned intelligent manufacturing in the workshop, digital management in the park and outdoor unmanned warehousing and logistics, it has taken the lead in realizing industrial digitalization, intelligent manufacturing, and intelligent management.

TW Solar 5G intelligent manufacturing production workshop

It is reported that compared with the traditional cell panel production line, the energy consumption of the production line of TW Solar Jintang Base is reduced by about 30%, and the production efficiency increases by about 161%. Therefore, it is a benchmark and model project of advanced manufacturing industry in the world. "We have accomplished the transformation from offline operations to online operations through the construction of manufacturing execution systems." said Li Jingxiang. In the past, many work orders and inspections were completed by workers holding paper documents, going to the production machines to check and record them one by one, but now the data are all recorded. read, generated and kept by the system automatically. In terms of process improvement, now we can trace the manufacturing process of more than 3 million cell panels every day through the single-chip traceability function, and correlate the parameters and indicators of each cell panel in each production link. In addition, the intelligent manufacturing production line of Tongwei has also been extended to the quality inspection. The product quality is detected by AI visual graphics algorithm, and the products are divided into different grades for qualification judgment with higher standard quality control. High-speed AI test improves the efficiency of production line, enhances the accuracy of quality judgment, and serves as a strong guarantee for end customers to obtain high-quality products. It is not an easy task to streamline the process when more attention is paid to the details, but if it is done, the company can undoubtedly reduce its costs and increase efficiency.

TW Solar intelligent manufacturing production line

In the intelligent TW Solar Jintang Base, the application of 5G technology is the core of all intelligence works and manufacturing. Compared with WIFI, the delay of 5G technology has decreased by 90%, the bandwidth increased by 300%, the stability increased from 99.8% to 99.999%, and the number of point locations decreased by 70%. Therefore, no matter cost or application effect, 5G technology is much better than WIFI. Intelligent manufacturing and lean management enable Tongwei to keep up with the latest trends in the industry, and in fact, Tongwei's smart factory has already developed to the third generation, which is far ahead in the industry. The first generation smart factory is composed of workers' carts and manned forklifts, and the transportation is mainly manual; the second generation smart factory consists of IGV intelligent robot with WIFI technology and manned forklifts, and the transportation in the workshop is unmanned; the third generation smart factory comprises IGV with 5G technology and unmanned forklifts, and the transportation inside and outside the workshop is unmanned. The IGV intelligent robot can run for 12 hours only by being charged for 3 hours, which can reduce the defective rate by 12.5% and the fragmentation rate by 25%, and can ensure the smoothness and stability of each process in the whole PV manufacturing process as much as possible. This September, TW Solar's Jintang Base received product certification and green product certification from Power (Beijing) Certification Center Co., Ltd. (PCCC), marking the alignment of Jintang Base's products with the high standards of the industry in terms of manufacturing, R&D level and technical quality as well as the strict requirements of the country and the power industry.

2. Leading the growth of the PV sector by technological innovation

STI can drive new industries, models, and driving forces, which are core to the development of NQPFs (new quality productive force). In 2024, Tongwei's THC and TNC modules set new world records with a power of 776.2 watts and 743.2 watts respectively. On October 30, the PV Technology Center at Tongwei Co., Ltd. announced a remarkable breakthrough: after rigorous test by TÜV, an authoritative certification agent, its independently developed THC 210 heterojunction module achieved a record-breaking maximum output power of 776.2 watts and a photoelectric conversion efficiency of 24.99% at a size of 2,384*1,303 mm. This milestone, marking the first heterojunction module to surpass the 775-watt threshold, is the ninth record set by Tongwei in power and efficiency since 2023. The reason for continuing to set a new record is the ultimate pursuit of Tongwei of technological innovation. In November 2023, the construction of Tongwei Global Innovation R&D Center was started. In April 2024, the first batch of process equipment was mobilized for works. In June, the first cell panel of heterojunction + copper metallization rolled off the assembly line, which marked that the Global Innovation R&D Center was fully put into operation. "In the Global Innovation R&D Center, there are a R&D workshop of 110,000 square meters and more than 1,200 R&D personnel. Six R&D workshops have been focusing on R&D of cell + module technology and reliability test of PV products," said Dr. Xing Guoqiang, Chief Technology Officer for the PV Business, Tongwei Co., Ltd. It is understood that Tongwei concentrates on the development and application of potential mainstream technologies of the future, including TOPCon, heterojunction, BC and perovskite/c-Si tandem solar cell technology. "We have built a 1 GW HJT+THL R&D pilot line with currently the most advanced technology in the industry, the most complete configuration and the most possible ways to improve technology in the future," he said, "In terms of metallization, we have silver-coated copper and copper metallization technology. At present, a GW-level scheme has been formed for our copper metallization technology that makes mass-production possible and viable. Our T2/T3 workshop is now capable of developing various BC cells + modules. In addition, we have perovskite/c-Si tandem solar cell research and development, which is a technical path with Tongwei characteristics. Our cell size starts directly from 210 half-cut."

First HJT+THL cell of Tongwei Global Innovation R&D Center rolled off the production line

Tongwei Co., Ltd. attaches great importance to technology R&D. According to public information, its cumulative investment has reached RMB 10.419 billion over the past three years. In the PV field, Tongwei Co., Ltd. has made industry-leading achievements in high-purity crystalline silicon, solar cell and module technologies, and has continuously made technological progress and innovations. However, technological innovation in products is only a small portion of the achievements made by Tongwei. For its manufacturing plant, Tongwei has also developed many environmental protection technologies and put the concept of green sustainable development into practice. It is reported that its Yancheng Base with 41 production lines is the largest module base in the global PV sector, and it is also a smart factory with the highest degree of digitalization, intelligence and automation. Compared with the traditional activated carbon waste gas treatment process, the waste gas treatment in Yancheng Base is realized through its zeolite rotor adsorption plus catalysis system, in which the zeolite rotor can be desorbed and recycled, which can reduce the amount of activated carbon and waste disposal by about 450 tons per year, while cut the operating cost by about RMB 4.5 million per year.

The intelligent manufacturing production line of high-efficiency modules of Tongwei

In November 2024, the Yancheng Base passed the energy supervision audit certification organized by TÜV SÜD (ISO 50001: 2018), which indicates that the base's achievements in energy management and green and low-carbon development have been recognized by various authoritative organizations. Moreover, the Yancheng Base has also introduced and applied advanced energy-efficient technologies, such as high-efficiency motors, intelligent lighting, heat recovery systems, and high-efficiency vacuum systems., further improving the energy efficiency. As symbols of intelligent manufacturing among PV enterprises in China, both Jintang Base and Yancheng Base are benchmark factories of PV intelligent manufacturing of Tongwei in China. The two bases not only demonstrate the high quality standards of the company's products, but also show the determination of Tongwei to continue to promote green technology innovation and to make contributions to the achievement of the goals of carbon peaking and carbon neutrality.