In Behind the rapid development of China’s photovoltaic industry is the continuous “cost reduction and efficiency increase” of enterprises. Especially in recent years, price reduction has become the theme of the domestic photovoltaic market. For this reason, many photovoltaic enterprises regard improving the photoelectric conversion efficiency as a “magic weapon” to seize the first opportunity. According to the interviewed industry insiders, although the conversion rate of photovoltaic cells is near the ceiling, with the continuous iteration of technology, improving the conversion efficiency will still be the main direction of the upstream and downstream photovoltaic industry chain.
The rise of ultra-high power market
Reviewing the development trend of photovoltaic industry, the conversion efficiency driven by technological progress has been continuously improved. Since the launch of 210mm silicon wafers by Central in 2019, in just one year, the ultra-high power photovoltaic ecological chain has been gradually improved. Battery manufacturers such as GCL Poly, Aixu, Tongwei, etc. have entered the market. Supports, junction boxes and other related accessories for 210 products have been well matched. At present, 210 module enterprises such as Trina Solar and Dongfang Risheng can mass produce ultra-high power batteries.
“The market for larger silicon chips and higher power components is optimistic. With the promotion of ultra-high power industrialization and continuous innovation and surpassing of technology, the mass production of 24%+high-efficiency batteries will exceed expectations. It is expected that ultra-high power batteries will usher in an outbreak next year.” President of Trina Solar China Component Sales Group, judged.
It is reported that Trina Solar has expanded production five times this year. It is estimated that by the end of 2021, the battery capacity will reach 26GW, and the ultra-high power components will exceed 50GW. Through continuous technology and process research and development and industrialization, the average mass production efficiency of PERC batteries has reached more than 23.20%. Through the introduction of independently developed PERC+project technology, the average mass production efficiency of batteries will continue to improve, and is expected to exceed the average mass production efficiency of 23.50% by the end of this year.
Huang Qiang, vice president of Dongfang Risheng New Energy Co., Ltd., also said in an interview that the photovoltaic ultra-high power market has a bright future. Through “210+heterojunction”, Dongfang Risheng has led the industry in the development of high power modules and high efficiency batteries. As one of the first batch of manufacturers to achieve mass production of 158.75mm 9BB heterojunction batteries, the highest mass production efficiency is up to 24.2%, becoming the first batch of suppliers in the industry to achieve the low-temperature welding packaging process of 9BB heterojunction half chip. In June 2020, the first major customer 35MW order was successfully connected to the grid for power generation.
PERC battery conversion efficiency is close to the ceiling
In the opinion of the industry insiders interviewed, the P-type single crystal PERC battery product is the mainstream of the market at this stage. Its mass production efficiency has exceeded 23% and is moving towards 24%. “We believe that the efficiency of the P-type PERC battery has room for improvement in the next two or three years, and it is also the technology with the highest cost performance ratio in mass production.” Wang Yingge, general manager of Longji, told reporters.
Zhuang Yinghong, the global marketing director of Dongfang Risheng, said in an interview that at present, the conversion efficiency of the company’s single crystal battery chips has exceeded 23.5%, the conversion efficiency of quasi single crystal battery chips has exceeded 23%, the conversion efficiency of silicon N-type single crystal battery chips has exceeded 24.2%, the conversion efficiency of single crystal modules has exceeded 21.4%, and the conversion efficiency of half heterojunction modules has exceeded 21.9%.
According to the analysis of EnergyTrend, a new energy research institution under Jibang Consulting, the global PV market’s P-type PERC battery capacity will reach 199.7GW in 2020, accounting for about 78% of the cell segment capacity. Among them, the conversion efficiency of single crystal PERC cells sold on the market is concentrated at 21.8% – 23%. In 2020, the efficiency of newly built production lines is generally above 22.5%, and the efficiency of single crystal PERC cells in the laboratory is about 24%. It can be seen that the mass production efficiency of PERC cells is close to the laboratory efficiency, and the development of this technology has entered a mature stage.
The reporter learned that since TOPCon technology is compatible with most processes of mainstream PERC battery production lines, the technology has more advantages in investment cost and maturity of supporting equipment. The research and development efficiency of TOPCon battery laboratory can reach 24.8%, and the mass production efficiency can reach 23.2% – 23.8%. Many enterprises, including LG, REC, Zhonglai, Trina Solar, Linyang, CSI, Jinke, Guodian Investment and others, have technical reserves of TOPCon battery, and have achieved high R&D or mass production conversion efficiency. It is estimated that the production capacity of TOPCon battery chips will reach 5.4GW in 2020.
According to the research of Yingya Securities, the battery is the fastest growing link in the photovoltaic industry chain. At present, the conversion efficiency of PERC is close to the ceiling, and the industry is exploring and deploying new technologies. PERC+, TOPCON, HJT and other emerging technologies are expected to promote the continuous progress of the industry and push the industry into a new round of cost reduction and efficiency increase.
“In the short term, TOPCon has strong cost advantages and high compatibility with existing PERC production lines, but in the medium and long term, HJT has greater mass production potential.” EnergyTrend analysis shows that at present, the medium and long-term plans of all enterprises are to conduct battery chip research and development in the way of HJT+IBC (HBC), TOPCon+IBC (TBC) and other technologies.
Yang Liyou, general manager of Jinneng Technology, told reporters that he was optimistic about the prospect of heterostructure technology in improving conversion efficiency. This technology has the advantages of less process flow, high conversion efficiency, ultra-low attenuation, ultra-low temperature coefficient, high double-sided ratio, and excellent weak light response performance. While exploring the mass production and cost reduction of heterojunction technology, the company is also exploring the combination of heterojunction technology and cutting-edge technologies such as perovskite to continuously improve the conversion efficiency and reduce the cost of photovoltaic power generation.
Technical iteration seeks efficiency breakthrough
Looking at the development trend of photovoltaic cells in recent years, its power generation cost has continued to decline, and the battery conversion rate has rapidly increased. According to the data, from 2007 to the first half of 2020, the component cost decreased by 24 times and the system cost decreased by 15 times. In terms of photovoltaic cell efficiency, the efficiency of polycrystalline, single crystal PERC, TOPCon, IBC, heterojunction and other technical routes has continuously broken records. The photoelectric conversion efficiency of efficient P-type single crystal PERC solar cells of Trina Solar alone has broken the world record of battery and module efficiency for 15 times.
This year, based on the trend of large-scale silicon chip, from the perspective of the mass production level of mainstream module enterprises in the photovoltaic industry chain, technologies such as slicing, multi grid, solder band improvement, high-density packaging, etc. optimize photovoltaic efficiency from the module aspect. The large-scale module production lines under construction by mainstream enterprises basically adopt multiple module technologies to stack, which will increase the module efficiency to more than 20%, and the power can reach 600W.
The reporter learned that at present, the improvement of mass production efficiency of PERC battery technology is mainly matched with the upgrading of advanced processes in each link to “PERC+”, and the upgrading routes of process batteries mainly include PERC+SE, PERC+MWT, double-sided PERC, SiNx optimization, etc. The average mass production efficiency of PERC batteries of mainstream enterprises such as Trina Solar, Jingao and Chint is above 22.8%. From the perspective of research and development expectation of battery chip manufacturers, the conversion efficiency of “PERC+” batteries is expected to further reach about 24.5%.
In Wang Yingge’s opinion, the precondition for PV technology iteration is reliability. Under the guarantee of reliability, on the one hand, the conversion efficiency is considered; On the other hand, look at the integration technology development of PV with different application scenarios and different energies, such as PV+energy storage, PV+hydrogen energy, PV+building integration, PV+electric vehicle charging pile, PV+data center, PV+5G base station, etc.
EnergyTrend said that TOPCon and HJT battery technologies, which are in the phase of mass production introduction, need enterprises such as equipment and auxiliary materials in all links of the industry chain to cooperate with the product end to optimize the production line. As the products pass the terminal power station application test verification, they are expected to enter the market promotion stage.
When interviewed by the reporter, the relevant person in charge of Jinko Energy said that there is a relatively clear technological progress path to improve the conversion efficiency of photovoltaic technology, and the development of various technologies is centered around several mainstream research directions, including substrate material improvement, passivation structure optimization, metallization performance improvement, and optical path optimization. From the perspective of current technology, efficient and low-cost batteries represented by TOPCon technology of N-type batteries will be the mainstream of technology development. On this basis, many new auxiliary technologies will form a generation of products. In addition, attention should also be paid to new photovoltaic substrate materials, such as perovskite, silicon carbide, third-generation semiconductor materials, etc. For structural efficiency improvement technology, stack battery technology and photon conversion technology can all be effective tools.