The global solar PV industry is now very serious about moving beyond PERC and of course, the options are two—HJT and TOPCon. Even as several companies are piloting both the technologies, most are opting for TOPCon as the first technology of choice in n-type realm as the next immediate phase of expansion. JA Solar is a leading Tier I player that's heavily investing in TOPCon, and parallelly continually evaluating other technologies in the background. But why TOPCon? TaiyangNews had an opportunity to talk to the Director of Product Technology Department of JA Solar Technology Co., Ltd. Tang Kun about the company's TOPCon investments and its future plans. Tang Kun has over a decade of experience in the field of solar and has been focused on the development of high-efficiency solar modules. He has completed more than 10 R&D projects on high-efficiency cells and modules that effectively improved the performance of solar products. In his role as Director of Product Technology Department, Kun says he is supporting and contributing to JA Solar's vision to provide the market with more high-quality solar products.
TaiyangNews: JA Solar has now announced big plans for TOPCon. On the other hand, you are also among the companies that started pilot projects with HJT. Does this mean that your company will completely focus on TOPCon or will continue to work on HJT as well?
Tang Kun: We see both TOPCon and HJT as promising technologies for mass production. However, to decide which technology will be mainly adopted in the end, we must consider the whole industry chain, such as equipment and process maturity, raw material cost, equipment cost, production cost, etc. The efficiency improvement and cost optimization roadmap are on the table at present and what we need to do is to find out whether they're available and feasible in the mass production line.
TaiyangNews: What are the factors that make sense for JA Solar to venture into TOPCon?
Tang Kun: Cost and power performance are the two points that give us confidence in this technology. It provides a clear guidance and direction achieving cell efficiency higher than 25%. On the other hand, decreasing the integrated cost per watt for TOPCon technology is promising and prospective in the next few years. We believe these two points are also the concerns of the entire photovoltaic industry.
TaiyangNews: Are there any major bottlenecks with TOPCon that still need to be addressed?
Tang Kun: We would rather say there're still something we can do to improve the performance of TOPCon, such as promoting minority carrier lifetime of wafer, Poly-Si preparing process, module encapsulation technology, etc. The main purpose is still to further improve product performance and quality, further reduce manufacturing costs and meet customer needs in multiple dimensions at the same time.
TaiyangNews: Can you comment on the deposition technologies you are employing for the application of tunneling oxide and poly for TOPCon?
Tang Kun: At present, there are two main deposition technologies for tunneling oxide and polysilicon preparation: LPCVD and PECVD. The technology principles of the two routes are not exactly the same. LPCVD is more stable in terms of maturity, but PECVD has a slight advantage in terms of production friendliness and future predictability. There is no essential difference in the overall performance of the two. Each manufacturer will make appropriate choices according to their own conditions, such as the production time, their own production capacity, and the expectation of future technology. Both technologies will be further optimized in terms of cell efficiency, production cost, lifetime of spare parts and material cost to achieve the best cost-performance ratio.
TaiyangNews: Are you employing selective emitter already in your structure? What is the efficiency gain with implementing the selective emitter?
Tang Kun: The SE technology is one of our cell efficiency enhancements in the R&D stage and is expected to deliver significant efficiency gains and become mainstream in the real production line.
TaiyangNews: Please share your current average and best production efficiencies, your best R&D efficiency with TOPCon and for benchmark PERC.
Tang Kun: The average efficiency of PERC cells in the current production line is 23.7% and the best production efficiency is close to 23.9%. The best R&D efficiency with TOPCon is over 25%.
TaiyangNews: What is your current capacity for PERC, TOPCon and HJT if any, and could you please explain your expansion plans both in short and long term?
Tang Kun: JA Solar has a planned module production capacity of over 50 GW at the end of this year, and over 75 GW at the end of 2023. The capacity of n-type cell will reach 27 GW at the end of 2023, and there will be production lines for cells based on other n-type technologies. There will also be a portion of externally sourced cells. Taking all this into consideration, we expect that n-type module will take 30% of the company's total shipment in 2023.
TaiyangNews: What are the manufacturing costs for TOPCon? Any comparison with HJT and PERC would be of great help?
Tang Kun: 1 cent per watt higher than that of PERC and 1.5 cent less than HJT.
TaiyangNews: What should be the efficiency gap that can compensate for higher costs associated with TOPCon
Tang Kun: Higher than 1%.
TaiyangNews: What is the cell architecture you will focus on beyond TOPCon?
Tang Kun: HJT Technology. We have already built an HJT solar cell production line. Actually, JA Solar is not only focused on TOPCon and HJT technologies, we also have R&D reserves for a variety of advanced technologies, such as back contact, tandem cell, etc. We prepare ourselves for revolutions and challenges.
TaiyangNews: Thank you for the interview.
JA Solar will present at our upcoming virtual conference on Reliable PV Module Design on Dec. 14. JA's Jerry Sun will speak about Factors Affecting The Reliability of High-Power Modules And How To Control Them. To view the agenda and register for free, click here.