HJT can still compete with TOPCon on cost and with BC technologies on efficiency, with strong fundamentals such as high bifaciality and suitability for tandem cells
Huasun, 3SUN, and Risen Energy outlined higher-power modules, safety enhancements, lower silver use, and roadmaps toward tandem applications
Broader adoption of HJT will depend on improved market conditions, lower capital costs, and supportive low-carbon and industrial policies, particularly in Europe
The TaiyangNews annual flagship High-Efficiency Solar Technologies 2025 Conference covered all important solar cell technologies currently available in mass production in the global PV markets. While back contact (BC) was the subject of attention on Day 1, the current leader by market share, TOPCon, dominated the discussions on Day 2 and Day 3.
Day 4 was devoted to heterojunction (HJT), where industry experts and manufacturers highlighted that HJT continues to hold strong potential despite market dominance by TOPCon and BC technologies. They believe that while HJT adoption is currently limited, ongoing technical improvements, cost reductions, and policy support could drive wider uptake in the coming years.
Kaining Ding, Head of the PV-ThynC Lab at Forschungszentrum Jülich, believes HJT solar technology is far from dead, despite claims to the contrary. He notes that while the number of commercial players is still limited, interest in the technology is growing; this is evident in the number of major manufacturers currently heavily invested in TOPCon or BC technologies running HJT pilot lines.
According to Ding, HJT must compete with BC on efficiency and with TOPCon on cost, but the gaps are not large and do not rule out its future. He highlighted HJT’s strong technology fundamentals, including high bifaciality, and stressed that upcoming advances such as copper plating, silver-free designs, and higher-throughput deposition tools could significantly reduce costs.
Ding added that HJT remains relevant for tandem cells even in the future. He expects wider adoption as market conditions improve, concluding that HJT is “very much alive and kicking.”
Christian Comes, the Head of Business Development Europe at Huasun Energy, presented the manufacturer’s recently announced 760 W HJT module. He pointed out that higher power classes, such as 900 W, are also emerging in the market with HJT technology.
Sharing the salient features of the new 760 W module, Comes explained that the module relies on a high-density multi-busbar (MBB) layout with ultra-large wafers and negative spacing. All of these improvements and additions, which improved the module's output by around 20 W, differentiate it from TOPCon technology. Above all, it supports a system voltage of 2,000 V.
Comes explained that meeting the required 15 mm creepage distance for 2,000 V systems with conventional tapes can be risky, as air can get trapped during manufacturing, thereby weakening insulation. Huasun addresses this by using butyl rubber encapsulation, which creates a single, air-free seal along the creepage path and ensures compliance with IEC standards, making it a safer solution for the industry. He said this approach improved safety and met international standards. The ultimate advantage of a 2,000 V module is reduced balance-of-system costs, at about RMB 11.57 cents/W compared with 1,500 V systems. These savings are associated with the reduction in the costs of mounting systems, foundation piles, cables, and the land of utility-scale projects.
He added that the modules were compatible with inverters from leading manufacturers and incorporated a second generation of potential-induced voltage (PIV) protection to enhance reliability.
He further noted that Huasun favored half-cut cell designs with large wafers and negative spacing, citing their mature manufacturing process and better manufacturing throughput and process yield compared with more complex triple-cut or quarter-cut designs. Comes said the company plans to implement these cell and module improvements across 4 GW of production capacity and is expected to achieve mass production of an 800 W HJT module by the end of 2026, widening the efficiency gap with competing technologies.
3SUN’s Head of Advanced Technology Development R&D and Technology Transfer, Marina Foti, said the Enel Group company expanded its 200 MW factory in Catania, Italy, to 3 GW cell and module manufacturing in September 2024. The facility's utilization remains below capacity at present due to market demand. The fab has the capacity to produce about 14,000 modules per day (5 million annually) and 800,000 cells per day (300 million annually), which makes it a lighthouse fab both for Europe and for HJT out of China.
She explained that 3SUN selected HJT technology for its high performance, strong bifaciality, low-temperature processing (≤200°C), high automation, and streamlined production with lower material use. These features also make HJT well-suited for future tandem applications, she added. As regards silver use, efforts are ongoing to reduce its consumption with the use of copper paste, with the eventual industry target of achieving zero silver consumption, she stressed.
Foti noted that 3SUN plans to launch a new utility-scale module in 2026 with an output range of 705 W to 730 W. It currently produces a 490 W to 510 W C&I module and a 610 W to 640 W utility-scale module.
3SUN is also advancing HJT-perovskite tandem development. Working with CEA-INES, the company achieved 30.8% tandem cell efficiency in late 2024 and is now upscaling the technology, with pilot work on large-area wafers planned through 2027 and a first line with 300 MW industrial tools targeted for 2028.
Foti added that while 3SUN is currently the only GW-scale HJT manufacturer in Europe, the company hopes others will follow, supported by wider implementation of the EU’s Net-Zero Industry Act across member states.
Risen Energy CTO Po-Chuan Yang outlined recent progress in the company’s HJT cell and module technology, positioning HJT as a highly sustainable solar option. He said HJT has a low carbon footprint of 376.5 kg CO₂/kWp and uses less electricity and water than TOPCon and xBC technologies, supporting long-term sustainability goals, especially as future regulatory frameworks across various regions are likely to mandate such requirements.
He highlighted major cost improvements, including over 70% reduction in silver use over 4 years, lowering pure silver consumption per watt to about 15%. As a result, HJT’s total metallization cost at Risen Energy is now lower than that of TOPCon and BC.
Yang also pointed to Risen’s Hyper-ion Pro 740 W module, a 132-cell bifacial HJT product with module efficiencies of 23.2% to 24%. The module offers a low power temperature coefficient and delivers around 3% higher power generation than comparable TOPCon and BC modules.
Looking beyond 2026, Yang said further innovation could raise HJT bifaciality to around 95% and reduce wafer thickness to below 110 μm, enabling tandem applications. At that stage, module costs could drop below $0.02/W over TOPCon products, marking the third generation of HJT technology.
On commercialization, he said Risen’s next-generation roadmap will focus on both cells and modules, including increasing wafer area within the same module size to further boost performance.
During a panel moderated by TaiyangNews Head of Technology Shravan Chunduri, Forschungszentrum Jülich’s Kaining Ding and Huasun Energy’s Christian Comes discussed how HJT technology could regain momentum.
Comes said HJT currently remains a niche technology mainly because of limited manufacturing capacity, not because of weak performance. He noted that HJT has clear technical strengths and can achieve further improvements over the next 2 to 3 years. According to him, HJT’s higher costs are largely driven by capital expenditure rather than materials. While HJT already uses less silver and has full-copper electrode solutions available, large-scale adoption is still constrained by implementation costs. It is also well-suited for new production lines, especially where low-carbon manufacturing is prioritized. Low-carbon mandates could improve its competitiveness and lower overall system costs.
For Ding, the current PV market is distorted, making it difficult to draw firm conclusions about long-term technology trends. He explained that the industry is likely to stabilize around 3 crystalline silicon technologies – TOPCon, BC, and HJT – with only small differences in cost and efficiency, as silicon approaches its theoretical efficiency limits. Tandem technologies are promising but unlikely to reach mass production in the near term. He stressed that there is no need to write off any technology as yet, since all it requires is just one or two major innovations to significantly change the outlook for HJT or even BC. It is important to look beyond the noise, stated Ding, towards the potential HJT brings to the PV industry.
Both speakers agreed that HJT’s future will also be driven by structural policy support and targeted innovation.
Mark your calendars for January 13, 2026, for the TaiyangNews Webinar on Solar & Storage Market 2025 Review & 2026 Outlook. Also on February 5 and 6, 2026, TaiyangNews will host the 2nd edition of the Solar Technology Conference India 2026 (STC.I 2026) in New Delhi, India. Details to follow soon.
