Photovoltaic giants want to step away from the penny-stakes card table.
Since Li Zhenguo, founder and Chief Technology Officer of LONGi Green Energy, stepped down from his positions as company director, general manager and legal representative last May to fully devote himself to the company's R&D and technology management work, he and Zhong Baoshen, the chairman, have made a rare joint public appearance at a technology launch event.
At the launch event, the ACM (Nano-alloy Matrix Contact) cell project, BC (Back Contact Cell), energy storage systems and other key products were given focused promotion. The core priority still falls on BC, which is also the technology direction that LONGi Green Energy has heavily bet on in recent years.
The industry trend is shifting. As one of the earliest enterprises that pushed BC into mass production, LONGi Green Energy was trapped in the core controversy of "betting on the wrong track" three years ago. But at this year's photovoltaic exhibition, BC has become the key layout priority for a large number of mainstream photovoltaic enterprises, evolving from a "niche option" to a mainstream technology.
"The whole industry says LONGi Green Energy 'won the bet', but we are not gambling at all. We just believe in the laws of physics," Zhong Baoshen said.
Source: Interviewee
In May this year, he publicly stated that the development path in the next 5 years will take BC as the core, take energy storage as the second growth curve, with the goal of "rebuilding a brand new LONGi Green Energy".
The market logic between TOPCon (Tunnel Oxide Passivated Contact) and BC has reversed. Against the current backdrop of price pressure and gross margin compression, the module costs of the two technologies are almost at the same level, but BC modules can obtain a premium of about 10% by virtue of their technical efficiency advantages, and its label is no longer "high efficiency, high cost".
Professor Shen Wenzhong, Director of the Institute of Solar Energy of Shanghai Jiao Tong University and consultant of China Photovoltaic Industry Association, pointed out bluntly that the replacement of TOPCon by BC is not a matter of "whether it will happen" but "how fast it will happen". "The dividend period of TOPCon has passed, and enterprises that seize the development opportunity of BC cells are expected to become the leading players in the next round of industry reshuffling."
However, BC has not yet formed a subversive replacement advantage, and the "full-scale BC popularization" and "premium realization" in the market still cannot be achieved at the same time.
Some views hold that BC has entered the mainstream sequence of centralized procurement, and the technical premium exists objectively, but customers are still unwilling to pay a higher technical premium for the high efficiency of BC. This still brings growing pains to LONGi Green Energy, which is in a stage of extremely rapid transformation. In the first quarter of 2026, the proportion of BC shipments surged to 66.1% from 25% for the whole of last year, but under the intense homogeneous competition, its estimated net loss in the first half of the year reached 3.4 billion to 3.8 billion yuan.
This is a predictable process. The main photovoltaic industry chain is still in the stage of capacity clearance, the imbalance between supply and demand has not been alleviated, and the dual impact of TOPCon's output and price is still squeezing the space for new technologies such as BC. Recently, the price of TOPCon modules has fallen further, officially breaking through the 0.7 yuan/W (watt) threshold, which is close to the industry's cash cost line.
While the production process of BC is more complex and takes longer to ramp up, especially for large leading companies such as LONGi Green Energy, the conversion of old production capacities is more complicated.
"The industry is promoting capacity clearance through technical means, and the overall pattern is expected to improve significantly next year," said Jiang Dongyu, Vice President of LONGi Green Energy and President of Photovoltaic Product Management Center. The capacity clearance of any industry follows certain rules — industries such as cement and home appliances have all gone through similar cycles in China.
In the transformation of this downturn cycle of the photovoltaic industry, LONGi Green Energy has placed more chips on technology, but it obviously needs a new model to gain pricing power, which can lead the whole industry to break away from the scale-oriented development path.
Cost Calculation
Shortly before the launch event, LONGi Green Energy just announced that its ACM cell project has achieved large-scale mass production at the Xixian production base. The core technological breakthrough is "silver-free metallization", which adopts a new type of alloy paste and matrix contact to realize reliability upgrading, and increase the power of each module by more than 3W.
In 2019, LONGi Green Energy launched internal research on this technology, and promoted the project R&D in 2023. Its long-term plan is to gradually replace the traditional metallization scheme.
There has long been a recognized "impossible triangle" in the photovoltaic industry, which refers to efficiency, cost and quality that can hardly be achieved at the same time. Over the past few years, the industry has carried out countless explorations, but the core element silver has never been able to be completely replaced. During this period, the price of silver rose rapidly: around 2010, the price of silver raw material was 3,000 to 6,000 yuan per kilogram, but since 2024, the price of silver has doubled in two years, once exceeding 32,000 yuan per kilogram.
Source: AI generated
But at present, the silver consumption per kilowatt of photovoltaic modules has dropped from about 170 grams in 2000 to about 7 grams; the width of the gate line has been reduced from 110 microns in the early stage to less than 20 microns. This naturally triggers a discussion about "necessity" — if the price of silver falls in the future, will the ACM technology still be promoted?
Li Zhenguo asked in reply: If the price of oil falls in the future, do you think people will go back to the era of fuel vehicles from electric vehicles?
"From the perspective of supply chain security, the promotion of ACM technology is also a required option," he said. The global proven silver reserves are only 640,000 tons, silver is an associated mineral, and the annual output is only 32,000 tons. "When the photovoltaic production and sales reach 1000GW, we will face the situation of no available silver within 10 years."
In Li Zhenguo's view, the design of thin gate lines has almost reached the physical limit — the smaller the cross-sectional area, the higher the resistance, and the higher the risk of gate line breakage. "In the high and low temperature cycle aging test, when the maximum temperature reaches 150℃, conventional modules have problems of hidden cracks and blackening failure, but ACM modules still perform well," said Tong Hongbo, Dean of the First Research Institute of the Central Research Institute and head of the General Product Department of the Photovoltaic Product Management Center.
Qian Xin, head of the Marketing Department for Distributed Business China Region of LONGi Green Energy, admitted frankly that ACM solves the "stuck neck" problem of silver, but the R&D of a new technology and the transformation of production lines correspond to costs, which will be apportioned into the module price. Although the material cost is reduced, the width of the gate line and the material consumption have increased by 5~7 times, so the overall cost actually rises.
This sounds like a paradox between technology and cost, but the LONGi management including Li Zhenguo has repeatedly emphasized the necessity of silver-free metallization.
"More than 20 years of photovoltaic development history shows that the improvement of conversion efficiency is the first principle of the photovoltaic industry," Li Zhenguo took the early circuit boards as an example: a simple circuit required countless flying wires, with complex structure, high cost and high failure rate, until the emergence of printed circuit boards changed the whole industry.
He made a calculation: the biggest driving force for the reduction of levelized cost of electricity is the improvement of photovoltaic conversion efficiency. For every 1% increase in photovoltaic conversion efficiency, the corresponding cost of labor, brackets, land and roof can be reduced by 4%.
"Don't underestimate this 1%. For a 100-megawatt project, it means a cost saving of nearly 5 million yuan; for China's annual new installed capacity of more than 100GW, it means an industrial dividend of tens of billions of yuan," Li Zhenguo said. Compared with a system that often breaks down and suffers severe attenuation, a high-quality system that can work stably for 25 years will have a levelized cost of electricity more than 20% lower, "which means that a 100-megawatt low-quality power station will lose nearly 100 million yuan of net profit in 25 years."
This is not a "small account". But at the critical moment when BC is competing with TOPCon, launching a technology that can improve efficiency but affect the price is a risky adventure for LONGi Green Energy.
Source: Interviewee
Tong Hongbo said that it is still in the stage of cost input now, which can bring more value-added performance. He compared this process to the R&D of the first-generation BC: "When the cost of the original technology is approaching, the investment in new technology has already started."
"Mainstream Option"
In the past two years, the situation of BC is reversing — that BC will become the next-generation photovoltaic technology has gradually become the industry consensus.
The structure of BC without gate lines on the front determines that its theoretical efficiency ceiling is higher than that of TOPCon. Shen Wenzhong said that the theoretical efficiency ceiling of TOPCon is 28.7%, while that of BC can reach 29.1%.
Source: Interviewee
Zhong Baoshen put it more directly: "BC has no occlusion on the front, which is a perfect photovoltaic cell structure." At present, the efficiency of mass-produced BC modules in the industry generally exceeds 25%, while the first-generation and second-generation TOPCon production lines built in the early stage have an efficiency of just over 23%.
The situation was completely different three years ago. At that time, LONGi Green Energy's "All in BC" strategy sparked widespread controversy, because the efficiency of TOPCon was improving rapidly, the previous generation of technology PERC (Passivated Emitter and Rear Contact) was still in shipment, and the capacity proportion of high-cost BC was less than 10%, which was undoubtedly a "niche player".
Many insiders held the view that BC is only a differentiated product for some segmented scenarios, while TOPCon is still the mainstream with a capacity proportion of more than 50%, which may continue to grow in the future.
Photovoltaic enterprises also reached a kind of "tacit understanding": JinkoSolar continues to invest in TOPCon R&D, Trina Solar and JA Solar adopt the parallel technical route of TOPCon and BC, while LONGi Green Energy and Aiko Solar are the only two enterprises in the market that heavily allocate resources to BC.
Zhong Baoshen once said: "The controversy over BC is real. A large number of enterprises in the market are still investing in and building TOPCon production capacities, which shows that they firmly recognize this direction."
The controversy was the most intense in 2024. In June that year, Zhong Baoshen made a "bet": 5 years later, BC technology will become the mainstream of the photovoltaic industry, with a market share of more than 50%. In December, he became more "radical": "From a practical point of view, I believe it will definitely come earlier than the time I bet on. I said 2029 at that time, but I believe this time point may be 2027 or 2028."
Chen Gang, Chairman of Aiko Solar, also called out: "I think BC is a must-have technology for photovoltaic enterprises to produce cells and modules. Please pay attention to the word 'must-have', and see if it is correct 3 years later."
In this year, BC capacity began to expand, and the industry said it launched a counterattack. LONGi Green Energy announced that the mass production efficiency of HPBC 2.0 cells exceeded 26.6%. In 2025, the yield of its BC cell mass production line reached 98.5%, and all indicators quickly caught up with TOPCon.
By 2026, BC has completely become a "highly sought-after product". At the SNEC Photovoltaic Exhibition, Trina Solar demonstrated its THBC route; Skyworth Photovoltaic launched its first ultra-high power photovoltaic module, the Skyworth CBC 825W Jingjie module; TCL Zhonghuan recently announced that it will invest 2.6 billion yuan to upgrade all its production capacities to BC cells...
At the investor exchange meetings, performance conferences and public activities of various photovoltaic enterprises, "what is your BC plan" has become a high-frequency question.
Customers are also making new "votes". Data shows that in the first half of 2026, the centralized module centralized procurement winning scale of LONGi Green Energy was 50.3GW, of which BC modules accounted for 22.5GW, close to 45% of the total scale. It plans to ship more than 30GW of BC modules in distributed scenarios throughout the year, accounting for 80% of the total sales in this scenario.
Source: AI generated
On various public platforms, "BC takes over from TOPCon" has become the hottest topic in the industry. Shen Wenzhong pointed out bluntly that in the next 5 to 8 years, the market share of BC will increase from 10% to 50%, while the market share of TOPCon will drop from the current 70%~80% to below 50%, "and this declining process will be very painful."
But the premise of all this is that BC can truly achieve large-scale mass production.
The primary condition is cost, which is also the core of the controversy in the past few years. Last year, Zhang Yingbin, head of product strategy and market of Trina Solar, once said that it is very difficult for BC to achieve a substantial increase in capacity, but if the power of BC modules can widen a significant gap with TOPCon and the cost per watt can be equal, it may be an opportunity.
Since March this year, LONGi Green Energy's BC production lines have reached full capacity, and the cost is basically the same as that of conventional TOPCon products.
This process is very difficult, because the way LONGi Green Energy promotes BC is different from any previous technology upgrade in the photovoltaic industry. Referring to the paths of TOPCon and PERC, usually a technical route is spread