in late December, the one-year battery technology iteration competition continued to heat up. after longji green energy (601012.SH) set the world record for single junction silicon battery conversion efficiency with HBC technology, aixu shares (600732.SH) followed suit to release the industry's first double-sided BC module to fill the vacancy in the centralized power station market.

different from the previous generation of PERC technology, the technical route of the n-type era shows the remarkable characteristic of "letting a hundred flowers blossom". the competition around what is the "mainstream" is still going on, and the final result is not yet known. however, the new generation of products represented by TOPCon, heterojunction and BC will continue to replace p-type products next year.

the reporter of the financial association learned from many people in the industry that the technical route of the head component factory has been basically determined since this year, which also shows that it will enter a full-scale confrontation in 2024. the improvement of conversion efficiency and the reduction of electricity cost will be more obvious, and the technical advantage may become a "safe haven" in this cycle of overcapacity ". In addition, the industrialization of perovskite and laminated technology is also accelerating, which is an important point of technological development next year.

TOPCon has become the "mainstream" at this stage

after the brewing and planning in 2022, the TOPCon (tunneling oxide passivation contact) battery component will officially usher in centralized mass production in 2023. According to industry statistics, the shipments of N-type TOPCon in 2023 will account for more than 25% of the total market. According to the recent actual bidding situation, the proportion of N-type products in large ground power stations will exceed 80%, and it is estimated that the proportion of N-type products will exceed 50% in 2024.

At present, head companies such as Junda (002865.SZ) and Jingke Energy (688223.SH) have announced that they will achieve 25.8 percent photoelectric conversion efficiency by the end of this year. Taking Jingke Energy as an example, on its planned efficiency improvement target, after further optimization on SE platform, the TOPCon battery conversion efficiency target will reach 26.5 in 2024, and after 2025, through equipment upgrading and material optimization, the conversion efficiency will gradually reach more than 27%.

The progress of heterojunctions has also received attention. The Caixin News Agency reporter learned from the industry that HJT efficiency reduction path includes double-sided microcrystalline, light transfer film, thin sheet, silver copper, 0BB and other technologies. At the same time, large-scale mass production and integrated layout have also become one of the directions of heterojunction reduction. Xu Xiaohua, chairman of Huasheng New Energy, believes that the heterojunction mass production technology has become mature, equipment and raw materials have been localized, 2024 will usher in the expansion of production "outbreak", many leading enterprises will enter the bureau, driving further optimization of manufacturing costs.

a photovoltaic module enterprise official told a reporter from the financial union that at present, the technical route of mainstream module enterprises is basically fixed, but they will generally keep their attention to the research and development of other technologies. even if they bet on TOPCon's head enterprises, they will not rule out that they will consider switching to other technical production capacity in the future when the technical route is mature, such as the cost of heterojunction can be greatly reduced. Especially in the next year, do not rule out a single technology route component companies to develop a variety of technologies to meet different market needs.

BC may be one of the important upgrade directions in the short and medium term in the future. In fact, before September this year, the technology dispute in the N-type era was mainly focused on TOPCon and heterojunction. BC battery (full name: BackContact, back contact battery technology) was a platform technology, and only Aixu shares were among the leading enterprises to test the water. With the announcement of LONGI green energy bet on BC battery, this technology is once again highly concerned.

But unlike the either-or relationship between TOPCon and heterojunctions, BC, as a platform technology, can be combined with a variety of technologies. Shen Wenzhong, director of the Solar Energy Research Institute of Shanghai Jiaotong University, believes that the development direction of crystalline silicon battery efficiency improvement will be based on HBC. According to his introduction, in the cell structure of single crystalline silicon + BC, HBC should have the highest limit efficiency. If HJT efficiency can reach 27.5, HBC cell should reach 28%-28.5. However, there are many challenges to achieve this goal, such as expensive equipment and high process difficulty.

While promoting industrialization, laboratory efficiency is constantly innovating. On December 19, according to the authoritative certification report of Germany's Hamelin Solar Energy Research Institute (ISFH), the back-contact crystalline silicon heterojunction solar cell (HBC) independently developed by Longji Green Energy adopted HJT + BC technology and achieved 27.09 percent cell conversion efficiency by using all-laser patterning mass production process, setting a new world record for the efficiency of single crystalline silicon solar cells.

Double-sided BC fills the gap in the centralized power plant market

The final battlefield of battery technology will return to the terminal application scenario. The above-mentioned component enterprises told Caixin that TOPCon battery can be recognized in the ground power station market, not only compared with the P-type higher photoelectric conversion efficiency, its double-sided rate advantage can directly bring about the improvement of power generation benefits. At present, the double-sided rate of mainstream TOPCon battery components can reach about 85%. If the light intensity on the back is 13.5, a 600W component can bring about 60W of additional income under the same floor area.

The BC battery has a relatively low double-sided rate, usually around 40%, due to its process characteristics that all gate lines are on the back. Therefore, BC technology has been considered for many years to exist only as a single-sided battery and component products. In order to avoid the existing positions of TOPCon, Longji and Aixu have aimed BC products at scenes that do not have double-sided power generation conditions, such as distributed roofs. In the early explanation of Longji Green Energy, the effect of the efficiency difference on the back side on the power generation is much lower than that of the front side, so when the efficiency of the front side is high enough, the power generation gain difference on the back side will be offset.

However, improving the double-sided rate is still an important task for BC batteries. In September this year, Longji Green Energy announced that it plans to invest in the construction of a 12GW single crystal battery project with an annual output of 12GW in Tongchuan New Materials Industrial Park, Shaanxi Province. The products adopt Longji Green Energy's self-developed HPBCpro high-efficiency battery technology. According to the company's previous disclosure, not only the power generation efficiency will be higher than the current stage of HPBC products, more importantly, the double-sided rate is expected to be greatly improved to enhance competitiveness in ground power stations.

The announcement shows that the project is expected to start gradual production in November 2024 and reach production in November 2025. In the company's plan, its actual BC battery capacity in 2024 is about 33GW. After 2025, BC products will grow rapidly.

The double-sided BC of Aixu shares came a little earlier. According to the company's disclosure data, the product called "Star Series" is based on self-developed ABC high-efficiency components, with a maximum mass production efficiency of 23.7, a maximum component power of 640W, and a double-sided rate of 70%.

Therefore, this component has been determined to be customized for centralized power station scenarios since its birth. If calculated under the above conditions, its back power generation income is expected to reach about 60W, which is no longer significantly different from TOPCon battery components. According to the plans of mainstream manufacturers, with the official advent of double-sided BC, it also means that it is expected to appear in the construction of ground power stations as early as 2024.

the relevant person in charge of aixu shares disclosed in an interview with the media that the central enterprises now have a separate BC product bidding plan for the market bidding mode next year. for example, the bidding issued by Datang in October clearly includes 3GW BC. Considering that there is not much supply of BC products, there will also be a market premium advantage in terms of price.

one thing that cannot be ignored is that compared with the current production capacity and shipment scale of TOPCon, BC production capacity is still in the climbing stage, and there is still a gap between becoming the "mainstream" in Longji's mouth. Aixu shares, 10GW Zhuhai factory and 15GW Yiwu factory up to production, the end of this year will form 25GW batteries and components of ABC capacity.

The industrialization of laminated batteries is still advancing

In addition to the BC cell, the stack cell is another way to improve the photoelectric conversion efficiency. According to the existing conditions, the final efficiency of mass production of single crystalline silicon cells is expected to be around 27%, and to achieve a conversion efficiency of more than 30%, lamination is almost the most feasible technology. In early November this year, Longji Green Energy announced that the efficiency of its self-developed crystalline silicon-perovskite laminated battery reached 33.9 percent, making it the highest efficiency record of crystalline silicon-perovskite laminated battery in the world.

Since the bottom cell of the laminated cell is usually partially based on a crystalline silicon cell, the top cell uses perovskite. Therefore, under the condition of relatively mature crystalline silicon battery technology, perovskites, which are still in the early stage of industrialization, are more concerned. Yu Zhenrui, president of polar light energy, said a few days ago that perovskite industrialization still needs breakthroughs in two key technologies, one is to improve efficiency in a large area, and the other is to reach and verify a 25-year life.

According to Shen Wenzhong, crystalline silicon-perovskite laminated batteries are the focus of future development. According to him, the average efficiency of mass production of perovskite cells is difficult to reach more than 20%, and it is difficult for pure perovskite to challenge crystalline silicon. Perovskite can only be used in crystalline silicon to do things that crystalline silicon cannot do, and the advantages of perovskite can be brought into play.

It is worth noting that the current mainstream N-type batteries can achieve stacking technology. The Caixin News Agency reporter learned from Baoxin Technology (002514.SZ) that the company's Xi'an laboratory perovskite/heterojunction laminated battery self-test efficiency has exceeded 32%. In terms of TOPCon/heterojunction laminated cells, a perovskite/crystalline silicon mechanical laminated solar cell with a stable efficiency of 29.65 was successfully prepared, which once again verified the application potential of perovskite/crystalline silicon laminated cells in the photovoltaic field.

Communication Planet APP co-founder Yu Xi told the Caixin News Agency reporter that as an emerging technology, laminated batteries have good application requirements in specific fields, but the current cost of laminated batteries is relatively high, and it is necessary to pass Technology innovation and scale effects to reduce costs and improve competitiveness.

In this regard, Xu Xiaohua, chairman of Huasheng New Energy, also believes that in the long run, heterojunction perovskite laminated cells are the best technology choice in the "double carbon" era, which is expected to achieve 30% mass production conversion efficiency and promote photovoltaic power generation to become the cheapest power source in history. According to its introduction, Huasheng has made a key layout in this technical direction, and the 100 MW pilot line is planned to be put into use in 2025.