Next generation photovoltaic cell technology? Big start and bottom of TOPCon: large-scale mass production is expected to start this year's production capacity or super heterostructure

In addition to heterojunction (HJT), another N-type high-efficiency battery technology in the photovoltaic industry is becoming more and more popular.

Yes, that's it, Topcon! As the industry saying goes, "the struggle between TopCon and HJT", guess who will take over PERC. However, a photovoltaic leader told the Kechuang Board Daily that new technologies may be made public in the industry, and it is not known who will dominate the world in the future.

A recent study pointed out that in terms of photovoltaic cell technology route, the trend of P-type to N-type iteration will be opened in 2021, towards a higher efficiency stage, the N-type technology route represented by TOPCon and HJT will make breakthroughs one after another, and the industrialization process is expected to be accelerated. TOPCon has high compatibility with the existing production line, and the efficiency of PERC is about 1-1.5pct higher than that of TOPCon, which can extend the vitality of existing assets. It is expected that the trend of upgrading from PERC to TOPCon in 2021 will be more obvious.

So, what is TOPCon?? In the post-PERC era, is the next generation of mass production battery technology Topcon or HJT?? (or something unknown? )

"Science and Technology Innovation Board Daily" reporter from all aspects of the industrial chain companies, photovoltaic investment and researchers to carry out research, and strive to restore the real situation of TOPCon industrialization.

Will mass production of 2021 TOPCon be launched?

Due to the difference of doping process, photovoltaic cells are divided into P-type cells and N-type cells. P-type silicon wafer production process is simple, low cost, represented by PREC cells, is also the mainstream of the photovoltaic industry.

N-type is known as "efficient", represented by HJT, TOPCon and so on, but the process is more complex and it is difficult to have large-scale production because of the high cost.

It can be said that 20 years ago, various advanced laboratories around the world laid down all kinds of cell technology routes in the future photovoltaic field, such as P-type battery chip technology, PERC, N-type battery chip technology, N-PERC, TopCon, HJT and IBC, which actually have a technological background in history. An insider of a photovoltaic module leader told Science and Technology Innovation Board Daily that "the photovoltaic industry has a technical iteration almost every 2-3 years, and the battery conversion efficiency is the most key indicator, but it is not easy to increase only 1%." With the efficiency of PERC tapping potential gradually approaching the limit, the industry will certainly look at the new generation of technology, in which the most likely to achieve commercialization is HJT and TOPCon, has become a basic consensus.

According to reports, at present, the mass production efficiency of PERC batteries is generally 22% Mel 22.4%, leading enterprises have exceeded 23% (national industrial upgrading requirements), and the conversion efficiency of single crystal PERC batteries has broken through 24%, approaching the limit efficiency of 24.5% day by day. At present, the average mass production efficiency of the HJT pilot line is generally about 24%, and the limit efficiency can reach 27.5%. At present, the average mass production efficiency of TOPCon is about 22.5%, the maximum mass production efficiency has reached 24.5%, and the limit efficiency is 28.7%, which means there is more room for improvement.

Figure shows the comparison of battery routes; source: founder Securities

TOPCon was actually put forward in 2015 and is in the process of long-term and in-depth research and development. Recently, why TOPCon has been mentioned more, because it is true that the technology is also relatively mature, and the industry has been laying out at the same time, and to a certain extent, it has reached the state of mass production (that is, conditions for mass production). " The aforementioned photovoltaic module leader insiders said, "TOPCon and HJT are essentially different. HJT is a completely incremental technology, while TOPCon is a compatible stock technology, more like an intermediate / transitional product upgraded from PERC. It is more compatible with existing equipment of PERC battery (it does not need to plan too many new devices like HJT), but the mass production conversion efficiency is a little higher than PERC, but the cost is lower. The ultimate efficiency is similar to that of HJT, and the room for improvement is huge, so it is regarded as the starting point for the next generation of industrialized N-type high-efficiency battery technology. "

Photovoltaic investors hold a similar view. "N-type battery is an important trend in the photovoltaic industry this year, in which TOPCon upgrade is relatively easier. You can upgrade some technical paths and parameters in the process of the original equipment, which is why the industrialization of TOPCon is likely to be faster."

The industrialization of HJT also leaves time for TOPCon. There is no doubt that HJT is subversive and revolutionary, its process is simpler, its energy consumption is lower, and it represents the future direction in the long run. However, it is reported that at present, the overall cost of HJT is more than 30% higher than that of PERC, which is still in the early stage, and the real commercialization may be after 2023.

Who is the entrant? Industry: production capacity or over HJT

"the production capacity of TOPCon in 2021 will be greater than that of HJT, the former will be more compatible and easier to land. TOPCon may be the highlight of the photovoltaic industry this year. " Some insiders of photovoltaic faucets believe.

According to a reporter from Science and Technology Innovation Board Daily, at present, the production of HJT in the photovoltaic industry is still in the small-scale and pilot-scale stage, the actual landing capacity of single-order production is only about 2GW, and the planned production capacity is about 20GW. There are no clear data on TOPCon's industry capacity.

What is the current investment in TOPCon in the industry?

In terms of integrated photovoltaic manufacturing, it is reported that Longji shares have a layout in TOPCon technology. Jingao Technology also revealed in an institutional survey in November last year that the company has also made a technological breakthrough, raising the efficiency of Topcon batteries to nearly 24%.

In the field of materials, it is understood that Zhonglai has started the research and development of TOPCon technology since 2017. Last October, the company launched a new generation of J-TOPCon2.0 technology, which is said to achieve an average mass production efficiency of more than 24 per cent and a yield of more than 97 per cent. In November of the same year, its subsidiary also produced TOPCon batteries with the highest efficiency of 24.5%, and the related production line is said to have produced more than 200000 pieces. In addition, the company's "annual production of 1.5GW N single crystal double-sided TOPCon battery" fund-raising project is expected to be available by the end of the first quarter of this year. According to the report, the company already has 2GW TOPCon production capacity.

In the battery field, a reporter from Science and Technology Innovation Board Daily learned from the industry that Tongwei Jintang (Phase I) 7.5GW High efficiency Solar Battery Project and Meishan (Phase II) 7.5GW High efficiency Solar Cell Project have reserved room for upgrading TOPCon new high efficiency battery technology. Tongwei shares replied to the "Science and Technology Innovation Board Daily" reporter that TopCon technology company has been concerned, and has invested in research and development and test line, but the specific situation is confidential information. Data show that Aixu shares also have TOPCon battery technology research and development, and is accumulating mass production experience.

In the field of photovoltaic modules, it is reported that Trina Solar Energy began the research and development of i-TOPCon cells in 2015, and the technology was industrialized in 2018. At present, the average mass production conversion efficiency is 23%. In May 2019, the company's i-TOPCon battery conversion efficiency reached 24.58%, breaking the world record.

Jingke Energy announced on January 7 this year that its large area N-type monocrystalline silicon single junction TOPCon battery efficiency reached 24.9%, breaking the world record again.

Dongfang Risheng disclosed in the 2019 report that the development of its N-type TOPCon battery is in the stage of small sample test and process optimization.

Zhongli Group is also reported to have invested in the research and development of TOPCon battery technology.

In the field of equipment, it is publicly shown that Jiejia Weichuang has basically achieved mass production of TOPCon wet equipment, and the research and development of passivation equipment has entered the process verification stage.

Although the giants have entered the game one after another, TopCon still faces many challenges to break through.

Industry experts have previously said that there is still room for TopCon efficiency and cost optimization. Of course, TOPCon battery also has some disadvantages, first of all, the process is complex, the process steps are significantly increased, from cleaning to testing, it takes 12-13 steps; secondly, the cost is high, and the cost increase caused by the process and double-sided silver paste is inevitable; finally, the real efficiency improvement of TOPCon may also be limited. And, in the future, whether TOPCon will be squeezed by PERC and heterojunction will be in an awkward position. After all, the efficiency of PERC is improving bit by bit, and the cost of heterojunction is decreasing bit by bit. "

PERC is still mainstream, at least in the short term, which is also the consensus of the industry. At present, the yield of PERC has reached 99%, and it is not a problem for its mass production efficiency to break the 23% threshold. The order volume of PREC in 2021 is still large, reaching about 140GW, while the order of HJT is less than 10GW.

In the future, PERC will eventually move towards HJT, TOPCon or something else, which will be answered in time.