Crystalline silicon or thin film? Mono or multi? There is no shortage of controversy and discussion in the battle for photovoltaic technology routes, and recently, major photovoltaic manufacturers have started a new round of debate.

First of all, Trina Solar (SH688599, stock price 28.00 yuan, market value 61.022 billion yuan) said that according to field tests conducted in Changzhou City, Jiangsu Province, TOPCon (tunneling oxide passivation contact) modules have an average gain of 3.15% per watt of power generation compared with XBC (back contact) modules, and a monthly relative gain of 3.4%.

On October 23, the official WeChat public account of LONGi Green Energy (Germany SH601012, stock price 20.08 yuan, market value 152.2 billion yuan) announced that the latest certification report of the Frauhoff Institute for Solar Cell Research, an international authoritative certification body, showed that the module efficiency of HPBC 2.0 (a BC technology) independently developed by LONGi reached 25.4%, breaking the world record for crystalline silicon module efficiency. The move also broke the 36-year-long monopoly of overseas PV brands on the efficiency record of crystalline silicon modules.

Trina Solar believes that the power generation gain of TOPCon modules is better than that of BC. However, LONGi Green Energy said that its HPBC module broke the world record for the efficiency of crystalline silicon modules. So, which component is more efficient, TOPCon or BC?

The controversy over the technical route has resurged

Recently, the two major module giants have emphasized the power generation gains brought by TOPCon modules. On October 18, PV Magazine, a well-known media in the photovoltaic industry, published an article saying that JinkoSolar (SH688223, stock price 9.51 yuan, market value 95.149 billion yuan) and Trina Solar respectively released relevant test reports, saying that their TOPCon technology provides superior power output compared with back contact. As for the test report mentioned by PV Magazine, the reporter of "National Business Daily" confirmed it from Trina Solar and JinkoSolar.

It is reported that JinkoSolar's test was carried out at the demonstration base in Kagoshima, Japan, and the test results were confirmed by the authoritative European testing agency TV North Germany. JinkoSolar tested three products, including JinkoSolar's 575 W double-glass N-type TOPCon module, as well as two other manufacturers' 580 W double-glass P-type BC modules and 605 W single-glass N-type BC modules.

JinkoSolar's experts used a CR1000X system to measure the power generation of TOPCon modules at 136.86 kWh/kW, compared to 133.87 kWh/kW for P-type BC and 129.98 kWh/kW for N-type BC.

"Due to its higher bifaciality and lower temperature coefficient, the module produces 2.22% more electricity than P-type BC and 5.29% higher than N-type BC when normalized to power rating for each module," JinkoSolar said. On sunny and cloudy days, TOPCon modules consistently generate 2% to 3% more electricity than P-type BC modules and 5% to 6% higher than N-type BC modules. ”

Trina Solar said in a separate report that it tested at its Changzhou proving ground and that its TOPCon modules had a 3.15% power generation gain over XBC modules.

JinkoSolar is endorsed by TV North Germany, while LONGi Green Energy is endorsed by the Frauhoff Solar Cell Research Institute in Germany.

Regarding JinkoSolar and Trina Solar's promotion of TOPCon's power generation gain better than BC, LONGi Green Energy staff replied to reporters: "Whether it is good or not, whether it is bad or not, must be determined by the first principle of physics." ”

Which route will be mainstream?

In 2023, P-type (boron-doped silicon wafer) modules will still dominate, while in the first half of 2024, N-type (phosphorus-doped silicon wafer) modules will rise rapidly, especially N-type TOPCon modules, which have an absolute advantage.

According to InfoLink data, in the first half of 2024, N-type TOPCon module shipments accounted for nearly 70% of total shipments, while HJT and XBC modules accounted for 1% and 4% of the total shipments of the top 10, respectively.

Relying on its first-mover advantage in the TOPCon field, JinkoSolar successfully counterattacked LONGi Green Energy and won the leading position in the photovoltaic module industry. Now, LONGi Green Energy wants to challenge JinkoSolar with its BC technology.

It should be noted that BC technology was originally mainly used in the field of distributed photovoltaics, and has recently begun to enter the bidding of large-scale ground power stations. According to Guosen Securities, on September 9, China Huaneng Group Co., Ltd. opened the bid for the 2024 photovoltaic module (second batch) framework agreement procurement, with a total of 15GW of centralized procurement, of which bid section 1 is 13.5GW of N-type bifacial double-glass modules, bid 2 is 0.5GW of HJT modules, and bid 3 is 1GW of BC modules, which is the first time that BC modules have entered the large-scale bidding of large central enterprises.

The new team of China Securities Construction Investment pointed out that the high power of BC photovoltaic modules has brought it a premium space, and it is recommended to pay attention to the mass production progress of leading enterprises. It believes that due to the high conversion efficiency, low attenuation coefficient and low temperature coefficient of BC modules, the comprehensive output efficiency of BC modules is slightly higher than that of TOPCon modules under the same version of modules, thereby reducing the cost of BOS (business operation) per watt of power station.

At present, BC battery modules are still in a relatively early stage, and they are still facing certain challenges in terms of cost, which mainly come from three aspects: silver consumption, yield, and equipment cost in BC cells. Taking equipment cost as an example, the localization of related equipment and large-scale cost reduction are not sufficient, so the current capital expenditure of BC battery per GW is relatively high, about 300 million yuan/GW.

It should be noted that at present, LONGi Green Energy has started the expansion of HPBC 2.0 production capacity. According to its staff, LONGi Green Energy's HPBC2.0 is an N-type technology.

In addition, according to the record of investor relations activities disclosed by LONGi Green Energy in September, the company currently has 1.5GW of HPBC second-generation cell production capacity. According to the existing plan, it is expected that by the end of 2025, the company will form 50GW of HPBC second-generation battery production capacity.