ehind the rapid development of my country's photovoltaic industry is the continuous "cost reduction and efficiency increase" of enterprises. Especially in recent years, price reduction has become the theme of the domestic photovoltaic market. For this reason, many photovoltaic companies regard the improvement of photoelectric conversion efficiency as a "magic weapon" to seize the opportunity. In the opinion of the interviewed industry insiders, although the current conversion rate of photovoltaic cells is close to the ceiling, with the continuous iteration of technology, improving the conversion efficiency will still be the main direction of the photovoltaic upstream and downstream industrial chain.

The rise of the ultra-high power market

Reviewing the development trend of the photovoltaic industry, technological progress drives the continuous improvement of conversion efficiency. Since the release of 210mm large-size silicon wafers by Zhonghuan in 2019, in just one year, the ultra-high-power photovoltaic ecological chain has been gradually improved. GCL-Poly, Aixu, Tongwei and other battery manufacturers have entered the scene to adapt to 210 products, junction boxes and other related accessories have been matched. At present, 210 component companies such as Trina Solar and Dongfang Risheng can even mass produce ultra-high power batteries.

"The market for larger silicon wafers and higher power modules is quite optimistic. With the promotion of ultra-high-power industrialization, technology continues to innovate and surpass, and the mass production of 24%+ high-efficiency batteries will exceed expectations. It is expected that ultra-high-power batteries next year It will usher in an explosive period." Zeng Yi, president of Trina Solar's China module sales group, judged.

It is reported that Trina Solar has expanded its production five times this year. It is estimated that by the end of 2021, the battery production capacity will reach 26GW, and the ultra-high power module will exceed 50GW. After continuous R&D and industrialization of technologies and processes, the average mass production efficiency of PERC batteries has reached over 23.20%, and through the introduction of self-developed PERC+ project technology, the average mass production efficiency of batteries will continue to increase. It is expected that by the end of this year, it can break through the average mass production efficiency of 23.50%.

In an interview with reporters, Huang Qiang, vice president of Risen Energy Co., Ltd., also said that the photovoltaic ultra-high power market has a bright future. Risen Energy has led the industry's progress in high power modules and high battery efficiency through the "210+ heterojunction". As the first manufacturer to achieve mass production of 158.75mm 9BB heterojunction cells, the highest mass production efficiency is as high as 24.2%, becoming the first supplier in the industry to achieve 9BB heterojunction half-cell low temperature soldering packaging process. In June 2020, the first major customer 35MW order was successfully connected to the grid for power generation.

PERC battery conversion efficiency is close to the ceiling

According to industry insiders interviewed, P-type mono-crystalline PERC battery products are the mainstream in the market at this stage, and their mass production efficiency has exceeded 23%, and they are moving towards 24%. "We believe that the efficiency of P-type PERC cells has room for improvement in the next two or three years, and it is also the most cost-effective technology for mass production." Wang Yingge, brand general manager of Longi, told reporters.

In an interview with reporters, Zhuang Yinghong, the global marketing director of Risen Energy, said that the company’s conversion efficiency of monocrystalline cells has exceeded 23.5%, and the conversion efficiency of similar monocrystalline cells has exceeded 23%, and the conversion efficiency of silicon N-type monocrystalline cells has exceeded 24.2%, the conversion efficiency of single crystal modules exceeded 21.4%, and the conversion efficiency of half-cell heterojunction modules exceeded 21.9%.

EnergyTrend, a new energy research institution under TrendForce, believes that in 2020, the global photovoltaic market P-type PERC cell capacity will reach 199.7GW, accounting for about 78% of the cell link capacity. Among them, the conversion efficiency of monocrystalline PERC cells sold on the market is concentrated in 21.8%-23%, the efficiency of newly built production lines in 2020 is generally above 22.5%, and the efficiency of laboratory monocrystalline PERC is about 24%, which shows the amount of PERC cells. Production efficiency is close to laboratory efficiency, and the development of this technology has entered a mature stage.

The reporter learned that because TOPCon technology is compatible with most processes of mainstream PERC battery production lines, the technology currently has more advantages in terms of investment cost and maturity of supporting equipment. The research and development efficiency of TOPCon battery laboratory can reach 24.8%, and the mass production efficiency can reach 23.2%-23.8%. Many companies including LG, REC, Zhonglai, Trina, Linyang, Canadian Solar, Jinko, State Power Investment and other companies have TOPCon battery technology reserves and have achieved high R&D or mass production conversion efficiency. It is expected in 2020 TOPCon cell production capacity reached 5.4GW.

Yingya Securities Research believes that the battery is the fastest growing link in the photovoltaic industry chain. The current PERC conversion efficiency is close to the ceiling, and the industry is exploring and deploying new technologies. A variety of emerging technologies such as PERC+, TOPCON, HJT, etc. are expected to promote the continuous progress of the industry and push the industry into a new wave of cost reduction and efficiency enhancement.

"From a short-term perspective, TOPCon has a strong cost advantage and high compatibility with existing PERC production lines, but from a mid- to long-term perspective, HJT has greater mass production potential." EnergyTrend analyzed that the current mid- to long-term plans of all companies are based on HJT+IBC( HBC), TOPCon+IBC (TBC) and other technology superposition methods for cell research and development.

Jinneng Technology General Manager Yang Liyou told reporters that he is optimistic about the prospects of heterojunction technology in improving conversion efficiency. This technology has the advantages of less process flow, high conversion efficiency, ultra-low attenuation, ultra-low temperature coefficient, high double-sided ratio, and excellent low-light response performance. While exploring the mass production and cost reduction of heterojunction technology, the company is also exploring the combination of heterojunction technology and cutting-edge technologies such as perovskite, in order to continuously improve conversion efficiency and reduce the cost of photovoltaic power generation.

Technical iteration for efficiency breakthrough

Looking at the development trend of photovoltaic cells in recent years, the cost of power generation has continued to decline, and the battery conversion rate has increased rapidly. Data show that from 2007 to the first half of 2020, component costs have dropped by 24 times, and system costs have dropped by 15 times. In terms of photovoltaic cell efficiency, the efficiency of polycrystalline, single-crystalline PERC, TOPCon, IBC, heterojunction and other technical routes continue to break records. The high-efficiency P-type mono-crystalline PERC solar cell photoelectric conversion efficiency of Trina Solar alone broke the world record of cell and module efficiency 15 times.

This year, based on the trend of large-size silicon wafers and the mass production level of mainstream module companies in the photovoltaic industry chain, technologies such as slicing, multi-busbar, ribbon improvement, and high-density packaging optimize photovoltaic efficiency from the module link. The large-size module production lines that mainstream companies are building basically use a variety of module technologies to superimpose the module efficiency to more than 20%, and the power can reach 600W.

The reporter learned from interviews that the current mass production efficiency of PERC battery technology is mainly matched with the advanced process upgrade of each link to "PERC+". The process battery upgrade route mainly includes PERC+SE, PERC+MWT, double-sided PERC, SiNx optimization, etc. The average mass production efficiency of PERC batteries from mainstream companies such as Trina, JA and Chint is above 22.8%. From the research and development expectations of cell manufacturers, the conversion efficiency of "PERC+" batteries is expected to further reach about 24.5%.

In Wang Yingge's view, the premise of photovoltaic technology iteration is reliability. Under the guarantee of reliability, on the one hand, look at the conversion efficiency; on the other hand, look at the development of the integration of photovoltaic and different application scenarios and different energy sources, such as photovoltaic + energy storage, photovoltaic +Hydrogen energy, photovoltaic + building integration, photovoltaic + electric vehicle charging pile, photovoltaic + data center, photovoltaic + 5G base station, etc.

EnergyTrend stated that the TOPCon and HJT battery technologies that are in the introduction phase of mass production require collaboration between companies such as equipment and auxiliary materials and the product end in each link of the industry chain to optimize the production line. Only after the products pass the terminal power station application test verification, they are expected to enter the market. In an interview with the reporter, the person in charge of JinkoSolar said that the conversion efficiency of photovoltaic technology has a relatively clear technological progress path, and the development of various technologies revolves around: substrate material improvement, passivation structure optimization, metalization performance improvement, optical path optimization and other mainstream research directions. Judging from the current technology, the high-efficiency and low-cost battery represented by the TOPCon technology of the N-type battery will be the mainstream of technological development. On this basis, there will be many emerging subsidiary technologies to form a generation of products. In addition, attention should also be paid to new photovoltaic substrate materials, such as perovskite, silicon carbide, and third-generation semiconductor materials. Regarding structural efficiency improvement technologies, laminated battery technology, photon conversion technology, etc. can all become efficient tools.

An expert from the Energy Research Institute of the National Development and Reform Commission told reporters that although the photovoltaic conversion efficiency is close to the ceiling, the current efficiency is comparable to the cost of coal power, and there is still room for efficiency improvement in the future. "In addition, some emerging technologies, such as the more mature heterojunctions and perovskites that are at the forefront of technology, if they can break through the scale and economy, the cost can be reduced to a lower level."