The 182 and 210 size solar module have just gained a foothold, and larger silicon wafers have come again.

Recently, a Tianjin silicon wafer manufacturer disclosed the latest P-type monocrystalline silicon wafer prices in its official WeChat, and released a 218.2-size silicon wafer quotation for the first time.

Since the 158.75-size silicon wafer was introduced internally in the industry in 2018, the speed of silicon wafer size iteration has continued to accelerate. In 2019, the 166 and 210 size silicon wafers are “competitive and brilliant”, and in 2020, the 182 size is “come to the top”, showing a “meshed” trend. Although large size is a recognized development trend for silicon wafers in the industry, can silicon wafers really be “endless”? How will the introduction of 218.2 size affect the photovoltaic industry?

218.2 silicon wafers are not a substitute for 210 silicon wafers, both of which are advanced production capacity

According to Lu Jinbiao, Joint Secretary-General of the China Photovoltaic Standards Technical Committee of the International Semiconductor Industry Association (SEMI), the introduction of the 218.2 size is essentially a continuation of the dispute between the 182 and 210 sizes. Some calculations show that if the 218.2 size is made into a 60-piece type, its area is similar to the 182-size 72-piece type. At the same time, the manufacturing cost of large-size silicon wafers is relatively lower, which can be said to occupy a cost advantage.

Lu Jinbiao pointed out that whether it is 210 size or 218.2 size, it is a product whose silicon wafer size has jumped to more than 200 mm. There is almost no difference in the manufacturing process and equipment selection between the two, and both require the use of a 12-inch single crystal furnace. “To produce 166 and 182 size silicon wafers, you only need to upgrade and transform the original single crystal furnace and production line. But to produce silicon wafers of 210 size or more, you need to invest in the construction of new single crystal furnaces and production lines.”

Yin, who has been engaged in the photovoltaic industry for a long time, made a set of calculations. The diameter of the silicon rod corresponding to the 210-size silicon wafer is 295 mm, and the diameter of the silicon rod corresponding to the 218.2-size silicon wafer is 306 mm, both of which belong to 12-inch products. The area of ​​the 218.2 size silicon wafer is about 8% larger than that of the 210 size, and the power is also greater after the cell is made. According to the calculation of the efficiency of PERC technology of 22.8%-23%, the power of a single chip has increased by 10.85-10.95 watts, and the non-silicon cost of the cell will also be diluted.

Yin revealed that in the view of manufacturers of silicon wafers, cells, modules, brackets, etc., as well as related persons in some design institutes, the introduction of the 218.2 size does not mean the failure of the 210 size. Both belong to the advanced production capacity of the 12-inch series. The goal is to replace the outdated and old production capacity, not to replace the 210 size with the 218.2 size.

However, Lu Jinbiao believes that after the replacement of the 12-inch single crystal furnace, not only the sizes of 210 and 218.2, but also the size of silicon wafers can be even greater in the past.

Several hurdles need to be passed to truly realize industrialization and commercialization

In fact, after the launch of 210-size silicon wafers, cell and component companies have “stand-by” one after another, and conducted a series of discussions on the changes in load and current of 210 components. The worries about large-size components within the industry and the market are not “groundless”.

Although the larger size brings cost reduction, but also pay attention to the safety hazards that follow, as well as upstream and downstream matching and standardization issues. Lv Jinbiao told reporters: “Increasing the size of silicon wafers is the same as reducing the thickness from 180 microns to 160 microns. It is mainly a means of increasing the output of the silicon wafer and reducing processing costs. Upstream and downstream matching brings troubles, and load and high current issues must be considered. Thinning may lead to the risk of chipping and component cracking. Once the above problems occur, the loss will inevitably increase. If the size of the silicon wafer is increased to reduce the cost, it cannot be covered. This loss is not worth the loss.”

In fact, after the 210-size components were launched, some people in the industry speculated whether there would be larger-size components coming out. Bo Zhongnan, the project manager of the FraunhoferISE photovoltaic module, system and reliability department, a European photovoltaic industry research organization, pointed out that further increase in the size of the module may bring higher labor requirements, increase labor costs and installation risks, and ultimately fail in manufacturing costs and systems. Bring value on cost. In addition, in terms of electrical safety, the safety risks of the system should also be emphasized and evaluated.

Lu Jinbiao emphasized that adjusting the size of silicon wafers not only involves wafer manufacturers, but also affects companies such as solar cells and components. If the new size is to be truly industrialized and commercialized, it is necessary to consider the standardized collaboration between upstream and downstream customers, equipment and auxiliary material suppliers.

Yin told reporters that some battery companies stated that they reserved room for upgrades when constructing the 210 production line, and a slight adjustment can support the production of 218.2 size. At the same time, auxiliary materials such as glass and back plate suitable for 182 size components can also be used in 218.2 size.

The upstream and downstream of the industry lack uniform standards, and only standardized standards can move towards high-quality development

Although there are more and more large-size silicon wafer specifications, and downstream options continue to increase, the industry is also facing challenges brought about by the diversification of silicon wafers, solar cells, and component sizes. A photovoltaic glass manufacturer is worried: “There are really too many large silicon wafers and high-power components emerging in an endless stream. The upstream and downstream enterprises in the industry chain need a unified industry standard to reduce the loss and cost caused by uneven size.”

The road of advanced technology towards industrialization and marketization requires the guidance of standards. In the early stages of product launch, as different manufacturers explored different technical routes, the differences in the specifications and dimensions of photovoltaic products are understandable. However, with the continuous development of the industry and the demand for cost reduction from upstream and downstream, uniform product specifications and sizes are the general trend. Liu Yiyang, deputy secretary-general of the China Photovoltaic Industry Association, believes that the standardization of module sizes is of great significance. “The standardization of module size is an important driving force for the sustainable development of China’s photovoltaic industry.”

The reporter noticed that in May of this year, the China Photovoltaic Industry Association organized a seminar to discuss the outline dimensions, mounting hole positions, and mounting hole dimensions of the 182 and 210 modules in order to speed up the standard formulation and release process, and then guide The product size of component manufacturers is rationalized and standardized.

Lu Jinbiao also specifically mentioned the need for standards. “In terms of standardizing the size of silicon wafers, SEMI China Photovoltaic Standards Technical Committee Silicon Wafer Working Group urgently revised the silicon wafer standards in 2020 and determined the sizes of 166, 182, and 210 respectively. It is not that the size of silicon wafers cannot be increased, but It is necessary to consider the safety and reliability of photovoltaic modules, as well as whether they can be matched with the upstream and downstream of the photovoltaic industry. Standards and regulations must be advanced, otherwise it may be “have hastened but not achieved.”