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Seven solar manufacturers, including tier-1 players, have signed up to a joint initiative aiming to establish a new standard size for silicon wafers at 182mm x 182mm. Conspicuously absent from the initiative is China’s Zhonghuan Semiconductor, which last year introduced a 210mm solar wafer, the largest seen in the industry so far.

Monocrystalline manufacturer Longi Green Energy today announced that it is among seven PV manufacturers in China to have signed up to an initiative calling on the whole PV industry to adopt 182 mm as a new standard for solar silicon wafers.

The seven companies to have joined the initiative so far, according to Longi, are JinkoSolar, Canadian Solar, JA Solar, Runyang Yueda Photovoltaic Technology, Lu’an Solar Technology and Zhongyu Photovoltaic Technology, as well as Longi itself.

In 2018, ‘M2’ wafers measuring 156.75mm were widely seen as the industry standard, representing more than 90% of the market. Since 2019 however, manufacturers have begun to see benefits in increasing wafer sizes, leading ultimately to modules rated at 500 W+ appearing on the market.

But the change has not happened uniformly, and now several sizes, all larger than M2, have gained ground in the module market. According to Longi, this has led to confusion among customers and a lack of coordination between the industry’s upstream and downstream segments, ultimately increasing costs.

With this in mind, the company now says that an industry wide standard is needed once again, and that it believes the 182mm M10 wafer will lead to optimized use of resources and ensure continued development of the PV industry. “We jointly call upon our industry partners and colleagues to support this initiative and embrace the M10 silicon wafer standard size (182mm x 182mm) in the development of next-generation silicon wafers, cells and module products, thus promoting the establishment of a unified supply chain and standardization of equipment manufacturing and customer applications for the entire industry,” reads a statement from Longi Green Energy Technology.

Shift in sizes

Longi was among the first major industry players to advocate a switch to larger wafers, initially advocating the 166mm M6 wafer as the ideal size for a new standard. This was challenged later in 2019 by Zhonghuan Semiconductor, which introduced the much larger M12 wafer measuring 210mm. Zhonghuan does not appear to be among the manufacturers now calling for a 182mm standard, pv magazine has reached out to the company for comment.

Both of these, and other wafer dimensions larger than M2, have seen adoption from module manufacturers, and most are reportedly keen to ensure that their equipment is compatible with all sizes up to M12. The M10 initiative announced today is backed by several major players, which should certainly give it some weight in establishing a standard. Such a development was forecast by analysts earlier in the year as likely to be the deciding factor on mainstream wafer size. “During the 2020-21 period, the top five module manufacturers will form alliances and develop wafer sizes of their own,” wrote PV InfoLink’s Corrine Lin earlier this year. “These developments will determine the mainstream wafer size in the future.”