• LONGi has discontinued mass production of its M2 wafer sizes as the technology falls out of favor with several manufacturers
  • Companies prefer larger wafer formats as these promise better yields over M2 wafer sizes
  • PV InfoLink observes prices for M2 wafer sizes slipping day after day thanks to weak demand

LONGi Group has discontinued mass production of its M2 wafer sizes as of April 2020. This was also underlined by the world leading mono wafer producer’s latest updates about the price trend for its wafer products. It is not manufacturing M2 wafer for mass production anymore, specified the company’s Director of Application Engineering and Key Customer Service, Yichun (YC) Wang in a recent LinkedIn post.

With a standard size of 156.75 mm x 156.75 mm, M2 wafer sizes are slowly falling out of favor with several manufacturers as the current trend is to produce larger wafer sizes which in turn brings down costs and improves cost dynamics for overall solar modules. While LONGi pushes the M6 format (166 mm x 166 mm), in August 2019, Tianjin Zhonghuan Semiconductor launched a 12-inch large wafer product (210 mm x 210 mm), called M12, claiming it to lead to an output of over 600 W, and have 80.5% more area compared to M2 wafers. Zhonghuan is supplying its M12 wafers to Risen Energy, and other big names which recently announced module products based on M12, such as Trina Solar, GCL System Integration, Aiko Solar, among others. However, for M12, basically completely new processing equipment is needed.

TaiyangNews covered the “Large Wafer” subject in depth in a webinar with industry experts in late 2019 concluding that manufacturers are increasingly looking at larger wafer formats to improve yield. Speaking during the webinar, LONGi Solar’s Head of Product Management and Chief Engineer Winfried Wahl explained that using a M6 wafer there is an increase of 12.21% in surface area compared to M2. Back then Wahl had confirmed his company’s plans to completely shift its production to M6 size for both monofacial and bifacial variants (see Big’ Benefit For Modules).

PV InfoLink claims M2 sized wafer products have their prices slipping down as there isn’t much demand for the same in the market. It wrote in a April 15 published post, “As end-market demand for M2-sized products is weakening and most mono-Si wafer makers have shifted to G1 (158.75 mm x 158.75 mm), the inventory of M2-sized products is being shrunk. Such products will be gradually phased out and made available only for customized orders.” PV InfoLink claims price reduction for M2 wafers is more prominent as these are ‘repeatedly unsold’.