LONGi calls for industry alignment on wafer size as Hi-MO4 sales top 2GW

August 21, 2019
Facebook
Twitter
LinkedIn
Reddit
Email
The Hi-MO4 launch at Intersolar Europe 2019.

The solar industry must work together to agree on standardised larger wafer sizes, according to monocrystalline solar manufacturer LONGi Group.

The company has revealed that its H-MO4 module, which utilises M6 (166mm) wafers, has now sold 2GW. PV Tech understands European availability is expected in Q4 2019.

This article requires Premium SubscriptionBasic (FREE) Subscription

Try Premium for just $1

  • Full premium access for the first month at only $1
  • Converts to an annual rate after 30 days unless cancelled
  • Cancel anytime during the trial period

Premium Benefits

  • Expert industry analysis and interviews
  • Digital access to PV Tech Power journal
  • Exclusive event discounts

Or get the full Premium subscription right away

Or continue reading this article for free

The firm is now backing that wafer size with a series of upgrades across its own facilities.

“By end 2020, LONGi will upgrade its existing cell and module lines and transform them for production with the 166mm wafer,” said Wang Yingge, executive assistant to the chairman of LONGi Solar. “New lines such as the 5GW monocrystalline cell line in Yinchuan will be designed for the 166mm size from the start,” said Yingge adding that large-scale production of Hi-MO4 will commence the third quarter of 2019.

Larger wafers create more efficient modules but also mean more weight and greater physical stresses. Production equipment must also be amended. According to LONGi, the divergence in larger wafer sizes began in 2018 and is leading to a number of mismatches along the supply chain.

“The 166mm wafer has reached the allowable limit of production equipment which is difficult to overcome. This would be the upper limit of the standard for a considerable period,” said Professor Shen Wenzhong, Director, Solar Energy Research Institute of Shanghai Jiaotong University.

“If manufacturers cannot reach an agreement on a size standard, it will restrict the development of the whole industry,” said Li Zhenguo, president of the LONGi Group. 

Shen Wenzhong added: “Existing crystal drawing and slicing equipment are compatible with 166mm size silicon wafer. Production equipment for cell and module needs to be modified, though the costs are lower and easier to achieve. Calculated by “flux”, cell and module production lines using 166mm wafers will increase capacity by 13% as compared with the 156mm size.”

At present, M6 wafer have a price premium of RMB0.4 (US$0.057) compared to the M2 wafer but as scale increases beyond 2019, Yingge said this premium is set to halve.

Read Next

Premium
December 18, 2025
PV Talk: Paul Gebhardt of Fraunhofer ISE discusses reliability issues facing advanced PV modules, an issue which isn't going anywhere.
December 17, 2025
JA Solar is a lead partner in a joint venture that broke ground this week on a new 2GW solar PV cell, 2GW module and 1GWh energy storage manufacturing facility in Egypt.
December 15, 2025
Solar manufacturer SEG Solar has started construction on a 3GW ingot and wafer manufacturing plant in Indonesia.
December 12, 2025
India’s flagship solar PV manufacturing incentive has driven “robust growth” in the sector since its launch, but hurdles remain to building a complete domestic supply chain.
Premium
December 11, 2025
Slowing solar PV and energy storage installations in Europe risks “competitiveness and security at a pivotal moment”, according to the head of SolarPower Europe.
December 9, 2025
Indian solar PV manufacturer Waaree Energies has signed a 288MWp solar module supply deal with US project developer Sabanci Renewables.

Upcoming Events

Solar Media Events
February 3, 2026
London, UK
Solar Media Events
March 24, 2026
Dallas, Texas
Solar Media Events
April 15, 2026
Milan, Italy
Solar Media Events
June 16, 2026
Napa, USA
Solar Media Events
November 24, 2026
Warsaw, Poland