LONGi boosting M6 solar-grade mono-Si wafers

The largest China-based solar-grade mono-Si wafer maker LONGi Green Energy Technology has been pushing for usage of M6 solar-grade mono-Si wafers (in a square shape eith side width of 166mm) through adopting such wafers for its in-house production of PERC (passivated emitter and rear cell) mono-Si solar cells, according to industry sources.

While M2 (side width of 156.75mm) is the mainstream size specification for solar-grade mono-Si wafers, some of China-based mono-Si solar cell makers have begun adoption of G1 models (side width of 158.75mm) because a larger wafer results in a larger solar cell and thereby more power generation as well as the adoption entails limited adjustment in solar cell manufacturing equipment, the sources indicated.

Since use of M6 solar-grade mono-Si wafers necessitates partial adjustment in solar cell manufacturing equipment and therefore the cost-effect ratio is higher than that for G1, the adoption of M6 is limited currently, the sources explained.

But if LONGi Green Energy has annual PV module production capacity of over 15GWp dedicated for using mono-Si solar cells made from M6 solar-grade mono-Si wafers, M6 is likely to occupy a considerable portion of total demand for solar-grade mono-Si wafers, the sources noted.

Taiwan-based solar cell makers, mainly due to reluctance to adjust manufacturing equipment arising from continued net operating losses from solar cell production, mostly adopt M2 solar-grade mono-Si wafers of which about 90% are imported from China, the sources said.