Solar mono-Si wafer maker Xi'an LONGi Silicon Materials has lowered prices for its wafers by 6.7% from CNY6.00 (US$0.91) to CNY5.60 in the China market, according to media reports.

In the Taiwan market, China-based makers have also decreased quotes for mono-Si wafers by about US$0.05 to US0.75 for 180-micron thick models and US$0.77 for 190-micron ones.

For global solar wafer production, the ratio between mono-Si and poly-Si ones was 5:95 in 2014, 15:85 in 2015, 27:73 in 2016, 36:64 in first-half 2017 and is expected to be 40:60 in the entire 2017.

In view of growing demand for solar mono-Si wafers, Xi'an LONGi is setting up three new factories with annual production capacities of 5GWp, 1GWp and 10GWp respectively in China, while Zhonghuan Semiconductor is expanding annual capacity by 15GWp, with all of the additional capacities beginning to come into operation in second-half 2017.

GCL-Poly Energy Holdings is constructing a solar mono-Si wafer factory with annual production capacity of 10GWp, of which 1GWp has come into production, while PV module makers Jinko Solar Holdings, CSI, Trina Solar and JA Solar Holdings are also setting up factories to produce such wafers.

In 2018, Xi'an LONGi will reach total annual production capacity of 25GWp and Zhonghuan will reach 23GWp. China-based makers' combined annual capacity for solar mono-Si wafers is expected to reach 60GWp at the end of 2018.

Many of China- and Taiwan-based solar cell makers have adopted PERC technology, which can hike energy conversion rates for mono-Si cells by 1.0-1.2pp and for poly-Si ones by 0.6-0.8pp. Therefore, most solar cell makers apply PERC technology to production of mono-Si cells. Global annual production capacity for PERCs at the end of 2017 is estimated at 20GWp.

However, prices for a PV module made of mono-Si cells are high than those for poly-Si ones by CNY0.15 on average. For PV power stations using mono-Si modules and poly-Si ones, the former's investment is higher by CNY0.108/W and power-generating cost is higher by CNY0.013/kWh.