Most factories are very cautious about the HP (high performance) polycrystalline technology. There is limited access to technical data, and most of it is not available in commercial sheets like the one distributed by LDK Solar for M2 wafers.
The majority of makers of high performance wafer are commonly recognized names with substantial technological background and had made noticeable improvements in the efficiency of their products in the past. Wafer producers are GCL-Poly (8,000MW), LDK Solar Co., Ltd (ADR)(NYSE:LDK) (4,300MW), Konca Solar , JA Solar (1,000MW) and ReneSola (2,200MW).
Other names with larger capacity include Jiangxi Sornid Hi-Tech Co (500MW) and Dongguan FullHoard PV (FH Solar), though most of them are still in the experimental phase, or supplying wafer from the sorting method only, which will help to achieve average efficiency over 17.1%.
Most of the full chain manufacturers like Trina Solar Limited (NYSE: TSL), Suntech Power Holdings Co., Ltd. (ADR)(NYSE:STP), Yingli Green Energy Hold. Co. Ltd. (ADR) (NYSE: YGE) and Hanwha SolarOne (NASDAQ:HSOL) are either having their wafers outsourced or experiment with them, like in the case of Suntech’s wholly owned subsidiary Zhenjiang Rietech New Energy Science Technology Co., Ltd.
Most small factories: Lightway Green New Energy, Zhongwei Yinyang New Energy Co., Ltd., Shandong Shunyi Solar Power Co., Ltd. Xi'an Huajing Electronic Technology Co., Ltd., etc., haven't yet started the research work, either because of a lack of technological edge or because those companies have no interest in pursuing high efficiency polycrystalline wafers.
The HP multicrystalline wafer concept was first shown during the SNEC in March 2012, when GCL launched its S+ mono-like and HP wafer. They claimed the HP wafer could achieve 17.2%. It was rumoured that they were just using the sorting method to get their S+ multi wafer.
More and more news about HP wafer development was heard in the following months. JA Solar Holdings Co., Ltd. (ADR)(NASDAQ: JASO) announced that it achieved 17.2% multicrystalline cell efficiency with its own wafer in June. LDK announced M2 multi, at 17.4%, in August. ReneSola Ltd. (ADR)(NYSE: SOL) claimed to achieve 17.2% in July.
Konca, owned in majority by GCL, as a private firm doesn't make announcements to the market, but customer feedback has shown that its wafers were going through a very steady increasing pace, with a July average of 17.0%, Sept. at 17.2%, and Nov. at 17.4%.
We could see a rapid jump of multi wafer efficiency in China over the last two quarters. Now, the common recognition by major cell makers is: normal wafer >17.2%, good wafer >17.4%, HP wafer >17.6%.
In the beginning many industry sources, even makers themselves, said that they were using the central-sorting method to get higher MCLT (minority carrier life-time) brick and wafers. The sorting method is manual, which involves picking nine central pieces of the brick out of the 25. Then, gradually, there came word that new techniques were applied to upgrade the process, machines and feedstock. For highest efficiency, over 17.8%, they used a combination of central sorting and upgraded process.
From bits and pieces of information we can see that the following approaches have been applied to get HP wafer:
a. Feedstock: definitely higher grade than what was commonly used in casting. In the past, blending was 50:50 virgin vs. recycling. Now, for HP, it's around 80:20. Any low quality recycling, such as brick side wall, top/tail, fines and so on, would be taken out.
b. Hardware: hotzone and crucible will be upgraded to higher purity, with graphite being a core part.
c. Process: the solidification process is longer than before. Temperature graduation control will be stricter than before, to achieve more consistent temperature change velocity. That will lead to smaller grain generated during crystallization, and better unity.
Factories do not count any additional cost from the sorting process. So, in the market, there is no premium over wafers below 17.2%. In early November, Konca was selling wafers with efficiencies averaging 17.4% for $0.78-0.80/pc. There is a consideration for a cost increase of 6 to 8% for wafers with 17.6%. Fox example, GCL was quoting at the time its 17.6% wafer at $0.91/pc. LDK was quoting M2 at $0.80/pc and M3 at $0.90/pc, but currently M3 wafer is not ready for commercial orders. As more and more HP wafers are available in the market its price might go down quickly, until the gap between normal and HP will disappear.
