At the Intersolar North America trade show last week, one of the background themes was the increased interest in technologies based on n-type silicon wafers. This follows a number of announcements over the last few weeks, most notably SolarCity’s plans to build a 1 GW solar PV module factory based on Silevo’s technology.
This alone would sharply increase demand for n-type monocrystalline silicon wafers, which currently make up a small portion of the overall wafer demand.
Additionally, last week Belgian research center imec announced a 21.5% efficient PV cell based on a PERT design, which utilizes n-type mono wafers. This is a shift from the company’s previous work with PERC, and imec told pv magazine that this was in part due to the more straightforward paths to higher efficiencies that technologies based on n-type mono offer.
Finally, in June GT Advanced Technologies announced a deal to supply its HiCz ingot pullers to Qatar Solar Energy, which the company will use to produce n-type wafers for production of high-efficiency PV at an integrated factory in Qatar.
GTM Research Analyst Shyam Mehta says that while there has been increased interest in n-type technologies lately, many companies have been pursuing high-efficiency PV designs based on n-type mono wafers for a number of years without significant success.
"People have been talking about the shift to n-type for a while, and we see it as part of a number of company’s roadmaps," explains Mehta. "But in terms of actual market adoption so far, it’s still pretty niche."
SEMI’s latest International PV (ITRPV) Roadmap also expresses a cautious optimism for the technology. While SEMI predicts that n-type wafers will grow from 5% of the market in 2013 to 20% in 2018, it also expects n-type wafers to be more expensive than p-type wafers at least through 2018, and says that this makes it difficult to predict market share.
Mehta of GTM Research says that Solargiga and Shanghai Comtec have both publicly announced that they will produce n-type wafers, and that the majority of production is currently going to SunPower and Panasonic.
And while SolarCity/Silevo and other companies will create the demand, Mehta notes that this must be met with upstream progress as well. "With a lot of these kinds of technologies that start upstream, you need to get that upstream supply chain to expand, and once that happens you can see some cost reductions from economies of scale, and you start seeing some improvement there."
All major projections show an increased share for n-type mono, but the extent of market adoption, and when this will happen, remain murky. "Calling the timing of that, even if you are sure this is more of an if thing than a when thing, is hard," notes Mehta.