Why p-type multi c-Si is seeing strong market share gains

Modules based on p-type multi c-Si technologies are set to dominate the PV industry over the next five years, according to analysis in the new NPD Solarbuzz PV Technology Roadmap report.

The findings from the new studies show that a dramatic shift to high-efficiency p-type multi c-Si module production and shipments has occurred in the past two years, together with a softening in the focus assigned by many of the market leaders to mono based technologies.

Across China and Southeast Asia, the push to improve multi performance – while driving down costs way more than any other PV technology – has revitalised the prospects for multi c-Si technologies, and provides a stark contrast to the somewhat academic, and idealistic, PV technology roadmaps that were often showed as a means of conveying technology leadership.

A subset of manufacturers is fixed on higher quality c-Si shipments. At the top-end, SunPower and Panasonic have no option but to use the highest quality n-type ingots being produced. A few others have n-type capacity, but based on more standard cell architectures that do not need the silicon grade of a SunPower cell, such as Yingli's Panda modules.

And then there are the cell makers that are able to flip lines over from mono-to-multi and vice-versa, needing only p-type wafer supply. Taiwan cell makers have done the multi-to-mono flip of recent, but it is questionable if this is sustainable in the long-term as the Japanese market finally succumbs to global price drivers over the next 18 months.

But p-type multi is winning the battle now, and is seeing strong market-share gains. In fact, it is really the high-efficiency multi wafer that has won the day here. Most – but not all – of the market-share gains from HE multi module shipments in the past 12-18 months can be tracked back to improvements in ingot growth. Interestingly having a HE multi module is not necessarily contingent on having the best cell line. This has enabled selected Chinese makers (that have stuck to standard cell operation) to increase module power ratings in the past couple of years.

It is possibly time for some observers to change their view on p-type multi, with many having considered multi of insufficient quality to feature prominently on PV technology roadmaps. There is no shortage of solar cell physics and chemistry on offer to back up this statement, but another crude way to look at this is as follows:

If you keep improving multi quality, then at some point, it becomes possible to do advanced process changes on multi that were previously only considered viable on mono. Yes, adding the PERC structures will work quicker on mono (everything works quicker on mono), but that by no means precludes efficiency improvements on multi as the substrate quality keeps getting better.

It is no co-incidence that the top two module suppliers to the PV industry (Yingli Green Energy and Trina Solar) are choosing p-type multi c-Si as their key offering to the industry going forward. Nor should it be a surprise that GCL is putting so much effort into having better ingot growth and wafer supply of p-type multi substrates to much of the key Asian suppliers today.

Some may argue that the pull of Yingli, Trina and GCL alone pretty much sets the deal in terms of HE p-type multi c-Si technology to dominate, but there is more.

Perhaps one of the other factors in multi's resilience and potential can be found with REC Solar and Hanwha Q-Cells in their fabs in Southeast Asia.

From a technology standpoint, REC Solar and Hanwha Q-Cells arguably have the most experienced c-Si R&D teams (outside of SunPower) in the industry, and are certainly aware of all the risks and opportunities that would come from adding any unknown process change (or anything that is prohibitively high cost) to multi c-Si manufacturing lines that are meeting customer needs.

Both REC and Q-Cells are staunch p-type multi c-Si cell proponents, with p-type multi module supply accounting for their entire end-market shipments. Expansions are p-type multi based, with module power increases again being mainly tracked back to the improvements in multi c-Si ingots in the past couple of years. Each company is tinkering with PERC additions, presumably once all front-side upgrades are complete.

As REC captured contract-after-contract for module supply recently in the US, did anyone bat an eyelid at the fact that these entire shipments will be from p-type multi c-Si panels? Of course not, -shipping 260-265W 60-cell panels (for rooftops or ground-mount) at the right cost point is easily accepted by the market. If need be, create a 72-cell equivalent. But how many developers or EPCs are insisting that mono modules are supplied?

The new PV Technology Roadmap studies at NPD Solarbuzz involved looking separately at what technology means from every aspect of the solar PV industry, something that had been a key omission in all technology roadmaps outlined previously to the PV industry. In fact, in the past, roadmaps were typically compiled by scientists that were not necessarily privy to end-market activity, or by R&D teams at companies that often just took their lead from the scientists' wish-lists.

Nothing wrong with that, but the roadmaps before that claimed the big market share swings to n-type, or (dare we say it) thin-film technologies, were just not of the real world. The reality was that the roadmaps were simply changed each year based on what the end-market was actually doing. And all too often, the end-market was choosing simplicity and gradual cost reduction and small (but meaningful) efficiency gains. And every year, the momentum and critical mass of p-type multi manufacturing has only added weight and traction, raising the bar for almost every other competing PV technology.

End-market pull on technology made

Had we stopped the PV technology analysis once the study of end-market trends was complete, the conclusions would not have been that far off the final output from the whole-industry analysis on technology.

Pulling apart every end-market – the rooftop supply activity, the commercial rooftop sector, the small and large ground-mounted systems – was one of the most valuable parts of the overall PV Technology Roadmap methodology. And then looking at the project pipeline across all developers and EPCs, and reviewing who supplies what and from whom. And at the micro-segment level (one specific country, one specific application segment), what are the trends for c-Si versus thin-film, ditto for c-Si mono vs. multi, and multi vs. HE multi, etc.

Figure 1 here shows just one of the final graphics that comes out of this study. In this case, we have extracted what is effectively the SAM for SunPower, Panasonic, TetraSun or Silevo; the forecasted geographic end-market demand for c-Si Premium modules. A secondary level of technology segmentation also falls out here, in that the split by country/region is provided for residential, commercial rooftops and ground-mounted segments. So almost by default, the roadmap starts to provide sales targets for technology-specific module suppliers, both from an application and geographic standpoint.

Figure 1: Forecasted shipment locations for Premium c-Si module supply out to 2018, derived bottom-up from end-market demand and project-developer/EPC/installer supply activity

Source: NPD Solarbuzz PV Technology Roadmap report, September 2014

Figure 1 also shows that even the technologies with a small market share can have strong growth trajectories. Growing from 1 to 6GW sounds great, but remember that 2014 is likely to end up close to 50GW and the growth trends to 2018 remain strong. So even extracting 6GW in 2018 for Premium n-type module supply (and similarly removing thin-film additions) still leaves a huge amount of market demand, and this is exactly where the p-type multi activity fits in.

Looking at mono and multi splits

Once the above two sub-segments are removed from the end-market technology analysis (Premium n-type and thin-film), the focus then returns to the standard n-type, p-type mono and p-type multi debate. So, this required a dive into all the activities of the tier 1 supply-chain from polysilicon to ingot/wafer, cells and right down to the branded shipments of the top-20 module suppliers to the industry.

Eventually, we are able to extract the p-type multi demand, and, as shown in Figure 2, separate out in a way that shows the incredible gains by HE multi in the market since 2011. In effect, this derives empirically what we alluded to at the start of the article here: that the market leaders continue to prioritise p-type multi, with the shift from standard to HE multi module supply being the catalyst in revitalising what many had assumed was a technology destined to be replaced by the more esoteric alternatives.

Figure 2: c-Si p-type multi is set to see further market share gains out to 2018, driven by the high-efficiency (HE) module variants that have helped salvage profitability across much of the upstream manufacturing segment during 2013 and 2014

Source: NPD Solarbuzz PV Technology Roadmap report, September 2014

The methodology used to derive the technology roadmap allows for plenty of technology related trends to be reviewed and discussed, down to process flow arrangements across cell makers, or technology shipments on rooftops by country and technology type. But one particularly interesting output relates to the module power rating forecasts.

To do this, we focused specifically on the module shipment volumes of the top-20 module suppliers, effectively removing variants that are offered to the market but whose market-share level is somewhat in the noise.

Therefore, knowing what is being installed in the end-market is essential here, not necessarily what is being offered on datasheets to the market.

When 48, 60, 72, and 96 cell variants are accounted for, across 5 and 6” cell types, and splitting into the relevant Premium n-type, mono and multi types, we ended up with 16 c-Si module variants. The power ratings (historic, current and forecast to the end of 2018) were analysed for each of these 16 c-Si module types, compared to existing data points from average mass production data of the top-20 module suppliers to the industry.

But, if one module type has to be ringfenced for display here, it is undoubtedly the 60-cell, 6” c-Si multi HE panel – the clear market-leader in the PV industry today. Figure 3 shows the trends in mass production for this module type, with typical upper/lower ratings that fall out of distribution curves. The strong growth in power ratings from 2010 to 2014 confirms the ingot/wafer trends discussed at the start of this feature. The uptick again in 2017 and 2018 assumes that some of the cell changes (largely thought to be mono specific) are implemented in mass production for multi cells.

As materials and equipment suppliers review their strategies for the next few years, it is hard to see how anyone can choose to ignore the opportunity from p-type multi HE supply, unless the sole target is to play within more technology-specific lower volume addressable markets. For some suppliers, this will be perfectly acceptable, with the strong growth in the end-market ensuring ongoing supply. But for those looking to address the large segment of the PV industry, keeping a focus on p-type multi HE activity will be essential.

Figure 3: Historic, current and future panel ratings (Wdc-p, STC) for the industry's most popular module, the p-type multi HE module, comprised of 60 cells of 6 inch size

Source: NPD Solarbuzz PV Technology Roadmap report, September 2014

Finally, the evolution of technology supply and geographic variations will also have a direct impact on planned capacity additions. Are companies limiting themselves through choice of technology, in terms of which end-markets to go after? While a few GW here and there is not going to change the overall picture in 2018, knowing that the competition is likely to be offering and which countries and segments will be awash with p-type HE multi modules is simply prudent housekeeping that should limit the surprises on offer going forward.

Originally published by NPD Solarbuzz. Reproduced with permission.