BIG Interview: Hongbin Fang, director of technical marketing at LONGi Solar, and Longi’s strategy director Max Aimin Xia discuss the growth and cost reduction potential of monocrystalline cells, and explain how a new hydrogenation process may well have solved the problem of light-induced degradation in mono PERC cells.
SNEC Daily: What is LONGi Solar’s main technological focus in 2017 and into 2018?
Hongbin Fang (HF): Last year we introduced our PERC product Hi-MO1 to the market, and for 2017 the main focus for LONGi Solar is to continue to refine our PERC process to improve the efficiency and power output of our cells. In addition to that we are continually working on module improvement to bring higher power gains to the market. We are looking at a 10 Watt (W) power gain every year going forward. There is a lot of technology that we are developing on the module side, including our half-cut cells and also our shingling modules that are poised to improve our power output significantly.
This year we have introduced our bifacial PERC module product Hi-MO2. This offers a big increase in terms of power output. On the frontside the output is equal to standard PERC, and on the backside you have an additional 8% to 25% power gain. This can help our customers to significantly lower their LCOE.
SNEC Daily: Recent analysis by IHS Markit has suggested that monocrystalline cells will increase their share of the market from 29% last year to as much as 37% by 2020. What is LONGi Solar’s view on how mono’s market share can grow?
HF: Our vision is that mono is going to continue to increase its market share, yes. We are aggressively expanding our ingot and wafer capacity, while also gradually increasing our module capacity. We think that at this point our wafer costs on mono are competitive with multi, with higher power gain on the cell and module side for mono. This means an improved end result for the customer, and looking ahead to the future, costs for mono can be even lower. We are confident that because of these realities mono will grab a larger market share.
Max Aimin Xia (MX): For a while, mono capacity is 7.5 GW by end of 2016 and was limited and largely unable to meet market demand before June 30,2017. But our recent another 5 GW Mono Ingot and Wafer capacity expansion in Yinchuan and Zhongning, Ningxia Province has eased the situation, and our recent capacity expansion in Taizhou has eased the situation, taking our cell and module capacity to 5 GW. This has eased the bottleneck that was holding back mono adoption, and I believe that it will aid market growth. In two to three years many companies are going to transfer to mono, and with costs continuing to fall closer to those of multi, this growth will accelerate.
SNEC Daily: At the SNEC conference on day it was revealed that LONGi Solar has been collaborating with the University of New South Wales on advanced hydrogenation solution on LID with PERC. What have been the results on this?
HF: The results of this collaboration have been very encouraging. It used to be the case that three to five years ago one of the main obstacles for PERC adoption was high light-induced degradation (LID). Because Longi Green Energy Technology [which owns LONGi Solar] is a vertically integrated company, we have approached LID issue from both wafer and cell processing. we have production and quality control from the wafers right up to the modules. We have conducted a lot of work to reduce the oxygen concentration in the wafer. By doing this, it helps us to lower the LID.
From cell processing side, with the collaboration with the UNSW, we have developed advanced passivation technology that can also slow lower the LID from the cell processing. So thanks to this hydrogenation collaboration research and application, we can have control of both the wafer and then the cell: this means now that our PERC product’s LID performance is similar to, or even lower than, the conventional multicrystalline process,and LONGi Solar just released LIR technology with UNSW to minimize the LID effect now.
SNEC Daily：So would you say that the hydrogenation process more or less solves the issue of LID with mono?
HF: It definitely does. Combine that with our wafer quality improvement where we can offer higher wafer purity than multi, we see that even right now the LID performance for Mono PERC is even better than multi.
SNEC Daily：What is the significance of LONGi Solar’s results of 23% efficiency on mono PERC – mentioned in Tuesday’s conference? What does this say for PERC in general?
HF: Currently the industrial production efficiency for LONGi Solar’s PERC cells is a little over 21.1% - 21.2%. So looking at our next generation cell technology it can help us to bring our power output to a higher level. This result of 22.17% in laboratory tests shows that PERC has not yet reached its limit. We still have a long way to go to reach even higher efficiency.
SNEC Daily：What is LONGi Solar’s roadmap towards getting there?
HF: By end of this year in terms of production we are looking at incremental increases, and we expect efficiencies of 21.4%, 21.5% for MONO PERC cells coming off the production line. Next year I am confident that we can increase that by an additional 0.3% taking us up to that next level. Exhibiting at the SNEC show are our most advanced PERC modules: 60- and 72-cell versions, all black for residential applications, which are targeted particularly for the U.S. and Europe. The new product is our HI-MO2 cell and module that offers additional power gain on top of PERC. Still in the development phase is our shingling modules, which is our next generation of products that we hope to introduce into the market some time next year. These offer an additional 8-10% power gain on top of PERC.
SNEC Daily: Moving on to the wider Chinese solar market, do you feel that China’s Top Runner program has helped to support high efficiency solar products in the country?
HF: The Top Runner basically tries to bring advanced technology to the market, and to increase high efficiency penetration. It is a good program to demonstrate the ability for high efficiency technology to drive market evolution and deliver better value for customers. You see the end results – customers have more opportunities to purchase better quality modules.
MX: As a solar producer, China has occupied around 80% of market share globally, but for the next generation of new technologies, there was often a reluctance among Chinese companies to invest in these technologies, so NEA felt they needed to promote new technology investment.
The program, which is released by NEA, pushes this industry to innovate and improve standards, and for Longi – being focused on high efficiency mono – this new generation total solution approach to reducing LCOE and improving the IRR is well suited to our own outlook. At the time the program was introduced, the government needed a pioneer in this area – a role that Longi has been able to play.
We think that the government will also push the program to instigate even further technology upgrades. Companies that want to invest in new technology will reap the benefits – not just in China but globally. Other countries can also benefit too; they can learn from China and follow its lead, and even collaborate with China to innovate and work together.
HF: This will benefit everyone, and help to bring down costs quickly while also improving standards – it’s a win-win.
SNEC Daily: Within China, do you share the view that the first half of the year is shaping up to be disappointing in terms of installations? Or will China reach the end of June with similar levels of growth as seen in H1 2016?
MX: We are seeing that in 2017 it is not quite as strong as last year, so far. The amount of installed capacity for ground mount is a bit lower. The Chinese government has released a new policy to promote distributed solar energy in some regions, particularly in the east and the north of the country. These areas are the most developed and consume the most energy, and so also have the highest levels of pollution. So the government is urgently promoting distributed generation (DG) solar in these regions. The FIT cut for grid-connected power stations in June will be around 15%, after which the support for DG solar will be around 50% higher compared to ground mount. To me, the policy direction is certainly now in support of distributed solar energy.
About LONGi Solar
LONGi Solar, a subsidiary company of LONGi Green Energy Technology Company Limited, manufactures monocrystalline solar cell and module, and is dedicated to providing cost-effecitive solutions for investors in solar power plants.