Day 1 of the TaiyangNews Virtual Conference on Cell & Module Production Equipment & Processing Materials saw leading companies talking about the efforts being made in the solar PV industry for cell optimization. Extending the optimization to the module level, day 2 of the conference was devoted to module production equipment and materials.
As the keynote speaker on day 2 of the conference, the CEO of RCT Solutions GmbH Dr. Peter Fath talked about building new capacities and manufacturing solar cells and modules at competitive costs. As a company, RCT helps companies across the globe set up GW-scale, vertically integrated solar PV factories. Sharing an example of a 10 GW vertically integrated solar PV factory from metallurgical silicon to modules and glass, Fath presented the approximate cost of establishing and running such a fab.
He factored in costs related to financing, overheads, O&M, utilities, depreciation, labor, logistics, and materials. According to his calculations, a 10 GW PERC fab will have the lowest production cost of $16 cents/W in China and a slightly higher cost of $18.3 cents/W in Algeria where electricity is cheaper. The same will have a production cost of $25 cents/W in Germany and $25.7 cents/W in the US. The average production cost of PERC is $9.7 cents/W.
Similarly, he provided the component-wise country of origin production cost for a 10 GW factory for TOPCon, heterojunction (HJT), and TBC. Fath argued that integrated horizontal and vertical manufacturing is a must for any market, since it ensures independence in the supply chain and reliable module supply, along with lower costs. If there is availability of competitive electricity, local supply chain and qualified labor, a factory with around 5 GW annual capacity can be realized in any economic region.
At the same time, it is important for manufacturing to run on carbon-neutral electricity to ensure green and socially responsible production, he added.
Jietai Solar or JTPV's R&D Manager Xinrui An discussed the cooperation to assemble high-quality modules using n-type solar cells. A part of China's Drinda Group, JTPV operates 40 GW n-type and 9.5 GW PERC capacities. It claims to have shipped 20 GW of n-type solar cell capacity out of 35 GW capacity shipped by the top 5 n-type cell makers globally in 2023. JTPV's n-type cell technology comprises the stack wafer deposition process, with emitted-metal contact optimization (J-SE+) and selective emitter (J-SE). The manufacturer also uses gradient-index coating and SMBB technology with super thin fingers for its cells. An claims JTPV's n-type cells help increase Voc by 12 mV with maximum cell open circuit voltage reaching 732 mV, while cell conversion efficiency goes up by 0.8% abs.
With the growing use of half-cut cells that undergo laser cutting, JTPV says it uses half-cut edge passivation (HEP) for its n-type cells wherein it deposits a thin layer of passivation film at the edge of the cell to reduce or even help it recover fully from laser damage.
An stressed, "HEP treatment can almost fully recover the pFF loss due to laser cutting at cell edges leading to increased cell efficiency." At the module level, JTPV believes an increase in Pmax of around 5W can be achieved with the HEP treatment, both for single- and double-glass modules.
The manufacturer plans to continue doing R&D on surface and contact recombination reduction while using high-quality wafers and metallization optimization including even finer fingers and zero busbar (0BB) architecture. An said the 0BB configuration helps bring down the silver cost for metallization, facilitating the use of narrower ribbons and low-temperature encapsulation.
JTPV's future direction also involves more advanced cell structures such as back contact (BC) and perovskite/silicon tandem, shared An.
Presenting ConfirmWare's PV equipment for n-type solar modules, the company's Director of Overseas Sales Department Leo Yu discussed the various adaptations and optimizations it has carried out to ensure good quality and efficient panels.
An automation equipment manufacturer, ConfirmWare works with PV module factories supplying its solar stringers and panel-making equipment, among other products.
Talking about the Chinese company's optimized equipment for n-type modules, Yu said its high-precision temperature control tunnel type Lightbox is equipped to control preheating, soldering and cooling in different sections to realize high-precision temperature control. It has been adapted and optimized to reduce the thermal shock of cells as well as hidden crack and fragmentation risks.
Similarly, to ensure consistency of ribbon traction and pavement, ConfirmWare uses a vertical gripper to enable precise control of ultra-thin ribbon. This 'innovative' gripper, according to Yu, prevents ribbon distortion and effectively improves yield rate. This vertical gripper is matched with overall tooling. ConfirmWare's machines incorporate tools like sponge sucker to enable gentler cell handling to avoid fragmentation.
He explained that for a 1 GW PV module highly automated production line from ConfirmWare, 24 people are required for double-glass modules and 18 for single-glass modules.
A Senior Engineer at Hangzhou First, Stephen Tang talked about the encapsulation materials for TOPCon modules during his presentation. The company touts an annual production capacity of around 380 GW for encapsulants and 50 GW for backsheets at its factories in China, Thailand, and Vietnam.
Hangzhou First produces EVA, POE, and EPE films. Reflecting on the best encapsulant for a long-lasting TOPCon module vis-à-vis the LECO process, Tang voted for the EVA, presenting the company's proprietary EBISU S Series. The 2 products in this series are anti-acid EVAs and suitable for modules in damp heat area environments. A Kyocera original product, Hangzhou First has exclusive license over the encapsulant.
While a LECO-encapsulated cell can corrode with long-term use, Tang argues that his company's EBISU S Series EVA can lower the generation of acetic acid and protect the cell from corrosion. It is recommended for glass to glass (G2G) modules.
As for POE, compared to the normal POE, Tang said Hangzhou First's TF4N POE has lower WVTR and anti-electromechanical properties that work well for glass to backsheet (G2B) modules.
Cybrid's Overseas Account Manager Jacob Harris focused on advanced backsheet structures for the latest cell technologies as he introduced his company's backsheets and reflective gap films aimed at extending the module lifespan.
Pointing to the growing trend of using transparent backsheets, especially for emerging cell technologies like TOPCon and HJT, Harris said Cybrid's water barrier backsheet caters to this segment. It uses an anti-UV layer of PE at the top, followed by an adhesive and specially formulated water barrier primer to achieve low levels of water vapor transition transmission. The primer does not interfere with the transparency, he claimed.
According to Harris, glass-film modules perform better than glass-glass modules and recommends the reflective gap film from Cybrid as opposed to the screen-printing process for a long life of solar modules.
He shared a case study of a Brazilian manufacturer who experienced 40% of all installed modules crack within 6 years of deployment. The company was sued and later found out that silkscreen printing was the reason for the cracks. This process requires high-temperature exposure, which leaves the glass more rigid and fragile from the stress.
Harris suggests that to improve the mechanical properties of tempered glass, it is ideal for companies to buy the glass blank and apply reflective films to create gap cover patterns. Cybrid's metallic gap films have a reflectivity of about 80% and slightly higher for white gap films, he added.
Continuing the discussion on encapsulants, part of the leading encapsulant supplier HIUV's Overseas Sales department, Rainbow Zheng presented a multi-scenario encapsulation technology for n-type cells. These include TOPCon and HJT modules, 0BB interconnection and lightweight dual-glass single-side encapsulation solutions.
While agreeing that there cannot be a picture-perfect film solution for different cell module technologies, Zheng said HIUV's upgraded n-TOPCon cell encapsulation is optimized to enhance the product's anti-PID polarization performance.
She claimed that HIUV's co-extruded EPE film has now become the standard for TOPCon module encapsulation. Its dual-glass EVA solutions help lower costs and increase efficiency with transparent white film promising higher moisture barrier effect and ultra-low acid value system.
Executive Panel
The panel discussion, moderated by the TaiyangNews Head of Technology Shravan Chunduri, focused on going local and what's needed to manufacture modules profitably around the world.
Dr. Peter Fath of RCT Solutions listed some prerequisites for anyone interested in venturing into solar PV manufacturing. These are identifying a suitable market, offtakers, and ensuring that the production can be at 5% to 15% above the cost leaders, without subsidies. Only then it will make sense to venture into this space.
At the same time, vertical integration is recommended for PV manufacturing since manufacturers need to factor in local conditions and requirements for their raw materials to be clear of any supply chain issues. The crux is to work in close cooperation with suppliers to ensure the products meet local regulations.
For instance, the US requires modules to be free of forced labor while Europe wants sustainability and recycling aspects to be considered. If the modules don't have a transparent supply chain, it can lead to problems later on, he contends.
Talking about the recent developments of solar PV manufacturers shutting shops in Europe, Fath listed 3 major challenges for the players operating in the continent. These include lengthy permitting processes, Europe being an unregulated market allows for the dumping of cheaper modules, and the lack of suitable land. These reasons, he said, are the primary culprits for projects' domestic manufacturing not taking off here as it should.
In a country like India, for instance, permitting is not seen to be a challenge if the project is backed by the state governments. In India, being a low-cost market where labor is also easily available, costs can be saved with a semi-automated fab as well.
Sharing his experience of establishing factories outside of China, ConfirmWare's Leo Yu said one crucial thing is the total time required to set up fabs beyond China, because the Asian giant is easy and quick with permitting, electricity supply etc. Outside, these challenges take time for a factory to ramp up fully.
He also reflected on the critical role that artificial intelligence (AI) plays with regard to cost-effectiveness. It is mainly seen in terms of manpower involvement. For instance, he explained, with the use of AI, only 1 person is needed to operate the stringer instead of 5 people otherwise. This can help the newer players or those undertaking expansion to save on costs.
Cybrid's Jacob Harris echoed the other panelists when he said it is important for manufacturers to understand their market and customers. Focus on procuring the right materials to ensure the company is safe from any potential lawsuits when the modules don't work as built. Harris also advised that manufacturers shouldn't skip module testing for various climates and environments as that ensures the product's reliability.
Harris shared that his company sees clients increasingly seeking customized solutions for their requirements, which is what Cybrid plans to focus on in the future. For instance, right now there is talk about recyclable modules in Europe, so the company is developing encapsulation that would be better suited for recycling.
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