On November 12, a customer value focused conference entitled “Advanced PV Technology for Better LCOE - 182mm Module and System Technology”, co-sponsored by JA Solar, Jinko Solar and LONGi Green Energy, was held in Shanghai. During the conference, solar inverter and tracker manufacturers, power design institutes, EPC companies and third-party certification institutions issued a comprehensive statement on the design, production cost, supporting infrastructure, system application and product certification of 182mm modules.
With the arrival of the grid parity era, the industry has recognized the benefits of deploying high-power modules in large sizes for their ability to reduce the LCOE. However, larger module sizes come with their own technology challenges.
Ji Zhenshuang, deputy director of China General Certification, said at the conference, “Larger sizes bring higher module power, but industry participants should also pay attention to the industry’s supply chain and system security. In particular, a constraint condition should be set to maintain safety and reliability in terms of electrical parameters. At present, as the modules remain in a rapid transition period, serialization and standardization under gradual adjustment would further contribute to the development of the solar industry.”
“The increase in module size requires consideration of a number of factors, ranging from module circuit and component matching design and reliability to process capability, packaging and transport, system design, and post-operation and maintenance,” said Zou Chicheng, Vice President of TUV Rheinland. Zou suggested that companies should seek an optimal solution between size and safety from the perspective of certification.
Li Shaotang, Senior Product Manager at LONGi Solar, commented, “As early as 2018, the industry had come out with the idea of having a larger module size to increase power. However, larger size doesn’t necessarily mean better performance. Various boundary conditions for thorough consideration include manufacturing, transportation, reliability and manual installation. The 182mm modules effectively support the existing industrial specifications and electrical systems. Additionally, in terms of LCOE, 182mm modules are superior to 210mm due to lower system cost, better generation capacity and reliability. The former is optimal for large-scale ground-mount power plants on flat terrain.”
Meanwhile, the industry has increasingly realized the cost savings brought by larger module sizes. Yu Hanbo, Senior Manager of Global Products at Jinko Solar, said, “Improving power generation by reducing line and internal loss is one of the ways to reduce costs. Compared with 210mm modules with the 55P version, 182 mm modules can reduce line loss by 0.21% and internal loss by 2%, which represents a reduction in EPC cost of more than 0.1 yuan/watt. On the BOS cost side, the 182mm module can provide approximately 2.6 cents/watt of savings compared with 210mm. When comparing different dimensions of electricity cost, BOS costs and IRR, 182mm products are the best choice.”
With the benefit of advanced 182 product planning, the modules have gradually entered into the mass production phase.“The crystal-pulling rate of 182mm is basically the same as that for 158mm, and there is still room for further improvement. The slicing rate is slightly lower but will soon reach parity with the 158mm wafers, and the cell efficiency can increase to 23.1% through the optimization process of each link. At present, mass production efficiency has reached more than 21%. In terms of transportation, compared with 158/166 products, each container for 182 products can be loaded with about 10% ~ 20% watts more,” said Monsoon Wang, Senior Vice President Assistant and Senior Product Technician at JA Solar. More importantly, 182mm products have a number of qualified suppliers in each of the processes, including crystal-pulling, slicing and cell and module manufacturing. It is estimated that, in 2021, the production capacity of crystal-pulling, glass and film for the 182mm products will represent more than 50% of the industry’s full capacity, and the proportion of crystal-pulling will be as high as 91.7%.
As for inverters, Huawei and Sungrow, the two leading manufacturers, indicated that their related products can comprehensively support 182mm modules. According to Gan Binbin, Global Solutions Director at Huawei, the high-power modules bring forward the challenge of matching the maximum current of the inverter MPPT with the working current of the modules. In addition, the reliability risks of cracks, hot spots and diodes also increase. However, Huawei's products can fully support all modules, utilizing AI BOOST's intelligent algorithms and diagnostics to effectively reduce cost and increase efficiency.
Zhang Yanhu, Vice President of Sungrow, said, "The rise in module current will increase the diameter of low-voltage DC cables, thus driving up the material cost. At the same time, excessive variation of module current will also affect the performance of string inverters and combiner boxes. While centralized inverters can be flexibly adapted to various versions of module, the DC combiner boxes can be adapted to both 182mm and 210mm modules.” As a representative of a power station integrator, Zhang calls for the industry to standardize module size, improve system compatibility, and focus on improving the efficiency of cells and modules as the next step in embracing the grid parity era.
In terms of PV trackers, Guo Zhikai, Senior Product Director at NEXTracker, said, “Tracking systems have met one challenge after another as solar modules have upgraded. For today's 182mm module, our 1P/NX Horizon and 2P/NX Gemini products are fully compatible with its 72-cell version. The 78-cell version modules can further reduce costs, with module load values confirmed, covering 100% of project requirements. In terms of reliability, it has passed the new wind tunnel test, and even the largest module size can be guaranteed stability on the tracker.”
The coordinated operation of the photovoltaic industry chain will accelerate the adoption rate of 182mm modules, but the ability to reduce costs and increase efficiency requires further guidance from design institute professionals.
Huang Chunlin, the Secretary of the Party Committee of the new Energy Engineering Academy at the Huadong Engineering Corporation, said “With the release of the capacity ratio limit, higher module power requires fewer strings and at the same time enables the expected capacity ratio. 182mm 585W modules with 14 strings will have a 1.1 capacity ratio. When the Y type terminal is adopted, the ratio will be even higher.”
Huang continued, “However, due to the high current adaptation issue, inverters with a single MPPT connected to a string of modules are the only type of existing inverter products that can be used to avoid the loss of high current, and the capacity ratio can only achieve 0.9x at most. In addition, larger current means more line loss or increased cable investment cost, while larger modules also increase tracker capacity. The 182mm modules have a relatively high matching capability with the tracker.”
In 2021, the combined manufacturing capacity of the three leading manufacturers is expected to reach 54GW, which provides confidence for the market. With strong support from the three companies, the production ramp of 182mm modules is expected to make a significant contribution to the PV market, enabling the industry to achieve overall grid parity.