Trina Solar and seven other well-known manufacturers of solar modules are working towards the standardization of 210 mm silicon wafers and modules.
The proposal envisages setting 210 ± 0.25 mm as the standard size for silicon wafers in the 210-220 mm size range in accordance with the International Photovoltaic Standards (SEMI) for semiconductor equipment and materials, while revising the existing module size standards.
For most of the past decade, the traditional wafer size has been 156.75 mm, which is more than 90% of the monocrystalline market. However, since 2019 manufacturers have seen advantages in increasing wafer sizes, which ultimately leads to modules with a power of 500 W + coming onto the market.
Because these modules are made by multiple manufacturers, resizing has not been consistent and this can create confusion and increased costs, according to proponents of the standard.
In addition to defining a standard size, the proposal led by Trina also provides for the promotion of standard sizes of silicon wafers and modules as follows:
Image: Trina Solar Image: Trina Solar
The companies, which include Risen Energy, Zhonghuan Semiconductor, Tongwei, Huansheng Photovoltaic, Runyang New Energy Technology, Canadian Solar, and Wuxi Shangji Automation in addition to Trina, argue that standardizing silicon wafers will allow the solar industry to achieve scalability and all Empowering companies to improve production efficiency, optimize supply chains and promote technological innovations.
Companies also argue that standardization will enable more competitive manufacturing by reducing the upfront investment for new businesses and knowing that investment won't be wasted when a new size becomes more popular.
Trina was the group leader, providing publications to support the effort and studies to demonstrate the value and safety of 210mm wafers.
For developers, the companies argue that a 210mm standard will reduce the balance between system costs and offset electricity costs for new solar projects.
This system cost balance applies to large, ground-mounted solar projects, the segment of the market where 210mm wafers currently come in handy. With standardization, these larger wafers could be manufactured for smaller modules with a lower power rating. However, until now they have been used in modules greater than 500W that are too large for typical rooftop installations.
Breakdown of the cost savings
In a company publication, Trina explains why 210mm is the group's preferred size choice by highlighting the flux, dumpling effect and the cost savings achieved by using fewer modules in one installation. (Fewer modules mean lower junction box, potting, combination box, DC cable, installation and construction costs).
The flow value refers to the increase in production capacity through large products, thereby reducing labor costs, depreciation, and operating, management and financial costs per unit of production.
The dumpling effect refers to the increase in the amount of auxiliary materials during transport, such as frames, glass, back panels, EVA, tape rails, pallets and packaging materials, which is less than the increase in module area when using large wafers in the module production, resulting in savings in the Brings encapsulation and transport costs.
The company also offered a cost calculation for 210mm wafers versus 166mm and 182mm wafers across the value chain:
Image: Trina Solar
High temperatures are not a problem
In a separate study, Trina addresses one of the most common problems in standardizing the wafer size of 210 mm: the high working temperature of such modules due to their high power output.
As the operating temperature of a module increases, the open-circuit voltage decreases, while the short-circuit current increases slightly, which leads to a reduction in the efficiency of the photovoltaic conversion and the cell performance. According to a company study, there is an energy loss of 0.20% for every 1 ℃ increase in operating temperature.
However, the same study found that the working temperature of 210mm and 182mm modules is almost the same under the same installation and cooling conditions. It is said that the cells only change the area with the same structure and efficiency of the passivated emitter and the rear cell (PERC).
According to Trina, 210 mm and 182 mm cells have the same PERC structure and their efficiency is almost the same. With similar packaging materials and under the same optical environment, there is almost no difference in the current density of such modules. The increase in current in the 210mm ultra-high performance module is driven by a larger cell because the current is the product of the current density multiplied by the cell area.
And although the current is greater, the efficiency remains the same with a constant current density and a larger cell area. With the same module efficiency, the amount of unused heat – the solar energy that cannot be converted into electrical energy – is the same in relation to the unit area.
Assuming the same installation and heat dissipation conditions, the operating temperatures for 210 mm ultra-high performance modules and 182 mm modules are roughly the same.
This content is protected by copyright and may not be reused. If you would like to work with us and would like to reuse some of our content, please contact: email@example.com.