With technological advancements and decreasing product prices, the global photovoltaic market scale will continue to grow rapidly, and the proportion of n-type products in various sectors is also increasing continuously. Multiple institutions predict that by 2024, the newly installed capacity of global photovoltaic power generation is expected to exceed 500GW (DC), and the proportion of n-type battery components will continue to increase each quarter, with an expected share of over 85% by the end of the year.
Why can n-type products complete technological iterations so rapidly? Analysts from SBI Consultancy pointed out that, on one hand, land resources are becoming increasingly scarce, necessitating the production of more clean electricity on limited areas; on the other hand, while the power of n-type battery components is rapidly increasing, the price difference with p-type products is gradually narrowing. From the perspective of bidding prices from several central enterprises, the price difference between n-p components of the same company is only 3-5 cents/W, highlighting the cost-effectiveness.
Technology experts believe that the continuous decrease in equipment investment, steady improvement in product efficiency, and sufficient market supply mean that the price of n-type products will continue to decline, and there is still a long way to go in reducing costs and increasing efficiency. At the same time, they emphasize that the Zero Busbar (0BB) technology, as the most directly effective route to reducing costs and increasing efficiency, will play an increasingly important role in the future photovoltaic market.
Looking at the history of changes in cell gridlines, the earliest photovoltaic cells only had 1-2 main gridlines. Subsequently, four main gridlines and five main gridlines gradually led the industry trend. Starting from the second half of 2017, Multi Busbar (MBB) technology began to be applied, and later developed into Super Multi Busbar (SMBB). With the design of 16 main gridlines, the path of current transmission to the main gridlines is reduced, increasing the overall output power of the components, lowering the operating temperature, and resulting in higher electricity generation.
As more and more projects begin to use n-type components, in order to reduce silver consumption, reduce dependence on precious metals, and lower production costs, some battery component companies have begun to explore another path – Zero Busbar (0BB) technology. It is reported that this technology can reduce silver usage by more than 10% and increase the power of a single component by more than 5W by reducing front-side shading, equivalent to raising one level.
The change in technology always accompanies the upgrading of processes and equipment. Among them, the stringer as the core equipment of component manufacturing is closely related to the development of gridline technology. Technology experts pointed out that the main function of the stringer is to weld the ribbon to the cell through high-temperature heating to form a string, bearing the dual mission of “connection” and “series connection”, and its welding quality and reliability directly affect the workshop’s yield and production capacity indicators. However, with the rise of Zero Busbar technology, traditional high-temperature welding processes have become increasingly inadequate and urgently need to be changed.
It is in this context that the Little Cow IFC Direct Film Covering technology emerges. It is understood that the Zero Busbar is equipped with Little Cow IFC Direct Film Covering technology, which changes the conventional string welding process, simplifies the process of cell stringing, and makes the production line more reliable and controllable.
Firstly, this technology does not use solder flux or adhesive in production, which results in no pollution and high yield in the process. It also avoids equipment downtime caused by maintenance of solder flux or adhesive, thus ensuring higher uptime.
Secondly, the IFC technology moves the metalization connection process to the laminating stage, achieving simultaneous welding of the entire component. This improvement results in better welding temperature uniformity, reduces void rates, and improves welding quality. Although the temperature adjustment window of the laminator is narrow at this stage, the welding effect can be ensured by optimizing the film material to match the required welding temperature.
Thirdly, as the market demand for high-power components grows and the proportion of cell prices decreases in component costs, reducing intercell spacing, or even using negative spacing, becomes a “trend.” Consequently, components of the same size can achieve higher output power, which is significant in reducing non-silicon component costs and saving system BOS costs. It is reported that IFC technology uses flexible connections, and the cells can be stacked on the film, effectively reducing intercell spacing and achieving zero hidden cracks under small or negative spacing. In addition, the welding ribbon does not need to be flattened during the production process, reducing the risk of cell cracking during lamination, further improving production yield and component reliability.
Fourthly, IFC technology uses low-temperature welding ribbon, reducing the interconnection temperature to below 150°C. This innovation significantly reduces the damage of thermal stress to the cells, effectively reducing the risks of hidden cracks and busbar breakage after cell thinning, making it more friendly to thin cells.
Finally, since 0BB cells do not have main gridlines, the positioning accuracy of the welding ribbon is relatively low, making component manufacturing simpler and more efficient, and improving yield to some extent. In fact, after removing the front main gridlines, the components themselves are more aesthetically pleasing and have gained widespread recognition from customers in Europe and the United States.
It is worth mentioning that the Little Cow IFC Direct Film Covering technology perfectly solves the problem of warping after welding XBC cells. Since XBC cells only have gridlines on one side, conventional high-temperature string welding can cause severe warping of the cells after welding. However, IFC uses low-temperature film covering technology to reduce thermal stress, resulting in flat and unwrapped cell strings after film covering, greatly improving product quality and reliability.
It is understood that currently, several HJT and XBC companies are using 0BB technology in their components, and several TOPCon leading companies have also expressed interest in this technology. It is expected that in the second half of 2024, more 0BB products will enter the market, injecting new vitality into the healthy and sustainable development of the photovoltaic industry.