Photovoltaics has become a globally valued renewable energy source not only because of its rapidly decreasing price but also because of its significant improvements in efficiency. One of the most obvious characteristics is the replacement of polycrystalline silicon with monocrystalline silicon, which has higher conversion efficiency.
However, having high-efficiency cells does not necessarily mean that module efficiency will also improve, because various losses occur during the module encapsulation process, leading to a decrease in conversion efficiency. Therefore, module manufacturers use various processes in the encapsulation stage to improve module efficiency, thereby maximizing the advantages of high-efficiency cells. Multi-busbar (MBB) technology is one of the more important technical means among them.
The grid lines of a photovoltaic (PV) module are the busbars of crystalline silicon cells, used to collect the current generated by the cells onto the busbar (soldering strip) so that the electricity generated by the photovoltaic system can be used. The more grid lines, the better the conversion efficiency and overall performance, making multi-grid technology a key research focus for many module manufacturers.
Typically, there are two or three grid lines, while multi-grid technology can reach four or even more. However, more grid lines are not necessarily better, because the module area is already limited, and too many grid lines will reduce the light-receiving area of the crystalline silicon cell. Therefore, module manufacturers have refined the grid lines to maximize the light-receiving area of the cell.
After numerous verifications, multi-busbar technology has successfully improved module efficiency. However, to fully leverage the advantages of multi-busbar technology, it is necessary to combine it with other processes such as shingled and half-cell technology to further enhance module conversion efficiency and improve the competitiveness of photovoltaic power generation.
