Wave-Shaped Wires for the Interconnection of Silicon Solar Cells without Pads or Busbars

A reliable interconnection of silicon solar cells without pads or busbars by soldering directly on the contact finger grid is possible using wave-shaped wires. However, disadvantages caused by the modified geometry of wire interconnectors are a higher electrical resistance, due to a longer current path, and an increased shading area on the solar cell surface. Both decreases the potential power of a PV module. In this study, the output power and the CTM ratio of PV modules with solar cells interconnected by busbars and ribbons, contact pads and straight wires, and wave-shaped wires soldered directly on contact fingers is simulated and compared. Furthermore, the influence of the wire number, the amplitude, and the wire diameter is analyzed to identify the configuration that results in the maximum PV module power. Despite a lower CTM ratio, caused by additional shading and resistance losses, the simulation results show a relative output power increase of up to +0.7% compared to wire and pad row interconnection and up to +1% compared to ribbon and busbar interconnection for a PV module with half solar cells and wave-shaped wires soldered on the contact finger grid.