Creep-fatigue lifetime estimation of efficient photovoltaic module ribbon interconnections

As the solar PV harvesting energy system are becoming more important sector of renewable energy day to day, improving the efficiency of the solar PV module and reducing the cost of modules are receiving more attentions of PV module manufacturers. Design of the PV module interconnection ribbons is one of the main focus for developing the efficiency of the PV modules and improving the reliability of the modules. In the last decade, new designs for the PV module interconnection ribbon have been introduced, however, there is still a need to optimize their configuration and geometry to achieve higher reliability without dropping the efficiency of the PV modules. Indeed, solely using the wider interconnection ribbons (to provide more joint length) may increase the reliability of the module, but it directly reduces the efficiency of module due to more shading effect. This study provides the results for determining the optimal design for long-term reliability of PV module interconnections. Three main PV module ribbon interconnection designs including Conventional Ribbon (CR), Light-Capturing Ribbon (LCR), and Multi-Busbar (MBB) interconnections are compared in terms of number of cycles to creep-fatigue failure. This study uses the FEM simulation and creep-fatigue reliability formulations to find the effect of the main geometrical parameters on the failure of different PV module ribbon interconnection designs. The finding showed that the MBB interconnections has up to 15 % higher creep-fatigue lifetime compared to the LCR and the CR interconnections.