Interconnection Technology in PV Modules: Impact of Ribbons, Tab Connectors and Electrically Conductive Backsheet on Module Performance

The interconnection technology is one of the aspects that is being continuously researched and developed in photovoltaic (PV) modules [1–4]. The aim of this study is to analyze the impact of the used interconnection technology in the PV module such as ribbons, tab connectors and electrically conductive backsheet (ECB) on cell-tomodule (CTM) power losses [5, 6]. To that end, we adapt and develop analytical models that consider the geometry of the contact metallization of the solar cell as well as the geometry and properties of the interconnector being it rectangular ribbon, round ribbon, tab connector or ECB. The study considers different loss and gain channels of the CTM analysis such as power loss due to solar cell’s active area shading and ohmic resistance of the interconnection. Simulation results show a maximum PV module power improvement of about 4% by using back contact solar cells interconnected using ECB compared to PV modules with solar cells interconnected using conventional rectangular ribbons. PV module with tab connectors exhibit a power improvement of about 3.4% compared to conventional cell interconnectors. That is a result of clearly less power loss due to ohmic resistance of the tab connectors, because of shorter current path as well as because of the larger cross section area of the current path using ECB. Furthermore, PV modules with back contact solar cells exhibit no loss due to shading of the interconnectors, because of the position of all contact pads on the backside of the solar cell compared to about 6 W power loss in case of rectangular ribbons. CTM analysis shows that the PV module with round ribbons exhibit about 3.6 W power gain due to light coupling by interconnectors compared to 1.5 W for the PV module with rectangular ribbons.