Applying and evaluating a new method to determine the interconnection-induced resistance in shingle solar modules

This work deals with shingle solar modules, in particular the interconnection of shingle solar cells by using an electrically conductive adhesive (ECA), as well as by simply overlapping the same type of shingle solar cells but omitting the ECA. For both types of interconnection, the resistance due to interconnection Rint and the corresponding cell-to-module (CTM) power loss ΔPMPP in the case of a full-size shingle module are quantified, finding Rint ≈ 0.26 mΩ and ΔPMPP ≈ −0.4 W for the ECA-based interconnection, and Rint ≈ 0.86 mΩ and ΔPMPP ≈ −1.2 W for the ECA-free interconnection. The work mainly focuses on the methodology used to derive these numbers from small-format modules containing shingle strings of different lengths. An extensive error discussion is given, as well as a discussion on the advantages over a different approach to determine Rint.