This work focuses on the evaluation of the robustness and reproducibility of the behaviour of microbial fuel cells (MFCs). Up to 112 MFCs were operated simultaneously under the same conditions, finding that the probability of high performance, maximum power, maximum current and internal resistance is 95%, 90%, 96% and 94% respectively. Reproducibility of stacks was also evaluated by testing different electrical connections, finding that when evaluating the performance of 7 stacks of 16 MFCs each connected in parallel and different combinations of series/parallel, the maximum power varies only between 1 and 2 mW. Results obtained also helps to demonstrate that the performance of the bioelectrochemical devices evaluated mainly depended on the internal resistance. All these information is of a great significance for future developments of the technology because it is a real first step in the characterization of the robustness of the bioelectrochemical technology.