This article elaborates a techno-economic approach that aims to optimize the conversion and energy storage unit chain of the first quick charge plug-in ferry. The choice of supercapacitors is motivated and then compared to other energy storage units for different kind of ferry exploitation. Several models were developed to be coupled with a global techno-economic model considering an exploitation strategy. In the last part, a typical application illustrates the cost reduction compared to the standard sizing approach. (C) 2015 Elsevier Ltd. All rights reserved.