The E-ferry is a fully electric, battery-powered passenger ferry, which will run on green wind mill energy and consequently will have no greenhouse gas (GHG) emission. As a fully emission free vessel, the E-ferry is exempt from following IMO’ Energy Efficiency Design Index (EEDI). Current battery technology means, however, that the more energy a vessel requires, the more battery capacity needs to be installed, and the more weighty and costly it will be to build. Consequently, fully electric vessels need to be designed in the most energy efficient manner possible. In this paper, we discuss different parameters that can be adjusted to decrease the power consumption of vessels. We conclude that most of these solutions are neither socio-economically or operationally feasible for passenger ferries. We consequently propose one main design dimension that can reduce the energy requirement of battery-powered passenger ferries - hull design – and present the E-ferry hull.