Since 2016, Ecole Centrale de Nantes has been investigating a radically new technology for conversion of the far-offshore wind energy into sustainable fuel, called the FARWIND energy system. It relies on mobile wind energy converters (energy ships) that are not grid-connected. Thus, the converters include on-board power-to-X plants for storage of the produced energy. In [16], we investigated the feasibility of hydrogen as the energy vector. It was found to be challenging because of high transportation and distribution cost due to the low volumetric energy density of hydrogen for standard conditions of temperature and pressure. In this paper, we first investigate other options which include synthetic natural gas, methanol, Fischer-Tropsch fuel and ammonia. Comparison of those options indicates that methanol is the most promising option. Then, net energy efficiency and cost of FARWIND-produced methanol is estimated. Despite the fact that the net energy efficiency is found to be smaller than for the hydrogen solution, it is shown that the methanol cost could be competitive for the transportation fuel market on the medium to long term.