A method for assessment of wind-hydrogen (H-2) energy systems is presented. The method includes chronological simulations and economic calculations, enabling optimised component sizing and calculation of H-2 cost. System components include a wind turbine, electrolyser, compressor, storage tank and power converter. A case study on a Norwegian island is presented. The commuting ferry is modelled as a H-2 ferry, representing the H-2 demand. The evaluation includes a grid-connected system and an isolated system with a backup power generator. Simulation results show that much larger components are needed for the isolated system. H-2 cost amounted to 2.8 (sic)/kg and 6.2 (sic)/kg for the grid-connected and isolated system, respectively. Sensitivity analyses show that a marginal decrease in wind turbine and electrolyser cost will reduce the H-2 cost substantially. Rate of return is also important due to high investment costs. The grid-connected system is by far the most economical, but the system involves frequent grid interaction. (C) 2006 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.