A parametric design method of metal hydride bulb keel as hydrogen storage system in sailing yachts

In sailing yacht, the solution to replace the traditional ballast with a hydrogen storage ballast presents some concerns related to the usage in water and to the effect of redesign the ballast on the stability of the vessel. This study proposes a parametric design method to generate bulb keel ballast capable of housing metal hydride as hydrogen storage system while preserving the original balance and hydrodynamic characteristics of the vessel. The approach is validated through six bulb configurations generated using TiFe and LaNi5 hydrides. Hydrodynamic performance was evaluated through resistance and velocity prediction analyses, showing that the increased bulb volume leads to only 2.8–4.0% higher resistance at cruise speed, with negligible impact on sailing behaviour. The assessment of the hydrogen fuel cell power highlighted that TiFe –based configurations offered the best trade-off, providing higher useable hydrogen mass and extending the operational range to values suitable for coastal navigation.