Building a carbon-neutral ferry is possible today. After a study into the application of alternative fuels on existing vessels, ship design company Conoship International says that bio-methanol is the most cost-effective option for low draught ferries in terms of greenhouse gases.
A ferry poses many challenges in regards to passenger safety regulations, according to Conoship. Zero-emission, or carbon-neutral, also poses several challenges regarding safety. That is why the company based its study on an existing, and thus technically feasible vessel: the Adler Rüm Hart ferry.
Bio-methanol and ventilation
The most suitable and future-proof fuel now is bio-methanol. Its properties make it suitable for a ferry with a fixed route (bunkering) and, compared to hydrogen, it is readily available and usable. With bio-methanol, emissions are largely reduced and, unlike LNG, it can reach CO2 neutrality when it is made from a biomass source or synthetically produced with renewable energy.
The overall conclusion of the case study is that it could be possible to sail on bio-methanol, since it will not have a significant effect on the general design of a ship. However, some systems need to be changed to achieve the functional requirements of the rules. The keyword being ventilation.
The picture above shows the risk assessment of hazardous zones on open deck with bio-methanol as a fuel. The inner spheres indicate a considerable chance that a flammable substance is ever present. The outer sphere indicates very exceptional chance. The aft mast is the outlet of the tanks and the foremast contains the inlets of them. The sphere on the foredeck is the bunkering station.
The development of a ferry on bio-methanol is new, and so is the regulatory process. In this case, Lloyd’s Register is working with Conoship towards a Class assessment for the design of this methanol powered ferry.
Adler Rüm Hart
The Adler Rüm Hart is a lightweight aluminum and very compact catamaran passenger ferry with room for 250 passengers, sailing up to 18 knots at 750 kW on the shallow waters of the Wadden Sea. The ship was built by Thecla Bodewes Shipyards in Harlingen, the Netherlands, and delivered to German island ferry operator Wyker Dampfschiffs-Reederei Föhr Amrum GmbH in 2019. The vessel manages to combine a relatively high speed with a very low draught.
The vessel is designed according to the strictest environmental standards, minimising ecological impact. For example, non-biocide coating is applied and the design complies to Blauer Engel “Umweltfreundliches Schiffsdesign” and “Umweltschonender Schiffsbetrieb”. The innovative hull of the catamaran was designed and optimized to reduce ship resistance, keeping fuel consumption to a minimum.
Pictures by Conoship International.