Shipping is vital to the world economy. It is a critical part of international import and export markets and supports the global distribution of goods. However, it also has a significant environmental impact.
Further research and investment can reduce the environmental impact of shipping. Shipping has great potential to reduce its environmental impact, especially through new propulsion technology. However, according to a report recently published by the Royal Academy of Engineering, the UK, there is no simple answer that can meet every need. Moreover, further work is needed to adapt current technologies from the maritime industries and elsewhere to broader application in different types of ship, and to research and develop innovative technologies specifically for maritime propulsion.
Led by John Carlton FREng, Professor of Marine Engineering at City University London, the Royal Academy of Engineering working party, which consists of more than 20 engineering experts, conducted a comprehensive survey of current and potential future marine propulsion systems. These propulsion systems were then measured against the twin but related objectives of energy efficiency and environmental sustainability.
Options investigated included greater use of LNG in current power units, battery and alternative fuel technologies, and nuclear-powered ships. In the case of LNG, it is certainly cheaper and cleaner than diesel, but requires a global infrastructure.
Other fuel technologies, such as biofuels and synthetic fuels, are potential direct replacements for current fuels, but to date lack practicalities such as storage and handling.
As for nuclear power, while this is used in naval ships, for merchant shipping, a long-term approach to design, building and operational methods would be necessary.
Further ahead, the report says that hydrogen could be an option for marine propulsion, but there are significant infrastructure issues as well as technology issues to be overcome.
The working party said that in the medium to long term, there was no form of technology that presented clear advantages over other forms. Moreover, operational issues were an important contributor to choice of power.
Prof. Carlton also said that simple operational measures could also prove to be effective. These measures include good seamanship in steering around bad weather and good housekeeping in minimising on-board energy consumption.