Shipping can cut down its impact on the environment through the adoption of new propulsion technologies, according to a new report by the UK's Royal Academy of Engineering.
However, the report found that no single solution would comply with the requirements of all vessels and suggested adapting current technologies while carrying out research to develop new systems specific to maritime propulsion.
According to the report, options including liquefied natural gas (LNG) bunkers, battery power, alternative fuels and nuclear power could help improve fuel efficiency and environmental sustainability.
City University London Marine Engineering professor John Carlton said there was no single winner in terms of technology in the medium to long term, with the operational issues being an important contributor to power choices.
"We know that larger ships are more carbon-efficient than smaller ships and that slower ship speeds effectively reduce emissions," Carlton said. "But fitting smaller engines in large ships may increase the risk of being under-powered in bad weather.
"Often there is significant benefit in simple operational measures: good seamanship in steering around bad weather for instance, or good housekeeping in minimising on-board energy consumption," Carlton added.
In the short-term, LNG will likely facilitate adoption as the shipping industry is aware of its standards and technical specifications despite the challenges of building LNG infrastructure, while wind and solar energy could act as appropriate auxiliary power sources.
In the medium and long-term, the shipping industry has to adapt the latest technologies, including biofuels and synthetic fuels, while developing other technologies like fuel cells, batteries and nuclear reactors, the report found.
Researchers also consider hydrogen as an option for marine propulsion, though it involves significant infrastructure and technology issues to overcome.
Image: Eidesvik's Viking Lady has been equipped with a lithium-ion battery pack as part of the FellowSHIP III project, making it the world's largest fully electric ferry. Photo: Eidesvik.