DNV GL has released a position paper, The Fuel Trilemma: Next Generation of Marine Fuels, which examines a diversifying ship fuel market and the threefold problem of affordability, sustainability and safety.
These factors will govern choices for emissions that meet regulations for CO2, SOx and NOx – requirements that already push limits of what can be achieved with conventional fuels and exhaust gas cleaning technology.
Among the diverse fuel options has been LNG, which is becoming more widely used and in turn has presented the potential for biofuels to gradually replace fossil fuels. Other power sources, such as grid-sourced electric power, methanol and hydrogen, will have a place in certain geographic areas and ship types, too.
“In all cases, the cost associated with machinery, as well as the expected fuel price, will play a dominant role for shipowners as they make changes to their fleet,” said Christos Chryssakis, senior researcher at DNV GL. “However, safety and sustainability have an impact on affordability. Sustainability, assessed from a lifecycle perspective, will determine the availability of various fuels in the future, and could constrain the energy mix locally or globally.
“Novel design solutions may introduce a level of complexity that affects newbuilding costs and operational reliability. Even well-known solutions such as LNG involve considerable ship design and equipment changes to ensure safe operation.”
But there are external risks to be considered. A major accident could turn regulators and the general public against an otherwise promising fuel option. “DNV GL advocates that the risks are manageable. One of the premises is that safety should head the agenda from the very beginning of a ship design project,” said Chryssakis.
The position paper analyses affordability, sustainability, safety and reliability and includes case studies involving LNG, shore-based electricity, biofuels (including pyrolysis oil and biomethanol) and hydrogen. It presents the benefits and challenges for each option.