A Rational Approach to the Ecological Transition in the Cruise Market: Technologies and Design Compromises for the Fuel Switch

Abstract

Supporting policies to achieve a green revolution and ecological transition is a global trend. Although the maritime transport of goods and people can rightly be counted among the least polluting sectors, much can be done to further reduce its environmental footprint. Moreover, to boost the ecological transition of vessels, a whole series of international regulations and national laws have been promulgated. Among these, the most impactful on both design and operational management of ships concern the containment of air-polluting emissions in terms of GHG, NOx, SOx and PM. To address this challenge, it might seem that many technologies already successfully used in other transport sectors could be applied. However, the peculiar characteristics of ships make this statement not entirely true. In fact, technological solutions recently adopted, for example, in the automotive sector must deal with the large size of vessels and the consequent large amount of energy necessary for their operation. In this paper, with reference to the case study of a medium/large-sized passenger cruise ship, the use of different fuels (LNG, ammonia, hydrogen) and technologies (internal combustion engines, fuel cells) for propulsion and energy generation on board will be compared. By imposing the design constraint of not modifying the payload and the speed of the ship, the criticalities linked to the use of one fuel rather than another will be highlighted. The current limits of application of some fuels will be made evident, with reference to the state of maturity of the relevant technologies. Furthermore, the operational consequences in terms of autonomy reduction will be presented. The obtained results underline the necessity for shipowners and shipbuilders to reflect on the compromises required by the challenges of the ecological transition, which will force them to choose between reducing payload or reducing performance.

Iberian Ports as a Funnel for Regulations on the Decarbonization of Maritime Transport

“…There are many works that have studied which alternative fuel is the most suitable for a specific type of vessel, and many of them have arrived at the conclusion that the main challenge for any of those alternative fuels is the reduction in autonomy due to the limited space onboard to install tanks for these new fuels with less volumetric energy density than the HFO or MDO. Therefore, with current technology, to comply with the new environmental regulations, owners will need to choose between reducing autonomy or sacrificing space dedicated to payload [24].…”

Mitigation of CO2 Emissions from Commercial Ships: Evaluation of the Technology Readiness Level of Carbon Capture Systems

“…Indeed, while this problem does not arise for industrial sites that are built around the chosen technology, on ships, the available space is limited and the size of the various solutions becomes key, affecting the selection of one system over another. This aspect is even more important when pursuing the objective of refitting old ships in order to limit their emissions; in fact, in these cases, the installation of new technologies has to deal with systems and devices already set up on board, and it is not always possible to make major arrangement changes [20]. Moreover, fostering the application of such technologies in the maritime sector implies the necessity to address other challenges, such as the inadequacy of geological storage capacity and the need to advance the TRL of many technologies that currently are only at a theoretical development level [6,21].…”