Environmental and economic sustainability assessment of emerging cruise ship energy system technologies

The environmental and the economic impact of ship energy systems is a rising concern for the shipping industry. A number of technologies to improve the sustainability of ship energy systems exists. The majority of previous research on ship energy systems selection focused on the techno-economic performance of one or two components. However, an approach of evaluating simultaneously the environmental and economic performance of the integrated ship energy systems is missing. In this respect, this work aims to identify the most sustainably performing configuration of cruise ship energy systems by quantifying and evaluating the life cycle cost and the CO2 lifetime gaseous emissions of the integrated ship energy systems. The machinery responsible for the propulsion, electric and thermal power production, as well as emission reduction and energy efficiency is included. The performance of existing and emerging technologies is modelled including fuel cells, carbon capture technology, waste heat recovery systems, as well as propulsion and auxiliary systems with alternative fuels such as LNG. Alternative system configurations of the investigated ship are generated and assessed based on on-board operational data of a cruise ship. A set of dominant solutions is derived by employing a multi-objective evolutionary algorithm and indicative results for the most sustainable configurations are presented. A sensitivity analysis is performed for future fuel prices and technologies capital cost for the year 2030. The derived results from the cruise ship case study indicate that the ship energy systems sustainability can be improved by adopting natural gas dual fuel technologies and fuel cells. In addition, introducing a carbon capture technology and a waste heat recovery in the ship energy systems can improve the carbon footprint