Cruise ships power plant optimisation and comparative analysis

The stringent regulatory framework for the emissions and safety from shipping operations as well as the market pressure to reduce the operational costs have led the cruise ship industry to pursue and investigate alternative solutions for both the new-built and the existing ships by using multi-objective optimisation methods. This study aims at investigating and comparatively analysing the optimal power plant solutions for different fuel types for a cruise ship by employing cost, emissions and safety objectives in a life-cycle basis. For this purpose, a bi-objective optimisation method is employed to identify optimal power plant configurations of a modern cruise ship considering the actual ship operational profile and several energy system design parameters. In subsequence, availability and the blackout event frequency were estimated using availability formulas and the Combinatorial Approach for Safety Assessment. The results demonstrate that the cruise ship power plant optimal configurations with dual fuel engines operating with natural gas exhibit lower lifecycle cost and lifetime emissions, whilst demonstrating a level of the systems safety comparable to the baseline power plant configuration. Furthermore, it is concluded that an increase in the generator sets redundancy does not necessary result in a considerable improvement of the power plant safety performance