Comparative assessment of alternative propulsion systems of ferries operating in ECAs

The objective of this paper is to comparatively assess four main alternative propulsion plants based on reciprocating internal combustion engines of a typical ferry or Ro-Ro ship operating in routes that include Emission Control Areas (ECAs). Specifically, the dual fuel (DF) engine propulsion plant is compared with a conventional Diesel engine plant. The cases of the installation of a Waste Heat Recovery (WHR) system are also investigated. The propulsion plants were modelled under steady state conditions, and the simulation results were analysed in order to compare the various configurations. Furthermore, using the simulation results, energy efficiency design index (EEDI) values for each case are calculated and the propulsion plants compliance with the respective IMO regulations is discussed. Then, the annual cost including investment and operational for each alternative propulsion plant is calculated for two ship sailing scenarios; the first considers the ship partly sailing inside Emission Control Areas (ECAs), whereas the other considers the ship sailing entirely within ECAs. The results are used for performing the economical evaluation of the examined propulsion plants. Finally, the annual carbon dioxide emissions are estimated and used for comparing the propulsion plant alternative solutions.