Analysis of energy efficiencies of in-port ferries and island passenger-ships and improvement policies to reduce CO2 emissions

Abstract

This study focuses on estimating CO₂ emissions and analysing energy efficiencies using the Energy Efficiency Operational Index (EEOI) for ferries sailing within an urban port of Taiwan and passenger-ships operating on island routes surrounding Taiwan. A comparative analysis of energy efficiency parameters showed that hybrid diesel-electric ferries had a 12% improved efficiency compared to the traditional full-diesel ferries, while high-speed passenger ships had up to 79% lower efficiency than medium-speed passenger ships. Some potential policies for reducing CO₂ emissions from in-port ferries and island passenger-ships are presented based on these results. The estimated CO₂ emissions from in-port ferries sailing within the urban port could be reduced by 10% when employing hybrid diesel-electric ferries instead of traditional full-diesel ferries. Emissions from island passenger-ships operating on island routes could be reduced by 11-26% through utilising small medium-speed passenger ships instead of small high-speed passenger ships and large passenger ships.

Keywords: Island country; Marine environmental policy; Passenger ship; Ship energy efficiency; Shipping emission.