Also Published As: Climate Change and Ships: Increasing Energy EfficiencyHistorically, the price of fuel has been the primary driver for improved efficiency and reduced fuel consumption on commercial ships. The highly competitive nature of the maritime industries meant that efforts to bring down fuel consumption were cost effective solutions, leading to overall optimization of the transport system. The IMO is developing the Energy
Efficiency Design Index (EEDI) for new ships, which is a gauge of a ship’s CO2 efficiency. The EEDI is a simple formula that estimates CO2 output per tonne-mile. Market mechanisms will be attached to the EEDI, providing ship owners with another economic driver for reducing CO2 emissions. There are challenges in creating an EEDI and associated baseline that are straightforward enough to be enforceable and sophisticated enough to promote emissions reduction in a cost-effective manner. ABS and HEC have jointly conducted a study which investigates the robustness of the EEDI and the potential shortcomings of the index by evaluating a parametric series of designs for three different ship types: tankers, containerships, and LNG carriers. By developing the series of
“standard” designs based on good design practice and consistent assumptions, the analysis provides a comparative basis for assessing the relative impact of assumptions such as the ship’s speed, deadweight and cargo carrying capability, and special features such as enhanced scantlings. By calculating CO2 emissions for representative round trip voyages for each of the designs, the study provides a basis for assessing whether the EEDI correlates with expected CO2 emissions. Finally, by evaluating the required freight rate per unit of cargo moved, the study provides background on the relative benefit-cost implications of various greenhouse reduction
measures available to the ship designer. This report summarizes the findings from this study, which were submitted to SNAME T&R Ad Hoc Panel 18 tasked with investigating the EEDI. The results are summarized in document MEPC 60/4/34, which has been submitted to IMO for consideration.