Strategies for Ship Decarbonisation: Technical Measure for Reducing Energy Efficiency Existing Ship Index

Abstract

Emerging energy efficiency regulations and ongoing industrial studies are boosting the reduction of ship pollutant emissions. Researches are progressively stimulating innovation in energy efficiency management allowing the adoption of new technologies by shipowners. In order to find new strategies to reach Greenhouse Gas (GHG) goals, the IMO imposed new technical requirements to reduce carbon intensity by means the Energy Efficiency Existing Ship (EEXI) Index. This new technical measure is compulsory for existing ships. These indexes estimate grams of CO2 per transport work (g of CO2 per tonne-mile). For each vessel in operation an Attained EEXI must be calculated and benchmarked for compliance with a Required EEXI. The parameters that have the greatest impact on the determination of the Attained EEXI values will be assessed and compared the Required EEXI. Therefore, case by case, different technical solutions able to reduce the EEXI Exceedance percentage (i.e., the difference between the Attained EEXI and the Required EEXI) are tailored for each vessel with reference to the operating profile/scenario. Furthermore, in this paper a case study referred to a merchant fleet engaged in global operations is presented.

Mitigation of CO2 Emissions from Commercial Ships: Evaluation of the Technology Readiness Level of Carbon Capture Systems

“…Thanks to the introduction by the IMO of the Energy Efficiency Design Index (EEDI) and the Ship Energy Efficiency Management Plan (SEEMP), emissions have decreased from 2008 levels; however, even the recent introduction of the Energy Efficiency Existing Index (EEXI) and the Carbon Intensity Indicator (CII) as measures for existing ships will not be sufficient to reach IMO's goals, targeted at reducing the total greenhouse gas (GHG) emissions from the maritime sector by at least 50% by 2050. In particular, the reduction of CO 2 should reach 85% in 2050, relative to the levels of 2008 [5,6].…”