Draft:Energy Efficiency Existing Ship Index

Energy Efficiency Existing Ship Index (EEXI) in the maritime industry is used to measure energy efficiency of all vessels falling under MARPOL convention. It is a mandatory instrument which would eventually help to achieve reduction in Greenhouse Gases (GHG) emitted from ships.

Background

Roots of present actions for reducing GHG in shipping can be traced back to Kyoto Protocol (1997) containing provisions for reducing such emissions from international aviation and shipping. In 2018 International Maritime Organization (IMO) published Initial Strategy aimed to reduce GHG emissions by at least 50% by year 2050 compared to 2008, "while, at the same time, pursuing efforts towards phasing them out entirely""UN body adopts climate change strategy for shipping".. In October 2018, IMO approved a follow-up planning tool with was designed up to 2023. In July 2023 Initial Strategy was revised and renamed "2023 IMO Strategy on Reduction of GHG Emissions from Ships". First IMO resolution in this respect was adopted in September 1997."CONFERENCE RESOLUTION 8 - CO2 EMISSIONS FROM SHIPS" (PDF).

EEXI Calculation

EEXI has to be calculated as per IMO guidelines.

Attained EEXI

This is a measure of ship’s actual energy efficiency. It’s calculated based on the ship’s design and operational data as per below formula:

$AttainedEEXI[{\frac {g}{ton}}.mile]={\frac {CO_{2}ConversionFactor\times SFC[{\frac {g}{kW}}]\times EnginePower[kW]}{Capacity[ton]\times EEXISpeed(V_{ref})[knot]}}$

Required EEXI

This is the benchmark or target your ship needs to meet as per IMO Guidelines and requirements. It’s based on the EEDI baseline, adjusted with a reduction factor that depends on the type of vessel.