Energy Efficiency Design Index (EEDI)

The Energy Efficiency Design Index (EEDI) is the IMO design-stage measure of a new ship’s CO2 output, expressed in grams of CO2 per tonne-mile of transport work, roughly engine CO2 emissions divided by capacity times reference speed. It was made mandatory by Resolution MEPC.203(62), which added Chapter 4 to MARPOL Annex VI and entered force 1 January 2013, applying to ships of 400 GT and above. The Attained EEDI of each ship must not exceed the Required EEDI, set by a type-specific reference line with reduction factors tightening in phases (Phase 1 from 2015, Phase 2 from 2020, Phase 3 from 2025). The calculation method is given in MEPC.308(73) as amended.