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GHG Rating

The efficiency of a vessel is determined by the ratio of grams of CO2 emitted per tonne nautical mile. Vessel efficiency is determined using data from one of two sources:

  1. EEDI– is a regulatory requirement for new ships developed by the IMO (and applied to existing vessels on a case by case basis), or

  2. EVDI– is a rating system, developed by RightShip, that can be applied to new and existing vessel (where EEDI is not available or applicable).

A vessels relative performance is rated from A through G with the most efficient vessels receiving A ratings and the least efficient receiving G ratings Vessels are only compared to other similarly sized vessels of the same ship type. The peer group comparison is based on the number of standard deviations a vessel’s EEDI or EVDI varies from the average for similar sized vessels of the same ship type.


Along with increasing transparency of energy efficiency, the key benefits of the GHG Rating include:

  • Assist the maritime industry transition to a low carbon economy through informed selection of more efficient ships,

  • Allows firms to benchmark and track emissions per journey and over time, giving them the ability to develop a baseline of emissions and an overall carbon-emissions target

  • Charterers can identify more efficient vessels and in-turn reduce their bunker bills

  • Ship-owners can benchmark their vessels against peer vessels to demonstrate the benefits of investing in efficiency

  • Financial institutions can reduce their risk by investing in efficient vessels ensuring a greater return on investment over the life of the asset.

  • Ports can reward efficient vessels through port incentive programs – reducing CO2 emissions and other criteria pollutants in port, and for the entire journey

To learn more visit: RightShip