What is EEDI?
Energy Efficiency Design Index (EEDI), Formulated during the design stage of newbuilding ships, is an index that estimates grams of CO2 per transport work (g of CO2 per tonne‐mile).
It is a function of:
- Installed power
- Speed of vessel
- Cargo carried
It can be expressed as the ratio of “Environmental Cost” divided by “Benefit for Society.”
EEDI = Impact to environment/Benefit for society or EEDI = CO2 Emission/Transport Work
What is EEXI?
With the Greenhouse Gas Strategy towards 2050, the IMO has set the goal to reduce carbon intensity by 40% within the next decade up to 2030 and by 50% in total (70% intensity) up to 2050. The Greenhouse Gas Strategy was approved by the IMO in 2018. The reduction rates are related to the baseline of 2008. Short-term, mid-term and long-term measures are distinguished to achieve the goal.
Short-term measures are meant to be set into force by 2023. Different measures were considered and widely discussed, and IMO has decided to introduce a combination of technical and operational measures. Whereas the EEXI is the technical measure, just looking at the design of the ship in a comparable way as the EEDI does for newbuilding vessels, the CII is an operational measure, which considers the actual consumption and distance travelled for each individual ship in service.
During MEPC 76 in June 2021, the IMO adopted amendments to MARPOL Annex VI, introducing an Energy Efficiency Design Index for existing ships (EEXI). The requirements will enter into force at 1st of January 2023.
What is Carbon Intensity Indicator (CII)?
From 2023, the CII requirements will take effect for all cargo, RoPax and cruise vessels above 5,000 GT and trading internationally.
The CII measures how efficiently a ship transports goods or passengers and is given in grams of CO2 emitted per cargo-carrying capacity and nautical mile. The ship is then given an annual rating ranging from A to E, whereby the rating thresholds will become increasingly stringent towards 2030.
While the EEXI is a one-time certification targeting design parameters, the CII addresses the actual emissions in operation