Energy Efficiency Existing Ship Index and Carbon Intensity Indicator

The EEXI indicates the CO2 emissions per cargo tonne and mile strictly based on the vessel’s design parameters. It determines the standardised CO2 emissions related to installed engine power, transport capacity and ship speed. The EEXI is a design index, not an operational index.

The EEXI was  adopted at MEPC 76 in June 2021 and will enter into force on 1 January 2023.

Different improvement measures are possible, e.g.

• Engine power limitation
• Shaft power limitation
• Engine derating
• Propulsion optimization
• Energy-saving devices

Please get in contact with KM's maritime advisory for a ship-specific evaluation.

The EEXI Technical File must be approved and the International Energy Efficiency Certificate re-issued by your flag administration or Recognized Organization at the first annual survey after 1 January 2023 at the latest.

The EEXI must be calculated for all cargo and cruise vessels above 400 GT falling under MARPOL Annex VI. In case of non-conventional propulsion (such as diesel-electric), please see MARPOL Annex VI for further clarification.

In case of a major conversion, the EEXI must be recalculated.

A required EEXI is applicable for all cargo and cruise vessels above a certain size threshold, depending on the ship type.

There will be an IMO review of the data in 2026.

The approval of the EEXI Technical File and the issuance of the IEEC has to be performed by the respective classification society. Any further support can also be provided by KM.

The required EEXI is based on the EEDI reference lines, with the below listed reduction factors applied. This is in most cases equal to the required EEDI in Phase 2 or Phase 3.

Bulk carrier ∆15–20% by size
Tanker ∆15–20% by size
Container ∆20–50% by size
General cargo ∆30%
Gas carrier ∆20–30% by size
LNG carrier ∆30%
Reefer ∆15%
Combo ∆20%
Ro-ro/ro-pax ∆5%
Ro-ro (vehicle) ∆15%
Cruise ship ∆30%

The IEE Certificate is re-issued with the first annual survey after 1 January 2023.

The Carbon Intensity Indicator (CII) is a measure of 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. The CII applies to all cargo, RoPax and cruise ships above 5,000 GT. 

The yearly CII is calculated based on reported IMO DCS data and the ship is given a rating from A to E. For ships that achieve a D rating for three consecutive years or an E rating in a single year, a corrective action plan needs to be developed as part of the SEEMP and approved.

For different ship segments, the CII is based on different ways of measuring the carbon footprint of the transport work. The Annual Efficiency Ratio (AER) and capacity gross ton distance (cgDist) are two such CIIs using different units. AER (emission per dwt-mile) is used for segments where the cargo is weight critical, and cgDist (emissions per gross ton-miles) for volume-critical cargo.

AER (emission per dwt-mile) and cgDist (emissions per gross ton-miles) are supported by data elements reported through the IMO DCS system. The IMO DCS system does not collect the cargo data required to calculate the EEOI (emission per tonne-mile). Therefore, the EEOI is not an option to use for the CII today. However, it will be possible to voluntarily report cargo data and report the EEOI for those who wish to do so.

The CII requirements will take effect from 2023. An enhanced SEEMP with an implementation plan for achieving the required CII needs to be approved and kept on board. The SEEMP will be subject to company audits, although the guidelines for the audit are still to be developed.

The reference year for CII is 2019 because this is the first year with verified DCS data reported to the IMO. Otherwise, the reference line would have to be established based on highly uncertain AIS data. The reduction factors are relative to 2019 and are adjusted considering achieved improvements between 2008 and 2019.

A strengthening of the SEEMP (enhanced SEEMP) to include mandatory content is a part of the CII regulation. The intention is to ensure continuous improvement of energy efficiency and lower carbon intensity. The enhanced SEEMP shall include an implementation plan on how to achieve the CII targets, and it will also be subject to approval and company audits. For ships that achieve a D rating for three consecutive years or an E rating in a single year, a corrective action plan needs to be developed as part of the SEEMP and approved.

Currently, the CII does not attribute fuel consumption to specific stages of a voyage or operations, including anchoring. Consumption during anchoring would simply be considered as consumption without distance travelled. However, certain exemptions or corrections, such as in cases of adverse weather conditions or extended time in port, are under discussion.

Poseidon Principles uses AER, and Sea Cargo Charters uses EEOI. Both are initiatives by major shipping banks and charterers or cargo owners, respectively, for driving the implementation of decarbonization and do not have a direct link to the IMO process of establishing the CII. In future, the Poseidon Principles and Sea Cargo Charters may align definitions and indicators with the IMO, although keeping their own trajectory.

The CII is based directly on the fuel consumption, which is influenced by how a specific ship is operated in combination with its technical efficiency and fuel. Its value will be affected by the type of fuel used, the efficiency of the vessel and operational parameters such as vessel speed, cargo transported, weather conditions and the general condition of the vessel (e.g. biofouling).

An owner can control the CII by optimizing operations and ensuring vessels are in a good condition. Charterers will have a major influence over the CII of the ships they charter by selecting the speed. It will be beneficial for owners/operators to continuously monitor the CII performance of the vessel to avoid having to take drastic measures unexpectedly. 

Majority of ships will presumably choose engine power limitation (EPL), as this will reduce the ship’s running costs and, as an efficiency improvement, lower fuel costs for main engines, which are the major component of the ship’s running costs. Furthermore, an EPL is carried out with less effort compared to other proposed measures.

Classification societies may have certain rules in place for engine limitation (e.g. if Ice class is applicable to your vessel).

All requirements regarding the applicable Ice class have to be considered. If it is not possible to fulfil both, Ice class and EEXI requirements, additional measures have to be considered.

You could limit your engine, for instance for a second time, if necessary to fulfil the requirements.

Yes, except if it is an LNG carrier or cruise passenger ship.

The following documents should be submitted:

• EPL Report (by engine manufacturer)
• Survey statement by class surveyor after EPL installation
• EPL Management Plan

It is recommended to carry out a model test to predict the performance improvement of the ESD before installation. This model test result will then be used for the calculation of the attained EEXI. The decision about the installation of an ESD should be based on a model test or CFD prediction.

Please get in contact with KM's Hydrodynamic advisory expert to carry out a model test