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EEXI – Energy Efficiency Existing Ship Index

As a shipowner, what will I need in order to comply?

Container, container ship in export and import business and logistics. Shipping cargo to harbor by crane. Water transport International. Aerial view and top view.

Regulatory background

In November 2020 (MEPC 75) the IMO agreed to amend MARPOL Annex VI to introduce a new technical efficiency standard for in-service vessels- the ‘Energy Efficiency Existing Ship Index’ (EEXI). This is due to be adopted in June 2021 (MEPC 76).

Entry into force is expected to be in the fourth quarter of 2022, but no later than 1 January 2023. The exact date will be confirmed in June.

Demonstration of compliance will be required by the vessel’s first survey for the issue or endorsement of the International Air Pollution Prevention Certification (IAPPC), following entry into force.

What is the EEXI?

Like the Energy Efficiency Design Index (EEDI), EEXI is a technical or ‘design’ efficiency index which requires a vessel to achieve a required level of technical efficiency (required EEXI) under specified reference conditions. Compliance is determined by the vessel’s design and arrangements This means an attained EEXI can only be changed through alterations to the vessel’s design or machinery and not day to day operational action such as speed reduction or reduced cargo.

In its simplest form, the attained EEXI is the vessel’s grams of CO2 emitted per capacity tonne mile under the ship specific reference conditions.

This is a function of the installed engine power (kW), the specific fuel consumption of the main and auxiliary engines and a carbon factor representing the conversion of fuel to CO2, vessel capacity and vessel reference speed.

However, there are many different correction factors and nuances which apply, depending on the ship type and capacity.

The required EEXI is the vessel’s required maximum grams of CO2 emitted by the vessel per capacity (deadweight) tonne mile under reference conditions, given its type and capacity. To comply with the regulation, the attained EEXI for a vessel must be less than or equal to the ‘required EEXI’.

As a shipowner, what will I need in order to comply?

For ships which comply, a new International Energy Efficiency Certificate (IEEC) will be issued which states the required EEXI and compliant attained EEXI (for EEDI-certified ships this will be alongside the required EEDI and attained EEDI).

Owners will need to develop an EEXI Technical File which will be used as a basis for verification of compliance with EEXI. In addition, ships using Overridable Power Limitation (OPL) to comply with EEXI should develop an Onboard Management Manual (OMM) based on guidance which will be approved by the IMO in June 2021. This should be done as soon as possible after June 2021.

The route to compliance is as follows:

  1. For pre-EEDI ships, calculate the attained EEXI and determine if it is equal to or lower than the required EEXI. For EEDI-certified ships, determine whether the attained EEDI is equal to or lower than the required EEXI
  2. For EEDI-certified ships which have an attained EEDI which is less than or equal to the required EEXI, go to step 6
  3. For ships where the calculated (attained) EEXI / EEDI) is greater than the required EEXI, take action to improve the attained EEXI. In addition to retrofitting of Energy Efficiency Technologies (EETs), or switching to a lower carbon fuel (other than a drop-in alternative fuel), EEXI allows the use of OPL to limit operational engine loads and fuel consumption. OPL may be either Engine Power Limitation (EPL) or Shaft Power Limitation (SHaPoLi)
  4. Re-evaluate the attained EEXI following any action taken to improve the attained EEXI.
  5. If the attained EEXI is less than or equal to the required, prepare the EEXI Technical file (which includes the data used for calculation of the attained EEXI)
  6. Apply to the Administration or a duly authorised recognised (RO) such as Lloyd’s Register for issue of the new IEEC. Where OPL is used to comply, issue of the IEEC will be subject to verification of the attained EEXI based on the EEXI Technical File and the OPL arrangements and OMM

Vessels which have not demonstrated compliance and had a new IEEC issued by the compliance deadline risk being unable to trade internationally.

Given the work required to ensure compliance, and large number of vessels effected, the time available for shipowners to demonstrate compliance is short.

Calculating the EEXI, developing the EEXI Technical File and OMM, if applicable, is relatively straightforward, however, a significant proportion of vessels will be required to take action to improve the attained EEXI. Early action to understand the impact of EEXI and the cost-effective compliance options available is essential.

How can LR help?

Although the changes will not be adopted until June 2021, we recommend you start planning for the requirement now. Our team of EEXI advisory specialists are on hand to support you every step of the way:

1. Calculation of existing EEXI (all applicable vessels)

We can provide a preliminary view of whether your vessel(s) will comply:

  • Firstly, we can assess any vessels in your fleet which already hold an attained EEDI by checking that this is below the required EEXI (based on the vessel type and capacity). If it is, your vessel will just need to be issued with an IEEC following EEXI entering into force
  • For vessels without an attained EEDI, our specialists will review all the available technical information for the ships and carry out the most accurate calculation possible according to the IMO calculation guidelines for EEXI. We’ll then compare the ships’ required EEXI to the calculated (attained) EEXI. If this indicates compliance, the vessel will not require any improvement measures*, just a technical file which can be used by the Flag/RO to approve the attained EEXI and issue the IEEC


*Unless there is a significant change to the legislative requirements upon adoption by IMO or your vessel subsequently undergoes a major conversion/redesign.

2. EEXI Improvement Calculation and Advisory Options (non-compliant vessels)

If your attained EEXI does meet the required threshold, we’ll first quantify the impacts each improvement option will have on your vessels.  

Using the MEPC draft guidelines we can provide;

  • The percentage engine (EPL) or shaft (SHaPoLi) power limitation required to achieve compliance
  • An estimate of the vessel’s maximum speed reduction if opting for EPL (as this will limit the maximum power available from the main engine and thus the maximum speed)
  • A minimum power assessment for ships which are subject to MARPOL Annex VI Regulation 21, if any non-overridable power limitation or de-rating has been used to achieve EEXI compliance
  • Compilation of the EPL or SHaPoLi OMM, following installation and verification if required
  • Further analysis into the use of Innovative Energy Efficiency Technologies (EET) to allow you to assess if EETs are a practical alternative to EPL to achieve compliance
  • Where opting to pursue EET retrofitting (e.g. pre-duct, PBCF, wind assist technology, or air lubrication) we can conduct a detailed techno-economical study for a subject ship to accurately determine performance improvement and estimate cost

3. EEXI Technical File (all vessels without a compliant attained EEDI)

We will compile your EEXI Technical File following the implementation of any solutions required for EEXI compliance based on the detailed calculations and EEXI guidelines

4. Statutory Approval, verification and certification services

The following will all need to be approved by the Flag Administration or a duly authorised RO before a new IEEC can be issued to your vessel:

  • Verification of the attained EEXI based on the EEXI Technical File or EEDI Technical File, (where appropriate)
  • Verification of OPL arrangements, including the OMM (where applicable)

LR’s Classification division will be able to help with this after the changes have been adopted and the guidelines finalised.

Contact us for more information

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