Updated GHG Rating methodology encompasses EEXI, looks ahead to CII - Q&A

What’s new?

RightShip is pressing ahead with its vision for a zero-harm maritime industry by enhancing the methodology for its well-established Greenhouse Gas (GHG) Rating, which has been providing emissions data transparency and insights to drive change in the maritime industry since 2012.

In 2023, the GHG Rating methodology will be updated to incorporate Energy Efficiency Existing Ship Index (EEXI) values. RightShip’s proprietary GHG Rating algorithm already uses data and outputs from either the Existing Vessel Design Index (EVDI), or the Energy Efficiency Design Index (EEDI) to generate a simple A – G rating of the theoretical CO₂ emissions of a peer group of vessels across similar size and type.

This makes our GHG Rating the industry’s first rating to incorporate all three indices, providing the maritime sector with one simple and easy to use rating when measuring and assessing a vessel’s emissions.

Why are we making changes to our GHG Rating formula?

The International Maritime Organization (IMO) is launching two new short-term decarbonisation measures, through the design focused Energy Efficiency Existing Ship Index (EEXI) and the operationally focused Carbon Intensity Indicator (CII), on 1 January 2023.

We’ll be updating our platform to incorporate the EEXI scores whilst enhancing our GHG Rating methodology to remove the undue mathematical influence of power limitation. This will ensure we continue to provide a ‘level playing field’ for the GHG Rating as a relative measure of efficiency between similar vessels.

The evolution is designed to provide a transparent and fair GHG Rating, and reward those who invest in decarbonisation through efficient design and energy saving equipment, by allowing them to obtain superior ratings in their relative peer group.

What are EEXI and CII?

The EEXI and CII are short-term IMO regulations which require a reduction in vessels’ GHG emissions per transport work, with reduction targets of 40% by 2030 and 70% by 2050. They contribute towards the IMO’s current minimum 50% absolute decarbonisation target for 2050.

The EEXI is a technical design measure based upon the EEDI methodology and calculates energy efficiency of vessels (g/CO2/tonne nm). Vessels within scope must attain a score on or below the IMO’s required EEXI.

EEXI compliance only needs to be met once and must be demonstrated at the first annual, intermediate or renewal survey taking place from 1 January 2023. EEXI compliance is applicable to existing ships (built prior to 2023), and the EEDI remains in place for newbuild vessels as per associated phase timelines.

The CII will provide greater transparency of operational performance over the previous 12-month period by measuring how many grams of CO2 are used by a vessel per tonne, per nautical mile, essentially measuring how efficiently cargoes are moved and/or ships are operated. Shipowners will begin to aggregate data for their voyages throughout 2023, with the first A – E CII ratings expected early 2024.

Whilst the EEXI requires one-time Class certification, the CII provides a rolling annual score of the operational efficiency of the vessel over a 12-month period, again approved by Class. Non-compliance with EEXI may results in vessels being unable to sail, whereas CII is designed to drive continual operational improvement against required IMO targets to encourage better ratings on the A – E scale.

When will the changes begin?

EEXI figures and technical files can be provided from January 2023, feeding into our existing GHG Rating. The methodology will be updated within 2023.

Since the 12-month data collection period for CII only commences on 1 January 2023, CII data and A-E ratings are not expected to be provided until early 2024. CII ratings will be updated on an annual basis.

​How does EEXI impact our GHG Rating?

The EEXI will be incorporated into our GHG Rating and has influenced the enhancement of the methodology. As such we have moved towards a speed-corrected approach to compare vessels within peer groups whilst retaining the original intent of providing a level playing field.

A key point of note is the application of Engine Performance Limitation (EPL) or Shaft Power Limitation (ShaPoLi). RightShip’s existing GHG Rating allows only a singular EPL per ship. However, in the revised GHG methodology, additional EPLs and SHaPoLis implemented to achieve compliance will become acceptable.

To counter the unintended consequences of the EPL reliance to comply with the EEXI regulation, the revised GHG Rating will compare vessels in peer groups operating at the same speed (common speed), removing the undue mathematical influence of EPLs or ShaPoLis.

In addition, the updated approach will support ship owners, ship managers and/or ship operators to avoid policy level restrictions where charterers reject vessels that introduced an EPL or ShaPoLi, or elect not to choose vessels from older tonnage as part of their ESG policies.

An in-depth methodology will be available on our website soon.

How will CII affect our GHG Rating?

The CII will work alongside our GHG Rating as separate metric providing further insight for charterers and owners.

RightShip’s GHG Rating will continue to provide a static benchmark of the theoretical design efficiency of the vessel, thus giving insights into how efficiently it can be operated.

The CII is a post-event metric looking at the previous 12 months’ operation. The CII will demonstrate how efficiently (or not) a vessel has been operated.

Combining data insights into design efficiency (revised GHG Rating) and post-event annual efficiency (CII) will allow both charterers and shipowners to meet ESG targets by operating / selecting vessels that meet their needs, by identifying opportunities for improvement and by further supporting innovation for decarbonisation.

Will EEXI / CII affect the GHG Rating A-G system?

RightShip are currently evaluating the potential impact of the CII ratings system (A-E) against our GHG Rating (A-G) and will release further information in 2023.

Will this change vetting?

Currently there are no changes to the standard RightShip vetting criteria, noting the IMO EEXI compliance requirements are captured within the Class Certification review.

However, we are working with key chartering customers to test and validate potential additional vetting criteria for GHG, EEXI and CII. Any changes made will be communicated to the industry through RightShip’s regular updates.