After introducing Energy Efficiency Design Index (EEDI) and Ship Energy Efficiency
Management Plan (SEEMP) in 2011, by 62nd session of the Marine Environment Protection
Committee (MEPC 62), International Maritime Organization (IMO) pursued its short- and
long-term goals to reduce greenhouse gas (GHG) emissions from ships by presenting an Energy
Efficiency Existing Ship Index (EEXI). Ships engaged in international voyage will be obliged
to comply with the EEXI (MARPOL Annex VI, reg. 23 and 25). In addition, they must satisfy
Regulation 28 of the same MARPOL Annex. Regulation 28 prescribes for the reduction of
Operational Carbon Intensity through the Carbon Intensity Indicator (CII). The effective date
for these changes to become operational is 1 January 2023.
Contrary to EEDI which is used for new ships solely, EEXI and CII is addressing the energy
efficiency of already built ships and is set to become formally applicable starting from 2023.
Given this, the new regulatory movement of 2021 forces shipowners to demonstrate, by the
initial or the next periodic survey, that their ships meet the requirements of EEXI and CII in
order for them to receive the International Energy Efficiency Certificate (IEEC) and/or the
International Air Pollution Prevention Certificate (IAPPC).
According to DNV, about 80% of the current fleet falling within the EEXI regulations are not
compliant and need to take measures by 2023.According to ABS, about 20% of the tanker, 46%
of the bulker and 25% of the container fleet are having difficulty to even reach the required
EEXI reduction factors, basis their attained values, which will be 15-30% lower than the latest
updated EEDI baselines.
This diploma thesis deals with various ways for ships to be EEXI compliant. After IMO strategy
and goals regarding energy efficiency, it presented a variety of innovative means through which
EEXI requirements could be satisfied. Energy Saving Devices (ESDs) are analyzed and divided
into different categories according to their contribution to the EEXI formula.
However, at this moment the easiest and most cost-effective measure for the reduction of EEXI
is the Engine Power Limitation or EPL. One of the most serious disadvantages derived from
the implementation of EPL is the vessel’s speed reduction. In case of large EPL, the vessel’s
speed will drop dramatically as the main engine power drops and simultaneously changes the
operational point of the propeller. With a significant reduction of the engine power in order to
comply with EEXI regulation, the efficiency factor of the propeller will drop dramatically.
Thus, a lot of shipowners will be led to the retrofit or redesign of the propeller.
In this paper is presented case studies with two vessels that will be evaluated on their required
and the currently attained EEXI before and after the implementation of ways to reduce it. Morespecifically, a product/ chemical tanker and a containership will be assessed for EEXI index
and an EPL application will be carried out in order to be compliant with the EEXI. An
economical feasibility study will then be carried out on the containership by retrofitting its
propeller. This retrofit will be evaluated both technically and economically, in order to be
shown whether such projects are not only environmentally but also economically feasible and
sustainable.
Being compliant with EEXI is a mandatory requirement according to the IMO from 1 January
2023. The implementation of overridable EPL or ShaPoLi is not an investment option. When
the ship has to drop its EEXI and engine operating power to a great extent, ESDs cannot achieve
this rate without the help of EPL/ShaPoLi. However, with the implementation of ESDs the ship
can reach pre-EEXI speeds so that no major changes in the operational profiles of most ships
will be observed from 2023. Thus, economic and technical feasibility studies on these issues
have been carried out for a long time in shipping companies, in order to achieve fuel savings in
addition to the mandatory reduction of emissions, and therefore this new ΕΕΧΙ project to make
the companies economically and energetically viable and efficient.
(EN)
National Technical University of Athens
