Revoked by MEPC.350(78)

 

RESOLUTION MEPC.333(76)

(adopted on 17 June 2021)

 

2021 GUIDELINES ON THE METHOD OF CALCULATION OF THE ATTAINED ENERGY EFFICIENCY EXISTING SHIP INDEX (EEXI)

 

THE MARINE ENVIRONMENT PROTECTION COMMITTEE,

 

RECALLING Article 38(a) of the Convention on the International Maritime Organization concerning the functions of the Marine Environment Protection Committee conferred upon it by international conventions for the prevention and control of marine pollution from ships,

 

NOTING that it adopted, by resolution MEPC.328(76), the 2021 revised MARPOL Annex VI, which is expected to enter into force on 1 November 2022 upon its deemed acceptance on 1 May 2022,

 

NOTING IN PARTICULAR that the 2021 revised MARPOL Annex VI contains amendments concerning mandatory goal-based technical and operational measures to reduce carbon intensity of international shipping,

 

NOTING FURTHER that regulation 23 of MARPOL Annex VI requires that the attained EEXI shall be calculated taking into account the guidelines developed by the Organization,

 

RECOGNIZING that the aforementioned amendments to MARPOL Annex VI require relevant guidelines for uniform and effective implementation of the regulations and to provide sufficient lead time for industry to prepare,

 

HAVING CONSIDERED, at its seventy-sixth session, draft 2021 Guidelines on the method of calculation of the attained Energy Efficiency Existing Ship Index (EEXI),

 

1          ADOPTS the 2021 Guidelines on the method of calculation of the attained Energy Efficiency Existing Ship Index (EEXI), as set out in the annex to the present resolution;

 

2          INVITES Administrations to take the annexed Guidelines into account when developing and enacting national laws which give force to and implement requirements set forth in regulation 23 of MARPOL Annex VI;

 

3          REQUESTS the Parties to MARPOL Annex VI and other Member Governments to bring the annexed Guidelines to the attention of masters, seafarers, shipowners, ship operators and any other interested parties;

 

4          AGREES to keep the Guidelines under review in light of experience gained with their implementation and in light of the review of EEXI regulations to be completed by the Organization by 1 January 2026 as identified in regulation 25.3 of MARPOL Annex VI.

 

ANNEX

 

2021 GUIDELINES ON THE METHOD OF CALCULATION OF THE ATTAINED ENERGY EFFICIENCY EXISTING SHIP INDEX (EEXI)

 

CONTENTS

 

1          Definitions

 

2          Energy Efficiency Existing Ship Index (EEXI)

 

2.1       EEXI formula

 

2.2       Parameters

 

2.2.1    P_ME(i) ; Power of main engines

 

2.2.2    P_AE(i) ; Power of auxiliary engines

 

2.2.3    V_ref ; Ship speed

 

2.2.4    SFC ; Certified specific fuel consumption

 

2.2.5    C_F ; Conversion factor between fuel consumption and CO₂ emission

 

2.2.6    Correction factor for ro-ro cargo and ro-ro passenger ships (f_jRoRo)

 

2.2.7    Correction factor for ro-ro cargo ships (vehicle carrier) (f_cVEHICLE)

 

APPENDIX     Parameters to calculate V_ref,app

 

1          Definitions

 

1.1       MARPOL means the International Convention for the Prevention of Pollution from Ships, 1973, as modified by the Protocols of 1978 and 1997 relating thereto, as amended.

 

1.2       For the purpose of these Guidelines, the definitions in MARPOL Annex VI, as amended, apply.

 

2          Energy Efficiency Existing Ship Index (EEXI)

 

2.1       EEXI formula

 

The attained Energy Efficiency Existing Ship Index (EEXI) is a measure of ship's energy efficiency (g/t*nm) and calculated by the following formula:

 

 

*        If part of the Normal Maximum Sea Load is provided by shaft generators, SFC_ME and C_FME may - for that part of the power - be used instead of SFC_AE and C_FAE

 

**      In case of P_PTI(i) > 0, the average weighted value of (SFC_ME∙C_FME) and (SFC_AE∙C_FAE) to be used for calculation of P_eff

 

Note: This formula may not be applicable to a ship having diesel-electric propulsion, turbine propulsion or hybrid propulsion system, except for cruise passenger ships and LNG carriers.

 

Ships falling into the scope of EEDI requirement can use their attained EEDI calculated in accordance with the 2018 Guidelines on the method of calculation of the attained EEDI for new ships (resolution MEPC.308(73), as amended, the "EEDI Calculation Guidelines" hereafter) as the attained EEXI if the value of the attained EEDI is equal to or less than that of the required EEXI.

 

2.2       Parameters

 

For calculation of the attained EEXI by the formula in paragraph 2.1, parameters under the EEDI Calculation Guidelines apply, unless expressly provided otherwise. In referring to the aforementioned guidelines, the terminology "EEDI" should be read as "EEXI".

 

2.2.1    P_ME(i) ; Power of main engines

 

In cases where overridable Shaft / Engine Power Limitation is installed in accordance with the 2021 Guidelines on the shaft / engine power limit to comply with the EEXI requirements and use of a power reserve (resolution MEPC.335(76)), P_ME(i) is 83% of the limited installed power (MCR_lim) or 75% of the original installed power (MCR), whichever is lower, for each main engine (i). In cases where the overridable Shaft / Engine Power Limitation and shaft generator(s) are installed, in referring to paragraph 2.2.5.2 (option 1) of the EEDI Calculation Guidelines, "MCR_ME" should be read as "MCR_lim".

 

For LNG carriers having steam turbine or diesel electric propulsion, P_ME(i) is 83% of the limited installed power (MCR_lim, MPP_lim), divided by the electrical efficiency in case of diesel electric propulsion system, for each main engine (i). For LNG carriers, the power from combustion of the excessive natural boil-off gas in the engines or boilers to avoid releasing to the atmosphere or unnecessary thermal oxidation should be deducted from P_ME(i) with the approval of the verifier.

 

2.2.2    P_AE(i) ; Power of auxiliary engines

 

2.2.2.1  P_AE(i) is calculated in accordance with paragraph 2.2.5.6 of the EEDI Calculation Guidelines.

 

2.2.2.2  For ships where power of auxiliary engines (P_AE) value calculated by paragraphs 2.2.5.6.1 to 2.2.5.6.3 of the EEDI Calculation Guidelines is significantly different from the total power used at normal seagoing, e.g. in cases of passenger ships, the P_AE value should be estimated by the consumed electric power (excluding propulsion) in conditions when the ship is engaged in a voyage at reference speed (V_ref) as given in the electric power table, divided by the average efficiency of the generator(s) weighted by power (see appendix 2 of the EEDI Calculation Guidelines).

 

2.2.2.3  In cases where the electric power table is not available, the P_AE value may be approximated either by:

 

.1       annual average figure of P_AE at sea from onboard monitoring obtained prior to the EEXI certification;

 

.2       for cruise passenger ships, approximated value of power of auxiliary engines (P_AE,app), as defined below:

P_AE,app = 0.1193 · GT + 1814.4                [kW]

 

.3       for ro-ro passenger ships, approximated value of power of auxiliary engines (P_AE,app), as defined below:

P_AE,app = 0.866 · GT^0.732                            [kW]

 

2.2.3    V_ref ; Ship speed

 

2.2.3.1  For ships falling into the scope of the EEDI requirement, the ship speed V_ref should be obtained from an approved speed-power curve as defined in the 2014 Guidelines on survey and certification of the Energy Efficiency Design Index (EEDI), as amended (resolution MEPC.254(67), as amended).

 

2.2.3.2  For ships not falling into the scope of the EEDI requirement, the ship speed V_ref should be obtained from an estimated speed-power curve as defined in the 2021 Guidelines on survey and certification of the attained EEXI (resolution MEPC.334(76)).

 

2.2.3.3  For ships not falling into the scope of the EEDI requirement but whose sea trial results, which may have been calibrated by the tank test, under the EEDI draught and the sea condition as specified in paragraph 2.2.2 of the EEDI Calculation Guidelines are included in the sea trial report, the ship speed V_ref may be obtained from the sea trial report:

 

 

where,

 

V_S,EEDI, is the sea trial service speed under the EEDI draught; and

 

P_S,EEDI is power of the main engine corresponding to V_S,EEDI.

 

2.2.3.4  For containerships, bulk carriers or tankers not falling into the scope of the EEDI requirement but whose sea trial results, which may have been calibrated by the tank test, under the design load draught and sea condition as specified in paragraph 2.2.2 of the EEDI Calculation Guidelines are included in the sea trial report, the ship speed V_ref may be obtained from the sea trial report:

 

 

where,

 

V_S,service is the sea trial service speed under the design load draught;

 

DWT_S,service is the deadweight under the design load draught;

 

P_S,service is the power of the main engine corresponding to V_S,service;

 

k is the scale coefficient, which should be:

 

.1       0.95 for containerships with 120,000 DWT or less;

 

.2       0.93 for containerships with more than 120,000 DWT;

 

.3       0.97 for bulk carrier with 200,000 DWT or less;

 

.4       1.00 for bulk carrier with more than 200,000 DWT;

 

.5       0.97 for tanker with 100,000 DWT or less; and

 

.6       1.00 for tanker with more than 100,000 DWT.

 

2.2.3.5 In cases where the speed-power curve is not available or the sea trial report does not contain the EEDI or design load draught condition, the ship speed V_ref can be approximated by V_ref,app to be obtained from statistical mean of distribution of ship speed and engine power, as defined below:

 

 

For LNG carriers having diesel electric propulsion system and cruise passenger ship having non-conventional propulsion,

 

 

where,

 

V_ref,avg is a statistical mean of distribution of ship speed in given ship type and ship size, to be calculated as follows:

 

V_ref,avg = A · B^C

 

where

 

A, B and C are the parameters given in the appendix;

 

m_V is a performance margin of a ship, which should be 5% of V_ref,avg or one knot, whichever is lower; and

 

MCR_avg is a statistical mean of distribution of MCRs for main engines and MPP_avg is a statistical mean of distribution of MPPs for motors in given ship type and ship size, to be calculated as follows:

 

MCR_avg or MPP_avg = D · E^F

 

where

 

D, E and F are the parameters given in the appendix;

 

In cases where the overridable Shaft / Engine Power Limitation is installed, the ship speed V_ref approximated by V_ref,app should be calculated as follows:

 

 

For LNG carriers having diesel electric propulsion system and cruise passenger ship having non-conventional propulsion, the ship speed V_ref approximated by V_ref,app should be calculated as follows:

 

 

2.2.3.6  Notwithstanding the above, in cases where the energy saving device* is installed, the effect of the device may be reflected in the ship speed V_ref with the approval of the verifier, based on the following methods in accordance with defined quality and technical standards:

 

.1       sea trials after installation of the device; and/or

 

.2       dedicated model tests; and/or

 

.3       numerical calculations.

_________________

*    Devices that shift the power curve, which results in the change of PP and V_ref, as specified in MEPC.1/Circ.815 on 2013 Guidance on treatment of innovative energy efficiency technologies for calculation and verification of the attained EEDI.

 

2.2.4    SFC; Certified specific fuel consumption

 

In cases where overridable Shaft / Engine Power Limitation is installed, the SFC corresponding to the P_ME should be interpolated by using SFCs listed in an applicable test report included in an approved NO_X Technical File of the main engine as defined in paragraph 1.3.15 of the NO_X Technical Code.

 

Notwithstanding the above, the SFC specified by the manufacturer or confirmed by the verifier may be used.

 

For those engines which do not have a test report included in the NO_X Technical File and which do not have the SFC specified by the manufacturer or confirmed by the verifier, the SFC can be approximated by SFC_app defined as follows:

 

SFC_MEapp = 190       [g/kWh]

 

SFC_AEapp = 215        [g/kWh]

 

2.2.5    C_F ; Conversion factor between fuel consumption and CO₂ emission

 

For those engines which do not have a test report included in the NO_X Technical File and which do not have the SFC specified by the manufacturer, the C_F corresponding to SFC_app should be defined as follows:

 

C_F = 3.114 [t ∙CO₂/t ∙ Fuel] for diesel ships (incl. HFO use in practice)

 

Otherwise, paragraph 2.2.1 of the EEDI Calculation Guidelines applies.

 

2.2.6    Correction factor for ro-ro cargo and ro-ro passenger ships (f_jRoRo)

 

For ro-ro cargo and ro-ro passenger ships, f_jRoRo is calculated as follows:

 

 

; if f_jRoRo > 1 then f_j = 1

 

 

where the Froude number, F_nL, is defined as:

 

 

where V_ref,F is the ship design speed corresponding to 75% of MCR_ME.:

 

and the exponents α, β, γ and δ are defined as follows:

 

Ship type	Exponent:
	α	β	γ	δ
Ro-ro cargo ship	2.00	0.50	0.75	1.00
Ro-ro passenger ship	2.50	0.75	0.75	1.00

 

2.2.7    Cubic capacity correction factor for ro-ro cargo ships (vehicle carrier) (f_cVEHICLE)

 

For ro-ro cargo ships (vehicle carrier) having a DWT/GT ratio of less than 0.35, the following cubic capacity correction factor, f_cVEHICLE, should apply:

 

           

 

Where DWT is the capacity and GT is the gross tonnage in accordance with the International Convention of Tonnage Measurement of Ships 1969, annex I, regulation 3.

 

APPENDIX

 

Parameters to calculate V_ref,avg

 

 

Parameters to calculate MCR_avg or MPP_avg (= D · E^F)