Annex - 2022 Interim Guidelines on Correction Factors and Voyage Adjustments for CII Calculations (CII Guidelines, G5)

1 Introduction

1.1 These Guidelines address the corrections factors and voyage adjustments which may be applied to the calculation of the attained annual operational carbon intensity indicator (CII_ship) of regulation 28 of MARPOL Annex VI, and as defined by the 2022 Guidelines on operational carbon intensity indicators and the calculation methods (CII Guidelines, G1) (resolution MEPC.352 (78)). It should be noted that the use of correction factors and voyage adjustments should in no way undermine the goal of reducing the carbon intensity of international shipping as set out in regulation 20 of MARPOL Annex VI.

2 Definitions

For the purpose of these Guidelines, the definitions in regulation 2 of MARPOL Annex VI, as amended, apply. In addition and for the scope of these guidelines, the following definitions apply.

2.1 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.

2.2 IMO DCS means the IMO Ship Fuel Oil Consumption Database referred to in regulation 27 and related provisions of MARPOL Annex VI.

2.3 A voyage period is a period of time where the ship meets the criteria to apply a voyage adjustment in these Guidelines.

2.4 A voyage adjustment deducts relevant fuel consumption, as well as the associated distance travelled from the calculation of attained CII for a defined period subject to certain threshold conditions being met.

2.5 A correction factor means a factor in the numerator or denominator of the CII formula which adjusts the calculation of the attained CII.

2.6 A refrigerated container is an intermodal shipping container that is refrigerated (including chilled and frozen containers) or heated for the transportation of temperature-sensitive cargo, which will receive its power from the ship's power supply.

2.7 Ice edge is defined by paragraph 4.4. of the WMO Sea-Ice Nomenclature, March 2014 as the demarcation at any given time between the open sea and sea ice of any kind, whether fast or drifting.

2.8 A tanker should be considered in Ship-to-Ship (STS) operation when operating in accordance with regulation 41.2 of MARPOL Annex I and applying the best practices in accordance with the OCIMF Ship to Ship Transfer Guide for Petroleum, Chemical and Liquefied Gases. For the purpose of these guidelines, a tanker is engaged in an STS voyage if a voyage between cargo loading and cargo discharging locations, or a voyage between cargo discharging and cargo loading locations does not exceed 600 nautical miles and the time for each of these voyages (which does not include port or discharge time) is limited to 72 hours.

2.9 A shuttle tanker is a tanker which is equipped with dynamic positioning and specialized cargo handling equipment making it capable of loading crude oil at offshore installations.

2.10 A self-unloading bulk carrier is a bulk carrier with an onboard cargo handling system that is utilized to discharge dry bulk cargo via a boom conveyor or shipboard cargo pipeline equipment.

3 Application

3.1 For all ships to which regulation 28 of MARPOL Annex VI applies, the operational carbon intensity formula defined in section 4 should be applied when using voyage adjustments or correction factors.

3.2 Rating of ships according to the 2022 Guidelines on the operational carbon intensity rating of ships (CII Rating Guidelines G4) (resolution MEPC.354(78)) should be carried out using the corrected attained annual operational CII.

3.3 Corrections factors for electrical related fuel consumption 𝐹𝐶_{𝑒𝑙𝑒𝑐𝑡𝑟𝑖𝑐𝑎𝑙}, boiler consumption 𝐹𝐶_{𝑏𝑜𝑖𝑙𝑒𝑟}, and other related fuel consumption 𝐹𝐶_{𝑜𝑡ℎ𝑒𝑟𝑠} should not be used for periods where voyage adjustments apply.

4 Attained annual operational CII (CII_Ship) formula for voyage adjustments and correction factors

Use of voyage adjustments and correction factors require changes to be made to the overall attained annual operational CII (CII_Ship) formula as follows:

Where:

𝑗 is the fuel type;
𝐶_{𝐹_𝑗} represents the fuel mass to CO₂ mass conversion factor for fuel type 𝑗, in line with those specified in the 2018 Guidelines on the method of calculation of the attained EEDI for new ships (resolution MEPC.308(73) as amended by resolutions MEPC.322(74) and MEPC.332(76)), as may be further amended);
𝐹𝐶_𝑗 is the total mass of consumed fuel of type 𝑗 in the calendar year, as reported under IMO DCS, converted to grams;
𝐹𝐶_{𝑣𝑜𝑦𝑎𝑔𝑒,𝑗} is the mass (in grams) of fuel of type 𝑗, consumed in voyage periods during the calendar year which may be deducted according to paragraph 4.1 of these Guidelines;
TF_𝑗 = (1−𝐴𝐹_{𝑇𝑎𝑛𝑘𝑒𝑟})⋅𝐹𝐶_𝑆,𝑗 represents the quantity of fuel j removed for STS or shuttle tanker operation, where 𝐹𝐶_𝑆,𝑗= 𝐹𝐶_𝑗 for shuttle tankers and 𝐹𝐶_𝑆,𝑗 is the total quantity of fuel j used on STS voyages for STS ships. If TF_𝑗>0 then 𝐹𝐶_{𝑒𝑙𝑒𝑐𝑡𝑟𝑖𝑐𝑎𝑙,𝑗}=𝐹𝐶_{𝑏𝑜𝑖𝑙𝑒𝑟,𝑗}= 𝐹𝐶_{𝑜𝑡ℎ𝑒𝑟𝑠,𝑗}=0;
𝐴𝐹_{𝑇𝑎𝑛𝑘𝑒𝑟} represents the correction factor to be applied to shuttle tankers or STS voyages according to paragraph 4.2 of these Guidelines;
𝑦_𝑖 is a consecutive numbering system starting at 𝑦₂₀₂₃=0, 𝑦₂₀₂₄=1, 𝑦₂₀₂₅=2, etc;
𝐹𝐶_{𝑒𝑙𝑒𝑐𝑡𝑟𝑖𝑐𝑎𝑙,𝑗} is the mass (in grams) of fuel type 𝑗, consumed for production of electrical power which is allowed to be deducted according to paragraph 4.3 of these Guidelines;
𝐹𝐶_{𝑏𝑜𝑖𝑙𝑒𝑟,𝑗} is the mass (in grams) of fuel type 𝑗, consumed by the boiler which may be deducted according to paragraph 4.4 of these Guidelines;
𝐹𝐶_{𝑜𝑡ℎ𝑒𝑟𝑠,𝑗} is the mass (in grams) of fuel type 𝑗, consumed by other related fuel consumption devices according to paragraph 4.5 of these Guidelines;
𝑓_𝑖 is the capacity correction factor for ice-classed ships as specified in the 2018 Guidelines on the method of calculation of the attained EEDI for new ships (resolution MEPC.308(73) as amended by resolutions MEPC.322(74) and MEPC.332(76), as may be further amended);
𝑓_𝑚 is the factor for ice-classed ships having IA Super and IA as specified in the 2018 Guidelines on the method of calculation of the attained EEDI for new ships (resolution MEPC.308(73) as amended by resolutions MEPC.322(74) and MEPC.332(76), as may be further amended);
𝑓_𝑐 represents the cubic capacity correction factors for chemical tankers as specified in paragraph 2.2.12 of the 2018 Guidelines on the method of calculation of the attained EEDI for new ships (resolution MEPC.308(73) as amended by resolutions MEPC.322(74) and MEPC.332(76), as may be further amended);
𝑓_{𝑖,𝑉𝑆𝐸} represents the correction factor for ship-specific voluntary structural enhancement as specified in paragraph 2.2.11.2 of the 2018 Guidelines on the method of calculation of the attained EEDI for new ships (resolution MEPC.308(73) as amended by resolutions MEPC.322(74) and MEPC.332(76), as may be further amended), to be applied only to self-unloading bulk carriers;
𝐶𝑎𝑝𝑎𝑐𝑖𝑡𝑦 is deadweight or gross tonnes as defined for each specific ship type in the 2022 Guidelines on the reference lines for use with operational carbon intensity indicators (CII Reference lines Guidelines, G2) (resolution MEPC.353(78));
𝐷_𝑡 represents the total distance travelled (in nautical miles), as reported under IMO DCS; and
𝐷_𝑥 represents distance travelled (in nautical miles) for voyage periods which may be deducted from CII calculation according to paragraph 4.1 of these Guidelines.

In case the above voyage exclusion or correction factors are applied, the ship should still report total fuel oil consumption (t) of each type of fuel, total hours under way (h) and total distance travelled (nm) to the Administration pursuant to regulation 27 of MARPOL Annex VI.

All relevant data should be recorded in the ship's logbook. Each parameter, if used, should also be reported to the Administration.

4.1 𝑭𝑪_{𝒗𝒐𝒚𝒂𝒈𝒆,𝒋} for voyage adjustment

The parameter 𝐹𝐶_{𝑣𝑜𝑦𝑎𝑔𝑒,𝑗} is the total mass (in grams) of fuel of type 𝑗, consumed in voyage periods during the calendar year which may be deducted from the calculation of the attained CII in case the ship encounters one of the following situations:

.1 scenarios specified in regulation 3.1 of MARPOL Annex VI, which may endanger safe navigation of a ship; and
.2 sailing in ice conditions, which means sailing of an ice-classed ship in a sea area within the ice edge.

In cases where 𝐹𝐶_{𝑣𝑜𝑦𝑎𝑔𝑒,𝑗} is used:

any associated distance travelled must also be deducted using 𝐷_𝑥 otherwise ships will benefit from distance travelled without any associated CO₂ emission.
the ship should report data for the deductions associated with voyage adjustments to the Administration in accordance with appendix 2 of these guidelines.

4.2 𝑨𝑭_{𝑻𝒂𝒏𝒌𝒆𝒓} for corrections to shuttle tankers or STS voyages on tankers

Tankers engaged in STS voyages as defined above in paragraph 2.8 may apply the correction factor AF_Tanker,STSto all fuel consumption relating to STS voyages, including cargo transfer at offshore location, voyage, cargo discharge and waiting periods at anchor or drifting during which the ship reports being part of an STS operation and voyage. The STS operation includes fuel consumption in port where the transferred cargo is discharged after such a voyage.

The correction is calculated as:

𝐴𝐹_{𝑇𝑎𝑛𝑘𝑒𝑟,𝑆𝑇𝑆} = 6.1742 × DWT^−0.246

Where AF_Tanker,STS is applied, FC_electrical, FC_boiler and FC_others should not be used.

Shuttle tankers equipped with dynamic positioning as defined above in paragraph 2.9 may apply the correction factor AF_{Tanker,Shuttle} to total fuel consumption:

The correction factor is calculated as:

𝐴𝐹_{𝑇𝑎𝑛𝑘𝑒𝑟,𝑆ℎ𝑢𝑡𝑡𝑙𝑒} = 5.6805 𝑥 𝐷𝑊𝑇^−0.208

Where AF_{Tanker,Shuttle} is applied, FC_electrical, FC_boiler, FC_others and AF_Tanker,STS should not be used.

4.3 𝑭𝑪_{𝒆𝒍𝒆𝒄𝒕𝒓𝒊𝒄𝒂𝒍,𝒋} for corrections relating to electrical power

The parameter 𝐹𝐶_{𝑒𝑙𝑒𝑐𝑡𝑟𝑖𝑐𝑎𝑙,𝑗} is the mass (in grams) of fuel of type 𝑗, consumed for production of electrical power during the calendar year which may be deducted from the calculation of the attained CII for the following purposes:

.1 Electrical consumption of refrigerated containers (on all ships where they are carried) using the calculation methodology specified in part A of appendix 1.
.2 Electrical consumption of cargo cooling/reliquefaction systems on gas carriers and LNG Carriers.
.3 Electrical consumption of discharge pumps on tankers.

4.4 𝑭𝑪_{𝑩𝒐𝒊𝒍𝒆𝒓,𝒋} for corrections relating to boiler fuel consumption

The parameter 𝐹𝐶_{𝐵𝑜𝑖𝑙𝑒𝑟,𝑗} is the mass (in grams) of fuel of type 𝑗, consumed by the oil-fired boiler during the calendar year which may be deducted from the calculation of the attained CII, for the purposes of cargo heating and cargo discharge on tankers. The calculation methodology for 𝐹𝐶_{𝐵𝑜𝑖𝑙𝑒𝑟,𝑗} is specified in part B of appendix 1.

4.5 𝑭𝑪_{𝒐𝒕𝒉𝒆𝒓𝒔,𝒋} for corrections relating to other related fuel consumption devices

The parameter 𝐹𝐶_{𝑜𝑡ℎ𝑒𝑟𝑠,𝑗} is the mass (in grams) of fuel of type 𝑗, consumed by standalone engine driven cargo pumps during discharge operations on tankers which may be deducted from the calculation of the attained CII.

4.6 EEDI and EEXI Correction factors

The EEDI correction factors as defined above in paragraph 4 may be applied, provided they are included in the ship's EEDI Technical File or EEXI Technical file.

APPENDIX 1 - CORRECTION FACTORS FOR USE IN CII CALCULATION

Part A. FC_Electrical for Corrections relating to electrical power

1 Refrigerated containers

For ships carrying refrigerated containers, the correction factor FC_Electrical may be applied as follows:

.1 For ships that have the ability to monitor reefer electrical consumption, the ship may calculate reefer container kWh consumption as follows:

𝐹𝐶_{𝑒𝑙𝑒𝑐𝑡𝑟𝑖𝑐𝑎𝑙_𝑟𝑒𝑒𝑓𝑒𝑟,𝑗}=𝑅𝑒𝑒𝑓𝑒𝑟 𝑘𝑊ℎ × 𝑆𝐹𝑂𝐶

where:

𝐹𝐶_{𝑒𝑙𝑒𝑐𝑡𝑟𝑖𝑐𝑎𝑙_𝑟𝑒𝑒𝑓𝑒𝑟,𝑗} (Reefer fuel oil consumption) represents the estimated fuel consumption attributed to in-use refrigerated containers carried.
𝑅𝑒𝑒𝑓𝑒𝑟 𝑘𝑊ℎ is measured on the ship by the kWh meter counter on the ship.
𝑆𝐹𝑂𝐶 represents the specific fuel consumption in g/kWh as a weighted average of the engines used to provide the electrical power, as per the EEDI/EEXI Technical File or the NO_x Technical File. In the case of ships without a Technical File, a default value of 175 g/kWh for 2 stroke engines and 200 g/kWh for 4 stroke engines may be applied. In the case of waste heat recovery systems as defined under Category C1 in MEPC.1/Circ.896 the SFOC to be used will be at the discretion of the Administration.

Alternatives such as derivation of fuel consumption or kWh from auto-logged data may be used subject to approval by the Administration. Note that ship reefer kWh consumption should not include consumption during voyage adjustment periods.

.2 For ships that do not have the ability to monitor reefer electrical consumption, the ship may calculate reefer kWh consumption as follows:

𝐹𝐶_{𝑒𝑙𝑒𝑐𝑡𝑟𝑖𝑐𝑎𝑙_
𝑟𝑒𝑒𝑓𝑒𝑟,𝑗}=𝐶𝑥⋅24⋅𝑆𝐹𝑂𝐶_𝑎𝑣𝑔⋅(𝑅𝑒𝑒𝑓𝑒𝑟_𝑑𝑎𝑦𝑠_𝑠𝑒𝑎+Σ𝑅𝑒𝑒𝑓𝑒𝑟_𝑑𝑎𝑦𝑠 _{𝑝𝑜𝑟𝑡})

where:

𝐶𝑥 represents a default reefer consumption of 2.75 kW/h.
𝑅𝑒𝑒𝑓𝑒𝑟_𝑑𝑎𝑦𝑠_𝑠𝑒𝑎 represents the number of in-use reefer-days over the declared period and may be derived using the number of reefer containers as recorded in the BAPLIE file multiplied by the number of days at sea.
𝑆𝐹𝑂𝐶_𝑎𝑣𝑔 represents the specific fuel consumption in g/kWh as a weighted average of the engines used to provide the electrical power, as per the EEDI/EEXI Technical File or NO_x Technical File. In the case of ships without a Technical File, a default value of 175 g/kWh for 2 stroke engines and 200 g/kWh for 4 stroke engines may be applied. In the case of waste heat recovery systems as defined under Category C1 in MEPC.1/Circ.896 the SFOC to be used will be at the discretion of the Administration.

In ports where shore-power is not used, the number of in-use reefers at port should be calculated as:

where:

𝐷𝑎𝑦𝑠_{𝑝𝑜𝑟𝑡} represents number of days in port.
𝑅𝑒𝑒𝑓𝑒𝑟_𝑑𝑎𝑦𝑠 _{𝑝𝑜𝑟𝑡} represents the number of in-use reefer days while at port.^footnote
𝑁𝑜_𝑐 𝐴𝑟𝑟𝑖𝑣𝑎𝑙 represents number of reefer containers on arrival.
𝑁𝑜_𝑐 𝐷𝑒𝑝𝑎𝑟𝑡𝑢𝑟𝑒 represents number of reefer containers at departure.

In all cases, the actual number of in-use reefers carried is documented in the BAPLIE file.

Note that ship reefer kWh consumption should not include consumption during voyage adjustment periods.

2 Cargo cooling systems on gas carriers and LNG carriers

For gas carriers and LNG carriers with electrical cargo cooling systems or reliquefaction plants, the correction factor FC_electrical may be applied as follows:

.1 Gas carriers and LNG carriers may calculate cargo cooling kWh consumption as follows:
- 𝐹𝐶_{𝑒𝑙𝑒𝑐𝑡𝑟𝑖𝑐𝑎𝑙_𝑐𝑜𝑜𝑙𝑖𝑛𝑔,𝑗} = 𝐶𝑜𝑜𝑙𝑖𝑛𝑔 𝑘𝑊ℎ × 𝑆𝐹𝑂𝐶
where:

𝐹𝐶_{𝑒𝑙𝑒𝑐𝑡𝑟𝑖𝑐𝑎𝑙_𝑐𝑜𝑜𝑙𝑖𝑛𝑔,𝑗} (cargo cooling fuel oil consumption) represents the estimated fuel consumption attributed to cooling of gas cargoes.
𝐶𝑜𝑜𝑙𝑖𝑛𝑔 𝑘𝑊ℎ is measured on the ship by the kWh meter counter on the ship.
𝑆𝐹𝑂𝐶 represents the specific fuel consumption in g/kWh associated with the relevant source of electrical power as per the EEDI/EEXI Technical File or NO_x Technical File. In the case of ships without a Technical File, a default value of 175 g/kWh for 2 stroke engines and 200 g/kWh for 4 stroke engines may be applied. In the case of waste heat recovery systems as defined under Category C1 in MEPC.1/Circ.896 the SFOC to be used will be at the discretion of the Administration.

Alternatives such as derivation of fuel consumption or kWh from auto-logged data may be used subject to approval by the Administration. Note that cargo cooling kWh consumption should not include consumption during voyage adjustment periods.

3 Electric cargo discharge pumps on tankers

For tankers with directly or indirectly electrically powered discharge pumps, the correction factor FC_electrical may be applied as follows:

.1 Tankers may calculate cargo discharge kWh consumption as follows:

𝐹𝐶_{𝑒𝑙𝑒𝑐𝑡𝑟𝑖𝑐𝑎𝑙_𝑑𝑖𝑠𝑐ℎ𝑎𝑟𝑔𝑒,𝑗} = 𝑑𝑖𝑠𝑐ℎ𝑎𝑟𝑔𝑒 𝑘𝑊ℎ × 𝑆𝐹𝑂𝐶

where:

𝐹𝐶_{𝑒𝑙𝑒𝑐𝑡𝑟𝑖𝑐𝑎𝑙_𝑑𝑖𝑠𝑐ℎ𝑎𝑟𝑔𝑒,𝑗} (cargo discharge fuel oil consumption) represents the estimated fuel consumption attributed to use of cargo discharge pumps.
𝐷𝑖𝑠𝑐ℎ𝑎𝑟𝑔𝑒 𝑘𝑊ℎ is measured on the ship by the kWh meter counter on the ship.
𝑆𝐹𝑂𝐶 represents the specific fuel oil consumption in g/kWh associated with the relevant source of electrical power as per the EEDI/EEXI Technical File or NO_x Technical File. In the case of ships without a Technical File, a default value of 175 g/kWh for 2 stroke engines and 200 g/kWh for 4 stroke engines may be applied. In the case of waste heat recovery systems as defined under Category C1 in MEPC.1/Circ.896 the SFOC to be used will be at the discretion of the Administration.

Alternatives such as derivation of actual fuel consumption from auto-logged data may be used subject to approval by the Administration. Note that cargo cooling kWh consumption should not include consumption during voyage adjustment periods.

Part B. FC_Boiler and FC_Others for corrections relating to cargo heating and discharge on tankers

1 FC_Boiler for cargo heating and discharge pumps on tankers

For tankers with fuel fired boilers used for cargo heating or steam driven cargo pumps, the following correction factor may be applied for the period that the cargo heating or discharge pumps are in operation:

.1 In the case of boilers used for cargo heating, the amount of fuel used by the boiler (𝐹𝐶_{𝐵𝑜𝑖𝑙𝑒𝑟}) should be measured by accepted means, e.g. tank soundings, flow meters.
.2 For tankers which use steam driven cargo pumps, the amount of fuel used by the boiler (𝐹𝐶_{𝐵𝑜𝑖𝑙𝑒𝑟}) should be measured by accepted means, e.g. tank soundings, flow meters.

Some amount of fuel consumed by the boiler during cargo heating or discharge operations may be attributed to other purposes, e.g. calorifiers. It is not necessary to split these out from reporting.

Note that boiler consumption should not include consumption during voyage adjustment periods.

2 FC_Others for discharge pumps on tankers

For tankers with discharge pumps powered by their own generator, the amount of fuel used for the period that the discharge pumps are in operation (𝐹𝐶_{𝑂𝑡ℎ𝑒𝑟𝑠}) should be measured by accepted means, e.g. tank soundings, flow meters.

Note that fuel deducted under FC_Others should not include consumption during voyage adjustment periods.

APPENDIX 2 - GUIDANCE ON REPORTING OF FUEL OIL CONSUMPTION AND DISTANCE TRAVELLED FOR VOYAGE PERIODS WHERE THE SHIP MEETS THE CRITERIA TO APPLY ANY VOYAGE ADJUSTMENT

In this appendix guidance is given for reporting and verification of fuel oil consumption and distance travelled concerning voyage adjustments when a scenario specified in regulation 3.1 of MARPOL Annex VI applies, which may endanger safe navigation of a ship, or when sailing in ice conditions.

1 Fuel oil consumption for voyage periods should include all the fuel oil consumed on board including but not limited to the fuel oil consumed by the main engines, auxiliary engines, gas turbines, boilers and inert gas generator, for each type of fuel oil consumed, regardless of whether a ship is under way or not. Methods for collecting data on fuel oil consumption in metric tonnes include the method using flow meters or method using bunker fuel oil tank monitoring on board as described in paragraphs 7.1.2 and 7.1.3 of the 2022 Guidelines for the development of a Ship Energy Efficiency Management Plan (SEEMP Guidelines) (resolution MEPC.346(78)) correspondingly.

2 The distance travelled over ground in nautical miles for voyage periods should be recorded in the logbook in accordance with SOLAS regulation V/28.1 and submitted to the Administration.

3 At the end of the voyage, if the ship has encountered ice conditions during its voyage, when the ship was under way sailing between the ice edges or between the ice edge and the port, or when a scenario specified in regulation 3.1 of MARPOL Annex VI applies:

.1 the fuel oil consumed measured in accordance with 7.1.2 or 7.1.3 of the SEEMP Guidelines for the voyage period should not be included in the calculations for the annual average attained CII index value;
.2 if the voyage period is excluded from calculations of the attained CII index value when a scenario specified in regulation 3.1 of MARPOL Annex VI applies, the distance travelled should be clearly marked in the SEEMP monitoring plan, the ship's logbook should include data entries for the voyage period with date, time and position of the ship, when a scenario specified in regulation 3.1 of MARPOL Annex VI started to apply and ceased to apply, and data should be added to the data reporting format;
.3 if the voyage period is excluded from calculations of the attained CII index value due to sailing in ice conditions, the distance travelled should be clearly marked in the SEEMP monitoring plan, the ship's logbook should include data entries for the voyage period with date, time and position of the ship when the ship encountered ice conditions and left ice conditions, and data should be added to the data reporting format.

4 The summary of monitoring data containing records of measured fuel oil consumption and distance travelled for voyage periods should be available on board. Ice charts related to the voyage periods should also be available if the ship has sailed in ice conditions.

Figure 1: An example of an ice chart of the Baltic Sea area