1 Introduction
1.1 In the Initial IMO Strategy on Reduction of GHG Emissions from Ships
(Resolution MEPC.304(72)), the level of ambition on carbon
intensity of international shipping is quantified by the CO2 emissions
per transport work, as an average across international shipping.
1.2 These Guidelines address the calculation methods and the applicability of the
operational carbon intensity indicator (CII) for individual ships to which chapter 4 of MARPOL Annex VI, as amended, applies.
2 Definitions
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 data collection system for fuel oil consumption of ships
referred to in regulation 27 and related provisions of MARPOL Annex
VI.
2.3 For the purpose of these Guidelines, the definitions in MARPOL Annex
VI, as amended, apply.
2.4 The metrics indicating the average CO2 emissions per transport work of
a ship are generally referred to as operational carbon intensity indicator (CII) in
these Guidelines.
-
.1 A specific CII calculated based on the actual or estimated mass or volume
of the shipment carried on board a ship is generally referred to as
demand-based CII; and
-
.2 A specific CII, in which calculation the capacity of a ship is taken as
proxy of the actual mass or volume of the shipment carried on board, is
generally referred to as supply-based CII.
2.5 The supply-based CII which uses DWT as the capacity is referred to as AER,
and the supply-based CII which uses GT as the capacity is referred to as
cgDIST.
3 Application
3.1 For all ships to which regulation
28 of MARPOL Annex
VI applies, the operational carbon intensity indicators defined in
section 4 should be applied.
3.2 The operational carbon intensity indicators defined in section 5 are encouraged
to be additionally used by ships, where applicable, for trial purposes.
4 Operational carbon intensity indicator (CII) of individual ships for
use in implementing regulation 28 of MARPOL Annex VI
In its most simple form, the attained annual operational CII of individual ships is
calculated as the ratio of the total mass of CO2 (M) emitted to
the total transport work (W) undertaken in a given calendar year, as
follows:
- attained CIIship = M / W (1)
4.1 Mass of CO2 emissions (M)
The total mass of CO2 is the sum of CO2 emissions (in grams)
from all the fuel oil consumed on board a ship in a given calendar year, as
follows:
where:
-
j is the fuel oil type;
-
FCj is the total mass (in grams) of consumed fuel oil of
type j in the calendar year, as reported under IMO DCS; and
-
CFj represents the fuel oil mass to
CO2 mass conversion factor for fuel oil type j , in
line with those specified in the 2018 Guidelines on the method of
calculation of the attained Energy Efficiency Design Index (EEDI) for
new ships (resolution MEPC.308(73)), as may be further
amended. In case the type of the fuel oil is not covered by the guidelines,
the conversion factor should be obtained from the fuel oil supplier
supported by documentary evidence.
4.2 Transport work (W)
In the absence of the data on actual transport work, the supply-based
transport work (Ws) can be taken as a proxy, which is defined as
the product of a shipʹs capacity and the distance travelled in a given calendar
year, as follows:
where:
-
C represents the shipʹs capacity:
-
- For bulk carriers, tankers, container ships, gas
carriers, LNG carriers, general cargo ships, refrigerated cargo
carrier and combination carriers, deadweight tonnage (DWT)footnote should be used as
Capacity;
-
- For cruise passenger ships, ro-ro cargo ships (vehicle
carriers), ro-ro cargo ships and ro-ro passenger ships, gross
tonnage (GT)footnote should be used as
Capacity; and
-
Dt represents the total distance travelled (in nautical
miles), as reported under IMO DCS.
5 Operational carbon intensity indicator (CII) of individual ships for trial
purpose
The following metrics are encouraged to be used for trial purposes, where applicable:
-
.1 Energy Efficiency Performance Indicator (EEPI)
-
.2 cbDIST
-
.3 clDIST
-
.4 EEOI, as defined in MEPC.1/Circ.684 on Guidelines for voluntary use
of the ship energy efficiency operational indicator (EEOI).
In the formulas above:
-
the mass of CO2 (M), the shipʹs capacity (C) and the
total distance travelled (Dt) are identical with
those used to calculate the attained CII of individual ships, as specified
in section 4.1 and 4.2;
-
Dl means the laden distance travelled (in nautical
miles) when the ship is loaded;
-
ALB means the number of available lower berths of a cruise passenger
ship; and
-
Lanemeter means the length (in metres) of the lanes of a ro-ro ship.