IMSML Website Article 30/2024: Resolution MEPC.364(79) - Adoption of 2022 Guidelines on the Method of Calculation of the Attained Energy Energy Efficinecy Design Index (EEDI) for New Ships
Resolution MEPC.364(79) applies an Annex 9 titled 2022 Guidelines on the Method of Calculation of the Attained Energy Efficiency Design Index (EEDI) for New Ships. It is applicable in Malaysia via Malaysian Shipping Notice (MSN 08/2023), Appendix I, issued on 31 March 2023.
The new 2022 Guidelines for Calculation of EEDI supersede the previous 2018 Guidelines on the Method of Calculation of the Attained Energy Efficiency Design Index (EEDI) for new ships which were previous adopted via Resolution MEPC.308(73) and amended accordingly by Resolutions MEPC.322(74) as well as MEPC.332(76) respectively.
The Energy Efficiency Design Index (EEDI) is an International Maritime Organisation (IMO) feature that has its roots in Regulation 22 of MARPOL Annex VI as the 'Attained Energy Efficiency Design Index (Attained EEDI)' which was calculated with the aid of guidelines developed by IMO.
References to MARPOL in the EEDI system mean the International Convention for the Prevention of Pollution from Ships, 1973 (as modified by the Protocols of 1978 and 1997 relating thereto), see Paragraph 2.1 of Annex 9. For the purpose of the 'Guidelines', the definitions in Chapter 4 of MARPOL Annex VI (as amended) apply, see Paragraph 1.2 of Annex 9.
The Complex EEDI Formula
The first thing one will notice about the EEDI formula is that it is fairly complex, with various parameters and variables to consider. The complex formula is found in Paragraph 2.1 of Annex 9.
Even though the author loves science and technology, the author does not have the necessary mathematics and/or engineering degree to give a detailed explanation of what the above formula is all about. Instead, what the author endeavours to do is provide an understanding of the parameters that go into the calculation of the EEDI formula.
CF - Conversion Factor Between Fuel Consumption and CO2 Emission
Paragraph 2.2.1 provides that this conversion factor is non-dimensional conversion factor between fuel consumption (measured in grams) and CO2 emission (also measured in grams) based on carbon content. The figure refers to both main and auxiliary engines. The carbon content has different lower calorific value (measured in kJ/kg) depending on the type of fuel, for example such as diesel / gas oil, light fuel oil (LFO), heavy fuel oil (HFO), liquefied petroleum gas (LPG), ethane, liquefied natural gas (LNG), methanol and ethanol.
If the ship is equipped with a dual-fuel main or auxiliary engine, the reference factors for 'gas fuel' and 'fuel oil' should apply. This has to be multiplied with the specific fuel oil consumption of each fuel at the relevant EEDI load point. Further, it has to be identified whether gas fuel should be regarded as the 'primary fuel'. The total gas fuel capacity on board will be expressed in m3.
Where specialised arrangements such as LNG tank-containers and/or arrangements allowing frequent gas refuelling are used, the capacity of the whole LNG fueling system should be used. This takes into account the boil-off rate (BOR) of gas cargo tanks, if it is connected to the fuel supply system (FGSS).
The total net liquid fuel capacity is measured in m3 for liquid fuel tanks permanently connected to the ship's fuel system. A fuel tank can be ignored for one fuel tank is disconnected by permanent sealing of valves.
Vref - Ship Speed
According to Paragraph 2.2.2, this is measured in nautical miles per hour (knot), on deep water in the condition corresponding to the capacity.
Note, this is differs depending on the capacity of ship type:
[1] Bulk carriers, tankers, gas carried, LNG carriers, ro-ro cargo ships (vehicle carriers), ro-ro cargo ships, ro-ro passenger ships, general cargo ships, refrigerated cargo carrier and combination carriers, see Paragraph 2.2.3.1. For this category, 'deadweight' should be used as 'capacity'.
[2] For containerships, 70 percent of the deadweight (DWT) should be used as capacity, see Paragraph 2.2.3.3
For passenger ships and cruise ships, the measured condition should be the summer load draught, see Paragraph 2.2.2
Note:
[1] This is the maximum summer draught as certified n the stability booklet provided by IMO or an organisation recognised by it, see Paragraph 2.2.4.
[2] In general, deadweight is the difference in tonnes between the displacement of a ship in water of relative density of 1,025 kg/m3 at the summer load draught and the lightweight of the shipowner, see Paragraph 2.2.4.
[3] According to Pagraph 2.2.3.2, for passenger ships and cruise ships, capacity is gross tonnage is in accordance with the International Convention of Tonnage Measurement of Ships 1969, Annex 1, Regulation 3.
P - Power of Main and Auxiliary Engines
This is the power of both the main and auxiliary engines, measured in kW (taking into account the number of engines), see Paragraph 2.2.2. The figures takes into account:
[1] Power of the main engine, P(ME)(i), is 75 percent of the rated installed power (MCR1) for each main engine (i). In particular for LNG carriers, the following factors are relevant:
[a] The rated output of the motor specified in the certified document;
[b] The product of electrical efficiency generator, transformer, converter and motor. This has to take into consideration the weighted average as necessary;
[c] Electrical efficiency is taken at 91.3 percent, but above this value, it should be verified by measurement of an approved verifier;
[d] The rated installed power to LNG carriers having steam turbine propulsion systems is 83 percent for each turbine system;
[2] Shaft generators, if installed, are 75 percent of the rated electrical power output of each.
[3] Shaft motors, where installed, are 75 percent of the rated power consumption of each shaft, divided by the weighted average efficiency of the generator(s), see Paragraph 2.2.5.2. This takes into account:
[a] The rated power consumption of each shaft motor; and
[b] The weighted average efficiency of the generator(s).
Note, where total propulsion power is higher than 75 percent of the power of the propulsion system, but is limited by verified technical means, then 75 percent of this limited power it to be used as the total propulsion power for determining reference speed for EEDI calculation, see Paragraph 2.2.5.3. Energy loss in the equipment (from switchboard to the shaft motor) could be reflected in the chain efficiency if there is a verified document to prove this.
[4] Innovative mechanical energy-efficient technology for main engine is rated at 75 percent of main engine power, see Paragraph 2.2.5.4. However, what need not be measured i the mechanical recovered waste energy directly coupled to shafts. If there is more than one engine, the power weighted average of all main engines should be taken.
[5] Innovative mechanical energy efficiency technology for auxiliary engine should take into account the auxiliary power reduction due to this technology, see Paragraph 2.2.5.5.
[6] Auxiliary engine power is the power required for normal maximum sea load including necessary power for propulsion machinery / systems and accommodation, see Paragraph 2.2.5.6. Examples of these systems include main engine pumps, navigational systems / equipment, and living on board. Not included in the calculations are power for the propulsion systems such as thrusters, cargo pumps / gear and cargo maintenance systems such as reefers and cargo hold fans.
[7] According to Paragraph 2.2.5.6.3, treatment of LNG carriers differ depending whether they are equipped with:
[a] A reliquefaction system / compressor;
[b] A direct diesel driven propulsion system or diesel electric propulsion system;
[c] A steam turbine propulsion system.
[8] There may be instances when auxiliary power value if significantly different from the total power used at normal seagoing, see Paragraph 2.2.5.7. The example given is in the case of passenger ships where the auxiliary power value should be the estimated by the consumed electric power (excluding propulsion). This value is in conditions when the ship is engaged in voyage reference speed stipulated in the electric power table. The value is then divided by the average efficiency of the generator(s) weighted by power.
[9] Capacity (Vref) and P values should be consistent with one another, see Paragraph 2.2.6.
SFC - Certified Specific Fuel Consumption
This is measured in g/kWh for both the engines or steam turbines, see Paragraph 2.2.7. Engines may be certified to the E2 or E3 test cycles of the MOX Technical Code 2008, see Paragraph 2.2.7.1. The engine specific fuel consumption is recorded in the test report included in a NOX Technical File. The engines are at 75 percent of MCR power's torque rating.
Gas mode should be used if gas fuel is used under the Guidelines on survey and certification of the EEDI, see Paragraph 4.2.3. This can benefit the submitted by the manufacturer and confirmed by the verifier where the installed engines have no approved NOX Technical file tested in gas mode, see Paragraph 2.2.7.1. The value should be corrected to the corresponding ISO Standard, see ISO 15550:2002 and ISO 3046 1:2022.
For steam turbines, factors that should be taken into account include fuel consumption of the boiler per hour (g/h), see Paragraph 2.2.7.2. It should be corrected to the value of LNG using the standard lower calorific value of LNG (48,000 kJ/kg).
F(j) - Ship Specific Design Elements
This is a correction factor which takes into account specific ship design elements, see Paragraph 2.2.8, such as power correction factor for the following:
[1] Ice-classed ships, see Paragraph 2.2.8.1;
[2] Shuttle tankers with propulsion redundancy, see Paragraph 2.2.8.2;
[3] Ro-Ro Cargo and Ro-Ro Passenger Ships, see Paragraph 2.2.8.3;
[4] General Cargo Ship, see Paragraph 2.2.8.4;
[5] Other Ship Types, see Paragraph 2.2.8.5.
F(w) - Factor for Speed Reduction at Sea
This indicates the decrease of speed in a representative sea conditions of wave height, wave frequency and wind speed (ie in accordance with the Beaufort Scale. It is a non-dimensional coefficient, calculated in the following manner, see Paragraph 2.2.9:
[1] The value of Fw is 1.00, calculated in accordance with the attained EEDI under Regulation 22 and 24 of MARPOL Annex IV, see Paragraph 2.2.9.1;
[2] Ship specific simulation on its performance at representative sea conditions can be determined. This must be verified by IMO or a recognised organisation, see Paragraph 2.2.9.2.1;
[3] The figure can be expressed as a function of capacity such as deadweight, and is based on data of actual speed reduction of as many existing ships as possible under the representative sea condition, see Paragraph 2.2.9.2.2;
F(eff(i)) - Factor of Each Innovative Energy Efficiency Technology
This measures the availability factor for each innovative energy efficiency technology. The value for waste energy recovery system should the 'One' (1.0).
F(i) - Capacity Factor for Technical / Regulatory Limitation on Capacity
This figure should be assumed to be one (1.0), if no necessity of the factor is granted, see Paragraph 2.2.11. There are different corrections factor depending on vessel type, for example:
[1] Ice classed ships - where the capacity correction factor is for ice-strengthening of the ship, see Paragraph 2.2.11.1;
[2] Bulk carrier, tanker and general cargo ship - where the block coefficient of the ship is taken into account, see Paragraph 2.2.11.1.
[3] The capacity correction factor for ice-strengthening of the ship can be calculated by a formula for the ship-specific voluntary enhancement correction coefficient.
F (iVSE) - Ship Specific Voluntary Structural Enhancement
This is expressed in the form of displacement, that also takes into account enhanced design. DWT before enhancements is the deadweight measurement before the structural enhancements have been made. It takes into account the application of voluntary structural enhancement, see Paragraph 2.2.11.2. The following change of material should not be allowed:
[1] Change between reference design and enhanced design (eg from aluminium alloy to steel);
[2] A change in the grade of the same material, eg in steel type, grades, properties and condition.
Two sets of structural plans should be submitted to the verifier for assessment, see Paragraph 2.2.11.2:
[1] Set 1 - for the ship without voluntary structural enhancement;
[2] Set 2 - for the same ship, with voluntary structural enhancement;
[3] Alternative for Set 2 - One set of structural plans of the reference design with annotations of voluntary structural enhancements should be acceptable.
F(iCSR) - Ships Under the Common Structural Rules (CSR)1
Common Structural Rules (CSR) of classification societies are used for building of bulk carrier and oil tankers. This should be used with the appropriate correction factor that takes into account both deadweight and light weight of the ship, see Paragraph 2.2.11.3. F(i) should be taken as one (1.0) for other ship types, see Paragraph 2.2.11.4.
F(c) - Cubic Correction Factor
This should also assumed to be one (1.0) if no necessity of factor is granted, see Paragraph 2.2.12. For chemical tankers, a capacity correction factor is applicable, which takes into account the capacity ratio of the deadweight of the ship (in tonnes) as divided by the total cubic capacity of the cargo tanks of the ship (in m3), see Paragraph 2.2.12.1.
For gas carriers that use direct diesel driven propulsion system for carriage of liquefied natural gas in bulk, uses the capacity ratio of deadweight of the ship (in tonnes) divided by the total cubic capacity of the cargo tanks of the ship (in m3), see Paragraph 2.2.12.2. Note that this capacity ratio is also applicable to LNG Carriers that are defined as ‘gas carriers’, see Regulation 2.2.14 of MARPOL Annex VI.
For Ro-Ro Passenger Ships, the DWT is the Capacity. Gross tonnage is in accordance with the International Convention of Tonnage Measurement of Ships 1969, Annex 1, Regulation 3.
Bulk Carriers Having 'R' Value of Less than 0.55
An example of this type of vessel are woodchip carriers. The F(c) in this context is for bulk carriers designed to carry light cargoes, where the R (Capacity Ratio) value is -0.15, see Paragraph 2.2.12.4. Note that R is the deadweight of the shipowner (in tonnes) divided by the total cubic capacity of the cargo holds of the ship (in m3).
L(pp) - Length Between Perpendiculars
This means 96 percent of the total length on a waterline at 85 percent of the following under Paragraph 2.2.13:
[1] The least moulded depth measured from the top of the keel; OR ...
[2] The length from the foreside of the stem to the axis of the rudder stock on that waterline (if that were greater).
Note that for ships designed with a rake of keel to the length on which this length is measured should be parallel to the designed waterline, see Paragraph 2.2.13. The measurement should be in metres.
F(l) - Factor for General Cargo Ships Equipped with Cranes and Cargo-Related Gear
The factor for ships that are fitted with such gear compensate for a loss in the deadweight of the ship, see Paragraph 2.2.14. The factors which are taken into account are whether the following equipment are present on the ship:
[1] Cranes;
[2] Side loaders;
[3] Ro-ro ramp.
The capacity of the cranes take into account, see Paragraph 2.2.14:
[1] SWL - Safe working load (as specified by the crane manufacturer in metric tonnes);
[2] Reach - Reach at which the safe working Load can be applied in metres;
[3] N - Number of cranes.
Note, for cargo gear such as side loaders and ro-ro ramps, the weight should be based on a direct calculation (by analogy to the F(ivse) factor), see Paragraph 2.2.14.
d(s) - Summer Load Line Draught
This is the vertical distance (in metres) from the moulded baseline at mid-length to the waterline. It corresponds to the summer freeboard draught to be assigned to the ship, see Paragraph 2.2.15.
The maximum summer draught should be used to calculate and the required the required / attained EEDI, taking into account (see Paragraph 2.2.15):
[1] Multiple load line certificates (for a new ship); OR ...
[2] A load line certificate containing multiple summer load lines
Note, all previous multiple EEDI assessments for several deadweights that correspond to multiple loads lines, should remain valid, see Paragraph 2.2.15.
B(s) - Breadth
This refers to the greatest moulded breadth of the ship (measured in metres) at or below the load line (ie d(s) ) draught, see Paragraph 2.2.16.
V - Volumetric Displacement
Usually measured in cubic metres (m3), this is the volume of moulded displacement of the ship, excluding appendages. This applies to ships with a metal shell and is the volume of displacement to the outer surface of the hull in a ship, with a shell of any other material. Both are taken at summer load line draught ( d(s) ) as stipulated in the approved stability booklet/loading manual, see Paragraph 2.2.17.
g - Gravitational Acceleration
The value of gravitational acceleration used in the calculation is 9.81 m/s2, see Pargraph 2.2.18.
f(m) - Factor for Ice-Classed Ships Having IA Super and IA
The value for this class of ships in 1.05, see Paragraph 2.2.1.9.
Note:
[1] For approximate correspondence between ice classes, see HELCOM Recommendation 25/7 at http://www.helcom.fi
[2] HELCOM is the Helsinki Commission. It is also known as the Baltic Marine Environment Protection Commission.
[3] HELCOM is an intergovernmental organisation and regional sea convention in the Baltic Sea area. It provides a platform for formulation of environmental policy established in 1974.
[4] HELCOM is governed by the Convention on the Protection of the Marine Environment of the Baltic Sea Area, 1974, which entered into force on 3 May 1980.
[5] All the information in Notes [1]-[4] above are available at http://www.helcom.fi
Paragraph 3 - Mandatory Reporting of Attained EEDI Values and Related Information
Paragraph 3.2 has 14 particular information details to be reported. These range from applicable EEDI phase (see Paragraph 3.2.1) to common commercial size reference (see Paragraph 3.2.4), to required and attained EEDI value (see Paragraph 3.2.7 and 3.2.8), as well as usage of innovative technologies (see Paragraph 3.2.11) to types of fuel used in the calculation (see Paragraph 3.2.13).
The reporting of details in Paragraph 3.2 is not necessary where the required and attained EEDI values have already been reported to IMO, see Paragraph 3.3.
The reporting of attained EEDI values and related information shall follow the mandatory format in Appendix 5, see Paragraph 3.4.
Appendix 1 to Annex 9
This appendix provides a flow diagram of a generic and simplified marine power plant, see p 22.
Appendix 2 to Annex 9
This appendix contains 'Guidelines for the Development of Electronic Power Tables for EEDI (EPT-EEDI)', see p 23. The guidelines range from the definitions of auxiliary load power (see Paragraph 2) and data to be included in the electric power table for EEDI (see Paragraph 3), to the data to be included in the electric power table for EEDI (see Paragraph 4), encompassing details such as:
[1] Load groups, see Paragraph 4.1;
[2] Loads description, see Paragraph 4.2;
[3] Loads identification tag, see Paragraph 4.3;
[4] Loads electric circuit identification, see Paragraph 4.4;
[5] Loads mechanical rated power - P(m), see Paragraph 4.5;
[6] Loads electric motor rated output power - kW, see Paragraph 4.6;
[7] Loads electric motor efficiency - 'e' (/), see Paragraph 4.7;
[8] Loads rated electric power - 'Pr' (kW), see Paragraph 4.8;
[9] Service factor of load - 'kl' (/), see Paragraph 4.9;
[10] Service factor of duty - 'kd' (/), see Paragraph 4.10;
[11] Service factor of time - 'kt' (/), see Paragraph 4.11;
[12] Service total factor of use - 'ku' (/), see Paragraph 4.12;
[13] Loads necessary power - 'Pload' (kW), see Paragraph 4.13;
[14] Groups necessary power (kW), see Paragraph 4.15;
[15] Auxiliaries load's power PAE (kW), see Paragraph 4.16;
[16] Layout and organisation of the data indicated in the electric power table for EEDI, see Paragraph 5;
Appendix 3 of Annex 9
The appendix contains a flow chart of 'Generic and Simplified Marine Power Plant for Cruise Passenger Ships Having Non-Conventional Propulsion", see p 30.
Appendix 4 of Annex 9
This appendix provides for the 'EEDI Calculation Examples for Use of Dual-Fuel Engines', see p 31.
Appendix 5 of Annex 9
This contains the 'Standard Format to Submit EEDI Information To Be Included In The EEDI Database', see p 37.
Thank you for reading IMSML Website Article 30/2024
Stay tuned for the next IMSML Website Article 31/2024: Resolution MEPC.365(79) - Adoption of 2022 Guidelines on Survey and Certification of the Energy Efficiency Design Index (EEDI)
Signing-off for today,
Dr Irwin Ooi Ui Joo, LL.B(Hons.)(Glamorgan); LL.M (Cardiff); Ph.D (Cardiff); CMILT
Professor of Maritime and Transport Law
Head of the Centre for Advocacy and Dispute Resolution
Faculty of Law
Universiti Teknologi MARA Shah Alam
Selangor, Malaysia
Tuesday, 28 May 2024
Note that I am the corresponding author for the IMSML Website Articles. My official email address is: uijoo310@uitm.edu.my