The attained new ship Energy Efficiency Design Index (EEDI) is a measure of ships CO2efficiency and calculated by the following formula:
CF is a non-dimensional conversion factor between fuel consumption measured in g and CO2emission also measured in g based on carbon content. The subscripts MEi and AEi refer to the main and auxiliary engine(s) respectively. CF corresponds to the fuel used when determining SFC listed in the applicable EIAPP Certificate. The value of CF is as follows:
|Type of fuel||Reference||Carbon content|
|1.||Diesel/Gas Oil||ISO 8217 Grades DMX through DMC|
|2.||Light Fuel Oil (LFO)||ISO 8217 Grades RMA through RMD|
|3.||Heavy Fuel Oil (HFO)||ISO 8217 Grades RME through RMK|
|5.1||Liquified Natural Gas|
Vref is the ship speed, measured in nautical miles per hour (knot), on deep water in the maximum design load condition (Capacity ) as defined in paragraph 3 at the shaft power of the engine(s) as defined in paragraph 5 and assuming the weather is calm with no wind and no waves. The maximum design load condition shall be defined by the deepest draught with its associated trim, at which the ship is allowed to operate. This condition is obtained from the stability booklet approved by the Administration.
Capacity is defined as follows:
For dry cargo carriers, tankers, gas tankers, containerships, ro-ro cargo and general cargo ships, deadweight should be used as Capacity .
For passenger ships and ro-ro passenger ships, gross tonnage in accordance with the International Convention of Tonnage Measurement of Ships 1969, Annex I, regulation 3 should be used as Capacity .
For containerships, the capacity parameter should be established at 65% of the deadweight.
Deadweight means the difference in tonnes between the displacement of a ship in water of relative density of 1,025 kg/m3 at the deepest operational draught and the lightweight of the ship.
P is the power of the main and auxiliary engines, measured in kW. The subscripts ME and AE refer to the main and auxiliary engine(s), respectively. The summation on i is for all engines with the number of engines (nME ). (See the diagram in the Appendix.)
PME(i) is 75% of the rated installed power (MCR) for each main engine (i ) after having deducted any installed shaft generator(s):
PME(i) = 0.75× (MCRMEi- PPTOi)
The following figure gives guidance for determination of PME(i):
PPTO(i)is 75% output of each shaft generator installed divided by the relevant efficiency of that shaft generator.
PPTI(i)is 75% of the rated power consumption of each shaft motor divided by the weighted averaged efficiency of the generator(s).
In case of combined PTI/PTO, the normal operational mode at sea will determine which of these to be used in the calculation.
Note: The shaft motor’s chain efficiency may be taken into consideration to account for the energy losses in the equipment from the switchboard to the shaft motor, if the chain efficiency of the shaft motor is given in a verified document.
Peff(i)is 75% of the main engine power reduction due to innovative mechanical energy efficient technology.
Mechanical recovered waste energy directly coupled to shafts need not be measured.
PAEeff (i)is the auxiliary power reduction due to innovative electrical energy efficient technology measured at PME(i).
PAEis the required auxiliary engine power to supply normal maximum sea load including necessary power for propulsion machinery/systems and accommodation, e.g., main engine pumps, navigational systems and equipment and living on board, but excluding the power not for propulsion machinery/systems, e.g., thrusters, cargo pumps, cargo gear, ballast pumps, maintaining cargo, e.g., reefers and cargo hold fans, in the condition where the ship engaged in voyage at the speed (Vref ) under the design loading condition of Capacity.
For cargo ships with a main engine power of 10000 kW or above, PAE is defined as:
For cargo ships with a main engine power below 10000 kW, PAEis defined as:
For ship types where the PAEvalue calculated by .1 or .2 above is significantly different from the total power used at normal seagoing, e.g., in cases of passenger ships, the PAE value should be estimated by the consumed electric power (excluding propulsion) in conditions when the ship is engaged in a voyage at reference speed (Vref) as given in the electric power table*, divided by the weighted average efficiency of the generator(s).
Vref, Capacity and P should be consistent with each other.
SFC is the certified specific fuel consumption, measured in g/kWh, of the engines. The subscripts ME(i) and AE(i) refer to the main and auxiliary engine(s), respectively. For engines certified to the E2 or E3 duty cycles of the NOxTechnical Code 2008, the engine Specific Fuel Consumption (SFCME(i)) is that recorded on the EIAPP Certificate(s) at the engine(s) 75% of MCR power or torque rating. For engines certified to the D2 or C1 duty cycles of the NOxTechnical Code 2008, the engine Specific Fuel Consumption (SFCAE(i)) is that recorded on the EIAPP Certificate(s) at the engine(s) 50% of MCR power or torque rating.
For ships where the PAE value calculated by 220.127.116.11 and 18.104.22.168 is significantly different from the total power used at normal seagoing, e.g., conventional passenger ships, the Specific Fuel Consumption (SFCAE ) of the auxiliary generators is that recorded in the EIAPP Certificate(s) for the engine(s) at 75% of PAEMCR power of its torque rating.
SFCAE is the weighted average among SFC AE(i) of the respective engines i .
For those engines which do not have an EIAPP Certificate because its power is below 130 kW, the SFC specified by the manufacturer and endorsed by a competent authority should be used.
fj is a correction factor to account for ship specific design elements.
The fjfor ice-classed ships is determined by the standard fj in Table 1.
Correction factor for power fj for ice-classed ships
For further information on approximate correspondence between ice classes,
see HELCOM Recommendation 25/7**
For other ship types, fj should be taken as 1.0.
fwis a non-dimensional coefficient indicating the decrease of speed in representative sea conditions of wave height, wave frequency and wind speed (e.g., Beaufort Scale 6), and should be determined as follows:
It can be determined by conducting the ship-specific simulation of its performance at representative sea conditions. The simulation methodology should be prescribed in the Guidelines developed by the Organization and the method and outcome for an individual ship shall be verified by the Administration or an organization recognized by the Administration.
In case that the simulation is not conducted, fw value should be taken from the “Standard fw ” table/curve. A “Standard fw ” table/curve, which is to be contained in the Guidelines, is given by ship type (the same ship as the “baseline” below), and expressed in a function of the parameter of Capacity (e.g., DWT). The “Standard fw ” table/curve is to be determined by conservative approach, i.e. based on data of actual speed reduction of as many existing ships as possible under representative sea conditions.
fw should be taken as one (1.0) until the Guidelines for the ship-specific simulation (paragraph .9.1) or fw table/curve (paragraph .9.2) becomes available.
feff(i)is the availability factor of each innovative energy efficiency technology. feff(i) for waste energy recovery system should be one (1.0).
fiis the capacity factor for any technical/regulatory limitation on capacity, and can be assumed one (1.0) if no necessity of the factor is granted.
fi for ice-classed ships is determined by the standard fi in Table 2.
Capacity correction factor fi for ice-classed ships
For further information on approximate correspondence between ice classes,
see HELCOM Recommendation 25/7*
For other ship types, fi should be taken as 1.0.
Length between perpendiculars , Lpp means 96 per cent of the total length on a waterline at 85 per cent of the least moulded depth measured from the top of the keel, or the length from the foreside of the stem to the axis of the rudder stock on that waterline, if that were greater. In ships designed with a rake of keel the waterline on which this length is measured shall be parallel to the designed waterline. The length between perpendiculars (Lpp) shall be measured in metres.