Ingangsdatum: 01-01-2013
Annex - Guidelines for calculation of reference lines for
use with the Energy Efficiency Design Index (EEDI)
1 The reference lines are established for each ship
type to which regulation 21 (Required EEDI) of MARPOL Annex VI is
applicable. The purpose of the EEDI is to provide a fair basis for
comparison, to stimulate the development of more efficient ships in
general and to establish the minimum efficiency of new ships
depending on ship type and size. Hence, the reference lines for each
ship type is calculated in a transparent and robust manner.
2 Ship types are defined in regulation 2 of MARPOL
Annex VI. The reference line for each ship type is used for the
determination of the required EEDI as defined in regulation 21 of
MARPOL Annex VI.
3 These guidelines apply to the following ships
types: bulk carrier, gas carrier, tanker, containership, general
cargo ship, refrigerated cargo carrier and combination carrier. It
is noted that a method of calculating reference lines has not been
established for ro-ro cargo ships, ro-ro cargo ships (vehicle),
ro-ro-passenger ships and passenger ships, as well as for ships with
diesel-electric propulsion, turbine propulsion and hybrid
propulsion.
Definition of a reference line
4 A
reference line is defined as a curve representing an average index
value fitted on a set of individual index values for a defined group
of ships.
5 One reference line is developed for each ship type
to which regulation 21 of MARPOL Annex VI is applicable, ensuring
that only data from comparable ships are included in the calculation
of each reference line.
6 The reference line value is formulated as
Reference line value = a (100% deadweight)-c
where "a" and "c" are parameters determined from the
regression curve fit.
7 Input data for the calculation of the reference
lines is filtered through a process where data deviating more than
two standard deviations from the regression line are discarded. The
regression is then applied again to generate a corrected reference
line. For the purpose of documentation, discarded data is listed
with the ships IMO number.
Data sources
8 IHS Fairplay (IHSF)
database is selected as the standard database delivering the primary
input data for the reference line calculation. For the purpose of
the EEDI reference line calculations, a defined version of the
database is archived as agreed between the Secretariat and IHSF.
9 For the purpose of calculating the reference
lines, data relating to existing ships of 400 GT and above from the
IHSF database delivered in the period from 1 January 1999 to 1
January 2009 are used.
10 The following data from the IHSF database on
ships with conventional propulsion systems is used when calculating
the reference lines:
- data on the ships' capacity is used as Capacity for each ship
type as defined in MEPC.XXX(63);
- data on the ships' service speed is used as reference speed
Vref; and
- data on the ships' total installed main power is used as
MCRME(i).
11 For some ships, some data entries may be blank or
contain a zero (0) in the database. Datasets with blank power,
capacity and/or speed data should be removed from the reference line
calculations. For the purpose of later references, the omitted ships
should be listed with their IMO number.
12 To ensure a uniform interpretation, the
association of ship types defined in regulation 2 of MARPOL Annex
VI, with the ship types given by the IHSF database and defined by
the so-called Stat codes, is shown in the appendix to this
guideline. Table 1 in the appendix lists the ship types from IHSF
used for the calculation of reference lines. Table 2 lists the IHSF
ship types not used when calculating the reference lines.
Calculation of reference lines
13
To calculate the reference line, an estimated index value for each
ship contained in the set of ships per ship type is calculated using
the following assumptions:
- the carbon emission factor is constant for all engines, i.e.
CF,ME = CF,AE = CF =
3.1144 g CO2/g fuel;
- the specific fuel consumption for all ship types is constant for
all main engines, i.e. SFCME = 190 g/kWh;
- PME(i) is 75% of the total installed main
power (MCRME(i));
- the specific fuel consumption for all ship types is constant for
all auxiliary engines, i.e. SFCAE = 215
g/kWh;
- PAE is the auxiliary power and is calculated
according to paragraphs 2.5.6.1 and 2.5.6.2 of the annex to
MEPC.XXX(63);
- no correction factors are used; and
- innovative mechanical energy efficiency technology, shaft motors
and other innovative energy efficient technologies are all
excluded from the reference line calculation, i.e.
PAEeff = 0, PPTI
= 0, Peff = 0.
14 The equation for calculating the estimated index
value for each ship (excluding containerships – see paragraph 15) is
as follows:
15 For containerships, 70 per cent of the deadweight
(70% DWT) is used as capacity for calculating the estimated index
value for each containership as follows:
Calculation of reference line parameters "a" and "c"
16 For all ship types to which these
guidelines apply, parameters "a" and "c" are determined from a
regression analysis undertaken by plotting the calculated estimated
index values against 100 per cent deadweight (100% DWT).
Documentation
17 For purposes of
transparency, the ships used in the calculation of the reference
lines should be listed with their IMO numbers and the numerator and
denominator of the index formula, as given in paragraphs 14 and 15.
The documentation of the aggregated figures preserves the individual
data from direct access but offers sufficient information for
possible later scrutiny.