Q:-With respect to energy efficiency design index explain in details the following:
Transport work is calculated by multiplying the ships capacity as designed with ships design speed measured at max design load condition.
- Attained energy efficiency design index
- Required energy efficiency design index
ANSWER :-
Amendments to MARPOL Annex VI were adopted during MEPC 62 in July 2011 (resolution MEPC. 203(62)), adding a new chapter 4 to Annex VI on Regulations on energy efficiency for ships to make mandatory the EEDI for new ships, and the SEEMP for all ships. The regulations apply to all ships of 400 gross tonnage and above and are expected to enter into force on 1 January 2013.
EEDI is a number accounting for the amount of CO2 generated per tonne-mile of cargo carried. A higher EEDI indicates a less energy efficient ship (by design)
Purpose of the EEDI
The Energy Efficiency Design Index for new ships creates a strong incentive for further improvements in ships’ fuel consumption. The purpose of IMO’s EEDI is:
- to require a minimum energy efficiency level for new ships;
- to stimulate continued technical development of all the components influencing the fuel efficiency of a ship;
- to separate the technical and design based measures from the operational and commercial measures (they will/may be addressed in other instruments); and
- to enable a comparison of the energy efficiency of individual ships to similar ships of the same size which could have undertaken the same transport work (move the same cargo).
A) Regulation 20:-Attained Energy Efficiency Design Index (Attained EEDI)
‘The actual EEDI of a vessel is called the attained EEDI and its calculated based on guideline published by IMO.’
The attained EEDI shall be calculated for:
- each new ship;
- each new ship which has undergone a major conversion; and
- each new or existing ship which has undergone a major conversion, that is so extensive that the ship is regarded by the Administration as a newly constructed ship.
- The attained EEDI shall be specific to each ship and shall indicate the estimated performance of the ship in terms of energy efficiency,
- The EEDI technical file that contains the information necessary for the calculation of the attained EEDI and that shows the process of calculation.
- The attained EEDI shall be verified, based on the EEDI technical file, either by the Administration or by any organisation duly authorised by it.
- The attained EEDI shall be calculated taking into account guidelines developed by the (IMO)Organisation RESOLUTION MEPC.212(63).
- The attained ship Energy Efficiency Design Index (EEDI) is a measure of ships energy efficiency (g/t*nm).
- The EEDI provides a specific figure for an individual ship design expressed in grams of CO2 per ship’s capacity mile and a smaller EEDI value indicate a more Energy efficient ship.
- Attained EEDI <= Required EEDI
The EEDI is calculated using the following simplified formula:
CO2 Emission
EEDI = -------------------------------
Transport Work
EEDI is a ship's carbon dioxide output divided by its cargo-carrying capacity.
Power · Specific Consumption · Carbon Conversion
EEDI = --------------------------------------------------------------------------
Capacity · Speed
The CO2 emission represents total CO2 emission from combustion of fuel at design stage , including propulsion and auxiliary engine taking into account the carbon content of the fuel in question. If some innovative energy efficient technology or non conventional source of energy is used on board the energy saved by this means will be deducted from the total CO2 emission based on actual efficiency of system.
Transport work is calculated by multiplying the ships capacity as designed with ships design speed measured at max design load condition.
In the equation above, the EEDI is a value calculated taking design values as parameters, and it expresses the CO2 emission reduction potential. EEDI is required to satisfy the IMO standard value for new ships to be built and is being introduced in phases as regulatory measures.
These ships will be required to have an International Energy Efficiency Certificate (IEEC).
Verification of the EEDI
Regulation 20 of the regulatory text requires the attained EEDI for a new ship to be verified. Guidelines on verification of the EEDI are to assist verifiers (ship surveyors) of the EEDI in conducting the verification in a uniform manner. The guidelines will also assist shipowners, shipbuilders as well as engine and equipment manufacturers, and other interested parties, in understanding the procedures of EEDI verification.
EEDI verification should be conducted on two stages:
- preliminary verification at the design stage,
- final verification at the sea trial, before issuance of the final report on the verification of the attained EEDI.
b.Required EEDI :-MARPOL Annex VI Chapter 4 Regulation 21
- The EEDI establishes a minimum energy efficiency requirement for new ships depending on ship type and size and is a robust mechanism to increase the energy efficiency of ships stepwise for many decades to come. The EEDI is a non-prescriptive, performance based mechanism that leaves the choice of technologies to use in a specific ship design to the industry. As long as the required energy efficiency level is attained, ship designers and builders would be free to use the most cost-efficient solutions for the ship to comply with the regulations. The reduction level in the first phase is set to 10% and will be tightened every five years to keep pace with technological developments of new efficiency and reduction measures. IMO has set reduction rates up to 2025 from when a 30% reduction is mandated for most ship types calculated from a reference line representing the average efficiency for ships built between 1999 and 2009.
- Required Energy Efficiency Design Index is the maximum value of attained EEDI that is allowed by MARPOL Annex 6 Chapter 4 Regulation 21 for the specific ship type and size.
The Required EEDI shall be applied for ship which falls into one of the categories defined in MARPOL Annex 6 Regulation 2.25 to 2.31 and to which MARPOL Annex 6 Chapter 4 is applicable.For each:
- new ship;
- new ship which has undergone a major conversion; and
- new or existing ship which has undergone a major conversion that is so extensive that the ship is regarded by the Administration as a newly constructed ship
- A ship’s attained EEDI must be equal to or less than the required EEDI for that ship type and size, which will be a function of the reference line value and a reduction factor X i.e
Attained EEDI ≦ Required EEDI
Required EEDI= (1-X/100) × Reference line value ,where X is the reduction factor.
- Reference lines have been developed by the IMO for a number of ship types. The EEDI reference lines refer to statistically average EEDI curves derived from data for existing ships. The reference lines are ship specific and dependent on ship type and size.
- The reference line value is formulated as
-c
Reference line value = a (100% deadweight)
-c
i.e. Reference line value = a × b
where "a" and "c" are parameters given in Table 2 of Marpol Annex VI , Chapter 20 determined from the regression curve fit and b is the deadweight.
Eg.
Capacity Depending on the ship type, different units for capacity are used:
- For bulk carriers, tankers, gas carriers, container ships, general cargo ships, refrigerated cargo ships, combination carriers, LNG carriers and all types of Ro-Ro ships deadweight (DWT) is used.
- For container ships the capacity is 70 % of DWT.
- For cruise passenger ships GT is used as capacity.
The EEDI phases are
- Phase 0 ( 1 Jan 2013 – 31 Dec 2014 ) – 0 %
- Phase 1 ( 1 Jan 2015 – 31 Dec 2019 ) – 10 %
- Phase 2 ( 1 Jan 2020 – 31 Dec 2024 ) – 20 % and -15%
- Phase 3 ( 1 Jan 2025 and onwards ) -30 %
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