INTERTANKO Safety, Technical & Environmental Committee

19 – 20 January 2009

Christian BREINHOLTDirector

Danish Maritime Authority

Attained and Required Energy Efficiency

Design Index

• Proposed by Denmark

• Further developed by IMO

• Additional proposals by Denmark

Attained and Required Energy Efficiency

Design Index

• Require a minimum energy efficiency of new ships• Stimulate technical development• Separate technical and design based measures from

operational and commercial measures• Compare the energy efficiency of an individual ship to

similar ships which could have taken its cargo

Objective

Attained Index

• Cost: Emission of CO2

• Benefit: Cargo capacity transported a certain distance

• Relates to a seagoing maximum condition

societyforBenefit

costtalEnvironmenindexdesign efficiencyenergy Attained

Attained Index

wrefi

F

fVCapacityf

P SFCCindexAttained

• CF: Conversion between fuel and CO2

• SFC: Specific fuel consumption

• P, Vref and Capacity: A consistent set of engine power required to

sail at a certain speed when the ship is carrying its capacity in calm

weather

• fw: Speed reduction in wind and waves

• fi: Correction for any regulatory limitation on capacity

wrefi

F

fVCapacityf

P SFCCindexAttained

• Conversion between fuel and CO2

• Non-dimensional

• g CO2 emitted when burning 1 g of fuel

• Refer to 2006 IPCC Guidelines (Intergovernmental Panel

on Climate Change)

CF

SFC

• Specific fuel oil consumption at engine power P• Measured in g/kWh

wrefi

F

fVCapacityf

P SFCCindexAttained

wrefi

F

fVCapacityf

P SFCCindexAttained

P

• Power of main and auxiliary engines

• Including:

– Propulsion related main and auxiliary power

– Auxiliary power for main engine and accommodation

• Excluding:

– Cargo related auxiliary power

• Measured in kW

wrefi

F

fVCapacityf

P SFCCindexAttained

Contributions from all engines

MEiFMEieff

neff

1ieffAEFAE

nWHR

1iWHRi

nPTI

1iTIiEAFAEAE

nME

1iiMEiMEiFME

F

SFCCPfSFCCPPSFCCPPSFCC

PSFCC

Main engines + Shaft motors - waste heat

Auxiliary engines - Innovative energy efficient technologiesin relation to main engine

P

• PMEi: 75 % MCR for each main engine

• PPTi: 75% rated power consumption of shaft motors divided by 0.9

• Denmark propose that P for diesel electric driven ships is PPTi

• PWHR: Rated electrical power generation at PMEi

• Peff: Main engine power reduction due to innovative energy efficient technology

• PAE: Required auxiliary engine power to supply Normal Maximum Sea Load when ship is under way

wrefi

F

fVCapacityf

P SFCCindexAttained

0

500

1000

1500

2000

2500

0 10000 20000 30000 40000

PME

PA

E (

kW)

PAE = 0,025*PME +250

PAE = 0,05*PME

250MCR0.025kW PnME

1iMEiAE

nME

1iMEiAE MCR0.05kW P

PAE

• For cargo ships with main engine power

of 10000 kW or above:

• For cargo ships with main engine power

below 10000 kW:

wrefi

F

fVCapacityf

P SFCCindexAttained

Shiptype

DWT (mt)Main engine MCR (kW)

Actual normal maximum sea load

(kW)Estimated by the

formula (kW)

Deviation from

actual value (%)

Influence on the overall index value

(%)

Chemical/Product Tanker 16500 6300 418 315 24.6 2.00

Chemical/Product Tanker 39000 9500 572 475 17.0 1.26

5000 PCTC 15500 13500 763 588 23.0 1.61

VLGC 58000 13500 762 588 22.9 1.60

Aframax Tanker 110000 15500 589 638 -8.2 -0.40

3500 TEU Container 41000 29000 1034 975 5.7 0.26

VLCC 308000 30000 892 1000 -12.1 -0.46

6200 TEU Container 57500 57000 1668 1675 -0.4 -0.02

6050 TEU Container 87500 63000 1701 1825 -7.3 -0.25

6600 TEU Container 116000 68000 1931 1950 -1.0 -0.04

9000 TEU Container 110000 68500 1829 1963 -7.3 -0.25

8100 TEU Container 107000 68500 1806 1963 -8.7 -0.29

0

500

1000

1500

2000

2500

6300

9500

1350

0

1350

0

1550

0

2900

0

3000

0

5700

0

6300

0

6800

0

6850

0

6850

0

Main engine MCR (kW)

No

rmal

max

imu

m s

ea lo

ad (

kW)

Actual

Estimate

Ship specific corrections

M

1jjff

• The product of corrections to the main engine power to account for ship specific design elements such as ice strengthening

wrefi

F

fVCapacityf

P SFCCindexAttained

wrefi

F

fVCapacityf

P SFCCindexAttained

• Capacity

• A measure of the benefit to society provided by the ship type

• Deepest operational draught and associated trim to which a ship is

allowed to be loaded

• *Ro-ro Pax proposed capacity – Tonnage (GT)

Ship type Capacity

Dry Bulk

Deadweight (DWT)

Tankers

Container ships

General cargo ships

Gas tankers

Ro-Ro cargo ships

* Ro-ro passenger ships

Passenger ships Tonnage (GT)

wrefi

F

fVCapacityf

P SFCCindexAttained

VRef

• Ship speed• Measured in knots• Result of specified engine power, capacity draft and trim

in deep water and calm weather – a consistent set of parameters

• Can be provided by the ship builder early in the design stage based on model tests or calculations

wrefi

F

fVCapacityf

P SFCCindexAttained

fw

• Decrease of speed in representative sea conditions of wave height, wave frequency and wind speed (e.g. BF 6 – head wind).

• Non-dimensional• Determined by ship specific simulation or standard

values from a table• Japanese research project

wrefi

F

fVCapacityf

P SFCCindexAttained

fi

• Capacity factor for any technical or regulatory limitation on capacity

feff

• Availability factor of any innovative energy efficient technology.

Attained Index

wrefi

MEiFMEieff

neff

1ieffAEFAE

nWHR

1iWHRi

nPTI

1iTIiEAFAEAE

nME

1iiMEiMEiFME

M

1jj

fVCapacityf

SFCCPfSFCCPP*SFCCPPSFCCf

* If shaft generator provided Normal Maximum Sea Load can be calculated using SFCME instead of SFCAE

Attained Index

Outstanding items to be addressed:

• PAE for passenger ships

• Verification of waste heat recovery contribution

Baseline

• Average attained index for the world fleet• Example: Dry bulk carriers

Bulker(>=400 gt, built 1998-2007)

y = 1354x-0,5117

R2 = 0,9287

0,00

2,00

4,00

6,00

8,00

10,00

12,00

14,00

16,00

18,00

20,00

0 50 000 100 000 150 000 200 000 250 000 300 000 350 000

Dwt

Gra

ms

pe

r to

nn

e*n

m

Excluded

Included

BaselinecbavalueBaseline

Ship type A b C

Dry Bulk 1354,0 DWT 0,5117

Tankers 1950,7 DWT 0,5337

Gas carriers 1252,6 DWT 0,4597

Container ships 139,38 DWT 0,2166

General cargo ships 290,28 DWT 0,3300

Ro-ro cargo ships 19788,0 DWT 0,7137

Passenger ships 5639,4 GT 0,6245

Ro-ro Passenger ships 2680 GT 0,4763

• If the design of a ship makes it possible to fall into more than one of the above ship type definitions the required energy efficiency design index for the ship the most stringent energy efficiency design index.

Required Index

valuebaseline)100

1(indexCOdesignRequired 2 X

• Attained index < Required index

• A new ship shall be X % more efficient than the average of existing ships of the same type and size

Base line and Required Index

0,00

2,00

4,00

6,00

8,00

10,00

12,00

10000 20000 40000 60000 80000 100000 120000 140000 160000 180000 200000

DWT

Ind

ex g

/to

n-k

m

World fleet average (base line) Required index (X % more efficient)

What if A ≥ R ?

• Design cannot be approved

• Improve design (hull, propeller etc.) to increase the speed available for the same engine size, or

• Reduce engine size