1. Correlated Emission Reduction Measures Ranking and Selection
YUAN JUN
IAEE, 2017

2. Introduction Shipping Industry
Carried by sea
More than 90% of the world’s trade is carried by sea (IMO, 2016)
CO2 emissions from shipping compared with global emissions (Second IMO GHG Study, 2009)
Shipping accounted for approximately 3.1% of annual global CO2 on average for the period (Third IMO GHG Study, 2014)

3. Introduction Mitigation (emission reduction) measures
International Maritime Organization (IMO) identified more than 50 measures
Operational Measures
Technical Measures
Speed Reduction
Hull coating I
Weather Routing
Hull coating II
Autopilot Adjustment
Optimization water flow of hull openings (grids, scallop)
Propeller Polishing when Required
Air Lubrication
Propeller polishing (at regular intervals)
Integrated Propeller and Rudder Upgrade
Propeller Upgrade
Propeller Boss Cap with Fins
Main Engine Tuning
Speed Control of Pumps and Fans
Impossible to implement all these measures

4. Introduction Some mitigation measures are correlated
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Some mitigation measures are correlated
For instance: Hull coating I (HC1) and Hull coating II (HC2)
Abatement (HC1+ HC2) ≠ Abatement (HC1) + Abatement (HC2)
Compared to main engine tuning (MET):
Abatement (HC1) > Abatement (MET)
and
Abatement (HC2) > Abatement (MET)
Abatement (HC1 + HC2) > Abatement (HC1 + MET) or
Abatement (HC1 + HC2) > Abatement (HC2 + MET)

5. Introduction Questions of interest
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Questions of interest
How to rank these mitigation measures ?
How to select correlated mitigation measures ?

6. Introduction
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To rank mitigation measures: Marginal Abatement Cost Curves (MACCs)
Use cost-effectiveness (CE) criterion:
𝐶𝐸= 𝐶𝑜𝑠𝑡 𝐴𝑏𝑎𝑡𝑒𝑚𝑒𝑛𝑡
Become a standard policy tool to prioritize mitigation options
Adopted by IMO to assess mitigation measures for maritime
Limitation: it is inappropriate to rank negative CE measures

7. Methodology Multi-objective ranking method (two objectives)
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Multi-objective ranking method (two objectives)
Objective 1: minimize {cost} maximize {negative cost}
Objective 2: maximize {abatement}
How to do multi-objective ranking?

8. Methodology Pareto front method
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Pareto front method
Measure 1 dominates measure 3 {-C(1) > -C(3) & A(1) > A(3)},
Measure 2 dominates measure 3 {-C(2) = -C(3) & A(2) > A(3)},
Measure 2 dominates measure 4 {-C(2) > -C(4) & A(2) > A(4)},
Rule 1: Measure i is better than j if i dominates j
Measure 1 and measure 2 are Pareto optimal
How to rank measure 1 and measure 2 ?

9. Methodology New ranking criterion: marginal cost-effectiveness (MCE)
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New ranking criterion: marginal cost-effectiveness (MCE)
To compare Pareto optimal measures:
Additional cost per additional tonne of abatement
Compared to accepted cost per additional tonne of abatement, CE0
Rule 2: Measure i is better than j if i is preferred than j using MCE

10. Methodology Ranking rules Measure i is better than measure j if:
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Ranking rules
Measure i is better than measure j if:
i dominates j
i is preferred than j using MCE
Otherwise, measure j is better than measure i

11. Methodology Correlated measures ranking and selection
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Correlated measures ranking and selection
Measures: Hull coating I (HC1), hull coating II (HC2), main engine tuning (MTE)
Question: which two measures are best?
Find all possible combinations: {(HC1+HC2); (HC1+MTE); (HC2+MTE)}
Evaluate cost and abatement for each combination
Rank all combinations
Select the best combination

12. Case study: shipping mitigation measures
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Comprehensive study over 14 measures
Measures
Total Cost (million US$)
Abatement Potential
Number
Name
Min
Max 1
Speed Reduction (due to fleet increase)
17802
19886
19.0%
36.0% 2
Weather Routing 28 55
0.1%
4.0% 3
Autopilot Adjustment
131
145
0.5%
3.0% 4
Propeller Polishing when Required
271
358
2.5%
8.0% 5
Propeller Polishing (at regular intervals)
103
172
2.0%
5.0% 6
Hull Coating I
811
874 7
Hull Coating II
2207
2548
1.0% 8
Optimization Water Flow of Hull Openings
448
462 9
Air Lubrication
1926
3550
15.0% 10
Integrated Propeller and Rudder Upgrade
3840
4211
6.0% 11
Propeller Upgrade
829
902
4.5% 12
Propeller Boss Cap with Fins
531
584 13
Main Engine Tuning
713
754 14
Speed Control of Pumps and Fans
819
900

13. Case study
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Ranking results: MACC VS Proposed method

14. Case study Correlated measures:
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Correlated measures:
measures 4 and 5; measures 6 and 7; measures 10, 11 and 12
Measure No.
Measures 1
Speed Reduction (due to fleet increase) 2
Weather Routing 3
Autopilot Adjustment 4
Propeller Polishing when Required 5
Propeller Polishing (at regular intervals) 6
Hull Coating I 7
Hull Coating II 8
Optimization Water Flow of Hull Openings (grids, scallop) 9
Air Lubrication 10
Integrated Propeller and Rudder Upgrade 11
Propeller Upgrade 12
Propeller Boss Cap with Fins 13
Main Engine Tuning 14
Speed Control of Pumps and Fans
Assumption: correlated measures are mutually exclusive

15. Case study Ranking results Ranking No. Measure No. CE criterion MCE
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Ranking results
Measure No.
Measures 1
Speed Reduction (due to fleet increase) 2
Weather Routing 3
Autopilot Adjustment 4
Propeller Polishing when Required 5
Propeller Polishing (at regular intervals) 6
Hull Coating I 7
Hull Coating II 8
Optimization Water Flow of Hull Openings (grids, scallop) 9
Air Lubrication 10
Integrated Propeller and Rudder Upgrade 11
Propeller Upgrade 12
Propeller Boss Cap with Fins 13
Main Engine Tuning 14
Speed Control of Pumps and Fans
Ranking No.
Measure No.
CE criterion
MCE
Correlated 1 5 2 9 3 4 8 11 6 7 12 10 13 14 −

16. Conclusion Solve the problem of MACCs to rank negative CE measures
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Solve the problem of MACCs to rank negative CE measures
Propose a ranking method with new criterion to rank all mitigation measures
Propose a method to select correlated mitigation measures
Speed reduction is the most cost effective way based on available cost and abatement data

17. Thank you!
Yuan Jun
Energy Studies Institute Heng Mui Keng Terrace Block A, # Singapore