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

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 2007-2012 (Third IMO GHG Study, 2014)

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

Introduction Some mitigation measures are correlated 12/1/2018 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)

Introduction Questions of interest 12/1/2018 Questions of interest How to rank these mitigation measures ? How to select correlated mitigation measures ?

Introduction 12/1/2018 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

Methodology Multi-objective ranking method (two objectives) 12/1/2018 Multi-objective ranking method (two objectives) Objective 1: minimize {cost} maximize {negative cost} Objective 2: maximize {abatement} How to do multi-objective ranking?

Methodology Pareto front method 12/1/2018 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 ?

Methodology New ranking criterion: marginal cost-effectiveness (MCE) 12/1/2018 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

Methodology Ranking rules Measure i is better than measure j if: 12/1/2018 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

Methodology Correlated measures ranking and selection 12/1/2018 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

Case study: shipping mitigation measures 12/1/2018 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

Case study 12/1/2018 Ranking results: MACC VS Proposed method

Case study Correlated measures: 12/1/2018 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

Case study Ranking results Ranking No. Measure No. CE criterion MCE 12/1/2018 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 −

Conclusion Solve the problem of MACCs to rank negative CE measures 12/1/2018 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

Thank you! Yuan Jun Email: yuanjun@nus.edu.sg Energy Studies Institute 29 Heng Mui Keng Terrace Block A, #10-01 Singapore 119620