Knowledge

Keyword: emission reduction

book

Speed Optimization for Sustainable Shipping

Psaraftis, Harilaos N.

Among the spectrum of logistics – based measures for sustainable shipping, this chapter focuses on speed optimization. This involves the selection of an appropriate speed by the vessel, so as to optimize a certain objective. As ship speed is not fixed, depressed shipping markets and/or high fuel prices induce slow steaming which is being practised in many sectors of the shipping industry. In recent years the environmental dimension of slow steaming has also become important, as ship emissions are directly proportional to fuel burned. Win-win solutions are sought, but they will not necessarily be possible. The chapter presents some basics, discusses the main trade-offs and also examines combined speed and route optimization problems. Some examples are presented so as to highlight the main issues that are at play, and the regulatory dimension of speed reduction via speed limits is also discussed.

Book chapter in Sustainable shipping: A cross-disciplinary view / 2019
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paper

Speed Optimization vs Speed Reduction: the Choice between Speed Limits and a Bunker Levy

Psaraftis, Harilaos N.

“Speed optimization and speed reduction” are included in the set of candidate short-term measures under discussion at the International Maritime Organization (IMO), in the quest to reduce greenhouse gas (GHG) emissions from ships. However, there is much confusion on what either speed optimization or speed reduction may mean, and some stakeholders have proposed mandatory speed limits as a measure to achieve GHG emissions reduction. The purpose of this paper is to shed some light into this debate, and specifically examine whether reducing speed by imposing a speed limit is better than doing the same by imposing a bunker levy. To that effect, the two options are compared. The main result of the paper is that the speed limit option exhibits a number of deficiencies as an instrument to reduce GHG emissions, at least vis-à-vis the bunker levy option.

Sustainability 2019, 11(8), 2249 / 2019
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paper

Decarbonization of maritime transport: to be or not to be?

Psaraftis, Harilaos N.

International shipping is at a crossroads as regards decarbonization. The Paris climate change agreement in 2015 (COP21) was hailed by many as a most significant achievement. Others were less enthusiastic, and more recently American President Trump decided to take the U.S. out of the agreement. Four years earlier, the International Maritime Organization (IMO) had adopted the most sweeping piece of regulation pertaining to maritime greenhouse gas (GHG) reduction, in the name of the Energy Efficiency Design Index (EEDI). In addition, one year after COP21, the IMO adopted a mandatory data collection system for fuel consumption of ships and agreed on an initial strategy and roadmap on the reduction of GHG emissions from ships. This paper takes a critical look at the above and other recent developments and focuses on the challenges faced by the industry if a path to significant CO2 reductions is to be successful. Difficulties and opportunities are identified, and the paper conjectures that the main obstacles are neither technical nor economic, but political.

Maritime Economics & Logistics, volume 21 / 2019
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book

Energy efficiency of ships

Psaraftis, Harilaos N.

The purpose of this chapter is to present some basics as regards the energy efficiency of ships, including related regulatory activity at the International Maritime Organization (IMO) and elsewhere. To that effect, the Energy Efficiency Design Index (EEDI) is first presented, followed by a discussion of Market Based Measures (MBMs) and the recent Initial IMO Strategy to reduce greenhouse gas (GHG) emissions from ships. The discussion includes commentary on possible pitfalls in the policy approach being followed.

Book chapter in Encyclopedia of Transportation SAGE Publications / 2019
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paper

Ship speed optimization: Concepts, models and combined speed-routing scenarios

Psaraftis, Harilaos N.; Kontovas, Christos A.

The purpose of this paper is to clarify some important issues as regards ship speed optimization at the operational level and develop models that optimize ship speed for a spectrum of routing scenarios in a single ship setting. The paper’s main contribution is the incorporation of those fundamental parameters and other considerations that weigh heavily in a ship owner’s or charterer’s speed decision and in his routing decision, wherever relevant. Various examples are given so as to illustrate the properties of the optimal solution and the various trade-offs that are involved.

Transportation Research Part C: Emerging Technologies, Volume 44 / 2014
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paper

Market based measures for the reduction of Green House gas emissions from ships: a possible way forward

Psaraftis, Harilaos N.; Lagouvardou, Sotiria

The International Maritime Organization (IMO) is a specialized United Nations (UN) agency regulating maritime transport. One of the very hot topics currently on the IMO agenda is decarbonization. In that regard, the IMO decided in 2018 to achieve by 2050 a reduction of at least 50% in maritime green house gas (GHG) emissions vis-à-vis 2008 levels. The purpose of this paper is to discuss the possible role of Market Based Measures (MBMs) so as to achieve the above target. To that effect, a brief discussion of MBMs at the IMO and the EU is presented, and a possible way forward is proposed, focusing on a bunker levy.

Samfundsoekonomen / 2019
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book

Reducing GHGs: the MBM and MRV Agendas

Psaraftis, Harilaos N.; Woodall, Poul

The purpose of this chapter is to introduce the concept of Market Based Measures (MBMs) to reduce Green House Gas (GHG) emissions from ships, and review several distinct MBM proposals that were under consideration by the International Maritime Organization (IMO). The chapter then moves on to discuss the concept of Monitoring, Reporting and Verification (MRV) of CO2 emissions and the distinct mechanisms set up the European Union (EU) and the IMO for MRV. The reason the MBM and MRV subjects are treated in the same chapter is twofold: (a) the MRV discussion essentially started when the MBM discussion was suspended in 2013, and (b) MRV is a critical step for any eventual MBM implementation in the future.

Book chapter in Sustainable shipping: A cross-disciplinary view / 2019
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report

DMA-DTU project on Market Based Measures (MBMs)

Psaraftis, Harilaos N.; Zis, Thalis; Lagouvardou, Sotiria

This report is in the context of the DMA-DTU project on Market Based Measures (MBMs) The aim of this project is to provide an overview and discussion of potential Market Based Measures under the Initial IMO Strategy for the reduction of green house gas (GHG) emissions from ships. In this context, some related developments are also seen as directly relevant to the scope of the project, mainly in the context of the possible inclusion of shipping into the EU Emissions Trading System (ETS). In 2010 an Expert Group was appointed by the IMO’s Secretary General after solicitation of member states and was tasked to evaluate as many as eleven (11) separate MBM proposals, submitted by various member states and other organizations. All MBM proposals described programs and procedures that would target GHG reductions through either ‘in-sector’ emissions reductions from shipping, or ‘out-of-sector’ reductions via the collection of funds to be used for mitigation activities in other sectors that would contribute towards global reduction of GHG emissions.

/ 2020
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paper

Energy Management of a Zero-Emission Ferry Boat With a Fuel-Cell-Based Hybrid Energy System: Feasibility Assessment

Rafiei, Mehdi; Boudjadar, Jalil; Khooban, Mohammad Hassan

Due to the increasing impacts of ships pollutants on the environment and the preventive laws that are tightening every day, the utilization of all-electric ships is a recent emerging technology. Being a promising technology, the usage of fuel cells as the main energy resource of marine vessels is an interesting choice. In this article, an all-electric hybrid energy system with zero emission based on fuel cell, battery, and cold-ironing is proposed and analyzed. To this end, actual data of a ferry boat, including load profiles and paths, are considered to assess the feasibility of the proposed energy system. The configuration of the boat and energy resources as well as the problem constraints are modeled and analyzed. Finally, the boat's energy management in hourly form for a one-day period is implemented. The improved sine cosine algorithm is used for the power dispatch optimization, and all models are implemented in MATLAB software. Based on the analysis results, the proposed hybrid system and the energy management method have high performance as an applicable method for the marine vessels. In addition, to be a zero-emission ship, the proposed system has an acceptable energy cost.

IEEE Transactions on Industrial Electronics ( Volume: 68, Issue: 2, Feb. 2021) / 2020
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paper

Speed optimizations for liner networks with business constraints

Reinhardt, Line Blander; Pisinger, David; Sigurd, Mikkel; Ahmt, Jonas

In 2018 the International Maritime Organization (IMO) agreed to cut the shipping sector’s overall CO2 output by 50% by 2050. One of the key methods in reaching this goal is to improve operations to limit fuel consumption. However, it is difficult to optimize speed for a complete liner shipping network as routes interact with each other, and several business constraints must be respected. This paper presents a unified model for speed optimization of a liner shipping network, satisfying numerous real-life business constraints. The speed optimization is in this research achieved by rescheduling the port call times of a network, thus, the network is not changed. The business constraints are among others related to transit times, port work shifts and emission control areas. Other restrictions are fixed times for canal crossing, speed restrictions in the piracy areas and desire for robust solutions. Vessel sharing agreements and other collaboration between companies must also be included. The modeling of the different restrictions is described in detail and tested on real-life data. The scientific contribution of this paper is threefold: We present a unified model for speed optimization together with numerous business constraints. We present a general framework for handling routes with different frequencies. Moreover, we present a bi-objective model for balancing robustness of schedules against fuel consumption. The tests show that the real-life requirements can be handled by mixed integer programming and that the model finds significant reductions of bunker consumption and cost for large-scale real-life instances.

European Journal of Operational Research, Volume 285 / 2020
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