Knowledge

Keyword: emission reduction

paper

Reduced environmental impact of marine transport through speed reduction and wind assisted propulsion

Tillig, Fabian; Ringsberg, Jonas W.; Psaraftis, Harilaos N.; Zis, Thalis

To achieve IMO’s goal of a 50% reduction of GHG emission by 2050 (compared to the 2008 levels), shipping must not only work towards an optimization of each ship and its components but aim for an optimization of the complete marine transport system, including fleet planning, harbour logistics, route planning, speed profiles, weather routing and ship design. ShipCLEAN, a newly developed model, introduces a coupling of a marine transport economics model to a sophisticated ship energy systems model – it provides a leap towards a holistic optimization of marine transport systems. This paper presents how the model is applied to propose a reduction in fuel consumption and environmental impact by speed reduction of a container ship on a Pacific Ocean trade and the implementation of wind assisted propulsion on a MR Tanker on a North Atlantic trade. The main conclusions show that an increase of the fuel price, for example by applying a bunker levy, will lead to considerable, economically motivated speed reductions in liner traffic. The case study sowed possible yearly fuel savings of almost 21 300 t if the fuel price would be increased from 300 to 1000 USD/t. Accordingly, higher fuel prices can motivate the installation of wind assisted propulsion, which potentially saves up to 500 t of fuel per year for the investigated MR Tanker on a transatlantic route.

Transportation Research Part D: Transport and Environment Volume 83 / 2020
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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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Reducing Sulfur Emissions: Logistical and Environmental Considerations

Zis, Thalis; Psaraftis, Harilaos N.

In recent years the issue of sulfur emissions from maritime transport has seen newfound attention. This chapter presents an overview of the main issues of sulfur emissions and the legislative framework that seeks to reduce the sulfur footprint of the maritime sector. It also analyzes potential modal shifts toward less efficient land-based modes which may happen as a result of sulfur regulations and investigates the related potential economic damage to ship operators. To that effect, this chapter presents findings from a recently finished project at DTU and the developed methodological framework that can be used to estimate such modal shifts, as well as to measure the efficacy of policy and ship operators’ measures to reverse such shifts.

Book chapter in H. N. Psaraftis (Ed.), Sustainable Shipping: A Cross-Disciplinary View / 2019
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paper

Regional Carbon Pricing for International Maritime Transport: Challenges and Opportunities for Global Geographical Coverage

Dominioni, Goran; Heine, Dirk; Romera, Beatriz Martinez

Although the existing literature identifies a fuel levy imposed by means of a global agreement as the most efficient policy for carbon pricing in the maritime sector, scholars and policy makers have debated the possibility for regional measures to be introduced in case a global agreement cannot be achieved. This debate has highlighted several economic, legal, and political challenges that the implementation of an efficient and effective regional scheme would have to face. This article compares the relative performance of various regional measures for carbon pricing based on the following criteria: jurisdictional basis, data availability, environmental effectiveness and avoidance strategies, impact on competitiveness, differentiation for developing countries, and incentives for reaching a global agreement. The main finding is that, if carefully designed, a cargo-based measure that covers the emissions released throughout the whole voyage to the cargo destination presents various advantages compared with other regional carbon pricing schemes. These advantages have been largely ignored in the literature.

Carbon & Climate Law Revie, Volume 12 / 2018
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Regulation of Greenhouse Gas Emissions from International Shipping and Jurisdiction of States

Tanaka, Yoshifumi

The regulation of greenhouse gas emissions from international shipping is becoming a matter of increasing concern. Two issues arise in particular. The first issue concerns the elaboration of rules on this subject. In this regard, Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL), amended in 2011, constitutes a key instrument because it was the first legally binding climate change instrument since the Kyoto Protocol. The second issue relates to effective compliance with relevant rules. While the flag State has the primary responsibility to implement relevant rules concerning the regulation of greenhouse gas emissions from international shipping, the flag State responsibility alone is inadequate to secure effective compliance with relevant rules. Thus, there is a need to examine the question whether and to what extent coastal and port States can regulate greenhouse gas emissions from vessels in international law. This article seeks to address these two issues. The article concludes that while port States can perform a valuable role in effectuating global rules provided in MARPOL Annex VI, port State control encounters several challenges. Thus, securing compliance with relevant rules should be an important issue in the regulation of greenhouse gas emissions from international shipping.

Review of European, Comparative & International Environmental Law, 25( 3) / 2016
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Reliability and Safety Improvement of Emission-Free Ships: Systemic Reliability-Centered Maintenance

Igder, Mosayeb Afshari; Rafiei, Mehdi; Boudjadar, Jalil; Khooban, Mohammad Hassan

The power system of an all-electric ship (AES) establishes an independent microgrid using the distributed energy resources, energy storage devices, and power electronic converters. As a hybrid energy system (HES), the power system of an AES works as a unified system where each part can affect the reliability of the other parts. The systemic reliability centered maintenance (SRCM), which efficiently enhances the reliability and safety of the AES by identifying optimal maintenance tasks of the AES, is considered in this article to apply to the entire system. In order to calculate the reliability and optimal maintenance schedule, the Markov process and Enhanced JAYA (EJAYA) are utilized. A layer of protection analysis (LOPA), which is a risk management technique, is adopted to assess the safety of the system. A hybrid molten carbonate fuel cell, photovoltaic (PV), and lithium-ion battery are considered as energy sources of the AES. Based on two common standards, DNVGL-ST-0033 and DNVGL-ST-0373, the suggested maintenance planning method can be used in industrial applications. Eventually, in order to validate the proposed method, a model-in-the-loop real-time simulation using dSPACE is carried out. The obtained results show the applicability and efficiency of the proposed method for improving reliability and safety.

IEEE Transactions on Transportation Electrification ( Volume: 7, Issue: 1, March 2021) / 2020
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Ship speed optimization considering ocean currents to enhance environmental sustainability in maritime shipping

Yang, Liqian; Chen, Gang; Zhao, Jinlou; Rytter, Niels Gorm Malý

Enhancing environmental sustainability in maritime shipping has emerged as an important topic for both firms in shipping-related industries and policy makers. Speed optimization has been proven to be one of the most effective operational measures to achieve this goal, as fuel consumption and greenhouse gas (GHG) emissions of a ship are very sensitive to its sailing speed. Existing research on ship speed optimization does not differentiate speed through water (STW) from speed over ground (SOG) when formulating the fuel consumption function and the sailing time function. Aiming to fill this research gap, we propose a speed optimization model for a fixed ship route to minimize the total fuel consumption over the whole voyage, in which the influence of ocean currents is taken into account. As the difference between STW and SOG is mainly due to ocean currents, the proposed model is capable of distinguishing STW from SOG. Thus, in the proposed model, the ship’s fuel consumption and sailing time can be determined with the correct speed. A case study on a real voyage for an oil products tanker shows that: (a) the average relative error between the estimated SOG and the measured SOG can be reduced from 4.75% to 1.36% across sailing segments, if the influence of ocean currents is taken into account, and (b) the proposed model can enable the selected oil products tanker to save 2.20% of bunker fuel and reduce 26.12 MT of CO2 emissions for a 280-h voyage. The proposed model can be used as a practical and robust decision support tool for voyage planners/managers to reduce the fuel consumption and GHG emissions of a ship

Sustainability 2020, 12(9), 3649 / 2020
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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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Ship speed vs power or fuel consumption: Are laws of physics still valid? Regression analysis pitfalls and misguided policy implications

Harilaos N. Psaraftis*, Sotiria Lagouvardou

There have been a number of recent papers in the literature that investigate the relationship between ship speed and required power, or between ship speed and fuel consumption. Using regression analyses for selected case studies these papers show that in many cases the traditional “cube law” is not valid, and exponents lower than 3 (and in some cases lower than 2 or even below 1) are more appropriate. Perhaps more important, they use these results to derive implications on the validity (or lack thereof) of policies to reduce greenhouse gas (GHG) emissions from ships through slow steaming. This paper reviews some of these papers and shows that their results are partially based on pitfalls in the analysis which are identified. Policy implications particularly on the quest to reduce GHG emissions from ships are also discussed.

Cleaner Logistics and Supply Chain / 2023
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paper

Shipping decarbonisation: overcoming the obstacles

Harilaos N. Psaraftis

The “Initial IMO Strategy” was adopted in the 72nd session of the Marine Environment Protection Committee (MEPC 72) of the International Maritime Organization (IMO) in April 2018. It has set, among other things, ambitious targets to reduce greenhouse gas (GHG) emissions from ships, and purports to express a strong political will to phase them out as soon as possible. The most ambitious of these targets is to reduce GHG emissions by 2050 at least 50% vis-à-vis 2008 levels, and there is also an intermediate target to reduce CO2 emissions per transport work by 2030 at least 40%, again vis-à-vis 2008 levels. More than three years since the adoption of the Initial IMO Strategy, this chapter takes stock at the status of shipping decarbonisation and attempts to assess prospects for the future. Obstacles towards achieving the IMO targets are identified and discussed.

The Handbook of Maritime Economics and Business / 2023
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