Knowledge

Keyword: greenhouse gas emissions

paper

Optimal ship lifetime fuel and power system selection under uncertainty

Benjamin Lagemann*, Sotiria Lagouvardou, Elizabeth Lindstad, Kjetil Fagerholt, Harilaos N. Psaraftis, Stein Ove Erikstad

Ship designers face increasing pressure to comply with global emission reduction ambitions. Alternative fuels, potentially derived from bio-feedstock or renewable electricity, provide promising solutions to this problem. The main challenge is to identify a suitable ship power system, given not only uncertain emission requirements but also uncertain fuel and carbon emission prices. We develop a two-stage stochastic optimization model that explicitly considers uncertain fuel and carbon emission prices, as well as potential retrofits along the lifetime. The bi-objective setup of the model shows how the choice of optimal power system changes with reduced emission levels. Methanol and LNG configurations appear to be relatively robust initial choices due to their ability to run on fuel derived from different feedstocks, and their better retrofittability towards ammonia or hydrogen. From a policy perspective, our model provides insight into the effect of the different types of carbon pricing mechanisms on a shipowner's decisions.

Transportation Research Part D: Transport and Environment / 2023
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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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A Literature Survey on Market-Based Measures for the Decarbonization of Shipping

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

This paper aims to conduct an updated literature survey on the Market-Based Measures (MBMs) currently being proposed by various member states and organizations at the International Maritime Organization (IMO) or by the scientific and grey literature as a cost-effective solution to reduce greenhouse gas (GHG) emissions from ships. Τhe paper collects, summarizes, and categorizes the different proposals to provide a clear understanding of the existing discussions on the field and also identifies the areas of prior investigation in order to prevent duplication and to avoid the future discussion at the IMO to start from scratch. Relevant European Union (EU) action on MBMs is also described. Furthermore, the study identifies inconsistencies, gaps in research, conflicting studies, or unanswered questions that form challenges for the implementation of any environmental policy at a global level for shipping. Finally, by providing foundational knowledge on the topic of MBMs for shipping and by exploring inadequately investigated areas, the study addresses concrete research questions that can be investigated and resolved by the scientific and shipping community

Sustainability 2020, 12(10), 3953 / 2020
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Decarbonization of Maritime Transport: Is There Light at the End of the Tunnel?

Harilaos N. Psaraftis*, Christos A. Kontovas

The purpose of this paper is to assess the status and prospects of the decarbonization of maritime transport. Already more than two years have passed since the landmark decision of the International Maritime Organization (IMO) in April 2018, which entailed ambitious targets to reduce greenhouse gas (GHG) emissions from ships. The paper attempts to address the following three questions: (a) where do we stand with respect to GHG emissions from ships, (b) how is the Initial IMO Strategy progressing, and (c) what should be done to move ahead? To that effect, our methodology includes commenting on some of the key issues addressed by the recently released 4th IMO GHG study, assessing progress at the IMO since 2018, and finally identifying other issues that we consider relevant and important as regards maritime GHG emissions, such as for instance the role of the European Green Deal and how this may interact with the IMO process. Even though the approach of the paper is to a significant extent qualitative, some key quantitative and modelling aspects are considered as well. On the basis of our analysis, our main conjecture is that there is not yet light at the end of the tunnel with respect to decarbonizing maritime transport.

Sustainability / 2020
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A literature survey on market-based measures for the decarbonization of shipping

Sotiria Lagouvardou*, Harilaos N. Psaraftis, Thalis Zis

This paper aims to conduct an updated literature survey on the Market-Based Measures (MBMs) currently being proposed by various member states and organizations at the International Maritime Organization (IMO) or by the scientific and grey literature as a cost-effective solution to reduce greenhouse gas (GHG) emissions from ships. The paper collects, summarizes, and categorizes the different proposals to provide a clear understanding of the existing discussions on the field and also identifies the areas of prior investigation in order to prevent duplication and to avoid the future discussion at the IMO to start from scratch. Relevant European Union (EU) action on MBMs is also described. Furthermore, the study identifies inconsistencies, gaps in research, conflicting studies, or unanswered questions that form challenges for the implementation of any environmental policy at a global level for shipping. Finally, by providing foundational knowledge on the topic of MBMs for shipping and by exploring inadequately investigated areas, the study addresses concrete research questions that can be investigated and resolved by the scientific and shipping community.

Sustainability (Switzerland) / 2020
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Decarbonization of Maritime Transport: Is There Light at the End of the Tunnel?

Psaraftis , Harilaos N.; Kontovas, Christos A.

The purpose of this paper is to assess the status and prospects of the decarbonization of maritime transport. Already more than two years have passed since the landmark decision of the International Maritime Organization (IMO) in April 2018, which entailed ambitious targets to reduce greenhouse gas (GHG) emissions from ships. The paper attempts to address the following three questions: (a) where do we stand with respect to GHG emissions from ships, (b) how is the Initial IMO Strategy progressing, and (c) what should be done to move ahead? To that effect, our methodology includes commenting on some of the key issues addressed by the recently released 4th IMO GHG study, assessing progress at the IMO since 2018, and finally identifying other issues that we consider relevant and important as regards maritime GHG emissions, such as for instance the role of the European Green Deal and how this may interact with the IMO process. Even though the approach of the paper is to a significant extent qualitative, some key quantitative and modelling aspects are considered as well. On the basis of our analysis, our main conjecture is that there is not yet light at the end of the tunnel with respect to decarbonizing maritime transport.

Sustainability 2021, 13(1), 237 / 2020
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Bunker Levy Schemes for Greenhouse Gas (GHG) Emission Reduction in International Shipping

Kosmas, Valiseios; Acciaro, Michele

A fuel levy is one of the market-based measures (MBMs) currently under consideration at the International Maritime Organization. MBMs have been proposed to improve the energy efficiency of the shipping sector and reduce its emissions. This paper analyses the economic and environmental implications of two types of levy on shipping bunker fuels by means of an analytical model built on the cobweb theorem. A unit-tax per ton of fuel and an ad-valorem tax, enforced as a percentage of fuel prices, are examined. In both cases, a speed and fuel-consumption reduction equivalent to an improvement in the energy efficiency of the sector would be expected as a result of the regulation enforcement. The speed reduction in the unit-tax case depends on fuel prices and the tax amount, whereas in the ad-valorem case it relies upon the enforced tax percentage.
Both schemes lead to industry profit decline, the extent of which depend on the structure of the levy and market conditions. Since there is concern that the costs resulting from the policy will be passed from shipping companies to their customers along the supply chain, the paper dwells on how the costs arising from the enforcement of the levy will be actually allocated between ship-owners and operators, and cargo-owners. In a market characterised by high freight rates and with no or limited excess capacity, a higher percentage of the total tax amount is transferred from ship-owners to shippers. In case of a recession the opposite happens.

Transportation Research. Part D: Transport & Environment, Volume 57 / 2017
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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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