Knowledge

Keyword: emission reduction

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Operational cycles for maritime transportation: Consolidated methodology and assessments

Amandine Godet, George Panagakos, Michael Bruhn Barfod*, Elizabeth Lindstad

Operational cycles for maritime transportation is a new concept to improve the assessment of ships’ energy efficiency and offer benchmarking options among similar ship types and sizes. This work extends previous research to consolidate the methodology, bring more comprehensiveness, and provide a more holistic assessment of these operational cycles. The cycles are designed from noon reports from a fleet of around 300 container ships divided into eight size groups. The comparison between cycles derived from speed and draft with those based on main engine power identifies that the cycles based on speed and draft are more accurate and allow for estimating the Energy Efficiency Operational Index but require more data. The main-engine-power cycles are more effective in benchmarking through the Annual Efficiency Ratio. These cycles reduce the inherent variability of the carbon intensity indicator and present good opportunities as a benchmarking tool for strengthening the regulatory framework of international shipping.

Transportation Research Part D: Transport and Environment / 2024
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From Mitigation to Adaptation: Problematizing Climate Change in the Maritime Transport Industry

Jan Stockbruegger, Christian Bueger

The literature on climate change in the maritime transport industry has grown rapidly in the last few years. Yet as the research agenda has progressed, scientific debates have become more isolated and fragmented, making it difficult to translate new findings into broader policy debates. This article draws on problematization methodology to help organize the scientific debate on maritime emissions and to identify analytical gaps and challenges. We argue that scholars investigate shipping's emission problem from four distinct analytical perspectives— (1) international laws and regulations, (2) markets and economics, (3) engineering and technology, and (4) authority and legitimacy. Each of these perspectives problematizes maritime emissions in specific ways, leading to different policies and strategies to address the problem. We call for better integrating these four literatures and highlight three crosscutting areas and problems for future research. First, developing institutions that facilitate market and engineering solutions; second, integrating climate mitigation and adaptation research; and third, focusing on justice concerns to ensure an equitable green transition in the maritime industry.

WIREs Climate Change / 2024
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Optimizing Sulfur Emission Control Areas for Shipping

Lu Zhen, Dan Zhuge, Shuaian Wang, Harilaos N. Psaraftis

The design of emission control areas (ECAs), including ECA width and sulfur limits, plays a central role in reducing sulfur emissions from shipping. To promote sustainable shipping, we investigate an ECA design problem that considers the response of liner shipping companies to ECA designs. We propose a mathematical programming model from the regulator’s perspective to optimize the ECA width and sulfur limit, with the aim of minimizing the total sulfur emissions. Embedded within this regulator’s model, we develop an internal model from the shipping liner’s perspective to determine the detoured voyage, sailing speed, and cargo transport volume with the aim of maximizing the liner’s profit. Then, we develop a tailored hybrid algorithm to solve the proposed models based on the variable neighborhood search meta-heuristic and a proposition. We validate the effectiveness of the proposed methodology through extensive numerical experiments and conduct sensitivity analyses to investigate the effect of important ECA design parameters on the final performance. The proposed methodology is then extended to incorporate heterogeneous settings for sulfur limits, which can help regulators to improve ECA design in the future.

Transportation Science / 2024
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Monitoring Carbon Emissions of Ships: Policy implications of a weather-normalized indicator

Amandine Marie Clémence Godet

Maritime transportation is an essential pillar of modern societies, serving as the backbone of global trade. The shipping industry relies heavily on fossil fuels, significantly impacting the environment and contributing to climate change. The International Maritime Organization (IMO) has introduced a strategy to reduce greenhouse gas emissions from international shipping and decarbonize the industry to combat this issue. This strategy aims to accomplish energy efficiency gains, transition to alternative fuels, and implement market-based measures.

Various energy efficiency indicators are in use to monitor the performance of ships, both from technical and operational perspectives. Building upon previous research that identified shortcomings in these indicators, this thesis investigates alternative methods of assessing the energy efficiency of ships. Emphasizing the importance of a benchmarking tool, the primary objective of this thesis is to contribute to the policy debate on reducing emissions in international shipping by developing a comprehensive carbon intensity indicator.

The thesis comprises four articles addressing various approaches to monitoring ship carbon emissions. The first article focuses on the influence of weather conditions on a ship’s energy efficiency, thereby contributing to the ongoing discussion on weather correction factors. Using model-based machine learning techniques, this article illustrates the diverse sea conditions encountered, their impact on energy efficiency, and the necessity of accounting for this diversity through multiple correction factors.

The second and third articles introduce and develop the concept of operational cycles for maritime transportation, drawing inspiration from the driving cycles employed in the automotive industry. The second article describes the process of generating operational cycles for the maritime sector as a novel concept. It validates this concept using real-world data obtained from a fleet of container ships. Building upon this foundation, the third article extends the concept by elaborating more comprehensive cycles that better represent real-world indicators.

The fourth article explores voluntary reporting frameworks in the shipping industry. It focuses on the Clean Cargo case and investigates the needs and interests of its members regarding this private initiative and related reporting framework. The discussion revolves around the role of these voluntary frameworks as complementary approaches to regulatory frameworks towards maritime decarbonization.

Based on the methodology developments and analysis through the thesis, the following key findings and recommendations are presented:

• The weather impact on ships’ fuel consumption prevents an accurate and real assessment of ships’ efficiency. Multiple weather correction factors for energy efficiency indicators introduce a novel approach.
• Inspired by the automotive industry, maritime operational cycles improve the assessment of technical and operational aspects of a ship’s energy efficiency. The cycles reduce the variability inherent to energy
efficiency indicators and are suitable as benchmarking tools.
• Although the IMO regulatory framework remains at the core of the maritime decarbonization strategy, regional regulatory frameworks and private initiatives have demonstrated their capacity to enhance industry
practices and facilitate regulatory developments.

This thesis contributes to enhancing carbon emissions monitoring in the maritime industry by introducing new methodologies and assessments. The resulting proposals are designed to enrich ongoing discussions within the IMO and complement the existing regulatory frameworks.

Technical University of Denmark / 2024
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GreenHopper: The Danish spearhead towards autonomous waterborne mobility

Mogens Blanke, Nicholas Hansen, Kjeld Dittmann, Thomas Thuesen Enevoldsen, Dimitrios Dagdilelis, Frederik Emil Thorsson Saabye Schöller, Martin Krarup Plenge-Feidenhans'l, Jonathan Binner Becktor, Dimitrios Papageorgiou, Roberto Galeazzi

GreenHopper is the first Danish zero-emission ferry developed as a test platform for autonomous waterborne navigation technologies. The paper presents technology development within the innovation project ShippingLab Autonomy, which led to the commissioning of GreenHopper at Limfjorden (DK) in December 2022. The technology research resulted in a holistic system architecture for surface vessel autonomy, based on distribution of functionality and responsibility on software modules, similar to the structure observed in the International Maritime Organization (IMO) Seafarers Training Certification and Watch-keeping (STCW) regulatory framework. The paper shows how this approach results in an architecture that supports safe behaviours of individual modules and of autonomous navigation at a system level. The paper presents the individual modules, specific features and benefits. Elements of the regulatory framework are highlighted to poise technology approval by maritime authorities. The paper reflects on lessons learned, discusses continued technology validation in dedicated operational scenarios.

Journal of Physics: Conference Series / 2024
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The Prospects for, and Implications of, Emissions Trading in Shipping

Anastasia Christodoulou, Kevin Cullinane*

The decarbonisation of shipping has become a high priority on the environmental and political agenda. The prospect of implementing an Emissions Trading System (ETS) for shipping has come to prominence as a proposed mechanism for speeding up the decarbonisation of the industry, with the EU taking proactive action to include shipping within the EU ETS by 2023. This paper analyses and provides a qualitative review of the historical development of the discussions and actions taken at both global level (by the International Maritime Organization (IMO)) and at regional level within the EU. A SWOT analysis of the potential implementation of an ETS for shipping is then presented. The paper concludes that an ETS for shipping can incentivise greater investment in, and deployment of, green technologies that will have the effect of reducing the carbon footprint of the shipping industry. However, the speed and significance of this effect will depend upon the specific shipping market segment and the relative stage in shipping market cycles over time. It is further concluded that despite the imminent unilateral introduction of shipping into the EU ETS, it is important that the IMO continues its work to develop a global ETS that promotes a ‘level playing field’ for competition within the sector and eliminates the risk of carbon leakage.

Maritime Economics & Logistics / 2024
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Subsidy strategy design for shore power utilization and promotion

Lu Zhen, Yingying Yuan, Dan Zhuge, Harilaos N. Psaraftis, Shuaian Wang

Shore power is an important green technology used by ports to reduce carbon emissions. This paper investigates how to design subsidy strategy for promoting the installation and utilization of shore power. However, while installation subsidies may promote the installation of SPI in ports, resulting in a reduction in ship emissions, utilization subsidies may attract more ship visits, which may increase the total emissions of a port. Therefore, subsidies for shore power utilization and installation should be optimized to minimize the cost to government (comprising the environmental costs of ship emissions, the cost of utilization or installation subsidies, and carbon taxes) and maximize the profit for ports (including profit from original and new ships, utilization and installation subsidies, and carbon taxes). Using the Stackelberg game methodology, we discuss five cases to give a comprehensive analysis of the design of different subsidy policies, including no subsidy, SPI-utilization subsidy undertaken by port, SPI-utilization subsidy undertaken by port and government, carbon emission tax policy considering SPI-utilization subsidy, and SPI-utilization and SPI-installation subsidies undertaken by port and government. Managerial insights are generated according to the theoretical analysis and numerical experiments results, which can give references to the government and port operators.

Maritime Policy and Management / 2024
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Prediction of harbour vessel emissions based on machine learning approach

Zhong Shuo Chen, Jasmine Siu Lee Lam*, Zengqi Xiao

Harbour vessel emissions are growing concerns in the maritime industry regarding environmental sustainability. Accurate emissions prediction can stand in monitoring and addressing the issue. This study proposes a machine-learning approach using Artificial Neural Network (ANN) for predicting harbour vessel emissions. The approach shows superiority over the bottom-up method introduced by the 4th IMO GHG Study regarding prediction accuracy. Actual emissions data from onboard measurements are used for training ANN models and as references for evaluating the methods. Compared to the bottom-up method, the improvement in error reduction can be up to 30% for predicting nitrogen oxides and 54% for carbon monoxide when only using ship-related factors as input variables. By adding selected meteorological factors in the experiments, the prediction accuracy enhancement can achieve up to 48% for nitrogen oxides and 62% for carbon monoxide. The proposed ANN approach could assist relevant stakeholders in improving emissions prediction and operations optimisation.

Transportation Research Part D: Transport and Environment / 2024
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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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Marginal abatement cost of alternative marine fuels and the role of market-based measures

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

Uncertainties on the global availability and affordability of alternative marine fuels are stalling the shipping sector’s decarbonization course. Several candidate measures are being discussed at the International Maritime Organization, including market-based measures (MBMs) and environmental policies such as carbon taxes and emissions trading systems, as means to decarbonize. Their implementation increases the cost of fossil fuel consumption and provides fiscal incentives to shipping stakeholders to reduce their greenhouse gas emissions reductions. MBMs can bridge the price gap between alternative and conventional fuels and generate revenues for funding the up-scaling of alternative fuels’ production, storage and distribution facilities and, thus, enhance their availability. By estimating the fuels’ implementation and operational costs and carbon abatement potential, this study calculates marginal abatement costs and estimates the level of carbon pricing needed to render investments into alternative fuels cost-effective. The results can assist policymakers in establishing robust and effective maritime decarbonization policies.

Nature Energy / 2023
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