Search Results (158)

The International Maritime Organization (IMO) has set a goal to reach net-zero greenhouse gas emissions from international shipping by or around 2050. The ship energy efficiency framework has played a positive role over the past decade in improving carbon intensity and reducing greenhouse gas emissions by employing the technical and operational energy efficiency metrics as effective appraisal tools. To quantify the ship energy efficiency performance and review the existing energy efficiency framework, this paper analyzed the data for the reporting year of 2023 extracted from the European Union (EU) monitoring, reporting, and verification (MRV) system, and investigated the operational profiles and energy efficiency for the ships calling at EU ports. The results show that the data accumulated in the EU MRV system could provide powerful support for conducting ship energy efficiency appraisals, which could facilitate the formulation of decarbonization policies for global shipping and management decisions for stakeholders. However, data quality, ship operational energy efficiency metrics, and co-existence with the IMO data collection system (DCS) remain issues to be addressed. With the improvement of IMO DCS system and the implementation of IMO Net-Zero Framework, harmonizing the two systems and avoiding duplicated regulation of shipping emissions at the EU and global levels are urgent. Full article

The maritime industry faces growing pressure to reduce greenhouse gas (GHG) emissions, reflected in the progressive adoption of stricter international energy regulations. Wind-Assisted Propulsion Systems (WAPS) offer a promising solution by significantly contributing to decarbonization. This paper presents a versatile simulation and optimization platform that supports the conceptual design of WAPS-equipped vessels and evaluates the viability of such investments. The platform uses a steady-state force equilibrium model to simulate vessel performance along predefined routes under realistic weather conditions, incorporating regulatory frameworks and economic assessments. A multi-objective optimization framework identifies optimal designs across user-defined criteria. To demonstrate its capabilities, the platform is applied to a bulk carrier operating between China and the USA, optimizing for capital expenditure, net present value (NPV), and CO₂ emissions. Results show the platform can effectively balance conflicting objectives, achieving substantial emissions reductions without compromising economic performance. The final optimized design achieved a 12% reduction in CO₂ emissions, a 7% decrease in capital expenditure, and a 6.6 million USD increase in net present value compared to the reference design with sails, demonstrating the platform’s capability to deliver balanced improvements across all objectives. The methodology is adaptable to various ship types, WAPS technologies, and operational profiles, offering a valuable decision-support tool for stakeholders navigating the transition to zero-carbon shipping. Full article

With the continuous expansion of global trade, achieving sustainable maritime transport optimization and operations has become a key strategic direction for transforming maritime transport companies. To summarize the current state of research and identify emerging trends in sustainable maritime transport optimization and operations, this study systematically examines representative studies from the past decade, focusing on three dimensions, technology, management, and policy, using data sourced from the Web of Science (WOS) database. Building on this analysis, potential avenues for future research are suggested. Research indicates that the technological field centers on the integrated application of alternative fuels, improvements in energy efficiency, and low-carbon technologies in the shipping and port sectors. At the management level, green investment decisions, speed optimization, and berth scheduling are emphasized as core strategies for enhancing corporate sustainable performance. From a policy perspective, attention is placed on the synergistic effects between market-based measures (MBMs) and governmental incentive policies. Existing studies primarily rely on multi-objective optimization models to achieve a balance between emission reductions and economic benefits. Technological innovation is considered a key pathway to decarbonization, while support from governments and organizations is recognized as crucial for ensuring sustainable development. Future research trends involve leveraging blockchain, big data, and artificial intelligence to optimize and streamline sustainable maritime transport operations, as well as establishing a collaborative governance framework guided by environmental objectives. This study contributes to refining the existing theoretical framework and offers several promising research directions for both academia and industry practitioners. Full article

The maritime sector is under pressure to increase ship energy efficiency and reduce greenhouse gas (GHG) emissions as a part of global decarbonization goals. Various innovative technologies are being adopted in recent years, raising concerns not only about technological feasibility but also about the economic viability of such technologies in the context of sustainable maritime practices. This study evaluates the operational performance, potential to increase energy efficiency, and economic feasibility of wind-assisted propulsion technologies such as rotor sails across different vessel types and operational profiles. As a contribution to cleaner and more efficient shipping, energy savings produced by rotor thrust were analyzed in relation to vessel dimensions and rotor configuration. The results derived from publicly available industry data including shipowner reports, manufacturer case studies, and classification society publications on 25 confirmed rotor sail installations between 2010 and 2025 indicate that savings typically range between 4% and 15%, with isolated cases reporting up to 25%. A simulation model was developed to assess payback time based on varying fuel consumption, investment cost, CO₂ pricing, and operational parameters. Monte Carlo analysis confirmed that under typical assumptions rotor sail investments can reach payback in three to six years (as the ship is also liable for CO₂ payments). These findings offer practical guidance for shipowners and operators evaluating wind-assisted propulsion under current and emerging environmental regulations and contribute to advancing sustainability in maritime transport. The research contributes to bridging the gap between simulation-based and real-world performance evaluations of rotor sail technologies. Full article

With the global maritime industry accelerating toward carbon neutrality, the adoption of alternative marine fuels has emerged as a pivotal pathway for achieving net-zero emissions. To identify the most promising fuel transition solution for multi-purpose heavy-lift vessels (MPHLVs), which are widely used for transporting large and complex industrial equipment and have specialized structural requirements, this study conducted a comprehensive techno-economic analysis based on a fleet of 12 MPHLVs. An eight-dimensional technical adaptability framework was established, and six types of marine fuel were evaluated. Concurrently, a total cost assessment model was developed using 2024 operational data of the fleet, incorporating the fuel procurement, the carbon allowances under the EU ETS, the FuelEU Maritime compliance costs, and the IMO Net-Zero penalties. The results show that methanol as an alternative fuel is the most compatible decarbonization pathway for this specialized vessel type. A case study of a 38,000 DWT methanol-fueled MPHLV further demonstrates engineering feasibility with minimal impact on cargo capacity, and validates methanol’s potential as a technically viable and strategically transitional fuel for MPHLVs, particularly in the context of stricter international decarbonization regulations. The proposed evaluation framework and engineering application offer practical guidance for fuel selection, ship design, and retrofit planning, supporting the broader goal of accelerating low-carbon development in heavy-lift shipping sector. Full article

The atomization performance of methanol fuel plays a crucial role in enhancing methanol engine efficiency, contributing to the decarbonization of the shipping industry. The droplet microscopic characteristics of methanol spray were experimentally investigated using a single-hole direct injection injector in a constant volume chamber. The particle image analysis (PIA) system equipped with a slicer was employed for droplet detecting at a series of measurement positions in both the dense spray region and dilute spray region, then the spatial distributions of droplet size and velocity were examined. Key findings reveal distinct atomization behaviors between dense and dilute spray regions. Along the centerline, the methanol spray exhibited poor atomization, characterized by a high concentration of aggregated droplets, interconnected liquid structures, and large liquid masses. In contrast, the spray periphery demonstrated effective atomization, with only well-dispersed individual droplets observed. Droplet size distribution analysis showed a sharp decrease from the dense region to the dilute region near the nozzle. In the spray midbody, droplet diameter initially decreased significantly within the dense spray zone, stabilized in the transition zone, and then exhibited a slight increase in the dilute region—though remaining smaller than values observed at the central axis. Velocity measurements indicated a consistent decline in the axial velocity component due to air drag. In contrast, the radial velocity component displayed irregular variations, attributed to vortex-induced flow interactions. These experimentally observed droplet behaviors provide critical insights for refining spray models and enhancing computational simulations of methanol injection processes. Full article

In the context of green shipping, carbon capture, utilization, and storage (CCUS) technology is widely recognized as an effective approach for maritime emission reduction. However, existing onboard CO₂ capture systems (OCCS) face challenges including high retrofit complexity, operational limitations, significant deadweight tonnage loss, and compromising feasibility. This study addresses these issues through modular redesign and standardization of two core components: the capture device and CO₂ storage system. We developed clustered storage units to ensure secure CO₂ storage while maximizing economic efficiency, with optimal deployment determined through parameter optimization. The work further examines post-capture processing methods and implementation barriers for onboard CCUS, establishing practical pathways to advance decarbonization technologies and mature maritime CCUS industry chains. Full article

In the context of global climate governance and the International Maritime Organization’s (IMO) stringent carbon reduction targets, the transition to green shipping fuels faces systemic challenges in supply chain coordination. This study focuses on the strategic interactions between governments and enterprises in the construction of green fuel supply chains. By constructing a multidimensional scenario framework encompassing time, technological development, social attention, policy intensity, and market competition, and using evolutionary game models and system dynamics simulations, we reveal the dynamic evolution mechanism of government–enterprise decision making. System dynamics simulations reveal that (1) short-term government intervention accelerates infrastructure development but risks subsidy inefficiency; (2) medium-term policy stability and market-driven mechanisms are critical for sustaining enterprise investments; and (3) high social awareness and mature technologies significantly reduce strategic uncertainty. This research advances the application of evolutionary game theory in sustainable supply chains and offers a decision support framework for balancing governmental roles and market forces in maritime decarbonization. Full article

This paper analyzes the potential of retrofitting in “greening” of European inland vessels and coastal ships, which are normally not the focus of major international environmental policies aimed at waterborne transport. Therefore, greening of the examined fleets would result, for the most part, in additional emission reductions to the environmental targets put forth by the International Maritime Organization. By scoping past and ongoing pilot projects, the most prominent retrofit trends in the greening of inland and coastal ships are identified. Assuming a scenario in which the observed trends are scaled up to the fleet level, the possible emission abatement is estimated (both on the tank-to-wake and well-to-wake bases), as well as the capital and operational costs associated with the retrofit. Therefore, the paper shows what can be achieved in terms of greening if the current trends are followed. The results show that the term “greening” may take a significantly different meaning contingent on the approaches, perspectives, and targets considered. The total costs of a retrofit of a single vessel may be excessively high; however, the costs may significantly vary depending on the vessel power requirements, operational profile, and technology applied. While some trends are worth following (electrification of ferries and small inland passenger ships), others may be too cost-intensive and not satisfactorily efficient in terms of emissions reduction (retrofit of offshore supply vessels with dual-fuel methanol engines). Nevertheless, the assessment of different retrofit technologies strongly depends on the adopted criteria, including but not limited to the total cost of the retrofit of the entire fleet segment, cost of the retrofit of a single vessel, emission abatement achieved by the retrofit of a fleet segment, average emission abatement per retrofitted vessel, and cost of abatement of one ton of greenhouse gases, etc. Full article

The maritime shipping sector is a major contributor to greenhouse gas emissions, particularly in coastal regions. In response, the adoption of electric ferries powered by renewable energy and supported by battery storage technologies has emerged as a viable decarbonization pathway. This study investigates the operational impacts of coordinated electric ferry charging on a medium-voltage distribution network at Gladstone Marina, Queensland, Australia. Using DIgSILENT PowerFactory integrated with MATLAB Simulink and a Python-based control system, four proposed ferry terminals equipped with BESSs (Battery Energy Storage Systems) are simulated. A dynamic model of BESS operation is optimized using a balanced hybrid metaheuristic algorithm combining GA-PSO-BFO (Genetic Algorithm-Particle Swarm Optimization-Bacterial Foraging Optimization). Simulations under 50% and 80% transformer loading conditions assess the effects of charge-only versus charge–discharge strategies. Results indicate that coordinated charge–discharge control improves voltage stability by 1.0–1.5%, reduces transformer loading by 3–4%, and decreases feeder line loading by 2.5–3.5%. Conversely, charge-only coordination offers negligible benefits. Further, quasi-dynamic analyses validate the system’s enhanced stability under coordinated energy management. These findings highlight the potential of docked electric ferries, operating under intelligent control, to act as distributed energy reserves that enhance grid flexibility and operational efficiency. Full article

Background: The maritime industry is undergoing a profound transformation to meet global decarbonization goals. As Industry 4.0 advanced digital technologies are increasingly integrated into shipping operations, the role of the human element is evolving significantly. This intersection of decarbonization, digitalization, and human element/workforce transformation lays the foundation for more structured initiatives such as Green Digital Shipping Corridors (GDSCs), a strategic solution to scale zero-emission, smart maritime routes. Methods: This paper explores the interconnected roles of decarbonization, digitalization, and human capital development through a systematic literature review. It examines how these pillars converge in the implementation of GDSCs, drawing on academic and industry sources to identify challenges and opportunities in workforce readiness, policy integration, and technological adoption. Results: The findings underscore the necessity of coordinated action across the three pillars, particularly highlighting the importance of structured training programs, cross-sector collaboration, and standardized regulations. GDSCs are presented as an applied framework to align these transitions, enabling scalable, digitally enabled, low-emission maritime routes. Conclusions: There is a significant gap in current research that holistically connects the human factor with technological and environmental imperatives in the context of maritime transformation. This paper addresses that gap by introducing GDSCs as a strategic outcome of integrated change, providing actionable insights for policymakers, industry leaders, and educators aiming to advance sustainable shipping. Full article

The maritime industry is crucial in mitigating global warming and advancing sustainable maritime development worldwide. As essential nodes in maritime supply chains and key energy hubs, ports must undergo decarbonization to support global sustainability efforts. Research on port decarbonization (PD) has gained increasing attention in recent years, with several reviews revisiting this topic. However, most existing studies have focused on specific aspects such as measures or policies rather than a holistic perspective. This study adopts a comprehensive approach by examining three key perspectives: PD measures, PD facilitation activities, and PD macro-environmental factors. By systematically analyzing 218 articles retrieved from the Scopus database through bibliometric and content analysis, this study identifies trends over time, geographic distribution, key journals, leading authors, prominent themes, research clusters, researched countries, and methodologies. Key findings highlight the following priorities: (i) broadening the focus to include various port types; (ii) more studies on ports in lower-middle-income economies; (iii) promoting cross regional and international research collaboration; (iv) studying alternative fuels and diversified PD measures through theoretical lenses, innovative, practical, and multifaceted perspectives, and within the context of green corridors and global and regional PD efforts; (v) identifying effective governance models, human resources strategies, infrastructure development, and collaboration mechanisms; and (vi) addressing the direct and indirect impacts of political, legal, and macro-environmental factors on PD. Full article

The main motivation for this paper was the lack of studies and comparative analyses on the new generation of alternative fuels in the marine sector, such as methane, methanol, ammonia and hydrogen. Firstly, a review of international legislation and the status of these new fuels was carried out, highlighting the current situation and the different existing alternatives for reducing greenhouse gas (GHG) emissions. In addition, the status and evolution of the current order book for ships since the beginning of this decade were used for this analysis. Secondly, each fuel and its impact on the geometry and operation of the engine were evaluated in a theoretical engine called MW-1. Lastly, an economic analysis of the current situation of each fuel and its availability in the sector was carried out in order to select, using the indicated methodology, the most viable fuel at present to replace traditional fuels with a view to the decarbonization set for 2050. Full article

Offshore wind energy is increasingly considered a vital resource to contribute to the renewable energy future. This renewable energy can be converted to clean energy alternatives such as hydrogen and ammonia via power-to-x technologies, enabling storage, energy security, and decarbonization of hard-to-abate sectors. This study assesses the techno-economic feasibility of integrating offshore wind energy with hydrogen and ammonia production as sustainable energy carriers and their transportation via pipelines or shipping. The methodology incorporates Proton Exchange Membrane (PEM) electrolysis for hydrogen production, seawater desalination, and the Haber–Bosch process for ammonia production. Offshore transport scenarios are compared to evaluate their cost-effectiveness based on distance and electrolyzer capacity. Results show the levelized cost of hydrogen (LCOH₂) ranges from EUR 6.7 to 9.8/kg (EUR 0.20–0.29/kWh), and the levelized cost of ammonia (LCOA) ranges from EUR 1.9 to 2.8/kg (EUR 0.37–0.55/kWh). Transportation costs vary significantly with distance and electrolyzer capacity, with levelized cost of transport (LCOT) between EUR 0.2 and 15/kg for pipelines and EUR 0.3 and 10.2/kg for shipping. Also, for distances up to 500 km, pipeline transport is the most cost-effective option for both hydrogen and ammonia. Despite high production costs, economies of scale and technological improvements can make offshore hydrogen and ammonia a promising means for a sustainable energy future. Full article

Maritime transport carries over 80% of global trade by volume and remains the most energy-efficient mode for long-distance goods movement. However, the sector contributes approximately 3% of global Greenhouse Gas (GHG) emissions, a share that could rise to 17% by 2050 without effective regulation. In response, the International Maritime Organization (IMO) has introduced initial and short-term measures to enhance energy efficiency and reduce emissions. In 2023, IMO Strategy expanded on these efforts with medium-term measures, including Market-Based Mechanisms (MBMs) such as a GHG levy, a feebate system, and fuel intensity regulations combined with carbon pricing. This study evaluates the economic and environmental impacts of these measures using an integrated computational simulation model that combines Ocean Engineering and Economics. Our results indicate that all proposed measures support the IMO’s intermediate emission reduction targets through 2035, cutting absolute emissions by more than 50%. However, economic impacts vary significantly across regions, with most of Africa, Asia, and South America experiencing the greatest adverse effects on GDP and trade. Among the measures, the GHG levy exerts the strongest pressure on economic activity and food prices, while a revised fuel intensity mechanism imposes lower costs, particularly in the short term. Revenue redistribution mitigates GDP losses but does so unevenly across regions. By leveraging a general equilibrium model (GTAP) to capture indirect effects often overlooked in prior studies, this analysis provides a comprehensive comparison of policy impacts. The findings underscore the need for equitable and pragmatic decarbonization strategies in the maritime sector, contributing to ongoing IMO policy discussions. Full article