Search Results (93)

The maritime industry faces an unprecedented challenge to achieve the net-zero emissions goal by or around 2050. While numerous alternative fuels are undergoing intense evaluation, the industry remains trapped in a profound ‘technological deadlock’ driven by the irreconcilable trade-offs of current options, where fuel might offer excellent environmental profiles but fail on economic viability or safety acceptance. This study addresses this uncertainty by systematically reviewing 39 studies published from 2015 to 2025 that evaluated alternative fuels for the shipping industry using various criteria. Unlike traditional reviews, this study employs a horizontal synthesis across environmental, economic, technical, safety, and social criteria. By cross-examining these fragmented dimensions, this study maps the core friction points that prevent the scalable deployment of alternative fuels. The synthesis indicates that the regulatory framework should shift from static measures to dynamic, phased carbon pricing to address the immediate green premium of alternative fuels. Additionally, the analysis points to a looming global human capital bottleneck and a significant geographic risk of a two-tier global fleet. Most significantly, this study consolidates a decade of marine fuel evaluations into a practical, strategic fuel-deployment matrix that provides industry managers and global policymakers with a clear roadmap to overcome decision-making inertia and safely guide the maritime transition. Full article

Maritime transport contributes 2.9% of global greenhouse gas emissions, traditionally evaluated through operational fuel cycles while neglecting lifecycle impacts. This study redefines merchant ship recycling as a strategic front-end pillar for global decarbonization by assessing Embodied Carbon Trade-offs. Utilizing a mixed PRISMA systematic and semi-systematic methodology of literature from 2019–2025, we analyzed bulk carriers, container ships, and tankers across six thematic clusters. Our findings demonstrate that scenarios involving the potential decommissioning of up to 22.2% of the global merchant fleet exceeding 20 years of age could significantly mitigate lifecycle emissions by displacing primary iron-ore smelting with circular electric arc furnace marine-steel recovery. Crucially, this environmental dividend is non-linear and bound by regional energy matrices; under deeply decarbonized grids, this technological displacement can theoretically yield an upper-bound 72% emissions reduction, whereas fossil-heavy power supplies significantly diminish net mitigation margins. Practically, this research provides an operational roadmap for shipowners and regulators navigating the Hong Kong Convention and carbon border mechanisms. This work concludes that sustainable shipbreaking has the potential to function as an economically viable, strategic reservoir of low-carbon raw materials essential for achieving international net-zero targets throughout the entire shipping structural lifecycle. Full article

Traditional techno-economic assessments of zero-emission mobility frequently rely on static Total Cost of Ownership (TCO) models that fail to capture the concurrent evolution of economic and environmental parameters. To address this research gap, this study develops a novel dynamic multi-objective optimization framework that jointly assesses TCO and Well-to-Wheel (WTW) emissions across the period 2026–2060, capturing the non-linear trade-offs between cost minimization and lifecycle decarbonization. The model developed compares light-duty hydrogen Fuel Cell Electric Vehicles (FCEVs) with diesel, petrol, and battery-electric vehicles (EVs), incorporating time-varying Capital Expenditure (CAPEX) learning curves, fuel price trajectories, carbon pricing effects, and emissions-decay pathways. Hydrogen break-even prices are computed annually against each competing technology to identify the market conditions under which FCEVs become cost competitive. The results show that light-duty hydrogen FCEVs face a substantial entry barrier in 2026, with a TCO of approximately €275,000, far above diesel, petrol and EV alternatives. However, their relative competitiveness improves over time as hydrogen production costs decline and fossil-fuel vehicle costs increase due to the EU ETS2 and Eurovignette CO₂ surcharges. The analysis identifies two key inflection points, that is, light-duty hydrogen FCEVs become more cost effective than petrol vehicles in 2037 and reach parity with EVs in 2046. In emissions terms, light-duty FCEVs occupy a strong position on the low-WTW frontier, while EVs combine the lowest TCO with similarly favorable emissions performance. To bridge the intermediate cost-parity gap and mitigate infrastructure lock-in risks, targeted policy measures, such as carbon-weighted road toll exemptions, upstream fuel-tax subsidies under the EU ETS2 framework, and capital grants for localized commercial fleet refueling units, are essential to accelerate early-stage market industrialization and secure the economic viability of hydrogen mobility. Full article

Electric trucks play a crucial role in achieving a zero-emission future. As battery electric technology advances, electric trucks are expected to become a cost-effective and sustainable alternative to diesel trucks. Long-haul trucks have unique driving patterns that affect their charging needs, and investigating the expected load profiles is fundamental to conducting a proper assessment of the impact of truck fleet electrification on the charging infrastructure. This article presents an agent-based modeling approach to estimate high-power charging station load profiles, leveraging open data and driver decision-making patterns. The methodology is implemented in a software tool, ABChargingSim, which includes heterogeneous charging logic (distinguishing between urgent mid-shift and long-dwell off-shift charging, as well as different driver triggers to initiate charging) alongside a vehicle’s SOC-dependent power tapering charging patterns. A case study along a Norwegian highway demonstrates the framework’s applicability for evaluating grid impacts under various heavy-duty transport electrification scenarios. The findings illustrate how driver behavior and heavy-duty vehicle charging processes shape expected load profiles, emphasizing the value of such simulation frameworks as essential decision-support tools for the strategic planning and operation of future high-power charging networks. Full article

To address the climate impact of maritime transport, the International Maritime Organization (IMO) has implemented regulations targeting ship emissions, particularly greenhouse gases (GHGs), to achieve net-zero emissions by 2050. Meeting these goals requires accurate estimates of air pollutant emissions and a clear understanding of emission trends. This study estimated air pollutant emissions from ships registered in Republic of Korea between 2021 and 2023 using a bottom-up approach. The methodology incorporates ship specification data, regression models, and correction factors based on actual fuel consumption. For ships lacking engine power data, power was estimated using a regression of gross tonnage by ship type. Annual fuel consumption was calculated using engine power, fuel type, engine configuration, and ship age, and emission factors were applied to estimate CO₂, CH₄, N₂O, and other air pollutants. The results showed that CO₂ accounts for over 98% of GHG emissions, while cargo ships, which represent only 10% of the fleet, contribute more than 60% of total GHG emissions. These findings highlight the importance of prioritizing cargo vessels in CO₂ reduction strategies. This study provides baseline data to align policy development with IMO regulations and underscores the need for a continuous national framework for estimating ship emissions. Full article

Against the backdrop of the global aviation industry’s commitment to achieving the “Net Zero Carbon Emissions by 2050” goal, the issue of superimposed peak loads on distribution networks—arising from the large-scale transition from fossil-fueled to electric Ground Service Equipment (GSE) at civil airports—has become increasingly prominent, emerging as a critical constraint on green airport development. Focusing on the high-value airside area, this paper presents the first systematic review of how Vehicle-to-Grid (V2G) technology can transform electric Ground Service Equipment (e-GSE) from mere “charging loads” into “dispatchable energy storage resources.” The study proposes that, through bidirectional DC charging/discharging and intelligent aggregation technologies, e-GSE fleets operating on predictable schedules can be integrated as flexible regulation units within airport microgrids. To realize this pathway, the study comprehensively examines the core technological framework, encompassing wide-power-range bidirectional charging infrastructure, grid-forming power conversion topologies, standardized communication and grid interconnection interfaces, flight-schedule-based potential assessment and dispatch algorithms, and photovoltaic storage–charging hybrid system integration schemes. The review demonstrates that this technology can not only enhance grid resilience and promote renewable energy accommodation through peak shaving, valley filling, and ancillary services but also yields significant economic benefits. Finally, the study identifies the technical, standardization, and business model barriers hindering large-scale deployment, thereby providing a theoretical reference and a technology roadmap for the energy system planning and construction of future “zero-carbon smart airports”. Full article

The IMO Net-Zero Framework and its carbon regulations impose binding constraints on fuel selection and fleet evolution. A techno-economic optimization model is developed to quantify this interaction along the Shanghai–Los Angeles green shipping corridor. The framework integrates vessel-level Mixed-Integer Non-Linear Programming (MINLP) with a Multinomial Logit formulation to simulate fleet diffusion, minimizing Total Cost of Ownership (TCO) over 2026–2050. The results identify a persistent marginal compliance regime driven by the tiered carbon penalty structure. Rather than achieving full compliance, fleets systematically position their Greenhouse Gas Fuel Intensity (GFI) near the penalty threshold, where limited penalties remain economically preferable to high-cost zero-carbon fuels. This behavior sustains fossil LNG as the dominant transitional option and delays the TCO crossover with ammonia until 2043. Under intensified penalties, the crossover advances to approximately 2030, triggering rapid cost escalation for LNG and eliminating the economic viability of drop-in biofuel strategies. Across all scenarios, absolute zero GHG emissions are not achieved due to residual fossil dependence and upstream Well-to-Wake (WTW) emissions. The transition is therefore bounded by the interaction between penalty avoidance behavior and the pace of Power-to-X fuel deployment. These findings indicate that carbon penalty levels determine the timing of decarbonization, while relative fuel prices govern technology selection, with direct implications for corridor-specific fuel infrastructure and investment decisions. Full article

This study examines Connecticut’s strategic approach to electric vehicle (EV) workforce development within the framework of the Bipartisan Infrastructure Law (BIL) and its National Electric Vehicle Infrastructure (NEVI) program. Amid the U.S. goal to transition to a zero-emission vehicle fleet by 2050, this research investigates whether Connecticut’s current policies sufficiently address the need to reskill automotive mechanics into qualified EV technicians. Using a qualitative case study methodology, semi-structured interviews were conducted with state workforce representatives and analyzed through inductive coding within Kotter’s 8-Step Change Model. Findings reveal that while Connecticut aligns with federal NEVI goals for infrastructure, it lacks a dedicated budget and clearly defined pathways for technician training. Stakeholder collaboration remains fragmented, and efforts to empower workforce transformation are in the early stages. The study concludes that Connecticut risks falling behind unless it integrates a robust workforce development strategy that includes cross-sector partnerships, pilot training programs, and transparent certification pathways. These findings highlight the importance of aligning state-level EV infrastructure planning with human capital development and offer actionable insights for other states navigating similar transitions. Full article

There is an important debate about the appropriate policy measures for reducing greenhouse gas (GHG) emissions in the transport sector. Strong expansion of battery electric vehicles (BEVs) following a ban on the registration of new vehicles with internal combustion engines (ICEs) by 2035 is a prominent but controversial proposal. To evaluate achievable GHG emission reductions, it is essential to understand the temporal dynamics of such a fleet transition. This study provides a time-resolved, policy-oriented quantification of annual and cumulative lifecycle GHG emissions during this process. Therefore, it uses an annual simulation model to assess GHG emissions from vehicle production and use during the transition of Germany’s passenger car fleet between 2019 and 2060. The analysis compares an ICE registration ban by 2035 with alternative scenarios and evaluates the effects of electricity decarbonization, greener BEV production, and the supply of additional Zero Emission Fuels (ZEFs). This study reveals a substantial time lag of 10–20 years between changes in new vehicle registrations and effective emission reductions. Even with a complete ICE ban by 2035, annual GHG emissions decline by only 3.7% by 2030 relative to 2025, while cumulative emissions over this period fall by just 1.6%. Larger reductions occur later, reaching 39% in 2040, 77% in 2050, and 82% in 2060 compared with 2025; cumulative emissions until 2060 decrease by 45%. Without an ICE ban and with a 75% BEV share from 2035 onward, cumulative reductions fall to 34%. Introducing additional ZEFs equivalent to 10% of 2030 fuel demand increases this value to 41%, compensating for much of the lower BEV uptake. Full article

The integration of large-scale electric vehicle (EV) fleets into vehicle-to-grid (V2G) systems offers significant potential for enhancing the operation of renewable-based smart grids. However, stochastic uncertainties in photovoltaic (PV) generation, vehicle availability, and load demand—coupled with battery degradation and life-cycle assessment (LCA) carbon emissions—pose major challenges to optimal scheduling. This paper proposes a scenario-based multi-objective MILP framework for a 500-EV fleet aggregator. The model incorporates Monte Carlo simulations for multi-source uncertainty quantification (±25% PV forecast errors, ±40% availability), LCA penalties (45 kgCO₂eq/kWh), and ancillary service revenues (25 USD/MW-h). Long-term state-of-health (SOH) projections, including a 1-year fade to 96.5%, are also integrated. Comparative analysis of V2X scenarios shows that the V2G Hybrid strategy reduces daily costs by 34.6% (from ~11,000 USD in the uncontrolled case to 7741 USD when reserve revenues are included), achieves over 50% peak shaving, and maintains voltage stability within 0.994–1.008 pu. The stochastic Pareto frontier identifies knee-point solutions that lower normalized expected costs to 134.61 while achieving 1–2% lower expected emissions compared to deterministic baselines. These results demonstrate a comprehensive framework, uncertainty-aware framework that balances economic viability, grid resilience, and environmental sustainability, offering actionable insights for fleet aggregators and policymakers working toward net-zero energy systems. Full article

The electrification of urban and industrial transport is driving the need for propulsion architectures that combine energy efficiency, operational flexibility and regulatory compliance. However, current electric platforms often lack the adaptability required for customized body configurations and multistage manufacturing, and their approval is hindered by the complexity of meeting electrical safety and electromagnetic compatibility (EMC) requirements at vehicle level. This article presents the conceptual design of a modular electric propulsion module developed within the MODULe project, in which the traction motor, inverter, battery pack, Battery Management System (BMS) and cooling circuits are integrated into a standardized module conceived as an Independent Technical Unit (ITU). The propulsion module dimensioned using a modified WLTP cycle, and the results indicate that the selected components can meet the dynamic demands of light and medium-duty vehicles, achieving an estimated consumption of around 50 kWh/100 km and a driving range above 160 km. By concentrating the critical regulatory requirements within a single module, the proposed architecture facilitates multistage vehicle approval, reduces development effort and supports the scalable electrification of commercial fleets. This approach may contribute to accelerating the deployment of zero-emission vehicles in urban logistics and industrial applications, with potential benefits for both the sector and society. Full article

Shared e-scooter systems are frequently characterized as zero-emission mobility solutions; however, lifecycle greenhouse gas (GHG) emissions depend on manufacturing, electricity generation, and operational logistics. While conventional life cycle assessment (LCA) studies quantify environmental impacts using static average parameters, they rarely integrate lifecycle emissions into real-time fleet decision-making. This study proposes a formally defined carbon-aware operational framework that integrates ride-level telemetry, time-varying electricity grid carbon intensity, amortized production emissions, and dynamically allocated logistics impacts into a unified optimization architecture. Lifecycle emissions are computed at ride-level granularity and incorporated into charging and rebalancing decisions through a constrained optimization framework. A multi-objective extension is introduced to account for environmental–economic trade-offs. An illustrative simulation of 1000 rides was conducted to evaluate the operational performance of the framework. Under the assumed baseline scenario, the illustrative carbon-aware simulation indicated a potential reduction of up to 24.5% relative to conventional scheduling. Sensitivity analysis across variations in grid carbon intensity, scooter lifetime, energy consumption, and logistics emissions demonstrated reduction outcomes ranging between 18% and 29%, indicating robustness to parameter uncertainty. The study does not present large-scale empirical validation but provides a mathematically formalized decision-support architecture that operationalizes lifecycle assessment within shared micro-mobility fleet management. The results suggest that integrating carbon metrics into operational control may substantially enhance the environmental performance of shared e-scooter systems. Future research should validate the framework using real-world fleet data and incorporate a comprehensive economic assessment. The proposed framework provides a scalable methodological basis for integrating environmental metrics into real-time micro-mobility management and urban sustainability planning. Full article

The recent expansion of mass public transit in Bangkok has increased demand for public motorcycle taxis as a first- and last-mile solution for sustainable urban mobility. This study presents the results of a real-world demonstration project that transitioned 50 conventional public motorcycle taxis into electric motorcycles supported by a battery-swapping system. The project evaluated vehicle performance, operational patterns, electricity consumption, and greenhouse gas (GHG) emissions under actual traffic conditions. Electric motorcycles deployed in taxi services must accommodate additional passenger load, provide sufficient acceleration for dense urban traffic, and sustain high daily travel distances. The findings show that participating riders accumulated a total driving distance of 759,354 km during the project period, demonstrating the technical and operational feasibility of electrification in high utilization fleets. Based on measured electricity consumption and Thailand’s grid emission factor, the transition resulted in an estimated reduction of approximately 1708.4 metric tons of CO₂ equivalent emissions, excluding additional benefits associated with modal shifts to mass public transit. The results further indicate that battery-swapping infrastructure is a critical operational enabler, as daily travel distances frequently exceed the single-charge range of typical electric motorcycles. Scenario projections aligned with Thailand’s 30-by-30 electric vehicle policy target suggest that large-scale electrification of motorcycle fleets could contribute substantially to national mitigation efforts, supporting the country’s accelerated goal of net-zero emissions target by 2050. Full article

Maritime decarbonization has shifted from a long-term aspiration to an engineering and systems-integrated problem under near-term compliance pressure. International regulatory bodies, governments, and a wide array of private-sector coalitions will tighten greenhouse-gas fuel-emission standards from 2028, translating climate targets into enforceable cost signals and accelerating interest in alternative-fuel and retrofit pathways. This review synthesizes the state of the art (SoA) of maritime decarbonization by mapping where technological bottlenecks concentrate along the well-to-wake (WtW) value chain for the main candidate pathways: biofuels, LNG/bio-LNG, hydrogen, ammonia, e-methanol, and electrification, and by benchmarking them side-by-side using a unified framework designed to compare their realizable well-to-wake GHG-reduction potential under maritime operating constraints. Building on that comparative lens, this work aims to connect pathway readiness to the near-term market and regulatory reality, while the alternative-fuel-capable fleet is projected to expand rapidly, creating a structural capability vs. supply gap, in which, for example, ship readiness can outpace low-GHG fuel availability and bunkering rollout. The merged evidence indicates that near-term abatement will be dominated by scalable drop-in biofuels, whereas deep-sea options (ammonia/hydrogen and e-fuels) remain gated by upstream low-GHG production, port infrastructure, and safety/regulatory maturation. Nevertheless, mid-term deployment of low-GHG fuels can act as a system “relief valve”, reducing infrastructure lock-in and accelerating emissions reductions while zero-carbon fuel supply chains scale up. Full article

The International Maritime Organization (IMO) committed at the 2015 Paris Climate Summit to reducing greenhouse gas (GHG) emissions from shipping. Many studies and classification society outlooks agree that meaningful decarbonisation of deep-sea shipping will require a shift to low- or zero-carbon fuels. This research systematically evaluates three leading alternative fuels—hydrogen, ammonia, and methanol—regarded as capable of helping the sector meet the IMO’s 2050 targets. Each fuel was assessed using technical, environmental, economic, and social criteria through a hybrid multi-criteria decision analysis (MCDA) approach combining the analytical hierarchy process (AHP) and TOPSIS (Technique for Order Preference by Similarity to Ideal Solution). Criteria weights were derived from an online survey of 57 maritime experts, while secondary data from existing literature informed the TOPSIS analysis. AHP results show that environmental performance is the most important factor in fuel selection, followed by technical, economic, and social considerations. The combined AHP and TOPSIS results show that ammonia is the most suitable alternative fuel to reach IMO 2050 goals. This study’s findings provide a structured and evidence-based comparison of the main deep-sea alternative fuels and offer practical guidance for maritime decision-makers seeking to identify the most suitable option for decarbonising their fleets in line with global GHG reduction goals for 2050 and beyond. Full article