Search Results (874)

This study investigates how the hydrogen supply chain should be designed under alternative carbon tax scenarios to decarbonize heavy-duty freight transportation. A bi-objective, multi-period optimization model is developed to minimize the total daily system cost while constraining CO₂ emissions using the Augmented ε-constraint approach, thereby revealing the trade-off between economic and environmental objectives. The model was applied to Türkiye’s heavy-duty transportation sector and solved under zero, moderate, and aggressive carbon tax scenarios. The results show that the levelized cost of hydrogen (LCOH) ranges from 2.06 to 14.06 $/kg H₂. High carbon pricing increases the LCOH by 29.06% in hybrid designs, while raising the renewable energy share from 2.04% to 46.97% in centralized supply chains. Sensitivity analysis reveals that a ±20% variation in electrolyzer-based production costs does not alter the network topology but shifts the LCOH between 13.10 and 15.02 $/kg H₂ in emission-focused solutions. The findings indicate that in renewable-energy-based decentralized structures, higher carbon tax policies primarily increase the LCOH. Still, the overall technology mix and network topology remain largely unchanged compared to the no-tax case. However, in centralized supply chains, carbon pricing affects both the energy sources and selected technologies. By integrating Türkiye’s 2030–2053 policy milestones into a multi-period framework, this study distinguishes itself by providing a comprehensive, multi-period planning framework tailored to the economic and logistical realities of developing countries. Unlike existing models, our approach quantifies how evolving carbon tax trajectories decisively drive infrastructure investment by analyzing the direct impact of different tax levels on the operational and strategic decisions of heavy-duty transport. This research represents the first joint assessment of carbon tax policy instruments and the evolution of long-term hydrogen supply chains, offering a decision-making framework for policy-driven energy transitions in similar emerging economies. Full article

The rapid expansion of the hydrogen economy has intensified the need for accessible production technologies. This study presents a comparative assessment of two next-generation hydrogen production systems showcased at the Hydrogen Expo Hamburg 2025: the containerised HyPro electrolyser and the modular Enapter EL 4.1. The analysis focuses on their technical specifications, operational philosophies, and indicative costs. Data were gathered through technical consultations with exhibitors and catalogue analyses. The evaluation highlights key differences in system architecture, production capacity, and installation requirements within academic research environments. The results demonstrate how suitability depends on the intended scale of application, contrasting a laboratory-ready modular approach with an industrial-oriented turnkey configuration. This study provides practical insights to support universities and research institutions in selecting hydrogen production equipment that aligns with their specific infrastructural and budgetary conditions. Full article

The transition toward a sustainable hydrogen economy requires the development of advanced materials capable of efficient hydrogen storage and energy conversion. In this work, we present a comprehensive first-principles investigation of the structural, electronic, elastic, and thermoelectric properties of cubic perovskite hydrides XMoH₃ (X = Na, K, and Rb) using the density functional theory within the generalized gradient approximation combined with the Boltzmann transport theory. The calculated gravimetric hydrogen storage capacities are 2.48 wt%, 2.19 wt%, and 1.64 wt% for NaMoH₃, KMoH₃, and RbMoH₃, respectively, indicating moderate storage potential. Elastic analysis confirms mechanical stability and reveals predominantly brittle-to-intermediate behavior with mixed bonding characteristics. Electronic band structures and density of states demonstrate metallic conductivity, driven mainly by Mo-d orbital contributions near the Fermi level, which may facilitate charge transport and hydrogen mobility. Thermoelectric analysis shows temperature-dependent electrical and thermal conductivities, with KMoH₃ and NaMoH₃ exhibiting relatively higher power factors at elevated temperatures, although the overall figure of merit (ZT < 0.3) remains below the threshold for high-performance thermoelectric applications. Despite these limitations, the combined properties of structural stability, metallic conductivity, and moderate hydrogen storage capacity highlight the potential of XMoH₃ compounds as multifunctional materials for integrated hydrogen storage and thermal energy recovery systems. This study provides fundamental insights into the design of perovskite hydrides and underscores their relevance as tunable platforms for future sustainable energy technologies. Full article

The transition to a hydrogen-based energy economy emphasizes the potential of hydrogen as a fuel for plug-in hybrid electric vehicles (PHEVs). The performance of a hydrogen engine within a PHEV depends on the choice of its operating modes, which influence both efficiency and emissions. This study proposes a method for developing engine operating lines (EOLs) on engine maps based on minimizing nitrogen oxide (NOx) emissions while considering constraints on maximum engine power. A total of 15 EOLs are proposed for configurations with both constant and variable maximum engine power. Using mathematical modeling of PHEV operation under the Worldwide Harmonized Light Vehicles Test Cycle (WLTC), the impact of EOL selection on engine characteristics, as well as on battery and generator parameters, is analyzed. For a comprehensive evaluation of EOL effectiveness, five criteria are introduced, considering fuel energy consumption, NOx emissions, wear, mechanical fatigue, and noise, vibration, and harshness (NVH). The Analytic Hierarchy Process (AHP) and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) are applied to determine the weighting factors of the criteria and to rank the proposed EOLs, thereby identifying the most efficient configurations. The results show that, for the base hydrogen engine configuration, selecting appropriate operating modes alone enables NOx emissions to be reduced significantly below Euro 6 limits, without any hardware modifications or exhaust aftertreatment. Full article

Waste-to-hydrogen (W2H) technology is gaining recognition as a viable pathway for simultaneous waste valorisation and clean energy production in the Gulf Cooperation Council (GCC). However, the water resource implications of hydrogen production pathways in this acutely water-scarce region have received insufficient analytical attention. This paper presents the first systematic comparative analysis of water consumption across grey, blue, green, and waste-to-hydrogen production pathways calibrated to the GCC context, using the ISO 14046 water footprint framework and accounting for the desalination penalty that arises when hydrogen facilities draw on energy-intensive desalinated water. The analysis shows that green hydrogen, widely promoted in GCC national hydrogen strategies, incurs a compound water–energy burden substantially greater than global benchmark figures suggest, with electrolysis requiring 9 to 18 litres of water per kilogram of hydrogen and desalination accounting for 4 to 20 per cent of GCC electricity consumption. In contrast, W2H gasification exhibits considerably more modest water demands at 10 litres per kilogram of hydrogen, with high potential for treated wastewater substitution and co-location with municipal waste infrastructure, positioning it as the most water-compatible near-term hydrogen production pathway for arid GCC economies. Drawing on the water–energy nexus and water governance literature, the paper proposes a Water–Hydrogen Governance Framework comprising four policy pillars: water efficiency standards for hydrogen production facilities, water allocation policy for industrial hydrogen projects, integrated water–energy planning at the national level, and regional GCC coordination on water–hydrogen governance. The framework is aligned with SDGs 6, 7, 13, and 17 and provides a structured and practical tool for GCC governments and development institutions seeking to integrate water security into hydrogen strategy. The findings contribute to the emerging literature on resource-constrained hydrogen deployment and offer a replicable governance model for other arid economies pursuing clean hydrogen transitions. Full article

Growing environmental concerns associated with non-renewable and persistent materials have intensified the search for sustainable alternatives, with cellulosic fibers and nanocellulose emerging as promising candidates. This review examines diverse product opportunities where interdigitation plays a critical role, including nanopaper and barrier films, wet wipe technologies, spun cellulose-based yarns, hydrogels, and composite materials. Particular emphasis is placed on the interplay between colloidal stability, fibrillar alignment, hydrogen bonding, and time-dependent network evolution in governing material performance. Additionally, emerging strategies such as hydroentanglement, ice-templating, in situ crosslinking, and post-formation modification are discussed as means to optimize interdigitated structures. The article further explores how conventional papermaking processes may be reimagined to better exploit interdigitation through innovations in fiber dispersion, alignment, and controlled crosslinking. Interdigitation is presented not as a discrete processing tool but as a unifying framework for understanding and engineering hierarchical cellulose networks. By leveraging the inherent fibrillar nature of cellulose and the dynamics of self-assembly, this paradigm offers new pathways towards the development of next-generation, high-performance, bio-based products that contribute to a circular economy. Full article

The reduction in driving range during winter remains a major barrier to the widespread adoption of battery electric buses (BEBs), as battery performance degradation and increased Heating, Ventilation and Air Conditioning (HVAC) energy demand significantly raise total energy consumption. This study investigates the use of proton exchange membrane fuel cells (PEMFCs) as auxiliary power units for range-extended electric buses (FC-REEBs) under low-temperature conditions to address this challenge. A comprehensive dynamic model was developed in MATLAB/Simulink 2025a version, integrating a fuel cell system, lithium-ion battery, power conversion unit, vehicle dynamics, and cabin thermal model. The model was evaluated under the World Harmonized Vehicle Cycle (WHVC) to compare three fuel cell operation strategies defined by fuel cell capacity and operating modes for cabin heating and battery charging. Performance was compared in terms of SOC variation, fuel cell loading patterns, hydrogen consumption, and equivalent fuel economy. Results indicate that the high-capacity strategy improves SOC stability but increases hydrogen consumption and reduces overall efficiency. In contrast, the strategy prioritizing cabin heating with minimal battery charging effectively utilizes waste heat and achieves the highest equivalent fuel economy. These findings highlight key trade-offs among different operating strategies and demonstrate that fuel cells can significantly enhance BEB efficiency and driving performance in cold environments while reducing battery load. Full article

The transition to low-carbon hydrogen is recognized as a priority decarbonization pathway, yet the risk profiles of hydrogen projects remain poorly characterized for non-Western, resource-rich, and geopolitically constrained economies. This study develops and applies a structured expert-based risk mapping framework for low-carbon hydrogen production in Russia. The framework integrates three procedural steps: (1) identification and classification of 21 risk factors across seven thematic groups based on systematic literature analysis; (2) construction of a directed interdependency matrix (7 × 7, ordinal scale 0–2) via structured expert elicitation (n = 10, February 2026); and (3) probability–impact prioritization using the P × S scoring heuristic (both axes on a 1–5 scale, per ISO 31000:2018). Results reveal three critical risk factors (P × S Score ≥ 20): high cost of capital and restricted access to external financing (Score = 24, P = 5, S = 5), dependence on imported electrolyzer components (Score = 20, P = 4, S = 4), and insufficient export infrastructure (Score = 20, P = 5, S = 4). The interdependency matrix identifies economic and financial risks as the primary “accumulator” of systemic influence, receiving maximum incoming impact from all other six groups. Regulatory risks occupy a medium position but exert disproportionate cascading effects on technology choice and project economics. The framework is explicitly designed for transferability to other resource-abundant, capital-constrained economies (Kazakhstan, Iran, Algeria), with structural adaptation conditions specified. Findings are relevant for policymakers, investors, and multilateral stakeholders shaping hydrogen value chains in non-Western contexts. Full article

The shift from fossil fuels to renewable energy is a key component in achieving global sustainability and dealing with climate change. Natural resources, such as sunlight, air, water, and biomass, have tremendous potential to create clean energy; however, exploiting these resources in an efficient, stable, and large-scale integration manner is difficult due to their variable and distributed nature. Artificial intelligence (AI) approaches that mimic human learning and decision-making have recently become viable approaches to solving renewable energy problems. This study mainly examines the current landscape of AI applications across solar, wind, hydro, geothermal, ocean, hydrogen, bioenergy, and hybrid energy systems. AI enhances renewable energy forecasting, improves power system frequency analysis and stability assessments, and optimizes dispatch and distribution networks. Beyond technical optimization, AI also contributes to broader sustainability goals, including energy efficiency improvements, intelligent smart grid management, and enabling mechanisms such as carbon trading and circular economy practices to reduce exposure to climate extremes. Drawing on evidence from a range of renewable energy areas, this review highlights the importance of AI in bridging the link between technological innovation and sustainable energy management. This paper discusses potential future research avenues, such as building sophisticated AI designs, energy-efficient chips, and data communication networks. Ultimately, the synergy between AI and renewable energy systems represents not only a technological advancement but also a transformative pathway toward a resilient, low-carbon future. Full article

Industrial-park integrated electricity–heat–hydrogen energy systems (IEHESs) face a challenging rolling dispatch problem because strong multi-energy coupling, intertemporal storage dynamics, and forecast uncertainty make it difficult to achieve economy, low-carbon operation, and hard-constraint feasibility simultaneously. To address this issue, this paper proposes a graph spatiotemporal world-model-driven rolling model predictive control (MPC) framework, termed GraphWorldModel_MPC, for low-carbon economic dispatch of industrial-park IEHESs. First, a unified graph-based representation is constructed to characterize the topology-aware coupling relationships among the electricity, heat, and hydrogen subsystems. Second, a graph spatiotemporal world model is developed to learn multi-step state transitions, while constraint-aligned physics-consistency terms are incorporated to align the predicted trajectories with multi-energy balance, storage-boundary evolution, and ramping semantics. In addition, the learned dynamics are embedded into a hard-constrained economic MPC framework, and a quantile-based safety-tightening mechanism is adopted to mitigate residual prediction uncertainty and enhance closed-loop feasibility. Case studies on an industrial-park IEHES show that the proposed method achieves an average 24-step normalized root mean square error (NRMSE) of 4.28% and reduces the monthly total operating cost by 6.07%, 3.83%, and 10.79% compared with conventional economic MPC (EMPC), distributionally robust adaptive MPC (DRAMPC), and GRU-MPC, respectively. It also reduces equivalent carbon emissions by 6.89%, 4.52%, and 9.50% relative to these benchmarks, while maintaining zero dispatch violations in the tested monthly horizon. Full article

Road freight contributes over half of China’s transport carbon emissions, making its decarbonization critical for carbon neutrality. This study combines total cost of ownership (TCO) and life cycle assessment (LCA) to analyze the economic efficiency and carbon emission effects of diesel, electric, and hydrogen fuel cell trucks. Combined with the LSTM neural network and vehicle ownership model, this study predicts the fleet emission reduction potential from 2020 to 2050. The results show that all new energy trucks can achieve TCO parity with diesel trucks before 2050, and electrification shows better economic competitiveness than hydrogen fuel cell technology across all vehicle types in the Chinese context. Fuel cell trucks powered via solar-powered water electrolysis exhibit the lowest carbon intensity, and grid decarbonization can significantly improve the emission reduction effects of electric and fuel cell trucks. Freight fleet carbon emissions are expected to peak around 2030. In an ideal scenario, emission reductions of 19.5%, 41.9%, and 82.9% can be achieved by 2030, 2040, and 2050, respectively. Heavy-duty trucks are the main emission contributors (47–58%) and the main target of emission reduction strategies. Short-term reduction depends on fuel economy, while long-term reduction prioritizes new energy substitution. Policy recommendations include promoting alternative fuel trucks, upgrading emission standards, and adopting differential taxation. Full article

The frequent occurrence of extreme climate events poses a severe challenge to the reliability of building energy systems. Hydrogen energy, with its long-term storage capacity, has become a key technology carrier for enhancing building resilience. This study constructs a resilience–environment–economy co-optimization framework that couples dynamic simulation and emergy analysis. Through a five-in-one approach of physical modeling, climate scenario generation, resilience quantification, emergy accounting, and multi-objective optimization, the resilience performance of building hydrogen energy systems under the scenario of extreme heat waves combined with grid failure is evaluated. The results show that the thermal time constant deviation of the electrolyzer is 4.06%, the correlation coefficient between the generated heat wave scenario sequence and the historical measured data is 0.94, the prediction deviation of the once-in-a-century extreme temperature is 0.5%, the environmental load rate is 4.33, the Pareto front contains 127 non-dominated solutions, and the comprehensive performance of the co-optimal solution is improved by 42% to 88%. Engineering suggestions: For public buildings in hot summer and cold winter regions, the hydrogen energy system should adopt a configuration of 50–60 kW electrolyzers and 50–70 kg hydrogen storage tanks, with a key load guarantee rate of no less than 95%, and the ecological cost is 35% lower than that of diesel backup. This study provides a quantitative decision-making tool for the resilience planning of building hydrogen energy systems under extreme climate conditions and can be extended to other high climate risk areas. Full article

Hydrogen embrittlement is a critical degradation mechanism in microalloyed and pipeline steels used in hydrogen-economy infrastructure. We present a physics-informed neural network (PINN) framework that embeds Fick’s second law and the Arrhenius temperature dependence directly into the loss function, trained on 22 temperature-dependent data points spanning pure α-Fe and API X65 pipeline steels (modern and vintage microstructures). The PINN recovered the pure-iron activation energy (4.2 kJ mol⁻¹ vs. literature 4.15 kJ mol⁻¹, R² = 1.00) and yielded Arrhenius activation energies of 28.5 and 45.2 kJ mol⁻¹ for modern and vintage X65, respectively, indicating substantially stronger trapping in older microstructures. McNabb–Foster analysis of ten ternary Fe–Me–C,N alloys revealed flat-trap binding enthalpies of 19 ± 2 kJ mol⁻¹ and deep-trap free energies of 57 ± 2 kJ mol⁻¹, with effective diffusivities spanning three orders of magnitude governed primarily by flat-trap density. The framework provides a computationally efficient and physically consistent tool for hydrogen transport prediction, with a clear roadmap for multi-feature extension incorporating compositional and microstructural descriptors. Full article

Addressing the challenges of fluctuating renewable energy integration and stable green ammonia production, this study develops and optimizes a deeply integrated system comprising Solid Oxide Electrolysis Cells (SOEC), Liquid Air Energy Storage (LAES), Air Separation Units (ASU), and Haber–Bosch (HB) synthesis. We constructed a simulation model in Aspen Plus incorporating Ru/C catalyst kinetic parameters to analyze key subsystem parameters and optimize operating conditions based on maximized economy and efficiency. At the integrated system level, a parametric analysis of ammonia condensation temperature was further conducted to investigate the coupling characteristics. Using real power output data from Inner Mongolia, we formulated a dynamic energy scheduling strategy satisfying 24-h self-balancing constraints. Results indicate that a system producing 1415 tons of ammonia per day achieves a maximum hourly integrated profit of 69,838 CNY under optimal conditions: a hydrogen-to-nitrogen ratio of 2.98:1, operating pressure of 169 bar, reactor inlet temperature of 380 °C, and ammonia condensation temperature of −9 °C. Increasing the LAES throttle valve outlet pressure from 1 bar to 9 bar improved round-trip efficiency from 52.65% to 72.18%. The integrated-level parametric analysis reveals that the specific electricity consumption per unit mass of ammonia exhibits a non-monotonic trend with a minimum of 8.67 kWh/kg at −10 °C, reflecting the trade-off between refrigeration power consumption and cold energy recovery. In dynamic scheduling scenarios, the system maintains a maximum constant load of 45.78 MW with a steady-state liquid ammonia output of 6543 kg/h. This work optimizes both economic performance and system stability, providing a significant reference for the large-scale development of green ammonia systems. Full article

Sustained cislunar logistics operations, including recurring support of the Lunar Gateway at EML1 and EML2, impose demanding propulsion requirements, including high ΔV budgets, restart capability, and long-duration propellant storage, which conventional propulsion approaches struggle to meet efficiently at scale. This study presents a novel cislunar mission architecture based on nuclear thermal propulsion (NTP), operating at a specific impulse of 900 s with liquid hydrogen as propellant and a hydrazine Reaction Control System (RCS) for proximity and docking maneuvers. The architecture is evaluated analytically through sequential application of the Tsiolkovsky rocket equation across two mission scenarios: a direct logistics transfer to EML1 (Scenario A) and a two-burn Gateway staging transfer from EML1 to EML2 (Scenario B), using a launch mass of 9000 kg, a 5% ΔV margin, and deterministic ΔV values of 3164 m/s for LEO→EML1, 160 m/s for EML1→EML2, and 37.36 m/s for RCS operations. The proposed architecture achieves a total propellant mass below 3044 kg and a total delivered mass between 5956 kg and 6071 kg across both scenarios. These results establish NTP as a technically credible foundation for scalable and sustainable cislunar transportation, with broad implications for the development of a permanent lunar economy. Full article