China, People’s Republic

Transitioning to renewable energy is vital to achieving decarbonization at the global level but energy storage is still a major challenge. This review discusses the role of energy storage in the energy transition and the blue economy focusing on technological development challenges and directions. Effective storage is vital for balancing intermittent renewable energy sources like wind solar and marine energy with the power grid. The development of battery technologies hydrogen storage pumped hydro storage and emerging technologies like sodium-ion and metal-air batteries is discussed for their potential for large-scale deployment. Shortages in critical raw materials environmental impact energy loss and costs are some of the challenges to large-scale deployment. The blue economy promises opportunities for offshore energy storage notably through ocean thermal energy conversion (OTEC) and compressed air energy storage (CAES). Moreover the capacity of datadriven optimization and artificial intelligence to enhance storage efficiency is discussed. Policy interventions and economic incentives are necessary to spur the development and deployment of sustainable energy storage technology. Education and workforce training are also important in cultivating future researchers engineers and policymakers with the ability to drive energy innovation. Merging sustainability training with an interdisciplinary approach can potentially establish an efficient workforce that is capable of addressing energy issues. Future work needs to focus on higher energy density efficiency recyclability and cost-effectiveness of the storage technologies without sacrificing their environmental sustainability. The study underlines the need for converging technological economic and educational approaches to enable a sustainable and resilient energy future.

Hydrogen fuel cell vessels represent a vital direction for green shipping but the risk of large-scale hydrogen leakage and diffusion in their enclosed compartments is particularly prominent. To enhance safety a simplified three-dimensional model of the deck-level cabins of the “Water-Go-Round” passenger ship was established using SolidWorks (2023) software. Based on a hydrogen leakage and diffusion model the effects of leakage location leakage aperture and initial ambient temperature on the diffusion patterns and distribution of hydrogen within the cabins were investigated using FLUENT software. The results show that leak location significantly affects diffusion direction with hydrogen leaking from the compartment ceiling diffusing horizontally much faster than from the floor. When leakage occurs at the compartment ceiling hydrogen can reach a maximum horizontal diffusion distance of up to 5.04 m within 540 s; the larger the leak aperture the faster the diffusion with a 10 mm aperture exhibiting a 40% larger diffusion range than a 6 mm aperture at 720 s. The study provides a theoretical basis for the safety design and risk prevention of hydrogen fuel cell vessels.

Amid escalating global climate crises and the urgent imperative to meet the Paris Agreement’s carbon neutrality targets the steel industry—a leading contributor to global greenhouse gas emissions—confronts unprecedented challenges in driving sustainable industrial transformation through innovative low-carbon steelmaking technologies. This paper examines decarbonization technologies across three stages (source process and end-of-pipe) for two dominant steel production routes: the long process (BF-BOF) and the short process (EAF). For the BF-BOF route carbon reduction at the source stage is achieved through high-proportion pellet charging in the blast furnace and high scrap ratio utilization; at the process stage carbon control is optimized via bottom-blowing O2-CO2-CaO composite injection in the converter; and at the end-of-pipe stage CO2 recycling and carbon capture are employed to achieve deep decarbonization. In contrast the EAF route establishes a low-carbon production system by relying on green and efficient electric arc furnaces and hydrogen-based shaft furnaces. At the source stage energy consumption is reduced through the use of green electricity and advanced equipment; during the process stage precision smelting is realized through intelligent control systems; and at the end-of-pipe stage a closed-loop is achieved by combining cascade waste heat recovery and steel slag resource utilization. Across both process routes hydrogen-based direct reduction and green power-driven EAF technology demonstrate significant emission reduction potential providing key technical support for the low-carbon transformation of the steel industry. Comparative analysis of industrial applications reveals varying emission reduction efficiencies economic viability and implementation challenges across different technical pathways. The study concludes that deep decarbonization of the steel industry requires coordinated policy incentives technological innovation and industrial chain collaboration. Accelerating large-scale adoption of low-carbon metallurgical technologies through these synergistic efforts will drive the global steel sector toward sustainable development goals. This study provides a systematic evaluation of current low-carbon steelmaking technologies and outlines practical implementation strategies contributing to the industry’s decarbonization efforts.

To address the collaborative optimization challenge in multi-microgrid systems with significant renewable energy integration this study presents a dual-layer optimization model incorporating power-hydrogen coupling. Firstly a hydrogen energy system coupling framework including photovoltaics storage batteries and electrolysis hydrogen production/fuel cells was constructed at the architecture level to realize the flexible conversion of multiple energy forms. From a modeling perspective the upper-layer optimization aims to minimize lifecycle costs by determining the optimal sizing of distributed PV systems battery storage hydrogen tanks fuel cells and electrolyzers within the microgrid. At the lower level a distributed optimization framework facilitates energy sharing (both electrical and hydrogen-based) across microgrids. This operational layer maximizes yearly system revenue while considering all energy transactions—both inter-microgrid and grid-to-microgrid exchanges. The resulting operational boundaries feed into the upper-layer capacity optimization with the optimal equipment configuration emerging from the iterative convergence of both layers. Finally the actual microgrid in a certain area is taken as an example to verify the effectiveness of the proposed method.

Hydrogen production from water electrolysis can not only reduce greenhouse gas emissions but also has abundant raw materials which is one of the ideal ways to produce hydrogen from new energy. The hydrogen production power supply is the core component of the new energy electrolytic water hydrogen production device and its characteristics have a significant impact on the efficiency and purity of hydrogen production and the service life of the electrolytic cell. In essence the DC/DC converter provides the large current required for hydrogen production. For the converter its input still needs the support of a DC power supply. Given the maturity and technical characteristics of new energy power generation integrating energy storage into offshore energy systems enables stable power supply. This configuration not only mitigates energy fluctuations from renewable sources but also further reduces electrolysis costs providing a feasible pathway for large-scale commercialization of green hydrogen production. First this paper performs a simulation analysis on the wind–solar hybrid energy storage power generation system to demonstrate that the wind–solar–storage system can provide stable power support. It places particular emphasis on the significance of hydrogen production power supply design—this focus stems primarily from the fact that electrolyzers impose specific requirements on high operating current levels and low current ripple which exert a direct impact on the electrolyzer’s service life hydrogen production efficiency and operational safety. To suppress the current ripple induced by high switching frequency and high output current traditional approaches typically involve increasing the output inductor. However this method substantially increases the volume and weight of the device reduces the rate of current change and ultimately results in a degradation of the system’s dynamic response performance. To this end this paper focuses on developing a virtual impedance control technology aiming to reduce the ripple amplitude while avoiding an increase in the filter inductor. Owing to constraints in current experimental conditions this research temporarily relies on simulation data. Specifically a programmable power supply is employed to simulate the voltage output of the wind–solar–storage hybrid system thereby bringing the simulation as close as possible to the actual operating conditions of the wind–solar–storage hydrogen production system. The experimental results demonstrate that the proposed method can effectively suppress the ripple amplitude maintain high operating efficiency and ultimately meet the expected research objectives. That makes it particularly suitable as a high-quality power supply for offshore hydrogen production systems that have strict requirements on volume and weight.

As the global push for carbon neutrality accelerates energy efficiency has become essential for sustainable development especially for nations like Nigeria that face rising energy demands and significant environmental challenges. This study explores how integrating energy efficiency with carbon neutrality can support Nigeria’s strategic energy goals while offering global lessons for other countries facing similar challenges focusing on key sectors including industry transport and power generation. The study systematically examines the impacts of renewable energy (RE) technologies like solar wind and hydropower—alongside policy reforms technological innovations and demand-side management strategies to advance energy efficiency in Nigeria. Key findings include the identification of strategic policy frameworks technological solutions and the transformative role of green hydrogen in decarbonizing hard-to-electrify sectors. The study also emphasizes the importance of international climate finance decentralized RE systems like solar mini-grids for improving energy access and economic opportunities for job creation in the RE sector. Furthermore it highlights the need for behavioral changes community engagement and consistent policy implementation to address infrastructure gaps and drive energy efficiency goals. The novelty of this research lies in its scenario-based analysis of Nigeria’s low-carbon transition detailing both the opportunities and challenges such as policy inconsistencies infrastructure deficits and financial constraints. The findings stress the importance of international collaboration technological advancements and targeted investments to overcome these challenges. By offering actionable insights and strategic recommendations this study provides a roadmap for policymakers industry stakeholders and researchers to drive Nigeria towards a sustainable carbon-neutral future by 2050.

With the growing significance of hydrogen in the global energy transition research on its pricing mechanisms has become increasingly crucial. Focusing on hydrogen markets predominantly supplied by electrolytic production this study proposes a nodal marginal hydrogen price decomposition algorithm that explicitly incorporates the time-delay dynamics inherent in hydrogen transmission. A four-dimensional price formation framework is established comprising the energy component network loss component congestion component and time-delay component. To address the nonconvex optimization challenges arising in the market-clearing model an improved second-order cone programming method is introduced. This method effectively reduces computational complexity through the reconstruction of time-coupled constraints and reformulation of the Weymouth equation. On this basis the analytical expression of the nodal marginal hydrogen price is rigorously derived elucidating how transmission dynamics influence each price component. Empirical studies using a modified Belgian 20-node system demonstrate that the proposed pricing mechanism dynamically adapts to load variations with hydrogen prices exhibiting a strong correlation with electricity cost fluctuations. The results validate the efficacy and superiority of the proposed approach in hydrogen energy market applications. This study provides a theoretical foundation for designing efficient and transparent pricing mechanisms in emerging hydrogen markets.

The operational optimization of industrial boilers utilizing hydrogen-enriched natural gas is constrained by two critical gaps: insufficient understanding of the coupled effects of hydrogen blending ratio equivalence ratio and boiler load on combustion performance— compounded by unresolved challenges of combustion instability flashback and elevated NOx emissions—and a lack of systematic investigations combining these parameters in industrial-scale systems (prior studies often focus on single variables like hydrogen fraction). To address this a comprehensive computational fluid dynamics (CFD) analysis was conducted on a 2.1 MW industrial boiler employing the Steady Laminar Flamelet Model (SLFM) with a modified k-ε turbulence model and the GRI-Mech 3.0 mechanism. Simulations covered hydrogen fractions (f(H2) = 0–25%) equivalence ratios (Φ = 0.8–1.2) and load conditions (15–100%). All NOx emissions reported herein are normalized to 3.5% O2 (mg/Nm3 ) for regulatory comparison. Results show that increasing the hydrogen content raises the flame temperature and NOx emissions while reducing CO and unburned hydrocarbons; a higher equivalence ratio elevates temperature and NOx with Φ = 0.8 balancing efficiency and emission control; and reducing load significantly lowers furnace temperature and NO emissions. Notably the boiler’s unique staged-combustion configuration (81% fuel supply to the central rich-combustion nozzle 19% to the concentric lean-combustion nozzle) was found to mitigate NOx formation by 15–20% compared to single-inlet burner designs and its integrated cyclone blades (generating maximum swirling velocity of 14.2 m/s at full load) enhanced fuel–air mixing which became particularly critical for maintaining combustion stability at low loads (≤20%) and high hydrogen blending ratios (≥20%). This study provides quantitative trade-off insights between combustion efficiency and pollutant formation offering actionable guidance for the safe efficient operation of hydrogen-enriched natural gas in industrial boilers.

The rapid adoption of hydrogen fuel cell vehicles (HFCVs) in the Beijing–Tianjin–Hebei (BTH) hub accentuates the mismatch between renewable-based hydrogen supply in Hebei and concentrated demand in Beijing and Tianjin. We develop a mixed-integer linear model that co-configures a hydrogen pipeline network and optimizes hourly flow schedules to minimize annualized cost and CO2 emissions simultaneously. For 15000 HFCVs expected in 2025 (137 t d−1 demand) the Pareto-optimal design consists of 13 production plants 43 pipelines and 38 refueling stations delivering 50767 t yr−1 at 68% pipeline utilization. Hebei provides 88% of the hydrogen 70% of which is consumed in the two megacities. Hourly profiles reveal that 65% of electrolytic output coincides with local wind–solar peaks whereas refueling surges arise during morning and evening rush hours; the proposed schedule offsets the 4–6 h mismatch without additional storage. Transport distances are 40% < 50 km 35% 50–200 km and 25% > 200 km. Raising the green hydrogen share from 10% to 70% increases total system cost from USD 1.56 bn to USD 2.73 bn but cuts annual CO2 emissions from 142 kt to 51 kt demonstrating the trade-off between cost and decarbonization. The model quantifies the value of sub-day pipeline scheduling in resolving spatial–temporal imbalances for large-scale low-carbon hydrogen supply.

Fuel cell electric vehicles (FCEVs) are zero-emission but face cost and power density challenges. To mitigate these limitations a novel 3D-ordered nano-structured self-supporting membrane electrode assembly (MEA) has been developed. This paper investigates the optimal component sizing of the battery and fuel cell in FCEVs equipped with 3D-ordered MEAs integrating the energy management. To explore the trade-offs between component cost operational cost and fuel cell degradation the sizing and energy management problem is formulated into a multi-objective optimisation problem. A Pareto frontier (PF) study is conducted using the decomposed multi-objective evolutionary algorithm (MOEA/D) for a more diverse distribution of feasible solutions. The modular design of fuel cells is derived from a scaled and stressed experiment. After executing MOEA/D across the three aggressive driving cycles power source configurations are selected from the corresponding PFs based on objective trade-offs ensuring robustness of the overall system. The optimisation performance of the MOEA/D is compared with that of the multi-objective Particle Swarm Optimisation. In addition the selected powertrain configurations are evaluated and compared through standard and realworld driving cycles in a simulation environment. This paper also performs a sensitivity analysis to reveal the influence of diverse component unit costs and hydrogen price. The results indicate that the mediumsized configuration consisting of a 63.31 kW fuel cell stack and a 52.15 kWh battery pack delivers the best overall performance. It achieves a 26.71% reduction in component cost and up to 12.76% savings in hydrogen consumption across various driving conditions. These findings provide valuable insights into the design and optimisation of fuel cell systems for FCEVs.