Applications & Pathways

Against the backdrop of the global transition towards clean energy deep-sea wind-power hydrogen production integrates offshore wind with green hydrogen technology. Addressing the technical coupling complexity and the impact of uncertain hydrogen prices this paper develops a capacity optimization model. The model incorporates floating wind turbine output the technical distinctions between alkaline (ALK) electrolyzers and proton exchange membrane (PEM) electrolyzers and the synergy with energy storage. Under three hydrogen price scenarios the results demonstrate that as the price increases from 26 CNY/kg to 30 CNY/kg the optimal ALK capacity decreases from 2.92 MW to 0.29 MW while the PEM capacity increases from 3.51 MW to 5.51 MW. Correspondingly the system’s Net Present Value (NPV) exhibits an upward trend. To address the limitations of traditional methods in handling multi-dimensional benefit correlations and information ambiguity a comprehensive benefit evaluation framework encompassing economic technical environmental and social synergies was constructed. Sensitivity analysis indicates that the comprehensive benefit level falls within a relatively high-efficiency interval. The numerical characteristics an entropy value of 3.29 and a hyper-entropy of 0.85 demonstrate compact result distribution and robust stability validating the applicability and stability of the proposed offshore wind–hydrogen benefit assessment model.

Crude oil distillation is one of the most energy-intensive processes in petroleum refining consuming up to 20% of total refinery energy. Improving the energy efficiency of crude distillation units (CDUs) is essential for reducing costs lowering emissions and achieving sustainable refining. Current studies often examine energy savings operational flexibility or renewable energy integration separately. This review brings these aspects together focusing on heat integration advanced control systems and renewable energy options such as solar-assisted preheating and green hydrogen. Advanced column designs including dividing-wall and hybrid systems can cut energy use by 15–30% while AI-based optimization improves process stability and flexibility. Solar-assisted preheating can reduce fossil fuel demand by up to 20% and green hydrogen offers strong potential for decarbonization. Our findings highlight that integrated strategies including advanced simulation tools and machine learning significantly improve CDU performance. We recommend exploring hybrid algorithms renewable energy integration and sustainable technologies to address these challenges and achieve long-term environmental and economic benefits.

Replacing the energy density and convenience of diesel fuel for all forms of fossil fuel-powered trains presents significant challenges. Unlike the traditional evolutions of rail which has largely self-optimised to different fuels and cost structures over 150 years the challenges now present with a timeline of just a few decades. Fortunately unlike the mid-1800s simulation and modelling tools are now quite advanced and a full range of scenarios of operations and train trips can be simulated before new traction systems are designed. Full trip simulations of large heavy haul trains or high speed passenger trains are routinely completed controlled by emulations of human drivers or automated control systems providing controls of the “virtual train”. Recent developments in digital twins can be used to develop flexible and dynamic models of passenger and freight rail systems to support the new complexities of decarbonisation efforts. Interactions between many different traction components and the train multibody system can be considered as a system of systems. Adopting this multi-modelling paradigm enables the secure and integrated interfacing of diverse models. This paper demonstrates the application of the multi-modelling approach to develop digital twins for rail decarbonisation traction and it presents physics-based multi-models that include key components required for studying rail decarbonisation problems. Specifically the challenge of evaluating zero-emission options is addressed by adding further layers of modelling to the existing fully detailed multibody dynamics simulations. The additional layers detail control options energy storage the alternate traction system components and energy management systems. These traction system components may include both electrical system and inertia dynamics models to accurately represent the driveline and control systems. This paper presents case study examples of full trip scenarios of both long haul freight trains and higher speed passenger trains. These results demonstrate the many complex scenarios that are difficult to anticipate. Flowing on from this risks can be assessed and practical designs of zero-emission systems can be proposed along with the required recharging or refuelling systems.

The shipping industry remains heavily dependent on heavy fuel oils which account for approximately 77% of fuel consumption and contribute significantly to greenhouse gas (GHG) emissions. In line with the IMO’s decarbonization targets ammonia has emerged as a promising carbon-free alternative. This study evaluates the strategic viability of ammonia especially green production as a marine fuel through a hybrid SWOT–Best–Worst Method (BWM) analysis combining literature insights with expert judgment. Data were collected from 17 maritime professionals with an average of 15.7 years of experience ensuring robust sectoral representation and methodological consistency. The results highlight that opportunities hold the greatest weight (0.352) particularly the criteria “mandatory carbonfree by 2050” (O3:0.106) and “ammonia–hydrogen climate solution” (O2:0.080). Weaknesses rank second (0.270) with “higher toxicity than other marine fuels” (W5:0.077) as the most critical concern. Strengths (0.242) underscore ammonia’s advantage as a “carbonfree and sulfur-free fuel” (S1:0.078) while threats (0.137) remain less influential though “costly green ammonia” (T3:0.035) and “uncertainty of green ammonia” (T1:0.034) present notable risks. Overall the analysis suggests that regulatory imperatives and environmental benefits outweigh safety technical and economic challenges. Ammonia demonstrates strong potential to serve as viable marine fuel in achieving the maritime sector’s long-term decarbonization goals.

This study presents a techno-economic and environmental optimization of hydrogen-based hybrid energy systems (HESs) for Broken Hill City Council in New South Wales Australia. Two configurations are evaluated: Configuration 1 includes solar PV battery fuel cell electrolyzer and hydrogen storage while Configuration 2 includes solar PV fuel cell electrolyzer and hydrogen storage but excludes the battery. The system is optimized using advanced metaheuristic algorithms such as Harris Hawks Algorithm (HHA) Red-Tailed Hawk Algorithm and Non-Dominated Sorting Genetic Algorithm-II while ensuring real-time supply–demand balance and system stability through a robust energy management strategy. This integrated approach simultaneously determines the optimal sizes of PV arrays battery storage (where applicable) fuel cells electrolyzers and hydrogen storage units and maintains reliable energy supply. Results show that HHA Configuration 1 achieves the lowest net present cost of $338111 a levelized cost of electricity of $0.185/kWh and a levelized cost of hydrogen of $4.60/kg. Sensitivity analysis reveals that PV module and hydrogen storage costs significantly impact system economics while improving fuel cell efficiency from 40% to 60% can reduce costs by up to 40%. Beyond cost-effectiveness life cycle analysis demonstrates annual CO2 emission reductions exceeding 500000 kg compared to an equivalent diesel generator system meeting the same load demand. Socio-economic assessments further indicate that the HES can support improvements in the Human Development Index by enhancing access to healthcare education and economic opportunities while also creating local jobs in PV installation battery maintenance and hydrogen infrastructure. These findings establish hydrogen-based HES as a scalable cost-effective and environmentally sustainable solution for energy access in remote areas.

Enhancing the economics of microgrid systems and achieving a balance between energy supply and demand are critical challenges in capacity allocation research. Existing studies often neglect the optimization of electrolyzer efficiency and multi-stack operation leading to inaccurate assessments of system benefits. This paper proposes a capacity allocation model for wind-PV-hydrogen integrated microgrid systems that incorporates hydrogen production efficiency optimization. This paper analyzes the relationship between the operating efficiency of the electrolyzer and the output power regulates power generation-load mismatches through a renewable energy optimization model and establishes a double-layer optimal configuration framework. The inner layer optimizes electrolyzer power allocation across periods to maximize operational efficiency while the outer layer determines configuration to maximize daily system revenue. Based on the data from a demonstration project in Jiangsu Province China a case study is conducted to verify that the proposed method can improve system benefits and reduce hydrogen production costs.

The integration of more-electric technologies into aero-engines has revolutionized their multi-power architectures substantially improving system maintainability and operational reliability. This advancement has established more-electric systems as a cornerstone of modern aerospace electrification research. Concurrently liquid hydrogen (LH2) emerges as a transformative solution for next-generation power generation systems particularly in enabling the transition from 100 kW to megawatt-class propulsion systems. Beyond its superior energy density LH2 demonstrates dual functionality in thermal management: it serves as both an efficient coolant for power electronics (e.g. controllers) and a cryogenic source for superconducting motor applications. This study systematically investigates the electrification pathway for LH2-fueled aero-engine multi-electric systems. First we delineate the technical framework elucidating its architectural characteristics and associated challenges. Subsequently we conduct a comprehensive analysis of three critical subsystems including LH2 storage and delivery systems cryogenic cooling systems for superconducting motors and Thermal management systems for high-power electronics. Finally we synthesize current research progress and propose strategic directions to accelerate the development of LH2-powered more-electric aero-engines addressing both technical bottlenecks and future implementation scenarios.

With the transition to a fully renewable energy grid arises the need for a green source of stability and baseload support which classical renewable generation such as wind and solar cannot offer due to their uncertain and highly-variable generation. In this paper we study whether green hydrogen can close this gap as a source of supplemental generation and storage. We design a two-stage mixed-integer stochastic optimization model that accounts for uncertainties in renewable generation. Our model considers the investment in renewable plants and hydrogen storage as well as the operational decisions for running the hydrogen storage systems. For the data considered we observe that a fully renewable network driven by green hydrogen has a greater potential to succeed when wind generation is high. In fact the main investment priorities revealed by the model are in wind generation and in liquid hydrogen storage. This long-term storage is more valuable for taking full advantage of hydrogen than shorter-term intraday hydrogen gas storage. In addition we note that the main driver for the potential and profitability of green hydrogen lies in the electricity demand and prices as opposed to those for gas. Our model and the investment solutions proposed are robust with respect to changes in the investment costs. All in all our results show that there is potential for green hydrogen as a source of baseload support in the transition to a fully renewable-powered energy grid.

The search for alternatives to fossil fuels has led to hydrogen becoming an important factor in the powering means of transportation. Its most effective application is in fuel cells. A single fuel cell is not a sufficient source of power which is why a stack of fuel cells is the more common solution. Fuel cells are tested using single units as this allows all cell parameters (the current density flow rates and efficiency) to be evaluated. Therefore the scalability of fuel cells is an essential factor. This paper analyses the scalability of fuel cells with a power of approximately 100 kW and 1.2 kW. Road tests of the fuel cells were compared with stationary tests which allowed the load to be reproduced and scaled. This provided a representation of the scaled current and the scalable power of the fuel cell. The research provided voltage–current characteristics of fuel cell stacks and their individual equivalents. It was concluded that regardless of the power scaling or current values the characteristics obtain similar patterns. A very important element of the research is the awareness of the properties of these cells (the number of cells and active charge exchange area) in order to compare the unit characteristics of fuel cells.

Implementing innovative solutions in the internal transport of manufacturing enterprises is becoming an important element of improving operational efficiency and reducing greenhouse gas emissions. This article assesses the potential of hydrogen fuel cell (HFCV) forklifts in a steel products manufacturing plant. The verification was carried out using a computer simulation which enabled the comparison of electric combustion and HFCV fleets under identical logistical conditions. The results showed that the HFCV fleet allowed for shorter process execution times and higher utilization compared to electric and combustion variants mainly due to the elimination of charging and refueling interruptions. Additionally when powered by green hydrogen the HFCV fleet offered clear environmental benefits and lower operating costs. The study confirms that HFCV technology can improve the efficiency of internal transport and reduce energy-related operating expenses although the costs of hydrogen refueling infrastructure were not included and should be addressed in future research.