Applications & Pathways

The paper discusses potential hazards at hydrogen refueling stations for transportation vehicles: cars and trucks. The main hazard analyzed here is an uncontrolled gas release due to a failure in one of the structures in the station: storage tanks of different pressure levels or a dispenser. This may lead to a hydrogen cloud occurring near the source of the release or at a given distance. The range of the cloud was analyzed in connection to the amount of the released gas and the wind velocity. The results of the calculations were compared for chosen structures in the station. Then potential fires and explosions were investigated. The hazard zones were calculated with respect to heat fluxes generated in the fires and the overpressure generated in explosions. The maximum ranges of these zones vary from about 14 to 30 m and from about 9 to 14 m for a fires and an explosions of hydrogen respectively. Finally human death probabilities are presented as functions of the distance from the sources of the uncontrolled hydrogen releases. These are shown for different amounts and pressures of the released gas. In addition the risk of human death is determined along with the area where it reaches the highest value in the whole station. The risk of human death in this area is 1.63 × 10−5 [1/year]. The area is approximately 8 square meters.

This study aims to explore the techno-economic potential of harnessing waste heat from a Small Modular Reactor (SMR) to fuel Direct Air Carbon Capture (DACC) and High Temperature Steam Electrolysis (HTSE) technologies. The proposed system’s material flows and energy demands are modelled via the ASPEN Plus v12.1 where results are utilised to provide estimates of the Levelised Cost of DACC (LCOD) and Levelised Cost of Hydrogen (LCOH). The majority of thermal energy and electrical utilities are assumed to be supplied directly by the SMR. A sensitivity analysis is then performed to investigate the effects of core operational parameters of the system. Key results indicate levelised costs of 4.66 $/kgH2 at energy demands of 34.37 kWh/kgH2 and 0.02 kWh/kgH2 thermal for HTSE hydrogen production and 124.15 $/tCO2 at energy demands of 31.67 kWh/tCO2 and 126.33 kWh/tCO2 thermal for carbon capture; parameters with most impact on levelised costs are air intake and steam feed for LCOD and LCOH respectively. Both levelised costs i.e. LCOD and LCOH would decrease with the production scale. The study implies that an integrated system of DACC and HTSE provided the best cost-benefit results however the cost-benefit analysis is heavily subjective to geography politics and grid demand.

The increase in the feasibility of hydrogen-based generation makes it a promising addition to the realm of renewable energies that are being employed to address the issue of electric vehicle charging. This paper presents technical and an economical approach to evaluate a newer off-grid hybrid PV-hydrogen energy-based recharging station in the city of Jamshoro Pakistan to meet the everyday charging needs of plug-in electric vehicles. The concept is designed and simulated by employing HOMER software. Hybrid PV-hydrogen and PV-hydrogenbattery are the two different scenarios that are carried out and compared based on their both technical as well as financial standpoints. The simulation results are evident that the hybrid PV- hydrogen-battery energy system has much more financial and economic benefits as compared with the PV-hydrogen energy system. Moreover it is also seen that costs of energy from earlier from hybrid PV-hydrogen-battery is more appealing i.e. 0.358 $/kWh from 0.412 $/kWh cost of energy from hybrid PV-hydrogen. The power produced by the hybrid PV- hydrogen - battery energy for the daily load demand of 1700 kWh /day consists of two powers produced independently by the PV and fuel cells of 87.4 % and 12.6 % respectively.

Hydrogen fuel cell electric vehicles (HFCEVs) provide significant environmental benefits. Integrating dual-motor coupling powertrains (DMCPs) further enhances efficiency and dynamic performance. This article proposes an energy management strategy (EMS) for the hydrogen fuel cell/battery/super-capacitor system in an HFCEV with DMCP. Model predictive control (MPC) is adopted as the framework to optimize economic performance defined in this study as the hydrogen consumption cost and fuel cell degradation cost. To improve the prediction horizon and accuracy the torque split ratio for two varying permanent magnet synchronous motors (PMSMs) and the corresponding mode switching rules of the vehicle are initially established. Subsequently a combination of Dynamic Programming (DP) and MPC is selected as the framework utilizing a Dung Beetle Optimizer (DBO)-optimized Bidirectional Long Short-Term Memory (BiLSTM) network to refine the predictive model. Finally comparisons with other predictive models and commonly used control strategies demonstrate that the proposed EMS notably improves economic performance.

Many industrialised nations recently concentrated their focus on hydrogen as a viable option for the decarbonisation of fossil-intensive sectors including maritime transportation. A sustainable alternative to the conventional production of hydrogen based on fossil hydrocarbons is water electrolysis powered by renewable energy sources. This paper presents a detailed techno-economic optimisation model for sizing an electrolyser and a hydrogen storage embedded in a multi-domain virtual power plant to produce green hydrogen for seaborne passenger transportation. We base our numerical analysis on three years of historical data from a renewable-dominated 60/10 kV substation on the Danish island of Bornholm and on data for ferries to the mainland of Sweden. Our analysis shows that an electrolyser system serves as a valuable flexibility asset on the electrical demand side while supporting the thermal management of the district heating system and contributing to meeting the ferries hydrogen demand. With a sized electrolyser of 9.63 MW and a hydrogen storage of 1.45 t the hydrogen assets are able to take up a large share of the local excess electricity generation. The waste heat of the electrolyser delivers a significant share of 21.4% of the annual district heating demand. Moreover the substation can supply 26% of the hydrogen demand of the ferries from local resources. We further examine the sensitivity of the asset sizing towards investment costs electrolyser efficiency and hydrogen market prices.

This paper presents an energy management system (EMS) based on a novel approach using model predictive control (MPC) for the optimized operation of power sources in a hybrid charging station for electric vehicles (EVs). The hybrid charging station is composed of a photovoltaic (PV) system a battery a complete hydrogen system based on a fuel cell (FC) electrolyzer (EZ) and tank as an energy storage system (ESS) grid connection and six fast charging units all of which are connected to a common MVDC bus through Z-source converters (ZSC). The MPC-based EMS is designed to control the power flow among the energy sources of the hybrid charging station and reduce the utilization costs of the ESS and the dependency on the grid. The viability of the EMS was proved under a long-term simulation of 25 years in Simulink using real data for the sun irradiance and a European load profile for EVs. Furthermore this EMS is compared with a simpler alternative that is used as a benchmark which pursues the same objectives although using a states-based strategy. The results prove the suitability of the EMS achieving a lower utilization cost (-25.3%) a notable reduction in grid use (-60% approximately) and an improvement in efficiency.

Hydrogen demand estimation for various transport modes supports policy and decision-making for the transition towards a sustainable low-carbon future transport system. It is one of the major factors that determine infrastructure construction production and distribution cost optimisation. Researchers have developed various methods for modelling hydrogen demand and its geographical distribution each based on different sets of predictor variables. This paper systematically reviews these methods and examines the key variables used in hydrogen demand estimation including the number of vehicles travel distance penetration rate and fuel economy. It emphasises the role of spatial analysis in uncovering the geographical distribution of hydrogen demand providing insights for strategic infrastructure planning. Furthermore the discussion underscores the significance of minimising uncertainty by incorporating multiple scenarios into the model thereby accommodating the dynamic nature of hydrogen adoption in transport. The necessity for multi-temporal estimation which accounts for the changing nature of hydrogen demand over time is also highlighted. In addition this paper advocates for a holistic approach to hydrogen demand estimation integrating spatiotemporal analysis. Future research could enhance the reliability of hydrogen demand models by addressing uncertainty through advanced modelling techniques to improve accuracy and spatial-temporal resolution.

This second edition of the European Maritime Transport Environmental Report (EMTER 2025) examines the progress made towards achieving Europe′s decarbonisation targets and environmental goals for the maritime sector while indicating the most important trends key challenges and opportunities. The objective was to update the indicators developed for the first report analyse new datasets and fill existing gaps to provide a data and knowledge-based assessment of the maritime transport sector′s transition to sustainability.

In this study Distribution of Relaxation Times (DRT) was successfully demonstrated in the analysis of the impedance spectra of High-Temperature Polymer Electrolyte Membrane Fuel Cells (HT-PEMFC) doped with phosphoric acid. Electrochemical impedance spectroscopy (EIS) was performed and the quality of the recorded spectra was verified by Kramers-Kronig relations. DRT was then applied to the measured spectra and polarization losses were separated on the basis of their typical time constants. The main features of the distribution function were assigned to the cell’s polarization processes by selecting appropriate experimental conditions. DRT can be used to identify individual internal HT-PEMFC fuel cell phenomena without any a-priori knowledge about the physics of the system. This method has the potential to further improve EIS spectra interpretation with either equivalent circuits or physical models.

Aviation is one of the most important industries in the current global scenario but it has a significant impact on climate change due to the large quantities of carbon dioxide emitted daily from the use of fossil kerosene-based fuels (jet fuels). Although technological advancements in aircraft design have enhanced efficiency and reduced emissions over the years the rapid growth of the aviation industry presents challenges in meeting the environmental targets outlined in the “Flightpath 2050” report. This highlights the urgent need for effective decarbonisation strategies. Hydrogen propulsion via fuel cells or combustion offers a promising solution with the combustion route currently being more practical for a wider range of aircraft due to the limited power density of fuel cells. In this context this paper designs and models a nitrogen–hydrogen heat exchanger architecture for use in an innovative hydrogen-propelled aircraft fuel system where the layout was recently proposed by the same authors to advance sustainable aviation. This system stores hydrogen in liquid form and injects it into the combustion chamber as a gas making the cryogenic heat exchanger essential for its operation. In particular the heat exchanger enables the vaporisation and superheating of liquid hydrogen by recovering heat from turbine exhaust gases and utilising nitrogen as a carrier fluid. A pipe-in-pipe design is employed for this purpose which to the authors’ knowledge is not yet available on the market. Specifically the paper first introduces the proposed heat exchanger architecture then evaluates its feasibility with a detailed thermodynamic model and finally presents the calculation results. By addressing challenges in hydrogen storage and usage this work contributes to advancing sustainable aviation technologies and reducing the environmental footprint of air travel.