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Decarbonizing the fishing and aquaculture sector is an important goal for Norway as well as for the global shipping trade. Hydrogen is potentially a good fit for the energy demand of fishing vessels. For the fleet to switch to hydrogen as primary fuel, solutions for ensuring sufficient energy onboard must be found. One such solution could be to bunker the hydrogen at sea, in locations closer to the areas of operation of a fishing fleet. In the present work, we have investigated the bunkering of 250 bar gaseous hydrogen onto fishing vessels that require 4000 kWh of energy onboard. The first part focuses on the bunkering of a single vessel and an analysis of the technical parameters that affect and constrain the hydrogen bunkering rate. The second part focuses on the bunkering of several fishing vessels from a hydrogen refuelling station located offshore. • Reduction of emissions from fishing and agriculture will most likely include hydrogen. • Dynamic model of gaseous hydrogen bunkering onto fishing vessels developed. • High bunkering rates makes the temperature in the onboard tanks to exceed the limit. • Comparison of bunkering station capacity with and without compressors are presented. [ABSTRACT FROM AUTHOR]

This study compares four computational fluid dynamics (CFD) models, i.e. k-ε, RSM, SAS, and LES, to simulate temperature non-uniformity during hydrogen tank refuelling. Three grids with a total number of control volumes of 64k, 363k, and 2.9 M were used. The maximum dimensionless wall distances, y + , were 80, 5 and 2.5, respectively. The predictive capability of the models was assessed by recommended statistical indicators using ten thermocouple locations during 620 s of the experiment. The comparative analysis demonstrated a better predictive capability of temperature non-uniformity and stratification by the LES model and a shorter simulation time. It is concluded that meshes with y + larger than 80 would overpredict the average hydrogen temperature while meshes with y + < 5 provide a good simulation accuracy. The results underline the importance of the turbulence model choice and the numerical grid resolution for proper prediction of temperature non-uniformity during hydrogen tank refuelling. • Comparative analysis of k-ε, RSM, SAS, and LES models in refuelling simulations. • Three meshes are studied to understand their effect on model predictive capability. • The performance of the models is evaluated by recommended statistical indicators. • LES model is the fastest and most accurate in predicting temperature non-uniformity. [ABSTRACT FROM AUTHOR]

Green hydrogen presents a promising solution for transitioning from fossil fuels to a clean energy future, particularly with the application of fuel cell electric vehicles (FCEVs). However, the hydrogen refuelling process for FCEVs requires extensive pre-cooling to achieve fast filling times. This study presents experiments and simulations of a hydrogen refuelling station equipped with an adaptable cold-fill unit, aiming to maximize fuelling efficiencies. For this purpose, we developed and experimentally validated simulation models for a hydrogen tank and an aluminium block heat exchanger. Different pre-cooling parameters affect the final tank temperatures during the parallel filling of three 350 L type IV tanks. The results indicate significant potential for optimizing the required cooling energy, with achievable savings of over 50 % depending on the pre-cooling strategy. The optimized pre-cooling strategies and energy savings aid in advancing the refuelling process for FCEVs, effectively contributing to the transition to clean energy. • Development and validation of an aluminium block heat exchanger model. • Development and validation of a 0D tank model. • Refuelling tests of a type IV tank dummy for heavy-duty applications. • Experimental investigation of different cooling strategies. • Parameter studies of the refuelling process with pre-cooling. [ABSTRACT FROM AUTHOR]

The transition towards carbon-free transportation is only possible by the adoption of renewable energy alternatives. Hydrogen-based transportation is an attractive option considering the availability of the required refuelling infrastructure. A well-established network of hydrogen refuelling infrastructure is important for the widespread commercialization of fuel-cell electric vehicles. The most expensive H 2 refuelling components originate from hydrogen compression. Due to their ability to run on solar thermal energy, a metal hydride hydrogen compressor is used in this study. In this communication, the aim is to present a study on solar thermal based hydrogen compressors for a hydrogen refuelling station. An analytical study is presented on the energy assessment of a metal hydride compressor by considering three candidate pairs of metal hydrides (Pair 1: Ti 0.95 Zr 0.05 Cr 0.8 Mn 0.8 V 0.2 Ni 0.2 /Ti 0.8 Zr 0.2 Cr 0.95 Fe 0.95 V 0.1 ; Pair 2: TiCr 1.55 Mn 0.2 Fe 0.2 /Ti 0.9 Zr 0.1 Mn 1.4 Cr 0.35 V 0.2 Fe 0.05 , Pair 3: La 0.35 Ce 0.45 Ca 0.2 Ni 4.95 Al 0.05 /Ti 0.8 Zr 0.2 Cr 0.95 Fe 0.95 V 0.1) to achieve refuelling pressure of 700 bar. The variation in thermal efficiency of the compressor and thermal energy requirements with changes in heat source temperature, supply pressure and heat losses are presented. Furthermore, the economics of three pairs of alloys for high-pressure compression is compared. It was found that Ti 0.95 Zr 0.05 Cr 0.8 Mn 0.8 V 0.2 Ni 0.2 /Ti 0.8 Zr 0.2 Cr 0.95 Fe 0.95 V 0.1 pair has the maximum compressor efficiency of 7.2% at supply pressure and heat source temperature of 25 bar and 150 °C, respectively. In addition, the study revealed that heat losses from the reactor could reduce efficiency by around 12.5%. The economic study revealed that the Ti 0.95 Zr 0.05 Cr 0.8 Mn 0.8 V 0.2 Ni 0.2 /Ti 0.8 Zr 0.2 Cr 0.95 Fe 0.95 V 0.1 pair has the least cost for hydrogen compression among the other chosen pairs. • Energy analysis of a solar based metal hydride compressor for refuelling station is presented. • Three candidate alloy pairs are compared for compression in the temperature range of 150–170 °C. • Effect of key parameters on the performance of solar thermal based compressor is investigated. • Maximum thermal efficiency of metal hydride compressor is reported to be 7.2%. • Economic study shows that pair 1 is a cheaper alternative for hydrogen compression in refuelling stations. [ABSTRACT FROM AUTHOR]

A transition towards zero-emission fuels is required in the mobility sector in order to reach the climate goals. Here (green) renewable hydrogen for use in fuel cells will play an important role, especially for heavy duty applications such as trucks. However, there are still challenges to overcome regarding efficient storage, infrastructure integration and optimization of the refuelling process. A key aspect is to reduce the refuelling duration as much as possible, while staying below the maximum allowed temperature of 85 °C. Experimental tests for the refuelling of a 320 l type III tank were conducted at different operating conditions and the tank gas temperature measured at the front and back ends. The results indicate a strongly inhomogeneous temperature field, where measuring and verifying the actual maximum temperatures proves difficult. Furthermore, a simulation approach is provided to calculate the average tank gas temperature at the end of the refuelling process. • Refuelling tests with a 320 l heavy-duty tank were conducted. • Measurements suggest inhomogeneous temperature field. • Maximum and average temperature cannot be determined with OTV built-in sensors. • Parameter fit for heat transfer correlation. • Simulation model for average tank temperature at the end of refuelling. [ABSTRACT FROM AUTHOR]

Hydrogen plays a vital role in decarbonizing the mobility sector. With the number of hydrogen vehicles expected to drastically increase, a network of refuelling stations needs to be built to keep up with the hydrogen demand. However, further research and development on hydrogen refuelling infrastructure, storage and standardization is required to overcome technical and economic barriers. Simulation tools can reduce time and costs during the design phase, but existing models do not fully support calculations of complete and arbitrary system layouts. Therefore, a flexible simulation toolbox for rapid investigations of hydrogen refuelling and extraction processes as well as development of refuelling infrastructure, vehicle tank systems and refuelling protocols for non-standardized applications was developed. Our model library, H2VPATT, comprises of typical components found in refuelling infrastructure. The key component is the hydrogen tank model. The simulation model was successfully validated with measurement data from refuelling tests of a 320 l type III tank. [Display omitted] • Development of a flexible and customizable tool for hydrogen filling/storage systems. • Model for simulation of custom refuelling protocols. • Model validation with experiments. [ABSTRACT FROM AUTHOR]

Long-haul heavy-duty vehicles, including trucks and coaches, contribute to a substantial portion of the modern-day European carbon footprint and pose a major challenge in emissions reduction due to their energy-intensive usage. Depending on the hydrogen fuel source, the use of fuel cell electric vehicles (FCEV) for long-haul applications has shown significant potential in reducing road freight CO 2 emissions until the possible maturity of future long-distance battery-electric mobility. Fuel cell heavy-duty (HD) propulsion presents some specific characteristics, advantages and operating constraints, along with the notable possibility of gains in powertrain efficiency and usability through improved system design and intelligent onboard energy and thermal management. This paper provides an overview of the FCEV powertrain topology suited for long-haul HD applications, their operating limitations, cooling requirements, waste heat recovery techniques, state-of-the-art in powertrain control, energy and thermal management strategies and over-the-air route data based predictive powertrain management including V2X connectivity. A case study simulation analysis of an HD 40-tonne FCEV truck is also presented, focusing on the comparison of powertrain losses and energy expenditures in different subsystems while running on VECTO Regional delivery and Longhaul cycles. The importance of hydrogen fuel production pathways, onboard storage approaches, refuelling and safety standards, and fleet management is also discussed. Through a comprehensive review of the H 2 fuel cell powertrain technology, intelligent energy management, thermal management requirements and strategies, and challenges in hydrogen production, storage and refuelling, this article aims at helping stakeholders in the promotion and integration of H 2 FCEV technology towards road freight decarbonisation. [ABSTRACT FROM AUTHOR]

Global shipping activity emits significant amounts of GHG (Greenhouse Gas) emissions, estimated to be around 2-3% of total global GHG emissions. Studies have been made for hydrogen refuelling hubs in the Pacific area, for container ships, that are the worst polluting sources in the oceans. The present paper will show an idea for creating such refuelling hubs using salt cavern for hydrogen storage in Black Sea, and also in other offshore places where the geological formations allow it. The study will allow also the using of hydrogen in military purposes for refuelling the coastal patrol ships or tactical warships like Romanian frigates. [ABSTRACT FROM AUTHOR]

Compared with single-stage hydrogen storage refuelling, cascade storage refuelling has more advantages and significantly reduces cooling energy consumption. In the cascade system, the parameters of cascade storage tanks are critical, especially the initial pressure and volume. This article analyzes the thermodynamic processes in a cascade hydrogen refuelling station (HRS) and establishes the simulation model in Matlab/Simulink platform. The state of charge (SOC) of the onboard storage tank and the cooling energy consumption of the refuelling system are obtained from different initial pressures and volumes of the cascade storage tanks by using the simulation model. These data are introduced into the artificial neural networks in Matlab to generate a relationship between the decision variables and objective functions. The decision variables are optimized to minimize the cooling energy consumption and maximize the SOC through the genetic algorithm and Pareto optimization. So that optimal initial pressure and volume of the cascade storage tanks are determined. The research shows that when the ambient temperature is 293.15 K, and the SOC is 0.98–0.99, using the optimal initial pressure and volume of the cascade storage tanks can reduce the cooling energy consumption by up to 11.43%, compared with the baseline situation. Among the factors affecting cooling energy consumption and SOC, initial pressure is more sensitive than volume, so optimizing initial pressure, especially for the high-pressure cascade storage tank, seems more meaningful than volume. This research is instructive for the construction of the cascade HRS. • A thermodynamic model for cascade hydrogen refuelling is developed and well validated. • Effect of initial pressure and cascade tank volume on SOC and cooling energy is studied. • Artificial neural network (ANN) is trained by orthogonal test data from physical model. • The ANN model is used to determine objective functions and constraints of optimization. • Genetic algorithm and Pareto algorithm are combined for multi-objective optimization. [ABSTRACT FROM AUTHOR]

The goal of the EU Horizon 2020 RISE project 778307 "Hydrogen fuelled utility vehicles and their support systems utilising metal hydrides" (HYDRIDE4MOBILITY), is in addressing critical issues towards a commercial implementation of hydrogen powered forklifts using metal hydride (MH) based hydrogen storage and PEM fuel cells, together with the systems for their refuelling at industrial customers facilities. For these applications, high specific weight of the metallic hydrides has an added value, as it allows counterbalancing of a vehicle with no extra cost. Improving the rates of H 2 charge/discharge in MH on the materials and system level, simplification of the design and reducing the system cost, together with improvement of the efficiency of system "MH store-FC", is in the focus of this work as a joint effort of consortium uniting academic teams and industrial partners from two EU and associated countries Member States (Norway, Germany, Croatia), and two partner countries (South Africa and Indonesia). The work within the project is focused on the validation of various efficient and cost-competitive solutions including (i) advanced MH materials for hydrogen storage and compression, (ii) advanced MH containers characterised by improved charge-discharge dynamic performance and ability to be mass produced, (iii) integrated hydrogen storage and compression/refuelling systems which are developed and tested together with PEM fuel cells during the collaborative efforts of the consortium. This article gives an overview of HYDRIDE4MOBILITY project focused on the results generated during its first phase (2017–2019). • Advanced metal hydrides for H storage and compression were proposed. • MH containers with improved H charge-discharge dynamic performance. • Integrated with PEM fuel cell hydrogen energy system was developed. • EU Horizon 2020 RISE project 778307 project HYDRIDE4MOBILITY. • Hydrogen powered forklift uses MH based H storage and PEM fuel cell. [ABSTRACT FROM AUTHOR]

• Filling model of zero-dimensional gas and one-dimensional wall is built and verified. • Modified formula and artificial neural networks (ANN) models for MC are proposed. • Latin hypercube sampling, Genetic algorithm and Sobol sensitivity analysis are used. • Modified formula and ANN models for MC parameter improve MC's calculation accuracy. • ANN model of MC extends applicability to situations of filling time less than 30s. The MC method was officially released in SAE J2601 protocol in 2016 to refuel light-duty hydrogen fuel cell vehicles quickly and safely. For the non-communication MC method, the pressure target for controlling the end of filling is calculated based on the formula of the final hydrogen temperature, which contains a key parameter, MC. SAE has proposed two formulas to estimate the MC parameter. This article proposes a modified formula and artificial neural networks (ANN) model for MC parameter. To generate simulated data for fitting the modified formula and training the ANN model, a hydrogen filling model (0D1D) with a zero-dimensional gas and a one-dimensional tank wall is established and thoroughly verified. In establishing the ANN model, Latin hypercube sampling (LHS) is used to sample independent variables randomly, and genetic algorithms (GA) are used to optimize the initial weights and biases of the ANN. The Sobol sensitivity analysis is used to determine the importance of various initial conditions on the MC parameter. Research shows that the final fueling time and initial pressure have a greater impact on the MC parameter , while the ambient and precooling temperatures have little impact. The modified formula of the MC parameter improves R2 from the original 0.76073 to 0.98132 when fitting the MC simulated data. In situations of short filling time, the modified formula and ANN models of the MC parameter reduce the relative error between the 0D1D model by 13.8 % − 58.8 % and 16.6 % − 82.3 %, respectively, thus improving the calculation accuracy of the final hydrogen temperature and ending pressure target. Moreover, the ANN model can predict the MC parameter during the whole fueling process, while the MC formula utilizes the fixed value when the fueling time is less than 30 s. This work has positive significance for improving refuelling protocol. [ABSTRACT FROM AUTHOR]

Hydrogen compression is a main contributor in the capital and operation costs of the H 2 refuelling infrastructure. The use of metal hydrides (MH) for thermally-driven H 2 compression can provide efficient solution to mitigate this challenge. MH compressors are particularly promising for industrial customers who possess necessary infrastructure including pipeline H 2 , sources of low-grade heat, etc. Here we present the details about layout of the H 2 refuelling station and its operation at Impala Platinum refineries in Springs, South Africa, since its start-up in September 2015. The station provides H 2 dispensing at the pressure up to 185 bar and uses pipeline H 2 (P = 50–60 bar) available at the customer site. H 2 compression to P = 200 bar with productivity up to 13 Nm3/h is provided by the integrated 1-stage MH H 2 compressor which uses steam (T∼140 °C) for the heating and circulating water (T∼20 °C) for the cooling; both steam and water are also available from the customer infrastructure. The station also includes H 2 dispenser, buffer tank (standard gas cylinder pack), and control block on the basis of Siemens Program Logic Controller (PLC) which provides fully automated system operation. Switching H 2 and steam/water flows is carried out with the help of remotely controlled, pneumatically actuated valves and auxiliary check valves. Additionally, at P = 200 bar the control block switches the system into standby mode when MH compression modules are cooled down and their gas manifolds are connected to the H 2 supply line. The H 2 dispensing is independent on the compressor operation and takes from 6 to 15 min. The refuelling station complies with South African safety regulations for operation in a fire and explosion hazardous environment. Image 1 • Hydrogen refuelling station with integrated metal hydride compressor. • Utilises services including low pressure H2 and low-grade steam available for industrial customers. • Dispensing capacity from 13 to 28 kg H2/day at a pressure of 185 bar. • Lower capital and operational costs as compared to high pressure stations available on the market. • In uninterrupted operation at Impala Platinum Refineries (South Africa) since September 2015. [ABSTRACT FROM AUTHOR]

Abstract Hydrogen technologies can play an important role in decarbonising our energy system in a variety of ways across the energy value chain. It is therefore critical to identify the strategic roles as well as the conditions under which hydrogen energy systems become attractive for the energy transition. In this paper, the authors present a techno-economic review of hydrogen energy systems including power-to-power, power-to-gas, hydrogen refuelling and stationary fuel cells. We focus on their optimal operation as flexible assets and we identify three actions that can foster their uptake beyond technological progress. First, we recommend optimal electricity supply with dedicated control strategies considering that electricity dominates the levelised cost of hydrogen production via electrolysis. Secondly, hydrogen can enable the further integration of traditionally independent sectors, namely electricity, heat and transport while contributing to decarbonise all. This position can also be advantageous for investors who sell heat and fuels as energy efficient products. Lastly, we examine a whole range of revenues from different products and applications which can be combined (i.e. benefit stacking) to match capital and operational expenditures. We discuss these roles in depth and we conclude that policy makers together with technology developers should elaborate smart strategies to reduce cost by scaling production, stimulate standardisation (e.g., similar to the PV industry) as well as develop new market structures and regulatory frameworks which allow hydrogen technologies to deliver multiple low carbon applications and products. Highlights • The role of PtG, power-to-power, hydrogen refuelling and fuel cell are evaluated. • The value of various products and services offered by hydrogen systems is given. • Recommendations are given for minimising the levelised cost of electrolysis. • We review electronics and control techniques for various hydrogen energy systems. • Key strategies such as further system linkage and benefit stacking are discussed. [ABSTRACT FROM AUTHOR]

During the filling of hydrogen tanks high temperatures can be generated inside the vessel because of the gas compression while during the emptying low temperatures can be reached because of the gas expansion. The design temperature range goes from −40 °C to 85 °C. Temperatures outside that range could affect the mechanical properties of the tank materials. CFD analyses of the filling and emptying processes have been performed in the HyTransfer project. To assess the accuracy of the CFD model the simulation results have been compared with new experimental data for different filling and emptying strategies. The comparison between experiments and simulations is shown for the temperatures of the gas inside the tank, for the temperatures at the interface between the liner and the composite material, and for the temperatures on the external surface of the vessel. [ABSTRACT FROM AUTHOR]

The influence of the initial tank temperature on the evolution of the internal gas temperature during the refuelling of on-board hydrogen tanks is investigated in this paper. Two different types of tanks, four different fuel delivery temperatures (from ambient temperature refuelling to a pre-cooled hydrogen at −40 °C), several filling rates and initial pressures are considered. It has been found that the final gas temperature increases linearly with the increase of the initial tank temperature while the temperature increase (ΔT) and the final state of charge (SOC) decrease linearly with increasing the initial temperature. This dependency has been found to be larger on type III than on type IV tank and larger the larger the initial pressure. Additionally CFD simulations are performed to better understand the role of the relevant phenomena on the gas temperature histories e.g. gas compression, gas mixing, and heat transfer. By comparing the results of calculations with adiabatic and diathermal tank walls, the effect of the initial gas temperature has been separated from the effect of the initial wall temperature on the process. [ABSTRACT FROM AUTHOR]

Abstract: Storage of gases under pressure, including hydrogen, is a well-known technology. However the use of hydrogen in vehicles at pressures much higher than those applicable in natural gas cars still requires safety and performance studies with respect to the verification and validation of the existing standards and regulations. The JRC-IET has developed a facility, GasTeF, for carrying out tests on full-scale high pressure vehicle's tanks for hydrogen or natural gas. A typical test performed in GasTeF is the hydrogen cycling, in which tanks are filled and slowly emptied using hydrogen pressurised up to 88 MPa, for at least 1000 times in line with the requirements of the EU regulation on type-approval of hydrogen-powered motor vehicles. The temperature evolution of the gas inside and outside the tank is monitored using a thermocouples array system specifically designed for this purpose. This paper presents the first experimental results on the temperature distribution during hydrogen cycling tests. [Copyright &y& Elsevier]

Abstract: We have measured the effects of the initial mass and the total fill time on the temperature rise and the temperature distribution within a compressed hydrogen cylinder during refuelling. A type 3, 74L hydrogen cylinder was instrumented internally with 63 thermocouples distributed along the mid vertical plane. The experimental fills were performed from initial pressures of 50, 75, 100, 150, and 200bar at gas delivery rates corresponding to nominal fill times of 1, 3, and 6min. The experimental conditions with larger ratios of final to initial mass produced larger temperature changes. However, the lower ratios generated the largest rates of temperature rise. Longer fill times produced lower final average gas temperatures (compared to shorter fills), and a temperature field with significant vertical stratification due to buoyancy forces at lower gas inlet velocities. A sensor located at the end opposite to the gas inlet could be suitable for fuel metering via temperature and pressure measurements only. [Copyright &y& Elsevier]