Netherlands
Impact of Capillary Pressure Hysteresis and Injection-withdrawal Scehemes on Performance of Underground Hydrogen Storage
Oct 2023
Publication
Underground hydrogen storage in depleted hydrocarbon reservoirs and aquifers has been proposed as a potential long-term solution to storing intermittently produced renewable electricity as the subsurface formations provide secure and large storage space. Various phenomena can lead to hydrogen loss in subsurface systems with the key cause being the trapping especially during the withdrawal cycle. Capillary trapping in particular is strongly related to the hysteresis phenomena observed in the capillary pressure/saturation and relative-permeability/saturation curves. This paper address two key points: (1) the sole impact of hysteresis in capillary pressure on hydrogen trapping during withdrawal cycles and (2) the dependency of optimal operational parameters (injection/withdrawal flow rate) and the reservoir characteristics such as permeability thickness and wettability of the porous medium on the remaining hydrogen saturation.<br/>Model<br/>To study the capillary hysteresis during underground hydrogen storage Killough [1] model was implemented in the MRST toolbox [2]. A comparative study was performed to quantify the impact of changes in capillary pressure behaviour by including and excluding the hysteresis and scanning curves. Additionally this study investigates the impact of injection/withdrawal rates and the aquifer permeability for various capillary and Bond numbers in a homogeneous system.<br/>Findings<br/>It was found that although the hydrogen storage efficiency is not considerably impacted by the inclusion of the capillary-pressure scanning curves the impact of capillary pressure on the well properties (withdrawal rate and pressure) can become significant. Higher injection and withdrawal rates does not necessarily lead to a better performance in terms of productivity. The productivity enhancement depends on the competition between gravitational capillary and viscous forces. The observed water upconing at relatively high capillary numbers resulted in low hydrogen productivity. highlighting the importance of well design and placement.
Meeting the Challenges of Large-scale Carbon Storage and Hydrogen Production
Mar 2023
Publication
There is a pressing need to rapidly and massively scale up negative carbon strategies such as carbon capture and storage (CCS). At the same time large-scale CCS can enable ramp-up of large-scale hydrogen production a key component of decarbonized energy systems. We argue here that the safest and most practical strategy for dramatically increasing CO2 storage in the subsurface is to focus on regions where there are multiple partially depleted oil and gas reservoirs. Many of these reservoirs have adequate storage capacity are geologically and hydrodynamically well understood and are less prone to injection-induced seismicity than saline aquifers. Once a CO2 storage facility is up and running it can be used to store CO2 from multiple sources. Integration of CCS with hydrogen production appears to be an economically viable strategy for dramatically reducing greenhouse gas emissions over the next decade particularly in oil- and gas-producing countries where there are numerous depleted reservoirs that are potentially suitable for large-scale carbon storage.
Impact on Canadian Residential End Use Appliances with the Introduction of Hydrogen into the Natural Gas Stream - An Application
Sep 2023
Publication
Canada’s commitment to be net-zero by 2050 combined with ATCO’s own Environmental Social and Governance goals has led ATCO to pursue hydrogen blending within the existing natural gas system to reduce CO2 emissions while continuing to provide safe reliable energy service to customers. Utilization of hydrogen in the distribution system is the least-cost alternative for decarbonizing the heating loads in jurisdictions like Alberta where harsh winter climates are encountered and low-carbon hydrogen production can be abundant. ATCO’s own Fort Saskatchewan Hydrogen Blending Project began blending 5% hydrogen by volume to over 2100 customers in the Fall of 2022 and plans to increase the blend rates to 20% hydrogen in 2023. Prior to blending ATCO worked together with DNV to examine the impact of hydrogen blended natural gas to twelve Canadian appliances: range/stove oven garage heater high and medium efficiency furnaces conventional and on demand hot water heaters barbeque clothes dryer radiant heater and two gas fireplaces. The tests were performed not only within the planned blend rates of 0-20% hydrogen but also to higher percentages to determine how much hydrogen can be blended into a system before appliance retrofits would be required. The testing was designed to get insights on safety-related combustion issues such as flash-back burner overheating flame detection and other performance parameters such as emissions and burner power. The experimental results indicate that the radiant heater is the most sensitive appliance for flashback observed at 30 vol% hydrogen in natural gas. At 50% hydrogen the range and the radiant burner of the barbeque tested were found to be sensitive to flashback. All other 9 appliances were found to be robust for flashback with no other short-term issues observed. This paper will detail the findings of ATCO and DNV’s appliance testing program including results on failure mechanisms and sensitivities for each appliance.
Renewable Hydrogen Production: A Techno-economic Comparison of Photoelectrochemical Cells and Photovoltaic-electrolysis
Aug 2020
Publication
The present paper reports a techno-economic analysis of two solar assisted hydrogen production technologies: a photoelectrochemical (PEC) system and its major competitor a photovoltaic system connected to a conventional water electrolyzer (PV-E system). A comparison between these two types was performed to identify the more promising technology based on the levelized cost of hydrogen (LCOH). The technical evaluation was carried out by considering proven designs and materials for the PV-E system and a conceptually design for the PEC system extrapolated to future commercial scale. The LCOH for the off-grid PV-E system was found to be 6.22 $/kgH2 with a solar to hydrogen efficiency of 10.9%. For the PEC system with a similar efficiency of 10% the LCOH was calculated to be much higher namely 8.43 $/kgH2. A sensitivity analysis reveals a great uncertainty in the LCOH of the prospective PEC system. This implies that much effort would be needed for this technology to become competitive on the market. Therefore we conclude that the potential techno-economic benefits that PEC systems offer over PV-E are uncertain and even in the best case limited. While research into photoelectrochemical cells remains of interest it presents a poor case for dedicated investment in the technology’s development and scale-up.
Electricity Supply Configurations for Green Hydrogen Hubs: A European Case Study on Decarbonizing Urban Transport
Aug 2024
Publication
In this study a techno-economic analysis tool for conducting detailed feasibility studies on the deployment of green hydrogen hubs for fuel cell bus fleets is developed. The study evaluates and compares five green hydrogen hub configurations’ operational and economic performance under a typical metropolitan bus fleet refuelling schedule. Each configuration differs based on its electricity sourcing characteristics such as the mix of energy sources capacity sizing financial structure and grid interaction. A detailed comparative analysis of distinct green hydrogen hub configurations for decarbonising a fleet of fuel-cell buses is conducted. Among the key findings is that a hybrid renewable electricity source and hydrogen storage are essential for cost-optimal operation across all configurations. Furthermore bi-directional grid-interactive configurations are the most costefficient and can benefit the electricity grid by flattening the duck curve. Lastly the paper highlights the potential for cost reduction when the fleet refuelling schedule is co-optimized with the green hydrogen hub electricity supply configuration.
Dynamic Hydrogen Demand Forecasting Using Hybrid Time Series Models: Insights for Renewable Energy Systems
Feb 2025
Publication
Hydrogen is gaining traction as a key energy carrier due to its clean combustion high energy content and versatility. As the world shifts towards sustainable energy hydrogen demand is rapidly increasing. This paper introduces a novel hybrid time series modeling approach designed and developed to accurately predict hydrogen demand by mixing linear and nonlinear models and accounting for the impact of non-recurring events and dynamic energy market changes over time. The model incorporates key economic variables like hydrogen price oil price natural gas price and gross domestic product (GDP) per capita. To address these challenges we propose a four-part framework comprising the Hodrick–Prescott (HP) filter the autoregressive fractionally integrated moving average (ARFIMA) model the enhanced empirical wavelet transform (EEWT) and high-order fuzzy cognitive maps (HFCM). The HP filter extracts recurring structural patterns around specific data points and resolves challenges in hybridizing linear and nonlinear models. The ARFIMA model equipped with statistical memory captures linear trends in the data. Meanwhile the EEWT handles non-stationary time series by adaptively decomposing data. HFCM integrates the outputs from these components with ridge regression fine-tuning the HFCM to handle complex time series dynamics. Validation using stochastic non-Gaussian synthetic data demonstrates that this model significantly enhances prediction performance. The methodology offers notable improvements in prediction accuracy and stability compared to existing models with implications for optimizing hydrogen production and storage systems. The proposed approach is also a valuable tool for policy formulation in renewable energy and smart energy transitions offering a robust solution for forecasting hydrogen demand
Preliminary Safety Assessment of a Liquid Hydrogen Storage System for Commercial Aviation
Mar 2025
Publication
The development of liquid hydrogen storage systems is a key aspect to enable future clean air transportation. However safety analysis research for such systems is still limited and is hindered by the limited experience with liquid hydrogen storage in aviation. This paper presents the outcomes of a preliminary safety assessment applied to this new type of storage system accounting for the hazards of hydrogen. The methodology developed is based on hazard identification and frequency evaluation across all system features to identify the most critical safety concerns. Based on the safety assessment a set of safety recommendations concerning different subsystems of the liquid hydrogen storage system is proposed identifying hazard scopes and necessary mitigation actions across various system domains. The presented approach has been proven to be suitable for identifying essential liquid hydrogen hazards despite the novelty of the technology and for providing systematic design recommendations at a relatively early design stage.
Lessons Learned from HIAD 2.0: Inspection and Maintenance to Avoid Hydrogen-induced Material Failures
Feb 2023
Publication
Hydrogen has the potential to make countries energetically self-sufficient and independent in the long term. Nevertheless its extreme combustion properties and its capability of permeating and embrittling most metallic materials produce significant safety concerns. The Hydrogen Incidents and Accidents Database 2.0 (HIAD 2.0) is a public repository that collects data on hydrogen-related undesired events mainly occurred in chemical and process industry. This study conducts an analysis of the HIAD 2.0 database mining information systematically through a computer science approach known as Business Analytics. Moreover several hydrogen-induced ma terial failures are investigated to understand their root causes. As a result a deficiency in planning effective inspection and maintenance activities is highlighted as the common cause of the most severe accidents. The lessons learned from HIAD 2.0 could help to promote a safety culture to improve the abnormal and normal events management and to stimulate a widespread rollout of hydrogen technologies.
Hydrogen Distribution in the Netherlands: Addressing Ambiguities in the Regulatory Framework
Aug 2025
Publication
Hydrogen is increasingly recognized as a key solution for decarbonizing the Dutch energy system particularly within the industrial sector. A national hydrogen network is under development to serve the five major industrial clusters in the Netherlands. However meeting the hydrogen needs of the industries outside these clusters which are collectively known as “Cluster 6” remains difficult. Regulatory unclarity and ambiguity around the hydrogen distribution infrastructure including restrictions on distribution system operators (DSOs) compound these challenges. This study investigates the complex and evolving regulatory landscape for hydrogen distribution across Cluster 6 in the Netherlands using a two-step approach of Institutional Network Analysis (INA) and stakeholder interviews. Findings outline possible pathways for delegating distribution responsibilities in current and future regulatory frameworks while stakeholders report structural and outcome uncertainty limiting their willingness to invest in hydrogen distribution initiatives. The research findings highlight the need for a more coherent regulatory and technical framework to support more effective development of physical hydrogen systems. Policy recommendations include clarification of distributor roles targeted support mechanisms and flexible regulations that can adapt to the rapidly developing hydrogen market.
How Company History and Hydrogen Type Shape Public Trust and Acceptability: A Reputation Management Perspective
Aug 2025
Publication
Hydrogen is gaining interest as a clean energy source from both governments and fossil fuel companies. For hydrogen projects to succeed securing public acceptability is crucial with trust in the implementing actors playing a central role. Drawing from reputation management and attribution theory we experimentally evaluated whether people’s perceptions of energy companies wanting to start producing hydrogen for sustainability reasons differ based on two features of hydrogen production. Specifically we examined the influence of (1) the type of hydrogen (blue versus green) and (2) the energy company’s history in energy production (fossil fuels versus renewables) on perceptions about the companies’ reputation management efforts —that is the belief that companies adopt hydrogen primarily to improve their public image— as well as on levels of trust both overall and specifically in terms of integrity and competence. We further explored whether perceived reputation management explains the effects on trust and whether these factors also shape public acceptability of hydrogen production itself. Results indicated that people perceived the company with a history of working with fossil fuels as trying to improve its reputation more than one associated with renewables and trusted it less. Furthermore perceived reputation management explained the lower (general and integrity-based) trust people had in companies with a past in fossil fuels. For public acceptability of hydrogen the company’s history was not relevant with green hydrogen being more acceptable than blue regardless of which company produced it. We discuss these findings in relation to the literature on public perceptions of hydrogen.
The Many Greenhouse Gas Footprints of Green Hydrogen
Aug 2022
Publication
Green hydrogen could contribute to climate change mitigation but its greenhouse gas footprint varies with electricity source and allocation choices. Using life-cycle assessment we conclude that if electricity comes from additional renewable capacity green hydrogen outperforms fossil-based hydrogen. In the short run alternative uses of renewable electricity likely achieve greater emission reductions.
Prospective LCA of Alkaline and PEM Electrolyser Systems
Nov 2023
Publication
This prospective life cycle assessment (LCA) compares the environmental impacts of alkaline electrolyser (AE) and proton exchange membrane (PEM) electrolyser systems for green hydrogen production with a special focus on the stack components. The study evaluates both baseline and near-future advanced designs considering cradle-to-gate life cycle from material production to operation. The electricity source followed by the stacks are identified as major contributors to environmental impacts. No clear winner emerges between AE and PEM in relation to environmental impacts. The advanced designs show a reduced impact in most categories compared to baseline designs which can mainly be attributed to the increased current density. Advanced green hydrogen production technologies outperform grey and blue hydrogen production technologies in all impact categories except for minerals and metals resource use due to rare earth metals in the stacks. Next to increasing current density decreasing minimal load requirements. improving sustainable mining practices (including waste treatment) and low carbon intensity steel production routes can enhance the environmental performance of electrolyser systems aiding the transition to sustainable hydrogen production.
Alkaline Electrolysis for Green Hydrogen Production: A Novel, Simple Model for Thermo-electrochemical Coupled System Analysis
Dec 2024
Publication
Alkaline water electrolysis (AWE) is the most mature electrochemical technology for hydrogen production from renewable electricity. Thus its mathematical modeling is an important tool to provide new perspectives for the design and optimization of energy storage and decarbonization systems. However current models rely on numerous empirical parameters and neglect variations of temperature and concentration alongside the electrolysis cell which can impact the application and reliability of the simulation results. Thus this study proposes a simple four-parameter semi-empirical model for AWE system analysis which relies on minimal fitting data while providing reliable extrapolation results. In addition the effect of model dimensionality (i.e. 0D 1/2D and 1D) are carefully assessed in the optimization of an AWE system. The results indicate that the proposed model can accurately reproduce literature data from four previous works (R 2 ≥ 0.98) as well as new experimental data. In the system optimization the trade-offs existing in the lye cooling sizing highlight that maintaining a low temperature difference in AWE stacks (76-80°C) leads to higher efficiencies and lower hydrogen costs.
Hydrogen Storage in Depleted Gas Reservoirs with Carbon Dioxide as a Cushion Gas: Exploring a Lateral Gas Seperation Strategy to Reduce Gas Mixing
Jan 2025
Publication
Large-scale H2 storage in depleted hydrocarbon reservoirs offers a practical way to use existing energy infra structure to address renewable energy intermittency. Cushion gases often constitute a large initial investment especially when expensive H2 is used. Cheaper alternatives such as CO2 or in-situ CH4 can reduce costs and in the case of CO2 integrate within carbon capture and storage systems. This study explored cushion and working gas dynamics through numerically modelling a range of storage scenarios in laterally extensive reservoirs – such as those in the Southern North Sea. In all simulations the cushion and working gases were separated laterally to limit contact surface area and therefore mixing. This work provides valuable insights into (i) capacity estima tions of CO2 storage and H2 withdrawal (ii) macro-scale fluid dynamics and (iii) the effects of gas mixing trends on H2 purity. The results underscore key trade-offs between CO2 storage volumes and H2 withdrawal and purity
A Hybrid Robust-stochastic Approach for Optimal Scheduling of Interconnected Hydrogen-based Energy Hubs
Jan 2021
Publication
The energy hub (EH) concept is an efficient way to integrate various energy carriers. Inaddition demand response programmes (DRPs) are complementary to improving anEH's efficiency and increase energy system flexibility. The hydrogen storage system as agreen energy carrier has an essential role in balancing supply and demand preciselysimilar to other storage systems. A hybrid robust‐stochastic approach is applied herein toaddress fluctuations in wind power generation multiple demands and electricity marketprice in a hydrogen‐based smart micro‐energy hub (SMEH) with multi‐energy storagesystems. The proposed hybrid approach enables the operator to manage the existinguncertainties with more flexibility. Also flexible electrical and thermal demands under anintegrated demand response programme (IDRP) are implemented in the proposedSMEH. The optimal scheduling of the hydrogen‐based SMEH problem considering windpower generation and electricity market price fluctuations as well as IDRP is modelledvia a mixed‐integer linear programming problem. Finally the validity and applicability ofthe proposed model are verified through simulation and numerical results.
Determining Onshore or Offshore Hydrogen Storage for Large Offshore Wind Parks: The North Sea Wind Power Hub Case
Aug 2024
Publication
The large-scale integration of renewable energy sources leads to daily and seasonal mismatches between supply and demand and the curtailment of wind power. Hydrogen produced from surplus wind power offers an attractive solution to these challenges. In this paper we consider a large offshore wind park and analyze the need for hydrogen storage at the onshore and offshore sides of a large transportation pipeline that connects the wind park to the mainland. The results show that the pipeline with line pack storage though important for day-to-day fluctuations will not offer sufficient storage capacity to bridge seasonal differences. Furthermore the results show that if the pipeline is sufficiently sized additional storage is only needed on one side of the pipeline which would limit the needed investments. Results show that the policy which determines what part of the wind power is fed into the electricity grid and what part is converted into hydrogen has a significant influence on these seasonal storage needs. Therefore investment decisions for hydrogen systems should be made by considering both the onshore and offshore storage requirements in combination with electricity transport to the mainland.
Hydrogen Sampling Systems Adapted to Heavy-duty Refuelling Stations' Current and Future Specifications - A Review
Sep 2024
Publication
To meet the new regulation for the deployment of alternative fuels infrastructure which sets targets for electric recharging and hydrogen refuelling infrastructure by 2025 or 2030 a large infrastructure comprising trucksuitable hydrogen refuelling stations will soon be required. However further standardisation is required to support the uptake of hydrogen for heavy-duty transport for Europe’s green energy future. Hydrogen-powered vehicles require pure hydrogen as some contaminants can reduce the performance of the fuel cell even at very low levels. Even if previous projects have paved the way for the development of the European quality infrastructure for hydrogen conformity assessment sampling systems and methods have yet to be developed for heavy-duty hydrogen refuelling stations (HD-HRS). This study reviews different aspects of the sampling of hydrogen at heavy-duty hydrogen refuelling stations for purity assessment with a focus on the current and future specifications and operations at HD-HRS. This study describes the state-of-the art of sampling systems currently under development for use at HD-HRS and highlights a number of aspects which must be taken into consideration to ensure safe and accurate sampling: risk assessment for the whole sampling exercise selection of cylinders methods to prepare cylinders before the sampling filling pressure and venting of the sampling systems.
Impact of an Electrode-diaphragm Gap on Diffusive Hydrogen Crossover in Alkaline Water Electrolysis
Oct 2023
Publication
Hydrogen crossover limits the load range of alkaline water electrolyzers hindering their integration with renewable energy. This study examines the impact of the electrode-diaphragm gap on crossover focusing on diffusive transport. Both finite-gap and zero-gap designs employing the state-of-the-art Zirfon UTP Perl 500 and UTP 220 diaphragms were investigated at room temperature and with a 12 wt% KOH electrolyte. Experimental results reveal a relatively high crossover for a zero-gap configuration which corresponds to supersaturation levels at the diaphragm-electrolyte interface of 8–80 with significant fluctuations over time and between experiments due to an imperfect zero-gap design. In contrast a finite-gap (500 μm) has a significantly smaller crossover corresponding to supersaturation levels of 2–4. Introducing a cathode gap strongly decreases crossover unlike an anode gap. Our results suggest that adding a small cathode-gap can significantly decrease gas impurity potentially increase the operating range of alkaline electrolyzers while maintaining good efficiency.
Green Hydrogen Techno-economic Assessments from Simulated and Measured Solar Photovoltaic Power Profiles
Nov 2024
Publication
Studies estimating the production cost of hydrogen-based fuels known as e-fuels often use renewable power profile time series obtained from open-source simulation tools that rely on meteorological reanalysis and satellite data such as Renewables.ninja or PVGIS. These simulated time series contain errors compared to real on-site measured data which are reflected in e-fuels cost estimates plant design and operational performance increasing the risk of inaccurate plant design and business models. Focusing on solar-powered e-fuels this study aims to quantify these errors using high-quality on-site power production data. A state-of-the-art optimization techno-economic model was used to estimate e-fuel production costs by utilizing either simulated or high-quality measured PV power profiles across four sites with different climates. The results indicate that in cloudy climates relying on simulated data instead of measured data can lead to an underestimation of the fuel production costs by 36 % for a hydrogen user requiring a constant supply considering an original error of 1.2 % in the annual average capacity factor. The cost underestimation can reach 25 % for a hydrogen user operating between 40 % and 100 % load and 17.5 % for a fully flexible user. For comparison cost differences around 20 % could also result from increasing the electrolyser or PV plant costs by around 55 % which highlights the importance of using high-quality renewable power profiles. To support this an open-source collaborative repository was developed to facilitate the sharing of measured renewable power profiles and provide tools for both time series analysis and green hydrogen techno-economic assessments.
Assessment of Hydrogen Transport Aircraft
Sep 2022
Publication
Zero-carbon-dioxide-emitting hydrogen-powered aircraft have in recent decades come back on the stage as promising protagonists in the fght against global warming. The main cause for the reduced performance of liquid hydrogen aircraft lays in the fuel storage which demands the use of voluminous and heavy tanks. Literature on the topic shows that the optimal fuel storage solution depends on the aircraft range category but most studies disagree on which solution is optimal for each category. The objective of this research was to identify and compare possible solutions to the integration of the hydrogen fuel containment system on regional short/medium- and large passenger aircraft and to understand why and how the optimal tank integration strategy depends on the aircraft category. This objective was pursued by creating a design and analysis framework for CS-25 aircraft capable of appreciating the efects that diferent combinations of tank structure fuselage diameter tank layout shape venting pressure and pressure control generate at aircraft level. Despite that no large diferences among categories were found the following main observations were made: (1) using an integral tank structure was found to be increasingly more benefcial with increasing aircraft range/size. (2) The use of a forward tank in combination with the aft one appeared to be always benefcial in terms of energy consumption. (3) The increase in fuselage diameter is detrimental especially when an extra aisle is not required and a double-deck cabin is not feasible. (4) Direct venting has when done efciently a small positive efect. (5) The optimal venting pressure varies with the aircraft confguration performance and mission. The impact on performance from sizing the tank for missions longer than the harmonic one was also quantifed.
Retrofitted Hydrogen-Electric Propulsion Aircraft: Performance Simulation of Critical Operating Conditions
Jan 2025
Publication
Retrofitting regional turboprop aircraft with hydrogen (H2)-electric powertrains using fuel cell systems (FCSs) has gained interest in the last decade. This type of powertrain eliminates CO2 NOx and fine particle emissions during flight as FCSs only emit water. In this context the “Hydrogen Aircraft Powertrain and Storage Systems” (HAPSS) project targets the development of a H2-electric propulsion system for retrofitting Dash 8- 300 series aircraft. The purpose of the study described in this paper is to analyze the performance of the retrofitted H2-electric aircraft during critical operating conditions. Takeoff as well as climb cruise and go-around performances are addressed. The NLR in-house tool MASS (Mission Aircraft and Systems Simulation) was used for the performance analyses. The results show that the retrofitted H2-electric aircraft has a slightly increased takeoff distance compared to the Dash 8-300 and it requires a maximum rated shaft power of 1.9 MW per propeller. A total rated FCS output power of 3.1 MW is sufficient to satisfy the takeoff requirements at the cost of lower cruise altitude and reduced cruise speed as compared to the Dash 8-300. Furthermore a higher-rated FCS is required to achieve the climb performance required for the typical climb profile of the Dash 8-300.
Will Hydrogen and Synthetic Fuels Energize our Future? Their Role in Europe's Climate-neutral Energy System and Power System Dynamics
Aug 2024
Publication
This study evaluates the technoeconomic impacts of direct and indirect electrification on the EU's net-zero emissions target by 2050. By linking the JRC-EU-TIMES long-term energy system model with PLEXOS hourly resolution power system model this research offers a detailed analysis of the interactions between electricity hydrogen and synthetic fuel demand production technologies and their effects on the power sector. It highlights the importance of high temporal resolution power system analysis to capture the synergistic effects of these components often overlooked in isolated studies. Results indicate that direct electrification increases significantly and unimpacted by biomass CCS and nuclear energy assumptions. However indirect electrification in the form of hydrogen varies significantly between 1400 and 2200 TWhH2 by 2050. Synthetic fuels are essential for sector coupling making up 6–12% of total energy consumption by 2050 with the power sector supplying most hydrogen and CO2 for their production. Varying levels of indirect electrification impact electrolysers renewable energy and firm capacities. Higher indirect electrification increases electrolyser capacity factors by 8% leading to more renewable energy curtailment but improves system reliability by reducing 11 TWh unserved energy and increasing flexibility options. These insights inform EU energy policies stressing the need for a balanced approach to electrification biomass use and CCS to achieve a sustainable and reliable net-zero energy system by 2050. We also explore limitations and sensitivities.
Using Hydro-Pneumatic Energy Storage for Improving Offshore Wind-Driven Green Hydrogen Production—A Preliminary Feasibility Study in the Central Mediterranean Sea
Aug 2025
Publication
This paper presents a preliminary feasibility study for integrating hydro-pneumatic energy storage (HPES) with off-grid offshore wind turbines and green hydrogen production facilities—a concept termed HydroGenEration (HGE). This study compares the performance of this innovative concept system with an off-grid direct wind-to-hydrogen plant concept without energy storage both under central Mediterranean wind conditions. Numerical simulations were conducted at high temporal resolution capturing 10-min fluctuations of open field measured wind speeds at an equivalent offshore wind turbine (WT) hub height over a full 1-year seasonal cycle. Key findings demonstrate that the HPES system of choice namely the Floating Liquid Piston Accumulator with Sea Water under Compression (FLASC) system significantly reduces Proton Exchange Membrane (PEM) electrolyser (PEMEL) On/Off cycling (with a 66% reduction in On/Off events) while maintaining hydrogen production levels despite the integration of the energy storage system which has a projected round-trip efficiency of 75%. The FLASC-integrated HGE solution also marginally reduces renewable energy curtailment by approximately 0.3% during the 12-month timeframe. Economic analysis reveals that while the FLASC HPES system does introduce an additional capital cost into the energy chain it still yields substantial operational savings exceeding EUR 3 million annually through extended PEM electrolyser lifetime and improved operational efficiency. The Levelized Cost of Hydrogen (LCOH) for the FLASC-integrated HGE system which is estimated to be EUR 18.83/kg proves more economical than a direct wind-to-hydrogen approach with a levelized cost of EUR 21.09/kg of H2 produced. This result was achieved through more efficient utilisation of wind energy interfaced with energy storage as it mitigated the natural intermittency of the wind and increased the lifecycle of the equipment especially that of the PEM electrolysers. Three scenario models were created to project future costs. As electrolyser technologies advance cost reductions would be expected and this was one of the scenarios envisaged for the future. These scenarios reinforce the technical and economic viability of the HGE concept for offshore green hydrogen production particularly in the Mediterranean and in regions having similar moderate wind resources and deeper seas for offshore hybrid sustainable energy systems.
A Systematic Review of Predictive, Optimization, and Smart Control Strategies for Hydrogen-based Building Heating Systems
Nov 2024
Publication
The use of energy in the built environment contributes to over one-third of the world’s carbon emissions. To reduce that effect two primary solutions can be adopted i.e. (i) renovation of old buildings and (ii) increasing the renewable energy penetration. This review paper focuses on the latter. Renewable energy sources typically have an intermittent nature. In other words it is not guaranteed that these sources can be harnessed on demand. Thus complement solutions should be considered to use renewable energy sources efficiently. Hydrogen is recognized as a potential solution. It can be used to store excess energy or be directly exploited to generate thermal energy. Throughout this review various research papers focusing on hydrogen-based heating systems were reviewed analyzed and classified from different perspectives. Subsequently articles related to machine learning models optimization algorithms and smart control systems along with their applications in building energy management were reviewed to outline their potential contributions to reducing energy use lowering carbon emissions and improving thermal comfort for occupants. Furthermore research gaps in the use of these smart strategies in residential hydrogen heating systems were thoroughly identified and discussed. The presented findings indicate that the semi-decentralized hydrogen-based heating systems hold significant potential. First these systems can control the thermal demand of neighboring homes through local substations; second they can reduce reliance on power and gas grids. Furthermore the model predictive control and reinforcement learning approaches outperform other control systems ensuring energy comfort and cost-effective energy bills for residential buildings.
Comprehensive Review of Geomechanics of Underground Hydrogen Storage in Depleted Reservoirs and Salt Caverns
Sep 2023
Publication
Hydrogen is a promising energy carrier for a low-carbon future energy system as it can be stored on a megaton scale (equivalent to TWh of energy) in subsurface reservoirs. However safe and efficient underground hydrogen storage requires a thorough understanding of the geomechanics of the host rock under fluid pressure fluctuations. In this context we summarize the current state of knowledge regarding geomechanics relevant to carbon dioxide and natural gas storage in salt caverns and depleted reservoirs. We further elaborate on how this knowledge can be applied to underground hydrogen storage. The primary focus lies on the mechanical response of rocks under cyclic hydrogen injection and production fault reactivation the impact of hydrogen on rock properties and other associated risks and challenges. In addition we discuss wellbore integrity from the perspective of underground hydrogen storage. The paper provides insights into the history of energy storage laboratory scale experiments and analytical and simulation studies at the field scale. We also emphasize the current knowledge gaps and the necessity to enhance our understanding of the geomechanical aspects of hydrogen storage. This involves developing predictive models coupled with laboratory scale and field-scale testing along with benchmarking methodologies.
A Novel Sustainable Approach for Site Selection of Underground Hydrogen Storage in Poland Using Deep Learning
Jul 2024
Publication
This research investigates the potential of using bedded salt formations for underground hydrogen storage. We present a novel artificial intelligence framework that employs spatial data analysis and multi-criteria decision-making to pinpoint the most appropriate sites for hydrogen storage in salt caverns. This methodology incorporates a comprehensive platform enhanced by a deep learning algorithm specifically a convolutional neural network (CNN) to generate suitability maps for rock salt deposits for hydrogen storage. The efficacy of the CNN algorithm was assessed using metrics such as Mean Absolute Error (MAE) Mean Squared Error (MSE) Root Mean Square Error (RMSE) and the Correlation Coefficient (R2 ) with comparisons made to a real-world dataset. The CNN model showed outstanding performance with an R2 of 0.96 MSE of 1.97 MAE of 1.003 and RMSE of 1.4. This novel approach leverages advanced deep learning techniques to offer a unique framework for assessing the viability of underground hydrogen storage. It presents a significant advancement in the field offering valuable insights for a wide range of stakeholders and facilitating the identification of ideal sites for hydrogen storage facilities thereby supporting informed decisionmaking and sustainable energy infrastructure development.
Hydrogen Storage Solutions for Residential Heating: A Thermodynamic and Economic Analysis with Scale-up Potential
Jul 2024
Publication
The study presents a thermodynamic and economic assessment of different hydrogen storage solutions for heating purposes powered by PV panels of a 10-apartment residential building in Milan and it focuses on compressed hydrogen liquid hydrogen and metal hydride. The technical assessment involves using Python to code thermodynamic models to address technical and thermodynamic performances. The economic analysis evaluates the CAPEX the ROI and the cost per unit of stored hydrogen and energy. The study aims to provide an accurate assessment of the thermodynamic and economic indicators of three of the storage methods introduced in the literature review pointing out the one with the best techno-economic performance for further development and research. The performed analysis shows that compressed hydrogen represents the best alternative but its cost is still too high for small residential applications. Applying the technology to a big system case would enable the solution making it economically feasible.
Impact of Experimentally Measured Relative Permeability Hysteresis on Reservoir-scale Performance of Undergound Hydrogen Storage (UHS)
Jan 2024
Publication
Underground Hydrogen Storage (UHS) is an emerging large-scale energy storage technology. Researchers are investigating its feasibility and performance including its injectivity productivity and storage capacity through numerical simulations. However several ad-hoc relative permeability and capillary pressure functions have been used in the literature with no direct link to the underlying physics of the hydrogen storage and production process. Recent relative permeability measurements for the hydrogen-brine system show very low hydrogen relative permeability and strong liquid phase hysteresis very different to what has been observed for other fluid systems for the same rock type. This raises the concern as to what extend the existing studies in the literature are able to reliably quantify the feasibility of the potential storage projects. In this study we investigate how experimentally measured hydrogen-brine relative permeability hysteresis affects the performance of UHS projects through numerical reservoir simulations. Relative permeability data measured during a hydrogen-water core-flooding experiment within ADMIRE project is used to design a relative permeability hysteresis model. Next numerical simulation for a UHS project in a generic braided-fluvial water-gas reservoir is performed using this hysteresis model. A performance assessment is carried out for several UHS scenarios with different drainage relative permeability curves hysteresis model coefficients and injection/production rates. Our results show that both gas and liquid relative permeability hysteresis play an important role in UHS irrespective of injection/production rate. Ignoring gas hysteresis may cause up to 338% of uncertainty on cumulative hydrogen production as it has negative effects on injectivity and productivity due to the resulting limited variation range of gas saturation and pressure during cyclic operations. In contrast hysteresis in the liquid phase relative permeability resolves this issue to some extent by improving the displacement of the liquid phase. Finally implementing relative permeability curves from other fluid systems during UHS performance assessment will cause uncertainty in terms of gas saturation and up to 141% underestimation on cumulative hydrogen production. These observations illustrate the importance of using relative permeability curves characteristic of hydrogen-brine system for assessing the UHS performances.
Modelling of Hydrogen Dispersion with Effects
Sep 2023
Publication
The paper shows the latest developments of Gexcon’s consequence modelling software EFFECTS with validation based on hydrogen experimental data for different storage conditions and scenarios including liquid hydrogen two-phase jet releases. The effect of atmospheric turbulence on the dispersion and potential worst-case scenarios of hydrogen which are very different from heavy gas releases are discussed. Beside validation for gaseous hydrogen releases a validation study for pressurised liquid hydrogen jet releases including a sensitivity analysis is performed and the results are compared with experimental data.
Benchmark of J55 and X56 Steels on Cracking and Corrosion Effects Under Hydrogen Salt Cavern Boundary Conditions
Feb 2024
Publication
Salt caverns have great potential to store relevant amounts of hydrogen as part of the energy transition. However the durability and suitability of commonly used steels for piping in hydrogen salt caverns is still under research. In this work aging effects focusing on corrosion and cracking patterns of casing steel API 5CT J55 and “H2ready” pipeline steel API 5L X56 were investigated with scanning electron microscopy and energy dispersive X-ray spectroscopy after accelerated stress tests with pressure/temperature cycling under hydrogen salt cavern-like conditions. Compared to dry conditions significant more corrosion by presence of salt ions was detected. However compared to X56 only for J55 an intensification of corrosion and cracking at the surface due to hydrogen atmosphere was revealed. Pronounced surface cracks were observed for J55 over the entire samples. Overall the results strongly suggest that X56 is more resistant than J55 under the conditions of a hydrogen salt cavern.
The Role of Hydrogen in the Ecological Benefits of Ultra Low Sulphur Diesel Production and Use: An LCA Benchmark
Apr 2019
Publication
Desulphurization of oil-based fuels is common practice to mitigate the ecological burden to ecosystems and human health of SOx emissions. In many countries fuels for vehicles are restricted to 10 ppm sulphur. For marine fuels low sulphur contents are under discussion. The environmental impact of desulphurization processes is however quite high: (1) The main current source for industrial hydrogen is Steam Methane Reforming (SMR) with a rather high level of CO2 emissions (2) the hydrotreating process especially below 150 ppm needs a lot of energy. These two issues lead to three research questions: (a) What is the overall net ecological benefit of the current desulphurization practice? (b) At which sulfphur ppm level in the fuel is the additional ecological burden of desulphurization higher than the additional ecological benefit of less SOx pollution from combustion? (c) To what extent can cleaner hydrogen processes improve the ecological benefit of diesel desulphurization? In this paper we use LCA to analyze the processes of hydrotreatment the recovery of sulphur via amine treating of H2S and three processes of hydrogen production: SMR without Carbon Capture and Sequestration (CCS) SMR with 53% and 90% CCS and water electrolysis with two types of renewable energy. The prevention-based eco-costs system is used for the overall comparison of the ecological burden and the ecological benefit. The ReCiPe system was applied as well but appeared not suitable for such a comparison (other damage-based indicators cannot be applied either). The overall conclusion is that (1) the overall net ecological benefit of hydrogen-based Ultra Low Sulphur Diesel is dependent of local conditions but is remarkably high (2) desulphurization below 10 ppm is beneficial for big cities and (3) cleaner production of hydrogen reduces eco-cost by a factor 1.8–3.4.
Recent Progress on Ammonia Cracking Technologies for Scalable Hydrogen Production
Jun 2024
Publication
The global energy transition necessitates the development of technologies enabling cost-effective and scalable conversion of renewable energies into storable and transportable forms. Green ammonia with its high hydrogen storage capacity emerges as a promising carbon-free hydrogen carrier. This article reviews recent progress in industrially relevant catalysts and technologies for ammonia cracking which is a pivotal step in utilizing ammonia as a hydrogen storage material. Catalysts based on Ru Ni Fe Co and Fe–Co are evaluated with Cobased catalysts showing exceptional potential for ammonia cracking. Different reactor technologies and their applications are briefly discussed. This review concludes with perspectives on overcoming existing challenges emphasizing the need for catalyst development effective reactor design and sustainable implementation in the context of the energy transition.
Integration of Solid Oxide Fuel Cell and Internal Combustion Engine for Maritime Applications
Oct 2020
Publication
The current literature on solid oxide fuel cell and internal combustion engine (SOFC-ICE) integration is focused on the application of advanced combustion technologies operating as bottoming cycles to generate a small load share. This integration approach can pose challenges for ships such as restricted dynamic capabilities and large space and weight requirements. Furthermore the potential of SOFC-ICE integration for marine power generation has not been explored. Consequently the current work proposes a novel approach of SOFC-ICE integration for maritime applications which allows for high-efficiency power generation while the SOFC anode-off gas (AOG) is blended with natural gas (NG) and combusted in a marine spark-ignited (SI) engine for combined power generation. The objective of this paper is to investigate the potential of the proposed SOFC-ICE integration approach with respect to system efficiency emissions load sharing space and weight considerations and load response. In this work a verified zero-dimensional (0-D) SOFC model engine experiments and a validated AOG-NG mean value engine model is used. The study found that the SOFC-ICE integration with a 67–33 power split at 750 kWe power output yielded the highest efficiency improvement of 8.3% over a conventional marine natural gas engine. Simulation results showed that promising improvements in efficiency of 5.2% UHC and NOx reductions of about 30% and CO2 reductions of about 12% can be achieved from a 33–67 SOFC-ICE power split with comparatively much smaller increments in size and weight of 1.7 times. Furthermore the study concluded that in the proposed SOFC-ICE system for maritime applications a power split that favours the ICE would significantly improve the dynamic capabilities of the combined system and that the possible sudden and large load changes can be met by the ICE.
Solid Oxide Fuel Cells for Marine Applications
May 2023
Publication
The marine industry must reduce emissions to comply with recent and future regulations. Solid oxide fuel cells (SOFCs) are seenas a promising option for efficient power generation on ships with reduced emissions. However it is unclear how the devices canbe integrated and how this affects the operation of the ship economically and environmentally. This paper reviews studies thatconsider SOFC for marine applications. First this article discusses noteworthy developments in SOFC systems includingpower plant options and fuel possibilities. Next it presents the design drivers for a marine power plant and explores how anSOFC system performs. Hereafter the possibilities for integrating the SOFC system with the ship are examined alsoconsidering economic and environmental impact. The review shows unexplored potential to successfully integrate SOFC withthermal and electrical systems in marine vessels. Additionally it is identified that there are still possibilities to improve marineSOFC systems for which a holistic approach is needed for design at cell stack module and system level. Nevertheless it isexpected that hybridisation is needed for a technically and economically feasible ship. Despite its high cost SOFC systemscould significantly reduce GHG NO X SO X PM and noise emissions in shipping
Review on Ammonia as a Potential Fuel: From Synthesis to Economics
Feb 2021
Publication
Ammonia a molecule that is gaining more interest as a fueling vector has been considered as a candidate to power transport produce energy and support heating applications for decades. However the particular characteristics of the molecule always made it a chemical with low if any benefit once compared to conventional fossil fuels. Still the current need to decarbonize our economy makes the search of new methods crucial to use chemicals such as ammonia that can be produced and employed without incurring in the emission of carbon oxides. Therefore current efforts in this field are leading scientists industries and governments to seriously invest efforts in the development of holistic solutions capable of making ammonia a viable fuel for the transition toward a clean future. On that basis this review has approached the subject gathering inputs from scientists actively working on the topic. The review starts from the importance of ammonia as an energy vector moving through all of the steps in the production distribution utilization safety legal considerations and economic aspects of the use of such a molecule to support the future energy mix. Fundamentals of combustion and practical cases for the recovery of energy of ammonia are also addressed thus providing a complete view of what potentially could become a vector of crucial importance to the mitigation of carbon emissions. Different from other works this review seeks to provide a holistic perspective of ammonia as a chemical that presents benefits and constraints for storing energy from sustainable sources. State-of-the-art knowledge provided by academics actively engaged with the topic at various fronts also enables a clear vision of the progress in each of the branches of ammonia as an energy carrier. Further the fundamental boundaries of the use of the molecule are expanded to real technical issues for all potential technologies capable of using it for energy purposes legal barriers that will be faced to achieve its deployment safety and environmental considerations that impose a critical aspect for acceptance and wellbeing and economic implications for the use of ammonia across all aspects approached for the production and implementation of this chemical as a fueling source. Herein this work sets the principles research practicalities and future views of a transition toward a future where ammonia will be a major energy player.
Flame Stabilization and Blow-off of Ultra-Lean H2-Air Premixed Flames
Apr 2021
Publication
The manner in which an ultra-lean hydrogen flame stabilizes and blows off is crucial for the understanding and design of safe and efficient combustion devices. In this study we use experiments and numerical simulations for pure H2-air flames stabilized behind a cylindrical bluff body to reveal the underlying physics that make such flames stable and eventually blow-off. Results from CFD simulations are used to investigate the role of stretch and preferential diffusion after a qualitative validation with experiments. It is found that the flame displacement speed of flames stabilized beyond the lean flammability limit of a flat stretchless flame (φ = 0.3) can be scaled with a relevant tubular flame displacement speed. This result is crucial as no scaling reference is available for such flames. We also confirm our previous hypothesis regarding lean limit blow-off for flames with a neck formation that such flames are quenched due to excessive local stretching. After extinction at the flame neck flames with closed flame fronts are found to be stabilized inside a recirculation zone.
Can an Energy Only Market Enable Resource Adequacy in a Decarbonized Power System? A Co-simulation with Two Agent-based-models
Feb 2024
Publication
Future power systems in which generation will come almost entirely from variable Renewable Energy Sources (vRES) will be characterized by weather-driven supply and flexible demand. In a simulation of the future Dutch power system we analyze whether there are sufficient incentives for market-driven investors to provide a sufficient level of security of supply considering the profit-seeking and myopic behavior of investors. We cosimulate two agent-based models (ABM) one for generation expansion and one for the operational time scale. The results suggest that in a system with a high share of vRES and flexibility prices will be set predominantly by the demand’s willingness to pay particularly by the opportunity cost of flexible hydrogen electrolyzers. The demand for electric heating could double the price of electricity in winter compared to summer and in years with low vRES could cause shortages. Simulations with stochastic weather profiles increase the year-to-year variability of cost recovery by more than threefold and the year-to-year price variability by more than tenfold compared to a scenario with no weather uncertainty. Dispatchable technologies have the most volatile annual returns due to high scarcity rents during years of low vRES production and diminished returns during years with high vRES production. We conclude that in a highly renewable EOM investors would not have sufficient incentives to ensure the reliability of the system. If they invested in such a way to ensure that demand could be met in a year with the lowest vRES yield they would not recover their fixed costs in the majority of years.
Carbon Footprint of Hydrogen-powered Inland Shipping: Impacts and Hotspots
Aug 2023
Publication
The shipping sector is facing increasing pressure to implement clean fuels and drivetrains. Especially hydrogen fuel cell drivetrains seem attractive. Although several studies have been conducted to assess the carbon footprint of hydrogen and its application in ships their results remain hard to interpret and compare. Namely it is necessary to include a variety of drivetrain solutions and different studies are based on various assumptions and are expressed in other units. This paper addresses this problem by offering a three-step meta-review of life cycle assessment studies. First a literature review was conducted. Second results from the literature were harmonized to make the different analyses comparable serving cross-examination. The entire life cycle of both the fuels and drivetrains were included. The results showed that the dominant impact was fuel use and related fuel production. And finally life-cycle hot spots have been identified by looking at the effect of specific configurations in more detail. Hydrogen production by electrolysis powered by wind has the most negligible impact. For this ultra-low carbon pathway the modes of hydrogen transport and the use of specific materials and components become relevant.
Lifetime Design, Operation, and Cost Analysis for the Energy System of a Retrofitted Cargo Vessel with Fuel Cells and Batteries
Oct 2024
Publication
Fuel cell-battery electric drivetrains are attractive alternatives to reduce the shipping emissions. This research focuses on emission-free cargo vessels and provides insight on the design lifetime operation and costs of hydrogen-hybrid systems which require further research for increased utilization. A representative round trip is created by analysing one-year operational data based on load ramps and power frequency. A low-pass filter controller is employed for power distribution. For the lifetime cost analysis 14 scenarios with varying capital and operational expenses were considered. The Net Present Value of the retrofitted fuel cell-battery propulsion system can be up to $ 2.2 million lower or up to $ 18.8 million higher than the original diesel mechanical configuration highly dependent on the costs of green hydrogen and carbon taxes. The main propulsion system weights and volumes of the two versions are comparable but the hydrogen tank (68 tons 193 m3 ) poses significant design and safety challenges.
Simulation of DDT in Obstructed Channels: Wavy Channels vs. Fence-type Obstacles
Sep 2023
Publication
The capabilities of an OpenFOAM solver to reproduce the transition of stoichiometric H2-air mixtures to detonation in obstructed 2-D channels were tested. The process is challenging numerically as it involves the ignition of a flame kernel its subsequent propagation and acceleration interaction with obstacles formation of shock waves ahead and detonation onset (DO). Two different obstacle configurations were considered in 10-mm high × 1-m long channels: (i) wavy walls (WW) that mimic the behavior of fencetype obstacles but prevent abrupt area changes. In this case flame acceleration (FA) is strongly affected by shock-flame interactions and DO often results from the compression of the gas present between the accelerating flame front and a converging section of the channel. (ii) Fence-type (FT) obstacles. In this case FA is driven by the increase in flame surface area as a result of the interaction of the flame front with the unburned gas flow field ahead particularly downstream of obstacles; shock-flame interactions play a role at the later stages of FA and DO takes place upon reflection of precursor shocks from obstacles. The effect of initial pressure p0 = 25 50 and 100 kPa at constant blockage ratio (BR = 0.6) was investigated and compared for both configurations. Results show that for the same initial pressure (p0 = 50 kPa) the obstacle configurations could lead to different final propagation regimes: a quasi-detonation for WW and a choked-flame for FT due to the increased losses for the latter. At p0 = 25 kPa however while both configurations result in choked flames WW seem to exhibit larger velocity deficits than FT due to longer flame-precursor shock distances during quasi-steady propagation and to the increased presence of unburnt mixture downstream of the tip of the flame that homogeneously explodes providing additional support to the propagation of the flame.
Energy Use and Greenhouse Gas Emissions of Traction Alternatives for Regional Railways
Feb 2024
Publication
This paper presents a method for estimating Well-to-Wheel (WTW) energy use and greenhouse gas (GHG) emissions attributed to the advanced railway propulsion systems implemented in conjunction with different energy carriers and their production pathways. The analysis encompasses diesel-electric multiple unit vehicles converted to their hybrid-electric plug-in hybrid-electric fuel cell hybrid-electric or battery-electric counterparts combined with biodiesel or hydrotreated vegetable oil (HVO) as the first and second generation biofuels liquefied natural gas (LNG) hydrogen and/or electricity. The method is demonstrated using non-electrified regional railway network with heterogeneous vehicle fleet in the Netherlands as a case. Battery-electric system utilizing green electricity is identified as the only configuration leading to emission-free transport while offering the highest energy use reduction by 65–71% compared to the current diesel-powered hybrid-electric system. When using grey electricity based on the EU2030 production mix these savings are reduced to about 27–39% in WTW energy use and around 68–73% in WTW GHG emissions. Significant reductions in overall energy use and emissions are obtained for the plug-in hybrid-electric concept when combining diesel LNG or waste cooking oil-based HVO with electricity. The remaining configurations that reduce energy use and GHG emissions are hybrid-electric systems running on LNG or HVO from waste cooking oil. The latter led to approximately 88% lower WTW emissions than the baseline for each vehicle type. When produced from natural gas or EU2030-mix-based electrolysis hydrogen negatively affected both aspects irrespective of the prime mover technology. However when produced via green electricity it offers a GHG reduction of approximately 90% for hybrid-electric and fuel cell hybrid-electric configurations with a further reduction of up to 92–93% if combined with green electricity in plug-in hybrid-electric systems. The results indicate that HVO from waste cooking oil could be an effective and instantly implementable transition solution towards carbon–neutral regional trains allowing for a smooth transition and development of supporting infrastructure required for more energy-efficient and environment-friendly technologies.
Coordinating Social Dynamics for Integrating Hydrogen in the Netherlands
Jan 2025
Publication
Integrating hydrogen into energy systems presents challenges involving social dynamics among stakeholders beyond technical considerations. A gap exists in understanding how these dynamics influence the deployment of hydrogen technologies and infrastructure particularly in infrastructure development and market demand for widespread adoption. In the Netherlands despite ambitious strategies and investments comprehensive explanations of social dynamics’ impact on integration processes and market development are lacking. This study addresses this gap by analyzing the hydrogen value chain and stakeholder interactions in the Dutch hydrogen sector. A literature review highlights system integration challenges and the need for decentralized coordination and cross-sector collaboration. Using the Dutch energy grid and its hydrogen initiatives as a case study social network analysis and semi-structured interviews are applied to analyze over 60 hydrogen initiatives involving more than 340 stakeholders. Initiatives are categorized into large-scale centralized and decentralized local types based on scale and stakeholder involvement allowing targeted analysis of stakeholder interactions in different contexts. Findings reveal that centralized networks may limit innovation due to concentrated influence while decentralized networks encourage innovation but require better coordination. These insights guide strategic planning and policymaking in hydrogen energy initiatives aiming to enhance scalability and efficiency of hydrogen technologies for sustainable energy solutions.
Design of Gravimetric Primary Standards for Field-testing of Hydrogen Refuelling Stations
Apr 2020
Publication
The Federal Institute of Metrology METAS developed a Hydrogen Field Test Standard (HFTS) that can be used for field verification and calibration of hydrogen refuelling stations. The testing method is based on the gravimetric principle. The experimental design of the HFTS as well as the description of the method are presented here.
Towards Low-carbon Power Networks: Optimal Location and Sizing of Renewable Energy Sources and Hydrogen Storage
Apr 2024
Publication
This paper proposes a systematic optimization framework to jointly determine the optimal location and sizing decisions of renewables and hydrogen storage in a power network to achieve the transition to low-carbon networks efficiently. We obtain these strategic decisions based on the multi-period alternating current optimal power flow (AC MOPF) problem that jointly analyzes power network renewable and hydrogen storage interactions at the operational level by considering the uncertainty of renewable output seasonality of electricity demand and electricity prices. We develop a tailored solution approach based on second-order cone programming within a Benders decomposition framework to provide globally optimal solutions. In a test case we show that the joint integration of renewable sources and hydrogen storage and consideration of the AC MOPF model significantly reduces the operational cost of the power network. In turn our findings can provide quantitative insights to decision-makers on how to integrate renewable sources and hydrogen storage under different settings of the hydrogen selling price renewable curtailment cost emission tax price and conversion efficiency.
Charting the Course: Navigating Decarbonisation Pathways in Greece, Germany, The Netherlands, and Spain’s Industrial Sectors
Jul 2024
Publication
In the quest for a sustainable future energy-intensive industries (EIIs) stand at the forefront of Europe’s decarbonisation mission. Despite their significant emissions footprint the path to comprehensive decarbonisation remains elusive at EU and national levels. This study scrutinises key sectors such as non-ferrous metals steel cement lime chemicals fertilisers ceramics and glass. It maps out their current environmental impact and potential for mitigation through innovative strategies. The analysis spans across Spain Greece Germany and the Netherlands highlighting sector-specific ecosystems and the technological breakthroughs shaping them. It addresses the urgency for the industry-wide adoption of electrification the utilisation of green hydrogen biomass bio-based or synthetic fuels and the deployment of carbon capture utilisation and storage to ensure a smooth transition. Investment decisions in EIIs will depend on predictable economic and regulatory landscapes. This analysis discusses the risks associated with continued investment in high-emission technologies which may lead to premature decommissioning and significant economic repercussions. It presents a dichotomy: invest in climate-neutral technologies now or face the closure and offshoring of operations later with consequences for employment. This open discussion concludes that while the technology for near-complete climate neutrality in EIIs exists and is rapidly advancing the higher costs compared to conventional methods pose a significant barrier. Without the ability to pass these costs to consumers the adoption of such technologies is stifled. Therefore it calls for decisive political commitment to support the industry’s transition ensuring a greener more resilient future for Europe’s industrial backbone.
Stakeholder Perspectives on the Scale-up of Green Hydrogen and Electrolyzers
Nov 2023
Publication
Green hydrogen is a promising alternative to fossil fuels. However current production capacities for electrolyzers and green hydrogen are not in line with national political goals and projected demand. Considering these issues we conducted semi-structured interviews to determine the narratives of different stakeholders during this transformation as well as challenges and opportunities for the green hydrogen value chain. We interviewed eight experts with different roles along the green hydrogen value chain ranging from producers and consumers of green hydrogen to electrolyzer manufacturers and consultants as well as experts from the political sphere. Most experts see the government as necessary for scale-up by setting national capacity targets policy support and providing subsidies. However the experts also accuse the governments of delaying development through overregulation and long implementation times for regulations. The main challenges that were identified are the current lack of renewable electricity and demand for green hydrogen. Demand for green hydrogen is influenced by supply costs which partly depend on prices for electrolyzers. However one key takeaway of the interviews is the skeptical assessments by the experts on the currently discussed estimates for price reduction potential of electrolyzers. While demand supply and prices are all factors that influence each other they result in feedback loops in investment decisions for the energy and manufacturing industries. A second key takeaway is that according to the experts current investment decisions in new production capacities are not solely dependent on short-term financial gains but also based on expected first mover advantages. These include experience and market share which are seen as factors for opportunities for future financial gains. Summarized the results present several challenges and opportunities for green hydrogen and electrolyzers and how to address them effectively. These insights contribute to a deeper understanding of the dynamics of the emerging green hydrogen value chain.
Multiperiod Modeling and Optimization of Hydrogen-Based Dense Energy Carrier Supply Chains
Feb 2024
Publication
The production of hydrogen-based dense energy carriers (DECs) has been proposed as a combined solution for the storage and dispatch of power generated through intermittent renewables. Frameworks that model and optimize the production storage and dispatch of generated energy are important for data-driven decision making in the energy systems space. The proposed multiperiod framework considers the evolution of technology costs under different levels of promotion through research and targeted policies using the year 2021 as a baseline. Furthermore carbon credits are included as proposed by the 45Q tax amendment for the capture sequestration and utilization of carbon. The implementation of the mixed-integer linear programming (MILP) framework is illustrated through computational case studies to meet set hydrogen demands. The trade-offs between different technology pathways and contributions to system expenditure are elucidated and promising configurations and technology niches are identified. It is found that while carbon credits can subsidize carbon capture utilization and sequestration (CCUS) pathways substantial reductions in the cost of novel processes are needed to compete with extant technology pathways. Further research and policy push can reduce the levelized cost of hydrogen (LCOH) by upwards of 2 USD/kg.
Techno-economic Analysis of Underground Hydrogen Storage in Europe
Dec 2023
Publication
Hydrogen storage is crucial to developing secure renewable energy systems to meet the European Union’s 2050 carbon neutrality objectives. However a knowledge gap exists concerning the site-specific performance and economic viability of utilizing underground gas storage (UGS) sites for hydrogen storage in Europe. We compile information on European UGS sites to assess potential hydrogen storage capacity and evaluate the associated current and future costs. The total hydrogen storage potential in Europe is 349 TWh of working gas energy (WGE) with site-specific capital costs ranging from $10 million to $1 billion. Porous media and salt caverns boasting a minimum storage capacity of 0.5 TWh WGE exhibit levelized costs of $1.5 and $0.8 per kilogram of hydrogen respectively. It is estimated that future levelized costs associated with hydrogen storage can potentially decrease to as low as $0.4 per kilogram after three experience cycles. Leveraging these techno-economic considerations we identify suitable storage sites.
Techno-economic Assessment of Low-carbon Ammonia as Fuel for the Maritime Sector
Mar 2025
Publication
Low-carbon ammonia has recently received interest as alternative fuel for the maritime sector. This paper presents a techno-economic analysis of the total cost of ownership (TCO) of a Post-Panamax vessel powered by low-carbon ammonia. We also calculate the annual increase in carbon tax needed to compensate for the increment in TCO compared to a vessel powered by very low sulfur fuel oil. The increment in TCO is calculated as function of propulsion efficiency to account for uncertainties in the thermodynamics of ammonia combustion for three different cost scenarios of low-carbon ammonia. We evaluate the benefits and drawbacks of hydrogen and diesel as dual fuel for three types of propulsion systems: a compression ignition engine a spark-ignition engine and a combination of a solid oxide fuel cell (SOFC) system and a spark-ignition engine. We incorporate three different cost levels for ammonia and a variable engine efficiency ranging from 35% to 55%. If the ammonia engine has the efficiency of a conventional marine engine the increment in TCO is 25% in the most optimistic cost scenario. SOFCs can reach a better efficiency and yield no pollutant emissions but the reduction in fuel expenses in comparison to conventional combustion engines only offsets their high investment costs at either low engine efficiency or high fuel prices. The increment in TCO and reduction in GHG emissions depend on whether high combustion efficiencies small dual fuel fractions and low NOx N2O and NH3 emissions can be simultaneously achieved.
The Making of H2-scapes in the Global South: Political Geography Perspectives on an Emergent Field of Research
Feb 2025
Publication
Clean hydrogen is touted as a cornerstone of the global energy transition. It can help to decarbonize hard-to-electrify sectors ship renewable power over great distances and boost energy security. Clean hydrogen’s appeal is increasingly felt in the Global South where countries seek to benefit from production export and consumption opportunities new infrastructures and technological innovations. These geographies are however in the process of taking shape and their associated power configurations spatialities and socio-ecological consequences are yet to be more thoroughly understood and examined. Drawing on political geography perspectives this article proposes the concept of “hydrogen landscape” – or in short H2-scape – to theorize and explore hydrogen transitions as space-making processes imbued with power relations institutional orders and social meanings. In this endeavor it outlines a conceptual framework for understanding the making of H2-scapes and offers three concrete directions for advancing empirical research on hydrogen transitions in the Global South: (1) H2-scapes as resource frontiers; (2) H2-scapes as port-centered arrangements; and (3) H2-scapes as failure. As hydrogen booms in finances projects and visibility the article illuminates conceptual tools and perspectives to think about and facilitate further research on the emergent political geographies of hydrogen transitions particularly in more uneven unequal and vulnerable Global South landscapes.
No more items...