Netherlands

The development of reliable hydrogen sensors is crucial for the safe use of hydrogen. One of the main concerns of end-users is sensor reliability in the presence of species other than the target gas which can lead to false alarms or undetected harmful situations. In order to assess the selectivity of commercial of the shelf (COTS) hydrogen sensors a number of sensors of different technology types were exposed to various interferent gas species. Cross-sensitivity tests were performed in accordance to the recommendations of ISO 26142:2010 using the hydrogen sensor testing facilities of NREL and JRC-IET. The results and conclusions arising from this study are presented.

Functionalization of semiconductors by metallic nanoparticle is considered to be one of the most effective procedure to improve photocatalytic hydrogen production. Photodeposition is frequently used for functionalization but particle sizes and dispersions are still difficult to control. Here Pt functionalization is achieved in a one-pot synthesis. The as-prepared samples are compared to reference materials prepared by conventional photodeposition and our results confirm that small and well-dispersed nanoparticles with superior stability are obtained by one-pot synthesis. The enhanced stability is attributed to a limited leaching of Pt nanoparticles during illumination likely caused by the preferable interaction of small well dispersed Pt nanoparticles with the TiO₂ support material. In addition our results demonstrate that Na-residues are detrimental for the photocatalytic performance and washing in acidic solution is mandatory to effectively reduce the sodium contamination.

In order to maximise European national and regional research and innovation potential the European Union is investing in these fields through different funding mechanisms such as the ESIF or H2020 programme. This investment plan is part of the European 2020 strategy where the concept of Smart Specialisation is also included.<br/>Smart Specialisation is an innovation policy concept designed to promote the efficient and effective use of public investment in regional innovation in order to achieve economic growth. The Smart Specialisation Platform was created to support this concept by assisting regions and Member States in developing implementing and reviewing their research and innovation Smart Specialisation strategies.<br/>The Smart Specialisation Platform comprises several thematic platforms. The thematic Smart Specialisation Platform on energy (S3PEnergy) is a joint initiative of three European Commission services: DG REGIO DG ENER and the Joint Research Centre (JRC). The main objective of the S3PEnergy is to support the optimal and effective uptake of the Cohesion Policy funds for energy and to better align energy innovation activities at national local and regional level through the identification of the technologies and innovative solutions that support in the most cost-effective way the EU energy policy priorities.<br/>In the particular case of hydrogen technologies the activities of the platform are mainly focused on supporting the new Fuel Cells and Hydrogen Joint Undertaking (FCH JU) initiative involving regions and cities. To date more than 80 European cities and regions have committed to participate in this initiative through the signature of a Memorandum of Understanding and more participants are expected to join. S3PEnergy is helping in the identification of potential combination of H2020 funding (provided through FCH JU) and ESIF.<br/>To identify potential synergies among these two funding sources a mapping of the different ESIF opportunities has been performed. In order to map these opportunities Operational Programmes (OPs) and research and innovation strategies for Smart Specialisation (RIS3) of the different European regions and Member States were analysed. The results of this mapping and analysis are presented in this paper."

Guidance on Sensor Placement was identified as the top research priority for hydrogen sensors at the 2018 HySafe Research Priority Workshop on hydrogen safety in the category Mitigation Sensors Hazard Prevention and Risk Reduction. This paper discusses the initial steps (Phase 1) to develop such guidance for mechanically ventilated enclosures. This work was initiated as an international collaborative effort to respond to emerging market needs related to the design and deployment equipment for hydrogen infrastructure that is often installed in individual equipment cabinets or ventilated enclosures. The ultimate objective of this effort is to develop guidance for an optimal sensor placement such that when integrated into a facility design and operation will allow earlier detection at lower levels of incipient leaks leading to significant hazard reduction. Reliable and consistent early warning of hydrogen leaks will allow for the risk mitigation by reducing or even eliminating the probability of escalation of small leaks into large and uncontrolled events. To address this issue a study of a real-world mechanically ventilated enclosure containing GH2 equipment was conducted where CFD modelling of the hydrogen dispersion (performed by AVT and UQTR and independently by the JRC) was validated by the NREL Sensor laboratory using a Hydrogen Wide Area Monitor (HyWAM) consisting of a 10-point gas and temperature measurement analyzer. In the release test helium was used as a hydrogen surrogate. Expansion of indoor releases to other larger facilities (including parking structures vehicle maintenance facilities and potentially tunnels) and incorporation into QRA tools such as HyRAM is planned for Phase 2. It is anticipated that results of this work will be used to inform national and international standards such as NFPA 2 Hydrogen Technologies Code Canadian Hydrogen Installation Code (CHIC) and relevant ISO/TC 197 and CEN documents.

A combined density functional theory and molecular dynamics approach is employed to study modifications of graphene at atomistic level for better H2 storage. The study reveals H₂ desorption from hydrogenated defective graphene structure V₂₂₂ to be exothermic. H₂ adsorption and desorption processes are found to be more reversible for V₂₂₂ as compared to pristine graphene. Our study shows that V₂₂₂ undergoes brittle fracture under tensile loading similar to the case of pristine graphene. The tensile strength of V₂₂₂ shows slight reduction with respect to their pristine counterpart which is attributed to the transition of sp2 to sp3-like hybridization. The study also shows that the V₂₂₂ structure is mechanically more stable than the defective graphene structure without chemically adsorbed hydrogen atoms. The current fundamental study thus reveals the efficient recovery mechanism of adsorbed hydrogen from V₂₂₂ and paves the way for the engineering of structural defects in graphene for H₂ storage.

Ammonia may be one of the energy carriers in the hydrogen economy. Although research has mostly focused on electrochemical ammonia synthesis this however remains a scientific challenge. In the current article we discuss the feasibility of single-pass thermochemical ammonia synthesis as an alternative to the high-temperature high-pressure Haber-Bosch synthesis loop. We provide an overview of recently developed low temperature ammonia synthesis catalysts as well as an overview of solid ammonia sorbents. We show that the low temperature low pressure single-pass ammonia synthesis process can produce ammonia at a lower cost than the Haber-Bosch synthesis loop for small-scale ammonia synthesis (<40 t-NH₃ d⁻¹).

This article presents an analysis of the permeation tests established in the current regulations for the type-approval of on board tanks in hydrogen vehicles. The analysis is done from the point of view of a test maker regarding the preparation for the execution of a permeation test. The article contains a description of the required instrumentation and set-up to carry out a permeation test according to the applicable standards and regulations. Tank conditions at the beginning of the test configuration of permeation chamber duration of the test or permeation rate to be reported are aspects that are not well-defined in regulations. In this paper we examine the challenges when carrying out a permeation test and propose possible solutions to overcome them with the intention of supporting test makers and helping the development of permeation test guidelines.

The competitiveness of biofuels may be increased by integrating biomass gasification plants with electrolysis units which generate hydrogen to be combined with carbon-rich syngas. This option allows increasing the yield of the final product by retaining a higher amount of biogenic carbon and improving the resilience of the energy sector by favoring electric grid services and sector coupling. This article illustrates a techno-economic comparative analysis of three flexible power and biomass to methanol plants based on different gasification technologies: direct gasification indirect gasification and sorptionenhanced gasification. The design and operational criteria of each plant are conceived to operate both without green hydrogen addition (baseline mode) and with hydrogen addition (enhanced mode) following an intermittent use of the electrolysis system which is turned on when the electricity price allows an economically viable hydrogen production. The methanol production plants include a gasification section syngas cleaning conditioning and compression section methanol synthesis and purification and heat recovery steam cycle to be flexibly operated. Due to the high oxygen demand in the gasifier the direct gasification-based plant obtains a great advantage to be operated between a minimum load to satisfy the oxygen demand at high electricity prices and a maximum load to maximize methanol production at low electricity prices. This allows avoiding large oxygen storages with significant benefits for Capex and safety issues. The analysis reports specific fixed-capital investments between 1823 and 2048 €/kW of methanol output in the enhanced operation and LCOFs between 29.7 and 31.7 €/GJLHV. Economic advantages may be derived from a decrease in the electrolysis capital investment especially for the direct gasification-based plants which employ the greatest sized electrolyzer. Methanol breakeven selling prices range between 545 and 582 €/t with the 2019 reference Denmark electricity price curve and between 484 and 535 €/t with an assumed modified electricity price curve of a future energy mix with increased penetration of intermittent renewables.

Fuel cells are electrochemical devices that are conventionally used to convert the chemical energy of fuels into electricity while producing heat as a byproduct. High temperature fuel cells such as molten carbonate fuel cells and solid oxide fuel cells produce significant amounts of heat that can be used for internal reforming of fuels such as natural gas to produce gas mixtures which are rich in hydrogen while also producing electricity. This opens up the possibility of using high temperature fuel cells in systems designed for flexible coproduction of hydrogen and power at very high system efficiency. In a previous study the flowsheet software Cycle-Tempo has been used to determine the technical feasibility of a solid oxide fuel cell system for flexible coproduction of hydrogen and power by running the system at different fuel utilization factors (between 60 and 95%). Lower utilization factors correspond to higher hydrogen production while at a higher fuel utilization standard fuel cell operation is achieved. This study uses the same basis to investigate how a system with molten carbonate fuel cells performs in identical conditions also using Cycle-Tempo. A comparison is made with the results from the solid oxide fuel cell study.

The intermittent nature of renewable energy resources such as wind and solar causes the energy supply to be less predictable leading to possible mismatches in the power network. To this end hydrogen production and storage can provide a solution by increasing flexibility within the system. Stored hydrogen as compressed gas can either be converted back to electricity or it can be used as feed-stock for industry heating for built environment and as fuel for vehicles. This research is the first to examine optimal strategies for operating integrated energy systems consisting of renewable energy production and hydrogen storage with direct gas-based use-cases for hydrogen. Using Markov decision process theory we construct optimal policies for day-to-day decisions on how much energy to store as hydrogen or buy from or sell to the electricity market and on how much hydrogen to sell for use as gas. We pay special emphasis to practical settings such as contractually binding power purchase agreements varying electricity prices different distribution channels green hydrogen offtake agreements and hydrogen market price uncertainties. Extensive experiments and analysis are performed in the context of Northern Netherlands where Europe’s first Hydrogen Valley is being formed. Results show that gains in operational revenues of up to 51% are possible by introducing hydrogen storage units and competitive hydrogen market-prices. This amounts to a e126000 increase in revenues per turbine per year for a 4.5 MW wind turbine. Moreover our results indicate that hydrogen offtake agreements will be crucial in keeping the energy transition on track.

The energy world is changing rapidly pushed also by the need for new green energy sources to reduce greenhouse gas emissions. The fast development of renewable energies has created many problems associated with grid management and stability which could be solved with storage systems. The hydrogen economy could be an answer to the need of storage systems and clean fuel for transportation. The Electrochemical Hydrogen Compressor (EHC) is an electrochemical device which could find a place in this scenario giving a solution for the hydrogen purification and compression for storage. This work analyzes through experimental and modeling studies the performance of the EHC in terms of polarization curve Hydrogen Recovery Factor (HRF) and outlet hydrogen purity. The influence of many input parameters such as the total inlet flow rate the hydrogen inlet concentration the contaminant in the feed and the cathode pressure have been investigated. Furthermore the EHC performance have been modelled in a 1D + 1D model implemented in Matlab® solving the Butler-Volmer system of equations numerically. The experimental campaign has shown that high purities can be obtained for the hydrogen separation from N2 and CH4 and purities over 98% feeding He. An increase in the cathode pressure has shown a slight improvement in the obtained purity. A comparison between PSA unit and EHC for a mixture 75% H2 – 25% CH4 at different outlet hydrogen pressure and purity was performed to analyze the energy consumption required. Results show PSA unit is convenient at large scale and high H2 concentration while for low concentration is extremely energy intense. The EHC proved to be worthwhile at small scale and higher outlet hydrogen pressure.

Underground Hydrogen Storage (UHS) as an emerging large-scale energy storage technology has shown great promise to ensure energy security with minimized carbon emission. A set of comprehensive UHS site evaluation criteria based on important factors that affect UHS performances is needed for its potential commercialization. This study focuses on the UHS site evaluation of gas mixing. The economic implications of gas mixing between injected hydrogen gas and the residual or cushion gas in a porous storage reservoir is an emerging problem for Underground Hydrogen Storage (UHS). It is already clear that reservoir scale heterogeneity such as formation structure (e.g. formation dip angle) and facies heterogeneity of the sedimentary rock may considerably affect the reservoir-scale mechanical dispersion-induced gas mixing during UHS in high permeability braided-fluvial systems (a common depleted reservoir type for UHS). Following this finding the current study uses the processmimicking modeling software to build synthetic meandering-fluvial reservoir models. Channel dimensions and the presence of abandoned channel facies are set as testing parameters resulting in 4 simulation cases with 200 realizations. Numerical flow simulations are performed on these models to investigate and compare the effects of reservoir and metre-scale heterogeneity on UHS gas mixing. Through simulation channel dimensions (reservoir-scale heterogeneity) are found to affect the uncertainty of produced gas composition due to mixing (represented by the P10-P90 difference of hydrogen fraction in a produced stream) by up to 42%. The presence of abandoned channel facies (metre-scale heterogeneity) depending on their architectural relationship with meander belts could also influence the gas mixing process to a comparable extent (up to 40%). Moreover we show that there is no clear statistical correlation between gas mixing and typical reservoir characterization parameters such as original gas in place (OGIP) average reservoir permeability and the Dykstra-Parsons coefficient. Instead the average time of travel of all reservoir cells calculated from flow diagnostics shows a negative correlation with the level of gas mixing. These results reveal the importance of 3D reservoir architecture analysis (integration of multiple levels of heterogeneity) to UHS site evaluation on gas mixing in depleted gas reservoirs. This study herein provides valuable insights into UHS site evaluation regarding gas mixing.

In this paper we aim to analyse the impact of hydrogen production decarbonisation and electrification scenarios on the infrastructure development generation mix CO2 emissions and system costs of the European power system considering the retrofit of the natural gas infrastructure. We define a reference scenario for the European power system in 2050 and use scenario variants to obtain additional insights by breaking down the effects of different assumptions. The scenarios were analysed using the European electricity market model COMPETES including a proposed formulation to consider retrofitting existing natural gas networks to transport hydrogen instead of methane. According to the results 60% of the EU’s hydrogen demand is electrified and approximately 30% of the total electricity demand will be to cover that hydrogen demand. The primary source of this electricity would be non-polluting technologies. Moreover hydrogen flexibility significantly increases variable renewable energy investment and production and reduces CO2 emissions. In contrast relying on only electricity transmission increases costs and CO2 emissions emphasising the importance of investing in an H2 network through retrofitting or new pipelines. In conclusion this paper shows that electrifying hydrogen is necessary and cost-effective to achieve the EU’s objective of reducing long-term emissions.

Reducing the gap between the electrodes and diaphragm to zero is an often adopted strategy to reduce the ohmic drop in alkaline water electrolyzers for hydrogen production. We provide a thorough account of the current–voltage relationship in such a zero-gap configuration over a wide range of electrolyte concentrations and current densities. Included are voltage components that are not often experimentally quantified like those due to bubbles hydroxide depletion and dissolved hydrogen and oxygen. As is commonly found for zero-gap configurations the ohmic resistance was substantially larger than that of the separator. We find that this is because the relatively flat electrode area facing the diaphragm was not active likely due to separator pore blockage by gas the electrode itself and or solid deposits. Over an e-folding time-scale of ten seconds an additional ohmic drop was found to arise likely due to gas bubbles in the electrode holes. For electrolyte concentrations below 0.5 M an overpotential was observed associated with local depletion of hydroxide at the anode. Finally a high supersaturation of hydrogen and oxygen was found to significantly increase the equilibrium potential at elevated current densities. Most of these voltage losses are shown to be easily avoidable by introducing a small 0.2 mm gap greatly improving the performance compared to zero-gap.

Although hydrogen is increasingly seen as a crucial energy carrier in future zero-carbon energy system a profitable exploitation of electrolysers requires still high amounts of subsidies. To analyze the profitability of electrolysers attention has to be paid not only to the costs but also to the interaction between electricity and hydrogen markets. Using a model of internationally integrated electricity and hydrogen markets this paper analyses the profitability of electrolysers plants in various future market circumstances. We find that in particular the future supply of renewable electricity the demand for electricity as well as the prices of natural gas and carbon strongly affect the profitability of electrolysis. In order to make massive investments in electrolysers profitable with significantly lower subsidy requirements the amount of renewable electricity generation needs to grow strongly and the carbon prices should be higher while the demand for electricity should not increase accordingly. This research underscores the critical role of market conditions in shaping the viability of hydrogen electrolysis providing valuable insights for policymakers and stakeholders in the transition to a zero-carbon energy system.

In August 2022 Shell started construction of Holland Hydrogen I (HH I) a 200 MW electrolyser plant in the port of Rotterdam’s industrial zone on Maasvlakte II in the Netherlands. HH I will produce up to 60000 kg of renewable hydrogen per day. The development and demonstration of a safe layout and plant design had been challenging due to ambitious HH I project premises many technical novelties common uncertainties in hydrogen leak effect prediction a lack of large-scale water electrolyzer operating history and limited standardization in this industry sector. This paper provides an industry perspective of the major challenges in commercial electrolyzer plant HSSE risk assessment and risk mitigation work processes required to develop and demonstrate a safe design and it describes lessons learned in this area during the HH I project. Furthermore the paper lists major common gaps in relevant knowledge engineering tools standards and OEM deliverables that need closure to enable future commercial electrolyzer plant projects to develop an economically viable and plant design and layout more efficiently and cost-effectively.

During a severe accident in a nuclear power plant one of the potential threats to the containment is the occurrence of energetic combustion events. In modern plants Severe Accident Management Guidelines (SAMG) as well as dedicated mitigation hardware are in place to minimize/mitigate this combustion risk and thus avoid the release of radioactive material into the environment. Advancements in SAMGs are in the focus of AMHYCO an EU-funded Horizon 2020 project officially launched on October 1st 2020. The project consortium consists of 12 organizations (from six European countries and one from Canada) and is coordinated by the Universidad Politécnica de Madrid (UPM). The progress made in the first two years of the AMHYCO project is here presented. A comprehensive bibliographic review has been conducted providing a common foundation to build the knowledge gained during the project. After an extensive set of accident transients simulated both for phases occurring inside and outside the reactor pressure vessel a set of challenging sequences from the combustion risk perspective for different power plant types were identified. At the same time three generic containment models for the three considered reactor designs have been created to provide the full containment analysis simulations with lumped parameter models 3-dimensional containment codes and CFD codes. In order to further consolidate the model base combustion experiments and performance tests on passive auto-catalytic recombiners under explosion prone H2/CO atmospheres were performed at CNRS (France) and FZJ (Germany). Finally it is worth saying that the experimental data and engineering models generated from the AMHYCO project are useful for other industries outside the nuclear one.

This paper aims to holistically study hydrogen production options essential for a sustainable and carbon-free future. This study also outlines the benefits and challenges of hydrogen production methods to provide sustainable alternatives to fossil fuels by meeting the global energy demand and net-zero targets. In this study sixteen hydrogen production methods are selected for sustainability investigation based on seven different criteria. The criteria selected in the comparative evaluation cover various dimensions of hydrogen production in terms of economic technical environmental and thermodynamic aspects for better sustainability. The current study results show that steam methane reforming with carbon capture could provide sustainable hydrogen in the near future while the other technologies’ maturity levels increase and the costs decrease. In the medium- and long-terms photonic and thermal-based hydrogen production methods can be the key to sustainable hydrogen production.

The absence of contaminants in the hydrogen delivered at the hydrogen refuelling station is critical to ensure the length life of FCEV. Hydrogen quality has to be ensured according to the two international standards ISO 14687–2:2012 and ISO/DIS 19880-8. Amount fraction of contaminants from the two hydrogen production processes steam methane reforming and PEM water electrolyser is not clearly documented. Twenty five different hydrogen samples were taken and analysed for all contaminants listed in ISO 14687-2. The first results of hydrogen quality from production processes: PEM water electrolysis with TSA and SMR with PSA are presented. The results on more than 16 different plants or occasions demonstrated that in all cases the 13 compounds listed in ISO 14687 were below the threshold of the international standards. Several contaminated hydrogen samples demonstrated the needs for validated and standardised sampling system and procedure. The results validated the probability of contaminants presence proposed in ISO/DIS 19880-8. It will support the implementation of ISO/ DIS 19880-8 and the development of hydrogen quality control monitoring plan. It is recommended to extend the study to other production method (i.e. alkaline electrolysis) the HRS supply chain (i.e. compressor) to support the technology growth.

Hydrogen is envisioned to become a fundamental energy vector for the decarbonization of energy systems. Two key factors that will define the success of hydrogen are its sustainability and competitiveness with alternative solutions. One of the many challenges for the proliferation of hydrogen is the creation of a sustainable supply chain. In this study a methodology aimed at assessing the economic feasibility of holistic hydrogen supply chains is developed. Based on the designed methodology a tool which calculates the levelized cost of hydrogen for the different stages of its supply chain: production transmission & distribution storage and conversion is proposed. Each stage is evaluated individually combining relevant technical and economic notions such as learning curves and scaling factors. Subsequently the findings from each stage are combined to assess the entire supply chain as a whole. The tool is then applied to evaluate case studies of various supply chains including large-scale remote and small-scale distributed green hydrogen supply chains as well as conventional steam methane reforming coupled with carbon capture and storage technologies. The results show that both green hydrogen supply chains and conventional methods can achieve a competitive LCOH of around €4/kg in 2030. However the key contribution of this study is the development of the tool which provides a foundation for a comprehensive evaluation of hydrogen supply chains that can be continuously improved through the inputs of additional users and further research on one or more of the interconnected stages.

This study develops a an optimization model focused on the layout and dispatch of a low-carbon hydrogen supply chain. The objective is to identify the lowest Levelized Cost of Hydrogen for a given demand. The model considers various elements including electricity supply from the local grid and renewable sources (photovoltaic and wind) alongside hydrogen production compression storage and transportation to end users. Applied to an industrial case study in Sweden the findings indicate that the major cost components are linked to electricity generation and investment in electrolyzers with the LCOH reaching 5.2 EUR/kgH2 under typical demand conditions. Under scenarios with higher peak demands and greater demand volatility the LCOH increases to 6.8 EUR/kgH2 due to the need for additional renewable energy capacity. These results highlight the critical impact of electricity availability and demand fluctuations on the LCOH emphasizing the complex interdependencies within the hydrogen supply chain. This study provides valuable insights into the feasibility and cost-effectiveness of adopting hydrogen as an energy carrier for renewable electricity in the context of decarbonizing industrial processes in the energy system.

Fluid dispersion directly influences the transport mixing and efficiency of hydrogen storage in depleted gas reservoirs. Pore structure parameters such as pore size throat geometry and connectivity influence the complexity of flow pathways and the interplay between advective and diffusive transport mechanisms. Hence these factors are critical for predicting and controlling flow behavior in the reservoirs. Despite its importance the relationship between pore structure and dispersion remains poorly quantified particularly under elevated flow conditions. To address this gap this study employs pore network modeling (PNM) to investigate the influence of sandstone and carbonate structures on fluid flow properties at the micro-scale. Eleven rock samples comprising seven sandstone and four carbonate were analyzed. Pore network extraction from CT images was used to obtain detailed pore structure parameters and their statistical measures. Pore-scale simulations were conducted across 60 scenarios with varying average interstitial velocities and water as the injected fluid. Effluent hydrogen concentrations were measured to generate elution curves as a function of injected pore volumes (PV). This approach enables the assessment of the relationship between the dispersion coefficient and pore structure parameters across all rock samples at consistent average interstitial velocities. Additionally dispersivity and n-exponent values were calculated and correlated with pore structure parameters.

The Philippines is exploring different alternative sources of energy to become energy-independent while significantly reducing the country’s greenhouse gas emissions. Green hydrogen from renewable energy is one of the most sustainable alternatives with its application as an energy carrier and as a source of clean and sustainable energy as well as raw material for various industrial processes. As a preliminary study in the country this paper aims to explore different production and utilization routes for a green hydrogen economy in the Philippines. Production from electrolysis includes various available renewable sources consisting of geothermal hydropower wind solar and biomass as well as ocean technology and nuclear energy when they become available in the future. Different utilization routes include the application of green hydrogen in the transportation power generation industry and utility sectors. The results of this study can be incorporated in the development of the pathways for hydrogen economy in the Philippines and can be applied in other emerging economies.

An integrated system is studied to supply green hydrogen feedstock for ammonia production in the Netherlands. The system is modeled to compare wind and solar resources when coupled to Alkaline Electrolysis (AEL) and Proton Exchange Membrane Electrolysis (PEMEL) technologies with a compressed hydrogen storage system. The nominal installed capacity of the electrolysis plant is around 2.3 GW with the most suitable energy source offshore wind and the preferred storage technology pressurized tubes. For Alkaline Electrolysis and Proton Exchange Membrane Electrolysis technologies the levelized cost of hydrogen is 5.30 V/kg H2 and 6.03 V/kg H2 respectively.

Water electrolysis is the most promising method for efficient production of high purity hydrogen (and oxygen) while the required power input for the electrolysis process can be provided by renewable sources (e.g. solar or wind). The thus produced hydrogen can be used either directly as a fuel or as a reducing agent in chemical processes such as in Fischer–Tropsch synthesis. Water splitting can be realized both at low temperatures (typically below 100 °C) and at high temperatures (steam water electrolysis at 500– 1000 °C) while different ionic agents can be electrochemically transferred during the electrolysis process (OH− H+ O2− ). Singular requirements apply in each of the electrolysis technologies (alkaline polymer electrolyte membrane and solid oxide electrolysis) for ensuring high electrocatalytic activity and long-term stability. The aim of the present article is to provide a brief overview on the effect of the nature and structure of the catalyst–electrode materials on the electrolyzer’s performance. Past findings and recent progress in the development of efficient anode and cathode materials appropriate for large-scale water electrolysis are presented. The current trends limitations and perspectives for future developments are summarized for the diverse electrolysis technologies of water splitting while the case of CO2/H2O co-electrolysis (for synthesis gas production) is also discussed.

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.

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.

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

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 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.

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.

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

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 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.

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.

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.

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.

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.

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.

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 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.

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

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.

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.

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.

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.

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.

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.

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.

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.