Publications

With the gradual maturity of wind power technology China’s wind power generation has grown rapidly over the recent years. However due to the on-site inconsumable electricity the phenomenon of large-scale “wind curtailment” occurs in some areas. In this paper a novel hybrid hydrogen/electricity refueling station is built near a wind farm and a part of the surplus wind power is used to charge electric trucks and the other part of the surplus power is used to produce “green hydrogen”. According to real-time load changes different amounts of liquid hydrogen and gas hydrogen can be properly coordinated to provide timely energy supply for hydrogen trucks. For a 400 MW wind farm in the western Inner Mongolia China the feasibility of the proposed system has been carried out based on the sensitivity and reliability analysis the static and dynamic economic modeling with an entire life cycle analysis. Compared to the conventional technology the initial investment of the proposed scheme (700.07 M$) decreases by 13.97% and the dynamic payback period (10.93 years) decreases by 25.87%. During the life cycle of the proposed system the accumulative NPV reaches 184.63 M$ which increases by 3.14 times compared to the case by conventional wind technology.

The UK government plans to phase out pure diesel trains by 2040 and fully decarbonize railways by 2050. Hydrogen fuel cell (HFC) trains electrified trains using pantographs (Electrified Trains) and battery electric multiple unit (BEMU) trains are considered the main solutions for decarbonizing railways. However the range of these decarbonization options’ line upgrade cost advantages is unclear. This paper analyzes the upgrade costs of three types of trains on different lines by constructing a cost model and using particle swarm optimization (PSO) including operating costs and fixed investment costs. For the case of decarbonization of the London St. Pancras to Leicester line the electrified train option is more cost-effective than the other two options under the condition that the service period is 30 years. Then the traffic density range in which three new energy trains have cost advantages on different line lengths is calculated. For route distances under 100 km and with a traffic density of less than 52 trips/day BEMU trains have the lowest average cost while electrified trains are the most costeffective in other ranges. For route distances over 100 km the average cost of HFC trains is lower than that of electrified trains at traffic densities below about 45 trips/day. In addition if hydrogen prices fall by 26 % the cost advantage range of HFC trains will increase to 70 trips per day. For route distances under 100 km BEMU trains still maintain their advantages in terms of lower traffic density.

Social risk is a comprehensive concept that considers not only internal/external physical risks but also risks (which are multiple varied and diverse) associated with social activity. It should be considered from diverse perspectives and requires a comprehensive evaluation framework that takes into account the synergistic impact of each element on others rather than evaluating each risk individually. Social risk assessment is an approach that is not limited to internal system risk from an engineering perspective but also considers the stakeholders development stage and societal readiness and resilience to change. This study aimed to introduce a social risk approach to assess the public safety of large-scale hydrogen systems. Guidelines for comprehensive social risk assessment were developed to conduct appropriate risk assessments for advanced science and technology activities with high uncertainties to predict major impacts on society before an accident occurs and to take measures to mitigate the damage and to ensure good governance are in place to facilitate emergency response and recovery in addition to preventive measures. In a case study this approach was applied to a hydrogen refueling station in Japan and risk-based multidisciplinary approaches were introduced. These approaches can be an effective supporting tool for social implementation with respect to large-scale hydrogen systems such as liquefied hydrogen storage tanks. The guidelines for social risk assessment of large-scale hydrogen systems are under the International Energy Agency Technology Collaboration Program Hydrogen Safety Task 43. This study presents potential case studies of social risk assessment for large-scale hydrogen systems for future.

The global shift toward sustainable energy solutions emphasises the urgent need to harness renewable sources for green hydrogen production presenting a critical opportunity in the transition to a low-carbon economy. Despite its potential integrating renewable energy with electrolysis to produce green hydrogen faces significant technological and economic challenges particularly in achieving high efficiency and cost-effectiveness at scale. This review systematically examines the latest advancements in electrolysis technologies—alkaline proton exchange membrane electrolysis cell (PEMEC) and solid oxide—and explores innovative grid integration and energy storage solutions that enhance the viability of green hydrogen. The study reveals enhanced performance metrics in electrolysis processes and identifies critical factors that influence the operational efficiency and sustainability of green hydrogen production. Key findings demonstrate the potential for substantial reductions in the cost and energy requirements of hydrogen production by optimising electrolyser design and operation. The insights from this research provide a foundational strategy for scaling up green hydrogen as a sustainable energy carrier contributing to global efforts to reduce greenhouse gas emissions and advance toward carbon neutrality. The integration of these technologies could revolutionise energy systems worldwide aligning with policy frameworks and market dynamics to foster broader adoption of green hydrogen.

The ecological transition in the transport sector is a major challenge to tackle environmental pollution and European legislation will mandate zero-emission new cars from 2035. To reduce the impact of petrol and diesel vehicles much emphasis is being placed on the potential use of synthetic fuels including electrofuels (e-fuels). This research aims to examine a levelised cost (LCO) analysis of e-fuel production where the energy source is renewable. The energy used in the process is expected to come from a photovoltaic plant and the other steps required to produce e-fuel: direct air capture electrolysis and Fischer-Tropsch process. The results showed that the LCOe-fuel in the baseline scenario is around 3.1 €/l and this value is mainly influenced by the energy production component followed by the hydrogen one. Sensitivity scenario and risk analyses are also conducted to evaluate alternative scenarios and it emerges that in 84% of the cases LCOe-fuel ranges between 2.8 €/l and 3.4 €/l. The findings show that the current cost is not competitive with fossil fuels yet the development of e-fuels supports environmental protection. The concept of pragmatic sustainability incentive policies technology development industrial symbiosis economies of scale and learning economies can reduce this cost by supporting the decarbonisation of the transport sector.

This study employs the FLACS code to analyze hydrogen leakage vapor dispersion and subsequent explosions. Utilizing pseudo-source models a liquid pool model and a hybrid model combining both we investigate dispersion processes for varying leak mass flow rates (0.225 kg/s and 0.73 kg/s) in a large open space. We also evaluate explosion hazards based on overpressure and impulse effects on humans. The computational results compared with experimental data demonstrated reasonable hydrogen vapor cloud concentration predictions especially aligned with the wind direction. For higher mass flow rate of 0.73 kg/s the pseudo-source model exhibited the most reasonable predictive performance for locations near the leak source despite the hybrid model yielded similar results to the pseudo-source model while the liquid pool model was more suitable for lower mass flow rate of 0.225 kg/s. Regarding explosion analyses using overpressure-impulse diagram higher mass flow rates leaded to potentially fatal overpressure and impulse effects on humans. However lower mass flow rates may cause severe eardrum damage at the maximum overpressure point.

Energy transition is a key driver to combat climate change and achieve zero carbon future. Sustainable and costeffective hydrogen production will provide valuable addition to the renewable energy mix and help minimize greenhouse gas emissions. This study investigates the performance of in-situ hydrogen production (IHP) process using a full-field compositional model as a precursor to experimental validation The reservoir model was simulated as one geological unit with a single point uniform porosity value of 0.13 and a five-point connection type between cell to minimize computational cost. Twenty-one hydrogen forming reactions were modelled based on the reservoir fluid composition selected for this study. The thermodynamic and kinetic parameters for the reactions were obtained from published experiments due to the absence of experimental data specific to the reservoir. A total of fifty-four simulation runs were conducted using CMG STARS software for 5478 days and cumulative hydrogen produced for each run was recorded. Results generated were then used to build a proxy model using Box-Behnken design of experiment method and Support Vector Machine with RBF kernel. To ascertain accuracy of the proxy models analysis of variance (ANOVA) was conducted on the variables. The average absolute percentage error between the proxy model and numerical simulation was calculated to be 10.82%. Optimization of the proxy model was performed using genetic algorithm to maximize cumulative hydrogen produced. Based on this optimized model the influence of porosity permeability well location injection rate and injection pressure were studied. Key results from this study reveals that lower permeability and porosity reservoirs supports more hydrogen yield injection pressure had a negligible effect on hydrogen yield and increase in oxygen injection rate corelated strongly with hydrogen production until a threshold value beyond which hydrogen yield decreased. The framework developed in the study could be used as tool to assess candidate reservoirs for in-situ hydrogen production.

Industry emits around a quarter of global greenhouse gas (GHG) emissions. This paper presents the first comprehensive review to identify the main decarbonization options for this sector and their abatement potentials. First we identify the important GHG emitting processes and establish a global average baseline for their current emissions intensity and energy use. We then quantify the energy and emissions reduction potential of the most significant abatement options as well as their technology readiness level (TRL). We find that energy-intensive industries have a range of decarbonization technologies available with medium to high TRLs and mature options also exist for decarbonizing low-temperature heat across a wide range of industrial sectors. However electrification and novel process change options to reduce emissions from high-temperature and sector-specific processes have much lower TRLs in comparison. We conclude by highlighting important barriers to the deployment of industrial decarbonization options and identifying future research development and demonstration needs.

With renewable energy sources projected to become the dominant source of electricity hydrogen has emerged as a crucial energy carrier to mitigate their intermittency issues. Water electrolysis is the most developed alternative to generate green hydrogen so far. However in the past two decades steam electrolysis has attracted increasing interest and aims to become a key player in the portfolio of electrolytic hydrogen. In practice steam electrolysis follows two distinct operational approaches: Solid Oxide Electrolysis Cell (SOEC) and Proton Exchange Membrane (PEM) at high temperature. For both technologies this work analyses critical cell components outlining material characteristics and degradation issues. The influence of operational conditions on the performance and cell durability of both technologies is thoroughly reviewed. The analytical comparison of the two electrolysis alternatives underscores their distinct advantages and drawbacks highlighting their niche of applications: SOECs thrive in high temperature industries like steel production and nuclear power plants whereas PEM steam electrolysis suits lower temperature applications such as textile and paper. Being PEM steam electrolysis less explored this work ends up by suggesting research lines in the domain of i) cell components (membranes catalysts and gas diffusion layers) to optimize and scale the technology ii) integration strategies with renewable energies and iii) use of seawater as feedstock for green hydrogen production.

In this research we developed a hydrogen (H2 ) electric generator in an H2 generation system based on chemical reactions. In the experiment we tested the performance of the H2 electric generator and measured the amount of H2 generated. The maximum output was 700 W and the thermal efficiency was 18.2%. The theoretical value and measured value were almost the same and the maximum error was 4%.

Hydrogen produced by renewable energy sources (green hydrogen) is at the centrepiece of European decarbonization strategies necessitating large imports from third countries. Egypt potentially stands out as major production hub. While technical and economic viability are broadly discussed in literature analyses of local acceptance are absent. This study closes this gap by surveying 505 locals in the Suez Canal Economic Zone (Port Said and Suez) regarding their attitudes towards renewable energy development and green hydrogen production. We find overall support for both national deployment and export to Europe. Respondents see a key benefit in rising income thereby strongly underlying the economic argument. Improved trade relationships or improved political relationships are seen as potential benefits of export but as less relevant for engaging in cooperation putting a spotlight on local benefits. Our study suggests that the local population is more positive than negative towards the development and scaling up of green hydrogen projects in Egypt.

With the continuous development of hydrogen storage systems power-to-gas (P2G) and combined heat and power (CHP) the coupling between electricity–heat–hydrogen–gas has been promoted and energy conversion equipment has been transformed from an independent operation with low energy utilization efficiency to a joint operation with high efficiency. This study proposes a low-carbon optimization strategy for a multi-energy coupled IES containing hydrogen energy storage operating jointly with a two-stage P2G adjustable thermoelectric ratio CHP. Firstly the hydrogen energy storage system is analyzed to enhance the wind power consumption ability of the system by dynamically absorbing and releasing energy at the right time through electricity–hydrogen coupling. Then the two-stage P2G operation process is refined and combined with the CHP operation with an adjustable thermoelectric ratio to further improve the low-carbon and economic performance of the system. Finally multiple scenarios are set up and the comparative analysis shows that the addition of a hydrogen storage system can increase the wind power consumption capacity of the system by 4.6%; considering the adjustable thermoelectric ratio CHP and the twostage P2G the system emissions reduction can be 5.97% and 23.07% respectively and the total cost of operation can be reduced by 7.5% and 14.5% respectively.

The decarbonization of industry heating and transportation is a major challenge for many countries’ energy transition. Hydrogen is a direct low-carbon fuel alternative to natural gas offering a higher flexibility in the range of possible applications yet currently most hydrogen is produced using carbonintensive steam methane reforming due to cost considerations. Therefore this study explores the economics of a prominent low-carbon method of hydrogen production comparing the cost of hydrogen generation from offshore wind farms with and without grid electricity imports to conventional hydrogen production methods. A novel techno-economic model for offshore electrolysis production costs is presented which makes hydrogen production fully dispatchable leveraging geological salt-cavern storage. This model determines the lifetime costs aportioned across the system components as well as the Levelized Cost of Hydrogen (LCOH). Using the United Kingdom as a case study LCOH from offshore wind power is calculated to be €8.68 /kgH2 using alkaline electrolysis (AEL) €10.49 /kgH2 using proton exchange membrane electrolysis (PEMEL) and €10.88 /kgH2 with grid electricity to backup the offshore wind power. A stochastic Monte-Carlo model is used to asses the uncertainty on costs and identify the cost of capital electrolyser and wind farm capital costs and cost of electricity as the most important drivers of LCOH across the different scenarios. Reducing the capital cost to comparative levels observed on today’s wind farms alone could see AEL LCOH fall to €5.32 /kgH2 near competitive with conventional generation methods.

Following the growing use of hydrogen in the industry gas explosions have become a critical safety issue. Computational Fluid Dynamic (CFD) and in particular the Large Eddy Simulation (LES) approach have already shown their great potential to reproduce such scenarios with high fidelity. However the computational cost of this approach is an obvious limiting factor since fine grid resolutions are often required in the whole computational domain to ensure a correct numerical resolution of the deflagration front all along its propagation. In this context Adaptive Mesh Refinement (AMR) is of great interest to reduce the computational cost as it allows to dynamically refine the mesh throughout the explosion scenario only in regions where Quantities of Interest (QoI) are detected. This study aims to demonstrate the strong potential of AMR for the LES of explosions. The target scenario is a hydrogen-air explosion in the GraVent explosion channel [1]. Using the massively parallel Navier- Stokes compressible solver AVBP a reference simulation is first obtained on a uniform and static unstructured mesh. The comparison with the experiments shows a good agreement in terms of absolute flame front speed overpressure and flow visualisation. Then an AMR simulation is performed targeting the same resolution as the reference simulation only in regions where QoI are detected i.e. inside the reaction zones and vortical structures. Results show that the accuracy of the reference simulation is recovered with AMR for only 12% of its computational cost.

The use of liquid hydrogen in maritime applications is expected to grow in the coming years in order to meet the decarbonisation goals that EU countries and countries worldwide have set for 2050. In this context The Norwegian Public Roads Administration commissioned large-scale LH2 dispersion and explosion experiments both indoors and outdoors which were conducted by DNG GL in 2019 to better understand safety aspects of LH2 in the maritime sector. In this work the DNV unignited outdoor and indoor tests have been simulated and compared with the experiments with the aim to validate the ADREA-HF Computational Fluid Dynamics (CFD) code in maritime applications. Three tests two outdoors and one indoors were chosen for the validation. The outdoor tests (test 5 and 6) involved liquid hydrogen release vertically downwards and horizontal to simulate an accidental leakage during bunkering. The indoor test (test 9) involved liquid hydrogen release inside a closed room to simulate an accident inside a tank connection space (TCS) connected to a ventilation mast.

This report of the High Level Group for Hydrogen and Fuel Cell Technologies sets out a vision for these technologies in future sustainable energy systems - improving energy security of supply and air quality whilst mitigating climate change. The report recommends actions for developing world-class European hydrogen technologies and fostering their commercial exploitation.

Hydrogen Economy and Cyclic Economy are advocated together with the use of perennial (solar wind hydro geo-power SWHG) and renewable (biomass) energy sources for defossilizing anthropic activities and mitigating climate change. Each option has intrinsic limits that prevent a stand-alone success in reaching the target. Humans have recycled goods (metals water paper and now plastics) to a different extent since very long time. Recycling carbon (which is already performed at the industrial level in the form of CO2 utilization and with recycling paper and plastics) is a key point for the future. The conversion of CO2 into chemicals and materials is carried out since the late 1800s (Solvay process) and is today performed at scale of 230 Mt/y. It is time to implement on a scale of several Gt/y the conversion of CO2 into energy products possibly mimicking Nature which does not use hydrogen. In the short term a few conditions must be met to make operative on a large scale the production of fuels from recycled-C namely the availability of low-cost: i. abundant pure concentrated streams of CO2 ii. non-fossil primary energy sources and iii. non-fossil-hydrogen. The large-scale production of hydrogen by Methane Steam Reforming with CO2 capture (Blue-H2) seems to be a realistic and sustainable solution. Green-H2 could in principle be produced on a large scale through the electrolysis of water powered by perennial primary sources but hurdles such as the availability of materials for the construction of long-living robust electrochemical cells (membranes electrodes) must be abated for a substantial scale-up with respect to existing capacity. The actual political situation makes difficult to rely on external supplies. Supposed that cheap hydrogen will be available its direct use in energy production can be confronted with the indirect use that implies the hydrogenation of CO2 into fuels (E-fuels) an almost ready technology. The two strategies have both pros and cons and can be integrated. E-Fuels can also represent an option for storing the energy of intermittent sources. In the medium-long term the direct co-processing of CO2 and water via co-electrolysis may avoid the production/transport/ use of hydrogen. In the long term coprocessing of CO2 and H2O to fuels via photochemical or photoelectrochemical processes can become a strategic technology.

Hydrogen as a primary carbon-free energy carrier is confronted by challenges in storage and transportation. However liquid organic hydrogen carriers (LOHCs) present a promising solution for storing and transporting hydrogen at ambient temperature and atmospheric pressure. Unlike circular energy carriers such as methanol ammonia and synthetic natural gas LOHCs do not produce by-products during hydrogen recovery. LOHCs only act as hydrogen carriers and the carriers can also be recycled for reuse. Although there are considerable advantages to LOHCs there are also some drawbacks especially relative to the energy consumption during the dehydrogenation step of the LOHC recycling. This review summarizes the recent progresses in LOHC technologies focusing on catalyst developments process and reactor designs applications and techno-economic assessments (TEA). LOHC technologies can potentially offer significant benefits to Australia especially in terms of hydrogen as an export commodity. LOHCs can help avoid capital costs associated with infrastructure such as transportation vessels while reducing hydrogen loss during transportation such as in the case of liquid hydrogen (LH2). Additionally it minimises CO2 emissions as observed in methane and methanol reforming. Thus it is essential to dedicate more efforts to explore and develop LOHC technologies in the Australian context.

Offshore electricity production mainly by wind turbines and eventually floating PV is expected to increase renewable energy generation and their dispatchability. In this sense a significant part of this offshore electricity would be directly used for hydrogen generation. The integration of offshore energy production into the hydrogen economy is of paramount importance for both the techno-economic viability of offshore energy generation and the hydrogen economy. An analysis of this integration is presented. The analysis includes a discussion about the current state of the art of hydrogen pipelines and subsea cables as well as the storage and bunkering system that is needed on shore to deliver hydrogen and derivatives. This analysis extends the scope of most of the previous works that consider port-to-port transport while we report offshore to port. Such storage and bunkering will allow access to local and continental energy networks as well as to integrate offshore facilities for the delivery of decarbonized fuel for the maritime sector. The results of such state of the art suggest that the main options for the transport of offshore energy for the production of hydrogen and hydrogenated vectors are through direct electricity transport by subsea cables to produce hydrogen onshore or hydrogen transport by subsea pipeline. A parametric analysis of both alternatives focused on cost estimates of each infrastructure (cable/pipeline) and shipping has been carried out versus the total amount of energy to transport and distance to shore. For low capacity (100 GWh/y) an electric subsea cable is the best option. For high-capacity renewable offshore plants (TWh/y) pipelines start to be competitive for distances above approx. 750 km. Cost is highly dependent on the distance to land ranging from 35 to 200 USD/MWh.

The aim of this paper is the design and implementation of an advanced model predictive control (MPC) strategy for the management of a wind–solar microgrid (MG) both in the islanded and grid-connected modes. The MG includes energy storage systems (ESSs) and interacts with external hydrogen and electricity consumers as an extra feature. The system participates in two different electricity markets i.e. the daily and real-time markets characterized by different time-scales. Thus a high-layer control (HLC) and a low-layer control (LLC) are developed for the daily market and the real-time market respectively. The sporadic characteristics of renewable energy sources and the variations in load demand are also briefly discussed by proposing a controller based on the stochastic MPC approach. Numerical simulations with real wind and solar generation profiles and spot prices show that the proposed controller optimally manages the ESSs even when there is a deviation between the predicted scenario determined at the HLC and the real-time one managed by the LLC. Finally the strategy is tested on a lab-scale MG set up at Khalifa University Abu Dhabi UAE.

Hydrogen fuel cell vehicles (HFCVs) represent an important breakthrough in the hydrogen energy industry. The safe utilization of hydrogen is critical for the sustainable and healthy development of hydrogen fuel cell vehicles. In this study risk factors and preventive measures are proposed for on-board hydrogen systems during the process of transportation storage and use of fuel cell vehicles. The relevant hydrogen safety standards in China are also analyzed and suggestions involving four safety strategies and three safety standards are proposed.

CFD modelling of compressed hydrogen fuelling provides information on the hydrogen and tank structure temperature dynamics required for onboard storage tank design and fuelling protocol development. This study compares five turbulence models to develop a strategy for costeffective CFD simulations of hydrogen fuelling while maintaining a simulation accuracy acceptable for engineering analysis: RANS models k-ε and RSM; hybrid models SAS and DES; and LES model. Simulations were validated against the fuelling experiment of a Type IV 29 L tank available in the literature. For RANS with wall functions and blended models with near-wall treatment the simulated average hydrogen temperatures deviated from the experiment by 1–3% with CFL ≈ 1–3 and dimensionless wall distance y + ≈ 50–500 in the tank. To provide a similar simulation accuracy the LES modelling approach with near-wall treatment requires mesh with wall distance y + ≈ 2–10 and demonstrates the best-resolved flow field with larger velocity and temperature gradients. LES simulation on this mesh however implies a ca. 60 times longer CPU time compared to the RANS modelling approach and 9 times longer compared to the hybrid models due to the time step limit enforced by the CFL ≈ 1.0 criteria. In all cases the simulated pressure histories and inlet mass flow rates have a difference within 1% while the average heat fluxes and maximum hydrogen temperature show a difference within 10%. Compared to LES the k-ε model tends to underestimate and DES tends to overestimate the temperature gradient inside the tank. The results of RSM and SAS are close to those of LES albeit of 8–9 times faster simulations.

Hydrogen component reliability and the hazard associated with failure rates is a critical area of research for the successful implementation and growth of hydrogen technology across the globe. The research team has partnered to quantify system risk reduction through earlier detection of hydrogen component failures. A model of hydrogen dispersion in a hydrogen equipment enclosure has been developed utilizing experimentally quantified hydrogen component leak rates as inputs. This model provides insight into the impact of hydrogen safety sensors and ventilation on the flammable mass within a hydrogen equipment enclosure. This model also demonstrates the change in safety sensor response time due to detector placement under various leak scenarios. The team looks to improve overall hydrogen system safety through an improved understanding of hydrogen component reliability and risk mitigation methods. This collaboration fits under the work program of IEA Hydrogen Task 43 Subtask E Hydrogen System Safety.

Experiments are performed in hydrogen-oxygen mixtures at the cryogenic temperature of 77 K with the equivalence ratio of 1.5 and 2.0. The optical fibers pressure sensors and the smoked foils are used to record the flame velocity overpressure evolution curve and detonation cells respectively. The 1st and 2nd shock waves are captured and they finally merge to form a stronger precursor shock wave prior to the onset of detonation. The cryogenic temperature will cause the larger expansion ratio which results in the occurrence of strong flame acceleration. The stuttering mode the galloping mode and the deflagration mode are observed when the initial pressure decreases from 0.50 atm to 0.20 atm with the equivalence ratio of 1.5 and the detonation limit is within 0.25-0.30 atm. The heat loss effect on the detonation limit is analysed. In addition the regularity of detonation cell is investigated and the larger post-shock specific heat ratio !"" and the lower normalized activation energy # at lower initial pressure will cause the more regular detonation cell. Also the detonation cell width is predicted by a model of = ($) ⋅ Δ# and the prediction results are mainly consistent with the experimental results.

Positive Energy Districts can be defined as connected urban areas or energy-efficient and flexible buildings which emit zero greenhouse gases and manage surpluses of renewable energy production. Energy storage is crucial for providing flexibility and supporting renewable energy integration into the energy system. It can balance centralized and distributed energy generation while contributing to energy security. Energy storage can respond to supplement demand provide flexible generation and complement grid development. Photovoltaics and wind turbines together with solar thermal systems and biomass are widely used to generate electricity and heating respectively coupled with energy system storage facilities for electricity (i.e. batteries) or heat storage using latent or sensible heat. Energy storage technologies are crucial in modern grids and able to avoid peak charges by ensuring the reliability and efficiency of energy supply while supporting a growing transition to nondepletable power sources. This work aims to broaden the scientific and practical understanding of energy storage in urban areas in order to explore the flexibility potential in adopting feasible solutions at district scale where exploiting the space and resource-saving systems. The main objective is to present and critically discuss the available options for energy storage that can be used in urban areas to collect and distribute stored energy. The concerns regarding the installation and use of Energy Storage Systems are analyzed by referring to regulations and technical and environmental requirements as part of broader distribution systems or as separate parts. Electricity heat energy and hydrogen are the most favorable types of storage. However most of them need new regulations technological improvement and dissemination of knowledge to all people with the aim of better understanding the benefits provided.

In order to study the flow blending and transporting process of hydrogen that injects into the natural gas pipelines a three-dimensional T-pipe blending model is established and the flow characteristics are investigated systematically by the large eddy simulation (LES). Firstly the mathematical formulation of hydrogen-methane blending process is provided and the LES method is introduced and validated by a benchmark gas blending model having experimental data. Subsequently the T-pipe blending model is presented and the effects of key parameters such as the velocity of main pipe hydrogen blending ratio diameter of hydrogen injection pipeline diameter of main pipe and operating pressure on the hydrogen-methane blending process are studied systematically. The results show that under certain conditions the gas mixture will be stratified downstream of the blending point with hydrogen at the top of the pipeline and methane at the bottom of the pipeline. For the no-stratified scenarios the distance required for uniformly mixing downstream the injection point increases when the hydrogen mixing ratio decreases the diameter of the hydrogen injection pipe and the main pipe increase. Finally based on the numerical results the underlying physics of the stratification phenomenon during the blending process are explored and an indicator for stratification is proposed using the ratio between the Reynolds numbers of the natural gas and hydrogen.

The current study comprehensively examines the application of wave tidal and undersea current energy sources of Turkiye for green hydrogen fuel production and cost analysis. The estimated potential capacity of each city is derived from official data and acceptable assumptions and is subject to discussion and evaluation in the context of a viable hydrogen economy. According to the findings the potential for green hydrogen generation in Turkiye is projected to be 7.33 million tons using a proton exchange membrane electrolyser (PEMEL). Cities with the highest hydrogen production capacities from marine applications are Mugla Izmir Antalya and Canakkale with 998.10 kt 840.31 kt 605.46 kt and 550.42 kt respectively. The study calculations obviously show that there is a great potential by using excess power in producing hydrogen which will result in an economic value of 3.01 billion US dollars. This study further helps develop a detailed hydrogen map for every city in Turkiye using the identified potential capacities of renewable energy sources and the utilization of electrolysers to make green hydrogen by green power. The potentials and specific capacities for every city are also highlighted. Furthermore the study results are expected to provide clear guidance for government authorities and industries to utilize such a potential of renewable energy for investment and promote clean energy projects by further addressing concerns caused by the usage of carbon-based (fossil fuels dependent) energy options. Moreover green hydrogen production and utilization in every sector will help achieve the national targets for a net zero economy and cope with international targets to achieve the United Nation's sustainable development goals.

The energy sector constitutes a dynamic and complex system indicating that its actions are influenced not just by its individual components but also by the emergent behavior resulting from interactions among them. Moreover there are crucial limitations of previous approaches for addressing the sustainability challenge of the energy sector. Changing transforming and integrating paradigms are the most relevant leverage points for transforming a given system. In other words nowadays the integration of new predominant paradigms in order to provide a unified framework could aim at this actual transformation looking for a sustainable future. This research aims to develop a new unified framework for the integration of the following three paradigms: (1) Sustainability (2) Complexity and (3) Systems Thinking which will be applied to achieving sustainable energy production (using hydrogen production as a case study). The novelty of this work relies on providing a holistic perspective through the integration of the aforementioned paradigms considering the multiple and complex interdependencies among the economy the environment and the economy. For this purpose an integrated seven-stage approach is introduced which explores from the starting point of the integration of paradigms to the application of this integration to sustainable energy production. After applying the Three-Paradigm approach for sustainable hydrogen production as a case study 216 feedback loops are identified due to the emerged complexity linked to the analyzed system. Additionally three system dynamics-based models are developed (by increasing the level of complexity) as part of the application of the Three-Paradigm approach. This research can be of interest to a broad professional audience (e.g. engineers policymakers) as looks into the sustainability of the energy sector from a holistic perspective considering a newly developed Three-Paradigm model considering complexity and using a Systems Thinking approach.

While hydrogen is regularly discussed as a possible option for storing regenerative energies its low minimum ignition energy and broad range of explosive concentrations pose safety challenges regarding hydrogen storage and there are also challenges related to hydrogen production and transport and at the point of use. A risk assessment of the whole hydrogen energy system is necessary to develop hydrogen utilization further. Here we concentrate on the most important hydrogen storage technologies especially high-pressure storage liquid hydrogen in cryogenic tanks methanol storage and salt cavern storage. This review aims to study the most recent research results related to these storage techniques by describing typical sensors and explosion protection measures thus allowing for a risk assessment of hydrogen storage through these technologies.

The growing emphasis on renewable energy highlights hydrogen’s potential as a clean energy carrier. However traditional hydrogen production methods contribute significantly to carbon emissions. This review examines the integration of carbon capture and storage (CCS) technologies with hydrogen production processes focusing on their ability to mitigate carbon emissions. It evaluates various hydrogen production techniques including steam methane reforming electrolysis and biomass gasification and discusses how CCS can enhance environmental sustainability. Key challenges such as economic technical and regulatory obstacles are analyzed. Case studies and future trends offer insights into the feasibility of CCS–hydrogen integration providing pathways for reducing greenhouse gases and facilitating a clean energy transition.

Accelerating the transition to a cleaner global energy system is essential for tackling the climate crisis and green hydrogen energy systems hold significant promise for integrating renewable energy sources. This paper offers a thorough evaluation of green hydrogen’s potential as a groundbreaking alternative to achieve near-zero greenhouse gas (GHG) emissions within a renewable energy framework. The paper explores current technological options and assesses the industry’s present status alongside future challenges. It also includes an economic analysis to gauge the feasibility of integrating green hydrogen providing a critical review of the current and future expectations for the levelized cost of hydrogen (LCOH). Depending on the geographic location and the technology employed the LCOH for green hydrogen can range from as low as EUR 1.12/kg to as high as EUR 16.06/kg. Nonetheless the findings suggest that green hydrogen could play a crucial role in reducing GHG emissions particularly in hard-to-decarbonize sectors. A target LCOH of approximately EUR 1/kg by 2050 seems attainable in some geographies. However there are still significant hurdles to overcome before green hydrogen can become a cost-competitive alternative. Key challenges include the need for further technological advancements and the establishment of hydrogen policies to achieve cost reductions in electrolyzers which are vital for green hydrogen production.

The decarbonization of industrial process heat is one of the bigger challenges of the global energy transition. Process heating accounts for about 20% of final energy demand in Germany and the situation is similar in other industrialized nations around the globe. Process heating is indispensable in the manufacturing processes of products and materials encountered every day ranging from food beverages paper and textiles to metals ceramics glass and cement. At the same time process heating is also responsible for significant greenhouse gas emissions as it is heavily dependent on fossil fuels such as natural gas and coal. Thus process heating needs to be decarbonized. This review article explores the challenges of decarbonizing industrial process heat and then discusses two of the most promising options the use of electric heating technologies and the substitution of fossil fuels with low-carbon hydrogen in more detail. Both energy carriers have their specific benefits and drawbacks that have to be considered in the context of industrial decarbonization but also in terms of necessary energy infrastructures. The focus is on high-temperature process heat (>400 ◦C) in energy-intensive basic materials industries with examples from the metal and glass industries. Given the heterogeneity of industrial process heating both electricity and hydrogen will likely be the most prominent energy carriers for decarbonized high-temperature process heat each with their respective advantages and disadvantages.

Grids require electricity storage. Two emerging storage technologies are battery storage (BS) and green hydrogen storage (GHS) (hydrogen produced and compressed with clean-renewable electricity stored then returned to electricity with a fuel cell). An important question is whether GHS alone decreases system cost versus BS alone or BS+GHS. Here energy costs are modeled in 145 countries grouped into 24 regions. Existing conventional hydropower (CH) storage is used along with new BS and/or GHS. A method is developed to treat CH for both baseload and peaking power. In four regions only CH is needed. In five CH+BS is lowest cost. Otherwise CH+BS+GHS is lowest cost. CH+GHS is never lowest cost. A metric helps estimate whether combining GHS with BS reduces cost. In most regions merging (versus separating) grid and non-grid hydrogen infrastructure reduces cost. In sum worldwide grid stability may be possible with CH+BS or CH+BS+GHS. Results are subject to uncertainties.

Green hydrogen has been considered a promising alternative to fossil fuels in chemical and energy applications. In this study a life cycle analysis is conducted for green hydrogen production sourced with a mixture of renewable energy sources (50 % solar and 50 % wind energy). Two advanced technologies of alkaline electrolysis are selected and compared for hydrogen production: pressurised alkaline electrolyser and capillary-fed alkaline electrolyser. The different value chain stages were assessed in SimaPro enabling the assessment of the environmental impacts of a green hydrogen production project with 60 MW capacity and 20 years lifetime. The results evaluate the environmental impacts depending on the components construction and operation requirements. The results demonstrated that capillary-fed alkaline electrolyser technology has lower potential environmental impacts by around 17 % than pressurised alkaline electrolyser technology for all the process stages. The total global warming potential was found to be between 1.98 and 2.39 kg of carbon dioxide equivalent per kg of hydrogen. This study contributes to the electrolysers industry and the planning of green hydrogen projects for many applications towards decarbonization and sustainability.

Hydrogen is gaining importance to decarbonize the energy system and tackle the climate crisis. This exploratory study analyzes three focus groups with representatives from relevant organizations in a Northern German region that has unique beneficial characteristics for the transition to a hydrogen economy. Based upon this data (1) a category system of innovation adoption barriers for hydrogen technologies is developed (2) decision levels associated with the barriers are identified (3) detailed insights on how decision levels contribute to the adoption barriers are provided and (4) the barriers are evaluated in terms of their importance. Our analysis adds to existing literature by focusing on short-term barriers and exploring relevant decision levels and their associated adoption barriers. Our main results comprise the following: flaws in the funding system complex approval procedures lack of networks and high costs contribute to hydrogen adoption barriers. The (Sub-)State level is relevant for the uptake of the hydrogen economy. Regional entities have leeway to foster the hydrogen transition especially with respect to the distribution infrastructure. Funding policy technological suitability investment and operating costs and the availability of distribution infrastructure and technical components are highly important adoption barriers that alone can impede the transition to a hydrogen economy.

This paper presents the “Three Gorges Hydrogen Boat No. 1” a novel green hydrogen-powered vessel that has been successfully delivered and is currently sailing. This vessel integrated with a hydrogen production and bunkering station at its dedicated dock achieves zero-carbon emissions. It stores 240 kg of 35 MPa gaseous hydrogen and has a fuel cell system rated at 500 kW. We analysed the engineering details of the marine hydrogen system including hydrogen bunkering storage supply fuel cell and the hybrid power system with lithium-ion batteries. In the first bunkering trial the vessel was safely refuelled with 200 kg of gaseous hydrogen in 156 min via a bunkering station 13 m above the water surface. The maximum hydrogen pressure and temperature recorded during bunkering were 35.05 MPa and 39.04 ◦C respectively demonstrating safe and reliable shore-toship bunkering. For the sea trial the marine hydrogen system operated successfully during a 3-h voyage achieving a maximum speed of 28.15 km/h (15.2 knots) at rated propulsion power. The vessel exhibited minimal noise and vibration and its dynamic response met load change requirements. To prevent rapid load changes to the fuel cells 68 s were used to reach 483 kW from startup and 62 s from 480 kW to zero. The successful bunkering and operation of this hydrogen-powered vessel demonstrates the feasibility of zero-carbon emission maritime transport. However four lessons were identified concerning bunkering speed hydrogen cylinder leakage hydrogen pressure regulator malfunctions and fuel cell room space. The novelty of this work lies in the practical demonstration of a fully operational hydrogen-powered maritime vessel achieving zero emissions encompassing its design building operation and lessons learned. These parameters and findings can be used as a baseline for further engineering research.

This paper investigates hydrogen’s potential to accelerate the energy transition in hardto-abate sectors such as steel petrochemicals glass cement and paper. The goal is to assess how hydrogen produced from renewable sources can foster both industrial decarbonization and the expansion of renewable energy installations especially solar and wind. Hydrogen’s dual role as a fuel and a chemical agent for process innovation is explored with a focus on its ability to enhance energy efficiency and reduce CO2 emissions. Integrating hydrogen with continuous industrial processes minimizes the need for energy storage making it a more efficient solution. Advances in electrolysis achieving efficiencies up to 60% and storage methods consuming about 10% of stored energy for compression are discussed. Specifically in the steel sector hydrogen can replace carbon as a reductant in the direct reduced iron (DRI) process which accounts for around 7% of global steel production. A next-generation DRI plant producing one million tons of steel annually would require approximately 3200 MW of photovoltaic capacity to integrate hydrogen effectively. This study also discusses hydrogen’s role as a co-fuel in steel furnaces. Quantitative analyses show that to support typical industrial plants hydrogen facilities of several hundred to a few thousand MW are necessary. “Virtual” power plants integrating with both the electrical grid and energy-intensive systems are proposed highlighting hydrogen’s critical role in industrial decarbonization and renewable energy growth.

As a clean energy source hydrogen not only helps to reduce the use of fossil fuels but also promotes the transformation of energy structure and sustainable development. This paper firstly introduces the development status of green hydrogen at home and abroad and then focuses on several advanced green hydrogen production technologies. Then the advantages and shortcomings of different green hydrogen production technologies are compared. Among them the future source of hydrogen tends to be electrolysis water hydrogen production. Finally the challenges and application prospects of the development process of green hydrogen technology are discussed and green hydrogen is expected to become an important part of realizing sustainable global energy development.

The study investigates the potential of transitioning Iraq a nation significantly dependent on fossil fuels toward a green hydrogen-based energy system as a pathway to achieving sustainable economic resilience. As of 2022 Iraqi energy supply is over 90% reliant on hydrocarbons which also account for 95% of the country foreign exchange earnings. The global energy landscape is rapidly shifting towards cleaner alternatives and the volatility of oil prices has made it imperative for the country to diversify its energy sources. Green hydrogen produced through water electrolysis powered by renewable energy sources such as solar and wind offers a promising alternative given country vast renewable energy potential. The analysis indicates that with strategic investments in green hydrogen infrastructure the country could reduce its hydrocarbon dependency by 30% by the year 2030. This transition could not only address pressing environmental challenges but also contribute to the economic stability of the country. However the shift to green hydrogen is not without significant challenges including water scarcity technological limitations and the necessity for a robust regulatory framework. The findings underscore the importance of international partnerships and supportive policies in facilitating this energy transition. Adopting renewable energy and green hydrogen technologies the country has the potential to become a leader in sustainable energy within the region. This shift would not only drive economic growth and energy security but also contribute to global efforts towards environmental sustainability positioning country favorably in a future low-carbon economy.

Climatic changes are reaching alarming levels globally seriously impacting the environment. To address this environmental crisis and achieve carbon neutrality transitioning to hydrogen energy is crucial. Hydrogen is a clean energy source that produces no carbon emissions making it essential in the technological era for meeting energy needs while reducing environmental pollution. Abundant in nature as water and hydrocarbons hydrogen must be converted into a usable form for practical applications. Various techniques are employed to generate hydrogen from water with solar hydrogen production—using solar light to split water—standing out as a cost-effective and environmentally friendly approach. However the widespread adoption of hydrogen energy is challenged by transportation and storage issues as it requires compressed and liquefied gas storage tanks. Solid hydrogen storage offers a promising solution providing an effective and low-cost method for storing and releasing hydrogen. Solar hydrogen generation by water splitting is more efficient than other methods as it uses self-generated power. Similarly solid storage of hydrogen is also attractive in many ways including efficiency and cost-effectiveness. This can be achieved through chemical adsorption in materials such as hydrides and other forms. These methods seem to be costly initially but once the materials and methods are established they will become more attractive considering rising fuel prices depletion of fossil fuel resources and advancements in science and technology. Solid oxide fuel cells (SOFCs) are highly efficient for converting hydrogen into electrical energy producing clean electricity with no emissions. If proper materials and methods are established for solar hydrogen generation and solid hydrogen storage under ambient conditions solar light used for hydrogen generation and utilization via solid oxide fuel cells (SOFCs) will be an efficient safe and cost-effective technique. With the ongoing development in materials for solar hydrogen generation and solid storage techniques this method is expected to soon become more feasible and cost-effective. This review comprehensively consolidates research on solar hydrogen generation and solid hydrogen storage focusing on global standards such as 6.5 wt% gravimetric capacity at temperatures between −40 and 60 ◦C. It summarizes various materials used for efficient hydrogen generation through water splitting and solid storage and discusses current challenges in hydrogen generation and storage. This includes material selection and the structural and chemical modifications needed for optimal performance and potential applications.

The significant growth of both the global population and economy in recent years has led to a rise in global energy demand. Fossil fuels have a significant contribution to generating energy which has raised concerns about sustainability and environmental impact. There are widespread efforts to find alternative sources in order to reduce dependence on fossil fuels and mitigate their environmental consequences. Among the alternative sources hydrogen has emerged as a promising option due to its potential to be a clean and sustainable energy source. Hydrogen possesses several advantages such as a high calorific value a high reaction rate various sources and the ability to integrate with other renewable energy sources and existing systems. These attributes render hydrogen a stable and reliable energy resource which can help reduce greenhouse gas emissions (GHG) and transition towards a sustainable future. In this review paper distinct hydrogen production technologies such as conventional renewable and nuclear energy are investigated and compared. In addition the challenges and limitations of the application of hydrogen fuel cells on vehicles and hydrogen circulation components are explored. Finally the environmental impact of hydrogen vehicles specifically their role in promoting sustainable development is investigated.

Despite the number of works on the techno-economics of offshore green hydrogen production there is a lack of research on the design of floating platforms to concomitantly support hydrogen production facilities and wind power generation equipment. Indeed previous studies on offshore decentralised configuration for hydrogen production implicitly assume that a floating platform designed for wind power generation (FOWT) can be also suitable as a floating wind hydrogen system (FWHS). This work proposes a novel design for an offshore decentralised FWHS and analyses the effects of the integration of the hydrogen facilities on the platform’s dynamics and how this in turn affects the performances of the wind turbine and the hydrogen equipment. Our findings indicate that despite the reduction in platform’s stability the performance of the wind turbine is barely affected. Regarding the hydrogen system our results aim at contributing to further assessment and design of this equipment for offshore conditions.

The current study seeks to greenhouse gas emissions reduction in an existing engine under dual-fuel combustion fueled with diesel fuel and natural gas due to great concerns about global warming. This simulation study focuses on the identification of areas prone to the formation of greenhouse gas emissions in engine cylinders. The simulation results of dual-fuel combustion confirmed that the possibility of incomplete combustion and the formation of greenhouse gas emissions in high levels are not far from expected. Therefore an efficient combustion strategy along with replacing natural gas with hydrogen was considered. Only changing the combustion mode to reactivity-controlled compression ignition has led to the improvement of the natural gas burning rate and guarantees a 32 % reduction in unburned methane and 50 % carbon monoxide. To further reduce engine emissions while changing the combustion mode a part of natural gas replacement with hydrogen to the complete elimination of it was evaluated. Increasing the share of hydrogen energy in the intake air-natural gas mixture up to 54 % without exhaust gas recirculation does not lead to diesel knock. Moreover improvement of engine load and efficiency can be achieved by up to 18 % and 6 % respectively. Natural gas consumption can be reduced by up to 67 %. Meanwhile the unburned methane and carbon dioxide mass known as greenhouse gas emissions can be reduced to less than 1 % and up to 50 % respectively. Continued replacement of natural gas with hydrogen until its complete elimination guarantees a reduction of 92000 cubic meters of natural gas per year in one engine cylinder. Although the engine efficiency and load face a decrease of 0.8 % and 5.0 % respectively; the amount of carbon dioxide can be decreased by about 4.5 times. Unburned methane carbon monoxide and nitrogen oxides can be reduced to below the relevant EURO VI range while the amount of unburned hydrogen compared to the hydrogen entering the engine is about 0.5 %.

In confined spaces hydrogen released with low momentum tends to accumulate in a layer below the ceiling; the concentration in this layer rises and can rapidly enter the flammability range. In this context ventilation is a key safety equipment to prevent the formation of such flammable volumes. To ensure its well-sizing to each specific industrial context it is necessary to dispose of reliable engineering models. Currently the existing engineering models dealing with the buoyancy-driven H2 dispersion in a ventilated enclosure mainly focus on the natural-ventilation phenomenon. However forced ventilation is in some situations more adapted to the industrial context as the wind direction and intensity remains constant and under control. Therefore two existing wind-assisted ventilation models elaborated by Hunt and Linden [1] and Lowesmith et al. [2] were tested on forced ventilation applications. The main assumption consists in assuming a blowing ventilation system rather than a suction system as the composition and velocity of the entering air are known. The fresh air enters the down opening and airhydrogen mixture escapes through the upper one. The adapted models are then validated with experimental data releasing helium rather than hydrogen. Experiments are conducted on a 1-m3 ventilated box controlling the release and ventilation rates. The agreement between both analytical and experimental results is discussed from the different comparisons performed.

To consider an appropriate evaluation method for hydrogen compatibility slow strain rate tensile (SSRT) tests were conducted on high strength piping materials cold-worked type 316 austenitic stainless steel (SUS316CW) and iron-based superalloy A286 used in hydrogen stations for two years.<br/>SUS316CW used at room temperature in 82 MPa gaseous hydrogen contained 7.8 mass ppm hydrogen. The SSRT test of SUS316CW was conducted in nitrogen at -40 °C. The fracture surface showed dimples and no hydrogen embrittlement behavior was observed. While the SSRT test of SUS316CW in 70 MPa gaseous hydrogen at -40 °C showed a slight decrease in reduction area and a brittle fracture morphology in the outer layer. This was considered to be the effect of high-pressure gaseous hydrogen during the SSRT test in addition to the pre-contained hydrogen.<br/>A286 used at -40 °C in 82 MPa gaseous hydrogen contained negligible hydrogen (0.14 mass ppm). SSRT tests were conducted at 150 °C in 70 MPa gaseous hydrogen and in air and showed a low relative reduction in area (RRA) value. To investigate the decrease in the RRA we switched the gas from hydrogen to air in the middle of the SSRT test and closely examined the RRA values and fracture morphology including side cracks. The hydrogen embrittlement was found to originate from the elastic deformation region. Stress cycling in the elastic deformation region also accelerated the effect of hydrogen. These were attributed to an increase in the lattice hydrogen content. While in the plastic deformation region hydrogen trapped in the defects and hydrogen through the generated surface cracks increased the hydrogen content at the crack tips reducing the RRA value. And there was a good correlation between the crack lengths and RRA values.<br/>Then hydrogen embrittlement mechanism depends on the operating conditions (stress and temperature) of the material and evaluating the hydrogen compatibility of materials by controlling their hydrogen content and strain according to the service environment is desirable.

This study investigates the light gas dispersion behaviour in a maintenance garage with natural or forced ventilation. A scaled-down garage model (0.71 m high 3.07 m long and 3.36 m wide) equipped with gas and velocity sensors was used in the experiments. The enclosure had four rectangular vents at the ceiling and four at the bottom on two opposing side walls. The experiments were performed by injecting helium continuously through a 1-mm downward-facing nozzle until a steady state was reached. The sensitivity parameters included helium injection rate the elevation of the injection nozzle and forced flow speeds. Exhaust fans were placed at one or all of the top vent(s) to mimic forced ventilation. Numerical simulations conducted using GOTHIC a general-purpose thermal-hydraulic code and calculations with engineering models were compared with experimental measurements to determine the relative suitability of each approach to predict the light gas transport behaviour. The GOTHIC simulations captured the trends of the helium distribution gas movement in the enclosure and the passive vent flows reasonably well. Lowesmith’s model predictions for the helium transients in the upper uniform layer were also in good agreement with the natural venting experiments.

This study develops a framework for designing hydrogen supply chains (HSC) in island territories using Mixed Integer Linear Programming (MILP) with a multi-period approach. The framework minimizes system costs greenhouse gas emissions and a risk-based index. Corsica is used as a case study with a Geographic Information System (GIS) identifying hydrogen demand regions and potential sites for production storage and distribution. The results provide an optimal HSC configuration for 2050 specifying the size location and technology while accounting for techno-economic factors. This work integrates the unique geographical characteristics of islands using a GIS-based approach incorporates technology readiness levels and utilizes renewable electricity from neighboring regions. The model proposes decentralized configurations that avoid hydrogen transport between grids achieving a levelized cost of hydrogen (LCOH) of €8.54/kg. This approach offers insight into future options and incentive mechanisms to support the development of hydrogen economies in isolated territories.

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 is experiencing an unprecedented global hype. Hydrogen is globally discussed as a possible future energy carrier and regarded as the urgently needed building block for the much needed carbon-neutral energy transition of hard-to-abate sectors to mitigate the effects of global warming. This article provides synthesised measurable sustainability criteria for analysing green hydrogen production proposals and strategies. Drawn from expert interviews and an extensive literature review this article proposes that a sustainable hydrogen production should consider six impact categories; Energy transition Environment Basic needs Socio-economy Electricity supply and Project planning. The categories are broken down into sixteen measurable sustainability criteria which are determined with related indicators. The article concludes that low economic costs can never be the only decisive criterion for the hydrogen production; social aspects must be integrated along the entire value chain. The compliance with the criteria may avoid social and ecological injustices in the planning of green hydrogen projects and increases inter alia the social welfare of the affected population.

Hydrogen produced from renewable energy sources is a valuable energy carrier for linking growing renewable electricity generation with the hard-to-abate sectors such as cement steel glass chemical and ceramics industries. In this context this paper presents a new model of hydrogen production based on solar photovoltaics and wind energy with application to a real-world ceramics factory. For this task a novel multipurpose profit-maximizing model is implemented using GAMS. The developed model explores hydrogen production with multiple value streams that enable technical and economical informed decisions under specific scenarios. Our results show that it is profitable to sell the hydrogen produced to the gas grid rather than using it for self-consumption for low-gas-price scenarios. On the other hand when the price of gas is significantly high it is more profitable to use as much hydrogen as possible for self-consumption to supply the factory and reduce the internal use of natural gas. The role of electricity self-consumption has proven to be key for the project’s profitability as without this revenue stream the project would not be profitable in any analysed scenario.