Large-scale Storage Research Articles

Current Hydrogen Storage Difficulties and Possible Solutions

Using hydrogen as an energy source is becoming increasingly popular around the globe. Compared to other traditional energy sources, hydrogen can be effectively produced and utilized. However, the technology of hydrogen storage is difficult and constrains hydrogen power to be applied globally on a large scale. Hydrogen can be stored in the liquid phase, chemically kept and retained in either a covalent or an ionic compound, in gas cylinders, on materials with a large specific surface area, and in oxidation of reactive metals in water. However, each of the above-mentioned hydrogen storage methods has its own flaws and their technical difficulties. Aquifers, exhausted natural gas and oil reserves, and salt caverns are all examples of ways and methods to physically store hydrogen underground. These places are often places where large-scale hydrogen storage takes place. If the issue could be resolved, and the challenge of hydrogen storage be overcome, it would be a huge improvement to the entire humanity as hydrogen is a very promising future energy source.

Data Utilization-Based Adaptive Data Management Method for Distributed Storage System in WAN Environment

Recently, research on a distributed storage system that efficiently manages a large amount of data has been actively conducted following data production and demand increase. Physical expansion limits exist for traditional standalone storage systems, such as I/O and file system capacity. However, the existing distributed storage system does not consider where data is consumed and is more focused on data dissemination and optimizing the lookup cost of data location. And this leads to system performance degradation due to low locality occurring in a Wide Area Network (WAN) environment with high network latency. This problem hinders deploying distributed storage systems to multiple data centers over WAN. It lowers the scalability of distributed storage systems to accommodate data storage needs. This paper proposes a method for distributing data in a WAN environment considering network latency and data locality to solve this problem and increase overall system performance. The proposed distributed storage method monitors data utilization and locality to classify data temperature as hot, warm, and cold. With assigned data temperature, the proposed algorithm adaptively selects the appropriate data center and places data accordingly to overcome the excess latency from the WAN environment, leading to overall system performance degradation. This paper also conducts simulations to evaluate the proposed and existing distributed storage methods. The result shows that our proposed method reduced latency by 38% compared to the existing method. Therefore, the proposed method in this paper can be used in large-scale distributed storage systems over a WAN environment to improve latency and performance compared to existing methods, such as consistent hashing.

Optimized Proactive Recovery in Erasure-Coded Cloud Storage Systems

Cloud data centers have started utilizing erasure coding in large-scale storage systems to ensure high reliability with limited overhead compared to replication. However, data recovery in erasure coding incurs high network bandwidth consumption compared to replication. Cloud storage systems also play an important role in the energy consumption of data centers. Heuristic proactive recovery algorithms select all data blocks from failure-predicted disk/machine and perform proactive replication that contributes to huge recovery bandwidth savings. However, they fail to optimize the selection. Optimization can further improve resource savings. To address this issue, we propose a recovery algorithm that applies minimization on data blocks selected for proactive replication by considering the necessary and appropriate constraints that are constructed based on the system’s current network traffic and data duplication information. We evaluate the proposed algorithm using extensive simulations. Experiments show that the recovery algorithm reduces network traffic by 60% and storage overhead by 46% compared to the heuristic proactive recovery approach. Also, the proposed proactive recovery methods reduce the storage system’s energy consumption by up to 52% compared to replication.

Identifying structure-function relationships to modulate crossover in nonaqueous redox flow batteries.

Nonaqueous redox flow batteries (NARFBs) offer a promising solution for large-scale storage of renewable energy. However, crossover of redox active molecules between the two sides of the cell is a major factor limiting their development, as most selective separators are designed for deployment in water, rather than organic solvents. This report describes a systematic investigation of the crossover rates of redox active organic molecules through an anion exchange separator under RFB-relevant non-aqueous conditions (in acetonitrile/KPF6) using a combination of experimental and computational methods. A structurally diverse set of neutral and cationic molecules was selected, and their rates of crossover were determined experimentally with the organic solvent-compatible anion exchange separator Fumasep FAP-375-PP. The resulting data were then fit to various descriptors of molecular size, charge, and hydrophobicity (overall charge, solution diffusion coefficient, globularity, dynamic volume, dynamic surface area, clogP). This analysis resulted in multiple statistical models of crossover rates for this separator. These models were then used to predict tether groups that dramatically slow the crossover of small organic molecules in this system.

Thermo-hydraulic performance of a cryogenic printed circuit heat exchanger for liquid air energy storage

• The nature of local flow and heat transfer was analyzed using vortex identification. • The reverse flow suppresses local heat transfer and increases the flow resistance. • The air side has larger thermal resistance (∼ 58%) in the absence of phase change. • The best comprehensive performance can be achieved at an inclined angle of 45°. • The pressure drop and heat transfer correlations for the best angle were developed. The liquid air energy storage assisted by liquefied natural gas is a promising large-scale storage method, but its development is limited by the lack of thermo-hydraulic data on the cryogenic printed circuit heat exchanger. A simplified model for conjugate heat transfer was built and solved by a commercial code FLUENT 14.5. Model validation was conducted by comparing results with experimental data. The nature of flow and heat transfer was revealed by quantifying the vortex strength and visualizing the vortex core. The influence of the inclined angle was investigated, and the Nusselt number and friction factor correlations for the best angle were developed. The minimum internal temperature approach for optimum system operation is approximately 6 K, located in the middle of the heat exchanger. Results indicate that the evolution of Dean vortices plays a crucial part in the augmentation of heat transfer. The secondary flow caused by elbows forces the fluid cores to strike the windward side periodically, which disturbs the boundary layer and enhances the fluid mixing. Entropy production analysis shows that the thermal entropy generation has a dominant share of total irreversibility. The best performance is achieved at an inclined angle of 45° since the irreversibility is reduced by augmenting the heat transfer.

Advanced Exergy Analysis of Adiabatic Underwater Compressed Air Energy Storage System

Rapid development in the renewable energy sector require energy storage facilities. Currently, pumped storage power plants provide the most large-scale storage in the world. Another option for large-scale system storage is compressed air energy storage (CAES). This paper discusses a particular case of CAES-an adiabatic underwater energy storage system based on compressed air-and its evaluation using advanced exergy analysis. The energy storage system is charged during the valleys of load and discharged at peaks. The model was built using Aspen HYSYS software. Advanced exergy analysis revealed interactions between system components and the potential for improving both system components individually and the system as a whole. The most significant reduction in exergy destruction can be achieved with heat exchangers. The round-trip efficiency of this system is 64.1% and 87.9% for real and unavoidable operation conditions, respectively.

Application of DFT Simulation to the Investigation of Hydrogen Embrittlement Mechanism and Design of High Strength Low Alloy Steel.

In this work, first-principles methods were performed to simulate interactions between hydrogen and common alloying elements of high strength low alloy (HSLA) steel. The world has been convinced that hydrogen could be one of the future clean energy sources. HSLA steel with a balance of strength, toughness, and hydrogen embrittlement susceptibility is expected for application in large-scale hydrogen storage and transportation. To evaluate the property deterioration under a hydrogen atmosphere, hydrogen embrittlement (HE) of HSLA steel attracts attention. However, due to the small size of hydrogen atoms, the mechanism of HE is challenging to observe directly by current experimental methods. To understand the HE mechanism at an atomic level, DFT methods were applied to simulate the effects of alloying elements doping in bcc-Fe bulk structure and grain boundary structure. Furthermore, the potential application of DFT to provide theoretical advice for HSLA steel design is discussed.

Capacity assessment and cost analysis of geologic storage of hydrogen: A case study in Intermountain-West Region USA

Hydrogen is an integral component of the current energy transition roadmap to decarbonize the economy and create an environmentally-sustainable future. However, surface storage options (e.g., tanks) do not provide the required capacity or durability to deploy a regional or nationwide hydrogen economy. In this study, we have analyzed the techno-economic feasibility of the geologic storage of hydrogen in depleted gas reservoirs, salt caverns, and saline aquifers in the Intermountain-West (I-WEST) region. We have identified the most favorable candidate sites for hydrogen storage and estimated the volumetric storage capacity. Our results show that the geologic storage of hydrogen can provide at least 72% of total energy consumption of the I-WEST region in 2020. We also calculated the capital and levelized costs of each storage option. We found that a depleted gas reservoir is the most cost-effective candidate among the three geologic storage options. Interestingly, the cushion gas type plays a significant role in the storage cost when we consider hydrogen storage in saline aquifers. The levelized costs of hydrogen storage in depleted gas reservoirs, salt caverns, and saline aquifers with large-scale storage capacity are approximately $1.15, $2.50, and $3.27 per kg of H2, respectively. This work provides essential guidance for the geologic hydrogen storage in the I-WEST region.

Review of underground hydrogen storage: Concepts and challenges

The energy transition is the pathway to transform the global economy away from its current dependence on fossil fuels towards net zero carbon emissions. This requires the rapid and large-scale deployment of renewable energy. However, most renewables, such as wind and solar, are intermittent and hence generation and demand do not necessarily match. One way to overcome this problem is to use excess renewable power to generate hydrogen by electrolysis, which is used as an energy store, and then consumed in fuel cells, or burnt in generators and boilers on demand, much as is presently done with natural gas, but with zero emissions. Using hydrogen in this way necessitates large-scale storage: the most practical manner to do this is deep underground in salt caverns, or porous rock, as currently implemented for natural gas and carbon dioxide. This paper reviews the concepts, and challenges of underground hydrogen storage. As well as summarizing the state-of-the-art, with reference to current and proposed storage projects, suggestions are made for future work and gaps in our current understanding are highlighted. The role of hydrogen in the energy transition and storage methods are described in detail. Hydrogen flow and its fate in the subsurface are reviewed, emphasizing the unique challenges compared to other types of gas storage. In addition, site selection criteria are considered in the light of current field experience. Cited as: Hematpur, H., Abdollahi, R., Rostami, S., Haghighi, M., Blunt, M. J. Review of underground hydrogen storage: Concepts and challenges. Advances in Geo-Energy Research, 2023, 7(2): 111-131. https://doi.org/10.46690/ager.2023.02.05

Numerical Simulation of CO2 Migration and Geochemical Reactions in Shihezi Formation Caprock, China

CO2 geological storage, which is an effective way to reduce CO2 emissions, is of great significance to mitigate the current greenhouse effect. In long-term CO2 storage, although the chemical reaction rate of CO2–brine–rock is slow, it can significantly change the mineral composition of rock and the structure and properties of pores and joints, and then change the transport process and distribution state of CO2 in porous media. Therefore, a simplified 2D geological model is established based on the geological data of the Shihezi Formation in the Ordos Basin, China. The mechanism of the CO2–brine–rock reaction and its effect on mineral transformation and pore permeability are studied. In the early stage of CO2 geological sequestration, the rate of CO2 intrusion into the caprock is fast, the CO2–brine–rock reaction in the early stage is mainly a dissolution reaction, and the porosity and permeability of the caprock show an increasing trend. During the period from 100 to 1000 years of CO2 sequestration, the vertical distance of CO2 intrusion into the caprock does not change much. During this period, the type of CO2–brine–rock reaction is mainly a precipitation reaction, which reduces the porosity and permeability of the caprock and increases the sealing ability of the caprock to a certain extent. Our results can not only provide theoretical support for the site selection and risk assessment of CO2 geological sequestration, but also provide a theoretical basis and practical guidance for large-scale commercial storage in the future.

Understanding Wavelength-Dependent Synergies between Morphology and Photonic Design in TiO2-Based Solar Powered Redox Cells.

Solar powered redox cells (SPRCs) are promising for large-scale and long-term storage of solar-energy, particularly when coupled with redox flow batteries (RFBs). While efforts have primarily focused on heterostructure engineering, the potential of synergistic morphology and photonic design has not been carefully studied. Here, we investigate the wavelength-dependent effects of light-absorption and charge transfer characteristics on the performance of gold decorated TiO2-based SPRC photoanodes operating with RFB-compatible redox couples. Through an in-depth optical and photoelectrochemical characterization of three complementary TiO2 microstructures, namely nanotubes, honeycombs, and nanoparticles, we elucidate the combined effects of nanometer-scale semiconductor morphology and plasmonic design across the visible spectrum. In particular, thin-walled TiO2 nanotubes exhibit a ∼ 50% increase in solar-to-chemical efficiency (STC) compared to thick-walled TiO2 honeycombs thanks to improved charge transfer. Au nanoparticles both increase generation and interfacial charge transfer (above bandgap) and promote hot carrier injection (below bandgap) leading to a further 25% increase in STC. Overall, Au/TiO2 nanotubes achieve a high photocurrent at 0.098 mA/cm2 and an excellent STC of 0.06%, among the highest with respect to the theoretical limit. The incident photon to current efficiency and internal quantum efficiency are also superior to those of bare TiO2 showing maximum values of 54.7% and 67%, respectively. Overall, nanophotonic engineering that synergistically combines morphology optimization and plasmonic sensitization schemes offer new avenues for improving rechargeable solar-energy technologies such as solar redox flow batteries.

Prospects for the Implementation of Underground Hydrogen Storage in the EU

The hydrogen economy is one of the possible directions of development for the European Union economy, which in the perspective of 2050, can ensure climate neutrality for the member states. The use of hydrogen in the economy on a larger scale requires the creation of a storage system. Due to the necessary volumes, the best sites for storage are geological structures (salt caverns, oil and gas deposits or aquifers). This article presents an analysis of prospects for large-scale underground hydrogen storage in geological structures. The political conditions for the implementation of the hydrogen economy in the EU Member States were analysed. The European Commission in its documents (e.g., Green Deal) indicates hydrogen as one of the important elements enabling the implementation of a climate-neutral economy. From the perspective of 2050, the analysis of changes and the forecast of energy consumption in the EU indicate an increase in electricity consumption. The expected increase in the production of energy from renewable sources may contribute to an increase in the production of hydrogen and its role in the economy. From the perspective of 2050, discussed gas should replace natural gas in the chemical, metallurgical and transport industries. In the longer term, the same process will also be observed in the aviation and maritime sectors. Growing charges for CO2 emissions will also contribute to the development of underground hydrogen storage technology. Geological conditions, especially wide-spread aquifers and salt deposits allow the development of underground hydrogen storage in Europe.

Mapping hydrogen storage capacities of UK offshore hydrocarbon fields and exploring potential synergies with offshore wind

Abstract Energy storage is an essential component of the transitioning UK energy system, a crucial mechanism for stabilizing intermittent renewable electricity supply and meeting seasonal variation in demand. Low-carbon hydrogen provides a balancing mechanism for variable renewable energy supply and demand, and a method for decarbonizing domestic heating, essential for meeting the UK's 2050 net-zero targets. Geological hydrogen storage in porous rocks offers large-scale energy storage over a variety of timescales and has promising prospects due to the widespread availability of UK offshore hydrocarbon fields, with established reservoirs and existing infrastructure. This contribution explores the potential for storage within fields in the UK Continental Shelf. Through comparison of available energy storage capacity and current domestic gas demands, we quantify the hydrogen required to decarbonize the UK gas network. We estimate a total hydrogen storage capacity of 3454 TWh, significantly exceeding the 120 TWh seasonal domestic demand. Multi-criteria decision analysis, in consultation with an expert focus group, identified optimal fields for coupling with offshore wind, which could facilitate large-scale renewable hydrogen production and storage. These results will be used as inputs for future energy system modelling, optimizing potential synergies between offshore oil and gas and renewables sectors, in the context of the energy transition.

Research on the Frequency Regulation Strategy of Large-Scale Battery Energy Storage in the Power Grid System

Driven by the carbon peaking and carbon neutrality target, the large-scale grid-connected of renewable energy such as wind and solar has increased, and the volatility and randomness have posed new challenges to the stability of the power grid frequency. In this case, battery energy storage is a grid auxiliary resource with fast response and adjustable parameters, which can provide frequency support for the grid system in a short period. This paper studies the frequency regulation strategy of large-scale battery energy storage in the power grid system from the perspectives of battery energy storage, battery energy storage station, and battery energy storage system, respectively. First of all, the droop control based on logistic function and the virtual inertia control based on piecewise function are proposed for battery energy storage frequency regulation, which improves the performance of battery energy storage power output effectively. Second, the weighting factor is set according to the current battery charge to achieve the most optimal distribution of frequency regulation power for each battery pack in the battery energy storage station. In the end, a control framework for large-scale battery energy storage systems jointly with thermal power units to participate in system frequency regulation is constructed, and the proposed frequency regulation strategy is studied and analyzed in the EPRI-36 node model. The results of the study show that the proposed battery frequency regulation control strategies can quickly respond to system frequency changes at the beginning of grid system frequency fluctuations, which improves the stability of the new power system frequency including battery energy storage. In addition, this paper also provides a certain reference for the construction of the new power system dispatching that integrates “Generation-Grid-Load-Storage” in the future.

CO2-Water-Rock Interaction and Pore Structure Evolution of the Tight Sandstones of the Quantou Formation, Songliao Basin

As an important part of carbon dioxide capture, utilization and storage (CCUS), the progress of injecting CO2 into oil reservoirs could increase the recovery rate and achieve large-scale carbon storage. It has become one of the most important carbon storage methods around the world. This paper selected the tight sandstone of the fourth member of the Quantou Formation in the southern Songliao Basin to carry out a CO2 storage physical simulation experiment. Representative samples were collected at 24 h, 72 h, 192 h and 432 h to study the CO2 water-rock interaction and to analyze the mineral composition, pore structure and the evolutionary characteristics of physical reservoir properties over time. Physical property analysis, Ion analysis, X-ray diffraction mineral analysis, QEMSCAN mineral analysis, scanning electron microscopy and high-resolution CT scanning techniques were adopted. The main points of understanding were: (i) It shows a differential evolution of different minerals following the storage time of CO2, and carbonate minerals are mainly dissolved with ankerite as a typical representation; a small amount of calcite is formed in 24 h, and dissolved in the later period; feldspar and quartz were partially dissolved; clay mineral precipitation blocked the pores and gaps; (ii) The evolution in mineral variation leads to the complexity of pore structure evolution, following a trend of “small pores decreasing and large pores increasing” with extending storage time. The final porosity and permeability ratios gradually increase from 4.07% to 21.31% and from 2.97% to 70.06% respectively; (iii) There is a negative correlation between the increasing ratio and the original physical properties of the tight stones due to the dissolution of ankerite. Relevant research could provide scientific guidance and technical support for the geological storage of CO2 in lacustrine tight continental sandstones and the development of CCUS technology.

Australian public perspectives on genomic data storage and sharing: Benefits, concerns and access preferences

Diagnostic genomic sequencing generates unprecedented amounts of data. In addition to its primary use, this data could be used for a wide range of secondary purposes, including research and informing future healthcare for the data donor. These opportunities may require data to be shared with third parties. Although effective data sharing relies on public support, there are barriers which may prevent people from choosing to donate their genomic data and surprisingly few studies explore these barriers in depth.To address this need, this study aimed to qualitatively explore the Australian public's views and preferences for storing and sharing genomic data. Online focus groups were recorded, transcribed, and analysed using inductive content analysis.A total of 7 focus groups were conducted with 39 members of the Australian public ranging from 18 to 67 years of age. Participants were mostly supportive of genomic data being stored and shared for secondary purposes, recognising the potential benefits for individual health and wider medical research. However, some concerns were identified. Participants felt genomic data was particularly sensitive information, and raised the potential for discrimination, stigma, and other malicious uses of such data. Concerns for privacy and security of the data were also prevalent.Trustworthiness of data users was important when considering who genomic data should be shared with. Although participants were supportive of data being freely available to health professionals and researchers, they were opposed to insurance companies and employers accessing the data. There was greater controversy around sharing data with law enforcement and pharmaceutical companies. Participants recognised both benefits and harms to sharing with law enforcement. They were also cognizant of the dual purpose of pharmaceutical companies as both research and profit-driven organisations. Finally, participants expressed varying perspectives about sharing genomic data with family members, yet most agreed that explicit consent from the data donor should be required to share their information with relatives.This study highlighted several of the Australian public's perceived barriers and motivators for the storage and sharing of genomic data. Participants recognised both the benefits of collecting, storing and sharing such data widely but also the potential for harm from data misuse. While public acceptance of such endeavours is required to maximise the volume of data made available, the concerns around data access and security need to be addressed before this can occur. These findings also highlight the nuance and ethical complexity of decisions about who we should allow to access donated genomic data. These perspectives will be essential in helping to shape the way large-scale genomic data storage and sharing is developed and implemented in Australia, and internationally.

Enhancement of extraction effectiveness and stability of anthocyanin from Hibiscus sabdariffa L.

Anthocyanin, a main bioactive compound found in Hibiscus sabdariffa L. extract, has attracted different fields such as food additives and functional foodstuffs due to its wide range of possible applications. However, commercial applications of anthocyanins as colourants and pharmaceuticals have been limited due to their defective extraction yield and poor stability. This study aimed to improve the extraction efficiency and enhance the stability of anthocyanin extracted from H. subdariffa L. The method of enzyme-microwave assisted extraction (EMAE, 15.37 ± 0.41 mg/g anthocyanin based on raw material) resulted in enhancing the anthocyanin recovery efficiency up to 15.35%, 23.68% and 28.04% compared to each technique of microwave-assisted extraction (MAE, 13.01 ± 0.22 mg/g), ultrasound-assisted extraction (UAE, 11.73 ± 0.28 mg/g) and enzyme-assisted extraction (EAE, 11.06 ± 0.33 mg/g). The FT-IR and UV–Vis spectra showed the identified characterization of anthocyanin. For stabilization, the colour deviation values of anthocyanin extract in cases of individuals adding catechin 1.5%, chitosan 2%, or chondroitin sulfate 3% were 9.22, 6.53, and 7.59, respectively, while the combination of the three co-pigments gave the lowest color deviation of 4.11 after 30 h investigation. This combined method prolonged the shelf-life of anthocyanin powder to 16.2 months and maintained its antioxidant activity by about 50%. In the trend of exploitation and application of bioactive components, this study would offer a promising approach to improve the extraction efficiency and the stability of anthocyanin from H. sabdariffa L. as well as valuable information for large-scale anthocyanin process and storage. • Extraction and stabilization conditions of Hibiscus sabdariffa L. anthocyanin were studied. • The method of enzyme-microwave-assisted extraction (EMAE) was the most effective. • Anthocyanin extraction yield of EMAE was 15.37 mg/g. • Catechin, chitosan and chondroitin sulfate were studied as co-pigments of anthocyanin. • The three co-pigments combination extended the shelf-life of anthocyanin powder by 6 months.

Fast Proactive Repair in Erasure-Coded Storage: Analysis, Design, and Implementation

Erasure coding offers a storage-efficient redundancy mechanism for maintaining data availability guarantees in large-scale storage clusters, yet it also incurs high performance overhead in failure repair. Recent developments in accurate disk failure prediction allow soon-to-fail (STF) nodes to be repaired in advance, thereby opening new opportunities for accelerating failure repair in erasure-coded storage. To this end, we present a fast proactive repair solution called FastPR, which carefully couples two repair methods, namely migration (i.e., relocating the chunks of an STF node) and reconstruction (i.e., decoding the chunks of an STF node through erasure coding), so as to fully parallelize the repair operation across the storage cluster. FastPR solves a bipartite maximum matching problem and schedules both migration and reconstruction in a parallel fashion. We show that FastPR significantly reduces the repair time over the baseline repair approaches for both Reed-Solomon codes and Azures Local Reconstruction Codes via mathematical analysis, large-scale simulation, and Amazon EC2 experiments.

Perovskite SrVO3 as novel cathode materials for high-rate aqueous zinc-ion batteries

Aqueous Zinc ion batteries (AZIBs) is well considered as a potential candidate with green, safety and low cost for large-scale grid storage. Perovskite oxide SrVO3 can be used as the cathode material for AZIBs due to its high electrically conductive. Therefore, the SrVO3 as a novel cathode material by sol–gel route was prepared to investigate the electrochemical performance. The SrVO3 exhibits outstanding rate capability with high reversible capacities of 142.7 mA h g−1 at 200 mA g−1, 134.9 mA h g−1 at 300 mA g−1, and 105.3 mA h g−1 at 2000 mA g−1 are ascribed to the fast diffusion reaction kinetics. Moreover, the cycling performance of SrVO3 was delivered with capacity retention of 79 % after 3000 cycles at a current density of 2000 mA g−1 in the 0.4–1.8 V voltage window. This work provides a new prospect for the development of perovskite-type cathode materials for AZIBs.

Low-cost hydrogen in the future European electricity system – Enabled by flexibility in time and space

The present study investigates four factors that govern the ability to supply hydrogen at a low cost in Europe: the scale of the hydrogen demand; the possibility to invest in large-scale hydrogen storage; process flexibility in hydrogen-consuming industries; and the geographical areas in which hydrogen demand arises. The influence of the hydrogen demand on the future European zero-emission electricity system is investigated by applying the cost-minimising electricity system investment model eNODE to hydrogen demand levels in the range of 0–2,500 TWhH2. It is found that the majority of the future European hydrogen demand can be cost-effectively satisfied with VRE, assuming that the expansion of wind and solar power is not hindered by a lack of social acceptance, at a cost of around 60–70 EUR/MWhH2 (2.0–2.3 EUR/kgH2). The cost of hydrogen in Europe can be reduced by around 10 EUR/MWhH2 if the hydrogen consumption is positioned strategically in regions with good conditions for wind and solar power and a low electricity demand. The cost savings potential that can be obtained from full temporal flexibility of hydrogen consumption is 3-fold higher than that linked to strategic localisation of the hydrogen consumption. The cost of hydrogen per kg increases, and the value of flexibility diminishes, as the size of the hydrogen demand increases relative to the traditional demand for electricity and the available VRE resources. Low-cost hydrogen is, thus, achieved by implementing efficiency and flexibility measures for hydrogen consumers, as well as increasing acceptance of VRE.