Publications

With the development of the hydrogen fuel automobile industry higher requirements are put forward for the construction of hydrogen energy infrastructure the matching of parameters and the control strategy of hydrogen filling rate in the hydrogen charging process of hydrogen refueling stations. At present the technological difficulty of hydrogen fueling is mainly reflected in the balanced treatment of reducing the temperature rise of hydrogen and shortening the filling time during the fast filling process. Vehicle hydrogen storage cylinder (VHSC) is one of the important components of hydrogen fuel cell vehicles. This study proposed a theoretical model for calculating the temperature rise in the VHSC during the high pressure refueling process and revealed the hydrogen temperature rise during refueling. A hydrogen temperature rise prediction model was constructed to elucidate the relationship between filling parameters and temperature rise. The filling process of VHSC was analyzed from the theoretical method. The theoretical analysis results were consistent with the simulation and experimental analysis results which provided a theoretical basis for the current hydrogen temperature control algorithm of the gas source in the hydrogen refueling station and then reduced the energy consumption required for hydrogen cooling in the hydrogen refueling station.

The investment in hydrogen-refueling stations (HRS) is key to the development of a hydrogen economy. This paper focuses on the decision-making for potential investors faced with the thought-provoking question of when the optimal timing to invest in HRS is. To fill the gap that exists due to the fact that few studies explain why HRS investment timing is critical we expound that earlier investment in HRS could induce the first mover advantages of the technology diffusion theory. Additionally differently from the previous research that only considered that HRS investment is just made by one individual firm we innovatively examine the HRS co-investment made by two different firms. Accordingly we compare these two optional investment modes and determine which is better considering either independent investment or co-operative investment. We then explore how the optimal HRS investment timing could be figured out under conditions of uncertainty with the real options approach. Given the Chinese HRS case under the condition of demand uncertainty the hydrogen demand required for triggering investment is viewed as the proxy for investment timing. Based on analytical and numerical results we conclude that one-firm independent investment is better than two-firm cooperative investment to develop HRS not only in terms of the earlier investment timing but also in terms of the attribute for dealing with the uncertainty. Finally we offer recommendations including stabilizing the hydrogen demand for decreasing uncertainty and accelerating firms’ innovation from both technological and strategic perspectives in order to ensure firms can make HRS investments on their own.

The results shown in this paper extend our research group’s previous work which presents the theoretically achievable hydrogen engine-out NOeo x (H2-NOeo x ) Pareto front of a hydrogen hybrid electric vehicle (H2-HEV). While the Pareto front is calculated offline which requires significant computing power and time this work presents an online-capable algorithm to tackle the energy management of a H2-HEV with explicit consideration of the H2-NOeo x trade-off. Through the inclusion of realistic predictive data on the upcoming driving mission a model predictive control algorithm (MPC) is utilized to effectively tackle the conflicting goal of achieving low hydrogen consumption while simultaneously minimizing NOeo x . In a case study it is shown that MPC is able to satisfy user-defined NOeo x limits over the course of various driving missions. Moreover a comparison with the optimal Pareto front highlights MPC’s ability to achieve close-to-optimal fuel performance for any desired cumulated NOeo x target on four realistic routes for passenger cars.

Hydrogen (H2) usage was 90 metric tonnes (Mt) in 2020 almost entirely for industrial and refining uses and generated almost completely from fossil fuels leading to nearly 900 Mt of carbon dioxide emissions. However there has been significant growth of H2 in recent years. Electrolysers' total capacity which are required to generate H2 from electricity has multiplied in the past years reaching more than 300 MW through 2021. Approximately 350 projects reportedly under construction could push total capacity to 54 GW by the year 2030. Some other 40 projects totalling output of more than 35 GW are in the planning phase. If each of these projects is completed global H2 production from electrolysers could exceed 8 Mt by 2030. It's an opportunity to take advantage of H2S prospects to be a crucial component of a clean safe and cost-effective sustainable future. This paper assesses the situation regarding H2 at the moment and provides recommendations for its potential future advancement. The study reveals that clean H2 is experiencing significant unparalleled commercial and political force with the amount of laws and projects all over the globe growing quickly. The paper concludes that in order to make H2 more widely employed it is crucial to significantly increase innovations and reduce costs. The practical and implementable suggestions provided to industries and governments will allow them to fully capitalise on this growing momentum.

Hydrogen has recently been proposed as a versatile energy carrier to contribute to archiving universal access to clean cooking. In hard-to-reach rural settings decentralized produced hydrogen may be utilized (i) as a clean fuel via direct combustion in pure gaseous form or blended with Liquid Petroleum Gas (LPG) or (ii) via power-to-hydrogen-to-power (P2H2P) to serve electric cooking (e-cooking) appliances. Here we present the first techno-economic evaluation of hydrogen-based cooking solutions. We apply mathematical optimization via energy system modeling to assess the minimal cost configuration of each respective energy system on technical and economic measures under present and future parameters. We further compare the potential costs of cooking for the end user with the costs of cooking with traditional fuels. Today P2H2P-based e-cooking and production of hydrogen for utilization via combustion integrated into the electricity supply system have almost equal energy system costs to simultaneously satisfy the cooking and electricity needs of the isolated rural Kenyan village studied. P2H2P-based e-cooking might become advantageous in the near future when improving the energy efficiency of e-cooking appliances. The economic efficiency of producing hydrogen for utilization by end users via combustion benefits from integrating the water electrolysis into the electricity supply system. More efficient and cheaper hydrogen technologies expected by 2050 may improve the economic performance of integrated hydrogen production and utilization via combustion to be competitive with P2H2P-based e-cooking. The monthly costs of cooking per household may be lower than the traditional use of firewood and charcoal even today when applying the current life-line tariff for the electricity consumed or utilizing hydrogen via combustion. Driven by likely future technological improvements and the expected increase in traditional and fossil fuel prices any hydrogen-based cooking pathway may be cheaper for end users than using charcoal and firewood by 2030 and LPG by 2040. The results suggest that providing clean cooking in rural villages could economically and environmentally benefit from utilizing hydrogen. However facing the complexity of clean cooking projects we emphasize the importance of embedding the results of our techno-economic analysis in holistic energy delivery models. We propose useful starting points for future aspects to be investigated in the discussion section including business and financing models.

This article investigates the potential of renewable and low-carbon fuel production for the maritime shipping sector using Sweden as a case in focus. Techno-economic modelling and socio-technical transition studies are combined to explore the conditions opportunities and barriers to decarbonising the maritime shipping industry. A set of scenarios have been developed considering demand assumptions and potential instruments such as carbon price energy tax and blending mandate. The study finds that there are opportunities for decarbonising the maritime shipping industry by using renewable marine fuels such as advanced biofuels (e.g. biomethanol) electrofuels (e.g. e-methanol) and hydrogen. Sweden has tremendous resource potential for bio-based and hydrogen-based renewable liquid fuel production. In the evaluated system boundary biomethanol presents the cheapest technology option while e-ammonia is the most expensive one. Green electricity plays an important role in the decarbonisation of the maritime sector. The results of the supply chain optimisation identify the location sites and technology in Sweden as well as the trade flows to bring the fuels to where the bunker facilities are potentially located. Biomethanol and hydrogen-based marine fuels are cost-effective at a carbon price beyond 100 €/tCO2 and 200 €/tCO2 respectively. Linking back to the socio-technical transition pathways the study finds that some shipping companies are in the process of transitioning towards using renewable marine fuels thereby enabling niche innovations to break through the carbon lock-in and eventually alter the socio-technical regime while other shipping companies are more resistant. Overall there is increasing pressure from (inter)national energy and climate policy-making to decarbonise the maritime shipping industry.

The realization of a carbon-neutral civilization which has been set as a goal for the coming decades goes directly hand-in-hand with the need for an energy system based on renewable energies (REs). Due to the strong weather-related daily and seasonal fluctuations in supply of REs suitable energy storage devices must be included for such energy systems. For this purpose an energy system model featuring hybrid energy storage consisting of a hydrogen unit (for long-term storage) and a lithium-ion storage device (for short-term storage) was developed. With a proper design such a system can ensure a year-round energy supply by using electricity generated by photovoltaics (PVs). In the energy system that was investigated hydrogen (H2) was produced by using an electrolyser (ELY) with a PV surplus during the summer months and then stored in an H2 tank. During the winter due to the lack of PV power the H2 is converted back into electricity and heat by a fuel cell (FC). While the components of such a system are expensive a resource- and cost-efficient layout is important. For this purpose a Matlab/Simulink model that enabled an energy balance analysis and a component lifetime forecast was developed. With this model the results of extensive parameter studies allowed an optimized system layout to be created for specific applications. The parameter studies covered different focal points. Several ELY and FC layouts different load characteristics different system scales different weather conditions and different load levels—especially in winter with variations in heating demand—were investigated.

In order to improve the consumption of renewable energy and reduce the carbon emissions of integrated energy systems (IESs) this paper proposes an optimal operation strategy for an integrated energy system considering the coordination of electricity and hydrogen in the context of carbon trading. The strategy makes full use of the traditional power-to-gas hydrogen production process and establishes a coupling model comprising cogeneration and carbon capture equipment an electrolytic cell a methane reactor and a hydrogen fuel cell. Taking a minimum daily operating cost and minimal carbon emissions from the system as objective functions a mixed-integer nonlinear optimal scheduling model is established. This paper designs examples based on MATLAB R2021b and uses the GUROBI solver to solve them. The results show that compared with the traditional two-stage operation process the optimization method can reduce the daily operation cost of an IES by 26.01% and its carbon emissions by 90.32%. The results show that the operation mode of electro-hydrogen synergy can significantly reduce the carbon emissions of the system and realize a two-way flow of electro-hydrogen energy. At the same time the addition of carbon capture equipment and the realization of carbon recycling prove the scheduling strategy’s ability to achieve a lowcarbon economy of the scheduling strategy.

With its ability to store and transport energy without releasing greenhouse gases hydrogen is considered an important driver for the decarbonisation of energy systems. As future hydrogen import prices from global markets are subject to large uncertainties it is unclear what impact different hydrogen and derivative import prices will have on the future German energy system. To answer that research question this paper explores the impact of three different import price scenarios for hydrogen and its derivatives on the German energy system in a climate-neutral setting for Europe in 2045 using three different energy system models. The analysis shows that the quantities of electricity generated as well as the installed capacities for electricity generation and electrolysis increase as the hydrogen import price rises. However the resulting differences between the import price scenarios vary across the models. The results further indicate that domestic German (and European) hydrogen production is often cost-efficient.

The demand for fossil fuels is rising rapidly leading to increased greenhouse gas emissions. Hydrogen has emerged as a promising clean energy alternative that could help meet future demands way sustainably especially if produced using renewable methods. For hydrogen to meaningfully contribute to energy transitions it needs more integration into sectors like transportation buildings and power that currently have minimal hydrogen usage. This requires developing extensive cross-sector hydrogen infrastructure. This review examines hydrogen combustion as a fuel by exploring and comparing production techniques enriching ammonia with hydrogen as a CO2-free option and hydrogen applications in engines. Additionally a techno-economic environmental risk analysis is discussed. Results showed steam methane reforming is the most established and cost-effective production method at $1.3–1.5/kg H2 and 70–85% efficiency but generates CO2. Biomass gasification costs $1.25–2.20/kg H2 and pyrolysis $1.77–2.05/kg H2 offering renewable options. However bio-photolysis currently has high costs of $1.42–2.13/kg H2 due to low conversion rates requiring large reactors. Blending H2/NH3 could enable carbon-free combustion aiding carbon neutrality pursuits but minimizing resultant NOx is crucial. Hydrogen’s wide uses from transportation to power underline its potential as a transformational energy carrier.

Renewable Energy Community (REC) is a new paradigm in European Union to produce transform share and sell renewables at a local consumer level also via e-fuel (i.e. hydrogen). This work investigates the economic feasibility of a hydrogen Power-to-Gas (PtG) system realized inside a REC using only excess renewable electricity not consumed by REC itself. A single centralized photovoltaic (PV) plant is directly connected to an electrolyser; a hydrogen compressor and two hydrogen storages at low and high pressure complete the PtG system. A scenario of a REC composed by 450 residential electric users (around 1000 people) has been analysed coupled with described PtG considering eight different sizes of PV plant. In the study Italian subsidies to REC shared energy are evaluated as incentives to hydrogen production. An optimal size of PtG components for each PV size is investigated at the limit of economical sustainability evaluating net present value (NPV) positive and near zero. Results show that for the considered REC it is possible to produce and sell up to around 3 tons per year of green hydrogen at most to the same lowest selling price declared currently in the Italian market (5 €/kg).

Hydrogen a green energy carrier is one of the most promising energy sources. However，it is currently mainly produced from depleting fossil fuels with high carbon emissions which has serious negative effects on the economy and environment. To address this issue sustainable hydrogen production from bio-energy with carbon capture and storage (HyBECCS) is an ideal technology to reduce global carbon emissions while meeting energy demand. This review presents an overview of the latest progress in alkaline thermal treatment (ATT) of biomass for hydrogen production with carbon storage especially focusing on the technical characteristics and related challenges from an industrial application perspective. Additionally the roles of alkali and catalyst in the ATT process are critically discussed and several aspects that have great influences on the ATT process such as biomass types reaction parameters and reactors are expounded. Finally the potential solutions to the general challenges and obstacles to the future industrial-scale application of ATT of biomass for hydrogen production are proposed.

China is by far the world’s largest producer and consumer of hydrogen mostly from coal and other fossil fuels and the country has an ambitious hydrogen strategy. In this podcast we dive into the provincial strategies on hydrogen in China and specifically discuss a recent paper published by the Institute entitled China’s hydrogen development: A tale of three cities. The paper looks at the experiences and plans of the pilot hydrogen clusters located in Datong Shanxi province Chengdu in Sichuan province and Zhangjiakou in the northern part of Hebei province which surrounds Beijing. In this podcast we are speaking with the paper’s author Arabella Miller-Wang recently an Aramco fellow at the Institute and also a Research Assistant at the Smith School of Enterprise and the Environment of The University of Oxford as well as with Michal Meidan director of the China Energy Programme at OIES and with Martin Lambert who heads hydrogen research at the OIES.

The podcast can be found on their website.

H2 production via membrane-assisted steam methane reforming (MA-SMR) can ensure higher energy efficiency and lower emissions compared to conventional reforming processes (SMR). Ceramic-supported Pd–Ag membranes have been extensively investigated for membrane-assisted steam methane reforming applications with outstanding performance. However costs sealings for integration in the reactor structure and resistance to solicitations remain challenging issues. In this work the surface quality of a low-cost porous Hastelloy-X filter is improved by asymmetric filling with α-Al2O3 of decreasing size and deposition of γ-Al2O3 as an interdiffusion barrier. On the modified support a thin Pd–Ag layer was deposited via electroless plating (ELP) resulting in a membrane with H2/N2 selectivity >10000. The permeation characteristics of the membrane were studied followed by testing for membrane-assisted methane steam reforming. The results showed the ability of the membrane reactor to overcome thermodynamic conversion of the conventional process for all explored operating conditions as well as ensuring 99.3% H2 purity in the permeate stream at 500 ◦C and 4 bar.

Grid-scale underground hydrogen storage (UHS) is essential for the decarbonization of energy supply systems on the path towards a zero-emissions future. This study presents the feasibility of UHS in an actual saline aquifer with a typical dome-shaped anticline structure to balance the potential seasonal mismatches between energy supply and demand in the UK domestic heating sector. As a main requirement for UHS in saline aquifers we investigate the role of well configuration design in enhancing storage performance in the selected site via numerical simulation. The results demonstrate that the efficiency of cyclic hydrogen recovery can reach around 70% in the short term without the need for upfront cushion gas injection. Storage capacity and deliverability increase in successive storage cycles for all scenarios with the co-production of water from the aquifer having a minimal impact on the efficiency of hydrogen recovery. Storage capacity and deliverability also increase when additional wells are added to the storage site; however the distance between wells can strongly influence this effect. For optimum well spacing in a multi-well storage scenario within a dome-shaped anticline structure it is essential to attain an efficient balance between well pressure interference effects at short well distances and the gas uprising phenomenon at large distances. Overall the findings obtained and the approach described can provide effective technical guidelines pertaining to the design and optimization of hydrogen storage operations in deep saline aquifers.

Global supply chains must be decarbonised as part of meeting climate targets set by the United Nations and world leaders. Rail networks are vital infrastructure in passenger and freight transport however have not received the same push for decarbonisation as road transport. In this investigation we used real world data from locomotives operating on seven rail corridors to identify optimal battery capacity and hydrogen fuel cell (HFC) power in hybrid systems. We found that the required battery capacity is dependent on both the available regenerative braking energy and on the capacity required to buffer surpluses and deficits from the HFC. The optimal system for each corridor was identified however it was found that one 3.6 MWh battery and 860 kW HFC system could service six of the seven corridors. The optimal systems presented in this work suggest an average of around 5 h of battery storage for the HFC power which is larger than the 2 h previously reported in literature. This may indicate a gap between purely theoretical works that use only route topography and speed and those that employ real world locomotive data.

The Green Deal Industrial Plan aims to boost the competitiveness of Europe’s net-zero industry and to accelerate the transition to climate neutrality. The Plan is based on four pillars: (1) a predictable and simplified regulatory environment; (2) faster access to funding; (3) developing skills for net-zero industry; and (4) open trade for resilient supply chains.

A direct drive wave power generation system (DDWPGS) has the advantages of a simple structure and easy deployment and is the first choice to provide electricity for islands and operation platforms in the deep sea. However due to the off-grid the source and load cannot be matched so accommodation is an important issue. Hydrogen storage is the optimal choice for offshore wave energy accommodation. Therefore aiming at the source-load mismatch problem of the DDWPGS an electric-hydrogen hybrid energy storage system (HESS) for the DDWPGS is designed in this paper. Based on the characteristics of the devices in the electric-hydrogen HESS a new dynamic power allocation strategy and its control strategy are proposed. Firstly empirical mode decomposition (EMD) is utilized to allocate the power fluctuations that need to be stabilized. Secondly with the state of charge (SOC) of the battery and the operating characteristics of the alkaline electrolyzer being considered the power assignments of the battery and the electrolyzer are determined using the rule-based method. In addition model predictive control (MPC) with good tracking performance is used to adjust the output power of the battery and electrolyzer. Finally the supercapacitor (SC) is controlled to maintain the DC bus voltage while also balancing the system’s power. A simulation was established to verify the feasibility of the designed system. The results show that the electric-hydrogen HESS can stabilize the power fluctuations dynamically when the DDWPGS captures instantaneous power. Moreover its control strategy can not only reduce the start-stop times of the alkaline electrolyzer but also help the energy storage devices to maintain a good state and extend the service life.

Tropical countries can approach their natural resources to produce low-carbon H2 from solar wind hydro and biomass resources to satisfy their domestic demand and to export it. To do so Colombia published the National Hydrogen Roadmap in which green H2 was prioritized. This study estimates Colombia's potential to produce green H2 and a timeline of scenarios displaying the required installed capacity capital investment and environmental analysis related to water utilization and CO2 capture. Accordingly Colombia can produce H2 at a rate of 9 Mt/a by 2050 by installing 121 GW renewables while processing 303 Mt/a of residual biomass. In this scenario Colombia's share of the H2 international market can reach 1.2% with a cumulative investment of over 244 billion USD by 2050. This study provides insights into potential global resources for low-carbon H2 generation.

Liquid hydrogen is one of the high-quality energy carriers but a large leak of liquid hydrogen can pose significant safety risks. Understanding its diffusion law after accidental leakage is an important issue for the safe utilization of hydrogen energy. In this paper a series of open-space large-volume liquid hydrogen release experiments are performed to observe the evolution of visible clouds during the release and an array of hydrogen concentration sensors is set up to monitor the fluctuation in hydrogen concentration at different locations. Based on the experimental conditions the diffusion of hydrogen clouds in the atmosphere under different release hole diameters and different ground materials is compared. The results show that with the release of liquid hydrogen the white visible cloud formed by air condensation or solidification is generated rapidly and spread widely and the visible cloud is most obvious near the ground. With the termination of liquid hydrogen release solid air is deposited on the ground and the visible clouds gradually shrink from the far field to the release source. Hydrogen concentration fluctuations in the far field in the case of the cobblestone ground are more dependent on spontaneous diffusion by the hydrogen concentration gradient. In addition compared with the concrete ground the cobblestone ground has greater resistance to liquid hydrogen extension; the diffusion of hydrogen clouds to the far field lags. The rapid increase stage of hydrogen concentration at N8 in Test 7 lags about 3 s behind N12 in Test 6 N3 lags about 7.5 s behind N1 and N16 lags about 8.25 s behind N14. The near-source space is prone to high-concentration hydrogen clouds. The duration of the high-concentration hydrogen cloud at N12 is about 15 s which is twice as long as the duration at N8 increasing the safety risk of the near-source space.

Utilizing renewable energy sources (RESs) such as wind and solar to convert electrical energy into hydrogen energy can promote the accommodation of green electricity. This paper proposes an optimal capacity planning approach for an industrial electricity-hydrogen multi-energy system (EHMES) aimed to achieve the local utilization of RES and facilitate the transition to carbon reduction in industrial settings. The proposed approach models the EHMES equipment in detail and divides the system’s investment and operation into producer and consumer sides with energy trading for effective integration. Through this effort the specialized management for different operators and seamless incorporation of RES into industrial users can be achieved. In addition the variations in investment and operating costs of equipment across different installed capacities are considered to ensure a practical alignment with real-world scenarios. By conducting a detailed case study the influence of various factors on the capacity configuration outcomes within an EHMES is analyzed. The results demonstrate that the proposed method can effectively address the capacity configuration of equipment within EHMES based on the local accommodation of RES and variable unit cost sequence. Wind power serves as the primary source of green electricity in the system. Energy storage acts as crucial equipment for enhancing the utilization rate of RES.

This is a summary report of a study which aimed to understand the safety feasibility cost and impacts for 7 industrial sites to switch from natural gas to 100% hydrogen for heating. The volunteer industrial sites:<br/>♦ are located away from industrial clusters<br/>♦ use natural gas to meet most of their energy demand<br/>♦ will likely be most impacted by decisions on the future of the natural gas grid<br/>We have published the report in order to share its findings with other industrial sites and wider industry in particular those considering hydrogen as an option for decarbonisation.<br/>Note that:<br/>♦ some work was carried out on a non-hydrogen alternative energy source but to a lesser level of detail and not to determine the optimal decarbonisation solution<br/>♦ the findings do not apply to other end user environments because of differences between these environments and the consumption of gas<br/>The study was commissioned in 2022 by the former Department for Business and Energy and undertaken by AECOM and their safety sub-contractor ESR.<br/>The evidence will inform strategic decisions in 2026 on the role of low carbon hydrogen as a replacement for natural gas heating.

In this podcast David Ledesma talks to Martin Lambert and Abdurahman Alsulaiman about the potential hydrogen import market particularly focusing on the EU which currently holds the largest and earliest hydrogen target. The podcast explores the emerging hydrogen trade market and considers numerous possibilities for its open up providing better clarity on policy statements and balance them against project announcements.

Throughout the podcast Martin and Abdulrahman delve into various key points – they shed light on the primary areas of focus for projects set to be completed by or before 2030 as well as the distinction between announcements and tangible progress such as projects currently at the Final Investment Decision stage or under construction.

Additionally they explore the EU’s role as one of the few countries to have publicly announced its requirements for hydrogen imports and its ambitious hydrogen import target. The EU is currently establishing a benchmark for the future hydrogen market. However in order for the EU to succeed in establishing future hydrogen supply lines with future trade partners it will be crucial to engage in open dialogues covering a wide range of topics.

Join us in this podcast as we uncover the potential of the hydrogen import market with a specific focus on the EU and discuss the necessary steps for its success.

The podcast can be found on their website.

This study examines the structural chemical and hydrogen storage properties of graphitic carbon nitride (gC3N4) nanotubes synthesized via a novel grinding-solution-synthesis (GSS) method which involve two consecutive precursor mixing processes: grinding and solution mixing. The impact of grinding duration on morphology surface area and hydrogen storage capacity was analyzed. X-ray diffraction (XRD) confirmed characteristic (100) and (002) peaks at ~13.1◦ and 28.0◦ respectively. Fourier-transform infrared (FTIR) spectroscopy identified tri-s-triazine heterocycles and hydrogen-bonded amino groups with a new peak at 1650 cm− 1 suggesting structural modifications. X-ray photoelectron spectroscopy (XPS) confirmed elemental composition with minor bonding variations. Nitrogen adsorption/desorption analyses showed that the 30-min ground sample (B1G30) had the highest specific surface area (321 m2 g-1) and pore volume (1.07 cm3 /g) while prolonged grinding (60–90 min) caused nanotube degradation reducing these properties. Scanning and transmission electron microscopy (SEM/TEM) confirmed nanotubular morphology with decreasing diameters and increasing structural collapse at longer grinding durations. Hydrogen storage tests revealed B1G30 exhibited the highest capacity (0.81 wt% at 3.7 MPa) decreasing with extended grinding (B1G60: 0.79 wt% B1G90: 0.75 wt%) due to structural collapse. Extrapolated data suggested B1G30 could reach ~4.0 wt% at 10 MPa. These findings underscore the importance of nanotube integrity in optimizing hydrogen adsorption and highlight g-C3N4 nanotubes’ potential for hydrogen storage applications. This GSS technique presents a cost-effective method for industrial-scale fabrication of high-surface-area g-C3N4 nanotubes enabling their large-scale use in energy storage carbon capture photocatalysis and other applications.

The demand for green hydrogen as an energy carrier is projected to exceed 350 million tons per year by 2050 driven by the need for sustainable distribution and storage of energy generated from sources. Despite its potential hydrogen production currently faces challenges related to cost efficiency compliance monitoring and safety. This work proposes Hydrogen 4.0 a cyber–physical approach that leverages Industry 4.0 technologies—including smart sensing analytics and the Internet of Things (IoT)—to address these issues in hydrogen energy plants. Such an approach has the potential to enhance efficiency safety and compliance through real-time data analysis predictive maintenance and optimised resource allocation ultimately facilitating the adoption of renewable green hydrogen. The following sections break down conventional hydrogen plants into functional blocks and discusses how Industry 4.0 technologies can be applied to each segment. The components benefits and application scenarios of Hydrogen 4.0 are discussed while how digitalisation technologies can contribute to the successful integration of sustainable energy solutions in the global energy sector is also addressed.