Publications

This paper delves into the enhancement and optimization of on-grid renewable energy systems using a variety of renewable energy sources with a particular focus on large-scale applications designed to meet the energy demand of a certain load. As global concerns surrounding climate change continue to mount the urgency of replacing traditional fossil fuel-based power generation with cleaner more cost-effective and dependable alternatives becomes increasingly apparent. In this context a comprehensive investigation is conducted on grid connected hybrid energy system that combines photovoltaic wind and fuel cell technologies. The study employs three state-of-the-art optimization algorithms namely Walrus Optimization Algorithm (WaOA) Coati Optimization Algorithm (COA) and Osprey Optimization Algorithm (OOA) to determine the optimal system size and energy management strategies all aimed at minimizing the cost of energy (COE) for grid-based electricity. The results of the optimization process are compared with the results obtained from the utilization of the Particle swarm optimization (PSO) and Grey Wolf optimizer (GWO). The findings of this study underscore both the practical feasibility and the critical importance of adopting on-grid renewable energy systems to decrease the dependence on traditional energy sources within the grid. The proposed WaOA succeeded to reach the optimal solution of the optimal design process with a COE of 0.51758129611 $//kwh while keeping the loss of power supply probability (LPSP) the reliability index at 7.303681e-19. The practical recommendations and forwardlooking insights provided within this research hold the potential to foster sustainable development and effectively mitigate carbon emissions in the future.

Dual fuel combustion has gained attention as a cost-effective solution for reducing the pollutant emissions of internal combustion engines. The typical approach is combining a conventional high-reactivity fossil fuel (diesel fuel) with a sustainable low-reactivity fuel such as bio-methane ethanol or green hydrogen. The last one is particularly interesting as in theory it produces only water and NOx when it burns. However integrating hydrogen into stock diesel engines is far from trivial due to a number of theoretical and practical challenges mainly related to the control of combustion at different loads and speeds. The use of 3D-CFD simulation supported by experimental data appears to be the most effective way to address these issues. This study investigates the hydrogen-diesel dual fuel concept implemented with minimum modifications in a light-duty diesel engine (2.8 L 4-cylinder direct injection with common rail) considering two operating points representing typical partial and full load conditions for a light commercial vehicle or an industrial engine. The numerical analysis explores the effects of progressively replacing diesel fuel with hydrogen up to 80% of the total energy input. The goal is to assess how this substitution affects engine performance and combustion characteristics. The results show that a moderate hydrogen substitution improves brake thermal efficiency while higher substitution rates present quite a severe challenge. To address these issues the diesel fuel injection strategy is optimized under dual fuel operation. The research findings are promising but they also indicate that further investigations are needed at high hydrogen substitution rates in order to exploit the potential of the concept.

In recent years global efforts towards a future with sustainable energy have intensified the development of renewable energy sources (RESs) such as offshore wind solar photovoltaics (PVs) hydro and geothermal. Concurrently green hydrogen produced via water electrolysis using these RESs has been recognized as a promising solution to decarbonizing traditionally hard-to-abate sectors. Furthermore hydrogen storage provides a long-duration energy storage approach to managing the intermittency of RESs which ensures a reliable and stable electricity supply and supports electric grid operations with ancillary services like frequency and voltage regulation. Despite significant progress the hydrogen economy remains nascent with ongoing developments and persistent uncertainties in economic technological and regulatory aspects. This paper provides a comprehensive review of the green hydrogen value chain encompassing production transportation logistics storage methodologies and end-use applications while identifying key research gaps. Particular emphasis is placed on the integration of green hydrogen into both grid-connected and islanded systems with a focus on operational strategies to enhance grid resilience and efficiency over both the long and short terms. Moreover this paper draws on global case studies from pioneering green hydrogen projects to inform strategies that can accelerate the adoption and large-scale deployment of green hydrogen technologies across diverse sectors and geographies.

Morocco despite its heavy reliance on imported fossil fuels which made up 68% of electricity generation in 2020 has recognised its significant renewable energy potential. The Nationally Determined Contribution (NDC) commitment is to reduce emissions by 45.5% from baseline levels with international assistance and abstain from constructing new coal plants. Moreover the Green Hydrogen Roadmap aims to export 10 TWh of green hydrogen by 2030 as well as use it for local electricity storage. This paper critically analyses this Roadmap and Morocco’s readiness to reach its ambitious targets focusing specifically on an energy trilemma perspective and using OSeMOSYS (Open-Source energy Modelling System) for energy modelling. The results reveal that the NDC scenario is only marginally more expensive than the least-cost scenario at around 1.3% (approximately USD 375 million) and facilitates a 23.32% emission reduction by 2050. An important note is the continued reliance on existing coal power plants across all scenarios which challenges both energy security and emissions. The assessment of the Green Hydrogen Scenarios highlights that it could be too costly for the Moroccan government to fund the Green Hydrogen Roadmap at this scale which leads to increased imports of polluting fossil fuels for cost reduction. In fact the emission levels are 39% higher in the green hydrogen exports scenario than in the least-cost scenario. Given these findings it is recommended that the Green Hydrogen Roadmap be re-evaluated with a suggestion for a postponement and reduction in scope.

Hydrogen production and carbon dioxide removal are considered two of the critical pieces to achieve ultimate sustainability target. This study proposes and investigates a new variation of potassium hydroxide thermochemical cycle in order to combine hydrogen production and carbon dioxide removal synergistically. An alkali metal redox thermochemical cycle developed where the potassium hydroxide is considered by using a nonequilibrium reaction. Also the multigeneration options are explored by using two stage steam Rankine cycle multi-effect distillation desalination Li-Br absorption chiller which are integrated with potassium hydroxide thermochemical cycle for hydrogen production carbon capture power generation water desalination and cooling purposes. A comparative assessment under different scenarios is carried out. The energy and exergy efficiencies of the hydrogen production thermochemical cycle are 44.2% and 67.66% when the hydrogen generation reaction is carried out at 180°C and the separation reactor temperature set at 400°C. Among the multigeneration scenarios a trigeneration option of hydrogen power and water indicates the highest energy efficiency as 66.02%.

Offshore green hydrogen emerges as a guiding light in the global pursuit of environmental sustainability and net-zero objectives. The burgeoning expansion of offshore wind power faces significant challenges in grid integration. This avenue towards generating offshore green hydrogen capitalises on its ecological advantages and substantial energy potential to efficiently channel offshore wind power for onshore energy demands. However a substantial research void exists in efficiently integrating offshore wind electricity and green hydrogen. Innovative designs of offshore hydrogen platforms present a promising solution to bridge the gap between offshore wind and hydrogen integration. Surprisingly there is a lack of commercially established offshore platforms dedicated to the hydrogen industry. However the wealth of knowledge from oil and gas platforms contributes valuable insights to hydrogen platform design. Diverging from the conventional decentralised hydrogen units catering to individual turbines this study firstly introduces a pioneering centralised Offshore Green Hydrogen Platform (OGHP) which seamlessly integrates modular production storage and offloading modulars. The modular design of facilitates scalability as wind capacity increases. Through a detailed case study centred around a 100-Megawatt floating wind farm the design process of offshore green hydrogen modulars and its floating sub-structure is elucidated. Stability analysis and hydrodynamic analysis are performed to ensure the safety of the OGHP under the operation conditions. The case study will enhance our understanding OGHP and its modularised components. The conceptual design of modular OGHP offers an alternative solution to ‘‘Power-to-X’’ for offshore renewable energy sector.

In the present study pilot simulations of the phenomena of blast wave and fireball generated by the rupture of a high-pressure (35 MPa) hydrogen tank (volume 72 L) due to fire were carried out. The computational fluid dynamics (CFD) model includes the realizable k-ε model for turbulence and the eddy dissipation model coupled with the one-step chemical reaction mechanism for combustion. The simulation results were compared with experimental data on a stand-alone hydrogen tank rupture in a bonfire test. The simulations provided insights into the interaction between the blast wave propagation and combustion process. The simulated blast wave decay is approximately identical to the experimental data concerning pressure at various distances. Fireball is first ignited at the ground level which is considered to be due to stagnation flow conditions. Subsequently the flame propagates toward the interface between hydrogen and air.

Introduction: The transition towards electrolysis-produced hydrogen in refineries and chemical industries is expected to have a potent impact on the local energy system of which these industries are part. In this study three urban areas with hydrogen-intense industries are studied regarding how the energy system configuration is affected if the expected future hydrogen demand is met in each node individually as compared to forming a “Hydrogen Valley” in which a pipeline can be used to trade hydrogen between the nodes.<br/>Method: A technoeconomic mixed-integer linear optimization model is used to study the investments in and dispatch of the included technologies with an hourly time resolution while minimizing the total system cost. Four cases are investigated based on the availability of offshore wind power and the possibility to invest in a pipeline.<br/>Results: The results show that investments in a pipeline reduces by 4%–7% the total system cost of meeting the demands for electricity heating and hydrogen in the cases investigated. Furthermore investments in a pipeline result in greater utilization of local variable renewable electricity resources as compared to the cases without the possibility to invest in a pipeline.<br/>Discussion: The different characteristics of the local energy systems of the three nodes in local availability of variable renewable electricity grid capacity and available storage options compared to local demands of electricity heating and hydrogen are found to be the driving forces for forming a Hydrogen Valley.

This study evaluates the technoeconomic impacts of direct and indirect electrification on the EU's net-zero emissions target by 2050. By linking the JRC-EU-TIMES long-term energy system model with PLEXOS hourly resolution power system model this research offers a detailed analysis of the interactions between electricity hydrogen and synthetic fuel demand production technologies and their effects on the power sector. It highlights the importance of high temporal resolution power system analysis to capture the synergistic effects of these components often overlooked in isolated studies. Results indicate that direct electrification increases significantly and unimpacted by biomass CCS and nuclear energy assumptions. However indirect electrification in the form of hydrogen varies significantly between 1400 and 2200 TWhH2 by 2050. Synthetic fuels are essential for sector coupling making up 6–12% of total energy consumption by 2050 with the power sector supplying most hydrogen and CO2 for their production. Varying levels of indirect electrification impact electrolysers renewable energy and firm capacities. Higher indirect electrification increases electrolyser capacity factors by 8% leading to more renewable energy curtailment but improves system reliability by reducing 11 TWh unserved energy and increasing flexibility options. These insights inform EU energy policies stressing the need for a balanced approach to electrification biomass use and CCS to achieve a sustainable and reliable net-zero energy system by 2050. We also explore limitations and sensitivities.

To improve the recovery of waste heat and avoid the problem of abandoning wind and solar energy a multi-energy complementary distributed energy system (MECDES) is proposed integrating waste heat and surplus electricity for hydrogen storage. The system comprises a combined cooling heating and power (CCHP) system with a gas engine (GE) solar and wind power generation and miniaturized natural gas hydrogen production equipment (MNGHPE). In this novel system the GE’s waste heat is recycled as water vapor for hydrogen production in the waste heat boiler while surplus electricity from renewable sources powers the MNGHPE. A mathematical model was developed to simulate hydrogen production in three building types: offices hotels and hospitals. Simulation results demonstrate the system’s ability to store waste heat and surplus electricity as hydrogen thereby providing economic benefit energy savings and carbon reduction. Compared with traditional energy supply methods the integrated system achieves maximum energy savings and carbon emission reduction in office buildings with an annual primary energy reduction rate of 49.42–85.10% and an annual carbon emission reduction rate of 34.88–47.00%. The hydrogen production’s profit rate is approximately 70%. If the produced hydrogen is supplied to building through a hydrogen fuel cell the primary energy reduction rate is further decreased by 2.86–3.04% and the carbon emission reduction rate is further decreased by 12.67–14.26%. This research solves the problem of waste heat and surplus energy in MECDESs by the method of hydrogen storage and system integration. The economic benefits energy savings and carbon reduction effects of different building types and different energy allocation scenarios were compared as well as the profitability of hydrogen production and the factors affecting it. This has a positive technical guidance role for the practical application of MECDESs.

The effective storage of hydrogen is a critical challenge that needs to be overcome for it to become a widely used and clean energy source. Various methods exist for storing hydrogen including compression at high pressures liquefaction through extreme cooling (i.e. -253 °C) and storage with chemical compounds. Each method has its own advantages and disadvantages. MAST3RBoost (Maturing the Production Standards of Ultraporous Structures for High Density Hydrogen Storage Bank Operating on Swinging Temperatures and Low Compression) is a European funded Project aiming to establish a reliable benchmark for cold-adsorbed H2 storage (CAH2) at low compression levels (100 bar or below). This is achieved through the development of advanced ultraporous materials suitable for mobility applications such as hydrogen-powered vehicles used in road railway air and water transportation. The MAST3RBoost Project utilizes cutting-edge materials including Activated Carbons (ACs) and high-density MOFs (Metalorganic Frameworks) which are enhanced by Machine Learning techniques. By harnessing these materials the project seeks to create a groundbreaking path towards meeting industry goals. The project aims to develop the world's first adsorption-based demonstrator at a significant kg-scale. To support the design of the storage tank the project employs Computational Fluid Dynamics (CFD) software which allows for numerical investigations. In this paper a preliminary analysis of the tank refilling process is presented with a focus on the impact of the effect of the tank and hydrogen temperatures on quantity of hydrogen adsorbed.

The Paris Agreement aims to limit global warming and one of the most polluting sectors is heavy industry where cement production is a significant contributor. This work briefly explores some alternatives recycling reducing clinker content waste heat recovery and carbon capture discussing their advantages and drawbacks. Then it examines the economic viability and benefits of increasing oxygen concentration in the primary burning air from 21 to 27 vol.% which could improve clinker production by 7% and the production of hydrogen through PEM electrolysis to make up 5% of the fuel thermal fraction considering both in a cement plant producing 3000 tons of clinker per day. This analysis used reference values from Secil an international company for cement and building materials to determine the required scale of the oxygen and hydrogen production respectively and calculate the CAPEX of each approach. It is concluded that oxygen enrichment can provide substantial fuel savings for a relatively low cost despite a possible significant increase in NOx emissions. However hydrogen production at this scale is not currently economically viable.

As the global energy transition progresses a range of drivers and barriers will continue to shape consumer attitudes and behavioural intentions towards emerging low-carbon technologies. The innovation-decision process for technologies composing the residential sector such as hydrogen-fuelled heating and cooking appliances is inherently governed by the complex interplay between perceptual cognitive and emotional factors. In response this study responds to the call for an integrated research perspective to advance theoretical and empirical insights on consumer engagement in the domestic hydrogen transition. Drawing on online survey data collected in the United Kingdom where a policy decision on ‘hydrogen homes’ is set for 2026 this study systematically explores whether an integrated modelling approach supports higher levels of explanatory and predictive power. Leveraging the foundations of the unified theory of domestic hydrogen acceptance the analysis suggests that production perceptions public trust perceived relative advantage safety perceptions knowledge and awareness and positive emotions will shape consumer support for hydrogen homes. Conversely perceived disruptive impacts perceived socio-economic costs financial perceptions and negative emotions may impede the domestic hydrogen transition. Consumer acceptance stands to significantly shape deployment prospects for hydrogen boilers and hobs which are perceived to be somewhat advantageous to natural gas appliances from a technological and safety perspective. The study attests to the predictive benefits of adopting an integrated theoretical perspective when modelling the early stages of the innovation-decision process while acknowledging opportunities for leveraging innovative research approaches in the future. As national hydrogen economies gain traction adopting a neuroscience-based approach may help deepen scientific understanding regarding the neural psychological and emotional signatures shaping consumer perspectives towards hydrogen homes.

Natural gas (NG) is favored for transportation due to its availability and lower CO2 emissions than fossil fuels despite drawbacks like poor lean combustion ability and slow burning. According to a few recent studies using hydrogen (H2 ) alongside NG and diesel in Tri-fuel mode addresses these drawbacks while enhancing efficiency and reducing emissions making it a promising option for diesel engines. Due to the importance and novelty of this the continuation of ongoing research and insufficient literature studies on HNG–diesel engine emissions that are considered helpful to researchers this research has been conducted. This review summarizes the recent research on the HNG–diesel Tri-fuel engines utilizing hydrogen-enriched natural gas (HNG). The research methodology involved summarizing the effect of engine design operating conditions fuel mixing ratios and supplying techniques on the CO CO2 NOx and HC emissions separately. Previous studies show that using natural gas with diesel increases CO and HC emissions while decreasing NOx and CO2 compared to pure diesel. However using hydrogen with diesel reduces CO CO2 and HC emissions but increases NOx. On the other hand HNG–diesel fuel mode effectively mitigates the disadvantages of using these fuels separately resulting in decreased emissions of CO CO2 HC and NOx. The inclusion of hydrogen improves combustion efficiency reduces ignition delay and enhances heat release and in-cylinder pressure. Additionally operational parameters such as engine power speed load air–fuel ratio compression ratio and injection parameters directly affect emissions in HNG–diesel Tri-fuel engines. Overall the Tri-fuel approach offers promising emissions benefits compared to using natural gas or hydrogen separately as dual-fuels.

Due to the aviation energy sector's increasing contribution to climate change and the impact of climate change on the aviation sector determining key energy policy and economic research priorities for enabling an effective and equitable aviation climate action is becoming an increasingly important topic. In this perspective we address this research need using a four-pronged methodology. It includes (i) identifying topical matters highlighted in the media (news); (ii) formulating novel and feasible policy and economic research challenges that pertain to these contemporary issues; (iii) cross-referencing the proposed research challenges with academic literature to confirm their novelty and refining them as necessary; and (iv) validating the importance novelty and feasibility of these research challenges through consultation with a diverse group of aviation experts in fuel policy technology and infrastructure fields. Our results highlight twelve main themes. Among these the top emerging policy and economic research challenges as prioritized by expert input are – (i) frameworks for equitable responsibility allocation between developed and developing country airlines for future emissions; (ii) cost analysis of airlines' net-zero by 2050 commitments; (iii) effectiveness and opportunity cost of airlines investing in offsetting relative to reduction measures; (iv) EU aviation policies' historical and potential effects on airfares demand emissions EU air carriers' competitiveness passenger traffic through EU hubs regional economies and social climate funds' ability to mitigate distributional effects of EU aviation policies. These identified priorities can steer both industry and academic research toward creating practical recommendations for policymakers and industry participants. When it comes to future research the ever-changing nature of the challenges in achieving aviation climate action means that our findings might need regular updates.

We present an optimization model of an energy district in South Italy that supplies baseload electricity and hydrogen services. The district is sized such that a nuclear reactor could provide these services. We define scenarios for 2050 to explore the system effects of discount rate sensitivity vetoes on technologies and cost uncertainties. We address the following issues relevant to decarbonization in South Italy: land-based wind and solar vs. exclusive solar rooftop extra cost of a veto on nuclear conservative assumptions on future storage technology and the role of pumped hydro storage lack of low-cost geological storage of hydrogen and the industrial competitiveness of this carrier and the methanation synergy with the agroforestry sector. Our results quantify the high system cost of vetoes on land-based wind and solar. Nuclear may enter the optimal mix only with a veto against onshore wind and a hypothesis of equal project risk hence an equal discount rate with renewables. Scenarios with land-based wind and solar obtain low-cost hydrogen and thus allow industrial uses for this carrier. The methanation synergy with the agroforestry sector does not offer a system cost advantage but improves the district’s configuration. The extra cost of full decarbonization relative to unregulated fossil gas is small with land-based wind and solar and significant with vetoes to these technologies.

The impacts of climate change are real and in many parts of the world testify to its harsh reality including rampant extreme weather events droughts heat wildfires and flooding which have recorded in places which have not experienced them in recent memory. In the quest to avert such events there is a growing awareness and demand for sustainable processes and operations. Today sustainability encompasses a balance between ecological footprint and human development index taking into consideration economics the green environment safety quality ethics diversity and inclusion (D&I) and communities. This article presents some steps that have been taken by Algeria to balance energetic autonomy and sustainable development and a case study on green hydrogen production employing membrane processes. Algeria’s objective to join the global fight against climate change is to develop its green hydrogen base. Given its resources including available solar and wind power seawater desalination plants building capacity and its favorable location it is developing its green hydrogen economy to supply hydrogen especially to Europe. This presents an opportunity for other developing nations especially in Africa to gain from this experience.

This study explores the potentiality of low/zero carbon fuels such as methanol methane and hydrogen for motor applications to pursue the goal of energy security and environmental sustainability. An experimental investigation was performed on a spark ignition engine equipped with both a port fuel and a direct injection system. Liquid fuels were injected into the intake manifold to benefit from a homogeneous charge formation. Gaseous fuels were injected in direct mode to enhance the efficiency and prevent abnormal combustion. Tests were realized at a fixed indicated mean effective pressure and at three different engine speeds. The experimental results highlighted the reduction of CO and CO2 emissions for the alternative fuels to an extent depending on their properties. Methanol exhibited high THC and low NOx emissions compared to gasoline. Methane and even more so hydrogen allowed for a reduction in THC emissions. With regard to the impact of gaseous fuels on the NOx emissions this was strongly related to the operating conditions. A surprising result concerns the particle emissions that were affected not only by the fuel characteristics and the engine test point but also by the lubricating oil. The oil contribution was particularly evident for hydrogen fuel which showed high particle emissions although they did not contain carbon atoms.

This study aimed to compare hydrogen ammonia methanol and waste-derived biofuels as shipping fuels using life cycle assessment to establish what potential they have to contribute to the shipping industry’s 100% greenhouse gas emission reduction target. A novel approach was taken where the greenhouse gas emissions associated with one year of global shipping fleet operations was used as a common unit for comparison therefore allowing the potential life cycle greenhouse gas emission reduction from each fuel option to be compared relative to Paris Agreement compliant targets for international shipping. The analysis uses life cycle assessment from resource extraction to use within ships with all GHGs evaluated for a 100-year time horizon (GWP100). Green hydrogen waste-derived biodiesel and bio-methanol are found to have the best decarbonisation po tential with potential emission reductions of 74–81% 87% and 85–94% compared to heavy fuel oil; however some barriers to shipping’s decarbonisation progress are identified. None of the alternative fuels considered are currently produced at a large enough scale to meet shipping’s current energy demand and uptake of alternative fuel vessels is too slow considering the scale of the challenge at hand. The decarbonisation potential from alternative fuels alone is also found to be insufficient as no fuel option can offer the 100% emission reduction required by the sector by 2050. The study also uncovers several sensitives within the life cycles of the fuel options analysed that have received limited attention in previous life cycle investigations into alternative shipping fuels. First the choice of allocation method can potentially double the life cycle greenhouse gas emissions of e-methanol due to the carbon ac counting challenges of using waste carbon dioxide streams during fuel production. This leads to concerns related to the true impact of using carbon dioxide captured from fossil-fuelled processes to produce a combustible product due to the resultant high downstream emissions. Second nitrous oxide emissions from ammonia combustion are found to be highly sensitive due to high greenhouse gas potency potentially offsetting any greenhouse reduction potential compared to heavy fuel oil. Further uncertainties are highlighted due to limited available data on the rate of nitrous oxide production from ammonia engines. The study therefore highlights an urgent need for the shipping sector to consider these factors when investing in new ammonia and methanol engines; failing to do so risks jeopardizing the sector’s progress towards decarbonisation. Finally whilst alternative fuels can offer good decarbonisation potential (particularly waste derived biomethanol and bio-diesel and green hydrogen) this cannot be achieved without accelerated investment in new and retrofit vessels and new fuel supply chains: the research concludes that existing pipeline of vessel orders and fuel production facilities is insufficient. Furthermore there is a need to integrate alternative fuel uptake with other decarbonisation strategies such as slow steaming and wind propulsion.

Hydrogen and methane as secondary fuels in diesel engines can be promising solutions to meet energy demand. The current study investigated the effect of the specialty gases of different compositions on diesel engine performance and exhaust gases. Four gases with various compositions of exhaust gas recirculation (Carbon monoxide Carbon dioxide and Nitrogen) and fuels (Hydrogen and Methane) were used at various mass flow rates of 10 20 and 25 LPM (liter per minute) and various engine speeds of 2000 2500 3000 and 3500 rpm (revolutions per minute). The procured results revealed that adding specialty gases improved brake thermal efficiency and power. Similarly the brake-specific fuel consumption was also massively retarded compared to diesel due to the influence of the hydrogen and methane composition. However the fuel with the higher nitrogen reported less BTE (brake thermal efficiency) and comparatively higher exhaust gas temperature owing to the higher presence of nitrogen in their composition. Regarding emissions including exhaust gas recirculation dropped the formation of pollutants efficiently compared to diesel. Among various fuels Case 1 (30 % H2 5 % CH4 5 CO2 and 60 % CO) reported the lowest emission of NOx and Case 2 (25 % H2 5 % CH4 5 CO2 30 % CO and 35 % N2) of CO and CO2 emissions. Generally specialty gases with a variable composition of exhaust gas recirculation gases can be a promising sustainable replacement for existing fossil fuels.

Intra-day control and scheduling of energy systems require high-speed computation and strong robustness. Conventional mathematical driven approaches usually require high computation resources and have difficulty handling system uncertainties. This paper proposes two data-driven scheduling approaches for hydrogen penetrated energy system (HPES) operational scheduling. The two data-driven approaches learn the historical optimization results calculated out using the mixed integer linear programing (MILP) and conditional value at risk (CVaR) respectively. The intra-day rolling optimization mechanism is introduced to evaluate the proposed data-driven scheduling approaches MILP data-driven approach and CVaR data-driven approach along with the forecasted renewable generation and load demands. Results show that the two data-driven approaches have lower intra-day operational costs compared with the MILP based method by 1.17% and 0.93%. In addition the combined cooling and heating plant (CCHP) has a lower frequency of changing the operational states and power output when using the MILP data-driven approach compared with the mathematical driven approaches.

To meet environmental goals while maintaining economic competitiveness worldwide ports have increased the amount of renewable energy production and have focused in optimizing performances and energy efficiency. However carbon-neutral operation of industrial port areas (IPA) is challenging and requires the decarbonization of industrial processes and heavy transport systems. This study proposes a comprehensive review of decarbon ization strategies for IPA with a particular focus on the role that green hydrogen could play when used as renewable energy carrier. Much information on existing and future technologies was also derived from the analysis of 74 projects (existing and planned) in 36 IPAs 80 % of which are in Europe concerning hydrogenbased decarbonization strategies. The overall review shows that engine operation of ships at berth are respon sible of more than 70 % of emissions in ports. Therefore onshore power supply (OPS) seems to be one of the main strategies to reduce port pollution. Nevertheless OPS powered by hydrogen is not today easily achievable. By overcoming the current cost-related and regulation barriers hydrogen can also be used for the import/export of green energy and the decarbonization of hard-to-abate sectors. The technical and economic data regarding hydrogen-based technologies and strategies highlighted in this paper are useful for further research in the field of definition and development of decarbonization strategies in the IPA.

Renewable Energy Sources (RESs) are characterized by high unevenness cyclicality and seasonality of energy production. Due to the trends in the production of electricity itself and the utilization of hydrogen distributed generation systems are preferred. They can be connected to the energy distribution network or operate without its participation (off-grid). However in both cases such distributed energy sources should be balanced in terms of power generation. According to the authors it is worth combining different RESs to ensure the stability of energy production from such a mix. Within the mix the sources can complement and replace each other. According to the authors an effective system for generating energy from RESs should contain at least two different sources and energy storage. The purpose of the analyses and calculations performed is to determine the characteristics of energy generation from a photovoltaic system and a wind turbine with a specific power and geographical location in the Lublin region in Poland. Another important goal is to determine the substitutability of the sources studied. Probabilistic analysis will be used to determine the share of given energy sources in the energy mix and will allow us to estimate the size of the stationary energy storage. The objective of these procedures is to strive for the highest possible share of renewable energy in the total energy required to charge electric vehicle fleets and to produce low-emission hydrogen for transportation. The article proves that the appropriately selected components of the photovoltaic and wind energy mix located in the right place lead to the self-balancing of the local energy network using a small energy storage. The conclusions drawn from the conducted research can be used by RES developers who intend to invest in new sources of power generation to produce low-emission hydrogen. This is in line with the current policy of the European Union aimed at climate and energy transformation of many companies using green hydrogen.

Alkaline water electrolysis is a key technology for large-scale hydrogen production. In this process safety and efficiency are among the most essential requirements. Hence optimization strategies must consider both aspects. While experimental optimization studies are the most accurate solution model-based approaches are more cost and time-efficient. However validated process models are needed which consider all important influences and effects of complete alkaline water electrolysis systems. This study presents a dynamic process model for a pressurized alkaline water electrolyzer consisting of four submodels to describe the system behavior regarding gas contamination electrolyte concentration cell potential and temperature. Experimental data from a lab-scale alkaline water electrolysis system was used to validate the model which could then be used to analyze and optimize pressurized alkaline water electrolysis. While steady-state and dynamic solutions were analyzed for typical operating conditions to determine the influence of the process variables a dynamic optimization study was carried out to optimize an electrolyte flow mode switching pattern. Moreover the simulation results could help to understand the impact of each process variable and to develop intelligent concepts for process optimization

Green hydrogen is considered the most suitable choice for the future energy market both as energy storage media energy vector and fuel for transportation industry and other applications. In the last twenty years increasing efforts have been dedicated to green hydrogen technologies development but still today a number of issues are claimed in justifying the delay in its large scale application and the star vation of its market. Moreover some new questions seem ready to be put on the table for justifying the delay in green hydrogen technologies applications. In this paper a critical analysis of recent literature and institutional reports is carried out with the aim of understanding what is the real state of the play. In particular peculiar advantages and shortcomings of different green hydrogen technologies (biomass pyrolysis and gasification water electrolysis etc.) have been analysed and compared with a focus on the electrolysis process as the most promising method for large scale and distributed generation of hydrogen. Some geopolitical and economic aspects associated with the transition to a green hydrogen economy - including the feared exacerbation of the water crisis - have been widely examined and discussed with the purpose of identifying approaches and solutions to accelerate the mentioned transition.

Green hydrogen has been identified as a critical enabler in the global transition to sustainable energy and decarbonized society but it is still not economically competitive compared to fossil-fuel-based hydrogen. To overcome this limitation we propose to couple photoelectrochemical (PEC) water splitting with the hydrogenation of chemicals. Here we evaluate the potential of coproducing hydrogen and methyl succinic acid (MSA) by coupling the hydrogenation of itaconic acid (IA) inside a PEC water splitting device. A negative net energy balance is predicted to be achieved when the device generates only hydrogen but energy breakeven can already be achieved when a small ratio (~2%) of the generated hydrogen is used in situ for IA-to-MSA conversion. Moreover the simulated coupled device produces MSA with much lower cumulative energy demand than conventional hydrogenation. Overall the coupled hydrogenation concept offers an attractive approach to increase the viability of PEC water splitting while at the same time decarbonizing valuable chemical production.

Energy and environmental challenges are two key issues related to the sustainable development of the Earth. Fossil fuels (oil coal and natural gas) still supply more than 85% of world energy consumption. Several nations around the globe are striving to provide access to clean and sustainable energy by 2030 (Hostettler et al. 2015). When the Paris Agreement entered into force in 2016 many countries have recently announced serious commitments to significantly reduce their carbon dioxide emissions promising to achieve “net zero” by 2050. he main goal is to limit global warming to well below 2 degrees Celsius preferably to 1.5 degrees Celsius compared to pre-industrial levels (IEA 2021). his requires a total transformation of the energy systems that underpin our economies. In the case of renewable energy technology deployment hydrogen may provide a complementary solution due to its flexibility as an energy carrier and storage medium. The European Union (EU) a signatory to the Paris Agreement demonstrated interest in hydrogen as an invaluable raw material in considerably reducing CO2 emissions. Hydrogen inthe EU energy mix is estimated to increase from the current level (less than 2%) to 13–14% in 2050 (EC 2018).

Due to the small characteristic molecular size of hydrogen small leaks are more common in hydrogen systems compared to similar systems with hydrocarbons. This together with the high reactivity makes an efficient ventilation system very important in hydrogen applications. There are several models available for ventilation sizing that are based on either a well-mixed assumption or a fully stratified situation. However experiments show that many realistic releases will be neither and therefore additional models are needed. One possibility is to use CFD-models but the small release sizes for pinhole releases (<<1 mm) make it difficult to find an appropriate mesh without excessive computational time (especially since the simulations need to be iterated to find the optimum ventilation size). An alternative approach which is described and benchmarked in the current paper is to use a multi-zone model where the domain is divided into several large cells where the mass exchange is simplified compared to CFD and thus simulation time is reduced. The flow in the model is governed by mass conservation and density differences due to concentration gradients using the Bernoulli equation. The release of gas generates a plume which is modelled based on an empirical plume model which gives the entrainment and hydrogen source term for each cell. The model has a short run time and will therefore allow optimization in a short time frame. The model is benchmarked against five experiments with helium at the Canadian Nuclear Laboratories (CNL) in Canada and one hydrogen experiment performed at Lodz University of Technology in Poland. The result shows that the model can reasonably well reproduce accumulation in the experiments with small release without ventilation but appears to slightly underestimate the level of stratification and the interface height for ventilated cases where the source is elevated from the floor level.

This study examines hydrogen production across 27 European countries highlighting disparities due to varying energy policies and industrial capacities. Germany leads with 109 plants followed by Poland France Italy and the UK. Mid-range contributors like the Netherlands Spain Sweden and Belgium also show substantial investments. Countries like Finland Norway Austria and Denmark known for their renewable energy policies have fewer plants while Estonia Iceland Ireland Lithuania and Slovenia are just beginning to develop hydrogen capacities. The analysis also reveals that a significant portion of the overall hydrogen production capacity in these countries remains underutilized with an estimated 40% of existing infrastructure not operating at full potential. Many countries underutilize their production capacities due to infrastructural and operational challenges. Addressing these issues could enhance output supporting Europe’s energy transition goals. The study underscores the potential of hydrogen as a sustainable energy source in Europe and the need for continued investment technological advancements supportive policies and international collaboration to realize this potential.

To expedite the development of the infrastructural expansion for hydrogen applications the research project “THEWA” was founded. Within this project the development of hydrogen-refueling stations is being advanced so that the hydrogen strategy for mobility in Germany can move forward. One development point of the project is to develop an evaluation model that recommends a concept for hydrogen-refueling stations for initial individual situations. In this work an evaluation method is developed that provides an appropriate recommendation. For this purpose basics such as the general structure of hydrogen-refueling stations their classification into functional areas and alreadyexisting evaluation methods for multi-criteria decisions are shown. The method for the evaluation of hydrogen-refueling stations will be developed in a component-based manner for which a selection of influencing factors of hydrogen-refueling stations will be explained and categorized. With the help of an expert workshop these are scaled so that the result is an evaluation method based on an expert assessment and the consideration of individual customer requirements. In addition the method is implemented in a tool so that it can be used more easily.

Hydrogen plays a pivotal role in transitioning to CO2-free energy systems yet challenges regarding costs and sourcing persist in supplying Europe with renewable hydrogen. Our paper proposes a simulation-based approach to determine cost-optimal combinations of electrolyser power and renewable peak power for off-grid hydrogen production considering location and energy source dependencies. Key findings include easy estimation of Levelized Costs of Hydrogen (LCOH) and optimal plant sizing based on the regional energy yield and source. Regional investment risks influence the LCOH by 7.9 % per 1 % change of the Weighted Average Cost of Capital. In Central Europe (Austria) hydrogen production costs range from 7.4 €/kg to 8.6 €/kg whereas regions like Chile exhibit cheaper costs at 5.1 €/kg to 6.8 €/kg. Despite the favourable energy yields in regions like Chile or the UAE domestically produced hydrogen can be cost-competitive when location-specific risks and transport costs are taken into account. This underlines the critical role of domestic hydrogen production and cost-effective hydrogen transport for Europe’s future hydrogen supply.

Renewable hydrogen is emerging as the key to a sustainable energy transition with multiple applications and uses. In the field of transport in addition to fuel cell vehicles it is necessary to develop an extensive network of hydrogen refueling stations (hereafter HRSs). The characteristics and properties of hydrogen make ensuring the safe operation of these facilities a crucial element for their successful deployment and implementation. This paper shows the outcomes of an analysis of hydrogen incidents and accidents considering their potential application to HRSs. For this purpose the HIAD 2.0 was reviewed and a total of 224 events that could be repeated in any of the major industrial processes related to hydrogen refueling stations were analyzed. This analysis was carried out using a mixed methodology of quantitative and qualitative techniques considering the following hydrogen value chain: production storage delivery and industrial use. The results provide general information segmented by event frequency damage classes and failure typology. The analysis shows the main processes of the value chain allow the identification of key aspects for the safety management of refueling facilities.

Switching to renewable resources for hydrogen production is essential. Present hydrogen resources such as coal oil and natural gas are depleted and rapidly moving to a dead state and they possess a high carbon footprint. Wastewater is a promising avenue in searching for a renewable hydrogen production resource. Profuse techniques are preferred for hydrogen production. Among them electrolysis is great with wastewater against biological processes by hydrogen purity. Present obstacles behind the process are conversion efficiency intensive energy and cost. This review starts with hydrogen demand wastewater availability and their H2 potential then illustrates the three main types of electrolysis. The main section highlights renewable energy-assisted electrolysis because of its low carbon footprint and zero emission potential for various water electrolysis. High-temperature steam solid oxide electrolysis is a viable option for future scaling due to the versatile adoption of photo electric and thermal energy. A glance at some effective aspirations to large-scale H2 economics such as co-generation biomass utilization Microbial electrolysis waste to low-cost green electrode Carbon dioxide hydrogenation and minerals recovery. This study gives a broader view of facing challenges via versatile future perspectives to eliminate the obstacles above. renewable green H2 along with a low carbon footprint and cost potential to forward the large-scale wastewater electrolysis H2 production in addition to preserving the environment from wastewater and fossil fuel. Geographical and seasonal availability constraints are unavoidable; therefore energy storage and coupling of power sources is essential to attain consistent supply. The lack of regulations and policies supporting the development and adoption of these technologies did not reduce the gap between research and implementation. Life cycle assessment of this electrolysis process is rarely available so we need to focus on the natural effect of this process on the environment.

Hydrogen refueling stations (HRS) can cause a significant fraction of the hydrogen refueling cost. The main cost contributor is the currently used mechanical compressor. Electrochemical hydrogen compression (EHC) has recently been proposed as an alternative. However its optimal integration in an HRS has yet to be investigated. In this study we compare the performance of a gaseous HRS equipped with different compressors. First we develop dynamic models of three process configurations which differ in the compressor technology: mechanical vs. electrochemical vs. combined. Then the design and operation of the compressors are optimized by solving multi-stage dynamic optimization problems. The optimization results show that the three configurations lead to comparable hydrogen dispensing costs because the electrochemical configuration exhibits lower capital cost but higher energy demand and thus operating cost than the mechanical configuration. The combined configuration is a trade-off with intermediate capital and operating cost.

As a versatile energy carrier hydrogen possesses tremendous potential to reduce greenhouse emissions and promote energy transition. Global interest in producing hydrogen from renewable energy sources and transporting storing and utilizing hydrogen is rising rapidly. However the high costs of producing clean hydrogen and the uncertain application scenarios for hydrogen energy result in its relatively limited utilization worldwide. It is necessary to find new promising technological paths to drive the development of hydrogen energy. As part of technological innovation emerging technologies have vital features such as prominent impact novelty relatively fast growth etc. Identifying emerging hydrogen-energy-related technologies is important for discovering innovation opportunities during the energy transition. Existing research lacks analysis of the characteristics of emerging technologies. Thus this paper proposes a method combining the latent Dirichlet allocation topic model and hydrogen-energy expert group decision-making. This is used to identify emerging hydrogen-related technology regarding two features of emerging technologies novelty and prominent impact. After data processing topic modeling and analysis the patent dataset was divided into twenty topics. Six emerging topics possess novelty and prominent impact among twenty topics. The results show that the current hotspots aim to promote the application of hydrogen energy by improving the performance of production catalysts overcoming the wide power fluctuations and large-scale instability of renewable energy power generation and developing advanced hydrogen safety technologies. This method efficiently identifies emerging technologies from patents and studies their development trends. It fills a gap in the research on emerging technologies in hydrogen-related energy. Research achievements could support the selection of technology pathways during the low-carbon energy transition.

This study investigates hydrogen (H2) as a supplementary fuel in heavy-duty diesel engines using pre-manifold injection. A H2-diesel dual-fuel (H2DF) system was implemented on a commercial class-8 heavy-duty diesel truck without modifying the original diesel injection system and engine control unit (ECU). Tests were conducted on a chassis dynamometer at engine speeds between 1000 and 1400 rpm with driver-demanded torques from 10 to 75%. The hydrogen energy fraction (HEF) was strategically controlled in the range between 10 and 30%. Overall CO2 reduction (comparable to the HEF level) was achieved with similar brake-specific energy consumption (BSEC) at all loads and speeds. To maintain the same shaft torque the driver-demanded torque was reduced in H2DF operation which resulted in a lower boost pressure. At higher loads engine-out BSNOx slightly decreased while BSCO and black carbon (BC) increased significantly due to lower oxygen concentration resulting from the lower boost pressure. At lower loads engine-out BSCO and BSBC decreased moderately while NO2/NO ratio increased substantially in H2DF operation. Deliberate air path and diesel injection control are expected to enable higher HEF and GHG reductions.

This report investigates the status and trend of Renewable Fuels of Non-Biological Origin (RFNBO) except hydrogen which are needed to cover part of the EU’s demand for low carbon renewable fuels in the coming years. The report is an update of the CETO 2023 report. Most of the conversion technologies investigated have been already demonstrated at small-scale and the current EU legislative framework under the recast of the Renewable Energy Directive (EU) 2018/2001 (Directive EU 2023/2413) sets specific targets for their use. As a pre-requisite well-established solid hydrogen supply chains are needed together with carbon capture technologies to provide carbon dioxide as Carbon Capture and Use (CCU). Fuels that may be produced starting from H2 and CO2 or N2 are hydrocarbons alcohols and ammonia. RFNBO may play a crucial role in the energytransition towards decarbonisation especially in hard-to-abate sectors where direct electrification is not possible. In addition most RFNBO can use existing infrastructure. The growing interest in these fuels is witnessed by the many funding programmes which are today available. Moreover EU leads the sector in terms of patents companies and demonstration activities. Finally the report considers the major challenges and the opportunities for a rapid market uptake of such fuels.

Africa has enormous potential to produce low-cost e-fuels e-chemicals and e-materials required for complete defossilisation using its abundant renewable resources widely distributed across the continent. This research builds on techno-economic investigations using the LUT Energy System Transition Model and related tools to assess the power-to-X potential in Africa for meeting the local demand and exploring the export potential of power-to-products applications. In this context we analysed the economic viability of exporting green e-fuel echemicals and e-materials from Africa to Europe. We also present the core elements of the Power-to-X Economy i.e. renewable electricity and hydrogen. The results show that hydrogen will likely not be traded simply due to high transport costs. However there is an opportunity for African countries to export e-ammonia e-methanol ekerosene jet fuel e-methane e-steel products and e-plastic to Europe at low cost. The results show that Africa’s low-cost power-to-X products backed by low-cost renewable electricity mainly supplied by solar photovoltaics is the basis for Africa’s vibrant export business opportunities. Therefore the Power-to-X Economy could more appropriately be called a Solar-to-X Economy for Africa. The Power-to-X Economy will foster socio-economic growth in the region including new industrial opportunities new investment portfolios boost income and stimulate local technical know-how thereby delivering a people-driven energy economy. Research on the topic in Africa is limited and at a nascent stage. Thus more studies are required in future to guide investment decisions and cater to policy decisions in achieving carbon neutrality with e-fuels e-chemicals and e-materials.

Life cycle assessment which evaluates the complete life cycle of a product is considered the standard methodological framework to evaluate the environmental performance of climate change solutions. However significant challenges exist related to datasets used to quantify these environmental indicators. Although extensive research and commercial data on climate change technologies pathways and facilities exist they are not readily available to practitioners of life cycle assessment in the right format and structure using an open platform. In this study we propose a new open data hub platform for life cycle assessment considering a hierarchical data flow starting with raw data collected on climate change technologies at laboratory pilot demonstration or commercial scales to provide the information required for policy and decision-making. This platform makes data accessible at multiple levels for practitioners of life cycle assessment while making data interoperable across platforms. The proposed data hub platform and workflow are explained through the polymer electrolyte membrane electrolysis hydrogen production as a case study. The climate change environment impact of 1.17 ± 0.03 kg CO2 eq./kg H2 was calculated for the case study. The current data hub platform is limited to evaluating environmental impacts; however future additions of economic and social aspects are envisaged.

With the advancement of Fuel Cell Vehicles (FCVs) detecting hydrogen leaks is critically important in facilities such as hydrogen refilling stations. Despite its significance the dynamic response performance of hydrogen sensors in confined spaces particularly under ceilings has not been comprehensively assessed. This study utilizes a catalytic combustion hydrogen sensor to monitor hydrogen leaks in a confined area. It examines the effects of leak size and placement height on the distribution of hydrogen concentrations beneath the ceiling. Results indicate that hydrogen concentration rapidly decreases within a 0.5–1.0 m range below the ceiling and declines more gradually from 1.0 to 2.0 m. The study further explores the attenuation pattern of hydrogen concentration radially from the hydrogen jet under the ceiling. By normalizing the radius and concentration it was determined that the distribution conforms to a Gaussian model akin to that observed in open space jet flows. Utilizing this Gaussian assumption the model is refined by incorporating an impact reflux term thereby enhancing the accuracy of the predictive formula.

In international regulations on explosion protection mechanical friction impact or abrasion is usually named as one of 13 ignition sources that must be avoided in hazardous zones with explosive atmospheres. In different studies it is even identified as one of the most frequent ignition sources in practice. The effectiveness of mechanical impacts as ignition source is dependent from several parameters including the minimum ignition energy of the explosive atmosphere the properties of the material pairing the kinetic impact energy or the impact velocity. By now there is no standard procedure to determine the effectiveness of mechanical impacts as ignition source. In some previous works test procedures with poor reproducibility or undefined kinetic impact energy were applied for this purpose. In other works only homogeneous material pairings were considered. In this work the effectiveness of mechanical impacts with defined and reproducible kinetic impact energy as ignition source for hydrogen containing atmospheres was studied systematically in dependence from the inhomogeneous material pairing considering materials with practical relevance like stainless steel low alloy steel concrete and non-iron-metals. It was found that ignition can be avoided if non-iron metals are used in combination with different metallic materials but in combination with concrete even the impact of non-iron-metals can be an effective ignition source if the kinetic impact energy is not further limited. Moreover the consequence of hydrogen admixture to natural gas on the effectiveness of mechanical impacts as ignition source was studied. In many cases ignition of atmospheres containing natural gas by mechanical impacts is rather unlikely. No influence could be observed for admixtures up to 25% hydrogen and even more. The results are mainly relevant in the context of repurposing the natural gas grid or adding hydrogen to the natural gas grid. Based on the test results it can be evaluated under which circumstances the use of tools made of non-iron-metals or other non-sparking materials can be an effective measure to avoid ignition sources in hazardous zones containing hydrogen for example during maintenance work.

The European Union aims to deploy a high share of renewable energy sources in Europe’s power system by 2050. Large-scale intermittent wind and solar power production requires flexibility to ensure an adequate supply–demand balance. Green hydrogen (GH) can increase power systems’ flexibility and decrease renewable energy production’s curtailment. However investing in GH is costly and dependent on electricity prices which are important for operational costs in electrolysis. Moreover the use of GH for power system flexibility might not be economically viable if there is no hydrogen demand from the hydrogen market. If so questions would arise as to what would be the incentives to introduce GH as a source of flexibility in the power system and how would electrolyzer costs hydrogen demand and other factors affect the economic viability of GH usage for power system flexibility. The paper implements a European power system model formulated as a stochastic program to address these questions. The authors use the model to compare various instances with hydrogen in the power system to a no-hydrogen instance. The results indicate that by 2050 deployment of approximately 140 GW of GH will pay off investments and make the technology economically viable. We find that the price of hydrogen is estimated to be around €30/MWh.

The global energy landscape is rapidly shifting toward cleaner lower-carbon electricity generation necessitating a transition to alternate energy sources. Hydrogen particularly green hydrogen looks to be a significant solution for facilitating this transformation as it is produced by water electrolysis with renewable energy sources such as solar irradiations wind speed and biomass residuals. Traditional energy systems are costly and produce energy slowly due to unpredictability in resource supply. To address this challenge this work provides a novel technique that integrates a multi-renewable energy system using multi objective optimization algorithm to meets the machine learning-based forecasted load model. Several forecasting models including Autoregressive Integrated Moving Average(ARIMA) Random Forest and Long Short-Term Memory Recurrent Neural Network (LSTMRNN) are assessed for develop the statistical metrics values such as RMSE MAE and MAPE. The selected Non-Sorting Moth Flame Optimization (NSMFO) algorithm demonstrates technological prowess in efficiently achieving global optimization particularly when handling multiple objective functions. This integrated method shows enormous promise in technological economic and environmental terms emphasizing its ability to promote energy sustainability targets.

Hydrogen Refueling Stations (HRS) are a key infrastructure to the successful deployment of hydrogen mobility. Their cost-effectiveness will represent an increasingly crucial issue considering the foreseen growth of vehicle fleets from few captive fleets to large-scale penetration of hydrogen vehicles. In this context a detailed component-oriented cost model is important to assess HRS costs for different design concepts layout schemes and possible customizations respect to aggregate tools which are mostly available in literature. In this work an improved version of a previously developed component-oriented scale-sensitive HRS cost model is applied to 5 different European HRS developed within the 3Emotion project with different refueling capacities (kgH2/day) hydrogen supply schemes (in-situ production or delivery) storage volumes and pressures and operational strategies. The model output allows to assess the upfront investment cost (CAPEX) the annual operational cost (OPEX) and the Levelized Cost of Hydrogen (LCOH) at the dispenser and identify the most crucial cost components. The results for the five analyzed HRS sites show an LCOH at the nozzle of around 8-9 €/kg for delivery based HRSs which are mainly dominated by the H2 retail price and transport service price and around 11-12 €/kg for on-site producing HRS for which the electrolyzer CAPEX and electricity price plays a key role in the cost structure. The compression storage and dispensing sections account for between 1-3 €/kg according to the specific design & performance requirements of the HRS. The total LCOH values are comparable with literature standard market prices for similar scale HRSs and with the 3Emotion project targets.

In order to achieve the ambitious goal of “carbon neutrality” countries around the world are striving to develop clean energy. Against this background this paper takes China and Italy as representatives of developing and developed countries to summarize the energy structure composition and development overview of the two countries. The paper analyzes the serious challenges facing the future energy development of both countries and investigates the possibilities of energy cooperation between the two countries taking into account their respective advantages in energy development. By comparing the policies issued by the two governments to encourage clean energy development this paper analyzes the severe challenges faced by the two countries’ energy development in the future and combines their respective energy development advantages to look forward to the possibility of energy cooperation between the two countries in the future. This lays the foundation for China and Italy to build an “Energy Road” after the “Silk Road”.

The production of green hydrogen through electrolysis utilizing renewable energies is recognized as a pivotal element in the pursuit of decarbonization. In order to attain cost competitiveness for green hydrogen reasonable generation costs are imperative. To identify cost-effective import partners for Germany given its limited green hydrogen production capabilities this study undertakes an exhaustive techno-economic analysis to determine the potential Levelized Cost of Hydrogen in Germany Norway Spain Algeria Morocco and Egypt for the year 2050 which represents a critical milestone in European decarbonization efforts. Employing a stochastic approach with Monte Carlo simulations the paper marks a significant contribution for projecting future cost ranges acknowledging the multitude of uncertainties inherent in related cost parameters and emphasizing the importance of randomness in these assessments. Country-specific Weighted Average Cost of Capital are calculated in order to create a refined understanding of political and economic influences on cost formation rather than using a uniform value across all investigated nations. Key findings reveal that among the evaluated nations PV-based hydrogen emerges as the most cost-efficient alternative in all countries except Norway with Spain presenting the lowest Levelized Cost of Hydrogen at 1.66 €/kg to 3.12 €/kg followed by Algeria (1.72 €/kg to 3.23 €/kg) and Morocco (1.73 €/kg to 3.28 €/kg). Consequently for economically favorable import options Germany is advised to prioritize PV-based hydrogen imports from these countries. Additionally hydrogen derived from onshore wind in Norway (2.24 €/kg to 3.73 €/kg) offers a feasible import alternative. To ensure supply chain diversity and reduce dependency on a single source a mixed import strategy is advisable. Despite having the lowest electricity cost Egypt shows the highest Levelized Cost of Hydrogen primarily due to a significant Weighted Average Cost of Capital.

Renewable hydrogen obtained from renewable energy sources especially when produced through water electrolysis is gaining attention as a promising energy vector to deal with the challenges of climate change and the intermittent nature of renewable energy sources. In this context this work analyzes a pilot plant that uses this technology installed in the Itumbiara Hydropower Plant located between the states of Goiás and Minas Gerais Brazil from technical and economic perspectives. The plant utilizes an alkaline electrolyzer synergistically powered by solar photovoltaic and hydro sources. Cost data for 2019 when the equipment was purchased and 2020–2023 when the plant began continuous operation are considered. The economic analysis includes annualized capital maintenance and variable costs which determines the levelized cost of hydrogen (LCOH). The results obtained for the pilot plant’s LCOH were USD 13.00 per kilogram of H2 with an efficiency loss of 2.65% for the two-year period. Sensitivity analysis identified the capacity factor (CF) as the main determinant of the LCOH. Even though the analysis specifically applies to the Itumbiara Hydropower Plant the CF can be extrapolated to larger plants as it directly influences hydrogen production regardless of plant size or capacity

Electrolysis of water to generate hydrogen fuel is an attractiverenewable energy storage technology. However grid-scale fresh-water electrolysis would put a heavy strain on vital water re-sources. Developing cheap electrocatalysts and electrodes that cansustain seawater splitting without chloride corrosion could ad-dress the water scarcity issue. Here we present a multilayer anodeconsisting of a nickel–iron hydroxide (NiFe) electrocatalyst layeruniformly coated on a nickel sulfide (NiSx) layer formed on porousNi foam (NiFe/NiSx-Ni) affording superior catalytic activity andcorrosion resistance in solar-driven alkaline seawater electrolysisoperating at industrially required current densities (0.4 to 1 A/cm2)over 1000 h. A continuous highly oxygen evolution reaction-active NiFe electrocatalyst layer drawing anodic currents towardwater oxidation and an in situ-generated polyatomic sulfate andcarbonate-rich passivating layers formed in the anode are respon-sible for chloride repelling and superior corrosion resistance of thesalty-water-splitting anode.

Under the guidance of energy-saving and emission reduction goals a lowcarbon economic operation method for integrated energy systems (IES) has been proposed. This strategy aims to enhance energy utilization efficiency bolster equipment operational flexibility and significantly cut down on carbon emissions from the IES. Firstly a thorough exploration of the two-stage operational framework of Power-to-Gas (P2G) technology is conducted. Electrolyzers methane reactors and hydrogen fuel cells (HFCs) are introduced as replacements for traditional P2G equipment with the objective of harnessing the multiple benefits of hydrogen energy. Secondly a cogeneration and HFC operational strategy with adjustable heat-to-electricity ratio is introduced to further enhance the IES’s low-carbon and economic performance. Finally a step-by-step carbon trading mechanism is introduced to effectively steer the IES towards carbon emission control.

The use of hydrogen-blended natural gas presents an efficacious pathway toward the rapid large-scale implementation of hydrogen energy with pipeline transportation being the principal method of conveyance. However pipeline materials are susceptible to hydrogen embrittlement in high-pressure hydrogen environments. Natural gas contains various impurity gases that can either exacerbate or mitigate sensitivity to hydrogen embrittlement. In this study we analyzed the mechanisms through which multiple impurity gases could affect the hydrogen embrittlement behavior of pipeline steel. We examined the effects of O2 and CO2 on the hydrogen embrittlement behavior of L360 pipeline steel through a series of fatigue crack growth tests conducted in various environments. We analyzed the fracture surfaces and assessed the fracture mechanisms involved. We discovered that CO2 promoted the hydrogen embrittlement of the material whereas O2 inhibited it. O2 mitigated the enhancing effect of CO2 when both gases were mixed with hydrogen. As the fatigue crack growth rate increased the influence of impurity gases on the hydrogen embrittlement of the material diminished.