Production & Supply Chain

Chemical looping dry reforming of methane (CLDRM) using perovskites as a catalyst is considered a promising option for producing hydrogen from biogas. In this work the life-cycle performance of a system compiling a CLDRM unit paired with a water gas shift unit a pressure swing adsorption unit and a combined cycle scheme to provide steam and electricity was assessed. The main data needed to reflect the behavior of the reforming reaction was obtained experimentally and implemented in an Aspen Plus® simulation. Inventory data was obtained through process simulation and used to assess the environmental performance of the process in terms of carbon footprint acidification freshwater eutrophication ozone depletion photochemical ozone formation and depletion of minerals and metals. Overall the environmental viability of the production of green hydrogen from biogas was found to be heavily dependent on the biogas leakage in anaerobic digestion plants. The CLDRM system was benchmarked against a conventional DRM implementation for the same feedstock. While the conventional DRM plant environmentally outperformed the perovskite-based CLDRM the latter might present advantages from an implementation point of view.

Increasing the share of renewable energy sources (RESs) in the energy mix of countries is one of the main objectives of the energy transition in national economies which must be established on circular economy principles. In the natural gas storage in geological structures (UGSs) natural gas is stored in a gas reservoir at high reservoir pressure. During a withdrawal cycle the energy of the stored pressurised gas is irreversibly lost at the reduction station chokes. At the same time there is a huge amount of produced reservoir water which is waste and requires energy for underground disposal. The manuscript explores harnessing the exergy of the conventional UGS reduction process to generate electricity and produce hydrogen via electrolysis using reservoir-produced water. Such a model which utilises sustainable energy sources within a circular economy framework is the optimal approach to achieve a clean energy transition. Using an innovative integrated mathematical model based on real UGS production data the study evaluated the application of a turboexpander (TE) for electricity generation and hydrogen production during a single gas withdrawal cycle. The simulation results showed potential to produce 70 tonnes of hydrogen per UGS withdrawal cycle utilising 700 m3 of produced field water. The analysis showed that hydrogen production was sensitive to gas flow changes through the pressure reduction station underscoring the need for process optimisation to maximise hydrogen production. Furthermore the paper considered the categorisation of this hydrogen as “green” as it was produced from the energy of pressurised gas a carbon-free process.

Combining electrolytic hydrogen production with wind–photovoltaic power can effectively smooth the fluctuation of power and enhance the schedulable wind–photovoltaic power which provides an effective solution to solve the problem of wind–photovoltaic power accommodation. In this paper the optimization operation strategy is studied for the wind–photovoltaic power-based hydrogen production system. Firstly to make up for the deficiency of the existing research on the multi-state and nonlinear characteristics of electrolyzers the three-state and power-current nonlinear characteristics of the electrolyzer cell are modeled. The model reflects the difference between the cold and hot starting time of the electrolyzer and the linear decoupling model is easy to apply in the optimization model. On this basis considering the operation constraints of the electrolyzer hydrogen storage tank battery and other equipment the optimization operation model of the wind–photovoltaic power-based hydrogen production system is developed based on the typical scenario approach. It also considers the cold and hot starting time of the electrolyzer with the daily operation cost as the goal. The results show that the operational benefits of the system can be improved through the proposed strategy. The hydrogen storage tank capacity will have an impact on the operation income of the wind–solar hydrogen coupling system and the daily operation income will increase by 0.32% for every 10% (300 kg) increase in the hydrogen storage tank capacity.

The article presents the application of the metalog family of probability distributions to predict the energy production of photovoltaic systems for the purpose of generating small amounts of green hydrogen in distributed systems. It can be used for transport purposes as well as to generate energy and heat for housing purposes. The monthly and daily amounts of energy produced by a photovoltaic system with a peak power of 6.15 kWp were analyzed using traditional statistical methods and the metalog probability distribution family. On this basis it is possible to calculate daily and monthly amounts of hydrogen produced with accuracy from the probability distribution. Probabilistic analysis of the instantaneous power generated by the photovoltaic system was used to determine the nominal power of the hydrogen electrolyzer. In order to use all the energy produced by the photovoltaic system to produce green hydrogen the use of a stationary energy storage device was proposed and its energy capacity was determined. The calculations contained in the article can be used to design home green hydrogen production systems and support the climate and energy transformation of small companies with a hydrogen demand of up to ¾ kg/day.

Low-cost green hydrogen production will be key in reaching net zero carbon emissions by 2050. Green hydrogen can be produced by electrolysis using renewable energy including wind energy. However the configuration of offshore wind-to-hydrogen systems is not yet standardised. For example electrolysis can take place onshore or offshore. This work presents a framework to assess and quantify which configuration is more resilient so that security of hydrogen supply is incorporated in strategic decisions with the following key findings. First resilience should be assessed according to hydrogen supply rather than hydrogen production. This allows the framework to be applicable for all identified system configurations. Second resilience can be quantified according to the quantity ratio and lost revenue of the unsupplied hydrogen.

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

With the increasingly severe climate change situation and the trend of green energy transformation the development and utilization of hydrogen energy has attracted extensive attention from government industry and academia in the past few decades. Renewable energy electrolysis stands out as one of the most promising hydrogen production routes enabling the storage of intermittent renewable energy power generation and supplying green fuel to various sectors. This article reviews the evolution and development of green hydrogen policies in the United States the European Union Japan and China and then summarizes the key technological progress of renewable energy electrolysis while introducing the progress of hydrogen production from wind and photovoltaic power generation. Furthermore the environmental social and economic benefits of different hydrogen production routes are analyzed and compared. Finally it provides a prospective analysis of the potential impact of renewable energy electrolysis on the global energy landscape and outlines key areas for future research and development.

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

The production of hydrogen from photovoltaics (PV) has gained attention due to its potential as an energy vector. In this context there are two basic configurations for electrically coupling PV to hydrogen electrolyzers: direct and indirect. The direct configuration operates variably based on meteorological conditions but has simplicity as an advantage. The indirect configuration involves a power stage (PS) with a maximum power point tracker and a DC-DC converter maintaining an optimal power transfer from PV to electrolyzers but incurs losses at the PS. The direct configuration avoids these losses but requires a specific design of the PV generator to achieve high electrical transfer. The comparative analysis of hydrogen production between these two approaches indicates that the indirect paradigm yields a 37.5% higher hydrogen output throughout a typical meteorological year compared to the optimized direct configuration. This increase enhances the overall sunlight-to-hydrogen efficiency elevating it from 5.0% in the direct case to 6.9% in the indirect one. Furthermore the direct setup sensitive to PV power fluctuations suffers an 18% reduction in hydrogen production with just a 5% reduction in photogenerated power. Under optimal performance the direct coupling produces less hydrogen unless the DCDC converter efficiency drops 17% below commercial standards.

Climate change is a major concern for the sustainable development of global energy systems. Hydrogen produced through water electrolysis offers a crucial solution by storing and generating renewable energy with minimal environmental impact thereby reducing carbon emissions in the energy sector. Our research evaluates current hydrogen production technologies such as alkaline water electrolysis (AWE) proton exchange membrane water electrolysis (PEMWE) solid oxide electrolysis (SOEC) and anion exchange membrane water electrolysis (AEMWE). We systematically review life cycle assessments (LCA) for these technologies analyzing their environmental impacts and recent technological advancements. This study fills essential gaps by providing detailed LCAs for emerging technologies and evaluating their scalability and environmental footprints. Our analysis outlines the strengths and weaknesses of each technology guiding future research and assisting stakeholders in making informed decisions about integrating hydrogen production into the global energy mix. Our approach highlights operational efficiencies and potential sustainability enhancements by employing comparative analyses and reviewing advancements in membrane technology and electrocatalysts. A significant finding is that PEMWE when integrated with renewable energy sources offers rapid response capabilities that are vital for adaptive energy systems and reducing carbon footprints.

Hydrogen energy is regarded as a key path to combat climate change and promote sustainable economic and social development. The fluctuation of renewable energy leads to frequent start/stop cycles in hydrogen electrolysis equipment. However electrochemical energy storage with its fast response characteristics helps regulate the power of hydrogen electrolysis enabling smooth operation. In this study a multi-objective constrained operation optimization model for a wind/battery storage/alkaline electrolyzer system is constructed. Both profit maximization and power abandonment rate minimization are considered. In addition some constraints such as minimum start/stop times upper and lower power limits and input fluctuation limits are also taken into account. Then the non-dominated sorting genetic algorithm II (NSGA-II) algorithm and the entropy method are used to optimize the operation strategy of the hybrid energy system by considering dynamic hydrogen production efficiency and through optimization to obtain the best hydrogen production power of the system under the two objectives. The change in dynamic hydrogen production efficiency is mainly related to the change in electrolyzer power and the system can be better adjusted according to the actual supply of renewable energy to avoid the waste of renewable energy. Our results show that the distribution of Pareto solutions is uniform which indicates the suitability of the NSGA-II algorithm. In addition the optimal solution indicates that the battery storage and alkaline electrolyzer can complement each other in operation and achieve the absorption of wind power. The dynamic hydrogen production efficiency can make the electrolyzer operate more efficiently which paves the way for system optimization. A sensitivity analysis reveals that the profit is sensitive to the price of hydrogen energy.

Green hydrogen generated via water electrolysis has become an essential energy carrier for achieving carbon neutrality globally because of its versatility in renewable energy consumption and decarbonization applications in hard-to-abate sectors; however there is a lack of systematic analyses of its abatement potential and economics as an alternative to traditional technological decarbonization pathways. Based on bibliometric analysis and systematic evaluation methods this study characterizes and analyzes the literature on the Web of Science from 1996 to 2023 identifying research hotspots methodological models and research trends in green hydrogen for mitigating climate change across total value chain systems. Our review shows that this research theme has entered a rapid development phase since 2016 with developed countries possessing more scientific results and closer partnerships. Difficult-to-abate sectoral applications and cleaner production are the most famous value chain links and research hotspots focus on three major influencing factors: the environment; techno-economics; and energy. Green hydrogen applications which include carbon avoidance and embedding to realize carbon recycling have considerable carbon reduction potential; however uncertainty limits the influence of carbon reduction cost assessment indicators based on financial analysis methods for policy guidance. The abatement costs in the decarbonization sector vary widely across value chains electricity sources baseline scenarios technology mixes and time scenarios. This review shows that thematic research trends are focused on improving and optimizing solutions to uncertainties as well as studying multisectoral synergies and the application of abatement assessment metrics.

Utilizing biological processes for hydrogen production via gasification is a promising alternative method to coal gasification. The present study proposes a dynamic simulation model that uses a one-dimensional heat-transfer analysis method to simulate a biohydrogen production system. The proposed model is based on an existing experimental design setup. It is used to simulate a biohydrogen production system driven by the waste heat from an integrated gasification combined cycle (IGCC) power plant equipped with carbon capture and storage technologies. The data from the simulated results are compared with the experimental measurement data to validate the developed model’s reliability. The results show good agreement between the experimental data and the developed model. The relative root-mean-square error for the heat storage feed-mixing and bioreactor tanks is 1.26% 3.59% and 1.78% respectively. After the developed model’s reliability is confirmed it is used to simulate and optimize the biohydrogen production system inside the IGCC power plant. The bioreactor tank’s time constant can be improved when reducing the operating volume of the feed-mixing tank by the scale factors of 0.75 and 0.50 leading to a 15.76% and 31.54% faster time constant respectively when compared with the existing design.

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

Meeting climate targets requires profound transformations in the energy system. Most energy uses should be electrified but where this is not feasible hydrogen can be part of the solution. However 98% of global hydrogen production involves greenhouse gas emissions with an average of 12 kg CO2e/kg H2. Therefore new hydrogen production pathways are needed in order to make hydrogen production compatible with climate targets. In this work we fill this gap by systematically comparing the energy and emissions intensity of 173 hydrogen production pathways suitable for the UK. Scenarios include onshore and offshore pathways and the use of repurposed infrastructure. Unlike fossil-fuel based pathways the results show that electrolytic hydrogen powered by fixed offshore wind could align with proposed emissions standards either onshore or offshore. However the embodied and fugitive emissions are important to consider for electrolytic pathways as they result in 10–50% of the total emissions intensity.

The electrolysis of water is one of the most promising ways of producing green hydrogen. This produces hydrogen using electricity and does not generate additional carbon dioxide like the more conventional reforming of fossil fuels. However making electrolysis competitive with conventional methods for hydrogen production is a challenge because of the cost of electricity and because of inefficiencies and costs in electrolysis systems. Initially this review looks at the basic design of water electrolysis and asks where energy is lost. Then a selection of the latest results in the area of magnetic field-enhanced water electrolysis are examined and discussed in particular focusing on the empirical results of magnetic field-assisted electrolysis with the aim of comparing findings and identifying limitations of current studies such that recommendations can be made for advanced design of hydrogen producing electrolysis systems.

This work presents a comparative novel evaluation of two distinct fuels methanol and hydrogen production and power generation routes via fuel cells. The first route includes the methanol production from direct partial oxidation of methane to methanol where the methanol is condensed stored and sent to a direct methanol fuel cell. The second route is hydrogen production from solar methane cracking (named as turquoise hydrogen) where heat is supplied from concentrated solar power and hydrogen is stored and directed to a hydrogen fuel cell. This study aims to provide insights into these fuel's production conditions storage methods energy and exergy efficiencies. The proposed system is simulated using the Engineering Equation Solver software and a thermodynamic analysis of the entire system including all the equipment and process streams is performed. The methanol and hydrogen route's overall energy and exergy efficiencies are 39.75% 38.35% 35.84% and 34.58% respectively. The highest exergy destruction rate of 1605 kW is observed for the partial oxidation of methane to methanol. The methanol and hydrogen routes generate 32.087 MWh and 11.582 MWh of electricity for 16-hour of fuel cell operation respectively. Sensitivity analysis has been performed to observe the effects of different parameters such as operating temperature and mass flow rate of fuels on the electricity production and energy efficiencies of the systems.

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

The present work aims to develop a novel integrated energy system to produce clean hydrogen power and biochar. The Palmaria palmata a type of seaweed and hydrogen sulfide from the industrial gaseous waste streams are taken as potential feedstock. A combined thermochemical approach is employed for the processing of both feedstocks. For clean hydrogen production the zinc sulfide thermochemical cycle is employed. Both stoichiometric and non-stoichiometric equilibrium-based models of the proposed plant design are developed in the Aspen Plus software and a comprehensive thermodynamic analysis of the system is also performed by evaluating energy and exergy efficiencies. The study further explores the modeling simulation and parametric analyses of various subsections to enhance the hydrogen and biochar production rate. The parametric analyses show that the first step of the thermochemical cycle (sulfurization reaction) follows stoichiometric pathway and the ZnO to H2S ratio of 1 represents the optimal point for reactant conversion. On the other hand the second step of the thermochemical cycle (regeneration reaction) does not follow a stoichiometric pathway and ZnS conversion of 12.87% is achieved at a high temperature of 1400oC. It is found that a hydrogen production rate of 0.71 mol/s is achieved with the introduction of 0.27 mol/s of H2S. The energy and exergy efficiencies of the zinc sulfide thermochemical cycle are found to be 65.23% and 35.58% respectively. A biochar production rate of 0.024 kg/s is obtained with the Palmaria palmata fed rate of 0.097 kg/s. The Palmaria to biochar energy and exergy efficiencies are found to be 55.43% and 45.91% respectively. The overall energy and exergy efficiencies of the proposed plant are determined to be 72.88% and 50.03% respectively.

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%.

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

A proton exchange membrane electrolyzer can effectively utilize the electricity generated by intermittent solar power. Different methods of generating electricity may have different efficiencies and hydrogen production rates. Two coupled systems namely PV/T- and CPV/T-coupling PEMEC respectively are presented and compared in this study. A maximum power point tracking algorithm for the photovoltaic system is employed and simulations are conducted based on the solar irradiation intensity and ambient temperature of a specific location on a particular day. The simulation results indicate that the hydrogen production is relatively high between 11:00 and 16:00 with a peak between 12:00 and 13:00. The maximum hydrogen production rate is 99.11 g/s and 29.02 g/s for the CPV/T-PEM and PV/T-PEM systems. The maximum energy efficiency of hydrogen production in CPV/T-PEM and PV/T-PEM systems is 66.7% and 70.6%. Under conditions of high solar irradiation intensity and ambient temperature the system demonstrates higher total efficiency and greater hydrogen production. The CPV/T-PEM system achieves a maximum hydrogen production rate of 2240.41 kg/d with a standard coal saving rate of 15.5 tons/day and a CO2 reduction rate of 38.0 tons/day. Compared to the PV/T-PEM system the CPV/T-PEM system exhibits a higher hydrogen production rate. These findings provide valuable insights into the engineering application of photovoltaic/thermal-coupled hydrogen production technology and contribute to the advancement of this field.

The use of green hydrogen as a high-energy fuel of the future may be an opportunity to balance the unstable energy system which still relies on renewable energy sources. This work is a comprehensive review of recent advancements in green hydrogen production. This review outlines the current energy consumption trends. It presents the tasks and challenges of the hydrogen economy towards green hydrogen including production purification transportation storage and conversion into electricity. This work presents the main types of water electrolyzers: alkaline electrolyzers proton exchange membrane electrolyzers solid oxide electrolyzers and anion exchange membrane electrolyzers. Despite the higher production costs of green hydrogen compared to grey hydrogen this review suggests that as renewable energy technologies become cheaper and more efficient the cost of green hydrogen is expected to decrease. The review highlights the need for cost-effective and efficient electrode materials for large-scale applications. It concludes by comparing the operating parameters and cost considerations of the different electrolyzer technologies. It sets targets for 2050 to improve the efficiency durability and scalability of electrolyzers. The review underscores the importance of ongoing research and development to address the limitations of current electrolyzer technology and to make green hydrogen production more competitive with fossil fuels.

The synergy between hydrogen and water is crucial in moving towards a sustainable energy future. This study explores the integration of geothermal energy with desalination and hydrogen production systems to address water and clean energy demands. Two configurations one using multi-effect distillation (MED) and the other reverse osmosis (RO) were designed and compared. Both configurations utilized geothermal energy with MED directly using geothermal heat and RO converting geothermal energy into electricity to power desalination. The systems are evaluated based on various performance indicators including net power output desalinated water production hydrogen production exergy efficiency and levelized costs. Multi-objective optimization using an artificial neural network (ANN) and genetic algorithm (GA) was conducted to identify optimal operational conditions. Results highlighted that the RO-based system demonstrated higher water production efficiency achieving a broader range of optimal solutions and lower levelized costs of water (LCOW) and hydrogen production while the MED-based system offered economic advantages under specific conditions. A case study focused on Canada illustrated the potential benefits of these systems in supporting hydrogen-powered vehicles and residential water needs emphasizing the significant impact of using high-quality desalinated water to enhance the longevity and efficiency of proton exchange membrane electrolyzers (PEME). This research provides valuable insights into the optimal use of geothermal energy for sustainable water and hydrogen production.

The present study comprehensively examines the application of hydro wave tidal undersea current and geothermal energy sources of Canada for green hydrogen fuel production. The estimated potential capacity of each province is derived from official data and acceptable assumptions and is subject to discussion and evaluation in the context of a viable hydrogen economy. According to the findings the potential for green hydrogen generation in Canada is projected to be 48.86 megatons. The economic value of the produced green hydrogen results in an equivalent of 21.30 billion US$. The top three provinces with the highest green hydrogen production potential using hydro resources including hydro wave tidal undersea current and geothermal are Alberta Quebec and British Columbia with 26.13 Mt 7.34 Mt and 4.39 Mt respectively. Quebec is ranked first by only considering the marine sources including 4.14 Mt with hydro 1.46 Mt with wave 0.27 Mt underwater current and 1.45 Mt with tidal respectively. Alberta is listed as the province with the highest capacity for hydrogen production from geothermal energy amounting up to 26.09 Mt. The primary objective is to provide comprehensive hydrogen maps for each province in Canada which will be based on the identified renewable energy potential and the utilization of electrolysers. This may further be examined within the framework of the prevailing policies implemented by local communities and officials in order to develop a sustainable energy plan for the nation.

Hydrogen has the capability of being a potential energy carrier and providing a long-term solution for sustainable lower-carbon and ecologically benign fuel supply. Because lower-carbon hydrogen is widely used in chemical synthesis it is regarded as a fuel with no emissions for transportation. This review paper offers a novel technique for producing hydrogen using wastewater in a sustainable manner. The many techniques for producing hydrogen with reduced carbon emissions from wastewater are recognized and examined in detail taking into account the available prospects significant obstacles and potential future paths. A comparison of the assessment showed that water electrolysis and dark fermentation technologies are the most effective methods for hydrogen generation from wastewater with microbial electrolysis and photofermentation. Thus the incorporation of systems that are simultaneously producing lower-carbon hydrogen and meant for wastewater treatment is important for the minimization of emissions from greenhouse gases and recovering the energy utilized in the treatment of wastewater.

While fossil fuels continue to be used and to increase air pollution across the world hydrogen gas has been proposed as an alternative energy source and a carrier for the future by scientists. Water electrolysis is a renewable and sustainable chemical energy production method among other hydrogen production methods. Hydrogen production via water electrolysis is a popular and expensive method that meets the high energy requirements of most industrial electrolyzers. Scientists are investigating how to reduce the price of water electrolytes with different methods and materials. The electrolysis structure equations and thermodynamics are first explored in this paper. Water electrolysis systems are mainly classified as high- and low-temperature electrolysis systems. Alkaline PEM-type and solid oxide electrolyzers are well known today. These electrolyzer materials for electrode types electrolyte solutions and membrane systems are investigated in this research. This research aims to shed light on the water electrolysis process and materials developments.

Hard-to-electrify sectors will require renewable fuels to facilitate the green transition in the future. Therefore it is crucial to identify promising production locations while taking into account the local biomass resources variable renewable energy sources and the synergies between sectors. In this study investments and dispatch operations are optimised of a large catalogue of renewable fuel production technologies in the opensource software SpineOpt and this is soft-linked to the comprehensive energy system model Balmorel. We analyse future production pathways by comparing various levels of hydrogen infrastructure including large-scale hydrogen storage and assess system impacts. The results indicate that methanol may provide synergies in its multipurpose use as an early (2030-2040) shipping fuel and later as an aviation fuel through further refining if ammonia becomes more competitive (2050). We furthermore show that a hydrogen infrastructure increases the competitiveness of non-flexible hydrogen-based fuel production technologies. Offshore electrolysis hubs decrease energy system impacts in scenarios with 105 TWh of Nordic hydrogen export. However hydrogen export scenarios are much costlier compared to scenarios with no export unless a high hydrogen price is received. Finally we find that emission taxes in the range of 250-265 euro/tCO2 will be necessary for renewable fuels to become competitive.

Oceanic energy sources notably offshore wind and wave power present a significant opportunity to generate green hydrogen through water electrolysis. This approach allows for offshore hydrogen production which can be efficiently transported through existing pipelines and stored in various forms offering a versatile solution to tackle the intermittency of renewable energy sources and potentially revolutionize the entire electrical grid infrastructure. This research focusses on assessing the technical and economic feasibility of this method in six strategic coastal regions in Morocco: Laayoune Agadir Essaouira Eljadida Casablanca and Larache. Our proposed system integrates offshore wind turbines oscillating water column wave energy converters and PEM electrolyzers to meet energy demands while aligning with global sustainability objectives. Significant electricity production estimates are observed across these regions ranging from 14 MW to 20 MW. Additionally encouraging annual estimates of hydrogen production varying between 20 and 40 tonnes for specific locations showcase the potential of this approach. The system’s performance demonstrates promising efficiency rates ranging from 13% to 18% while maintaining competitive production costs. These findings underscore the ability of oceanic energy-driven green hydrogen to diversify Morocco’s energy portfolio bolster water resilience and foster sustainable development. Ultimately this research lays the groundwork for comprehensive energy policies and substantial infrastructure investments positioning Morocco on a trajectory towards a decarbonized future powered by innovative and clean technologies.

Hydrogen has been receiving a lot of attention in the last few years since it is seen as a viable yet not thoroughly dissected alternative for addressing climate change issues namely in terms of energy storage and therefore great investments have been made towards research and development in this area. In this context a study about the main options for hydrogen production along with the analysis of a variety of the main power electronics converter topologies for such applications is presented as the purpose of this paper. Much of the analyzed available literature only discusses a few types of hydrogen production methods so it becomes crucial to include an analysis of all known types of methods for producing hydrogen according to their production type along with the color code associated with each type and highlighting the respective contextualization as well as advantages and disadvantages. Regarding the topologies of power electronics converters most suitable for hydrogen production and more specifically for green hydrogen production a list of them was analyzed through the available literature and a discussion of their advantages and disadvantages is presented. These topologies present the advantage of having a low ripple current output which is a requirement for the production of hydrogen.

The scientific and industrial communities worldwide have recently achieved impressive technical advances in developing innovative electrocatalysts and electrolysers for water and seawater splitting. The viability of water electrolysis for commercial applications however remains elusive and the key barriers are durability cost performance materials manufacturing and system simplicity especially with regard to running on practical water sources like seawater. This paper therefore primarily aims to provide a concise overview of the most recent disruptive water-splitting technologies and materials that could reshape the future of green hydrogen production. Starting from water electrolysis fundamentals the recent advances in developing durable and efficient electrocatalysts for modern types of electrolysers such as decoupled electrolysers seawater electrolysers and unconventional hybrid electrolysers have been represented and precisely annotated in this report. Outlining the most recent advances in water and seawater splitting the paper can help as a quick guide in identifying the gap in knowledge for modern water electrolysers while pointing out recent solutions for cost-effective and efficient hydrogen production to meet zero-carbon targets in the short to near term.

Global attention is being given to hydrogen as it is seen as a versatile energy carrier and a flexible energy vector in transitioning to a low-carbon economy. Hydrogen production/storage/conveyance is metal intensive and it is crucial to understand if there is material availability to fulfil the committed plans. Using the material intensity of electrolysers pipelines and desalinators along with the projected Portuguese and European Union roadmaps we are able to identify possible bottlenecks in the supply chains. The availability of the vast majority of raw materials does not represent a threat to hydrogen technologies implementation with electrolysers requiring almost up to 3 Mt of raw materials and pipelines up to 2.5 Mt. The evident exception is iridium although representing less than 0.001 % of the material requirements it may hinder the widespread implementation of proton exchange membrane electrolysers. Desalinators have the least material footprint of the studied infrastructure.