Policy & Socio-Economics

Green hydrogen is a promising energy vector for replacing fossil fuels in hard-to-abate sectors but its cost hinders widespread deployment. This research develops an exact MILP model to optimize the design of integrated green energy projects minimizing the total annual cost between different power configurations. The model is applied to a case study in regional Victoria Australia which supports a fleet of nine fuel cell electric buses requiring 1160 kg of hydrogen per week. The optimal system includes a 453 kW electrolyzer 212 kg of storage in compressed hydrogen vessels 704 kW of solar PV and 635 kW of wind power firmed with grid electricity. The LCOH is 14.8 A$/kg which is higher than other estimates in the literature for Australia. This is arguably due to the idle capacities resulting from intermittent hydrogen demand. Producing additional hydrogen with surplus or low-priced electricity could reduce LCOH to 12.4 A$/kg. Sensitivity analyzes confirm the robustness of the system to variations in key parameter costs resource availability and estimated energy supply and demand.

Increasing renewable energy technology penetration into electrical grids to meet net zero CO2 emission targets is a key challenge in terms of intermittency; one solution is the provision of sufficient energy storage. In the current study we considered future projections of electrical demand and renewable energy (in 2042) for the Southwest Interconnected System grid in Western Australia. Required energy storage considered is a mixture of battery energy storage systems and underground hydrogen storage in a depleted gas reservoir. The Southwest Interconnected System serves as an excellent case study given that it is a comparatively large isolated grid with substantial potential access to renewable energy resources as well as potential underground hydrogen storage sites. This work utilised a dynamic energy model that summates the wind and solar energy resources on an hourly basis. Excess energy utilised battery energy storage systems capacity first followed by underground hydrogen storage. The relative size of the renewables and the storage options is then optimised in terms of minimising wholesale energy production costs. This unique optimisation analysis across the full integrated system clearly indicated that both battery energy storage systems and underground hydrogen storage are required; underground hydrogen storage is predominately necessary to meet seasonal unmet energy demand that amounts to approximately 6% of total demand. Underground hydrogen storage costs were dominated by the required electrolyser requirements. The optimised levelised cost of electricity was found to be US$106/MWh which is approximately 45% larger than current wholesale electricity prices.

Biodiesel production through transesterification results in a large quantity of crude glycerol as a byproduct the utilization of which is technically and economically challenging. Because of the ability to efficiently process wet feedstocks supercritical water gasification (SCWG) is utilized in this study to convert crude glycerol into hydrogen-rich syngas. A significant challenge addressed through this study is the decomposition routes of different heterogeneous components of crude glycerol during SCWG. Pure glycerol methanol and oleic acid were investigated for SCWG as the model compounds of crude glycerol. SCWG of model compounds at temperature pressure feedstock concentration and reaction time of 500 ◦C 23–25 MPa 10 wt% and 1 h respectively revealed methanol to exhibit the highest H2 yield of 7.7 mmol/g followed by pure glycerol (4.4 mmol/g) and oleic acid (1.1 mmol/g). The effects of feedstock concentration from 30 wt% to 10 wt% increased H2 yield from all model compounds. Response surface methodology (RSM) was used to develop a response curve to visualize the interactive behavior and develop model equations for the prediction of H2 -rich gas yields as a function of the composition of model compounds in the crude glycerol mixture. Predictive models showed a good agreement with experimental results demonstrating high accuracy and robustness of the model. These findings demonstrated a strong potential of crude glycerol for SCWG to generate H2 -rich syngas.

Hydrogen is gaining interest as a clean energy source from both governments and fossil fuel companies. For hydrogen projects to succeed securing public acceptability is crucial with trust in the implementing actors playing a central role. Drawing from reputation management and attribution theory we experimentally evaluated whether people’s perceptions of energy companies wanting to start producing hydrogen for sustainability reasons differ based on two features of hydrogen production. Specifically we examined the influence of (1) the type of hydrogen (blue versus green) and (2) the energy company’s history in energy production (fossil fuels versus renewables) on perceptions about the companies’ reputation management efforts —that is the belief that companies adopt hydrogen primarily to improve their public image— as well as on levels of trust both overall and specifically in terms of integrity and competence. We further explored whether perceived reputation management explains the effects on trust and whether these factors also shape public acceptability of hydrogen production itself. Results indicated that people perceived the company with a history of working with fossil fuels as trying to improve its reputation more than one associated with renewables and trusted it less. Furthermore perceived reputation management explained the lower (general and integrity-based) trust people had in companies with a past in fossil fuels. For public acceptability of hydrogen the company’s history was not relevant with green hydrogen being more acceptable than blue regardless of which company produced it. We discuss these findings in relation to the literature on public perceptions of hydrogen.

For low-carbon hydrogen to become a viable decarbonization solution the creation of a robust and effective market is essential. This paper examines the applicability of market reforms from the renewable energy natural gas and liquefied natural gas (LNG) sectors with a focus on pricing mechanisms business models and infrastructure access to facilitate hydrogen market development. Applying the Structure-Conduct-PerformanceRegulation (SCP-R) framework and informed by stakeholder insights we identify critical enablers for advancing the hydrogen market formation. Our analysis highlights the importance of innovative pricing strategies and regulatory measures incentivizing investment and managing risks. Establishing a market reference price for low-carbon hydrogen — akin to benchmarks in the natural gas and LNG sectors—is critical for ensuring transparency predictability and regional adaptability in trade. Additionally customized business models are also needed to mitigate volume risks for producers. Government interventions such as offtake agreements and the development of hydrogen hubs are indispensable for fostering competition and driving decarbonization.

Demand for hydrogen is expected to increase in the coming years to defossilize hard-to-abate sectors. In the European Union the question remains in which quantities and at what cost hydrogen can be produced to satisfy the growing demand. This paper applies different approaches to model costs and potentials of off-grid hydrogen production within the European Union. The modeled approaches distinguish the effects of different spatial and technological resolutions on hydrogen production potentials costs and prices. According to the results the hydrogen potential within the European Union is above 6800 TWh. This figure far surpasses the expected demand range of 1423 to 1707 TWh in 2050. The cost of satisfying the demand exceeds 100 billion euro at marginal costs of hydrogen below 85 euro per megawatt-hour. Additionally the results show that an integrated European Union market would reduce the overall system costs notably compared to a setup in which each country covers its own hydrogen demand domestically. Just a few countries would be able to supply the entire European Union’s hydrogen demand in the case of an integrated market. This finding leads to the conclusion that an international hydrogen infrastructure seems advantageous.

Understanding what people think about hydrogen energy and how this influences their acceptance of the associated technology is a critical area of research. The public’s willingness to adopt practical applications of hydrogen energy such as hydrogen fuel-cell vehicles (HFCVs) is a key factor in their deployment. To analyse the direct and indirect effects of key attitudinal variables that could influence the intention to use HFCVs in Spain an online questionnaire was administered to a representative sample of the Spanish population (N = 1000). A path analysis Structural Equation Model (SEM) was applied to determine the effect of different attitudinal variables. A high intention to adopt HFCVs in Spain was found (3.8 out of 5) assuming their wider availability in the future. The path analysis results indicated that general acceptance of hydrogen technology and perception of its benefits had the greatest effect on the public’s intention to adopt HFCVs. Regarding indirect effects the role of trust in hydrogen technology was notable having significant mediating effects not only through general acceptance of hydrogen energy and local acceptance of hydrogen refuelling stations (HRS) but also through positive and negative emotions and benefits perception. The findings will assist in focusing the future hydrogen communication strategies of both the government and the private (business) sector.

Vietnam recognizes hydrogen as a key fuel for decarbonization under its National Hydrogen Strategy. Here we quantified the environmental and economic performance of Vietnam’s optimal hydrogen-production pathways by evaluating combinations of green and blue hydrogen under varying demand scenarios using life-cycle assessment and optimization modeling techniques. The environmental performance of hydrogen production proved highly sensitive to the electricity source with water electrolysis powered by renewable energy offering the most favorable outcomes. Although green hydrogen production reduced carbon emissions it shifted environmental burdens toward increased resource extraction. Producing 20 Mt of hydrogen by 2050 would require 741.56 TWh of electricity 178 Mt of water and USD 294 billion in investment and it would emit 50.48 Mt CO2. These findings highlight the importance of strategic hydrogen planning and resource strategy aligned with national priorities for energy transition to navigate trade-offs among technology selection emissions costs and resource consumption.

The Middle East and North Africa region has not played a major role in climate action so far and several countries depend economically on fossil fuel exports. However this is a region with vast solar energy resources which can be exploited affordably for power generation and hydrogen production at scale to eventually reach carbon neutrality. In this paper we elaborate on the case of the United Arab Emirates and explore the aspirations and feasibility of its net-zero by 2050 target. While we affirm the concept per se we also highlight the technological complexity and economic dimensions that accompany such transformation. We expect the UAE’s electricity demand to triple between today and 2050 and the annual green hydrogen production is expected to reach 3.5 Mt accounting for over 40% of the electricity consumption. Green hydrogen will provide power-to-fuel solutions for aviation maritime transport and hard-to-abate industries. At the same time electrification will intensify—most importantly in road transport and low-temperature heat demands. The UAE can meet its future electricity demands primarily with solar power followed by natural gas power plants with carbon capture utilization and storage while the role of nuclear power in the long term is unclear at this stage.

This study presents a techno-economic environmental risk analysis (TERA) of large-scale green hydrogen production using Alkaline Water Electrolysis (AWE) and Proton Exchange Membrane (PEM) systems. The analysis integrates commercial data market insights and academic forecasts to capture variability in capital expenditure (CAPEX) efficiency electricity cost and capacity factor. Using Libya as a case study 81 scenarios were modelled for each technology to assess financial and operational trade-offs. For AWE CAPEX is projected between $311 billion and $905.6 billion for 519 GW (gigawatts) of installed capacity equivalent to 600–1745 $/kW. PEM systems show a wider range of $612 billion to $1020 billion for 510 GW translating to 1200–2000 $/kW. Results indicate that AWE while requiring greater land use provides significant cost advantages due to lower capital intensity and scalability. In contrast PEM systems offer compact design and operational flexibility but at substantially higher costs. The five most economical scenarios for both technologies consistently feature low CAPEX and high efficiency while sensitivity analyses confirm these two parameters as the dominant cost drivers. The findings emphasise that technology choice should reflect context-specific priorities such as land availability budget and performance needs. This study provides actionable guidance for policymakers and investors developing cost-effective hydrogen infrastructure in emerging green energy markets.

Access to renewable energy is vital for rural development and climate change mitigation. The intermittency of renewable sources necessitates efficient energy storage especially in off-grid applications. This study evaluates the technical economic and environmental performance of an off-grid hybrid system for the rural settlement of Soma Turkey. Using HOMER Pro 3.14.2 software a system consisting of solar wind battery and hydrogen components was modeled under four scenarios with Cyclic Charging (CC) and Load Following (LF) control strategies for optimization. Life cycle assessment (LCA) and hydrogen leakage impacts were calculated separately through MATLAB R2019b analysis in accordance with ISO 14040 and ISO 14044 standards. Scenario 1 (PV + wind + battery + H2) offered the most balanced solution with a net present cost (NPC) of USD 297419 with a cost of electricity (COE) of USD 0.340/kWh. Scenario 2 without batteries increased hydrogen consumption despite a similar COE. Scenario 3 with wind only achieved the lowest hydrogen consumption and the highest efficiency. In Scenario 4 hydrogen consumption decreased with battery reintegration but COE increased. Specific CO2 emissions ranged between 36–45 gCO2-eq/kWh across scenarios. Results indicate that the control strategy and component selection strongly influence performance and that hydrogen-based hybrid systems offer a sustainable solution in rural areas.

Every five years as mandated in its founding regulation the European Environment Agency (EEA) publishes a state of the environment report. Europe's environment 2025 provides decision makers at European and national levels as well as the general public with a comprehensive and cross-cutting assessment on environment climate and sustainability in Europe. Europe's environment 2025 is the 7th state of the environment report published by the EEA since 1995. Europe's environment 2025 has been prepared in close collaboration with the EEA’s European Environment Information and Observation Network (Eionet). The report draws on the Eionet’s vast expertise of leading experts and scientists in the environmental field across the EEA’s 32 member countries and six cooperating countries.

This report supports the European Commission (DG ENER) in the design and implementation of a European import auction for renewable hydrogen and its derivatives under the European Hydrogen Bank (EHB). The EHB aims to contribute to the EU's climate neutrality goal by 2050. While domestic auctions have already been launched under the EHB its international leg focusing on renewable fuels of non-biological origin (RFNBO) imports from third countries remains to be designed. This report offers strategic recommendations based on hydrogen market analyses the assessment of existing and planned hydrogen auction schemes in Europe and beyond as well as preliminary considerations on auction design. The analysis highlights the potential for hydrogen imports from regions like North America Australia Latin America and the MENA region. It includes concrete case studies on both pipeline-based imports of pure hydrogen and ship-based imports of key derivatives (ammonia methanol and synthetic aviation fuels (eSAF) to reflect Member State preferences and provides a concrete starting point for further defining import auctions. Priority considerations for auction design include ensuring fair competition between domestic production and imports addressing geopolitical risks and achieving cost efficiency. The case studies serve as a flexible blueprint for implementing EHB import auctions considering Member State interests and aligning with the EU's broader objectives.

The governance of the EU energy sector has gradually evolved over time to reflect and support the closer integration of the Internal Electricity Market. As the EU energy sector faces new challenges both at the local and cross-border levels its governance might once again need to be reviewed to ensure that it remains fit for the future. This Policy Brief highlights three opportunities for streamlining the governance of the electricity (and gas) sector(s) at the cross-border level related to: (i) the ‘all TSOs’ or ‘all relevant TSOs’ processes; (ii) the regulatory oversight of EU-wide entities; and (iii) the operation of the electricity market coupling. Other areas for improvement in the current governance framework may also emerge and one suggestion relates to the dual role of the ENTSOs both as (i) entities responsible for a number of essential tasks for the energy sector and (ii) associations with TSOs as their members.

Insular regions face unique energy management challenges due to physical isolation. Graciosa (Azores) has high renewable energy sources (RES) potential theoretically enabling a 100% green system. However RES intermittency combined with the lack of energy storage solutions reduces renewable penetration and raises curtailment. This article studies the technical and economic feasibility of producing green hydrogen from curtailment energy in Graciosa through two distinct case studies. Case Study 1 targets maximum renewable penetration with green hydrogen serving as chemical storage converted back to electricity via fuel cells during RES shortages. Case Study 2 focuses on maximum profitability where produced gases are sold to monetize curtailment without additional electricity production. Levelized Cost of Hydrogen (LCOH) values of €3.06/kgH2 and €2.68/kgH2 respectively and Internal Rate of Return (IRR) values of 3.7% and 17.1% were obtained for Case Studies 1 and 2 with payback periods of 15.2 and 6.1 years. Hence only Case Study 2 is economically viable but it does not allow increasing the renewable share in the energy mix. Sensitivity analysis for Case Study 1 shows that overall efficiency and CAPEX are the main factors affecting viability highlighting the need for technological advances and economies of scale as well as the importance of public funding to promote projects like this.

This report aims to summarise the status of the European hydrogen policy landscape. It is based on the information available at the European Hydrogen Observatory (EHO) website the leading source of data on hydrogen in Europe. The data presented in this report is based on research conducted by Hydrogen Europe until the end of July 2024 but also goes beyond this timeline for major policies legislations or standards implemented recently. This report builds upon the previous version published in April 2024 which reflected data as of August 2023 providing updated insights on European policies and legislation national strategies national policies and legislation and codes and standards. Interactive data dashboards can be accessed on the website: https://observatory.cleanhydrogen.europa.eu/ The EU policies and legislation section provides insights into the main European policies and legislation relevant to the hydrogen sector which are briefly summarized on content and their potential impact to the sector. The national hydrogen strategies chapter offers a comprehensive examination of the hydrogen strategies adopted in Europe. It summarizes the quantitative indicators that have been published (targets and estimates) and provides brief summaries of the different national strategies that have been adopted. The section referring to national policies and legislation focuses on the policy framework measures incentives and targets in place that have an impact on the development of the respective national hydrogen markets within Europe. The codes and standards section provides information on current European standards and initiatives developed by the standardisation bodies including CEN CENELEC ISO IEC OIML The standards are categorised according to the different stages of the hydrogen value chain: production distribution and storage and end-use applications.

Hydrogen’s promise as a transformative energy solution has been consistently unfulfilled. This perspective article suggests that the primary barrier is not necessarily technological but a systemic failure to apply holistic systems thinking and genuine interdisciplinary collaboration. Through historical analysis and contemporary case studies we argue that only by integrating technical economic policy and social expertise within a holistic systems framework across the entire value chain can hydrogen overcome its boom-and-bust cycles and become a foundational component of the low-carbon energy future.

We develop a bidding strategy for a hybrid power plant combining co-located wind turbines and an electrolyzer constructing a price-quantity bidding curve for the day-ahead electricity market while optimally scheduling hydrogen production. Without risk management single imbalance pricing leads to an all-or-nothing trading strategy which we term “betting”. To address this we propose a data-driven pragmatic approach that leverages contextual information to train linear decision policies for both power bidding and hydrogen scheduling. By introducing explicit risk constraints to limit imbalances we move from the all-or-nothing approach to a “trading” strategy where the plant diversifies its power trading decisions. We evaluate the model under three scenarios: when the plant is either conditionally allowed always allowed or not allowed to buy power from the grid which impacts the green certification of the hydrogen produced. Comparing our data-driven strategy with an oracle model that has perfect foresight we show that the risk-constrained data-driven approach delivers satisfactory performance.

As global demand for green hydrogen rises potential hydrogen exporters move into the spotlight. While exports can bring countries revenue large-scale on-grid hydrogen electrolysis for export can profoundly impact domestic energy prices and energy-related emissions. Our investigation explores the interplay of hydrogen exports domestic energy transition and temporal hydrogen regulation employing a sector-coupled energy model in Morocco. We find substantial co-benefits of domestic carbon dioxide mitigation and hydrogen exports whereby exports can reduce market-based costs for domestic electricity consumers while mitigation reduces costs for hydrogen exporters. However increasing hydrogen exports in a fossil-dominated system can substantially raise market-based costs for domestic electricity consumers but surprisingly temporal matching of hydrogen production can lower these costs by up to 31% with minimal impact on exporters. Here we show that this policy instrument can steer the welfare (re-)distribution between hydrogen exporting firms hydrogen importers and domestic electricity consumers and hereby increases acceptance among actors.

The utilisation of renewable energy sources for hydrogen production is increasingly vital for ensuring the long-term sustainability of global energy systems. Currently the Sultanate of Oman is actively integrating renewable energy particularly through the deployment of solar photovoltaic (PV) systems as part of its ambitious targets for the forthcoming decades. Also Oman has target to achieve 1 million tonnes of green-H2 production annually. Leveraging Oman's abundant solar resources to produce green hydrogen and promote the clean transportation industry could significantly boost the country's sustainable energy sector. This paper outlines a standalone bifacial solar-powered system designed for large-scale green hydrogen (H2) production and storage to operate both a hydrogen refuelling station and an electric vehicle charging station in Sohar Oman. Using HOMER software three scenarios: PV/Hydrogen/Battery PV/Hydrogen PV/Battery systems were compared from a techno-economic perspective. Also the night-time operation (Battery/Hydrogen) was investigated. Varying cost of electricity were obtained depending on the system from $3.91/kWh to $0.0000565kWh while the bifacial PV/Hydrogen/Battery system emerged as the most efficient option boasting a unit cost of electricity (COE) of $3.91/kWh and a levelized cost of hydrogen (LCOH) value of $6.63/kg with net present cost 199M. This system aligns well with Oman's 2030 objectives with the capacity to generate 1 million tonnes of green-H2 annually. Additionally the findings show that the surplus electricity from the system could potentially cover over 30% of Oman's total energy consumption with zero harmful emissions. The implementation of this system promises to enhance Oman's economic and transportation industries by promoting the adoption of electric and fuel cell vehicles while reducing reliance on traditional energy sources.

Introduction: The implementation of national hydrogen strategies targeting zero-emission goals has sparked public discussions regarding energy and environmental communication. However gaining societal acceptance for hydrogen technology poses a significant challenge in numerous countries. Hence this research investigates the framing of hydrogen technology through a comparative analysis of opinion-leading newspapers in Germany Saudi Arabia the United Arab Emirates and Egypt. Methods: Utilizing a quantitative framing analysis based on Entman’s framing approach this research systematically identifies media frames and comprehend their development through specific frame characteristics. A factor analysis identified six distinct frames: Hydrogen as a Sustainable Energy Solution Benefits of Economic and Political Collaboration Technological and Scientific Challenges Governance Issues and Energy Security Industrial and Climate Solutions and Economic Risk. Results: The findings reveal that newspapers frames vary significantly due to contextual factors such as national hydrogen strategies media systems political ideologies article types and focusing events. Specifically German newspapers display diverse and balanced framing in line with its pluralistic media environment and national emphasis on green hydrogen and energy security while newspapers from MENA countries primarily highlight economic and geopolitical benefits aligned with their national strategies and state-controlled media environments. Additionally the political orientation of newspapers affects the diversity of frames particularly in Germany. Moreover non-opinion articles in Germany exhibit greater framing diversity compared to opinion pieces while in the MENA region the framing remains uniform regardless of article type due to centralized media governance. A notable shift in media framing in Germany was found after a significant geopolitical event which changed the frame from climate mitigation to energy security. Discussion: This study underscores the necessity for theoretical and methodological thoroughness in identifying frames as well as the considerable impact of contextual factors on the media representation of emerging sustainable technologies.

Under the constraints of the “dual carbon” goals accurately depicting the full life cycle carbon footprint of green hydrogen and its derivatives and quantifying the potential for emission reduction is a prerequisite for hydrogen energy policy and investment decisions. This paper constructs a unified life cycle model covering the entire process from “wind and solar power generation–electrolysis of water to producing hydrogen-synthesis of methanol/ammonia-terminal transportation” and includes the manufacturing stage of key front-end equipment and the negative carbon effect of CO2 capture within a single system boundary and also presents an empirical analysis. The results show that the full life cycle carbon emissions of wind power hydrogen production and photovoltaic hydrogen production are 1.43 kgCO2/kgH2 and 3.17 kgCO2/kgH2 respectively both lower than the 4.9 kg threshold for renewable hydrogen in China. Green hydrogen synthesis of methanol achieves a net negative emission of −0.83 kgCO2/kgCH3OH and the emission of green hydrogen synthesis of ammonia is 0.57 kgCO2/kgNH3. At the same time it is predicted that green hydrogen green ammonia and green methanol can contribute approximately 1766 66.62 and 30 million tons of CO2 emission reduction respectively by 2060 providing a quantitative basis for the large-scale layout and policy formulation of the hydrogen energy industry.

Hydrogen Valley represents localised ecosystems that enable the integrated production storage distribution and utilisation of hydrogen to support the decarbonisation of the energy system. However planning such integrated systems necessitates a detailed evaluation of their interconnections with variable renewable generation sector coupling and system flexibility. The novelty of this work lies in addressing a critical gap in system-level modelling for Hydrogen Valleys by introducing an optimization-based framework to determine their optimal configuration. This study focuses on the scenario-based multiobjective design of local hydrogen energy systems considering renewable integration infrastructure deployment and sector coupling. We developed and simulated three scenarios based on varying hydrogen pathways and penetration levels using the EnergyPLAN model implemented through a custom MATLAB Toolbox. Several decision variables such as renewable energy capacity electrolyser size and hydrogen storage were optimised to minimise CO₂ emissions total annual system cost and critical excess electricity production simultaneously. The findings show that Hydrogen Valley deployment can reduce CO₂ emissions by up to 30 % triple renewable penetration in the primary energy supply and lower the levelized cost of hydrogen from 7.6 €/kg to 5.6 €/kg despite a moderate increase in the total cost of the system. The approach highlights the potential of sector coupling and Power-to-X technologies in enhancing system flexibility and supporting green hydrogen integration. The outcome of our research offers valuable insights for policymakers and planners seeking to align local hydrogen strategies with broader decarbonisation targets and regulatory frameworks.

Transitioning to renewable energy is vital to achieving decarbonization at the global level but energy storage is still a major challenge. This review discusses the role of energy storage in the energy transition and the blue economy focusing on technological development challenges and directions. Effective storage is vital for balancing intermittent renewable energy sources like wind solar and marine energy with the power grid. The development of battery technologies hydrogen storage pumped hydro storage and emerging technologies like sodium-ion and metal-air batteries is discussed for their potential for large-scale deployment. Shortages in critical raw materials environmental impact energy loss and costs are some of the challenges to large-scale deployment. The blue economy promises opportunities for offshore energy storage notably through ocean thermal energy conversion (OTEC) and compressed air energy storage (CAES). Moreover the capacity of datadriven optimization and artificial intelligence to enhance storage efficiency is discussed. Policy interventions and economic incentives are necessary to spur the development and deployment of sustainable energy storage technology. Education and workforce training are also important in cultivating future researchers engineers and policymakers with the ability to drive energy innovation. Merging sustainability training with an interdisciplinary approach can potentially establish an efficient workforce that is capable of addressing energy issues. Future work needs to focus on higher energy density efficiency recyclability and cost-effectiveness of the storage technologies without sacrificing their environmental sustainability. The study underlines the need for converging technological economic and educational approaches to enable a sustainable and resilient energy future.

The climate crisis and global warming have created an urgent need for the scalable adoption of affordable and clean energy sources to achieve net-zero carbon emissions by 2050. Decarbonization of global industries is critical to achieving the targets of the Paris Agreement and the United Nations Sustainable Development Goals (especially Goals 7 and 13). Green hydrogen is becoming a key solution in the transition to renewable energy and the decarbonization with low-carbon energy options. This review presents an overview of the status and trends of hydrogen production storage transportation and application as well as key research areas with a forward-looking perspective to 2050. It explores the key challenges such as limited infrastructure high production costs and heavy energy demands. The study also identifies the drivers and barriers influencing hydrogen adoption across utility-scale electricity generation heating and niche markets. Key actions of governments in these pillar areas are necessary to accelerate hydrogen deployment through strategic investments and a policy framework to reduce technological costs and drive innovation. Transformative innovation in power generation transportation industrial processes and infrastructure will be essential to achieving deep decarbonization. In addition progress in digitalization automation data-driven decision-making recycling incentives and circular economies are essential to a social transformation and a global transition toward sustainability. Emerging hydrogen markets are also playing an increasingly dominant role in economic and human development particularly in low- and middle-income countries as the world works to transition to the use of renewable hydrogen.

As the European countries strive to meet their ambitious climate goals renewable hydrogen has emerged to aid in decarbonizing energy-intensive sectors and support the overall energy transition. To ensure that hydrogen production aligns with these goals the European Commission has introduced criteria for additionality temporal correlation and geographical correlation. These criteria are designed to ensure that hydrogen production from renewable sources supports the growth of renewable energy. This study assesses the impact of these criteria on green hydrogen production focusing on production costs and technology impacts. The European energy market is simulated up to 2048 using stochastic programming applying these requirements exclusively to green hydrogen production without the phased-in compliance period outlined in the EU regulations. The findings show that meeting the criteria will increase expected system costs by €82 billion from 2024 to 2048 largely due to the rapid shift from fossil fuels to renewable energy. The additionality requirement which mandates the use of new renewable energy installations for electrolysis proves to be the most expensive but also the most effective in accelerating renewable energy adoption.

China’s dual-carbon goals have positioned hydrogen as a central pillar of its energy transition. This review examines the recent development of China’s hydrogen supply chain with particular focus on manufacturing technologies for alkaline electrolysers high-pressure cylinders and diaphragm compressors. In 2024 China produced 36.5 million tons of hydrogen of which 77 % was grey and only 1 % derived from electrolysis. Storage and transportation account for nearly 30 % of end-use costs while reliance on imported compressors increases refuelling station expenses by approximately 40 %. We identify key bottlenecks including limited electrolyser efficiency the high cost of carbon fibres for Type III/IV cylinders and insufficient domestic capacity for highreliability compressors. To address these challenges targeted advances are proposed: membrane materials with engineered hydrophilicity advanced surface modifications and hydrophilic inhibitors; liner design incorporating grooved-liner braided layers with double-fibre configurations; and a three-layer diaphragm compressor architecture. By consolidating fragmented studies this review provides the integrated manufacturing perspective on China’s hydrogen supply chain offering both scientific insights and practical guidance for accelerating costeffective large-scale low-carbon hydrogen deployment.

A lot of countries have recently published updated hydrogen strategies with many of them increasing and renewing their commitment. In parallel corresponding policy mechanisms are increasingly coming into focus with the first ones already having awarded funding contracts to projects and construction being underway. However these policies are usually translated from renewable energy policy without considering the specific risks and uncertainties spillovers and positive externality of operating grid-conducive electrolyzers in electricity grids which are increasingly subjected to electricity supply volatility from renewables. This article details how different aspects of a dedicated hydrogen policy can address the technology’s specific issues from an economic perspective namely funding provision market and technology risk mitigation and the complex relationship with further actors in electricity markets. Results show that compared to renewable energy policy mechanisms need to emphasize the input side more strongly as price risks and intermittency from electricity markets are more prominent than from hydrogen markets. Also it proposes a targeted mechanism to capture the positive externality of mitigating excess electricity in the grid while keeping investment security high. Economic policy should consider such approaches before scaling support and avoiding the design shortcomings experienced with early RE policy.

Discussions about the transition to hydrogen in various applications have become an important topic in recent years. A key factor for an effective transition is public acceptance of hydrogen technologies. However the increase in acceptance depends among other things on individual knowledge about the hydrogen colors and the linked hydrogen production pathways currently under discussion. In communications colors such as green grey and blue are used to distinguish hydrogen sources. With new research additional colors have become necessary. Unfortunately there is no unified definition for the colors. The aim of this perspective is to identify the most frequent hydrogen colors used by scientists and the public derive open definitions and propose a solution to a representation problem. The general use of hydrogen colors in communication and the implications on public acceptance are briefly outlined. We then identified definitions for colors associated with a specific pathway and discussed some discrepancies between science and media use. To make better use of the existing colors more open definitions were formulated. We point out the representation problem with shades of a color and provide a connection between the assigned color and a view-independent RGB color code as proposal. The derived definitions can be used to unify communication in science and public media.

The ongoing digitalization of energy infrastructure is a crucial enabler for improving efficiency reliability and sustainability in gas distribution networks especially in the context of decarbonization and the integration of alternative energy carriers (e.g. renewable gases including biogas green hydrogen). This study presents the development and application of a Digital Twin framework for a real-world gas distribution network developed using open-source tools. The proposed methodology covers the entire digital lifecycle: from data acquisition through smart meters and GIS mapping to 3D modelling and simulation using tools such as QGIS FreeCAD and GasNetSim. Consumption data are collected processed and harmonized via Python-based workflows hourly simulations of network operation including pressure flow rate and gas quality indicators like the Wobbe Index. Results demonstrate the effectiveness of the Digital Twin in accurately replicating real network behavior and supporting scenario analyses for the introduction of greener energy vectors such as hydrogen or biomethane. The case study highlights the flexibility and transparency of the workflow as well as the critical importance of data quality and availability. The framework provides a robust basis for advanced network management optimization and planning offering practical tools to support the energy transition in the gas sector.

Energy in the microwave spectrum is increasingly applied in clean energy technologies. This review discusses recent innovations using microwave fields in hydrogen production and synthesis of new battery materials highlighting the unique properties of microwave heating. Key innovations include microwave-assisted hydrogen generation from water hydrocarbons and ammonia and the synthesis of high-performance anode and cathode materials. Microwave-assisted catalytic water splitting using Gd-doped ceria achieves efficient hydrogen production below 250°C. For hydrocarbons advanced microwave-active catalysts Fe–Ni alloys and ruthenium nanoparticles enable high conversion rates and hydrogen yields. In ammonia synthesis microwaves reduce the energy demands of the Haber–Bosch process and enhance hydrogen production efficiency using catalysts such as ruthenium and Co2Mo3N. In battery technology microwave-assisted synthesis of cathode materials like LiFePO4 and LiNi0.5Mn1.5O4 yields high-purity materials with superior electrochemical performance. Developing nanostructured and composite materials including graphene-based anodes significantly improves battery capacities and cycling stability. The ability of microwave technology to provide rapid selective heating and enhance reaction rates offers significant advancements in clean energy technologies. Ongoing research continues to bridge theoretical understanding and practical applications driving further innovations in this field. This review aims to highlight recent advances in clean energy technologies based upon the novel use of microwave energy. The potential impact of these emerging applications is now being fully understood in areas that are critical to achieving net zero and can contribute to the decarbonization of key sectors. Notable in this landscape are the sectors of hydrogen fuel and battery technologies. This review examines the role of microwaves in these areas.

Hydrogen energy one of the renewable energy sources plays a crucial role in combating climate change since its usage aims to reduce carbon emissions and enhance energy security. As the global energy trend moves toward cleaner alternatives countries start to adapt their energy strategies. In this transition hydrogen is one of the energy sources with the potential to increase long-term energy security. Developing countries face challenges such as high energy import dependency rising industrial demand and the need for infrastructure modernization making hydrogen valleys one of the viable solutions since they integrate hydrogen production storage distribution and utilization at one facility. However establishing small-scale hydrogen valleys requires a comprehensive decision-making strategy consisting of technical financial environmental social and political factors while addressing uncertainties in the system. To systematically manage the process this study proposes a Z-numberbased fuzzy cognitive mapping approach which models the interdependencies among success factors supported by Z-number Decision-Making Trial and Evaluation Laboratory for structured prioritization with a multi-expert perspective. The results indicate that Financial Factors emerged as the most critical category with Government Incentives Infrastructure Investment Cost and Land Acquisition Cost ranking as the top three sub-success factors. Availability of Skilled Workforce and Regional Energy Supply followed in importance which demonstrates the importance of social and technical dimensions in the hydrogen valley development. These findings demonstrate the critical role of policy support infrastructure readiness and workforce availability in the design process. Sensitivity analyses are also conducted to present robustness of the given decisions for the analysis of the results. Based on the results and analyses possible implications based on the policy and practical dimensions are also discussed. By integrating fuzzy logic and Z-numbers the study aims to minimize loss of information enhances the analytical background for decision-making and provides a strategic roadmap for hydrogen valley development.

Bioenergy is a promising alternative to fossil fuels-based energy with significant potential to transform global energy systems and promote environmental sustainability. This review provides a comprehensive overview of the evolution of bioenergy emphasizing its role in the global transition to sustainable energy. It explores a diverse range of biomass sources including forest and agricultural residues algae and industrial by-products and their conversion into energy via thermochemical biochemical and physicochemical pathways. The paper also highlights recent technological advancements and assesses the environmental sustainability of bioenergy systems. Additionally it examines key challenges hindering bioenergy development such as feedstock logistics technological limitations economic viability and policy gaps that need resolution to fully realise its potential. By synthesizing literature from 2010 to 2025 the review identifies strategic priorities for research and deployment aiming to inform efforts that align bioenergy utilization with global decarbonization goals.

To meet decarbonization targets demand for low-emission hydrogen is increasing. A considerable share of supply will come from latecomer countries. We study how latecomer countries and firms participate in the emerging global low-emission hydrogen economy and how industrial policies can help maximize societal benefits. This requires a specific conceptualization of industrial policy: First the latecomer condition calls for specific policy mixes as latecomers typically cannot build on established innovation systems and network externalities and rather need to combine FDI attraction with measures strengthening absorptive capacity and ensuring knowledge transfer from FDI to domestic firms; second low-emission hydrogen is a policy-induced alternative that requires creating entirely new firm ecosystems while competing with lower-cost emission-intensive incumbent technologies. Hence industrial policies need to account for enhanced coordination failure and internalization of environmental costs. We analyze the published national hydrogen strategies of 20 latecomer economies and derive a novel typology differentiating four hydrogen-specific industrial development pathways. For each pathway we assess entry barriers and risks identify the policies suggested in the country strategies and discuss how likely those are to be successful. The novel pathway typology and comparison of associated policy mixes may help policymakers maximize the gains of hydrogen investments.