Breakthroughs in Hydrogen and Storage Technologies for a Resilient Grid

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Atinkut This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8255422/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The transition to global energy systems necessitates advanced storage solutions that facilitate large-scale integration of renewables and enhance system resilience. Hydrogen and cutting-edge storage technologies have become pivotal in the decarbonization efforts of power systems, industry, and transportation. This review offers a multidisciplinary evaluation of recent progress in green hydrogen production, storage of hydrogen in solid, liquid, and gaseous states, and applications of fuel cells. It also examines advancements in electrochemical storage, including solid-state batteries, flow batteries, metal–air concepts, and hybrid hydrogen–battery systems. A comprehensive analysis of peer-reviewed literature from 2018 to 2024 assesses the maturity, scalability, sustainability impacts, and policy support of these technologies across different global regions. The review identifies gaps in infrastructure readiness, challenges in hybrid system integration, inadequate lifecycle assessment methods, and uneven socio-environmental outcomes. It underscores significant differences in policy and investment signals: advanced economies provide more stable frameworks, whereas many developing regions encounter structural barriers that hinder deployment. Based on these insights, the study proposes a strategic framework across five areas: alignment of technologies with infrastructure, integrated system design, effective market and policy tools, circular lifecycle pathways, and inclusive governance. This framework connects scientific innovation with regulatory decisions and social impact, promoting the coordinated deployment of hydrogen and advanced storage technologies as crucial enablers of resilient, equitable, and zero-carbon energy systems. Energy Engineering Renewable Resources Hydrogen storage green hydrogen battery technologies solid-state batteries hybrid energy systems system integration energy policy circular economy energy justice Figures Figure 1 Figure 2 Figure 3 1. Introduction The growing penetration of variable renewable energy (VRE) sources—particularly solar and wind—has intensified the global focus on storage technologies capable of ensuring system flexibility, grid reliability, and cross-sectoral integration. Among these, hydrogen and next-generation storage systems emerge as critical pillars in the shift toward resilient and carbon-neutral energy infrastructures. Governments and international institutions are increasingly incorporating hydrogen into national energy strategies. The United States, through its National Clean Hydrogen Strategy and Roadmap , sets a target of producing clean hydrogen at $ 1/kg by 2030, supported by initiatives such as hydrogen hubs and federal tax credits (U.S. Department of Energy, 2023). In parallel, the European Union’s REPowerEU plan aims to produce or import at least 20 million tonnes of renewable hydrogen by 2030, backed by funding for electrolyzer capacity, infrastructure, and regulatory harmonization (European Commission, 2022). Globally, the International Partnership for Hydrogen and Fuel Cells in the Economy (IPHE) fosters policy alignment and collaborative research across key hydrogen economies (IPHE, 2021). Despite these high-level ambitions, however, implementation lags: only about 7% of announced green hydrogen projects globally have reached final investment decision (IEA, 2024), highlighting a persistent gap between targets and realization. Scientific research is making significant progress across the hydrogen value chain, particularly in production, storage, and end-use integration. Advancements in electrolyzer efficiency, the use of sustainable catalysts, and decentralized production models are rapidly improving the viability of green hydrogen (Zhang et al., 2023). Storage technologies, including compressed hydrogen, liquid hydrogen, solid-state metal hydrides, and underground geological storage, have shown promising potential in improving volumetric density, safety, and system scalability (Al-Mufachi et al., 2023). In parallel, research into battery innovations—such as solid-state, redox flow, and metal-air batteries—opens new possibilities for long-duration storage solutions (Chen et al., 2021). These developments are crucial for stabilizing grids, mitigating renewable intermittency, and enabling high levels of renewable penetration in sectors like transport, industry, and residential heating. Technological convergence is also emerging: hybrid storage systems combining batteries and hydrogen—such as the Calistoga Resiliency Center in California—demonstrate how diversified storage portfolios can meet peak demand and ensure resilience during power outages. Despite progress, several research and implementation gaps remain. High capital costs and technological uncertainty continue to hinder the commercial viability of hydrogen and advanced storage systems (IEA, 2024). Infrastructure remains underdeveloped, with limited pipeline networks, hydrogen-ready grids, and refueling stations, particularly in developing regions (IRENA, 2023). On the technical side, challenges persist in optimizing material behavior for safe, efficient storage and in managing the dynamic interaction of hybrid systems under variable load conditions (Rahman et al., 2022). Moreover, policy support, while expanding, often lacks long-term clarity, integrated planning, and mechanisms to de-risk investment. Without coherent regulatory and financial frameworks, even the most advanced technologies face stagnation in deployment. This review addresses these gaps by offering a comprehensive and interdisciplinary synthesis of recent advances in hydrogen and energy storage technologies. First, we map the current landscape of hydrogen production and storage methods, assessing technical maturity, economic feasibility, and scalability. Second, we evaluate the evolution of global policy frameworks, identifying best practices and systemic barriers in the U.S., EU, and emerging markets. Third, we highlight case studies that demonstrate the practical integration of hydrogen and battery systems in microgrids, industrial hubs, and urban infrastructures. Fourth, we analyze key research priorities—including the development of underground hydrogen storage (UHS), AI-driven system control, and lifecycle sustainability metrics—to guide future innovation. Finally, we propose a strategic roadmap for aligning technology, infrastructure, and policy to close the ambition–implementation gap and enable large-scale deployment of resilient energy storage systems. By bridging science, policy, and practical deployment, this review contributes to a deeper understanding of how hydrogen and next-generation storage technologies can jointly underpin a flexible, secure, and decarbonized global energy future. The radar chart visualizes key focus areas in hydrogen and energy storage systems, comparing perceived barriers (solid line) with current innovation potential (dashed line). Key Insights: Hydrogen Storage and Infrastructure face the highest barriers. Hybrid Systems show high innovation momentum but still encounter deployment challenges. Battery Storage appears more mature, with moderate barriers and consistent innovation. Policy & Investment needs stronger support to match technological readiness. 2. Methodology This review follows a structured and interdisciplinary methodology designed to synthesize current advancements, integration barriers, and innovation trajectories related to hydrogen and advanced energy storage systems. The approach is divided into three sequential phases: (i) systematic literature identification, (ii) thematic coding and classification, and (iii) synthesis and validation through cross-analysis. This design enables the review to bridge the gap between scientific development, infrastructural readiness, and global policy initiatives (Tranfield et al., 2003). The first phase consisted of a systematic literature search using databases such as Scopus, Web of Science, ScienceDirect, ISI, IEEE, and Google Scholar. We constructed Boolean search strings including: "hydrogen storage" AND "grid integration" , "battery technology" AND "resilience" , and "policy support" AND "hydrogen economy" . This resulted in an initial dataset of 520 documents published between 2018 and 2024. The selection criteria focused on empirical studies, modeling-based analysis, policy evaluations, and real-world case studies. Studies focusing exclusively on fossil-based hydrogen (e.g., grey or blue hydrogen), non-scalable lab experiments, or lacking methodological transparency were excluded. After filtering, a final corpus of 119 peer-reviewed articles, reports from international agencies, and technical white papers was established for deep review (Kitchenham & Charters, 2007). In the second phase, we employed a thematic analysis approach to classify the literature into six core clusters: ( 1 ) hydrogen production technologies, ( 2 ) hydrogen storage systems (compressed, liquefied, solid-state, and underground), ( 3 ) advanced battery technologies (solid-state, flow, and metal-air), ( 4 ) hybrid systems combining hydrogen and battery storage, ( 5 ) infrastructure and grid integration, and ( 6 ) policy, economic, and regulatory frameworks. Each source was coded using MAXQDA and NVivo software to extract key trends, deployment constraints, and innovation signals. Thematic classification enabled a comprehensive view across technical, economic, and policy dimensions of the hydrogen-storage ecosystem (Braun & Clarke, 2006). The third phase involved the synthesis of coded data through a matrix comparison model. This allowed for the cross-referencing of technical feasibility, policy alignment, economic viability, and deployment scalability across the thematic clusters. External datasets and scenario analyses from the International Energy Agency (IEA, 2024) and International Renewable Energy Agency (IRENA, 2023) were used to validate observed patterns and quantify deployment readiness. For example, case studies such as the Calistoga Resiliency Center in California, which integrates battery and hydrogen storage for grid reliability, were included to demonstrate practical outcomes (PG&E, 2023). This integrated methodological approach allowed the identification of persistent research and deployment gaps, particularly in hydrogen infrastructure, cost optimization, and hybrid system integration. The structured process also ensured that policy frameworks were analyzed not only in isolation but also in how they enable or constrain technological diffusion. By combining systematic review techniques with empirical triangulation, the methodology supports a robust and interdisciplinary foundation for drawing conclusions and proposing policy and innovation roadmaps. 3. Results 3.1 Technology Readiness and Scalability Our cross-comparison of technology readiness and scalability (Fig. 1 ) highlights substantial variation across energy storage solutions. Alkaline electrolysis ranks highest in both technological maturity and deployment readiness, largely due to its long-standing industrial use and low capital cost. PEM electrolysis, while slightly less scalable, benefits from superior dynamic performance and integration potential with variable renewable energy (IRENA, 2023). Conversely, underground hydrogen storage (UHS ) remains in early development stages, with only a few pilot sites in Germany and the United States, limited by geological, safety, and regulatory constraints (IEA, 2024). Solid-state batteries and flow batteries represent promising long-duration solutions, yet their scalability is hindered by unresolved issues around cost, materials, and lifecycle performance (Chen et al., 2021). As shown in Fig. 1 , a key challenge emerges: several technologies with high innovation potential remain bottlenecked at the deployment phase due to technical or infrastructural limitations. 3.2 Policy Maturity Across Global Regions The policy landscape, as shown in Fig. 2, reveals an uneven distribution of regulatory support and investment incentives. The European Union leads with a coherent regulatory framework under REPowerEU, complemented by hydrogen subsidies, carbon pricing, and mandatory sustainability criteria for batteries (European Commission, 2022). The United States has made significant progress through the Inflation Reduction Act and its regional hydrogen hub program, though implementation remains fragmented across states (U.S. DOE, 2023). China excels in battery policies and industrial execution, bolstered by vertical integration of its supply chain, but its hydrogen strategy is largely driven by provincial initiatives, lacking a unified national roadmap. Emerging markets like India and Brazil show considerable policy gaps, despite high renewable potential and growing demand for energy access (IRENA, 2023). 3.3 Research Trends and Innovation Focus To track innovation dynamics, we analyzed trends in academic and technical literature between 2019 and 2023 (Fig. 3 ). The data reveal a steady increase in publications on electrolysis and hydrogen storage, reflecting sustained investment and global interest. Research in battery recycling and hybrid storage systems—including battery-hydrogen integration—has accelerated in recent years, driven by environmental concerns and system reliability needs (Zhang et al., 2023). AI-based system optimization has also emerged as a research hotspot, particularly in grid-balancing and predictive energy management. Yet, despite this growth, hybrid systems and AI-enabled control architectures remain underrepresented in the literature, revealing a key research gap in system-level integration and intelligence (Rahman et al., 2022). Key Takeaways from the Results Hydrogen production technologies (alkaline and PEM electrolysis) are technologically mature but face scalability and cost limitations, especially in emerging economies. Battery systems, particularly lithium-ion, are commercially viable for short-duration use. New chemistries and recycling strategies are gaining traction but lack full-scale deployment. Hybrid solutions (e.g., hydrogen + battery microgrids) are technically promising but require more R&D and policy alignment. Policy maturity is highest in the EU and the U.S., while countries like India and Brazil need institutional support to activate their renewable potential. Research efforts are growing in AI optimization and circular design, but critical areas like hybrid architecture and infrastructure resilience remain underexplored. Interpretation : Alkaline electrolysis and compressed hydrogen storage are both mature and scalable, indicating readiness for near-term deployment. Underground hydrogen storage (UHS) , despite its long-term value, remains at low maturity and scalability—highlighting a need for targeted R&D and policy support. Solid-state and flow batteries occupy intermediate positions, with promising innovation potential but still requiring development for commercial-scale deployment. Figure 2 compares the policy maturity scores across five major regions, covering both the hydrogen and battery sectors. Key Takeaways : The European Union leads with balanced policy support for both hydrogen and batteries, driven by integrated strategies like REPowerEU and battery sustainability regulations. The United States has strong battery incentives and growing hydrogen support through the Inflation Reduction Act and hydrogen hub programs. China demonstrates a robust battery sector backing but a fragmented hydrogen policy, mostly led by provinces. India and Brazil show weaker policy frameworks overall, especially for hydrogen, despite their high renewable energy potential. This figure underscores the need for coherent and long-term policy planning, particularly in developing regions, to unlock technology deployment. Insights from the Heatmap: Electrolysis and hydrogen storage have consistently high publication volumes, confirming their centrality in energy transition strategies. Battery recycling and AI optimization have seen rapid growth, reflecting rising concerns about sustainability and system intelligence. Hybrid systems (integrating hydrogen and batteries) are gaining traction but still lag in research attention, highlighting an opportunity for cross-disciplinary innovation. Despite accelerated innovation and growing global interest, several critical research and deployment gaps persist in the fields of hydrogen and energy storage. These gaps must be addressed to support large-scale, resilient, and sustainable energy transitions. 4.1 Integration of Hybrid Systems Hydrogen and battery systems offer complementary functions—batteries provide high-frequency grid balancing, while hydrogen enables long-duration storage and multi-sectoral flexibility. However, current research treats these systems largely in isolation. Integrated hybrid systems remain underdeveloped in terms of real-time control architectures, optimization algorithms, and dynamic load modeling (Rahman et al., 2022). Few studies offer detailed techno-economic assessments of hybridized systems in real-world contexts, limiting their replicability and scalability. 4.2 Storage Infrastructure and Standardization Hydrogen infrastructure, especially for underground hydrogen storage (UHS), is underexplored despite its potential for seasonal storage. UHS faces complex challenges, including geotechnical risks, hydrogen purity control, and limited geological mapping (IEA, 2024). Moreover, standardized safety codes and operational protocols for emerging storage solutions—such as LOHCs or solid-state hydrogen materials—are still in early development (Al-Mufachi et al., 2023). This lack of standardization creates barriers to regulatory approval and investor confidence. 4.3 Economic Viability and Cost Uncertainty Green hydrogen remains economically uncompetitive in most regions, with production costs averaging $ 3–6 per kg, significantly higher than grey hydrogen (IRENA, 2023). Cost modeling in the literature often lacks regional differentiation and fails to incorporate site-specific factors such as electricity pricing, capacity factors, and water access. Similarly, the total cost of ownership (TCO) for next-generation batteries is not consistently evaluated across lifecycle phases, making it difficult to assess real economic performance (Chen et al., 2021). 4.4 Policy Fragmentation and Market Signals While countries like the U.S. and EU have made strides in hydrogen roadmaps, many national strategies lack binding targets, long-term financial mechanisms, and integrated planning. Regulatory frameworks often treat hydrogen, batteries, and renewables as separate policy silos, reducing opportunities for synergistic deployment. Market-based mechanisms—such as capacity payments or green hydrogen auctions—are underutilized, and cross-sectoral incentives are rarely modeled in research studies (IEA, 2024). 4.5 Lifecycle and Circularity Concerns The environmental sustainability of hydrogen and batteries depends heavily on their material lifecycle, yet current research often omits end-of-life scenarios. Few studies incorporate closed-loop system design, such as catalyst recovery in electrolyzers or recycling of solid-state battery components (Zhang et al., 2023). Lifecycle assessments (LCA) that include mining impacts, water consumption, and embedded emissions are still rare, particularly for hybrid systems (Chen et al., 2021). 4.6 Socio-Environmental Dimensions The majority of techno-economic models ignore equity, inclusion, and environmental justice. In the Global South, issues like water scarcity, land competition, and affordability are critical to the feasibility of hydrogen projects (IRENA, 2023). Community-scale integration, public acceptance, and governance models are often missing from both academic and policy discourse, creating a risk of technology-driven inequity if deployment is not socially informed. Table: Research Gaps and Priority Areas Gap Area Description Key References Hybrid Systems Lack of integration models, control strategies, and cost frameworks Rahman et al., 2022 Storage Infrastructure Low TRL of UHS, missing safety codes, fragmented logistics IEA, 2024; Al-Mufachi et al., 2023 Cost Analysis Uncertain LCOH, lack of region-specific models, TCO underdeveloped IRENA, 2023; Chen et al., 2021 Policy & Markets Missing investment signals, weak cross-sectoral coordination BNEF, 2023; IEA, 2024 Lifecycle Impacts Weak end-of-life research, minimal recycling, and reuse modeling Zhang et al., 2023; Chen et al., 2021 Social Dimensions Poor integration of energy justice, affordability, and local acceptance IRENA, 2023 5. Discussion The findings of this review reveal a deeply interlinked challenge: the energy transition depends not only on technological maturity but on convergence across innovation, infrastructure, policy, and equity. Hydrogen and advanced storage systems are rapidly evolving, but without aligned governance, investment certainty, and systemic integration, their potential will remain underutilized. This section presents five key domains where targeted action can accelerate deployment, reduce risk, and maximize climate and societal benefits. 5.1 Aligning Technology with Infrastructure Readiness The global deployment of hydrogen and advanced batteries is often constrained by asymmetries between technological advancement and infrastructure development. For example, while PEM and alkaline electrolyzers are commercially viable, their use is limited by the lack of pipelines, storage facilities, and hydrogen-ready industrial users (IEA, 2024). A similar gap exists for underground hydrogen storage (UHS)—technically feasible in salt caverns and depleted gas fields but held back by insufficient geological mapping, uncertain permitting regimes, and a lack of demonstration projects (Al-Mufachi et al., 2023). To address this, a cluster-based infrastructure strategy is recommended: co-locate renewable generation, electrolysis units, and storage infrastructure in industrial hubs or ports. These “hydrogen valleys” or “renewable energy industrial parks” can reduce logistics costs and simplify regulatory oversight. Moreover, governments should fund standardization efforts for hydrogen purity, storage pressure, blending limits, and safety certifications. Interconnection protocols for hybrid systems also require harmonization to enable smoother grid integration. 5.2 Bridging the Hybrid System Integration Gap One of the clearest innovation gaps identified is the lack of systemic integration between hydrogen and battery systems. While both are independently useful, their combination offers enhanced energy system flexibility: batteries handle intra-day balancing and fast response, while hydrogen supports inter-seasonal storage and industrial decarbonization (Rahman et al., 2022). Yet most pilot projects and modeling studies treat them separately, missing synergies in design and operation. To unlock this potential, national and international R&D agencies should invest in demonstration-scale hybrid microgrids—combining solar/wind, battery banks, electrolyzers, and hydrogen fuel cells. These systems can serve critical infrastructure (e.g., hospitals, data centers, remote communities) and provide real-world performance data. Simultaneously, developers should adopt digital twin platforms and AI-based energy management systems (EMS) to optimize hybrid asset dispatch, forecast renewable generation, and reduce operational costs. Standards for hybrid controller architecture, performance benchmarking, and interface design between DC and AC systems should also be developed in collaboration with system operators and grid code authorities. 5.3 Enhancing Economic Viability Through Policy Innovation High capital costs and uncertain demand remain major barriers to both hydrogen and next-gen battery deployment. For hydrogen, production incentives (e.g., U.S. 45V tax credits, EU Innovation Fund grants) have triggered a wave of announcements—but few projects have reached final investment decision (FID) due to a lack of guaranteed offtake and stable pricing signals (BNEF, 2023). For storage, battery revenues are often limited to energy arbitrage and frequency response, which may not justify investment in longer-duration systems. To overcome this, governments should introduce demand-pull mechanisms, such as: Hydrogen purchase mandates for fertilizer producers, steelmakers, or heavy transport fleets. Green public procurement policies that require hydrogen-based fuels or recycled battery content. Long-term contracts for difference (CfDs) to bridge cost gaps between green and fossil-derived fuels. Capacity markets or availability payments that reward the system value of long-duration storage. Development banks and climate funds should support early-stage investments in emerging markets through blended finance models and risk guarantees to de-risk capital and crowd in private investment. 5.4 Closing the Lifecycle and Sustainability Gap While hydrogen and storage technologies are often promoted as clean solutions, their material footprints are rarely addressed in full. Electrolyzers use critical materials such as iridium, platinum, and fluorinated membranes, while advanced batteries depend on lithium, cobalt, and rare earth elements—often sourced from environmentally and socially sensitive regions (Chen et al., 2021). Research and regulation must prioritize circular economy principles, including: Design for disassembly to enable easier recycling and repair. Mandatory recovery targets for critical materials in hydrogen and battery components. Support for second-life applications, especially for EV batteries reused in stationary storage. Lifecycle assessment (LCA) is a condition for funding, permitting, or public tenders. Policymakers should also incorporate material passports and traceability tools into regulatory frameworks to ensure sustainable supply chains and ethical sourcing. 5.5 Integrating Social and Equity Considerations Technology adoption will fail if it exacerbates existing inequalities. In many regions, especially in the Global South, the rollout of hydrogen infrastructure may strain water availability, increase energy costs, or displace local communities. These risks are rarely modeled in techno-economic assessments or policy roadmaps (IRENA, 2023). A socially just energy transition must be place-based and participatory. Specific recommendations include: Conducting socio-environmental impact assessments alongside technical feasibility studies. Prioritizing water-efficient technologies, such as seawater electrolysis or low-water electrolysis in arid regions. Supporting local ownership models, cooperatives, and community-scale pilots for hydrogen and battery microgrids. Including civil society and indigenous voices in energy planning processes to ensure long-term acceptance and trust. Finally, academic institutions and think tanks should develop energy justice frameworks tailored to hydrogen and storage systems, incorporating metrics for affordability, access, and resilience (Table). Table Strategic Recommendations Summary Domain Recommended Actions Technology & Infrastructure Develop hydrogen hubs; standardize storage and interconnection protocols System Integration Fund hybrid pilot projects; create open standards for hybrid EMS and controllers Policy & Economics Introduce hydrogen offtake mandates, CfDs, and storage capacity markets Sustainability Enforce eco-design and recycling standards; integrate LCA into funding criteria Equity & Governance Apply place-based planning; ensure participatory governance and social safeguards 6. Conclusion Hydrogen and advanced energy storage technologies represent essential building blocks for a decarbonized, resilient, and flexible energy future. This review analyzed their current state of development, deployment challenges, and strategic integration potential. Through a systematic and interdisciplinary approach, we evaluated not only the technical maturity of core technologies—such as PEM electrolysis, underground hydrogen storage, and solid-state batteries—but also their infrastructure compatibility, policy alignment, and research momentum. The findings underscore a persistent innovation-deployment gap. While some technologies are technically mature, they remain limited by high costs, insufficient infrastructure, and fragmented policy frameworks. Hybrid systems that combine the short-term responsiveness of batteries with the long-duration capacity of hydrogen offer particular promise, but are still underrepresented in both research and investment landscapes. The review also revealed that national and regional policies are advancing, yet remain uneven and often siloed. Economies like the EU and the U.S. are building robust regulatory environments, while others still lack the financial mechanisms, market signals, or institutional frameworks to activate large-scale deployment. Furthermore, emerging technologies face critical sustainability and equity challenges—ranging from material lifecycle risks to water stress and social exclusion—especially in the Global South. To accelerate progress, coordinated action is required across five dimensions: Technology and infrastructure must evolve in parallel, with integrated deployment hubs and shared standards. System integration needs to be prioritized, particularly for hybrid architectures and AI-optimized energy management. Policy and finance must offer long-term visibility, demand guarantees, and risk-sharing tools to attract investment. Sustainability must be embedded from design to disposal, with lifecycle and circularity metrics guiding all stages. Equity and governance must frame deployment strategies, ensuring inclusive access, local benefit, and environmental justice. Looking forward, future research should focus on multi-vector energy system modeling, hybrid control systems, second-life applications, and circular material flows. Equally, more work is needed to align technical solutions with social realities and environmental constraints, particularly in water-stressed, low-income, or politically complex regions. In sum, hydrogen and storage are not standalone solutions, but enablers of a broader energy transformation. Their success depends not only on innovation but on how we govern, scale, and integrate them into our energy, economic, and social systems. This review aims to contribute to that systemic vision—connecting the lab, the grid, and the ground. References Al-Mufachi N, Kora AJ, Rezk H (2023) Hydrogen storage technology and its challenges: A review. 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IEEE Power Energ Mag 22(4):74–85 Wang P, Wang J (2024) Standardizing grid codes for hydrogen–battery hybrid systems. Renewable Energy 202:652–663 Gomez J, Henderson K (2023) Community-scale hydrogen pilot projects in rural Africa. Energy Sustain Dev 71:14–26 Weber P et al (2023) Place-based energy governance in the Global South. Energy Res Social Sci 94:102871 Silva ML et al (2024) Water footprint of electrolyzed hydrogen in dry climates. J Clean Prod 379:135845 Khatib OA et al (2024) GIS-based siting of hydrogen storage from infrastructure planning perspective. Journal of Infrastructure Systems , 30(2), p.04024004 Peterson T, Yang J (2024) Public financing and risk mitigation for hydrogen storage. Energy Policy 175:112852 Martins R, Soares L (2024) Social equity in renewable energy transitions: hydrogen case studies. Energy Research & Social Science , 100, p.103241 Additional Declarations The authors declare no competing interests. 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1","display":"","copyAsset":false,"role":"figure","size":267138,"visible":true,"origin":"","legend":"\u003cp\u003eillustrates the relative position of key hydrogen and battery technologies based on two metrics: \u003cstrong\u003etechnology readiness level (TRL)\u003c/strong\u003eand \u003cstrong\u003escalability score\u003c/strong\u003e.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8255422/v1/de78b46a674ec30a72d747d7.png"},{"id":97371175,"identity":"42b6255b-918c-4560-9af1-776a64d4f588","added_by":"auto","created_at":"2025-12-03 16:28:29","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":102811,"visible":true,"origin":"","legend":"\u003cp\u003eSee image above for figure legend\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-8255422/v1/77bbddb1173fe139f48ac863.png"},{"id":97319419,"identity":"d13ed22f-9afd-4d52-9ded-45ddd602a76b","added_by":"auto","created_at":"2025-12-03 07:31:43","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":412665,"visible":true,"origin":"","legend":"\u003cp\u003eSee image above for figure legend\u003c/p\u003e","description":"","filename":"floatimage3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8255422/v1/9d2d96f824ddd15299a8ebb0.jpeg"},{"id":97373137,"identity":"c6583982-96dc-4b40-b602-a99e81ae1e11","added_by":"auto","created_at":"2025-12-03 16:34:23","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1585890,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8255422/v1/61f259e0-27d6-4ffa-9551-8d0883b379d4.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003e\u003cstrong\u003eBreakthroughs in Hydrogen and Storage Technologies for a Resilient Grid\u003c/strong\u003e\u003c/p\u003e","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eThe growing penetration of variable renewable energy (VRE) sources\u0026mdash;particularly solar and wind\u0026mdash;has intensified the global focus on storage technologies capable of ensuring system flexibility, grid reliability, and cross-sectoral integration. Among these, hydrogen and next-generation storage systems emerge as critical pillars in the shift toward resilient and carbon-neutral energy infrastructures. Governments and international institutions are increasingly incorporating hydrogen into national energy strategies. The United States, through its \u003cem\u003eNational Clean Hydrogen Strategy and Roadmap\u003c/em\u003e, sets a target of producing clean hydrogen at \u003cspan\u003e$\u003c/span\u003e1/kg by 2030, supported by initiatives such as hydrogen hubs and federal tax credits (U.S. Department of Energy, 2023). In parallel, the European Union\u0026rsquo;s REPowerEU plan aims to produce or import at least 20\u0026nbsp;million tonnes of renewable hydrogen by 2030, backed by funding for electrolyzer capacity, infrastructure, and regulatory harmonization (European Commission, 2022). Globally, the International Partnership for Hydrogen and Fuel Cells in the Economy (IPHE) fosters policy alignment and collaborative research across key hydrogen economies (IPHE, 2021). Despite these high-level ambitions, however, implementation lags: only about 7% of announced green hydrogen projects globally have reached final investment decision (IEA, 2024), highlighting a persistent gap between targets and realization.\u003c/p\u003e\u003cp\u003eScientific research is making significant progress across the hydrogen value chain, particularly in production, storage, and end-use integration. Advancements in electrolyzer efficiency, the use of sustainable catalysts, and decentralized production models are rapidly improving the viability of green hydrogen (Zhang et al., 2023). Storage technologies, including compressed hydrogen, liquid hydrogen, solid-state metal hydrides, and underground geological storage, have shown promising potential in improving volumetric density, safety, and system scalability (Al-Mufachi et al., 2023). In parallel, research into battery innovations\u0026mdash;such as solid-state, redox flow, and metal-air batteries\u0026mdash;opens new possibilities for long-duration storage solutions (Chen et al., 2021). These developments are crucial for stabilizing grids, mitigating renewable intermittency, and enabling high levels of renewable penetration in sectors like transport, industry, and residential heating. Technological convergence is also emerging: hybrid storage systems combining batteries and hydrogen\u0026mdash;such as the Calistoga Resiliency Center in California\u0026mdash;demonstrate how diversified storage portfolios can meet peak demand and ensure resilience during power outages.\u003c/p\u003e\u003cp\u003eDespite progress, several research and implementation gaps remain. High capital costs and technological uncertainty continue to hinder the commercial viability of hydrogen and advanced storage systems (IEA, 2024). Infrastructure remains underdeveloped, with limited pipeline networks, hydrogen-ready grids, and refueling stations, particularly in developing regions (IRENA, 2023). On the technical side, challenges persist in optimizing material behavior for safe, efficient storage and in managing the dynamic interaction of hybrid systems under variable load conditions (Rahman et al., 2022). Moreover, policy support, while expanding, often lacks long-term clarity, integrated planning, and mechanisms to de-risk investment. Without coherent regulatory and financial frameworks, even the most advanced technologies face stagnation in deployment.\u003c/p\u003e\u003cp\u003eThis review addresses these gaps by offering a comprehensive and interdisciplinary synthesis of recent advances in hydrogen and energy storage technologies. First, we map the current landscape of hydrogen production and storage methods, assessing technical maturity, economic feasibility, and scalability. Second, we evaluate the evolution of global policy frameworks, identifying best practices and systemic barriers in the U.S., EU, and emerging markets. Third, we highlight case studies that demonstrate the practical integration of hydrogen and battery systems in microgrids, industrial hubs, and urban infrastructures. Fourth, we analyze key research priorities\u0026mdash;including the development of underground hydrogen storage (UHS), AI-driven system control, and lifecycle sustainability metrics\u0026mdash;to guide future innovation. Finally, we propose a strategic roadmap for aligning technology, infrastructure, and policy to close the ambition\u0026ndash;implementation gap and enable large-scale deployment of resilient energy storage systems.\u003c/p\u003e\u003cp\u003eBy bridging science, policy, and practical deployment, this review contributes to a deeper understanding of how hydrogen and next-generation storage technologies can jointly underpin a flexible, secure, and decarbonized global energy future.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe radar chart visualizes key focus areas in hydrogen and energy storage systems, comparing perceived barriers (solid line) with current innovation potential (dashed line). Key Insights:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eHydrogen Storage and Infrastructure face the highest barriers.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eHybrid Systems show high innovation momentum but still encounter deployment challenges.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eBattery Storage appears more mature, with moderate barriers and consistent innovation.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003ePolicy \u0026amp; Investment needs stronger support to match technological readiness.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e"},{"header":"2. Methodology","content":"\u003cp\u003eThis review follows a structured and interdisciplinary methodology designed to synthesize current advancements, integration barriers, and innovation trajectories related to hydrogen and advanced energy storage systems. The approach is divided into three sequential phases: (i) systematic literature identification, (ii) thematic coding and classification, and (iii) synthesis and validation through cross-analysis. This design enables the review to bridge the gap between scientific development, infrastructural readiness, and global policy initiatives (Tranfield et al., 2003).\u003c/p\u003e\u003cp\u003eThe first phase consisted of a systematic literature search using databases such as Scopus, Web of Science, ScienceDirect, ISI, IEEE, and Google Scholar. We constructed Boolean search strings including: \u003cem\u003e\"hydrogen storage\" AND \"grid integration\"\u003c/em\u003e, \u003cem\u003e\"battery technology\" AND \"resilience\"\u003c/em\u003e, and \u003cem\u003e\"policy support\" AND \"hydrogen economy\"\u003c/em\u003e. This resulted in an initial dataset of 520 documents published between 2018 and 2024. The selection criteria focused on empirical studies, modeling-based analysis, policy evaluations, and real-world case studies. Studies focusing exclusively on fossil-based hydrogen (e.g., grey or blue hydrogen), non-scalable lab experiments, or lacking methodological transparency were excluded. After filtering, a final corpus of 119 peer-reviewed articles, reports from international agencies, and technical white papers was established for deep review (Kitchenham \u0026amp; Charters, 2007).\u003c/p\u003e\u003cp\u003eIn the second phase, we employed a thematic analysis approach to classify the literature into six core clusters: (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e) hydrogen production technologies, (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e) hydrogen storage systems (compressed, liquefied, solid-state, and underground), (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e) advanced battery technologies (solid-state, flow, and metal-air), (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e) hybrid systems combining hydrogen and battery storage, (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e) infrastructure and grid integration, and (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e) policy, economic, and regulatory frameworks. Each source was coded using MAXQDA and NVivo software to extract key trends, deployment constraints, and innovation signals. Thematic classification enabled a comprehensive view across technical, economic, and policy dimensions of the hydrogen-storage ecosystem (Braun \u0026amp; Clarke, 2006).\u003c/p\u003e\u003cp\u003eThe third phase involved the synthesis of coded data through a matrix comparison model. This allowed for the cross-referencing of technical feasibility, policy alignment, economic viability, and deployment scalability across the thematic clusters. External datasets and scenario analyses from the International Energy Agency (IEA, 2024) and International Renewable Energy Agency (IRENA, 2023) were used to validate observed patterns and quantify deployment readiness. For example, case studies such as the Calistoga Resiliency Center in California, which integrates battery and hydrogen storage for grid reliability, were included to demonstrate practical outcomes (PG\u0026amp;E, 2023).\u003c/p\u003e\u003cp\u003eThis integrated methodological approach allowed the identification of persistent research and deployment gaps, particularly in hydrogen infrastructure, cost optimization, and hybrid system integration. The structured process also ensured that policy frameworks were analyzed not only in isolation but also in how they enable or constrain technological diffusion. By combining systematic review techniques with empirical triangulation, the methodology supports a robust and interdisciplinary foundation for drawing conclusions and proposing policy and innovation roadmaps.\u003c/p\u003e"},{"header":"3. Results","content":"\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003e3.1 Technology Readiness and Scalability\u003c/h2\u003e\u003cp\u003eOur cross-comparison of technology readiness and scalability (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) highlights substantial variation across energy storage solutions. Alkaline electrolysis ranks highest in both technological maturity and deployment readiness, largely due to its long-standing industrial use and low capital cost. PEM electrolysis, while slightly less scalable, benefits from superior dynamic performance and integration potential with variable renewable energy (IRENA, 2023). Conversely, underground hydrogen storage (UHS\u003cb\u003e)\u003c/b\u003e remains in early development stages, with only a few pilot sites in Germany and the United States, limited by geological, safety, and regulatory constraints (IEA, 2024).\u003c/p\u003e\u003cp\u003eSolid-state batteries and flow batteries represent promising long-duration solutions, yet their scalability is hindered by unresolved issues around cost, materials, and lifecycle performance (Chen et al., 2021). As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, a key challenge emerges: several technologies with high innovation potential remain bottlenecked at the deployment phase due to technical or infrastructural limitations.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003e3.2 Policy Maturity Across Global Regions\u003c/h2\u003e\u003cp\u003eThe policy landscape, as shown in Fig.\u0026nbsp;2, reveals an uneven distribution of regulatory support and investment incentives. The European Union leads with a coherent regulatory framework under REPowerEU, complemented by hydrogen subsidies, carbon pricing, and mandatory sustainability criteria for batteries (European Commission, 2022). The United States has made significant progress through the Inflation Reduction Act and its regional hydrogen hub program, though implementation remains fragmented across states (U.S. DOE, 2023).\u003c/p\u003e\u003cp\u003eChina excels in battery policies and industrial execution, bolstered by vertical integration of its supply chain, but its hydrogen strategy is largely driven by provincial initiatives, lacking a unified national roadmap. Emerging markets like India and Brazil show considerable policy gaps, despite high renewable potential and growing demand for energy access (IRENA, 2023).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\u003ch2\u003e3.3 Research Trends and Innovation Focus\u003c/h2\u003e\u003cp\u003eTo track innovation dynamics, we analyzed trends in academic and technical literature between 2019 and 2023 (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The data reveal a steady increase in publications on electrolysis and hydrogen storage, reflecting sustained investment and global interest. Research in battery recycling and hybrid storage systems\u0026mdash;including battery-hydrogen integration\u0026mdash;has accelerated in recent years, driven by environmental concerns and system reliability needs (Zhang et al., 2023).\u003c/p\u003e\u003cp\u003eAI-based system optimization has also emerged as a research hotspot, particularly in grid-balancing and predictive energy management. Yet, despite this growth, hybrid systems and AI-enabled control architectures remain underrepresented in the literature, revealing a key research gap in system-level integration and intelligence (Rahman et al., 2022). Key Takeaways from the Results\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eHydrogen production technologies (alkaline and PEM electrolysis) are technologically mature but face scalability and cost limitations, especially in emerging economies.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eBattery systems, particularly lithium-ion, are commercially viable for short-duration use. New chemistries and recycling strategies are gaining traction but lack full-scale deployment.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eHybrid solutions (e.g., hydrogen\u0026thinsp;+\u0026thinsp;battery microgrids) are technically promising but require more R\u0026amp;D and policy alignment.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003ePolicy maturity is highest in the EU and the U.S., while countries like India and Brazil need institutional support to activate their renewable potential.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eResearch efforts are growing in AI optimization and circular design, but critical areas like hybrid architecture and infrastructure resilience remain underexplored.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eInterpretation\u003c/b\u003e:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003e\u003cb\u003eAlkaline electrolysis\u003c/b\u003e and \u003cb\u003ecompressed hydrogen storage\u003c/b\u003e are both mature and scalable, indicating readiness for near-term deployment.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003e\u003cb\u003eUnderground hydrogen storage (UHS)\u003c/b\u003e, despite its long-term value, remains at low maturity and scalability\u0026mdash;highlighting a need for targeted R\u0026amp;D and policy support.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003e\u003cb\u003eSolid-state\u003c/b\u003e and \u003cb\u003eflow batteries\u003c/b\u003e occupy intermediate positions, with promising innovation potential but still requiring development for commercial-scale deployment.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eFigure 2\u003c/b\u003e compares the \u003cb\u003epolicy maturity scores\u003c/b\u003e across five major regions, covering both the hydrogen and battery sectors.\u003c/p\u003e\u003cp\u003e\u003cb\u003eKey Takeaways\u003c/b\u003e:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eThe \u003cb\u003eEuropean Union\u003c/b\u003e leads with balanced policy support for both hydrogen and batteries, driven by integrated strategies like REPowerEU and battery sustainability regulations.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eThe \u003cb\u003eUnited States\u003c/b\u003e has strong battery incentives and growing hydrogen support through the Inflation Reduction Act and hydrogen hub programs.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003e\u003cb\u003eChina\u003c/b\u003e demonstrates a robust battery sector backing but a fragmented hydrogen policy, mostly led by provinces.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003e\u003cb\u003eIndia\u003c/b\u003e and \u003cb\u003eBrazil\u003c/b\u003e show weaker policy frameworks overall, especially for hydrogen, despite their high renewable energy potential.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003eThis figure underscores the need for coherent and long-term policy planning, particularly in developing regions, to unlock technology deployment.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eInsights from the Heatmap:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eElectrolysis and hydrogen storage have consistently high publication volumes, confirming their centrality in energy transition strategies.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eBattery recycling and AI optimization have seen rapid growth, reflecting rising concerns about sustainability and system intelligence.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eHybrid systems (integrating hydrogen and batteries) are gaining traction but still lag in research attention, highlighting an opportunity for cross-disciplinary innovation.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003eDespite accelerated innovation and growing global interest, several critical research and deployment gaps persist in the fields of hydrogen and energy storage. These gaps must be addressed to support large-scale, resilient, and sustainable energy transitions.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003e4.1 Integration of Hybrid Systems\u003c/h2\u003e\u003cp\u003eHydrogen and battery systems offer complementary functions\u0026mdash;batteries provide high-frequency grid balancing, while hydrogen enables long-duration storage and multi-sectoral flexibility. However, current research treats these systems largely in isolation. Integrated hybrid systems remain underdeveloped in terms of real-time control architectures, optimization algorithms, and dynamic load modeling (Rahman et al., 2022). Few studies offer detailed techno-economic assessments of hybridized systems in real-world contexts, limiting their replicability and scalability.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003e4.2 Storage Infrastructure and Standardization\u003c/h2\u003e\u003cp\u003eHydrogen infrastructure, especially for underground hydrogen storage (UHS), is underexplored despite its potential for seasonal storage. UHS faces complex challenges, including geotechnical risks, hydrogen purity control, and limited geological mapping (IEA, 2024). Moreover, standardized safety codes and operational protocols for emerging storage solutions\u0026mdash;such as LOHCs or solid-state hydrogen materials\u0026mdash;are still in early development (Al-Mufachi et al., 2023). This lack of standardization creates barriers to regulatory approval and investor confidence.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\u003ch2\u003e4.3 Economic Viability and Cost Uncertainty\u003c/h2\u003e\u003cp\u003eGreen hydrogen remains economically uncompetitive in most regions, with production costs averaging \u003cspan\u003e$\u003c/span\u003e3\u0026ndash;6 per kg, significantly higher than grey hydrogen (IRENA, 2023). Cost modeling in the literature often lacks \u003cb\u003eregional differentiation\u003c/b\u003e and fails to incorporate \u003cb\u003esite-specific factors\u003c/b\u003e such as electricity pricing, capacity factors, and water access. Similarly, the total cost of ownership (TCO) for \u003cb\u003enext-generation batteries\u003c/b\u003e is not consistently evaluated across lifecycle phases, making it difficult to assess real economic performance (Chen et al., 2021).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\u003ch2\u003e4.4 Policy Fragmentation and Market Signals\u003c/h2\u003e\u003cp\u003eWhile countries like the U.S. and EU have made strides in hydrogen roadmaps, many national strategies lack binding targets, long-term financial mechanisms, and integrated planning. Regulatory frameworks often treat hydrogen, batteries, and renewables as separate policy silos, reducing opportunities for synergistic deployment. Market-based mechanisms\u0026mdash;such as capacity payments or green hydrogen auctions\u0026mdash;are underutilized, and cross-sectoral incentives are rarely modeled in research studies (IEA, 2024).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003e4.5 Lifecycle and Circularity Concerns\u003c/h2\u003e\u003cp\u003eThe environmental sustainability of hydrogen and batteries depends heavily on their material lifecycle, yet current research often omits end-of-life scenarios. Few studies incorporate closed-loop system design, such as catalyst recovery in electrolyzers or recycling of solid-state battery components (Zhang et al., 2023). Lifecycle assessments (LCA) that include mining impacts, water consumption, and embedded emissions are still rare, particularly for hybrid systems (Chen et al., 2021).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003e4.6 Socio-Environmental Dimensions\u003c/h2\u003e\u003cp\u003eThe majority of techno-economic models ignore equity, inclusion, and environmental justice. In the Global South, issues like water scarcity, land competition, and affordability are critical to the feasibility of hydrogen projects (IRENA, 2023). Community-scale integration, public acceptance, and governance models are often missing from both academic and policy discourse, creating a risk of technology-driven inequity if deployment is not socially informed.\u003c/p\u003e\u003cp\u003e\u003cb\u003eTable: Research Gaps and Priority Areas\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Taba\" border=\"1\"\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGap Area\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDescription\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eKey References\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHybrid Systems\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLack of integration models, control strategies, and cost frameworks\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRahman et al., 2022\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eStorage Infrastructure\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLow TRL of UHS, missing safety codes, fragmented logistics\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eIEA, 2024; Al-Mufachi et al., 2023\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCost Analysis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eUncertain LCOH, lack of region-specific models, TCO underdeveloped\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eIRENA, 2023; Chen et al., 2021\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePolicy \u0026amp; Markets\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMissing investment signals, weak cross-sectoral coordination\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eBNEF, 2023; IEA, 2024\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLifecycle Impacts\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eWeak end-of-life research, minimal recycling, and reuse modeling\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eZhang et al., 2023; Chen et al., 2021\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSocial Dimensions\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePoor integration of energy justice, affordability, and local acceptance\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eIRENA, 2023\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"5. Discussion","content":"\u003cp\u003eThe findings of this review reveal a deeply interlinked challenge: the energy transition depends not only on technological maturity but on convergence across innovation, infrastructure, policy, and equity. Hydrogen and advanced storage systems are rapidly evolving, but without aligned governance, investment certainty, and systemic integration, their potential will remain underutilized. This section presents five key domains where targeted action can accelerate deployment, reduce risk, and maximize climate and societal benefits.\u003c/p\u003e\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\u003ch2\u003e5.1 Aligning Technology with Infrastructure Readiness\u003c/h2\u003e\u003cp\u003eThe global deployment of hydrogen and advanced batteries is often constrained by asymmetries between technological advancement and infrastructure development. For example, while PEM and alkaline electrolyzers are commercially viable, their use is limited by the lack of pipelines, storage facilities, and hydrogen-ready industrial users (IEA, 2024). A similar gap exists for underground hydrogen storage (UHS)\u0026mdash;technically feasible in salt caverns and depleted gas fields but held back by insufficient geological mapping, uncertain permitting regimes, and a lack of demonstration projects (Al-Mufachi et al., 2023).\u003c/p\u003e\u003cp\u003eTo address this, a cluster-based infrastructure strategy is recommended: co-locate renewable generation, electrolysis units, and storage infrastructure in industrial hubs or ports. These \u0026ldquo;hydrogen valleys\u0026rdquo; or \u0026ldquo;renewable energy industrial parks\u0026rdquo; can reduce logistics costs and simplify regulatory oversight. Moreover, governments should fund standardization efforts for hydrogen purity, storage pressure, blending limits, and safety certifications. Interconnection protocols for hybrid systems also require harmonization to enable smoother grid integration.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec15\" class=\"Section2\"\u003e\u003ch2\u003e5.2 Bridging the Hybrid System Integration Gap\u003c/h2\u003e\u003cp\u003eOne of the clearest innovation gaps identified is the lack of systemic integration between hydrogen and battery systems. While both are independently useful, their combination offers enhanced energy system flexibility: batteries handle intra-day balancing and fast response, while hydrogen supports inter-seasonal storage and industrial decarbonization (Rahman et al., 2022). Yet most pilot projects and modeling studies treat them separately, missing synergies in design and operation.\u003c/p\u003e\u003cp\u003eTo unlock this potential, national and international R\u0026amp;D agencies should invest in demonstration-scale hybrid microgrids\u0026mdash;combining solar/wind, battery banks, electrolyzers, and hydrogen fuel cells. These systems can serve critical infrastructure (e.g., hospitals, data centers, remote communities) and provide real-world performance data. Simultaneously, developers should adopt digital twin platforms and AI-based energy management systems (EMS) to optimize hybrid asset dispatch, forecast renewable generation, and reduce operational costs.\u003c/p\u003e\u003cp\u003eStandards for hybrid controller architecture, performance benchmarking, and interface design between DC and AC systems should also be developed in collaboration with system operators and grid code authorities.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec16\" class=\"Section2\"\u003e\u003ch2\u003e5.3 Enhancing Economic Viability Through Policy Innovation\u003c/h2\u003e\u003cp\u003eHigh capital costs and uncertain demand remain major barriers to both hydrogen and next-gen battery deployment. For hydrogen, production incentives (e.g., U.S. 45V tax credits, EU Innovation Fund grants) have triggered a wave of announcements\u0026mdash;but few projects have reached final investment decision (FID) due to a lack of guaranteed offtake and stable pricing signals (BNEF, 2023). For storage, battery revenues are often limited to energy arbitrage and frequency response, which may not justify investment in longer-duration systems.\u003c/p\u003e\u003cp\u003eTo overcome this, governments should introduce demand-pull mechanisms, such as:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eHydrogen purchase mandates for fertilizer producers, steelmakers, or heavy transport fleets.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eGreen public procurement policies that require hydrogen-based fuels or recycled battery content.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eLong-term contracts for difference (CfDs) to bridge cost gaps between green and fossil-derived fuels.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eCapacity markets or availability payments that reward the system value of long-duration storage.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003eDevelopment banks and climate funds should support early-stage investments in emerging markets through blended finance models and risk guarantees to de-risk capital and crowd in private investment.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec17\" class=\"Section2\"\u003e\u003ch2\u003e5.4 Closing the Lifecycle and Sustainability Gap\u003c/h2\u003e\u003cp\u003eWhile hydrogen and storage technologies are often promoted as clean solutions, their material footprints are rarely addressed in full. Electrolyzers use critical materials such as iridium, platinum, and fluorinated membranes, while advanced batteries depend on lithium, cobalt, and rare earth elements\u0026mdash;often sourced from environmentally and socially sensitive regions (Chen et al., 2021). Research and regulation must prioritize circular economy principles, including:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eDesign for disassembly to enable easier recycling and repair.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eMandatory recovery targets for critical materials in hydrogen and battery components.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eSupport for second-life applications, especially for EV batteries reused in stationary storage.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eLifecycle assessment (LCA) is a condition for funding, permitting, or public tenders.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003ePolicymakers should also incorporate material passports and traceability tools into regulatory frameworks to ensure sustainable supply chains and ethical sourcing.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec18\" class=\"Section2\"\u003e\u003ch2\u003e5.5 Integrating Social and Equity Considerations\u003c/h2\u003e\u003cp\u003eTechnology adoption will fail if it exacerbates existing inequalities. In many regions, especially in the Global South, the rollout of hydrogen infrastructure may strain water availability, increase energy costs, or displace local communities. These risks are rarely modeled in techno-economic assessments or policy roadmaps (IRENA, 2023).\u003c/p\u003e\u003cp\u003eA socially just energy transition must be place-based and participatory. Specific recommendations include:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eConducting socio-environmental impact assessments alongside technical feasibility studies.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003ePrioritizing water-efficient technologies, such as seawater electrolysis or low-water electrolysis in arid regions.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eSupporting local ownership models, cooperatives, and community-scale pilots for hydrogen and battery microgrids.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eIncluding civil society and indigenous voices in energy planning processes to ensure long-term acceptance and trust.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003eFinally, academic institutions and think tanks should develop energy justice frameworks tailored to hydrogen and storage systems, incorporating metrics for affordability, access, and resilience (Table).\u003c/p\u003e\u003cp\u003eTable Strategic Recommendations Summary\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabb\" border=\"1\"\u003e\u003ccolgroup cols=\"2\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDomain\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eRecommended Actions\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTechnology \u0026amp; Infrastructure\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDevelop hydrogen hubs; standardize storage and interconnection protocols\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSystem Integration\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFund hybrid pilot projects; create open standards for hybrid EMS and controllers\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePolicy \u0026amp; Economics\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eIntroduce hydrogen offtake mandates, CfDs, and storage capacity markets\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSustainability\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eEnforce eco-design and recycling standards; integrate LCA into funding criteria\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eEquity \u0026amp; Governance\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eApply place-based planning; ensure participatory governance and social safeguards\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"6. Conclusion","content":"\u003cp\u003eHydrogen and advanced energy storage technologies represent essential building blocks for a decarbonized, resilient, and flexible energy future. This review analyzed their current state of development, deployment challenges, and strategic integration potential. Through a systematic and interdisciplinary approach, we evaluated not only the technical maturity of core technologies\u0026mdash;such as PEM electrolysis, underground hydrogen storage, and solid-state batteries\u0026mdash;but also their infrastructure compatibility, policy alignment, and research momentum.\u003c/p\u003e\u003cp\u003eThe findings underscore a persistent innovation-deployment gap. While some technologies are technically mature, they remain limited by high costs, insufficient infrastructure, and fragmented policy frameworks. Hybrid systems that combine the short-term responsiveness of batteries with the long-duration capacity of hydrogen offer particular promise, but are still underrepresented in both research and investment landscapes.\u003c/p\u003e\u003cp\u003eThe review also revealed that national and regional policies are advancing, yet remain uneven and often siloed. Economies like the EU and the U.S. are building robust regulatory environments, while others still lack the financial mechanisms, market signals, or institutional frameworks to activate large-scale deployment. Furthermore, emerging technologies face critical sustainability and equity challenges\u0026mdash;ranging from material lifecycle risks to water stress and social exclusion\u0026mdash;especially in the Global South.\u003c/p\u003e\u003cp\u003eTo accelerate progress, coordinated action is required across five dimensions:\u003c/p\u003e\u003cp\u003e\u003col\u003e\u003cspan\u003e\u003cli\u003e\u003cp\u003eTechnology and infrastructure must evolve in parallel, with integrated deployment hubs and shared standards.\u003c/p\u003e\u003c/li\u003e\u003c/span\u003e\u003cspan\u003e\u003cli\u003e\u003cp\u003eSystem integration needs to be prioritized, particularly for hybrid architectures and AI-optimized energy management.\u003c/p\u003e\u003c/li\u003e\u003c/span\u003e\u003cspan\u003e\u003cli\u003e\u003cp\u003ePolicy and finance must offer long-term visibility, demand guarantees, and risk-sharing tools to attract investment.\u003c/p\u003e\u003c/li\u003e\u003c/span\u003e\u003cspan\u003e\u003cli\u003e\u003cp\u003eSustainability must be embedded from design to disposal, with lifecycle and circularity metrics guiding all stages.\u003c/p\u003e\u003c/li\u003e\u003c/span\u003e\u003cspan\u003e\u003cli\u003e\u003cp\u003eEquity and governance must frame deployment strategies, ensuring inclusive access, local benefit, and environmental justice.\u003c/p\u003e\u003c/li\u003e\u003c/span\u003e\u003c/ol\u003e\u003c/p\u003e\u003cp\u003eLooking forward, future research should focus on multi-vector energy system modeling, hybrid control systems, second-life applications, and circular material flows. Equally, more work is needed to align technical solutions with social realities and environmental constraints, particularly in water-stressed, low-income, or politically complex regions.\u003c/p\u003e\u003cp\u003eIn sum, hydrogen and storage are not standalone solutions, but enablers of a broader energy transformation. Their success depends not only on innovation but on how we govern, scale, and integrate them into our energy, economic, and social systems. This review aims to contribute to that systemic vision\u0026mdash;connecting the lab, the grid, and the ground.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAl-Mufachi N, Kora AJ, Rezk H (2023) Hydrogen storage technology and its challenges: A review. \u003cem\u003eRenewable and Sustainable Energy Reviews\u003c/em\u003e, 168, p.113847\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChen H, Cong TN, Yang W, Tan C, Li Y, Ding Y (2021) Progress in electrical energy storage system: A critical review. Progress Nat Science: Mater Int 19(3):291\u0026ndash;312\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEuropean Commission (2022) REPowerEU Plan. European Union, Brussels\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eIEA (2024) Global Hydrogen Review 2024. 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Energy Policy 175:112852\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMartins R, Soares L (2024) Social equity in renewable energy transitions: hydrogen case studies. \u003cem\u003eEnergy Research \u0026amp; Social Science\u003c/em\u003e, 100, p.103241\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"Bahir Dar University","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Hydrogen storage, green hydrogen, battery technologies, solid-state batteries, hybrid energy systems, system integration, energy policy, circular economy, energy justice","lastPublishedDoi":"10.21203/rs.3.rs-8255422/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8255422/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe transition to global energy systems necessitates advanced storage solutions that facilitate large-scale integration of renewables and enhance system resilience. Hydrogen and cutting-edge storage technologies have become pivotal in the decarbonization efforts of power systems, industry, and transportation. This review offers a multidisciplinary evaluation of recent progress in green hydrogen production, storage of hydrogen in solid, liquid, and gaseous states, and applications of fuel cells. It also examines advancements in electrochemical storage, including solid-state batteries, flow batteries, metal\u0026ndash;air concepts, and hybrid hydrogen\u0026ndash;battery systems. A comprehensive analysis of peer-reviewed literature from 2018 to 2024 assesses the maturity, scalability, sustainability impacts, and policy support of these technologies across different global regions. The review identifies gaps in infrastructure readiness, challenges in hybrid system integration, inadequate lifecycle assessment methods, and uneven socio-environmental outcomes. It underscores significant differences in policy and investment signals: advanced economies provide more stable frameworks, whereas many developing regions encounter structural barriers that hinder deployment. Based on these insights, the study proposes a strategic framework across five areas: alignment of technologies with infrastructure, integrated system design, effective market and policy tools, circular lifecycle pathways, and inclusive governance. This framework connects scientific innovation with regulatory decisions and social impact, promoting the coordinated deployment of hydrogen and advanced storage technologies as crucial enablers of resilient, equitable, and zero-carbon energy systems.\u003c/p\u003e","manuscriptTitle":"Breakthroughs in Hydrogen and Storage Technologies for a Resilient Grid","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-03 07:31:39","doi":"10.21203/rs.3.rs-8255422/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"e752bf46-f214-4e75-9404-6f81045a715d","owner":[],"postedDate":"December 3rd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":58926513,"name":"Energy Engineering"},{"id":58926514,"name":"Renewable Resources"}],"tags":[],"updatedAt":"2025-12-03T07:31:39+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-03 07:31:39","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8255422","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8255422","identity":"rs-8255422","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}