ABSTRACT Although investments in renewable energy, particularly solar photovoltaic (PV) systems, have increased over the past decade, the energy transition still faces dilemmas related to several socio‐technical and environmental aspects. To clarify the benefits, challenges, and trade‐offs of distributed urban solar PV, this article conducts a multidimensional literature review and develops an integrated trade‐off framework that considers technical, economic, social, regulatory, and environmental perspectives. The review highlights the controversial aspects that support and challenge the potential of on‐grid urban solar systems to enhance energy security, improve efficiency, and support community engagement through technological innovation and novel social practices. Several concerns arise, including investment risks, social equity, energy security, environmental impact, maintenance, and aesthetics, all of which require strategic mitigation. Integrating solar PV into smart urban environments also presents constraints related to energy storage, consumer adaptability, business model innovation (BMI), stakeholder engagement, and potential health hazards. Addressing these issues requires balancing socio‐technical and environmental aspects. Based on a systematic assessment of European case studies—including Amsterdam's solar‐EV ecosystem, Spain's post‐2018 regulatory reforms, and France's inclusive financing models—we find that successful pathways combine modernized interconnection standards, streamlined permitting, collective self‐consumption frameworks, performance‐based regulation, and targeted financial instruments for low‐income households. BMI and policy reforms are essential drivers for the successful diffusion of solar PV systems. Achieving a sustainable energy future in urban areas requires stakeholder collaboration, public‐private partnerships (PPPs), innovative solutions, and careful balancing of multiple trade‐offs. This article sheds light on the current state of the art on distributed solar PV and emphasizes the need for informed decision‐making to address the complexities of on‐grid urban solar systems, aiming for a sustainable, resilient, efficient, and inclusive urban energy future.
ABSTRACT Parabolic trough solar collectors (PTSCs) can play a crucial role in providing industrial process heat (IPH) by harnessing solar energy efficiently. To contribute to this domain, this review maps the global industrial footprint of PTSC‐based IPH installations. It identifies possible integration strategies (preheating, steam generation, and process heating) along with practical constraints (space availability, data scarcity, etc.). The review shows that system‐level design choices, such as thermal energy storage and operational flexibility, often govern achievable solar fraction and economic competitiveness more than collector performance alone. Additionally, several studies on the optimization of PTSCs for industrial use are presented and analyzed. It reveals a clear shift from single‐parameter tuning toward AI‐assisted and multiobjective paradigms that simultaneously address thermal performance, cost metrics, and operational reliability. Further, literature on dynamic modeling of the PTSC and its control is examined. It highlights the necessity of maintaining stable operations amid fluctuating solar input and varying industrial load conditions. Overall, the review distils convergent trends, highlights persistent gaps, and outlines actionable research directions to accelerate robust PTSC deployment for industrial decarbonization. This article is categorized under: Sustainable Energy > Solar Energy Sustainable Development > Goals Sustainable Energy > Energy Efficiency
ABSTRACT This study conducts a comprehensive bibliometric analysis combined with text mining to explore the influence of clean cooking fuel on women's empowerment. Here, we have analyzed 305 research publications indexed in the Web of Science to explore trends in research on clean cooking fuels, shedding light on their intersection with gender dynamics, health, and socio‐economic development. The bibliometric analysis showed a significant growth in terms of published papers from 2015 onwards, influenced by global attention to clean energy and its socio‐environmental benefits. We identified six common topics through topic modeling, including the health benefits of clean cooking technologies for women, reduced indoor air pollution, and the socio‐economic advantage of cleaner fuels. The results underscore the critical role of clean cooking fuels in enhancing women's health, reducing their domestic labor burden, and advancing gender equality. Geographical disparities in how impactful research is highlighted; the USA and China lead for citations. Despite such progress, challenges such as economic and cultural barriers to adoption in rural populations remain, necessitating targeted policy action. Although previous literature had focused on clean energy transitions, this study contributes by demonstrating the potential benefits of clean cooking programs on women's empowerment and general well‐being. This article is categorized under: Human and Social Dimensions > Gender Equity Sustainable Development > Goals Policy and Economics > Research and Development
ABSTRACT Building‐integrated photovoltaics (BIPV) are emerging as a strategic interface technology linking building decarbonization and urban climate resilience, with research rapidly shifting from device‐level efficiency enhancement to system integration and urban‐scale deployment. Yet, coherent frameworks linking devices, components, buildings, and cities remain limited. This study presents a structured scientometric analysis of 2525 core publications (2003–2024), integrating co‐occurrence mapping, co‐citation clustering, temporal evolution modeling, and burst detection to map the field's structural evolution and thematic frontiers. Findings reveal three developmental phases: an initial focus on prototyping and grid integration; a subsequent shift toward multi‐physics modeling and building‐level simulation; and a recent expansion into high‐performance material integration, AI‐driven operation, carbon analytics, and urban deployment modeling. Global collaboration networks show growing multipolarity, with research output shaped by policy incentives. China leads in productivity and centrality, while emerging markets gain prominence. Institutional pathways diverge between materials–systems and architectural integration, and journals increasingly support interdisciplinary knowledge exchange across these domains. The evolution of BIPV is fundamentally driven by the cross‐scale transmission of performance criteria and boundary conditions, transforming technical metrics into deployable, verifiable strategies. Future research should prioritize engineering‐oriented evaluation of multifunctional materials for building applications, intelligent control systems that incorporate degradation and uncertainty, co‐optimization frameworks for thermal and visual comfort at façade boundaries, and urban deployment models that integrate semantic accuracy, hosting capacity, and grid‐integration costs. This study reconstructs BIPV's multi‐scalar knowledge landscape and proposes a capability framework for scalable and auditable deployment, offering strategic alignment across policy, practice, and scholarly agendas. This article is categorized under: Sustainable Energy > Solar Energy Cities and Transportation > Buildings Energy and Power Systems > Distributed Generation
ABSTRACT Increasing penetrations of variable renewable energy sources like wind and solar photovoltaic (PV) systems are challenging power system stability worldwide. Leveraging demand‐side behavior is becoming more popular to help overcome contemporary issues concerning balancing electricity generation and demand. As significant energy users with the potential to act as electricity producers through renewable energy sources, buildings are attractive assets for contributing to power system control from energy efficiency and demand response perspectives. Meanwhile, the proliferation of “smarter” buildings equipped with network‐connected sensors and devices using Internet of Things (IoT) platforms produces significant data volumes that lend themselves to novel artificial intelligence (AI) and machine learning (ML) methods that we can apply across the suite of demand response design steps. This paper reviews the application of AI and ML methods across these steps, which include building energy analysis and auditing, modeling and predicting building load demand, detecting and classifying building energy and power flexibility, implementing flexible building load control, and participating in demand response and other ancillary service markets. Throughout the paper, we comprehensively analyze the application of various AI and ML methods, highlighting their effectiveness and limitations. We also identify emerging pertinent challenges of interest to practitioners and researchers examining the implementation of such approaches for building demand response provision. This article is categorized under: Cities and Transportation > Buildings Energy and Power Systems > Energy Infrastructure Energy and Power Systems > Energy Management
ABSTRACT Green hydrogen is increasingly positioned to play a transformational role in the decarbonization of the global economy. The number of announced green hydrogen projects is growing rapidly, with a substantial portion located in water‐stressed regions. Commercial‐scale green hydrogen projects rely on PEM and alkaline electrolysis to produce hydrogen from water, powered by electricity generated from renewable sources. The objective of this article is to provide a comprehensive review of water consumption in green hydrogen production, addressing the often‐overlooked implications of freshwater use in large‐scale electrolysis. Water resources represent a critical constraint for hydrogen production, and their availability must be carefully addressed. A review of ongoing green hydrogen projects showed that most of them rely on desalinated seawater, though reclaimed wastewater is emerging as an increasingly attractive alternative source. Currently, PEM electrolysis is the most water‐efficient technology for producing green hydrogen, consuming an average of 17.5 L of water/kg of hydrogen. Of this amount, 51% is used directly in the electrolysis process, while the remaining 49% is allocated to cooling. There are opportunities to improve water efficiency in green hydrogen production by focusing on the optimization of water consumption for cooling. The most relevant ones are the adjustment of the cycles of concentration in cooling towers, the reuse of blowdown water, and the use of adiabatic cooling systems. In coastal areas with favorable bathymetric conditions, the use of seawater could also help lower the demand for cooling water.
ABSTRACT Flexible supercapacitors with hybrid anodes have emerged as a pivotal research focus in energy storage, showcasing remarkable potential for specific capacitance, power density, and flexibility. This part of the review focuses on freestanding carbon‐based hybrid anodes, examining the composition, morphology, and surface modification strategies of metal‐based active materials, including oxides, sulfides, phosphides, and other compounds. These diverse metal‐based compounds are employed to fabricate efficient supercapacitors, encompassing both symmetric and asymmetric configurations. This review presents a comprehensive summary of metal‐based compounds utilized as active redox materials for anodes, along with modifying strategies that elevate their electrochemical performance. This review also summarizes how the proposed materials classes, their structural features, and surface engineering properties affect the electrochemical properties, including charge storage, mechanical integrity, and cyclic stability. Besides, the key strategies for enhancing active sites, conductivity, and device flexibility are also presented, providing a comprehensive perspective to guide the design of efficient, real‐world flexible supercapacitor electrodes. This article is categorized under: Emerging Technologies > Energy Storage Emerging Technologies > Materials
ABSTRACT Cold‐climate wind power represents a major subset of onshore global capacity, with approximately one third of existing installations located in regions prone to low temperatures and icing. The main technical challenge in cold‐climate conditions is ice accretion on turbine blades, which degrades aerodynamic performance and causes production losses, while ice falling from turbines poses a significant safety risk. These issues have driven the development of specialized technological solutions, including ice detection and mitigation systems and detailed forecasting models. In parallel, specific policy approaches have also been developed to address increased icing risks. This review focuses on wind turbine blade icing and related issues for onshore wind. It presents state‐of‐the‐art technical solutions for icing‐related challenges, as well as approaches for icing modeling and forecasting of icing conditions. In addition, relevant policies from different countries are reviewed. Production losses due to icing are highly variable, influenced by ice thickness, shape, and post‐icing wind conditions. Accurate estimation and forecasting of these losses require advanced tools, ranging from SCADA‐based analyses to machine learning methods and mesoscale weather prediction models. Ice detection technologies are being developed based on both direct and indirect measurement principles. Efforts to validate and certify these systems for operational use, such as automatically stopping and starting turbines, are ongoing. Icing mitigation includes both active technologies, such as blade heating systems, and passive approaches, such as icephobic coatings. Uncertainty quantification has become central to project financing and planning, with standards emerging to guide risk assessment. Policy and regulatory responses vary internationally: some regions, like Québec, mandate cold‐climate certifications and real‐time operational data reporting, while others focus on risk assessments and safety zones. Regulatory approaches remain somewhat fragmented and guided by local priorities. Further harmonization is needed to address critical safety issues such as ice throw. This article is categorized under: Sustainable Energy > Wind Energy Policy and Economics > Governance and Regulation
ABSTRACT Efficient and scalable electrochemical energy storage devices are crucial for the global transition to renewable energy. The decoupling of energy and power densities has extended the operational life and continuous operation capabilities of slurry flow electrodes (SFEs), making them a potential solution. This study comprehensively examines the design principles, rheological behavior, electrochemical performance, and prospective applications of SFE systems across diverse domains, including grid‐scale energy storage, capacitive deionization, and hydrogen storage. Thorough literature research was conducted in conjunction with an examination of current experimental advances, including the use of carbon foam and aqueous slurries based on multi‐walled carbon nanotubes. This current work highlights the synergistic role of novel materials, optimized flow field architectures, and externally applied magnetic fields in addressing persistent challenges, including excessive viscosity, particle agglomeration, and limited electronic conductivity. Furthermore, the study evaluates recent developments in both membrane‐based and membrane‐less SFE configurations, emphasizing their roles in flow‐electrode capacitive deionization and lithium slurry battery systems.
ABSTRACT The renewable energy transition in high‐density Asian economies is defined not by the “Not In My Backyard” (NIMBY) psychology prevalent in Western discourse, but by a structural reality of “No Backyard Available.” This study challenges dominant theoretical paradigms by conducting a bibliometric analysis ( n = 306) and qualitative meta‐synthesis ( n = 52) to map the specific mechanics of land‐use conflict in land‐scarce Asia. The review identifies three pervasive conflict archetypes—the Food‐Energy Nexus, Green‐on‐Green Paradox, and Blue Space contestation—where energy infrastructure directly competes with essential livelihood systems and biodiversity rather than esthetic preferences. A critical assessment gap is revealed, in which GIS‐based technical potential systematically overestimates capacity by ignoring complex tenure systems, subsistence constraints, and the social costs of displacement. To resolve this impasse, the review proposes the “Ladder of Land‐Use Efficiency,” a theoretical framework that prioritizes siting strategies—ranging from built‐environment integration to technological co‐location—based on their ability to decouple energy generation from the consumption of marginal land. The findings demonstrate that achieving net‐zero targets in Asia necessitates a fundamental policy shift from laissez‐faire financial‐cost optimization to active state‐led spatial planning that internalizes the social premium of land integrity. This research provides a prescriptive roadmap for environmental managers to reconcile aggressive decarbonization with the region's complex spatial and socio‐economic realities.
Starting in the 1970s, and most notably from the 1990s to 2025, the US federal government served as a market leader in demonstrating green building design and performance with its own facilities and thereby influencing the market through “leadership by example.” Over the decades, the government achieved measurable progress in reducing building energy and water use, while saving significantly on utility bills and maintaining occupant satisfaction. This article draws on the author's long‐term participation in this federal movement, supplemented by many additional sources, to outline the strategies behind the success of these policies and where they fell short. Strategies discussed include providing bipartisan leadership; creating and promoting showcase facilities; drawing on internal and external expertise; convening, educating and recognizing agency champions and practitioners; creating standards and frameworks for implementation; leveraging financial resources; testing innovations; and greening military properties. The author discusses how and why these approaches worked, instances where they confronted barriers and how key players worked to overcome them. The analysis reveals a picture of a richly complex, iterative process, not strictly driven from above (leadership) versus below (staff) or from inside versus outside the government, but as a learning process of continuous interaction and advancement. In the wake of the downsizing or elimination of many of these programs by the second Trump administration and the exit of many of their champions and practitioners from the government, the article concludes with a discussion of challenges to reviving US federal green building and posits approaches to overcome these challenges. This article is categorized under: Policy and Economics > Governance and Regulation. Sustainable Energy > Energy Efficiency. Cities and Transportation > Buildings.
ABSTRACT The sustainable future can be realized by utilizing solar energy and converting it to different forms of energy that can be effectively stored. Hydrogen (H 2 ) and its derivatives are widely regarded as future energy carriers essential for achieving a sustainable and decarbonized energy system. One of the most promising approaches to produce clean H 2 is by converting solar energy directly into chemical energy via water splitting. This can be achieved using photoelectrochemical processes that harness sunlight to produce H 2 from water (H 2 O). There are three primary solar‐driven pathways for hydrogen generation: photocatalysis (PC), photoelectrochemical cells (PEC), and photovoltaic–electrochemical (PV–EC) systems. This review provides a systematic comparison of these methods by examining their operating principles, materials, stability, and solar‐to‐hydrogen (STH) conversion efficiency, offering insights into their scalability and suitability for sustainable hydrogen production. The research on these conversion systems is widely spread across different fields, and experimental works were done under different standards. These works are unintegrated and very few works have systematically compared them to benchmark their performances. In this work, we systematically review three different systems by examining their working mechanism, materials, stability, and efficiency, providing insights into their potentials for large‐scale, sustainable hydrogen production. This work provides evidence‐based insight into different technologies to help different stakeholders and decision makers. We observed the triple‐junction PV‐EC system exhibit 30% STH with exceptional stability.
Emissions trading systems (ETSs) have expanded over the past 20 years to cover over 23% of global GHG emissions. This growth reflects their demonstrated ability to reduce emissions by diverse sources at low cost with no adverse economic impacts. Their approach to allocating free allowances and to managing the supply of allowances has become more effective. Linking multiple ETSs has worked well. An ETS encourages sources to implement mitigation measures whose marginal cost is lower than the allowance price. This means that existing ETSs have achieved only limited reductions by sources in difficult-to-abate industries with high abatement costs. To stabilize the climate, all of these industries must be transformed to net zero emitters. This paper proposes a design for linked ETSs to achieve the needed transformation. Each ETSs should cover a substantial share of the global production and consumption of a single industry. The design promotes low emitting new entrants and retirement of high-emitting facilities. It includes provisions to ensure a competitive allowance market and to assist developing countries. A trade agreement for the industry's products would complement the system .This article is categorized under: Climate and Environment > Net Zero Planning and Decarbonization Policy and Economics > Regional and International Strategies Policy and Economics > Governance and Regulation
As modern buildings face increasing sustainability and performance demands, simulation-based optimization and machine learning have become essential tools in the design process. This article highlights the limitations of traditional design methods and explores how multi-objective optimization and surrogate modeling enable scalable, efficient, and data-driven evaluation of building performance. The design paradigm has shifted from rule-based approaches to intelligent, algorithm-driven processes that balance energy, comfort, cost, and emissions. Simulation-based optimization integrates dynamic simulation with advanced algorithms to explore complex design spaces and identify optimal trade-offs. To this end, a case study of a low-rise residential building in Patras, Greece, is presented using the Non-dominated Sorting Genetic Algorithm II. The model evaluated 12 envelope-related design variables and generated a well-distributed Pareto front of 65 non-dominated solutions, highlighting trade-offs between heating energy demand and construction cost. The sensitivity patterns observed across the Pareto set showed that insulation thickness and glazing performance were the most influential drivers of heating demand. Machine learning-based surrogate modeling enhances optimization further by approximating computationally expensive simulations with fast, predictive models. Trained on sampled simulation data, these surrogates enable rapid optimization and sensitivity analysis. A second case study, referring to a school retrofit in Portugal, demonstrated that an Artificial Neural Network surrogate reduced computation time from approximately 75 days to just 3 days while maintaining high predictive accuracy. Sensitivity analysis indicated that window upgrades, HVAC efficiency, and solar thermal integration had the strongest influence on energy use and thermal discomfort. These quantitative and sensitivity-based insights demonstrate how combining simulation-based and machine learning methodologies supports high-performance, cost-effective, and environmentally responsible building design and retrofit. This article is categorized under: Sustainable Energy > Energy Efficiency Cities and Transportation > Buildings
Fragmented regulations, limited access to green finance, and underdeveloped carbon markets impede ASEAN's clean energy transition. This paper assesses global best practices, including the EU Emissions Trading System (EU ETS), the Carbon Border Adjustment Mechanism (CBAM), and green bond standards, through comparative policy analysis, evaluating their suitability for ASEAN's context. By examining specific national cases from Indonesia, Singapore, and Thailand, we identify critical opportunities for enhancing institutional capacities, harmonizing regulatory frameworks, and scaling climate-aligned investment. A strategic roadmap is developed, focusing particularly on carbon pricing mechanisms, blended finance solutions, and digital innovations such as blockchain and artificial intelligence for regional energy market integration. Findings underline the necessity of coordinated regional carbon markets, standardized green finance instruments, and digitally driven transparency tools. This integrated approach offers ASEAN a pragmatic pathway to accelerate its low-carbon transition, ensuring both economic resilience and regional cooperation. Future research is recommended to explore socioeconomic impacts on vulnerable sectors and strategies for operationalizing regional carbon pricing across ASEAN's diverse political economies. This article is categorized under:
The deployment of distributed renewable energy (DRE) is a crucial strategy for enhancing energy security and mitigating the impact of climate change. However, its development faces significant challenges related to system integration, operational management, and benefit distribution. This paper presents a bibliometric analysis of DRE literature, offering insights into key research directions, emerging trends, and frontiers in this field from both quantitative and visual perspectives. In addition, traditional content analysis methods were used to examine the development paths of DRE in five representative countries, considering the heterogeneity of their respective contexts. The results revealed that research in the DRE field is becoming increasingly interdisciplinary and diversified. Frontier studies now focus on the democratization, marketization, integration, and intelligence of the DRE. This reflects a broader trend toward transforming DRE into an integrated system. Furthermore, differences in DRE promotion paths across countries are influenced not only by resource endowments, technological capabilities, and social contexts but also by policies and market mechanisms. Based on global development trends and empirical evidence, this study suggests that future research should focus on policy and market mechanism design, technological advancement and intelligent integration, the diversification of application scenarios, and social acceptance and public participation.
Hydrogen gas is a crucial fuel for the green energy transition as its combustion yields energy and water. However, it is mainly produced through fossil fuels, hindering its potential for environmental benefits. Therefore, the trend is shifting toward green hydrogen produced through renewable sources. Electrolysis by solid oxide electrolysis cells (SOECs) is one of the most promising methods for green hydrogen production due to its high efficiency and chemical conversion flexibility. In addition to producing hydrogen and oxygen by steam electrolysis, SOECs can also produce other electro-fuels such as syngas and ammonia by co-electrolysis of steam and carbon dioxide and co-electrolysis of steam and air, respectively. Conventional SOECs utilize oxide ionic conductor ceramic electrolytes such as zirconia; however, proton-conducting ceramic electrolytes have recently emerged due to their efficient electrochemical cell designs and improved performance at low operating temperatures. This review presents the status of the oxide ion conductor (SOEC) and proton conductor (PCEC) cell configurations. For this purpose, we summarize the most used materials, fabrication methods, and characterization techniques. Furthermore, we critically investigated the issues related to cell performance and stability by performing a systematic analysis of the degradation mechanisms for both oxide ion conductor and proton conductor electrolysis cells. The recommendations provided in this work would help researchers identify the key issues hindering the commercialization of promising SOEC technology.
Local Energy Markets (LEMs) have added global attention as a potential solution for transitioning to a decentralized and sustainable energy system. This article delves into the context of exploring the status, policy framework, and regulatory barriers related to grid stability, energy access, and environmental sustainability. Study extends to institutional and legal frameworks and issues surrounding stakeholder and consumer engagement. Execution of the Green Energy Open Access (GEOA) Rules in 2022 has been crucial in India, resulting in an incredible rise of 90.4% in annual installed capacity for both industrial and commercial customers within FY2023 and FY2024. Cumulative capacity has reached 18.7 gigawatts by the completion of FY2024. India has actively taken steps to diversify its energy balance, encourage renewable sources, and enhance energy efficiency by reducing the threshold for open access from 1 MW to 100 kW, enabling smaller companies to participate in energy trading. A coordinated strategy combining the federal and state governments, regulatory bodies, DISCOMs, and private parties is needed to overcome the obstacles. The Indian government has instigated various policies to ensure the sustainable development of the energy industry, demonstrating a commitment to reducing regulatory barriers to attracting investments and fostering sectoral growth. This study provides actionable advice for policymakers and regulators to address identified obstacles, expediting the transition toward a decentralized and sustainable energy future. This article is categorized under:
The ASEAN region faces mounting pressure to decarbonize its transport sector amid rising energy demand, urbanization, and climate commitments. Road transport dominates ASEAN energy use and emissions; in 2022 oil supplied 91.2% of transport energy and the sector produced 18.5% of total GHGs. This review synthesizes electric vehicle (EV) and biofuel policies across ASEAN member states using primary government sources, peer-reviewed literature, national strategies, and global assessments. The scope is road transport, covering both passenger and freight segments, with outcomes reported for 2022–2025. We identify policy instruments, infrastructure readiness, and deployment patterns, and assess synergies and constraints in the dual transition to e-mobility and sustainable biofuels. Key findings include heterogeneous progress: Thailand leads EV car uptake; Singapore shows the highest availability per car (charging points); and two-wheeler-dominant markets require adjusted denominators. On biofuels, Indonesia's B35 underpins large-scale biodiesel production, Malaysia lacks a fuel ethanol market, the Philippines sustains E10 with imports, and Viet Nam is preparing E10 blending. We propose a structured policy framework tailored to diverse national contexts, emphasizing coordinated regional strategies, public–private collaboration, and long-term investment. By consolidating policy detail and recent outcomes, the review supports a clearer, evidence-based gap analysis and provides practical guidance for scaling sustainable transport across ASEAN. This article is categorized under:
Hydrogen is emerging as a pivotal energy carrier for the industrial, transportation, and power sectors due to its high energy density and potential for decarbonization. Water electrolysis is a promising, emission-free method for hydrogen production, with various electrolyzer technologies—alkaline water electrolysis (AWE), proton exchange membrane electrolysis (PEME), and anion exchange membrane electrolysis (AEME)—in active development. This review critically analyzes the advancements in electrode materials, focusing on the transition from support-based to self-supported electrodes (SSEs), which offer enhanced performance and stability under high current densities. The review emphasizes the critical shift from traditional supporting electrodes to self-supported electrodes (SSEs), which provide enhanced mechanical stability, reduce ohmic resistance, and improve overall performance at high current densities. PEM electrolyzers, for instance, generate 4.0 A/cm 2 at 2.36 V, achieving 70%–80% energy efficiency, while AEM electrolyzers perform at the same current density but at a lower voltage of 1.9 V. SSEs, such as Ru@Cu-TM cathodes, have exhibited superior performance, delivering current densities of 1.0 A/cm 2 at 1.69 V and maintaining stability over prolonged operational periods. While SSEs eliminate the limitations of traditional electrodes—such as catalyst peeling and binder instability—further research is needed to optimize their mechanical properties and scalability. Integrating advanced SSEs can significantly lower hydrogen production costs, with estimates as low as US$2.09/kg H 2 , positioning them as a pivotal solution for sustainable energy. This review provides valuable insights into the future of SSE-based electrolyzers and their role in accelerating the global transition to green hydrogen. This article is categorized under:
