Search Results (428)

The development of energy systems toward a decarbonized economy is increasingly constrained not only by technological challenges, but also by deficiencies in the organization, coordination, and governability of sustainable financing. This study aims to substantiate an integrated conceptual model and a multi-level governance framework for the sustainable financing mechanism of energy system development under decarbonization, ensuring the alignment of financial instruments with transition strategies, performance indicators, and feedback mechanisms. The methodology combines a bibliometric analysis of Scopus-indexed journal publications with an examination of international statistical and analytical data produced by leading global organizations, complemented by systemic, institutional, and comparative analytical approaches. The bibliometric analysis was conducted in 2025 and covered peer-reviewed articles published during 2017–2025, while empirical financial indicators were synthesized for the most recent available period of 2022–2024 using comparable time-series data reported by international institutions. The results indicate that despite global energy investments reaching approximately $3 trillion in 2024—nearly $2 trillion of which was allocated to clean energy technologies—a persistent annual financing gap for climate change mitigation in the energy sector remains. Moreover, to remain consistent with the Net Zero trajectory, investments in clean energy must increase by approximately 1.7 times by 2030. The synthesis of contemporary research and empirical evidence reveals a predominance of studies focused on individual green and transition finance instruments, accompanied by persistent fragmentation between financial flows, governance structures, and measurable decarbonization outcomes. To address this gap, the paper proposes a conceptual model that interprets sustainable finance as a governed system rather than a collection of isolated instruments, together with a multi-level governance framework integrating strategic (policy), sectoral, and project-level decision-making with systems of key performance indicators, monitoring, and feedback. The findings demonstrate that the effectiveness of sustainable financing critically depends on the coherence between financial instruments, governance architectures, and decarbonization objectives, which ultimately determines the capacity to translate mobilized capital into tangible energy infrastructure modernization and measurable emissions reductions. The proposed approach provides a practical foundation for improving energy transition policies and investment strategies at both national and supranational levels. Full article

The northern coast of Mauritania presents a strategic opportunity for clean energy investment due to its remarkable potential for green hydrogen production through wind energy. To determine the best location for wind-based green hydrogen production, this paper established a Multi-Criteria Decision-Making framework (MCDM) that combines the Analytic Hierarchy Process (AHP) and Evidential Reasoning (ER) to assess five coastal sites: Nouakchott, Nouamghar, Tasiast, Boulanoir, and Nouadhibou. Four main criteria (i.e., economic, technical, environmental, and social) and twelve sub-criteria were taken into account in the assessment. To ensure reliability and contextual accuracy, the data used in this study were obtained from geographic databases, peer-reviewed literature, and structured expert questionnaires. The results indicate that site 5 (Nouadhibou) is the most suitable location for green hydrogen generation using wind energy. Sensitivity analysis confirms the robustness of the ranking results, validating the reliability of the proposed hybrid framework. The findings of this study provide critical, data-driven decision-support insights for investors and policymakers, guiding the strategic development of sustainable wind-based green hydrogen projects along Mauritania’s coastline. Full article

Environmental sustainability has emerged as a global imperative in the context of accelerating climate change, rapid industrialization, and increasing ecological stress. Ecological quality is necessary for countries to pursue because of its overall benefits to the entire ecosystem. Therefore, due to the significant role that the United Arab Emirates (UAE) plays in the global environment, this research examines the role of Green Innovation (GI), Financial Globalization (FG), Economic Growth (GDP), and Foreign Direct Investment (FDI) in influencing Environmental Quality (EQ) in the UAE from 1991–2022. The UAE is well known for these economic indices. Furthermore, this study employed the innovative Quantile Augmented Dickey–Fuller (QADF) test, Wavelet Quantile Regression (WQR), Wavelet Quantile Correlation (WQC), and Quantile-on-Quantile Granger Causality (QQGC). WQR is able to identify connections between series over a range of quantiles and periods. WQC evaluates the co-movement between variables at different quantile levels and across several scales. The QQGC captures the causal effect of the regressors on EQ. These methods are quite advanced compared to other traditional econometric methods. Based on the outcome of the WQR and WQC methods, evidence shows that GI contributes to EQ across all quantiles in the short, medium, and long term, while FG, GDP, and FDI reduces EQ across all quantiles in the short, medium, and long term. The QQGC results also affirm causality among the variables, implying that GI, FG, GDP, and FDI can predict EQ across all quantiles. This research recommends that the UAE should improve on its environmental policies both domestically and internationally by making them more stringent, and continue to promote clean energy investments. Full article

Climate change and increasing greenhouse gas emissions are driving the global transition to clean energy, with solar energy experiencing the fastest growth among renewable sources in 2024. Solar PV for energy generation in Kenya is gaining momentum as the country moves towards achieving 100% clean energy by 2030. As solar PV penetration in the grid grows, it is necessary to evaluate its impact on system costs to inform policy decisions on capacity expansion options in the Least-Cost Power Development Plan (LCPDP). This study investigates the effect of large-scale solar PV expansion on electricity costs using the Open-Source Energy Modelling System (OSeMOSYS), a modular, bottom-up capacity expansion model. Four scenarios were developed to assess different levels of solar PV penetration: business-as-usual (BAU), moderate-solar-PV expansion (MSPV), high-solar-PV expansion (HSPV), and very-high-solar-PV expansion (VHSPV). The results indicate that, while overall solar PV expansion significantly contributes to decarbonising Kenya’s electricity mix by displacing fossil-based generation, it also increases annual investment obligations and, consequently, total system costs. The system-levelised cost of electricity (LCOE) is shown to rise by 0.2%, 5.7%, and 14.0% under MSPV, HSPV, and VHSPV, respectively, compared to BAU. Analysing the various cost components against sustainability indicators reveals that the least-cost scenario is BAU while the most favourable scenario based on sustainability indicators is VHSPV, which performs best across technical, environmental, and institutional dimensions but less favourably on economic and social aspects, thereby highlighting a trade-off between sustainability and cost minimisation, at least in the short term. Full article

Improving the energy efficiency of buildings is a highly desirable investment in the context of implementing the sustainable development paradigm, as it reduces the building’s energy demand. Consequently, the economic costs of heating the building are diminished. Reducing the building’s negative environmental impact is also crucial. This article presents programs that subsidize thermal modernization investments for single-family buildings in Poland. Particular attention was paid to the Clean Air program. A methodology for the economic and ecological assessment of thermal modernization investments eligible for funding under this program was proposed. The methodology is based on the Net Present Value indicator, whereas the ecological analysis utilized the Life Cycle Assessment method. A case study was conducted for a model single-family building using the introduced methodology. The scope of the thermal modernization investment included replacing windows and doors, replacing the heat source, and thermal insulation of the vertical external walls. The analyzed thermal modernization investment brings substantial ecological benefits, significantly reducing the building’s negative environmental impact. Unfortunately, the economic viability for the investor is not so obvious and depends primarily on the level of subsidy. Full article

This study examines the determinants of energy efficiency in G20 economies over the period of 2000–2024 using the method of moments quantile regression (MMQR) to analyze the variation in the impacts of green innovation, green investment, green finance, the strength of energy policy, and trade openness across different levels of energy intensity. The results reveal that these variables do not affect all countries equally; their effects vary with the maturity of institutional and technological structures. Economies with strong regulations benefit more from green innovation and expanded environmental financial instruments, whereas countries with limited ready-made institutions struggle to turn these variables into tangible gains. This study also showed that energy policy was the most stable factor across all levels, while innovation, finance, and investment became more impactful in countries that had made significant progress in energy intensity. This study proposes a differential policy that responds to various institutional readiness levels. Low-intensity energy economies should prioritize strengthening regulatory frameworks and improving energy governance, medium-performing countries should expand green finance opportunities and direct investments toward clean technology, and developed countries should focus on deepening innovation and broadening the base of technology transfer to promote long-term sustainability. Overall, the results confirm that the green shift in the G20 economies requires specialized strategies rather than uniform policies that overlook economic structural differences. Full article

Against the background of global energy transformation and low-carbon development, numerous difficult-to-mine coal resources (e.g., deep, thin coal seams and low-quality coal) remain underdeveloped, leading to potential resource waste. This study systematically summarizes the feasibility of developing these resources via underground coal gasification (UCG) technology, clarifies its basic chemical/physical processes and typical gas supply/gas withdrawal arrangements, and establishes an analytical framework covering resource utilization, gas production quality control, environmental impact, and cost efficiency. Comparative evaluations are conducted among UCG, surface coal gasification (SCG), natural gas conversion, and electrolysis-based hydrogen production. Results show that UCG exhibits significant advantages: wide resource adaptability (recovering over 60% of difficult-to-mine coal resources), better environmental performance than traditional coal mining and SCG (e.g., less surface disturbance, 50% solid waste reduction), and obvious economic benefits (total capital investment without CCS is 65–82% of SCG, and hydrogen production cost ranges from 0.1 to 0.14 USD/m³, significantly lower than SCG’s 0.23–0.27 USD/m³). However, UCG faces challenges, including environmental risks (groundwater pollution by heavy metals, syngas leakage), geological risks (ground subsidence, rock mass strength reduction), and technical bottlenecks (difficult ignition control, unstable large-scale production). Combined with carbon capture and storage (CCS) technology, UCG can reduce carbon emissions, but CCS only mitigates carbon impact rather than reversing it. UCG provides a large-scale, stable, and economical path for the efficient clean development of difficult-to-mine coal resources, contributing to global energy structure transformation and low-carbon development. Full article

Europe’s hydrogen strategy has centred almost exclusively on green hydrogen produced through renewable electrolysis as the cornerstone of its decarbonisation agenda. However, recent discoveries of naturally occurring “white hydrogen” in France, Spain, and other parts of Europe raise the prospect of a new, abundant, and low-cost clean energy resource. White hydrogen, generated geologically and extractable directly from subsurface reservoirs, could complement or even disrupt the current power-to-X pathway by offering production costs estimated at €0.75–1 per kilogram, far below today’s €6–8 for green hydrogen. Early geological findings suggest potentially vast reserves, yet the scale, renewability, and environmental impacts remain uncertain. This policy note critically reassesses the European Union’s hydrogen strategy in light of these developments, examining the economic, environmental, and regulatory implications of integrating white hydrogen. It argues for a balanced, adaptive approach: continuing to scale green hydrogen to meet near-term decarbonisation targets while fostering exploration, regulation, and pilot projects for white hydrogen. Such an approach can safeguard Europe’s climate ambitions, mitigate energy security risks, and avoid stranded investments, while positioning the EU to benefit if natural hydrogen proves viable at scale. Full article

The shift to renewable energy is a key goal for the European Union as it aims for climate neutrality; however, the effectiveness of climate-focused funding instruments varies significantly across member states. This research investigates the influences of mitigation investments, R&D spending, environmental tax revenues, subsidies, GDP growth, and capital formation on renewable energy expansion within the EU-27, placing particular emphasis on the structural differences between Old Member States (OMS) and New Member States (NMS). The study utilizes robust long-run estimation techniques alongside causality analysis over a span of 13 years, from 2010–2023. The findings highlight notable distinctions among the EU-27, OMS, and NMS regions. While the EU-27 and OMS show that funds designated for climate mitigation and R&D are critical drivers of the clean energy transition, in the NMS, environmental taxes, subsidies, innovation, and gross fixed capital formation play vital roles in advancing this transition. Furthermore, economic development shows mixed results in achieving sustainable objectives, underscoring the necessity for climate-oriented funding and initiatives. Therefore, policy measures should focus on mitigation finance and innovation across the EU, while the design of subsidies and environmental tax structures must be tailored to each region to ensure a fair and expedited transition. Full article

This study explores the effect of Energy Inequality (EINQ) on environmental sustainability within the frameworks of the Environmental Kuznets Curve (EKC) and the Load Capacity Curve (LCC), while accounting for technological progress (TECH), financial development (FD), and foreign direct investment (FDI). Using annual data for six Gulf Cooperation Council (GCC) countries from 2005 to 2024, the analysis applies the Method of Moments Quantile Regression (MMQR) to capture heterogeneous effects across the distribution of the Load Capacity Factor (LCF). The results show that energy inequality consistently reduces environmental sustainability, indicating that unequal access to efficient and clean energy services heightens ecological pressure. In contrast, technological innovation and financial development enhance sustainability by improving energy efficiency and supporting green investments. Economic growth exhibits an inverted U-shape, validating the EKC and LCC hypotheses. These findings are especially important for the GCC, where hydrocarbon dependence, uneven access to clean energy, and rapid structural change intensify the environmental consequences of inequality. The study underscores the need for policies that promote equitable energy access, innovation-led diversification, and sustainable financial mechanisms. Full article

The global energy transition faces a chasm between current policy commitments (IEA’s STEPS) and the deep, rapid transformation required to realize all national net zero pledges (IEA’s APC). This perspective addresses the critical innovation and policy gap blocking the APC pathway, where many high-impact, clean technologies remain at low-to-medium Technology Readiness Levels (TRLs 3–6) and lack formal policy support. The insufficient nature of current climate policy nomenclature is highlighted, which often limits Nature-based Solutions (NbS) to incremental projects rather than driving systemic technological change (Bio-inspiration). Then, we propose that a deliberate shift from simple biomimetics (mimicking form) to biomimicry (emulating life cycle sustainability) is the essential proxy for acceleration. Biomimicry inherently targets the grand challenges of resilience, resource efficiency, and multi-functionality that carbon-centric metrics fail to capture. To institutionalize this change, we advocate for the mandatory integration of bio-inspired design into National Determined Contributions (NDCs) by reframing NbS as Nature-based Innovation (NbI) and introducing novel quantitative metrics. Finally, a three-step roadmap to guide this systemic shift is presented, from deployment of prototypes (2025–2028), to scaling evidence and standardization (2029–2035), to consolidation and regenerative integration (2036–2050). Formalizing these principles through policy will de-risk investment, mandate greater R&D rigor, and ensure that the next generation of energy infrastructure is not just carbon-neutral, but truly regenerative, aligning technology deployment with the necessary speed and depth of the APC scenario. Full article

This study examines the patterns of renewable energy consumption across 29 European countries from 2000 to 2024. We utilised Bias-Corrected estimation techniques to analyse the relationship between renewable energy consumption, Human Development Index (HDI), labour force, and population dynamics, employing three distinct estimation models: global, rural, and urban. The results indicate that higher levels of human development and a larger labour force are positively associated with renewable energy consumption in the global and rural models, while the urban model shows an opposite effect for the labour force. Conversely, population growth is negatively related to renewable energy consumption in the global and rural contexts but positively in urban areas. These findings underscore the importance of socio-economic and demographic contexts in shaping renewable energy outcomes. They suggest that renewable energy can support economic and social development, but its effectiveness depends on regional structural conditions. From a policy perspective, the renewable transition should be approached as both an environmental and socio-economic strategy, aligning clean energy goals with employment generation, education, and inclusion, particularly in line with SDGs 7, 8, 10, and 13. Policies that promote green skills, innovation, and equitable regional investment can enhance social acceptance, competitiveness, and sustainable growth across Europe. Full article

In recent decades, rotating dynamic filtration (RDF) has attracted considerable attention due to its high efficiency and low energy consumption. While most studies have focused on separation behavior and membrane fouling, energy consumption in RDF has received limited attention. This study investigates the specific energy consumption (SEC) of the RDF process for ship exhaust gas cleaning (EGC) desulfurization wastewater treatment and proposes an optimization method based on both energy consumption and equipment cost. The total SEC increases with rotational velocity, circulation flow, feed concentration, and membrane size but decreases with temperature and remains unaffected by the number of membrane elements. In RDF, the total SEC is only 9.05–19.29% of that in tubular cross-flow filtration (CFF) at equivalent shear force ranging from 3.86 Pa to 121.14 Pa. Operating energy and investment costs are primarily determined by the number of membrane elements and the rotational velocity. According to the economic analysis, the lowest treatment cost for EGC wastewater is CNY 6.09 per cubic meter for a 5 m³·h⁻¹ capacity, using 84 membrane elements (374 mm, 0.2 µm) at a rotational velocity of 200 rpm, an operating pressure of 200 kPa, and a temperature of 40 °C. Full article

The urgent pursuit of climate-resilient agriculture and clean energy systems, central to the Energy–Agriculture Nexus and the UN Sustainable Development Goals, has accelerated global interest in agrivoltaic (Agri-PV) technologies. This paper presents a global systematic review and meta-analysis of 160 peer-reviewed studies, structured through a five-stage thematic synthesis: (1) mapping global and regional Agri-PV deployment and potential, (2) analyzing system design and modeling methodologies, (3) evaluating crop suitability under partial shading, (4) reviewing enabling policies and regulatory frameworks, and (5) assessing techno-economic feasibility and investment barriers. Results reveal that Europe and Asia lead Agri-PV development, driven by incentive-based policies and national tenders, while limited regulatory clarity and high capital costs constrain wider adoption. Despite technological progress, no integrated model fully captures the coupled energy, water, and crop dynamics essential for holistic assessment. Strengthening economic valuation, policy coherence, and standardized modeling approaches will be critical to scale Agri-PV systems as a cornerstone of sustainable and climate-resilient land use. Full article

The clean energy transition of the power sector is essential for achieving sustainable development. However, an important question is how, and to what extent, government subsidy policies contribute to this transition. Using county-level data on wind and photovoltaic capacity and power generation in China, we demonstrate that Feed-in Tariff (FIT) subsidies have substantially increased both the installed capacity and power generation of wind and PV energy. Specifically, for every 10% increase in FIT subsidies, wind power installed capacity increases by 24.33%, and power generation increases by 19.33%. Similarly, PV power installed capacity increases by 19.80%, and power generation increases by 15.50%. Further analysis reveals that FIT incentivizes market participants to invest in wind and PV power generation by increasing the likelihood of profitability for renewable energy enterprises. However, fixed FIT subsidies, probably due to over-incentivization, transmission constraints, and the intermittent nature of renewable energy, cause a decline in the capacity utilization rate of wind and PV power. Additionally, our findings highlight that tailoring FIT policies to local resource endowments and improving transmission infrastructure can enhance policy effectiveness and support the clean energy transition. Full article