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In third-generation centralized heating systems, qualitative regulation of the heat transfer medium parameters is mainly performed at heat sources, while quantitative regulation is implemented at central and individual heating points, with buildings remaining passive heat consumers. Unlike fourth-generation systems, such systems generally do not employ renewable energy sources, thermal energy storage, or low-temperature operating regimes. Third-generation centralized heating systems operate based on design high-temperature schedules and centralized control, without considering the actual thermal loads of consumers. Under conditions of physical deterioration of heating networks, hydraulic imbalance, and operational constraints, the actual parameters of the heat transfer medium supplied to buildings often deviate from design values, resulting in deviations of thermal conditions at the level of end consumers and disruptions of thermal comfort. This study proposes the concept of an intelligent active individual heating point (IAIHP), designed to provide adaptive qualitative–quantitative regulation of heat transfer medium parameters at the level of individual buildings. Unlike approaches focused on demand-side management, the use of thermal energy storage, or the integration of renewable energy sources, the proposed solution is based on the application of a local thermal energy source. The IAIHP compensates for deviations in heat transfer medium parameters and acts as a local thermal energy source within the building heat supply system (BHSS). Control of the IAIHP operation is performed by a developed automation system that provides combined qualitative and quantitative regulation of the heat transfer medium supplied to the BHSS. The study assesses the potential scale of IAIHP implementation in third-generation centralized heating systems, develops a methodology for selecting the capacity of a local heat source, and presents the operating algorithm of the automatic control system of the IAIHP. At present, the reconstruction of an individual heating point of a kindergarten connected via a dependent scheme is being carried out based on the developed project documentation. Modeling and calculations show that the application of the IAIHP makes it possible to ensure indoor thermal comfort by reducing the risk of temperature deviations, which are otherwise typically compensated for by electric heaters. The proposed concept provides a methodological basis for a gradual transition from third-generation to fourth-generation centralized heating systems, while equipping the IAIHP with an intelligent control system opens opportunities for improving the energy efficiency of urban heating networks. The proposed integrated solution and the developed automatic control algorithms exhibit scientific novelty and practical relevance for Russia and other countries operating third-generation centralized heating systems, including Northern and Eastern European states, where large-scale infrastructure modernization and the implementation of fourth-generation technologies are technically or economically constrained. Full article

Currently, renewable energy projects are growing, and one of the critical unforeseen consequences that has emerged is curtailment. This study focuses on characterizing a full dataset of real operational curtailed electricity from wind energy projects in one-hour time steps, obtained through Supervisory Control and Data Acquisition over the years 2022 and 2025 of operation in Chile. The case study is based on the national electrical system of Chile, and the analysis incorporates both curtailment patterns and more significant features. These results can ultimately be used as an input source for annexed projects, such as energy storage systems or green hydrogen production. The total installed capacity increased from 3.0 GW to 5.0 GW during this period, representing a 66% expansion, while energy generation increased by only 22%. Curtailed energy increased from 7% to 13% of total potential output, equivalent to approximately 3.4 TWh of unused clean energy. Location analysis reveals that around 60% of generation and curtailment occur in northern Chile, where grid congestion is most pronounced. Monthly trends show a pattern that combines a linear upward increase associated with growth in installed capacity and a cyclical seasonal component driven by resource variability. These findings highlight that curtailment has become a structural limitation for renewable integration, primarily due to insufficient transmission expansion and system flexibility. Full article

Rapid decarbonization and decentralization of power systems are driving the integration of renewable generation, energy storage and digital technologies into unified energy ecosystems. In this context, photovoltaic (PV) systems combined with battery and hydrogen storage and blockchain-based platforms represent a promising pathway toward sustainable and transparent energy management. This study evaluates the techno-economic performance and operational feasibility of integrated PV systems combining battery and hydrogen storage with a blockchain-based peer-to-peer (P2P) energy trading platform. A simulation framework was developed for two representative consumer profiles: a scientific–educational institution and a residential household. Technical, economic and environmental indicators were assessed for PV systems integrated with battery and hydrogen storage. The results indicate substantial reductions in grid electricity demand and CO₂ emissions for both profiles, with hydrogen integration providing additional peak-load stabilization under current cost constraints. Blockchain functionality was validated through smart contracts and a decentralized application, confirming the feasibility of P2P energy exchange without central intermediaries. Grid electricity consumption is reduced by up to approximately 45–50% for residential users and 35–40% for institutional buildings, accompanied by CO₂ emission reductions of up to 70% and 38%, respectively, while hydrogen integration enables significant peak-load reduction. Overall, the results demonstrate the synergistic potential of integrating PV generation, battery and hydrogen storage and blockchain-based trading to enhance energy independence, reduce emissions and improve system resilience, providing a comprehensive basis for future pilot implementations and market optimization strategies. Full article

In the effort to mitigate climate change, the Marine Hydrokinetic (MHK) energy from ocean currents emerges as an important renewable source due to its large potential, although it remains underexploited. In the Southwestern Tropical Atlantic, surface potentials linked to the North Brazil Current (NBC) are known, but the subsurface North Brazil Undercurrent (NBUC) remained unquantified. This study addressed this gap by applying a two-step approach using more than 20 years of high-resolution (1/12°) climatological and daily reanalysis data to estimate current power density (CPD) throughout the water column along the Brazilian shelf (4° N–12° S), with focus on energetic hotspots where maximum CPD exceeds 1000 W m⁻². The climatological analysis revealed 12 persistent hotspots (H1–H12). Daily analyses show highly energetic but seasonally variable surface hotspots north of 4° S linked to the NBC (H4–H12; >885 W·m⁻²) and weaker but more stable subsurface hotspots south of 4° S associated with the NBUC at depths of 130–266 m (H1–H3; 831–808 W·m⁻²). These patterns are likely influenced by flow–topography interactions along the continental margin. Overall, subsurface resources exhibit greater reliability than surface counterparts, highlighting the importance of incorporating subsurface dynamics in future MHK assessments and development along the Brazilian margin. Full article

The present study investigates the potential of poplar (Populus spp.) biomass from phytoremediation plantations as a feedstock for downdraft fixed bed gasification. The biomass was characterized in terms of moisture, ash content, elemental composition (C, H, N, O), and calorific values (HHV and LHV), confirming its suitability for thermochemical conversion. Gasification tests yielded a volumetric syngas production of 1.79 Nm³ kg⁻¹ biomass with an average composition of H₂ 14.58 vol%, CO 16.68 vol%, and CH₄ 4.74 vol%, demonstrating energy content appropriate for both thermal and chemical applications. Alkali and alkaline earth metals (AAEM), particularly Ca (273 mg kg⁻¹) and Mg (731 mg kg⁻¹), naturally present enhanced tar reforming and promoted reactive gas formation, whereas heavy metals such as Cd (0.27 mg kg⁻¹), Pb (0.02 mg kg⁻¹), and Bi (0.01 mg kg⁻¹) were detected only in trace amounts, posing minimal environmental risk. The results indicate that poplar pruning residues from phytoremediation sites can be a renewable and sustainable energy resource, transforming a waste stream into a process input. In this perspective, the integration of soil remediation with syngas production constitutes a tangible model of circular economy, based on the efficient use of resources through the synergy between environmental remediation and the valorization and sustainable management of marginal biomass—i.e., pruning residues—generating environmental, energetic, and economic benefits along the entire value chain. Full article

Artificial intelligence (AI) is increasingly regarded as a transformative enabler of sustainable logistics and supply chain management, particularly in the context of global energy transition and decarbonization efforts. This study provides a comprehensive conceptual and exploratory assessment of the multidimensional role of AI, highlighting both its potential to enhance energy efficiency and reduce greenhouse gas emissions, as well as its inherent environmental costs associated with digital infrastructures such as data centers. The findings reveal the dual character of digitalization: while predictive algorithms and digital twin applications facilitate demand forecasting, process optimization, and real-time adaptation to market fluctuations, they simultaneously generate additional energy demand that must be offset through renewable energy integration and intelligent energy balancing. The analysis underscores that the effectiveness of AI deployment cannot be captured solely through economic metrics but requires a holistic evaluation framework that incorporates environmental and social dimensions. Moreover, regional disparities are identified, with advanced economies accelerating AI-driven green transformations under regulatory and societal pressures, while developing economies face constraints linked to infrastructure gaps and investment limitations. The analysis emphasizes that AI-driven predictive models and digital twin applications are not only tools for energy optimization but also mechanisms that enhance systemic resilience by enabling risk anticipation, adaptive resource allocation, and continuity of operations in volatile environment. The contribution of this study lies in situating AI within the digital–green synergy discourse, demonstrating that its role in logistics decarbonization is conditional upon integrated energy–climate strategies, organizational change, and workforce reskilling. By synthesizing emerging evidence, this article provides actionable insights for policymakers, managers, and scholars, and calls for more rigorous empirical research across sectors, regions, and time horizons to verify the long-term sustainability impacts of AI-enabled solutions in supply chains. Full article

With the large-scale integration of renewable energy, the operational complexity of power systems has increased, placing higher demands on the accuracy of load forecasting. To address the nonlinear characteristics of load variations and improve feature utilization, this paper proposes an IAVOA–EATCN load forecasting model. In the feature engineering stage, an expand–reduce transformation is employed to reconstruct the original multi-feature inputs, and variational mode decomposition (VMD) is further applied to extract low- and high-frequency components, thereby compressing redundant features while preserving essential information structures. In terms of model architecture, the nonlinear representation capability of the temporal convolutional network (TCN) is enhanced by introducing the FlexSwish activation function, and an Efficient Channel Attention (ECA) mechanism is integrated to strengthen the perception of critical features. For parameter optimization, an improved African Vulture Optimization Algorithm (IAVOA) is proposed, which initializes the population using perturbation-enhanced dynamic Tent mapping, balances global exploration and local exploitation through adaptive parameter control, and incorporates elite retention and migration mechanisms to avoid premature convergence. Experimental results on real-world load data demonstrate that the proposed model achieves RMSE, R², and MAE values of 26.5544, 0.9804, and 18.5589, respectively, significantly outperforming benchmark methods and exhibiting strong generalization capability and practical potential for intelligent load forecasting. Full article

Driving the circular economy in road construction requires the effective use of secondary materials like recycled concrete aggregate (RCA) and fly ash (FA). A key obstacle is the performance trade-off in concretes incorporating both materials. This research investigates feasible mix designs for road concrete, using RCA as a full gravel replacement and FA as a cement substitute. Polypropylene fiber (36 mm) and a superplasticizer were utilized to mitigate fresh and hardened state drawbacks. The experimental program included 15 modified mixtures with recycled aggregate and 3 control mixtures with natural aggregate. The workability of all concrete mixtures was kept constant at slump class S1. Road concretes with RCA, containing a 10–12% FA by cement replacement, at least 2 kg/m³ of polypropylene fiber (PF), and 4 kg/m³ of superplasticizer (SP), achieve compressive strength of at least 50 MPa and flexural strength of no less than 5 MPa at the design age. This performance is comparable to that of control mixtures. Furthermore, the abrasion resistance ranges between 0.48–0.50 g/cm², and the brittleness index falls within 0.095–0.100, significantly enhancing the durability of concrete for rigid pavement applications. The conducted cradle-to-gate life-cycle assessment (stages A1–A3) of the constituent materials for 1 m³ of concrete indicates the following environmental impacts: Global Warming Potential (GWP) of 195 kg CO₂ equation, Non-renewable Primary Energy Demand (PENRE) of 1140 MJ, Abiotic Depletion Potential for Fossil resources (ADPF) of 1120 MJ, Acidification Potential (AP) of 0.45 mol H⁺ equation, and Eutrophication Potential (EP) of 0.07 kg PO₄³⁻ equation It is established that the modified compositions not only meet the required performance criteria but also contribute to the goals of resource conservation in road construction. Full article

Decarbonizing industry, improving urban sustainability, and expanding clean energy use are key global priorities. This study presents a techno-economic analysis (TEA) and life-cycle assessment (LCA) of green hydrogen (GH₂) production via water electrolysis for low-carbon applications in the Central Asian region, with Uzbekistan considered as a representative case study. Solar PV and wind power are used as renewable electricity sources for a 44 MW electrolyzer. The assessment also incorporates recent advances in alkaline water electrolyzers (AWE) enhanced with metal–organic framework (MOF) materials, reflecting improvements in efficiency and hydrogen output. The LCA, performed using SimaPro, evaluates the global warming potential (GWP) across the full hydrogen production chain. Results show that the MOF-enhanced AWE system achieves a lower levelized cost of hydrogen (LCOH) at 5.18 $/kg H₂, compared with 5.90 $/kg H₂ for conventional AWE, with electricity procurement remaining the dominant cost driver. Environmentally, green hydrogen pathways reduce GWP by 80–83% relative to steam methane reforming (SMR), with AWE–MOF delivering the lowest footprint at 1.97 kg CO₂/kg H₂. In transport applications, fuel cell vehicles powered by hydrogen derived from AWE–MOF emit 89% less CO₂ per 100 km than diesel vehicles and 83% less than using SMR-based hydrogen, demonstrating the substantial climate benefits of advanced electrolysis. Overall, the findings confirm that MOF-integrated AWE offers a strong balance of economic viability and environmental performance. The study highlights green hydrogen’s strategic role in the Central Asian region, represented by Uzbekistan’s energy transition, and provides evidence-based insights for guiding low-carbon hydrogen deployment. Full article

Fisheries and aquaculture residues pose escalating environmental challenges due to their high moisture content, nutrient loads, and pollutant potential when improperly managed. Conventional valorization routes, such as fishmeal, fish oil, and silage, offer partial mitigation but remain limited in scalability, conversion efficiency, and environmental performance. In this study, fish processing residues were subjected to hydrothermal carbonization (HTC) under controlled subcritical conditions (180–220 °C), along with a high-severity catalytic run (325 °C) using sodium bicarbonate (NaHCO₃) as an additive. The latter condition exceeded the typical HTC range and entered the subcritical hydrothermal liquefaction (HTL) regime. The resulting solid, liquid, and gaseous fractions were comprehensively characterized to assess their energy potential, chemical composition, and reactivity. Hydrochars achieved higher heating values (HHVs) ranging from 14.2 to 25.7 MJ/kg. These results underscore their suitability as renewable solid fuels. The gas products were dominated by CO₂ under standard HTC conditions. In contrast, the catalytic run in the subcritical HTL regime achieved a hydrogen enrichment of up to 30 vol.%, demonstrating the efficacy of NaHCO₃ in promoting the water-gas shift reaction. Subsequent air gasification confirmed the high reactivity of the hydrochars, producing syngas enriched in H₂ and CO at elevated temperatures. Overall, this study demonstrates a scalable multiproduct valorization route for fishery residues, supporting circular bioeconomy strategies and contributing to the achievement of UN Sustainable Development Goals (SDGs 7, 12, and 13). Full article

Underground hydrogen storage (UHS) in saline aquifers offers a viable alternative to surface-based storage systems, which are limited by capacity constraints, high operational pressures, complex thermal regulation, low energy densities, and potential safety hazards. This study uses a fully compositional reservoir simulation model to evaluate hydrogen behavior in the Mt. Simon Sandstone in the Illinois Basin. The analysis focuses on the effects of hysteresis, solubility, diffusivity, and production well perforation location on recovery efficiency. Cyclic injection and withdrawal scenarios were simulated to assess storage performance and operational strategies. The results show that accounting for hydrogen diffusivity shows essentially unchanged withdrawal efficiency at 79%, the same as the base case. Solubility causes a slight decrease to 78%, while hysteresis leads to a more significant reduction to 63%. The location of injection well perforations also influences recovery: top-perforated wells increase efficiency from 60% after the first cycle to 74% after six cycles, whereas bottom-perforated injection wells increase efficiency from 56% to 79% over the same period. These findings emphasize the importance of accounting for multiphase flow dynamics and strategic well placement in optimizing UHS system performance. The insights contribute to advancing reliable, large-scale hydrogen storage solutions essential for supporting renewable energy integration and long-term energy security. Full article

Active citizen participation in both consumption and production is essential for a successful renewable energy transition. The paper explores the early development of prosumerism in Jerusalem, a city characterized by socio-political fragmentation and unequal access to infrastructure. Based on a 320-sample survey conducted in East and West Jerusalem, the paper analyzes awareness, motivation, and barriers to solar energy adoption in the city. The results show that only 12% of respondents currently produce and consume their own energy, while 66% had never heard of the term “prosumerism.” Financial savings were shown to be the primary driver of implementing solar systems, both in East and West Jerusalem. Key barriers included high installation costs, limited regulatory knowledge, and administrative complexity. Despite these obstacles, 70% of respondents expressed interest in community energy initiatives, highlighting significant potential for citizen-led models in fragmented urban contexts. Full article

The development of sustainable catalysts from renewable resources is a key challenge for reducing the cost of industrial catalytic processes and waste valorization. In this work, low-cost heterogeneous active catalysts were prepared based on pyrolyzed forest residues, forming valuable porous support materials (Biochar) able to efficiently accommodate the highly active heteropolyacid HPW₁₂. Further, magnetic functionality was incorporated in the novel catalytic materials by the impregnation of NiFe₂O₄. The resulting magnetic composites were characterized by FTIR-ATR, SEM-EDS, ICP-OES, BET, XRD, potentiometric titration and magnetometry. The novel HPW₁₂@NiFe₂O₄@Biochar composites were able to valorize the glycerol to produce the fuel additive solketal with high conversion and high selectivity after only 3 h of reaction via acetalization reaction with acetone. The biochar catalytic composite prepared from cork presented higher pore size than the same prepared from forest biomass. This property was crucial to achieve the best conversion (89%) and the highest solketal selectivity (96%). Additionally, reusability capacity was verified, supporting the potential of the cork-pyrolyzed-based composites as potential low-cost catalytic material to produce fuel additives, such as solketal, under sustainable conditions. This may contribute one step further toward a future with greener energy, increasing the viability of biodiesel industry waste. Full article

This study investigates how economic development interacts with sustainability performance in the European Union, focusing on the structural and technological factors that shape progress in the green transition. Using Eurostat data for 27 EU member states over the period 2015–2023, the analysis employs panel econometric models (Pooled Ordinary Least Squares, Fixed Effects, and Random Effects) to explore how circular economy performance, innovation capacity, human capital, and renewable energy use influence environmental and economic outcomes across member states. The results show that R&D intensity and skilled human resources are key drivers of sustainability. Higher levels of circular material use and resource productivity contribute to long-term competitiveness. In contrast, uneven progress in renewable energy deployment points to persistent regional disparities and possible structural constraints that limit convergence. Northern and Western Europe record the strongest advances in innovation and environmental efficiency, whereas Southern and Eastern regions remain affected by industrial legacies and lower absorptive capacity. The findings highlight that, in the short term, renewable energy expansion may involve adjustment costs and potential trade-offs with economic competitiveness in less technologically developed economies. This study provides new comparative evidence on the differentiated pathways of the green transition across the EU. Policy implications suggest the need to reinforce R&D investment, expand circular manufacturing, and support an inclusive technological transition consistent with the European Green Deal and the United Nations 2030 Agenda. Full article

This study develops a carbon emissions reduction strategy for solar-powered coffee machines in Taiwanese convenience stores, aiming to strike a balance between profitability and decarbonization. An integrated framework of the fuzzy nonlinear multi-objective programming (FNMOP) model, Sobol sensitivity analysis, and Monte Carlo simulation was applied to quantify uncertainties in electricity supply, consumer demand, and investment costs. Solar-powered machines reduce annual CO₂ emissions by 172–215 kg per store. Allocating 0.49–0.61% of coffee profits as subsidies shortens payback to [6.5, 9.375] years. Monte Carlo simulation confirms robustness with a 95% confidence interval of [5.8, 11.2] years, while urban stores achieve payback 18–25% faster. Sobol analysis identifies annual savings and net profit margins as key drivers. The framework demonstrates scalability and international applicability, providing empirical evidence for policymakers and retailers to accelerate the adoption of renewable energy in consumer-facing operations. Its methodological integration and consumer-side focus offer a replicable model for convenience store chains in high-density retail markets worldwide, with potential multiplier effects across sectors and supply chains. Full article