Pub Date : 2026-01-31DOI: 10.1016/j.renene.2026.125362
Xuan-Xin Chen , Zhi-Yi He , Yun-Yan Gao , Hao Zhang , Hou-Feng Wang , Raymond Jianxiong Zeng
Food waste digestate (FD), a byproduct of anaerobic digestion, poses resource potential but also challenges due to high moisture, low calorific value, and high ash content, which limit direct incineration. This study investigated co-pelletization of FD with bamboo powder (BP), a high-calorific biomass with binding capacity, to produce stable, energy-dense fuel. FD and BP were blended at ratios from 90:10 to 50:50 and pelletized at 120 °C and 120 MPa. BP addition enhanced pellet structure, with compressive strength increased by >120% and abrasion loss dropping below 1% at FD/BP = 5:5, while storage stability improved. The higher heating value (HHV) increased by 30.3% to 13.3 MJ/kg, and thermogravimetric analysis showed synergistic effects: ignition and burnout temperatures fell to 277 °C and 542 °C, and the combustion index reached 5.07 × 10−7. Gas analysis indicated slightly higher CO2 release but more complete CO oxidation and reduced NO emissions at higher BP levels. Ash characterization confirmed enhanced slagging resistance via higher Si/Al and lower base-to-acid ratios, yielding fusion temperatures >1300 °C. Overall, FD/BP co-pelletization converts digestate into durable, energy-rich fuel with improved combustion and slagging resistance, offering a promising route for waste valorization, subject to further pilot-scale validation and TEA/LCA evaluation.
{"title":"High-performance solid recovered fuel from food waste digestate and bamboo powder: Mechanistic insights into structural reinforcement and combustion stability","authors":"Xuan-Xin Chen , Zhi-Yi He , Yun-Yan Gao , Hao Zhang , Hou-Feng Wang , Raymond Jianxiong Zeng","doi":"10.1016/j.renene.2026.125362","DOIUrl":"10.1016/j.renene.2026.125362","url":null,"abstract":"<div><div>Food waste digestate (FD), a byproduct of anaerobic digestion, poses resource potential but also challenges due to high moisture, low calorific value, and high ash content, which limit direct incineration. This study investigated co-pelletization of FD with bamboo powder (BP), a high-calorific biomass with binding capacity, to produce stable, energy-dense fuel. FD and BP were blended at ratios from 90:10 to 50:50 and pelletized at 120 °C and 120 MPa. BP addition enhanced pellet structure, with compressive strength increased by >120% and abrasion loss dropping below 1% at FD/BP = 5:5, while storage stability improved. The higher heating value (HHV) increased by 30.3% to 13.3 MJ/kg, and thermogravimetric analysis showed synergistic effects: ignition and burnout temperatures fell to 277 °C and 542 °C, and the combustion index reached 5.07 × 10<sup>−7</sup>. Gas analysis indicated slightly higher CO<sub>2</sub> release but more complete CO oxidation and reduced NO emissions at higher BP levels. Ash characterization confirmed enhanced slagging resistance via higher Si/Al and lower base-to-acid ratios, yielding fusion temperatures >1300 °C. Overall, FD/BP co-pelletization converts digestate into durable, energy-rich fuel with improved combustion and slagging resistance, offering a promising route for waste valorization, subject to further pilot-scale validation and TEA/LCA evaluation.</div></div>","PeriodicalId":419,"journal":{"name":"Renewable Energy","volume":"262 ","pages":"Article 125362"},"PeriodicalIF":9.1,"publicationDate":"2026-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146096107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-30DOI: 10.1016/j.renene.2026.125351
Yanlong Zhang , Pengzhen Guo , Mengfan Tian , He Chen , Rongqiang Liu , Zongquan Deng , Lifang Li
The advancement of solar-thermal concentrators requires architectures that combine high flux density, uniform focal distribution, and structural simplicity. However, multi-dish systems often suffer from coupled trade-offs among concentration, spot uniformity, and geometric stability, which can limit thermal efficiency and increase hot-spot risk in high-temperature applications. This study targets this coupled-design challenge by enabling a controllable and robust focal spot in a modular multi-dish architecture. This study presents a four-dish off-axis conjugate concentrator optimized through a global optimization framework that integrates ray-tracing simulations with a unified objective function. The objective is to achieve high effective concentration while simultaneously improving flux uniformity and spot geometry under practical alignment/manufacturing uncertainties. The framework adopts a staged dynamic-weighting strategy to achieve a smooth transition from "energy concentration" to "focal spot quality". Unlike traditional approaches that vary numerous complex structural parameters, the proposed design constrains the optimization space to radial and axial displacement, focal length, and receiver dimensions, thereby simplifying assembly requirements while still enabling high-dimensional exploration of optical behavior. Optimization results demonstrate coordinated improvements across all metrics: the concentrator sustains above the design threshold ( 600), increases spot uniformity from 0.38 to 0.53, reduces RMS radius to 38 mm, and lowers the shape factor to 0.25, yielding a compact and geometrically stable focal spot. Outdoor validation confirmed these findings: under 35 °C and 620 W/m2, the prototype reached 783 °C within 4 s and achieved 742, exhibited uniform, repeatable heat maps with strong tolerance to disturbances. These results contribute a four-dish off-axis conjugate architecture that suppresses off-axis aberration-induced spot degradation, and a staged, unified optimization framework that explicitly balances concentration–uniformity–spot geometry with experimental validation, providing a practical pathway toward deployable high-flux multi-dish concentrators.
{"title":"Stepwise multi-objective optimization for high-concentration and uniform four-dish solar concentrators","authors":"Yanlong Zhang , Pengzhen Guo , Mengfan Tian , He Chen , Rongqiang Liu , Zongquan Deng , Lifang Li","doi":"10.1016/j.renene.2026.125351","DOIUrl":"10.1016/j.renene.2026.125351","url":null,"abstract":"<div><div>The advancement of solar-thermal concentrators requires architectures that combine high flux density, uniform focal distribution, and structural simplicity. However, multi-dish systems often suffer from coupled trade-offs among concentration, spot uniformity, and geometric stability, which can limit thermal efficiency and increase hot-spot risk in high-temperature applications. This study targets this coupled-design challenge by enabling a controllable and robust focal spot in a modular multi-dish architecture. This study presents a four-dish off-axis conjugate concentrator optimized through a global optimization framework that integrates ray-tracing simulations with a unified objective function. The objective is to achieve high effective concentration while simultaneously improving flux uniformity and spot geometry under practical alignment/manufacturing uncertainties. The framework adopts a staged dynamic-weighting strategy to achieve a smooth transition from \"energy concentration\" to \"focal spot quality\". Unlike traditional approaches that vary numerous complex structural parameters, the proposed design constrains the optimization space to radial and axial displacement, focal length, and receiver dimensions, thereby simplifying assembly requirements while still enabling high-dimensional exploration of optical behavior. Optimization results demonstrate coordinated improvements across all metrics: the concentrator sustains <span><math><mrow><msub><mi>C</mi><mn>95</mn></msub></mrow></math></span> above the design threshold (<span><math><mrow><msub><mi>C</mi><mtext>threshold</mtext></msub><mo>=</mo></mrow></math></span> 600), increases spot uniformity from 0.38 to 0.53, reduces RMS radius to 38 mm, and lowers the shape factor to 0.25, yielding a compact and geometrically stable focal spot. Outdoor validation confirmed these findings: under 35 °C and 620 W/m<sup>2</sup>, the prototype reached 783 °C within 4 s and achieved <span><math><mrow><msub><mi>C</mi><mrow><mn>95</mn><mo>≈</mo></mrow></msub></mrow></math></span> 742, exhibited uniform, repeatable heat maps with strong tolerance to disturbances. These results contribute a four-dish off-axis conjugate architecture that suppresses off-axis aberration-induced spot degradation, and a staged, unified optimization framework that explicitly balances concentration–uniformity–spot geometry with experimental validation, providing a practical pathway toward deployable high-flux multi-dish concentrators.</div></div>","PeriodicalId":419,"journal":{"name":"Renewable Energy","volume":"262 ","pages":"Article 125351"},"PeriodicalIF":9.1,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146096110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-29DOI: 10.1016/j.renene.2026.125347
Alexandros Arsalis , Angelos Nousdilis , Gianni Celli , Vladislav Grigorovitch , Aggelos Bouhouras , Georgios Christoforidis , Susanna Mocci , Marina Grigorovitch , Erez Gal , George E. Georghiou
The real-world performance and optimization potential of solar photovoltaic-battery energy storage system microgrids is implemented in public buildings across Mediterranean environments. Using data collected over an extended period, several aspects are evaluated, including system commissioning outcomes, operational behavior under varying time and seasonal conditions, and the effectiveness of scenario-based strategies. The latter aim at improving key performance indicators, such as self-consumption and self-sufficiency rates, which are analyzed across daily, weekly, and seasonal timescales. Moreover, scenario simulations explore the impact of varying photovoltaic and storage capacities as well as different levels of demand-side flexibility. Results show that instead of simply increasing the component capacity, it is more effective to increase load flexibility, which leads to the enhancement of system performance and the reduction of battery cycling. Moreover, factors such as occupancy schedules and climatic conditions significantly affect system behavior and optimization outcomes. The study demonstrates that integrating high-resolution monitoring data with scenario modeling offers valuable insights into the dynamic operation of photovoltaic-battery energy storage system microgrids. Across the four pilot sites, measured annual self-sufficiency rates reach up to 70–95 % under baseline operation, while scenario-based demand-side flexibility increases SSR by 10–25 percentage points compared to capacity scaling alone. Results consistently show that moderate load flexibility yields higher performance gains and lower battery cycling than equivalent increases in PV or storage capacity.
{"title":"Enhancing public building sustainability through integrated solar photovoltaic-based microgrid pilots: commissioning, operation, and performance insights","authors":"Alexandros Arsalis , Angelos Nousdilis , Gianni Celli , Vladislav Grigorovitch , Aggelos Bouhouras , Georgios Christoforidis , Susanna Mocci , Marina Grigorovitch , Erez Gal , George E. Georghiou","doi":"10.1016/j.renene.2026.125347","DOIUrl":"10.1016/j.renene.2026.125347","url":null,"abstract":"<div><div>The real-world performance and optimization potential of solar photovoltaic-battery energy storage system microgrids is implemented in public buildings across Mediterranean environments. Using data collected over an extended period, several aspects are evaluated, including system commissioning outcomes, operational behavior under varying time and seasonal conditions, and the effectiveness of scenario-based strategies. The latter aim at improving key performance indicators, such as self-consumption and self-sufficiency rates, which are analyzed across daily, weekly, and seasonal timescales. Moreover, scenario simulations explore the impact of varying photovoltaic and storage capacities as well as different levels of demand-side flexibility. Results show that instead of simply increasing the component capacity, it is more effective to increase load flexibility, which leads to the enhancement of system performance and the reduction of battery cycling. Moreover, factors such as occupancy schedules and climatic conditions significantly affect system behavior and optimization outcomes. The study demonstrates that integrating high-resolution monitoring data with scenario modeling offers valuable insights into the dynamic operation of photovoltaic-battery energy storage system microgrids. Across the four pilot sites, measured annual self-sufficiency rates reach up to 70–95 % under baseline operation, while scenario-based demand-side flexibility increases SSR by 10–25 percentage points compared to capacity scaling alone. Results consistently show that moderate load flexibility yields higher performance gains and lower battery cycling than equivalent increases in PV or storage capacity.</div></div>","PeriodicalId":419,"journal":{"name":"Renewable Energy","volume":"262 ","pages":"Article 125347"},"PeriodicalIF":9.1,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146096109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-28DOI: 10.1016/j.renene.2026.125344
Zunshi Han , Hao Lu , Wenjun Zhao , Chuanxiao Zheng
Dust deposition on photovoltaic panels severely degrades power output. The combination of droplets and hydrophobic surfaces can effectively solve this problem. However, the underlying physics of droplet-based cleaning and its quantitative impact on generation remain poorly understood. This study employs an innovative multiphysics framework, integrating computational fluid dynamics with the discrete element method, coupled with a photovoltaic power prediction model that links dust deposition directly to photo-generation physics, to simulate droplet-mediated dust cleaning and its impact on power output. The droplet dynamics are analyzed using a multiphase volume of fluid model, and the dust particle behavior are revealed by Edinburgh elastic-plastic adhesion model. Smaller particles (dp ≤ 100 μm) are readily removed, achieving a dust removal rate of 22.7 % at dp = 50 μm. However, particles that agglomerate due to cohesive forces after droplet cleaning become difficult to remove. Droplet cleaning efficiency correlates with the Weber number. At Weber number = 1.91, both coverage radius and contact frequency reach optimal values, yielding a peak dust removal rate of 14.1 %. Coupling dust deposition density with cleaning efficiency results and inputting them into a photovoltaic power generation model indicates that each 1 g/m2 increase in deposition density causes a maximum power degradation of 2.26 %. Under droplet cleaning conditions with Weber number = 1.91, photovoltaic power significantly increases by 2.9 % under small particle conditions. This study provides theoretical basis and parameter optimization paradigms for self-cleaning design of super-hydrophobic photovoltaic.
{"title":"Synergistic optimization analysis of dust cleaning efficiency and power generation enhancement on super-hydrophobic photovoltaic panel for droplets with different Weber numbers","authors":"Zunshi Han , Hao Lu , Wenjun Zhao , Chuanxiao Zheng","doi":"10.1016/j.renene.2026.125344","DOIUrl":"10.1016/j.renene.2026.125344","url":null,"abstract":"<div><div>Dust deposition on photovoltaic panels severely degrades power output. The combination of droplets and hydrophobic surfaces can effectively solve this problem. However, the underlying physics of droplet-based cleaning and its quantitative impact on generation remain poorly understood. This study employs an innovative multiphysics framework, integrating computational fluid dynamics with the discrete element method, coupled with a photovoltaic power prediction model that links dust deposition directly to photo-generation physics, to simulate droplet-mediated dust cleaning and its impact on power output. The droplet dynamics are analyzed using a multiphase volume of fluid model, and the dust particle behavior are revealed by Edinburgh elastic-plastic adhesion model. Smaller particles (<em>d</em><sub><em>p</em></sub> ≤ 100 μm) are readily removed, achieving a dust removal rate of 22.7 % at <em>d</em><sub><em>p</em></sub> = 50 μm. However, particles that agglomerate due to cohesive forces after droplet cleaning become difficult to remove. Droplet cleaning efficiency correlates with the Weber number. At Weber number = 1.91, both coverage radius and contact frequency reach optimal values, yielding a peak dust removal rate of 14.1 %. Coupling dust deposition density with cleaning efficiency results and inputting them into a photovoltaic power generation model indicates that each 1 g/m<sup>2</sup> increase in deposition density causes a maximum power degradation of 2.26 %. Under droplet cleaning conditions with Weber number = 1.91, photovoltaic power significantly increases by 2.9 % under small particle conditions. This study provides theoretical basis and parameter optimization paradigms for self-cleaning design of super-hydrophobic photovoltaic.</div></div>","PeriodicalId":419,"journal":{"name":"Renewable Energy","volume":"262 ","pages":"Article 125344"},"PeriodicalIF":9.1,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146096108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-27DOI: 10.1016/j.renene.2026.125341
Rafael de Moraes Altafini , Juan Carlos López-Linares , Alba Mei González-Galán , Maria Teresa Garcia-Cubero , Valeria Reginatto , Monica Coca
Pineapple peel, a residue rich in free sugars, can be hydrolyzed under mild conditions. Here, direct enzymatic hydrolysis (EH) of pineapple peel in the presence of Cellic CTec 2 at only 5 FPU g−1 of pineapple peel dry mass yielded a hydrolysate containing 50.3 g L−1 total sugars, but which was poorly fermentable. Pretreating the pineapple peel with microwave (MW) at 130 °C in the presence of water provided a fermentable residue containing 43.7 g L−1 total sugars that generated 8.4 g L−1 butanol. Thus, thermal treatment helped to overcome fermentation hindrance. Treating the pineapple peel with MW at 130 °C followed by EH at enzyme loading of 5 FPU g−1 DM gave a fermentable hydrolysate containing 50.6 g L−1 total sugars. Fermenting this hydrolysate in a bioreactor with in-situ butanol recovery by gas stripping with a pulse of glucose/fructose solution increased the butanol concentration to 9.8 ± 0.4 g L−1. Overall, microwave pretreatment was essential to obtain a fermentable hydrolysate from pineapple peel, while gas stripping facilitated butanol removal during fermentation.
菠萝皮是一种富含游离糖的残留物，在温和的条件下可以水解。在这里，在Cellic CTec 2存在下，仅以5 FPU g−1的菠萝皮干质量对菠萝皮进行直接酶解（EH），产生了含有50.3 g L−1总糖的水解产物，但其发酵性很差。用微波（MW）在130°C有水的条件下预处理菠萝皮，得到含有43.7 g L−1总糖的可发酵残留物，产生8.4 g L−1丁醇。因此，热处理有助于克服发酵障碍。用MW在130°C下处理菠萝皮，然后在5 FPU g−1 DM的酶负荷下进行EH处理，得到含有50.6 g L−1总糖的可发酵水解产物。该水解产物在生物反应器中发酵，采用葡萄糖/果糖溶液脉冲气提法原位丁醇回收，丁醇浓度提高到9.8±0.4 g L−1。总的来说，微波预处理对于从菠萝皮中获得可发酵的水解物是必不可少的，而气体剥离有助于在发酵过程中去除丁醇。
{"title":"A green strategy to transform pineapple peel into biobutanol includes microwave pretreatment and in-situ butanol recovery","authors":"Rafael de Moraes Altafini , Juan Carlos López-Linares , Alba Mei González-Galán , Maria Teresa Garcia-Cubero , Valeria Reginatto , Monica Coca","doi":"10.1016/j.renene.2026.125341","DOIUrl":"10.1016/j.renene.2026.125341","url":null,"abstract":"<div><div>Pineapple peel, a residue rich in free sugars, can be hydrolyzed under mild conditions. Here, direct enzymatic hydrolysis (EH) of pineapple peel in the presence of Cellic CTec 2 at only 5 FPU g<sup>−1</sup> of pineapple peel dry mass yielded a hydrolysate containing 50.3 g L<sup>−1</sup> total sugars, but which was poorly fermentable. Pretreating the pineapple peel with microwave (MW) at 130 °C in the presence of water provided a fermentable residue containing 43.7 g L<sup>−1</sup> total sugars that generated 8.4 g L<sup>−1</sup> butanol. Thus, thermal treatment helped to overcome fermentation hindrance. Treating the pineapple peel with MW at 130 °C followed by EH at enzyme loading of 5 FPU g<sup>−1</sup> DM gave a fermentable hydrolysate containing 50.6 g L<sup>−1</sup> total sugars. Fermenting this hydrolysate in a bioreactor with <em>in-situ</em> butanol recovery by gas stripping with a pulse of glucose/fructose solution increased the butanol concentration to 9.8 ± 0.4 g L<sup>−1</sup>. Overall, microwave pretreatment was essential to obtain a fermentable hydrolysate from pineapple peel, while gas stripping facilitated butanol removal during fermentation.</div></div>","PeriodicalId":419,"journal":{"name":"Renewable Energy","volume":"261 ","pages":"Article 125341"},"PeriodicalIF":9.1,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-26DOI: 10.1016/j.renene.2026.125340
Zhenhong Liu, Zhen Wang, Laishun Yang, Dexin Zhang, Weiwei Cui
Numerical simulations are carried out to investigate the influence of secondary branching palmate mesh vein fins on the melting of phase change materials (PCMs). The combined impact of four structural variables on the complete melting time and the heat transfer rate is evaluated by response surface methodology (RSM), and the predictive correlation equation is derived. The fin structure is optimised using the non-dominated sorting genetic algorithm II (NSGA-II) to obtain the Pareto-optimal solution. The results demonstrate that the Pareto optimal point achieved the shortest melting time of 1600.1s and the maximum heat transfer rate of 959.8W. Building on this foundation, a comparative analysis is conducted across three dimensions: the number of secondary branching layers, the arrangement type, and the fin geometry. This analysis illustrates the superiority of the proposed fin structure. Analysis indicates that melting performance improves with increasing secondary branching layers, with the most pronounced strengthening effect observed when secondary branching occurs at the first layer. Compared to unidirectional arrangements, bidirectional fins facilitate heat transfer from both the inner and outer tubes, resulting in a more uniform heat distribution. Compared to rectangular and tree-shaped fins, the secondary branching palmate vein fins facilitate heat diffusion across a broader PCM area, thereby accelerating PCM melting. In summary, the secondary branching palmate vein fins exhibit an exceptionally uniform temperature distribution within the PCM domain and outstanding melting performance.
{"title":"Melting performance study and multi-objective optimisation of phase change triplex tube heat exchangers with secondary branching palmate mesh vein fins","authors":"Zhenhong Liu, Zhen Wang, Laishun Yang, Dexin Zhang, Weiwei Cui","doi":"10.1016/j.renene.2026.125340","DOIUrl":"10.1016/j.renene.2026.125340","url":null,"abstract":"<div><div>Numerical simulations are carried out to investigate the influence of secondary branching palmate mesh vein fins on the melting of phase change materials (PCMs). The combined impact of four structural variables on the complete melting time and the heat transfer rate is evaluated by response surface methodology (RSM), and the predictive correlation equation is derived. The fin structure is optimised using the non-dominated sorting genetic algorithm II (NSGA-II) to obtain the Pareto-optimal solution. The results demonstrate that the Pareto optimal point achieved the shortest melting time of 1600.1s and the maximum heat transfer rate of 959.8W. Building on this foundation, a comparative analysis is conducted across three dimensions: the number of secondary branching layers, the arrangement type, and the fin geometry. This analysis illustrates the superiority of the proposed fin structure. Analysis indicates that melting performance improves with increasing secondary branching layers, with the most pronounced strengthening effect observed when secondary branching occurs at the first layer. Compared to unidirectional arrangements, bidirectional fins facilitate heat transfer from both the inner and outer tubes, resulting in a more uniform heat distribution. Compared to rectangular and tree-shaped fins, the secondary branching palmate vein fins facilitate heat diffusion across a broader PCM area, thereby accelerating PCM melting. In summary, the secondary branching palmate vein fins exhibit an exceptionally uniform temperature distribution within the PCM domain and outstanding melting performance.</div></div>","PeriodicalId":419,"journal":{"name":"Renewable Energy","volume":"261 ","pages":"Article 125340"},"PeriodicalIF":9.1,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-26DOI: 10.1016/j.renene.2026.125337
Enyu Wang , Yanqing Li , Tao Sun , Jiaqi Zhang , Lanlan Wu , Shuiping Yan
Solar-driven interfacial evaporation of water has attracted an increasing attention for clean water production due to its energy efficiency and environmental friendliness. However, it still suffers from the relatively low water evaporation rate, generally due to the limited water transport capacity of conventional evaporators and challenges in fabricating the precisely controlled air-water interface. In this study, we developed a simple and scalable physical deposition method to fabricate two types of hydrophobic-hydrophilic Janus anodic aluminum oxide (AAO) membrane evaporators. The hydrophobically modified TiO2 or carbon nanotube (CNT) were coated onto one surface of hydrophilic AAO membrane by using a polyvinylidene fluoride (PVDF) binder to achieve a hydrophobic membrane surface, while the other AAO membrane surface was still hydrophilic. Under heating-driven conditions, the TiO2-coated Janus membrane with asymmetric water contact angles of 117.38 ± 5.83°/55.42 ± 4.35°achieved a high water evaporation rate of 1.31 kg/m2·h at 45 °C (bulk water temperature), which was 56.32 % higher than the natural evaporation. This increased water evaporate rate was mainly attributed to a system-level synergy between a rapid capillary-driven water transport through the nanochannels and an enhanced heat and mass transfer at the Janus interface, as evidenced by a reduction in intrinsic phase transition barrier driven by the Janus interface, resulting in a low apparent evaporation enthalpy of water with 1635 kJ/kg. Moreover, driven by solar energy, the CNT-coated Janus membrane (3.18 mg-CNT/cm2 loading) exhibited an excellent water evaporation rate of 3.13 kg/m2·h under 1 sun illumination (1 kW/m2), which was 42.27 % higher than TiO2-coated Janus membrane, demonstrating a superior photothermal conversion efficiency. Furthermore, the CNT-coated Janus AAO membrane evaporator was also successfully adopted to concentrate the dark biogas slurry featured with a strong solar absorption performance, a ∼4 % improvement in water evaporation efficiency and a high ammonia nitrogen rejection rate of ∼91 % were achieved when compared to the natural evaporation, confirming its practical potential for wastewater concentration and nutrient recovery.
{"title":"Hydrophobic-hydrophilic Janus anodic aluminum oxide membrane via physical deposition for enhanced interfacial water evaporation","authors":"Enyu Wang , Yanqing Li , Tao Sun , Jiaqi Zhang , Lanlan Wu , Shuiping Yan","doi":"10.1016/j.renene.2026.125337","DOIUrl":"10.1016/j.renene.2026.125337","url":null,"abstract":"<div><div>Solar-driven interfacial evaporation of water has attracted an increasing attention for clean water production due to its energy efficiency and environmental friendliness. However, it still suffers from the relatively low water evaporation rate, generally due to the limited water transport capacity of conventional evaporators and challenges in fabricating the precisely controlled air-water interface. In this study, we developed a simple and scalable physical deposition method to fabricate two types of hydrophobic-hydrophilic Janus anodic aluminum oxide (AAO) membrane evaporators. The hydrophobically modified TiO<sub>2</sub> or carbon nanotube (CNT) were coated onto one surface of hydrophilic AAO membrane by using a polyvinylidene fluoride (PVDF) binder to achieve a hydrophobic membrane surface, while the other AAO membrane surface was still hydrophilic. Under heating-driven conditions, the TiO<sub>2</sub>-coated Janus membrane with asymmetric water contact angles of 117.38 ± 5.83°/55.42 ± 4.35°achieved a high water evaporation rate of 1.31 kg/m<sup>2</sup>·h at 45 °C (bulk water temperature), which was 56.32 % higher than the natural evaporation. This increased water evaporate rate was mainly attributed to a system-level synergy between a rapid capillary-driven water transport through the nanochannels and an enhanced heat and mass transfer at the Janus interface, as evidenced by a reduction in intrinsic phase transition barrier driven by the Janus interface, resulting in a low apparent evaporation enthalpy of water with 1635 kJ/kg. Moreover, driven by solar energy, the CNT-coated Janus membrane (3.18 mg-CNT/cm<sup>2</sup> loading) exhibited an excellent water evaporation rate of 3.13 kg/m<sup>2</sup>·h under 1 sun illumination (1 kW/m<sup>2</sup>), which was 42.27 % higher than TiO<sub>2</sub>-coated Janus membrane, demonstrating a superior photothermal conversion efficiency. Furthermore, the CNT-coated Janus AAO membrane evaporator was also successfully adopted to concentrate the dark biogas slurry featured with a strong solar absorption performance, a ∼4 % improvement in water evaporation efficiency and a high ammonia nitrogen rejection rate of ∼91 % were achieved when compared to the natural evaporation, confirming its practical potential for wastewater concentration and nutrient recovery.</div></div>","PeriodicalId":419,"journal":{"name":"Renewable Energy","volume":"262 ","pages":"Article 125337"},"PeriodicalIF":9.1,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146096111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-23DOI: 10.1016/j.renene.2026.125201
Wen-Ting Lin , Kangming Liu , Guo Chen , Jueyou Li , Degang Yang , Tingzhen Ming
With the increasing integration of renewable energy into regional power grids, significant spatial differences in carbon intensity have emerged. These differences highlight the need for carbon-aware workload allocation in geographically distributed Internet Data Centers, where aligning computational loads with low-carbon regions can enhance both environmental and economic outcomes. In this paper, we propose a two-stage optimization framework that integrates renewable-aware workload allocation and strategic carbon allowance procurement. In the first stage, a robust optimization model based on column-and-constraint generation is developed to manage uncertainties in workload demand and carbon prices, enabling stable and cost-effective workload distribution across regions with varying renewable energy penetration. In the second stage, a multi-class mean field game model is constructed to capture strategic interactions and behavioral heterogeneity among Internet Data Centers in carbon markets. We apply a Deep Galerkin Method to solve the resulting high-dimensional partial differential equations, yielding a robust and convergent procurement strategy. Simulation results demonstrate that the proposed framework achieves over 28% cost savings while ensuring carbon compliance and workload satisfaction. This study offers theoretical and practical insights for carbon-regulated Internet Data Center operations, and supports the broader integration of renewable energy in large-scale digital infrastructure.
{"title":"Carbon-aware optimization for Internet Data Centers with renewable generation: Robust workload allocation and carbon procurement via multi-class mean field game","authors":"Wen-Ting Lin , Kangming Liu , Guo Chen , Jueyou Li , Degang Yang , Tingzhen Ming","doi":"10.1016/j.renene.2026.125201","DOIUrl":"10.1016/j.renene.2026.125201","url":null,"abstract":"<div><div>With the increasing integration of renewable energy into regional power grids, significant spatial differences in carbon intensity have emerged. These differences highlight the need for carbon-aware workload allocation in geographically distributed Internet Data Centers, where aligning computational loads with low-carbon regions can enhance both environmental and economic outcomes. In this paper, we propose a two-stage optimization framework that integrates renewable-aware workload allocation and strategic carbon allowance procurement. In the first stage, a robust optimization model based on column-and-constraint generation is developed to manage uncertainties in workload demand and carbon prices, enabling stable and cost-effective workload distribution across regions with varying renewable energy penetration. In the second stage, a multi-class mean field game model is constructed to capture strategic interactions and behavioral heterogeneity among Internet Data Centers in carbon markets. We apply a Deep Galerkin Method to solve the resulting high-dimensional partial differential equations, yielding a robust and convergent procurement strategy. Simulation results demonstrate that the proposed framework achieves over 28% cost savings while ensuring carbon compliance and workload satisfaction. This study offers theoretical and practical insights for carbon-regulated Internet Data Center operations, and supports the broader integration of renewable energy in large-scale digital infrastructure.</div></div>","PeriodicalId":419,"journal":{"name":"Renewable Energy","volume":"262 ","pages":"Article 125201"},"PeriodicalIF":9.1,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146096106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-23DOI: 10.1016/j.renene.2026.125312
Hyun Ju Oh , Jung Ho Ahn , Gyeongtaek Gong , Ja Kyong Ko , Sun-Mi Lee , Youngsoon Um
Hexanol production via gas fermentation using acetogens has emerged as a promising alternative to fossil fuel-derived hexanol. However, product inhibition significantly limits hexanol accumulation without in situ removal. This study aimed to enhance hexanol production by employing in situ adsorption during CO fermentation with Clostridium carboxidivorans P7. Among four tested adsorbents (L-493, SD-2, GSP-25, and activated carbon), activated carbon (AC) demonstrated superior performance, achieving 8.40 g/L hexanol production while maintaining effective product removal through its high adsorption capacity. Process optimization through initial pH adjustment and reduced AC loading shortened the acidogenesis phase, further increasing hexanol production to 9.82 g/L. To reduce carbon loss from CO2 generation during CO metabolism, H2 was co-supplied with CO (70:30 ratio) as an additional electron donor, promoting alcohol production and enabling CO2 reutilization. This strategy achieved a hexanol titer of 11.93 g/L while reducing the CO2 evolution/CO consumption ratio by 16.9–18.7 % compared to CO-only fermentation. These findings demonstrate that adsorption-assisted gas fermentation with CO/H2 co-utilization represents a promising strategy for sustainable hexanol production with reduced carbon emissions.
{"title":"High hexanol production from syngas by Clostridium carboxidivorans P7 through in situ hexanol recovery by adsorption","authors":"Hyun Ju Oh , Jung Ho Ahn , Gyeongtaek Gong , Ja Kyong Ko , Sun-Mi Lee , Youngsoon Um","doi":"10.1016/j.renene.2026.125312","DOIUrl":"10.1016/j.renene.2026.125312","url":null,"abstract":"<div><div>Hexanol production via gas fermentation using acetogens has emerged as a promising alternative to fossil fuel-derived hexanol. However, product inhibition significantly limits hexanol accumulation without <em>in situ</em> removal. This study aimed to enhance hexanol production by employing <em>in situ</em> adsorption during CO fermentation with <em>Clostridium carboxidivorans</em> P7. Among four tested adsorbents (L-493, SD-2, GSP-25, and activated carbon), activated carbon (AC) demonstrated superior performance, achieving 8.40 g/L hexanol production while maintaining effective product removal through its high adsorption capacity. Process optimization through initial pH adjustment and reduced AC loading shortened the acidogenesis phase, further increasing hexanol production to 9.82 g/L. To reduce carbon loss from CO<sub>2</sub> generation during CO metabolism, H<sub>2</sub> was co-supplied with CO (70:30 ratio) as an additional electron donor, promoting alcohol production and enabling CO<sub>2</sub> reutilization. This strategy achieved a hexanol titer of 11.93 g/L while reducing the CO<sub>2</sub> evolution/CO consumption ratio by 16.9–18.7 % compared to CO-only fermentation. These findings demonstrate that adsorption-assisted gas fermentation with CO/H<sub>2</sub> co-utilization represents a promising strategy for sustainable hexanol production with reduced carbon emissions.</div></div>","PeriodicalId":419,"journal":{"name":"Renewable Energy","volume":"261 ","pages":"Article 125312"},"PeriodicalIF":9.1,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-23DOI: 10.1016/j.renene.2026.125332
Xu Bai, Chenyang Lu, Wen Zhang, Zhenbang Yang
The Vortex-Induced Vibration for Aquatic Clean Energy converter is an effective device for harvesting energy from low-speed ocean currents but suffers from short spring lifespan and significant transmission losses. Integrating magnetic levitation support and a linear generator can substantially reduce frictional losses; however, system performance strongly depends on the coordinated effects of magnetic stiffness and electromagnetic damping. This paper proposes a magneto–electro–fluid–structure fully coupled model combined with parametric analysis to systematically investigates the effects of magnetic stiffness and electromagnetic damping on the system's vibration characteristics and energy harvesting performance. Results show that magnetic stiffness dominates the resonance behavior and energy capture efficiency, while electromagnetic damping primarily controls the conversion efficiency from mechanical to electrical energy. The synergistic design improves energy capture efficiency by 11.95 % compared to the single-factor design. Under low damping conditions, lower stiffness leads to larger vibration amplitudes (A∗ = 0.845 at Kmag∗ = 0.72) and a broader lock-in range. Under high damping conditions, higher stiffness (Kmag∗ = 0.79) produces greater power output (PL = 0.85W at U = 1.0 m/s), whereas lower stiffness (Kmag∗ = 0.74) results in higher energy capture efficiency ( = 27.33 % at U = 0.7 m/s). These findings offer practical guidance for the coordinated design and parameter optimization of magnetically-levitated converters, contributing to the development of high-performance ocean energy harvesting systems.
涡流激振水产清洁能源转换器是一种从低速洋流中获取能量的有效装置，但其弹簧寿命短，传输损失大。将磁悬浮支架与线性发电机集成，可以大大减少摩擦损失；然而，系统的性能在很大程度上取决于磁刚度和电磁阻尼的协同作用。为了系统地研究磁刚度和电磁阻尼对系统振动特性和能量收集性能的影响，本文提出了一种结合参数分析的磁-电-流-结构全耦合模型。结果表明，磁刚度对谐振行为和能量捕获效率起主导作用，而电磁阻尼主要控制机械能到电能的转换效率。与单因素设计相比，协同设计提高了11.95%的能量捕获效率。在低阻尼条件下，较低的刚度导致较大的振动幅值（在Kmag∗= 0.72时A∗= 0.845）和较宽的锁定范围。在高阻尼条件下，较高的刚度（Kmag∗= 0.79）产生更大的功率输出（PL = 0.85W, U = 1.0 m/s），而较低的刚度（Kmag∗= 0.74）产生更高的能量捕获效率（η = 27.33%, U = 0.7 m/s）。这些研究结果为磁悬浮变换器的协调设计和参数优化提供了实用指导，有助于开发高性能海洋能量收集系统。
{"title":"Coupled effects of magnetic stiffness and electromagnetic damping on energy harvesting performance of a maglev VIVACE converter","authors":"Xu Bai, Chenyang Lu, Wen Zhang, Zhenbang Yang","doi":"10.1016/j.renene.2026.125332","DOIUrl":"10.1016/j.renene.2026.125332","url":null,"abstract":"<div><div>The Vortex-Induced Vibration for Aquatic Clean Energy converter is an effective device for harvesting energy from low-speed ocean currents but suffers from short spring lifespan and significant transmission losses. Integrating magnetic levitation support and a linear generator can substantially reduce frictional losses; however, system performance strongly depends on the coordinated effects of magnetic stiffness and electromagnetic damping. This paper proposes a magneto–electro–fluid–structure fully coupled model combined with parametric analysis to systematically investigates the effects of magnetic stiffness and electromagnetic damping on the system's vibration characteristics and energy harvesting performance. Results show that magnetic stiffness dominates the resonance behavior and energy capture efficiency, while electromagnetic damping primarily controls the conversion efficiency from mechanical to electrical energy. The synergistic design improves energy capture efficiency by 11.95 % compared to the single-factor design. Under low damping conditions, lower stiffness leads to larger vibration amplitudes (<em>A∗</em> = 0.845 at <em>K</em><sub><em>mag</em></sub><em>∗</em> = 0.72) and a broader lock-in range. Under high damping conditions, higher stiffness (<em>K</em><sub><em>mag</em></sub><em>∗</em> = 0.79) produces greater power output (<em>P</em><sub><em>L</em></sub> = 0.85W at <em>U</em> = 1.0 m/s), whereas lower stiffness (<em>K</em><sub><em>mag</em></sub><em>∗</em> = 0.74) results in higher energy capture efficiency (<span><math><mrow><mi>η</mi></mrow></math></span> = 27.33 % at <em>U</em> = 0.7 m/s). These findings offer practical guidance for the coordinated design and parameter optimization of magnetically-levitated converters, contributing to the development of high-performance ocean energy harvesting systems.</div></div>","PeriodicalId":419,"journal":{"name":"Renewable Energy","volume":"261 ","pages":"Article 125332"},"PeriodicalIF":9.1,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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