Article
Energy & Fuels
A. Barbon, J. A. Fernandez-Rubiera, L. Martinez-Valledor, A. Perez-Fernandez, L. Bayon
Summary: The new open-loop solar tracking system for a small-scale linear Fresnel reflector is able to automatically position itself with an accuracy of +/- 0.006 degrees, providing 16.64% more energy and a 78.46% higher energy-to-area ratio compared to the classic tracking system.
Article
Energy & Fuels
Alberto Pardellas, Pedro Fortuny Ayuso, Luis Bayon, Arsenio Barbon
Summary: We propose a design of a secondary cavity for Small-Scale Fresnel Reflectors in photovoltaic applications. This cavity has two focal points and produces a non-symmetrical distribution of irradiance. Our analytic study provides formulas for any number of reflections and includes numerical simulations using MATLAB. By comparing with two classical designs, V-trough and Compound Parabolic concentrators, our design shows better concentration ratios without compromising the ray acceptance rate.
Article
Thermodynamics
Gang Wang, Zijun Ge, Jianqing Lin
Summary: The current study evaluates the performance of a novel photovoltaic thermal system using a compact linear Fresnel reflector and a nanofluids beam splitting device. The system exhibits high optical efficiency and can enhance thermal efficiency by adjusting the flow velocity and temperature of the nanofluids.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Energy & Fuels
Arsenio Barbon, Covadonga Bayon-Cueli, Jose A. Fernandez Rubiera, Luis Bayon
Summary: This study presents a theoretical justification and computation of the optimum values of two longitudinal tilt angles for a small-scale linear Fresnel reflector. It is found that the optimum angle for the mobile structure is half the latitude of the geographic location, while the optimum angle for the secondary reflector system is equal to that latitude. Additionally, brute-force verification is conducted for five EU cities to validate the findings.
Article
Engineering, Chemical
M. Sheikholeslami, Z. Ebrahimpour
Summary: This study aimed to improve the productivity of a unit in an LFR system by using innovative swirl flow tapes and hybrid nanoparticles. The thermal feature of water was enhanced by dispersing Al2O3 + CuO nanoparticles. A solar unit was designed with 12 mirrors, one absorber tube, and a secondary reflector. SolTrace was used to calculate the heat source in the solid zone of the tube. The effects of inlet flow rate, temperature, pitch ratio, and height ratio were examined, and the inclusion of hybrid nanomaterial was found to enhance the Nusselt number, thermal productivity, and Darcy factor.
ADVANCED POWDER TECHNOLOGY
(2022)
Article
Thermodynamics
Zafar Said, Mokhtar Ghodbane, Arun Kumar Tiwari, Hafiz Muhammad Ali, Boussad Boumeddane, Ziad M. Ali
Summary: The study on solar water heater conducted in Blida area, Algeria during winter showed significant convergence between experimental and numerical results. The research focused on optical efficiency, thermal efficiency, exergy efficiency, hot water temperature, and system performance, achieving positive outcomes in these aspects.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Thermodynamics
A. Khosravi, A. Santasalo-Aarnio, S. Syri
Summary: The study found that solar thermal collectors can effectively reduce fuel consumption and decrease the levelized cost of energy. Increasing solar irradiance can enhance the energy efficiency gains of a hybrid system. In comparisons, the proposed hybrid system performed the best in terms of levelized cost of energy.
Article
Thermodynamics
Buchu Lu, Taixiu Liu, Xiangyu Yan, Zhimei Zheng, Qibin Liu
Summary: A new method for hydrogen production is proposed, which combines a linear Fresnel reflector, a compound parabolic concentrator, a mid-and-low temperature receiver/reactor, and methanol steam reforming reaction to achieve a more uniform distribution of solar flux, temperature, and deformation in the receiver/reactor. The study shows that the linear Fresnel reflector can achieve a more uniform temperature distribution compared to the traditional parabolic trough collector, effectively alleviating local overheating and decreasing thermal deformation.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
M. Sheikholeslami, Z. Ebrahimpour
Summary: In this study, the thermal treatment of Linear Fresnel Reflector (LFR) unit was enhanced by the application of multi-way twisted tape (MWTT). Finite volume simulations were used to predict the flow and thermal performance, and SolTrace and ANSYS FLUET were used to extract the distribution of absorb flux. The results showed that the rotation, width, and number of wings of the twisted tape significantly affected the fluid flow and thermal efficiency.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Green & Sustainable Science & Technology
Tahsin Atalay, Yusuf Yakut, Yavuz Koysal, Seyda Ozbektas, Hakan Bulbul, Bahattin Topaloglu
Summary: This study aimed to determine the energy generation capacity of a thermoelectric system mounted on a two-axis solar tracking system, comparing the results with a previous study using a one-axis tracking system. Experimental measurements were conducted on different days in October 2019, with good agreement observed between model data and experimental results. The study found that the dual-axis tracking system showed improved efficiency compared to the one-axis system in terms of TEG output voltage and solar radiation values.
INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING-GREEN TECHNOLOGY
(2022)
Article
Thermodynamics
Xiaoyan Zhao, Zhuang Chen, Suying Yan, Tingzhen Ming, Ze Wu, Rui Ma
Summary: The study investigated the impact of dust accumulation on the reflectivity of a linear Fresnel reflector, finding that an increase in dust density over time resulted in a decrease in relative reflectivity. Additionally, the dust density increased while the reflectivity decreased with a decrease in mirror tilt angle. The main component of the dust particles was found to be SiO2, and a model was proposed to predict the influence of natural dust accumulation on the relative reflectivity of the reflector.
JOURNAL OF THERMAL SCIENCE
(2021)
Article
Energy & Fuels
Z. Ebrahimpour, M. Sheikholeslami
Summary: The study discusses a new design for domestic usage where mirrors are used as primary reflectors, with the implementation of trapezoidal tanks and the use of alumina-water as the operating fluid to enhance optical performance. The analysis also examines the impact of twisted tapes and different parameters on various scenarios, while reporting on the irreversibility and thermal behavior of each case.
CHEMICAL ENGINEERING AND PROCESSING-PROCESS INTENSIFICATION
(2021)
Review
Thermodynamics
B. Kalidasan, Muhammed A. Hassan, A. K. Pandey, Subramaniyan Chinnasamy
Summary: Hollow cavity receivers are a new type of structure that overcomes the drawbacks of conventional evacuated tube receivers. They have advantages such as extended working temperature ranges, reduced thermal losses, and improved efficiency. Future research should focus on optimization and economic assessments to promote the diversified development of the solar receiver industry.
APPLIED THERMAL ENGINEERING
(2023)
Article
Energy & Fuels
Yanbo Feng, Wei Cai, Shengxu Wang, Caixia Zhang, Yaxin Liu
Summary: This paper presents a conceptual study on the energy cycle performance using a combination of linear Fresnel reflector (LFR) technology, Stirling engine, thermoelectric generator (TG), and pumped-hydro-compressed air (PHCA) technology. The power generation subsystem was able to produce 1.46 kW of electricity, with the Stirling engine accounting for 72.6% and TG for 27.4% of the electricity generation. The efficiencies of power generation and energy storage were 39.52% and 63.75% respectively.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2021)
Article
Optics
Hakon J. D. Johnsen, Juan C. Minano, Jan Torgersen
Summary: Line-focus solar concentrators have been limited by the 2D concentration limit, but we propose a new design principle that bypasses this limit and achieves higher concentration ratios. By combining the concepts of etendue squeezing and tracking integration, we demonstrate a design example and provide efficiency values under different design conditions. This design principle opens up the design space for high-concentration line-focus solar concentrators and allows for a reconsideration of the trade-off between concentration and acceptance angle.
Article
Thermodynamics
A. Barbon, P. Fortuny Ayuso, L. Bayon, J. A. Fernandez-Rubiera
Summary: This study analyzes the design causes of non-uniform illumination in small-scale linear Fresnel reflectors, optimize the main parameters and design a uniform illumination SSLFR. The maximum optimal transverse incidence angle is computed to study its influence on various aspects of the system.
Article
Mathematics, Applied
L. Bayon, P. Fortuny Ayuso, J. M. Grau, A. M. Oller-Marcen, M. M. Ruiz
Summary: This paper discusses the Multi-returning secretary problem, where each candidate has m identical copies. The paper provides an efficient algorithm to compute the optimal threshold and the probability of success for every m, based on certain conjectures. Additionally, a method for determining their asymptotic values is given by solving a system of m ODEs.
DISCRETE APPLIED MATHEMATICS
(2022)
Article
Energy & Fuels
Arsenio Barbon, Luis Bayon, Guzman Diaz, Carlos A. Silva
Summary: Rooftop photovoltaic generation plays a crucial role in cities' transition to clean energy. The determination of the optimal tilt angle for solar photovoltaic modules is complex and depends on various factors such as albedo. This study analyzed 47 Spanish province capitals using different equations and albedo types to calculate the optimum annual tilt angle. The results showed that using equations as a function of latitude increased the annual relative energy harvested by increasing the albedo. Comparisons with the method of maximizing total irradiation incident on a tilted surface revealed variations in the percentage of relative energy harvested per year. Additionally, a simplified polynomial regression model was proposed to estimate the optimum tilt angle based on latitude, altitude, and albedo.
Article
Green & Sustainable Science & Technology
A. Barbon, M. Ghodbane, L. Bayon, Z. Said
Summary: This study presents an optimization algorithm for the deployment of photovoltaic modules on irregular flat roof shapes, taking into account various factors and aiming to increase solar energy received by the modules.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Mathematics
L. Bayon, P. Fortuny Ayuso, J. M. Grau, A. M. Oller-Marcen, M. M. Ruiz
Summary: We propose a new method to compute the asymptotic values of optimal threshold and probability of success in optimal stopping problems. By solving a first-order linear differential equation, these values can be obtained systematically in various situations. We illustrate the method using nine variants of the secretary problem, including both well-known ones from literature and four unpublished ones.
BULLETIN OF THE MALAYSIAN MATHEMATICAL SCIENCES SOCIETY
(2023)
Article
Energy & Fuels
Arsenio Barbon, Angel Gutierrez, Luis Bayon, Covadonga Bayon-Cueli, Javier Aparicio-Bermejo
Summary: This study identifies the optimal operational strategy for floating photovoltaic power plants and pumped hydroelectric power plants in the day-ahead Iberian electricity market. Different operating scenarios were analysed based on forecast accuracy and deviations in the day-ahead market. The choice between independent and joint operation modes for both plants is determined by these scenarios.
Article
Energy & Fuels
Alberto Pardellas, Pedro Fortuny Ayuso, Luis Bayon, Arsenio Barbon
Summary: We propose a design of a secondary cavity for Small-Scale Fresnel Reflectors in photovoltaic applications. This cavity has two focal points and produces a non-symmetrical distribution of irradiance. Our analytic study provides formulas for any number of reflections and includes numerical simulations using MATLAB. By comparing with two classical designs, V-trough and Compound Parabolic concentrators, our design shows better concentration ratios without compromising the ray acceptance rate.
Article
Computer Science, Information Systems
Arsenio Barbon, Javier Aparicio-Bermejo, Luis Bayon, Ramy Georgious
Summary: This paper aims to analyze the parameters that influence the mode of operation of an FPV power plant combined with a PHS power plant. The results show that the joint operation of a floating photovoltaic system with a pumped hydroelectric storage power plant is a cost-effective and reliable alternative for sustainable energy supply under uncertain solar resource conditions.
Article
Computer Science, Information Systems
Jose Angel Fernandez-Rubiera, Arsenio Barbon, Luis Bayon, Mokhtar Ghodbane
Summary: A novel sawtooth V-cavity design method based on an optimization algorithm was proposed to achieve uniform irradiance distribution on photovoltaic cells. The reliability of the design was verified using the Monte Carlo ray-tracing method and a laser experiment. A prototype was built using 3D printing technology with a biodegradable green polymer material known as polylactic acid.
Article
Energy & Fuels
A. Barbon, P. Fortuny Ayuso, L. Bayon, C. A. Silva
Summary: This paper explores an advantage of using mountainous terrain for solar plant installation: higher annual solar irradiation incident of single-axis N-S trackers installed on sloping terrain compared to horizontal ones. Theoretical study, numerical simulations, and experimental results confirm this advantage. Theoretical values for energy gain at different slopes between latitudes of 6 degrees and 60 degrees in the northern hemisphere are provided, with gains reaching up to 13.5%.
Article
Green & Sustainable Science & Technology
Cameron Bracken, Nathalie Voisin, Casey D. Burleyson, Allison M. Campbell, Z. Jason Hou, Daniel Broman
Summary: This study presents a methodology and dataset for examining compound wind and solar energy droughts, as well as the first standardized benchmark of energy droughts across the Continental United States (CONUS) for a 2020 infrastructure. The results show that compound wind and solar droughts have distinct spatial and temporal patterns across the CONUS, and the characteristics of energy droughts are regional. The study also finds that compound high load events occur more often during compound wind and solar droughts than expected.
Article
Green & Sustainable Science & Technology
Ning Zhang, Yanghao Yu, Jiawei Wu, Ershun Du, Shuming Zhang, Jinyu Xiao
Summary: This paper provides insights into the optimal configuration of CSP plants with different penetrations of wind power by proposing an unconstrained optimization model. The results suggest that large solar multiples and TES are preferred in order to maximize profit, especially when combined with high penetrations of wind and photovoltaic plants. Additionally, the study demonstrates the economy and feasibility of installing electric heaters (EH) in CSP plants, which show a linear correlation with the penetration of variable energy resources.
Article
Green & Sustainable Science & Technology
M. Szubel, K. Papis-Fraczek, S. Podlasek
Article
Green & Sustainable Science & Technology
J. Silva, J. C. Goncalves, C. Rocha, J. Vilaca, L. M. Madeira
Summary: This study investigated the methanation of CO2 in biogas and compared two different methanation reactors. The results showed that the cooled reactor without CO2 separation achieved a CO2 conversion rate of 91.8%, while the adiabatic reactors achieved conversion rates of 59.6% and 67.2%, resulting in an overall conversion rate of 93.0%. Economic analysis revealed negative net present worth values, indicating the need for government monetary incentives.
Article
Green & Sustainable Science & Technology
Yang Liu, Yonglan Xi, Xiaomei Ye, Yingpeng Zhang, Chengcheng Wang, Zhaoyan Jia, Chunhui Cao, Ting Han, Jing Du, Xiangping Kong, Zhongbing Chen
Summary: This study investigated the effect of using nanofiber membrane composites containing Prussian blue-like compound nanoparticles (PNPs) to relieve ammonia nitrogen inhibition of rural organic household waste during high-solid anaerobic digestion and increase methane production. The results showed that adding NMCs with 15% PNPs can lower the concentrations of volatile fatty acids and ammonia nitrogen, and increase methane yield.
Article
Green & Sustainable Science & Technology
Zhong Ge, Xiaodong Wang, Jian Li, Jian Xu, Jianbin Xie, Zhiyong Xie, Ruiqu Ma
Summary: This study evaluates the thermodynamic, exergy, and economic performance of a double-stage organic flash cycle (DOFC) using ten eco-friendly hydrofluoroolefins. The influences of key parameters on performance are analyzed, and the advantages of DOFC over single-stage type are quantified.
Article
Green & Sustainable Science & Technology
Nicolas Kirchner-Bossi, Fernando Porte-Agel
Summary: This study investigates the optimization of power density in wind farms and its sensitivity to the available area size. A novel genetic algorithm (PDGA) is introduced to optimize power density and turbine layout. The results show that the PDGA-driven solutions significantly reduce the levelized cost of energy (LCOE) compared to the default layout, and exhibit a convex relationship between area and LCOE or power density.
Article
Green & Sustainable Science & Technology
Chunxiao Zhang, Dongdong Li, Lin Wang, Qingpo Yang, Yutao Guo, Wei Zhang, Chao Shen, Jihong Pu
Summary: In this study, a novel reversible liquid-filled energy-saving window that effectively regulates indoor solar radiation heat gain is proposed. Experimental results show that this window can effectively reduce indoor temperature during both summer and winter seasons, while having minimal impact on indoor illuminance.
Article
Green & Sustainable Science & Technology
Alessandro L. Aguiar, Martinho Marta-Almeida, Mauro Cirano, Janini Pereira, Leticia Cotrim da Cunha
Summary: This study analyzed the Brazilian Equatorial Shelf using a high-resolution ocean model and found significant tidal variations in the area. Several hypothetical barrages were proposed with higher annual power generation than existing barrages. The study also evaluated the installation effort of these barrages.
Article
Green & Sustainable Science & Technology
Francesco Superchi, Nathan Giovannini, Antonis Moustakis, George Pechlivanoglou, Alessandro Bianchini
Summary: This study focuses on the optimization of a hybrid power station on the Tilos island in Greece, aiming to increase energy export and revenue by optimizing energy fluxes. Different scenarios are proposed to examine the impact of different agreements with the grid operator on the optimal solution.
Article
Green & Sustainable Science & Technology
Peimaneh Shirazi, Amirmohammad Behzadi, Pouria Ahmadi, Sasan Sadrizadeh
Summary: This research presents two novel energy production/storage/usage systems to reduce energy consumption and environmental effects in buildings. A biomass-fired model and a solar-driven system integrated with photovoltaic thermal (PVT) panels and a heat pump were designed and assessed. The results indicate that the solar-based system has an acceptable energy cost and the PVT-based system with a heat pump is environmentally superior. The biomass-fired system shows excellent efficiency.
Article
Green & Sustainable Science & Technology
Zihao Qi, Yingling Cai, Yunxiang Cui
Summary: This study aims to investigate the operational characteristics of the solar-ground source heat pump system (SGSHPS) in Shanghai under different operation modes. It concludes that tandem operation mode 1 is the optimal mode for winter operation in terms of energy efficiency.
Article
Green & Sustainable Science & Technology
L. Bartolucci, S. Cordiner, A. Di Carlo, A. Gallifuoco, P. Mele, V. Mulone
Summary: Spent coffee grounds are a valuable biogenic waste that can be used as a source of biofuels and valuable chemicals through pyrolysis and solvent extraction processes. The study found that heavy organic bio-oil derived from coffee grounds can be used as a carbon-rich biofuel, while solvent extraction can extract xantines and p-benzoquinone, which are important chemicals for various industries. The results highlight the promising potential of solvent extraction in improving the economic viability of coffee grounds pyrolysis-based biorefineries.
Article
Green & Sustainable Science & Technology
Luiza de Queiroz Correa, Diego Bagnis, Pedro Rabelo Melo Franco, Esly Ferreira da Costa Junior, Andrea Oliveira Souza da Costa
Summary: Building-integrated photovoltaics, especially organic solar technology, are important for reducing greenhouse gas emissions in the building sector. This study analyzed the performance of organic panels laminated in glass in a vertical installation in Latin America. Results showed that glass lamination and vertical orientation preserved the panels' performance and led to higher energy generation in winter.
Article
Green & Sustainable Science & Technology
Zhipei Hu, Shuo Jiang, Zhigao Sun, Jun Li
Summary: This study proposes innovative fin arrangements to enhance the thermal performance of latent heat storage units. Through optimization of fin distribution and prediction of transient melting behaviors, it is found that fin structures significantly influence heat transfer characteristics and melting behaviors.
