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Preprint ARTICLE | doi:10.20944/preprints201806.0082.v1

Computing the Real Impact of Wind Turbine Power Curve Upgrades: A SCADA-Based Multivariate Linear Method and a Vortex Generator Test Case

Davide Astolfi, Francesco Castellani, Mario Luca Fravolini, Silvia Cascianelli, Ludovico Terzi

Subject: Engineering, Energy And Fuel Technology Keywords: wind energy; wind turbines; supervisory control and data acquisition; retrofitting; performance evaluation

Online: 6 June 2018 (10:17:12 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202312.1971.v1

Harvesting Renewable Energy to Supply Power for Electric Buses

Shwan Hussein Awla, Simon Philbin

Subject: Engineering, Energy And Fuel Technology Keywords: Renewable Energy Technologies; Solar Modules; Wind Turbines; Piezoelectric Materials; Electric Buses; Energy Efficiency; Urban Public Transportation; Techno-Economic Analysis; Environmental Sustainability; Charging Infrastructure Reduction

Online: 27 December 2023 (01:47:42 CET)

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Preprint ARTICLE | doi:10.20944/preprints202108.0264.v1

Proposal Design of a Hybrid Solar PV-Wind-Battery Energy Storage for Standalone DC Microgrid Application

Mwaka Juma, Bakari M. M. Mwinyiwiwa, Consalva J. Msigwa, Aviti T. Mushi

Subject: Engineering, Electrical And Electronic Engineering Keywords: solar photovoltaic (PV); wind turbine coupled to permanent synchronous generator (WT-PMSG); battery energy storage (BESS); maximum power point tracking (MPPT); DC/DC converters

Online: 11 August 2021 (15:10:26 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202311.0208.v1

Periodic Behavior of Selected Solar, Geomagnetic and Cosmic Activity Indices during Solar Cycle 24

Ali Kilcik, Atila Ozguc, Jean-Pierre Rozelot

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Solar cycles; Solar flares; Geomagnetic activity indices; Cosmic rays; Period analysis

Online: 3 November 2023 (11:23:50 CET)

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Preprint ARTICLE | doi:10.20944/preprints202302.0486.v1

MHD Simulation in the Solar Corona to Obtain Conditions for the Acceleration of Cosmic Rays during Solar Flares

Alexander Podgorny, Igor Podgorny, Alexei Borisenko

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: solar flare; solar cosmic rays; current sheet; magnetohydrodynamic simulation; active region

Online: 28 February 2023 (02:23:20 CET)

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Preprint ARTICLE | doi:10.20944/preprints202208.0046.v2

Solar Activity Cycles Recur Epidemic and Pandemic Viruses: Space Weather Alerts

Ramy Mawad, Hanafy M. Madbouly, Ehab M. B. Mahdy

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Space weather; Solar terrestrial connection; Climate change; Solar cycle; Environment; Epidemiology

Online: 12 January 2023 (02:36:30 CET)

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Preprint ARTICLE | doi:10.20944/preprints202001.0072.v1

Thermal Efficiency of a Concentrating Solar Collector Under High-Vacuum

Davide De Maio, Carmine D' Alessandro, Daniela De Luca, Marilena Musto, Emilano Di Gennaro, Giuseppe Rotondo, Roberto Russo

Subject: Engineering, Energy And Fuel Technology Keywords: solar energy; Compound Parabolic Concentrators (CPC); high vacuum insulated solar collectors

Online: 9 January 2020 (05:31:26 CET)

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Preprint ARTICLE | doi:10.20944/preprints201907.0101.v1

Design and Analysis of Domestic Micro-Cogeneration Potential for an ORC System Adapted to a Solar Domestic Hot Water System

Daniel Leal-Chavez, Ricardo Beltran-Chacon, Paola Cardenas-Terrazas, Saul Islas, Nicolas Velazquez

Subject: Engineering, Energy And Fuel Technology Keywords: solar domestic cogeneration; Organic Rankine Cycle; acetone; evacuated tube solar collector

Online: 8 July 2019 (04:15:59 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201812.0091.v1

Solar Power Interpolation and Analysis Using Spatial Autocorrelation

Syed Muhammad Ahsan Gillani

Subject: Engineering, Energy And Fuel Technology Keywords: solar power interpolation; solar power attenuation; spatial autocorrelation; semi-variograms; geosatistics

Online: 7 December 2018 (03:55:55 CET)

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Preprint ARTICLE | doi:10.20944/preprints201805.0062.v1

A Study on Photostability of Amphetamines and Ketamine in Hair Irradiated under Artificial Sunlight

Giorgia Miolo, Marianna Tucci, Luca Menilli, Giulia Stocchero, Susanna Vogliardi, Salvatore Scrivano, Massimo Montisci, Donata Favretto

Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: hair; solar light; photodegradation; amphetamines; MDMA; ketamine; photoproduct; photostability; solar simulator

Online: 3 May 2018 (09:11:57 CEST)

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Background: Drug incorporated in hair are exposed to the environment and to cosmetic and chemical treatments, with possible decrease of their content. Knowledge concerning the effect of sun light on drug content in hair can be helpful to the forensic toxicologist, in particular when investigating on drug concentrations above or below pre-determined cut-offs. Materials and Methods: Twenty authentic positive hair samples were selected that had previously tested positive for amphetamines and/or ketamine. Washed hairs were divided into two identical strands: the former was exposed at 765 W/m² (310–800 nm spectrum of irradiance) for 48 hours in a solar simulator, the latter was kept in the dark. Hair samples were extracted and analyzed by LC-HRMS detection. The percent photodegradation was calculated for each analyte (amphetamine, methamphetamine, methylendioxyamphetamine methylendioxymethamphetamine, ketamine, norketamine). In parallel, photodegradation processes of standard molecules dissolved in aqueous and organic solutions were studied. Results: In 20 hair samples positive for the targeted analytes, exposure to artificial sun light induced an appreciable decrease of drug concentrations. The concentration ranges in the non-irradiated hair samples were 0.01–24 ng/mg; 65% of samples exhibited a decrease in post-irradiation samples, with reduction from 3% to 100%. When more drugs were present in the same hair sample (e.g, MDMA and ketamine) the degradation yields were compound dependent. A degradation product induced by irradiation of ketamine in aqueous and methanol solutions was identified; it was also found to be present in a true positive hair sample after irradiation. Conclusions: Ketamine, amphetamines and their metabolites incorporated in hair of drug users undergo degradation when irradiated by artificial sunlight. Only for ketamine a photoproduct was identified in irradiated standard solutions and in true positive irradiated hair. When decisional cut-offs are applied to hair analysis, photodegradation must be taken into account since sunlight may produce false negative results. Moreover, new markers could be investigated as evidence of illicit drug use.

Preprint ARTICLE | doi:10.20944/preprints202307.0927.v1

Understanding the Characteristics of Vertical Structure for Wind Speed Observation via Wind-LIDAR in Jeju Island

Dong-won Yi, Sang-Sam Lee, Hee-Wook Choi, Yong Hee Lee

Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: Wind-LIDAR; multiple-level winds; diurnal cycle; atmospheric boundary layer; maximum wind speed

Online: 13 July 2023 (11:15:12 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202011.0529.v1

A Unifying Perspective on Transfer Function Solutions to the Unsteady Ekman Problem

Jonathan M. Lilly, Shane Elipot

Subject: Environmental And Earth Sciences, Oceanography Keywords: Ekman currents; ocean surface currents; wind stress forcing; transfer function; wind-driven response

Online: 20 November 2020 (09:32:45 CET)

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Preprint REVIEW | doi:10.20944/preprints202403.0300.v2

A review on the present and future of solar power in Africa

Ahmed Rachid, Nouhaila NAJMI

Subject: Physical Sciences, Other Keywords: Solar energy; Development; Africa; Solar farms; Mini-grids; Off-grid; Solar houses; Irrigation; Legislation; Business models; NGOs; International companies

Online: 14 March 2024 (09:34:59 CET)

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Preprint ARTICLE | doi:10.20944/preprints202007.0695.v1

Performance Study of Integrated Solar-Water Supply System for Isolated Agricultural Areas in Thailand: Two Case-Study Villages of The Royal Initiative Project

Thanongsak Imjai, Kamon Thinsurat, Pakorn Ditthakit, Warit Wipulanusat, Monthian Setkit, Reyes Garcia

Subject: Environmental And Earth Sciences, Water Science And Technology Keywords: water resource management; solar-water; solar-water supply system; SWSS; decision support; solar pumping; climate change; royal initiative project

Online: 29 July 2020 (11:40:50 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202310.0951.v1

Looking for the Optimal Shape of a Photovoltaic Panel

Eduardo Diedrich

Subject: Engineering, Energy And Fuel Technology Keywords: Optima Shape; Solar Panel

Online: 16 October 2023 (09:37:07 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202105.0488.v9

The Solar System: Nature and Mechanics

Mario Ljubičić

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: solar system; complete relativity; nature; mechanics

Online: 19 July 2023 (09:29:20 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202403.1540.v1

Evaluation of a High Resolution WRF Model for Southeast Brazilian Coast: The Importance of Physical Parameterization to Wind Representation

Layrson Gonçalves, Júlia Kaiser, Ronaldo Palmeira, Marcos Gallo, Carlos Eduardo Parente

Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: WRF model; Wind simulation; Parameterizations

Online: 26 March 2024 (07:27:50 CET)

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Preprint ARTICLE | doi:10.20944/preprints202403.0038.v1

Environmental Factors Affecting Requirements for Wind Power Stations

Olga Orynycz, Paweł Ruchała, Karol Tucki, Andrzej Wasiak

Subject: Environmental And Earth Sciences, Sustainable Science And Technology Keywords: wind turbine; efficiency; power, environmental

Online: 1 March 2024 (12:33:10 CET)

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Preprint ARTICLE | doi:10.20944/preprints202307.1511.v1

Evaluation of Wear Models for the Wear Calculation of Journal Bearings for Planetary Gears in Wind Turbines

Benjamin Lehmann, Philipp Trompetter, Francisco Gutiérrez Guzmán, Georg Jacobs

Subject: Engineering, Mechanical Engineering Keywords: Journal Bearing; Wear; Wind Turbine

Online: 24 July 2023 (02:12:27 CEST)

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To increase the power density of the electromechanical drive train of wind turbines, journal bearings can be used as planetary gear bearings instead of rolling bearings. This technological change presents new challenges. For example, wind turbine drive systems are subject to dynamic and low-speed operating conditions which can lead to an accelerated abrasive wear of the journal bearings. In addition, oil supply failure or peak loads due to wind gusts and grid and power converter faults could potentially result in catastrophic failure due to adhesive wear in a very short time. Such operating characteristics are, therefore, critical regarding the journal bearing wear lifetime and must be considered in the design. The successful implementation of journal bearings in wind turbines depends on a reliable estimation of adhesive and abrasive wear. In this paper, five different models for the wear calculation of journal bearings are evaluated regarding their suitability of wear calculation of planetary gear bearings in wind turbines. For this purpose, the following evaluation criteria were defined: parameter uncertainty, parametrization effort, in particular number of parameters, parameterization method and load case dependency of parameters and calculation effort. In order to be able to evaluate the wear models, the wear models are numerically implemented and the wear of a test journal bearing is exemplarily calculated under load conditions, which are comparable to load conditions in a wind turbine. Relevant influences from the wind turbine system such as lubricant, material and manufacturing dependent surface influences like roughness and hardness are considered. The wear models are evaluated with respect to their fulfillment of the defined criteria. The resulting evaluation allows the selection of a wear model that can be used to calculate the wear of planetary gear journal bearings in wind turbines, considering the available input variables.

Preprint ARTICLE | doi:10.20944/preprints202210.0252.v1

Assessing Wind Farm Site Suitability in Bangladesh: A GIS-AHP Approach

Md. Rabiul Islam, Md. Rakibul Islam, H. M. Imran

Subject: Engineering, Energy And Fuel Technology Keywords: wind farm; GIS; AHP; Bangladesh

Online: 18 October 2022 (05:54:22 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201801.0222.v1

Bumpless Transfer of Parametrized Multivariable Disturbance Observer Based Controller to Reduce Cyclic Loads of Wind Turbine

Raja Muhammad Imran, Dil Muhammad Akbar Hussain, Bhawani Shanker Chowdhry, Arbab Waleed

Subject: Engineering, Control And Systems Engineering Keywords: wind turbine; LPV; DOBC; multivariable

Online: 24 January 2018 (07:03:52 CET)

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Preprint REVIEW | doi:10.20944/preprints202401.2160.v1

Advancements in Photovoltaic Cell Materials: Silicon, Organic, and Perovskite Solar Cells

Abniel Machín, Francisco Márquez

Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: photovoltaic cells; silicon-based solar cells; organic-based cells; perovskite solar cells

Online: 31 January 2024 (05:53:39 CET)

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Preprint REVIEW | doi:10.20944/preprints202309.2044.v1

A Review of Photocatalytic Water Splitting for Hydrogen Production Using Tandem Solar Cell

Nur Ain Atiqah Mohd Amin, Hayyiratul Fatimah Mohd Zaid

Subject: Engineering, Chemical Engineering Keywords: photocatalytic water splitting; photoelectrochemical cell; dye solar cell; tandem solar cell; hydrogen

Online: 29 September 2023 (08:05:11 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202304.0706.v1

Solar Business in an Oil-Rich Country? A Socio-technical Investigation of Solar PV Businesses in Iran

Leila Aghlimoghadam

Subject: Environmental And Earth Sciences, Sustainable Science And Technology Keywords: solar business; solar PV; social acceptance; energy transition; oil-rich country; Iran

Online: 21 April 2023 (09:49:31 CEST)

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Taking a socio-technical perspective, I focus on solar businesses (niche market actors) in Iran. As one of the key stakeholder groups whose business prosperity is tied to the development of solar PV, they play a crucial role in accelerating the energy transition. Given the incumbent fossil-based electricity sector in Iran and the least enabling policies, I am first interested to find (i) the main drivers and barriers of solar businesses; and (ii) the roles these solar businesses play in bringing solar PV deployment forward in Iran. I collected the data via 20 semi-structured interviews with solar businesses in Golestan, Guilan, Tehran, Khorasan Razavi, and Eastern Azerbaijan Provinces in Iran. Taking an inductive approach, I considered sustainability transition and social acceptance theories as sensitising concepts to investigate common and specific points of solar business acceptance in Iran. I find ecological awareness, belief in intergenerational justice, and willingness to innovate, as the main intrinsic drivers and socioeconomic opportunity and tackling the energy imbalance as extrinsic drivers; while the lack of a common vision with the energy governors, and the low knowledge of solar PV among the customers, escalating prices, and challenges to accessing good quality solar equipment are the most prior obstacles. Moreover, I understand educating people, driving the innovative deployment of solar PV, and facilitating the diffusion of it, as the major roles of solar businesses in Iran. I find that the sustainability transition literature overlooked the key role of solar businesses specially in fossil-based and developing economies. My findings suggest that the positive intrinsic mechanisms among the solar businesses, in combination with better-enabling policy frameworks and external factors, like lifting the sanctions and joining the global energy market, climate change mitigation commitments and standards, can help solar businesspeople to lead and accelerate solar PV development in Iran.

Preprint ARTICLE | doi:10.20944/preprints202312.1158.v1

An Assessment of Urban Wind Potential and the Stakeholders Involved in Energy Decision-Making

Alexander Vallejo Díaz, Idalberto Herrera Moya, Edwin Garabitos Lara, Cándida K. Casilla Victorino

Subject: Environmental And Earth Sciences, Sustainable Science And Technology Keywords: urban wind energy; renewable energy; RACI matrix; energy potential, small wind turbines, Dominican Republic

Online: 15 December 2023 (08:57:18 CET)

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Preprint ARTICLE | doi:10.20944/preprints201901.0281.v1

Wind Turbine Maintenance Cost Reduction by Deep Learning Aided Drone Inspection Analysis

ASM Shihavuddin, Xiao Chen, Vladimir Fedorov, Nicolai Andre Brogaard Riis, Anders Nymark Christensen, Kim Branner, Anders Bjorholm Dahl, Rasmus Reinhold Paulsen

Subject: Computer Science And Mathematics, Artificial Intelligence And Machine Learning Keywords: Wind Energy; Wind Turbine; Drone Inspection; Damage Detection; Deep Learning; Convolutional Neural Network (CNN)

Online: 28 January 2019 (15:50:04 CET)

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Preprint ARTICLE | doi:10.20944/preprints202404.0138.v1

Design and Optimization of Electrical Parameters of Perovskites-based Thin Film Solar Cell

Muhammad Muneeb Khan, Sadiq Ahmad, Ali Hassan, And Furqan Shaukat

Subject: Engineering, Energy And Fuel Technology Keywords: Electrical Parameters; Perovskite; Optimization; Renewable Power; SCAPS-1D; PVSyst; Solar Module; Solar Cell

Online: 2 April 2024 (09:25:09 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202311.1854.v1

SISA: The First Extreme-Ultraviolet Solar Integral Field Spectrograph Using Slicers

Ariadna Calcines Rosario, Hamish Andrew Sinclair Reid, Sarah Matthews, Frédéric Auchère, Alain Jody Corso, Giulio Del Zanna, Jaroslav Dudik, Samuel Gissot, Laura Hayes, Graham Stewart Kerr, Christian Kintziger, Sophie Musset, Vanessa Polito, Daniel F. Ryan, David Orozco Suárez

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: EUV Spectroscopy; solar IFS; EUV slicers; image slicers; solar space mission; particle acceleration

Online: 29 November 2023 (10:56:44 CET)

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Preprint ARTICLE | doi:10.20944/preprints202111.0572.v1

Synthesis and Characterization of Al-doped NiO Nanostructured Thin Films Elaborated by Solar Spray Pyrolysis Technique, for Photovoltaic Cells

Abdelbaki NID, Lilia ZIGHED, Yacine AOUN, Bedreddine MAAOUI

Subject: Physical Sciences, Applied Physics Keywords: Nickel oxide; Thin films; Al doping ratio; Solar spray pyrolysis; Solar heater; Furnace.

Online: 30 November 2021 (13:29:11 CET)

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Preprint ARTICLE | doi:10.20944/preprints201902.0074.v1

Solar Green Roofs: A Unified Outlook Twenty Years On

Rosaria Ciriminna, Francesco Meneguzzo, Mario Pecoraino, Mario Pagliaro

Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: solar energy; solar green roof; energy transition; biosolar roof; green roof; air pollution

Online: 7 February 2019 (13:02:10 CET)

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Preprint ARTICLE | doi:10.20944/preprints202402.1061.v1

Enhancing Reliability in Wind Turbine Power Curve Estimation

Pere Marti-Puig, José Ángel Hernández, Jordi Solé-Casals, Moisès Serra-Serra

Subject: Engineering, Energy And Fuel Technology Keywords: Wind Power Curve Modeling; Artificial neural networks (ANN); Wind Turbine (WT); SCADA Data.; Industrial AI

Online: 19 February 2024 (12:24:46 CET)

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Preprint ARTICLE | doi:10.20944/preprints202307.1323.v1

Riveaux Road Fire Driven by Dynamic Winds in Tasmania, Australia

Mitsuhiro Ozaki, Grant Williamson, Paul Fox-Hughes, Peter Love, Jagannath Aryal

Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: AFDRS; dynamic wind; rugged terrain; downslope wind; terrain forced channelling; buttongrass moorland; wildfire; fire intensity

Online: 19 July 2023 (10:10:26 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202204.0187.v1

Gravity-Assist Might be a Solution to Save Earth from Global Warming

Sohrab Rahvar

Subject: Environmental And Earth Sciences, Space And Planetary Science Keywords: Dynamics; Solar System; Global Warming

Online: 20 April 2022 (08:53:55 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202003.0162.v1

A Publicly Available Cost Simulation of Sustainable Construction Options for Residential Houses

Lawrence Fulton, Bradley Beauvauis, Matthew Brooks, Scott Kruse, Kim Lee

Subject: Engineering, Architecture, Building And Construction Keywords: construction; rainwater harvesting; simulation; solar

Online: 10 March 2020 (10:26:12 CET)

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Preprint ARTICLE | doi:10.20944/preprints201810.0452.v1

Solar Neutrinos Spectroscopy with Borexino Phase-II

Lino Miramonti, M. Agostini, K. Altenmueller, S. Appel, V. Atroshchenko, Z. Bagdasarian, D. Basilico, G. Bellini, J. Benziger, D. Bick, I. Bolognino, G. Bonfini, D. Bravo, B. Caccianiga, F. Calaprice, A. Caminata, S. Caprioli, M. Carlini, P. Cavalcante, F. Cavanna, A. Chepurnov, K. Choi, L. Collica, S. Davini, A. Derbin, X.F. Ding, A. Di Ludovico, L. Di Noto, I. Drachnev, K. Fomenko, A. Formozov, D. Franco, F. Gabriele, C. Galbiati, M. Gschwender, C. Ghiano, M. Giammarchi, A. Goretti, M. Gromov, D. Guffanti, C. Hagner, T. Houdy, E. Hungerford, Aldo Ianni, Andrea Ianni, A. Jany, D. Jeschke, V. Kobychev, D. Korablev, G. Korga, T. Lachenmaier, M. Laubenstein, E. Litvinovich, F. Lombardi, P. Lombardi, L. Ludhova, G. Lukyanchenko, L. Lukyanchenko, I. Machulin, G. Manuzio, S. Marcocci, J. Maricic, J. Martyn, E. Meroni, M. Meyer, M. Misiaszek, L. Papp, O. Penek, L. Pietrofaccia, N. Pilipenko, A. Pocar, A. Porcelli, G. Raikov, G. Ranucci, A. Razeto, A. Re, M. Redchuk, A. Romani, N. Rossi, S. Rottenanger, S. Schönert, D. Semenov, M. Skorokhvatov, O. Smirnov, A. Sotnikov, L.F.F. Stokes, Y. Suvorov, R. Tartaglia, G. Testera, J. Thurn, M. Toropova, E. Unzhakov, A. Vishneva, R.B. Vogelaar, F. von Feilitzsch, S. Weinz, M. Wojcik, M. Wurm, Z. Yokley, O. Zaimidoroga, S. Zavatarelli, K. Zuber, G. Zuzel

Subject: Physical Sciences, Particle And Field Physics Keywords: solar neutrinos; neutrino oscillation; Borexino

Online: 19 October 2018 (11:49:06 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202405.0146.v1

The Relationship between Wind Conditions and Fire Ignition Causes: Central Portugal Case Study

Luis Filipe Carreira dos Santos, Vasco Augusto Lopes, Robert Mazur

Subject: Other, Environmental And Earth Sciences Keywords: Wildfires; wind intensity; Policy; Ignitions; causes

Online: 3 May 2024 (11:22:37 CEST)

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In recent decades the Mediterranean area observed an increase in large fires, despite the decrease in the number of fire ignitions, following a worldwide tendency. Climate change has been the main culprit for large burnt areas, and alterations of forest ecosystems, resulting in the increased recurrence of forest fires. In Portugal, the analogous trend resulted in the destruction of large rural, urban and industrial areas, where after the 2017 months of June and October catastrophic events, the government implemented the 2019 specific policies for preventing fire outbreaks and defending the forest against fires. This compulsory policy demanded that landowners and local governments alike needed to contact specific authorities requesting authorization for their intentions to clean properties in and around urban areas, roads, and forest limits. Despite policy and careful monitoring, ignitions still occur, and in many cases resulting from the implementation of such policies. The study analyses the before and after policy implementation, considering 6904 ignitions records from the period between 2014 and 2023 from the central area of Portugal, covering the transition area between the agricultural fields of the Tagus valley and the Monte-junto-Estrela Mountain range, the district of Santarém. The authorization to use fire in clearance practices is granted according to a set of weather conditions, temperature, wind intensity, and relative humidity, when analyzing fire ignitions with the average daily wind intensity at the site of the occurrence, we observed that more than half of wildfires occur on days with winds between 10 and 20 Km/h, whereas intensities greater than 30 Km/h only 1% of the total occurrences, and of these 22% occurred due to the use of fire in the burning of agricultural leftovers and cut and piled bushes. The circulation of the thermal depression in the Iberian Peninsula gives rise to increasing intensity throughout the day, reaching a maximum in the late afternoon, this factor combined with the misjudgment of safe conditions leads us to suggest stricter intervals and the need for awareness of daily variation in conditions.

Preprint COMMUNICATION | doi:10.20944/preprints202312.0165.v1

Challenges in the Forecasting of Severe Typhoon Koinu in 2023

P.W. Chan, Y.H. He

Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: tropical cyclone; track; intensity; wind; rainfall

Online: 4 December 2023 (11:35:44 CET)

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Preprint COMMUNICATION | doi:10.20944/preprints202309.1634.v1

Super Typhoon Saola (2309) affecting Hong Kong in September 2023–Forecasting Aspect

P.W. Chan, Y.H. He, Y.S. Lui

Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: tropical cyclone; track; intensity; wind structure

Online: 25 September 2023 (09:32:43 CEST)

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Preprint REVIEW | doi:10.20944/preprints202308.1156.v1

Methodologies for Wind Field Reconstruction in the U-SPACE: A Review

Edoardo Bucchignani

Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: U_SPACE; drone flight; wind field reconstruction

Online: 16 August 2023 (08:15:44 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202201.0058.v1

Ducted Wind Turbine in Generating Set Air Flow

Ivan Anzanello

Subject: Engineering, Energy And Fuel Technology Keywords: Wind power; Generating set; Venturi Effect

Online: 6 January 2022 (10:01:16 CET)

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Preprint ARTICLE | doi:10.20944/preprints202107.0300.v1

The Development of Wind Farms Business and the Central Control of Smart Grid in Spain: Making a Virtue of Necessity

Santiago M López, Mar Cebrián

Subject: Business, Economics And Management, Economics Keywords: regulatory economics; smart grids; wind farms

Online: 13 July 2021 (11:24:23 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201907.0098.v1

Confronting Urban Electricity Demand with Wind Energy Supply: Case Study in Ecuador

Manuel Ayala, Genís Riba

Subject: Engineering, Energy And Fuel Technology Keywords: wind power; urban areas; power management

Online: 8 July 2019 (03:37:09 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201810.0262.v1

Comparison of Blade Element Method and CFD Simulations of a 10 MW Wind Turbine

Galih Bangga

Subject: Engineering, Energy And Fuel Technology Keywords: aerodynamics; BEM; CFD; simulation; wind turbine

Online: 12 October 2018 (08:05:56 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201807.0501.v1

Short-Term Forecast of Wind Speed through Mathematical Models

Moniki Ferreira, Alexandre Santos, Paulo Lucio

Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: wind speed; ANN model; hybrid model

Online: 26 July 2018 (04:22:14 CEST)

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Preprint REVIEW | doi:10.20944/preprints202307.0803.v1

The Trend of Solar Energy Utilization and Its Offshore Assessment in Nigeria

Wasiu Olalekan Idris, Mohd Zamri Ibrahim, Aliashim Alibani

Subject: Engineering, Energy And Fuel Technology Keywords: solar PV system; renewable energy system; solar radiation; net present value; cost of electricity

Online: 12 July 2023 (11:44:28 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202201.0397.v1

Effect Of The Aerosol Vertical Distribution On The Modelling Of Solar Radiation

Ilias Fountoulakis, Kyriakoula Papachristopoulou, Emmanouil Proestakis, Vassilis Amiridis, Charalampos Kontoes, Stelios Kazadzis

Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: aerosol profile; aerosol extinction coefficient; aerosol radiative effects; spectral solar radiation; solar radiation profile

Online: 26 January 2022 (12:52:00 CET)

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Preprint ARTICLE | doi:10.20944/preprints202008.0162.v2

Efficiency of Selective Solar Absorber in High Vacuum Flat Solar Thermal Panels: The Role of Emissivity

Davide De Maio, Carmine D'Alessandro, Antonio Caldarelli, Marilena Musto, Daniela De Luca, Emiliano Di Gennaro, Roberto Russo

Subject: Engineering, Energy And Fuel Technology Keywords: thermal emittance; conversion efficiency; selective solar absorber; thermal energy; evacuated flat panel; solar energy

Online: 20 October 2020 (12:18:01 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201804.0318.v2

Techno-Economic Feasibility of Hybrid Solar Photovoltaic and Battery Energy Storage Power System for a Soshanguve Mobile Cellular Base Station in South Africa

Banjo Ayoade Aderemi, SP Daniel Chowdhury, Thomas O. Olwal, Adnan M. Abu-Mahfouz

Subject: Engineering, Electrical And Electronic Engineering Keywords: Solar PV, Green Energy, Hybrid Power Source, Mobile Cellular Base Station, OPEX, Solar Irradiance

Online: 25 July 2018 (14:30:45 CEST)

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Over the years, sustainability, impact on the environment, as well as the operation expenditure have been a major concern to the deployment of mobile cellular base stations worldwide. This is because the mobile cellular base stations are known to consume a high percentage of power within the mobile cellular network. Such energy consumption contributes to the emission of Greenhouse Gases (GHG) through the use of conventional diesel generating a set. As a result, the mobile cellular operators are faced with the dilemma of minimising the power consumption, GHG emission, and the operation cost, while improving the Quality of Service of the networks. In attempting to find a solution, this study presents the feasibility and simulation of a solar photovoltaic (PV) with battery hybrid power system (HPS) as a predominant source of power for a specific mobile cellular base station site situated in Soshanguve area of the city of Pretoria, South Africa. It also presents the technical development, showed the environmental advantage and cost benefits of using a solar PV-battery HPS to power a base station site of a 24 hrs daily load of 241.10 kWh/d and the peak load of 20.31 kW as compared to using the HPS of solar PV-diesel generating set-battery. The solar resource pattern for the city of Pretoria was collected from The National Aeronautics and Space Administration and modelled statistically. Thus, the statistical modelling done using solar radiation resource exposure characteristic patterns of Pretoria, South Africa, revealed an average annual daily solar radiation of 5.4645 Wh/m2/d and 0.605 clearness index. The simulation and the design were done using the Hybrid Optimization Model for Electric Renewables and Matlab/Simulink software. The simulation finding shows that the HPS of solar PV-battery combination has about 59.62 % saving on Net Present Cost, Levelized Cost of Energy, and 80.87% saving on Operating cost as against conventional BS powered with Gen Set-Battery.

Preprint ARTICLE | doi:10.20944/preprints202309.1650.v1

Nonlinear Finite Element Analysis and Fatigue Damage Assessment of Wind-Induced Vibration for the Tension Cable-Supported Power Transmission Structure

Jingyang Li, Bangjie Wang, Tao Wang, Zhengliang Li

Subject: Engineering, Civil Engineering Keywords: Tension cable-supported power transmission structure; Wind-induced vibration; Nonlinear finite element; Wind-induced fatigue damage

Online: 25 September 2023 (09:32:35 CEST)

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The tension cable-supported power transmission structure (TC-PTS) is a new type of power transmission structure suitable for mountainous terrain, which is sensitive to wind load. In this regard, a nonlinear finite element analysis model of wind-induced vibration is proposed for the TC-PTS, and the wind-induced vibration response of the structure is analyzed. Firstly, the tangent stiffness matrix of the three-dimensional truss element for the supporting suspension cable and transmission line, considering the geometric nonlinearity of structures, is derived through the relationship between the element elastic energy and its displacement. Subsequently, the element mass matrix and damping matrix of the supporting suspension cable and transmission line, as well as the element nodal load vector obtained from wind load equivalence are given. Then, based on the nonlinear finite element theory, the nonlinear dynamic equation of wind-induced vibration is established for the TC-PTS and solved by Newmark-β method combined with Newton-Raphson iterative method. Furthermore, the rain-flow counting method and Miner's linear fatigue cumulative damage theory were used for wind induced fatigue damage assessment. Finally, a two-span TC-PTS is selected as an example, and the wind-induced nonlinear vibration and fatigue damage assessment are analyzed through the proposed model. The results show that the proposed model has high computational accuracy and efficiency. With the increase of wind speed and wind direction angle, the maximum lateral displacement and tension of the supporting suspension cable and transmission line increase, and their degree of increase shows a nonlinear trend. In terms of the wind-induced fatigue analysis results of TC-PTS, the fatigue damage at the end of the supporting-conductor suspension cable is greater than the fatigue damage at its midpoint. Compared to the fatigue damage at the midpoint of the conductor, the fatigue damage at the end of the conductor is less affected by wind direction angle, and both are more significantly affected by the wind speed.

Preprint ARTICLE | doi:10.20944/preprints202307.0643.v1

Design Considerations on Semi-submersible Columns and Pontoons for Floating Wind

Glib Ivanov, I Jen Hsu, Kai-Tung Ma

Subject: Engineering, Marine Engineering Keywords: Floating Wind; FOWT; Hull design; Wave load; Bracing; Structural Analysis; Manufacturing; Offshore Wind; Renewable Energy; Optimization

Online: 10 July 2023 (15:57:21 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202306.1787.v1

Methods for Ensuring Stable Operation of Wind Turbines under Standard Disturbances in Distribution Networks

Aleksandr Simonov, Pavel Ilyushin, Konstantin Suslov, Sergey Filippov

Subject: Engineering, Energy And Fuel Technology Keywords: wind farm; wind turbine; inverter; Low Voltage Ride Through characteristic; standard disturbance; voltage dip; relay protection

Online: 26 June 2023 (10:21:23 CEST)

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In the context of energy decarbonization, wind farms with type IV wind turbines from various manufacturers are being massively put into operation. These wind turbines comply with the requirements of the grid codes of the countries where they are designed and/or manufactured, but do not factor in the specific features of the distribution networks of other countries to which they are connected. The study at issue involves a comparative analysis of the requirements of grid codes of different countries for the stable operation of wind turbines under standard disturbances. The Low Voltage Ride Through (LVRT) characteristic implemented in type IV wind turbine inverters makes it possible to prevent wind turbine shutdowns in case of short-term voltage dips of a given depth and duration. The calculations of transient processes indicate that wind turbines may not meet the requirements of the grid code of a particular country for their stable operation. As a result, standard disturbances will block the reactive current injection and the wind turbine will be switched off. This is often caused by the relay protection devices with a time delay of 1-2 s, which are used in distribution networks and implement the functions of long-range redundancy. Excessive shutdowns of wind turbines lead to emergency rise in the load for the generating units of conventional power plants, aggravating the post-accident conditions and disconnecting consumers of electricity. The paper presents a method for checking the LVRT characteristic settings for compliance with the technical requirements for wind turbines. To prevent wind turbine outages, one should either change the configuration of the LVRT characteristic, or upgrade the relay protection devices in the distribution network adjacent to the wind farm, or implement group or individual technical solutions at the wind farm. The performance of the proposed technical solutions is confirmed by the calculations of transient processes.

Preprint CONCEPT PAPER | doi:10.20944/preprints201911.0037.v1

ESwift: Smart and Self-Stabilizing Water-Wind Floating Turbine

Minh N. Doan, Mehdi Badri, Trung B. Tran, Yuriko Kai

Subject: Engineering, Energy And Fuel Technology Keywords: marine hydrokinetic turbine; wind energy; floating offshore wind turbine; mooring lines; floating platform; vertical axis turbine

Online: 4 November 2019 (05:13:32 CET)

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Preprint ARTICLE | doi:10.20944/preprints202208.0228.v1

Calculating the Speed Ratio of Wind Turbines with General Cone and Axis Angle for the Unsteady Blade Element Momentum Theory (UBEMT)

Dieter Scholz

Subject: Engineering, Energy And Fuel Technology Keywords: Wind power; Wind turbines; Aerodynamics; Differential Geometry; Airfoils; Blade Element Momentum Theory; BEMT; BEM; HAWT; Wagner rotor

Online: 12 August 2022 (07:53:19 CEST)

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Preprint REVIEW | doi:10.20944/preprints201809.0538.v1

A Review on Fault Current Limiting Devices to Enhance Fault Ride-through Capability of Doubly Fed Induction Generator Based Wind turbine

Seyed Behzad Naderi, Pooya Davari, Dao Zhou, Michael Negnevitsky, Frede Blaabjerg

Subject: Engineering, Electrical And Electronic Engineering Keywords: Wind power; Fault current limiters, Doubly-fed induction generator; Fixed speed wind turbine; Series dynamic braking resistor

Online: 27 September 2018 (10:00:12 CEST)

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Preprint REVIEW | doi:10.20944/preprints201710.0046.v1

Full-Scale/Model Test Comparisons to Validate the Traditional ABL Wind Tunnel Simulation Technique: A Literature Review

X.X. Cheng, J. Dong, Y. Peng, L. Zhao, Y.J. Ge

Subject: Engineering, Civil Engineering Keywords: comparative study; full-scale measurement; wind tunnel model test; multiple-fan actively controlled wind tunnel; research scheme

Online: 9 October 2017 (06:38:40 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202310.1520.v1

Formulation of an Efficiency Model Valid for High Vacuum Flat Plate Collectors

Eliana Gaudino, Antonio Caldarelli, Roberto Russo, Marilena Musto

Subject: Engineering, Energy And Fuel Technology Keywords: solar energy; High Vacuum Flat Plate Collectors; HVFP; Thermal efficiency model; Solar collector performance evaluation

Online: 24 October 2023 (13:05:02 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202209.0174.v1

Open-source Photovoltaic - Electrical Vehicle Carport Designs

Nicholas Vandewetering, Koami Soulemane Hayibo, Joshua M. Pearce

Subject: Engineering, Civil Engineering Keywords: open-source; photovoltaic; mechanical design; electric vehicle; solar energy; solar carport; electric vehicle charging station

Online: 13 September 2022 (10:41:43 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202312.0391.v1

A Wind Field Reconstruction from Numerical Weather Prediction Data Based on a Meteo–Particle Model

Edoardo Bucchignani

Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: Limited Area Models; wind field reconstruction; MPM

Online: 6 December 2023 (12:17:05 CET)

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Preprint ARTICLE | doi:10.20944/preprints202308.0713.v1

An Observational Study of Typhoon Talim over the Northern Part of the South China Sea in July 2023

Junyi He, Q.S. Li, Pak Wai Chan, C.W. Choy, Betty Mak, C.C. Lam, H.Y. Luo

Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: typhoon; LIDAR; wind profiler; dropsonde; ocean radar

Online: 9 August 2023 (07:10:12 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202302.0243.v1

Comparisons of Initial Condition Perturbation Methods for Regional Ensemble Forecasts of Wind Speed in Gansu of China

Zifen Han, Diangang Hu, Qingquan Lv, And Xiaohui Zhong

Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: ensemble; wind forecast; dynamical downscaling; breeding; blending

Online: 14 February 2023 (09:36:21 CET)

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Preprint TECHNICAL NOTE | doi:10.20944/preprints202301.0584.v1

Assessment of Wind Speed Statistics in Samaria Region

Sergei Kolesnik, Yossi Rabinowitz, Michael Byalsky, Asher Yahalom, Alon Kuperman

Subject: Engineering, Energy And Fuel Technology Keywords: Wind statistics assessment; Weibull distribution; Rayleigh distribution.

Online: 31 January 2023 (11:30:30 CET)

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Preprint ARTICLE | doi:10.20944/preprints202111.0003.v2

Impact of Ocean Currents on Wind Stress in the Tropical Indian Ocean

Neethu Chacko, M M Ali

Subject: Environmental And Earth Sciences, Oceanography Keywords: Scatterometer; wind stress; surface currents; Indian Ocean

Online: 31 December 2021 (14:50:47 CET)

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Preprint ARTICLE | doi:10.20944/preprints202101.0190.v1

Valuation of Wind Energy Turbines Using Volatility of Wind and Price

Doron Greenberg, Michael Byalsky, Asher Yahalom

Subject: Engineering, Automotive Engineering Keywords: Wind energy; Renewable resources; Black-Scholes model

Online: 11 January 2021 (12:33:54 CET)

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Preprint ARTICLE | doi:10.20944/preprints201905.0258.v1

Experimental Study of The Summation of Flicker Caused by Wind Turbines

Koldo Redondo, José Julio Gutiérrez, Izaskun Azcarate, Purificación Saiz, Luis Alberto Leturiondo, Sofía Ruiz de Gauna

Subject: Engineering, Energy And Fuel Technology Keywords: power quality; wind power plant; voltage fluctuations

Online: 21 May 2019 (11:19:57 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201708.0046.v1

Encompassing Electricity Market Predictions and Weather Forecasts in Power Plan O&M Strategies

Linda Ponta, Luca Oneto, Davide Anguita, Silvano Cincotti

Subject: Engineering, Control And Systems Engineering Keywords: Electricity markets; Proactive maintenance; Wind energy systems.

Online: 12 August 2017 (21:03:55 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202311.1346.v1

A Study on the Recovery of Valuable Metals from Solar Cells Using Acid Leaching and Substitution Reactions

Kim Hyun Jong, Erdenebold Urtnasan, Jei-Pil Wang

Subject: Engineering, Metallurgy And Metallurgical Engineering Keywords: solar cell; recovery; silicon; silver; leaching

Online: 21 November 2023 (14:24:23 CET)

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Preprint ARTICLE | doi:10.20944/preprints202311.0730.v1

Synergistic Zinc(II) and Formate Doping of alpha-FAPbI₃ Perovskite: Thermal Stabilization and Enhanced Photoluminescence Lifetime

Merk M. Hoeksma, René M. Williams

Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: solar cells; formamidinium; lead; iodide; alloys

Online: 13 November 2023 (10:03:11 CET)

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Preprint ARTICLE | doi:10.20944/preprints202307.1858.v2

Thermospheric Density Response to the Solar Activity and QBO

Bo Li, Ruifei Cui, Libin Weng, Jianfang Fei

Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: thermospheric density; GAMDM; QBO; solar activity

Online: 31 July 2023 (11:23:50 CEST)

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Preprint REVIEW | doi:10.20944/preprints202109.0508.v2

How Fast Is the Distance between Earth and the Sun Changing in the Solar System?

Jim Henry, Mesut Yurukcu, George Nnanna

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Solar System; Earth; Sun; Expansion; Universe

Online: 12 October 2021 (14:27:15 CEST)

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Working Paper ARTICLE

Mechanics of the Gyroscopic Precession and Calculation of the Galactic Mass

Jian Sun, Ting Xu, Zheng Jiao, Hui Wang

Subject: Physical Sciences, Acoustics Keywords: gyroscopic precession; solar system; galactic mass

Online: 25 May 2021 (11:16:16 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202105.0138.v1

Effects of Aerosols and Clouds on the Levels of Surface Solar Radiation and Solar Energy in Cyprus

Ilias Fountoulakis, Panagiotis Kosmopoulos, Kyriakoula Papachristopoulou, Panagiotis-Ioannis Raptis, Rodanthi-Elisavet Mamouri, Argyro Nisantzi, Antonis Gkikas, Jonas Witthuhn, Sebastian Bley, Anna Moustaka, Johannes Buehl, Patric Seifert, Diofantos G. Hadjimitsis, Charalampos Kontoes, and Stelios Kazadzis

Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: solar energy; dust; aerosol; clouds; Cyprus

Online: 7 May 2021 (10:36:00 CEST)

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Preprint REVIEW | doi:10.20944/preprints202103.0260.v1

Current Status, Scenario, and Prospective of Renewable Energy in Algeria: A Review

Younes Zahraoui, M. Reyasudin Basir Khan, Ibrahim Al Hamrouni, Saad Mekhilef, Mahrous Ahmed

Subject: Engineering, Automotive Engineering Keywords: Algeria; Africa; Renewable Energy; Solar; PENREE

Online: 9 March 2021 (10:50:33 CET)

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Preprint ARTICLE | doi:10.20944/preprints201912.0407.v1

Re-desiging and Fabrication of the Contact Area of a Solar Milk Pasteurizer

Enebe Vincent, Moveh Samuel

Subject: Engineering, Industrial And Manufacturing Engineering Keywords: re-designing; fabrication; solar; milk; pasteurizer

Online: 31 December 2019 (10:22:43 CET)

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Preprint DATA DESCRIPTOR | doi:10.20944/preprints201811.0120.v2

SolarView: Georgia Solar Adoption in Context

Jacqueline Hettel Tidwell, Abraham Tidwell, Steffan Nelson, Marcus Hill

Subject: Engineering, Energy And Fuel Technology Keywords: solar; technology adoption; demographics; mixed methods

Online: 30 November 2018 (15:47:46 CET)

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Working Paper HYPOTHESIS

Hypothesis and Feasible Mechanism for Appearance of Post-Post-Fe Nuclei in Solar System

Elizabeth Pavlova-Tito, Vadim I. Pavlov

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Hypothesis, Fission, Heavy Post-Post-Fe Elements, Solar System

Online: 23 July 2019 (11:17:56 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202306.0491.v1

Further Explanation on the Excitation Mechanism of Stay Cable Vibration in Dry Conditions

Duy Thao Nguyen, Duy Hung Vo

Subject: Engineering, Civil Engineering Keywords: Dry-state galloping; excitation mechanism; Karman vortex; low-frequency-vortices; shedding correlation; along-wind component; vertical-wind component

Online: 7 June 2023 (05:33:12 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202305.0994.v1

Research on Aeolian Sand Erosion and Deposition Patterns in the Arid Region of the Xiliugou Tributary on the Upper Reaches of Yellow River within Inner Mogolia

Sheng hong Zhao, Yong Gao, Hong xiao Dang, Shuang Feng, Ju zhong Meng, Xin zheng Chen

Subject: Environmental And Earth Sciences, Environmental Science Keywords: The Yellow River basin; The Xiliugou tributary; underlying surface; wind-sand flow; wind erosion characteristics; sediment transport flux

Online: 15 May 2023 (07:39:22 CEST)

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The survey findings reveal that rivers worldwide carry an annual sediment load of 15 billion tons into the sea, and the Yellow River basin alone contributes 1.6 billion tons of sand. Therefore, understanding the science of wind and sand in the Yellow River is crucial to ensuring the safe development of similar basins across China and the world. This study examines the midstream wind and sand area of the Xiliugou tributary, a part of the upper Yellow River. The researchers used a stepped sand collector combined with an anemometer to measure the sand transport flux at 0-50 cm height on various underlying surfaces of the basin. Then, they estimated the amount of wind and sand entering the Yellow River using a function model based on the measured factors. Furthermore, the team analyzed the particle size composition of wind-eroded sand to better understand the principles of wind and sand erosion and accumulation in the basin. The results of the study show that the sand transport flux per unit area varies significantly across different underlying surfaces. Moreover, the contribution of moving sandy land, semi-fixed sand, and fixed sand to wind and sand deposition in the Yellow River basin was 77.08%, 15.30%, and 7.62%, respectively. The vertical change of sand transport rate on the basin's surface demonstrates that the total sand transport rate is an exponential function of wind speed. Based on this relationship, the researchers estimated that the total annual average wind and sand entering the Yellow River basin via the Xiliugou tributary is approximately 8.09×105t. Due to the basin's unique geography and sand source, the particle size composition of wind-eroded sand differs between the east and west sides of the river channel. On the west side, desert sand, mainly fine sand, and very fine sand constitutes the sand source. Conversely, on the east side, sand collected in the riverbed by secondary wind erosion is the primary sand source. Furthermore, human activities have disturbed the grain composition, mainly comprising powder and clay particles. This phenomenon, known as "wind-blown mud and water-washed sand," is evident in this geographical unit. In conclusion, the Yellow River basin still faces significant ecological security hazards. Understanding the coupling relationship between desert-basin-sand and wind is the foundation for effectively controlling wind and sand flow into the Yellow River basin.

Preprint ARTICLE | doi:10.20944/preprints202204.0253.v1

Research on Monitoring and Operation and Maintenance Technology of Far-Reaching Sea Smart Wind Farm

Zhen Wang, Yaohua Guo, Haijun Wang

Subject: Engineering, Marine Engineering Keywords: Offshore Wind power; Operation and maintenance management; Intelligent operation and maintenance robot; Smart wind farm technology; 5g technology

Online: 27 April 2022 (08:57:55 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202211.0095.v1

Solar System-Like Systems with Special Reference to Relativistic Quantum Mechanics and Weak Gravitational Field

Peter Gara

Subject: Physical Sciences, Quantum Science And Technology Keywords: Solar system-like systems; Relativistic Quantum Mechanics; Weak Gravity; Proper Time Scale of the Solar System

Online: 4 November 2022 (13:42:21 CET)

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Preprint ARTICLE | doi:10.20944/preprints202304.1277.v1

Design Features and Numerical Investigation of Counter-Rotating VAWT with Co-Axial Rotors Displaced from Each Other Along the Axis of Rotation

Ihor Shchur, Volodymyr Klymko, Shengbai Xie, David Schmidt

Subject: Engineering, Energy And Fuel Technology Keywords: vertical axis wind turbine (VAWT); dual-rotor wind turbine; counter-rotating wind turbine; dual-rotor permanent magnet synchronous generator (PMSM); control system; computational fluid dynamics (CFD); actuator line modeling (ALM)

Online: 28 April 2023 (10:14:17 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202001.0289.v1

Sudden Variation Effect of Aerodynamic Loads and Safety Analysis of Running Trains when Entering Tunnel under Crosswind

Weichao Yang, E Deng, Zhihui Zhu, Mingfeng Lei, ChengHua Shi, Hong He

Subject: Engineering, Civil Engineering Keywords: tunnel entrance; crosswind; wind–train–track coupling dynamic model; transient response of aerodynamic load; sudden wind effect; traffic safety

Online: 24 January 2020 (15:07:07 CET)

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Preprint ARTICLE | doi:10.20944/preprints202106.0166.v1

Effects of Natural Weathering on the Performance of High Solar Reflective Index Paint Surfaces Exposed in Harsh Climatic Conditions of United Arab Emirates

Tirumala Uday Kumar Nutakki, Waqar Ullah Kazim

Subject: Engineering, Automotive Engineering Keywords: Cool materials; cool coatings; solar reflective index; solar reflectance; thermal emittance; natural weathering; green buildings; reflective paints

Online: 7 June 2021 (11:13:00 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202401.0073.v1

Analyzing Extreme Winds over Turkey and Their Relationships with Synoptic Patterns Using Cluster Analysis

Umut Gül Başar Görgün, Şükran Sibel Menteş

Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: extreme wind; NEWA; cluster analysis; synoptic patterns, SOM

Online: 3 January 2024 (02:14:24 CET)

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Preprint ARTICLE | doi:10.20944/preprints202312.1457.v1

Cold Ironing and the Study of RES Utilization for Maritime Electrification on Lesvos Island Port

Alexandros Kelmalis, Andreas Dimou, Demetris Francis Lekkas, Stergios Vakalis

Subject: Engineering, Energy And Fuel Technology Keywords: Electrification; Green Transition; Wind Power; Electric Ports; Maritime

Online: 19 December 2023 (12:03:32 CET)

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The maritime sector, grapples with environmental challenges, but the adoption of "cold ironing" emerges as a promising solution, signifying a shift toward sustainability by providing energy to ships at port, reducing reliance on fossil fuels, and significantly lowering emissions, contributing to global climate change efforts. This transition towards renewable energy is especially crucial for islands like Lesvos, addressing challenges of high energy costs and environmental degradation resulting from reliance on imported fossil fuels, highlighting the potential for positive economic and environmental impacts. The existing literature highlights a research gap in the development of Renewable Energy Sources (RES) to support cold ironing operations, specifically due to the absence of specific data for the power demand needed in such operations and the lack of monitoring data for accurate calculations. This study's primary objective is to utilize real monitoring data from the port of Lesvos to evaluate the power demand for a potential cold ironing application. Additionally, the study aims to analyze the implementation of a wind power park to meet the energy needs of an electric port and evaluate the potential reduction in CO2 emissions. The database of Marine Traffic S.A. was utilized, while the determination of the energy used in-port per ship depended on factors such as the number of arrivals, the duration of hoteling, and the type of engine used by the ships. In addition, the software RETSCREEN was used for the energy analysis of a simulated 20 MW wind park that can support the in-port operations. The combined monthly energy demand for both main and auxiliary engines of shipping vessels at Mytilini port was assessed to be 6118 MWh and averaging a power demand equaled to 8.2 MW. The simulation analysis indicates that the annual electricity delivered to the port can be72080 MWh, with a significant portion remaining unused and exported to the grid, amounting to 14956 MWh annually. Due to demand fluctuations, in-port activities require an additional 924 MWh from the main electrical grid, which highlights the importance of additional measures like energy storage and demand-response practices for the gradual transition to 100% Renewable Energy Sources (RES) operations.

Preprint ARTICLE | doi:10.20944/preprints202309.1074.v1

The Comparison of Numerical Simulations of Offshore and Onshore Wind Turbines with Experimental Data. Part II: Steady-State Flows

Mohammad Ali AsemanBakhsh, Omid Karimi

Subject: Engineering, Aerospace Engineering Keywords: renewable energies; horizontal axis wind turbine; turbulence model

Online: 18 September 2023 (02:38:42 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202306.2113.v1

Aerodynamic Characteristics of Different Heights Buildings in Close Proximity

Orest Voznyak, Edyta Dudkiewicz, Nadiia Spodyniuk, Oleksandr Dovbush, Iryna Sukholova, Olena Savchenko, Mariana Kasynets

Subject: Engineering, Civil Engineering Keywords: Natural ventilation; Wind tunnel; Air pressure; Aerodynamic coefficients.

Online: 29 June 2023 (11:14:30 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202301.0554.v1

Analysis of the Skyscraper Wind around High-Rise Buildings in Coastal Region, South Korea, during Typhoon 'Hinnamnor'

Jongyeong Kim, Yongju Kwon, Byeonggug Kang, Joowon Choi, Soonchul Kwon

Subject: Environmental And Earth Sciences, Environmental Science Keywords: Field measurement; Typhoon; High-rise building; Strong wind

Online: 30 January 2023 (10:13:31 CET)

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Preprint ARTICLE | doi:10.20944/preprints202212.0531.v1

Model Wind Optimization with Satellite Wind Observations for Operational Sea Level Prediction

Francesco De Biasio, Stefano Zecchetto

Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: scatterometer; sea surface wind; storm surge; atmospheric model

Online: 28 December 2022 (08:24:58 CET)

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Preprint ARTICLE | doi:10.20944/preprints202212.0018.v1

AWEbox: an Optimal Control Framework for Single- and Multi-Aircraft Airborne Wind Energy Systems

Jochem De Schutter, Rachel Colette Leuthold, Thilo Bronnenmeyer, Elena Malz, Sebastien Gros, Moritz Diehl

Subject: Engineering, Control And Systems Engineering Keywords: airborne wind energy; optimal control; open-source software

Online: 1 December 2022 (08:54:28 CET)

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Preprint ARTICLE | doi:10.20944/preprints202007.0628.v2

Super Twisting Algorithm Direct Power Control of DFIG Using Space Vector Modulation

Farida Mazouz, Sebti Belkacem

Subject: Engineering, Energy And Fuel Technology Keywords: DFIG; SVM; VC; Wind Turbine (WT); parameters uncertainly

Online: 16 June 2021 (12:04:39 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202010.0513.v1

Spatio-Temporal Kriging Based Economic Dispatch Problem Including Wind Uncertainty

Julio Cuenca, Carlos Correa-Florez, Diego Patino, José Vuelvas

Subject: Engineering, Automotive Engineering Keywords: Economic Dispatch; Spatio-temporal kriging; Wind power; Uncertainty

Online: 26 October 2020 (11:08:13 CET)

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Preprint ARTICLE | doi:10.20944/preprints202009.0268.v1

Revaluation of Fatigue Thickness Effect Based on Fatigue Test Database

Wangwen Zhao, Wei-Ting Hsu

Subject: Engineering, Mechanical Engineering Keywords: fatigue; thickness effect; offshore wind turbine; corrosion fatigue

Online: 12 September 2020 (09:54:28 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202005.0300.v1

Retrieval of Sea Surface Wind Speed from Spaceborne SAR over the Arctic Marginal Ice Zone with a Neural Network

Xiao-ming Li, Tingting Qin, Ke Wu

Subject: Environmental And Earth Sciences, Oceanography Keywords: synthetic aperture radar; sea surface wind; neural network

Online: 18 May 2020 (10:50:03 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201908.0175.v1

Monin-Obukhov Similarity Theory for Modeling of Wind Turbine Wakes under Atmospheric Stable Conditions: Breakdown and Modifications

Xing Xing Han, De You Liu, Chang Xu, Wen Zhong Shen, Lin Min Li, Fei Fei Xue

Subject: Engineering, Energy And Fuel Technology Keywords: wind turbine; wake; atmospheric stability; MOST; turbulence models

Online: 16 August 2019 (07:52:44 CEST)

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Monin-Obukhov similarity theory (MOST) overestimates wind shear in some atmospheric stable conditions, i.e. Richardson number $R_f<0.25$. The overestimated wind shear that leads to an under-predicted friction wind speed and a lower ambient turbulence intensity for a given hub-height reference wind speed and a given roughness length, could influence wake modeling of a wind turbine. This work investigates the side effects of the breakdown of MOST on wake modeling under stable conditions and makes some modifications to the flow similarity functions to eliminate these side effects. Based on a field measurement in a wind farm, we firstly show that MOST predicts a larger wind shear for the atmospheric stability parameter $\zeta>0.1$ and proposes new flow similarity functions without constraining $R_f$ to limit the overestimated wind shear by MOST. Next, different turbulence models based on MOST and a modified one based on the new similarity functions are investigated through numerical simulations. These turbulence models are combined with the actuator disk model (AD) and Reynolds-averaged Navier–Stokes equations (RANS) to model wind turbine wakes under stable conditions. As compared to measurements, numerical results show that turbulence models based on MOST result in larger wake deficits and slower wake recovery rate with a square root of the mean-squared-error (RSME) of wake deficit in the range of 0.07-0.18. This overestimated wake effect is improved by applying the new similarity functions and the RSME of wake deficit is averagely reduced by 0.05. Finally, we check the role of the under-predicted turbulence intensity playing in the larger wake deficit predicted by models based MOST. Additional numerical simulations using the modified turbulence model are carried out, in which the roughness length is reduced to impose a hub-height ambient turbulence intensity equivalent to the MOST case. Simulation results show that reducing turbulence intensity enhances wake effects, however, it cannot reproduce the large wake deficit predicted by models based on MOST, which suggests that the overestimated wake effect by MOST could be also related to the overestimated wind shear.

Preprint ARTICLE | doi:10.20944/preprints201907.0029.v1

A BEM-Based Actuator Disk Model for Wind Turbine Wakes Considering Atmospheric Stability

Xing Xing Han, De You Liu, Chang Xu, Wen Zhong Shen, Lin Min Li, Fei Fei Xue

Subject: Engineering, Energy And Fuel Technology Keywords: wind turbine; wake; atmospheric stability; actuator disk; BEM

Online: 2 July 2019 (04:11:13 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201904.0225.v1

Investigation of Laminar-Turbulent Transition on a Rotating Wind Turbine Blade of Multi Megawatt Class with Thermography and a Microphone Array

Torben Reichstein, Alois Peter Schaffarczyk, Christoph Dollinger, Nicolas Balaresque, Erich Schuelein, Clemens Jauch, Andreas Fischer

Subject: Engineering, Energy And Fuel Technology Keywords: boundary layer transition; wind turbine; thermography; aerodynamic glove

Online: 19 April 2019 (11:58:41 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201610.0070.v1

The RUNE Experiment–A Database of Remote-Sensing Observations of Near-Shore Winds

Rogier Floors, Alfredo Peña, Guillaume Lea, Nikola Vasiljevic, Elliot Simon, Michael Courtney

Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: coastal; experiment; lidar; near-shore; offshore; wind resources

Online: 18 October 2016 (07:51:46 CEST)

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Preprint REVIEW | doi:10.20944/preprints201609.0118.v1

Enabling Inertial Response of Variable-Speed Wind Turbines: A Survey and New Perspectives

Lei Shang

Subject: Engineering, Control And Systems Engineering Keywords: inertial response; internal voltage; variable speed wind turbines

Online: 29 September 2016 (11:38:53 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202402.0514.v1

Experimental Analysis of a Polygeneration System: Assessment of the Thermal Sub-system

Andre Rodrigues, Ana Palmero-Marrero, Joao Soares, Szabolcs Varga, Armando Coelho Oliveira

Subject: Engineering, Mechanical Engineering Keywords: polygeneration; solar; ejector; thermal storage; cooling; heating

Online: 9 February 2024 (02:39:13 CET)

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Preprint ARTICLE | doi:10.20944/preprints202401.1237.v1

Spatiotemporal Evolution of the Land Cover over Deception Island, Antarctica, Its Driving Mechanisms and Its Impact on the Shortwave Albedo

Javier F. Calleja, Rubén Muñiz, Jaime Otero, Francisco Navarro, Carleen Reijmer, Miguel Ángel De Pablo, Susana del Carmen Fernández

Subject: Environmental And Earth Sciences, Remote Sensing Keywords: cryosphere; albedo; landscape; air temperature; solar radiation

Online: 16 January 2024 (12:36:52 CET)

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The aim of this work is to provide a full description of how air temperature and solar radiation induce changes in the land cover over an Antarctic site. We use shortwave broadband albedo (albedo integrated in the range 300-3000 nm) from a spaceborne sensor and from field surveys to calculate the monthly relative abundance of landscape units. Field albedo data were collected using a portable albedometer over seven landscape units: clean fresh snow; clean old snow; rugged landscape composed of dirty snow with disperse pyroclasts and rocky outcrops; dirty snow; stripes of bare soil and snow; shallow snow with small bare soil patches; bare soil. MODIS MCD43A3 daily albedo product was downloaded using the Google Earth Engine API from the 2000-2001 season to the 2020-2021 season. Each landscape unit was characterized by an albedo normal distribution. The monthly relative abundance of the landscape units were calculated by fitting a linear combination of the normal distributions to the histogram of the MODIS monthly mean albedo. The monthly relative abundance of the landscape unit consisting of rugged landscape composed of dirty snow, with dispersed clasts and small rocky outcrops exhibits a high linear positive correlation with the monthly mean albedo (R2=0.87) and a high linear negative correlation with the monthly mean air temperature (R2= 0.69). The increase of the solar radiation energy flux from September to December coincides with the decrease of the relative abundance of the landscape unit composed of dirty snow with dispersed clasts and small rocky outcrops. We propose a mechanism to describe the evolution of the landscape: uncovered pyroclasts act as melting centres favouring the melting of surrounding snow. Ash does not play a decisive role in the melting of the snow. The results also explain the observed decreasing of the thaw depth of the permafrost on the island in the period 2006-2014, resulting from an increase in the snow cover over the whole island.

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