Development of Self-Cleaning Solar Collectors for Minimizing Energy Yield Loss Caused by Dust Deposition

2013 ◽  
Author(s):  
Malay Mazumder ◽  
Mark Horenstein ◽  
Jeremy Stark ◽  
Daniel Erickson ◽  
Arash Sayyah ◽  
...  
Keyword(s):  
Large Scale ◽  
Yield Loss ◽  
Research Effort ◽  
Large Fraction ◽  
Dust Removal ◽  
Energy Yield ◽  
Solar Collectors ◽  
Dust Deposition ◽  
Prototype Development ◽  
Self Cleaning

Concentrated Solar Power (CSP) systems used for photothermal conversion of solar energy to electricity are capable of meeting a large fraction of the global energy requirements. CSP plants are inherently robust with respect to the availability of materials, technology, and energy storage. However, dust depositions on solar collectors cause energy yield loss annually, ranging from 10 to 50% depending upon their location in the semi-arid and desert lands. Mitigation of energy loss requires manual cleaning of solar mirrors with water. A brief review of the soiling related losses in energy yield of the CSP plants is presented, which shows that cleaning of the CSP mirrors and receivers using water and detergent is an expensive and time-consuming process at best and is often impractical for large-scale installations where water is scarce. We report here our research effort in developing an electrodynamic dust removal technology that can be used for keeping the solar collectors clean continuously without requiring water and manual labor. Transparent electrodynamic screens (EDS), consisting of rows of transparent parallel electrodes embedded within a transparent dielectric film can be integrated on the front surface of the mirrors and on the receivers for dust removal for their application as self-cleaning solar collectors. When the electrodes are activated, over 90% of the deposited dust is removed. A summary of the current state of prototype development and evaluation of EDS integrated solar mirrors and experimental data on the removal of desert dust samples are presented. A brief analysis of cost-to-benefit ratio of EDS implementation for automated dust removal from large-scale solar collectors is included.

Optical Modeling of Reflectivity Loss Caused by Dust Deposition on CSP Mirrors and Restoration of Energy Yield by Electrodynamic Dust Removal

2014 ◽  
Author(s):  
Jeremy Stark ◽  
Julius Yellowhair ◽  
John N. Hudelson ◽  
Mark Horenstein ◽  
Malay Mazumder
Keyword(s):  
Power Plants ◽  
Specular Reflection ◽  
Mie Scattering ◽  
Dust Removal ◽  
Dust Particles ◽  
Energy Yield ◽  
Dust Deposition ◽  
Optical Modeling ◽  
Specular Reflectivity ◽  
Semi Arid

For large scale CSP power plants, vast areas of land are needed in deserts and semi-arid climates where uninterrupted solar irradiance is most abundant. These power facilities use large arrays of mirrors to reflect and concentrate sunlight onto collectors, however, dust deposition on the optical surfaces causes obscuration of sunlight, resulting in large energy-yield losses in solar plants. This problem is compounded by the lack of natural clean water resources for conventional cleaning of solar mirrors, often with reflective surface areas of large installations exceeding a million square meters. To investigate the application of transparent electrodynamic screens (EDS) for efficient and cost effective dust removal from solar mirrors, both optical modeling and experimental verifications were performed. Prototype EDS-integrated mirrors were constructed by depositing a set of parallel transparent electrodes into the sun-facing surface of solar mirrors and coating electrodes with thin transparent dielectric film. Activation of the electrodes with a three-phase voltage creates an electrodynamic field that charges and repels dust electrostatically by Coulomb force and sweeps away particles by a traveling electrodynamic wave. We report here brief discussions on (1) rate of deposition and the properties of dust with respect to their size distribution and chemical composition in semi-arid areas of the southwest US and Mojave Desert and their adhesion to solar mirrors, (2) optical models of: (a) specular reflection losses caused by scattering and absorption by dust particles deposited on the surface based on Mie scattering theory, and (b) reflection loss by the integration of EDS on the mirror surface, computed by FRED ray-tracing model. The objective is to maintain specular reflectivity of 90% or higher by frequent removal of dust by EDS. Our studies show that the incorporation of transparent EDS would cause an initial loss of 3% but would be able to maintain specular reflectivity more than 90% to meet the industrial requirement for CSP plants. Specular reflection measurements taken inside a climate controlled environmental chamber show that EDS integration can restore specular reflectivity and would be able to prevent major degradation of the optical surface caused by the deposition of dust.

Development of Transparent Electrodynamic Screens on Ultrathin Flexible Glass Film Substrates for Retrofitting Solar Panels and Mirrors for Self-Cleaning Function

MRS Advances ◽  
2016 ◽  
Vol 1 (15) ◽  
pp. 1003-1012 ◽  
Author(s):  
M. K. Mazumder ◽  
J. W. Stark ◽  
C. Heiling ◽  
M. Liu ◽  
A. Bernard ◽  
...  
Keyword(s):  
Large Scale ◽  
Transmission Efficiency ◽  
Silver Nanowire ◽  
Dust Particles ◽  
Glass Film ◽  
Solar Collectors ◽  
Solar Panels ◽  
Labor Costs ◽  
Adhesive Film ◽  
Self Cleaning

ABSTRACTDevelopment of transparent electrodynamic screens (EDS) printed on ultrathin flexible glass film substrates for retrofitting on solar panels and solar mirrors to perform self cleaning function is reviewed. Large-scale solar plants are generally installed in semi-arid and desert areas where dust layers build up on solar collectors causes major energy-yield loss. Maintaining designed plant capacities requires more than 90% reflectivity for CSP mirrors and 90% transmission efficiency for PV modules; solar collectors must therefore be cleaned at a frequency depending on the rate of dust deposition. Scarcity of water in these regions requires a cleaning method that drastically reduces or eliminates water and the associated labor costs for high efficiency operation of large-scale solar plants. An EDS film consists of rows of interdigitated, transparent conducting parallel electrodes embedded within a flexible ultrathin glass film and an optically clear adhesive film used for retrofitting the film on the surface of solar collectors. When phased voltage pulses activate the electrodes, the dust particles are first electrostatically charged, then repelled and removed from the surface of the solar collectors by Coulomb force, restoring transmission efficiency greater than 90%. The electrodes of EDS are either made from silver nanowire or another conductive transparent material printed on a highly transparent, ultrathin (100-μm thick), flexible borosilicate glass film. Applications of different conducting transparent electrodes and methods of printing are reviewed for optimizing self-cleaning function of solar panels and mirrors.

Development and Evaluation of Prototype Transparent Electrodynamic Screen (EDS) Integrated Solar Collectors for Automated Dust Removal

2014 ◽  
Author(s):  
John N. Hudelson ◽  
Jeremy Stark ◽  
Hannah Gibson ◽  
Fang Hao ◽  
Zhongkai Xu ◽  
...  
Keyword(s):  
Specular Reflection ◽  
Short Circuit ◽  
Test Chamber ◽  
Short Circuit Current ◽  
Dust Particles ◽  
Laboratory Evaluation ◽  
Solar Collectors ◽  
Solar Panels ◽  
Dust Deposition ◽  
Self Cleaning

The integration of transparent electro-dynamic screen (EDS) on the front surface of solar mirrors and glass cover plates of photovoltaic panels has a strong potential to significantly reduce the frequency of water-based cleaning needed to mitigate losses from dust depositions present in arid regions. The objective of our research was to develop and evaluate prototype transparent EDS-integrated mirrors and solar panels for their self-cleaning functions, with an aim to keep the collectors clean at a low cost without water or manual labor. This paper focuses on the design, fabrication, and laboratory evaluation of a prototype EDS integrated second surface mirrors and solar panels. The EDS consists of a set of parallel transparent electrodes screen-printed on the optical surface and embedded in a thin transparent dielectric film. By applying three-phase, low current, low frequency high voltage-pulses to the electrodes, electro-dynamic repulsion forces and a traveling wave are created for removing dust particles from the surface of the collectors. Design and construction of an environmental test chamber to simulate different atmospheric conditions of semi-arid and arid areas with respect to temperature, RH, and dust deposition conditions are briefly described. A non-contact specular reflectometer was designed, constructed and calibrated for measuring specular reflection efficiency of the mirrors. Laboratory evaluation of the performance of the EDS-integrated collectors was completed using humidity controlled environment test chamber where the prototype mirrors and panels were examined for their self-cleaning action. In each experiment, the solar collectors were loaded with dust until the specular reflectance of the test mirror or the short circuit current of the panel showed a significant decrease. The EDS was then operated for one minute and the relative output was recorded. The results show that the specular reflectivity of EDS mirrors and the short circuit current of the EDS panels can be restored by more than 90% of the values measured under the clean conditions.

scholarly journals Energy yield loss caused by dust deposition on photovoltaic panels

Solar Energy ◽  
2014 ◽  
Vol 107 ◽  
pp. 576-604 ◽  
Author(s):  
Arash Sayyah ◽  
Mark N. Horenstein ◽  
Malay K. Mazumder
Keyword(s):  
Yield Loss ◽  
Energy Yield ◽  
Dust Deposition ◽  
Photovoltaic Panels

scholarly journals A Combined Approach for Model-Based PV Power Plant Failure Detection and Diagnostic

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1261
Author(s):  
Christopher Gradwohl ◽  
Vesna Dimitrievska ◽  
Federico Pittino ◽  
Wolfgang Muehleisen ◽  
András Montvay ◽  
...  
Keyword(s):  
Power Plants ◽  
Large Scale ◽  
Failure Detection ◽  
Energy Yield ◽  
Combined Approach ◽  
Levelized Cost Of Electricity ◽  
Term Operation ◽  
Model Based

Photovoltaic (PV) technology allows large-scale investments in a renewable power-generating system at a competitive levelized cost of electricity (LCOE) and with a low environmental impact. Large-scale PV installations operate in a highly competitive market environment where even small performance losses have a high impact on profit margins. Therefore, operation at maximum performance is the key for long-term profitability. This can be achieved by advanced performance monitoring and instant or gradual failure detection methodologies. We present in this paper a combined approach on model-based fault detection by means of physical and statistical models and failure diagnosis based on physics of failure. Both approaches contribute to optimized PV plant operation and maintenance based on typically available supervisory control and data acquisition (SCADA) data. The failure detection and diagnosis capabilities were demonstrated in a case study based on six years of SCADA data from a PV plant in Slovenia. In this case study, underperforming values of the inverters of the PV plant were reliably detected and possible root causes were identified. Our work has led us to conclude that the combined approach can contribute to an efficient and long-term operation of photovoltaic power plants with a maximum energy yield and can be applied to the monitoring of photovoltaic plants.

Energy efficiency of multivariate cultivation techniques in pasture forage production

2021 ◽  
pp. 3-6
Author(s):  
К.Н. Привалова ◽  
Р.Р. Каримов
Keyword(s):  
Energy Efficiency ◽  
Production Process ◽  
Large Scale ◽  
Exchange Energy ◽  
Production Costs ◽  
Energy Yield ◽  
Total Production ◽  
Forage Production ◽  
Machinery Construction ◽  
Natural Factors

Исследования по определению энергетической эффективности пастбищных систем со злаковыми и бобово-злаковыми травостоями проведены в Федеральном научном центре кормопроизводства и агроэкологии им. В. Р. Вильямса. В статье приведены результаты агроэнергетической оценки многовариантных пастбищных систем со злаковыми травостоями, созданными в 1946 году. Даны количественные показатели по сбору обменной энергии, совокупным затратам на её производство, окупаемости затрат в зависимости от системы ведения пастбищ. Изучена эффективность совокупных затрат в виде овеществлённого труда (на семена, удобрения, сельскохозяйственные машины, средства огораживания загонов и прочее) и живого труда (работы трактористов, пастухов и строителей и др.). Обоснована высокая агроэнергетическая эффективность изучаемых пастбищных систем благодаря мобилизации в продукционный процесс природных факторов, долевое участие которых в структуре производства обменной энергии составило 69–84%. Природные факторы, участвующие в продукционном процессе луговых агроэкосистем, характеризуются большим разнообразием. Это не только использование солнечной энергии и азотфиксация бобовыми травами, но и долголетие травостоев, самовозобновление фитоценозов, дерновообразовательный процесс (повышение плодородия почвы), получение дешёвого корма и улучшение здоровья животных при летнем выпасе. Роль возобновляемых природных факторов выявлена на основе балансового метода, принятого в экономике (по разнице сбора обменной энергии и антропогенных затрат). Благодаря ведущей роли природных факторов в структуре произведённой продукции агроэнергетический коэффициент окупаемости совокупных затрат антропогенной энергии (АК) за счёт сбора обменной энергии достигал 3–6 раз в среднем за 45 лет. Разработанные в результате долголетних исследований многовариантные энергосберегающие пастбищные системы обосновывают возможность рекомендовать их производству с учётом применения различного уровня энергозатрат. Ключевые слова: культурные пастбища, системы ведения, долголетние травостои, сбор обменной энергии, совокупные антропогенные затраты, окупаемость затрат. The investigation was conducted at the Federal Williams Research Center of Fodder Production and Agroecology and was aimed at testing energy efficiency of gramineous and legume-gramineous swards. This article presents the results obtained on pasture ecosystems with gramineous planted in 1946. Exchange energy yield, total production costs and economic effectiveness were analyzed. Total production costs comprised costs for seeds, fertilizers, machinery, construction materials, labor, etc. Introduction of natural factors into the production process resulted in higher energy efficiency. Their share amounted to 69–84% in the final exchange energy yield. There are a lot of natural factors that affect grass productivity such as solar energy, nitrogen-fixation, sward longevity and regeneration, soil fertility, low-cost feed production, and livestock health. The value of natural factors was determined according to the balance method (by the difference between exchange energy yield and anthropogenic costs). Since environmental factors had a leading role in the production process, the return rate raised by 3–6 times for 45 years due to exchange energy increase. Therefore, pasture ecosystems developed can be recommended for a large-scale forage production.

scholarly journals Investigation of Atmospheric Rivers Impacting the Pigeon River Basin of the Southern Appalachian Mountains

2018 ◽  
Vol 33 (1) ◽  
pp. 283-299 ◽  
Author(s):  
Douglas K. Miller ◽  
David Hotz ◽  
Jessica Winton ◽  
Lukas Stewart
Keyword(s):  
North Carolina ◽  
River Basin ◽  
Large Scale ◽  
Large Fraction ◽  
Appalachian Mountains ◽  
Warm Season ◽  
Atmospheric Rivers ◽  
Southern Appalachian Mountains ◽  
Low Level ◽  
Southern Appalachian

Abstract Rainfall observations in the Pigeon River basin of the southern Appalachian Mountains over a 5-yr period (2009–14) are examined to investigate the synoptic patterns responsible for downstream flooding events as observed near Knoxville, Tennessee, and Asheville, North Carolina. The study is designed to address the hypothesis that atmospheric rivers (ARs) are primarily responsible for the highest accumulation periods observed by the gauge network and that these periods correspond to events having a societal hazard (flooding). The upper 2.5% (extreme) and middle 33% (normal) rainfall events flagged using the gauge network observations showed that half of the heaviest rainfall cases were associated with an AR. Of those extreme events having an AR influence, over 73% had a societal hazard defined as minor-to-major flooding at the USGS river gauge located in Newport, Tennessee, or flooding observations for locations near the Tennessee and North Carolina border reported in the Storm Data publication. Composites of extreme AR-influenced events revealed a synoptic pattern consisting of a highly amplified slow-moving positively tilted trough, suggestive of the anticyclonic Rossby wave breaking scenario that sometimes precedes hydrological events of high impact. Composites of extreme non-AR events indicated a large-scale weather pattern typical of a warm season scenario in which an anomalous low-level cyclone, cut off far from the primary upper-tropospheric jet, was located in the southeastern United States. AR events without a societal hazard represented a large fraction (75%–88%) of all ARs detected during the study period. Synoptic-scale weather patterns of these events were fast moving and had weak low-level atmospheric dynamics.

scholarly journals The Microbe Directory: An annotated, searchable inventory of microbes’ characteristics

2018 ◽  
Vol 2 ◽  
pp. 3 ◽  
Author(s):  
Heba Shaaban ◽  
David A. Westfall ◽  
Rawhi Mohammad ◽  
David Danko ◽  
Daniela Bezdan ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Large Scale ◽  
Research Effort ◽  
Gram Stain ◽  
Web Interface ◽  
Ongoing Effort ◽  
Student Researchers ◽  
User Friendly ◽  
Optimal Ph ◽  
Online Web

The Microbe Directory is a collective research effort to profile and annotate more than 7,500 unique microbial species from the MetaPhlAn2 database that includes bacteria, archaea, viruses, fungi, and protozoa. By collecting and summarizing data on various microbes’ characteristics, the project comprises a database that can be used downstream of large-scale metagenomic taxonomic analyses, allowing one to interpret and explore their taxonomic classifications to have a deeper understanding of the microbial ecosystem they are studying. Such characteristics include, but are not limited to: optimal pH, optimal temperature, Gram stain, biofilm-formation, spore-formation, antimicrobial resistance, and COGEM class risk rating. The database has been manually curated by trained student-researchers from Weill Cornell Medicine and CUNY—Hunter College, and its analysis remains an ongoing effort with open-source capabilities so others can contribute. Available in SQL, JSON, and CSV (i.e. Excel) formats, the Microbe Directory can be queried for the aforementioned parameters by a microorganism’s taxonomy. In addition to the raw database, The Microbe Directory has an online counterpart (https://microbe.directory/) that provides a user-friendly interface for storage, retrieval, and analysis into which other microbial database projects could be incorporated. The Microbe Directory was primarily designed to serve as a resource for researchers conducting metagenomic analyses, but its online web interface should also prove useful to any individual who wishes to learn more about any particular microbe.

scholarly journals Transcriptional and post-transcriptional regulation and transcriptional memory of chromatin regulators in response to low temperature

2019 ◽  
Author(s):  
K. Vyse ◽  
L. Faivre ◽  
M. Romich ◽  
M. Pagter ◽  
D. Schubert ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Low Temperature ◽  
Transcriptional Activation ◽  
Large Scale ◽  
Transcriptional Profiling ◽  
Large Fraction ◽  
Histone Variants ◽  
Transcriptional Level ◽  
Large Set ◽  
Dynamic Regulation

AbstractChromatin regulation ensures stable repression of stress-inducible genes under non-stress conditions and transcriptional activation and memory of such an activation of those genes when plants are exposed to stress. However, there is only limited knowledge on how chromatin genes are regulated at the transcriptional and post-transcriptional level upon stress exposure and relief from stress. We have therefore set-up a RT-qPCR-based platform for high-throughput transcriptional profiling of a large set of chromatin genes. We find that the expression of a large fraction of these genes is regulated by cold. In addition, we reveal an induction of several DNA and histone demethylase genes and certain histone variants after plants have been shifted back to ambient temperature (deacclimation), suggesting a role in the memory of cold acclimation. We also re-analyse large scale transcriptomic datasets for transcriptional regulation and alternative splicing (AS) of chromatin genes, uncovering an unexpected level of regulation of these genes, particularly at the splicing level. This includes several vernalization regulating genes whose AS results in cold-regulated protein diversity. Overall, we provide a profiling platform for the analysis of chromatin regulatory genes and integrative analyses of their regulation, suggesting a dynamic regulation of key chromatin genes in response to low temperature stress.

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