Optical and adhesive properties of dust deposits on solar mirrors and their effects on specular reflectivity and electrodynamic cleaning for mitigating energy-yield loss

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.

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Development of Hybrid Structures of Silver Nanowire Electrodes for the Electrodynamic Screen (EDS) Films to Mitigate Energy Yield Loss Incurred by Solar Collectors Due to Soiling

MRS Advances ◽

10.1557/adv.2019.120 ◽

2019 ◽

Vol 4 (5-6) ◽

pp. 343-350

Author(s):

Annie Rabi Bernard ◽

Ryan Eriksen ◽

Malay Mazumder

Keyword(s):

Yield Loss ◽

Water Immersion ◽

Protective Layer ◽

Immersion Test ◽

Silver Nanowire ◽

Hybrid Structures ◽

Energy Yield ◽

Protective Layers ◽

Test Conditions ◽

Sandwiched Structure

ABSTRACTThis study aims at establishing environmentally stable and viable silver nanowire (AgNW) electrodes of an Electrodynamic Screen (EDS) film, by the inclusion of one or more protective layers of zinc oxide (ZnO) produced in lab by combining tetrahydrofuran (THF) and diethylzinc (DEZ). The electrodes can be realized as 1) stacked structure where the AgNW electrode has a layer of ZnO on top for protection or 2) sandwiched structure where the AgNW electrode is covered by ZnO layers, protecting it from the top and bottom. Experiments are done to test the effect of accelerated exposure to ultraviolet light, high temperature and passage of high voltage on the AgNW samples and are compared with the results obtained from the AgNW samples that have the ZnO protective layer which have also been subjected to the aforementioned test conditions. A complete water immersion test is performed in order to ensure functionality and efficiency of the ZnO/AgNW samples that are to be patterned as electrodes of the EDS film. This will demonstrate viability of the structure in the case of rain.

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

ASME 2013 7th International Conference on Energy Sustainability ◽

10.1115/es2013-18365 ◽

2013 ◽

Cited By ~ 14

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.

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Energy yield loss caused by dust deposition on photovoltaic panels

Solar Energy ◽

10.1016/j.solener.2014.05.030 ◽

2014 ◽

Vol 107 ◽

pp. 576-604 ◽

Cited By ~ 190

Author(s):

Arash Sayyah ◽

Mark N. Horenstein ◽

Malay K. Mazumder

Keyword(s):

Yield Loss ◽

Energy Yield ◽

Dust Deposition ◽

Photovoltaic Panels

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Model studies on the adhesive properties of mucus and similar polymer solutions

Archives of Internal Medicine ◽

10.1001/archinte.126.3.504 ◽

1970 ◽

Vol 126 (3) ◽

pp. 504-507 ◽

Cited By ~ 1

Author(s):

A. Besarab

Keyword(s):

Polymer Solutions ◽

Adhesive Properties ◽

Model Studies

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Elemental chlorine-free bleaching of North American hardwood kraft pulps: Evaluation of oxidant-reinforced extraction variables on overall bleaching optimization

TAPPI Journal ◽

10.32964/tj12.10.33 ◽

2013 ◽

Vol 12 (10) ◽

pp. 33-41 ◽

Cited By ~ 4

Author(s):

BRIAN N. BROGDON

Keyword(s):

Response Surface ◽

Chlorine Dioxide ◽

North American ◽

Yield Loss ◽

Alkaline Extraction ◽

Kraft Pulps ◽

Pulp Bleaching ◽

Response Surface Models ◽

Elemental Chlorine ◽

Surface Models

This investigation evaluates how higher reaction temperatures or oxidant reinforcement of caustic extraction affects chlorine dioxide consumption during elemental chlorine-free bleaching of North American hardwood pulps. Bleaching data from the published literature were used to develop statistical response surface models for chlorine dioxide delignification and brightening sequences for a variety of hardwood pulps. The effects of higher (EO) temperature and of peroxide reinforcement were estimated from observations reported in the literature. The addition of peroxide to an (EO) stage roughly displaces 0.6 to 1.2 kg chlorine dioxide per kilogram peroxide used in elemental chlorine-free (ECF) bleach sequences. Increasing the (EO) temperature by Δ20°C (e.g., 70°C to 90°C) lowers the overall chlorine dioxide demand by 0.4 to 1.5 kg. Unlike what is observed for ECF softwood bleaching, the presented findings suggest that hot oxidant-reinforced extraction stages result in somewhat higher bleaching costs when compared to milder alkaline extraction stages for hardwoods. The substitution of an (EOP) in place of (EO) resulted in small changes to the overall bleaching cost. The models employed in this study did not take into account pulp bleaching shrinkage (yield loss), to simplify the calculations.

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Optimizing genotype-environment-management interactions to ensure silage maize production in the Chinese Maize Belt

Climate Research ◽

10.3354/cr01599 ◽

2020 ◽

Vol 80 (2) ◽

pp. 133-146

Author(s):

L Zhang ◽

Z Zhang ◽

J Cao ◽

Y Luo ◽

Z Li

Keyword(s):

Field Experiments ◽

Weather Conditions ◽

Growth Cycle ◽

High Energy ◽

Risk Level ◽

Energy Yield ◽

Maize Production ◽

Early Date ◽

Environment Management ◽

Silage Maize

Grain maize production exceeds the demand for grain maize in China. Methods for harvesting good-quality silage maize urgently need a theoretical basis and reference data in order to ensure its benefits to farmers. However, research on silage maize is limited, and very few studies have focused on its energetic value and quality. Here, we calibrated the CERES-Maize model for 24 cultivars with 93 field experiments and then performed a long-term (1980-2017) simulation to optimize genotype-environment-management (G-E-M) interactions in the 4 main agroecological zones across China. We found that CERES-Maize could reproduce the growth and development of maize well under various management and weather conditions with a phenology bias of <5 d and biomass relative root mean square error values of <5%. The simulated results showed that sowing long-growth-cycle cultivars approximately 10 d in advance could yield good-quality silage. The optimal sowing dates (from late May to July) and harvest dates (from early October to mid-November) gradually became later from north to south. A high-energy yield was expected when sowing at an early date and/or with late-maturing cultivars. We found that Northeast China and the North China Plain were potential silage maize growing areas, although these areas experienced a medium or even high frost risk. Southwestern maize experienced a low risk level, but the low soil fertility limited the attainable yield. The results of this paper provide information for designing an optimal G×E×M strategy to ensure silage maize production in the Chinese Maize Belt.

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Recent data on the causative agent of pale green dwarf (Acholeplasma laidlawii var. granulum incertae sedis) in Ukraine: pathogenicityand virulence factors and host reactions

Agricultural science and practice ◽

10.15407/agrisp2.01.030 ◽

2015 ◽

Vol 2 (1) ◽

pp. 30-34

Author(s):

K. Korobkova ◽

V. Patyka

Keyword(s):

Phenylalanine Ammonia Lyase ◽

Proteolytic Enzymes ◽

Physiological State ◽

Plant Cells ◽

Temporary Increase ◽

Adhesive Properties ◽

The Impact ◽

Signaling Interactions ◽

Pale Green

Contemporary state of the distribution of mycoplasma diseases of cultivated crops in Ukraine was analyzed. The changes of the physiological state of plant cells under the impact of mollicutes were investigated. It was demonstrated that there is temporary increase in the activity of peroxidase, catalase, polyphenoloxidase, phenylalanine-ammonia-lyase at the early stages of interaction. The adhesive properties are changed in the mollicutes under the impact of plant lectin; there is synthesis of new polypeptides. It was determined that the phytopathogenic acholeplasma is capable of producing a complex of proteolytic enzymes into the culture me- dium. It was concluded that when plant cells are infected with acholeplasma, a number of signaling interactions and metabolic transformations condition the recognition of pathogenesis and ensure the aggregate response of a plant to stress in the form of defense reactions. It was assumed that some specifi cities of the biology of phy- topathogenic acholeplasma determine their avoiding the immune mechanisms of plants and promote long-term persistence of mollicutes.

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