D. DeJarnette, N. Brekke, Ebrima Tunkara, P. Hari, K. Roberts, T. Otanicar
A nanoparticle fluid filter used with concentrating hybrid solar/thermal collector design is presented. Nanoparticle fluid filters could be situated on any given concentrating system with appropriate customized engineering. This work shows the design in the context of a trough concentration system. Geometric design and physical placement in the optical path was modeled using SolTrace. It was found that a design can be made that blocks 0% of the traced rays. The nanoparticle fluid filter is tunable for different concentrating systems using various PV cells or operating at varying temperatures.
{"title":"Design and feasibility of high temperature nanoparticle fluid filter in hybrid thermal/photovoltaic concentrating solar power","authors":"D. DeJarnette, N. Brekke, Ebrima Tunkara, P. Hari, K. Roberts, T. Otanicar","doi":"10.1117/12.2186117","DOIUrl":"https://doi.org/10.1117/12.2186117","url":null,"abstract":"A nanoparticle fluid filter used with concentrating hybrid solar/thermal collector design is presented. Nanoparticle fluid filters could be situated on any given concentrating system with appropriate customized engineering. This work shows the design in the context of a trough concentration system. Geometric design and physical placement in the optical path was modeled using SolTrace. It was found that a design can be made that blocks 0% of the traced rays. The nanoparticle fluid filter is tunable for different concentrating systems using various PV cells or operating at varying temperatures.","PeriodicalId":142821,"journal":{"name":"SPIE Optics + Photonics for Sustainable Energy","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133580185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, we investigate the design, fabrication and characterization of a multilayer selective solar absorber made of metallic and dielectric thin films. The investigated selective absorber exhibits theoretical spectral absorptance higher than 95% within solar spectrum and infrared emittance lower than 5%, due to the Fabry-Perot resonance and antireflection effect. In terms of fabrication, different materials are tested under high temperatures in order to obtain the structure with best thermal stability. Structures with different materials are fabricated with sputtering, chemical vapor deposition and electron beam evaporation techniques. The near normal reflectance is characterized with a Fourier Transform Infrared spectrometer for these structures before and after heat treatment. Meanwhile, Rutherford backscattering Spectroscopy is employed to analyze the diffusion and oxidation conditions during the heating process. Moreover, better material choice and fabrication techniques are considered to construct solar absorber sample with better high temperature thermal stability.
{"title":"High-temperature selective solar thermal absorber based on Fabry-Perot resonance cavity","authors":"Hao Wang, Liping Wang","doi":"10.1117/12.2186839","DOIUrl":"https://doi.org/10.1117/12.2186839","url":null,"abstract":"In this work, we investigate the design, fabrication and characterization of a multilayer selective solar absorber made of metallic and dielectric thin films. The investigated selective absorber exhibits theoretical spectral absorptance higher than 95% within solar spectrum and infrared emittance lower than 5%, due to the Fabry-Perot resonance and antireflection effect. In terms of fabrication, different materials are tested under high temperatures in order to obtain the structure with best thermal stability. Structures with different materials are fabricated with sputtering, chemical vapor deposition and electron beam evaporation techniques. The near normal reflectance is characterized with a Fourier Transform Infrared spectrometer for these structures before and after heat treatment. Meanwhile, Rutherford backscattering Spectroscopy is employed to analyze the diffusion and oxidation conditions during the heating process. Moreover, better material choice and fabrication techniques are considered to construct solar absorber sample with better high temperature thermal stability.","PeriodicalId":142821,"journal":{"name":"SPIE Optics + Photonics for Sustainable Energy","volume":"471 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133022119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andre F. S. Guedes, V. P. Guedes, M. L. Souza, S. Tartari, I. J. Cunha
Flexible organic photovoltaic solar cells have drawn intense attention due to their advantages over competing solar cell technologies. The method utilized to deposit as well as to integrate solutions and processed materials, manufacturing organic solar cells by the Electrodeposition System, has been presented in this research. In addition, we have demonstrated a successful integration of a process for manufacturing the flexible organic solar cell prototype and we have discussed on the factors that make this process possible. The maximum process temperature was 120°C, which corresponds to the baking of the active polymeric layer. Moreover, the new process of the Electrodeposition of complementary active layer is based on the application of voltage versus time in order to obtain a homogeneous layer with thin film. This thin film was not only obtained by the electrodeposition of PANI-X1 on P3HT/PCBM Blend, but also prepared in perchloric acid solution. Furthermore, these flexible organic photovoltaic solar cells presented power conversion efficiency of 12% and the inclusion of the PANI-X1 layer reduced the effects of degradation on these organic photovoltaic panels induced by solar irradiation. Thus, in the Scanning Electron Microscopy (SEM), these studies have revealed that the surface of PANI-X1 layers is strongly conditioned by the dielectric surface morphology.
{"title":"The electrodeposition of multilayers on a polymeric substrate in flexible organic photovoltaic solar cells","authors":"Andre F. S. Guedes, V. P. Guedes, M. L. Souza, S. Tartari, I. J. Cunha","doi":"10.1117/12.2189872","DOIUrl":"https://doi.org/10.1117/12.2189872","url":null,"abstract":"Flexible organic photovoltaic solar cells have drawn intense attention due to their advantages over competing solar cell technologies. The method utilized to deposit as well as to integrate solutions and processed materials, manufacturing organic solar cells by the Electrodeposition System, has been presented in this research. In addition, we have demonstrated a successful integration of a process for manufacturing the flexible organic solar cell prototype and we have discussed on the factors that make this process possible. The maximum process temperature was 120°C, which corresponds to the baking of the active polymeric layer. Moreover, the new process of the Electrodeposition of complementary active layer is based on the application of voltage versus time in order to obtain a homogeneous layer with thin film. This thin film was not only obtained by the electrodeposition of PANI-X1 on P3HT/PCBM Blend, but also prepared in perchloric acid solution. Furthermore, these flexible organic photovoltaic solar cells presented power conversion efficiency of 12% and the inclusion of the PANI-X1 layer reduced the effects of degradation on these organic photovoltaic panels induced by solar irradiation. Thus, in the Scanning Electron Microscopy (SEM), these studies have revealed that the surface of PANI-X1 layers is strongly conditioned by the dielectric surface morphology.","PeriodicalId":142821,"journal":{"name":"SPIE Optics + Photonics for Sustainable Energy","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122517886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We propose an elliptical silicon nanohole (SiNH) array for broadband light absorption in thin film silicon solar cells. Our analysis shows that this architecture is capable of increasing the ultimate efficiency of a thin film silicon solar cell by 17.6 % in comparison to that of the circular SiNH array with the same fill fraction. Lattice symmetry breaking and extension of the irreducible Brillouin zone are responsible for the enhancement of the absorption.
{"title":"Light absorption enhancement in elliptical nanohole array for photovoltaic application","authors":"Zihuan Xia, Yonggang Wu, Yongdong Pan, Xuefei Qin, Jian Zhou, Zongyi Zhang","doi":"10.1117/12.2187591","DOIUrl":"https://doi.org/10.1117/12.2187591","url":null,"abstract":"We propose an elliptical silicon nanohole (SiNH) array for broadband light absorption in thin film silicon solar cells. Our analysis shows that this architecture is capable of increasing the ultimate efficiency of a thin film silicon solar cell by 17.6 % in comparison to that of the circular SiNH array with the same fill fraction. Lattice symmetry breaking and extension of the irreducible Brillouin zone are responsible for the enhancement of the absorption.","PeriodicalId":142821,"journal":{"name":"SPIE Optics + Photonics for Sustainable Energy","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123160195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jesus D. Ortega, J. Christian, J. Yellowhair, C. Ho
Traditional tubular receivers used in concentrating solar power are formed using tubes connected to manifolds to form panels; which in turn are arranged in cylindrical or rectangular shapes. Previous and current tubular receivers, such as the ones used in Solar One, Solar Two, and most recently the Ivanpah solar plants, have used a black paint coating to increase the solar absorptance of the receiver. However, these coatings degrade over time and must be reapplied, increasing the receiver maintenance cost. This paper presents the thermal efficiency evaluation of novel receiver tubular panels that have a higher effective solar absorptance due to a light-trapping effect created by arranging the tubes in each panel into unique geometric configurations. Similarly, the impact of the incidence angle on the effective solar absorptance and thermal efficiency is evaluated. The overarching goal of this work is to achieve effective solar absorptances of ~90% and thermal efficiencies above 85% without using an absorptance coating. Several panel geometries were initially proposed and were down-selected based on structural analyses considering the thermal and pressure loading requirements of molten salt and supercritical carbon-dioxide receivers. The effective solar absorptance of the chosen tube geometries and panel configurations were evaluated using the ray-tracing modeling capabilities of SolTrace. The thermal efficiency was then evaluated by coupling computational fluid dynamics with the ray-tracing results using ANSYS Fluent. Compared to the base case analysis (flat tubular panel), the novel tubular panels have shown an increase in effective solar absorptance and thermal efficiency by several percentage points.
{"title":"Coupled optical-thermal-fluid and structural analyses of novel light-trapping tubular panels for concentrating solar power receivers","authors":"Jesus D. Ortega, J. Christian, J. Yellowhair, C. Ho","doi":"10.1117/12.2188235","DOIUrl":"https://doi.org/10.1117/12.2188235","url":null,"abstract":"Traditional tubular receivers used in concentrating solar power are formed using tubes connected to manifolds to form panels; which in turn are arranged in cylindrical or rectangular shapes. Previous and current tubular receivers, such as the ones used in Solar One, Solar Two, and most recently the Ivanpah solar plants, have used a black paint coating to increase the solar absorptance of the receiver. However, these coatings degrade over time and must be reapplied, increasing the receiver maintenance cost. This paper presents the thermal efficiency evaluation of novel receiver tubular panels that have a higher effective solar absorptance due to a light-trapping effect created by arranging the tubes in each panel into unique geometric configurations. Similarly, the impact of the incidence angle on the effective solar absorptance and thermal efficiency is evaluated. The overarching goal of this work is to achieve effective solar absorptances of ~90% and thermal efficiencies above 85% without using an absorptance coating. Several panel geometries were initially proposed and were down-selected based on structural analyses considering the thermal and pressure loading requirements of molten salt and supercritical carbon-dioxide receivers. The effective solar absorptance of the chosen tube geometries and panel configurations were evaluated using the ray-tracing modeling capabilities of SolTrace. The thermal efficiency was then evaluated by coupling computational fluid dynamics with the ray-tracing results using ANSYS Fluent. Compared to the base case analysis (flat tubular panel), the novel tubular panels have shown an increase in effective solar absorptance and thermal efficiency by several percentage points.","PeriodicalId":142821,"journal":{"name":"SPIE Optics + Photonics for Sustainable Energy","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114845233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recent studies in monocrystalline semiconductor solar cells are focused on mechanically stacking multiple cells from different materials to increase the power conversion efficiency. Although, the results show promising increase in the device performance, the cost remains as the main drawback. In this study, we calculated the theoretical limits of multistacked 1D and 2D microstructered inorganic monocrstalline solar cells. This system is studied for Si and Ge material pair. The results show promising improvements in the surface reflection due to enhanced light trapping caused by photon-microstructures interactions. The theoretical results are also supported with surface reflection and angular dependent power conversion efficiency measurements of 2D axial microwall solar cells. We address the challenge of cost reduction by proposing to use our recently reported mass-manufacturable fracture-transfer- printing method which enables the use of a monocrystalline substrate wafer for repeated fabrication of devices by consuming only few microns of materials in each layer of devices. We calculated thickness dependent power conversion efficiencies of multistacked Si/Ge microstructured solar cells and found the power conversion efficiency to saturate at 26% with a combined device thickness of 30 μm. Besides having benefits of fabricating low-cost, light weight, flexible, semi-transparent, and highly efficient devices, the proposed fabrication method is applicable for other III-V materials and compounds to further increase the power conversion efficiency above 35% range.
{"title":"Theoretical limits of the multistacked 1D and 2D microstructured inorganic solar cells","authors":"E. Yengel, H. Karaagac, Logeeswaran. Vj, M. Islam","doi":"10.1117/12.2188355","DOIUrl":"https://doi.org/10.1117/12.2188355","url":null,"abstract":"Recent studies in monocrystalline semiconductor solar cells are focused on mechanically stacking multiple cells from different materials to increase the power conversion efficiency. Although, the results show promising increase in the device performance, the cost remains as the main drawback. In this study, we calculated the theoretical limits of multistacked 1D and 2D microstructered inorganic monocrstalline solar cells. This system is studied for Si and Ge material pair. The results show promising improvements in the surface reflection due to enhanced light trapping caused by photon-microstructures interactions. The theoretical results are also supported with surface reflection and angular dependent power conversion efficiency measurements of 2D axial microwall solar cells. We address the challenge of cost reduction by proposing to use our recently reported mass-manufacturable fracture-transfer- printing method which enables the use of a monocrystalline substrate wafer for repeated fabrication of devices by consuming only few microns of materials in each layer of devices. We calculated thickness dependent power conversion efficiencies of multistacked Si/Ge microstructured solar cells and found the power conversion efficiency to saturate at 26% with a combined device thickness of 30 μm. Besides having benefits of fabricating low-cost, light weight, flexible, semi-transparent, and highly efficient devices, the proposed fabrication method is applicable for other III-V materials and compounds to further increase the power conversion efficiency above 35% range.","PeriodicalId":142821,"journal":{"name":"SPIE Optics + Photonics for Sustainable Energy","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122135574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Silvana Ayala, Yuechen Wu, S. Vorndran, Raphael Perci Santiago, R. Kostuk
In this paper we introduce an approach to damping intermittency in photovoltaic (PV) system output due to fluctuations in solar illumination generated by use of a hybrid PV-thermal electric (TE) generation system. We describe the necessary constrains of the PV-TE system based on its thermodynamic characteristics. The basis for the approach is that the thermal time constant for the TE device is much longer than that of a PV cell. When used in combination with an optimized thermal storage device short periods of intermittency (several minutes) in PV output due to passing clouds can be compensated. A comparison of different spectrum splitting systems to efficiently utilize the incident solar spectrum between the PV and TE converters are also examined. The time-dependent behavior of a hybrid PV-TE converter with a thermal storage element is computed with SMARTS modeled irradiance data and compared to real weather and irradiation conditions for Tucson, Arizona.
在本文中,我们介绍了一种方法来阻尼光伏(PV)系统输出的间歇性由于使用混合PV-thermal - electric (TE)发电系统产生的太阳照度波动。基于PV-TE系统的热力学特性,我们描述了其必要的约束条件。该方法的基础是TE器件的热时间常数比PV电池的长得多。当与优化的储热装置结合使用时,可以补偿由于云层通过而导致的PV输出的短时间间歇性(几分钟)。比较了不同的分光系统,以有效地利用PV和TE转换器之间的入射太阳光谱。采用SMARTS模型辐照度数据计算了带有储热元件的混合PV-TE转换器的时间依赖行为,并与亚利桑那州图森市的实际天气和辐照条件进行了比较。
{"title":"Model and analysis of solar thermal generators to reduce the intermittency of photovoltaic systems with the use of spectrum splitting","authors":"Silvana Ayala, Yuechen Wu, S. Vorndran, Raphael Perci Santiago, R. Kostuk","doi":"10.1117/12.2187071","DOIUrl":"https://doi.org/10.1117/12.2187071","url":null,"abstract":"In this paper we introduce an approach to damping intermittency in photovoltaic (PV) system output due to fluctuations in solar illumination generated by use of a hybrid PV-thermal electric (TE) generation system. We describe the necessary constrains of the PV-TE system based on its thermodynamic characteristics. The basis for the approach is that the thermal time constant for the TE device is much longer than that of a PV cell. When used in combination with an optimized thermal storage device short periods of intermittency (several minutes) in PV output due to passing clouds can be compensated. A comparison of different spectrum splitting systems to efficiently utilize the incident solar spectrum between the PV and TE converters are also examined. The time-dependent behavior of a hybrid PV-TE converter with a thermal storage element is computed with SMARTS modeled irradiance data and compared to real weather and irradiation conditions for Tucson, Arizona.","PeriodicalId":142821,"journal":{"name":"SPIE Optics + Photonics for Sustainable Energy","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123846255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Taylor, Yasitha Hewakuruppu, D. DeJarnette, T. Otanicar
Concentrating optics enable solar thermal energy to be harvested at high temperature (<100oC). As the temperature of the receiver increases, radiative losses can become dominant. In many concentrating systems, the receiver is coated with a selectively absorbing surface (TiNOx, Black Chrome, etc.) to obtain higher efficiency. Commercial absorber coatings are well-developed to be highly absorbing for short (solar) wavelengths, but highly reflective at long (thermal emission) wavelengths. If a solar system requires an analogous transparent, non-absorbing optic – i.e. a cover material which is highly transparent at short wavelengths, but highly reflective at long wavelengths – the technology is simply not available. Low-e glass technology represents a commercially viable option for this sector, but it has only been optimized for visible light transmission. Optically thin metal hole-arrays are another feasible solution, but are often difficult to fabricate. This study investigates combinations of thin film coatings of transparent conductive oxides and nanoparticles as a potential low cost solution for selective solar covers. This paper experimentally compares readily available materials deposited on various substrates and ranks them via an ‘efficiency factor for selectivity’, which represents the efficiency of radiative exchange in a solar collector. Out of the materials studied, indium tin oxide and thin films of ZnS-Ag-ZnS represent the most feasible solutions for concentrated solar systems. Overall, this study provides an engineering design approach and guide for creating scalable, selective, transparent optics which could potentially be imbedded within conventional low-e glass production techniques.
聚光光学可以在高温(<100℃)下收集太阳能。随着接收器温度的升高,辐射损耗可能成为主导。在许多浓缩系统中,接收器上涂有选择性吸收表面(TiNOx, Black Chrome等)以获得更高的效率。商业吸收涂层已经发展到对短波(太阳)具有高吸收,但对长波(热辐射)具有高反射。如果一个太阳系需要一种类似的透明的、不吸收的光学材料——即一种在短波长高度透明,但在长波长高度反射的覆盖材料——这种技术根本不可用。Low-e玻璃技术代表了该领域商业上可行的选择,但它只针对可见光传输进行了优化。光学薄金属孔阵列是另一种可行的解决方案,但通常难以制造。本研究探讨了透明导电氧化物和纳米颗粒薄膜涂层的组合,作为选择性太阳能罩的潜在低成本解决方案。本文通过实验比较了沉积在各种衬底上的现成材料,并通过“选择性效率因子”(代表太阳能集热器中辐射交换的效率)对它们进行了排名。在所研究的材料中,氧化铟锡和ZnS-Ag-ZnS薄膜代表了聚光太阳能系统最可行的解决方案。总的来说,这项研究提供了一种工程设计方法和指南,用于创建可扩展的、选择性的、透明的光学器件,这些光学器件可能嵌入传统的低电子玻璃生产技术中。
{"title":"Fabrication and comparison of selective, transparent optics for concentrating solar systems","authors":"R. Taylor, Yasitha Hewakuruppu, D. DeJarnette, T. Otanicar","doi":"10.1117/12.2185742","DOIUrl":"https://doi.org/10.1117/12.2185742","url":null,"abstract":"Concentrating optics enable solar thermal energy to be harvested at high temperature (<100oC). As the temperature of the receiver increases, radiative losses can become dominant. In many concentrating systems, the receiver is coated with a selectively absorbing surface (TiNOx, Black Chrome, etc.) to obtain higher efficiency. Commercial absorber coatings are well-developed to be highly absorbing for short (solar) wavelengths, but highly reflective at long (thermal emission) wavelengths. If a solar system requires an analogous transparent, non-absorbing optic – i.e. a cover material which is highly transparent at short wavelengths, but highly reflective at long wavelengths – the technology is simply not available. Low-e glass technology represents a commercially viable option for this sector, but it has only been optimized for visible light transmission. Optically thin metal hole-arrays are another feasible solution, but are often difficult to fabricate. This study investigates combinations of thin film coatings of transparent conductive oxides and nanoparticles as a potential low cost solution for selective solar covers. This paper experimentally compares readily available materials deposited on various substrates and ranks them via an ‘efficiency factor for selectivity’, which represents the efficiency of radiative exchange in a solar collector. Out of the materials studied, indium tin oxide and thin films of ZnS-Ag-ZnS represent the most feasible solutions for concentrated solar systems. Overall, this study provides an engineering design approach and guide for creating scalable, selective, transparent optics which could potentially be imbedded within conventional low-e glass production techniques.","PeriodicalId":142821,"journal":{"name":"SPIE Optics + Photonics for Sustainable Energy","volume":"9559 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130338556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Electrowetting control of liquid lenses has emerged as a novel approach for solar tracking and concentration. Recent studies have demonstrated the concept of steering sunlight using thin electrowetting cells without the use of any bulky mechanical equipment. Effective application of this technique may facilitate designing thin and flat solar concentrators. Understanding the behavior of liquid-liquid and liquid-solid interface of the electrowetting cell through trial and error experimental processes is not efficient and is time consuming. In this paper, we present a simulation model to predict the liquid-liquid and liquid-solid interface behavior of electrowetting cell as a function of various parameters such as applied voltage, dielectric constant, cell size etc. We used Comsol Multiphysics simulations incorporating experimental data of different liquids. We have designed both two dimensional and three dimensional simulation models, which predict the shape of the liquid lenses. The model calculates the contact angle using the Young-Lippman equation and uses a moving mesh interface to solve the Navier-stokes equation with Navier slip wall boundary condition. Simulation of the electric field from the electrodes is coupled to the Young-Lippman equation. The model can also be used to determine operational characteristics of other MEMS electrowetting devices such as electrowetting display, optical switches, electronic paper, electrowetting Fresnel lens etc.
{"title":"Simulation of an electrowetting solar concentration cell","authors":"Iftekhar Khan, G. Rosengarten","doi":"10.1117/12.2186904","DOIUrl":"https://doi.org/10.1117/12.2186904","url":null,"abstract":"Electrowetting control of liquid lenses has emerged as a novel approach for solar tracking and concentration. Recent studies have demonstrated the concept of steering sunlight using thin electrowetting cells without the use of any bulky mechanical equipment. Effective application of this technique may facilitate designing thin and flat solar concentrators. Understanding the behavior of liquid-liquid and liquid-solid interface of the electrowetting cell through trial and error experimental processes is not efficient and is time consuming. In this paper, we present a simulation model to predict the liquid-liquid and liquid-solid interface behavior of electrowetting cell as a function of various parameters such as applied voltage, dielectric constant, cell size etc. We used Comsol Multiphysics simulations incorporating experimental data of different liquids. We have designed both two dimensional and three dimensional simulation models, which predict the shape of the liquid lenses. The model calculates the contact angle using the Young-Lippman equation and uses a moving mesh interface to solve the Navier-stokes equation with Navier slip wall boundary condition. Simulation of the electric field from the electrodes is coupled to the Young-Lippman equation. The model can also be used to determine operational characteristics of other MEMS electrowetting devices such as electrowetting display, optical switches, electronic paper, electrowetting Fresnel lens etc.","PeriodicalId":142821,"journal":{"name":"SPIE Optics + Photonics for Sustainable Energy","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122091057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The ability to effectively characterize Fresnel lenses over large areas is essential to verifying their system performance and efficiency for concentrating photovoltaics and solar thermal systems. Under high concentration, it becomes challenging to perform detailed spatial and spectral measurements under full sun conditions. We have developed a method to characterize large Fresnel lenses with unknown optical qualities for concentrating solar applications. Our Lens Characterization Unit (LCU) analyzes the resultant pattern of an incident laser beam which may be scanned across the lens. Using the LCU, we can evaluate the portion of refracted light that is concentrated on the receiver area at each incidence point.
{"title":"Fresnel lens characterization for solar concentration efficiency","authors":"W. Harris, M. Hallam, C. Madsen, J. Simcik","doi":"10.1117/12.2188674","DOIUrl":"https://doi.org/10.1117/12.2188674","url":null,"abstract":"The ability to effectively characterize Fresnel lenses over large areas is essential to verifying their system performance and efficiency for concentrating photovoltaics and solar thermal systems. Under high concentration, it becomes challenging to perform detailed spatial and spectral measurements under full sun conditions. We have developed a method to characterize large Fresnel lenses with unknown optical qualities for concentrating solar applications. Our Lens Characterization Unit (LCU) analyzes the resultant pattern of an incident laser beam which may be scanned across the lens. Using the LCU, we can evaluate the portion of refracted light that is concentrated on the receiver area at each incidence point.","PeriodicalId":142821,"journal":{"name":"SPIE Optics + Photonics for Sustainable Energy","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122123949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}