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Bortolini, Marco. "Design, control and management of renewable energy plants and technologies." Doctoral thesis, Università degli studi di Padova, 2013. http://hdl.handle.net/11577/3422587.
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Nowadays, and even more in the next decades, the availability and easy-access to energy sources represent a crucial asset for the world development and the progress of people and nations. At the same time, the depletion of natural resources, together with the increase of the anthropic activity impact on the Earth ecosystem and climate, force communities and institutions, at all levels, to discuss and actuate different approaches to achieve the social and economic growth, based on the so-called sustainable development pattern. In such a scenario, renewable energy sources, i.e. solar, wind, hydro, biomass, geothermal, etc., certainly play a key role to join progress and attention to the environmental issues.
The present Ph.D. dissertation focuses on such topics investigating strategies, methods and innovative approaches for the effective design, control and management of renewable energy plants and technologies.
Specifically, the energy scenario is investigated from a global point of view proposing studies and optimization models highlighting the relevance and the potential impact of the major energy sources, both renewable and conventional. Such sources represent the elements of a big puzzle, i.e. the energy mix, in which their economic and environmental strengths should be emphasized minimizing the associated negative impacts and weaknesses.
Among renewable sources, solar energy is of primary importance for availability, diffusion and potential impact. The present Ph.D. dissertation particularly investigates such a source presenting models, methods and prototypes to increase its relevance in the energy mix. The fundamentals of solar energy, together with innovative approaches to estimate the solar radiation components, are provided. Furthermore, the pioneering concentrating solar sector is deeply focused presenting the design, development and preliminary field-test of a bi-axial Fresnel solar photovoltaic/thermal (PV/T) concentrating prototype. Possible solar tracking strategies and control algorithms are, then, investigated describing a customized semi-automatic motion control platform, developed in LabViewTM programming environment. Finally, the last section, proposes an effective approach for the design of a solar simulator, the most frequently adopted device in solar optic laboratory tests.
In conclusion, the present Ph.D. dissertation describes effective strategies for the renewable energy spread, considering their performances and their potential impact to achieve the ambitious challenge of a sustainable living planet.Oggigiorno, ed in misura crescente nei prossimi decenni, la disponibilità e facilità di accesso alle fonti energetiche rappresenta un fattore determinante per lo sviluppo mondiale ed il progresso di popoli e nazioni. Parallelamente a ciò, il progressivo sfruttamento delle risorse naturali, unito all’aumento dell’impatto delle attività antropiche sull’ecosistema terrestre e sul clima, impongono a comunità ed istituzioni, ad ogni livello, un ripensamento e l’attuazione di differenti strategie per garantire lo sviluppo sociale ed economico attraverso il ricorso ad approcci basati sul concetto di sviluppo sostenibile. In questo contesto, le fonti energetiche rinnovabili, i.e. solare, eolica, idroelettrica, da biomasse, geotermica, ecc., assumono certamente un ruolo determinante per coniugare progresso ed attenzione alle tematiche ambientali. La presente Tesi di Dottorato si incentra su queste tematiche approfondendo strategie, metodi ed approcci innovativi per l’efficace progettazione, controllo e gestione di impianti e tecnologie per le energie rinnovabili. Nel dettaglio, lo scenario d’insieme delle fonti energetiche è analizzato con logica di sistema ed orientamento all’ottimizzazione globale proponendo studi e modelli che evidenzino l’importanza ed il potenziale delle principali risorse, rinnovabili e non, come elementi di un grande mosaico, i.e. il mix energetico globale, nel quale le potenzialità economiche ed ambientali di ogni risorsa sono enfatizzate minimizzando, nel contempo, gli impatti negativi e le rispettive debolezze. Tra le possibili fonti rinnovabili, la fonte solare assume primaria importanza per disponibilità, diffusione ed impatto potenziale. La presente Tesi di Dottorato analizza, in dettaglio, questa risorsa energetica presentando modelli, metodi ed impianti sviluppati per accrescere l’incidenza di questa risorsa nel mix energetico. Gli elementi ed aspetti fondamentali, insieme ad approcci innovativi per la stima delle componenti della radiazione solare, sono presentati nell’elaborato. Successivamente, l’innovativo settore della concentrazione solare è analizzato, in dettaglio, anche attraverso l’illustrazione delle scelte progettuali, lo sviluppo e la campagna sperimentale preliminare di un concentratore solare fotovoltaico/termico (PV/T) a lenti di Fresnel ed inseguimento biassiale. Nel seguito, vengono approfondite possibili strategie per l’inseguimento biassiale ed algoritmi di controllo, implementati in una piattaforma semi-automatizzata sviluppata in ambiente di programmazione grafica LabViewTM. L’ultima sezione propone, infine, un approccio per la progettazione di un simulatore solare, un dispositivo spesso adottato nei test di ottica solare. In conclusione, la presente Tesi di Dottorato, descrive una molteplicità di strategie orientate alla diffusione delle energie rinnovabili, con attenzione alle performance ed all’impatto potenziale che esse hanno verso il raggiungimento dell’obiettivo ambizioso di un sostenibile living planet.
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Sholin, Veronica. "Luminescent solar concentrators and all-inorganic nanoparticle solar cells for solar energy harvesting /." Diss., Digital Dissertations Database. Restricted to UC campuses, 2008. http://uclibs.org/PID/11984.
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Kwarikunda, Nicholas. "On the characterisation of solar cells using light beam induced current measurements." Thesis, Nelson Mandela Metropolitan University, 2015. http://hdl.handle.net/10948/11147.
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The presence of inhomogeneities in semiconductor materials used to fabricate solar cell devices may result in spatial non uniformities in the device properties which may affect current generation in these devices. Besides, current reducing defects such as inclusions, local shunts and optical blockages may be introduced during the various device manufacturing processes which may adversely affect the performance and overall efficiency of solar cells. Diagnostic techniques are therefore needed to identify these defects so as to improve the production technology. This thesis presents the Light Beam Induced Current (LBIC) technique for mapping spatial non uniformities in solar cell devices. The LBIC is a non destructive characterisation technique that uses a focused light beam to raster scan a solar cell surface as the photo-generated current is recorded as a function of position to generate a photo-response map. The technique was used to obtain photoresponse maps for a mc-Si, Back contact Back junction (BC-BJ) silicon solar cell and the InGaP/InGaAs/Ge concentrating triple junction (CTJ) solar cell from which various local current reducing defects were mapped. A reflection signal detector was incorporated into the LBIC measurement system to enable us distinguish between optical blockages on the cell surface and current reducing defects within the solar cell devices. By dynamically biasing the solar cell devices, the electrical activity of the identified defects was investigated and also point-by-point current-voltage (I-V) characteristics were obtained. An interval division algorithm was applied to the measured point-by-point I-V characteristics to extract device and performance parameters from which device and performance parameter uniformity of the devices were mapped. Dark and full cell solar illumination I-V characteristics were also measured to extract device parameters. Analysis of extracted parameters revealed differences between extracted dark and illuminated device parameters which was attributed to departure from the superposition principle due to non-linearity of the semiconductor device equations with respect to carrier concentration. An investigation into the effect of illumination intensity on the I-V parameters of a spot illuminated BC-BJ Si solar cell showed a linear increase and a logarithmic increase of the short circuit current and open circuit voltage respectively with intensity while the series resistance decreased with intensity, which was attributed to increase in conductivity of the active layer. The ideality factor and saturation current were observed to increase while the shunt resistance initially increased before decreasing at higher intensity levels. Under monochromatic illumination, the photo-response of the BC-BJ Si cell was higher at 785nm than at 445nm due to low absorption coefficient of Si for longer wavelength radiations, resulting in carrier generation within the bulk, where there is a higher probability of carriers being collected at the p-n junction before they recombine. Under solar illumination, as the spectral content was altered using long pass colour filters with cut off wavelengths of 610nm and 1000nm, the performance parameters were observed to decrease and this was mainly due to decrease in intensity. For the CTJ solar cell, however, blocking of radiations below 610nm resulted in current mismatch that severely degraded the short circuit current (Isc). The current mismatch affected the extracted device and performance parameters. With a 1000nm long pass filter, a dark I-V was obtained since only the bottom Ge subcell was activated.
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Reusswig, Philip David. "Sensitized energy transfer for organic solar cells, optical solar concentrators, and solar pumped lasers." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/93831.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 123-130).
The separation of chromophore absorption and excitonic processes, such as singlet exciton fission and photoluminescence, offers several advantages to the design of organic solar cells and luminescent solar concentrators (LSCs) for the end goal of achieving a lower cost solar energy generation. This thesis explores three new device architectures to overcome limited solar absorption in singlet-exciton-fission based solar cells and neodymium based LSCs. The process of singlet exciton fission is de-coupled from photon absorption, exciton diffusion, and charge transport in singlet-exciton-fission based solar cells by inserting a singlet fission material at the donor-acceptor interface of an organic solar cell. Singlet excitons generated in the singlet exciton donor are transferred to the singlet fission material through near field energy transfer. In this device structure, the singlet donor can be chosen for high photon absorption, exciton diffusion, and charge transport, and the singlet fission sensitizer can be selected for high singlet fission efficiency. We demonstrated a doubling of the external quantum efficiency from 12.8% to 27.6% in a singlet donor (TPTPA) through the introduction of thin film singlet fission sensitizer (rubrene) for high efficiency organic solar cells. To reduce the cost of electricity generated by sunlight via LSC systems, replacing the expensive high efficiency visible photovoltaic (PV) elements with cheap, high efficiency, earth abundant near-infrared PV elements made with silicon. This requires replacing within the LSC the visible emitting chromophores with near infrared emitters. Here, we present the use of a lanthanide ion, neodymium--colloidal nanocrystal energy cascade system as a promising LSC emitter scheme for the silicon spectral region. Peak optical quantum efficiencies of 43% in a Nd³+:glass based LSC are demonstrated with simulated high geometric gain performance. With cascade energy transfer, the optical quantum efficiency in the visible of a Nd³+:glass is significantly improved with peak efficiency of 28%. The enhanced solar absorption of Nd³+:glass through cascade energy transfer can be extended into the infrared with more optimal sensitizers. The idea of directly converting broad-band solar radiation into coherent and narrow-band laser radiation could enable many attractive technologies for solar energy. Here, we present an architecture for solar pumped lasers that uses a luminescent solar concentrator to decouple the conventional trade-off between solar absorption efficiency and the mode volume of the optical gain material. We report a 750-[mu]m-thick Nd³+-doped YAG planar waveguide sensitized by a luminescent CdSe/CdZnS (core/shell) colloidal nanocrystal, yielding a peak cascade energy transfer of 14%, a broad spectral response in the visible portion of the solar spectrum, and an equivalent quasi-CW solar lasing threshold of 20 W-cm2 , or approximately 200 suns. The efficient coupling of incoherent, spectrally broad sunlight in small gain volumes should allow the generation of coherent laser light from intensities of less than 100 suns.
by Philip David Reusswig.
Ph. D.
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Enshayan, Kamyar Short Ted H. "Measurement of solar radiation transmission in solar ponds /." Connect to resource, 1989. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1145375001.
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Parand, Foroutan. "Solar energy utilisation and evacuated tubular solar collectors." Thesis, Brunel University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292989.
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Enshayan, Kamyar. "Measurement of solar radiation transmission in solar ponds." The Ohio State University, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=osu1145375001.
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Fallows, R. A. "Studies of solar wind throughout a solar cycle." Thesis, Aberystwyth University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.594095.
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Mahoney, Luther. "Solar hydrogen and solar electricity using mesoporous materials." Thesis, University of South Dakota, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3723927.
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The development of cost-effective materials for effective utilization of solar energy is a major challenge for solving the energy problems that face the world. This thesis work relates to the development of mesoporous materials for solar energy applications in the areas of photocatalytic water splitting and the generation of electricity. Mesoporous materials were employed throughout the studies because of their favorable physico-chemical properties such as high surface areas and large porosities. The first project was related to the use of a cubic periodic mesoporous material, MCM-48. The studies showed that chromium loading directly affected the phase of mesoporous silica formed. Furthermore, within the cubic MCM-48 structure, the loading of polychromate species determined the concentration of solar hydrogen produced. In an effort to determine the potential of mesoporous materials, titanium dioxide was prepared using the Evaporation-Induced Self-Assembly (EISA) synthetic method. The aging period directly determined the amount of various phases of titanium dioxide. This method was extended for the preparation of cobalt doped titanium dioxide for solar simulated hydrogen evolution. In another study, metal doped systems were synthesized using the EISA procedure and rhodamine B (RhB) dye sensitized and metal doped titania mesoporous materials were evaluated for visible light hydrogen evolution. The final study employed various mesoporous titanium dioxide materials for N719 dye sensitized solar cell (DSSC) materials for photovoltaic applications. The materials were extensively characterized using powder X-ray diffraction (XRD), nitrogen physisorption, diffuse reflectance spectroscopy (DRS), UV-Vis spectroscopy, Fourier-Transform-Infrared Spectroscopy (FT-IR), Raman spectroscopy, chemisorption, photoluminescence (PL), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). In addition, photoelectrochemical measurements were completed using current-voltage (I-V) curves, external quantum efficiency (EQE) curves, electrochemical impedance spectroscopy (EIS), and transient spectroscopy. The thesis work presented provides a better understanding of the role of mesoporous materials for solar hydrogen and solar electricity production.
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Contino, Alessandro Patrizio. "Solar mirrors characterization for concentrating solar power technology." Doctoral thesis, Università di Catania, 2012. http://hdl.handle.net/10761/993.
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The increasing availability on the market of different types of solar reflectors such as: polymeric film mirrors, aluminum mirrors and thin glass mirrors, together with: the lack of available norms in this area, and a valid methodology to compare the performances of the candidate reflectors; highlights the necessity to conduct a more detailed analysis on these new technologies.
The objective of the present work is to suggest a valuable method to compare the reflectance performance of mirrors, evaluating also their performances in order to assess:
- the most durable to ageing and weathering effects;
- the different reflectance behavior with the variation of the solar incident angle.
.For these reasons the work here proposed was carried out with an experimental apparatus composed by:
- An Agilent Cary 5000 UV/Vis/NIR spectrophotometer to test the different performance of the mirrors at different characterization steps;
- An integrating sphere of 150 mm in diameter (DRA ¡V Diffuse Reflectance Accessory);
- A VASRA (Variable Angle Specular Reflection Accessory);
- A UV chamber to accelerate the ageing process;
- A £gScan SMS Scatterometer for RMS Roughness and BDSF measurement;
- An outdoor bench
The work was completed with two modeling tools:
- An engineering equation solver (Mathcad) to dynamically evaluate the behavior;
- A ray tracing software (Soltrace) to evaluate the system¡¦s optical efficiency.
The analysis indicates that the candidate reflectors can be accurately characterized with five fundamental parameters:
a) £lSWH, the solar-weighted hemispherical reflectance;
b) £lSWS, the solar-weighted specular reflectance;
c) £lSWS( á), the solar weighted specular reflectance function of the variable angle of incidence;
d) BDSF, Bi Directional Scattering Function;
e) RMS Roughness
This evaluation will provide a valuable tool, for the companies who want to invest in concentrating solar power technology, to decide whether or not using a candidate reflectors to realize new plants, assessing their performances, their costs, and their durability.
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Bafana, Ramzi, and Zain Zulfiqar. "Solar Energy." Thesis, Blekinge Tekniska Högskola, Institutionen för tillämpad signalbehandling, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-2079.
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This thesis is about Photovoltaic (PV) cells and its stresses in various directions by calculating the power generated using solar cells under different conditions to improve its efficiency. Our research studies found that using multi-junction cells with larger substrates can increase the efficiency to some extent which in practice is limited to 43 percent. The experiment was conducted using ten solar cells each with an area of 20.9〖cm〗 ^2, where each cell gives 0.5 V and 0.4 A and a 1.25 Ω resistor was used. The cells were connected in series. Once, the PV cells were fixed horizontally and the other time tested in tilted position under same outdoor condition. The purpose of testing PV cells was to investigate the efficiency under above mentioned conditions. The data collected from the readings was used in calculation, and we have obtained from the calculations that horizontally fixed cells gave 4.8 percent efficiency whereas tilted cells gave 6.6 percent efficiency. Hence, the ratio showed that fixed cells produced 37.5 percent more power compared to horizontally fixed cells. Our other experiment consisted of testing PV cells under different temperature conditions that was done using a freezer and an oven for temperature variation and a tungsten bulb was used as a light source. The purpose of performing this experiment was to investigate how the efficiency of PV cells is affected under extreme conditions. Part of our thesis was also including studies and analysis of produced energy by the solar panel installed on the roof of “BTH” building in Karlskrona, Sweden. The data consisted of energy produced from February up to August 2014. The investigation also included finding the highest produced energy during these months. We have found that the highest energy was generated on the 1st of July which was 12.86 kWh. Furthermore, we went deep into investigation of the 1st of July to know exactly which hour of that day the highest energy was produced. The data showed that the highest produced energy was at 12:19 and 13:19 which was 2.03 kWh.Ramzi: +46723231353, +966561993488 Zain:
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Serio, Ulises Daniel. "Energía solar." Bachelor's thesis, Universidad Nacional de Cuyo. Facultad de Ciencias Económicas, 2012. http://bdigital.uncu.edu.ar/5250.
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La energía solar posee un enorme potencial, por ejemplo, si un 10% del desierto de Sahara fuera instalado con paneles solares (suponiendo una efectividad de captación de radiación del 10%), produciría una cantidad de energía eléctrica equivalente al doble del consumo eléctrico mundial. De este modo no existe un problema de recursos o fuentes de energía, sino un problema de costos (actualmente, la energía solar es 10 veces más cara de producir que la provista por una central térmica tradicional) y las demás formas limpias de generar electricidad (hidroeléctrica, geotérmica, mareomotriz, eólica, etc.) no poseen la capacidad técnica de alimentar al planeta dado los recursos
limitados de las mismas (Lackner y Sachs 2005).
En Argentina el uso de este tipo de tecnología es todavía muy limitado. No obstante ha
aumentado recientemente la popularidad del uso de la energía solar (y calefones solares) en la región de Cuyo haciendo verdaderamente importante un estudio sobre si esta tendencia es correcta y conviene a la sociedad o si sus recursos serían mejor invertidos en otras tecnologías o gastos (incluso dentro del ámbito energético).
Un aspecto que resulta importante evaluar es la conveniencia de la implementación de estas tecnologías desde el punto de vista económico-privado ya que de esta manera se pueden direccionar acciones de políticas tendientes a incentivar el uso de las mismas.Fil: Serio, Ulises Daniel. Universidad Nacional de Cuyo. Facultad de Ciencias Económicas.
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Усенко, Наталія Миколаївна, Наталия Николаевна Усенко, Nataliia Mykolaivna Usenko, and I. V. Oliinyk. "Solar window." Thesis, Вид-во СумДУ, 2011. http://essuir.sumdu.edu.ua/handle/123456789/22075.
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In recent years various companies are developing technology to turn ordinary windows into solar panels. And now the U.S. firm New Energy Technologies has also decided to compete in the creation of new sources of energy generation, providing SolarWindow.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/22075
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Nawas, Yousef Ibrahim. "Solar House." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/9753.
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The Solar House is an investigation that resulted from an inter-disciplinary, design built competition ( the Solar Decathlon). This event was sponsored by the U.S. Department of Energy in an atempt to integrate architecture, technology, and dwelling.
The investigation focused on making a house using matter as a conduit to the spiritual, by emphasising two different natures in contrasting conditions. At the same time inclusive of all the technological aspects of a building that operates on solar energy, embedded with the complexities of building systems and new materials.Master of Architecture
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Elluru, Shailaja. "Solar vehicles." OpenSIUC, 2021. https://opensiuc.lib.siu.edu/theses/2824.
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Transportation-related greenhouse gas emissions are one of the most serious environmental concerns, and they are rising at an alarming pace. As a result, solar energy for transportation might be able to solve this problem. The aim of the proposed work is to contribute a technology that promotes Renewable energy; for example, imagine a situation in which we might use solar energy to charge electric cars that have solar panels-built in. solar powered vehicles that can collect and store solar power during their daily trips in their onboard solar batteries These cars can store some solar energy in the batteries and can run smoothly at night and also in the absence of sunlight. As vehicles return to their base stations, they move their Excess power collection to bigger base station batteries, which can be used later.
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Morini, Matteo. "Solar Wheel." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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L'elaborato tratta una particolare ruota solare prodotta da Marand, usata per le competizioni automobilistiche solari.
Dopo un'introduzione, che spiega chi è Marand, in cosa consiste la ruota a grandi linee e gli aspetti generali di cui tenere conto, segue una descrizione dei componenti principali che formano la ruota ed infine la procedura per smontarla/montarla.
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Marshall, Benjamin John. "Solar glider." Thesis, Marshall, Benjamin John (2012) Solar glider. Other thesis, Murdoch University, 2012. https://researchrepository.murdoch.edu.au/id/eprint/7459/.
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This report outlines the design and construction of a solar powered, radio controlled electric glider.
The design called for an electric glider that could take-off, climb and maintain continuous level flight during daylight hours on solar power alone in favourable atmospheric conditions.
The project required the successful completion of the following steps:
• Research and selection of a suitable airframe
• Selection of a propulsion system i.e. electric
motor, gearbox, propeller, and speed controller
• Selection of off-the-shelf radio transmitter, receiver, and servo actuators to control the glider from the ground
• Selection of a battery for energy storage
• The design of a solar array that can be integrated into the wing surface of the glider
• Research, design, construction and testing of a small, light and efficient maximum power point tracker (MPPT) based on a boost DC to DC converter.
The selection of the airframe used and the design and construction of the various sub-systems was aided by a mathematical model. This model was based on an energy balance and a weight balance of an aircraft in level flight.
The glider is now complete and testing has shown that the glider can fly on solar power alone in ideal atmospheric conditions. However these conditions do not exist very frequently in summer in Perth, Western Australia.
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Zomer, Clarissa Debiazi. "Megawatt Solar." reponame:Repositório Institucional da UFSC, 2012. http://repositorio.ufsc.br/xmlui/handle/123456789/93727.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Civil, Florianópolis, 2010Made available in DSpace on 2012-10-25T02:45:18Z (GMT). No. of bitstreams: 1 279104.pdf: 12142340 bytes, checksum: ee36755aa6b85baae4cefb09fe871d54 (MD5)
A inserção de geradores convencionais de energia geralmente ocorre em locais afastados dos grandes centros urbanos, pois tende a acarretar problemas para o entorno como poluição do ar, poluição sonora e poluição visual. No entanto, com a energia cada vez mais necessária para o desenvolvimento humano, utilizar a fonte de geração próxima ao ponto de consumo é uma maneira eficaz de reduzir as perdas por transmissão e distribuição (T&D), Neste contexto, destaca-se a energia solar fotovoltaica, que, além de gerar eletricidade de forma distribuída, diferenciando-se da forma como se constitui o setor elétrico brasileiro, é inesgotável, silenciosa, estática, extremamente simples em sua operação, possui característica modular e pode integrar-se a edificações. Tem-se então, através da geração fotovoltaica, a oportunidade de instalar geradores limpos, renováveis e silenciosos em meio urbano. O objetivo desta dissertação é analisar a inserção do que poderia ser o maior gerador fotovoltaico da América do Sul de que se tem notícia até o presente, integrado ao envelope da edificação da Eletrosul, empresa do setor elétrico, localizada em área urbana de Florianópolis - SC. Através do estudo de área disponível na edificação e suas áreas adjacentes, quantificou-se o potencial fotovoltaico existente na Eletrosul. A partir daí, estimou-se a geração fotovoltaica horária, mensal e anual, a fim de comparar com o consumo da edificação. Com 1 MWp instalado, a contribuição anual seria de 31% do consumo energético, chegando a 42% no mês de dezembro. Na comparação horária, verificaram-se momentos de geração energética superior ao consumo, resultando em energia injetada na rede. Como o consumo e a geração fotovoltaica apresentaram curvas semelhantes, constatou-se a possibilidade de uma recontratação de demanda pela empresa, agregando mais valor à integração fotovoltaica. Por fim, analisou-se a participação da geração deste sistema de grande porte na redução de consumo energético no alimentador em que a edificação está inserida. Neste caso, a contribuição foi de 5% do consumo anual. Através das análises, pode-se quantificar a contribuição energética de um gerador fotovoltaico de grande porte tanto para a edificação quanto para o alimentador em que ela está inserida.
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Invidiata, Andrea. "Solar Decathlon." reponame:Repositório Institucional da UFSC, 2013. https://repositorio.ufsc.br/handle/123456789/106838.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-graduação em Arquitetura e Urbanismo, Florianópolis, 2013.Made available in DSpace on 2013-12-05T22:31:27Z (GMT). No. of bitstreams: 1 321418.pdf: 52040815 bytes, checksum: bfd73e577ec371789136ebb5f371b7ab (MD5) Previous issue date: 2013
O progresso e a pesquisa para tornar os edifícios mais eficientes e, ao mesmo tempo, mais confortáveis, vêm sendo o foco do novo conceito de arquitetura. Um exemplo de como essa evolução está sendo concretizada é o Solar Dechatlon, uma competição (criada em 2002) entre universidades do mundo todo que projetam e constroem casas autossuficientes energeticamente, pois operam utilizando apenas energia solar. A competição visa a construção de casas extremamente eficientes, avaliadas em diferentes quesitos, dentre os quais está a eficiência energética. Em setembro de 2012, foi sediada em Madri e na Espanha, contando pela primeira vez com uma equipe brasileira, representada pela Ekó House. O projeto da Ekó House foi realizado considerando as condições climáticas de Madri, no mês de setembro, para conseguir o melhor desempenho possível da casa durante a competição. A casa, no panorama brasileiro, não apresenta a mesma eficiência que na cidade da competição, com um balanço energético final que só as cidades de Brasília, Montes Claros e Goiânia têm um resultado parecido com a cidade de Madri. Esta pesquisa de Mestrado, portanto, tem o objetivo de avaliar a casa nas diferentes zonas bioclimáticas brasileiras por meio de três metodologias distintas (balanço energético, RTQ-R prescritivo e RTQ-R simulação) e propor, para cada região, um modelo adaptado às condições das diferentes cidades brasileiras analisadas. O objetivo da pesquisa é reutilizar o projeto Ekó House no Brasil da maneira mais eficiente para as condições climáticas do país, e, ao mesmo tempo, criar uma referência projetual para futuras participações na competição Solar Decathlon, tendo como foco, além da competição, a aplicação da casa no território brasileiro. A revisão bibliográfica é centrada em um melhor conhecimento da competição Solar Decathlon e da casa brasileira, abordando também os temas de arquitetura bioclimática e da eficiência energética nas edificações, tendo como foco o uso de tecnologias de energia solar. Por fim, uma análise das normas brasileiras relacionadas à eficiência energética nas edificações concluirá a revisão bibliográfica. A metodologia, por sua vez, é baseada na análise quantitativa da casa na cidade da competição e nas cidades brasileiras escolhidas. A avaliação da eficiência energética da casa será feita por meio de três métodos de análise diferentes: balanço energético, método prescritivo do RTQ-R e método de simulação do RTQ-R. Por último, a casa será alterada nas diferentes regiões, de acordo com as entrevistas feitas com os membros da equipe, com as normas brasileiras e de análise climática das cidades ! onde a casa será avaliada. Dessa forma, será obtido para cada cidade um modelo de casa Ekó House mais eficiente. Os resultados finais demonstram que a casa obteve um melhor desempenho energético por meio das alterações de projeto propostas em todas as cidades brasileiras. As cidades com condições climáticas mais quentes apresentaram um maior benefício das alterações de projeto aportadas, reduzindo o consumo em até 20% comparado com o projeto original da casa
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Karlsson, Jimmy. "Solar tracker." Thesis, Uppsala universitet, Signaler och System, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-387629.
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We are facing a climate crisis, and the world needs to generate electricity in more climate neutral ways. One alternative is to use solar energy. The highest efficiency can be achieved if the surface normal is pointed towards the sun, instead of just having it stationary. To solve this, people make a system called a solar tracker. In this project a prototype of a solar tracker is made, which can follow the sun in any direction. The solar tracker consists of a mechanical structure, two DC-motors that move the structure, and a microcontroller that implements the regulator to control the motors. All the mechanical parts were constructed and then printed using a 3D-printer. Manual control was implemented for making troubleshooting and testing easier. The electrical system is soldered on an experimental board and then mounted with the motor driver and mechanical construction on a bottom structure. There are a few interesting things that could be further developed. One is to implement sensors at the start point and end point of the sun tracking so that the tracker can return to the starting point after the sunset. It would be interesting to scale up the construction a bit and make some more useful measurements on larger panels to see if the system is energy effective enough to be useful; to make some outdoor tests and see how the sensors and control system work in a real-world environment; and to investigate and eventually develop its ability to adapt to cloudy weather.
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Sukki, Firdaus Muhammad. "Optimised solar concentrator for the soar photonic optoelectronic transformer system." Thesis, Glasgow Caledonian University, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.601455.
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Malaysia is one of the countries that have started to elevate the usage of renewable - specifically solar photovoltaic (PV) - in delivering its energy needs. This thesis is divided into two main sections. The first section evaluates the solar PV installations in the residential sector in Malaysia for the past 20 years; in terms of policies, research and development activities and implementations. Recently, the Feed-in Tariff (FiT) scheme was introduced in Malaysia and based on the financial analysis, any installation of solar PV could generate a lucrative monthly income to the household owner under the FiT scheme. However, a preliminary survey indicated that Malaysians are not interested in investing in a solar PV system, mainly due to the high cost of implementation. The next section focuses on the design of solar concentrators - particularly the family of Dielectric Totally Internally Reflecting Concentrators (DTIRCs) - with the aim of achieving a low cost solar PV system. Part of the PhD project is the optimisation of the concentrator design in the Solar Photonic Optoelectronic Transformer (SPOT), the main component of SolarBrane, a static building integrated PV (BlPV) system developed by SolarEmpower Ltd. An optimised design has been proposed using a DTIRC based on the Maximum Concentration Method (MCM). It has been demonstrated via simulations that the optimised design could potentially increase the output of the SolarBrane, at the cost of having a slightly larger structure. A novel type of DTIRC family. known as the Asymmetrical DTIRC (ADTIRC). has been developed to provide additional gain at the "extrusion" plane of the concentrator, and further reducing the size of the PV cell needed. It is concluded tbat this new design generates a much higher gain compared to the concentrator in the SolarBranel. The results from the indoor experiments indicate that the ADTIRC-PV structure could increase the electrical output by 4.2x when compared with the non-concentrating solar PV cell.
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Leblois, Richard. "Solar Impulse - Around the World in a Solar Airplane." Universitätsbibliothek Chemnitz, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-86938.
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- Einführung in das Projekt Solar Impulse (Entstehung, Herausforderung, Errungenschaften)
- Beschreibung der eingesetzten Software Tools zur Entwicklung des Flugzeuges
- Fallbeispiele für den Einsatz von Mathcad
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Nygren, Martin Alexander. "Solar Simulation for the NTNU Test Satellite Solar Cells." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for teknisk kybernetikk, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-24434.
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The relevant energy theory behind intensity and spectral irradiance from the sun is discussed with regard to how it changes due to factors like Earth-Sun distance, solid angle of the sun disk and circumsolar region, angle of incidence and atmospheric mass. This translates to how the experienced conditions for solar cells vary, how and why solar simulation is done the way it is with such stringent requirements, as well as what can be expected in terms of difference between controlled, fixed conditions and operation in environments where we are not free to modify the variables as easily. The most essential theory of solar cell structure and performance is reviewed, with emphasis on the theory needed to understand the design principles, characteristics and behavior of the high-efficiency multijunction solar cells available for the NUTS project. The most commonly encountered components of a solar simulator is discussed to the point where the information provided should allow for a well-informed evaluation and selection of design for most applications, and be of guidance if one were to wish to attempt to create a device able to simulate aspects of the solar irradiation.Solar cell characteristics are developed by the use of a solar simulator under controlled testing conditions to ensure reproducible results. The effect of controlled sunlight from a range of different angles onto a solar cell is investigated in terms of current-voltage characteristics, and in particular the effect on short circuit current as compared to what is expected of theory. It is found that the angle of incidence of light can be calculated from the measured current with a general accuracy of about 1 degree, when compensating for reflectivity in the solar cell cover glass.
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Bame, Aaron T. "Optimization of Solar-Coal Hybridization for Low Solar Augmentation." BYU ScholarsArchive, 2021. https://scholarsarchive.byu.edu/etd/8942.
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One approach to enabling a larger penetration of renewable sources of energy is the implementation of hybrid power plants. This work presents a process to determine the preliminary optimal configuration of a concentrating solar power-coal hybrid power plant with low solar augmentation, and is demonstrated on a coal power plant in Castle Dale, UT. A representative model is developed and validated against published data for a coal power plant of a different configuration than Hunter Unit 3. The simplifications within the representative model include combining multiple feedwater heaters, combining turbines that operate across the same boundary states, and the mass-average calculation for extraction properties to the combined feedwater heaters. It is shown that the representative model can accurately and consistently simulate a coal power plant. Comparing net power generation and boiler heating estimates from the representative model to the benchmark power plant, the representative model is accurate to within +/- 1% the accepted value from the benchmark power plant. The methods for quantifying solar resource with data from the National Renewable Energy Laboratory are presented with the derivation of an algorithm to simulate a concentrating solar power field arrangement. The solar contribution to electrical power output is estimated using an exergy balance. A simplified financial model is also developed to estimate the solar marginal levelized cost of electricity and payback time using a cash-flow analysis. Estimates for solar resource, solar contribution, and financial performance are consistent with data published by the National Renewable Energy Laboratory or in archival literature. A multi-objective optimization routine is developed consisting of the representative model, the augmentation of solar energy into the solar integration model by means of feedwater heater bypass, solar contribution, levelized cost of electricity, and payback time. Because this study considered complete FWH bypass, higher solar augmentation (>3% of boiler heating) is required for a hybrid design to be considered feasible. However, for higher solar augmentation, the costs are also considerably higher and the financial benefit is insufficient to make any hybrid designs feasible unless a carbon tax is in place. A carbon tax will amplify the financial benefit of hybridization, so optimization results are provided assuming a carbon tax value equivalent to the value used in California's Emissions Trading System (16 USD sh.tn.^-1). The impact of a green energy premium price paid by consumers is also explored in the context of payback time. The resulting optimal design for the Hunter Unit 3 with a carbon tax and no premium is using parabolic trough collector technology at an augment fraction of k=9% to bypass feedwater heater 6. The resulting marginal solar levelized cost of electricity is 9.5 x 10^-4 USD kWh^-1 with an estimated payback time of 25.2 years. This process can be applied to any coal power plant for which operating data and meteorological data are available to evaluate preliminary hybridization feasibility.
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Trinkl, Pierce. "Meekatharra virtual solar farm with centralised solar smoothing battery." Thesis, Trinkl, Pierce (2016) Meekatharra virtual solar farm with centralised solar smoothing battery. Honours thesis, Murdoch University, 2016. https://researchrepository.murdoch.edu.au/id/eprint/35812/.
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As increasing amounts of renewable energy systems are being integrated into traditional power systems; a number of issues relating to the level of renewable energy penetration are arising. Horizon Power, an operator of islanded microgrids in Western Australia, is particularly susceptible to these problems as small microgrids can be destabilised by relatively low amounts of renewable energy generation compared with larger interconnected systems. This problem was brought to the forefront when a consortium of customers on Horizon Power’s Meekatharra microgrid applied to install solar generation that would collectively make up one third of Meekatharra’s maximum load.
This project is a feasibility study to determine the financial impact that connecting such a large amount of renewable energy generation to the network will have on both the customers and Horizon Power. It takes into consideration not only the impact of the solar generation being installed but also the accompanying solar smoothing battery required to allow such high renewable energy penetration. Furthermore, the possibility of a solar trading platform, to allow customers on the network to trade their excess energy, was explored and a financial model developed to assess the additional impact this would have on Horizon Power.
HOMER Energy was used to model the expected energy flows of each individual customer using real hourly load profiles supplied by Horizon Power. The requirements of the solar smoothing battery, and an accompanying cost estimate, were developed in conjunction with Horizon Power engineers using DIgSILENT’s PowerFactory. Financial modelling was completed in Excel based on these energy flows and battery pricing estimates. Finally, the likely value extracted from Horizon Power by a trading platform was estimated in Excel, again using the HOMER energy flows as a basis.
The outcomes of this study provided Horizon Power with a complete set of results to consider, when deciding whether to invest in the project. The key finding was currently the centralised solar smoothing battery is economically infeasible, leading to the decision not to invest in this project at this time and instead to wait until battery prices have declined. Once prices have reached the amount shown in the sensitivity analysis to make the project economically feasible, it will be reconsidered and the models developed through this project updated and re-simulated.
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Hassanain, Ahmed A. "Investigation of solar chimneys and tubular transpired solar air heaters as improved systems for solar dryers." Thesis, University of Ulster, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393770.
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Berryman, Ian. "Optimisation, design, development, and trial of a low-cost solar oven with novel concentrator geometry." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:42de9b33-18e1-4f22-8a44-3ddfd532bd0b.
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A promising and novel solar concentrator design has been thoroughly investigated and optimised. A prototype concentrator based on this novel geometry was validated using ray tracing techniques. This ray tracing demonstrated the comparative performance of this novel concentrator in regards to equivalent parabolic dishes. The effect of mirror surface normal errors on performance was established using Monte-Carlo based ray tracing code, which agreed well with the optical performance of this prototype which was determined experimentally. A need for low-cost solar cookers to replace bio-mass worldwide was identified, and the concentrator design was then developed as a low-cost solar oven. Despite existing in some number, no current design is able to achieve high performance at low-cost. An industrial partner, Dytecna, was initially involved in the process of this development of the system as a solar cooker. In support of a field trial for the solar cooker developed with Dytecna, a detailed thermal model of the oven was developed. A low-cost lightmeter was constructed and calibrated in order to measure the direct normal irradiance during the field trial in Italy. Laboratory work provided baseline results for the heating of various thermal masses in the oven. The Italian field trials provided a wealth of feedback into the design of the system and many valuable results. The solar cooker was able to bring 0.75L of water to the boil in 33 minutes with an average heat throughput of 203W. Important benchmark results and practical experience of several competing receiver materials was obtained; further lab testing provided more accurate measurements of the receivers' performances. The experiences of the Italian field trial were fed back into the design of a subsequent prototype, intended for a much larger field trial in Tanzania. Improvements in the hotplate, receiver material, and the oven were all incorporated into the design. Additionally, the structure of the solar cooker was redesigned to incorporate a low-cost wooden construction. Supporting work was conducted for the month long trial in which 8 solar cookers would be distributed to families in Tanzania. The field trial in Tanzania provided a wealth of user feedback into the design. At the same time the new solar cooker exceeded previously established performances in Italy. The new design was able to provide an average of 246W of heat to 1kg of water, which was brought to boiling point in 25 minutes. This represents a heating efficiency of 66% compared to the incident solar flux on the hotplate. In response to findings during the Tanzanian trials, further laboratory work was conducted into establishing the reflectivities of low-cost candidate mirror materials. Throughout all phases of the project the design of the solar cooker was refined and improved with the goal of a solar cooker design that could reach price-point, performance, and usability standards which would ensure market success.
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Almeida, Carlos Eduardo Freire d’. "Análise comparativa do sistema solar termodinâmico vs. sistema solar térmico." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/21199.
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Mestrado em Sistemas Energéticos SustentáveisCom este trabalho pretende-se comparar energética e financeiramente o sistema solar térmico e o sistema solar termodinâmico aplicados para captura de energia solar em sistema de água quente sanitária. Para isso comparou-se, a partir do software Retscreen e EcoREN, o desempenho e performance de cada sistema, que depende em muito da temperatura do ar e da radiação incidente local, para três cidades portuguesas: Bragança, Coimbra e Faro. Daí foi possível percecionar o fluxo de caixa anual de cada sistema solar em relação a um sistema de referência (termoacumulador elétrico), e obtiveram-se os dados financeiros que demonstram a viabilidade de cada projeto e auxiliam na escolha do sistema solar mais adequado a implementar em cada uma das cidades referenciadas. Os resultados obtidos indicam que o sistema solar térmico está mais dependente da radiação, e, portanto, tem maior oscilação da fração solar ao longo do ano, e do local (Bragança 55 %, Coimbra 61 % e Faro 68 %). Já no sistema solar termodinâmico, a fração solar obtida é relativamente constante, mantendo-se a cerca de 65%, independentemente da localização, sendo compensado por um maior trabalho e consumo elétrico por parte do compressor em períodos de menor eficiência térmica. Em termos financeiros o sistema solar térmico apresentou payback inferior para Coimbra e Faro, tal como um maior fluxo de caixa, pois o sistema solar termodinâmico tem custos extra associados ao compressor.
The aim of this work is to make an energy and financial comparison between a solar thermal system and a thermodynamic solar system, when applied as a domestic hot water heater. With the support of Retscreen and EcoREN software, was modeled the performance of each system, which are mainly affected by air temperature and incident solar radiation. The study was conducted for three portuguese cities: Bragança, Coimbra and Faro. Therefore, it was possible to compare the cashflow of different systems relative to a reference technology (electric thermal accumulator). The financial data in particular was key in determining the viability of each solar system and may work as a support in the decision making for the most suitable solar system which should be implemented in each of the studied cities. The obtained results show that the solar thermal system is more dependent of the radiation, therefore there is a major swing of the solar fraction throughout the year, and the location (Bragança 55 %, Coimbra, 61 % and Faro 68 %). As for the thermodynamic solar system, the solar fraction is relatively constant, around 65 %, no matter the location, although more work is required from the compressor. As for the financial aspect, with the solar thermal system the payback is lower for Coimbra and Faro, and also have higher cashflow, because the thermodynamic solar system has extra costs with the compressor
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Mayere, Abdulkarim. "Solar powered desalination." Thesis, University of Nottingham, 2011. http://eprints.nottingham.ac.uk/12331/.
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Despite water being apparently abundant, up to half of the world’s population is faced with water crises which is growing at an alarming rate most especially in developing countries such as African countries where both physical and economic water scarcities prevail. Thus with the abundant salty water and solar intensity in the regions or seasons when water is mostly scarce, solar powered desalination presents an attractive and promising solution towards availability of clean water. A unique and simple solar desalination system has been developed. The system which based on humidification/dehumidification process is a low cost solution and very competitive with conventional desalination systems. It can be used to provide clean water to the over one billion population who have no access or have water shortages which threaten their health and economies. The developed solar desalination system consists of a purposely designed concentrating solar collector and the desalination core which consist of the humidification and dehumidification chambers. The novel concentrating v-trough solar collector which has its focal point at the bottom of the concentrator provides enough thermal energy required to heat up seawater which is then pumped and sprayed to humidify the incoming air in the humidification chamber. The humidified air enters the dehumidification chamber and is cooled by the incoming cold seawater. The moisture is condensed out and the pure water is accumulated at the base of the chamber, and the dehumidified air is discharged to the outside. The key point is the psychrometric energy re-use, most of the energy is from the condensing of the moisture in the carrier gas. Both theoretical analysis and experimental tests were carried out and good water output up to 20kg/h and COP around 3 was obtained. This would require 8m2 of the newly designed v-trough collector operating at 100°C at 1000W/m2 solar intensity. And economic and environmental analysis showed that the solar powered desalination system can achieve a 6 year payback period when compared with when driven by electricity and also a saving of up to 4730 kgCO2 per year. The system can be manufactured from inexpensive plastics rather than exotic and expensive metals. It can easily be sized and scaled to location’s needs, can be operated in diverse geographies unattended on a continuous basis and require minimal maintenance.
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Tan, Bertha. "Nanorod solar cell." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42160.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2007.Includes bibliographical references (p. 68-70).
The crude oil supply crisis the world is facing today along with the disastrous global warming caused primarily as a result the green house gases, has heightened the need for an eco-friendly and renewable energy technology. Solar cells, with their ability to convert the free and gigantic energy supply of the sun into electricity, are one such attractive choice. In this thesis, a study of the use of new technologies for enhanced solar cell performance based on conversion efficiency is carried out by first understanding the mechanism of selected major solar cell types, followed by an analysis of external or internal factors that affect their performance. One new technology under investigation to boost solar cell efficiency is the introduction of nanorod/wire structures into existing designs. This report discusses this approach in detail, highlighting beneficial characteristics offered and also looking into the structure realization through advanced nanostructure processing techniques. Finally, having a complete technology background at hand, various potential markets for new solar cell technologies are examined.
by Bertha Tan.
M.Eng.
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Ehrler, Bruno. "Nanocrystalline solar cells." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607785.
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Musselman, Kevin Philip Duncan. "Nanostructured solar cells." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609003.
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Gruber, Malte. "Solar Cell Simulator." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-200619.
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Corinna, Anne 1936. "Celula solar simplificada." [s.n.], 1987. http://repositorio.unicamp.br/jspui/handle/REPOSIP/260357.
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Orientador : Alberto Martins JorgeTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Campinas
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Resumo: Inicialmente é dado um histórico das células solares de silício monocristalino. A partir de dados de energia solar, de pré-requisitos para a obtenção do efeito fotovoltáico e de considerações sobre o silício e processos atuais em microeletrônica, são estabelecidos os objetivos específicos para obtenção, caracterização e modelamento de uma célula solar simplificada. Esta é construída sobre silício P a partir de filmes de organosilicatos centrifugados à temperatura ambiente. A difusão é realizada simultaneamente para arsênio e boro, à 1050º e diversos tempos de difusão, originando homojunções fotovoltáicas tipo NPP+. As características essenciais são estudadas em células de 3 x 3 mm², sem camada antirefletora e com apenas um ponto de fio de 25 µm de alumínio como contato superior. É feito um modelamento através do qual podemos visualizar em cada camada, N, de depleção e P, a distribuição de minoritários resultante de geração, difusão e recombinação, assim como a corrente externa esperada em diferentes situações de absorção de fótons. O potencial destas células solares para desenvolvimento com a adição de novos processos pode ser estudado através das distribuições de minoritários e correntes totais em diversas condições de velocidade de recombinação. Em apêndice são dadas as bases da interação do campo eletromagnético com junções de silício formando uma célula solar e uma alternativa de modela mento para a camada N
Abstract: Initially we give a small historical development of monocrystalline silicon solar cells. Then, the photovoltaic effect, the available solar energy, the silicon material and our possibilities in microelectronic processing are studied to establish the scope of this work. Doping sources are obtained from organosilicate films deposited by centrifugation at ambient temperature. The diffusion process and parameters are studied and simultaneous diffusion of arsenium and boron at 1050º at several times is used to obtain photovoltaic homojunctions NPP+. Their essential characteristics are studied in cells of 3 x 3 mm² without antireflective coating and a point of aluminum wire of 25 µm diameter as upper contact. In chapter IV we model the devices giving means to determine in each layer, N, depletion and P, the minority carriers distribution resulting from generation, diffusion and recombination, and the external current expected in different photon absorption conditions. The potential development of these solar cells by addition of new processes can be studied through the distribution of minority carriers and total currents in several situations of recombination velocity. In the appendices the physical basis of interaction of eletromagnetic field with matter shaped in semiconductor junctions can be found, as well as an alternative modelling for the N+ layers effect on the total current
Doutorado
Doutor em Engenharia Elétrica
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Rodrigues, Olívia Maria Arteiro do Couto. "O Ciclo solar." Master's thesis, Universidade do Porto. Reitoria, 2000. http://hdl.handle.net/10216/10010.
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Dissertação de Mestrado em Ensino da Astronomia apresentada à Faculdade de Ciências da Universidade do PortoA observação do Sol é uma prática antiga embora só a partir da descoberta do telescópio se tenha iniciado o estudo da sua superfície e registado os primeiros desenhos com particular relevância para as manchas. Mais tarde verificou-se que as manchas possuíam um comportamento peculiar, não só na alteração do seu aspecto mas também no modo como se distribuíam no disco solar. Do seu movimento concluiu-se a rotação e a inclinação do eixo do Sol. A periodicidade do seu comportamento definiu o ciclo solar. A previsão com base nos registos acumulados durante séculos levou à necessidade de verificar as conclusões. A observação com a ajuda de instrumentos mais avançados e com telescópios de olhar diferente (em outros comprimentos de onda) encontrou fenómenos que poderão estar relacionados com as manchas. Actualmente a tecnologia dispõe de meios para observar o Sol de muito perto, de muitas formas e de modo contínuo. A nossa compreensão sobre o Sol e do mecanismo que conduz à formação das manchas ainda não está esclarecido, por isso continua a existir a necessidade de observar, registar, sistematizar e correlacionar os factos. Este trabalho tem por base a recolha de dados observacionais e a sua análise posterior de modo a verificar algumas propriedades relacionadas com a rotação e actividade do Sol, ambas inferidas a partir do estudo das manchas solares.
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Lira, Jiménez Hernán. "Climatizador solar SCS01." Tesis, Universidad de Chile, 2004. http://www.repositorio.uchile.cl/handle/2250/113326.
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Diseñador IndustrialLa presente memoria contiene el desarrollo proyectual del "Diseño de un Sistema de Climatización Solar pasivo de recintos" o SCS, el cual aporta al control ambiental en el interior de recintos.Este tema es motivo de estudio de las investigaciones de Ventilación Natural en Edificios Enfermos y Circulación y Calidad de Aire en Edificios que plantean la aplicación de estrategias de diseño que favorezcan los requerimientos de ventilación natural y sustituyan a los sistemas artificiales de aire acondicionado, para mejorar las condiciones de calidad de vida, reducir el consumo energético y lograr eficientes niveles de renovación y movimiento de aire en los edificios. El proyecto plantea diseñar un climatizador solar el cual soporte al control ambiental en el interior de recintos contribuyendo al confort de las personas.
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Міхно, Світлана Василівна, Свитлана Васильевна Михно, Svitlana Vasylivna Mikhno, and A. Trokhimenko. "Solar thermal collector." Thesis, Видавництво СумДУ, 2011. http://essuir.sumdu.edu.ua/handle/123456789/13475.
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A solar thermal collector is a solar collector designed to collect heat by absorbing sunlight. The actuality of sun collectors today is unquestionable. They allow to heat dwellings, industrial, commercial buildings, and also to provide a hot water-supply in them.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/13475
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Subbaiyan, Navaneetha Krishnan. "Supramolecular Solar Cells." Thesis, University of North Texas, 2012. https://digital.library.unt.edu/ark:/67531/metadc149672/.
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Supramolecular chemistry - chemistry of non-covalent bonds including different type of intermolecular interactions viz., ion-pairing, ion-dipole, dipole-dipole, hydrogen bonding, cation-p and Van der Waals forces. Applications based on supramolecular concepts for developing catalysts, molecular wires, rectifiers, photochemical sensors have been evolved during recent years. Mimicking natural photosynthesis to build energy harvesting devices has become important for generating energy and solar fuels that could be stored for future use. In this dissertation, supramolecular chemistry is being explored for creating light energy harvesting devices. Photosensitization of semiconductor metal oxide nanoparticles, such as titanium dioxide (TiO2) and tin oxide (SnO2,), via host-guest binding approach has been explored. In the first part, self-assembly of different porphyrin macrocyclic compounds on TiO2 layer using axial coordination approach is explored. Supramolecular dye sensitized solar cells built based on this approach exhibited Incident Photon Conversion Efficiency (IPCE) of 36% for a porphyrin-ferrocene dyad. In the second part, surface modification of SnO2 with water soluble porphyrins and phthalocyanine resulted in successful self-assembly of dimers on SnO2 surface. IPCE more than 50% from 400 - 700 nm is achieved for the supramolecular self-assembled heterodimer photocells is achieved. In summary, the axial ligation and ion-pairing method used as supramolecular tools to build photocells, exhibited highest quantum efficiency of light energy conversion with panchromatic spectral coverage. The reported findings could be applied to create interacting molecular systems for next generation of efficient solar energy harvesting devices.
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Stenberg, Jonas. "Perovskite solar cells." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-137302.
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Perovskite solar cells (PSC) performance has risen rapidly the last few years with the current record having power conversion efficiency (PCE) of 22.1 %. This has attracted a lot of attention towards this alternative solar cell that can be manufactured with less energy and toxic material than traditional silicon solar cells. The purpose of this thesis is to reproduce high performance PSC from known recipe by Zhang et al. with potential of PCE reaching above 18 %. The thesis covers the theory regarding how a PSC operates, how they are measured and which parameters are important for a high performance PSC. The thesis includes a detailed manuscript on how to manufacture high performance PSC layer by layer and how to characterize the performance of the cells by IV-measurements. Furthermore, it includes scanning electron microscopy (SEM), by which the cells surface layers and cross-section could be evaluated. The result shows that it is possible to reproduce the PSC from literature and achieve a PCE of 18.8 %. However, the cells PCE decrease by 15 % during 2 hours of constant illumination, due to lack of stability. The manufactured PSC was used to power two catalysts that splits water into O2 and H2 and managed to reach a solar to hydrogen conversion efficiency (STHCE) of 13 %.
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Hauger, John. "Solar panel experiment." Click here to view, 2009. http://digitalcommons.calpoly.edu/eesp/13/.
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Thesis (B.S.)--California Polytechnic State University, 2009.Project advisor: Ali Shaban. Title from PDF title page; viewed on Feb. 4, 2010. Includes bibliographical references. Also available on microfiche.
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Wang, Zheng. "Solar Power Forecasting." Thesis, The University of Sydney, 2019. https://hdl.handle.net/2123/21248.
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Solar energy is a promising environmentally-friendly energy source. Yet its variability affects negatively the large-scale integration into the electricity grid and therefore accurate forecasting of the power generated by PV systems is needed. The objective of this thesis is to explore the possibility of using machine learning methods to accurately predict solar power. We first explored the potential of instance-based methods and proposed two new methods: the data source weighted nearest neighbour (DWkNN) and the extended Pattern Sequence Forecasting (PSF) algorithms. DWkNN uses multiple data sources and considers their importance by learning the best weights based on previous data. PSF1 and PSF2 extended the standard PSF algorithm deal with data from multiple related time series. Then, we proposed two clustering-based methods for PV power prediction: direct and pair patterns. We used clustering to partition the days into groups with similar weather characteristics and then created a separate PV power prediction model for each group. The direct clustering groups the days based on their weather profiles, while the pair patterns consider the weather type transition between two consecutive days. We also investigated ensemble methods and proposed static and dynamic ensembles of neural networks. We first proposed three strategies for creating static ensembles based on random example and feature sampling, as well as four strategies for creating dynamic ensembles by adaptively updating the weights of the ensemble members based on past performance. We then explored the use of meta-learning to further improve the performance of the dynamic ensembles. The methods proposed in this thesis can be used by PV plant and electricity market operators for decision making, improving the utilisation of the generated PV power, planning maintenance and also facilitating the large-scale integration of PV power in the electricity grid.
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Rodrigues, Olívia Maria Arteiro do Couto. "O Ciclo solar." Dissertação, Universidade do Porto. Reitoria, 2000. http://hdl.handle.net/10216/10010.
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Dissertação de Mestrado em Ensino da Astronomia apresentada à Faculdade de Ciências da Universidade do PortoA observação do Sol é uma prática antiga embora só a partir da descoberta do telescópio se tenha iniciado o estudo da sua superfície e registado os primeiros desenhos com particular relevância para as manchas. Mais tarde verificou-se que as manchas possuíam um comportamento peculiar, não só na alteração do seu aspecto mas também no modo como se distribuíam no disco solar. Do seu movimento concluiu-se a rotação e a inclinação do eixo do Sol. A periodicidade do seu comportamento definiu o ciclo solar. A previsão com base nos registos acumulados durante séculos levou à necessidade de verificar as conclusões. A observação com a ajuda de instrumentos mais avançados e com telescópios de olhar diferente (em outros comprimentos de onda) encontrou fenómenos que poderão estar relacionados com as manchas. Actualmente a tecnologia dispõe de meios para observar o Sol de muito perto, de muitas formas e de modo contínuo. A nossa compreensão sobre o Sol e do mecanismo que conduz à formação das manchas ainda não está esclarecido, por isso continua a existir a necessidade de observar, registar, sistematizar e correlacionar os factos. Este trabalho tem por base a recolha de dados observacionais e a sua análise posterior de modo a verificar algumas propriedades relacionadas com a rotação e actividade do Sol, ambas inferidas a partir do estudo das manchas solares.
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Ray, Mike C. T. "Solar Data Analysis." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/1078.
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The solar industry has grown considerably in the last few years. This larger scale has introduced more problems as well as possibilities. One of those possibilities is analyzing the data coming from the sites that are now being monitored, and using the information to answer a variety of questions.
We have four questions which are of prime importance identified in this thesis:
1. Can data from customers be trusted?
2. Can we use data from existing sites to determine which sites need the most improvement?
3. Can we implement a location-based algorithm to reduce the amount of false positives for performance, or other alarms?
4. Can we improve upon the current predicted power algorithm?
We find that not only can we answer these questions definitively, but the improvements found are of significant value. Each of these items represents an important question that either directly or indirectly translates into increased revenue and engineering improvements for the solar industry as a whole.
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Walker, Catherine C. "Variations of solar wind parameters over a solar cycle : expectations for NASA's Solar TErrestrial RElations Observatory (STEREO) mission /." Connect to online version, 2007. http://ada.mtholyoke.edu/setr/websrc/pdfs/www/2007/226.pdf.
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Noglik, Jane B. "Beyond the solar surface : an observational study of solar coronal loops." Thesis, University of Central Lancashire, 2007. http://clok.uclan.ac.uk/20126/.
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This thesis presents an observational analysis of structures in the solar corona. The plasmafl in the corona is low (< I), therefore, the emitting material is intimately linked to the magnetic fleldlines. The initial aim of this work, outlined in Chapter 3, is to take advantage of this relationship to calculate realistic magnetic reconnection rates from EUV observations. Then, Chapters 4-6 concentrate upon examining a colour-colour method to provide temperature profiles of coronal structures. Firstly, TRACE 171 A and 195 A data are used to indirectly determine a magnetic reconnection rate for a flare loop system on the limb of the Sun. The magnetic reconnection rate is calculated by measuring the footpoint velocity of the loop system and following the method adopted by Isobe et al. (2002). The footpoint velocity is thought to be equal to the rate at which successive loops brighten, in the emission lines, during the postflare phase. A typical footpoint velocity of 1.5 kms'±0.7 kmr' is obtained and a reconnection rate of -.0.00 1-0.03 is determined. Secondly, the double filter ratio temperature analysis method employed upon TRACE 171, 195 and 284 A coronal images is re-addressed. Two features from TRACE datasets published initially in Isobe et al. (2002) are reanalysed and a new TRACE example is also included for comparison. Only one of the original examples along with the new dataset are easily shown to be present in all three EUV passbands. This work investigates two important changes to the original analysis. A new temperature colour-colour curve is employed which utilises revised TRACE response functions; these take into account the emission from Fe VIII which significantly affects the 195 A passband. Also three different background subtraction techniques are used. Subsequently, the results show that when using this method for these examples, it is very difficult to assign specific temperature values to individual data points. Thirdly, an extensive investigation into the colour-colour curve is performed. Monte Carlo statistics based on a Poisson distribution are used to get an error estimate for the curve. Based on these error statistics, the probability of analysed data points corresponding to differing temperatures can be found. The flare loop system studied in Chapter 3 is investigated, using the SOHO/EJT data, applied to the colour-colour curve. Also TRACE 171 and 195 A images are analysed with the original single filter ratio technique, for comparison to the EIT data. Both methods appear ambiguous indicating temperatures of either —0.3 M K or - 1.1 MK. Two possible reasons which could push the analysed points off the c-c curve are investigated: (I) the poor resolution of the EIT data could lead to viewing a multi-thermal structure; and (2) if the structure was cooling over the time period of the observations the temperature would change from one passband image to the next. Fourthly, TRACE and CDS data of the same active region are analysed to try and determine the usefulness of the colour-colour method for temperature determination. The TRACE data under investigation is bright in all three wavelengths, and two loop structures are chosen from within the active region for analysis. One structure appeared to be static over the half hour period of the observations, whereas the second structure chosen showed a significant decrease in brightness over the same time period. The results show that the CDS data depicts the coronal structures to be initially at around --1.45 MK, with an increase to 1.58 MK over the time of the observations. The TRACE data seems to show that these structures are slightly cooler at around —1.3 MK, but there is an increase in filter ratio values over the same time period. The biggest discrepancy seen in these two observational datasets is that TRACE shows the temperature of structure 1 to be decreasing towards its apex, whereas CDS shows the temperature increasing. These results reflect the need for better instrumentation. Finally a summary of the conclusions and future work are presented.
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Foley, Brian S. B. (Brian M. ). Massachusetts Institute of Technology. "Solar thermal collector system modeling and testing for novel solar cooker." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/92179.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (page 22).
Solar cookers are aimed at reducing pollution and desertification in the developing world. However, they are often disregarded as they do not give users the ability to cook after daylight hours. The Wilson solar cooker is a solar cooker designed to address this problem by converting solar energy and storing that energy as heat in the form of molten salt (lithium nitrate). This thesis involved research, modeling, and experimentation for the solar collection system of the cooker. This thesis looked at prior research on glazing, Fresnel lenses, and absorber surface treatments to identify and evaluate elements for use in the collection system. Borosilicate glass, with a thermal conductivity of 1.005 W/mK and a solar transmittance of 0.91, and flat black paint, with absorptivity 0.96 and emissivity 0.88 were identified as potential elements for use in first trials. Experimentation was performed on copper and aluminum samples with various surface treatments powered by various Fresnel lenses to evaluate the relative efficiency of these treatments. A novel treatment method, machining a conical hole into the sample, was found to improve efficiency on untreated samples, but inferior to flat black paint. Modeling predicted that the minimum collection area for an acrylic Fresnel lens off-number 1.2 was 0.60 m² for and 0.65 m² for the proposed collector without and with glazing, respectively. A recommendation of collection area 1 m² was proposed to account for unexpected losses due to manufacturing errors, positioning errors, and environmental variation. This thesis also analyzed a proposal for a novel solar collector, a polished aluminum cone. Modeling and efficiency testing showed the cone to be inadequate for the radiation collection needed for the solar cooker.
by Brian Foley.
S.B.
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Winkler, R. "Cryogenic Solar Absolute Radiometer : a potential SI standard for solar irradiance." Thesis, University College London (University of London), 2013. http://discovery.ucl.ac.uk/1381929/.
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This thesis reports the development of an instrument which could act as a future standard for Solar Irradiance. The instrument is called Cryogenic Solar Absolute Radiometer (CSAR), and it exploits the advances made in the field of cryogenic radiometry in the last few decades. The aim is to significantly reduce the measurement uncertainty as compared to the current standard (the World Radiometric Reference) and to guarantee the long-term stability of the measurement record. Several tests were carried out in order to verify the performance of CSAR. In a first test, CSAR was found to agree within 0.01% with the National Physical Laboratory’s SI standard for radiant power. In a second test, CSAR and the World Radiometric Reference were compared on the World Radiation Center’s solar tracker in Davos/Switzerland. In this comparison, the World Radiometric Reference measured 0.309% higher than CSAR; the relative standard uncertainty of the comparison was 0.028%. This difference between the current Solar Irradiance standard and CSAR is able to explain the offset between the two space experiments VIRGO/SOHO and TIM/SORCE. The CSAR result is further confirmed by the fact that a similar offset between the World Radiometric Reference and the SI-scale has been determined through experiments independently performed at the Laboratory for Atmospheric and Space Physics (University of Colorado Boulder). CSAR has also been designed with space flight in mind. Although no full evaluation of the space-worthiness has been carried out, thermal tests indicate that CSAR could cope with the limited cooling power provided by readily available space coolers. The relative standard uncertainty of space-based Total Solar Irradiance measurements by CSAR is estimated to be 0.011%.
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Pierce, Warrick Tait. "Solar assisted power generation (SAPG) : investigation of solar preheating of feedwater." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80139.
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Thesis (MEng)--Stellenbosch University, 2013.ENGLISH ABSTRACT: Solar Assisted Power Generation (SAPG) can be seen as a synergy of solar and fossil plants – combining the environmental benefits of the former and the scale, efficiency and reliability of the latter. SAPG offers great potential for cost effective utilization of solar energy on utility scale and could accelerate the adoption of solar thermal energy technologies in the short and medium term, especially in countries with a significant coal base and a good solar resource such as Australia, China, United States, India and South Africa. SAPG is the replacement of bled-off steam in a Regenerative Rankine power cycle. Power plant simulations were performed using weather data for Lephalale, South Africa (Matimba power station). With an increase in the solar field outlet temperature, an increase in overall solar to electric efficiency was observed, superior to a stand-alone Solar Thermal Power Plant(s) (STPP) at similar temperatures. The performance of four solar collector technologies was compared: flat plate, evacuated tube, Linear Fresnel (LF) and Parabolic Trough (PT). This comparison was limited to the normal incidence angles of irradiation. For this application, nonconcentrating technologies are not competitive. For non-normal incidence angles, annual simulations were limited to PT and LF at final feedwater heater temperatures. The actual aperture area of around 80 000 m2 was used (50 MW thermal based on LF). On an equal aperture area basis, PT outperforms LF significantly. For the conventional North-South arrangement, LF needs to be around 53% of the specific installation cost (in $/m2 aperture area) of PT to be cost competitive. A SAPG plant at Lephalale was compared to a stand-alone Solar Thermal Power Plant STPP in a good solar resource area, namely Upington, South Africa – Parabolic Trough solar collector fields of equal size were considered for both configurations. It was found that the annual electricity generated with a SAPG plant is more than 25% greater than a stand-alone STPP. If the cost of SAPG is taken as 72% of the cost of a stand-alone STPP, this translates into SAPG being 1.8 times more cost effective than stand-alone STPP. Furthermore, SAPG performs better in high electricity demand months (South African winter – May to August). Stand-alone STPP have been adopted in South Africa and are currently being built. This was achieved by the government creating an attractive environment for Independent Power Producers (IPP). Eskom, the national power supplier, is currently investigating solar boosting at existing Eskom sites. This report argues that on a national level, SAPG, specifically solar preheating of feedwater, is a more viable solution for South Africa, with both its significant coal base and good solar resource.
AFRIKAANSE OPSOMMING: Son ondersteunde krag generasie (SOKG) kan gesien word as sinergie van sonkrag en fossiele brandstof aanlegte – dit voeg die omgewings voordele van die eersgenoemde en die grote, effektiwiteit en betroubaarheid van die laasgenoemde by mekaar. SOKG opper groot potensiaal vir koste effektiewe gebruik van son energie op nutsmaatskappyskaal en kan die aanvaarding van sontermiese energietegnologieë in die kort en medium termyn versnel, veral in lande met beduidende kool reserwes en goeie sonkrag voorkoms soos Australië, China, Verenigde State van Amerika, Indië en Suid-Afrika. SOKG impliseer die vervanging van aftap stoom in die regeneratiewe Rankine krag kringloop. Kragstasie simulasies was gedoen met die gebruik van weer data van Lephalale, Suid-Afrika (Matimba kragstasie). Met die toename van die sonveld uitlaat temperatuur kon oorhoofse son-na-elektrisiteit effektiwiteit vasgestel word, wat hoër is as die van alleenstaande sontermiese krag stasie (STKS) by soortgelyke temperature. Die effektiwiteit van vier son kollekteerder tegnologieë was vergelyk: plat plaat, vakuum buis, lineêre Fresnel (LF) en paraboliese trog (PT). Die vergelyking was beperk tot normale inval van bestraling. Vir hierdie toepassing is nie-konsentreerende tegnologie nie mededingend nie. Vir nie-normale inval hoeke was jaarlange simulasies beperk tot PT en LF by finale voedingswater temperatuur. Die werklike opening area van omtrent 80 000 m2 was gebruik (50 MW termies gebaseer op LF). By gelyke opening area, uitpresteer PT LF beduidend. Vir die gebruiklike Noord-Suid rankskikking benodig LF omtrent 53% van die spesifieke installasie kostes (in $/m2 opening area) van PT om kostes mededingend te kan wees. ‘n SOKG aanleg by Lephalale was vergelyk met alleenstaande STKS in die goeie son voorkoms gebied van Upington, Suid-Afrika – Paraboliese trog kollekteerder velde van gelyke grote was oorweeg vir al twee konfigurasies. Dit was gevind dat die jaarlikse elektrisiteit gegenereer vanaf SOKG meer as 25% is as die van alleenstaande STKS. Indien SOKG oorweeg word met 72% van die kostes van alleenstaande STKS, dan beteken dit dat SOKG 1.8 keer meer koste effektief is as alleenstade STKS. Verder, SOKG presteer beter in die hoer elektrisiteitsnavraag maande (Suid- Afrikaanse winter – May tot Augustus). Alleenstaande STKS is gekies vir Suid-Afrika en word tans gebou. Dit is bereik deur dat die regering ‘n aantreklike omgewing geskep het vir onafhanglike krag produsente. Eskom ondersoek tans SOKG by bestaande Eskom persele. Hierdie verslag beweer dat op nasionale/Eskom vlak, SOKG, besonders son voorverhitting van voedingswater, meer haalbare oplossing is vir Suid-Afrika met sy beduidende koolreserwes en goeie son voorkoms.
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Bader, Tobias. "Solar desiccant evaporative cooling with multivalent use of solar thermal heat." Thesis, De Montfort University, 2014. http://hdl.handle.net/2086/10891.
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Solar DEC (Desiccant and Evaporative Cooling) air-conditioning is a renewable technological approach to the future air-conditioning of buildings driven with solar-thermal heat. The principal acceptance of solar airconditioning has led to system prototypes mainly across Europe, however the diffusion of this innovative technology is proceeding slowly due to little field testing experience. In climates with coexisting heating demand particularly, a multivalent system approach that utilizes solar-heat not only for air-conditioning but also for hot water preparation and heating has potential as a feasible concept. However, previous research focused on systems using solar heat exclusively for the DEC-process. This research contributes to the advancement of the solar DEC-technology with multivalent use of solar thermal heat. The investigation consists of an initial detailed in-situ monitoring analysis of a system prototype operated in an industrial environment, followed by the development of optimised system concepts and a climate-specific analysis of the solar DEC-technology. The monitoring provided in-depth knowledge about the system operation, revealing the reasons for the insufficient refrigeration capacity achieved in practice. A detailed simulation model for an entire multivalent solar DEC-system including the heat sinks, DEC-system, heating and hot-water preparation was developed and a DEC-control strategy has been formulated. A new optimised control strategy for multivalent systems with simultaneous sink supply concept was devised. A sensitivity analysis was carried out to investigate the key design parameters for the dimensioning of multivalent solar DEC-systems. The research concluded that the auxiliary primary energy consumption of the optimised system was lower by one third compared to the initial system. Finally, a methodological zoning approach was developed, to systematically produce design-specific outline data for the application of the solar DEC-technology at climatically different sites.
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Garcia, Dário M. "Forno solar com lentes de Fresnel e aplicações em laser solar." Master's thesis, Faculdade de Ciências e Tecnologia, 2013. http://hdl.handle.net/10362/10055.
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Dissertação para obtenção do Grau de Mestre em Engenharia FísicaCom este trabalho pretendeu-se estudar a eficácia de dois tipos de fornos solar com lentes de Fresnel e compará-los com os fornos solares parabólicos já existentes. Foi desenvolvido um protótipo para um dos fornos solares estudados. Ao longo deste trabalho foram feitas simulações computacionais no software de simulação ótica ZEMAX© para encontrar o esquema do forno solar ideal, com o objetivo de obter o maior fluxo e potência solar no foco. Os esquemas de forno solar baseiam-se na redirecção e focagem de luz com lentes de Fresnel para uma região focal comum. A melhor configuração para forno solar foi encontrada para um esquema de 6 lentes de Fresnel e 6 espelhos planos. Este esquema foi também simulado para bombeamento de um disco de Nd:YAG, com um concentrador secundário e respetivo sistema de arrefecimento, para produção de laser. A potência do laser e qualidade de feixe foram analisadas através do software LASCAD©. Com a ajuda do Professor Dawei Liang e Msc. Joana Almeida foi realizada a construção do forno solar com 21 espelhos planos e 21 lentes de Fresnel.