The main objective of this diploma thesis is to provide a paradigmatic view on the solar energy market within the environment of system dynamics. To reach this goal, it was necessary to create a dynamic model which will be sufficiently informative and reliable for generating the main behaviour patterns of the solar energy market. This model provides a macroscopic view on the problematic of solar energy market and therefore includes all its key components. Thesis further includes simulations of hypothetical scenarios aimed both on historical and future market development.

Orientador: Carla Kazue Nakao Cavaliero / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-24T10:55:11Z (GMT). No. of bitstreams: 1 Lopes_DaviGabriel_D.pdf: 26107046 bytes, checksum: d57644d6634b5c3909c4f246fc86a5bd (MD5) Previous issue date: 2013 / Resumo: Atingir o desenvolvimento sustentável é algo relativo e difícil de ser mensurado, haja vista a complexidade do tema e as discussões em diversas esferas institucionais, porém o passo para se discutir esse tema no âmbito da geração de energia elétrica passa necessariamente pelas emissões de gases de efeito estufa (GEEs). Isso porque o Mecanismo de Desenvolvimento Limpo (MDL) está consolidado em esfera mundial como uma ferramenta que mensura e aponta os possíveis benefícios socioambientais de atividades de projetos executados em países em desenvolvimento que utilizam, por exemplo, fontes de energia renováveis. Assim, a presente tese busca inserir os Sistemas Fotovoltaicos Conectados à Rede (SFCR) nesse contexto e utiliza a Chamada Estratégica nº 13 da ANEEL (Chamada 13) para avaliar quantitativamente a sua contribuição para a redução das emissões de CO2e. A partir da estimativa da energia elétrica gerada pelos 13 projetos aprovados nessa Chamada, realizada com o Software PVsyst 6.1.0, e da aplicação da metodologia aprovada pela UNFCCC, adequada às condições de geração, foi estimada a emissão evitada de CO2e com a inserção dessa energia na rede do Sistema Interligado Nacional (SIN). Além disso, descreveu-se e analisou-se a contribuição desses projetos para o desenvolvimento sustentável, avaliação indispensável para qualquer projeto de MDL. Dentre os resultados encontrados verificou-se que a geração de energia elétrica total é de 25.619 MWh/ano e que a Chamada 13 pode evitar emissões de 6.285 tCO2e/ano, usando o ano base 2011; e 11.229 tCO2e/ano, no ano base 2012. Os projetos de SFCR podem colaborar para o desenvolvimento sustentável gerando 454 "empregos solares" diretos, aumentando direta e indiretamente a renda da população local, contribuindo para a capacitação tecnológica nacional e auxiliando diversos setores da economia brasileira que fazem parte da cadeia dos SFCR. Ao final, visando aplicar os resultados obtidos, preencheu-se o Documento de Concepção do Projeto (DCP), exigido para a submissão das atividades de projeto no âmbito do MDL, com os dados da Usina Solar de Tanquinho/CPFL, um dos 13 projetos aprovados na Chamada 13 e que foi adotado como projeto de referência para as estimativas realizadas nessa tese / Abstract: Achieving sustainable development is relative and difficult to measure, given the complexity of the issue and the discussions in institutional spheres, but the first step to discuss this topic in power generation necessarily involves the estimation of greenhouse gases emissions (GHGs). That is partly because the Clean Development Mechanism (CDM) is a global tool consolidated that measures and indicates the possible social and environmental benefits of project activities implemented in developing countries that use renewable energy sources, for example. Thus, within the context describe above, this thesis has the objective to analyze the Grid-Connected Photovoltaic Systems of the Strategic Call n°13 from ANEEL to quantitatively evaluate its contribution to the reduction of emissions of CO2e. The estimation of electrical power generated by the 13 projects approved in this Call was held with the PVsyst Software 6.1.0, and then the methodology adopted by UNFCCC was applied to estimate avoided emissions of CO2e in the National Grid. Furthermore, the contribution of these projects to sustainable development was described and analyzed, which is an evaluation indispensable for any CDM project. Among the findings it was determined that the total electricity generation is 25,619 MWh/year and that can avoid emissions of 6,285 tCO2e/year , if using the base year 2011, and 11,229 tCO2e/year, if using base year 2012. The Grid-Connected Photovoltaic Systems projects can contribute to sustainable development by direct generating 454 "solar employments", as well as indirect jobs increasing the income of local people, encouraging the national technological capability and helping various sectors of the Brazilian economy. Finally, the results were applied and the Project Design Document (PDD) was filled in with data from the Solar Power Plant of Tanquinho/CPFL, one of 13 projects approved on Call 13. This document is required for project activities under the CDM, and it was adopted as the reference design for the estimates made in this thesis / Doutorado / Planejamento de Sistemas Energeticos / Doutor em Planejamento de Sistemas Energéticos

[ES] El objetivo principal de esta tesis es contribuir al avance de nuevas técnicas de elaboración con bajo coste, utilizando materiales tipo de cobre, indio, galio y selenio CIGS y Perovskita para aplicaciones en energía solar fotovoltaica. CIGS parecen ser adecuadas ya que son de bajo costo de producción y se han reportado eficiencias de conversión del 23,35%. Por otro lado, las perovskitas híbridas de haluros de plomo orgánicos-inorgánicos han aparecido como nuevos materiales excepcionales para celdas solares, especialmente porque la eficiencia de las celdas solares basadas en perovskita ha aumentado del 3.8% al 22.7% en menos de un lustro. Este trabajo se ha dedicado a experimentar sobre la elaboración y caracterización de CIGS y los perovskitas de metilamonio de yoduro de plomo de (MAPbI3) y formamidinio de yoduro de plomo (FAPbI3), que se utilizo tanto en la aplicación a las células solares de perovskitas y en las células Tándem CIGS-perovskita. Las películas se caracterizaron por difracción de rayos X, espectroscopía Raman, microscopía electrónica de barrido, análisis de espectroscopía de energía dispersiva, microscopía de fuerza atómica, transmisión electrónica microscopía, fotoluminiscencia y espectroscopia UV-Vis. En las capas de CIGS depositadas por electrodeposición se investigó el efecto de diferentes parámetros, También investigamos en detalle el efecto del contacto posterior en las propiedades estructurales y ópticas de CIGS. Constatamos que el tipo de contacto posterior tiene un efecto significativo en el rendimiento posterior de las películas delgadas CIGS. Además, estudiamos la técnica de espray pirólisis para producir películas CIGS. Se estudió el proceso de recocido, que es el factor clave para mejorar el rendimiento de las células solares. Se elaboraron diferentes películas delgadas constituidas de nuestro dispositivo CdZnS/CdS/CIGS/Mo eso utilizó una capa conductora transparente de CdZnS para minimizar la alineación de la interfaz. Por otro lado, se analizó el proceso de cristalización y la estabilidad de las capas MAPbI3. Las capas de MAPbI3 se trataron añadiendo antisolvente a diferentes velocidades. Durante el tratamiento se producen intercambios complejos que influencian muchas propiedades fisicoquímicas. Se investigaron las propiedades ópticas y eléctricas de las películas de MAPbI3. Para mejorar la estabilidad de MAPbI3, se incorporó tetrabutilamonio (TBA), observando una mejora en la formación de la estructura perovskita que crece en la dirección preferente (110). La fase cristalina de MAPbI3 dopada con TBA presenta mejor cristalinidad, gran tamaño de grano, morfología superficial sin poros lo que es adecuado para la fabricación de dispositivos optoelectrónicas con mayor rendimiento. Además, hemos identificado el impacto de TBA en las propiedades foto físicas de MAPbI3. En las muestras de TBA:MAPbI3 aumenta la intensidad de la fotoluminiscencia al reducir la densidad de los estados de trampa y la absorción óptica muestra un cambio significativo hacia longitudes de onda más largas y la banda prohibida óptica varió de 1.8 a 1.52 eV. Finalmente, las muestras dopadas con 5% TBA mejoraron su estabilidad y se encontró que después de 15 días la estabilidad permanecía excelente en una humedad de ~ 60%. Por otra parte, investigamos el efecto de guanidinio (GA) sobre las propiedades estructurales y ópticas de FAPbI3. La relación entre la fase a de perovskita deseable y la fase indeseable y se ha estudiado en función del contenido de GA. Se comprobó que el dopaje con GA es eficaz en el control de la relación de fases a/y y luego en la estabilización de la fase a. Los resultados muestran que añadiendo una cantidad adecuada del 10% GA conduce a una mejora de película de perovskita que se evidencia en la homogeneidad de la fase a estable, granos de mayor tamaño y capas libres de poros. Además, 10% GA:FaPbI3 demostraron una excelente estabilidad después de ser envejecidas durante 15 días en un ambiente con humedad relativa del 60%. / [EN] The thesis work presented is part of the work in the Laboratory of New Materials for Photovoltaic Energy in the main target to use low cost techniques for elaboration of Perovskite and Copper, indium, gallium, and selenium CIGS materials for photovoltaic application. Organic-inorganic lead halides perovskites have currently and exceptionally appeared as new materials for low cost thin film solar cells specially that the efficiency of perovskite based solar cell have jumped from 3.8% to 22.7% in short time.in other hand, CIGS solar cells record 23.35% efficiency and still can be boosted. Here, we report the elaboration and characterization of CIGS as well as methylammonium lead iodide perovskites MAPbI3 and formamidinuim iodide lead iodide perovskites FAPbI3 absorbers for perovskite-based solar cells and Tandem Perovskites/ CIGS. The thin films prepared were characterized by X-ray diffraction (XRD), Raman spectroscopy (RS), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis, atomic force microscopy (AFM), transmission electron microscopy (TEM), Photoluminescence analysis (PL) and UV-Vis spectroscopy. The first stage was devoted for the effect of different parameters on the growth of CIGS by electrodeposition and we investigate the impact of different back contact in structural and optical proprieties. In a second stage, we report the growth of CIGS films by spray pyrolysis, we studied the effect of experimental parameter also the annealing process which is the key factor for improving the performance of solar cells,subsequently we elaborated different films constituted CdZnS/CdS/CIGS/Mo solar cells, the approach is to change the toxic ZnO by using a transparent, conductive CdZnS layer. In other hand, MAPbI3 film was investigated in order to optimize the chemical composition and to study the crystallization process also to get sight about the stability of perovskite materials to meet the requirement of their application as an active layer in perovskite solar cell. For this purpose. the MAPbI3 film surface was treated by adding diethyl ether antisolvent with different rates. during the treatment complex exchanges are appearing at the same time under the influence of quite a lot of physicochemical properties. A whole understanding of this topic is critically important for improving solar cell performance. MAPbI3 doped by the tetrabutylammonium TBA is boosting the formation of perovskite structure, leading to a higher orientation along the (110) and shows better crystallinity, large grain size, pinhole-free, which is suitable for the manufacturing of the optoelectronic devices with higher performance. Also, we have identified the impact of TBA in the photo-physical properties, we have noticed that the TBA improve the photoluminescence emission by reducing the density of trap states and the optical absorption indicates a significant shift to the lower wavelength and optical bandgap varied from 1.8 to 1.52 eV. Finally, the stability was explored for 5% TBA, it found that after 15 days the stability remained excellent in relative humidity of ~60%. These results would be helpful for realizing stable and high performance MAPbI3-based devices. Furthermore, we inspect the effect of monovalent cation substitution of Guanidinium (GA) on the structural and optical properties of FAPbI3 thin films perovskites. The ratio between the desirable a-phase and the undesirable y yellow phase is studied as a function of GA content. GA doping is shown to be efficient in the control of a/y phases ratio and then in the stabilization of the a-FaPbI3 phase. We qualitatively evaluate the impact of 10% of guanidinium on the phase composition and microstructure of films. The results show that an adequate amount of 10% GA:FaPbI3 leads to a homogeneous perovskite film with stable a phase, large grains, and free pinholes. 10% GA: FaPbI3 films demonstrate excellent stability after aging for 15 days in relative humidity of~60%. / [CA] L'objectiu principal d'aquesta tesi és contribuir a l'avanç de noves tècniques d'elaboració de baix cost, fent servir materials d'aliatges del tipus de coure, indi, gal·li i seleni (CIGS) i perovskites, per a aplicacions en energia solar fotovoltaica. El CIGS sembla ser adequat ja que són de baix cost de producció i s'han reportat eficiències de conversió del 23,35%. D'altra banda, les perovskites híbrides d'halurs de plom orgànics-inorgànics han aparegut com a nous materials excepcionals per cel·les solars, especialment perquè l'eficiència de les cel·les solars basades en perovskites ha augmentat del 3.8% al 22.7% en menys d'un lustre. En el present treball, reportem l'elaboració i caracterització de CIGS y de perovskitas de iodur de plom de metilamoni (MAPbI3) i de iodur de plom de formamidini (FaPbI3) per a les cèl·lules solars de CIGS i tàndem Perovskites/CIGS. En les capes de CIGS dipositades per electrodeposició es va investigar l'efecte dels diferents paràmetres sobre el procés d'electrodeposició, així com l'efecte del contacte posterior sobre les propietats estructurals i òptiques del CIGS. Ens trobem que el tipus de contacte posterior té un efecte significatiu en la posterior interpretació de pel·lícules primes CIGS. A més, vam estudiar la tècnica de polvorització de la piròlisi per produir pel·lícules de CIGS. Es va estudiar el procés de recuit, que és el factor clau per millorar el rendiment de les cèl·lules solars. Es van produir diferents pel·lícules fines formades pel nostre dispositiu CdZnS/CdS/CIGS/Mo que utilitzaven una capa conductiva CdZnS transparent per minimitzar l'alineació de la interfície. D'altra banda, es van investigar perovskites MAPbI3, amb la finalitat d'optimitzar la composició química i estudiar el procés de cristal·lització també per a conèixer l'estabilitat dels materials de perovskita. la cristal·lització s'aconsegueix alentint la solubilitat en una solució saturada mitjançant l'addició d'una quantitat diferent de l'antisolvent d'èter dietílic. Durant el tractament apareixen al mateix temps intercanvis complexos sota la influència de moltes propietats fisicoquímiques. Una comprensió completa d'aquest tema és de vital importància per a millorar el rendiment. Amb l'objectiu principal d'augmentar l'estabilitat de MAPbI3, el tetrabutilamoni (TBA) es pot incorporar a MAPbI3, impulsant la formació de l'estructura de perovskita, la qual cosa porta a una major orientació al llarg de (110). MAPbI3 dopades amb TBA presenten una millora de la cristalinitat, major grandària, la qual cosa és adequada per a la fabricació de dispositius optoelectròniques de major rendiment. A més, hem identificat l'impacte de TBA en les propietats foto físiques de MAPbI3. Hem notat que el dopatge amb TBA millora tant l'emissió de la fotoluminiscència en reduir la densitat dels estats de trampes com l'absorció òptica on apareix un canvi significatiu de la banda òptica prohibida cap a longituds d'ona més llargues que significa disminuir l'energia del gap, que va variar de 1.8 a 1.52 eV. Finalment, es va explorar l'estabilitat per les perovsquites dopades amb 5%TBA. Es va trobar que després de 15 dies l'estabilitat romania excel·lent en un humitat de 60%. A més, hem estudiat FAPbI3 com un dels materials de perovskita més atractius. Hem investigat l'efecte de la substitució de guanidini (GA) sobre les propietats estructurals i òptiques de FAPbI3. La relació entre la fase a de perovskita desitjable i la fase indesitjable y es va estudiar en funció del contingut de GA. Es mostra que el dopatge amb GA és eficaç en el control de la relació de fases a /y i després en l'estabilització de la fase a-FaPbI3. Els resultats mostren que una quantitat adequada de 10% GA condueix a una pel·lícula homogènia amb fase a estable, grans grans lliures de porus i forats. Les pel·lícules de 10% GA:FaPbI3 demostraren una excel·lent estabilitat després de l'envelliment durant 15 dies en un ambient humit (humitat relativa de 60%). / Bouich, A. (2020). Study and Characterization of Hybrid Perovskites and Copper-Indium-Gallium Selenide thin films for Tandem Solar Cells [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/160621

Call number: LD2668 .T4 1984 S39 / Master of Science / Biological and Agricultural Engineering

Poster exhibited at GPSC Student Showcase, February 24th, 2016, University of Arizona. / To make photovoltaics (PV) and concentrated solar thermal power (CSP) more practical forms of alternative energy, creative innovations to current solar energy methods must be employed. The PVMirror – a new technology – is our solution to that problem. The PVMirror combines PV and CSP technologies by splitting the spectrum of sunlight using a dichroic mirror film. Light that is not transmitted to the solar cell is to instead be reflected to a focus, by way of a curved mirror. This hybrid of technologies is competitive, as it is both efficient and affordable compared to many other innovations in renewable energy. The PVMirror is designed to be an easy and cost-effective replacement to the reflectors used in existing CSP plants. Ultimately, we hope to demonstrate this PVMirror technology on a large scale and market it. As validated from interviewing with industry professionals, this technology has the potential to impact the world of solar energy because many industrial companies and utility-scale CSP project developers are interested in pairing CSP and PV to increase efficiency. Currently, using an outdoor sun tracker, we are testing an 18 inch by 18 inch prototype with four solar cells.

Thesis presented in partial fulfilment of the requirements for the degree of Master of Engineering in Renewable and Sustainable Energy at the Stellenbosch University. / Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: This project investigated the feasibility of incorporating photovoltaic cells into plastic roof tiles using injection moulding. Such tiles have the potential to provide robust and distributed electricity contained within the building envelope. Current-voltage curves of amorphous silicon modules were measured under illumination using the PVPM 2540C power measuring instrument, both before and after moulding. The efficiency after moulding was reduced by 53% to 88%, with modules that were heated for longer being degraded more. Thus the duration of exposure to high temperatures affected the extent of performance reduction during moulding. This suggested that faster moulding at a lower temperature or faster cooling could solve the problem. Economic feasibility was examined by calculating the levellised cost of electricity provided by the tiles. A large-scale development in the Western Cape was simulated using a typical meteorological year of weather data and using the anisotropic diffuse irradiance model of Perez et al. (1988). Avoided costs due to replaced roofing, avoided costs due to electricity distribution infrastructure, and Clean Development Mechanism credits were accounted for. The cost of energy calculated was R11/kWh in 2010 rands, which did not compete with the price of conventional grid-based electricity at R1.8/kWh. The importance of the cost of balance-of-system components, such as the inverter, and not only of the photovoltaic modules, was highlighted for future cost reductions. Several clear guidelines for manufacturing photovoltaic roof tiles were discovered. The most important of these was that many bypass diodes make the system more robust. / AFRIKAANSE OPSOMMING: Hierdie projek het die haalbaarheid van die integrasie van fotovoltaïse selle in plastiek dakteëls deur spuitvorming ondersoek. Sulke dakteëls het die vermoë om robuuste en verspreide elektrisiteit te lewer, sonder om die gebou se vorm te verander. Stroom-spanning kurwes van struktuurlose silikon eenhede is onder verligting gemeet met die PVPM 2540C kragmeet instrument, voor en na spuitvorming. Die doeltreffendheid na spuitvorming is met 53% tot 88% verminder, met groter vermindering in die eenhede wat langer warm was. Dus het die duur van blootstelling aan hoë temperature die mate van vermindering van doeltreffendheid beïnvloed. Dit het suggereer dat óf vinniger spuitvorming by laer temperature óf vinniger verkoeling die probleem kan oplos. Ekonomiese haalbaarheid is ondersoek deur die koste van die elektrisiteit wat deur die dakteëls gelewer is te bereken. ’n Groot behuisingsontwikkeling in die Wes-Kaap is gesimuleer deur ’n tipiese weerkundige jaar van weerdata en die anisotroop model vir verspreide ligstraling van Perez et al. (1988) te gebruik. Vermyde kostes van vervangde dakteëls, vermyde kostes van elektrisiteit distribusie infrastruktuur en krediete van die Meganisme vir Skoonontwikkeling is in ag geneem. Die elektrisiteitskoste was R11/kWh in 2010 se randwaarde, wat nie mededingend met die R1.8/kWh koste van gewone netwerk elektrisiteit was nie. Die belang van die kostes van die res van die installasieonderdele, soos die wisselrigter, en nie net die fotovoltaïse eenhede nie, is beklemtoon vir kostevermindering in die toekoms. Verskeie duidelike riglyne vir die vervaardiging van fotovoltaïse dakteëls is voorgestel. Die belangrikste van hierdie was dat meer omloopdiodes die installasie meer robuust maak. / Centre for Renewable and Sustainable Energy Studies

Project report presented in partial fulfilment of the requirements for the degree of Master of Engineering at the University of Stellenbosch. / Thesis (MScEng (Mechanical and Mechatronic Engineering))--Stellenbosch University, 2008. / Three SunSlates™ were investigated to predict the performance of a fully installed system. The three slates were mounted on a fixed tilt of 30°, but with different orientations. The tilt is close to latitude of the Stellenbosch site, which is 33.92°. The one faces due east, another due west and last due north. This is to determine the effect that orientation has on the energy from the SunSlates™. Another slate, also facing north, was mounted on an adjustable framework. The framework was used to adjust the tilt angle of the slate, the orientation of the slate was constantly north. This slate was used to determine the effect of tilt on the total daily energy produced by the slate. To determine the performance of the slates daily measurements of temperature, solar insolation and wind was taken. These were used to investigate the effects on the SunSlates™. During the test period, which scheduled from September to November, the results show a difference, smaller than commonly believed, in the daily and annual energy delivered from the differently orientated slates. The slates facing east and west, however, have similar energy outputs, even though the power profiles differ. The north facing slate has the highest annual energy output, as expected. It was found that during the months of summer, November to January, the optimal tilted slate (Slate tilted to have a incidence angle of 0° from solar rays at noon) had a slightly lower energy output, but higher maximum power output per day than the 30 degree tilted slate. This is in contrast to the energy output predictions for the winter months where in the winter the energy can be as much as double that of the 30 degree tilted slate. The thorough testing and expert installation of the SunSlates™ are essential. From the case study it can be seen that some problems during installation, possibly a single faulty slate or shadowing, can cause a complete system to lose 30% of its efficiency. / Centre for Renewable and Sustainable Energy Studies

Thesis (MEng)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: In the present study, research was conducted to determine the feasibility of water energy storage through which the output of heated air by an upward facing solar air heater could be prolonged. Following a systematic approach, a number of experimental test swere initially performed on an upward facing solar air heater in order to obtain a benchmark that could be used to evaluate the influence of water storage during the day-time performance of a solar air heater. As expected, an increase in the air mass flow rate not only led to an increase in the collector efficiency but also to a decrease in the temperature gain across the collector. In addition, a number of day- and night-time experiments were executed on a plastic covered water tank in order to evaluate it's ability to store and discharge thermal energy. Results clearly indicated that the plastic covered water tank was both an ideal collector and storage medium of solar energy. Experimental results also revealed that the plastic covered water tank was an ideal source of thermal energy for a solar air heater during night-time operation. Subsequently, both day- and night-time experiments were performed on an upward facing solar air heater in which plastic covered water tanks were installed. Day-time experimental results revealed that the modified solar air heater still had the same collector efficiency tendency, as observed in the initial solar air heater experiments, but that the water energy storage led to a dramatic decrease in the absorber plate temperature and in the corresponding temperature gain experienced across the collector. In contrast, the night-time operation results clearly indicated that the water energy storage was not only able to prolong the output of heated air by the solar air heater, but was further able to increase the air temperature by between 7.5 and 1.5 °e, depending on the air mass flow rate. It was furthermore shown in the study that available theory is able to accurately predict the performance of an upward facing solar air heater, either with or without water energy storage, as long as the equations are employed within their range of validity / AFRIKAANSE OPSOMMING:In die hierdie studie is daar ondersoek ingestel na die lewensvatbaarhied van son-energiestoring in water ten einde die tydperk van lugverhitting deur 'n son-Iugverwarmer te verleng. 'n Sistematiese prasedure is gevolg waardeur daar aanvanklik 'n aantal eksperimente op 'n son-Iugverwarmer uitgevoer is am sodoende die eienskappe van so 'n lugverhiUingstelsel, sander energie storing, te vekry. Die resultate het getoon dat 'n toename in die massavloei tempo van die lug lei tot 'n toename in die kollektor effektiwiteit van die stelsel, maar terselfdetyd lei tot 'n afname in die temperatuur styging in die kollektor. Met die eienskappe van die lugverwarmingstelsel bekend, is daar voorts 'n aantal dag- en nag-eksperimente uitgevoer op 'n plastiek bedekte watertenk am die storing en vryselling van termiese energie deur die watertenk te kwantifiseer. Die resultate het daarap gedui dat die plastiek bedekte watertenk nie net beide 'n goeie kollektor en stoor medium vir son-energie is nie, maar oak dat dit 'n ideale bran van termiese energie vir 'n lugverwarmingstelsel tydens die nag is. Met inagname van die vorige resultate, is daar dan 'n aantal plastiek bedekte watertenks in die apparaat geinstalleer, en 'n aantal dag- en nag-eksperimente is uitgevoer. Die dageksperimente het getoon dat die die nuwe lugverwarmer met water energie storing dieselfde eienskappe toon ten opsigte van die kollektor effektiwiteit as die oorspronkilke son-Iugverwarmer. Tog, as gevolg van die laer absoberende plaat temperature was die temperatuur toename in die kollektor heelwat laer. In kontras hiermee dui die nagresultate aan dat die plastiek bedekte watertenks nie net die vermoe het am die tydperk van lugverwarming te verleng nie, maar oak dat die lug tempertuur, afhangende van die massavloei tempo van die lug, met tussen 1.5 en 7.5 °C verhoog kan word. Die studie het laastens oak getoon dat dit moontlik is am met behulp van beskikbare teorie die temperatuur toename in die kollektor van 'n son-Iugverwarmer met of sander water energie storing, akkuraat te voorspel, mits die vergelykings binne hul geldige gebiede gebruik word.

No description available.

In this work, two distinct types of Diffractive Optical Elements (DOEs) are designed to laterally distribute the solar spectrum across multiple photovoltaic (PV) cells. Each PV cell receives a spectral band near its bandgap energy to maximize overall solar-to-electric conversion efficiency of the system. The first DOE is an off-axis volume holographic lens. Design parameters include lateral grating period and slant angle, index modulation, film thickness, and control of swelling and index modulation attenuation in the film development process. Diffraction efficiency across the holographic lens is simulated using Rigorous Coupled Wave Analysis (RCWA). A full system model is created, and non-sequential raytracing is performed. Performance is evaluated under AM 1.5 conditions and annual insolation in Tucson, AZ, and Seattle, WA. A proof-of-concept off-axis holographic lens is fabricated and its performance is measured to confirm the optical properties of this system. The second DOE is an algorithmically-designed freeform surface relief structure. The Gerchberg-Saxton design algorithm is expanded to consider multiple wavelengths, resulting in a Broadband Gerchberg-Saxton (BGS) algorithm. All design variables are evaluated in a parametric study of the algorithm. Several DOE designs are proposed for spectrum splitting, and two of these designs are fabricated and measured. Additional considerations, such as finite sampling of the discrete Fourier transform, fabrication error, and solar divergence are addressed. The dissertation will conclude with a summary of spectrum splitting performance of all proposed DOEs, as well as a comparison to ideal spectrum splitting performance and discussion of areas for improvement and future work.