Дисертації: "Solar energy Industrial applications"

1

Hilpert, Benjamin. "Application of Industrial Ecology Concepts in Solar Energy Heat Systems in Mexico." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-256554.

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The increased understanding of the growing environmental harm linked to today's throughput industry reaches politics and the general public more and more. This study objects to increase resource use of materials and reduce the associated environmental impact. It is being conducted in the solar energy sector of the middle-income country, Mexico, on the basis of an underlying sample company. The chosen concept to achieve this goal is with Industrial Ecology, which combines several other approaches like an umbrella, far-reaching and represents an alternative to counteract the problems today´s and future generations are facing. Application-based approaches like Circular Economy, Waste Management, Loop Closing, and Industrial Symbiosis are taken into consideration to reduce the use of virgin materials and lessen the environmental impact of industrial activities in the middle-income country Mexico. Existing definitions and provided possibilities of Industrial Ecology and its included approaches were studied to set the base of the investigations together with a literature review of the manufacturing and the importance of small and medium-sized companies in Mexico. Primary data collection regarding company-specific information and their procedures were carried out as follows; after the preparation of the plans and schemes for the different areas of the company's value chain, the internal processes, the material flow, as well as the transportation were examined in more detail. Together with interviews of the company's managers, plans were verified and potentials for improvement towards sustainable development were identified. Using the previously acquired information of the considered approaches of IE, development opportunities in all areas of the value chain as well as the external collaboration possibilities could now be developed. The results show that the emissions of the example company mainly arise in the production of hot water storage tanks and solar collector frames, The implementation of the measures could also lead to more efficient use of materials, improved use of infrastructure, and reveals great potential of improvements in particular in industrial symbiosis. There are various opportunities to achieve environmental goals through new collaboration and networking. Improvements in the use of available materials, the recycling policy, as well as the transport of products and residues to and from the installation site could be achieved for the sample company. By demonstrating external cooperation opportunities such as transport or service sharing and their benefits to the participating companies, it has been shown that it would be possible to create an innovative and sustainable competitive advantage and to positively influence the financing pattern even for middle-income countries. The outcomes of the study show that with IE and the associated application-based approaches it is also practically possible to achieve further development of companies towards sustainable production and development. The implementation of the concepts of IE known from literature is generally more complicated in practice than it is described in theory. Also, because literature just give a rough picture of how such systems should look like but they do not provide any specific details. Nevertheless, it has been shown that it is also feasible in the case of middle-income countries to establish and organize themselves sustainably as a company for the future. In addition to the internal optimization measures of the business, also the exploration of the external possibilities of Industrial Symbiosis and collaboration are recommended.
Det största problemet på jorden idag är att naturresurserna är ändliga och att det bara finns en atmosfär att bo i. Vi måste hantera produktionen och utsläppen varsamt för att få en hållbar värld. Industriell ekologi (IE) är ett holistiskt koncept för att designa om industriella aktiviteter. Det är baserat på antagandet att miljöpåverkan från mänskliga aktiviteter måste minskas. Konceptet beskriver en möjlig lösning för dagens industriella och sociala dödläge genom att använda naturliga ekosystem som förebild. Den växande förståelsen för den stegrande miljöpåverkan som är associerad med moderna materialflöden från industrin har nått politiken och den allmänna massan med ökad hastighet. Dessutom har Cirkulär Ekonomi uppmärksammats mer under senaste tiden för att minska industriella miljöproblem. Även om litteraturen är i ett tidigt stadium verkar IE erbjuda värdefulla insikter som förenar användbara miljöaspekter. Det finns begränsat med studier om IE i industrin, speciellt när det kommer till ett medelinkomstland som Mexiko. Detta arbete fokuserar på tillämpningen av IE-koncept med tillhörande aspekter för att minimera miljöpåverkan från industriella aktiviteter och minska användningen av jungfruliga material. Det resulterar i hållbar utveckling för ett exempelföretag som undersöks, skapande av samarbeten för industriell symbios (IS) och ett hänsynstagande för hållbart företagande (BM). The valda aspekterna är först introducerade för att visa dess generella potential. Sedan för att skapa en grund, introduceras signifikansen av små och medelstora företag (‘pequeña y mediana empresa’ - PyMEs) i Mexiko, fördelar i konkurrenskraft genom IE och miljöpåverkan från sådana fabriker. Dessa steg är utförda i en litteraturstudie. I nästa del inhämtas företagets specifika data för deras processer och miljö genom semi-strukturerade intervjuer och rundturer i driften. Genom att använda information av utvecklingspotential i alla steg av värdekedjan kan nu externa samarbetsmöjligheter. Dessutom är genomförbarheten för åtgärder hos liknande företag granskade. Till sist föreslår studien framtida lösningar för exempelföretaget för att skapa fler hållbara industriella aktiviteter och för att stödja ytterligare IE-användning inom industrin.

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2

Turk, Mustafa. "Substituting Natural Gas with Solar Energy in Industrial Heating Applications : A Multiple Case Study within Italy and Spain." Thesis, Uppsala universitet, Industriell teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-447350.

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With the increasing awareness of global warming and the need for limiting greenhouse gas emissions, several sectors are witnessing comprehensive transformations towards sustainable generation and consumption. The European Union can be considered the home for most of these transformations given the union’s efforts to enable decarbonization through regulatory frameworks and initiatives. However, one overlooked source of carbon emissions is the industrial heating sector which is heavily dependent on fossil fuel. Emerging technologies such as solar thermal could provide a solution for limiting the greenhouse gases emitted by this sector. This study examines the factors influencing the diffusion of solar thermal technology and its potential for substituting natural gas in the industrial heating sector. Specifically, the study examines the thermal energy supply side as being a potential facilitator for the diffusion of solar thermal technology. Certain elements from Everett Rogers’ (1995) work on the diffusion of innovations are applied to solar thermal technology along with the concept of lead users by Hippel (1986). The study follows a qualitative approach in collecting and analyzing data through interviews and document analysis. Experts from the energy sector were interviewed along with examining public documents of two major utility companies. The findings suggest that utility companies examined, despite their evident decarbonization efforts, do not represent a suitable vehicle for the diffusion of solar thermal technology. Instead, a business model based on energy efficiency could be the possible breakthrough for this technology. Finally, the study concludes with suggestions for possible actions to expedite the diffusion of solar thermal in the industrial sector.

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3

Hayden, Steven C. "Novel applications of nanotechnology in medicine and green energy." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/51927.

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The development of techniques for colloidal nanoparticle synthesis has allowed scientists to fabricate materials that can manipulate light on a scale that is small even compared to the wavelength of the light itself. This ability has led to the development of myriad and diverse applications of nanostructures in wide-ranging fields. This thesis focuses on the investigation and exploitation of nanoscale material properties in the fields of medicine and energy. The unique optical properties of nanoparticles arise from their size and their high surface area to volume ratios compared to bulk materials. As a result of this relationship, the surface characteristics of nanoparticles generally dominate their properties, whereas in bulk materials the surface atoms have very little bearing on the properties of the composite. Chapter 1 gives an introduction to nanoparticles and their optical properties, including a discussion of the plasmon resonance and the properties imbued upon nanoparticles possesing such a resonance as well as the applicability of these properties that will be explored in the subsequent chapters. Chapter 2 presents a study of the interaction of cationic, hydrophobic gold nanoparticles as probes to elucidate specific regions of interest on cell surfaces. The high imaging contrast of gold nanoparticles in electron microscopy allows for visual, macroscopic observation of the aggregation patterns formed by these nanoparticles on cell surfaces. Plasmon resonant coupling between proximal nanoparticles is exploited in order to monitor nanoprobe binding and localization over time with the use of extinction spectroscopy. The role of surface proteins in the nanoparticle-cell surface interaction is elucidated, generating composite data with relevance in pharmaceutical development and pharmacokinetics. Additionally, bacteria strain-dependent toxicity is observed and subsequently investigated for smaller gold nanoparticle probes, demonstrating a potential use for nanoparticles as strain-specific antibiotics. The development of affordable, effective antibiotic technology is one of the major scientific challenges of our time; infections from pathogen-infested drinking water alone account for millions of deaths each year worldwide. In Chapter 3, we investigate the use of titanium dioxide as an inexpensive method to harness solar energy to split water into reactive species and thereby decontamitate solutions of E. coli. Though titanium dioxide is an excellent catalyst for water splitting, it requires UV irradiation, which is fairly lacking in the solar emission spectrum. Further, recuperation of titanium dioxide nanoparticles from solution is non-trivial, and its immobilization into a film greatly limits its surface area and charge carrier efficiency, thereby limiting its activity. We treat both the poor visible light absorption capability as well as the surface area limitation in this study. CdS semiconductor nanocrystals are used to extend the absorption edge of TiO₂ further into the visible light region of the spectrum by providing for lower-energy photon absorption and charge injection into titanium dioxide. TiO₂ is also electrochemically anodized to generate TiO₂ nanotube arrays, which have greatly increased surface area as well as more efficient charge transfer properties compared to thin films of TiO₂ nanoparticles. The utility of nanoparticles in increasing the light absorption of other systems continues as a theme in the work presented in the next two chapters. Chapter 4 ex- amines the plasmonic enhancement of the solar energy conversion in a biomimetic system. In this endeavor, we enhance the photocurrent generated by a light-transducing, proton-pumping protein, bacteriorhodopsin, in a 3-dimensional wet electrochemical cell. First, we increase the overall charge carrier separation with the use of a proton- selective membrane in order to minimize ionic depolarization in the cell. We then use plasmonic nanoparticles to exploit an irregularity in the bacteriorhodopsin photocycle known as the blue light effect. This effect shortens the timescale of the photocyle by more than 99% via blue photon absorption, but it has a very low natural occurrence. Plasmonic nanoparticles tuned to the blue wavelength region increase the flux of blue photons on a local level and thereby increase the overall photocurrent generation. We first examine the importance of nanoparticle field strength to photocurrent enhancement using silver nanospheres with different capping shell thicknesses. We then consider the trade-off between (1) using a nanoparticle with a plasmon resonance tuned perfectly to the blue wavelength region and (2) using a nanoparticle with a stronger field intensity but weaker energetic presence in the blue. By minimizing ionic depolarization, minimizing shielding of the plasmon electromagnetic field, and maximizing the field strength while maintaining the plasmon frequency at the proper wavelength, we demonstrate an enhancement of 5,000-fold in the photocurrent production by bacteriorhodopsin. Chapter 5 explores a variation on the theme of Chapter 4 with an application in cancer therapeutics. Here, a photodynamic cancer drug, protoporphyrin IX (PpIX), is incorporated into complexes with silver nanospheres, gold nanospheres, and gold nanorods. Each of these nanoparticles displays a plasmon resonance in a different region of the spectrum, with consequent different overlap with the absorption or emission of the drug. Photodynamic therapeutic potential is measured in situ and in vivo, and the drug activity is shown to be strongest when drug absorption overlaps with plasmon resonance. Absorption by electronic excitations in the particle crystal lattice is shown to function as a competitive light filter and decrease drug activity. Additionally, the method of attachment of the drug to the nanoparticle is examined. Maximum enhancement of drug activity is shown to require the drug to remain bound close to the nanoparticle surface, where the electromagnetic field strength is highest. This plasmonic enhancement effect on drug activity is shown to outstrip the increase in drug activity seen when using the nanoparticle solely as a delivery platform. In Chapter 6, some synthetic techniques are presented for various nanomaterials. Included are syntheses for gold, silver, and semiconductor nanoparticles of a variety of shapes and sizes as well as for TiO₂ nanotube arrays. The relationship of the ratio of capping agent to metal salt is explored for gold nanospheres, and a method for facile tuning of the longitudinal plasmon resonance displayed by gold nanorods is presented. Synthetic techniques are also presented for the nanoparticles whose applications are explored in the preceding chapters.

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4

Osório, Tiago Vaz Pato. "Linear solar concentrators: new testing tools and facilities, application to novel CPC-type collectors for industrial process heat." Doctoral thesis, Universidade de Évora, 2019. http://hdl.handle.net/10174/25797.

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Solar energy can be converted into heat in small-scale or large-scale systems that work at low, medium or high temperatures. Presently, a major growth is being observed in large-scale systems for district heating and industrial process heat. Linear concentrators have a well-recognized role in this context and new configurations and solutions are in demand. These must be within the scope of product certification schemes, which rely on international testing standards. This thesis discusses the limitations of the current standards for linear concentrators and presents the design and construction of the Solar Concentrators Testing Platform at the University of Évora. The use of ray-tracing simulation tools to complement and extend the experimental results is also explored. This thesis goes on to present the development of new collector solutions for medium temperature applications (100–250 °C). The principles of non-imaging optics were used in the design of low-concentration (1 to 5) linear CPC-type solar reflectors with evacuated receivers that can generate high-performance, flexibly mounted and affordable solutions. Two collector concepts were investigated. The first is a stationary CPC-type collector with acceptance of 90°. The manufacturing process was considered by analysing different virtual absorber geometries. A prototype was built and tested. The second concept is a quasi-stationary CPC-type collector that only requires a few changes in its position along the year and does not need a sun-tracking system. As the search for the optimal collector design for a specific installation is complex, a thermo-economic optimization method was developed. Two prototypes were built and tested in a collaboration with the company MCG mind for metal. This collector, which is now at its final development stage, will be installed at an industrial facility - KEMET Electronics - in Évora, Portugal; Sumário: Concentradores solares lineares: novas ferramentas e infraestruturas de ensaio, aplicação a novos colectores do tipo CPC para calor de processo industrial A energia solar pode ser convertida em calor em sistemas de pequena ou grande escala, que funcionam a baixas, médias ou altas temperaturas. Actualmente, regista-se um grande crescimento na instalação de sistemas de grande escala para redes de calor e calor de processo industrial. Os concentradores lineares têm um papel reconhecido neste contexto e novas configurações e soluções estão em desenvolvimento. Estas devem integrar-se do âmbito dos esquemas de certificação, que se baseiam em normas de ensaio internacionais. Esta tese discute as limitações das normas actuais no ensaio de concentradores lineares e apresenta o projecto e a construção da Plataforma de Ensaio de Concentradores Solares na Universidade de Évora. O uso de ferramentas de simulação, através de técnicas de traçado de raios, é explorado com o fim de complementar e ampliar os resultados experimentais. A tese prossegue apresentando o desenvolvimento de novas soluções de colectores para aplicações a média temperatura (100–250 °C). Os princípios da óptica não reprodutora de imagem foram usados no desenho de refletores solares lineares do tipo CPC, de baixa concentração (1 a 5), com receptores evacuados que podem originar soluções com bom desempenho, montagem flexível e custos acessíveis. Dois conceitos de coletores foram investigados. O primeiro é um coletor estacionário do tipo CPC com aceitação de 90 graus. O processo de fabricação foi considerado através da análise de diferentes geometrias dos absorsores virtuais. Um protótipo foi construído e ensaiado. O segundo conceito é um coletor quasi-estacionário do tipo CPC, que requer apenas algumas mudanças na sua posição ao longo do ano, dispensando sistemas de seguimento solar. Devido à complexidade na definição do design ideal do coletor para uma instalação específica, foi desenvolvido um método de otimização termoeconómica. Foram construidos e ensaiados dois protótipos em colaboração com a empresa MCG mind for metal. Este colector, que se encontra actualmente no seu estágio final de desenvolvimento, será instalado num edifício industrial - a KEMET Electronics - em Évora, Portugal.

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5

Hallberg, Maria, and Elin Hallme. "Introducing a central receiver system for industrial high-temperature process heat applications : A techno-economic case study of a large-scale CST plant system in a South African manganese sinter plant." Thesis, KTH, Kraft- och värmeteknologi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-249067.

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The objective of this thesis was to investigate the potential for introducing a concentrating solar thermal (CST) central receiver plant system based on flexible heliostats - HelioPods - to provide high-temperature process heat in industrial applications. A CST plant system was designed in MATLAB, optically simulated for three design days in the ray-tracing software Tonatiuh and further analyzed in MATLAB by interpolating the results for each hour of the year. A case study was made on introducing a CST plant system based on HelioPods in a South African manganese sinter plant. The study included an investigation of the profitability of up- and downsizing the heliostat field annually with fluctuating heat demand. A circular heliostat field was modelled for the chosen location. The final field had a radius of 53 meters with the receiver located 60% from the field centre. The storage size was 16 demand hours and 17 plants were required. The results showed that 88% of the annual heat demand could be covered by solar heat in the design year. The marketing approach used for the following years was that the heat demand covered by solar heat should never be below the share at the first year, despite the predicted fluctuations in demand. Thus, a minimum solar share of 88% was used as a strategy for annual up- and downsizing of the fields throughout the investigated period of 25 years. That resulted in a field radius differing between 52 and 55 meters. The payback period of the final system was 4.35 years, the NPV was 54.33 MUSD over a period of 25 years and the LCOH was 35.39 USD/MWht. However, it was found that the profitability of the system was sensitive to the different scenarios for predicted future diesel prices, this since the pricing of the solar heat was set to 90% of the diesel price. The results in this thesis show that a CST plant system based on HelioPods is a suitable solution to supply high-temperature process heat to industrial applications. It also shows that the HelioPods can unlock potential for flexibility with changing production patterns in the industry of implementation. The results from the study can be used also for other industries with similar temperature range and heat demand. Thus, it could be argued that the implementation of a HelioPod based CST plant system also can be suitable for other industries located in high-DNI areas with dependency on conventional fuels and steady production throughout the whole day.
Syftet med denna uppsats var att undersöka potentialen för implementering av koncentrerad termisk solvärme (CST) från ett soltorn med ett heliostatfält baserat på flexibla heliostater - HelioPods – för att generera högtempererad processvärme för industriell tillämpning. Ett CST-system designades i MATLAB, simulerades för tre designdagar i det optiska ray-tracingprogrammet Tonatiuh och analyserades sedan åter i MATLAB genom att interpolera de genererade resultaten för årets alla timmar. En fallstudie av ett CST-system baserat på HelioPods i ett sydafrikanskt sinterverk för mangan genomfördes därefter. Studien innehöll en undersökning av lönsamheten av årlig ökning och minskning av heliostatfältet vid fluktuerande värmebehov. Ett cirkulärt heliostatfält modellerades för den valda platsen. Det slutgiltiga fältet hade en radie om 53 meter med mottagaren placerad 60% från fältets mittpunkt. Storleken på lagringsfaciliteten var 16 timmar av full tillförsel och antalet verk uppgick till 17. Resultaten visade att 88% av det årliga värmebehovet kunde förses med solvärme under designåret. Marknadsstrategin för de resterande åren var att den procentuella andelen solvärme aldrig skulle vara lägre än under designåret, oberoende av fluktuationer i värmebehovet på grund av ändrad produktion. Således sattes 88% solvärme som ett minimikrav och utgjorde strategin för den årliga ökningen och minskningen av fältet för den undersökta perioden av 25 år. Det resulterade i en fältradie mellan 52 och 55 meter. Återbetalningstiden för det slutgiltiga fältet var 4.35 år, nuvärdesberäkningen av det framtida kassaflödet var 54.22 miljoner USD över en 25-årsperiod och produktionskostnaden för värme (LCOH) var 35.39 USD/MWht. Dock var systemets lönsamhet känslig för de olika prognoser av framtida dieselpriser som undersöktes, detta eftersom priset för solvärme sattes till 90% av dieselpriset. Resultaten i denna uppsats visar att ett CST-system baserat på HelioPods är en lämplig lösning för att generera högtempererad processvärme för industriell tillämpning. De visar även att HelioPods kan öka potentialen för flexibilitet vid förändringar i produktionsmönstret i vederbörande industri. Resultaten kan även användas i andra industrier med likartade temperaturer och värmebehov. Hävdas kan således att implementation av ett CST-system kan vara lämpligt även för andra industrier belägna i områden med högt DNI som är beroende på konventionella energikällor och har jämn produktion dygnet runt.

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6

Videira, Jose Joao Henriques. "Novel applications of luminescence for solar energy." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/53373.

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Luminescent solar concentrators (LSCs) provide indirect light concentration by absorbing both direct and indirect incident light, and have applications in building-integrated photovoltaics (BIPV). Fibre LSCs were found to have a linear relationship between photon concentration and fibre lengths in scales suitable for LSC modules. Using raytrace modelling, cylindrical LSC arrays were found to exhibit light trapping properties at certain angles of incidence, which can pave the way for more efficient BIPV applications. Novel optics for a double-illuminated water splitting reactor were introduced, for the objective of solar hydrogen for energy storage and sustainable transport fuels. A reflective cone embedded in a waveguide reflects incident concentrated light into the waveguide. Raytrace modelling and practical high concentration measurements demonstrate the viability of the optical system as well as necessity for a perfectly smooth reflective cone. It was also shown that replaced the reflective cone with a quantum well solar cell (QWSC) in order to harness the photoluminescence (PL) is not a viable concept with current QWSC structures. Another form of sustainable transport fuels is to use biofuels produced by algae. Algae have evolved to absorb excess amounts of energy, even when it is detrimental to their own growth and survival. This causes inefficiencies when growing algae in raceway ponds. The luminescent solar diffuser (LSD) is an optical funnel, optimisable by use of a genetic algorithm, that can be retrofitted into an algae raceway pond in order to better distribute incident light into the pond depths. This was calculated to increase algae growth rates in the pond, thereby increasing the yield of an algae farm.

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7

Shang, Xiangjun. "Study of quantum dots on solar energy applications." Doctoral thesis, KTH, Teoretisk kemi och biologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-94021.

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This thesis studies p-i-n GaAs solar cells with self-assembled InAs quantum dots (QDs) inserted. The values of this work lie in three aspects. First, by comparing the cell performance with QDs in the i-region and the n-region, the photocurrent (PC) production from QDs by thermal activation and/or intermediate band (IB) absorption is proved to be much lower in efficiency than tunneling. Second, the efficiency of PC production from QDs, characterized by PC spectrum, is helpful to design QD-based photodetectors. Third, closely spaced InAs QD layers allow a strong inter-layer tunneling, leading to an effective PC production from QD deep states, potential for solar cell application. Fourth, from the temperature-dependent PC spectra the minority photohole thermal escape is found to be dominant on PC production from QDs in the n-region. The thermal activation energy reflects the potential variations formed by electron filling in QDs. Apart from InAs QDs, this thesis also explores the blinking correlation between two colloidal CdSe QDs. For QD distance of 1 µm or less, there is a bunched correlation at delay τ = 0, meaning that the two QDs blink synchronously. Such correlation disappears gradually as QD distance increases. The correlation is possibly caused by the stimulated emission between the two nearby QDs.
QC 20120507

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Brus, Linda. "Nonlinear Identification and Control with Solar Energy Applications." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8594.

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9

Al-Motawakel, M. K. "Solar energy applications in the Yemen Arab Republic." Thesis, Cranfield University, 1986. http://dspace.lib.cranfield.ac.uk/handle/1826/5710.

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It is indeed seldom that a specialised subject can be considered independently. Usually it is allied to and embodied in a systematic sequence of principles, and its field is generally an integral part of a reflection of some broader conception. This is especially true of this thesis, which is concerned with the climatic environmental influences on regional architecture. In the process of evolving the passive solar aspects, theoretical considerations yielded some interesting details and solutions. Examples studied showed a great variety of design principles. Thus as the material grew it suggested an entity -a theme itself. Cont/d.

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Thompson, Nicholas John. "Singlet exciton fission : applications to solar energy harvesting." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/89959.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2014.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 141-147).
Singlet exciton fission transforms a single molecular excited state into two excited states of half the energy. When used in solar cells it can double the photocurrent from high energy photons increasing the maximum theoretical power efficiency to greater than 40%. The steady state singlet fission rate can be perturbed under an external magnetic field. I utilize this effect to monitor the yield of singlet fission within operating solar cells. Singlet fission approaches unity efficiency in the organic semiconductor pentacene for layers more than 5 nm thick. Using organic solar cells as a model system for extracting photocurrent from singlet fission, I exceed the convention limit of 1 electron per photon, realizing 1.26 electrons per incident photon. One device architecture proposed for high power efficiency singlet fission solar cells coats a conventional inorganic semiconducting solar with a singlet fission molecule. This design requires energy transfer from the non-emissive triplet exciton to the semiconducting material, a process which has not been demonstrated. I prove that colloidal nanocrystals accept triplet excitons from the singlet fission molecule tetracene. This enables future devices where the combine singlet fission material and nanocrystal system energy transfer triplet excitons produced by singlet fission to a silicon solar cell.
by Nicholas J. Thompson.
Ph. D.

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Ek, Ludvig, and Tim Ottosson. "Optimization of energy storage use for solar applications." Thesis, Linköpings universitet, Elektroniska Kretsar och System, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-149305.

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Energy storage systems is very useful to use in solar panel systems to save money, but also tobe more environment-friendly. The project was given by the solar energy companyPerpetuum Automobile (PPAM) and the project is for their customer, the condominiumcompound Ekoxen. The task is to make a energy regulation for Ekoxen's energy storage sothey can save more money. The energy storage primary task is to shave the top-peaks of theconsumption for Ekoxen. Which means that the battery will supply the household instead forthe three-phase grid. This will make the electric bill for Ekoxen cheaper. Thesimulation/analysis of the energy regulation is done in a spreadsheet tool, where one partworks as a Time-of-Use program and the other work as a modbus feature. Time-of-Use is aweb-based program for PV systems with battery storage, where time-periods can be set toaffect the battery behavior. The modbus feature simulates a system where an algorithm can beimplemented. The results will show that the time-periods for charging the battery with theTime-of-Use program needs to be changed two times per year. One time for the summermonths and a second time for the rest of the months. The results will also show that themodbus feature is better on peak shaving than the time-of-use program.

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Onigbajumo, Adetunji. "Integration of concentrated solar thermal energy for industrial hydrogen production." Thesis, Queensland University of Technology, 2022. https://eprints.qut.edu.au/235889/1/Adetunji%2BOnigbajumo_Thesis%281%29.pdf.

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The research demonstrated a balanced process, energy, and techno-economic argument for the utilisation of concentrated solar thermal energy, essentially, for hydrogen production and other industrial process systems. The representative case studies undertaken in the research addressed process and solar thermal energy modelling, energy integration, process optimisation, exergy assessment, and techno-economic evaluation as it relates to renewable hydrogen and hydrogen-based fuel production. The research established that economic assessment studies, process-energy configuration, choice of renewable energy, and mixed energy options are key to the shift from fossil fuel to green energy and industrial production to significantly reduce the impact of climate change.

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Nilsson, Josefine. "Optical durability of reflector materials for solar energy applications." Thesis, Umeå universitet, Institutionen för fysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-144908.

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In line with The Paris Agreement, the world is now changing towards more sustainable options for all sorts of energy development. The solar energy sector is growing rapidly as a result of this. One area that holds great potential in changing many of the worlds heating processes, is concentrating solar power (CSP). The basic principle of CSP is to reflect incoming sunlight and concen- trate it to heat a fluid. To do so, it is crucial to find a reflector material that shows both good optical performance initially as well as over time to produce heat in the most efficient way possible and compete with the fossil fueled options. In this investigation, four different, commercially available reflecting materi- als, for concentrating solar power, have been tested under accelerated aging conditions to simulate the wear of outside conditions for many years. Impacts from humidity, temperature fluctuations, UV radiation and acid rain have been included in the study. From the results, it will be argued that a silver based polymer film is the best option, out of the four tested, in terms of the combination of durability and high reflectance properties. However, conclusions about how to properly mea- sure the reflectance of a solar reflector is also presented and advices on how to get reliable results in a similar investigation in the future is presented.

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Hasnain, Syed Mahmood. "Latent heat thermal energy storage for solar heating applications." Thesis, University of Leeds, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252924.

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Maiolo, James Reynold Gray Harry B. Lewis Nathan Saul. "Photoelectrochemistry of microstuctured silicon materials for solar energy applications /." Diss., Pasadena, Calif. : California Institute of Technology, 2009. http://resolver.caltech.edu/CaltechETD:etd-05142009-130434.

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Chen, Zhi Yuan. "Efficient power management design for energy harvesting biomedical applications." Thesis, University of Macau, 2018. http://umaclib3.umac.mo/record=b3952096.

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Absalyamova, Viktoriya. "Energy Analysis within Industrial Hydraulics and Correspondent Solar PV System Design." Thesis, Högskolan Dalarna, Maskinteknik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:du-5099.

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Energy efficiency and renewable energy use are two main priorities leading to industrial sustainability nowadays according to European Steel Technology Platform (ESTP). Modernization efforts can be done by industries to improve energy consumptions of the production lines. These days, steel making industrial applications are energy and emission intensive. It was estimated that over the past years, energy consumption and corresponding CO2 generation has increased steadily reaching approximately 338.15 parts per million in august 2010 [1]. These kinds of facts and statistics have introduced a lot of room for improvement in energy efficiency for industrial applications through modernization and use of renewable energy sources such as solar Photovoltaic Systems (PV).The purpose of this thesis work is to make a preliminary design and simulation of the solar photovoltaic system which would attempt to cover the energy demand of the initial part of the pickling line hydraulic system at the SSAB steel plant. For this purpose, the energy consumptions of this hydraulic system would be studied and evaluated and a general analysis of the hydraulic and control components performance would be done which would yield a proper set of guidelines contributing towards future energy savings. The results of the energy efficiency analysis showed that the initial part of the pickling line hydraulic system worked with a low efficiency of 3.3%. Results of general analysis showed that hydraulic accumulators of 650 liter size should be used by the initial part pickling line system in combination with a one pump delivery of 100 l/min. Based on this, one PV system can deliver energy to an AC motor-pump set covering 17.6% of total energy and another PV system can supply a DC hydraulic pump substituting 26.7% of the demand. The first system used 290 m2 area of the roof and was sized as 40 kWp, the second used 109 m2 and was sized as 15.2 kWp. It was concluded that the reason for the low efficiency was the oversized design of the system. Incremental modernization efforts could help to improve the hydraulic system energy efficiency and make the design of the solar photovoltaic system realistically possible. Two types of PV systems where analyzed in the thesis work. A method was found calculating the load simulation sequence based on the energy efficiency studies to help in the PV system simulations. Hydraulic accumulators integrated into the pickling line worked as energy storage when being charged by the PV system as well.

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Apergi, Maria Evgenia. "The drivers of energy access : evidence from solar energy applications in Guinea-Bissau." Thesis, London School of Economics and Political Science (University of London), 2018. http://etheses.lse.ac.uk/3700/.

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This thesis aims to explore how some of the findings from behavioural economics and the social capital literature can apply in the case of electricity access in developing countries with a focus on solar off-grid electrification. And specifically on solar home systems and solar hybrid mini-grid electrification in rural Guinea-Bissau. Specifically, I am drawing from studies looking at the role of discounting anomalies on technology adoption and recurring payments, the role of trust on technology adoption and the role of computational limitations and the use of simplification strategies on the accuracy of frequency and expenditure reporting in surveys. This exercise aims to inform electrification policy in developing countries, demonstrate instances where insights from behavioural economics and social capital can enrich our understanding of the underlying barriers and drivers of electrification access, but also demonstrate how some selected case studies can help to strengthen empirical findings from other contexts. Chapter 1 provides an introduction on the issues surrounding electrification access in developing countries and introduces the research motivation and the research objectives of this thesis. This chapter also discusses the relevant gaps in the literature, how this thesis attempts to address them and the contribution to knowledge. Finally, the research location is introduced. Chapter 2 presents the results of a stated preference study that uses a choice experiment to estimate willingness to pay for a solar home system, and the trade-off between different repayment schemes and maintenance responsibilities, in the region of Bafatá in Guinea-Bissau. Results suggest that preferences are driven both by income constraints as well as self-control problems, excessive discounting and self-reported trust for a number of actors. Chapter 3 explores the main determinants in the decision to connect to a solar hybrid mini-grid, in the semi-urban community of Bambadinca in Guinea-Bissau, with a focus on social capital as expressed in trust. Connections are driven largely by the socio-economic background of the households and prior energy use patterns. However, there is evidence that social capital as expressed in self-reported trust for one’s neighbours, also has a positive effect on connections through facilitating the informal expansion of the grid, whereby households use their neighbours’ infrastructure to connect to the service. Chapter 4 explores how the technology of prepaid meters can help researchers acquire more insight regarding the accuracy of survey responses and the response strategies used. More specifically, this chapter tests the accuracy of reported energy expenditure in surveys, when using differently defined recall periods, namely a ‘usual’ week versus a ‘specific’ (i.e. last) week. We compare real expenditure data for prepaid meters for electricity, from a solar hybrid mini-grid operating in the semi-urban community of Bambadinca in Guinea-Bissau, with answers from a survey where respondents are asked to state their expenditures, randomly, in different recall periods. Overall, our results show that respondents tend to over-report the level and frequency of their energy expenditures, but reporting is more accurate when the ‘specific’ period rather than when the ‘usual’ period is used. Chapter 5 investigates the role of self-control problems on prepayment patterns for electricity provided by a solar hybrid mini-grid installed in the semi-urban community of Bambadinca in Guinea-Bissau. Prepayment patterns are found to be mostly driven by income constraints and equipment in use however there is evidence that individuals with self-control problems as well as individuals being charged with an additional time-varying tariff (a higher tariff between 7pm to 12am) resort to smaller refill levels possibly as a strategy to consume less electricity at home. Chapter 6 provides concluding remarks.

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Gohary, Mohamed Morsy Abdel Meguid Salama el. "Diesel engines and solar energy for electric and cooling applications." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=973168242.

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Freeman, James. "Solar-thermal combined energy systems for distributed small-scale applications." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/54776.

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Solar power has the potential to provide a significant amount of the global energy requirement for power, heating, cooling and fresh water production. Solar thermal power systems based on steam Rankine cycles tend to be feasible for large-scale centralised power plants, with concentrating collectors generating temperatures of 400 °C or higher. This limits operation to locations that receive focusable direct beam radiation, uninterrupted by cloud cover. On the small scale, photovoltaic (PV) systems dominate the domestic solar market, with solar to electrical efficiencies of around 15%. Compared to PV, solar thermal systems are able to make use of a larger proportion of the solar resource through recovery of useful heat for thermal processes. In this thesis the potential of a small-scale solar combined heat and power (S-CHP) system based on an Organic Rankine Cycle (ORC) is investigated, for the combined provision of heating and power for domestic applications. The system consists of a solar collector array of total area equivalent to that available on the roof of a typical UK home, an ORC engine featuring a generalised positive-displacement expander, and a hot water storage tank. Water heating is provided through the precooling of the superheated exhaust vapour from the ORC expander, and an optional further contribution from the solar collector array. A thermo-economic model is developed in order to evaluate the performance and cost of the S-CHP system under various configurations and climatic conditions. Concentrating and non-concentrating solar collector designs suitable for small-scale applications are compared by way of annual maximum work assessments based on reversible and endoreversible analyses. The thermo-economic model is used to perform a parametric analysis of the S-CHP system to determine the optimum operational settings, and to simulate the system performance over an annual period. For the system simulated with non-concentrating collectors, electrical outputs equivalent to 19% and 33% of the typical household annual demand are predicted in the climates of London (UK) and Larnaca (Cyprus) respectively. In addition, the ability to provide up to 28% (London) and 58% (Larnaca) of annual hot water demand through recovery of rejected heat from the ORC engine is also predicted. A hot-water prioritisation mode is also identified for which hot water output is increased, at the expense of a decrease in electrical output. A cost analysis is performed in order to compare the system with other solar heat and power systems. The whole system capital cost is €9,700-10,500 (£8,000-8,800). The cost per unit average electrical output is higher than that for PV-based systems, however when compared to hybrid PV-thermal (PVT) systems, the total capital cost is found to be lower, and the potential to match local demand by varying the proportional outputs of electricity and hot water is seen as an additional advantage for the S-CHP system. Two experimental apparatus were designed and constructed for the purpose of evaluating the S-CHP system model. The first was an outdoor solar collector testing facility to measure solar collector efficiencies under a range of operating conditions. Steady-state tests were performed on an evacuated tube collector at fluid inlet temperatures up to 112 °C. This exceeds the normal range of operation in water-heating applications but is closer to the optimal temperatures found in the maximum work analysis. The results were used to provide a more reliable model of collector performance at higher temperatures for the purposes of the S-CHP system modelling. Dynamic tests were also performed in which the collector's response to a step change in solar irradiance was measured. The results were used to determine the collector's effective thermal capacity, and to evaluate a range of dynamic solar collector models. The experimentally obtained thermal capacity value was found to provide improved predictions of dynamic collector behaviour when implemented into a lumped dynamic model, resulting in a ~35% reduction in modelling error; while conventional estimation methods for the effective thermal capacity were found to result in significant under-predictions of the collector's thermal response time and an over-prediction of the daily energy yield. An experimental ORC apparatus was also designed and constructed in order to evaluate the performance of small-scale ORC components. The system featured a 1 kWe scroll expander and the working fluid R245fa. Thermal input was provided by an 18 kWth electrical oil heater. Measurements of electrical power output were taken over a range of thermal input settings and working fluid mass flow-rates, while expander rotational speed was also adjusted by varying the electrical load. The experimental results were compared to the predictions from the ORC system model and the performance of the various system components were investigated. The ORC system model was found to over-predict the gross thermal efficiency by 30-90%, attributed to off-design operation of the expander during the experiments and to thermal losses from components such as the heat exchanger, expander and pipework that were not included in the model. A maximum gross thermal efficiency of 5.3% and an expander isentropic efficiency of 49% were obtained during testing.

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Forslund, Axel. "Synthesis and characterisation of delafossite CuFeO2 for solar energy applications." Thesis, Uppsala universitet, Fasta tillståndets fysik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-297710.

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Delafossite CuFeO2 is an intrinsic p-type semiconductor with a band gap around 1.5 eV. Further, it is composed of relatively abundant, nontoxic elements, and therefor have potential to be an attractive material for solar energy harvesting.This work examines three routes to synthesise this material. The first includes a sol-gel deposition and then relies on solid state reaction above 650 degrees Celsius in inert gas atmosphere. In this work, no delafossite is obtained with this method.The second method is a hydrothermal route to make particles under hydrostatic pressure in an autoclave. Delafossite is obtained mixed with other phases.The third route includes aqueous precipitation similar to the second route, but a temperature of 70 degrees Celsius and ambient pressure is sufficient to produce a pure delafossite particle phase. It provides a robust and simple way to make delafossite CuFeO2 particles.The resulting particles are deposited and compressed on glass into thin films.The films have a band gap slightly below 1.5 eV and show some photoactivity in electrochemical measurements.

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Javadian-Deylami, Seyd Payam. "Metal Hydrides as Energy Storage for Concentrated Solar Thermal Applications." Thesis, Curtin University, 2017. http://hdl.handle.net/20.500.11937/58986.

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Hydrogen storage properties of LiBH4 may be changed by interaction with other complex hydrides due to an intimate interaction between the respective alkaline metals and boron which facilitate a relatively larger hydrogen storage capacity. The cyclic stability of the following binary complex hydride systems LiBH4-Ca(BH4)2, LiBH4-NaBH4 and LiBH4-NaAlH4 shows significant reversibility and due to their relative high gravimetric H2 storage capacity and specific heat storage capacity, they may potentially act as heat storage materials.

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Liu, Yan. "Superhydrophobic surfaces for electronic packaging and energy applications." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/52164.

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Superhydrophobic surfaces, which display water contact angles of larger than 150°, have attracted more and more attention due to their importance in both fundamental research and practical applications. This dissertation is mainly focused on the fundamental understanding and exploring applications of superhydrophobic surfaces. First, some specific examples of superhydrophobic surface fabrication were given, which include superoleophobic Si surface, robust superhydrophobic SiC surface, and reversible wettability nanocomposite films. Based on the study of superhydrophobic surfaces, the application of superhydrophobic surfaces in electronic packaging were explored. Superhydrophobic silica/epoxy nanocomposite coating serves as an encapsulant to improve the electronic device reliability. Such superhydrophobic coating showed good stability under humidity at elevated temperatures and was applied on the triple track resistors test coupons. In addition, the applications of superhydrophobic surfaces in solar cells were studied. Two multi-functional hierarchical structure solar cells with self-cleaning, low reflection and high efficiency properties were built up by coating or etching methods.

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Gadkari, Sagar A. "A HYBRID RECONFIGURABLE SOLAR AND WIND ENERGY SYSTEM." Cleveland State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=csu1225821057.

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Griffin, Paul Robert. "Investigation of quantum well solar cells for concentrator and thermophotovoltaic applications." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267810.

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Waide, Paul. "The characterisation and synthesis of weather data for solar thermal applications." Thesis, Cranfield University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359587.

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Zainal, Nurfarina. "Rapid melt growth of crystalline germanium for solar energy harvesting applications." Thesis, Queen's University Belfast, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.677964.

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Recent development of energy conversion devices namely photovoltaic (PV) cells or solar cells and thermophotovoltaic (TPV) cells require the use of bulk germanium as substrate material for efficient devices performance. Germanium is preferred to be employed in solidstate structure of terrestrial or space energy conversion devices due to its excellent electrical properties. With bandgap of 0.66 e V energy from infrared region of solar or thermal spectrum can be absorbed and converted into electrical energy. At present, multi-junction solar cells show the highest performance with bulk germanium as substrate material.' but have complicated and expensive manufacture processes. The major contributor to the high cells cost is the substrate material, germanium, which is an expensive and scarce material. One of the possibilities to resolve these issues is by using thin film instead of thick bulk germanium. To date, development of thin film germanium for energy conversion devices has not been established. By providing germanium on insulator structures a good quality thin film germanium can be attained and thus, offer a low cost route. The rapid melt growth (RMG) technique has been proposed, where it could potentially produces thin film germanium with quality similar to that of bulk germanium. In the existing technology via the RMG process germanium thickness was limited to 100 run. For photovoltaic applications thicker germanium films are required to have more energy absorption, thus leads to efficient performance.

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Matta, Sri Kasi Venkata Nageswara Rao. "Computational exploration of two-dimensional (2D) materials for solar energy applications." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/134244/1/Sri%20Kasi%20Venkata%20Nageswara%20Rao%20Matta%20Thesis_Redacted.pdf.

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This project is to find innovative and alternate Nano-sized materials for solar energy applications. This include conversion of solar light energy into electricity or generate clean environment friendly fuels by breaking water into Oxygen and Hydrogen. The study has explored material characteristics at electronic level to reveal new properties. These revelations then compared amongst some of the organic and inorganic materials for the intended purpose. Innovative design of new carbon-compounds (termed as carbon Quantum dots) included in the study for use in the new generation Perovskite solar cells for charge transfer.

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Fernandez, Randyll R. M. "A novel Photovoltaic Power Converter for military and space applications." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Sep%5FFernandez.pdf.

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Mewes, Daniela. "Applications of Solar Thermal Technology for Plastic Waste Management in Developing Communities." Thesis, KTH, Energiteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-232672.

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As the plastic industry continues to grow globally, with plastic materials contained in a vast quantity of consumer products, the management of the resultant waste has become one of the greatest challenges of our time. Greater than 8 million metric tons of plastics were estimated to enter the world’s oceans as of 2010, with an even larger amount remaining on land. The associated ecological and health effects of plastic waste disposal are many, and existing solutions can only tackle small portions of the waste.China and Indonesia top the current list of contributors to ocean contamination with plastic waste, which is dominated by Asian countries. China in particular is positioned as the world’s leader in plastic production. The waste management scenarios of these countries and associated energy outlooks are discussed, where the plastic waste of the islands of Indonesia is mostly a result of residential, not industrial activities. These calculations are projected to 2025 with recent values of population growth, as an update to previous literature, with Vietnam now expected to supersede both Indonesia and the Philippines. Given the available solar resource in the top coastal plastic waste producing nations, many of which lie within close proximity to the equator, the feasibility of applying solar thermal power for the melting of plastic waste is examined. Melting points of common plastics are typically below 200°C, and thus lie within the range of low-temperature parabolic solar thermal systems.A prototype non-evacuated tube parabolic trough was constructed following methodologies for accessible technologies for the developing world. Tests in Stockholm, Sweden demonstrated its ability to partially melt waste ABS from a 3D printer. Internal temperatures up to 211°C were recorded in further tests in Ioannina, Greece, where HDPE, LDPE, and PP were successfully melted along with waste household items. Heat loss was calculated as well as associated internal dynamics, examining the interaction of ambient conditions with the chosen design parameters. Additional testing is needed to constrain surface heat loss for higher temperature applications such as plastics like PET that melt above the exhibited range. Future refinements to the design are discussed as well as the role micro-projects have in the reduction of plastic waste at its source within developing countries.
Plastindustrin fortsätter att växa årligen, med plast som finns i en stor mängd konsumentprodukter, har hanteringen av det resulterande avfallet blivit en av de största utmaningarna i vår tid. Mer än 8 miljoner ton av plast beräknades nå världens hav varje år enligt en studie ifrån 2010, med en ännu större mängd kvar på land. De därmed sammanhängande ekologiska och hälsopåverkande effekterna av att leva med en sådan mängd plastavfall är många, och befintliga lösningar kan bara hantera små delar av avfallet.Kina och Indonesien leder nuvarande lista över bidragsgivare till havsplast, som domineras av asiatiska länder. Kina är i synnerhet världsledande inom plastproduktion. Avfallshanteringsscenarierna i dessa länder och därtill hörande energiutsikter diskuteras, där plastavfallet på Indonesiens öar främst är ett resultat av bostads-, och inte industriell verksamhet. Dessa beräkningar projiceras till 2025 med de senaste värdena av befolkningstillväxt, som en uppdatering till tidigare litteratur, där Vietnam nu förväntas överträffa både Indonesien och Filippinerna. Med tanke på den tillgängliga solressursen i de största bidragande kustområderna, av vilka många ligger i närheten av ekvatorn, undersöks möjligheten att applicera solvärme för smältning av plastavfall. Smältpunkterna av vanlig plast är vanligtvis under 200 °C och ligger således inom området för lågtemperaturparabola solvärmesystem.En prototyp med icke-evakuerat rörparaboliskt tråg konstruerades enligt metoder och tillgänglig teknik för utvecklingsvärlden. Test i Stockholm visade på förmåga att delvis smälta rest ABS från en 3D-skrivare. Interna temperaturer upp till 211 °C registrerades i ytterligare tester i Ioannina, Grekland, där HDPE, LDPE och PP framgångsrikt smältes tillsammans med avfallshushållsartiklar. Värmeförlusten beräknades liksom tillhörande inre dynamik, genom att undersöka samspelet mellan omgivningsförhållandena och de utvalda designparametrarna. Ytterligare testning behövs för att begränsa ytvärmeförlusten vid högre temperaturapplikationer, såsom PET plast som smälter över det uppvisade intervallet. Framtida förädlingar till designen diskuteras liksom den roll som lokala mindre projekt har i minskningen av plastavfall vid dess källa inom utvecklingsländerna.

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Hosseinian, Ahangharnejhad Ramez. "Fabrication of Perovskite Solar Cells & Applications in Multijunction Configurations." University of Toledo / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1575980394222122.

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Moschatos, A. "Solar applications in Greece : Optimization of storage systems for residential space and water heating." Thesis, Open University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234783.

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Erickson, Daniel S. "Fabrication and cost analysis of screen-printed electrodynamic shields for solar applications." Thesis, Boston University, 2013. https://hdl.handle.net/2144/21148.

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Thesis (M.Sc.Eng.) PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.
Electrodynamic Shields (EDS) have been targeted as a technology to help mitigate degradation of power output caused by dust deposition on various solar collectors. Though printed circuit board based EDS prototypes have shown promising dust removal efficiencies, an inexpensive method of transparent EDS fabrication must be realized before the EDS technology is adopted by the solar industry. Development of a screen-printing process is presented as a scalable, low-cost method of EDS fabrication. The process is established using a silver-based ink on borosilicate glass substrates and then adapted to incorporate transparent conductive PEDOT:PSS and ITO nanoparticle solutions. Successful EDS prototypes are characterized and integrated with photovoltaic cells and second surface mirrored substrates. Removal efficiencies of the screen-printed EDS are tested by measuring the restoration in specular reflection and transmission in integrated EDS-mirror and EDSPV modules after dust depositions. Finally, a cost analysis of the EDS screen-printing process is performed in order to predict the economic viability of the EDS technology when used in conjunction with solar collecting technologies.
2031-01-01

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Hebert, Lionel Michel Daniel. "The Industrial Village Energy Approach: A Cost-Effective Approach To Balance Interests and Collaboratively Harness Onsite Solar Energy." Thesis, Curtin University, 2020. http://hdl.handle.net/20.500.11937/83167.

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While the residential sector has seen a strong and rapid uptake of photovoltaic panels on rooftops in the last decade, especially in Australia, the uptake has been much slower on commercial and industrial roofs. This research focuses on how commercial and industrial precincts can transition to cost-effective long-term solar energy generation in a manner that creates multiple benefits. The outcome is a new approach that benefits the energy customers, the embedded utility and the environment.

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Dicaire, Daniel N. "Long Term Thermal Energy Storage in Adsorbent Beds for Solar Heating Applications." Thesis, University of Ottawa (Canada), 2010. http://hdl.handle.net/10393/28539.

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Long term thermal energy storage in adsorbent beds is investigated as means to store excess solar heat from the summer and release it during the winter for residential heating applications. Adsorption is a reversible exothermic process which releases heat when mesoporous materials, called adsorbents, are exposed to gaseous species, called adsorbates. The adsorbate is adsorbed into the crystal lattice and energy is released. Since the process is reversible, heat can be used to regenerate saturated adsorbent, release the adsorbate and store energy. Adsorption thermal energy storage has many advantages over conventional thermal storage methods and can be combined with all types of solar panels. When incorporated into a solar heating system, the adsorption thermal energy storage system could provide solar heat year round and reduce the home's energy cost by up to 80%. In this study, an activated alumina and zeolite 13X hybrid from Rio Tinto Alcan was identified as the best adsorbent when combined with water as the adsorbate, through an extensive screening procedure. The adsorption and regeneration cycles of the adsorbent were characterized using the prototype system. A maximum performance of 200 kWh/m3 was recorded. A model for predicting adsorbent performance based on the regeneration temperature was created and then tested using a different adsorbent. The efficiency of the system was also calculated in order to identify critical design parameters. The adsorbent was modified by impregnating inorganic salt hydrates into the crystal lattice. The resulting modified adsorbents have a 25% increase in performance, with some adsorbents reaching 300 kWh/m3. Using the performance and efficiency results of the prototype, the practical and economic feasibility of a large scale adsorption thermal energy storage system was investigated in various scenarios. Although adsorption shows several practical improvements over other forms of thermal energy storage, the cost of the systems remains a bottle neck to commercialization.

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Bollinger, Joshua David. "Applications of solar energy to power stand-alone area and street lighting." Diss., Rolla, Mo. : University of Missouri-Rolla, 2007. http://scholarsmine.umr.edu/thesis/pdf/Joshua_Bollinger_Thesis_09007dcc8031b71d.pdf.

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Thesis (M.S.)--University of Missouri--Rolla, 2007.
Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed April 17, 2007) Includes bibliographical references (p. 88-91).

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Kevin, Punarja. "On the synthesis, measurement and applications of solar energy materials and devices." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/on-the-synthesis-measurement-and-applications-of-solar-energy-materials-and-devices(9273d60d-cc5a-4992-8fae-ac9ddefa506b).html.

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Second generation solar cells based on thin film semiconductors emerged as a result of the past ten years of intense research in the thin film preparation technology. Thin film solar cell technology can be cost effective as it uses comparatively cheap materials suitable for solar building integration. Chemical Vapour Deposition (CVD) is a well-known method for the deposition of high quality thin films. This thesis describes the synthesis of novel tin(II)dithiocarbamate [Sn(S2CNEt2)2] and bis(diphenylphosphinediselenoato) tin(II) [Sn(Ph2PSe2)2] and these complexes as single source precursor for the deposition of SnS and SnSe and by using the combination of [Sn(Ph2PSe2)2] with [Cu(acac)2], Cu2SnSe3 thin films were deposited by AACVD. By using suitable combinations of metal complexes ([nBu2Sn(S2CNEt2)2], [Cu(S2CNEt2)2] [Zn(S2CNEt2)2] [Zn(Se2CNEt2)2] [Zn(acac)2], [Sn(OAc)4], [Cu(PPh3){Ph2P(Se)NP(Se)Ph2}] thin films and nanocomposites of CZTS, CFTS, CZTSe, CFTSe, CZFTS, , CZFTSe, CZTSSE, CFTSSe and CZFTSSe were prepared. The effect of precursor concentration and deposition temperature on the structure, morphology and composition of the thin films were studied in detail using by powder X-ray diffraction (p-XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and elemental mapping. This thesis addressing the structural inhomogeneity, control of growth and material characterization is expected to yield closer performance parity between CZTS-Se and CIGS solar cells. A series of systematic experiments were carried out. Through AACVD and simple solvothermal methods CZFTS nanoparticles and thin films were prepared. The simple, potentially, low-cost nature of the CZTS nanoparticles and the enhancement of charge carrier mobility achieved suggest that these nanoparticles have potential in the improvement of OFETs and perhaps other organic electronic devices.

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Al-Ayfari, Hadi H. K. "Experimental measurement and mathematical modelling of meteorological parameters for solar energy applications." Thesis, University of Birmingham, 1986. http://etheses.bham.ac.uk//id/eprint/5888/.

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A new meteorological research station has been established and set up in the Solar Energy Laboratory which measures solar radiation (total and diffuse) on a horizontal surface, ambient air temperature, wind speed and wind direction. An inexpensive data logger based on an APPLE II microcomputer was designed and built. This data logger was used for more than 21 months and provided processed data for transcribing onto a main frame computer. A microdata (M1600L) microprocessor based automatic data logger was used later for the continuous monitoring of measured parameters. Four years of monitored data were used for analysis. Two mathematical models have been developed for the estimation of both total and diffuse solar radiation on a horizontal surface from different meteorological parameters. Several mathematical models developed by others were used to relate solar radiation and meteorological parameters measured in Birmingham. The results of these were compared, analysed and the best six were identified. The best models were tested and evaluated with (a) Birmingham data, (b) data from nine different sites in Europe. The best results show that the Birmingham models give the best estimation for total and diffuse solar radiation. The work reported here forms part of a continuous project of the Solar Energy Laboratory in meteorological research applied to solar energy utilization.

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Martínez-Denegrí, Sánchez Guillermo. "Light harvesting and energy efficiency in perovskite solar cells and their applications." Doctoral thesis, Universitat Politècnica de Catalunya, 2021. http://hdl.handle.net/10803/672666.

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The environmental issues associated with the use of conventional fuels necessitates the utilisation of renewable energy sources, as well as the implementation of energy efficient designs, in order to decrease electricity consumption. Photovoltaic (PV) technology can be employed for both approaches by converting not only natural but, also, artificial light into electricity. Among the different emerging PVs, perovskites achieve the highest power conversion efficiency, providing a widely tuneable bandgap with minimum open circuit losses. Moreover, their fabrication uses readily available materials, and does not necessarily require either the use of high temperature processes or vacuum deposition techniques. In this thesis, we enhance light harvesting in perovskite solar cells, and approach the energy efficiency concept through their optimised fabrication and integration in light selective structures. This is accomplished by the implementation of optical and material strategies applied to specific perovskite solar cell designs. The results prove that such strategies provide enhanced light absorption and optimal PV performance in low temperature devices, and enable the recycling of light into electricity for alternative photonic applications. The approaches presented could be utilised in future procedures to decrease the amount of Pb employed in perovskite solar cells, and to reduce the energy consumption during fabrication and the operation of other optoelectronic devices. The thesis is organised into four chapters. Chapter 1 serves as an introduction, where the current energy situation and PV technology are analysed, together with an insight into light harvesting and energy efficiency in perovskite solar cells. In Chapter 2, we demonstrate the employment of a periodic structure to propagate ergodic light in order to increase light absorption in perovskite solar cells, as would happen by employing randomly textured surfaces. This structure serves as a tool to decrease the Pb content used in perovskite solar cells, since 30% less material can be used to obtain a solar cell with equal performance. Then, in Chapter 3, the same periodic configuration with a thin film structure deposited on its surface is applied as a waveguide, which is also able to transmit polarised light. Moreover, two perovskite solar cells integrated on the sides recycle the non-transmitted light into electricity, increasing the energy efficiency of the optical process, with further application in liquid crystal displays (LCDs). Finally, in Chapter 4, we demonstrate the suitable application of a nanoparticle bilayer made of one layer of SnO2 and another of TiO2 as n-type materials in perovskite solar cells. These types of devices, based on low temperature processes, are proven to perform better than those containing one type of nanoparticles, especially in semi-transparent devices. In such devices we achieved an enhancement in performance of up to 30% for solar cells based on extremely thin active layers.
Los problemas medioambientales asociados al uso de combustibles convencionales requieren del uso de fuentes de energía renovables, así como de la implementación de diseños eficientemente energéticos para reducir el consumo de energía. La tecnología fotovoltaica puede emplearse para cubrir ambas estrategias convirtiendo no sólo la luz natural, sino también la artificial, en electricidad. De entre las diferentes tecnologías fotovoltaicas emergentes, las perovskitas alcanzan la más alta eficiencia en conversión de potencia, al mismo tiempo que proporcionan una banda de energía prohibida ampliamente ajustable con pérdidas mínimas de tensión de circuito abierto. Además, su fabricación usa materiales abundantemente disponibles, y no requiere necesariamente de procesos a alta temperatura ni de técnicas de deposición en vacío. En esta tesis, mejoramos la colección de luz en celdas de perovskitas, a la vez que abordamos el concepto de eficiencia energética a través de una fabricación optimizada y su integración en estructuras selectivas de luz. Esto es conseguido gracias a la implementación de estrategias ópticas y materiales aplicadas a diseños específicos de celdas solares de perovskita. Los resultados demuestran que tales estrategias proporcionan una colección de luz y un rendimiento fotovoltaico mayor aplicable a dispositivos fabricados a baja temperatura, y permiten el reciclaje de luz en electricidad para aplicaciones fotónicas alternativas. Las técnicas presentadas podrían ser utilizadas en procedimientos futuros para disminuir la cantidad de Pb empleado en celdas solares de perovskita, y para reducir el consumo de energía durante su fabricación y el funcionamiento de otros dispositivos optoelectrónicos. La tesis está organizada en cuatro capítulos. El Capítulo 1 sirve como una introducción, donde la actual situación energética y la tecnología fotovoltaica son analizadas junto a una descripción de la recolección de luz y la eficiencia energética en celdas solares de perovskita. En el Capítulo 2, demostramos el uso de una estructura periódica para propagar luz ergódicamente y así aumentar la absorción de luz en las celdas solares de perovskita, de manera equivalente a lo que se obtendría usando superficies aleatoriamente texturizadas. Esta estructura sirve como herramienta para reducir el contenido de Pb empleado en celdas solares de perovskita, ya que se puede utilizar 30% menos de material para obtener una celda solar con un rendimiento equivalente. En el Capítulo 3, la misma configuración periódica con una estructura de capa fina depositada en su superficie es empleada como guía de luz, la cual es, además, capaz de transmitir luz polarizada. Además, dos celdas de perovskita integradas en sus laterales reciclan la luz no transmitida en electricidad, incrementando la eficiencia energética del proceso óptico, lo cual podría tener futura aplicación en pantallas de cristal líquido. Finalmente, en el Capítulo 4, demostramos la aplicación de una bicapa de nanopartículas hecha de una capa de SnO2 y otra de TiO2 como materiales de tipo n en celdas solares perovskita. Este tipo de dispositivos, basados en procesos a baja temperatura, funcionan mejor que los que integran un único tipo de nanopartículas, especialmente en dispositivos semitransparentes. En tales dispositivos conseguimos un funcionamiento hasta 30% mejor para celdas solares basadas en capas activas extremadamente finas.
Fotònica

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40

Zacharopoulos, Aggelos. "Optical design modelling and experimental characterisation of line-axis concentrators for solar photovoltaic and thermal applications." Thesis, University of Ulster, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342344.

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41

Shao, Hui. "System design and power management for ultra low energy applications using energy harvesting techniques /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?ECED%202009%20SHAO.

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42

Tived, Alexander. "Artificial Intelligence in the Solar PV value chain : Current applications and future prospects." Thesis, KTH, Kraft- och värmeteknologi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-287025.

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With the increase in computational power, tools and data generation, the use of AI is increasing in various sectors. Currently used methods in the solar photovoltaic industry related to solar irradiance forecasting, system optimization, solar tracking etc. has been found to deliver relatively inaccurate results. By using artificial intelligence to perform these tasks, a higher degree of accuracy and precision can be achieved and is now a highly interesting topic. This thesis will investigate how artificial intelligence will impact the solar photovoltaic value chain. The investigation consists of mapping the current available artificial intelligence technologies, identifying possible future uses of artificial intelligence and also quantifying cost and social impact. This was accomplished through literature reviews, survey-style interviews, cost analysis and a case study. As the technology is fairly immature, the results found are purely theoretical, but a decrease in levelized cost of electricity could be as high as 36%. Further, given more accuracy in forecasting, a more precise estimate of cost can be made which could attract more investors and increase the penetration of solar photovoltaic in the global energy mix. Although artificial intelligence is a powerful tool it still requires large amounts of data and in order to further drive this development, data sharing agreements between actors would have to be in place.
Med ökningen av beräkningskraft, verktyg och dataproduktion ökar användningen av AI inom olika sektorer. Nuvarande metoder inom solcellsindustrin relaterade till solbestrålningsprognoser, systemoptimering, solar tracking etc. har visat sig leverera relativt felaktiga resultat. Genom att använda artificiell intelligens för att utföra dessa uppgifter kan en högre grad av noggrannhet och precision fås och är nu ett mycket attraktivt ämne för vidare forskning. Detta arbete kommer att undersöka hur artificiell intelligens kan komma att påverka värdekedjan för solpaneler. Undersökningen består i att kartlägga den nuvarande tillgängliga artificiella intelligensteknologin, identifiera möjliga framtida användningar av artificiell intelligens och även att kvantifiera kostnader och social påverkan. Detta åstadkoms genom litteraturgranskningar, intervjuer i enkätstil, kostnadsanalys och en fallstudie. Eftersom tekniken är relativt oetablerad är resultaten från denna undersökning rent teoretiska, men en minskning av levelized cost of electricity kan vara så hög som 36%. Med tanke på mer noggrannhet i prognoser kan man dessutom göra en mer exakt uppskattning av kostnaden som skulle kunna locka fler investerare och öka solcellernas penetration i den globala energimixen. Även om artificiell intelligens är ett kraftfullt verktyg kräver det fortfarande stora mängder data och för att ytterligare driva utvecklingen måste data delas mellan aktörer.

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Manning, R. E. "An investigation of thermal energy storage and its applications to industrial systems." Thesis, Cranfield University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.352684.

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Chen, Nian. "Understanding and development of cost-effective industrial aluminum back surface field (Al-BSF) silicon solar cells." Thesis, The University of North Carolina at Charlotte, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3721023.

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For the long-term strategy of gradual decarbonization of the world’s energy supply, high penetration of PV electricity is critical in the future world energy landscape. In order to achieve this, solar electricity with competitive cost to fossil fuel energy is necessary. To be able to obtain high efficiency solar cells, many advanced cell architectures have been developed commercially by PV industry. However, the fabrication of these cells necessitates complex processing steps and high requirements on semiconductor materials, which make it not as cost-effective as the state-of-the-art conventional Al-BSF structure. In order to keep the cost of PV cell low and improve on the efficiency with fewer processing steps, this thesis work focuses on the understanding of the conventional Al-BSF solar cell structure. The research work therefore, focuses on the (i) design, and modeling of front metal electrodes including the use of multi-bus-bar capable of decreasing the gridline resistance, (ii) fine-line printing and (iii) metal contact co-firing using high belt speed that is not common to the solar industry to achieve ~20% efficient industrial Al-BSF silicon solar cells.

In order to achieve the objectives of this thesis work, firstly, the appropriate Al paste was investigated for lowest back surface recombination velocity (BSRV), which gives high open circuit voltage (V_oc). Secondly, the impact of emitter sheet resistance on solar cell performance was modeled to determine the optimal sheet resistance, and the uniformity of emitter was also investigated. Thirdly, modeling on the front metal electrodes was carried out to investigate the optimal number of busbars, and determine the optimum number of gridlines and gridline geometries that would result in low series resistance (R_s), high fill factor (FF) and hence high efficiency. Fourthly, the modeled results were experimentally validated through fine-line printing and optimized contact co-firing. By combining each layer to make solar cells, V_oc of ~642 mV, J_sc of ~38.5 mA/cm² and FF of ~80.4% led to average ~19.8% efficient cell. Based on the experimental results, other innovative front grid designs are proposed that can lead to >20% energy conversion efficiency.

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Corr, Mandi Lee. "Renewable energy in Montana system applications and technlogy /." [Missoula, Mont.] : The University of Montana, 2008. http://etd.lib.umt.edu/theses/available/etd-04212009-123850/unrestricted/Mandi_Corr_Thesis.pdf.

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Ramos, Archibold Antonio Miguel. "Thermal Assessment of a Latent-Heat Energy Storage Module During Melting and Freezing for Solar Energy Applications." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5433.

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Capital investment reduction, exergetic efficiency improvement and material compatibility issues have been identified as the primary techno-economic challenges associated, with the near-term development and deployment of thermal energy storage (TES) in commercial-scale concentrating solar power plants. Three TES techniques have gained attention in the solar energy research community as possible candidates to reduce the cost of solar-generated electricity, namely (1) sensible heat storage, (2) latent heat (tank filled with phase change materials (PCMs) or encapsulated PCMs packed in a vessel) and (3) thermochemical storage. Among these the PCM macro-encapsulation approach seems to be one of the most-promising methods because of its potential to develop more effective energy exchange, reduce the cost associated with the tank and increase the exergetic efficiency. However, the technological barriers to this approach arise from the encapsulation techniques used to create a durable capsule, as well as an assessment of the fundamental thermal energy transport mechanisms during the phase change. A comprehensive study of the energy exchange interactions and induced fluid flow during melting and solidification of a confined storage medium is reported in this investigation from a theoretical perspective. Emphasis has been placed on the thermal characterization of a single constituent storage module rather than an entire storage system, in order to, precisely capture the energy exchange contributions of all the fundamental heat transfer mechanisms during the phase change processes. Two-dimensional, axisymmetric, transient equations for mass, momentum and energy conservation have been solved numerically by the finite volume scheme. Initially, the interaction between conduction and natural convection energy transport modes, in the absence of thermal radiation, is investigated for solar power applications at temperatures (300 - 400°). Later, participating thermal radiation within the storage medium has been included in order to extend the conventional natural convection-dominated model and to analyze its influence on the melting and freezing dynamics at elevated temperatures (800 - 850°). A parametric analysis has been performed in order to ascertain the effects of the controlling parameters on the melting/freezing rates and the total and radiative heat transfer rates at the inner surface of the shell. The results show that the presence of thermal radiation enhances the melting and solidification processes. Finally, a simplified model of the packed bed heat exchanger with multiple spherical capsules filled with the storage medium and positioned in a vertical array inside a cylindrical container is analyzed and numerically solved. The influence of the inlet mass flow rate, inner shell surface emissivity and PCM attenuation coefficient on the melting dynamics of the PCM has been analyzed and quantified.

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MORENO, MENDAZA JOSEBA. "SOLAR COLLECTORS FOR AIR HEATING : PROFITABILITY ANALYSIS." Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-16963.

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Solar energy constitutes one of the main alternatives for facing the energy problems of the future, taking into account the foreseeable depletion of the fossil fuels. Transpired solar air collectors are relatively simple alternatives, which do not need a continuous supervision and are mostly maintenance free. Their life cycle is relatively high, around 25 years, and the total investment can be fully recovered in the short-term. The aim of this master’s thesis is to analyze the feasibility of installing transpired solar air collectors as secondary systems in big industrial buildings, for heating purposes. The collectors would be designed for compensating the heat losses of a building which is mainly heated up by a heat pump system. Precisely, this work tries to evaluate the profitability of installing these collectors in Gävle, taking into account the particularities of this location in the considered study. This project work is focused on testing if these systems can provide enough thermal energy for heating up big-sized industrial buildings. For this purpose, firstly, the heat demand of the building for each month was calculated; secondly, the maximum output from the collector was estimated, using WINSUN simulator; and, finally, the energy difference that had to be covered by the main system was calculated. Once this was done, the yearly running cost for the main system and the total investment for the transpired air solar collector were estimated. Due to the lack of experimental data, the obtained results can only be taken as approximations. All the calculations and estimations have been made using WINSUN, a simulator that has been configured according to the particularities of the project. The results show that the solar collector provides a total thermal output of 29.700 kWh/year (system which has a total investment of 77.000 SEK). The total heat demand of the building is estimated to be of 87.100 kWh/year, being 51.800 kWh/year fulfilled by the heat pump system (which has a yearly running cost of 24.000 SEK/year). The collector has an average efficiency of 51,04%.

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Mira, Sebastião Bittencourt de. "Sustainable Energy Solutions for Water Purification Applications: Municipal and Industrial Case Studies." Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc500086/.

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In several areas around the world, clean water is a precious asset that at anytime, and mainly due to circumstances of weather and climate, can become scarce. Mainly in the dry and remote places, people suffer with lack of water. A solution for this suffering can be a water desalination system, which makes water potable and usable for industry. That solution inherently, brings the problem of power requirement, which is sometimes arduous to accomplish in such remote areas of difficult access and long distances to overcome to build the infrastructure required to operate an electric power plant. Texas and the USA also face this scenario for many regions, for which the government has been creating some programs and driving forward incentives, looking for solutions to support water desalination. Water desalination has future applications for municipalities water-consuming or for arid and remote regions, as well as for industries that rely on heavy water usage, such as natural gas drilling operations, for which millions of gallons are trucked overland to the site and also hauled away afterwards, when the waste water produced must be treated. This thesis created the concept of autonomy for water desalination plants replacing the actual power supply from fossil fuel to a renewable source from wind or sun, giving capacity to them to produce its own electricity to operate as an autonomous unit, as demonstrated in the business case done for the Brownsville water desalination facility.

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Yuan, Guangbi. "Synthesis and Applications of Vertically Aligned Silicon Nanowire Arrays for Solar Energy Conversion." Thesis, Boston College, 2012. http://hdl.handle.net/2345/3738.

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Thesis advisor: Dunwei Wang
Solar energy, the most abundant and free renewable energy, holds great promise for humanity's sustainable development. How to efficiently and inexpensively capture, covert solar energy and store it for off peak usages constitutes a grand challenge for the scientific community. Photovoltaic devices are promising candidates but are too costly to be implemented in large scales. On a fundamental level, this is due to the dilemma that the length scales of the optical pathways and electrical pathways often do not match within the photovoltaic device materials. Consider traditional Si solar cell as an example, effective light absorption requires up to hundreds of microns material while the photogenerated charge carries can only diffuse less than a few microns or even shorter before recombination. Such a problem may be solved by using Si nanowires (SiNWs) because vertically aligned nanowires can orthogonalize the light absorption and charge carrier collection pathways, thereby enabling the use of low-cost materials for practically appealing solar energy conversion devices. The objective of this thesis work is to explore low-cost synthesis of vertically aligned SiNW arrays and study their performance in both solar energy conversion and storage devices. We developed a method to synthesize vertically aligned SiNW arrays in a hot-wall chemical vapor deposition system with tunable length, doping level, and diameter for systematical studies. Empowered by the synthetic control, various types of vertical SiNW arrays were characterized by both steady-state (photoelectrochemical measurement) and transient (electrochemical impedance spectroscopy) techniques in a photoelectrochemical cell platform. Additionally, SiNWs were demonstrated to be a promising candidate for photoelectrochemical aromatic ketone reduction and CO₂ fixation. The reactions studied in this thesis are in close resemblance to natural photosynthesis and the resulted product molecules are precursors to nonsteroidal anti-inflammatory drugs, ibuprofen and naproxen. Lastly, vertical transparent conductive oxide nanotubes were prepared from vertical SiNW array templates. Ultrathin hematite (Fe₂O₃) film was coated on the nanotube scaffold by atomic layer deposition to form a heteronanostructure photoelectrode for efficient solar water oxidation. Our results highlight the potential of vertically aligned SiNW arrays in solar cell, solar water splitting and artificial photosynthesis applications
Thesis (PhD) — Boston College, 2012
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry

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Arthur, Owen C. "Investigation of high temperature nanofluids for concentrating solar collector applications." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/104747/4/Owen_Arthur_Thesis.pdf.

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This thesis investigated the potential of using molten salt nanofluids as a directly absorbing heat transfer fluid in concentrating solar receiver applications. The investigation was conducted through the development of a two dimensional fluid dynamics model in COMSOL utilising the radiative heat transfer and mixture model physics. Two molten salts were studied, NaNO3-KNO3 and Li2CO3-K2CO3 doped with graphene nanoparticles and the effects of receiver length and height, inlet velocity, nanoparticle volume fraction and solar concentration on receiver performance were evaluated.

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