This master's thesis is focused on properties of direct solar radiation, diffuse radiation and their usage in solar systems. Goal of this paper is to compare the different sources of light with the radiation and selection source for the solar radiation simulator, followed by a measuring device for homogeneous distribution of solar radiation and implemantation of solar simulator.

This thesis presents a new type of solar simulator and new measurement methods that allow for fast power rating of photovoltaic devices and for fast performance measurements for energy rating and energy yield predictions indoors under controlled, and more realistically simulated outdoor conditions. A novel indoor measurement system for photovoltaic device characterisation based on light emitting diodes (LEDs) as the light sources is described. The solar simulator is capable of reproducing spectral changes seen in natural sunlight, with its intricacies of variable air mass and weather conditions, to a better match than previously possible. Furthermore, it allows measurements under varying light intensity and device temperature. The prototype LED-based solar simulator developed is characterised and its measurement quality is analysed. The system achieves a class BAA solar simulator classification with a class B spectral match, class A light intensity uniformity and a class A temporal stability. It is the first system of its kind that meets the standards of a solar simulator in spectral match to the standard sunlight spectrum and in terms of minimum light intensity. An uncertainty analysis shows that calibration uncertainty for crystalline silicon solar cells is 5% in maximum power with a 95.45% level of confidence. Recommendations for further versions of the solar simulator are given and show potential of reducing this uncertainty down to 2.9% across all measurement spectra (1.8% with a primary calibrated reference cell). A new method for automated power-rating of single- and multi-junction devices is developed. The method uses a unique spectral response measurement and fitting method. It eliminates the need of external measurement equipment for determining spectral response. A simulated characterisation of an amorphous silicon single- and double-junction solar cell show accuracy of better than 0.5% in maximum power. First measurements on the LED-based solar simulator show a measurement error of 4.5% in maximum power, which is due to a lack of measurement feedback of spectral output and measurement irradiance. The first three-dimensional performance matrix for use in photovoltaic energy rating is reported, utilising the LED-based solar simulator. Device characteristics are measured indoors under varying irradiance, temperature and spectrum. A measurement method is detailed and utilised on a crystalline and amorphous silicon solar cell. It allows for the first time a direct investigation of spectral effects on photovoltaic devices under controlled conditions. Results show that amorphous silicon devices are very sensitive to changes in spectrum. Thus, spectral effects should not be neglected in energy yield predictions for such devices.

A new receiver concept utilizing impinging jet cooling technology has been developed for a small scale solar dish-Brayton system. In a typical impinging receiver design, the jet nozzles are distributed evenly around the cylindrical absorber wall above the solar peak flux region for managing the temperature at an acceptable level. The absorbed solar irradiation is partially lost to the ambient by radiation and natural convection heat transfer, the major part is conducted through the wall and taken away by the impingement jets to drive a gas turbine. Since the thermal power requirement of a 5 kWe Compower® micro gas turbine (MGT) perfectly matches with the power collected by the EuroDish when the design Direct Normal Irradiance (DNI) input is 800 W/m2, the boundary conditions for the impinging receiver design in this work are based on the combination of the Compower®MGT and the EuroDish system. In order to quickly find feasible receiver geometries and impinging jet nozzle arrangements for achieving acceptable temperature level and temperature distributions on the absorber cavity wall, a novel inverse design method (IDM) has been developed based on a combination of a ray-tracing model and a heat transfer analytical model. In this design method, a heat transfer model of the absorber wall is used for analyzing the main heat transfer process between the cavity wall outer surface, the inner surface and the working fluid. A ray-tracing model is utilized for obtaining the solar radiative boundary conditions for the heat transfer model. Furthermore, the minimum stagnation heat transfer coefficient, the jet pitch and the maximum pressure drop governing equations are used for narrowing down the possible nozzle arrangements. Finally, the curves for the required total heat transfer coefficient distribution are obtained and compared with different selected impinging arrangements on the working fluid side, and candidate design configurations are obtained. Furthermore, a numerical conjugate heat transfer model combined with a ray-tracing model was developed validating the inverse design method and for studying the thermal performance of an impinging receiver in detail. With the help of the modified inverse design method and the numerical conjugate heat transfer model, two impinging receivers based on sintered α-SiC (SSiC) and stainless steel 253 MA material have been successfully designed. The detailed analyses show that for the 253 MA impinging receiver, the average air temperature at the outlet and the thermal efficiency can reach 1071.5 K and 82.7% at a DNI level of 800 W/m2 matching the system requirements well. Furthermore, the local temperature differences on the absorber can be reduced to 130 K and 149 K for two different DNI levels, which is a significant reduction and improvement compared with earlier published cavity receiver designs. The inverse design method has also been verified to be an efficient way in reducing the calculation costs during the design procedure. For the validation and demonstration of the receiver designs, a unique experimental facility was designed and constructed. The facility is a novel high flux solar simulator utilizing for the first time Fresnel lenses to concentrate the light of 12 commercial high power Xenon-arc lamps. Finally, a prototype of a 253 MA based impinging was experimentally studied with the help of the 84 kWe Fresnel lens based high flux solar simulator in KTH. / <p>QC 20151123</p> / Optimised Microturbine Solar Power System , OMSOP

Driven by the limitations of solar-optimized roof space and International Energy Association (IEA) Task 35, there is a renewed interest in photovoltaic solar thermal (PVT) hybrid systems. Current PVT systems focus on cooling the solar photovoltaic (PV) cells to improve the electrical performance. This however, causes the thermal component (T) to underperform. An exergetic study was completed comparing a PVT, PV + T and a PV only system in Detroit, Denver and Phoenix. It was found that the PVT system outperformed the PV + T system by 72% for each location and by 8, 8.6 and 9.9% for Detroit, Denver and Phoenix when compared to the PV only system. To further improve the PVT system, using hydrogenated amorphous silicon (a-Si:H) PV as the absorber layer of the solar thermal device was explored. The temperature coefficient and annealing properties of a-Si:H allow the thermal component to run more efficiently, while enabling the a-Si:H i-layers to be thicker resulting in more electricity production. It was found that running i-layer thicker cells (630nm and 840nm) stabilized at higher efficiencies at 90°C (potential PVT operating temperatures) than the thinner cell (420nm) by 2% and 0.5% respectively. In addition, spike annealing, which is a new concept of stagnating a PVT system to allow for the a-Si:H PV to anneal and return it to its original efficiencies was also investigated. It was found that over the lifetime of the system with the spike annealing occurring once a day 10.6% more electricity was produced than a system without stagnation. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2011-11-14 11:09:16.727

Studying the microstructural features, optical, and electrical properties of the thin-filmperovskite solar cells (PSC) is the main objective of this thesis work. All the PSCs used in thisthesis work were prepared by spin coating assisted with gas quenching process and the samplesreceived from Interuniversity Microelectronics Centre (IMEC), Belgium.Microstructural and architectural details of the stagewise prepared PSCs were investigatedusing a Scanning Electron Microscope (SEM) - Focused Ion Beam (FIB) technique. With thereference to the given specification from IMEC, the SEM-FIB examinations of the as-preparedPSCs confirmed the presence of different layers such as hole transport layer (HTL), perovskitelayer, and electron transport layer (ETL). Further, the thickness of the perovskite layers wasmeasured and found to be 400 and 500 nm which validates the specification of the as-preparedsamples 1 and 2, respectively. The observed average grain size of the perovskite of the asprepared samples 1 and 2 are significantly different and the values are approximately 83 and169 nm, respectively. The average surface roughness values of perovskite layers (as-preparedsamples 1 and 2) and electron transport layer (as-prepared samples 3) were evaluated by atomicforce microscopy (AFM) and the values are 10, 19, and 12 nm, respectively. Furthermore, theconductive-AFM was performed to evaluate the electrical properties of the perovskite layers,and the results confirmed that the as-prepared sample 2 showed a higher mean current value of4.1 nA, than sample 1 resulted in 2.9 nA. The higher electrical performance of the as-preparedsample 2 could be correlated to the larger grain size, higher thickness, and higher surfaceroughness values of the perovskite layer.Moreover, the performance evaluation of a complete perovskite solar device with a similarconfiguration was evaluated between the as-prepared (newly fabricated) and the exposedsamples (tested under sunlight for ten weeks), and their behavior was studied. The optical andelectrical characteristics of the solar cell at the device level were examined with the help ofphotoluminescence (PL), electroluminescence (EL), and solar simulator techniques. The peakand fullwidth half maximum (FWHM) values of the PL emission spectra of the as-prepareddevice are in line with IMEC specification, whereas these values are slightly decreased for theexposed perovskite solar device. Also, during the EL examination, predominantly uniformluminescence was observed for the as-prepared device, whereas discontinuity in the emissionof electrons, and in some parts absence of luminescence-effect was observed for the exposedsolar cell. The current-voltage characteristics obtained from the solar simulator resultsconfirmed that the power conversion efficiency of the as-prepared device is at least 6 timeshigher than the exposed device. Based on the PL, EL, and PCE results it could be confirmedthat the perovskite solar cell exposed to sunlight for 10 weeks has started to degrade.

An LED-based solar simulator has been designed, constructed, and qualified under ASTM standards for use in the Cal Poly Space Environments Laboratory. The availability of this simulator will enhance the capability of undergraduate students to evaluate solar cell and thermal coating performance, and offers further research opportunities. The requirements of ASTM E927-19 for solar simulators intended for photovoltaic cell testing were used primarily, supplemented by information from ASTM E491-73 for solar simulators intended for spacecraft thermal vacuum testing. Three main criteria were identified as design goals - spectral match ratio, spatial non-uniformity, and temporal instability. An electrical design for an LED-based simulator to satisfy these criteria was developed and implemented, making use of existing lab equipment where possible to minimize cost. The resulting simulator meets the desired spatial non-uniformity and temporal instability requirements of ASTM E927-19, but falls short of the spectral match ratio needed. This is shown to be due to a calibration issue that is easily amended via software. The simulator is overall Class UCB under ASTM E927, and Class CCC under ASTM E491. The simulator was used to conduct the same laboratory procedure for solar cell I-V curve testing as performed by undergraduate students, showing excellent promise as a course enhancement.

The Swedish Institute of Space Physics (IRF) at Kiruna focuses on research activities in the ionosphere, magnetosphere, and upper atmosphere of the planet as well as the development and production of various sensors and detectors for space research. The test facility includes the IRF SpaceLab which is equipped with multiple testing equipment. One of the testing resources available is the Solar Simulator, which consists of a vacuum chamber equipped with four metal halide lamps that produce a spectrum closely resembling that of the Sun. When any spacecraft payload or instrument is exposed to the Sun and its radiations, the most important factors to consider are the type of radiation, flux, and how the exposed material will react. Thermal designing and solar balance tests are important factors in achieving expected conditions for different missions. By testing and verifying these lamps, this solar simulator can be used not only for IRF missions but also for other institutes and private organizations that can access it. The characterization of four lamps is done in terms of temperature distribution, radiation, and power. According to preliminary experimental measured values obtained from the setup, exposed material, and its properties can be varied and the best suitable coating can be selected that includes α (absorptivity) and ϵ (emissivity) valueconsideration. The thesis is divided into four phases: Designing, Manufacturing, Testing, and Analyzing. Before entering into these phases, the basic knowledge of thermal engineering and thermal simulation is acquired. Thermal modeling and simulations are done in Airbus Defence &amp; Space’s Systema Thermica software tool. The design phase includes designing a frame structure and a 350 x 350 mm screen in Autodesk Inventor software. Manufacturing of the frame structure and the screen was done in the IRF workshop. This screen kept hanging with the support of a frame structure which is mounted on the copper table inside the chamber. The screen is kept in the field of view of each lamp and every lamp is illuminated accordingly. The analysis is done by measuring the temperature of the back side of the screen. Temperature sensors were mounted and clamped mechanically instead of kapton tape to avoid direct contact with the screen. The obtained values are analyzed and compared with the thermally simulated values. Pressure and the temperature of the system were monitored with independent systems throughout the test procedure. This thesis report could operate as a foundation for future examination of the solar simulator’s lamps in order to determine precise efficiency.

Currently, a sustainable energy transition is underway to reduce CO2 emissions. To meet the targets outlined in international agreements like the Kyoto Protocol, a rapid expansion of renewable energy sources, particularly photovoltaic (PV) systems, is underway. Due to photovoltaic technology's rapid development and integration, reliable testing and evaluation methods are essential. This master's thesis is dedicated to developing a PV system simulator to study the PV systems. PV simulators serve as precious tools due to their capacity to control and replicate the environmental conditions experienced by PV panels. Consequently, these simulators facilitate thorough research, design refinement, and PV system performance assessment. The developed PV system simulator is essentially a PV remote lab, offering the capability to monitor, gather data, and evaluate the performance of the PV system remotely. The proposed system's flexibility and scalability enable its application to study various types of PV installation. The PV remote lab is expected to be a training centre for students and industry professionals. A comprehensive literature review on photovoltaic technology has been undertaken. Following the literature review, the different components that form a PV system have been defined and selected. The system will have a communication block to achieve a flexible and scalable PV remote lab. In this way, different configurations of the PV panels and different system outputs can be implemented. This commutation block can be remotely controlled using an Arduino, and an interface can be designed where the desired PV panel configurations and system outputs can be selected. In this interface, visualising the tests' results will also be possible. / För närvarande pågår en hållbar energiomställning för att minska koldioxidutsläppen. För att uppfylla de mål som fastställts i internationella avtal som Kyotoprotokollet pågår en snabb utbyggnad av förnybara energikällor, särskilt solcellssystem (PV). På grund av solcellsteknikens snabba utveckling och integration är tillförlitliga test- och utvärderingsmetoder av avgörande betydelse. Denna masteruppsats handlar om att utveckla en solcellssimulator för att studera solcellssystem. PV-simulatorer är värdefulla verktyg eftersom de kan kontrollera och återskapa de miljöförhållanden som PV-panelerna utsätts för. Följaktligen underlättar dessa simulatorer grundlig forskning, designförbättring och bedömning av PV-systemets prestanda. Den utvecklade PV-systemsimulatorn är i grunden ett fjärrstyrt PV-labb som gör det möjligt att övervaka, samla in data och utvärdera PV-systemets prestanda på distans. Det föreslagna systemets flexibilitet och skalbarhet gör att det kan användas för att studera olika typer av solcellsinstallationer. PV-fjärrlabbet förväntas bli ett utbildningscenter för studenter och yrkesverksamma inom branschen. En omfattande litteraturgenomgång om solcellsteknik har genomförts. Efter litteraturgenomgången har de olika komponenterna som bildar ett solcellssystem definierats och valts ut. Systemet kommer att ha ett kommunikationsblock för att uppnå ett flexibelt och skalbart PV-fjärrlabb. På så sätt kan olika konfigurationer av solcellspanelerna och olika systemutgångar implementeras. Detta kommutationsblock kan fjärrstyras med en Arduino och ett gränssnitt kan utformas där de önskade konfigurationerna av solcellspaneler och systemutgångar kan väljas. I detta gränssnitt kommer det också att vara möjligt att visualisera testresultaten.

Segundo o Atlas Brasileiro de Energia Solar, apesar das diferentes características climáticas observadas no Brasil, pode-se constatar que a média anual de irradiação solar global apresenta boa uniformidade e elevados índices por todo o país. Os valores desta grandeza em quase toda a extensão do território brasileiro (4200-6700 Wh/m2/dia) são superiores aos da maioria dos países da União Europeia, como Alemanha (900-1250 Wh/m2/dia), França (900-1650 Wh/m2/dia) e Espanha (1200-1850 Wh/m2/dia), onde projetos para aproveitamento de energia solar, alguns contando com fortes incentivos governamentais, são amplamente disseminados. Grande parte dos avanços científicos obtidos nos estudos sobre aproveitamento da energia solar se deve à utilização de simuladores solares compactos nos experimentos de longa duração. Ao substituir o Sol por fontes artificiais, como lâmpadas capazes de emitir radiação próxima à solar, os simuladores eliminam a dependência de fatores naturais como condições climáticas, horário do dia, intermitência e movimento de direção da radiação solar. O projeto proposto para esta dissertação de Mestrado teve como objetivo o domínio do processo de concepção e fabricação de um simulador solar concentrador formado por lâmpadas e um refletor ótico. Uma vez dominada a técnica, um modelo piloto de simulador solar foi construído e alguns testes executados para avaliar a qualidade do projeto, a resistência dos componentes e o fator de concentração do aparato. / According to the Brazilian Atlas of Solar Energy, despite the different climatic characteristics observed in Brazil, the annual average of global solar irradiation has good uniformity and high levels throughout the country. The values of global solar irradiation in almost the entire length of Brazil (4200-6700 Wh/m2/day) are higher than those observed in most European Union countries, like Germany (900-1250 Wh/m2/day), France (900-1650 Wh/m2/day) and Spain (1200-1850 Wh/m2/day), where projects for solar energy applications, some of them relying on strong government incentives, are widely disseminated. Several scientific and technological advances made in the study of solar energy applications are due to the use of compact solar simulators in long-term experiments. Replacing the Sun by artificial sources, such as arc lamps with radiation emission similar to the Sun spectrum, indoor simulators avoid the dependence on natural conditions such as the weather, the daytime, the sunlight intermittence and the directional change of the solar radiation. The project proposed for this dissertation aimed to master the design and manufacturing processes of a high-flux solar simulator consisting of arc lamps and an optical reflector. Once technique was understood, a solar simulation pilot model was built and some tests were performed to assess the project quality, the resistance of components and the apparatus concentration factor.

A atrazina (ATZ) é um herbicida utilizado em larga escala no Brasil de forma intensiva em culturas de cana-de-açúcar, milho e sorgo. A ATZ possui caráter persistente e recalcitrante, de forma que os tratamentos convencionais de efluentes não são capazes de removê-lo. Nesse contexto, os processos oxidativos avançados, como a fotocatálise heterogênea, têm se mostrado eficientes para remoção deste poluente. Este trabalho tem por objetivo avaliar o desempenho dos fotocatalisadores TiO2 P25 e C-TiO2 Kronos vlp 7000 modificado com carbono para a degradação do pesticida atrazina em solução aquosa, utilizando um reator fotoquímico com coletor parabólico composto irradiado por um simulador solar. Os catalisadores TiO2 P25 e C-TiO2 Kronos foram caracterizados por meio de difração de raios-X, espectroscopia de infravermelho, área superficial específica BET e análise de reflectância difusa. As concentrações de TiO2 P25 e C-TiO2 Kronos empregadas foram 500 e 100 mg L&-1, respectivamente. Os resultados obtidos mostraram significativa remoção de ATZ ao final de 120 minutos (100; 98; 98; 93; 86% para concentrações iniciais de ATZ de 1; 5; 10; 20 e 30 mg L-1, respectivamente) com emprego do catalisador TiO2 P25. No entanto, as análises de carbono orgânico total (COT) indicaram que não houve mineralização significativa da ATZ, com valores inferiores a 20% com o uso do TiO2 P25. Para o catalisador C-TiO2 Kronos não se obteve remoção importante da ATZ ao final de 120 minutos de experimento, quando comparado com o TiO2 P25. Neste caso, o catalisador C-TiO2 Kronos permitiu obter remoções do pesticida de 37; 35; 38; 39 e 45%, aproximadamente, para as concentrações iniciais de ATZ de 1; 5; 10; 20 e 30 mg L-1, respectivamente. Apesar disso, o catalisador C-TiO2 Kronos apresentou melhor desempenho em mineralizar a ATZ a CO2 e H2O em relação ao proporcionado pelo TiO2 P25, com aproximadamente 38% de mineralização. O modelo de Langmuir-Hinshelwood (LH) constitui uma aproximação adequada para a cinética de degradação da atrazina para ambos os catalisadores estudados, com valores de Kr e Kads iguais a 1,54 mg L-1 min-1 e 15,47 L mg-1, respectivamente, para o catalisador TiO2 P25 e de 1,34 mg L-1 min-1 e 132,95 L mg-1, respectivamente para o catalisador C-TiO2 Kronos vlp 7000. / Atrazine (ATZ) is a widely used herbicide in Brazil, where it is intensively applied in sugarcane, corn and sorghum cultivations. However, conventional wastewater treatments are not able to remove ATZ due to its persistent and recalcitrant properties. Advanced oxidation processes, such as heterogeneous photocatalysis, have been proved effective for the removal of this pollutant. This study aims to evaluate the performance of TiO2 P25 and carbon-modified TiO2 Kronos vlp 7000 photocatalysts in the degradation of ATZ in aqueous systems using a tubular photochemical reactor equipped with a compound parabolic collector (CPC) irradiated by simulated solar light. Catalysts TiO2 P25 and C-TiO2 Kronos were characterized by X-ray diffraction, infrared spectroscopy, BET analysis and diffuse reflectance analysis. The concentrations of TiO2 P25 and C-TiO2 Kronos were 500 and 100 mg L-1, respectively. For TiO2 P25, the results showed significant ATZ removals after 120 minutes of irradiation (100; 98; 98; 93; 86% for initial ATZ concentrations of 1; 5; 10; 20, and 30 mg L-1, respectively). In contrast, the total organic carbon (TOC) analyses indicated that no significant ATZ mineralization occurred, with values lower than 20% for TiO2 P25. In comparison with TiO2 P25, C-TiO2 was not able to completely remove ATZ at the end of 120 minutes of irradition. In this case, pesticide removals of about 37; 35; 38; 39 and 45% were obtained for initial ATZ concentrations of 1; 5; 10; 20, and 30 mg L-1, respectively. Nevertheless, C-TiO2 Kronos showed better performance for ATZ mineralization to CO2 and H2O in comparison with TiO2 P25, with approximately 38% total carbon organic removal. The Langmuir-Hinshelwood (LH) model was shown to be an appropriate approximation for the degradation kinetics of atrazine for both catalysts, with values of Kr and Kads equal to 1.54 mg L-1 min-1 and 15.47 mg L-1, respectively, for the P25 TiO2 and 1.34 mg L-1 min-1 and 132.95 mg L-1, respectively, for C-TiO2 Kronos vlp 7000.