Ingeniero Civil de Minas / El trabajo realizado aborda la opción de utilizar energía solar fotovoltaica para el proceso de electroobtención de cobre, realizando evaluación técnica y económica. Para ello se realiza un dimensionamiento considerando tres tipos de sistemas: conectado a la red, fuera de la red y mixto; siendo el primero aquél donde se realiza una evaluación como generador y los siguientes una evaluación desde una inversión por parte de la empresa minera. Esto se realiza de modo de cuantificar los ingresos según el modelo de negocio. El trabajo es realizado en dos tópicos, la evaluación técnica que pretende identificar problemas en la conexión entre la generación fotovoltaica y la nave de electroobtención; y la evaluación económica que busca mostrar la viabilidad financiera de realizar o no este tipo de instalaciones. La evaluación técnica consiste en ver los problemas asociados a la conexión entre la carga y el generador, tales como los voltajes y los requerimientos de electricidad exigidos por la nave de electroobtención, en cada tipo de sistema realizado. Como resultado se obtiene que existe la tecnología para permitir la conexión entre la planta fotovoltaica y la nave, pero requiere un período de ajuste debido a las variaciones de potencia entregada a la carga de forma diaria y mensual; siendo el sistema mixto el que presenta mejores condiciones técnicas para operar. En la evaluación económica se generaron los escenarios de precios para realizar la inversión en la tecnología y ver si se sustentan financieramente. Se obtiene como resultado que en la situación actual no es viable realizar un sistema mixto, puesto que el escenario de precios de electricidad está un 5% debajo del límite para que el proyecto sea interesante. No obstante la opción de un sistema conectado a la red muestra una interesante oportunidad de negocio, que podría ser aplicada a otra área de una faena minera que no requiera una potencia constante. La generación mediante energías renovables no convencionales en la industria minera podría generar un impacto positivo en la comunidad puesto que permite disminuir en grandes consideraciones las emisiones, pero presenta dificultades legales en la implementación que pueden ser salvadas por la industria minera cuando este tipo de proyectos sean rentables.

5 p. / Solar energy systems can help Arizona individuals, families, and businesses achieve energy conservation goals beyond the adoption of energy-efficient appliances, and LED bulbs. Which type of system is the best? Knowing which system to select is the first important question. This factsheet will focus on solar photovoltaic energy systems. The term photovoltaic refers to the conversion of light energy to electricity.

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第14168号 / 工博第3002号 / 新制||工||1445(附属図書館) / 26474 / UT51-2008-N485 / 京都大学大学院工学研究科分子工学専攻 / (主査)教授 今堀 博, 教授 田中 庸裕, 教授 渡辺 宏 / 学位規則第4条第1項該当

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M.Ing. / A dissertation presented on the basic solar design principles such as sun-earth geometry, energy wavelengths, optics, incidence angles, parabolic collector configurations and design, materials for solar applications, efficiencies, etc to be considered in Solar Concentrating Collector design. These principles were applied in the design and fabrication of a prototype solar collector. The solar collector was tested to verify and correct mathematical models that were generated from existing literature; as well as for optimization work.

4 p. / The adoption of solar photovoltaic (PV) energy systems to serve as an energy source for residential, commercial and agriculture applications is growing. Early use of solar PV energy as an alternative energy source to fossil fuels became popular in the 1970’s during the rise of the environmental movement. The cost of solar power in 1977 was $76.00 per watt. A combination of factors including public awareness, demand for solar, availability of product and service, and improving technology has dropped the cost per solar watt. In 2015, the cost of solar power was $0.613 per watt (Shahan, 2014). Energy rebates offered by local, state, and federal agencies has made the adoption of solar energy more affordable.

Since the Kennelly- Heaviside hypothesis in 1902 of the existence of a partially conducting layer in the upper atmosphere was proved to be true by the experiments of APPLETON and BARNETT (1925) and BREIT and TUVE (1926), this region has become known as the ionosphere. The ionosphere was soon discovered to consist of, not one but several layers (Fig. 1) (i) A layer at a height of just over 100 km. called the E layer. (ii) A layer at a height of approximately 300km. called the F₂ layer. (iii) A layer at a height of approximately 200 km. called the F₁ layer; this layer differs from the other two in that it is only present during the day time in Summer. (iv) Occasional intense reflections from a height of about 100 km. are found - these cannot be attributed to the normal E layer and have received the name "Sporadic E". The presence of two E layers (E₁ and E₂) has been suggested by HALLIDAY (1936) and BEST and RATCLIFFE (l978) but until recently most workers still seem to attribute these reflections to Sporadic E. Recent measurement by rockets of the electron density at E layer heights still do not confirm whether such bifurcation exists in the E region. The diurnal and seasonal variations of the first three layers indicate that the sun is the chief agent in their production. It is generally agreed that these layers consist of ionised molecules or atoms and free electrons produced by radiation from the sun. The origin of Sporadic E ionisation is still obscure, but it is thought that these sudden increases in ionisation which occur in E layer heights are due to passing meteors. Recently it has also been suggested by SEDDON, PICKAR and JACKSON (1954) from rocket measurements that Sporadic E might be due to a steep electron density gradient above the B layer.

CHAPTER I A description of the sun and the type of radio radiation it emits is given. The relation that exists between this and other events occurring on the sun's surface is studied. CHAPTER II The literature dealing with the origin of solar radio noise is reviewed. CHAPTER III The method of specifying polarized radiation and the effect of a magneto- ionic medium on such radiation is discussed. The possible origin of the polarization of solar radio noise is examined and the literature relating to this and to the observations of polarization of solar noise is reviewed. A short outline of the methods used in measuring polarization is given. CHAPTER IV A detailed outline of the construction of a polarimeter is given together with full circuit diagrams and illustrative photographs. CHAPTER V A brief discussion of the operation of the polarimeter, the results obtained and suggestions for its future operation is given.

Master of Science / Department of Electrical and Computer Engineering / Medhat M. Morcos / Solar energy is the energy that is basically obtained from the sun. It is used for purposes of generating electricity by using solar thermal systems of photovoltaic panels. This report discusses the utilization of solar energy in Kuwait for purposes of generating electricity. The report is divided into six chapters. Chapter 1 discusses the introduction, which will be limited to the use of electricity in Kuwait and the possibilities of utilizing solar energy as a renewable source of energy to generate electricity. Chapter 2 discusses the background of the use of solar energy, where the reasons and the advantages of using solar energy are analyzed. Chapter 3 gives an in-depth discussion on solar energy. The generation of electricity from photovoltaic solar panels and solar thermal electricity systems are presented. Chapter 4 discusses the comparison between solar power farm and natural gas with the aid of data from Kuwait. Chapter 5 gives a discussion on the use of solar energy in Kuwait. Chapter 6 includes the conclusions and recommendations for future work.

Solar cells allow the energy from the sun to be converted into electrical energy; this makes solar energy much more environmentally friendly than fossil fuel energy sources. These solar cells are connected together in a photovoltaic (PV) module to provide the higher current, voltage and power outputs necessary for electrical applications. However, the performance of the PV module is limited by the performance of the individual cells. Cell mismatch occurs when some cells are damaged or shaded and produce lower current output than the other cells in the series connected string. The cell mismatch lowers the module performance and can result in further damage as the weak cells are reverse biased and dissipate heat. Bypass diodes can be connected into the module to increase the module current output and prevent further damage. Since cell mismatch results in a significant decrease in the performance of deployed modules it is important to fully understand and characterise its effect on PV modules. PV modules can be characterised using various techniques, each providing important information about the performance of the module. Most commonly the current-voltage (I-V) characteristic curve of a module is measured in outdoor, fully illuminated conditions. This allows performance parameters such as short circuit current (Isc), open circuit voltage (Voc) and maximum power (Pmax) to be determined. In addition to this the shape of the curve allows device parameters like series and shunt resistances to be determined using parameter extraction algorithms like Particle Swarm Optimisation (PSO). The extracted parameters can be entered into the diode equation to model the I-V curve of the module. The I-V characteristic of the module can also be used to identify poor current producing cells in the module by using the worst-case cell determination method. In this technique a cell is shaded and the greater the drop in current in the whole module the better the current production of the shaded cell. The photoresponse of cells in a module can be determined by the Large-area Light Beam Induced Current (LA-LBIC) technique which involves scanning a module with a laser beam and recording the current generated. Electroluminescence (EL) is emitted by a forward biased PV module and is used to identify defects in cell material. Defects such as cracks and broken fingers can be detected as well as material features such as grain boundaries. These techniques are used to in conjunction to characterise the modules used in this study. The modules investigated in this study each exhibit cell mismatch resulting from different causes. Each module is characterised using a combination of characterisation techniques which allows the effect of cell mismatch be investigated. EL imaging enabled cracks and defects, invisible to the naked eye, to be detected allowing the reduced performance observed in I-V curves to be explained. It was seen that the cracked cells have a significant effect on the current produced by a string, while the effect of delaminated areas is less severe. Hot spots are observed on weak cells indicating they are in reverse bias conditions and will degrade further with time. PSO parameter extraction from I-V curves revealed that the effect of module degradation of device parameters like series and shunt resistances. A module with cracked cells and degradation of the antireflective coating has low shunt resistance indicating current losses due to shunting. Similar shunting is observed in a module with delamination and moisture ingress. The extracted parameters are used to simulate the I-V curves of modules with reasonable fit. The fit could be improved around the “knee” of the I-V curve by improving the methods of parameter extraction. This study has shown the effects of cell mismatch on the performance and I-V curves of the PV modules. The different causes of cell mismatch are discussed and modules with different cell configuration and damage are characterised. The characterisation techniques used on each module provide information about the photoresponse, current generation, material properties and cell defects. A comprehensive understanding of these techniques allows the cell mismatch in the modules to be fully characterized.