An existing solar-powered water pumping system located in Mutomo, Kenya has beenevaluated in this paper. The requirement for this system is to produce a minimum of25m³ water per day throughout the year.The aim of this thesis is to investigate theperformance of the currently installed system and find a suitable replacement in termsof efficiency and economic viability. In order to acquire the necessary knowledge forthis project, a literature study was carried out to analyse the research within the area.Three simulation models were created which all include an electric motor driven by aphotovoltaic array and are connected to a submersible groundwater pump. Allmodels utilise space vector pulse width modulation. One model of an inductionmotor that represents the currently installed system, one induction motor thatdelivers a minimum of 25 m³ water per day, and one model of a permanent magnetsynchronous motor for comparison. Simulations using weather data, representing anaverage day for each month of the year were carried out. It was shown that thecurrently installed system does not fulfil the requirement of producing 25 m³ waterper day, and in addition produces a significant amount of energy that can not beutilised. It was also shown that the efficiency of the permanent magnet synchronousmotor was superior to the induction motors. In order to compare the systems interms of economic viability, price quotations from world leading manufacturers wereacquired. The results of the economic comparison show that the superior efficiencyof the permanent magnet synchronous motor was not enough to compensate for thehigher investment cost.

This project examines the initial system analysis and system level design for an integrated elect cal system to be used in a solar powered car. The system design includes the ability to collect and store solar power, as well as manage control signals. The electrical motor for the purposes of this report is considered as part of the mechanical system of the car. The report follows the rigorous systems approach format for as adapted from Blanchard and Fabrycky's Systems Engineering and Analysis 1990). The report begins with a statement of the problem, and continues through preliminary design. / Master of Science

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Detta examensarbete riktar sig in på att undersöka olika typer av solceller, batterier och lampor för att ta fram och jämföra två system av solcellsdriven gatubelysning i Stockholm och Kiruna. Sverige befinner sig väldigt norr ut på jordklotet vilket innebär en stor kontrast i soltimmar under sommar- och vinterhalvåret. Arbetets huvudsyfte är att ta fram ett solcellsdrivet system där energi genererad under sommaren kan lagras i ett batteri och sedan kompensera för energiunderskottet under vintern. Resultaten visar att skillnaden av genererad energi är stor beroende på vilken solcell som används. Beroende på val av solceller skiljer sig även kravet på batterikapaciteten för respektive ort. Energiupptaget från solceller i Stockholm och Kiruna skiljer sig markant, detta beror på olikheten av globalstrålningen.  Resultaten från kostnadsberäkningen visar att belysningssystemen som studeras i arbetet är dyrare i Kiruna än i Stockholm, detta beror på skillnaden i krav på batterikapacitet utifrån genererad energi från solcellerna. Val av batteri- och solcellstyp har även en påverkan på kostnaden. / This thesis focuses on examining different types of solar cells, batteries, and lamps to develop and compare two systems of solar-powered street lighting in Stockholm and Kiruna. Sweden is located very north of the globe, which means a great contrast in sunny hours during the summer and winter months. The main purpose of the study is to develop a solar-powered system where energy generated during the summer can be stored in a battery and then compensate for the energy deficit during the winter. The results show that the difference in generated energy is large depending on which solar cell is used. Depending on the choice of solar cells, the requirement for battery capacity for each location also differs. The energy uptake from solar cells in Stockholm and Kiruna differs significantly, this is due to the difference in global radiation. The results from the cost calculations show that the lighting systems studied in the thesis are more expensive in Kiruna than in Stockholm, this is due to the difference in requirements for battery capacity based on the energy generated from the solar cells. The choice of battery and solar cell type also has an impact on the cost.

Solar Energy and Hydrogen (energy carrier) are possible replacement options for fossil fuel and its associated problems of availability and high prices which are devastating small, developing, oil-importing economies. But a major drawback to the full implementation of solar energy, in particular photovoltaic (PV), is the lowering of conversion efficiency of PV cells due to elevated cell temperatures while in operation. Also, hydrogen as an energy carrier must be produced in gaseous or liquid form before it can be used as fuel; but its‟ present major conversion process produces an abundance of carbon dioxide which is harming the environment through global warming. In search of resolutions to these issues, this research investigated the application of Thermal Management to Photovoltaic (PV) modules in an attempt to reverse the effects of elevated cell temperature. The investigation also examined the effects of coupling the thermally managed PV modules to a proton exchange membrane (PEM) Hydrogen Generator for the production of hydrogen gas in an environmentally friendly and renewable way. The research took place in Kingston, Jamaica. The thermal management involved the application of two cooling systems which are Gravity-Fed Cooling (GFC) and Solar-Powered Adsorption Cooling (SPAC) systems. In both systems Mathematical Models were developed as predictive tools for critical aspects of the systems. The models were validated by the results of experiments. The results of the investigation showed that both cooling systems stopped the cells temperatures from rising, reversed the negative effects on conversion efficiency, and increased the power output of the module by as much as 39%. The results also showed that the thermally managed PV module when coupled to the hydrogen generator impacted positively with an appreciably increase of up to 32% in hydrogen gas production. The results of this work can be applied to the equatorial belt but also to other regions with suitable solar irradiation. The research has contributed to the wider community by the development of practical, environmentally friendly, cost effective Thermal Management Systems that guarantee improvement in photovoltaic power output, by introducing a novel way to use renewable energy that has potential to be used by individual household and/or as cottage industry, and by the development of Mathematical Tools to aid in photovoltaic power systems designs.

New Horizons, Voyager 1 & 2, and Pioneer 10 & 11 are the only spacecraft to ever venture past Pluto and provide information about space at those large distances. These spacecraft were very expensive and primarily designed to study planets during gravitational assist maneuvers. They were not designed to explore space past Pluto and their study of this environment is at best a secondary mission. These spacecraft rely on radioisotope thermoelectric generators (RTGs) to provide power, an expensive yet necessary approach to generating sufficient power. With Cubesats graduating to interplanetary capabilities, such as the Mars-bound MarCO spacecraft, matching the modest payload requirements to study the outer Solar System (OSS) with the capabilities of low-power nano-satellites may enable much more affordable access to deep space. This paper explores a design concept for a low-cost, small spacecraft, designed to study the OSS and satisfy mission requirements with solar power. The general spacecraft design incorporates a parabolic reflector that acts as both a solar concentrator and a high gain antenna. This paper explores a working design concept for a small spacecraft to operate up to 100 astronomical units (AU) from the sun. Deployable reflector designs, thermal and radiation environments, communications and power requirements, solar system escape trajectory options, and scientific payload requirements are detailed, and a working system is proposed that can fulfill mission requirements with expected near-future innovations in a few key technologies.

The dissertation aims to expand access through a low-cost technological innovation system S-MLS to learners in underdeveloped areas with difficulties in accessing education. Technology is advancing rapidly. However, many parts of the world need access to educational advances, which are hindered due to war, political situations, and low literacy and income. A qualitative phenomenological approach explores the lived experience using the solar-powered computing and learning management system (LMS) to support the development of educational access in underrepresented societies, developing countries, and rural areas where access to proper classroom education is non-existent. Proof of concept is used with a group of students in a rural area, a developing country, and within an underrepresented population to check the feasibility of using the equipment in a real-world setting. A technology acceptance model would be used to identify the user's perceived interest and user acceptance. The community of inquiry theory would find the first-hand experience and point of view of the learner. The student group interviews would be through semi-structured interviews. Observations, surveys, video/audio recordings, and artifacts would be gathered for further analysis. The data collected would be analyzed using interpretative phenomenology analysis (IPA), close examination, and management of development themes through thoughts, observations, and reflections on the technological experience and future research and implementations provided. The projected finding would be to check that a solar-powered Raspberry Pi system with MoodleBox operating system that runs Moodle (Modular Object-Oriented Dynamic Learning Environment) LMS would be feasible to provide learning underdeveloped areas to enhance education.

Effects of engine placement on flutter characteristics of a very flexible high-aspect-ratio wing are investigated using the code NATASHA (Nonlinear Aeroelastic Trim And Stability of HALE Aircraft). The analysis was validated against published results for divergence and flutter of swept wings and found to be in excellent agreement with the experimental results of the classical wing of Goland. Moreover, modal frequencies and damping obtained for the Goland wing were found in excellent agreement with published results based on a new continuum-based unsteady aerodynamic formulation. Gravity for this class of wings plays an important role in flutter characteristics. In the absence of aerodynamic and gravitational forces and without an engine, the kinetic energy of the first two modes are calculated. Maximum and minimum flutter speed locations coincide with the area of minimum and maximum kinetic energy of the second bending and torsion modes. Time-dependent dynamic behavior of a turboshaft engine (JetCat SP5) is simulated with a transient engine model and the nonlinear aeroelastic response of the wing to the engine's time-dependent thrust and dynamic excitation is presented. Below the flutter speed, at the wing tip and behind the elastic axis, the impulse engine excitation leads to a stable limit cycle oscillation; and for the ramp kind of excitation, beyond the flutter speed, at 75% span, behind the elastic axis, it produces chaotic oscillation of the wing. Both the excitations above the flutter speed are stabilized, on the inboard portion of the wing. Effects of engine placement and sweep on flutter characteristics of a backswept flying wing resembling the Horten IV are explored using NATASHA. This aircraft exhibits a non-oscillatory yawing instability, expected in aircraft with neither a vertical tail nor yaw control. More important, however, is the presence of a low frequency “body-freedom flutter” mode. The aircraft center of gravity was held fixed during the study, which allowed aircraft controls to trim similarly for each engine location, and minimized flutter speed variations along the inboard span. Maximum flutter speed occurred for engine placement just outboard of 60% span with engine center of gravity forward of the elastic axis. The body-freedom flutter mode was largely unaffected by the engine placement except for cases in which the engine is placed at the wing tip and near the elastic axis. In the absence of engines, aerodynamics, and gravity, a region of minimum kinetic energy density for the first symmetric free-free bending mode is also near the 60% span. A possible relationship between the favorable flutter characteristics obtained by placing the engines at that point and the region of minimum kinetic energy is briefly explored. Effects of multiple engine placement on a similar type of aircraft are studied. The results showed that multiple engine placement increases flutter speed particularly when the engines are placed in the outboard portion of the wing (60% to 70% span), forward of the elastic axis, while the lift to drag ratio is affected negligibly. The behavior of the sub- and supercritical eigenvalues is studied for two cases of engine placement. NATASHA captures a hump body-freedom flutter with low frequency for the clean wing case, which disappears as the engines are placed on the wings. In neither case is there any apparent coalescence between the unstable modes. NATASHA captures other non-oscillatory unstable roots with very small amplitude, apparently originating with flight dynamics. For the clean-wing case, in the absence of aerodynamic and gravitational forces, the regions of minimum kinetic energy density for the first and third bending modes are located around 60% span. For the second mode, this kinetic energy density has local minima around the 20% and 80% span. The regions of minimum kinetic energy of these modes are in agreement with calculations that show a noticeable increase in flutter speed at these regions if engines are placed forward of the elastic axis. High Altitude, Long Endurance (HALE) aircraft can achieve sustained, uninterrupted flight time if they use solar power. Wing morphing of solar powered HALE aircraft can significantly increase solar energy absorbency. An example of the kind of morphing considered in this thesis requires the wings to fold so as to orient a solar panel to be hit more directly by the sun's rays at specific times of the day. In this study solar powered HALE flying wing aircraft are modeled with three beams with lockable hinge connections. Such aircraft are shown to be capable of morphing passively, following the sun by means of aerodynamic forces and engine thrusts. The analysis underlying NATASHA was extended to include the ability to simulate morphing of the aircraft into a “Z” configuration. Because of the “long endurance” feature of HALE aircraft, such morphing needs to be done without relying on actuators and at as near zero energy cost as possible. The emphasis of this study is to substantially demonstrate the processes required to passively morph a flying wing into a Z-shaped configuration and back again.

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