Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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  • Master Thesis
    Modelling and Controlling of Hybrid Energy Systems With Hydrogen Storage
    (01. Izmir Institute of Technology, 2023) Çağlar, Başar; Altın, Müfit; Çağlar, Başar; Altın, Müfit; 03.06. Department of Energy Systems Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Hybrid renewable energy systems are gaining more attention for the problems like Global Warming and high CO2 emissions. Another topic that increases its popularity is hydrogen. Because it is a very good alternative fuel. In this work, every component of a basic Hybrid Renewable Energy System (HRES) will be modeled and short-time simulations will be made for any transient response of individual components. MATLAB Simulink is used for every model and simulation. HRES includes a wind turbine, PV array, battery energy storage, and electrolyzer. The system is also grid-connected. Additionally, different control strategies are investigated, obtained, and created. Maximum Power Point Tracking (MPPT) algorithms for Wind Energy Conversion System (WECS) and PV array were conducted. A control algorithm that combines the battery and the PV array was made and necessary circuits were designed. An overall model for different sizes and operations is created. One-day-long simulations were made for 11 different cases. The user can alter the overall model for different turbines, PV modules, and battery sizes. The total amount of hydrogen produced, energy generation, and consumption were observed for every case.
  • Master Thesis
    Efficiency Studies of Cu2znsns2 Thin Film Solar Cell
    (Izmir Institute of Technology, 2018) Meriç, Ece; Aral, Gürcan; Özyüzer, Lütfi; Özyüzer, Lütfi; Aral, Gürcan; 04.05. Department of Pyhsics; 04. Faculty of Science; 01. Izmir Institute of Technology
    Cu2ZnSnS4 (CZTS) is a promising candidate as an absorber layer for thin film solar cells due to not only its low cost but also nontoxic properties contrary to alternative materials such as CdTe and Cu(In,Ge)Se2 (CIGS). Recently, CZTS and similar chalcogenides have attracted remarkable attention because of their suitable properties. In my thesis; I studied the efficiency of Cu2ZnSnS4 thin film solar cells for various stoichiometric cases. Besides, the effect of back contact, buffer layer thickness and sulfurization time were investigated. CZTS thin films were fabricated by DC magnetron sputtering method on Molybdenum (Mo) coated Soda Lime Glass (SLG) and Ti foil substrates. Cu, Sn, Zn, Cu layers were, respectively, deposited on the substrates, and then sulfurization process was followed as the second step in the growth process to obtain a desirable CZTS formation. The as grown CZTS structure was investigated using Raman and X-Ray Diffraction (XRD) spectroscopies. Scanning electron microscopy (SEM) was used to investigate the surface morphology of the films. Energy dispersive spectroscopy (EDS) was used to define the chemical structure of the surface of the films. Next, a CdS buffer layer was deposited on CZTS absorber layer using CBD method at 85oC for varying times (60, 75 and 90 min). Then, ZnO and Al doped ZnO (AZO) layers were deposited on CdS. J-V curves were obtained for SLG/Mo/CZTS/CdS/ZnO/AZO solar cell structure. The photovoltaic characteristic of solar cells was studied and their dependence on CdS deposition time were found. Among all the device we produced, the highest efficiency was obtained for the device with the lowest CdS deposition time. In addition; effect of sulfurization time on the solar cell conversion efficiency was studied.
  • Master Thesis
    Hybrid Energy Capacity of Turkey for Small and Micro Scale Energy Production
    (Izmir Institute of Technology, 2017) Yıldız, Mustafa; Bingöl, Ferhat; Gökçen Akkurt, Gülden; Bingöl, Ferhat; Gökçen Akkurt, Gülden; 03.06. Department of Energy Systems Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Turkish state has opened a new possibility on investing small or micro scale energy production without license in 2014. This is a new step in Turkish energy market and two renewable energy sources are considered to be the main interest; wind and solar. Although there are studies covering both technology separately, currently there is no hybrid system assessment methodology and results for the country. This thesis aims to create a quantified hybrid energy capacity of Turkey. The study will include total energy capacity of a given location based on small scale wind and solar and furthermore would be able to suggest an optimum balance between these two sources to get the maximum production capacity out. The study does not cover areas that such investment cannot be done; environmental protected areas, historical places, city centers etc.
  • Master Thesis
    3d-Printed Multiprobe Analysis System for Solar Fuel Research; Design, Fabrication and Testing
    (Izmir Institute of Technology, 2016) Harmanlı, İpek; Karabudak, Engin; Ebil, Özgenç; Karabudak, Engin; Ebil, Özgenç; 04.01. Department of Chemistry; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of Technology
    Methods of generating electricity with unlimited, clean and cheap energy from solar energy are tried to be investigated and developed in practical and theoretical academic fields. Especially, photocatalytic water splitting (PWS) systems have been identified as the main method in this study as well as in many studies due to the advantages provided by production of solar fuels from water. In this research, a study was carried out on the alternatives of the both used experimental set-up and used photocatalytic material for PWS systems. A study has been carried out on both the used experimental setup and the used photocatalytic material alternatives in PWS systems. As an alternative experimental setup that allows small volume analysis for PWS by Unisense gas microsensors, a mini photoreactor was designed using 3-D drawing and printing techniques and its usability was tested for PWS applications. Moreover, some characterization results for the electronic band structure and the band gap of the lead (II) trioxovanadate (V) chloride [PbVO3Cl] crystal, which was discovered by Eanes and co-workers in 2007 at IZTECH, was introduced in this study by not only theoretical (DFT approximations; LDA, GGA and HSE06) but also experimental (XRD, Diffuse Reflectance Method- Tauc Plot, Raman Spectroscopy, Four Probe) methods. Also, its estimated theoretical price and its potential for future application in tandem solar fuel device as a photoanode in combination with Si photocathode was calculated and discussed. The results showed that the designed mini photoreactor system is an open to development apparatus that is suitable for PWS, besides, PbVO3Cl has an "indirect transition" band structure and a band energy of ~ 2.2 eV. Although it did not give an effective result in PWS applications done by the designed mini photoreactor, it can be said that it is a semiconductor which is worth studying and developing in detail for other researches in this field due to the compatibility of its band energy amount and optical properties for PWS.
  • Master Thesis
    Optimization of a Hybrid Combination of a Photovoltaic Syste and a Wind Energy Conversion System: Izmir Institute of Technology Campus Area Case
    (Izmir Institute of Technology, 2003) Ekren, Orhan; Özerdem, Barış; Özerdem, Mehmet Barış; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Renewable energy resources have gained the great importance due to the growing concerns of environmental problems. The integrated utilization of renewable energies such assolar and wind are becoming very attractive, especially, in most of the isolated and remote areas in many parts of the world.In the present study, firstly, wind and solar radiation measurements, made on Izmir Institute of Technology (IZTECH) Campus area, have been analyzed in order to determine the, both, solar and wind energy potentials of the location. The monthly average wind speeds range from 5.7 m/s to 7.7 m/s, the monthly average of daily values of solar radiation range from 2.1 kWh/m2 to 5.7 kWh/m2 at the monitoring station throughout the measurement period of 12 months between 01.01.2002 and 31.12.2002.Secondly, a procedure is described which determines the hybrid system parameters such as photovoltaic (PV) array area and rotor swept area of wind turbine while satisfying a specific load distribution. The employed method is a graphical construction to figure out the optimum configuration of the generators that satisfies the energy demand mentioned above.
  • Master Thesis
    Experiment Station To Observe the Solar Charge Station Behaviour for a Year Period
    (Izmir Institute of Technology, 2003) Tatar, Farah; Atagündüz, Gürbüz; Atagündüz, Gürbüz; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    The main purpose of this project is to set-up an experiment station, which will investigate the behavior of a portable "Solar Charge Station" that charges electric or hybrid vehicles, which work at the city centers.The solar charge station is constructed on Classrooms Building in Engineering Faculty of Izmir Institute of Technology. Sixteen monocrystalline silicon photovoltaic modules having the dimensions of 1.293mx 0.329mx 0.034m and 55W power rating are used as the photovoltaic generator of the solar charge station. Modules are mounted as if they create an .Omega Shape. which gives its name to the station (Omega Type Solar Charge Station). Vertical and tilted reflectors are used to enhance the electricity generation. Generated electricity is used to charge a lead acid battery, which is protected by five solar charge regulators in order to prevent discharging and overcharging. 50 W halogen lamps working with direct current are chosen as the loads. The system is analyzed both theoretically and experimentally. Theoretical results have shown that Omega Type Solar Charge Station generates more or less steady electricity, approximately 240 MJ through a year period. The reflectors operate better in winter than in summer, theoretically. According to the stations shape, it uses less space on rooftops. Experiments have shown that efficiency of the charge station during summer is considerably high. The efficiencies calculated by using direct solar radiation on inclined surface is 31.65315%, for the experiment on 21.08.2003, 27.90379% for the experiment carried out without reflectors on 11.09.2003 and 35.70939% for the experiment carried out with optimum inclination angles for September, on 12.09.2003.Omega shape of the station and the reflectors increase the efficiency more or less 3% in Omega shape of the station and the reflectors increase the efficiency more or less 3% in cost of the station if the energy gain is considered.
  • Master Thesis
    The Use of Cell Polyurethane Foams in Air-Type Solar Collectors as the Heat Absorbing Element
    (Izmir Institute of Technology, 2006) Değirmencioğlu, Can; İlken, Zafer; İlken, Zafer; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    After the energy crisis in early 1970.s, the priority of alternative energy resources is expanded. There have been many researches, to increase the efficiency of solar energy utilization systems, for domestic and industrial usage since early 1980.s up to now. In many fields air-type solar collectors are applicable. They generally used in food industry to dry agricultural products, textile industry to dry fabrics and space heating. Drying grains (wheat, barley, maize, etc.), fruits (grape, fig, apricot etc.), vegetables, tea are examples for food industry. Greenhouse heating and hospital heating to obtain fresh air are examples of space heating. These examples show that improving their performance is indispensable for commercial acceptance. In this study, the open-cell polyurethane foam as an absorber material, placed in a south facing, flat plate air-type solar collector at fixed tilt angle and effect of this material on collector efficiency has been investigated. The collector designed specially, in order to get maximum heat gain from the useful solar intensity falling on the glazing and insulated to loose minimum heat from collector case and transfer channels. Collector is tested under the regulations of ASHRAE 93-1986 standard named .Methods of Testing to Determine The Thermal Performance of Solar Collectors.. Air passing through the collector has been provided by a fan. Tests are repeated with three air speeds 1.266 m/s, 1.5825 m/s and 1.899 m/s. Maximum average efficiency is calculated on 1.5825 m/s. Maximum average temperature difference of air between inlet and outlet sections observed on 1.266 m/s. Maximum outlet temperature that we get is on the same day with maximum average temperature difference.