Physical Sciences and Mathematics Commons^™

Molecular Organic Photovoltaic Cells And Applications, Julie Liu

Theses and Dissertations

The absorption, light scattering, and anti-Stoke’s fluorescence of chlorophyll and closely related sodium copper chlorophyllin were examined in various solutions with a wide range of refractive index and permittivity. It was evident that radiative photo electron decay corresponded to low permittivity solvents, but not to solvent refractive index. Additionally, non-radiative decay was dominant in high permittivity solvents. The properties suggest evolution has provided plants with an ability to redirect light to the chlorophyll in the high permittivity (water) photosynthesis center. Exploratory solar cells exploiting lifetime switching were developed and tested, wherein strong photovoltaic response was exhibited, along with the unique …

Improving The Programmability Of Networked Energy Systems, Noman Bashir

Doctoral Dissertations

Global warming and climate change have underscored the need for designing sustainable energy systems. Sustainable energy systems, e.g., smart grids, green data centers, differ from the traditional systems in significant ways and present unique challenges to system designers and operators. First, intermittent renewable energy resources power these systems, which break the notion of infinite, reliable, and controllable power supply. Second, these systems come in varying sizes, spanning over large geographical regions. The control of these dispersed and diverse systems raises scalability challenges. Third, the performance modeling and fault detection in sustainable energy systems is still an active research area. Finally, …

Foam-Based Floatovoltaics: A Potential Solution To Disappearing Terminal Natural Lakes, Koami Soulemane Hayibo, Joshua M. Pearce

Electrical and Computer Engineering Publications

Terminal lakes are disappearing worldwide because of direct and indirect human activities. Floating photovoltaics (FPV) are a synergistic system with increased energy output because of water cooling, while the FPV reduces water evaporation. This study explores how low-cost foam-based floatovoltaic systems can mitigate the disappearance of natural lakes. A case study is performed on 10%–50% FPV coverage of terminal and disappearing Walker Lake. Water conservation is investigated with a modified Penman-Monteith evapotranspiration method and energy generation is calculated with an operating temperature model experimentally determined from foam-based FPV. Results show FPV saves 52,000,000 m3/year of water and US$6,000,000 at 50% …

Flexible Quantum Dot Solar Cell With Nanostructure Titanium Dioxide Photoanode With Modified Counter Electrode, Haimanti Majumder

Theses and Dissertations

Because of unique photovoltaic properties, nanostructured morphologies of TiO2 on flexible substrate have been studied widely in recent years in dye-sensitized solar cells (DSSCs). Nanostructured electrode materials with high surface area can promote rapid charge transport and thus improve the light-to-current conversion efficiency. Herein, this project generates an improved photoanode with forest like photoactive TiO2 hierarchical microstructure using a simple and facile hydrothermal route. To improve the photocurrent efficiency, PbS quantum dot has been applied in different thicknesses to evaluate the best performance. The deposition of quantum dot was done by easy SILAR cycle. Four different SILAR cycle has been …

Can Parallel Gravitational Search Algorithm Effectively Choose Parameters For Photovoltaic Cell Current Voltage Characteristics?, Alan Kirkpatrick

Honors Projects

This study asks the question “Can parallel Gravitational Search Algorithm (GSA) effectively choose parameters for photovoltaic cell current voltage characteristics?” These parameters will be plugged into the Single Diode Model to create the IV curve. It will also investigate Particle Swarm Optimization (PSO) and a population based random search (PBRS) to see if GSA performs the search better and or more quickly than alternative algorithms

Dynamic Analysis Of A Microgrid Powered With An Inverter And Machine-Based Distributed Resources, Brandon William Blackstone

UNLV Theses, Dissertations, Professional Papers, and Capstones

The proliferation of renewable distributed energy resources, particularly photovoltaic (PV) power systems, and the increasing need for a reliable power supply has led to the concept of microgrids, a mini-grid that consists of locally connected power generation units and needs, able to operate connected or disconnected from the utility grid, using controlled and coordinated methods to provide for the users of the microgrid the best possible conditions for their needs. The main technical issues facing microgrids include some of the following, seamless transition from stand-alone to utility grid connected operation, how to preserve frequency and voltage stability, and provide the …

Computational Analysis Beyond The Monomer Frontier Orbitals For Photovoltaic Donor-Polymer Candidates, Mitchell E. Lahm, Megan M. Niblock, John M. Migliore, Kendra M. Mckenzie, Hans P. Lüthi, Rollin A. King

Chemistry Faculty Publications

Scharber et al. proposed an efficiency model for organic photovoltaic cells based on the orbital energies of the monomers of the donor- and acceptor- polymers [Advanced Materials 18 (2006) 789–794]. We report theoretical extensions of this approach. First, the frontier-orbital energies and electronic spectra of n-length oligomers (n = 1 − 5) of 3-butylthiophene have been determined. The results show reasonable convergence with respect to system size at the point of a trimer with alkyl end caps. The HOMO-LUMO gap well matches computed excitation energies. Second, the structures and electronic spectra of dimers formed by three different monomers, with various …

Small And Medium Enterprises’ Green Energy Strategies For Profitability, Ekok Ajom Okpokam

Walden Dissertations and Doctoral Studies

Lack of business strategies can negatively impact the generation of green energy, which may hinder business profitability and growth. Managers of small and medium enterprises (SMEs) who struggle to generate green energy to increase profitability are at high risk of their business failure. Grounded in the diffusion of innovation theory, the purpose of this qualitative multiple case study was to explore the business strategies managers of SMEs use to generate green energy to increase profitability. The participants were three SME managers in three energy companies in Lagos, Nigeria, who effectively used business strategies to generate green energy to increase profitability. …

Unsymmetrical Zinc Phthalocyanines Containing Thiophene And Amine Groups As Donor For Bulk Heterojunction Solar Cells, Gülnur Keser Karaoğlan, Öznur Dülger Kutlu, Ahmet Altindal

Turkish Journal of Chemistry

Photovoltaic technology is an alternative resource for renewable and sustainable energy and low costs organic photovoltaic devices such as bulk-heterojunction (BHJ) solar cells, which are selective candidates for the effective conversion of solar energy into electricity. Asymmetric phthalocyanines containing electron acceptor and donor groups create high photovoltaic conversion efficiency in dye sensitized solar cells. In this study, a new unsymmetrical zinc phthalocyanine was designed and synthesized including thiophene and amine groups at peripherally positions for BHJ solar cell. The structure of the targeted compound (4) was characterized comprehensively by FT-IR, UV-Vis, 1H-NMR, and MALDI-TOF MS spectroscopies. The potential of this …

Organic-Inorganic Halide Perovskite Nanocrystals And Solar Cells, Rui Guo

FIU Electronic Theses and Dissertations

A great challenge facing humanity in the 21^st century is finding inexhaustible and inexpensive energy sources to power the planet. Renewable energies are the best solutions because of their abundance, diversity, and pollution-free emission. Solar energy is the cleanest and most abundant renewable energy source available. In the continuing quest for efficient and low-cost solar cells, perovskite solar cells (PSCs) have emerged as a potential replacement for silicon solar cells. Since 2009, the record efficiencies of PSCs have been skyrocketing from 3.8 % to 25.2 % and are now approaching the theoretical limit. Along with the three-dimensional perovskites used …

Investigation Into Reduced Thermal Conductivity For Half-Heusler Alloys And Identification Of Novel Multinary Chalcogenides Possessing Intrinsically Low Thermal Conductivity, Dean Hobbis

USF Tampa Graduate Theses and Dissertations

The current climate makes the need for sustainable energy production a priority, leading to keen interest towards the advancement of “green” energy sources and technology. This necessity has led to a multidisciplinary scientific approach with collaborations across various fields that are looking to solve this extremely important problem. One such technology is thermoelectric devices, which are attractive due to the fact that they provide direct solid-state conversion of heat to electrical power, and vice versa. This in turn allows for both waste heat recovery and sustainable refrigeration. One key aspect that is preventing the wide scale commercial use of thermoelectric …

Design Of Novel Substituted Phthalocyanines; Synthesis And Fluorescence, Dft,Photovoltaic Properties, Mehmet Sali̇h Ağirtaş, Derya Güngördü Solğun, Ümi̇t Yildiko, Abdullah Özkartal

Turkish Journal of Chemistry

The 4-(2-[3,4-dimethoxyphenoxy] phenoxy) phthalonitrile was synthesized as the starting material of new syntheses. Zinc, copper, and cobalt phthalocyanines were achieved by reaction of starting compound with Zn(CH3COO)2, CuCl2, and CoCl2 metal salts. Basic spectroscopic methods such as nuclear magnetic resonance electronic absorption, mass and infrared spectrometry were used in the structural characterization of the compounds. Absorption, excitation, and emission measurements of the fluorescence zinc phthalocyanine compound were also investigated in THF. Then, structural, energy, and electronic properties for synthesized metallophthalocyanines were determined by quantum chemical calculations, including the DFT method. The bandgap of HOMO and LUMO was determined to be …

The Effect Of Snowfall And Icing On The Sustainability Of The Power Output Of A Grid-Connected Photovoltaic System In Konya, Turkey, Mehmet Ali̇ Anadol, Erman Erhan

Turkish Journal of Electrical Engineering and Computer Sciences

When the module surface is covered with various factors such as snow and icing which prevent the solar irradiance from reaching the photovoltaic cells, the power production of the system and its performance decrease. The purpose of this study is to determine the energy production losses of a grid-connected photovoltaic plant due to snowfall and icing. The effect of snowfall and icing has been examined on a photovoltaic system consisting of a hybrid inverter with two separate maximum power point tracking inputs and 36 monocrystalline modules, which are mounted on the supporting system horizontally in the south direction and at …

Three-Dimensional Nanotube Arrays For Solar Energy Harvesting And Production Of Solar Fuels, Wipula P. R. Liyanage

Doctoral Dissertations

"Over the past decade extensive research has been carried out on photovoltaic semiconductors to provide a solution towards a renewable energy future. Fabricating high-efficiency photovoltaic devices largely rely on nanostructuring the photoabsorber layers due to the ability of improving photoabsorption, photocurrent generation and transport in nanometer scale. Vertically aligned, highly uniform nanorods and nanowire arrays for solar energy conversion have been explored as potential candidates for solar energy conversion and solar-fuel generation owing to their enhanced photoconversion efficiencies.

However, controlled fabrication of nanorod and especially nanotube arrays with uniform size and shape and a pre-determined distribution density is still a …

A Review: Thermal Stability Of Methylammonium Lead Halide Based Perovskite Solar Cells, Tanzila Tasnim Ava, Abdullah Al Mamun, Sylvain Marsillac, Gon Namkoong

Electrical & Computer Engineering Faculty Publications

Perovskite solar cells have achieved photo-conversion efficiencies greater than 20%, making them a promising candidate as an emerging solar cell technology. While perovskite solar cells are expected to eventually compete with existing silicon-based solar cells on the market, their long-term stability has become a major bottleneck. In particular, perovskite films are found to be very sensitive to external factors such as air, UV light, light soaking, thermal stress and others. Among these stressors, light, oxygen and moisture-induced degradation can be slowed by integrating barrier or interface layers within the device architecture. However, the most representative perovskite absorber material, CH_{3 …}

Application Of Silicon Nanohair Textured P-N Junctions In A Photovoltaic Device, Michael Small

Electronic Theses and Dissertations

The goal of this project is to design and develop a fabrication process for a silicon photovoltaic device which incorporates a nanohair textured p-n junction. The silicon nanowires are etched into a silicon wafer, comprising an epitaxial p-layer on n-substrate, via metal-assisted chemical etching (MACE). The resulting nanowires contain p-n junctions that lie along the length of the vertical nanowires. This construct has the potential to increase the optical bandwidth of a silicon photovoltaic device by allowing a greater amount of short wavelength light to reach the junction. In addition, the MACE method of nanofabrication has the potential for decreasing …

Study On The Design Method Of Integration Of Roof And Photovoltaic Based On Aesthetics, Technology And Energy-Saving Characteristic, Hongxin Feng, Juanli Guo, Gang Liu, Jiehui Wang

International Building Physics Conference 2018

The development and utilization of new energy has been concerned due to the traditional energy is increasingly scarce. In recent years, solar building has developed rapidly in the construction industry which is a major energy consuming component. As an organic part of the building, the combination of roof and solar energy has become the focus of attention because of its large size, less shielding and other characteristics. Based on the works of recent years’ Solar Decathlon, this paper analysed the design and implementation of the integration of solar building’s roof and photovoltaic. Meanwhile, taking an office building in Xinjiang, China …

Supercapacitor Utilization For Power Smoothening And Stability Improvement Of Ahybrid Energy System In A Weak Grid Environment, Rahul Sharma, Sathans Suhag

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a novel control scheme based on the application of a supercapacitor (SC) is proposed for power smoothening and stability improvement of a hybrid energy system (HES) in weak grid conditions. The basic property of fast charging/discharging of the SC is utilized to design the proposed control. In weak grid conditions, the control structure is proposed for power smoothening and DC link voltage regulation with the help of the SC. Moreover, the stability is increased, ripples in voltage are reduced, there is fast dynamic response, and oscillations are damped out under different conditions. In conventional control, voltage controller …

An Economic Analysis Of Residential Photovoltaic Systems With And Without Energy Storage, Rodney Moses Kizito

Graduate Theses and Dissertations

Residential photovoltaic (PV) systems serve as a source of electricity generation that is separate from the traditional utilities. Investor investment into residential PV systems provides several financial benefits such as federal tax credit incentives for installation, net metering credit from excess generated electricity added back to the grid, and savings in price per kilowatt-hour (kWh) from the PV system generation versus the increasing conventional utility price per kWh. As much benefit as stand-alone PV systems present, the incorporation of energy storage yields even greater benefits. Energy storage (ES) is capable of storing unused PV provided energy from daytime periods of …

Indirect Adaptive Neurofuzzy Hermite Wavelet Based Control Of Pv In A Grid-Connected Hybrid Power System, Sidra Mumtaz, Laiq Khan

Turkish Journal of Electrical Engineering and Computer Sciences

Owing to the evolution of the smart grid, the emergence of hybrid power systems (HPSs), and the proliferation of plug-in-hybrid electric vehicles, the development of efficient and robust maximum power point tracking (MPPT) algorithms for renewable energy sources due to their inherent intermittent nature has overwhelmed the power industry. In this paper, an incremental conductance (IC) based Hermite wavelet incorporated neurofuzzy indirect adaptive MPPT control paradigm for a photovoltaic (PV) system in a grid-connected HPS is proposed. The performance of the proposed adaptive Hermite wavelet incorporated neurofuzzy MPPT control paradigm is validated through a comprehensive grid-connected HPS test-bed developed in …

Structure Stability And Optical Response Of Lead Halide Hybrid Perovskite Photovoltaic Materials: A First-Principles Simulation Study, Siddharth Narendrakumar Rathod

Browse all Theses and Dissertations

A third-generation of solar cell is based on organic-inorganic hybrid perovskite materials. These have reached up to 22.1% conversion efficiency through exponential growth just within the last decade, compared to much longer improvement times for other photovoltaic technologies. Lead halide perovskites are among the most commonly used materials in this context. Despite the relatively large number of available works on some of these materials, in particular CH3NH3PbI3, others are less investigated. Here, we focused on CH3NH3PbCl3, CH3NH3PbBr3 and CH3NH3PbI3 for assessing structure stability and optical response. Using quantum-mechanics-based first principles approaches, we calculated the optimized structures of these three materials …

Configuration And Electronic Properties Of The Interface Between Lead Iodide Hybrid Perovskite And Self-Assembled Monolayers In Solar Cells, Parin Divya Amlani

Browse all Theses and Dissertations

Hybrid perovskite photovoltaic materials are currently the most promising functional materials for solar cell applications with efficiency reaching to those of more conventional materials such as silicon. Using self-assembled monolayers between photovoltaic materials and electrodes is a method for improving the stability and functionality. Recent experiments have shown that using 4-mercaptobenzoic acid and pentafluorobenzenethiol monolayers bridging lead iodide hybrid perovskite photovoltaic materials and electrodes result in improved stability and efficiency. The details of monolayer assembly, molecular adsorption configuration, and resulting modification of electronic properties are important characteristics related to solar cell performance. These characteristics can be obtained through accurate computer …

Power Quality Improvement In Fuel Cell Based Hybrid Power System Using Statcom, Sandipan Patra

Student Journal of Energy Research

This paper presents the power quality improvement in a microgrid, supplying a nonlinear and unbalanced load using fuzzy logic controller based static synchronous compensator (STATCOM). The microgrid contains a hybrid combination photovoltaic (PV), fuel cell (FC) along with the battery energy storage system (BESS) where a decentralized power sharing algorithm is used to control its power management. Here, STATCOM is used as a compensator for the hybrid system to reduce the harmonics in the voltage and current profile at the point of common coupling (PCC). The current reference is generated taking into account, the active and reactive power to be …

Theory Of Carrier Transport From First Principles: Applications In Photovoltaic And Thermoelectric Materials, Alireza Faghaninia

McKelvey School of Engineering Theses & Dissertations

New sources of energy that are environmentally friendly, cost-effective, and renewable are essential if we are to combat the effects of global climate change. Two of these sources are solar photovoltaic (PV) cells to convert sunlight into electricity and thermoelectric (TE) devices to convert heat to electricity. To be practical on a large scale, the properties (e.g. electrical conductivity, band gap, Seebeck coefficient, etc) of the the underlying materials must be improved significantly through judicious control of structure and composition. Significant understanding of materials properties is required to design and engineer new high-performing materials. First principles calculations using density functional …

A Novel Approach For Evaluating The Impact Of Fixed Variables On Photovoltaic (Pv) Solar Installations Using Enhanced Meta Data Analysis Among Higher Education Institutions In The United States, Diane N. De Hoyos

Open Access Theses & Dissertations

The global demand for electric energy has continuously increased over the last few decades. Some mature, alternative generation methods are wind, power, photovoltaic panels, biogas and fuel cells. In order to find alternative sources of energy to aid in the reduction of our nation's dependency on non-renewable fuels, energy sources include the use of solar energy panels. The intent of these initiatives is to provide substantial energy savings and reduce dependence on the electrical grid and net metering savings during the peak energy-use hours.

The focus of this study explores and provides a clearer picture of the adoption of solar …

A Current-Based Simple Analog Mppt Circuit For Pv Systems, Bülent Büyükgüzel, Murat Aksoy

Turkish Journal of Electrical Engineering and Computer Sciences

A new single pilot-sensor maximum power point tracking (MPPT) system, consisting of a buck type DC/DC converter, was developed. It is controlled by an analog-based unit. The main difference between the proposed MPPT system and other systems is that the short circuit current of the pilot-PV module in our system is used to control the DC/DC converter. The circuit of the proposed system does not utilize an expensive digital signal processor nor a microcontroller; hence, the cost and the complexity of the system are reduced.

Solar Irradiation Estimator Based On A Self-Calibrated Reference Solar Cell, Touria Hassboun, Lhoussain El Bahir, Youness Aite Driss, Mustapha El Adnani

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper we propose a concept for estimating solar irradiation based on measurements of the current, voltage, and temperature of a photovoltaic (PV) cell. The estimation of the irradiation is obtained by processing these measurements using a PV cell mathematical model combined with a PI controller. Since the PV cell current is very sensitive to the irradiance level, the principle of the method is to force the model to reproduce the same current as that measured on the cell by applying an appropriate irradiance as input, for measured temperature and voltage. The appropriate irradiance, which is the output of …

A Conceptual Implementation Of A Buck Converter For An Off-Grid Hybrid System Consisting Of Solar And Wind Turbine Sources, Ahmad Shukri Fazil Rahman, Abdul Rahim Abdul Razak, Syed Idris Syed Hassan

Turkish Journal of Electrical Engineering and Computer Sciences

A hybrid renewable power generation system is proposed through parallel connection between two potential energy resources: photovoltaic (PV) and wind turbines. The method consists of incorporating a buck converter connected by a wind turbine to provide adjustment according to PV potential. Unlike the conventional buck-boost converter topology that is normally used, this research tries to emphasize the use of a buck converter as part of the system configuration. Design schemes were carefully performed and the postdesign system was tested through system simulation with MATLAB/Simulink software. The simulated system offers promising and significant results, thus making it suitable for hardware implementation.

A New Algorithm Of Parameter Estimation Of A Photovoltaic Solar Panel, Mustapha Belarbi, Kamel Haddouche, El-Habib Belarbi, Amine Boudghene-Stambouli

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we present a new approach for estimating the one-diode model parameters of a photovoltaic solar panel according to the irradiance and temperature. These parameters are given, at a known irradiance and temperature, from the knowledge of three operating points: short circuit, open circuit, and maximum power. In the first step, the adopted approach concerns the resolution of the system of equations constituting the three operating points to write all the model parameters according to series resistance. Secondly, we make an iterative resolution at the optimal operating point by using the Newton--Raphson method to calculate the series resistance …

Photovoltaics: An Investigation Into The Origins Of Efficiency On All Scales, Jeremy Alexander Bannister

Senior Projects Spring 2016

This project is comprised of a set of parallel investigations, which share the common mo- tivation of increasing the efficiency of photovoltaics. First, the reader is introduced to core concepts of photovoltaic energy conversion via a semi-classical description of the phys- ical system. Second, a key player in photovoltaic efficiency calculations, the exciton, is discussed in greater quantum mechanical detail. The reader will be taken through a nu- merical derivation of the low-energy exciton states in various geometries, including a line segment, a circle and a sphere. These numerical calculations are done using Mathematica, a computer program which, due to …