Power and Energy Commons^™

Synthesis Of Graphene And Its Applications For Dye-Sensitized Solar Cells, Hui Wang

Dissertations, Master's Theses and Master's Reports - Open

Graphene, which is a two-dimensional carbon material, exhibits unique properties that promise its potential applications in photovoltaic devices. Dye-sensitized solar cell (DSSC) is a representative of the third generation photovoltaic devices. Therefore, it is important to synthesize graphene with special structures, which possess excellent properties for dye-sensitized solar cells.

This dissertation research was focused on (1) the effect of oxygen content on the structure of graphite oxide, (2) the stability of graphene oxide solution, (3) the application of graphene precipitate from graphene oxide solution as counter electrode for DSSCs, (4) the development of a novel synthesis method for the three-dimensional …

Development And Implementation Of A Simplified Residential Energy Asset Rating Model, Daire Reilly, Aidan Duffy, David Willis, Michael Conlon

Other resources

In accordance with national and European policies, the provision of financial assistance to residential energy consumers has led to a greater awareness of and interest in energy retrofit technologies. However, at present Irish energy consumers have no appropriate advice on the future performance of retrofit options available to them. This is a significant limitation to decision making and technology uptake, since this group need to know whether their investment is likely to be worthwhile.

The asset rating methodology developed for the certification of energy performance of buildings is the current industry standard of prediction of energy demand and post retrofit …

Geothermal Injection Well Monitoring, Timothy Rempher

Electrical Engineering

People depend on electricity all over the world. They depend on it for anything from drying their hair to global communications to heating up food. Many methods of power generation exist, each using a different fuel such as nuclear power, natural gas, coal, wind or the sun. This project focuses on a power plant which uses the naturally hot water in the ground to generate electricity. This process of generating power is called “Geothermal.” This project consists of two parts. The first and major part is the design logic of a PLC program that monitors the flow rate of an …

Economic Challenges And Optimisation Of Ocean Energy Electrical Systems, Fergus Sharkey

Books/Book chapters

No abstract provided.

Fundamentals Of Pv Efficiency Interpreted By A Two-Level Model, Muhammad A. Alam, Mohammad Ryyan Khan

Birck and NCN Publications

We consider the physics of photovoltaic (PV) energy conversion in a two-level, atomic PV and explain the conditions for which the Carnot efficiency is reached and how it can be exceeded. The loss mechanisms—thermalization, angle entropy, and below-bandgap transmission—explain the gap between Carnot efficiency and the Shockley-Queisser limit. Techniques developed to reduce these losses (e.g., solar concentrators, tandem cells, etc.) are reinterpreted using a simple two-level model. Remarkably, this simple model captures the essence of PV operation and reproduces the key results and important insights that that have been previously obtained using more complicated derivations.

Synthesis And Characterization Of Graphene Oxide/Sulfur Nanocomposite For Lithium-Ion Batteries, Aaron Joseph Blake

Browse all Theses and Dissertations

The growing need for clean and efficient energy storage systems has recently peaked due to concerns of climate change and increased global energy consumption. However, efficiently integrating renewable resources such as solar and wind energy into society will require a complex electrical energy storage (EES) system capable of storing and expending significant amounts of energy. A battery based on the lithium/sulfur couple can yield a theoretical specific energy of 2600Wh/kg, which is about five times higher than that offered by present Li-ion batteries, and hence, is a promising and attractive technology. Despite recent developments in addressing various issues inherent to …

Resilience Governance Through Serious Energy Gaming, Adrian V. Gheorghe, Dan V. Vamanu

Engineering Management & Systems Engineering Faculty Publications

Physical analogies emphasizing cooperative behavior in systems are explored and integrated into so called 'serious energy games', to contribute in a better understanding, monitoring and good governance of some of the complex security issues confronting the evolvement of contemporary energy systems. It is believed that such exercises might be supportive in the necessary attempt, by the many stakeholders and actors / agents involved, to bring balance to prevailing policies of which seems to be “Go change yourself - in a resilient fashion!” An extrapolation of several findings to other than energy systems tempted to implement drastic changes based on substantial …

Investigation Of Cds Nanowires And Planar Films For Enhanced Performance As Window Layers In Cds-Cdte Solar Cell Devices, Jianhao Chen

Theses and Dissertations--Electrical and Computer Engineering

Cadmium sulfide (CdS) and cadmium telluride (CdTe) are two leading semiconductor materials used in the fabrication of thin film solar cells of relatively high power conversion efficiency and low manufacturing cost. In this work, CdS/CdTe solar cells with a varying set of processing parameters and device designs were fabricated and characterized for comparative evaluation. Studies were undertaken to elucidate the effects of (i) each step in fabrication and (ii) parameters like thickness, sheet resistance, light absorptivity solution concentration, inert gas pressure etc. Best results were obtained when the thickness of CdS planar film for the window layer was in the …

Copper Indium Diselenide Nanowire Arrays In Alumina Membranes Deposited On Molybdenum And Other Back Contact Substrates, Bhavananda R. Nadimpally

Theses and Dissertations--Electrical and Computer Engineering

Heterojunctions of CuInSe₂ (CIS) nanowires with cadmium sulfide (CdS) were fabricated demonstrating for the first time, vertically aligned nanowires of CIS in the conventional Mo/CIS/CdS stack. These devices were studied for their material and electrical characteristics to provide a better understanding of the transport phenomena governing the operation of heterojunctions involving CIS nanowires. Removal of several key bottlenecks was crucial in achieving this. For example, it was found that to fabricate alumina membranes on molybdenum substrates, a thin interlayer of tungsten had to be inserted. A qualitative model was proposed to explain the difficulty in fabricating anodized aluminum oxide …

Cal Poly Nano Hydro, Brandon N. Fujio, Alex J. Sobel, Andrew F. Del Prete

Mechanical Engineering

This projects goal was to design, construct, and test a machine capable of generating a usable amount of energy from naturally flowing water. The device conceived for this purpose is a portable raft with a turbine mounted to the underside. The turbine is mated directly to a low angular velocity generator which outputs to a power electronics system on shore. Using a Gorlov Helical turbine, this proof-of-concept is designed to output ~50 Watts of electricity to charge a battery for later use. Possible applications for this device include camping in remote locations, supplemental power generation for a home, or for …

An Investigation Into Energy Consumption And Existing Energy Management Practices In A Dublin Sports Centre, Colin J. Conway

Dissertations

Rising energy costs are a concern to all businesses but especially to those who have a large energy demand. Sports centres with swimming pools have large requirements for heat and electricity in order to maintain thermal comfort within the pool and surrounding areas.

Sports centres which were built in the 1970s were designed at a time when energy was cheap and many of today’s control strategies and energy efficiency measures were unavailable.

This project is an investigation into the electrical and thermal consumption of the Tallaght Sports Complex. The Tallaght Sports Complex was built in the 1970s and is lacking …

An Evaluation Of Seawater Pumped Hydro Storage For Regulating The Export Of Wind Energy To The National Grid, Eoin D. Mclean

Dissertations

Hydroelectric power generation has been in use for a very long time. From the earliest watermills to the current large scale Hydro power plants, this is a technology that is proven to be reliable and commercially viable. The use of wind energy to provide mechanical power for the purpose of turning a rotor is also not a new concept.Four years ago TCD Professor of Applied Physics Igor Shvets conceived the idea of solving Ireland’s energy crisis by taking these two proven renewable technologies and combining them. (McGreevey, 2012) The spirit of Ireland initiative seeks to resolve the biggest issues facing …

Optimal Power Generation In Microgrids Using Agent-Based Technology, Thair Mahmoud

Theses: Doctorates and Masters

The existing power grids that form the basis of the respective electrical power infrastructures for various states and nations around the world, are expected to undergo a period of rapid change in the near future. The key element driving this change is the emergence of the Smartgrid. The Smartgrid paradigm represents a transition towards an intelligent, digitally enhanced, two-way power delivery grid. The aim of the Smartgrid is to promote and enhance the e_cient management and operation of the power generation and delivery facilities, by incorporating advanced communications, information technology, automation, and control methodologies into the power grid proper. Smartgrid's …

Optimal Control Of Power Quality In Microgrids Using Particle Swarm Optimisation, Waleed Abood Baddai Al-Saedi

Theses: Doctorates and Masters

Driven by environmental protection, economic factors, conservation of energy resources, and technical challenges, the microgrid has emerged as an innovative small-scale power generation network. Microgrids consist of a cluster of Distributed Generation units that encompass a portion of an electric power distribution system and may rely on different energy sources. Functionally, the microgrid is required to provide adequate levels and quality of power to meet load demands. The issue of power quality is significant as it directly affects the characteristics of the microgrid’s operation. This problem can be defined as an occurrence of short to long periods of inadequate or …

Nanoscale Electrochemistry By In-Situ Transmission Electron Microscopy, Qi Gao

Dissertations, Master's Theses and Master's Reports - Open

Nanoscale research in energy storage has recently focused on investigating the properties of nanostructures in order to increase energy density, power rate, and capacity. To better understand the intrinsic properties of nanomaterials, a new and advanced in situ system was designed that allows atomic scale observation of materials under external fields. A special holder equipped with a scanning tunneling microscopy (STM) probe inside a transmission electron microscopy (TEM) system was used to perform the in situ studies on mechanical, electrical, and electrochemical properties of nanomaterials. The nanostructures of titanium dioxide (TiO2) nanotubes are characterized by electron imaging, diffraction, and chemical …

High Voltage Electrophoretic Deposition For Electrochemical Energy Storage And Other Applications, Sunand Santhanagopalan

Dissertations, Master's Theses and Master's Reports - Open

High voltage electrophoretic deposition (HVEPD) has been developed as a novel technique to obtain vertically aligned forests of one-dimensional nanomaterials for efficient energy storage. The ability to control and manipulate nanomaterials is critical for their effective usage in a variety of applications. Oriented structures of one-dimensional nanomaterials provide a unique opportunity to take full advantage of their excellent mechanical and electrochemical properties. However, it is still a significant challenge to obtain such oriented structures with great process flexibility, ease of processing under mild conditions and the capability to scale up, especially in context of efficient device fabrication and system packaging. …

Experimental Investigation Into Particulate Matter Distribution In Catalyzed Particulate Filters Using A 3d Terahertz Wave Scanner, Ryan Kristopher Foley

Dissertations, Master's Theses and Master's Reports - Open

The particulate matter distribution (PM) trends that exist in catalyzed particulate filters (CPFs) after loading, passive oxidation, active regeneration, and post loading conditions are not clearly understood. These data are required to optimize the operation of CPFs, prevent damage to the CPFs caused by non-uniform distributions, and develop accurate CPF models. To develop an understanding of PM distribution trends, multiple tests were conducted and the PM distribution was measured in three dimensions using a terahertz wave scanner. The results of this work indicate that loading, passive oxidation, active regeneration, and post loading can all cause non-uniform PM distributions. The density …

Local Digital Control Of Power Electronic Converters In A Dc Microgrid Based On A-Priori Derivation Of Switching Surfaces, Bibaswan Banerjee

Dissertations, Master's Theses and Master's Reports - Open

In power electronic basedmicrogrids, the computational requirements needed to implement an optimized online control strategy can be prohibitive. The work presented in this dissertation proposes a generalized method of derivation of geometric manifolds in a dc microgrid that is based on the a-priori computation of the optimal reactions and trajectories for classes of events in a dc microgrid. The proposed states are the stored energies in all the energy storage elements of the dc microgrid and power flowing into them. It is anticipated that calculating a large enough set of dissimilar transient scenarios will also span many scenarios not specifically …

Computational Modeling Of Graphene Oxide Exfoliation And Lithium Storage Characteristics, Reza Mortezaee

Browse all Theses and Dissertations

Graphene oxide is a two dimensional material obtained by adsorption of oxygen or oxygen-containing groups on graphene. Stacked layers of graphene oxide constitute graphite oxide. These materials have various applications such as a source material for graphene production, transport support for electron microscopy, flexible organic photovoltaic cells and use in Li-ion batteries. Generation of exfoliated graphene oxide from a graphite oxide precursor is achieved relatively easily in solution as compared to graphene exfoliation. In this study we investigate the details of the graphene oxide exfoliation procedure in solution by calculating the Gibb's free energies and reaction rates. We consider two …

Design And Fabrication Of An Eddy Current Brake Dynamometer For Efficiency Determination Of Electric Wheelchair Motors, Wesley Brin

Browse all Theses and Dissertations

Electric wheelchairs have a considerable impact on improving the quality of life for the millions of disabled persons around the world. These modern pieces of technology offer freedom and mobility for disabled persons to interact with the world outside of their homes. The goal of this project is to assist in advancements of conventional electric wheelchairs. This includes replacing the heavy, bulky, and inefficient lead acid batteries and worm gear drive systems with lithium-ion batteries and wheel hub motors in order to decrease weight and size, and increase efficiency. This master thesis research is focused on designing, fabricating, and testing …

Fpga To Power System Theorization For A Fault Location And Specification Algorithm, Christina Yeoman

Theses and Dissertations--Electrical and Computer Engineering

Fault detection and location algorithms have allowed for the power industry to alter the power grid from the traditional model to becoming a smart grid. This thesis implements an already established algorithm for detecting faults, as well as an impedance-based algorithm for detecting where on the line the fault has occurred and develops a smart algorithm for future HDL conversion using Simulink. Using the algorithms, the ways in which this implementation can be used to create a smarter grid are the fundamental basis for this research. Simulink was used to create a two-bus power system, create environment variables, and then …

Active Optimal Control Strategies For Increasing The Efficiency Of Photovoltaic Cells, Sharif Aljoaba

Theses and Dissertations--Electrical and Computer Engineering

Energy consumption has increased drastically during the last century. Currently, the worldwide energy consumption is about 17.4 TW and is predicted to reach 25 TW by 2035. Solar energy has emerged as one of the potential renewable energy sources. Since its first physical recognition in 1887 by Adams and Day till nowadays, research in solar energy is continuously developing. This has lead to many achievements and milestones that introduced it as one of the most reliable and sustainable energy sources. Recently, the International Energy Agency declared that solar energy is predicted to be one of the major electricity production energy …

Power System State Estimation Using Phasor Measurement Units, Jiaxiong Chen

Theses and Dissertations--Electrical and Computer Engineering

State estimation is widely used as a tool to evaluate the real time power system prevailing conditions. State estimation algorithms could suffer divergence under stressed system conditions. This dissertation first investigates impacts of variations of load levels and topology errors on the convergence property of the commonly used weighted least square (WLS) state estimator. The influence of topology errors on the condition number of the gain matrix in the state estimator is also analyzed. The minimum singular value of gain matrix is proposed to measure the distance between the operating point and state estimation divergence.

To study the impact of …

Power Control Of Single-Stage Pv Inverter For Distribution System Volt-Var Optimization, Xiao Liu

Theses and Dissertations--Electrical and Computer Engineering

The output power variability of intermittent renewable sources can cause significant fluctuations in distribution system voltages. A local linear controller that exploits the capability of a photovoltaic inverter to provide both real and reactive power is described. This controller substitutes reactive power for real power when fluctuations in the output of the photovoltaic source are experienced. In this way, the inverter can help mitigate distribution system voltage fluctuations. In order to provide real and reactive to the grid, a three-phase grid-connected single-stage photovoltaic system with maximum power point tracking and power control is described. A method of reducing the current …

Contingency Analysis Of Power Systems In Presence Of Geomagnetically Induced Currents, Sivarama Karthik Vijapurapu

Theses and Dissertations--Electrical and Computer Engineering

Geomagnetically induced currents (GIC) are manifestations of space weather phenomena on the electric power grid. Although not a new phenomenon, they assume great importance in wake of the present, ever expanding power grids. This thesis discusses the cause of GICs, methodology of modeling them into the power system and the ramifications of their presence in the bulk power system. GIC is treated at a micro level considering its effects on the power system assets like Transformers and also at a macro level with respect to issues like Voltage instability. In illustration, several simulations are made on a transformer & the …

Dc-Dc Converter Input Protection System For The Energy Harvesting From Exercise Machines (Ehfem) Project, Ryan Turner, Zack Weiler

Electrical Engineering

The ongoing Energy Harvesting from Exercise Machines (EHFEM) project at Cal Poly San Luis Obispo seeks to provide renewable energy without the high cost of implementation by harvesting DC power generated on machines used for physical exercise. The EHFEM project consists of numerous subprojects that involve converting different types of exercise machines for power generation. This project specifically works by scaling the output voltage from an elliptical machine using a DC-DC converter and sending it through an Enphase Micro-inverter to feed AC power back to the power grid and minimize energy spending. As a subset of the much larger project, …

Wireless Sensor Networks And The Internet Of Things, Yingtao Jiang, Lei Zhang, Ling Wang

Electrical & Computer Engineering Faculty Research

It is estimated that mobile internet devices that can act as sensors will outnumber humans this year (2013), and by 2015, there will be about 15 billion internet-connected devices. Related applications are thriving in commercial, civic, and scientific operations that involve sensors, web, and services, leading by both academic societies and industry companies. It is commonly accepted that the next generation of internet is becoming the “Internet of Things (IoT)” which is a worldwide network of interconnected objects and their virtual representations uniquely addressable based on standard communication protocols. Identified by a unique address, any object including computers, mobile phones, …

Tunable Fano Resonances Based On Two-Beam Interference In Microring Resonator, Ting Hu, Ping Yu, Chen Qui, Huiye Qui, Fan Wang, Mei Yang, Xiaoqing Jiang, Hui Yu, Jianyi Yang

Electrical & Computer Engineering Faculty Research

In this paper, a resonant system is demonstrated on silicon-on-insulator wafer to achieve tunable Fano resonances. In this system, the Fano resonance originates from the interference of two beams resonant in the microring resonator. The shapes of the Fano resonances are tunable through controlling the phase difference of the two beams. Both large slope and high extinctionratio (ER) are obtained when the phase difference is 0.5π or 1.5π. Experimental results show that Fano resonances with steep slope and ER over 20 dB are achieved in the whole free spectral range by controlling the microheaters to meet the phase condition.

Estimation Of Performance Indices For The Planning Of Sustainable Transportation Systems, Alexander Paz, Pankaj Maheshwari

Electrical & Computer Engineering Faculty Research

In the context of sustainable transportation systems, previous studies have either focused only on the transportation systemor have not used a methodology that enables the treatment of incomplete, vague, and qualitative information associated with the available data. This study proposes a system of systems (SOS) and a fuzzy logic modeling approach. The SOS includes the Transportation, Activity, and Environment systems. The fuzzy logic modeling approach enables the treatment of the vagueness associated with some of the relevant data. Performance Indices (PIs) are computed for each system using a number of performance measures. The PIs illustrate the aggregated performance of each …

Framework For Simulation Of Heterogeneous Mpsoc For Design Space Exploration, Bisrat Tafesse, Venkatesan Muthukumar

Electrical & Computer Engineering Faculty Research

Due to the ever-growing requirements in high performance data computation, multiprocessor systems have been proposed to solve the bottlenecks in uniprocessor systems. Developing efficient multiprocessor systems requires effective exploration of design choices like application scheduling, mapping, and architecture design. Also, fault tolerance in multiprocessors needs to be addressed. With the advent of nanometer-process technology for chip manufacturing, realization of multiprocessors on SoC (MpSoC) is an active field of research. Developing efficient low power, fault-tolerant task scheduling, and mapping techniques for MpSoCs require optimized algorithms that consider the various scenarios inherent in multiprocessor environments. Therefore there exists a need to develop …