Engineering Commons^™

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 …

Investigation Of Efficiency Loss Of Distributed Solar Power Due To Soiling And Efficiency Recovery By Rainfall, Amanda Mayumi Tanaka

UNLV Theses, Dissertations, Professional Papers, and Capstones

As the concern with global warming increases causing the need for CO2 reduction, renewable energy is of great interest as it has lower carbon footprint when compared to conventional sources (natural gas, coal, oil and nuclear). Solar energy has been drawing worldwide attention since it can transform sunlight directly into electricity with the use of photovoltaic (PV) cells. However, this technology has some drawbacks that need to be addressed including dust deposition on solar panels, also known as soiling. Soiling can decrease PV panel’s efficiency thereby resulting in less energy production. The soiling rates are very site specific and depend …

The Impact Of Waters Of Low Quality On Soiling Removal From Photovoltaic Panels, Alisson Luiz Boeing

UNLV Theses, Dissertations, Professional Papers, and Capstones

Soiling, bird droppings, or the accumulation of dust on the surface of photovoltaic cells, can significantly reduce the solar energy absorption and produce power losses. In solar plants where soiling is a problem, solar facilities use demineralized or distilled water for washing the panels to avoid mineral scale deposits that might interfere with solar irradiance absorption. However, in arid and dusty environments, water is normally scarce. For cleaning solar panels, the use of low quality water in lieu of the industry-standard demineralized water could conserve fresh water. The objectives of this research were as follows: evaluate the impacts of low …

Chemical And Electronic Structure Of Surfaces And Interfaces In Cadmium Telluride Based Photovoltaic Devices, Douglas Arthur Duncan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The surface and interface properties are of the upmost importance in the understanding, optimization, and application for photovoltaic devices. Often the chemical, electronic, and morphological properties of the films are empirically optimized, however when progress slows, a fundamental understanding of these properties can lead to breakthroughs. In this work, surfaces and interfaces of solar cell-relevant films are probed with a repertoire of X-ray analytical and microanalysis techniques including X-ray photoelectron (XPS), X-ray excited Auger electron (XAES), X-ray emission (XES) spectroscopies, and atomic force (AFM) and scanning electron (SEM) microscopies.

Silicon-based devices currently dominate the solar market, which is rather inflexible …

Dynamic Modelling Of Single Phase Grid Connected Photovoltaic System, Gopi Krishna Ari

UNLV Theses, Dissertations, Professional Papers, and Capstones

Grid-connected photovoltaic (PV) power systems have been sustaining an exponential growth rate during the past decade. This steep growth is driven by a growing concern about climate change, the adoption of an aggressive regional renewable portfolio standard, rebates and tax incentives, and reduction in PV system cost. One of the main technical barriers that can ultimately limit further PV penetration is the fast variations in the PV system's output power induced by cloud transients. Such events are known to cause voltage fluctuations which may lead to excessive operations of voltage regulation equipment and light flickering.

Solar irradiance variability, which can …