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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Wind energy projects in Mexico

Calderon, Gilberto Adolfo 24 August 2010 (has links)
The interest in renewable energy has grown in recent decades because of environmental effects of fossil fuels and technological advances that have made some renewable energy technologies competitive with conventional gas fired power plants. Wind energy is playing a major role in increasing renewable energy’s share of electricity production worldwide. The global installed capacity of wind power has grown at a rate of more than 20% each year since the year 2000 (WWEA, 2009). Currently, the Mexican electricity sector is comprised of fossil fuel fired power plants. However, Mexico has a large endowment of renewable energy resources that can be harnessed to generate electricity. For example, the Comisión Reguladora de Energía estimates that Oaxaca´s wind power potential is about 10,000 MW (CRE, 2006). Studies have shown that Baja California´s wind power potential is also about 10,000 MW (KEMA, 2008). This thesis focuses on wind energy because it is expected to grow at the fastest rate during the next decade in Mexico relative to other renewable energy sources (Sener, 2008). Mexico’s installed wind power capacity is 202.5 MW. This capacity will increase by 456 MW by the end of 2010. Another 2,123 MW will be added during the period 2010-2012 (AMDEE, 2006). This research investigates various aspects of the wind farm development process in Mexico. The initial chapters describe the electricity sector and its participants. Subsequent chapters describe the regulatory framework and the mechanisms used by private investors to finance renewable energy projects. The final chapters describe the economic aspects of wind energy projects using a conventional discounted cash flow model. Statistical simulation is used to estimate capacity factors, and design of experiments is used to statistically analyze performance under different scenarios. / text
2

An investigation of H configuration vertical axis wind turbine dynamic instability

Courtney, M. S. January 1986 (has links)
No description available.
3

An Adaptive Control Algorithm For Maximum Power Point Tracking for Wind Energy Conversion Systems

Hui, Joanne 16 December 2008 (has links)
Wind energy systems are being closely studied because of its benefits as an environmentally friendly and renewable source of energy. Because of its unpredictable availability, power management concepts are essential to extract as much power as possible from the wind when it becomes available. The purpose of this thesis is to presents a new adaptive control algorithm for maximum power point tracking (MPPT) in wind energy systems. The proposed control algorithm allows the generator to track the optimal operation points of the wind turbine system under fluctuating wind conditions and the tracking process speeds up over time. This algorithm does not require the knowledge of intangible turbine mechanical characteristics such as its power coefficient curve, power characteristic or torque characteristic. The algorithm uses its memory feature to adapt to any given wind turbine and to infer the optimum rotor speeds for wind speeds that have not occurred before. The proposed algorithm uses a modified version of Hill Climb Search (HCS) and intelligent memory to implement its power management scheme. This algorithm is most suitable for smaller grid or battery connected wind energy systems. PSIM simulation studies have been done to confirm the effectiveness of the proposed algorithm. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2008-12-15 20:47:44.884
4

Application of wind modelling techniques in complex terrain

Hannah, Paul January 1993 (has links)
No description available.
5

The aerodynamic control of the V-type vertical axis wind turbine

Robotham, A. J. January 1989 (has links)
The V-type vertical axis wind turbine (V-VAWT) is of simple design and construction, has a low aerodynamic efficiency, yet its originators consider that it will be a cost effective configuration in electricity generation applications. However, the quality and reliability of its power output must be ensured; this necessarily requires continual control of rotor speed and power. The initial V-VAWT investigations of Sharpe and Taylor, and methods of wind turbine control are reviewed. Partial-span pitch angle variation is considered the most promising option, and the systematic investigation of this control method in V-VAWT applications is reported. This work includes the design, construction and performance testing of a small V-VAWT with pitching blade tips. The tests showed that rotor power can be regulated with small blade tip areas, however, correlation between the measured and theoretical results was not good. Wind tunnel test were undertaken to determine the characteristics of the NACA0025 aerofoil used for the model blades. Performance predictions using this data showed better correlation between experimental and- theoretical results. This has allowed the theoretical model to be used with confidence for predicting the performance of larger V-VAWTs with partial-span pitch control. A theoretical model of the dynamic behaviour of a V-VAWT generator integrated with an electricity supply network has been developed and embodied in the computer program DYNVAWT. This program has allowed the dynamic behaviour of a 5kW sized V-VAWT to be simulated, and an active control strategy developed. The simulation studies show that active partial-span pitch control ensures the quality and reliability of the electricity supply can be maintained even when the V-VAWT is operating in turbulent wind conditions.
6

Statistical characteristics and mapping of near-surface and elevated wind resources in the Middle East

Yip, Chak Man Andrew 28 November 2018 (has links)
Wind energy is expected to contribute to alleviating the rise in energy demand in the Middle East that is driven by population growth and industrial development. However, variability and intermittency in the wind resource present significant challenges to grid integration of wind energy systems. The first chapter addresses the issues in current wind resource assessment in the Middle East due to sparse meteorological observations with varying record lengths. The wind field with consistent space-time resolution for over three decades at three hub heights over the whole Arabian Peninsula is constructed using the Modern Era Retrospective-Analysis for Research and Applications (MERRA) dataset. The wind resource is assessed at a higher spatial resolution with metrics of temporal variations in the wind than in prior studies. Previously unrecognized locations of interest with high wind abundance and low variability and intermittency have been identified in this study and confirmed by recent on-site observations. The second chapter explores high-altitude wind resources that may provide alternative energy resources in this fossil-fuel-dependent region. This study identifies areas favorable to the deployment of airborne wind energy (AWE) systems in the Middle East and computes the optimal heights at which such systems would best operate. AWE potential is estimated using realistic AWE system specifications and assumptions about deployment scenarios and is compared with the near-surface wind generation potential concerning diurnal and seasonal variability. The results show the potential utility of AWE in areas in the Middle East where the energy demand is high. The third chapter investigates the potential for wind energy to provide a continuous energy supply in the region. We characterize the wind power variability at various time-scales of power operations to illustrate its effects across the Middle East via spectral analysis and clustering. Using a high-resolution dataset obtained from Weather Forecasting and Research (WRF) model simulations, this study showcases how aggregate variability may impact operation, and informs the planning of large-scale wind power integration in the Middle East in light of the scarcity of observational data.
7

Comparison of Large Scale Renewable Energy Projects for the United States Air Force

Hughes, Jeffrey S. 16 October 2012 (has links)
This thesis focused on the performance of large-scale renewable energy projects for the United States Air Force. As global energy demands continue to rise, the need to find ways to save energy and produce alternative sources of energy will increase. The Federal Government has begun to address the challenge of energy production and energy security in recent years. In order to increase both the energy production and energy security for the Air Force, there is a trend to increase the amount of renewable energy produced on military installations. The goal of this research was to compare the estimated and actual performance of these large-scale on-site renewable energy projects at Air Force installations. The variables considered for this research were the execution methods and the renewable energy sources. The performance of each project was evaluated against factors identified in previous sustainable construction studies. The study found that actual performance of third party owned and operated projects differed from the expected performance by less than the Air Force owned and operated projects, and that performance of renewable energy projects differed from the expected performance by less than high performance buildings from previous studies. The study also found factors that contributed to the gap between the expected and actual performance including optimistic modeling, unusual weather, operational issues and higher than expected maintenance of the projects. The results of this research were an initial step in understanding the actual performance of large-scale renewable energy projects. / Master of Science
8

The challenges to integrating wind energy : a study of ERCOT’s ability to integrate substantial amounts of wind energy by 2030

Lapierre, Nathan Richard 26 October 2010 (has links)
The wind energy industry in the U.S. has seen robust growth within the last two decades. The amount of renewable resources available throughout the U.S. is substantial, and as renewable energy penetration approaches a significant proportion of total electricity generation, grid operators and utilities will be presented with a myriad of challenges. Such is the case in wind’ rich Texas, where the rate of wind installations surpasses every other state and rivals that of China. By the end of 2009, the ERCOT region of Texas had approximately 9000 MW installed, serving 6.5% of the annual electricity load . The intermittent nature of wind energy can place a burden on existing generators as they are increasingly relied on to provide regulation of power, frequency control and back-up energy services when wind production is low. Exacerbating the difficulty of integrating wind energy is the mismatch of wind generation and electricity demand. Although Texas is blessed with plentiful wind resources, the majority of energy produced typically occurs at night when electricity demands are low. The result is transmission congestion that prevents cost effective generators from serving load. Despite these integration difficulties, ERCOT is paving the way forward with transformative infrastructure plans and proactive rulemaking. This report provides a background on the state of the wind energy industry in the U.S., with a review of power system operation strategies and wind integration best practices. With that context, this study concludes that ERCOT’s electricity market operations, transmission plans, and Texas’ renewable energy policies will act to reasonably and reliably accommodate wind generation capacity that serves over 15% of annual load by 2030. / text
9

Wind energy in Kansas: to build…or not to build?

Elder, Roderic L. January 1900 (has links)
Master of Arts / Department of Landscape Architecture/Regional and Community Planning / Claude A. Keithley / In these times of high energy costs, dwindling supplies of fossil fuels, and talk of “global warming,” we must decide what we are going to do to with the abundance of wind energy available in Kansas. We can no longer afford to “drift,” not caring about the sources of our electricity, or what we are doing to the planet. We must act now to ensure a bright future for our children. Many wind turbines are being erected across Kansas, and this natural resource of wind energy is one that should be tapped, but only after careful planning. There are many factors to consider regarding wind farms; environmental concerns, economics, impacts on the health and well-being of individuals living near wind farms, and tax implications, to mention only a few. Studies are being completed on these issues, and due consideration must be given prior to construction. There are areas across the state that should be avoided when locating wind farms, and other areas in which wind turbines might be a natural “fit.” It is the latter areas which should be the focus of attention for construction, but again, only after giving careful consideration to the overall effects. Wind energy has become a part of Kansas, but future site selections should be done only after careful planning.
10

An appraisal of wind energy conversion systems for agricultural enterprises

Macmillan, Susan January 1989 (has links)
No description available.

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