The influence of deployment of planned wind farms on the power output and energy yield of wind farms located in close proximity at downwind sites is investigated. The atmospheric model Weather Research and Forecasting (WRF) has been employed to simulate wind resource and energy yield from wind farms in the Baja California region of Northern Mexico. Accuracy of predicted wind speed and wind turbine energy supply are evaluated against full-scale measurements from a met-mast and from each of five 2 MW turbines at the La Rumorosa wind-farm. For this wind farm location, wind speed distribution is predicted to within 1.4% and the energy supply from the farm predicted to within 5.25%. Accuracy depends on the boundary layer model and atmospheric dataset employed. Wind farms are modelled using the scheme developed by Fitch et al. (2012) in which a momentum sink and turbulent kinetic energy source are defined as a function of the turbine thrust coefficient and power output, each of which vary with wind speed as defined by the manufacturer. Planned farms of up to 72 MW installed capacity are defined in terms of turbine number, rated power and spacing at four sites such that each farm operates with a typical capacity factor. For a single farm of 2 MW turbines located 10 km upwind, wind speed at the case study wind-farm is reduced by 3.00% and power output reduced by up to 5.84%. These deficits increase if 5 MW turbines are deployed rather than 2 MW turbines due to the development of a longer far-wake. The net energy supply from several sites in the region is assessed.

Master of Regional and Community Planning / Department of Landscape Architecture/Regional and Community Planning / John W. Keller / The Great Plains possesses one of the best sources of wind energy in North America. Based upon the need to diversify energy production domestically, wind energy’s future in both the immediate and long term should be dynamic. The success of wide scale development of this potential will be largely determined by the perceptions of local residents, who are most affected by the siting and design of wind energy projects. Currently, regulation of this natural resource is left largely to state and county governments. A majority of these entities in the Great Plains region have no regulations governing wind energy development or employ a patchwork of "borrowed" codes from across the nation. The system of regulation of natural resources by political boundary is archaic. It fails to recognize that there are high degrees of correlation between social, economic, and natural resources without respect for artificial political boundaries. This study is the first in the Great Plains to examine public attitudes toward the development of wind energy and its relationship to the landscape based upon ecological regions rather than political boundaries. The analysis of collected data will provide a useful tool for local planners, policy makers, and the general public in understanding the prevalent issues involved with wind energy development in this region.

Made available in DSpace on 2014-06-11T19:22:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-28Bitstream added on 2014-06-13T19:28:01Z : No. of bitstreams: 1 ugazpena_jc_me_ilha.pdf: 1313528 bytes, checksum: cf937a97b0176d9fd8659ab572e66915 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente estudo propõe a utilização do conversor integrado Buck-Boost monofásico no aproveitamento da energia proveniente de pequenos geradores eólicos, considerando-se o atual crescimento da utilização em pequena escala de potência das fontes de energia alternativas, o que motiva o desenvolvimento de novas e eficientes tecnologias para os sistemas de conversão. Tipicamente, os sistemas de conversão de energia eólica, em baixas potências, disponibilizam tensões contínuas de saída na faixa de 12 V até 48 V (valores médios), por outro lado, a grande maioria das cargas de uso domiciliar necessitam de tensão alternada com valores eficazes entre 110 V a 240 V. Isto leva à necessidade da utilização de conversores CC-CA, denominados de inversores. As estruturas inversoras tradicionais fornecem tensões alternadas cujo valor de pico está limitado ao valor máximo da tensão de entrada, o que leva à necessidade de incluir um estágio elevador adicional ao sistema de conversão de energia eólica, antes de realizar a conversão CC-CA, resultando em redução do rendimento, aumento de peso e volume. O inversor integrado apresentado neste trabalho realiza, em uma única estrutura, as funções de elevação e redução da tensão, próprias do conversor Buck-Boost CC-CC, e a função de conversão de tensão contínua em alternada, garantindo uma baixa distorção harmônica para a tensão de saída e um rendimento elevado. Porém, as características dinâmicas são as correspondentes às do conversor Buck-Boost CC-CC, o que significa a presença de um zero no semi-plano positivo, com a conseqüente limitação no projeto dos controladores. Para resolver esta situação, adotou-se como estratégia o controle em modo corrente por valores médios instantâneos. Um requisito para a realização desta estratégia... / This work proposes the utilization of the single-phase integrated Buck-Boost inverter in small wind energy conversion systems, considering the constant increase use of low power renewable and alternative energy systems in the last decade. This fact has been encouraging the development of new and more efficient technologies for these conversion systems. Typically, small wind energy conversion systems supply DC voltages within 12 to 48 Volts (mean values). However, the most of the domestic loads require AC voltage to operate (with rms values within 110 to 240 V) and it is necessary to use DC-AC converters (known as inverters). Traditional inverters supply AC voltage with peak values that are lower than the peak value of the input DC voltage, then an extra boost input stage is required before the DC- AC conversion, resulting in additional losses and reduced efficiency, greater size and weight. The proposed inverter is able to reduce and boost the DC input voltage (as an buck- boost converter) and also to make the DC-AC conversion with low harmonics and high efficiency, all in a single stage. However, dynamics are the same of the DC-DC buck-boost converter; this means a right half-plane zero which limits the compensator performance. To overcome this limitation, the used control strategy is the current programming mode. In order to obtain a linear equivalent model (required for this control strategy) the converter is modeled by the state averaging method. Furthermore, as buck-boost is an inductive accumulation converter, the resulting topology is a current source inverter. Thus, reverse blocking capability is required for the transistors at the inverter bridge. Two alternatives were considered to implement the inverter bridge: IGBTs with reverse blocking capability (RB- IGBTs) and the series association of diode and... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:30:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-12-02Bitstream added on 2014-06-13T20:00:04Z : No. of bitstreams: 1 britto_rf_me_guara.pdf: 555381 bytes, checksum: 48e1967b9a09218a2f0f11946626a05b (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste trabalho é desenvolver um estudo técnico e econômico de alternativas de suprimento energético por autoprodução em condomínios residenciais horizontais a partir do desenvolvimento de um modelo de otimização. O estudo de caso foi realizado em um condomínio residencial de São José dos Campos, cidade do estado de São Paulo. O modelo proposto analisa formas alternativas de produção de energia, compatíveis com este tipo de “empresa”, a saber: eólica, fotovoltaica e geração de energia elétrica com motor de combustão interna; desta forma, busca estabelecer as bases técnicas das alternativas energéticas, considerando os aspectos técnicos e econômicos. Foram identificadas as necessidades elétricas das áreas comuns do condomínio em base temporal, nas quais o consumo e os custos são compartilhados entre os moradores. O modelo de otimização é baseado na concepção inicial de uma superestrutura que considera equipamentos comerciais para produção de energia de origem fotovoltaica, eólica e a partir de motor de combustão interna. O software LINGO foi utilizado para simulação de diferentes situações e obtenção da rota tecnológica ótima correspondente. Foram simulados cenários com diferentes condições de preços de energia e custos dos equipamentos de modo a se obter as condições nas quais as tecnologias renováveis conseguem se habilitar a compor a configuração final do sistema de autoprodução de energia elétrica / The main purpose of this work is to develop a technical and economic study of energy supply alternatives by self-production in horizontal condominiums. The case study was developed in a neighborhood of São José dos Campos city, state of São Paulo. The proposed model analyzes alternative forms of energy production, compatible with this type of business, namely: wind, solar and electric power generation with an internal combustion engine, thus, seeks to establish the technical basis of alternatives energy, considering the technical and economic aspects.It was identified the electrical needs of the common areas of the condominium in time basis, in which the consumption and costs are shared among the residents. The optimization model is based on the initial design of a superstructure where it is considered commercial equipment for generating energy from photovoltaic and wind sources and from internal combustion engine. The software LINGO was used to simulate different situations and obtain the corresponding optimal technological route. Were considered the simulation scenarios with different conditions of energy prices and equipment costs in order to obtain the conditions under which renewable technologies are able to be qualified to compose the final configuration of the system of electricity self-generation

Diplomová práce zkoumá možnost využití větrného proudění jako hnacího elementu architektonického návrhu za účelem integrace větru jako jeden ze zdrojů získávání energie. Větrné turbíny byly již využity v několika architektonických projektech, spíše však jako doplněk k výškovým budovám, jejichž výška je zřejmým předpokladem pro snažší získávání větrné energie díky dosahu k rychlejším proudům vzduchu. Tento projekt prověřuje skrze architektonický návrh možnost získávání energie z větru i v menších výškách, kde není energetický potenciál tak zřejmý, kvůli výrazně menším rychlostem větru. Výchozím bodem pro rozšíření využití větrné energie je Venturiho efekt, jehož výskyt je možné pozorovat v urbánním prostředí především jako negativní jev působící nepohodlí obyvatelům města, kvůli zvýšeným rychlostem větru. Naproti tomu, když je venturiho efekt předpokládán, může být využit pro zrychlení proudění vzduchu a následného sběru energie. Za účelem podpoření Venturiho efektu pro sběr energie zkoumá projekt, jaký má tvarové uspořádání vliv na proudění vzduchu. Za pomoci simulací proudění tekutin(CFD) a na základě hodinových dat povětrnostních podmínek vybrané lokality, odvozuje možné množství získané energie, různými tvarovými uspořádáními. Energetické zisky jsou srovnávány s předpokládanou energetickou náročností stavby a následně je skrze architektonickou studii prověřována využitelnost stavby jako vítr urychlujícího tvaru stejně tak, jako objektu umožňujícího běžné obývání.

In this report we discuss the use of k-ε RANS (Reynolds-averaged Navier-Stokes equations) turbulence model for wind turbine applications. This model has been implemented in the new wind turbine wake CFD code that is being developed at ECN. Simulations of the wind turbine test site EWTW are compared with measurements conducted between 2005 and 2009 and with FarmFlow, ECN's current wind turbine wake code. Based on the results the uncertainties in the current approach are highlighted and areas for possible improvement are discussed.

No description available.

The research reported in this thesis is part of a project to develop a remote wireless sensing network for monitoring the health of highway bridges. Remote health monitoring that does not require direct human observation has many advantages in terms of cost and increased productivity. However, bridges that cannot be easily connected to the power grid require alternative means of acquiring power. This thesis describes the design of a wind energy harvester to power a particular component in the sensor network, the wireless router. The work discussed in this thesis provides a review of relevant literature and development of a detailed analytical modeling of wind turbine behavior. The analytical model provides key information on sizing generators and choosing appropriate wind turbine dimensions to provide the required amount of power. The analytical model also distinguishes the performance of vertical and horizontal axis wind turbines. The model is verified through design and testing of a first generation prototype and benchmarking of a commercially available turbine. Based on these results, the design of the next generation wind harvesting system is described. A new methodology to design non-destructive attachment systems is also discussed. / text

Wind energy has dramatically changed the energy portfolio of Texas and more specifically, a region covering 75% of the state designated as ERCOT (Electric Reliability Council of Texas). Hardly existent at all ten years ago, the amount of capacity the wind farms provide is over 9000MW and accounts for 10% of the total generation. Due to the intermittent nature of wind and limitations of transmission lines, short and long term storage of this energy would benefit wind farms and the grid as a whole. This paper studies the relationship between wind, storage and real time electricity prices by analyzing prices and simulating a wind farm with different wind storage strategies over the course of a year. Based on these simulations, it is found that an ideal storage medium with no losses could be in the money for $17.50/kW for long term storage and $1,998/kW for short term storage for prices similar to 2009-2010. / text

Turkey wants to encourage renewable electricity generation to reduce dependence on imported natural gas and meet its highly growing power demand. The government’s objective is to increase the share of renewable resources in electricity generation to at least 30 percent by 2023, and the specific target for the installed wind energy capacity is 20 GW by that date. Fortunately, Turkey has an enormous wind energy potential to exploit for electricity generation. When from “good” to “outstanding” wind clusters are taken into account, the overall technical wind power generation capacity in Turkey is calculated to be nearly 48 GW. In this context, this thesis investigates whether policy instruments in the Turkish regulatory frame contribute to economic viability for wind power projects or not. The financial results point out that an electricity price of 7.3 USD cent/kWh, which is the guaranteed price for wind power generation by current regulations, does not make a typical onshore wind power plant located in a “good” windy resource economically viable. However, when locally produced wing blades and turbine towers are used in the project, the purchase price increases to 8.7 USD cent/kWh, and the project becomes economically viable. As a result, the local content element introduced in recent regulations promotes wind energy investments and helps government to reach its renewable target for 2023. / text