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Geração de energia a partir de fonte eólica com gerador assíncrono conectado a conversor estático duplo. ; Wind energy generation using asynchronous generator conected to back to back converters.

Campos, Fábio Galízia Ribeiro de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 07/06/2004 PT
Relevância na Pesquisa
66.16%
Após o choque do racionamento de energia elétrica, decorrente do desequilíbrio entre oferta e demanda, os vários setores da sociedade brasileira constataram a real e iminente necessidade de diversificação das fontes de geração de energia elétrica e de seu uso racional. Busca-se hoje novas fontes, entre as quais a eólica, uma alternativa nova e promissora. A geração de energia elétrica deve atender a rígidos requisitos normatizados de qualidade quanto à freqüência elétrica, injeção de harmônicos, controle de tensão, geração de potencia reativa entre outros. As pesquisas sobre este tema apontam para soluções tecnológicas capazes de satisfazer a estas exigências. Este trabalho descreve os princípios da geração eólica, através de um gerador assíncrono com rotor bobinado conectado a um conversor estático duplo em ligação “back-to-back” com circuito CC intermediário, utilizando a técnica de modulação em largura de pulsos (PWM) e Controle Vetorial. É apresentada a comparação de preços entre duas alternativas distintas para a parte elétrica de uma turbina eólica: Gerador com rotor em gaiola e gerador com rotor bobinado em anéis (duplamente excitado). Finalmente, é ainda apresentada uma simulação...

Energia eólica e desenvolvimento sustentável no Brasil: estimativa da geração de empregos por meio de uma matriz insumo-produto ampliada; Wind energy and sustainable development in Brazil: estimating job creation through an extended input-output approach

Simas, Moana Silva
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 15/05/2012 PT
Relevância na Pesquisa
66.2%
A preocupação com as questões ambientais e a busca pela mitigação das mudanças climáticas levaram a uma corrida pelo desenvolvimento e inserção de tecnologias de energias renováveis na matriz elétrica em diversos países. Dentre as tecnologias, a energia eólica foi a que recentemente obteve maior sucesso, tendo um crescimento de quase 15 vezes entre 2000 e 2011. A adoção de políticas de incentivo, muitas vezes baseadas em subsídios, levou à discussão dos benefícios sociais e econômicos trazidos por esta tecnologia, principalmente sobre o impacto no nível de empregos. Neste contexto, diversos estudos têm sido realizados para quantificar os empregos gerados pelas tecnologias de energias renováveis, chegando à conclusão de que estas são mais intensivas em empregos que as tecnologias tradicionais a combustíveis fósseis. No entanto, os estudos que buscam a avaliação da geração de empregos por estas tecnologias diferem em metodologias e premissas adotadas e apresentam os resultados de maneira agregada, não permitindo a comparação entre estes, além de não haver estudos disponíveis para mercados eólicos na América Latina. No Brasil, o crescimento da energia eólica passou por um longo período de lento crescimento...

Comercialização de energia eólica no Brasil: desenvolvimento de sistemas de apoio em leilões para agentes geradores.; Wind energy trade in Brazil development of auction support systems for generating agents.

Ribeiro, Marlene Nazaré
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 18/04/2013 PT
Relevância na Pesquisa
66.25%
A participação da energia eólica na matriz energética brasileira tem aumentado significativamente nos últimos três anos, dada a contratação da fonte em leilões organizados pelo governo, que contabilizaram cerca de 7,0 GW contratados no final de 2012. No entanto, frente às vantagens como fonte renovável, a geração eólica possui desvantagens como fonte regular de energia devido à sazonalidade e dependência do regime de ventos. Assim, considerando o cenário de contratação da fonte via leilões, foi desenvolvido um modelo que, integrando cenários para a geração observada no parque eólico (associando as incertezas de geração) e para os preços do mercado de energia elétrica (associando a alta volatilidade dos preços), submetidos às regras de contratação pactuadas, avalia os riscos na comercialização da energia gerada por um parque eólico nos quais, o agente gerador está exposto. Tendo sido o modelo aplicado para dois parques eólicos reais no âmbito dos Leilões de Energia Nova (tipo A-3) e Leilões de Energia de Reserva, verificou- se que no Brasil o esquema de contratação de energia eólica considera a produção média ao longo dos anos, permitindo reajustes e compensações, notadamente nos leilões para a contratação de Energia de Reserva para todo o sistema brasileiro. Considerando a busca pela máxima rentabilidade associada ao menor risco...

Estudo comparativo entre o potencial eólico e a energia efetivamente gerada no complexo eólico de Osório; Comparative study of the wind potential and the wind energy generated in osorio wind complex

Pereira, Maurício Vieira da Rocha
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Trabalho de Conclusão de Curso Formato: application/pdf
POR
Relevância na Pesquisa
66.24%
O Brasil está se tornando uma potência mundial na geração de energia eólica, no entanto, apresenta poucas informações disponíveis para avaliar a qualidade dos parques eólicos existentes em operação. O presente estudo apresenta indicadores de desempenho do Complexo Eólico de Osório, para o período compreendido entre 2007 e 2010, utilizando a metodologia computacional do WAsP. Inicialmente é feita uma revisão bibliográfica onde são comentados trabalhos disponíveis na literatura, relacionando-os aos principais parâmetros utilizados neste trabalho. A contextualização no panorama eólico brasileiro é feita também neste capítulo. A metodologia baseia-se na seleção da fonte de dados eólicos que melhor representa o regime de ventos na região do complexo eólico e na modelagem numérica do sofware WAsP. Por fim conclui-se que o Complexo Eólico de Osório apresenta índices de desempenho razoáveis e coerentes com o previsto no local de estudo. O valor da razão de energia eólica gerada e prevista dos aerogeradores é de 94.3% e o fator de capacidade anual médio para o período de estudo - 2007 a 2010 - é de 0.29.; Brazil is becoming a world power in wind energy generation, however it has little information available to evaluate the quality of existing wind farms in operation. This paper presents performance indicators about the Osorio Wind Farm for the period between 2007 and 2010...

A comparative study of MPPT strategies and a novel singlephase integrated buck-boost inverter for small wind energy conversion systems

Peña, José C.U.; De Brito, Moacyr A.G.; E Melo, Guilherme de A.; Canesin, Carlos A.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Conferência ou Objeto de Conferência Formato: 458-465
ENG
Relevância na Pesquisa
66.19%
This paper presents the analysis of some usual MPPT (Maximum Power Point Tracking) strategies intended for small wind energy conversion (up to 1kW) based on permanent magnet synchronous generators (PMSG), considering the stand-alone application for a novel buck-boost integrated inverter. Each MPPT method is analytically introduced and then it is simulated using MatLab/Simulink considering standard conditions of wind and also commercially available turbines and generators. The extracted power in each case is compared with the maximum available power, so the tracking factor is calculated for each method. Thus, the focus is on the application to improve the efficiency of stand-alone wind energy conversion systems (WECS) with battery chargers and AC load supplied by inverter. Therefore, for this purpose a novel single phase buck-boost integrated inverter is introduced. Finally, the main experimental results for the introduced inverter are presented. © 2011 IEEE.

As políticas de inovação da indústria de energia eólica ; : uma análise do caso brasileiro com base no estudo de experiências internacionais; Innovation policies of wind energy industry : an analysis of Brazilian case based on a study of international experiences

Edilaine Venancio da Rocha
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 22/08/2013 PT
Relevância na Pesquisa
66.19%
O principal objetivo deste trabalho é analisar a pertinência das políticas brasileiras de inovação em energia eólica, iniciadas com o Programa de Incentivo às Fontes Alternativas de Energia (PROINFA). Especificamente, questiona-se (i) se houve lacunas nas políticas brasileiras; (ii) se a estratégia de promoção à energia eólica foi a mais adequada para entrar nesta indústria; (iii) se o país poderia ter seguido por outro caminho e desenvolvido uma indústria nacional energia eólica. Para a realização dessa análise, foram construídos quadros de referência a partir do estudo da experiência de dois grupos de países líderes na indústria de energia eólica: os pioneiros ou inovadores - Dinamarca, Alemanha e Estados Unidos - e os latecomers ou seguidores - Espanha, China e Índia. A elaboração dos quadros de referência baseou-se em um mapeamento das políticas de inovação em energia eólica desses países. Em linha com as abordagens evolucionária e sistêmica do processo de inovação, a construção desses quadros, bem como o desenvolvimento da análise proposta, se norteou pelos seguintes argumentos: (i) as políticas de inovação tem um caráter multifacetado e devem atuar de forma concomitante e coordenada em esferas diversas; (ii) as políticas de inovação coevoluem com a tecnologia e a indústria...

Electricity power planning : the role of wind energy

Ferreira, Paula Varandas; Araújo, Maria Madalena Teixeira de; O’Kelly, M. E. J.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2010 ENG
Relevância na Pesquisa
66.17%
Combining energy efficiency with renewable energy sources constitutes a key strategy for a sustainable future. The wind power sector stands out as a fundamental element for the achievement of the European renewable objectives and Portugal is no exception to the increase of the wind energy for the electricity generation. This work proposes an optimization model for the long range electricity power planning in a system similar to the Portuguese one, where the expected impacts of the increasing installed wind power on the operating performance of thermal power plants are taken into account. The main results indicate that the increasing penetration of wind power in the electricity system will have significant effects on the combined cycle gas power plants operation and on the theoretically expected cost reduction and environmental gains. This research demonstrated the need to address the impact that energy sources with variable output may have, not only on the short-term operational planning, but especially on the medium to long range planning activities, in order to meet the strategic objectives for the energy sector.; Fundação para a Ciência e Tecnologia (FCT); COMPETE – Programa Operacional Factores de Competitividade under Research Project PTDC/SEN-ENR/099578/2008

Wind energy resource modelling in Portugal and its future large-scale alteration due to anthropogenic induced climate changes; Simulação do recurso eólico em Portugal e respectivas futuras alterações de larga escala devido a alterações climáticas de origem antropogénica

Carvalho, David João da Silva
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Tese de Doutorado
ENG
Relevância na Pesquisa
66.3%
The high dependence of Portugal from foreign energy sources (mainly fossil fuels), together with the international commitments assumed by Portugal and the national strategy in terms of energy policy, as well as resources sustainability and climate change issues, inevitably force Portugal to invest in its energetic self-sufficiency. The 20/20/20 Strategy defined by the European Union defines that in 2020 60% of the total electricity consumption must come from renewable energy sources. Wind energy is currently a major source of electricity generation in Portugal, producing about 23% of the national total electricity consumption in 2013. The National Energy Strategy 2020 (ENE2020), which aims to ensure the national compliance of the European Strategy 20/20/20, states that about half of this 60% target will be provided by wind energy. This work aims to implement and optimise a numerical weather prediction model in the simulation and modelling of the wind energy resource in Portugal, both in offshore and onshore areas. The numerical model optimisation consisted in the determination of which initial and boundary conditions and planetary boundary layer physical parameterizations options provide wind power flux (or energy density), wind speed and direction simulations closest to in situ measured wind data. Specifically for offshore areas...

Conhecimento sobre energia eólica: um estudo exploratório a partir das redes semânticas naturais de estudantes da cidade de Natal; Knowledge about wind energy: an exploratory study taking into account natural semantic networks of students from Natal-RN

Pessoa, Viviany Silva
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Psicologia; Psicologia, Sociedade e Qualidade de Vida Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Psicologia; Psicologia, Sociedade e Qualidade de Vida
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
66.2%
The human being has a fundamental role in issues concerning scarcity of energy resources as well as in the success of technologies which favor the use of renewable sources, such as wind energy. But what does wind energy mean for people? What are the psychological meanings concerning this term? Aiming to answer these questions, the general objective of this dissertation was to identify and to analyze the knowledge about wind energy taking into account a network of psychological meanings. One hundred and ninety one (191) university students from Natal-RN participated in the study, being male the majority (53%); aged between 17 and 51 years old (M=23.3 years; SD=5.7). Participants responded to self reports using the Natural Semantic Networks (NSW) technique, as well as to several sociodemographic questions. The results showed a consistent, positive and useful general semantic network. In this semantic network, knowledge about wind energy was represented by words that correspond to the appeal of (pro) environmental stance (e.g., clean and nature), that evinced both the technological aspect (e.g., force) and the economic aspect (e.g., economy). Results from different groups were also analyzed. The first set of groups (non-environemental and environmental) was divided considering the course (e.g....

Desenvolvimento de modelo computacional de sistemas eólicos utilizando geradores síncronos para estudos de desempenho no contexto da qualidade da energia eletrica; Development of a computational modeling of wind energy conversion systems with synchronous generators for power quality studies

Carvalho, Bismarck Castillo
Fonte: Universidade Federal de Uberlândia Publicador: Universidade Federal de Uberlândia
Tipo: Tese de Doutorado
POR
Relevância na Pesquisa
66.16%
Grande parte dos sistemas de conversao de energia eólica (WECS) atualmente em operação no mundo utiliza geradores assíncronos para a transformação da energia contida no vento em energia ellétrica. No Brasil, embora se reconheça que a parcela de centrais eólicas ainda seja bastante reduzida, destaca-se que o princípio da geração empregada e majoritariamente síncrona, o que está em consonância com a tecnologia denominada por conceito alemão. Dentro deste princípio, a turbina opera com veloci dade variável e a sincronização da geração com a rede é feita através de conversores estáticos de frequência. Neste particular ressalta-se que os recursos de simulação atual mente disponíveis, e que utilizam a tecnologia aqui destacada, ainda são escassos. Este fato norteou o tema de pesquisa desta tese, o qual encontra-se direcionado para o de senvolvimento de um software destinado µa modelagem e estudos de desempenho de parques eolicos de velocidade variável e sua correlação com aspectos associados com a qualidade da energia elétrica. A técnica de modelagem empregada fundamenta-se no domínio do tempo e assim procedendo obtém-se uma ferramenta que contempla situa ções transitórias e permanentes de funcionamento do complexo elétrico considerado. Distintas situações operacionais e representativas de condições ideais e não ideais da rede elétrica de conexção são avaliadas e seus impactos sobre os indicadores de quali- dade enfatizam a potencialidade do modelo/programa como ferramenta para estudos de acesso de novas instalações ao sistema elétrico interligado. ______________________________________________________________________________ ABSTRACT; The majority of wind energy conversion systems (WECS) currently in operation in the world uses asynchronous generators for the transformation of the energy contained in the wind into electric energy. In Brazil...

An analysis of the current and future prospects of wind energy in Castilla y Leon

Sanz Lallana, Jorge
Fonte: Universidade de Cantabria Publicador: Universidade de Cantabria
Tipo: Trabalho de Conclusão de Curso
ENG
Relevância na Pesquisa
66.23%
The wind energy in Castilla y León is one of the main energy sources and is more developed than in other communities of Spain, this is because of the good location of Castilla y León and the efforts made by the autonomic government and the regional companies. Castilla y León is a very suitable region for this type of energy because it is a rural community and located in a plateau in which there are sustained winds. It has obtained information about the current situation of the wind energy in this community and with this information, a research has been done to develop the wind energy in Castilla y León and in this way increase the performance of the energy and get more economic costs. The main advantage is that the wind energy is a renewable source which makes it interesting develop of this energy and the major disadvantage is its availability due to this energy depends on the presence of relatively strong winds, for this reason, alternatives have been researched to make it more productive. Taking advantage of that the wind power is a renewable energy source, a project have been done to study the viability of the replacement of the nuclear power in Spain using wind energy. The obtained results confirm the viability of this energy and the necessity to keep developing this energy because today in Castilla y León and Spain this is the main renewable energy and still it could be more developed y make Spain a country more respectful with the environment; Ingeniería técnica Industrial. Especialidad en Mecánica

Bidding wind energy under uncertainty

Usaola, Julio; Angarita, Jorge
Fonte: IEEE Publicador: IEEE
Tipo: Conferência ou Objeto de Conferência Formato: application/pdf
Publicado em /05/2007 ENG
Relevância na Pesquisa
66.16%
The integration of wind energy into electricity markets implies that the wind energy must commit their production for a given time period. This requires the use of short term wind power prediction tools to prepare the bids for the spot market. The output of these tools have a limited accuracy, and, therefore, these predictions are uncertain. Optimal bids must take into account this uncertainty in order to get the maximum revenue from the sell of energy, minimizing losses due to imbalance costs. The consequence is that the optimal bids sent to the market do not coincide with the best predictions. Regulatory authorities must consider if this situation is good for the system operation, and encourage TSOs to have their own prediction tools and have results independent of bidding strategies.; International Conference on Clean Electrical Power, ICCEP '07 (Capri, 21-23 May 2007). P. 754-759

Wind Energy in Colombia : A Framework for Market Entry

Vergara, Walter; Deeb, Alejandro; Toba, Natsuko; Cramton, Peter; Leino, Irene
Fonte: World Bank Publicador: World Bank
Tipo: Publications & Research :: Publication; Publications & Research :: Publication
ENGLISH
Relevância na Pesquisa
66.34%
The purpose of this report is to provide decision makers in Colombia (and by extension other countries or regions), who are considering the deployment or consolidation of wind power, with a set of options to promote its use. The options presented are the result of an analysis of the Colombian market; this analysis included simulations and modeling of the country's power sector, and extensive consultations with operators, managers, and agents. More information on the analysis and simulations is presented in the appendixes. Wind was chosen to exemplify the range of renewable energy alternatives available to complement traditional power sector technologies on the basis of its technical maturity, its relatively low cost compared to other options, the country's experience, and its wind power potential. This report constitutes the second phase of a barrier analysis to wind energy in Colombia.

Adaptive Slope-Assist Maximum Power Point Tracking and Power Limit Search for Intelligent Power Management of Small Wind Energy Systems

Hui, Joanne Chung Yan
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
66.26%
Due to its high energy generation capability and minimal environmental impact, wind energy is an elegant solution to the growing global energy demand. Though wind energy systems can yield large amounts of energy, frequent atmospheric changes make it difficult to effectively harness the energy in the wind because maximum power extraction occurs at a different operating point for each wind condition. Therefore, maximum power point tracking (MPPT) control algorithms are used in wind energy systems to increase its power extraction efficiency. Basic MPPT algorithms use pre-determined mathematical relationships that represent a specific wind system’s power/torque characteristics for maximum power capture. Due to system aging, the efficiency of these basic algorithms deteriorates over time since it cannot adapt to any system changes. As a result, perturb and observe (P&O) parameter-independent algorithms were developed to actively search for the system’s optimal operating points by perturbing the system and observing the resultant behavior. However, P&O algorithms are susceptible to logical errors when subjected to frequent atmospheric variations and ignore the effects of air density. This thesis proposes a parameter independent intelligent power management controller that consists of a slope-assisted MPPT and a power limit search (PLS) algorithm for small wind energy systems. The proposed MPPT actively searches for MPPs and establishes a maximum power curve (MPC) relationship that characterizes the behavior of the given wind turbine to assist in future MPP searches. The algorithm is robust to changes in wind speed and/or air density conditions by monitoring internal system behavior. The slope assist MPPT uses an internally derived slope parameter to ‘remember and revert’ to the system’s last operating state before the atmospheric change to increase MPP search efficiency. The controller’s PLS is able to minimize the production of surplus energy to minimize the heat dissipation requirements of the energy release mechanism. The PLS seeks the operating points that result in the desired power rather than the maximum power. Finally...

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

Hui, Joanne
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado Formato: 1269311 bytes; application/pdf
EN; EN
Relevância na Pesquisa
66.22%
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...

Performance assessment of a wind energy conversion system using a hierarchical controller structure

Melicio, Rui
Fonte: Energy Conversion and Management-Elsevier Publicador: Energy Conversion and Management-Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
76.12%
This paper deals with a hierarchical structure composed by an event-based supervisor in a higher level and two distinct proportional integral (PI) controllers in a lower level. The controllers are applied to a variable speed wind energy conversion system with doubly-fed induction generator, namely, the fuzzy PI control and the fractional-order PI control. The event-based supervisor analyses the operation state of the wind energy conversion system among four possible operational states: park, start-up, generating or brake and sends the operation state to the controllers in the lower level. In start-up state, the controllers only act on electric torque while pitch angle is equal to zero. In generating state, the controllers must act on the pitch angle of the blades in order to maintain the electric power around the nominal value, thus ensuring that the safety conditions required for integration in the electric grid are met. Comparisons between fuzzy PI and fractional-order PI pitch controllers applied to a wind turbine benchmark model are given and simulation results by Matlab/Simulink are shown. From the results regarding the closed loop point of view, fuzzy PI controller allows a smoother response at the expense of larger number of variations of the pitch angle...

The Effect of Utilities Regulation on the Economics of Wind Energy in North Carolina

Vale, Susannah
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project Formato: 1607149 bytes; application/pdf
EN_US
Relevância na Pesquisa
66.24%
In order for wind energy to be feasible in the sounds of North Carolina, it must be economical. The price paid for electricity produced by wind must be sufficiently high to translate into a reasonable rate of return for developers and investors. Countervailing tensions on regulators, utilities and the renewable energy generators function to depress the price of wind energy. Lawmakers have passed utility regulations in order to improve the economic situation of wind energy projects by either diminishing the initial capital needed, lowering the risk or ensuring a fair price. The two primary utility statutes affecting the economics of wind energy in North Carolina, the federal Public Utility Regulatory Policies Act of 1978 and North Carolina’s Renewable Portfolio Standard of 2007, have thus far been ineffectual. If the North Carolina legislature wants to develop wind energy in their state, it should amend NC REPS to add a wind energy percentage requirement to put it on equal footing with solar. Alternatively, adding externalities into the cost calculation would make wind one of the most economical of all the electricity options.

A Regulatory Framework for Wind Energy in North Carolina

Kimrey, Erin
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Master's project Formato: 2529155 bytes; application/pdf
Publicado em //2006; 2006 EN_US
Relevância na Pesquisa
66.29%
Wind energy is the fastest growing energy sector in the U.S., and while it provides a clean, renewable source of energy, it is not without environmental and other impacts. The first utility-scale wind farm was proposed in the mountains of North Carolina in July, 2006, bringing to the forefront a question that has been brewing for some time: How is the siting of wind facilities currently regulated in North Carolina and what, if any, changes are needed to ensure that wind energy is sited in an appropriate and environmentally sound manner? This master’s project provides: (1) an overview of siting issues associated with wind farms; (2) an analysis of the current regulatory structure governing the siting of wind farms in North Carolina; (3) an analysis of regulatory frameworks for wind energy in nine states (Texas, California, Iowa, Minnesota, Washington, Oregon, Pennsylvania, Vermont and Virginia); and (4) an evaluation of five policy options for North Carolina. The policy options range in regulatory intensity, from removing regulatory barriers to wind projects but adding no additional regulatory oversight, to requiring environmental review for all projects, to developing a statewide regulatory framework specific to wind energy. The policy options are evaluated against three main criteria – minimizing negative impacts...

Using participatory GIS to examine social perception towards proposed wind energy landscapes

Lombard,Andrea
Fonte: Journal of Energy in Southern Africa Publicador: Journal of Energy in Southern Africa
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2015 EN
Relevância na Pesquisa
76.2%
Thirteen onshore wind farm projects, totalling approximately 700 wind turbines, are proposed for the West Coast Region (WCR) of the Western Cape Province in South Africa. Wind energy exploitation possesses the ability to transform what can be classified as natural landscapes into landscapes of power, making the type of landscape on which wind turbines are deployed a prominent factor in its social acceptance or rejection. This paper examines the landscape aesthetics and land use interference of proposed wind farms in the WCR of South Africa through determining if social acceptance or rejection of proposed wind farms is dependent on the residents and visitors scenic and land use valuation of the natural landscape. The results indicate that the visual intrusion of wind turbines is the impact that respondents are least concerned with contrasting with the findings of international literature and further reasons for this anomaly are interrogated against the background of South Africa's dire electricity needs. The paper concludes that visual impact assessments alone are not sufficient for evaluating landscapes and this paper recommends that participatory geographic information systems (PGIS) be used in addition to existing wind energy landscape assessments.

Electrical and thermal analysis of an asynchronous machine for application in wind energy generation

Okoro,O I; Chikuni,E
Fonte: Journal of Energy in Southern Africa Publicador: Journal of Energy in Southern Africa
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2008 EN
Relevância na Pesquisa
76.08%
The electromagnetic (electrical) and mechanical design of an Asynchronous machine for application in wind energy generation depends on the knowledge of heat transfer within the various parts of the machine. Unfortunately, the analysis of thermal effect in Asynchronous motors is usually more complex, more non-linear and more difficult than the electromagnetic behaviour. This paper therefore, sets out to investigate the effect of coupling the electrical model with the thermal model of the machine. The results of the analysis show that the proposed coupled model is capable of predicting the stator phase currents, rotor bar temperature, stator windings temperature, heat losses, rotor speed and electromagnetic torque of the test machine under dynamic conditions and at rated load operation. The analysis finds application in wind energy generation especially when modified and applied to synchronous generators. By so doing, the prediction of critical temperatures of machine parts can be achieved prior to machine operation.