This study aims to investigate the methodological differences of wind power project economic analysis and to indicate the preferred methodology among the considered cases. The study compares the economic appraisals of onshore wind power projects. The economic appraisals of wind power projects are for evaluating wind power projects' impact on an economy. Economic appraisals of wind power projects include economic justifications of projects in comparison with the next best alternative projects, consider negative and positive externalities but exclude transfer payments such as taxes and subsidies. Also, in wind power project economic appraisals, the valuations of costs and benefits are at shadow prices and discounting of future costs and benefits at a social discount rate. There are methodological guidelines from different institutions on how to conduct project economic analysis. This study compares methodologies of three onshore wind power project economic appraisals conducted by the European Investment Bank, the Asian Development Bank, and the Mott MacDonald and discusses methodological differences for each case study in comparison with each other. The results of this study are for any investors, institutions and government authorities involve in wind power projects and seek not only corporate profits but also social benefits. They may consider the methodological differences identified in this study to improve the assessment of wind power project economic impacts. The results indicate that the identified methodological differences complement each other rather than substitute. The preferred methodology for onshore wind power projects economic analysis would be the methodology that considers the identified differences for the comprehensive evaluations.

The offshore wind potential of the Caribbean Sea has barely been exploited. Currently, the offshore wind power industry in Latin America and the Caribbean region is still at very early stages, leaving aside an important resource that otherwise could contribute to satisfy the growing energy demand of the zone. In this study the possibilities arising from a massive exploitation of the wind resource in the Caribbean Sea are assessed. The objective is to investigate if the resources contained in it would be sufficient to satisfy the energy demand of Latin America and the Caribbean, which is foreseen to be about 1900 TWh/year by 2020. To address this question, the “Infinite wind farm” concept is used as a simple way to model the meteorological behaviour and the wind speed in the area. The model is utilized in combination with the bathymetric data of the Caribbean Sea and with a simple economic analysis, to evaluate what the requirements to satisfy the energy demand would be in terms of area, number of turbines, and levelized cost of energy (LCoE). The assessment is performed utilizing different turbine sizes, and inter-turbine separations to find the combination that minimizes the LCoE. It is found that the energy demand of Latin America and the Caribbean could be satisfied using only 125000 km2 (4.5% of the total Caribbean Sea area) of waters shallower than 25m at a cost of 69 €/MWh, if the turbines were separated 6.5D from one another and if they had a rotor diameter of 250m. In that case, 47760 turbines should be installed using only conventional monopile foundations.

Most of the modern wind turbines are based on doubly fed induction generators (DFIG), with a back to back power converter connecting the rotor to the network. It is known that voltage dips at the stator terminals can cause overcurrents in the rotor windings, which could threaten the converter integrity. In order to protect the converter, several strategies have been proposed in technical literature, requiring in some cases the converter deactivation, which disables the control that the converter has over the power transference between the generator and the system. This last is not a desirable behavior since it can put on risk the voltage stability of the electric system. It is the aim of this dissertation to introduce and compare five of those protection strategies, through the computational simulation of their performance in case of balanced voltage dips. In order to achieve this, the electromagnetic dynamic model of the DFIG was theoretically developed, as well as the models of the strategies of interest. Subsequently, the computational model of the system was assembled in the software Matlabs Simulink to finally perform the desired simulations and its corresponding analysis. / A maioria das turbinas eólicas modernas é baseada em geradores de indução duplamente alimentados (GIDE), com um back to back conversor de energia que liga o rotor para a rede. Sabe-se que as quedas de tensão nos terminais do estator podem causar sobrecorrentes nos enrolamentos do rotor, que podem ameaçar a integridade do conversor. A fim de proteger o conversor, várias estratégias têm sido propostas na literatura técnica, exigindo, em alguns casos, a desativação do conversor, o qual desativa o controlo do conversor, que possui ao longo da transferência de energia entre o gerador e o sistema. Este último não é um comportamento desejável, uma vez que pode colocar em risco a estabilidade de tensão do sistema elétrico. É o objetivo desta dissertação apresentar e comparar cinco dessas estratégias de proteção, através da simulação computacional de seu desempenho em caso de quedas de tensão equilibrada. A fim de alcançar este objetivo, o modelo dinâmico eletromagnética do DFIG teoricamente foi desenvolvido, bem como os modelos das estratégias de interesse. Subsequentemente, o modelo computacional do sistema foi montado no software Simulink do Matlab para finalmente executar as simulações desejadas e sua análise correspondente.

A energia eólica é uma das fontes de energia renovável mais promissoras e que cresce mais rapidamente em todo o mundo. O uso da energia eólica pode contribuir para reduzir as emissões de gases de efeito estufa derivados da queima de combustíveis fósseis. Estima-se que o Brasil dispõe de um significativo potencial eólico offshore na sua Zona Econômica Exclusiva de cerca de 1,78 TW. Entretanto, um dos fatores limitantes para o desenvolvimento da energia eólica offshore no Brasil é a inexistência de um marco regulatório. O marco regulatório é uma condição essencial para atrair investimentos no setor e permitir o desenvolvimento do potencial latente. Este estudo tem como objetivo analisar princípios e experiências regulatórias brasileiras e internacionais para subsidiar o debate na formulação de instrumentos normativos com vista a inserção da energia eólica offshore no Brasil. O estudo apresenta um panorama do estado da arte e das tendências tecnológicas para geração de energia eólica offshore que ajuda a compreender como a construção e operação de usinas pode provocar impactos socioambientais e conflitos no espaço oceânico. Uma síntese do conceito de potencial eólico é elaborada, e as rendas econômicas do recurso eólico offshore são analisadas ressaltando-se a necessidade de atuação do Estado na arbitragem de sua extração e distribuição. Por meio da investigação do arcabouço jurídico-regulatório brasileiro, e com uso da metodologia descritiva, constatou-se que não há instrumentos capazes de dar suporte ao desenvolvimento de parques eólicos offshore no Brasil. A partir da análise de princípios e experiências regulatórias brasileiras em geração de energia eólica onshore, geração de energia hidrelétrica, exploração e produção de petróleo e gás natural, e, em geração de energia eólica offshore do Reino Unido, Alemanha, Dinamarca, Holanda, Bélgica, China e Estados Unidos, foram elaborados quadros de referências para servirem de base para o caso do Brasil. Em conclusão, princípios dos modelos brasileiros para outorga de usinas hidrelétricas; princípios do modelo de exploração e produção de petróleo e gás natural, assim como das experiências internacionais em energia eólica offshore aderentes ao ambiente institucional do Brasil, podem ser adotados na formulação de instrumentos jurídicos e normativos com vista a inserção da energia eólica offshore no país. / Wind power is one of the most promising and fastest growing renewable energy sources in the world. The use of wind power can contribute to reduce greenhouse gas emissions from burning fossil fuels. It is estimated that Brazil has a significant offshore wind potential in its Exclusive Economic Zone of about 1.78 TW. However, one of the limiting factors for the development of offshore wind power in Brazil is the lack of a regulatory framework. The regulatory framework is an essential condition to attract investments in the sector and allowing the development of latent potential. This study aims to analyze Brazilian and international regulatory principles and experiences to support the debate in the formulation of normative instruments for the insertion of offshore wind energy in Brazil. The study presents an overview of the state of the art and technological trends for offshore wind power generation that helps to understand how the construction and operation of power plants can cause socio-environmental impacts and conflicts in the ocean space. A synthesis of the concept of wind potential is elaborated, and the economic rents of the offshore wind resource are analyzed emphasizing the necessity of State action in the arbitration of its extraction and distribution. Based on the investigation of the Brazilian legal-regulatory framework and by using the descriptive methodology it was verified that there are no instruments capable of supporting the development of offshore wind farms in Brazil. Based on the analysis of Brazilian principles and regulatory experiences in onshore wind power generation, hydroelectric power generation, oil and natural gas exploration and production, and in offshore wind power generation in the United Kingdom, Germany, Denmark, the Netherlands, Belgium, China, and United States, frameworks of the conceptual references were developed to serve as a basis for the case of Brazil. In conclusion, principles of the Brazilian model for the grant of hydroelectric plants; principles of the Brazilian model for oil, and natural gas exploration and production, as well as of the international offshore wind experiences adhering to the institutional environment of Brazil, can be adopted in the formulation of legal and normative instruments aiming the insertion of offshore wind power in the country.

The goal of this Thesis is to demonstrate, through experimentation, that ocean waves have a positive effect on the performance of an offshore wind turbine. A scale model wind turbine was placed into a wave tank that was completely covered and fitted with a variable speed fan to create different wind and wave conditions for testing. Through testing, different power coefficient vs. tip speed ratio graphs were created and a change in power coefficient was observed between steady operating conditions and operating conditions with waves. The results show a promising increase in power production for offshore wind turbines when allowed to operate with the induced motion caused by the amplitude and frequency of water waves created. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2013.

Nos recentes leilões de energia realizados no setor elétrico brasileiro, a energia térmica foi uma das principais vencedoras. Este trabalho avalia a possibilidade de reversão desta tendência, mantendo a trajetória anterior de uma matriz limpa e renovável. A maior parte da eletricidade brasileira tem sido proveniente de hidrelétricas. O plano energético oficial, com horizonte de 2030, elaborado para o Governo pela Empresa de Pesquisa Energética (EPE) dá ênfase à geração térmica, à gás natural, carvão e nuclear, como alternativa de complementação à geração hídrica. Neste estudo, em contraponto à proposta oficial, a geração eólica é analisada como opção de complementação, ao invés da energia térmica. A curva de aprendizado da tecnologia eólica, no Brasil e no mundo, é investigada e seu resultado evidencia o potencial de competitividade quando comparada a outras fontes, como térmicas nucleares, a gás e a carvão. A substituição do parque de expansão térmica pela eólica é simulada mediante a análise comparativa dos custos de capital, combustível, operação e manutenção, considerando a curva de aprendizado potencial. Os resultados da simulação, em termos de custo a valor presente das alternativas, indicam que a geração eólica pode se tornar atrativa, tendo como atrativo adicional a redução da emissão de gases de efeito estufa. Dificuldades e barreiras para a penetração da geração da energia eólica são avaliadas. Também é analisada a possibilidade do atendimento da demanda de energia no Brasil no contexto do cenário da estabilização populacional e do consumo, na década de 2040, mediante oferta de energia renovável, substancialmente hidro-eólica. / In the recent energy auctions held in the Brazilian electric sector, thermal power plants were the major winners. This study evaluates the possibility of reversing such trend, maintaining the previous path of a clean and renewable energy mix. Most of Brazil\'s electricity has been generated by hydropower. However the official energy plan, with the horizon of 2030, prepared for the Government by the Energy Research Company (EPE) gives emphasis to the thermal generation to natural gas, coal and nuclear energy as an alternative to hydropower generation complementation. In this study, in contrast to the official proposal, wind generation is considered as an option to complement, rather than the thermal energy. The learning curve of wind technology in Brazil and worldwide, is investigated and its result shows the potential of competitiveness compared to other sources such as nuclear thermal, gas and coal. The replacement of thermal based expansion by the wind is simulated, by a comparative analysis of capital costs, fuel, operation and maintenance, considering the potential learning. The simulation results in terms of present value cost of the alternatives indicate that wind generation can become attractive, with the added benefit of reduction in emission of greenhouse gases. Difficulties and barriers to the penetration of wind power generation are evaluated. The possibility of meeting the demand for energy in Brazil in the context of the scenario population and energy demand stabilization, in the 2040s, through renewable and sustainable energy sources, substantially hydro and wind, is also assessed.

Orientador: Laurence Duarte Colvara / Banca: Dionízio Paschoareli Jr. / Banca: Jean Marcos de Souza Ribeiro / Banca: Igor Kopcak / Banca: Walmir de Freitas Filho / Resumo: Propõe-se neste trabalho o desenvolvimento de um método analítico para o estudo da estabilidade dos geradores de indução duplamente alimentados (DFIG - Doubly Fed Induction Generator) com base no monitoramento da tensão interna E', uma vez que a degradação da mesma resulta na perda da capacidade de transmissão de potência. Deste modo, faz-se a análise do desempenho transitório da máquina pela observação da grandeza em que efetivamente reside a causa da instabilidade. Uma vez detectada a possível causa da instabilidade do gerador, um controle é proposto sobre a grandeza em que se desenvolve a instabilidade do gerador. A filosofia de controle desenvolvida baseia-se no controle da magnitude da tensão interna, contribuindo decisiva e positivamente para o aumento da capacidade de transmissão e, consequentemente, das forças restaurativas de equilíbrio do DFIG, resultando em melhoria da estabilidade do sistema. A validação da aplicação do controle via metodologia da tensão E' é realizada por meio de simulações computacionais em diversas contingências e com a ação conjunta do circuito crowbar. Evidencia-se que este método pode ser empregado para avaliação da criticidade do sistema em tempo real / Abstract: This thesis proposes the development of an analytical method for stability analysis of the Doubly Fed Induction Generator (DFIG) based on the monitoring of the internal voltage E', since its degradation implies in decreasing of power transmission capacity and as consequence the reduction of transient performance. Thus, the analysis of the transient performance of the machine is performed by observing the quantity which is the effective cause of instability. Once detected the possible cause of the instability of the generator, is proposed a control of the quantity which originates the generator instability. The control philosophy is based on internal voltage magnitude control, contributing decisive and positively to the increase of transmission capacity and the DFIG equilibrium restorative forces, resulting improved stability of the system. The validation of the application of control methodology via voltage E' is proven through computational simulations in diverse contingencies, with and without action of crowbar circuit control. It is evident that this method can be used to evaluate the criticality of the system in real time / Doutor

This dissertation describes methodologies for evaluating a set of anticipated and recommended energy infrastructure changes essential to achieving deep greenhouse gas emissions reductions in a dense urban area: Deep penetration of grid-connected wind power, widespread adoption of electric heat pumps, multiple potential services from extensive deployment of distributed generation, and increasing focus on auxiliary energy in heating and cooling systems as cities continue to grow in population and height. The focus of the research presented here was New York City and the surrounding New York State electricity supply infrastructure. After developing a wind power model based on an NREL model wind data set, a linear program model showed that after passing a low-curtailment threshold of 10 GW, energy-related wind power curtailment is driven largely by continuous operation of baseload generation and misalignment of winter wind power peaks and existing summer electricity demand peaks. Separate analyses showed the potential for increase wind-generated electricity utilization through increased use of heat pumps in New York City. A suite of models was developed to assess the zonal effects in New York City of deep statewide penetration of wind power and widespread adoption of electric heat pumps in New York City. New York City was found to have highly fluctuating net loads in deep wind penetration scenarios. Further, with large amounts of existing space heating demand replaced by heat pumps, the increased winter electricity demand peaks occurred infrequently enough that the additional generation capacity required to meet those loads would have a capacity factor well less than 1%. Small-scale, natural gas-fueled internal combustion engines deployed as distributed generation were shown to improve the ability of the system to respond to load fluctuations, to be a more economical option than new large centralized generators at the low capacity factor, and to reduce overall system gas usage due to mitigating part-load effects and startup fuel requirements. This distributed generation, which could in reality also include combined heat and power systems as well as battery storage standing alone, connected to rooftop solar or in electric vehicles, also has potential system resilience benefits. The last research effort described here included long-term monitoring of a high-rise mixed use building’s hydronic system before and after a retrofit of hydraulic equipment. Significant annual reductions of 40% energy usage for pumping were computed, primarily due to part-load flow control effects. Analysis of the monitoring data, as well as computations related to theoretical performance of hydraulic networks, showed that this approach also has potential to reduce peak loads, particularly in high-rise buildings.

The 2040 governmental goal of 100 % renewable electricity in Sweden means that there will be a shift in electricity production and a phasing out of nuclear power. This nuclear power has to be replaced by some other source. Wind power is a viable alternative, thanks to its reliability and the abundance of wind in Sweden. However, wind power production requires a large amount of land and carries the risk of disrupting the landscape. Wind energy is therefore often difficult to develop, and when developed it is often in rural areas where it disturbs as few people as possible. This study presents an alternative to rural exploitation, it investigates whether it is possible to produce sufficient wind power to satisfy urban demand within 20 000 meters of the 20 largest cities in Sweden. Firstly, the criteria for areas where wind power can be developed were synthesised. Secondly a numerical model was used to simulate energy demand in TWh considering the future growth in demand and the phasing out of nuclear power. The demand for wind power was then translated into correlating area in km2. Finally, a GIS analysis was conducted to estimate the extent of area suitable for wind power development based on the criteria above and within a 20 000m perimeter from the 20 largest cities in Sweden. The analysis showed that only 35 % of the required area for wind power development fulfilled the criteria within the given perimeter. From the GIS analysis only 940.73 km2 was found to be suitable. From the numerical model, the results showed that for it to be sufficient, there would have to be at least 2687.1 km2 suitable land. The conclusion from this study is that in order to phase out the nuclear power, the majority of the wind power has to be located in the rural areas.

China's renewable energy (RE) sector is developing rapidly, driven by growing energy needs, increased awareness of climate change, and heightened concerns for environmental degradation caused by the country's industrialisation process over the past decades. The Chinese government has been dedicated to the development of its RE industry and has engaged extensively in drawing lessons from abroad and applying these lessons to its own experiences in the post transfer learning process to develop policies that have contributed to the development of the largest wind power sector in the world. This thesis provides a perspective of how China, a ‘socialist market economy', has applied primarily market mechanisms from liberalised market systems found in Western Europe and the United States to develop its domestic wind power sector. Having similar economic, political and cultural value systems is not necessarily a prerequisite to policy learning; rather policy objective compatibility is a more important criterion when drawing and transferring lessons. The objective of this thesis is to analyse how the policy learning from abroad, policy transfer and the post transfer process has influenced the development of wind power policies in China through the application of a framework to analyse the policies. The framework was specifically developed for this thesis and was largely based on policy learning and policy transfer concepts as well as general learning literature. Using the wind power policies in China as a case study, this thesis identifies elements of policy learning from abroad and examines how transferred policies have been applied in first level policies that are top-level coordinating policies (e.g. mid- to long-term strategies and frameworks) as well as second level policies, with specific objectives focusing on diffusion and adoption (e.g. renewable energy policy instruments). Overall, studying policy learning from abroad, policy transfer and the post transfer process contributes to understanding how learning across political boarders contributes to the domestic policy formation and implementation process.