Página 1 dos resultados de 18313 itens digitais encontrados em 0.019 segundos

Aerial sonic anemometry for wind resource assessment

Ribeiro, Luís Frölén; Marques, Filipe
Fonte: American Wind Energy Association Publicador: American Wind Energy Association
Tipo: Conferência ou Objeto de Conferência
POR
Relevância na Pesquisa
46.47%
This project intends to recur to sonic anemometers in a airborne platforms to get wind information over the flying area between met masts or waypoints. Multiple platforms measuring simultaneously to complement ground based measurements. The concept is being tested and preliminary results show that key issues are related to the positioning system – differential GPS and autopilot.

Convergent-diffuser for small horizontal wind turbines

Ribeiro, Luís Frölén; Paulo, Jorge; Garcia, Valdemar
Fonte: American Wind Energy Association Publicador: American Wind Energy Association
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
46.66%
A small horizontal axis wind turbine (HAWT) equipped with an annular Convergent-Diffuser (C-D) is under development. Small to medium wind turbines equipped solely with a diffuser are becoming quite common: the annular structure around the rotor decreases the pressure downstream the rotor, augmenting the air velocity and power output. It also may replace the wind vane. Previous studies for such designs, for instance Ohya, Y. 2010, report a maximum increase in power output up to 150%. We present the preliminary results of an alternative design for a convergent-divergent annular structure that involves the rotor. This structure was optimized in CFD-simulations and 2 models where built for wind tunnel measurements. The maximum power output obtained was 187% higher than the case for a rotor without the C-D structure. Field tests are undergoing at this moment for a C-D adapted in model Rutland 913 Windcharger of 90 W.

Simulação do desempenho de aerogeradores de pequeno porte; Performance simulation of small wind turbines

Rafael Valotta Rodrigues
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 09/05/2014 PT
Relevância na Pesquisa
36.8%
A participação da energia eólica na matriz elétrica brasileira vem aumentando continuamente desde 2005. A conexão de Aerogeradores de Grande Porte à rede elétrica foi permitida após a regulamentação do setor eólico no Brasil pela ANEEL, culminando com o crescimento contínuo do setor nos últimos cinco anos e a consolidação da participação da fonte eólica na matriz elétrica brasileira. O interesse pela utilização de Aerogeradores de Pequeno Porte no país aumentou, posto que sua conexão com a rede elétrica foi regulamentada pela ANEEL através da resolução 482. Acompanhando a evolução do uso de aerogeradores, metodologias para avaliação e simulação do desempenho de aerogeradores foram extensivamente desenvolvidas no século passado. Uma delas é o Método do Momento no Elemento de Pá, um modelo numérico unidimensional desenvolvido inicialmente por Glauert em 1920, utilizado para aferir o desempenho aerodinâmico do rotor do aerogerador. Neste trabalho, as curva de desempenho de potência e curvas adimensionais de desempenho de dois aerogeradores de pequeno porte foram simuladas teoricamente utilizando o Método do Momento no Elemento de Pá. Posteriormente, a aplicação desses aerogeradores na situação de conexão com a rede elétrica ou em um sistema isolado eólico-baterias foi simulada por meio do programa computacional Homer...

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
36.82%
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...

New design chart for basic wind speeds in Brazil

Beck,André T.; Corrêa,Márcio R. S.
Fonte: Associação Brasileira de Ciências Mecânicas Publicador: Associação Brasileira de Ciências Mecânicas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2013 EN
Relevância na Pesquisa
36.81%
The design charts for basic wind speeds currently in use in Brazil [1] were created in 1977, based on wind speed records from 1950 to 1974. The database covered up to 25 years of wind records obtained in 49 weather stations, totaling 919 stationyears of data. Since 1974, additional 37 years of wind records became available, but have not been incorporated in the design code. Hence, the updated wind charts proposed in this paper are long overdue. In this paper, 62 years of wind records in Brazil are gathered in order to construct updated and more reliable wind charts. The original data by Padaratz [2] are complemented by data from 104 airport weather stations, made available through the Wolfram Research Database [3]. In total, 4142 stationyears of data are used in the present study, hence providing much better cover in terms of space and time span. Maximum annual wind speeds for the individual stations are fitted to Gumbel distributions, from which basic wind speeds are evaluated (mean return period of 50 years). Basic wind speeds are used to build a non-linear regression model, using the p-value of the Anderson-Darling goodness-of-fit test as regression weight. This ensures that extreme value wind distributions for which a good fit is obtained are given more importance in the regression model...

Greening the Wind : Environmental and Social Considerations for Wind Power Development

Ledec, George C.; Rapp, Kennan W.; Aiello, Roberto G.
Fonte: World Bank Publicador: World Bank
Relevância na Pesquisa
36.87%
This report identifies good practices for managing the key environmental and social issues associated with wind power development and provides advice on how best to address these issues in project planning, construction, and operation and maintenance. It provides detailed background information on wind power, with special focus on two emerging themes of growing scientific and public interest: namely the biodiversity-related impacts and the broader socioeconomic and cultural dimensions of wind power development. Like wind power itself, the scope of this report is worldwide although special attention is paid to the issues characteristic of the Latin America and Caribbean (LAC) region. While the principal focus is on land-based wind power, it also briefly addresses the environmental and social impacts related to off shore wind development. Wind power today is widely regarded as a key component of an environmentally sustainable, low-carbon energy future because it is renewable, requires almost no water, and generates near-zero emissions of greenhouse gases and other pollutants. In many parts of the world...

Burgos Wind Farm Project : The Philippines Technical Desk Review

Cronin, Tom; Clausen, Niels-Erik; Nielsen, Morten; Jørgensen, Erik
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
EN_US
Relevância na Pesquisa
36.82%
This report presents the findings of a review carried out by Riso National Laboratory of a 30MW wind farm in Northern Luzon, The Philippines. The review was commissioned by the World Bank and is intended as a brief second opinion desk review of the technical, contractual and financial aspects of the project. The evaluation of the Annual Energy Production of the site by PNOC-EDC seems to follow accepted practice and where shortcomings have been found by the review, it is considered that their correction would not change the outcome significantly. For example, only data from one year has been used but the review has found that it is probably unnecessary to correct the data for long term deviations, having looked at historical data from other sources. Two wind turbine layouts were assessed and it was seen that, apart from some minor adjustments, the layout is more or less optimal. The precise layout and optimization will, in any case, be done by the contractor.

How Fit are Feed-in Tariff Policies? Evidence from the European Wind Market

Zhang, Fan
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
EN_US
Relevância na Pesquisa
36.84%
Feed-in tariffs have become the most widely used policy instrument to promote renewable energy deployment around the world. This paper examines the relation between tariff setting and policy outcome based on wind capacity expansion in 35 European countries over the 1991-2010 period. Using a dynamic panel data model, it estimates the long-run elasticity of wind deployment with respect to the level of feed-in support. The analysis finds that higher subsidies do not necessarily yield greater levels of wind installation. Non-economic barriers and rent-seeking may have contributed to the weak correlation. On the other hand, the length of feed-in contract and guaranteed grid access are important determinants of policy effectiveness. A one-year extension of an original 5-year agreement on average increases wind investment by 6 percent annually, while providing an interconnection guarantee almost doubles wind investment in one year.

The Economics of Policy Instruments to Stimulate Wind Power in Brazil

Landis, Florian; Timilsina, Govinda R.
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Trabalho em Andamento
EN_US
Relevância na Pesquisa
36.81%
Large-scale deployment of renewable energy technologies, such as wind power and solar energy, has been taking place in industrialized and developing economics mainly because of various fiscal and regulatory policies. An understanding of the economy-wide impacts of those policies is an important part of an overall analysis of them. Using a perfect foresight computable general equilibrium model, this study analyzes the economy-wide costs of achieving a 10 percent share of wind power in Brazil’s electricity supply mix by 2030. Brazil is in the midst of an active program of wind capacity expansion. The welfare loss would be small, 0.1 percent of total baseline welfare in the absence of the 10 percent wind power expansion. The study also finds that, in the case of Brazil, production subsidies financed through increased value-added tax would have superior impacts on welfare and greenhouse gas mitigation, compared with a consumption mandate where electricity utilities are allowed to pass the increased electricity supply costs directly to consumers. These two policies would impact various production sectors differently to achieve the wind power expansion targets: the burden of the mandate falls mostly on electricity-intensive production and consumption...

Analysis and modelling of the effects of inertia and parameter errors on wind turbine output power.

Tang, Chun
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2010
Relevância na Pesquisa
36.84%
Wind energy is an important renewable energy source. The average output power of a wind turbine is one of the main concerns in wind generation systems. The factors which affect the average output power include the location, the wind characteristics, the design of the blades and the control system etc. In this thesis, the effects of the inertia of a wind turbine under dynamic wind speed conditions, and the effects of the parameter errors under steady-state operation on the average output power are examined. Maximum power point tracking is used to control the generator of a wind turbine in order to maximise the electrical output power of the wind turbine. However, under rapidly changing wind conditions, the output power of the wind turbines is reduced due to their inertia preventing them operating at the optimal turbine speed. Limited research into analysing this power reduction has been performed. Even under steady-state operating conditions, the maximum power coefficient and the optimal tip-speed ratio of the wind turbine generally need to be known for maximum power point tracking. Errors in the estimated parameters will result in an output power reduction for the wind turbine. Therefore, an understanding of the sensitivity of wind turbine blade parameter errors to the output power reduction under steady-state conditions of wind turbines is also a significant issue. The first part of the work in this thesis investigates the wind turbine output power reduction due to inertia under dynamic wind speed conditions. It is assumed that the wind turbine blade characteristics is known accurately and that a maximum power point strategy based on controlling the generator input torque as a function of generator speed is used (optimal torque control). The concept of the small-signal turbine time constant is introduced to denote the time constant of the response of a wind turbine for a small change in wind speed under the maximum power point operating conditions. It is shown that the turbine time constant is inversely proportional to the average wind speed...

Examining the Effects of Wind Turbine Industrial Development on Rural Areas

Sinkaus, Bradley
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Relatório
Relevância na Pesquisa
36.83%
There has been an international shift to 'green energy' in the past few decades, and a focus of this shift has been to develop wind turbines to generate wind energy. Because the implementation of wind energy targets are a large part of many countries' renewable energy plans, including Australia, it is essential to understand what kind of effects wind turbines have on the rural areas in which they are constructed. Many rural communities across Australia, as well as communities in other parts of the world, have seen property values fall as a result of the erection of wind turbines. In places like the United States and Denmark, legislation has been instituted to protect landowners from having their home value decrease as a result of nearby wind turbine construction. Rural communities have also been subject to a noise increase due to the turbines, and numerous studies have deduced that the noise from wind turbines can negatively affect the daily lives of rural residents, leading to sleep deprivation. While wind turbine companies deny this fact, they have also been held responsible for leaving communities out of the process of constructing wind turbines, and writing complicated contracts that the average resident cannot understand. Rural residents have experienced negative health effects as a result of living in proximity to the turbines. Researchers have surveyed rural residents and found that detrimental health effects can occur...

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
36.85%
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.

Wind Power Development : Economics and Policies

van Kooten, G. Cornelis; Timilsina, Govinda R.
Fonte: Banco Mundial Publicador: Banco Mundial
Tipo: Publications & Research :: Policy Research Working Paper
ENGLISH
Relevância na Pesquisa
36.87%
This study reviews the prospects of wind power at the global level. Existing studies indicate that the earth's wind energy supply potential significantly exceeds global energy demand. Yet, only 1 percent of the global electricity demand is currently derived from wind power despite 40 percent annual growth in wind generating capacity over the past 25 years. More than 98 percent of total current wind power capacity is installed in the developed countries plus China and India. It has been estimated that wind power could supply 7 to 34 percent of global electricity needs by 2050. However, wind power faces a large number of technical, economic, financial, institutional, market, and other barriers. To overcome these barriers, many countries have employed various policy instruments, including capital subsidies, tax incentives, tradable energy certificates, feed-in tariffs, grid access guarantees and mandatory standards. Besides these policies, climate change mitigation initiatives resulting from the Kyoto Protocol (e.g....

Implementing Onshore Wind Power Projects

Elizondo Azuela, Gabriela; Ben, Rafael
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Journal Article; Publications & Research :: Brief
EN_US
Relevância na Pesquisa
36.84%
The kinetic energy in wind is converted into mechanical power in specialized propeller-driven turbines mounted on towers. A generator inside the turbine converts the mechanical power into electricity. Utility-scale wind turbines range in size from 100 kilowatts to as large as several megawatts. Turbines can be built on land or offshore and are grouped into 'wind farms' that provide bulk power to the electrical grid. Smaller turbines are used for homes, telecommunications dishes, and water pumping, sometimes in connection with diesel generators, batteries, and photovoltaic systems. Such hybrid wind systems are typically used in remote, off-grid locations, where a connection to the utility grid is not available. This note focuses on onshore wind energy, which is more widely established and has lower risks than offshore wind.

China - Meeting the Challenges of Offshore and Large-Scale Wind Power : Regulatory Review of Offshore Wind in Five European Countries

World Bank
Fonte: World Bank Publicador: World Bank
Tipo: Economic & Sector Work :: Energy Study
ENGLISH
Relevância na Pesquisa
36.85%
The objective of this study is to review international experience in offshore wind power development and draw on the lessons learned from the experience of different countries. To date, that experience has predominantly been limited to Europe. Significantly different regulatory and physical planning approaches have been taken in the different countries. Hence, the experience is particularly helpful in providing suggestions for a new market. The study focuses on describing the past, present, and planned future regulatory regime in each country. Both positive and negative experiences to date have been explored in the context of regulatory arrangements, and they have been used to draw general conclusions on the characteristics of the most effective systems. At the same time, it has been recognized throughout that a single model is unlikely to provide the 'best fit' for all countries, given national differences. Chapters two, three, and four, focusing on market development, targets and incentives, and regulatory framework...

China - Meeting the Challenges of Offshore and Large-Scale Wind Power : Strategic Guidance

World Bank
Fonte: World Bank Publicador: World Bank
Tipo: Economic & Sector Work :: Energy Study
ENGLISH
Relevância na Pesquisa
36.86%
In view of the escalating global problems associated with the environment, energy, and natural resources, especially the increasing sign of global climate change, wind power is receiving more and more high-level attention on a global scale, and it has reached a rapid rate of development as a result of the combined efforts of various countries. The world's installed capacity of wind power has already surpassed 100 GW, and wind power has become an essential part of the world's energy structure. This publication comprises three main parts: i) part A contains the key messages emerging from the research and analytical work undertaken by Garrad Hassan and Partners Limited, the team of Chinese experts led by the national energy administration, and staff and consultants of the World Bank; ii) part B comprises the Garrad Hassan and Partners Limited study, 'implementation guidance for offshore and large-scale onshore wind power development in China,' and its annexes; and iii) part C focuses on the workshop on offshore and intertidal wind power development in China...

BALANCING WIND DOWN RAMPS WITH DEMAND RESPONSE: The opportunity for load participation in ancillary service markets spurred by high wind penetration

Ballal, Sangeeta; Nourafshan, Andrew; Brumleve, Nicholas
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project
Publicado em 27/04/2012
Relevância na Pesquisa
36.82%
Large “down-ramps,” inherent in the pronounced variability of wind power generation, are a threat to grid stability as the share of wind resources increases in power markets. Balancing Authorities face the challenge of how best to address the externalities that wind variability places on the grid. Our analysis assesses U.S. power markets that offer the greatest opportunities for demand response to act as a wind balancing resource. More specifically, this study evaluates market opportunities for third-party demand response aggregators to bid the capacity of responsive load into ancillary services markets to address these “down-ramp” events. This evaluation was performed through both the establishment of a qualitative framework and the creation of a quantitative, Microsoft Excel-based, model. In the qualitative framework, we reviewed the existing wind integration literature to identify the critical characteristics of a balancing authority that are predictive of the local grid’s relative capability to accommodate wind ramping behavior. In this framework, we additionally outline key qualities of loads that make them viable candidates for the demand response services required in the balancing of wind ramps. Lastly, we discuss several potential approaches for forecasting future wind penetration in a balancing authority. We have found that demand response for wind balancing can be a favorable emerging business opportunity in a power system at the confluence of these three aforementioned analyses: 1) the balancing authority’s structure and other conditions lead to a limited ability to effectively respond to increasing wind penetration...

Balancing Wind Down Ramps With Demand Response: The opportunity for load participation in ancillary service markets spurred by high wind penetration

Nourafshan, Andrew; Ballal, Sangeeta; Brumleve, Nick
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project
Publicado em 27/04/2012 EN_US
Relevância na Pesquisa
36.82%
Large “down-ramps,” inherent in the pronounced variability of wind power generation, are a threat to grid stability as the share of wind resources increases in power markets. Balancing Authorities face the challenge of how best to address the externalities that wind variability places on the grid. Our analysis assesses U.S. power markets that offer the greatest opportunities for demand response to act as a wind balancing resource. More specifically, this study evaluates market opportunities for third-party demand response aggregators to bid the capacity of responsive load into ancillary services markets to address these “down-ramp” events. This evaluation was performed through both the establishment of a qualitative framework and the creation of a quantitative, Microsoft Excel-based, model. In the qualitative framework, we reviewed the existing wind integration literature to identify the critical characteristics of a balancing authority that are predictive of the local grid’s relative capability to accommodate wind ramping behavior. In this framework, we additionally outline key qualities of loads that make them viable candidates for the demand response services required in the balancing of wind ramps. Lastly, we discuss several potential approaches for forecasting future wind penetration in a balancing authority. We have found that demand response for wind balancing can be a favorable emerging business opportunity in a power system at the confluence of these three aforementioned analyses: 1) the balancing authority’s structure and other conditions lead to a limited ability to effectively respond to increasing wind penetration...

Balancing Wind Down Ramps With Demand Response: The opportunity for load participation in ancillary service markets spurred by high wind penetration

Brumleve, Nick; Ballal, Sangeeta; Nourafshan, Andrew
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project
Publicado em 27/04/2012 EN_US
Relevância na Pesquisa
36.83%
Large “down-ramps,” inherent in the pronounced variability of wind power generation, are a threat to grid stability as the share of wind resources increases in power markets. Balancing Authorities face the challenge of how best to address the externalities that wind variability places on the grid. Our analysis assesses U.S. power markets that offer the greatest opportunities for demand response to act as a wind balancing resource. More specifically, this study evaluates market opportunities for third-party demand response aggregators to bid the capacity of responsive load into ancillary services markets to address these “down-ramp” events. This evaluation was performed through both the establishment of a qualitative framework and the creation of a quantitative, Microsoft Excel-based, model. In the qualitative framework, we reviewed the existing wind integration literature to identify the critical characteristics of a balancing authority that are predictive of the local grid’s relative capability to accommodate wind ramping behavior. In this framework, we additionally outline key qualities of loads that make them viable candidates for the demand response services required in the balancing of wind ramps. Lastly, we discuss several potential approaches for forecasting future wind penetration in a balancing authority. We have found that demand response for wind balancing can be a favorable emerging business opportunity in a power system at the confluence of these three aforementioned analyses: 1) the balancing authority’s structure and other conditions lead to a limited ability to effectively respond to increasing wind penetration...

Design and operation of power systems with large amounts of wind power: State of the art report

Holttinen, Hannele; Lemstrom, Bettina; Meibom, Peter; Bindner, Henrik; Orths, Antje; Van Hulle, Frans; Ensslin, Cornel; Tiedemann, Albrecht; Hofmann, Lutz; Winter, Wilhelm; Tuohy, Aidan; O'Malley, Mark; Smith, Paul; Pierik, Jan; Tande, John O.; Estanqueir
Fonte: VTT Publicador: VTT
Tipo: Livro
Publicado em //2007 ENG
Relevância na Pesquisa
36.83%
High penetration of wind power has impacts that have to be managed through proper plant interconnection, integration, transmission planning, and system and market operations. This report is a summary of case studies addressing concerns about the impact of wind powers variability and uncertainty on power system reliability and costs. The case studies summarized in this report are not easy to compare due to different methodology and data used, as well as different assumptions on the interconnection capacity available. Integration costs of wind power need to be compared to something, like the production costs or market value of wind power, or integration cost of other production forms. There is also benefit when adding wind power to power systems: it reduces the total operating costs and emissions as wind replaces fossil fuels. Several issues that impact on the amount of wind power that can be integrated have been identified. Large balancing areas and aggregation benefits of large areas help in reducing the variability and forecast errors of wind power as well as help in pooling more cost effective balancing resources. System operation and working electricity markets at less than day-ahead time scales help reduce forecast errors of wind power. Transmission is the key to aggregation benefits...