The Experts below are selected from a list of 30144 Experts worldwide ranked by ideXlab platform
Lennart Söder - One of the best experts on this subject based on the ideXlab platform.
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An overview of Wind Energy-status 2002
Renewable & Sustainable Energy Reviews, 2002Co-Authors: Thomas Ackermann, Lennart SöderAbstract:The paper provides an overview of the historical development of Wind Energy Technology and discusses the current world-wide status of grid-connected as well as stand-alone Wind power generation. During the last decade of the twentieth century, grid-connected world-wide Wind capacity has doubled approximately every three years. Due to the fast market development, Wind turbine Technology has experienced an important evolution over time. An overview of the different design approaches is given and issues like power grid integration, economics, environmental impact and special system applications, such as offshore Wind Energy, are discussed. Due to the complexity of the Wind Energy Technology, however, this paper mainly aims at presenting a brief overview of the relevant Wind turbine and Wind project issues. Therefore, detailed information to further readings and related organisations is provided. This paper is an updated version of the article 'Wind Energy Technology and Current Status: A Review', published in Renewable and Sustainable Energy Reviews, 4/2000, pp. 315-374. This update was requested by Elsevier due to the large interest in Wind power.
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Wind Energy Technology and current status : a review
Renewable and Sustainable Energy Reviews, 2000Co-Authors: Thomas Ackermann, Lennart SöderAbstract:The paper provides an overview of the historical development of Wind Energy Technology and discusses the current status of grid-connected as well as stand-alone Wind power generation worldwide. During the last decade of the 20th century, grid-connected Wind capacity worldwide has doubled approximately every three years. Due to the fast market development, Wind turbine Technology has experienced an important evolution over time. An overview of the different design approaches is given and issues like power grid integration, economics, environmental impact and special system applications, such as offshore Wind Energy, are discussed. Due to the complexity of the Wind Energy Technology, however, this paper mainly aims at presenting a brief overview of the relevant Wind turbine and Wind project issues. Therefore, detailed information on further readings and related organisations is included.
Thomas Ackermann - One of the best experts on this subject based on the ideXlab platform.
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An overview of Wind Energy-status 2002
Renewable & Sustainable Energy Reviews, 2002Co-Authors: Thomas Ackermann, Lennart SöderAbstract:The paper provides an overview of the historical development of Wind Energy Technology and discusses the current world-wide status of grid-connected as well as stand-alone Wind power generation. During the last decade of the twentieth century, grid-connected world-wide Wind capacity has doubled approximately every three years. Due to the fast market development, Wind turbine Technology has experienced an important evolution over time. An overview of the different design approaches is given and issues like power grid integration, economics, environmental impact and special system applications, such as offshore Wind Energy, are discussed. Due to the complexity of the Wind Energy Technology, however, this paper mainly aims at presenting a brief overview of the relevant Wind turbine and Wind project issues. Therefore, detailed information to further readings and related organisations is provided. This paper is an updated version of the article 'Wind Energy Technology and Current Status: A Review', published in Renewable and Sustainable Energy Reviews, 4/2000, pp. 315-374. This update was requested by Elsevier due to the large interest in Wind power.
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Wind Energy Technology and current status : a review
Renewable and Sustainable Energy Reviews, 2000Co-Authors: Thomas Ackermann, Lennart SöderAbstract:The paper provides an overview of the historical development of Wind Energy Technology and discusses the current status of grid-connected as well as stand-alone Wind power generation worldwide. During the last decade of the 20th century, grid-connected Wind capacity worldwide has doubled approximately every three years. Due to the fast market development, Wind turbine Technology has experienced an important evolution over time. An overview of the different design approaches is given and issues like power grid integration, economics, environmental impact and special system applications, such as offshore Wind Energy, are discussed. Due to the complexity of the Wind Energy Technology, however, this paper mainly aims at presenting a brief overview of the relevant Wind turbine and Wind project issues. Therefore, detailed information on further readings and related organisations is included.
Ludovico Terzi - One of the best experts on this subject based on the ideXlab platform.
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CFD three dimensional wake analysis in complex terrain
Journal of Physics: Conference Series, 2017Co-Authors: Francesco Castellani, Davide Astolfi, Ludovico TerziAbstract:Even if Wind Energy Technology is nowadays fully developed, the use of Wind Energy in very complex terrain is still challenging. In particular, it is challenging to characterize the combination effects of Wind ow over complex terrain and wake interactions between nearby turbines and this has a practical relevance too, for the perspective of mitigating anomalous vibrations and loads as well improving the farm efficiency. In this work, a very complex terrain site has been analyzed through a Reynolds-averaged CFD (Computational Fluid Dynamics) numerical Wind field model; in the simulation the inuence of wakes has been included through the Actuator Disk (AD) approach. In particular, the upstream turbine of a cluster of 4 Wind turbines having 2.3 MW of rated power is studied. The objective of this study is investigating the full three-dimensional Wind field and the impact of three-dimensionality on the evolution of the waked area between nearby turbines. A post-processing method of the output of the CFD simulation is developed and this allows to estimate the wake lateral deviation and the wake width. The reliability of the numerical approach is inspired by and crosschecked through the analysis of the operational SCADA (Supervisory Control and Data Acquisition) data of the cluster of interest.
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data mining techniques for performance analysis of onshore Wind farms
Applied Energy, 2015Co-Authors: Davide Astolfi, Francesco Castellani, Alberto Garinei, Ludovico TerziAbstract:Wind turbines are an Energy conversion system having a low density on the territory, and therefore needing accurate condition monitoring in the operative phase. Supervisory Control And Data Acquisition (SCADA) control systems have become ubiquitous in Wind Energy Technology and they pose the challenge of extracting from them simple and explanatory information on goodness of operation and performance. In the present work, post processing methods are applied on the SCADA measurements of two onshore Wind farms sited in southern Italy. Innovative and meaningful indicators of goodness of performance are formulated. The philosophy is a climax in the granularity of the analysis: first, Malfunctioning Indexes are proposed, which quantify goodness of merely operational behavior of the machine, irrespective of the quality of output. Subsequently the focus is shifted to the analysis of the farms in the productive phase: dependency of farm efficiency on Wind direction is investigated through the polar plot, which is revisited in a novel way in order to make it consistent for onshore Wind farms. Finally, the inability of the nacelle to optimally follow meandering Wind due to wakes is analysed through a Stationarity Index and a Misalignment Index, which are shown to capture the relation between mechanical behavior of the turbine and degradation of the power output.
Shun-chung Lee - One of the best experts on this subject based on the ideXlab platform.
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enhancing renewable and sustainable Energy development based on an options based policy evaluation framework case study of Wind Energy Technology in taiwan
Renewable & Sustainable Energy Reviews, 2011Co-Authors: Shun-chung Lee, Lihsing ShihAbstract:Global warming and climate change have shifted the focus of industrial development towards low-carbon renewable Energy (RE), as evidence by global efforts to develop RE-based sustainable Energy policies. However, the generally cost-ineffective nature of RE investments explains continued governmental subsidies and draft assistance measures to encourage related industrial development, reduce research and development (R&D) costs, and increase innovativeness. Besides measures to accelerate supply and reduced demand for Energy, sustainable Energy policies must enact thoroughly planned legal and regulatory mechanisms. Notable examples of establishing a legal basis for a low-carbon society in Taiwan include the Energy Management Act, Renewable Energy Development Bill, Greenhouse Gas Reduction Act (Draft), and Energy Tax Act (Draft). However, such legislative efforts occasionally conflict or compete with each other, warranting further integration. Additionally, RE technologies are characterized by high R&D costs, long-term planning, and high investment risks. Therefore, based on global trends in Wind power development and related policy planning, this study analyzes the feasibility of implementing management strategies in the development process and the correlations between such strategies. Additionally, the achievements, polices, functions, mechanisms, promotion measures, and future plans for related renewable and sustainable Energy laws in Taiwan is thoroughly reviewed. An options-based policy evaluation framework is also constructed based on governmental administrative considerations. Moreover, the characteristics of options that lead to unforeseen circumstances during the planning of RE development policies are discussed, allowing us to derive real-time response measures with a decision-making value. Results of this study provide a valuable reference for governmental efforts to evaluate the merits and limitations of related policies concisely, ultimately facilitating the formulation of RE development policies.
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Using real option analysis for highly uncertain Technology investments: The case of Wind Energy Technology
Renewable and Sustainable Energy Reviews, 2011Co-Authors: Shun-chung LeeAbstract:This study examines the feasibility of using a theoretical model and empirical analysis methods to value renewable Energy (RE) investment from perspective of real option analysis (ROA). Based on use of a ROA approach, the RE value is evaluated with respect to its ability to conform to the main sensitivity analysis of RE investment, as well as an empirical method devised to value RE investment by using actual data. The economic intuitiveness underlying the decision-making process for RE investment is elucidated, while empirical analysis is performed to demonstrate the effectiveness of the options value embedded in current development planning in Taiwan for Wind Energy. In addition to revealing the advantages of RE development when considering real option, analytical results indicate that ROA is a highly effective means of quantifying how investment planning uncertainty (including managerial flexibility) influences RE development. Besides evaluating the value of current RE investment, this study demonstrates that results of the theoretical model, empirical analysis, and sensitivity analysis correlate well with each other. Restated, the value of developing RE increases when increasing the underlying price, time to maturity, risk-free rate, and volatility. Conversely, the value of developing RE decreases when increasing the exercise price.
Davide Astolfi - One of the best experts on this subject based on the ideXlab platform.
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Condition monitoring of Wind turbine gearboxes through on-site measurement and vibration analysis techniques
'Springer Science and Business Media LLC', 2020Co-Authors: Davide Astolfi, Francesco Castellani, Garibaldi Luigi, Daga, Alessandro PaoloAbstract:Condition monitoring of gear-based mechanical systems undergoing non-stationary operation conditions is in general very challenging. In particular, this issue is remarkable as regards Wind Energy Technology because most of the modern Wind turbines are geared and gearbox damages account for at least the 20% of their unavailability time. In this work, a new method for the diagnosis of gearbox damages is proposed: the main idea is that vibrations are measured at the tower, instead that at the gearbox. This implies that measurements can be performed without impacting on the Wind turbine operation, as desirable by the point of view of Wind turbine practitioners. A test case study is discussed: it deals with a Wind farm owned by Renvico, featuring 6 Wind turbines with 2 MW of rated power each. The vibration measurements at a Wind turbine suspected to be damaged and at reference Wind turbines are processed through a multivariate Novelty Detection algorithm in the feature space. The application of this algorithm is justified by univariate statistical tests on the time-domain features selected and by a visual inspection of the data set via Principal Component Analysis. Finally, a novelty index based on the Mahalanobis distance is used to detect the anomalous conditions at the damaged Wind turbine
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CFD three dimensional wake analysis in complex terrain
Journal of Physics: Conference Series, 2017Co-Authors: Francesco Castellani, Davide Astolfi, Ludovico TerziAbstract:Even if Wind Energy Technology is nowadays fully developed, the use of Wind Energy in very complex terrain is still challenging. In particular, it is challenging to characterize the combination effects of Wind ow over complex terrain and wake interactions between nearby turbines and this has a practical relevance too, for the perspective of mitigating anomalous vibrations and loads as well improving the farm efficiency. In this work, a very complex terrain site has been analyzed through a Reynolds-averaged CFD (Computational Fluid Dynamics) numerical Wind field model; in the simulation the inuence of wakes has been included through the Actuator Disk (AD) approach. In particular, the upstream turbine of a cluster of 4 Wind turbines having 2.3 MW of rated power is studied. The objective of this study is investigating the full three-dimensional Wind field and the impact of three-dimensionality on the evolution of the waked area between nearby turbines. A post-processing method of the output of the CFD simulation is developed and this allows to estimate the wake lateral deviation and the wake width. The reliability of the numerical approach is inspired by and crosschecked through the analysis of the operational SCADA (Supervisory Control and Data Acquisition) data of the cluster of interest.
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data mining techniques for performance analysis of onshore Wind farms
Applied Energy, 2015Co-Authors: Davide Astolfi, Francesco Castellani, Alberto Garinei, Ludovico TerziAbstract:Wind turbines are an Energy conversion system having a low density on the territory, and therefore needing accurate condition monitoring in the operative phase. Supervisory Control And Data Acquisition (SCADA) control systems have become ubiquitous in Wind Energy Technology and they pose the challenge of extracting from them simple and explanatory information on goodness of operation and performance. In the present work, post processing methods are applied on the SCADA measurements of two onshore Wind farms sited in southern Italy. Innovative and meaningful indicators of goodness of performance are formulated. The philosophy is a climax in the granularity of the analysis: first, Malfunctioning Indexes are proposed, which quantify goodness of merely operational behavior of the machine, irrespective of the quality of output. Subsequently the focus is shifted to the analysis of the farms in the productive phase: dependency of farm efficiency on Wind direction is investigated through the polar plot, which is revisited in a novel way in order to make it consistent for onshore Wind farms. Finally, the inability of the nacelle to optimally follow meandering Wind due to wakes is analysed through a Stationarity Index and a Misalignment Index, which are shown to capture the relation between mechanical behavior of the turbine and degradation of the power output.
