[ { "key": "RKI7XUU4", "version": 27, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/RKI7XUU4", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/RKI7XUU4", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "Adaramola and Krogstad", "parsedDate": "2011-08", "numChildren": 0 }, "data": { "key": "RKI7XUU4", "version": 27, "itemType": "journalArticle", "title": "Experimental investigation of wake effects on wind turbine performance", "creators": [ { "creatorType": "author", "firstName": "M.S.", "lastName": "Adaramola" }, { "creatorType": "author", "firstName": "P.-Å.", "lastName": "Krogstad" } ], "abstractNote": "The wake interference effect on the performance of a downstream wind turbine was investigated experimentally. Two similar model turbines with the same rotor diameter were used. The effects on the performance of the downstream turbine of the distance of separation between the turbines and the amount of power extracted from the upstream turbine were studied. The effects of these parameters on the total power output from the turbines were also estimated. The reduction in the maximum power coefficient of the downstream turbine is strongly dependent on the distance between the turbines and the operating condition of the upstream turbine. Depending on the distance of separation and blade pitch angle, the loss in power from the downstream turbine varies from about 20 to 46% compared to the power output from an unobstructed single turbine operating at its designed conditions. By operating the upstream turbine slightly outside this optimum setting or yawing the upstream turbine, the power output from the downstream turbine was significantly improved. This study shows that the total power output could be increased by installing an upstream turbine which extracts less power than the following turbines. By operating the upstream turbine in yawed condition, the gain in total power output from the two turbines could be increased by about 12%.", "publicationTitle": "Renewable Energy", "publisher": "", "place": "", "date": "August 2011", "volume": "36", "issue": "8", "section": "", "partNumber": "", "partTitle": "", "pages": "2078-2086", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Renewable Energy", "DOI": "10.1016/j.renene.2011.01.024", "citationKey": "", "url": "http://www.sciencedirect.com/science/article/pii/S0960148111000462", "accessDate": "2013-06-21T14:40:29Z", "PMID": "", "PMCID": "", "ISSN": "0960-1481", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "ScienceDirect", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-21T14:40:29Z", "dateModified": "2013-06-21T14:40:29Z" } }, { "key": "FC6X3GUW", "version": 25, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/FC6X3GUW", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/FC6X3GUW", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "Husien et al.", "parsedDate": "2013-01", "numChildren": 0 }, "data": { "key": "FC6X3GUW", "version": 25, "itemType": "journalArticle", "title": "Effect of the wake behind wind rotor on optimum energy output of wind farms", "creators": [ { "creatorType": "author", "firstName": "Walid", "lastName": "Husien" }, { "creatorType": "author", "firstName": "Wedad", "lastName": "El-Osta" }, { "creatorType": "author", "firstName": "Elhadi", "lastName": "Dekam" } ], "abstractNote": "This study deals with the modeling of the wake effect on the energy extracted from the wind farms. It covers the wake effect of the interaction of the upstream wind rotor with/without the upstream right and/or upstream left wind rotor. A mathematical model representing a single wake model based on the linear description of the wake is developed in order to predict the wind speed inside the wake region at any downstream distance within the wind farm. Two different types of turbines with diameters of 62 m and 100 m are considered. Accordingly the effect of the wake on the energy produced from the wind farms is estimated. A number of different wind farm layouts are studied. Case studies including 3 × 3, 4 × 4, 6 × 6, 1 × 16, 16 × 1, 2 × 8, and 8 × 2 layouts are considered. Extracted energy is calculated in each case and an optimum layout is determined from different layouts. The effectiveness of the other layouts with respect to the optimum is obtained. The results showed that there is a drop in the annual extracted energy from the above mentioned layouts depending on the W.T. distances separating the W.T.'s. The wind speed was assumed to be 15 m/s with 10D downstream distances. The losses are estimated to be 20% for 3 × 3 (rows × column), 32% for 4 × 4, 46% for 6 × 6, 12.8% for 16 × 1, 23.3% for 2 × 8, and 29% for 8 × 2 when these layouts are compared to 1 × 16 layout as an optimum layout.", "publicationTitle": "Renewable Energy", "publisher": "", "place": "", "date": "January 2013", "volume": "49", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "128-132", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Renewable Energy", "DOI": "10.1016/j.renene.2012.01.048", "citationKey": "", "url": "http://www.sciencedirect.com/science/article/pii/S0960148112000596", "accessDate": "2013-06-21T14:39:46Z", "PMID": "", "PMCID": "", "ISSN": "0960-1481", "archive": "", "archiveLocation": "", "shortTitle": "Selected papers from World Renewable Energy Congress - XI", "language": "", "libraryCatalog": "ScienceDirect", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-21T14:39:46Z", "dateModified": "2013-06-21T14:39:46Z" } }, { "key": "9IJ3N7JG", "version": 24, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/9IJ3N7JG", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/9IJ3N7JG", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "Aubrun", "parsedDate": "2012", "numChildren": 0 }, "data": { "key": "9IJ3N7JG", "version": 24, "itemType": "journalArticle", "title": "Wind turbine wake: a disturbance to wind resource in wind farms", "creators": [ { "creatorType": "author", "firstName": "Sandrine", "lastName": "Aubrun" } ], "abstractNote": "", "publicationTitle": "International Journal of Engineering Systems Modelling and Simulation", "publisher": "", "place": "", "date": "2012", "volume": "4", "issue": "1/2", "section": "", "partNumber": "", "partTitle": "", "pages": "2", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1504/IJESMS.2012.044839", "citationKey": "", "url": "http://www.inderscience.com/link.php?id=44839", "accessDate": "2013-06-21T14:39:02Z", "PMID": "", "PMCID": "", "ISSN": "1755-9758, 1755-9766", "archive": "", "archiveLocation": "", "shortTitle": "Wind turbine wake", "language": "", "libraryCatalog": "CrossRef", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-21T14:39:02Z", "dateModified": "2013-06-21T14:39:02Z" } }, { "key": "7VK3G986", "version": 22, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/7VK3G986", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/7VK3G986", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "Han et al.", "parsedDate": "2012", "numChildren": 0 }, "data": { "key": "7VK3G986", "version": 22, "itemType": "journalArticle", "title": "Adequacy study of a wind farm considering terrain and wake effect", "creators": [ { "creatorType": "author", "firstName": "X.", "lastName": "Han" }, { "creatorType": "author", "firstName": "J.", "lastName": "Guo" }, { "creatorType": "author", "firstName": "P.", "lastName": "Wang" } ], "abstractNote": "When wind passes over a hilly land, the complex terrain feature will observably change wind speed. Wind speed distribution on a hill is much different from that on a flat area. The wake produced by an upstream wind turbine generator (WTG) may affect power output of a downstream WTG. When a WTG fails, wind speed distribution over a wind farm also changes, which leads to different wind power output. This study proposes a time sequential Monte Carlo simulation technique to evaluate adequacy of a wind farm with considering the combined effect of terrain, wake and WTG reliability. A quadratic interpolation method is used to study the optimal locations of WTGs in order to maximise power output of a wind farm. A test wind farm and the IEEE reliability test system (RTS) are analysed to illustrate the models and proposed technique.", "publicationTitle": "IET Generation, Transmission Distribution", "publisher": "", "place": "", "date": "2012", "volume": "6", "issue": "10", "section": "", "partNumber": "", "partTitle": "", "pages": "1001-1008", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1049/iet-gtd.2011.0704", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "1751-8687", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "IEEE Xplore", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-21T14:37:56Z", "dateModified": "2013-06-21T14:37:56Z" } }, { "key": "BZTGX6NZ", "version": 21, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/BZTGX6NZ", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/BZTGX6NZ", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "Prospathopoulos et al.", "parsedDate": "2011", "numChildren": 0 }, "data": { "key": "BZTGX6NZ", "version": 21, "itemType": "journalArticle", "title": "Evaluation of the effects of turbulence model enhancements on wind turbine wake predictions", "creators": [ { "creatorType": "author", "firstName": "J. M.", "lastName": "Prospathopoulos" }, { "creatorType": "author", "firstName": "E. S.", "lastName": "Politis" }, { "creatorType": "author", "firstName": "K. G.", "lastName": "Rados" }, { "creatorType": "author", "firstName": "P. K.", "lastName": "Chaviaropoulos" } ], "abstractNote": "The modelling of wind turbine wakes is investigated in this paper using a Navier–Stokes solver employing the k–ω turbulence model appropriately modified for atmospheric flows. It is common knowledge that even single-wind turbine wake predictions with computational fluid dynamic methods underestimate the near wake deficit, directly contributing to the overestimation of the power of the downstream turbines. For a single-wind turbine, alternative modelling enhancements under neutral and stable atmospheric conditions are tested in this paper to account for and eventually correct the turbulence overestimation that is responsible for the faster flow recovery that appears in the numerical predictions. Their effect on the power predictions is evaluated with comparison with existing wake measurements. A second issue addressed in this paper concerns multi-wake predictions in wind farms, where the estimation of the reference wind speed that is required for the thrust calculation of a turbine located in the wake(s) of other turbines is not obvious. This is overcome by utilizing an induction factor-based concept: According to it, the definition of the induction factor and its relationship with the thrust coefficient are employed to provide an average wind speed value across the rotor disk for the estimation of the axial force. Application is made on the case of five wind turbines in a row.", "publicationTitle": "Wind Energy", "publisher": "", "place": "", "date": "03/2011", "volume": "14", "issue": "2", "section": "", "partNumber": "", "partTitle": "", "pages": "285-300", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1002/we.419", "citationKey": "", "url": "http://doi.wiley.com/10.1002/we.419", "accessDate": "2013-06-21T14:36:37Z", "PMID": "", "PMCID": "", "ISSN": "10954244", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "CrossRef", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-21T14:36:37Z", "dateModified": "2013-06-21T14:36:56Z" } }, { "key": "EPE5T5QD", "version": 18, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/EPE5T5QD", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/EPE5T5QD", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "González-Longatt et al.", "parsedDate": "2012-03", "numChildren": 0 }, "data": { "key": "EPE5T5QD", "version": 18, "itemType": "journalArticle", "title": "Wake effect in wind farm performance: Steady-state and dynamic behavior", "creators": [ { "creatorType": "author", "firstName": "F.", "lastName": "González-Longatt" }, { "creatorType": "author", "firstName": "P.", "lastName": "Wall" }, { "creatorType": "author", "firstName": "V.", "lastName": "Terzija" } ], "abstractNote": "The aim of this paper is to evaluate the impact of the wake effect on both the steady-state operation and dynamic performance of a wind farm and provide conclusions that can be used as thumb rules in generic assessments where the full details of the wind farms are unknown. A simplified explicit model of the wake effect is presented, which includes: the cumulative impact of multiple shadowing, the effects of wind direction and the wind speed time delay. The model is implemented in MATLAB® and then integrated into a power system simulation package to describe the wake effect and its impact on a wind farm, particularly in terms of the wake coefficient and overall active power losses. Results for two wind farm layouts are presented to illustrate the importance of wind turbine spacing and the directionality of wind speeds when assessing the wake effect during steady-state operation and dynamic behavior.", "publicationTitle": "Renewable Energy", "publisher": "", "place": "", "date": "March 2012", "volume": "39", "issue": "1", "section": "", "partNumber": "", "partTitle": "", "pages": "329-338", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Renewable Energy", "DOI": "10.1016/j.renene.2011.08.053", "citationKey": "", "url": "http://www.sciencedirect.com/science/article/pii/S0960148111005155", "accessDate": "2013-06-21T14:35:50Z", "PMID": "", "PMCID": "", "ISSN": "0960-1481", "archive": "", "archiveLocation": "", "shortTitle": "Wake effect in wind farm performance", "language": "", "libraryCatalog": "ScienceDirect", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-21T14:35:50Z", "dateModified": "2013-06-21T14:35:50Z" } }, { "key": "EKQ2WN78", "version": 17, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/EKQ2WN78", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/EKQ2WN78", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "Kim et al.", "parsedDate": "2012", "numChildren": 0 }, "data": { "key": "EKQ2WN78", "version": 17, "itemType": "journalArticle", "title": "Simulation and Estimation of Reliability in a Wind Farm Considering the Wake Effect", "creators": [ { "creatorType": "author", "firstName": "Hagkwen", "lastName": "Kim" }, { "creatorType": "author", "firstName": "Chanan", "lastName": "Singh" }, { "creatorType": "author", "firstName": "Alex", "lastName": "Sprintson" } ], "abstractNote": "In this paper, wake effect is explicitly incorporated in the reliability evaluation of a wind farm. Energy loss resulting from this effect is included in calculating the reliability indices. Three models for wake effect are discussed and the Jensen model is used in this research. In this model, wind shade, shear effect, and wind direction are also reflected. After incorporating the wake effect, the Monte Carlo technique is used to compute reliability indices. Wind farm model and correlation between load and wind speed are considered. The proposed methodology is applied to a wind farm using wind speed data from the National Renewal Energy Laboratory and load from IEEE Reliability Test Systems. The simulation results show that the proposed techniques are effective and efficient in practical applications.", "publicationTitle": "IEEE Transactions on Sustainable Energy", "publisher": "", "place": "", "date": "04/2012", "volume": "3", "issue": "2", "section": "", "partNumber": "", "partTitle": "", "pages": "274-282", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1109/TSTE.2011.2174260", "citationKey": "", "url": "http://ieeexplore.ieee.org/lpdocs/epic03/wrapper.htm?arnumber=6170992", "accessDate": "2013-06-21T14:34:15Z", "PMID": "", "PMCID": "", "ISSN": "1949-3029, 1949-3037", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "CrossRef", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-21T14:34:15Z", "dateModified": "2013-06-21T14:34:31Z" } }, { "key": "7AHXFG2J", "version": 16, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/7AHXFG2J", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/7AHXFG2J", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "McKay et al.", "parsedDate": "2013", "numChildren": 0 }, "data": { "key": "7AHXFG2J", "version": 16, "itemType": "journalArticle", "title": "Wake impacts on downstream wind turbine performance and yaw alignment", "creators": [ { "creatorType": "author", "firstName": "Phillip", "lastName": "McKay" }, { "creatorType": "author", "firstName": "Rupp", "lastName": "Carriveau" }, { "creatorType": "author", "firstName": "David S-K.", "lastName": "Ting" } ], "abstractNote": "Aerodynamic wake interaction between commercial scale wind turbines can be a significant source of power losses and increased fatigue loads across a wind farm. Significant research has been dedicated to the study of wind turbine wakes and wake model development. This paper profiles influential wake regions for an onshore wind farm using 6 months of recorded SCADA (supervisory control and data acquisition) data. An average wind velocity deficit of over 30% was observed corresponding to power coefficient losses of 0.2 in the wake region. Wind speed fluctuations are also quantified for an array of turbines, inferring an increase in turbulence within the wake region. A study of yaw data within the array showed turbine nacelle misalignment under a range of downstream wake angles, indicating a characteristic of wind turbine behaviour not generally considered in wake studies. The turbines yaw independently in order to capture the increased wind speeds present due to the lateral influx of turbulent wind, contrary to many experimental and simulation methods found in the literature. Improvements are suggested for wind farm control strategies that may improve farm-wide power output. Additionally, possible causes for wind farm wake model overestimation of wake losses are proposed.Copyright © 2012 John Wiley & Sons, Ltd.", "publicationTitle": "Wind Energy", "publisher": "", "place": "", "date": "2013", "volume": "16", "issue": "2", "section": "", "partNumber": "", "partTitle": "", "pages": "221–234", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1002/we.544", "citationKey": "", "url": "http://onlinelibrary.wiley.com/doi/10.1002/we.544/abstract", "accessDate": "2013-06-21T14:32:57Z", "PMID": "", "PMCID": "", "ISSN": "1099-1824", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "Copyright © 2012 John Wiley & Sons, Ltd.", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-21T14:32:57Z", "dateModified": "2013-06-21T14:32:57Z" } }, { "key": "FAAZ45G4", "version": 14, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/FAAZ45G4", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/FAAZ45G4", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "Pérez et al.", "parsedDate": "2013-05", "numChildren": 0 }, "data": { "key": "FAAZ45G4", "version": 14, "itemType": "journalArticle", "title": "Offshore wind farm layout optimization using mathematical programming techniques", "creators": [ { "creatorType": "author", "firstName": "Beatriz", "lastName": "Pérez" }, { "creatorType": "author", "firstName": "Roberto", "lastName": "Mínguez" }, { "creatorType": "author", "firstName": "Raúl", "lastName": "Guanche" } ], "abstractNote": "Offshore wind power is a renewable energy of growing relevance in current electric energy systems, presenting favorable wind conditions in comparison with the sites on land. However, the higher energy yield has to compensate the increment in installation and maintenance costs, thus the importance of optimizing resources. One relevant aspect to increase profitability is the wind farm layout. The aim of this paper is to propose a new method to maximize the expected power production of offshore wind farms by setting the appropriate layout, i.e. minimizing the wake effects. The method uses a sequential procedure for global optimization consisting of two steps: i) an heuristic method to set an initial random layout configuration, and ii) the use of nonlinear mathematical programming techniques for local optimization, which use the random layout as an initial solution. The method takes full advantage of the most up-to-date mathematical programming techniques while performing a global optimization approach, which can be easily parallelized. The performance of the proposed procedure is tested using the German offshore wind farm Alpha Ventus, located in the North Sea, yielding an increment of expected annual power production of 3.52% with respect to the actual configuration. According to current electricity prices in Germany, this constitutes an expected profit increment of almost 1 M€ per year.", "publicationTitle": "Renewable Energy", "publisher": "", "place": "", "date": "May 2013", "volume": "53", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "389-399", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Renewable Energy", "DOI": "10.1016/j.renene.2012.12.007", "citationKey": "", "url": "http://www.sciencedirect.com/science/article/pii/S0960148112007628", "accessDate": "2013-06-21T14:29:10Z", "PMID": "", "PMCID": "", "ISSN": "0960-1481", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "ScienceDirect", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-21T14:29:10Z", "dateModified": "2013-06-21T14:29:10Z" } }, { "key": "CJPJD3UC", "version": 12, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/CJPJD3UC", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/CJPJD3UC", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "Barthelmie et al.", "parsedDate": "2013", "numChildren": 0 }, "data": { "key": "CJPJD3UC", "version": 12, "itemType": "journalArticle", "title": "Meteorological Controls on Wind Turbine Wakes", "creators": [ { "creatorType": "author", "firstName": "R.J.", "lastName": "Barthelmie" }, { "creatorType": "author", "firstName": "K.S.", "lastName": "Hansen" }, { "creatorType": "author", "firstName": "S.C.", "lastName": "Pryor" } ], "abstractNote": "The primary control on the magnitude of the power losses induced by wind turbine wakes in large wind farms is the hub-height wind speed via its link to the turbine thrust coefficient. Hence, at low to moderate wind speeds (between cut-in and rated turbine wind speeds) when the thrust coefficient is high, wake losses are proportionally larger and decrease to be virtually undetectable at wind speeds above rated wind speeds. Wind direction is also critical. Not only does it determine the effective spacing between turbines but also the wind speed distribution is primarily determined by synoptic forcing and typically has a predominant direction from which wind speeds tend to be higher (from southwest for much of the central United States and northern Europe). Two other interlinked variables, turbulence intensity (TI), and atmospheric stability also dictate wake losses. Quantifying, understanding, modeling, and predicting this complex and interdependent system is therefore critical to understanding and modeling wind farm power losses due to wakes, and to optimizing wind farm layout. This paper quantifies the impact of these variables on the power loss due to wakes using data from the large offshore wind farms located at Horns Rev and Nysted in Denmark.", "publicationTitle": "Proceedings of the IEEE", "publisher": "", "place": "", "date": "2013", "volume": "101", "issue": "4", "section": "", "partNumber": "", "partTitle": "", "pages": "1010-1019", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1109/JPROC.2012.2204029", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "0018-9219", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "IEEE Xplore", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-21T14:28:09Z", "dateModified": "2013-06-21T14:28:09Z" } }, { "key": "6DVSGWUF", "version": 11, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/6DVSGWUF", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/6DVSGWUF", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "Politis et al.", "parsedDate": "2012", "numChildren": 0 }, "data": { "key": "6DVSGWUF", "version": 11, "itemType": "journalArticle", "title": "Modeling wake effects in large wind farms in complex terrain: the problem, the methods and the issues", "creators": [ { "creatorType": "author", "firstName": "E. S.", "lastName": "Politis" }, { "creatorType": "author", "firstName": "J.", "lastName": "Prospathopoulos" }, { "creatorType": "author", "firstName": "D.", "lastName": "Cabezon" }, { "creatorType": "author", "firstName": "K. S.", "lastName": "Hansen" }, { "creatorType": "author", "firstName": "P. K.", "lastName": "Chaviaropoulos" }, { "creatorType": "author", "firstName": "R. J.", "lastName": "Barthelmie" } ], "abstractNote": "Computational fluid dynamic (CFD) methods are used in this paper to predict the power production from entire wind farms in complex terrain and to shed some light into the wake flow patterns. Two full three-dimensional Navier–Stokes solvers for incompressible fluid flow, employing k − ϵ and k − ω turbulence closures, are used. The wind turbines are modeled as momentum absorbers by means of their thrust coefficient through the actuator disk approach. Alternative methods for estimating the reference wind speed in the calculation of the thrust are tested. The work presented in this paper is part of the work being undertaken within the UpWind Integrated Project that aims to develop the design tools for next generation of large wind turbines. In this part of UpWind, the performance of wind farm and wake models is being examined in complex terrain environment where there are few pre-existing relevant measurements. The focus of the work being carried out is to evaluate the performance of CFD models in large wind farm applications in complex terrain and to examine the development of the wakes in a complex terrain environment. Copyright © 2011 John Wiley & Sons, Ltd.", "publicationTitle": "Wind Energy", "publisher": "", "place": "", "date": "2012", "volume": "15", "issue": "1", "section": "", "partNumber": "", "partTitle": "", "pages": "161–182", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1002/we.481", "citationKey": "", "url": "http://onlinelibrary.wiley.com/doi/10.1002/we.481/abstract", "accessDate": "2013-06-18T16:39:21Z", "PMID": "", "PMCID": "", "ISSN": "1099-1824", "archive": "", "archiveLocation": "", "shortTitle": "Modeling wake effects in large wind farms in complex terrain", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "Copyright © 2011 John Wiley & Sons, Ltd.", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-18T16:39:21Z", "dateModified": "2013-06-18T16:39:21Z" } }, { "key": "T3MFM99S", "version": 9, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/T3MFM99S", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/T3MFM99S", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "O'Reilly et al.", "parsedDate": "2012", "numChildren": 0 }, "data": { "key": "T3MFM99S", "version": 9, "itemType": "conferencePaper", "title": "Offshore wind farm siting using a genetic algorithm", "creators": [ { "creatorType": "author", "firstName": "C.M.", "lastName": "O'Reilly" }, { "creatorType": "author", "firstName": "A.R.", "lastName": "Grilli" }, { "creatorType": "author", "firstName": "G.R.", "lastName": "Potty" } ], "abstractNote": "This study uses a genetic algorithm to optimize a wind farm layout considering the engineering challenges and the ecosystem services as constraints to the turbine siting. Included is an analysis of how wake effects influence the power produced using a simple wake model called the WAsP model. The current study considers the location of the proposed Deep Water Wind Inc. Offshore Wind Farm Project, southeast of Block Island, Rhode Island. The proposed project consists of six, 6MW Siemens wind turbines located within the Rhode Island State waters that extend roughly 4.8 km off of the Block Island coast. The optimum solution produces turbine locations best conforming to areas of low technical, ecological, and social costs, while simultaneously distributing the turbines to minimize turbine wake interaction. Future model improvements will consist of more accurately describing wind conditions within the wind farm and incorporating turbine cable interconnection installation costs.", "proceedingsTitle": "2012 International Conference on Green Technologies (ICGT)", "conferenceName": "2012 International Conference on Green Technologies (ICGT)", "publisher": "", "place": "", "date": "2012", "eventPlace": "", "volume": "", "issue": "", "numberOfVolumes": "", "pages": "208-214", "series": "", "seriesNumber": "", "DOI": "10.1109/ICGT.2012.6477974", "ISBN": "", "citationKey": "", "url": "", "accessDate": "", "ISSN": "", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "IEEE Xplore", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-18T16:38:34Z", "dateModified": "2013-06-18T16:38:34Z" } }, { "key": "9VZ6DA9I", "version": 8, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/9VZ6DA9I", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/9VZ6DA9I", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "Gaumond et al.", "parsedDate": "2013", "numChildren": 0 }, "data": { "key": "9VZ6DA9I", "version": 8, "itemType": "journalArticle", "title": "Evaluation of the wind direction uncertainty and its impact on wake modeling at the Horns Rev offshore wind farm", "creators": [ { "creatorType": "author", "firstName": "M.", "lastName": "Gaumond" }, { "creatorType": "author", "firstName": "P.-E.", "lastName": "Réthoré" }, { "creatorType": "author", "firstName": "S.", "lastName": "Ott" }, { "creatorType": "author", "firstName": "A.", "lastName": "Peña" }, { "creatorType": "author", "firstName": "A.", "lastName": "Bechmann" }, { "creatorType": "author", "firstName": "K. S.", "lastName": "Hansen" } ], "abstractNote": "Accurately quantifying wind turbine wakes is a key aspect of wind farm economics in large wind farms. This paper introduces a new simulation post-processing method to address the wind direction uncertainty present in the measurements of the Horns Rev offshore wind farm. This new technique replaces the traditional simulations performed with the 10 min average wind direction by a weighted average of several simulations covering a wide span of directions. The weights are based on a normal distribution to account for the uncertainty from the yaw misalignment of the reference turbine, the spatial variability of the wind direction inside the wind farm and the variability of the wind direction within the averaging period. The results show that the technique corrects the predictions of the models when the simulations and data are averaged over narrow wind direction sectors. In addition, the agreement of the shape of the power deficit in a single wake situation is improved. The robustness of the method is verified using the Jensen model, the Larsen model and Fuga, which are three different engineering wake models. The results indicate that the discrepancies between the traditional numerical simulations and power production data for narrow wind direction sectors are not caused by an inherent inaccuracy of the current wake models, but rather by the large wind direction uncertainty included in the dataset. The technique can potentially improve wind farm control algorithms and layout optimization because both applications require accurate wake predictions for narrow wind direction sectors.Copyright © 2013 John Wiley & Sons, Ltd.", "publicationTitle": "Wind Energy", "publisher": "", "place": "", "date": "2013", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "n/a–n/a", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1002/we.1625", "citationKey": "", "url": "http://onlinelibrary.wiley.com/doi/10.1002/we.1625/abstract", "accessDate": "2013-06-18T16:38:06Z", "PMID": "", "PMCID": "", "ISSN": "1099-1824", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "Copyright © 2013 John Wiley & Sons, Ltd.", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-18T16:38:06Z", "dateModified": "2013-06-18T16:38:06Z" } }, { "key": "DFVZJCHR", "version": 8, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/DFVZJCHR", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/DFVZJCHR", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "Hansen et al.", "parsedDate": "2012", "numChildren": 0 }, "data": { "key": "DFVZJCHR", "version": 8, "itemType": "journalArticle", "title": "The impact of turbulence intensity and atmospheric stability on power deficits due to wind turbine wakes at Horns Rev wind farm", "creators": [ { "creatorType": "author", "firstName": "Kurt S.", "lastName": "Hansen" }, { "creatorType": "author", "firstName": "Rebecca J.", "lastName": "Barthelmie" }, { "creatorType": "author", "firstName": "Leo E.", "lastName": "Jensen" }, { "creatorType": "author", "firstName": "Anders", "lastName": "Sommer" } ], "abstractNote": "The wind turbine operational characteristics, power measurements and meteorological measurements from Horns Rev offshore wind farm have been identified, synchronized, quality screened and stored in a common database as 10 min statistical data. A number of flow cases have been identified to describe the flow inside the wind farm, and the power deficits along rows of wind turbines have been determined for different inflow directions and wind speed intervals. A method to classify the atmospheric stability based on the Bulk-Ri number has been implemented. Long-term stability conditions have been established, which confirms, in line with previous results, that conditions tend towards near neutral as wind speeds increase but that both stable and unstable conditions are present at wind speeds up to 15 m s −1. Moreover, there is a strong stability directional dependence with southerly winds having fewer unstable conditions, whereas northerly winds have fewer observations in the stable classes. Stable conditions also tend to be associated with lower levels of turbulence intensity, and this relationship persists as wind speeds increase. Power deficit is a function of ambient turbulence intensity. The level of power deficit is strongly dependent on the wind turbine spacing; as turbulence intensity increases, the power deficit decreases. The power deficit is determined for four different wind turbine spacing distances and for stability classified as very stable, stable and others (near neutral to very unstable). The more stable the conditions are, the larger the power deficit. Copyright © 2011 John Wiley & Sons, Ltd.", "publicationTitle": "Wind Energy", "publisher": "", "place": "", "date": "2012", "volume": "15", "issue": "1", "section": "", "partNumber": "", "partTitle": "", "pages": "183–196", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1002/we.512", "citationKey": "", "url": "http://onlinelibrary.wiley.com/doi/10.1002/we.512/abstract", "accessDate": "2013-06-18T16:37:51Z", "PMID": "", "PMCID": "", "ISSN": "1099-1824", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "Copyright © 2011 John Wiley & Sons, Ltd.", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-18T16:37:51Z", "dateModified": "2013-06-18T16:37:51Z" } }, { "key": "RXRR69D4", "version": 8, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/RXRR69D4", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/RXRR69D4", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "Churchfield et al.", "parsedDate": "2012", "numChildren": 0 }, "data": { "key": "RXRR69D4", "version": 8, "itemType": "journalArticle", "title": "A numerical study of the effects of atmospheric and wake turbulence on wind turbine dynamics", "creators": [ { "creatorType": "author", "firstName": "Matthew J.", "lastName": "Churchfield" }, { "creatorType": "author", "firstName": "Sang", "lastName": "Lee" }, { "creatorType": "author", "firstName": "John", "lastName": "Michalakes" }, { "creatorType": "author", "firstName": "Patrick J.", "lastName": "Moriarty" } ], "abstractNote": "Although the atmospheric sciences community has been studying the effects of atmospheric stability and surface roughness on the planetary boundary layer for some time, their effects on wind turbine dynamics have not been well studied. In this study, we performed numerical experiments to explore some of the effects of atmospheric stability and surface roughness on wind turbine dynamics. We used large-eddy simulation to create atmospheric winds and compute the wind turbine flows, and we modeled the wind turbines as revolving and flexible actuator lines coupled to a wind turbine structural and system dynamic model. We examined the structural moments about the wind turbine blade, low-speed shaft, and nacelle; power production; and wake evolution when large 5-MW turbines are subjected to winds generated from low- and high-surface roughness levels representative of offshore and onshore conditions, respectively, and also neutral and unstable atmospheric conditions. In addition, we placed a second turbine 7 rotor diameters downwind of the first one so that we could explore wake effects under these different conditions. The results show that the turbulent structures generated within the atmospheric boundary layer wind simulations cause isolated loading events at least as significant as when a turbine is waked by an upwind turbine. The root-mean-square (RMS) turbine loads are consistently larger when the surface roughness is higher. The RMS blade-root out-of-plane bending moment and low-speed shaft torque are higher when the atmospheric boundary layer is unstable as compared with when it is neutral. However, the RMS yaw moments are either equal or reduced in the unstable case as compared with the neutral case. For a given surface roughness, the ratio of power produced by the downwind turbine relative to that of the upwind turbine is 15–20% higher when the conditions are unstable as compared with neutral. For a given atmospheric stability, this power ratio is 10% higher with the onshore roughness value versus the offshore one. The main conclusion is that various coherent turbulent structures that form under different levels of atmospheric stability and surface roughness have important effects on wind turbine structural response, power production, and wake evolution.", "publicationTitle": "Journal of Turbulence", "publisher": "", "place": "", "date": "2012", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "N14", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1080/14685248.2012.668191", "citationKey": "", "url": "http://www.tandfonline.com/doi/abs/10.1080/14685248.2012.668191", "accessDate": "2013-06-18T16:37:38Z", "PMID": "", "PMCID": "", "ISSN": "", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "Taylor and Francis+NEJM", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-18T16:37:38Z", "dateModified": "2013-06-18T16:37:38Z" } }, { "key": "WAKZXIRX", "version": 7, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/WAKZXIRX", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/WAKZXIRX", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "Zhao et al.", "parsedDate": "2012", "numChildren": 0 }, "data": { "key": "WAKZXIRX", "version": 7, "itemType": "journalArticle", "title": "Fatigue distribution optimization for offshore wind farms using intelligent agent control", "creators": [ { "creatorType": "author", "firstName": "Rongyong", "lastName": "Zhao" }, { "creatorType": "author", "firstName": "Wenzhong", "lastName": "Shen" }, { "creatorType": "author", "firstName": "Torben", "lastName": "Knudsen" }, { "creatorType": "author", "firstName": "Thomas", "lastName": "Bak" } ], "abstractNote": "A novel control approach is proposed to optimize the fatigue distribution of wind turbines in a large-scale offshore wind farm on the basis of an intelligent agent theory. In this approach, each wind turbine is considered to be an intelligent agent. The turbine at the farm boundary communicates with its neighbouring downwind turbines and organizes them adaptively into a wind delivery group along the wind direction. The agent attributes and the event structure are designed on the basis of the intelligent agent theory by using the unified modelling language. The control strategy of the intelligent agent is studied using topology models. The reference power of an individual wind turbine from the wind farm controller is re-dispatched to balance the turbine fatigue in the power dispatch intervals. In the fatigue optimization, the goal function is to minimize the standard deviation of the fatigue coefficient for every wind turbine. The optimization is constrained such that the average fatigue for every turbine is smaller than what would be achieved by conventional dispatch and such that the total power loss of the wind farm is restricted to a few percent of the total power. This intelligent agent control approach is verified through the simulation of wind data from the Horns Rev offshore wind farm. The results illustrate that intelligent agent control is a feasible way to optimize fatigue distribution in wind farms, which may reduce the maintenance frequency and extend the service life of large-scale wind farms. Copyright © 2012 John Wiley & Sons, Ltd.", "publicationTitle": "Wind Energy", "publisher": "", "place": "", "date": "2012", "volume": "15", "issue": "7", "section": "", "partNumber": "", "partTitle": "", "pages": "927–944", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1002/we.1518", "citationKey": "", "url": "http://onlinelibrary.wiley.com/doi/10.1002/we.1518/abstract", "accessDate": "2013-06-18T16:35:31Z", "PMID": "", "PMCID": "", "ISSN": "1099-1824", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "Copyright © 2012 John Wiley & Sons, Ltd.", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-18T16:35:31Z", "dateModified": "2013-06-18T16:35:31Z" } }, { "key": "BBQAXNG3", "version": 5, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/BBQAXNG3", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/BBQAXNG3", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "Chowdhury et al.", "parsedDate": "2012-02", "numChildren": 0 }, "data": { "key": "BBQAXNG3", "version": 5, "itemType": "journalArticle", "title": "Unrestricted wind farm layout optimization (UWFLO): Investigating key factors influencing the maximum power generation", "creators": [ { "creatorType": "author", "firstName": "Souma", "lastName": "Chowdhury" }, { "creatorType": "author", "firstName": "Jie", "lastName": "Zhang" }, { "creatorType": "author", "firstName": "Achille", "lastName": "Messac" }, { "creatorType": "author", "firstName": "Luciano", "lastName": "Castillo" } ], "abstractNote": "A new methodology, the Unrestricted Wind Farm Layout Optimization (UWFLO), that addresses critical aspects of optimal wind farm planning is presented in this paper. This methodology simultaneously determines the optimum farm layout and the appropriate selection of turbines (in terms of their rotor diameters) that maximizes the net power generation. The farm layout model obviates traditional restrictions imposed on the location of turbines. A standard analytical wake model has been used to account for the velocity deficits in the wakes created by individual turbines. The wind farm power generation model is validated against data from a wind tunnel experiment on a scaled down wind farm. Reasonable agreement between the model and experimental results is obtained. The complex nonlinear optimization problem presented by the wind farm model is effectively solved using constrained Particle Swarm Optimization (PSO). It is found that an optimal combination of wind turbines with differing rotor diameters can appreciably improve the farm efficiency. A preliminary wind farm cost analysis is performed to express the cost in terms of the turbine rotor diameters and the number of turbines in the farm. Subsequent exploration of the influences of (i) the number of turbines, and (ii) the farm land size, on the cost per Kilowatt of power produced, yields important observations.", "publicationTitle": "Renewable Energy", "publisher": "", "place": "", "date": "February 2012", "volume": "38", "issue": "1", "section": "", "partNumber": "", "partTitle": "", "pages": "16-30", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Renewable Energy", "DOI": "10.1016/j.renene.2011.06.033", "citationKey": "", "url": "http://www.sciencedirect.com/science/article/pii/S0960148111003260", "accessDate": "2013-06-18T16:33:07Z", "PMID": "", "PMCID": "", "ISSN": "0960-1481", "archive": "", "archiveLocation": "", "shortTitle": "Unrestricted wind farm layout optimization (UWFLO)", "language": "", "libraryCatalog": "ScienceDirect", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-18T16:33:07Z", "dateModified": "2013-06-18T16:33:07Z" } }, { "key": "5WNIWEEE", "version": 4, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/5WNIWEEE", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/5WNIWEEE", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "Meyers and Meneveau", "parsedDate": "2012", "numChildren": 0 }, "data": { "key": "5WNIWEEE", "version": 4, "itemType": "journalArticle", "title": "Optimal turbine spacing in fully developed wind farm boundary layers", "creators": [ { "creatorType": "author", "firstName": "Johan", "lastName": "Meyers" }, { "creatorType": "author", "firstName": "Charles", "lastName": "Meneveau" } ], "abstractNote": "As wind farms become larger, the asymptotic limit of the ‘fully developed’, or ‘infinite’, wind farm has been receiving an increased interest. This limit is relevant for wind farms on flat terrain whose length exceeds the height of the atmospheric boundary layer by over an order of magnitude. Recent computational studies based on large eddy simulation have identified various mean velocity equilibrium layers and have led to parameterizations of the effective roughness height that allow the prediction of the wind velocity at hub height as a function of parameters such as wind turbine spacing and loading factors. In the current paper, we employ this as a tool in making predictions of optimal wind turbine spacing as a function of these parameters, as well as in terms of the ratio of turbine costs to land surface costs. For realistic cost ratios, we find that the optimal average turbine spacing may be considerably higher than that conventionally used in current wind farm implementations. Copyright © 2011 John Wiley & Sons, Ltd.", "publicationTitle": "Wind Energy", "publisher": "", "place": "", "date": "2012", "volume": "15", "issue": "2", "section": "", "partNumber": "", "partTitle": "", "pages": "305–317", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1002/we.469", "citationKey": "", "url": "http://onlinelibrary.wiley.com/doi/10.1002/we.469/abstract", "accessDate": "2013-06-18T16:32:47Z", "PMID": "", "PMCID": "", "ISSN": "1099-1824", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "Copyright © 2011 John Wiley & Sons, Ltd.", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-18T16:32:47Z", "dateModified": "2013-06-18T16:32:47Z" } }, { "key": "DSW7JMVC", "version": 3, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/DSW7JMVC", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/DSW7JMVC", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "Larsen et al.", "parsedDate": "2013", "numChildren": 0 }, "data": { "key": "DSW7JMVC", "version": 3, "itemType": "journalArticle", "title": "Validation of the dynamic wake meander model for loads and power production in the Egmond aan Zee wind farm", "creators": [ { "creatorType": "author", "firstName": "Torben J.", "lastName": "Larsen" }, { "creatorType": "author", "firstName": "Helge Aa.", "lastName": "Madsen" }, { "creatorType": "author", "firstName": "Gunner C.", "lastName": "Larsen" }, { "creatorType": "author", "firstName": "Kurt S.", "lastName": "Hansen" } ], "abstractNote": "This paper investigates wake effects on load and power production by using the dynamic wake meander (DWM) model implemented in the aeroelastic code HAWC2. The instationary wind farm flow characteristics are modeled by treating the wind turbine wakes as passive tracers transported downstream using a meandering process driven by the low frequent cross-wind turbulence components. The model complex is validated by comparing simulated and measured loads for the Dutch Egmond aan Zee wind farm consisting of 36 Vestas V90 turbine located outside the coast of the Netherlands. Loads and production are compared for two distinct wind directions—a free wind situation from the dominating southwest and a full wake situation from northwest, where the observed turbine is operating in wake from five turbines in a row with 7D spacing. The measurements have a very high quality, allowing for detailed comparison of both fatigue and min–mean–max loads for blade root flap, tower yaw and tower bottom bending moments, respectively. Since the observed turbine is located deep inside a row of turbines, a new method on how to handle multiple wakes interaction is proposed. The agreement between measurements and simulations is excellent regarding power production in both free and wake sector, and a very good agreement is seen for the load comparisons too. This enables the conclusion that wake meandering, caused by large scale ambient turbulence, is indeed an important contribution to wake loading in wind farms. Copyright © 2012 John Wiley & Sons, Ltd.", "publicationTitle": "Wind Energy", "publisher": "", "place": "", "date": "2013", "volume": "16", "issue": "4", "section": "", "partNumber": "", "partTitle": "", "pages": "605–624", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1002/we.1563", "citationKey": "", "url": "http://onlinelibrary.wiley.com/doi/10.1002/we.1563/abstract", "accessDate": "2013-06-18T16:29:28Z", "PMID": "", "PMCID": "", "ISSN": "1099-1824", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "Copyright © 2012 John Wiley & Sons, Ltd.", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-18T16:29:28Z", "dateModified": "2013-06-18T16:29:28Z" } }, { "key": "IHVWJ7VM", "version": 2, "library": { "type": "group", "id": 175831, "name": "wake effects", "links": { "alternate": { "href": "https://www.zotero.org/groups/wake_effects", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/175831/items/IHVWJ7VM", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/wake_effects/items/IHVWJ7VM", "type": "text/html" } }, "meta": { "createdByUser": { "id": 250494, "username": "tsandberg", "name": "Tami Sandberg", "links": { "alternate": { "href": "https://www.zotero.org/tsandberg", "type": "text/html" } } }, "creatorSummary": "Hasager et al.", "parsedDate": "2013-02-05", "numChildren": 0 }, "data": { "key": "IHVWJ7VM", "version": 2, "itemType": "journalArticle", "title": "Wind Farm Wake: The Horns Rev Photo Case", "creators": [ { "creatorType": "author", "firstName": "Charlotte", "lastName": "Hasager" }, { "creatorType": "author", "firstName": "Leif", "lastName": "Rasmussen" }, { "creatorType": "author", "firstName": "Alfredo", "lastName": "Peña" }, { "creatorType": "author", "firstName": "Leo", "lastName": "Jensen" }, { "creatorType": "author", "firstName": "Pierre-Elouan", "lastName": "Réthoré" } ], "abstractNote": "The aim of the paper is to examine the nowadays well-known wind farm wake photographs taken on 12 February 2008 at the offshore Horns Rev 1 wind farm. The meteorological conditions are described from observations from several satellite sensors quantifying clouds, surface wind vectors and sea surface temperature as well as ground-based information at and near the wind farm, including Supervisory Control and Data Acquisition (SCADA) data. The SCADA data reveal that the case of fog formation occurred 12 February 2008 on the 10:10 UTC. The fog formation is due to very special atmospheric conditions where a layer of cold humid air above a warmer sea surface re-condensates to fog in the wake of the turbines. The process is fed by warm humid air up-drafted from below in the counter-rotating swirl generated by the clock-wise rotating rotors. The condensation appears to take place primarily in the wake regions with relatively high axial velocities and high turbulent kinetic energy. The wind speed is near cut-in and most turbines produce very little power. The rotational pattern of spiraling bands produces the large-scale structure of the wake fog.", "publicationTitle": "Energies", "publisher": "", "place": "", "date": "2013-02-05", "volume": "6", "issue": "2", "section": "", "partNumber": "", "partTitle": "", "pages": "696-716", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.3390/en6020696", "citationKey": "", "url": "http://www.mdpi.com/1996-1073/6/2/696/", "accessDate": "2013-06-18T16:26:33Z", "PMID": "", "PMCID": "", "ISSN": "1996-1073", "archive": "", "archiveLocation": "", "shortTitle": "Wind Farm Wake", "language": "", "libraryCatalog": "CrossRef", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2013-06-18T16:26:33Z", "dateModified": "2013-06-18T16:26:47Z" } } ]