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Sample records for wind prev class

  1. Class Generation for Numerical Wind Atlases

    DEFF Research Database (Denmark)

    Cutler, N.J.; Jørgensen, B.H.; Ersbøll, Bjarne Kjær

    2006-01-01

    A new optimised clustering method is presented for generating wind classes for mesoscale modelling to produce numerical wind atlases. It is compared with the existing method of dividing the data in 12 to 16 sectors, 3 to 7 wind-speed bins and dividing again according to the stability...... of the atmosphere. Wind atlases are typically produced using many years of on-site wind observations at many locations. Numerical wind atlases are the result of mesoscale model integrations based on synoptic scale wind climates and can be produced in a number of hours of computation. 40 years of twice daily NCEP...... adapting to the local topography. The purpose of forming classes is to minimise the computational time for the mesoscale model while still representing the synoptic climate features. Only tried briefly in the past, clustering has traits that can be used to improve the existing class generation method...

  2. Wind class sampling of satellite SAR imagery for offshore wind resource mapping

    DEFF Research Database (Denmark)

    Badger, Merete; Badger, Jake; Nielsen, Morten

    2010-01-01

    developed for mesoscale modeling of wind resources. Its performance in connection with sampling of SAR scenes is tested against two sets of random SAR samples and meteorological observations at three sites in the North Sea during 2005–08. Predictions of the mean wind speed and the Weibull scale parameter......High-resolution wind fields retrieved from satellite synthetic aperture radar (SAR) imagery are combined for mapping of wind resources offshore where site measurements are costly and sparse. A new sampling strategy for the SAR scenes is introduced, based on a method for statistical......-dynamical downscaling of large-scale wind conditions using a set of wind classes that describe representative wind situations. One or more SAR scenes are then selected to represent each wind class and the classes are weighted according to their frequency of occurrence. The wind class methodology was originally...

  3. Reliability and Energy Loss in Full-scale Wind Power Converter Considering Grid Codes and Wind Classes

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Franke, Toke

    2014-01-01

    With the increasing penetration of the wind power, reliable operation and cost-effective wind energy production are of more and more importance. As one of the promising configurations, the cost on reliability and production losses of permanent-magnet synchronous generator based full-scale wind......, if the specific designed wind turbine system operates at different wind classes, it can be seen that higher wind class level results in lower lifetime of the power converter. In respect to the cost of the reactive power, either the OE or the UE reactive power increases the energy loss per year significantly...... power converter is studied considering the grid code with reactive power production as well as the annual wind profile. Regarding the reliability, it is found that either the Over-Excited (OE) or the Under-Excited (UE) reactive power injection threatens the lifespan under all wind classes. Meanwhile...

  4. Thermal Loading and Reliability of 10 MW Multilevel Wind Power Converter at Different Wind Roughness Classes

    DEFF Research Database (Denmark)

    Isidori, Andrea; Rossi, Fabio Mario; Blaabjerg, Frede

    2014-01-01

    This paper focuses on the design, thermal loading, and reliability of a three-level neutral-point-clamped back-to-back full-scale converter for a 10-MW direct-drive wind turbine equipped with a permanent-magnet synchronous generator. The reliability performance of the three-level converter...... is strongly influenced by the thermal behavior of the semiconductor devices and their mission profile which directly affects the lifetime and the cost of the entire converter. Therefore, a simulation platform is developed in a Matlab/Simulink and PLECS simulation environment to analyze the dynamics...... of the system using different kinds of modulation strategies and analyzing the different wind-load conditions that are dependent on roughness classes. This paper shows that the 60 ° discontinuous pulsewidth-modulation strategies allow better thermal performance and increase the estimated lifetime...

  5. Thermal loading and reliability of 10 MW multilevel wind power converter at different wind roughness classes

    DEFF Research Database (Denmark)

    Isidori, Andrea; Rossi, Fabio Mario; Blaabjerg, Frede

    2012-01-01

    This paper focuses on the design, thermal loading and reliability of a three-level Neutral Point Clamped (3-L NPC) back-to-back full scale converter for a 10 MW direct-drive wind turbine equipped with a Permanent Magnet Synchronous Generator (PMSG). The reliability performance of the three......-level converter is strongly influenced by the thermal behaviour of the semiconductor devices and their mission profile which directly affects the lifetime and the cost of the whole converter. Therefore, the simulation platform is developed in Matlab/Simulink and PLECS simulation environment to analyse...... the dynamics of the system using different kinds of modulation strategies and analyzing different wind load conditions dependent on roughness classes. It is concluded that 60° discontinuous PWM modulation strategies show better thermal performance and increase the estimated lifetime of the converter...

  6. A new class of actuator surface models for wind turbines

    Science.gov (United States)

    Yang, Xiaolei; Sotiropoulos, Fotis

    2018-05-01

    Actuator line model has been widely employed in wind turbine simulations. However, the standard actuator line model does not include a model for the turbine nacelle which can significantly impact turbine wake characteristics as shown in the literature. Another disadvantage of the standard actuator line model is that more geometrical features of turbine blades cannot be resolved on a finer mesh. To alleviate these disadvantages of the standard model, we develop a new class of actuator surface models for turbine blades and nacelle to take into account more geometrical details of turbine blades and include the effect of turbine nacelle. In the actuator surface model for blade, the aerodynamic forces calculated using the blade element method are distributed from the surface formed by the foil chords at different radial locations. In the actuator surface model for nacelle, the forces are distributed from the actual nacelle surface with the normal force component computed in the same way as in the direct forcing immersed boundary method and the tangential force component computed using a friction coefficient and a reference velocity of the incoming flow. The actuator surface model for nacelle is evaluated by simulating the flow over periodically placed nacelles. Both the actuator surface simulation and the wall-resolved large-eddy simulation are carried out. The comparison shows that the actuator surface model is able to give acceptable results especially at far wake locations on a very coarse mesh. It is noted that although this model is employed for the turbine nacelle in this work, it is also applicable to other bluff bodies. The capability of the actuator surface model in predicting turbine wakes is assessed by simulating the flow over the MEXICO (Model experiments in Controlled Conditions) turbine and a hydrokinetic turbine.

  7. Full-load converter connected asynchronous generators for MW class wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Akhmatov, Vladislav

    2005-06-15

    Wind turbines equipped with full-load converter-connected asynchronous generators are a known concept. These have rating up to hundreds of kW and are a feasible concept for MW class wind turbines and may have advantages when compared to conventional wind turbines with directly connected generators. The concept requires the use of full-scale frequency converters, but the mechanical gearbox is smaller than in conventional wind turbines of the same rating. Application of smaller gearbox may reduce the no-load losses in the wind turbines, which is why such wind turbines with converter connected generators may start operation at a smaller wind speed. Wind turbines equipped with such converted connected asynchronous generators are pitch-controlled and variable-speed. This allows better performance and control. The converter control may be applied to support the grid voltage at short-circuit faults and to improve the fault-ride-through capability of the wind turbines, which makes the concepts relevant for large wind farms. The Danish transmission system operator Energinet-DK has implemented the general model of wind turbines equipped with converter connected asynchronous generators with the simulation tool Powerfactory (DlgSilent). The article presents Energinet-DK's experience of modeling this feasible wind turbine concept. (Author)

  8. A new class of galactic discrete gamma ray sources: Chaotic winds of massive stars

    Science.gov (United States)

    Chen, Wan; White, Richard L.

    1992-01-01

    We propose a new class of galactic discrete gamma-ray sources, the chaotic, high mass-loss-rate winds from luminous early-type stars. Early-type stellar winds are highly unstable due to intrinsic line-driven instabilities, and so are permeated by numerous strong shocks. These shocks can accelerate a small fraction of thermal electrons and ions to relativistic energies via the first-order Fermi mechanism. A power-law-like photon spectrum extending from keV to above 10 MeV energies is produced by inverse Compton scattering of the extremely abundant stellar UV photons by the relativistic electrons. In addition, a typical pi(sup 0)-decay gamma-ray spectrum is generated by proton-ion interactions in the densest part of the winds.

  9. Optimalizácia monitorovania sieťovej prevádzky

    Directory of Open Access Journals (Sweden)

    František Jakab

    2013-06-01

    Full Text Available Tento príspevok sa zaoberá otvorenými problémami vyskytujúcimi sa pri pasívnom prístupe merania sieťových charakteristík. Opisuje najpoužívanejšie prístupy merania sieťových parametrov ako aj charakteristiky, ktoré sa pri monitorovaní najčastejšie sledujú. Hlavným cieľom tohto príspevku je predstavenie konceptuálneho návrhu riešenia opísaných problémov, ktorý by sa mal docieliť automatizovaným prispôsobením exportu záznamov o tokoch prevádzky k aktuálnemu stavu siete.

  10. Investing in mental health and well-being: findings from the DataPrev project

    Science.gov (United States)

    Mcdaid, David; Park, A-La

    2011-01-01

    A systematic review was conducted to determine the extent to which an economic case has been made in high-income countries for investment in interventions to promote mental health and well-being. We focused on areas of interest to the DataPrev project: early years and parenting interventions, actions set in schools and workplaces and measures targeted at older people. Economic evaluations had to have some focus on promotion of mental health and well-being and/or primary prevention of poor mental health through health-related means. Studies preventing exacerbations in existing mental health problems were excluded, with the exception of support for parents with mental health problems, which might indirectly affect the mental health of their children. Overall 47 studies were identified. There was considerable variability in their quality, with a variety of outcome measures and different perspectives: societal, public purse, employer or health system used, making policy comparisons difficult. Caution must therefore be exercised in interpreting results, but the case for investment in parenting and health visitor-related programmes appears most strong, especially when impacts beyond the health sector are taken into account. In the workplace an economic return on investment in a number of comprehensive workplace health promotion programmes and stress management projects (largely in the USA) was reported, while group-based exercise and psychosocial interventions are of potential benefit to older people. Many gaps remain; a key first step would be to make more use of the existence evidence base on effectiveness and model mid- to long-term costs and benefits of action in different contexts and settings. PMID:22079932

  11. Composite Structural Analysis of Flat-Back Shaped Blade for Multi-MW Class Wind Turbine

    Science.gov (United States)

    Kim, Soo-Hyun; Bang, Hyung-Joon; Shin, Hyung-Ki; Jang, Moon-Seok

    2014-06-01

    This paper provides an overview of failure mode estimation based on 3D structural finite element (FE) analysis of the flat-back shaped wind turbine blade. Buckling stability, fiber failure (FF), and inter-fiber failure (IFF) analyses were performed to account for delamination or matrix failure of composite materials and to predict the realistic behavior of the entire blade region. Puck's fracture criteria were used for IFF evaluation. Blade design loads applicable to multi-megawatt (MW) wind turbine systems were calculated according to the Germanischer Lloyd (GL) guideline and the International Electrotechnical Commission (IEC) 61400-1 standard, under Class IIA wind conditions. After the post-processing of final load results, a number of principal load cases were selected and converted into applied forces at the each section along the blade's radius of the FE model. Nonlinear static analyses were performed for laminate failure, FF, and IFF check. For buckling stability, linear eigenvalue analysis was performed. As a result, we were able to estimate the failure mode and locate the major weak point.

  12. Design of a family of new advanced airfoils for low wind class turbines

    International Nuclear Information System (INIS)

    Grasso, Francesco

    2014-01-01

    In order to maximize the ratio of energy capture and reduce the cost of energy, the selection of the airfoils to be used along the blade plays a crucial role. Despite the general usage of existing airfoils, more and more, families of airfoils specially tailored for specific applications are developed. The present research is focused on the design of a new family of airfoils to be used for the blade of one megawatt wind turbine working in low wind conditions. A hybrid optimization scheme has been implemented, combining together genetic and gradient based algorithms. Large part of the work is dedicated to present and discuss the requirements that needed to be satisfied in order to have a consistent family of geometries with high efficiency, high lift and good structural characteristics. For each airfoil, these characteristics are presented and compared to the ones of existing airfoils. Finally, the aerodynamic design of a new blade for low wind class turbine is illustrated and compared to a reference shape developed by using existing geometries. Due to higher lift performance, the results show a sensitive saving in chords, wetted area and so in loads in idling position

  13. Combining choice experiments with psychometric scales to assess the social acceptability of wind energy projects: A latent class approach

    International Nuclear Information System (INIS)

    Strazzera, Elisabetta; Mura, Marina; Contu, Davide

    2012-01-01

    A choice experiment exercise is combined with psychometric scales in order: (1) to identify factors that explain support/opposition toward a wind energy development project; and (2) to assess (monetary) trade-offs between attributes of the project. A Latent Class estimator is fitted to the data, and different utility parameters are estimated, conditional on class allocation. It is found that the probability of class membership depends on specific psychometric variables. Visual impacts on valued sites are an important factor of opposition toward a project, and this effect is magnified when identity values are attached to the specific site, so much that no trade-off would be acceptable for a class of individuals characterized by strong place attachment. Conversely, other classes of individuals are willing to accept compensations, in form of private and/or public benefits. The distribution of benefits in the territory, and preservation of the option value related to the possible development of an archeological site, are important for a class of individuals concerned with the sustainability of the local economy. - Highlights: ► A Choice Experiment approach is used to assess acceptability of a wind farm project. ► Psychometric variables are used to model heterogeneity in a Latent Class model. ► No trade-off would be acceptable for a class of individuals. ► Another class of individuals is interested in private benefits. ► Other classes are interested in public benefits and sustainability of the development.

  14. Red Geyser: A New Class of Galaxy with Large-scale AGN-driven Winds

    Science.gov (United States)

    Roy, Namrata; Bundy, Kevin; Cheung, Edmond; MaNGA Team

    2018-01-01

    A new class of quiescent (non-star-forming) galaxies harboring possible AGN-driven winds have been discovered using the spatially resolved optical spectroscopy from the ongoing SDSS-IV MaNGA (Sloan Digital Sky Survey-IV Mapping Nearby Galaxies at Apache Point Observatory) survey. These galaxies named "red geysers" constitute 5%-10% of the local quiescent galaxy population and are characterized by narrow bisymmetric ionized gas emission patterns. These enhanced patterns are seen in equivalent width maps of Hα, [OIII] and other strong emission lines. They are co-aligned with the ionized gas velocity gradients but significantly misaligned with stellar velocity gradients. They also show very high gas velocity dispersions (~200 km/s). Considering these observations in light of models of the gravitational potential, Cheung et al. argued that red geysers host large-scale AGN-driven winds of ionized gas that may play a role in suppressing star formation at late times. In this work, we test the hypothesis that AGN activity is ultimately responsible for the red geyser phenomenon. We compare the nuclear radio activity of the red geysers to a matched control sample of galaxies of similar stellar mass, redshift, rest frame NUV–r color and axis ratio. and additionally, control for the presence of ionized gas. We have used 1.4 GHz radio continuum data from the VLA FIRST Survey to stack the radio flux from the red geyser sample and control sample. We find that the red geysers have a higher average radio flux than the control galaxies at > 3σ significance. Our sample is restricted to rest-frame NUV–r color > 5, thus ruling out possible radio emission due to star formation activity. We conclude that red geysers are associated with more active AGN, supporting a feedback picture in which episodic AGN activity drives large-scale but relatively weak ionized winds in many in many early-type galaxies.

  15. Near-IR spectroscopic monitoring of CLASS I protostars: Variability of accretion and wind indicators

    Energy Technology Data Exchange (ETDEWEB)

    Connelley, Michael S. [Institute for Astronomy, University of Hawaii, 640 N. Aohoku Place, Hilo, HI 96720 (United States); Greene, Thomas P. [NASA Ames Research Center, M.S. 245-6, Moffett Field, CA 94035 (United States)

    2014-06-01

    We present the results of a program that monitored the near-IR spectroscopic variability of a sample of 19 embedded protostars. Spectra were taken on time intervals from 2 days to 3 yr, over a wavelength range from 0.85 μm to 2.45 μm, for 4-9 epochs of observations per target. We found that the spectra of all targets are variable and that every emission feature observed is also variable (although not for all targets). With one exception, there were no drastic changes in the continua of the spectra, nor did any line completely disappear, nor did any line appear that was not previously apparent. This analysis focuses on understanding the connection between accretion (traced by H Br γ and CO) and the wind (traced by He I, [Fe II], and sometimes H{sub 2}). For both accretion and wind tracers, the median variability was constant versus the time interval between observations; however, the maximum variability that we observed increased with the time interval between observations. Extinction is observed to vary within the minimum sampling time of 2 days, suggesting extinguishing material within a few stellar radii at high disk latitudes. The variability of [Fe II] and H{sub 2} were correlated for most (but not all) of the 7 young stellar objects showing both features, and the amplitude of the variability depends on the veiling. Although the occurrence of CO and Br γ emission are connected, their variability is uncorrelated, suggesting that these emissions originate in separate regions near the protostar (e.g., disk and wind). The variability of Br γ and wind tracers were found to be positively correlated, negatively correlated, or uncorrelated, depending on the target. The variability of Br γ, [Fe II], and H{sub 2} always lies on a plane, although the orientation of the plane in three dimensions depends on the target. While we do not understand all interactions behind the variability that we observed, we have shown that spectroscopic variability is a powerful tool

  16. Envelhecimento, depressão e quedas: um estudo com os participantes do Projeto Prev-Quedas

    Directory of Open Access Journals (Sweden)

    Hugo Leonardo Prata

    Full Text Available INTRODUÇÃO: No Brasil a depressão é um problema de saúde pública, tendo 10 milhões de pessoas com esse diagnóstico. A queda de idosos é outro comprometedor da saúde, que muitas vezes apresenta uma combinação com a depressão. OBJETIVOS: Verificar a associação entre estados depressivos e número de quedas. MATERIAIS E MÉTODOS: Estudo seccional em que foi aplicado o GDS-15 e um questionário específico. Os dados foram trabalhados no programa R pelo teste Qui-Quadrado, ao nível de significância de 95%. Foram incluídas idosas que participam do Projeto Prev-Quedas e o critério de exclusão foi apresentar deficiência auditiva não corrigida ou apresentar estágios avançados de distúrbios cognitivos e/ou doenças mentais que impedissem o entendimento das perguntas. DISCUSSÃO E RESULTADOS: Foram entrevistadas 78 idosas, com idade média de 72 anos. O percentual de pessoas com possível quadro de depressão foi de 21,8%. Não foi encontrada associação entre depressão e as variáveis idade, estado civil, morar com alguém (p > 0,05. Foi encontrada associação entre quedas e depressão (p < 0,01. CONCLUSÃO: A tendência a estados depressivos encontrada na amostra foi considerada alta, acima da média nacional observada em 1999. A associação encontrada entre o quadro de depressão e um maior número de quedas sofridas pelos participantes pode indicar a necessidade de maior atenção das políticas públicas ao problema. A ausência de medidas preventivas estaria ligada ao pior padrão de qualidade de vida relacionada à saúde.

  17. Low Wind Speed Turbine Project Phase II: The Application of Medium-Voltage Electrical Apparatus to the Class of Variable Speed Multi-Megawatt Low Wind Speed Turbines; 15 June 2004--30 April 2005

    Energy Technology Data Exchange (ETDEWEB)

    Erdman, W.; Behnke, M.

    2005-11-01

    Kilowatt ratings of modern wind turbines have progressed rapidly from 50 kW to 1,800 kW over the past 25 years, with 3.0- to 7.5-MW turbines expected in the next 5 years. The premise of this study is simple: The rapid growth of wind turbine power ratings and the corresponding growth in turbine electrical generation systems and associated controls are quickly making low-voltage (LV) electrical design approaches cost-ineffective. This report provides design detail and compares the cost of energy (COE) between commercial LV-class wind power machines and emerging medium-voltage (MV)-class multi-megawatt wind technology. The key finding is that a 2.5% reduction in the COE can be achieved by moving from LV to MV systems. This is a conservative estimate, with a 3% to 3.5% reduction believed to be attainable once purchase orders to support a 250-turbine/year production level are placed. This evaluation considers capital costs as well as installation, maintenance, and training requirements for wind turbine maintenance personnel. Subsystems investigated include the generator, pendant cables, variable-speed converter, and padmount transformer with switchgear. Both current-source and voltage-source converter/inverter MV topologies are compared against their low-voltage, voltage-source counterparts at the 3.0-, 5.0-, and 7.5-MW levels.

  18. 3D electromagnetic design and electrical characteristics analysis of a 10-MW-class hightemperature superconducting synchronous generator for wind power

    International Nuclear Information System (INIS)

    Kim, J. H.; Park, S. I.; Le, T. D.; Kim, H. M.

    2014-01-01

    In this paper, the general electromagnetic design process of a 10-MW-class high-temperature superconducting (HTS) synchronous generator that is intended to be utilized for large scale offshore wind generator is discussed. This paper presents three-dimensional (3D) electromagnetic design proposal and electrical characteristic analysis results of a 10-MW-class HTS synchronous generator for wind power. For more detailed design by reducing the errors of a two-dimensional (2D) design owing to leakage flux in air-gap, we redesign and analyze the 2D conceptual electromagnetic design model of the HTS synchronous generator using 3D finite element analysis (FEA) software. Then electrical characteristics which include the no-load and full-load voltage of generator, harmonic contents of these two load conditions, voltage regulation and losses of generator are analyzed by commercial 3D FEA software.

  19. RBF neural network based PI pitch controller for a class of 5-MW wind turbines using particle swarm optimization algorithm.

    Science.gov (United States)

    Poultangari, Iman; Shahnazi, Reza; Sheikhan, Mansour

    2012-09-01

    In order to control the pitch angle of blades in wind turbines, commonly the proportional and integral (PI) controller due to its simplicity and industrial usability is employed. The neural networks and evolutionary algorithms are tools that provide a suitable ground to determine the optimal PI gains. In this paper, a radial basis function (RBF) neural network based PI controller is proposed for collective pitch control (CPC) of a 5-MW wind turbine. In order to provide an optimal dataset to train the RBF neural network, particle swarm optimization (PSO) evolutionary algorithm is used. The proposed method does not need the complexities, nonlinearities and uncertainties of the system under control. The simulation results show that the proposed controller has satisfactory performance. Copyright © 2012 ISA. Published by Elsevier Ltd. All rights reserved.

  20. In-Class Quantification of the Mentos and Diet Coke Analogue Experiment: Effects of Wind on Volcanic Isopach Patterns

    Science.gov (United States)

    Quane, S.; Klos, Z.; Jacobsen, R.

    2009-05-01

    The Mentos and Diet Coke experiment, where instantaneous emplacement of Mentos candy in Diet Coke creates a soda/CO2 eruptive plume, is a common educational analogue for a volcanic eruption. In this paper, we quantify the effects of varying directional wind speeds on the eruptive plume as a learning tool in advanced Introductory Geology and Volcanology courses. The Mentos and Diet Coke reaction is a fun, safe and affordable analogue for explosive, single pulse, basaltic eruptions (e.g., Strombolian eruptions). Specifically, the physical and chemical reaction nucleating CO2 bubbles on the pitted surface of Mentos candy is directly analogous to the collapsing foam eruption regime described by Parfitt (2004) where inertia driven fragmentation of the liquid (Namiki and Manga, 2008) leads to basaltic pyroclastic eruptions. Often, in these systems, the pyroclasts are carried downwind, resulting lopsided (downwind side taller) cinder cones. In our experiments, we create a single pulse eruption by simultaneously dropping four Mentos candies into a 16.9 oz. bottle of Diet Coke. The experiments are run under different wind conditions created by three stacked box fans in the off (control experiment) low, medium and high settings. Wind speed is measured using a hand held anemometer. The pyroclast dispersal is recorded by degree of liquid saturation through four layers of newspaper. The liquid is allowed to soak in for thirty seconds post eruption and then the individual layers of newspaper are separated and the saturation envelope is traced with a black marker and digitally photographed. The pyroclast dispersal envelope (or saturation area) is then quantified from the photos by image analysis in Adobe Photoshop. In addition, the experiments are videotaped to quantify ejection velocity using frame by frame analysis in iMovie. The resulting isopach ("deposit thickness") maps indicate a strong tightening of dispersal envelopes with increasing wind speed as seen in natural

  1. Evaluation of work-based screening for early signs of alcohol-related liver disease in hazardous and harmful drinkers: the PrevAIL study.

    Science.gov (United States)

    Cook, Penny A; Morleo, Michela; Billington, David; Sanderson-Shortt, Kevin; Jones, Colin; Gabbay, Mark; Sheron, Nick; Bellis, Mark A; Phillips-Howard, Penelope A; Gilmore, Ian T

    2015-06-04

    The direct cost of excessive alcohol consumption to health services is substantial but dwarfed by the cost borne by the workplace as a result of lost productivity. The workplace is also a promising setting for health interventions. The Preventing Alcohol Harm in Liverpool and Knowsley (PrevAIL) project aimed to evaluate a mechanism for detecting the prevalence of alcohol related liver disease using fibrosis biomarkers. Secondary aims were to identify the additive effect of obesity as a risk factor for early liver disease; to assess other impacts of alcohol on work, using a cross-sectional survey. Participants (aged 36-55 y) from 13 workplaces participated (March 2011-April 2012). BMI, waist circumference, blood pressure and self-reported alcohol consumption in the previous week was recorded. Those consuming more than the accepted UK threshold (men: >21 units; female: >14 units alcohol) provided a 20 ml venous blood sample for a biomarker test (Southampton Traffic Light Test) and completed an alcohol questionnaire (incorporating the Severity of Alcohol Dependence Questionnaire). The screening mechanism enrolled 363 individuals (52 % women), 39 % of whom drank above the threshold and participated in the liver screen (n = 141, complete data = 124 persons). Workplaces with successful participation were those where employers actively promoted, encouraged and facilitated attendance. Biomarkers detected that 30 % had liver disease (25 %, intermediate; 5 % probable). Liver disease was associated with the frequency of visits to the family physician (P = 0.036) and obesity (P = 0.052). The workplace is an important setting for addressing alcohol harm, but there are barriers to voluntary screening that need to be addressed. Early detection and support of cases in the community could avert deaths and save health and social costs. Alcohol and obesity should be addressed simultaneously, because of their known multiplicative effect on liver disease risk, and because employers

  2. Prevención de la adicción a videojuegos: eficacia de las técnicas de control de la impulsividad en el programa PrevTec 3.1

    OpenAIRE

    Marco Puche, Clara

    2013-01-01

    Participaron 1.1106 alumnos de Educación Primaria y Secundaria de 13 centros educativos de la ciudad de Valencia y su área metropolitana. Se aplicó un diseño mixto o de medidas parcialmente repetidas, con una variable intra-sujeto –momento de medida- y una variable entre-sujetos –un grupo recibió las sesiones del programa PrevTec 3.1 (tradicional), otro recibió el programa con técnicas de control de la impulsividad adicionales, y un tercer grupo conformó el grupo en lista de espera-. Las ...

  3. Wind energy

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter discusses the role wind energy may have in the energy future of the US. The topics discussed in the chapter include historical aspects of wind energy use, the wind energy resource, wind energy technology including intermediate-size and small wind turbines and intermittency of wind power, public attitudes toward wind power, and environmental, siting and land use issues

  4. Distribution, nesting activities, and age-class of territorial pairs of golden eagles at the Altamont Pass Wind Resource Area, California, 2014–16

    Science.gov (United States)

    Kolar, Patrick S.; Wiens, J. David

    2017-03-22

    The substantial numbers of golden eagles (Aquila chrysaetos) killed by collisions with oldgeneration wind turbines each year at the Altamont Pass Wind Resource Area (APWRA) in California has been well documented from previous studies. Few eagle nests have been documented in the APWRA, however, and adults and subadults 3+ years of age killed by turbines were generally not associated with nearby territories. We searched a subset of randomly selected survey plots for territorial pairs of golden eagles and associated nesting attempts within the APWRA as part of a broader investigation of population dynamics in the surrounding northern Diablo Range. In contrast to limited historical observations from 1988 to 2013, our surveys documented up to 15 territorial pairs within 3.2 kilometers (km) of wind turbines at the APWRA annually, 9 of which were not previously documented or only observed intermittently during historical surveys. We found evidence of nesting activity by adult pairs at least once during our study at six of these territories. We also determined that 23–36 percent of territories identified within 3.2 km of the APWRA had a subadult pair member, but that no pairs with a subadult member attempted to nest. These data will be useful to developers, wildlife managers, and future raptor studies in the area to evaluate and minimize the potential effects of wind energy or other development activities on previously unknown territorial pairs in the area.

  5. Selected Issues of Legislation with regard to Operating Pharmacies in the Slovak Republic / Vybrané problémy právnej úpravy prevádzkovania lekární v podmienkach Slovenskej republiky

    Directory of Open Access Journals (Sweden)

    Capandová Petra

    2015-06-01

    Full Text Available Medzi základné práva a slobody, upravené v druhej hlave Ústavy Slovenskej republiky patrí aj právo na ochranu zdravia, bezplatnú zdravotnú starostlivosť na základe zdravotného poistenia, právo na zdravotnícke pomôcky za zákonom stanovených podmienok. Tieto práva sú garantované v ustanovení Čl. 40 Ústavy Slovenskej republiky v rámci ekonomických, sociálnych a kultúrnych práv a vzťahujú sa na každú fyzickú osobu, t. j. na človeka. Keďže sú tieto práva považované za ľudské práva v zmysle medzinárodného práva, sú garantované aj v mnohostranných medzinárodných zmluvách, ktorých signatárom je aj Slovenská republika, ako napríklad Medzinárodný pakt o hospodárskych, sociálnych a kultúrnych právach. Právna úprava prevádzkovania lekární v Slovenskej republike zahŕňa široké spektrum otázok a je pomerne rozsiahla. Snahou zákonodarcu bolo nastaviť také pravidlá, ktoré by stransparentnili a zjednodušili právne prostredie v tomto sektore. V niektorých oblastiach sú pravidlá dané legislatívou Európskej únie a slovenský právny poriadok ich iba prevzal. Najdôležitejším prvokom v tejto sfére, ktorý nie je priamo upravovaný legislatívou EÚ, je poskytovanie lekárenskej starostlivosti a využívanie systému verejného zdravotného poistenia v tejto oblasti. Hlavným cieľom príspevku je poukázať na vybrané problémy, ktoré sa spájajú s postavením prevádzkovateľa lekárne a jeho povinnosťami, ktoré mu vyplývajú zo zákona o liekoch a s ktorými sa musí ako prevádzkovateľ lekárne vysporiadať. Táto oblasť podnikania je pomerne prísne regulovaná a preto je potrebné byť oboznámený s príslušnými právnymi predpismi. Príspevok z právno-teoretického hľadiska rieši viaceré otázky upravené v zákone o liekoch, či vyhláške o správnej lekárenskej praxi.

  6. Negocio fiduciario de inversión: único vehículo fiduciario que prevé protección para el fideicomitente y el fideicomisario, como inversionistas del mercado de valores

    Directory of Open Access Journals (Sweden)

    David Andrés Aguirre Soriano

    2013-07-01

    Full Text Available El objeto de este artículo es describir la fiducia de inversión como un vehículo fiduciario único dentro de los tipos de negocio fiduciario, debido a la presencia de algunos instrumentos de protección del inversionista que hacen aún más atractiva la fiducia de inversión, toda vez que por tratarse de una operación de intermediación en el mercado de valores, prevé instrumentos tales como la protección del fideicomitente y del fideicomisario, también llamado beneficiario, vía consumidor financiero tradicional de una sociedad de servicios financieros, y vía inversionista del mercado de valores; lo cual resulta muy atractivo para los futuros constituyentes, respecto de la protección que ofrece el ordenamiento jurídico en el resto de vehículos fiduciarios, tales como la fiducia de administración, inmobiliaria, etc., que se reducen solo al consumidor financiero.

  7. Negocio fiduciario de inversión: único vehículo fiduciario que prevé protección para el fideicomitente y el fideicomisario, como inversionistas del mercado de valores

    Directory of Open Access Journals (Sweden)

    David Andrés Aguirre Soriano

    2013-06-01

    Full Text Available El objeto de este artículo es describir la fiducia de inversión como un vehículo fiduciario único dentro de los tipos de negocio fiduciario, debido a la presencia de algunos instrumentos de protección del inversionista que hacen aún más atractiva la fiducia de inversión, toda vez que por tratarse de una operación de intermediación en el mercado de valores, prevé instrumentos tales como la protección del fideicomitente y del fideicomisario, también llamado beneficiario, vía consumidor financiero tradicional de una sociedad de servicios financieros, y vía inversionista del mercado de valores; lo cual resulta muy atractivo para los futuros constituyentes, respecto de la protección que ofrece el ordenamiento jurídico en el resto de vehículos fiduciarios, tales como la fiducia de administración, inmobiliaria, etc., que se reducen solo al consumidor financiero.

  8. Design and Implement a Digital H{sub {infinity}}Robust Controller for a MW-Class PMSG-Based Grid-Interactive Wind Energy Conversion System

    Energy Technology Data Exchange (ETDEWEB)

    Howlander, Abdul Motin [Faculty of Engineering, Univ. of the Ryukyus, Okinawa (Japan); Urasaki, Naomitsu [Faculty of Engineering, Univ. of the Ryukyus, Okinawa (Japan); Yona, Atsushi [Faculty of Engineering, Univ. of the Ryukyus, Okinawa (Japan); Senjyu, Tomonobu [Faculty of Engineering, Univ. of the Ryukyus, Okinawa (Japan); Saber, Ahmed Yousuf [Operation Technology, Irvine, CA (United States)

    2013-04-15

    A digital H{sub {infinity}}controller for a permanent magnet synchronous generator (PMSG) based wind energy conversion system (WECS) is presented. Wind energy is an uncertain fluctuating resource which requires a tight control management. So, it is still an exigent task for the control design engineers. The conventional proportional-integral (PI) control is not ideal during high turbulence wind velocities, and the nonlinear behavior of the power converters. These are raising interest towards the robust control concepts. The robust design is to find a controller, for a given system, such that the closed-loop system becomes robust that assurance high-integrity and fault tolerant control system, robust H{sub {infinity}}control theory has befallen a standard design method of choice over the past two decades in industrial control applications. The robust H{sub {infinity}}control theory is also gaining eminence in the WECS. Due to the implementation complexity for the continuous H{sub {infinity}}controller, and availability of the high speedy micro-controllers, the design of a sample-data or a digital H{sub {infinity}}controller is very important for the realistic implementation. But there isn’t a single research to evaluate the performance of the digital H{sub {infinity}}controller for the WECS. In this paper, the proposed digital H{sub {infinity}}controller schemes comprise for the both generator and grid interactive power converters, and the control performances are compared with the conventional PI controller and the fuzzy controller. Simulation results confirm the efficacy of the proposed method Energies 2013, 6 2085 which are ensured the WECS stabilities, mitigate shaft stress, and improving the DC-link voltage and output power qualities.

  9. Design and Implement a Digital H∞ Robust Controller for a MW-Class PMSG-Based Grid-Interactive Wind Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Tomonobu Senjyu

    2013-04-01

    Full Text Available A digital H∞ controller for a permanent magnet synchronous generator (PMSG based wind energy conversion system (WECS is presented. Wind energy is an uncertain fluctuating resource which requires a tight control management. So, it is still an exigent task for the control design engineers. The conventional proportional-integral (PI control is not ideal during high turbulence wind velocities, and the nonlinear behavior of the power converters. These are raising interest towards the robust control concepts. The robust design is to find a controller, for a given system, such that the closed-loop system becomes robust that assurance high-integrity and fault tolerant control system, robust H∞ control theory has befallen a standard design method of choice over the past two decades in industrial control applications. The robust H∞ control theory is also gaining eminence in the WECS. Due to the implementation complexity for the continuous H∞ controller, and availability of the high speedy micro-controllers, the design of a sample-data or a digital H∞ controller is very important for the realistic implementation. But there isn’t a single research to evaluate the performance of the digital H∞ controller for the WECS. In this paper, the proposed digital H∞ controller schemes comprise for the both generator and grid interactive power converters, and the control performances are compared with the conventional PI controller and the fuzzy controller. Simulation results confirm the efficacy of the proposed method Energies 2013, 6 2085 which are ensured the WECS stabilities, mitigate shaft stress, and improving the DC-link voltage and output power qualities.

  10. Wind: new wind markets

    International Nuclear Information System (INIS)

    Cameron, A.

    2005-01-01

    The June 2005 edition of 'Wind Force 12' suggests that wind could generate 12% of global electricity requirements by 2020. But what moves a potential market into an emerging one? Geographical factors include a good wind resource, plenty of open space and the ability to get the generated electricity to end-users. A country's political framework is equally important, with fixed price systems, renewable quota systems and political will all playing a part. Some potential wind markets around the world are thought to have the conditions necessary to become key players in the wind industry. The emerging markets in countries such as Australia, Brazil, Canada, France, Japan and the Philippines are highlighted as examples

  11. Wind Energy

    International Nuclear Information System (INIS)

    Rodriguez D, J.M.

    1998-01-01

    The general theory of the wind energy conversion systems is presented. The availability of the wind resource in Colombia and the ranges of the speed of the wind in those which is possible economically to use the wind turbines are described. It is continued with a description of the principal technological characteristics of the wind turbines and are split into wind power and wind-powered pumps; and its use in large quantities grouped in wind farms or in autonomous systems. Finally, its costs and its environmental impact are presented

  12. Starting to Explore Wind Power

    Science.gov (United States)

    Hare, Jonathan

    2008-01-01

    Described is a simple, cheap and versatile homemade windmill and electrical generator suitable for a school class to use to explore many aspects and practicalities of using wind to generate electrical power. (Contains 8 figures.)

  13. Performance Data from a Wind-Tunnel Test of Two Main-rotor Blade Designs for a Utility-Class Helicopter

    Science.gov (United States)

    Singleton, Jeffrey D.; Yeager, William T., Jr.; Wilbur, Matthew L.

    1990-01-01

    An investigation was conducted in the NASA Langley Transonic Dynamics Tunnel to evaluate an advanced main rotor designed for use on a utility class helicopter, specifically the U.S. Army UH-60A Blackhawk. This rotor design incorporated advanced twist, airfoil cross sections, and geometric planform. For evaluation purposes, the current UH-60A main rotor was also tested and is referred to as the baseline blade set. A total of four blade sets were tested. One set of both the baseline and the advanced rotors were dynamically scaled to represent a full scale helicopter rotor blade design. The remaining advanced and baseline blade sets were not dynamically scaled so as to isolate the effects of structural elasticity. The investigation was conducted in hover and at rotor advance ratios ranging from 0.15 to 0.4 at a range of nominal test medium densities from 0.00238 to 0.009 slugs/cu ft. This range of densities, coupled with varying rotor lift and propulsive force, allowed for the simulation of several vehicle gross weight and density altitude combinations. Performance data are presented for all blade sets without analysis; however, cross referencing of data with flight condition may be useful to the analyst for validating aeroelastic theories and design methodologies as well as for evaluating advanced design parameters.

  14. Wind potential assessment of Quebec Province

    International Nuclear Information System (INIS)

    Ilinca, A.; Chaumel, J.-L.; Retiveau, J.-L.

    2003-01-01

    The paper presents the development of a comprehensive wind atlas of the Province of Quebec. This study differs from previous studies by 1) use of a standard classification index to categorize the wind resource, 2) extensive review of surface and upper air data available for the Province to define the wind resource, and 3) integration of available wind data with the topography of the Province. The wind resource in the Province of Quebec is classified using the scheme proposed by Battelle-Pacific Northwest Laboratory (PNL). The Battelle-PNL classification is a numerical one which includes rankings from Wind Power Class 1 (lowest) to Wind Power Class 7 (highest). Associated with each numerical classification is a range of wind power and associated mean wind speed at 10 m and 50 m above ground level. For this study, a classification for 30 m above ground level was interpolated and used. A significant amount of wind data was gathered for the Province. These data were obtained from Atmospheric Environment Service (AES), Canada, from wind project developers, and from climatological summaries of surface and upper air data. A total of 35 primary data sites were selected in the Province. Although a number of wind data sites in the Province were identified and used in the analysis, large areas of the Province lacked any specific wind information. The Province was divided into grid blocks having dimensions of 1/4 o latitude by 1/3 o longitude. Each grid block is assigned a numerical Wind Power Class value ranging from 1 to 7. This value is based on the integration of the available wind data and the topography within the square. The majority of the Province was classified as 1 or 2. Coastal locations and topographic features in the interior of the Province typically have Wind Power Class 3 or higher. (author)

  15. Assessment of wind energy potential in China

    Institute of Scientific and Technical Information of China (English)

    Zhu Rong; Zhang De; Wang Yuedong; Xing Xuhuang; Li Zechun

    2009-01-01

    China wind atlas was made by numerical simulation and the wind energy potential in China was calculated. The model system for wind energy resource assessment was set up based on Canadian Wind Energy Simulating Toolkit (WEST) and the simulating method was as follows. First, the weather classes were obtained depend on meteorological data of 30 years. Then, driven by the initial meteorological field produced by each weather class, the meso-scale model ran for the distribution of wind energy resources according each weather class condition one by one. Finally, averaging all the modeling output weighted by the occurrence frequency of each weather class, the annual mean distribution of wind energy resources was worked out. Compared the simulated wind energy potential with other results from several ac-tivities and studies for wind energy resource assessment, it is found that the simulated wind energy potential in mainland of China is 3 times that from the second and the third investigations for wind energy resources by CMA, and is similar to the wind energy potential obtained by NREL in Solar and Wind Energy Resource Assessment (SWERA) project. The simulated offshore wind energy potential of China seems smaller than the true value. According to the simulated results of CMA and considering lots of limited factors to wind energy development, the final conclusion can be obtained that the wind energy availability in China is 700~1 200 GW, in which 600~1 000 GW is in mainland and 100~200 GW is on offshore, and wind power will become the important part of energy composition in future.

  16. Dependent Classes

    DEFF Research Database (Denmark)

    Gasiunas, Vaidas; Mezini, Mira; Ostermann, Klaus

    2007-01-01

    of dependent classes and a machine-checked type soundness proof in Isabelle/HOL [29], the first of this kind for a language with virtual classes and path-dependent types. [29] T.Nipkow, L.C. Poulson, and M. Wenzel. Isabelle/HOL -- A Proof Assistant for Higher-Order Logic, volume 2283 of LNCS, Springer, 2002......Virtual classes allow nested classes to be refined in subclasses. In this way nested classes can be seen as dependent abstractions of the objects of the enclosing classes. Expressing dependency via nesting, however, has two limitations: Abstractions that depend on more than one object cannot...... be modeled and a class must know all classes that depend on its objects. This paper presents dependent classes, a generalization of virtual classes that expresses similar semantics by parameterization rather than by nesting. This increases expressivity of class variations as well as the flexibility...

  17. Wind energy

    International Nuclear Information System (INIS)

    Kotevski, Darko

    2003-01-01

    Wind is not only free, it is inexhaustible. Wind energy has come a very long way since the prototypes of just 20 years ago. today's wind turbines are state-of-the-art technology - modular and quick to install anywhere where there is sufficient wind potential to provide secure, centralised or distributed generation. It is a global phenomenon, the world's fastest growing energy sector, a clean and effective modern technology that completely avoids pollution and thus reducing the 'green house' effect. (Original)

  18. Great expectations: large wind turbines

    International Nuclear Information System (INIS)

    De Vries, E.

    2001-01-01

    This article focuses on wind turbine product development, and traces the background to wind turbines from the first generation 1.5 MW machines in 1995-6, plans for the second generation 3-5 MW class turbines to meet the expected boom in offshore wind projects, to the anticipated installation of a 4.5 MW turbine, and offshore wind projects planned for 2000-2002. The switch by the market leader Vestas to variable speed operation in 2000, the new product development and marketing strategy taken by the German Pro + Pro consultancy in their design of a 1.5 MW variable speed pitch control concept, the possible limiting of the size of turbines due to logistical difficulties, opportunities offered by air ships for large turbines, and the commissioning of offshore wind farms are discussed. Details of some 2-5 MW offshore wind turbine design specifications are tabulated

  19. Wind Structure and Wind Loading

    DEFF Research Database (Denmark)

    Brorsen, Michael

    The purpose of this note is to provide a short description of wind, i.e. of the flow in the atmosphere of the Earth and the loading caused by wind on structures. The description comprises: causes to the generation of windhe interaction between wind and the surface of the Earthhe stochastic nature...

  20. Wind power

    International Nuclear Information System (INIS)

    Gipe, P.

    2007-01-01

    This book is a translation of the edition published in the USA under the title of ''wind power: renewable energy for home, farm and business''. In the wake of mass blackouts and energy crises, wind power remains a largely untapped resource of renewable energy. It is a booming worldwide industry whose technology, under the collective wing of aficionados like author Paul Gipe, is coming of age. Wind Power guides us through the emergent, sometimes daunting discourse on wind technology, giving frank explanations of how to use wind technology wisely and sound advice on how to avoid common mistakes. Since the mid-1970's, Paul Gipe has played a part in nearly every aspect of wind energy development from installing small turbines to promoting wind energy worldwide. As an American proponent of renewable energy, Gipe has earned the acclaim and respect of European energy specialists for years, but his arguments have often fallen on deaf ears at home. Today, the topic of wind power is cropping up everywhere from the beaches of Cape Cod to the Oregon-Washington border, and one wind turbine is capable of producing enough electricity per year to run 200 average American households. Now, Paul Gipe is back to shed light on this increasingly important energy source with a revised edition of Wind Power. Over the course of his career, Paul Gipe has been a proponent, participant, observer, and critic of the wind industry. His experience with wind has given rise to two previous books on the subject, Wind Energy Basics and Wind Power for Home and Business, which have sold over 50,000 copies. Wind Power for Home and Business has become a staple for both homeowners and professionals interested in the subject, and now, with energy prices soaring, interest in wind power is hitting an all-time high. With chapters on output and economics, Wind Power discloses how much you can expect from each method of wind technology, both in terms of energy and financial savings. The book updated models

  1. Cutting Classes

    Science.gov (United States)

    Hacker, Andrew

    1976-01-01

    Provides critical reviews of three books, "The Political Economy of Social Class", "Ethnicity: Theory and Experience," and "Ethnicity in the United States," focusing on the political economy of social class and ethnicity. (Author/AM)

  2. Modelling the wind climate of Ireland

    DEFF Research Database (Denmark)

    Frank, H.P.; Landberg, L.

    1997-01-01

    The wind climate of Ireland has been calculated using the Karlsruhe Atmospheric Mesoscale Model KAMM. The climatology is represented by 65 frequency classes of geostrophic wind that were selected as equiangular direction sectors and speed intervals with equal frequency in a sector. The results...... are compared with data from the European Wind Atlas which have been analyzed using the Wind Atlas Analysis and Application Program, WA(S)P. The prediction of the areas of higher wind power is fair. Stations with low power are overpredicted....

  3. Offshore wind power in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Holttinen, H. [VTT Energy, Espoo (Finland)

    1998-12-31

    The objectives of the project were to estimate the technical offshore wind power potential of the Gulf of Bothnia, with cost assessments, to study icing conditions and ice loads, and to design a foundation suitable for the environmental conditions. The technical offshore potential from Vaasa to Tornio is huge, more than 40 TWh/a, although the cost of offshore wind power is still higher than on land. Wind turbines have not previously been designed for the icing conditions found in Gulf of Bothnia and the recommendations for load cases and siting of megawatt-class turbines are an important result of the project. (orig.)

  4. Wind energy.

    Science.gov (United States)

    Leithead, W E

    2007-04-15

    From its rebirth in the early 1980s, the rate of development of wind energy has been dramatic. Today, other than hydropower, it is the most important of the renewable sources of power. The UK Government and the EU Commission have adopted targets for renewable energy generation of 10 and 12% of consumption, respectively. Much of this, by necessity, must be met by wind energy. The US Department of Energy has set a goal of 6% of electricity supply from wind energy by 2020. For this potential to be fully realized, several aspects, related to public acceptance, and technical issues, related to the expected increase in penetration on the electricity network and the current drive towards larger wind turbines, need to be resolved. Nevertheless, these challenges will be met and wind energy will, very likely, become increasingly important over the next two decades. An overview of the technology is presented.

  5. Performance of the CORDEX regional climate models in simulating offshore wind and wind potential

    Science.gov (United States)

    Kulkarni, Sumeet; Deo, M. C.; Ghosh, Subimal

    2018-03-01

    This study is oriented towards quantification of the skill addition by regional climate models (RCMs) in the parent general circulation models (GCMs) while simulating wind speed and wind potential with particular reference to the Indian offshore region. To arrive at a suitable reference dataset, the performance of wind outputs from three different reanalysis datasets is evaluated. The comparison across the RCMs and their corresponding parent GCMs is done on the basis of annual/seasonal wind statistics, intermodel bias, wind climatology, and classes of wind potential. It was observed that while the RCMs could simulate spatial variability of winds, well for certain subregions, they generally failed to replicate the overall spatial pattern, especially in monsoon and winter. Various causes of biases in RCMs were determined by assessing corresponding maps of wind vectors, surface temperature, and sea-level pressure. The results highlight the necessity to carefully assess the RCM-yielded winds before using them for sensitive applications such as coastal vulnerability and hazard assessment. A supplementary outcome of this study is in form of wind potential atlas, based on spatial distribution of wind classes. This could be beneficial in suitably identifying viable subregions for developing offshore wind farms by intercomparing both the RCM and GCM outcomes. It is encouraging that most of the RCMs and GCMs indicate that around 70% of the Indian offshore locations in monsoon would experience mean wind potential greater than 200 W/m2.

  6. Grid Integration of Offshore Wind | Wind | NREL

    Science.gov (United States)

    Grid Integration of Offshore Wind Grid Integration of Offshore Wind Much can be learned from the existing land-based integration research for handling the variability and uncertainty of the wind resource Arklow Bank offshore wind park consists of seven GE Wind 3.6-MW wind turbines. Integration and

  7. Wind Energy

    Energy Technology Data Exchange (ETDEWEB)

    Beurskens, H.J.M. [SET Analysis, Kievitlaan 26, 1742 AD Schagen (Netherlands); Brand, A.J. [Energy research Centre of the Netherlands ECN, Unit Wind Energy, P.O. Box 1, 1755 ZG Petten (Netherlands)

    2013-02-15

    Over the years, wind energy has become a major source of renewable energy worldwide. The present chapter addresses the wind resource, which is available for exploitation for large-scale electricity production, and its specific physical properties. Furthermore, the technical options available to convert the energy of the air flow into mechanical energy and electricity are described. Specific problems of large-scale integration of wind energy into the grid as well as the present and future market developments are described in this chapter. Finally, environmental aspects are discussed briefly.

  8. World Wind

    Data.gov (United States)

    National Aeronautics and Space Administration — World Wind allows any user to zoom from satellite altitude into any place on Earth, leveraging high resolution LandSat imagery and SRTM elevation data to experience...

  9. Wind power

    International Nuclear Information System (INIS)

    2009-01-01

    At the end of 2008,the European wind power capacity had risen to 65,247 MW which is a 15,1% increase on 2007. The financial crisis does not appear to have any real consequences of the wind power sector's activity in 2008. At the end of 2008 the European Union accommodated 53,9% of the world's wind power capacity. The top ten countries in terms of installed wind capacities are: 1) Usa with 25,388 MW, 2) Germany with 23,903 MW, 3) Spain with 16,740 MW, 4) China with 12,200 MW, 5) India with 9,645 MW, 6) Italy with 3,736 MW, 7) France with 3,542 MW, 8) U.K. with 3,406 MW, 9) Denmark with 3,166 MW and 10) Portugal with 2,862 MW. (A.C.)

  10. Wind power

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    This publication describes some of the technical, economic, safety and institutional considerations involved in the selection, installation and evaluation of a wind generation system. This information is presented, where possible, in practical, non-technical terms. The first four sections provide background information, theory, and general knowledge, while the remaining six sections are of a more specific nature to assist the prospective owner of a wind generator in his calculations and selections. Meteorological information is provided relating to the wind regime in Nova Scotia. The section on cost analysis discusses some of the factors and considerations which must be examined in order to provide a logical comparison between the alternatives of electricity produced from other sources. The final two sections are brief summaries of the regulations and hazards pertaining to the use of wind generators. The cost of wind-generated electricity is high compared to present Nova Scotia Power Corporation rates, even on Sable Island, Nova Scotia's highest wind area. However, it may be observed that Sable Island is one of the areas of Nova Scotia which is not presently supplied through the power grid and, particularly if there was a significant increase in the price of diesel oil, wind-generated electricity may well be the most economical alternative in that area. Generally speaking, however, where a consumer can purchase electricity at the normal domestic rate, wind generators are not economical, and they will not become economical unless there is a great reduction in their cost, an great increase in electricity rates, or both. Includes glossary. 23 figs., 11 tabs.

  11. Autonomous Aerial Sensors for Wind Power Meteorology

    DEFF Research Database (Denmark)

    Giebel, Gregor; Schmidt Paulsen, Uwe; Reuder, Joachim

    2011-01-01

    , UAVs could be quite cost-effective. In order to test this assumption and to test the limits of UAVs for wind power meteorology, this project assembles four different UAVs from four participating groups. Risø has built a lighter-than-air kite with a long tether, Bergen University flies a derivative......This paper describes a new approach for measurements in wind power meteorology using small unmanned flying platforms. Large-scale wind farms, especially offshore, need an optimisation between installed wind power density and the losses in the wind farm due to wake effects between the turbines. Good...... movement. In any case, a good LIDAR or SODAR will cost many tenthousands of euros. Another current problem in wind energy is the coming generation of wind turbines in the 10-12MW class, with tip heights of over 200m. Very few measurement masts exist to verify our knowledge of atmospheric physics, and most...

  12. Word classes

    DEFF Research Database (Denmark)

    Rijkhoff, Jan

    2007-01-01

    in grammatical descriptions of some 50 languages, which together constitute a representative sample of the world’s languages (Hengeveld et al. 2004: 529). It appears that there are both quantitative and qualitative differences between word class systems of individual languages. Whereas some languages employ...... a parts-of-speech system that includes the categories Verb, Noun, Adjective and Adverb, other languages may use only a subset of these four lexical categories. Furthermore, quite a few languages have a major word class whose members cannot be classified in terms of the categories Verb – Noun – Adjective...... – Adverb, because they have properties that are strongly associated with at least two of these four traditional word classes (e.g. Adjective and Adverb). Finally, this article discusses some of the ways in which word class distinctions interact with other grammatical domains, such as syntax and morphology....

  13. Class size versus class composition

    DEFF Research Database (Denmark)

    Jones, Sam

    Raising schooling quality in low-income countries is a pressing challenge. Substantial research has considered the impact of cutting class sizes on skills acquisition. Considerably less attention has been given to the extent to which peer effects, which refer to class composition, also may affect...... bias from omitted variables, the preferred IV results indicate considerable negative effects due to larger class sizes and larger numbers of overage-for-grade peers. The latter, driven by the highly prevalent practices of grade repetition and academic redshirting, should be considered an important...

  14. Wind Generators

    Science.gov (United States)

    1989-01-01

    When Enerpro, Inc. president, Frank J. Bourbeau, attempted to file a patent on a system for synchronizing a wind generator to the electric utility grid, he discovered Marshall Space Flight Center's Frank Nola's power factor controller. Bourbeau advanced the technology and received a NASA license and a patent for his Auto Synchronous Controller (ASC). The ASC reduces generator "inrush current," which occurs when large generators are abruptly brought on line. It controls voltage so the generator is smoothly connected to the utility grid when it reaches its synchronous speed, protecting the components from inrush current damage. Generator efficiency is also increased in light winds by applying lower than rated voltage. Wind energy is utilized to drive turbines to generate electricity for utility companies.

  15. Wind turbine

    Science.gov (United States)

    Cheney, Jr., Marvin C.

    1982-01-01

    A wind turbine of the type having an airfoil blade (15) mounted on a flexible beam (20) and a pitch governor (55) which selectively, torsionally twists the flexible beam in response to wind turbine speed thereby setting blade pitch, is provided with a limiter (85) which restricts unwanted pitch change at operating speeds due to torsional creep of the flexible beam. The limiter allows twisting of the beam by the governor under excessive wind velocity conditions to orient the blades in stall pitch positions, thereby preventing overspeed operation of the turbine. In the preferred embodiment, the pitch governor comprises a pendulum (65,70) which responds to changing rotor speed by pivotal movement, the limiter comprising a resilient member (90) which engages an end of the pendulum to restrict further movement thereof, and in turn restrict beam creep and unwanted blade pitch misadjustment.

  16. 78 FR 29364 - Exelon Corporation, Exelon Wind 1, LLC, Exelon Wind 2, LLC, Exelon Wind 3, LLC, Exelon Wind 4...

    Science.gov (United States)

    2013-05-20

    ...-005, QF07-55-005, QF07-56-005, QF07-257-004] Exelon Corporation, Exelon Wind 1, LLC, Exelon Wind 2, LLC, Exelon Wind 3, LLC, Exelon Wind 4, LLC, Exelon Wind 5, LLC, Exelon Wind 6, LLC, Exelon Wind 7, LLC, Exelon Wind 8, LLC, Exelon Wind 9, LLC, Exelon Wind 10, LLC, Exelon Wind 11, LLC, High Plains...

  17. Remote Sensing Wind and Wind Shear System.

    Science.gov (United States)

    Contents: Remote sensing of wind shear and the theory and development of acoustic doppler; Wind studies; A comparison of methods for the remote detection of winds in the airport environment; Acoustic doppler system development; System calibration; Airport operational tests.

  18. Social Classes

    DEFF Research Database (Denmark)

    Aktor, Mikael

    2018-01-01

    . Although this social structure was ideal in nature and not equally confirmed in other genres of ancient and medieval literature, it has nevertheless had an immense impact on Indian society. The chapter presents an overview of the system with its three privileged classes, the Brahmins, the Kṣatriyas......The notions of class (varṇa) and caste (jāti) run through the dharmaśāstra literature (i.e. Hindu Law Books) on all levels. They regulate marriage, economic transactions, work, punishment, penance, entitlement to rituals, identity markers like the sacred thread, and social interaction in general...

  19. Wind energy

    International Nuclear Information System (INIS)

    Portilla S, L.A.

    1995-01-01

    The wind energy or eolic energy is a consequence of solar energy, the one which is absorbed by the atmosphere and is transformed into energy of movement of large bulks of air. In this process the atmosphere acts as the filter to the solar radiation and demotes the ultraviolet beams that result fatal to life in the Earth. The ionosphere is the most external cap and this is ionized by means of absorption process of ultraviolet radiation arising to the Sun. The atmosphere also acts as a trap to the infrared radiation, it that results from the continual process of energetic degradation. In this way, the interaction between Earth - Atmospheres, is behaved as a great greenhouse, maintaining the constant temperatures, including in the dark nights. Processes as the natural convection (that occur by the thermodynamic phenomenon), equatorial calmness, trade winds and against trade winds and global distribution of the air currents are described. The other hand, techniques as the transformation of the wind into energy and its parameters also are shown

  20. Wind power

    International Nuclear Information System (INIS)

    2006-06-01

    This road-map proposes by the Group Total aims to inform the public on the wind power. It presents the principles, the technology takes off, its applications and technology focus, the global market trends and the outlooks and Total commitments in the domain. (A.L.B.)

  1. Wind Energy Japan

    Energy Technology Data Exchange (ETDEWEB)

    Komatsubara, Kazuyo [Embassy of the Kingdom of the Netherlands, Tokyo (Japan)

    2012-06-15

    An overview is given of wind energy in Japan: Background; Wind Energy in Japan; Japanese Wind Energy Industry; Government Supports; Useful Links; Major Japanese Companies; Profiles of Major Japanese Companies; Major Wind Energy Projects in Japan.

  2. Wind energy systems

    Science.gov (United States)

    Stewart, H. J.

    1978-01-01

    A discussion on wind energy systems involved with the DOE wind energy program is presented. Some of the problems associated with wind energy systems are discussed. The cost, efficiency, and structural design of wind energy systems are analyzed.

  3. Landscape externalities from onshore wind power

    International Nuclear Information System (INIS)

    Meyerhoff, Juergen; Ohl, Cornelia; Hartje, Volkmar

    2010-01-01

    The expansion of renewable energy is a central element of the German Federal Government's climate and energy policy. The target for 2020 is to produce 30% of the electricity from renewable energies. Wind power has been selected to be a major contributor to this change. Replacing old wind turbines by modern ones and building new turbines on land will be crucial in meeting this target. However, the expansion of onshore wind power is not universally accepted. In several regions of Germany residents are protesting against setting up new wind turbines. To determine the negative effects two choice experiments were applied in Westsachsen and Nordhessen, Germany. In both regions the externalities of wind power generation until 2020 based on today's state of technology were measured. The results show that negative landscape externalities would result from expanding wind power generation. Using latent class models three different groups of respondents experiencing different degrees of externalities were identified.

  4. Birthing Classes

    Science.gov (United States)

    ... management options. Breastfeeding basics. Caring for baby at home. Birthing classes are not just for new parents, though. ... midwife. Postpartum care. Caring for your baby at home, including baby first aid. Lamaze One of the most popular birthing techniques in the U.S., Lamaze has been around ...

  5. Wind effect in turbulence parametrization

    Science.gov (United States)

    Colombini, M.; Stocchino, A.

    2005-09-01

    The action of wind blowing over a closed basin ultimately results in a steady shear-induced circulation pattern and in a leeward rising of the free surface—and a corresponding windward lowering—known as wind set-up. If the horizontal dimensions of the basin are large with respect to the average flow depth, the occurrence of local quasi-equilibrium conditions can be expected, i.e. the flow can be assumed to be locally driven only by the wind stress and by the opposing free surface gradient due to set-up. This wind-induced flow configuration shows a strong similarity with turbulent Couette-Poiseuille flow, the one dimensional flow between parallel plates generated by the simultaneous action of a constant pressure gradient and of the shear induced by the relative motion of the plates. A two-equation turbulence closure is then employed to perform a numerical study of turbulent Couette-Poiseuille flows for different values of the ratio of the shear stresses at the two walls. The resulting eddy viscosity vertical distributions are analyzed in order to devise analytical profiles of eddy viscosity that account for the effect of wind. The results of this study, beside allowing for a physical insight on the turbulence process of this class of flows, will allow for a more accurate description of the wind effect to be included in the formulation of quasi-3D and 3D models of lagoon hydrodynamics.

  6. Wind Loads on Structures

    DEFF Research Database (Denmark)

    Dyrbye, Claes; Hansen, Svend Ole

    Wind loads have to be taken into account when designing civil engineering structures. The wind load on structures can be systematised by means of the wind load chain: wind climate (global), terrain (wind at low height), aerodynamic response (wind load to pressure), mechanical response (wind...... pressure to structural response) and design criteria. Starting with an introduction of the wind load chain, the book moves on to meteorological considerations, atmospheric boundary layer, static wind load, dynamic wind load and scaling laws used in wind-tunnel tests. The dynamic wind load covers vibrations...... induced by wind turbulence, vortex shedding, flutter and galloping. The book gives a comprehensive treatment of wind effects on structures and it will be useful for consulting engineers designing wind-sensitive structures. It will also be valuable for students of civil engineering as textbook...

  7. Stellar winds

    International Nuclear Information System (INIS)

    Weymann, R.J.

    1978-01-01

    It is known that a steady outflow of material at comparable rates of mass loss but vastly different speeds is now known to be ubiquitous phenomenon among both the luminous hot stars and the luminous but cool red giants. The flows are probably massive enough in both cases to give rise to significant effects on stellar evolution and the mass balance between stars and the interstellar medium. The possible mechanisms for these phenomena as well as the methods of observation used are described. In particular, the mass-loss processes in stars other than the sun that also involve a steady flow of matter are considered. The evidence for their existence is described, and then the question of whether the process thought to produce the solar wind is also responsible for producing these stellar winds is explored

  8. Assessment of wind power generation along the coast of Ghana

    Energy Technology Data Exchange (ETDEWEB)

    Adaramola, Muyiwa S., E-mail: muyiwa.adaramola@umb.no [Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, Ås (Norway); Agelin-Chaab, Martin [Department of Automotive, Mechanical and Manufacturing Engineering, University of Ontario Institute of Technology, Oshawa, ON (Canada); Paul, Samuel S. [REHAU Industries, Winnipeg, Manitoba (Canada)

    2014-01-15

    Highlights: • The wind energy and its economic viability along the coastal region of Ghana are examined. • Wind resource along the coastal region of Ghana fall into Class 2 or less wind resource. • Wind turbine with rated speed from 9 to 11 m/s is suggested for wind power development. • The unit cost of wind generated electricity is found be between 0.0732 GH¢/kW h and 0.2905 GH¢/kW h. - Abstract: This study examined the wind energy potential and the economic viability of using wind turbine for electricity generation in selected locations along the coastal region of Ghana. The two-parameter Weibull probability density function was employed to analyze the wind speed data obtained from the Ghana Energy Commission. The energy output and unit cost of electricity generated from medium size commercial wind turbine models with rated powers ranging from 50 kW to 250 kW were determined. It was found that the wind resource along the coastal region of Ghana can be classified into Class 2 or less wind resource which indicate that this resource in this area is marginally suitable for large scale wind energy development or suitable for small scale applications and be useful as part of hybrid energy system. It was further observed that wind turbine with designed cut-in wind speed of less than 3 m/s and moderate rated wind speed between 9 and 11 m/s is more suitable for wind energy development along the coastal region of Ghana. Based on the selected wind turbine and assumptions used in this study, it was estimated that the unit cost of electricity varied between 0.0695 GH¢/kW h and 0.2817 GH¢/kW h.

  9. Assessment of wind power generation along the coast of Ghana

    International Nuclear Information System (INIS)

    Adaramola, Muyiwa S.; Agelin-Chaab, Martin; Paul, Samuel S.

    2014-01-01

    Highlights: • The wind energy and its economic viability along the coastal region of Ghana are examined. • Wind resource along the coastal region of Ghana fall into Class 2 or less wind resource. • Wind turbine with rated speed from 9 to 11 m/s is suggested for wind power development. • The unit cost of wind generated electricity is found be between 0.0732 GH¢/kW h and 0.2905 GH¢/kW h. - Abstract: This study examined the wind energy potential and the economic viability of using wind turbine for electricity generation in selected locations along the coastal region of Ghana. The two-parameter Weibull probability density function was employed to analyze the wind speed data obtained from the Ghana Energy Commission. The energy output and unit cost of electricity generated from medium size commercial wind turbine models with rated powers ranging from 50 kW to 250 kW were determined. It was found that the wind resource along the coastal region of Ghana can be classified into Class 2 or less wind resource which indicate that this resource in this area is marginally suitable for large scale wind energy development or suitable for small scale applications and be useful as part of hybrid energy system. It was further observed that wind turbine with designed cut-in wind speed of less than 3 m/s and moderate rated wind speed between 9 and 11 m/s is more suitable for wind energy development along the coastal region of Ghana. Based on the selected wind turbine and assumptions used in this study, it was estimated that the unit cost of electricity varied between 0.0695 GH¢/kW h and 0.2817 GH¢/kW h

  10. Coding Class

    DEFF Research Database (Denmark)

    Ejsing-Duun, Stine; Hansbøl, Mikala

    Denne rapport rummer evaluering og dokumentation af Coding Class projektet1. Coding Class projektet blev igangsat i skoleåret 2016/2017 af IT-Branchen i samarbejde med en række medlemsvirksomheder, Københavns kommune, Vejle Kommune, Styrelsen for IT- og Læring (STIL) og den frivillige forening...... Coding Pirates2. Rapporten er forfattet af Docent i digitale læringsressourcer og forskningskoordinator for forsknings- og udviklingsmiljøet Digitalisering i Skolen (DiS), Mikala Hansbøl, fra Institut for Skole og Læring ved Professionshøjskolen Metropol; og Lektor i læringsteknologi, interaktionsdesign......, design tænkning og design-pædagogik, Stine Ejsing-Duun fra Forskningslab: It og Læringsdesign (ILD-LAB) ved Institut for kommunikation og psykologi, Aalborg Universitet i København. Vi har fulgt og gennemført evaluering og dokumentation af Coding Class projektet i perioden november 2016 til maj 2017...

  11. Wind conditions for wind turbine design

    Energy Technology Data Exchange (ETDEWEB)

    Maribo Pedersen, B.

    1999-04-01

    Delegates from Europe and USA attended the meeting and discussed general aspects of wind conditions for wind turbine design. The subjects and the presented papers covered a very broad range of aspects of wind conditions and related influence on the wind turbine. (EHS)

  12. 2015 Wind Technologies Market Report

    Energy Technology Data Exchange (ETDEWEB)

    Wiser, Ryan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Electricity Markets and Policy Group; Bolinger, Mark [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Electricity Markets and Policy Group; Barbose, Galen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Darghouth, Naim [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hoen, Ben [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mills, Andrew [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rand, Joe [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Millstein, Dev [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Porter, Kevin [Exeter Associates, Columbia, MD (United States); Widiss, Rebecca [Exeter Associates, Columbia, MD (United States); Oteri, Frank [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tegen, Suzanne [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tian, Tian [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-08-03

    Annual wind power capacity additions in the United States surged in 2015 and are projected to continue at a rapid clip in the coming five years. Recent and projected near-term growth is supported by the industry’s primary federal incentive—the production tax credit (PTC)—having been extended for several years (though with a phase-down schedule, described further on pages 68-69), as well as a myriad of state-level policies. Wind additions are also being driven by improvements in the cost and performance of wind power technologies, yielding low power sales prices for utility, corporate, and other purchasers. At the same time, the prospects for growth beyond the current PTC cycle remain uncertain: growth could be blunted by declining federal tax support, expectations for low natural gas prices, and modest electricity demand growth. This annual report—now in its tenth year—provides a detailed overview of developments and trends in the U.S. wind power market, with a particular focus on 2015. The report begins with an overview of key installation-related trends: trends in U.S. wind power capacity growth; how that growth compares to other countries and generation sources; the amount and percentage of wind energy in individual states; the status of offshore wind power development; and the quantity of proposed wind power capacity in various interconnection queues in the United States. Next, the report covers an array of wind power industry trends: developments in turbine manufacturer market share; manufacturing and supply-chain developments; wind turbine and component imports into and exports from the United States; project financing developments; and trends among wind power project owners and power purchasers. The report then turns to a summary of wind turbine technology trends: turbine size, hub height, rotor diameter, specific power, and IEC Class. After that, the report discusses wind power performance, cost, and pricing trends. In so doing, it describes

  13. Wind Power Meteorology

    DEFF Research Database (Denmark)

    Lundtang Petersen, Erik; Mortensen, Niels Gylling; Landberg, Lars

    Wind power meteorology has evolved as an applied science, firmly founded on boundary-layer meteorology, but with strong links to climatology and geography. It concerns itself with three main areas: siting of wind turbines, regional wind resource assessment, and short-term prediction of the wind...... resource. The history, status and perspectives of wind power meteorology are presented, with emphasis on physical considerations and on its practical application. Following a global view of the wind resource, the elements of boundary layer meteorology which are most important for wind energy are reviewed......: wind profiles and shear, turbulence and gust, and extreme winds. The data used in wind power meteorology stem mainly from three sources: onsite wind measurements, the synoptic networks, and the re-analysis projects. Wind climate analysis, wind resource estimation and siting further require a detailed...

  14. Wind Energy Basics | NREL

    Science.gov (United States)

    Wind Energy Basics Wind Energy Basics We have been harnessing the wind's energy for hundreds of grinding grain. Today, the windmill's modern equivalent-a wind turbine can use the wind's energy to most energy. At 100 feet (30 meters) or more aboveground, they can take advantage of the faster and

  15. Prospecting for Wind

    Science.gov (United States)

    Swapp, Andy; Schreuders, Paul; Reeve, Edward

    2011-01-01

    Many people use wind to help meet their needs. Over the years, people have been able to harness or capture the wind in many different ways. More recently, people have seen the rebirth of electricity-generating wind turbines. Thus, the age-old argument about technology being either good or bad can also be applied to the wind. The wind can be a…

  16. Careers in Wind Energy

    Science.gov (United States)

    Liming, Drew; Hamilton, James

    2011-01-01

    As a common form of renewable energy, wind power is generating more than just electricity. It is increasingly generating jobs for workers in many different occupations. Many workers are employed on wind farms: areas where groups of wind turbines produce electricity from wind power. Wind farms are frequently located in the midwestern, western, and…

  17. Economic feasibility of developing wind turbines in Aligoodarz, Iran

    International Nuclear Information System (INIS)

    Mohammadi, Kasra; Mostafaeipour, Ali

    2013-01-01

    Highlights: • Three hourly long term measured wind speed data from 2005 to 2009 for city of Aligoodarz in Iran was analyzed. • Wind power density and wind energy density of the region were estimated using Weibull distribution. • Performance of six different wind turbine models were analyzed. • Economic evaluation was performed and installing of E-3120 (50 kW) model turbine was suggested. - Abstract: This study evaluates the economic feasibility of electricity generation using wind turbines in city of Aligoodarz situated in the west part of Iran. For this purpose, the wind energy potential and its characteristics were assessed in terms of diurnal, monthly and annual analysis using five years measured wind speed data from 2005 to 2009 at 10 m height. The analysis results specified a nearly stable wind pattern in different hours and months of the year which demonstrated more suitability of the region for wind energy harnessing to meet the electricity demand in all time intervals throughout the year. According to Pacific Northwest Laboratory (PNL) wind power classification, the wind resource in Aligoodarz falls in class 3 and the location was recognized as a moderate location for wind energy development. The economic feasibility of six different wind turbines with rated powers ranging from 20 to 150 kW was evaluated. Among all turbines examined, the E-3120 wind turbine was introduced as the most attractive option for installation

  18. An evaluation of wind energy potential at Kati Bandar, Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Ullah, Irfan [Department of Mechanical Engineering, NWFP University of Engineering and Technology, Peshawar (Pakistan); Chaudhry, Qamar-uz-Zaman [Pakistan Meteorological Department, Sector H-8/2, Islamabad (Pakistan); Chipperfield, Andrew J. [Computational Engineering and Design Group, School of Engineering Sciences, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom)

    2010-02-15

    As a developing nation of energy-starved people, Pakistan urgently needs new sources of affordable, clean energy. Wind energy is potentially attractive because of its low environmental impact and sustainability. This work aims to investigate the wind power production potential of sites in south-eastern Pakistan. Wind speed data measured over a one-year period at a typical site on the south-east coast of Pakistan are presented. Frequency distributions of wind speed and wind power densities at three heights, seasonal variations of speed, and estimates of power likely to be produced by commercial turbines are included. The site investigated is found to be a class 4 wind power site with annual average wind speed of 7.16 m/s and power density of 414 W/m{sup 2} at 50 m height. The site is, therefore, likely to be suitable for wind farms as well as small, stand-alone systems. (author)

  19. WindFloat Pacific Project, Final Scientific and Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Banister, Kevin [Principle Power, Inc., Emeryville, CA (United States)

    2017-01-17

    PPI’s WindFloat Pacific project (WFP) was an up to 30 MW floating offshore wind demonstration project proposed off the Coast of Oregon. The project was to be sited approximately 18 miles due west of Coos Bay, in over 1000 ft. of water, and is the first floating offshore wind array proposed in the United States, and the first offshore wind project of any kind proposed off the West Coast. PPI’s WindFloat, a semi-submersible foundation designed for high-capacity (6MW+) offshore wind turbines, is at the heart of the proposed project, and enables access to the world class wind resource at the project site and, equally, to other deep water, high wind resource areas around the country.

  20. Wind energy program overview

    International Nuclear Information System (INIS)

    1992-02-01

    This overview emphasizes the amount of electric power that could be provided by wind power rather than traditional fossil fuels. New wind power markets, advances in technology, technology transfer, and wind resources are some topics covered in this publication

  1. Wind: small is beautiful

    International Nuclear Information System (INIS)

    Vries, E. de

    2005-01-01

    The small wind sector (0.5-100 kW) is often overlooked but could provide decentralised energy systems. Small wind turbines have been used for homes, farms and small businesses for over 80 years (e.g. in the USA and the Netherlands), receiving a boost in the 1970s and 1980s following the 1973 oil crisis when a new generation of turbines entered the European and US markets. Bergey Windpower and Southwest Windpower from the USA are the market leaders in this sector in terms of sales volume but are still classed as medium-sized enterprises. Small turbines have the disadvantage of higher costs compared with large turbines due to higher manufacturing costs, technical factors associated with the tendency to use small turbines on relatively short towers, small production runs and a failure to keep up with the latest design developments such as cost-effective state-of-the-art frequency converters. Most small turbines are horizontal axis turbines, though vertical axis turbines are produced by some manufacturers. Examples of the systems available from European suppliers are described

  2. Wind energy in Germany

    International Nuclear Information System (INIS)

    Molly, J.P.

    1994-01-01

    End of June 1994 429 MW in about 2100 wind energy converters (WECs) have been installed in Germany, able to produce 1.1% of the electrical energy demand of the five German coastal states Lower Saxony, Bremen, Hamburg, Schleswig-Holstein and Mecklenburg-Vorpommern. Determining factor for the again increased installation rate, compared with 1993, is the new 500/600-kW-class which now dominates the market. Dramatically reduced WEC prices during the last two years now allow an economic operation in good wind speed regions even without any subsidy. The goal to reach a total of 2000 MW WEC installations in the year 2000 is suddenly near at hand. In the course of the next seven years an installation rate of 250 MW/year will be necessary, a value which could be reached already in 1994. Nevertheless, there still is a long way to go, if the 2000 MW shall be achieved in the year 2000. New obstacles have arisen due to the increasingly restrictive handling of WEC site permission by conservationists, often in discrepancy with the generally recognized global ideas of the eco-organizations. After more than two years of experience, the WEC quality dependent subsidy as applied in Lower Saxony proofs to be a very effective stimulation for the technical development. WECs are now optimized for maximum energy production and minimum noise emission. The new 500/600-kW class is only half as noisy as could be expected from an extrapolation based on smaller WEC units. The energy cost reduction with the size of the WECs is still going on, indicating that the new Megawatt-WECs in development can offer again an economic advantage for the operator. (orig.)

  3. Modelling Wind for Wind Farm Layout Optimization Using Joint Distribution of Wind Speed and Wind Direction

    OpenAIRE

    Ju Feng; Wen Zhong Shen

    2015-01-01

    Reliable wind modelling is of crucial importance for wind farm development. The common practice of using sector-wise Weibull distributions has been found inappropriate for wind farm layout optimization. In this study, we propose a simple and easily implementable method to construct joint distributions of wind speed and wind direction, which is based on the parameters of sector-wise Weibull distributions and interpolations between direction sectors. It is applied to the wind measurement data a...

  4. Wind farm project economics : value of wind

    Energy Technology Data Exchange (ETDEWEB)

    Bills-Everett, T. [Mainstream Renewable Power, Toronto, ON (Canada)

    2010-07-01

    This PowerPoint presentation discussed methods of increasing the value of wind power projects. Appropriate turbine selection and layout is needed to ensure that wind resources are fully developed. Construction costs have a significant impact on project costs. The world turbine price index has not significantly fluctuated since 2006. Operating costs, and the value of wind power projects, are linked with OPEX fluctuations. Wind power projects can significantly reduce greenhouse gas (GHG) emissions. An increase in wind power capacity will reduce the overall cost of energy produced from wind power. Countries can use wind power as part of a renewable energy portfolio designed to reduce risks related to diminishing petroleum supplies. Wind power will help to ensure a global transition to renewable energy use. tabs., figs.

  5. Wind turbines, is it just wind?

    International Nuclear Information System (INIS)

    Boiteux, M.

    2012-01-01

    The author first outlines that wind energy is not only random, but almost absent in extreme situations when it would be needed (for example and notably, very cold weather without wind). He suggests the association of a gas turbine to each wind turbine, so that the gas turbine will replace non operating wind turbines. He notices that wind turbines are not proximity energy as they were said to be, and that profitability in fact requires tens of grouped giant wind turbines. He also outlines the high cost of construction of grids for the connection of these wind turbines. Thus, he states that wind energy is far from being profitable in the present conditions of electricity tariffs in France

  6. Wind of opportunity

    International Nuclear Information System (INIS)

    Jamieson, Peter

    1999-01-01

    This article traces the move towards the offshore exploitation of wind energy in Europe, and presents information on existing offshore wind energy projects and proposed wind turbine prototypes for offshore operation. The building of the first major offshore wind project at Vindeby, the use of rock socketed monopile foundations for pile drilling and erection of the wind turbines from a mobile jack-up barge, the costs of wind turbines, the fatigue loads on the support structures due to the wind loading, and the offshore wind market in the UK and Europe are discussed. (UK)

  7. Advanced structural wind engineering

    CERN Document Server

    Kareem, Ahsan

    2013-01-01

    This book serves as a textbook for advanced courses as it introduces state-of-the-art information and the latest research results on diverse problems in the structural wind engineering field. The topics include wind climates, design wind speed estimation, bluff body aerodynamics and applications, wind-induced building responses, wind, gust factor approach, wind loads on components and cladding, debris impacts, wind loading codes and standards, computational tools and computational fluid dynamics techniques, habitability to building vibrations, damping in buildings, and suppression of wind-induced vibrations. Graduate students and expert engineers will find the book especially interesting and relevant to their research and work.

  8. Statistical analysis of wind speed for electrical power generation in ...

    African Journals Online (AJOL)

    Also, the results have shown that Jos, Kano and Minna fall in class 4 and therefore suitable for both off grid and grid connected modes. In addition, the effects of c and k parameters on the probability distribution functions have been presented. Keywords: Wind speed - probability - density function – wind energy conversion ...

  9. Opportunities in Canada's growing wind energy industry

    International Nuclear Information System (INIS)

    Lovshin Moss, S.; Bailey, M.

    2006-01-01

    Investment in Canada's wind sector is projected to reach $8 billion by 2012, and growth of the sector is expected to create over 16,000 jobs. Canada's wind energy capacity grew by 54 per cent in 2005 alone, aided in part by supportive national policies and programs such as the Wind Power Production Incentive (WPPI); the Canadian Renewable Conservation Expense (CRCE) and Class 43.1 Capital Cost Allowance; and support for research and development. Major long-term commitments for clean power purchases, standard offer contracts and renewable portfolio standards in several provinces are encouraging further development of the wind energy sector. This paper argued that the development of a robust Canadian wind turbine manufacturing industry will enhance economic development, create opportunities for export; and mitigate the effects of international wind turbine supply shortages. However, it is not known whether Canadian wind turbine firms are positioned to capitalize on the sector's recent growth. While Canada imports nearly all its large wind turbine generators and components, the country has technology and manufacturing strengths in advanced power electronics and small wind systems, as well as in wind resource mapping. Wind-diesel and wind-hydrogen systems are being developed in Canada, and many of the hybrid systems will offer significant opportunities for remote communities and off-grid applications. Company partnerships for technology transfer, licensing and joint ventures will accelerate Canada's progress. A recent survey conducted by Industry Canada and the Canadian Wind Energy Association (CanWEA) indicated that the total impact of wind energy related expenditures on economic output is nearly $1.38 billion for the entire sector. Annual payroll for jobs in Canada was estimated at $50 million, and substantial employment growth in the next 5 years is expected. Canada offers a strong industrial supply base capable of manufacturing wind turbine generators and

  10. Wind power development field test project at Ashibe-cho. Detailed wind characteristics survey; Ashibecho ni okeru furyoku kaihatsu field test jigyo (fukyo seisa) hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-11-01

    A detailed wind characteristics survey was conducted at Ashibe-cho, Iki-gun, Nagasaki Prefecture, on the assumption that a wind power generation system would be constructed. The survey was a 1-year project from October 1998 through September 1999, and wind characteristics such as the average wind speed, average wind direction, standard deviation of wind velocity, and the maximum instantaneous wind speed were observed. The observation point was fixed at 20m above ground, the minimum time unit for observation was 10 minutes, and the 10-minute average value was defined as the measured value. For the maximum instantaneous wind speed, the minimum time unit for observation was set to be 2 seconds. The yearly average wind speed was 5.8m/s and the maximum wind speed in the period was 35m/s. Winds came from the prevailing direction of NE (21.3%), and then from NNE (14.7%) and ENE (7.9%). The wind axis was in the NE-SW direction, and the total wind direction occurrence rate from the 6 directions was 60.2%. Turbulence intensity was 0.19 at wind speed 2.0m/s or more and 0.17 at wind speed 4.0m/s or more. Estimated wind turbine yearly operating factors of 66-84% were obtained using rated values of a 150kW, 300kW, and 750kW-class wind turbines. (NEDO)

  11. PDF models and synthetic model for the wind speed fluctuations based on the resolution of Langevin equation

    International Nuclear Information System (INIS)

    Calif, Rudy

    2012-01-01

    Highlights: ► Probability Density Functions are proposed to fit the wind speed fluctuations distributions for three representative classes. ► Stochastic simulations are performed using a Langevin equation for each class. ► The properties of simulated and measured wind speed sequences are close. -- Abstract: Wind energy production is very sensitive to turbulent wind speed. Thus rapid variation of wind speed due to changes in the local meteorological conditions can lead to electrical power variations of the order of the nominal power output, in particular when wind power variations on very short time scales, range at few seconds to 1 h, are considered. In small grid as they exist on islands (Guadeloupean Archipelago: French West Indies) such fluctuations can cause instabilities in case of intermediate power shortages. The developed analysis in reveals three main classes of time series for the wind speed fluctuations. In this work, Probability Density Functions (PDFs) are proposed to fit the wind speed fluctuations distributions in each class. After, to simulate wind speed fluctuations sequences, we use a stochastic differential equation, the Langevin equation considering Gaussian turbulence PDF (class I), Gram–Charlier PDF (class II) and a mixture of gaussian PDF (class III). The statistical and dynamical properties of simulated wind sequences are close to those of measured wind sequences, for each class.

  12. Wind engineering in Africa

    NARCIS (Netherlands)

    Wisse, J.A.; Stigter, C.J.

    2007-01-01

    The International Association for Wind Engineering (IAWE) has very few contacts in Africa, the second-largest continent. This paper reviews important wind-related African issues. They all require data on wind climate, which are very sparse in Africa. Wind engineering in Africa can assist in

  13. Galactic winds and the hubble sequence

    International Nuclear Information System (INIS)

    Bregman, J.N.

    1978-01-01

    The conditions for maintenance of supernova-driven galactic winds have been investigated to assess their role in the morphology of disk-bulge galaxies. A fluid mechanical model with gas and stars which includes galactic rotation has been used to investigate several classes of winds. It is found that many galaxies, once their initial gas is depleted, can maintain a wind throughout the entire galaxy, a conditon most easily satisfied by systems with a small bulge-to-disk ratio. If the ratio of supernova heating to total mass loss falls below a critical value that depends on galaxy type and mass, only a partial wind exterior to a critical surface can exist, with infall occurring at interior points. Galaxies in which only the bulge was depleted of gas may support a bulge wind that does not interact with the colder and denser gas in the disk.These results indicate that if SO galaxies are a transition class between elliptical and spiral galaxies, it is probably because early galactic winds, which may initially deplete a galaxy of gas, are more prevalent in SO than in spiral galaxies. However, if SO's form a parallel sequence with spirals, the initial gas-depletion mechanism must be independent of bulge-to-disk ratio. These results are not strongly influenced by altering the galactic mass model, including electron conduction in the flow equations, or adding massive halos

  14. Aleutian Pribilof Islands Wind Energy Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Bruce A. Wright

    2012-03-27

    Under this project, the Aleutian Pribilof Islands Association (APIA) conducted wind feasibility studies for Adak, False Pass, Nikolski, Sand Point and St. George. The DOE funds were also be used to continue APIA's role as project coordinator, to expand the communication network quality between all participants and with other wind interest groups in the state and to provide continued education and training opportunities for regional participants. This DOE project began 09/01/2005. We completed the economic and technical feasibility studies for Adak. These were funded by the Alaska Energy Authority. Both wind and hydro appear to be viable renewable energy options for Adak. In False Pass the wind resource is generally good but the site has high turbulence. This would require special care with turbine selection and operations. False Pass may be more suitable for a tidal project. APIA is funded to complete a False Pass tidal feasibility study in 2012. Nikolski has superb potential for wind power development with Class 7 wind power density, moderate wind shear, bi-directional winds and low turbulence. APIA secured nearly $1M from the United States Department of Agriculture Rural Utilities Service Assistance to Rural Communities with Extremely High Energy Costs to install a 65kW wind turbine. The measured average power density and wind speed at Sand Point measured at 20m (66ft), are 424 W/m2 and 6.7 m/s (14.9 mph) respectively. Two 500kW Vestas turbines were installed and when fully integrated in 2012 are expected to provide a cost effective and clean source of electricity, reduce overall diesel fuel consumption estimated at 130,000 gallons/year and decrease air emissions associated with the consumption of diesel fuel. St. George Island has a Class 7 wind resource, which is superior for wind power development. The current strategy, led by Alaska Energy Authority, is to upgrade the St. George electrical distribution system and power plant. Avian studies in Nikolski

  15. Model of analysis of maximum loads in wind generators produced by extreme winds

    International Nuclear Information System (INIS)

    Herrera – Sánchez, Omar; Schellong, Wolfgang; González – Fernández, Vladimir

    2010-01-01

    The use of the wind energy by means of the wind turbines in areas of high risk of occurrence of Hurricanes comes being an important challenge for the designers of wind farm at world for some years. The wind generator is not usually designed to support this type of phenomena, for this reason the areas of high incidence of tropical hurricanes of the planning are excluded, that which, in occasions disables the use of this renewable source of energy totally, either because the country is very small, or because it coincides the area of more potential fully with that of high risk. To counteract this situation, a model of analysis of maxims loads has been elaborated taken place the extreme winds in wind turbines of great behavior. This model has the advantage of determining, in a chosen place, for the installation of a wind farm, the micro-areas with higher risk of wind loads above the acceptable for the standard classes of wind turbines. (author)

  16. Breezy Power: From Wind to Energy

    Science.gov (United States)

    Claymier, Bob

    2009-01-01

    This lesson combines the science concepts of renewable energy and producing electricity with the technology concepts of design, constraints, and technology's impact on the environment. Over five class periods, sixth-grade students "work" for a fictitious power company as they research wind as an alternative energy source and design and test a…

  17. Wind power plant

    Energy Technology Data Exchange (ETDEWEB)

    Caneghem, A.E. von

    1975-07-24

    The invention applies to a wind power plant in which the wind is used to drive windmills. The plant consists basically of a vertical tube with a lateral wind entrance opening with windmill on its lower end. On its upper end, the tube carries a nozzle-like top which increases the wind entering the tube by pressure decrease. The wind is thus made suitable for higher outputs. The invention is illustrated by constructional examples.

  18. Wind energy analysis system

    OpenAIRE

    2014-01-01

    M.Ing. (Electrical & Electronic Engineering) One of the most important steps to be taken before a site is to be selected for the extraction of wind energy is the analysis of the energy within the wind on that particular site. No wind energy analysis system exists for the measurement and analysis of wind power. This dissertation documents the design and development of a Wind Energy Analysis System (WEAS). Using a micro-controller based design in conjunction with sensors, WEAS measure, calcu...

  19. Wind power. [electricity generation

    Science.gov (United States)

    Savino, J. M.

    1975-01-01

    A historical background on windmill use, the nature of wind, wind conversion system technology and requirements, the economics of wind power and comparisons with alternative systems, data needs, technology development needs, and an implementation plan for wind energy are presented. Considerable progress took place during the 1950's. Most of the modern windmills feature a wind turbine electricity generator located directly at the top of their rotor towers.

  20. Wind Regimes in Complex Terrain of the Great Valley of Eastern Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Birdwell, Kevin R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2011-05-01

    This research was designed to provide an understanding of physical wind mechanisms within the complex terrain of the Great Valley of Eastern Tennessee to assess the impacts of regional air flow with regard to synoptic and mesoscale weather changes, wind direction shifts, and air quality. Meteorological data from 2008 2009 were analyzed from 13 meteorological sites along with associated upper level data. Up to 15 ancillary sites were used for reference. Two-step complete linkage and K-means cluster analyses, synoptic weather studies, and ambient meteorological comparisons were performed to generate hourly wind classifications. These wind regimes revealed seasonal variations of underlying physical wind mechanisms (forced channeled, vertically coupled, pressure-driven, and thermally-driven winds). Synoptic and ambient meteorological analysis (mixing depth, pressure gradient, pressure gradient ratio, atmospheric and surface stability) suggested up to 93% accuracy for the clustered results. Probabilistic prediction schemes of wind flow and wind class change were developed through characterization of flow change data and wind class succession. Data analysis revealed that wind flow in the Great Valley was dominated by forced channeled winds (45 67%) and vertically coupled flow (22 38%). Down-valley pressure-driven and thermally-driven winds also played significant roles (0 17% and 2 20%, respectively), usually accompanied by convergent wind patterns (15 20%) and large wind direction shifts, especially in the Central/Upper Great Valley. The behavior of most wind regimes was associated with detectable pressure differences between the Lower and Upper Great Valley. Mixing depth and synoptic pressure gradients were significant contributors to wind pattern behavior. Up to 15 wind classes and 10 sub-classes were identified in the Central Great Valley with 67 joined classes for the Great Valley at-large. Two-thirds of Great Valley at-large flow was defined by 12 classes. Winds

  1. A Virtual Class Calculus

    DEFF Research Database (Denmark)

    Ernst, Erik; Ostermann, Klaus; Cook, William Randall

    2006-01-01

    Virtual classes are class-valued attributes of objects. Like virtual methods, virtual classes are defined in an object's class and may be redefined within subclasses. They resemble inner classes, which are also defined within a class, but virtual classes are accessed through object instances...... model for virtual classes has been a long-standing open question. This paper presents a virtual class calculus, vc, that captures the essence of virtual classes in these full-fledged programming languages. The key contributions of the paper are a formalization of the dynamic and static semantics of vc...

  2. Wind power development field test project at Hirashima, Sakito-cho. Detailed wind characteristics survey; Sakitocho Hirashima ni okeru furyoku kaihatsu field test jigyo (fukyo seisa) hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-11-01

    A detailed wind characteristics survey was conducted at Hirashima, Sakito-cho, Nishisonogi-gun, Nagasaki Prefecture, on the assumption that a wind power generation system would be constructed. The survey was a 1-year project from October 1998 through September 1999, and wind characteristics such as the average wind speed, average wind direction, standard deviation of wind velocity, and the maximum instantaneous wind speed were observed. The observation point was fixed at 20m above ground, the minimum time unit for observation was 10 minutes, and the 10-minute average value was defined as the measured value. For the maximum instantaneous wind speed, the minimum time unit for observation was set to be 2 seconds. The yearly average wind speed was 7.1m/s and the maximum wind speed in the period was 37m/s. Winds came prevalently from N (13.9%), and then from NNE (13.3%), NW (12.2%), and NE (10.7%). The total wind direction occurrence rate involving the 4 directions was 50.1%. Turbulence intensity was 0.14 at wind speed 2.0m/s or more and 0.12 at wind speed 4.0m/s or more. Estimated wind turbine yearly operating factors of 77-87% were obtained using rated values of a 150kW, 300kW, and 750kW-class wind turbines. (NEDO)

  3. Extreme wind estimate for Hornsea wind farm

    DEFF Research Database (Denmark)

    Larsén, Xiaoli Guo

    The purpose of this study is to provide estimation of the 50-year winds of 10 min and 1-s gust value at hub height of 100 m, as well as the design parameter shear exponent for the Hornsea offshore wind farm. The turbulence intensity required for estimating the gust value is estimated using two...... approaches. One is through the measurements from the wind Doppler lidar, WindCube, which implies serious uncertainty, and the other one is through similarity theory for the atmospheric surface layer where the hub height is likely to belong to during strong storms. The turbulence intensity for storm wind...... strength is taken as 0.1. The shear exponents at several heights were calculated from the measurements. The values at 100 m are less than the limit given by IEC standard for all sectors. The 50-year winds have been calculated from various global reanalysis and analysis products as well as mesoscale models...

  4. Climatic wind tunnel for wind engineering tasks

    Czech Academy of Sciences Publication Activity Database

    Kuznetsov, Sergeii; Pospíšil, Stanislav; Král, Radomil

    2015-01-01

    Roč. 112, 2-B (2015), s. 303-316 ISSN 1897-628X R&D Projects: GA ČR(CZ) GA14-12892S Keywords : climatic tunnel * wind tunnel * atmospheric boundary layer * flow resistance * wind tunnel contraction Subject RIV: JM - Building Engineering https://suw.biblos.pk.edu.pl/resources/i5/i6/i6/i7/i6/r56676/KuznetsovS_ClimaticWind.pdf

  5. Wind Generation on Winnebago Tribal Lands

    Energy Technology Data Exchange (ETDEWEB)

    Multiple

    2009-09-30

    The Winnebago Wind Energy Study evaluated facility-scale, community-scale and commercial-scale wind development on Winnebago Tribal lands in northeastern Nebraska. The Winnebago Tribe of Nebraska has been pursuing wind development in various forms for nearly ten years. Wind monitoring utilizing loaned met towers from NREL took place during two different periods. From April 2001 to April 2002, a 20-meter met tower monitored wind data at the WinnaVegas Casino on the far eastern edge of the Winnebago reservation in Iowa. In late 2006, a 50-meter tower was installed, and subsequently monitored wind data at the WinnaVegas site from late 2006 through late 2008. Significant challenges with the NREL wind monitoring equipment limited the availability of valid data, but based on the available data, average wind speeds between 13.6 – 14.3 miles were indicated, reflecting a 2+/3- wind class. Based on the anticipated cost of energy produced by a WinnaVegas wind turbine, and the utility policies and rates in place at this time, a WinnaVegas wind project did not appear to make economic sense. However, if substantial grant funding were available for energy equipment at the casino site, and if either Woodbury REC backup rates were lower, or NIPCO was willing to pay more for wind power, a WinnaVegas wind project could be feasible. With funding remaining in the DOE-funded project budget,a number of other possible wind project locations on the Winnebago reservation were considered. in early 2009, a NPPD-owned met tower was installed at a site identified in the study pursuant to a verbal agreement with NPPD which provided for power from any ultimately developed project on the Western Winnebago site to be sold to NPPD. Results from the first seven months of wind monitoring at the Western Winnebago site were as expected at just over 7 meters per second at 50-meter tower height, reflecting Class 4 wind speeds, adequate for commercial development. If wind data collected in the remaining

  6. Wind Atlas for Egypt

    DEFF Research Database (Denmark)

    The results of a comprehensive, 8-year wind resource assessment programme in Egypt are presented. The objective has been to provide reliable and accurate wind atlas data sets for evaluating the potential wind power output from large electricityproducing wind turbine installations. The regional wind...... climates of Egypt have been determined by two independent methods: a traditional wind atlas based on observations from more than 30 stations all over Egypt, and a numerical wind atlas based on long-term reanalysis data and a mesoscale model (KAMM). The mean absolute error comparing the two methods is about...... 10% for two large-scale KAMM domains covering all of Egypt, and typically about 5% for several smaller-scale regional domains. The numerical wind atlas covers all of Egypt, whereas the meteorological stations are concentrated in six regions. The Wind Atlas for Egypt represents a significant step...

  7. Wind Atlas for Egypt

    DEFF Research Database (Denmark)

    Mortensen, Niels Gylling; Said Said, Usama; Badger, Jake

    2006-01-01

    The results of a comprehensive, 8-year wind resource assessment programme in Egypt are presented. The objective has been to provide reliable and accurate wind atlas data sets for evaluating the potential wind power output from large electricityproducing wind turbine installations. The regional wind...... climates of Egypt have been determined by two independent methods: a traditional wind atlas based on observations from more than 30 stations all over Egypt, and a numerical wind atlas based on long-term reanalysis data and a mesoscale model (KAMM). The mean absolute error comparing the two methods is about...... 10% for two large-scale KAMM domains covering all of Egypt, and typically about 5% for several smaller-scale regional domains. The numerical wind atlas covers all of Egypt, whereas the meteorological stations are concentrated in six regions. The Wind Atlas for Egypt represents a significant step...

  8. Optimal application of climate data to the development of design wind speeds

    DEFF Research Database (Denmark)

    Kruger, Andries C.; Retief, Johan V.; Goliger, Adam M.

    2014-01-01

    Africa (WASA project) focuses, amongst others, on the development of a Regional Extreme Wind Climate (REWC) for South Africa. Wind farms are planned for areas with relatively strong and sustained winds, with wind turbines classed according to their suitability for different wind conditions. The REWC...... statistics are used during the construction and design phase to make assumptions about the local strong wind climate that the wind turbines will be exposed to, with the local environment and topography as additional input. The simultaneous development of the REWC and revision of the extreme wind statistics...... of South Africa created an opportunity to bring together a range of expertise that could contribute to the optimal development of design wind speed information. These include the knowledge of the statistical extraction of extreme wind observations from reanalysis and model data, the quality control...

  9. Final Project Report, Bristol Bay Native Corporation Wind and Hydroelectric Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Vaught, Douglas J.

    2007-03-31

    The Bristol Bay Native Corporation (BBNC) grant project focused on conducting nine wind resource studies in eight communities in the Bristol Bay region of southwest Alaska and was administered as a collaborative effort between BBNC, the Alaska Energy Authority, Alaska Village Electric Cooperative, Nushagak Electric Cooperative (NEC), Naknek Electric Association (NEA), and several individual village utilities in the region. BBNC’s technical contact and the project manager for this study was Douglas Vaught, P.E., of V3 Energy, LLC, in Eagle River, Alaska. The Bristol Bay region of Alaska is comprised of 29 communities ranging in size from the hub community of Dillingham with a population of approximately 3,000 people, to a few Native Alaska villages that have a few tens of residents. Communities chosen for inclusion in this project were Dillingham, Naknek, Togiak, New Stuyahok, Kokhanok, Perryville, Clark’s Point, and Koliganek. Selection criteria for conduction of wind resource assessments in these communities included population and commercial activity, utility interest, predicted Class 3 or better wind resource, absence of other sources of renewable energy, and geographical coverage of the region. Beginning with the first meteorological tower installation in October 2003, wind resource studies were completed at all sites with at least one year, and as much as two and a half years, of data. In general, the study results are very promising for wind power development in the region with Class 6 winds measured in Kokhanok; Class 4 winds in New Stuyahok, Clark’s Point, and Koliganek; Class 3 winds in Dillingham, Naknek, and Togiak; and Class 2 winds in Perryville. Measured annual average wind speeds and wind power densities at the 30 meter level varied from a high of 7.87 meters per second and 702 watts per square meter in Kokhanok (Class 6 winds), to a low of 4.60 meters per second and 185 watts per square meter in Perryville (Class 2 winds).

  10. Large superconducting wind turbine generators

    DEFF Research Database (Denmark)

    Abrahamsen, Asger Bech; Magnusson, Niklas; Jensen, Bogi Bech

    2012-01-01

    and the rotation speed is lowered in order to limit the tip speed of the blades. The ability of superconducting materials to carry high current densities with very small losses might facilitate a new class of generators operating with an air gap flux density considerably higher than conventional generators...... and thereby having a smaller size and weight [1, 2]. A 5 MW superconducting wind turbine generator forms the basics for the feasibility considerations, particularly for the YBCO and MgB2 superconductors entering the commercial market. Initial results indicate that a 5 MW generator with an active weight of 34...

  11. 75 FR 23263 - Alta Wind I, LLC; Alta Wind II, LLC; Alta Wind III, LLC; Alta Wind IV, LLC; Alta Wind V, LLC...

    Science.gov (United States)

    2010-05-03

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL10-62-000] Alta Wind I, LLC; Alta Wind II, LLC; Alta Wind III, LLC; Alta Wind IV, LLC; Alta Wind V, LLC; Alta Wind VI, LLC; Alta Wind VII, LLC; Alta Wind VIII, LLC; Alta Windpower Development, LLC; TGP Development Company, LLC...

  12. 77 FR 29633 - Alta Wind VII, LLC, Alta Wind IX, LLC, Alta Wind X, LLC, Alta Wind XI, LLC, Alta Wind XII, LLC...

    Science.gov (United States)

    2012-05-18

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL12-68-000] Alta Wind VII, LLC, Alta Wind IX, LLC, Alta Wind X, LLC, Alta Wind XI, LLC, Alta Wind XII, LLC, Alta Wind XIII, LLC, Alta Wind XIV, LLC, Alta Wind XV, LLC, Alta Windpower Development, LLC, TGP Development Company, LLC...

  13. Wind energy information guide

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    This book is divided into nine chapters. Chapters 1--8 provide background and annotated references on wind energy research, development, and commercialization. Chapter 9 lists additional sources of printed information and relevant organizations. Four indices provide alphabetical access to authors, organizations, computer models and design tools, and subjects. A list of abbreviations and acronyms is also included. Chapter topics include: introduction; economics of using wind energy; wind energy resources; wind turbine design, development, and testing; applications; environmental issues of wind power; institutional issues; and wind energy systems development.

  14. Arctic wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Peltola, E. [Kemijoki Oy (Finland); Holttinen, H.; Marjaniemi, M. [VTT Energy, Espoo (Finland); Tammelin, B. [Finnish Meteorological Institute, Helsinki (Finland)

    1998-12-31

    Arctic wind energy research was aimed at adapting existing wind technologies to suit the arctic climatic conditions in Lapland. Project research work included meteorological measurements, instrument development, development of a blade heating system for wind turbines, load measurements and modelling of ice induced loads on wind turbines, together with the development of operation and maintenance practices in arctic conditions. As a result the basis now exists for technically feasible and economically viable wind energy production in Lapland. New and marketable products, such as blade heating systems for wind turbines and meteorological sensors for arctic conditions, with substantial export potential, have also been developed. (orig.)

  15. Arctic wind energy

    International Nuclear Information System (INIS)

    Peltola, E.; Holttinen, H.; Marjaniemi, M.; Tammelin, B.

    1998-01-01

    Arctic wind energy research was aimed at adapting existing wind technologies to suit the arctic climatic conditions in Lapland. Project research work included meteorological measurements, instrument development, development of a blade heating system for wind turbines, load measurements and modelling of ice induced loads on wind turbines, together with the development of operation and maintenance practices in arctic conditions. As a result the basis now exists for technically feasible and economically viable wind energy production in Lapland. New and marketable products, such as blade heating systems for wind turbines and meteorological sensors for arctic conditions, with substantial export potential, have also been developed. (orig.)

  16. Wind power today

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    This publication highlights initiatives of the US DOE`s Wind Energy Program. 1997 yearly activities are also very briefly summarized. The first article describes a 6-megawatt wind power plant installed in Vermont. Another article summarizes technical advances in wind turbine technology, and describes next-generation utility and small wind turbines in the planning stages. A village power project in Alaska using three 50-kilowatt turbines is described. Very brief summaries of the Federal Wind Energy Program and the National Wind Technology Center are also included in the publication.

  17. Wind Power Career Chat

    Energy Technology Data Exchange (ETDEWEB)

    L. Flowers

    2011-01-01

    This document will teach students about careers in the wind energy industry. Wind energy, both land-based and offshore, is expected to provide thousands of new jobs in the next several decades. Wind energy companies are growing rapidly to meet America's demand for clean, renewable, and domestic energy. These companies need skilled professionals. Wind power careers will require educated people from a variety of areas. Trained and qualified workers manufacture, construct, operate, and manage wind energy facilities. The nation will also need skilled researchers, scientists, and engineers to plan and develop the next generation of wind energy technologies.

  18. Wind energy potential analysis in Al-Fattaih-Darnah

    Energy Technology Data Exchange (ETDEWEB)

    Tjahjana, Dominicus Danardono Dwi Prija, E-mail: danar1405@gmail.com; Salem, Abdelkarim Ali, E-mail: keemsalem@gmail.com; Himawanto, Dwi Aries, E-mail: dwiarieshimawanto@gmail.com [University of Sebelas Maret, Jl. Ir. Sutami No. 36 A, Surakarta, Indonesia 57126 (Indonesia)

    2016-03-29

    In this paper the wind energy potential in Al-Fattaih-Darnah, Libya, had been studied. Wind energy is very attractive because it can provide a clean and renewable energy. Due mostly to the uncertainty caused by the chaotic characteristics of wind near the earth’s surface, wind energy characteristic need to be investigated carefully in order to get consistent power generation. This investigation was based on one year wind data measured in 2003. As a result of the analysis, wind speed profile and wind energy potential have been developed. The wind energy potential of the location is looked very promising to generate electricity. The annual wind speed of the site is 8.21 m/s and the wind speed carrying maximum energy is 7.97 m/s. The annual power density of the site is classified into class 3. The Polaris P50-500 wind turbine can produce 768.39 M Wh/year and has capacity factor of 17.54%.

  19. RxClass

    Data.gov (United States)

    U.S. Department of Health & Human Services — The RxClass Browser is a web application for exploring and navigating through the class hierarchies to find the RxNorm drug members associated with each class....

  20. Evolution of wind towards wind turbine

    NARCIS (Netherlands)

    Giyanani, A.H.; Bierbooms, W.A.A.M.; Van Bussel, G.J.W.

    2015-01-01

    Remote sensing of the atmospheric variables with the use of LiDAR is a relatively new technology field for wind resource assessment in wind energy. The validation of LiDAR measurements and comparisons is of high importance for further applications of the data.

  1. Urban Wind Energy

    DEFF Research Database (Denmark)

    Beller, Christina

    important for the implementation of wind energy conversion systems are the macro and micro wind climate, the siting within a micro wind climate and the choice of a wind turbine model most appropriate for the selected site. In the frame of this work, all these important elements are analyzed and a row......New trends e.g. in architecture and urban planning are to reduce energy needs. Several technologies are employed to achieve this, and one of the technologies, not new as such, is wind energy. Wind turbines are installed in cities, both by companies and private persons on both old and new buildings....... However, an overview of the energy content of the wind in cities and how consequently turbines shall be designed for such wind climates is lacking. The objective of the present work is to deliver an objective and fundamental overview of the social, practical and physical conditions relevant...

  2. Leadership Team | Wind | NREL

    Science.gov (United States)

    Leadership Team Leadership Team Learn more about the expertise and technical skills of the wind Initiative and provides leadership in the focus areas of high-fidelity modeling, wind power plant controls

  3. Danish Wind Power

    DEFF Research Database (Denmark)

    Lund, Henrik; Hvelplund, Frede; Østergaard, Poul Alberg

    In a normal wind year, Danish wind turbines generate the equivalent of approx. 20 percent of the Danish electricity demand. This paper argues that only approx. 1 percent of the wind power production is exported. The rest is used to meet domestic Danish electricity demands. The cost of wind power...... misleading. The cost of CO2 reduction by use of wind power in the period 2004-2008 was only 20 EUR/ton. Furthermore, the Danish wind turbines are not paid for by energy taxes. Danish wind turbines are given a subsidy via the electricity price which is paid by the electricity consumers. In the recent years...... is paid solely by the electricity consumers and the net influence on consumer prices was as low as 1-3 percent on average in the period 2004-2008. In 2008, the net influence even decreased the average consumer price, although only slightly. In Denmark, 20 percent wind power is integrated by using both...

  4. Superconducting Wind Turbine Generators

    Directory of Open Access Journals (Sweden)

    Yunying Pan

    2016-08-01

    Full Text Available Wind energy is well known as a renewable energy because its clean and less polluted characteristic, which is the foundation of development modern wind electricity. To find more efficient wind turbine is the focus of scientists around the world. Compared from conventional wind turbines, superconducting wind turbine generators have advantages at zero resistance, smaller size and lighter weight. Superconducting wind turbine will inevitably become the main trends in this area. This paper intends to introduce the basic concept and principle of superconductivity, and compare form traditional wind turbine to obtain superiority, then to summary three proposed machine concept.While superconductivity have difficulty  in modern technology and we also have proposed some challenges in achieving superconducting wind turbine finally.

  5. An evaluation of the WindEye wind lidar

    DEFF Research Database (Denmark)

    Dellwik, Ebba; Sjöholm, Mikael; Mann, Jakob

    Prevision of the wind field by remote sensing wind lidars has the potential to improve the performance of wind turbines. The functionality of a WindEye lidar developed by Windar Photonics A/S (Denmark) for the wind energy market was tested in a two months long field experiment. The WindEye sensor...... with a high accuracy during the whole campaign....

  6. Wind Power Utilization Guide.

    Science.gov (United States)

    1981-09-01

    The expres- sions for the rotor torque for a Darrieus machine can be found in Reference 4.16. The Darrieus wind turbine offers the following... turbine generators, wind -driven turbines , power conditioning, wind power, energy conservation, windmills, economic ana \\sis. 20 ABS 1"ACT (Conti,on... turbines , power conditioning requirements, siting requirements, and the economics of wind power under different conditions. Three examples are given to

  7. Wind electric power generation

    International Nuclear Information System (INIS)

    Koch, M.K.; Wind, L.; Canter, B.; Moeller, T.

    2001-01-01

    The monthly statistics of wind electric power generation in Denmark are compiled from information given by the owners of the private wind turbines. For each wind turbine the name of the site and of the type of turbine is given, and the power generation data are given for the month in question together with the total production in 1999 and 2000. Also the data of operation start are given. On the map of Denmark the sites of the wind turbines are marked. (CLS)

  8. Wind electric power generation

    International Nuclear Information System (INIS)

    Koch, M. K.; Wind, L.; Canter, B.; Moeller, T.

    2002-01-01

    The monthly statistics of wind electric power generation in Denmark are compiled from information given by the owners of the private wind turbines. For each wind turbine the name of the site and of the type of turbine is given, and the power generation data are given for the month in question together with the total production in 2000 and 2001. Also the data of operation start are given. On the map of Denmark the sites of the wind turbines are marked. (SM)

  9. Turbulence and wind turbines

    DEFF Research Database (Denmark)

    Brand, Arno J.; Peinke, Joachim; Mann, Jakob

    2011-01-01

    The nature of turbulent flow towards, near and behind a wind turbine, the effect of turbulence on the electricity production and the mechanical loading of individual and clustered wind turbines, and some future issues are discussed.......The nature of turbulent flow towards, near and behind a wind turbine, the effect of turbulence on the electricity production and the mechanical loading of individual and clustered wind turbines, and some future issues are discussed....

  10. The Irish Wind Atlas

    Energy Technology Data Exchange (ETDEWEB)

    Watson, R [Univ. College Dublin, Dept. of Electronic and Electrical Engineering, Dublin (Ireland); Landberg, L [Risoe National Lab., Meteorology and Wind Energy Dept., Roskilde (Denmark)

    1999-03-01

    The development work on the Irish Wind Atlas is nearing completion. The Irish Wind Atlas is an updated improved version of the Irish section of the European Wind Atlas. A map of the irish wind resource based on a WA{sup s}P analysis of the measured data and station description of 27 measuring stations is presented. The results of previously presented WA{sup s}P/KAMM runs show good agreement with these results. (au)

  11. Market Suitability and Performance Tradeoffs Offered by Commercial Wind Turbines across Differing Wind Regimes

    Directory of Open Access Journals (Sweden)

    Souma Chowdhury

    2016-05-01

    Full Text Available The suitability of turbine configurations to different wind resources has been traditionally restricted to considering turbines operating as standalone entities. In this paper, a framework is thus developed to investigate turbine suitability in terms of the minimum cost of energy offered when operating as a group of optimally-micro-sited turbines. The four major steps include: (i characterizing the geographical variation of wind regimes in the onshore U.S. market; (ii determining the best performing turbines for different wind regimes through wind farm layout optimization; (iii developing a metric to quantify the expected market suitability of available turbine configurations; and (iv exploring the best tradeoffs between the cost and capacity factor yielded by these turbines. One hundred thirty one types of commercial turbines offered by major global manufacturers in 2012 are considered for selection. It is found that, in general, higher rated power turbines with medium tower heights are the most favored. Interestingly, further analysis showed that “rotor diameter/hub height” ratios greater than 1.1 are the least attractive for any of the wind classes. It is also observed that although the “cost-capacity factor” tradeoff curve expectedly shifted towards higher capacity factors with increasing wind class, the trend of the tradeoff curve remained practically similar.

  12. Wind and Yaw correlation

    DEFF Research Database (Denmark)

    Kock, Carsten Weber; Vesth, Allan

    The report describes measurements carried out on a given turbine and period. The measurements are carried out in accordance to Ref. [1]. A comparison between wind speed and wind direction on the met mast and nacelle wind speed and yaw direction is made in accordance to Ref. [2] and the results...

  13. Offshore wind energy developments

    DEFF Research Database (Denmark)

    Stolpe, Mathias; Buhl, Thomas; Sumer, B. Mutlu

    2014-01-01

    This chapter will give a brief overview of a few of the activities within offshore wind energy research, specifically 1) Support structure optimization, 2) Blade coatings for wind turbines; 3) Scour protection of foundations, 4) Offshore HVDC and 5) Offshore wind services....

  14. Wind power outlook 2006

    Energy Technology Data Exchange (ETDEWEB)

    anon.

    2006-04-15

    This annual brochure provides the American Wind Energy Association's up-to-date assessment of the wind industry in the United States. This 2006 general assessment shows positive signs of growth, use and acceptance of wind energy as a vital component of the U.S. energy mix.

  15. Modelling Wind for Wind Farm Layout Optimization Using Joint Distribution of Wind Speed and Wind Direction

    DEFF Research Database (Denmark)

    Feng, Ju; Shen, Wen Zhong

    2015-01-01

    Reliable wind modelling is of crucial importance for wind farm development. The common practice of using sector-wise Weibull distributions has been found inappropriate for wind farm layout optimization. In this study, we propose a simple and easily implementable method to construct joint distribu...

  16. Canadian small wind market

    International Nuclear Information System (INIS)

    Moorhouse, E.

    2010-01-01

    This PowerPoint presentation discussed initiatives and strategies adopted by the Canadian Wind Energy Association (CanWEA) to support the development of Canada's small wind market. The general public has shown a significant interest in small wind projects of 300 kW. Studies have demonstrated that familiarity and comfort with small wind projects can help to ensure the successful implementation of larger wind projects. Small wind markets include residential, farming and commercial, and remote community applications. The results of CanWEA market survey show that the small wind market grew by 78 percent in 2008 over 2007, and again in 2009 by 32 percent over 2008. The average turbine size is 1 kW. A total of 11,000 turbines were purchased in 2007 and 2008. Global small wind market growth increased by 110 percent in 2008, and the average turbine size was 2.4 kW. Eighty-seven percent of the turbines made by Canadian mid-size wind turbine manufacturers are exported, and there is now a significant risk that Canada will lose its competitive advantage in small wind manufacturing as financial incentives have not been implemented. American and Canadian-based small wind manufacturers were listed, and small wind policies were reviewed. The presentation concluded with a set of recommendations for future incentives, educational programs and legislation. tabs., figs.

  17. Wind Power Now!

    Science.gov (United States)

    Inglis, David Rittenhouse

    1975-01-01

    The government promotes and heavily subsidizes research in nuclear power plants. Federal development of wind power is slow in comparison even though much research with large wind-electric machines has already been conducted. Unless wind power programs are accelerated it will not become a major energy alternative to nuclear power. (MR)

  18. Power from the Wind

    Science.gov (United States)

    Roman, Harry T.

    2004-01-01

    Wind energy is the fastest-growing renewable energy source in the world. Over the last 20 years, the wind industry has done a very good job of engineering machines, improving materials, and economies of production, and making this energy source a reality. Like all renewable energy forms, wind energy's successful application is site specific. Also,…

  19. Wind power soars

    Energy Technology Data Exchange (ETDEWEB)

    Flavin, C. [Worldwatch Inst., Washington, DC (United States)

    1996-12-31

    Opinions on the world market for wind power are presented in this paper. Some data for global wind power generating capacity are provided. European and other markets are discussed individually. Estimated potential for wind power is given for a number of countries. 3 figs.

  20. Wind and Yaw correlation

    DEFF Research Database (Denmark)

    Kock, Carsten Weber; Vesth, Allan

    The report describes measurements carried out on a given turbine and period. The measurements are carried out in accordance to Ref. [1]. A comparison between wind speed and wind direction on the met mast and nacelle wind speed and yaw direction is made in accordance to Ref. [2] and the results ar...

  1. Wind and Yaw correlation

    DEFF Research Database (Denmark)

    Federici, Paolo; Kock, Carsten Weber

    The report describes measurements carried out on a given turbine and period. The measurements are carried out in accordance to Ref. [1]. A comparison between wind speed and wind direction on the met mast and nacelle wind speed and yaw direction is made in accordance to Ref. [2] and the results...... are presented on graphs and in a table....

  2. Denmark Wind Energy Programme

    DEFF Research Database (Denmark)

    Shen, Wen Zhong

    2015-01-01

    In this chapter, a summary of some ongoing wind energy projects in Denmark is given. The research topics comprise computational model development, wind turbine (WT) design, low-noise airfoil and blade design, control device development, wake modelling and wind farm layout optimization....

  3. Wind: French revolutions

    International Nuclear Information System (INIS)

    Jones, C.

    2006-01-01

    Despite having the second best wind resources in Europe after the UK, the wind industry in France lags behind its European counterparts with just 6 W of installed wind capacity per person. The electricity market in France is dominated by the state-owned Electricite de France (EdF) and its nuclear power stations. However, smaller renewable generators are now in theory allowed access to the market and France has transposed the EU renewables directive into national law. The French governement has set a target of generating 10,000 MW of renewable capacity by 2010. The announcement of an increased feed-in tariff and the introduction of 'development zones' (ZDEs) which could allow fast-tracking of planning for wind projects are also expected to boost wind projects. But grid access and adminstrative burdens remain major barriers. In addition, French politicians and local authorities remain committed to nuclear, though encouraged by the European Commission, wind is beginning to gain acceptance; some 325 wind farms (representing 1557 MW of capacity) were approved between February 2004 and January 2005. France is now regarded by the international wind energy sector as a target market. One of France's leading independent wind developers and its only listed wind company, Theolia, is expected to be one of the major beneficiaries of the acceleration of activity in France, though other companies are keen to maximise the opportunities for wind. France currently has only one indigenous manufacturer of wind turbines, but foreign suppliers are winning orders

  4. Wind energy in Mediterranean Basin

    International Nuclear Information System (INIS)

    Gaudiosi, G.

    1991-01-01

    In its examination of wind energy potential in the Mediterranean Basin, this paper provides brief notes on the Basin's geography; indicates power production and demand; describes the area's wind characteristics and wind monitoring activities; illustrates wind velocity distributions; estimates local wind power production potential; reviews the Basin's wind energy marketing situation and each bordering country's wind energy programs; surveys installed wind energy farms; and assesses national research and commercialization efforts

  5. Offshore wind resource estimation for wind energy

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Badger, Merete; Mouche, A.

    2010-01-01

    Satellite remote sensing from active and passive microwave instruments is used to estimate the offshore wind resource in the Northern European Seas in the EU-Norsewind project. The satellite data include 8 years of Envisat ASAR, 10 years of QuikSCAT, and 23 years of SSM/I. The satellite observati......Satellite remote sensing from active and passive microwave instruments is used to estimate the offshore wind resource in the Northern European Seas in the EU-Norsewind project. The satellite data include 8 years of Envisat ASAR, 10 years of QuikSCAT, and 23 years of SSM/I. The satellite...... observations are compared to selected offshore meteorological masts in the Baltic Sea and North Sea. The overall aim of the Norsewind project is a state-of-the-art wind atlas at 100 m height. The satellite winds are all valid at 10 m above sea level. Extrapolation to higher heights is a challenge. Mesoscale...... modeling of the winds at hub height will be compared to data from wind lidars observing at 100 m above sea level. Plans are also to compare mesoscale model results and satellite-based estimates of the offshore wind resource....

  6. Wind power plant

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, G

    1975-11-20

    A wind power plant is proposed suitable for electicity generation or water pumping. This plant is to be self-adjusting to various wind velocities and to be kept in operation even during violent storms. For this purpose the mast, carrying the wind rotor and pivotable around a horizontal axis is tiltable and equipped with a wind blind. Further claims contain various configurations of the tilting base resp. the cut in of an elastic link, the attachment and design of the wind blind as well as the constructive arrangement of one or more dynamos.

  7. Visualization of wind farms

    International Nuclear Information System (INIS)

    Pahlke, T.

    1994-01-01

    With the increasing number of wind energy installations the visual impact of single wind turbines or wind parks is a growing problem for landscape preservation, leading to resistance of local authorities and nearby residents against wind energy projects. To increase acceptance and to form a basis for planning considerations, it is necessary to develop instruments for the visualization of planned wind parks, showing their integration in the landscape. Photorealistic montages and computer animation including video sequences may be helpful in 'getting the picture'. (orig.)

  8. Wind electric power generation

    International Nuclear Information System (INIS)

    Groening, B.; Koch, M.; Canter, B.; Moeller, T.

    1995-01-01

    The monthly statistics of wind electric power generation in Denmark are compiled from information given by the owners of private wind turbines. For each wind turbine the name of the site and of the type of turbine is given, and the power generation data are given for the month in question together with the total production in 1988 and 1989. Also the data of operation start are given. On the map of Denmark the sites of the wind turbines are marked. The statistics for December 1994 comprise 2328 wind turbines

  9. Potentials of wind power

    International Nuclear Information System (INIS)

    Bezrukikh, P.P.; Bezrukikh, P.P.

    2000-01-01

    The ecological advantages of the wind power facilities (WPF) are considered. The possibilities of small WPF, generating the capacity from 40 W up to 10 kW, are discussed. The basic technical data on the national and foreign small WPF are presented. The combined wind power systems are considered. Special attention is paid to the most perspective wind-diesel systems, which provide for all possible versions of the electro-power supply. Useful recommendations and information on the wind power engineering are given for those, who decided to build up a wind facility [ru

  10. Mapping Wind Energy Controversies

    DEFF Research Database (Denmark)

    Munk, Anders Kristian

    As part the Wind2050 project funded by the Danish Council for Strategic Research we have mapped controversies on wind energy as they unfold online. Specifically we have collected two purpose built datasets, a web corpus containing information from 758 wind energy websites in 6 different countries......, and a smaller social media corpus containing information from 14 Danish wind energy pages on Facebook. These datasets have been analyzed to answer questions like: How do wind proponents and opponents organize online? Who are the central actors? And what are their matters of concern? The purpose of this report...

  11. Wind energy systems

    International Nuclear Information System (INIS)

    Richardson, R.D.; McNerney, G.M.

    1993-01-01

    Wind energy has matured to a level of development where it is ready to become a generally accepted utility generation technology. A brief discussion of this development is presented, and the operating and design principles are discussed. Alternative designs for wind turbines and the tradeoffs that must be considered are briefly compared. Development of a wind energy system and the impacts on the utility network including frequency stability, voltage stability, and power quality are discussed. The assessment of wind power station economics and the key economic factors that determine the economic viability of a wind power plant are presented

  12. Low Wind Speed Turbine Developments in Convoloid Gearing: Final Technical Report, June 2005 - October 2008

    Energy Technology Data Exchange (ETDEWEB)

    Genesis Partners LP

    2010-08-01

    This report presents the results of a study conducted by Genesis Partners LP as part of the United States Department of Energy Wind Energy Research Program to develop wind technology that will enable wind systems to compete in regions having low wind speeds. The purpose of the program is to reduce the cost of electricity from large wind systems in areas having Class 4 winds to 3 cents per kWh for onshore systems or 5 cents per kWh for offshore systems. This work builds upon previous activities under the WindPACT project, the Next Generation Turbine project, and Phase I of the Low Wind Speed Turbine (LWST) project. This project is concerned with the development of more cost-effective gearing for speed increasers for wind turbines.

  13. Wind power report Germany 2014

    International Nuclear Information System (INIS)

    Rohrig, Kurt

    2015-01-01

    Record year 2014. In Germany, the expansion figures attained were so high on land and at sea that the overall new installation figure of 5,188 MW surpassed the previous maximum (from 2002) by more than 60%. With an overall capacity of 39,259 MW, for the first time, wind energy in Germany covers 9.7% of gross power consumption. On the global scale a capacity of more than 51,000 MW has been added - another record high for wind energy installations. Power mix. At 161 TWh, renewable energies in Germany covered 27.8% of gross power consumption and provided for the first time more energy than any other energy source. Coming into force of the new REA in August 2014, modified support schemes caused the expansion of biogas plants and large-scale PV installations to falter. The record expansion seen for wind energy can be interpreted as a pull-forward effect due to the tender procedures coming into force in 2017. Grid integration. Loss of production caused by feed-in management measures rose by 44% to 555 GWh as compared to 2012. Wind turbines were affected in 87% of cases but the impact on PV installations is increasing. Power generation must be more flexible and grids expanded to limit loss of production. Of the 23 expansion projects (1,887 km) in the Electricity Grid Expansion Act, just a quarter of them had been realized by the end of 2014 (463 km). In the preliminary analysis results for the 2014 grid development plan, the extent of grid upgrading and conversion was 3050 km. Offshore, the HelWin 1 grid link with a capacity of 580 MW went online. SylWin 1 and BorWin 2, with a total capacity of 1660 MW, are currently being tested in a trial. In the preliminary analysis results for the 2014 offshore grid development plan, grid connections having an overall capacity of 10.3 GW are planned. Onshore. 2014 saw a total of 44 different turbine types installed in Germany. For the first time, virtually the same number of turbines were added in the 3-4 MW class, as in the 2-3 MW

  14. Wind Tunnel Measurements at LM Wind Power

    DEFF Research Database (Denmark)

    Bertagnolio, Franck

    2012-01-01

    This section presents the results obtained during the experimental campaign that was conducted in the wind tunnel at LM Wind Power in Lunderskov from August 16th to 26th, 2010. The goal of this study is to validate the so-called TNO trailing edge noise model through measurements of the boundary...... layer turbulence characteristics and the far-field noise generated by the acoustic scattering of the turbulent boundary layer vorticies as they convect past the trailing edge. This campaign was conducted with a NACA0015 airfoil section that was placed in the wind tunnel section. It is equipped with high...

  15. Wind energy in Europe

    International Nuclear Information System (INIS)

    Evans, L.C.

    1992-01-01

    Wind energy should be an important part of the energy supply mix, both at home and abroad, to provide cleaner air and a more stable fuel supply. Not only can wind energy contribute to solving complex global issues, it also can provide a large market for American technological leadership. Even though utilities are paying more attention to wind in a number of states, there are no plans for major installations of wind power plants in the United States. At the same time, European nations have developed aggressive wind energy development programs, including both ambitious research and development efforts and market incentives. Many countries recognize the importance of the clean energy provided by wind technology and are taking steps to promote their fledgling domestic industries. The emphasis on market incentives is starting to pay off. In 1991, European utilities and developers installed nearly twice as much wind capacity as Americans did. In 1992 the gap will be even greater. This article reviews aggressive incentives offered by European governments to boost their domestic wind industries at home and abroad in this almost $1 billion per year market. By offering substantial incentives - considerably more than the American Wind Energy Association (AWEA) is proposing - European nations are ensuring dramatic near-term wind energy development and are taking a major step toward dominating the international wind industry of the 21st century

  16. Wind integration in Alberta

    International Nuclear Information System (INIS)

    Frost, W.

    2007-01-01

    This presentation described the role of the Alberta Electric System Operator (AESO) for Alberta's interconnected electric system with particular reference to wind integration in Alberta. The challenges of wind integration were discussed along with the requirements for implementing the market and operational framework. The AESO is an independent system operator that directs the reliable operation of Alberta's power grid; develops and operates Alberta's real-time wholesale energy market to promote open competition; plans and develops the province's transmission system to ensure reliability; and provides transmission system access for both generation and load customers. Alberta has over 280 power generating station, with a total generating capacity of 11,742 MW, of which 443 is wind generated. Since 2004, the AESO has been working with industry on wind integration issues, such as operating limits, need for mitigation measures and market rules. In April 2006, the AESO implemented a temporary 900 MW reliability threshold to ensure reliability. In 2006, a Wind Forecasting Working Group was created in collaboration with industry and the Canadian Wind Energy Association in an effort to integrate as much wind as is feasible without compromising the system reliability or the competitive operation of the market. The challenges facing wind integration include reliability issues; predictability of wind power; the need for dispatchable generation; transmission upgrades; and, defining a market and operational framework for the large wind potential in Alberta. It was noted that 1400 MW of installed wind energy capacity can be accommodated in Alberta with approved transmission upgrades. figs

  17. Wind power takes over

    International Nuclear Information System (INIS)

    2002-01-01

    All over the industrialized world concentrated efforts are being made to make wind turbines cover some of the energy demand in the coming years. There is still a long way to go, however, towards a 'green revolution' as far as energy is concerned, for it is quite futile to use wind power for electric heating. The article deals with some of the advantages and disadvantages of developing wind power. In Norway, for instance, environmentalists fear that wind power plants along the coast may have serious consequences for the stocks of white-tailed eagle and golden eagle. An other factor that delays the large-scale application of wind power in Norway is the low price of electricity. Some experts, however, maintain that wind power may already compete with new hydroelectric power of intermediate cost. The investment costs are expected to go down with one third by 2020, when wind power may be the most competitive energy source to utilize

  18. Wind energy conversion system

    Science.gov (United States)

    Longrigg, Paul

    1987-01-01

    The wind energy conversion system includes a wind machine having a propeller connected to a generator of electric power, the propeller rotating the generator in response to force of an incident wind. The generator converts the power of the wind to electric power for use by an electric load. Circuitry for varying the duty factor of the generator output power is connected between the generator and the load to thereby alter a loading of the generator and the propeller by the electric load. Wind speed is sensed electro-optically to provide data of wind speed upwind of the propeller, to thereby permit tip speed ratio circuitry to operate the power control circuitry and thereby optimize the tip speed ratio by varying the loading of the propeller. Accordingly, the efficiency of the wind energy conversion system is maximized.

  19. Estonian wind climate

    International Nuclear Information System (INIS)

    Kull, Ain

    1999-01-01

    Estonia is situated on the eastern coast of the Baltic Sea. This is a region with intensive cyclonic activity and therefore with a relatively high mean wind speed. Atmospheric circulation and its seasonal variation determine the general character of the Estonian wind regime over the Atlantic Ocean and Eurasia. However, the Baltic sea itself is a very important factor affecting wind climate, it has an especially strong influence on the wind regime in costal areas. The mean energy density (W/m 2 ) is a wind energy characteristic that is proportional to the third power of wind speed and describes energy available in a flow of air through a unit area. The mean energy density is a characteristic which has practical importance in regional assessment of snowdrift, storm damage and wind energy

  20. Extreme winds in Denmark

    DEFF Research Database (Denmark)

    Kristensen, L.; Rathmann, O.; Hansen, S.O.

    2000-01-01

    (Technical Report, Danish Technical press, 1970) and by Abild (Technical Report R-522 (EN), Riso National Laboratory, 1994). A short discussion of the wind storm on the 3rd of December 1999 is included. It is demonstrated how the data can be applied to non-standard situations where the roughness length......Wind-speed data from four sites in Denmark have been analyzed in order to obtain estimates of the basic wind velocity, defined as the 50 yr wind speed (10 min averages) under standard conditions, i.e., 10 m over a homogeneous terrain with the roughness length 0.05 m, The sites are Skjern (15 yr......), Kegnaes (7 yr), Sprogo (20 yr), and Tystofte (16 yr). The measured data are wind speed, wind direction, temperature and pressure. The wind records are cleaned for terrain effects by means of WASP (Mortensew ct al., Technical Report I-666 (EN), Riso National Laboratory, 1993. Vol. 2. User's Guide...

  1. Wind tower service lift

    Science.gov (United States)

    Oliphant, David; Quilter, Jared; Andersen, Todd; Conroy, Thomas

    2011-09-13

    An apparatus used for maintaining a wind tower structure wherein the wind tower structure may have a plurality of legs and may be configured to support a wind turbine above the ground in a better position to interface with winds. The lift structure may be configured for carrying objects and have a guide system and drive system for mechanically communicating with a primary cable, rail or other first elongate member attached to the wind tower structure. The drive system and guide system may transmit forces that move the lift relative to the cable and thereby relative to the wind tower structure. A control interface may be included for controlling the amount and direction of the power into the guide system and drive system thereby causing the guide system and drive system to move the lift relative to said first elongate member such that said lift moves relative to said wind tower structure.

  2. Kansas Wind Energy Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Gruenbacher, Don [Kansas State Univ., Manhattan, KS (United States)

    2015-12-31

    This project addresses both fundamental and applied research problems that will help with problems defined by the DOE “20% Wind by 2030 Report”. In particular, this work focuses on increasing the capacity of small or community wind generation capabilities that would be operated in a distributed generation approach. A consortium (KWEC – Kansas Wind Energy Consortium) of researchers from Kansas State University and Wichita State University aims to dramatically increase the penetration of wind energy via distributed wind power generation. We believe distributed generation through wind power will play a critical role in the ability to reach and extend the renewable energy production targets set by the Department of Energy. KWEC aims to find technical and economic solutions to enable widespread implementation of distributed renewable energy resources that would apply to wind.

  3. Second wind in the offshore wind industry

    International Nuclear Information System (INIS)

    Philippe, Edouard; Neyme, Eric; Deboos, Christophe; Villageois, Jean-Remy; Gouverneur, Philippe; Gerard, Bernard; Fournier, Eric; Petrus, Raymond; Lemarquis, David; Dener, Marc; Bivaud, Jean-Pierre; Lemaire, Etienne; Nielsen, Steffen; Lafon, Xavier; Lagandre, Pierre; Nadai, Alain; Pinot de Villechenon, Edouard; Westhues, Markus; Herpers, Frederick; Bisiaux, Christophe; Sperlich, Miriam; Bales, Vincent; Vandenbroeck, Jan; His, Stephane; Derrey, Thierry; Barakat, Georges; Dakyo, Brayima; Carme, Laurent; Petit, Frederic; Ytournel, Sophie; Westhues, Markus; Diller, Armin; Premont, Antoine de; Ruer, Jacques; Lanoe, Frederic; Declercq, Jan; Holmager, Morten; Fidelin, Daniel; Guillet, Jerome; Dudziak, Gregory; Lapierre, Anne; Couturier, Ludovic; Audineau, Jean-Pierre; Rouaix, Eric; De Roeck, Yann-Herve; Quesnel, Louis; Duguet, Benjamin

    2011-06-01

    After several keynote addresses, this publication contains contributions and Power Point presentations proposed during this conference on the development of offshore wind energy. The successive sessions addressed the following issues: the offshore mass production of electricity (examples of Denmark and Belgium, laying and protecting offshore cables), the space, economic and environmental planning (the Danish experience, the role of the Coastal area integrated management, importance of the public debate, so on), the logistics of port infrastructures (simulation tools, example of Bremerhaven, issues related to project management), innovation at the core of industrial strategies (high power wind turbines, the 6 MW Alstom turbine, chain value and innovation in offshore wind energy, the Vertiwing innovating project of a floating wind turbine, a bench test in Charleston, foundations, gravity base structures, the British experience, the Danish experience), the economic and organisational conditions for development, the validation and certification of technologies

  4. Conceptual Design of a Single Phase 33 MVA HTS Transformer with a Tertiary Winding

    International Nuclear Information System (INIS)

    Lee, S. W.; Kim, W. S.; Hahn, S. Y.; Hwang, Y. I.; Choi, K. D.

    2006-01-01

    We have proposed a 3 phase, 100 MVA, 154 kV class HTS transformer substituting for a 60 MVA conventional transformer. The power transformer of 154 kV class has a tertiary winding besides primary and secondary windings. So the HTS transformer should have the 3rd superconducting winding. In this paper, we designed conceptually the structure of the superconducting windings of a single phase 33 MVA transformer. The electrical characteristics of the HTS transformer such as % impedance and AC loss vary with the arrangement of the windings and gaps between windings. We analyzed the effects of the winding parameters, evaluated the cost of each design, and proposed a suitable HTS transformer model for future power distribution system.

  5. Diagnostics of the solar wind transition region

    International Nuclear Information System (INIS)

    Lotova, N.A.; Nagelis, Ya.V.; Rudnitskij, G.M.; Smirnova, T.V.; AN Latvijskoj SSR, Riga. Radioastrofizicheskaya Observatoriya; Moskovskij Gosudarstvennyj Univ.; AN SSSR, Moscow. Fizicheskij Inst.)

    1988-01-01

    Possibilities are discussed of a more complete study of hardly observable regions of the interplanetary medium, in the zone of the solar wind formation, where transition from subsonic to supersonic flow occurs at R sun . It is shown that an investigation of fine structure of the extended transonic region of the solar wind and of the sequence of changes in the parameters of the interplanetary plasma in the region of the solar wind formation with the changing distance from the Sun can be effectuated by using jointly different modifications of the occupation method. Combination of two or more modifications of this method supposes using compact radio sources of different classes and observations in two different wavelength ranges, namely at short centimeter and at meter waves

  6. Observability of wind power

    International Nuclear Information System (INIS)

    Gonot, J.P.; Fraisse, J.L.

    2009-01-01

    The total installed capacity of wind power grows from a few hundred MW at the beginning of 2005 to 3400 MW at the end of 2008. With such a trend, a total capacity of 7000 MW could be reached by 2010. The natural variability of wind power and the difficulty of its predictability require a change in the traditional way of managing supply/demand balance, day-ahead margins and the control of electrical flows. As a consequence, RTE operators should be informed quickly and reliably of the real time output power of wind farms and of its evolvement some hours or days ahead to ensure the reliability of the French electrical power system. French specificities are that wind farms are largely spread over the territory, that 95 % of wind farms have an output power below 10 MW and that they are connected to the distribution network. In this context, new tools were necessary to acquire as soon as possible data concerning wind power. In two years long, RTE set up an observatory of wind production 'IPES system' enable to get an access to the technical characteristics of the whole wind farms, to observe in real time 75 % of the wind generation and to implement a forecast model related to wind generation. (authors)

  7. Financing wind projects

    International Nuclear Information System (INIS)

    Manson, J.

    2006-01-01

    This presentation reviewed some of the partnership opportunities available from GE Energy. GE Energy's ecomagination commitment has promised to double research investment, make customers true partners and reduce greenhouse gases (GHGs). GE Energy's renewable energy team provides a broad range of financial products, and has recently funded 30 wind farms and 2 large solar projects. The company has a diverse portfolio of technology providers and wind regimes, and is increasing their investment in technology. GE Energy recognizes that the wind industry is growing rapidly and has received increased regulatory support that is backed by strong policy and public support. It is expected that Canada will have 3006 wind projects either planned or under construction by 2007. According to GE Energy, successful wind financing is dependent on the location of the site and its wind resources, as well as on the wind developer's power sales agreement. The success of a wind project is also determined by clear financing goals. Site-specific data is needed to determine the quality of wind resource, and off-site data can also be used to provide validation. Proximity to load centres will help to minimize capital costs. Power sales agreements should be based on the project's realistic net capacity factor as well as on the cost of the turbines. The economics of many wind farms is driven by the size of the turbines used. Public consultations are also needed to ensure the success of wind power projects. It was concluded that a good partner will have staying power in the wind power industry, and will understand the time-lines and needs that are peculiar to wind energy developers. refs., tabs., figs

  8. Noise from wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Fegeant, Olivier [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Building Sciences

    2002-02-01

    A rapid growth of installed wind power capacity is expected in the next few years. However, the siting of wind turbines on a large scale raises concerns about their environmental impact, notably with respect to noise. To this end, variable speed wind turbines offer a promising solution for applications in densely populated areas like the European countries, as this design would enable an efficient utilisation of the masking effect due to ambient noise. In rural and recreational areas where wind turbines are sited, the ambient noise originates from the action of wind on the vegetation and about the listener's ear (pseudo-noise). It shows a wind speed dependence similar to that of the noise from a variable speed wind turbine and can therefore mask the latter for a wide range of conditions. However, a problem inherent to the design of these machines is their proclivity to pure tone generation, because of the enhanced difficulty of avoiding structural resonances in the mechanical parts. Pure tones are deemed highly annoying and are severely regulated by most noise policies. In relation to this problem, the vibration transmission of structure-borne sound to the tower of the turbine is investigated, in particular when the tower is stiffened at its upper end. Furthermore, since noise annoyance due to wind turbine is mostly a masking issue, the wind-related sources of ambient noise are studied and their masking potentials assessed. With this aim, prediction models for wind-induced vegetation noise and pseudo-noise have been developed. Finally, closely related to the effect of masking, is the difficulty, regularly encountered by local authorities and wind farm developers, to measure noise immission from wind turbines. A new measurement technique has thus been developed in the course of this work. Through improving the signal-to-noise ratio between wind turbine noise and ambient noise, the new technique yields more accurate measurement results.

  9. NASA World Wind: A New Mission

    Science.gov (United States)

    Hogan, P.; Gaskins, T.; Bailey, J. E.

    2008-12-01

    Virtual Globes are well into their first generation, providing increasingly rich and beautiful visualization of more types and quantities of information. However, they are still mostly single and proprietary programs, akin to a web browser whose content and functionality are controlled and constrained largely by the browser's manufacturer. Today Google and Microsoft determine what we can and cannot see and do in these programs. NASA World Wind started out in nearly the same mode, a single program with limited functionality and information content. But as the possibilities of virtual globes became more apparent, we found that while enabling a new class of information visualization, we were also getting in the way. Many users want to provide World Wind functionality and information in their programs, not ours. They want it in their web pages. They want to include their own features. They told us that only with this kind of flexibility, could their objectives and the potential of the technology be truly realized. World Wind therefore changed its mission: from providing a single information browser to enabling a whole class of 3D geographic applications. Instead of creating one program, we create components to be used in any number of programs. World Wind is NASA open source software. With the source code being fully visible, anyone can readily use it and freely extend it to serve any use. Imagery and other information provided by the World Wind servers is also free and unencumbered, including the server technology to deliver geospatial data. World Wind developers can therefore provide exclusive and custom solutions based on user needs.

  10. Wind Turbine Converter Control Interaction with Complex Wind Farm Systems

    DEFF Research Database (Denmark)

    Kocewiak, Lukasz Hubert; Hjerrild, Jesper; Bak, Claus Leth

    2013-01-01

    . The same wind turbine converter control strategy is evaluated in two different wind farms. It is emphasised that the grid-side converter controller should be characterised by sufficient harmonic/noise rejection and adjusted depending on wind farms to which it is connected. Various stability indices......This study presents wind turbine converter stability analysis of wind farms in frequency domain. The interaction between the wind turbine control system and the wind farm structure in wind farms is deeply investigated. Two wind farms (i.e. Horns Rev II and Karnice) are taken into consideration...... in this study. It is shown that wind farm components, such as long high-voltage alternating current cables and park transformers, can introduce significant low-frequency series resonances seen from the wind turbine terminals that can affect wind turbine control system operation and overall wind farm stability...

  11. Structural evaluation of safety class components to natural phenomena loadings

    International Nuclear Information System (INIS)

    Conrads, T.J.

    1989-01-01

    This paper addresses the efforts completed at the US Department of Energy Hanford Site near Richland, Washington, to qualify structurally a number of existing safety class components in the Plutonium Finishing Plant complex. Design, fabrication, and installation of the facility occurred in the 1950s and 1960s and were based on the Uniform Building Code criteria for wind and earthquake loads. Recently the buildings were qualified to site-specific wind and seismic hazards. The methodology employed to qualify seismically the safety class components is discussed

  12. Wind Energy Systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Ma, Ke

    2017-01-01

    transmission networks at the scale of hundreds of megawatts. As its level of grid penetration has begun to increase dramatically, wind power is starting to have a significant impact on the operation of the modern grid system. Advanced power electronics technologies are being introduced to improve......Wind power now represents a major and growing source of renewable energy. Large wind turbines (with capacities of up to 6-8 MW) are widely installed in power distribution networks. Increasing numbers of onshore and offshore wind farms, acting as power plants, are connected directly to power...... the characteristics of the wind turbines, and make them more suitable for integration into the power grid. Meanwhile, there are some emerging challenges that still need to be addressed. This paper provides an overview and discusses some trends in the power electronics technologies used for wind power generation...

  13. Wind energy economics

    International Nuclear Information System (INIS)

    Milborrow, D.J.

    1995-01-01

    The economics of wind energy have improved rapidly in the past few years, with improvements in machine performance and increases in size both contributing to reduce costs. These trends are examined and future costs assessed. As bank loan periods for wind projects are shorter than for thermal plant, the effect on the price of wind energy is discussed. It is argued that wind energy has a higher value than that of centralised plant, since it is fed into the low voltage distribution network and it follows that the price of wind energy is converging with its value. The paper also includes a brief review of the capacity credit of wind plant and an assessment of the cost penalties which are incurred due to the need to hold extra plant on part load. These penalties are shown to be small. (author)

  14. Wind power in France

    International Nuclear Information System (INIS)

    Tuille, F.; Courtel, J.

    2015-01-01

    After 3 years of steady decreasing, wind power has resumed growth in 2014 in France and the preliminary figures of 2015 confirm this trend. About 1100 MW were installed in 2014 which was almost twice as much as it was installed the year before. This renaissance is mostly due to the implementation of Brottes' law that eases the installations of wind farms by suppressing the wind power development areas (that were interfering with regional wind power schemes) and by suppressing the minimum number of 5 turbines for any new wind farms. Another important incentive measure was the announcement in January 2015 of a new financial support scheme in replacement of the policy of guaranteed purchase price for the electricity produced. In 2014 the total wind power produced in mainland France reached 17 TW which represented 3.1% of the production of electricity. (A.C.)

  15. Wind Turbines Wake Aerodynamics

    DEFF Research Database (Denmark)

    Vermeer, L.; Sørensen, Jens Nørkær; Crespo, A.

    2003-01-01

    The aerodynamics of horizontal axis wind turbine wakes is studied. The contents is directed towards the physics of power extraction by wind turbines and reviews both the near and the far wake region. For the near wake, the survey is restricted to uniform, steady and parallel flow conditions......, thereby excluding wind shear, wind speed and rotor setting changes and yawed conditions. The emphasis is put on measurements in controlled conditions.For the far wake, the survey focusses on both single turbines and wind farm effects, and the experimental and numerical work are reviewed; the main interest...... is to study how the far wake decays downstream, in order to estimate the effect produced in downstream turbines.The article is further restricted to horizontal axis wind turbines and excludes all other types of turbines....

  16. Noise from wind turbines

    International Nuclear Information System (INIS)

    Andersen, B.; Jakobsen, J.

    1992-11-01

    Based on a previous project concerning the calculation of the amount of noise emanating from wind turbine arrays, this one examines the subject further by investigating whether there could be significant differences in the amount of noise made by individual wind turbines in an array, and whether the noise is transmitted in varying directions - so that when it is carried in the same direction as the wind blows it would appear to be louder. The aim was also to determine whether the previously used method of calculation lacked precision. It was found that differences in noise niveaux related to individual wind turbines were insignificant and that noise was not so loud when it was not borne in the direction of the wind. It was necessary to change the method of calculation as reckoning should include the influence of the terrain, wind velocity and distance. The measuring and calculation methods are exemplified and the resulting measurements are presented in detail. (AB)

  17. Medicine Bow wind project

    Science.gov (United States)

    Nelson, L. L.

    1982-05-01

    The Bureau of Reclamation (Bureau) conducted studies for a wind turbine field of 100 MW at a site near Medicine Bow, WY, one of the windiest areas in the United States. The wind turbine system would be electrically interconnected to the existing Federal power grid through the substation at Medicine Bow. Power output from the wind turbines would thus be integrated with the existing hydroelectric system, which serves as the energy storage system. An analysis based on 'willingness to pay' was developed. Based on information from the Department of Energy's Western Area Power Administration (Western), it was assumed that 90 mills per kWh would represent the 'willingness to pay' for onpeak power, and 45 mills per kWh for offpeak power. The report concludes that a 100-MW wind field at Medicine Bow has economic and financial feasibility. The Bureau's construction of the Medicine Bow wind field could demonstrate to the industry the feasibility of wind energy.

  18. Wind farm economics

    International Nuclear Information System (INIS)

    Milborrow, D.J.

    1995-01-01

    The economics of wind energy are changing rapidly, with improvements in machine performance and increases in size both contributing to reduce costs. These trends are examined and future costs assessed. Although the United Kingdom has regions of high wind speed, these are often in difficult terrain and construction costs are often higher than elsewhere in Europe. Nevertheless, wind energy costs are converging with those of the conventional thermal sources. At present, bank loan periods for wind projects are shorter than for thermal plant, which means that energy prices are higher. Ways of overcoming this problem are explored. It is important, also, to examine the value of wind energy. It is argued that wind energy has a higher value than energy from centralized plant, since it is fed into the low-voltage distribution network. (Author)

  19. SERI Wind Energy Program

    Energy Technology Data Exchange (ETDEWEB)

    Noun, R. J.

    1983-06-01

    The SERI Wind Energy Program manages the areas or innovative research, wind systems analysis, and environmental compatibility for the U.S. Department of Energy. Since 1978, SERI wind program staff have conducted in-house aerodynamic and engineering analyses of novel concepts for wind energy conversion and have managed over 20 subcontracts to determine technical feasibility; the most promising of these concepts is the passive blade cyclic pitch control project. In the area of systems analysis, the SERI program has analyzed the impact of intermittent generation on the reliability of electric utility systems using standard utility planning models. SERI has also conducted methodology assessments. Environmental issues related to television interference and acoustic noise from large wind turbines have been addressed. SERI has identified the causes, effects, and potential control of acoustic noise emissions from large wind turbines.

  20. Economics of wind energy

    International Nuclear Information System (INIS)

    Ranganathan, V.; Kumar, H.P.S.

    1991-01-01

    Conventional economic analysis of wind energy often ignores the fact that it is not an energy source available on tap, but is intermittent. The analysis at times is discriminatory in the sense that the costs of transmission and distribution are added to the central grid alternative but the costs of the locational constraints of wind energy siting are not quantified. This paper evaluates wind energy after correcting for these two factors. The results are not encouraging

  1. Wind power barometer

    International Nuclear Information System (INIS)

    2014-01-01

    The worldwide wind power increased by 12.4% in 2013 to reach 318.6 GW but the world market globally decreased by losing 10 GW: only 35.6 GW have been installed in 2013 which is even less than was installed in 2009. This activity contraction is mainly due to the collapse of the American market, American authorities having been late to decide to maintain federal incentives. The European wind power market also contracted in 2013 because of the lack of trust of the investors in the new energy policies of the European governments. In the rest of the world wind energy has kept on growing particularly in China and Canada. At the end of 2013 the cumulated wind power reached 117,73 GW in Europe. About 1.5 MW out of 10 MW of wind power installed in Europe in 2013 come from off-shore wind farms, United-Kingdom and Denmark being the most important players by totalling more than 70% of the off-shore wind power installed at the end of 2013. Various charts and tables give the figures of the wind power cumulated and installed in 2013 in different parts of the world: Europe, North America and Asia, the time evolution of the worldwide wind power since 1995, the wind power cumulated and installed in 2013 for the different countries of Europe and the ratio between the cumulated wind power and the country population. A table lists the main manufacturers of wind turbines and gives their turnover and number of employees at the end of 2013

  2. Wind power generation

    International Nuclear Information System (INIS)

    Anon.

    1999-01-01

    The monthly statistics of wind electric power generation in Denmark are compiled from information given by the owners of private wind turbines. The data are arranged according to the size of the turbines. For each wind turbine the name of the site and type of turbine is given as well as the production during the last 3 months in 1998, and the total production in 1997 and 1998. Data on the operation is given

  3. Enabling Wind Power Nationwide

    Energy Technology Data Exchange (ETDEWEB)

    Jose Zayas, Michael Derby, Patrick Gilman and Shreyas Ananthan,

    2015-05-01

    Leveraging this experience, the U.S. Department of Energy’s (DOE’s) Wind and Water Power Technologies Office has evaluated the potential for wind power to generate electricity in all 50 states. This report analyzes and quantifies the geographic expansion that could be enabled by accessing higher above ground heights for wind turbines and considers the means by which this new potential could be responsibly developed.

  4. Wind and Yaw correlation

    DEFF Research Database (Denmark)

    Kock, Carsten Weber; Vesth, Allan

    The report describes measurements carried out on a given wind turbine. A comparison between wind speed on the metmast and Nacelle Windspeed are made and the results are presented on graphs and in a table. The data used for the comparison are identical with the data used for the Risø-I-3246(EN) po......) power curve report. The measurements are carried out in accordance to Ref. [1] and the wind and yaw correlation is analyzed in accordance to Ref. [2]....

  5. Wind power development field test project at Aoyama Heights, Aoyama-cho. Detailed wind characteristics survey; Aoyamacho Aoyama Kogen ni okeru furyoku kaihatsu field test jigyo (fukyo seisa) hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-11-01

    A detailed wind characteristics survey was conducted at Aoyama Heights, Aoyama-cho, Naga-gun, Mie Prefecture, on the assumption that a wind power generation system would be constructed. The survey was a 1-year project from October 1998 through September 1999, and wind characteristics such as the average wind speed, average wind direction, standard deviation of wind velocity, and the maximum instantaneous wind speed were observed. The observation point was fixed at 20m above ground, the minimum time unit for observation was 10 minutes, and the 10-minute average value was defined as the measured value. For the maximum instantaneous wind speed, the minimum time unit for observation was set to be 2 seconds. The yearly average wind speed was 5.3m/s and the maximum wind speed in the period was 32m/s. Winds came prevalently from WNW (31.6%), and then from NW (16.8%), ESE (20.9%), and E (9.9%). The wind axis was in the direction of WNW-ESE, and the total wind direction occurrence rate was 89.0%. Turbulence intensity was 0.25 at wind speed 2.0m/s or more and 0.23 at wind speed 4.0m/s or more. Estimated wind turbine yearly operating factors of 70-84% were obtained using rated values of a 150kW, 300kW, and 750kW-class wind turbines. (NEDO)

  6. Vertical axis wind turbines

    Science.gov (United States)

    Krivcov, Vladimir [Miass, RU; Krivospitski, Vladimir [Miass, RU; Maksimov, Vasili [Miass, RU; Halstead, Richard [Rohnert Park, CA; Grahov, Jurij [Miass, RU

    2011-03-08

    A vertical axis wind turbine is described. The wind turbine can include a top ring, a middle ring and a lower ring, wherein a plurality of vertical airfoils are disposed between the rings. For example, three vertical airfoils can be attached between the upper ring and the middle ring. In addition, three more vertical airfoils can be attached between the lower ring and the middle ring. When wind contacts the vertically arranged airfoils the rings begin to spin. By connecting the rings to a center pole which spins an alternator, electricity can be generated from wind.

  7. Vertical axis wind turbine

    International Nuclear Information System (INIS)

    Obretenov, V.; Tsalov, T.; Chakarov, T.

    2012-01-01

    In recent years, the interest in wind turbines with vertical axis noticeably increased. They have some important advantages: low cost, relatively simple structure, reliable packaging system of wind aggregate long period during which require no maintenance, low noise, independence of wind direction, etc.. The relatively low efficiency, however, makes them applicable mainly for small facilities. The work presents a methodology and software for approximately aerodynamic design of wind turbines of this type, and also analyzed the possibility of improving the efficiency of their workflow

  8. Microsystem Aeromechanics Wind Tunnel

    Data.gov (United States)

    Federal Laboratory Consortium — The Microsystem Aeromechanics Wind Tunnel advances the study of fundamental flow physics relevant to micro air vehicle (MAV) flight and assesses vehicle performance...

  9. Wind power in Norway

    International Nuclear Information System (INIS)

    1998-01-01

    This report analyses business costs and socio-economic costs in the development of wind power in Norway and policy instruments to encourage such a development. It is founded on an analysis of the development of wind power in other countries, notably U.S.A, Denmark, Germany, the Netherlands and Britain. The report describes the institutional background in each country, the policy instruments that have been used and still are and the results achieved. The various cost components in Norwegian wind power development and the expected market price of wind power are also discussed. The discussion of instruments distinguishes between investment oriented and production oriented instruments. 8 refs., 9 figs., 3 tabs

  10. Could wind replace nuclear?

    International Nuclear Information System (INIS)

    2017-01-01

    This article aims at assessing the situation produced by a total replacement of nuclear energy by wind energy, while facing consumption demand at any moment, notably in December. The authors indicate the evolution of the French energy mix during December 2016, and the evolution of the rate between wind energy production and the sum of nuclear and wind energy production during the same month, and then give briefly some elements regarding necessary investments in wind energy to wholly replace nuclear energy. According to them, such a replacement would be ruinous

  11. Wind Turbine Technologies

    DEFF Research Database (Denmark)

    Hansen, Anca Daniela

    2017-01-01

    , and with or without gearboxes, using the latest in power electronics, aerodynamics, and mechanical drive train designs [4]. The main differences between all wind turbine concepts developed over the years, concern their electrical design and control. Today, the wind turbines on the market mix and match a variety......, the design of wind turbines has changed from being convention driven to being optimized driven within the operating regime and market environment. Wind turbine designs have progressed from fixed speed, passive controlled and with drive trains with gearboxes, to become variable speed, active controlled......,6] and to implement modern control system strategies....

  12. Winds of change

    International Nuclear Information System (INIS)

    Palmer, C.; Short, L.

    1998-01-01

    The British countryside is oversubscribed with multiple and often irreconcilable demands. The siting of wind turbines is but one facet of this situation. While the problems of these demands are widely recognised, there is little understanding or agreement on how to resolve them. The 1996 Future Landscape: New Partnerships was an attempt to address this challenge. The use of wind energy as a case study initiated a partnership between contemporary artists and the wind energy industry. It became clear that artists have an important role to play in creating new ways of seeing that will establish wind turbines as new icons for a sustainable future. (Author)

  13. Wind farm radar study

    International Nuclear Information System (INIS)

    Davies, N.G.

    1995-01-01

    This report examines the possible degradations of radar performance that may be caused by the presence of a wind turbine generator within the radar coverage area. A brief literature survey reviews the previously published work, which is mainly concerned with degradation of broadcast TV reception. Estimates are made of wind turbine generator scattering cross-sections, and of the time and Doppler characteristics of the echo signals from representative wind turbine generator. The general characteristics of radar detection and tracking methods are described, and the behaviour of such systems in the presence of strong returns from a wind turbine generator (or an array of them) is discussed. (author)

  14. Wind power prediction models

    Science.gov (United States)

    Levy, R.; Mcginness, H.

    1976-01-01

    Investigations were performed to predict the power available from the wind at the Goldstone, California, antenna site complex. The background for power prediction was derived from a statistical evaluation of available wind speed data records at this location and at nearby locations similarly situated within the Mojave desert. In addition to a model for power prediction over relatively long periods of time, an interim simulation model that produces sample wind speeds is described. The interim model furnishes uncorrelated sample speeds at hourly intervals that reproduce the statistical wind distribution at Goldstone. A stochastic simulation model to provide speed samples representative of both the statistical speed distributions and correlations is also discussed.

  15. Wind on the moors

    International Nuclear Information System (INIS)

    Martin, S.

    1992-01-01

    A local town councillor describes the setting up of a wind farm in the south Pennines which plans to sell electricity to the local electricity suppliers. The Coal Clough wind farm will generate sufficient electricity to meet the average demand of 7,500 households and will be managed by a consortium known as Wind Resources Limited linking the construction company and the utilities aiming to buy the electricity produced. While wind power offers many environmental advantages over other means of power generation, local opposition was strong on the basis of the noise produced and clearly visible structures in an area designated as being of outstanding natural beauty. (UK)

  16. Offshore Wind Farms

    DEFF Research Database (Denmark)

    Lundtang Petersen, Erik; Hasager, Charlotte Bay; Courtney, Michael

    2015-01-01

    : the rotor, the nacelle, the tower, and the foundation. Further the determinations of the essential environmental conditions are treated: the wind field, the wave field, the sea current, and the soil conditions. The various options for grid connections, advantages, and disadvantages are discussed. Of special...... concern are the problems associated with locating the turbines close together in a wind farm and the problems of placing several large wind farms in a confined area. The environmental impacts of offshore wind farms are also treated, but not the supply chain, that is, the harbors, the installation vessels...

  17. Climate Wind Power Resources

    Directory of Open Access Journals (Sweden)

    Nana M. Berdzenishvili

    2013-01-01

    Full Text Available Georgia as a whole is characterized by rather rich solar energy resources, which allows to construct alternative power stations in the close proximity to traditional power plants. In this case the use of solar energy is meant. Georgia is divided into 5 zones based on the assessment of wind power resources. The selection of these zones is based on the index of average annual wind speed in the examined area, V> 3 m / s and V> 5 m / s wind speed by the summing duration in the course of the year and V = 0. . . 2 m / s of passive wind by total and continuous duration of these indices per hour.

  18. Wind energy statistics

    International Nuclear Information System (INIS)

    Holttinen, H.; Tammelin, B.; Hyvoenen, R.

    1997-01-01

    The recording, analyzing and publishing of statistics of wind energy production has been reorganized in cooperation of VTT Energy, Finnish Meteorological (FMI Energy) and Finnish Wind Energy Association (STY) and supported by the Ministry of Trade and Industry (KTM). VTT Energy has developed a database that contains both monthly data and information on the wind turbines, sites and operators involved. The monthly production figures together with component failure statistics are collected from the operators by VTT Energy, who produces the final wind energy statistics to be published in Tuulensilmae and reported to energy statistics in Finland and abroad (Statistics Finland, Eurostat, IEA). To be able to verify the annual and monthly wind energy potential with average wind energy climate a production index in adopted. The index gives the expected wind energy production at various areas in Finland calculated using real wind speed observations, air density and a power curve for a typical 500 kW-wind turbine. FMI Energy has produced the average figures for four weather stations using the data from 1985-1996, and produces the monthly figures. (orig.)

  19. Wind Energy Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Laurie, Carol

    2017-02-01

    This book takes readers inside the places where daily discoveries shape the next generation of wind power systems. Energy Department laboratory facilities span the United States and offer wind research capabilities to meet industry needs. The facilities described in this book make it possible for industry players to increase reliability, improve efficiency, and reduce the cost of wind energy -- one discovery at a time. Whether you require blade testing or resource characterization, grid integration or high-performance computing, Department of Energy laboratory facilities offer a variety of capabilities to meet your wind research needs.

  20. Wind Power in Georgia

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    Georgia has good wind power potential. Preliminary analyses show that the technical wind power potential in Georgia is good. Meteorological data shows that Georgia has four main areas in Georgia with annual average wind speeds of over 6 m/s and two main areas with 5-6 m/s at 80m. The most promising areas are the high mountain zone of the Great Caucasus, The Kura river valley, The South-Georgian highland and the Southern part of the Georgian Black Sea coast. Czech company Wind Energy Invest has recently signed a Memorandum of Understanding with Georgian authorities for development of the first wind farm in Georgia, a 50MW wind park in Paravani, Southern Georgia, to be completed in 2014. Annual generation is estimated to 170.00 GWh and the investment estimated to 101 million US$. Wind power is suited to balance hydropower in the Georgian electricity sector Electricity generation in Georgia is dominated by hydro power, constituting 88% of total generation in 2009. Limited storage capacity and significant spring and summer peaks in river flows result in an uneven annual generation profile and winter time shortages that are covered by three gas power plants. Wind power is a carbon-free energy source well suited to balance hydropower, as it is available (often strongest) in the winter and can be exported when there is a surplus. Another advantage with wind power is the lead time for the projects; the time from site selection to operation for a wind power park (approximately 2.5 years) is much shorter than for hydro power (often 6-8 years). There is no support system or scheme for renewable sources in Georgia, so wind power has to compete directly with other energy sources and is in most cases more expensive to build than hydro power. In a country and region with rapidly increasing energy demands, the factors described above nevertheless indicate that there is a commercial niche and a role to play for Georgian wind power. Skra: An example of a wind power development

  1. Class 1 Areas

    Data.gov (United States)

    U.S. Environmental Protection Agency — A "Class 1" area is a geographic area recognized by the EPA as being of the highest environmental quality and requiring maximum protection. Class I areas are areas...

  2. PRCR Classes and Activities

    Data.gov (United States)

    Town of Cary, North Carolina — This data is specific to Parks and Recreation classes, workshops, and activities within the course catalog. It contains an entry for upcoming classes.*This data set...

  3. Comparative study of Danish and foreign wind turbine economics

    International Nuclear Information System (INIS)

    Godtfredsen, F.

    1993-02-01

    This comparative study indicates that Denmark still is the leading nation in wind turbine technology in regard to economics as well as energy output and nacelle weight per swept rotor area. For roughness class 1, the levellized socioeconomic costs of wind power from Danish wind turbines is DKK 0.396 - 0.536 per kWh compared with production costs of DKK 0.525 for the most economic of the foreign wind turbines investigated. Furthermore it is pointed out, that there seems to be no correlation between generator capacity or swept rotor area and costs of windpower for the wind turbines investigated. Nevertheless there are arguments for the statement that large scale wind turbines will be relatively more economic in the future. Danish wind turbine manufacturers only produce tree-bladed, stall- or pitch regulated wind turbines with constant rotational speed. In Holland, Germany and UK two-bladed wind turbines and turbines with variable speed has been introduced. Still the new concepts are less economic, but not without future interest. (au)

  4. The impact of turbulence intensity and atmospheric stability on power deficits due to wind turbine wakes at Horns Rev wind farm

    DEFF Research Database (Denmark)

    Hansen, Kurt Schaldemose; Barthelmie, Rebecca J.; Jensen, Leo E.

    2012-01-01

    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...

  5. Class Notes for "Class-Y-News."

    Science.gov (United States)

    Stuart, Judy L.

    1991-01-01

    A self-contained class of students with mild to moderate disabilities published a monthly newsletter which was distributed to students' families. Students became involved in writing, typing, drawing, folding, basic editing, and disseminating. (JDD)

  6. Classed identities in adolescence

    OpenAIRE

    Jay, Sarah

    2015-01-01

    peer-reviewed The central argument of this thesis is that social class remains a persistent system of inequality in education, health, life chances and opportunities. Therefore class matters. But why is it that so little attention has been paid to class in the psychological literature? Three papers are presented here which draw together theoretical advances in psychological understandings of group processes and sociological understandings of the complexity of class. As western labour marke...

  7. Innovative Offshore Wind Plant Design Study

    Energy Technology Data Exchange (ETDEWEB)

    Hurley, William L. [Glosten Associates, Inc., Seattle, WA (United States); Nordstrom, Charles J. [Glosten Associates, Inc., Seattle, WA (United States); Morrison, Brent J. [Glosten Associates, Inc., Seattle, WA (United States)

    2013-12-18

    Technological advancements in the Glosten PelaStar floating wind turbine system have led to projected cost of energy (COE) reductions from today’s best-in-class offshore wind systems. The PelaStar system is projected to deliver a COE that is 35% lower than that delivered by the current offshore wind plants. Several technology developments have been achieved that directly target significant cost of energy reductions. These include: Application of state-of-the-art steel construction materials and methods, including fatigue-resistant welding techniques and technologies, to reduce hull steel weight; Advancements in synthetic fiber tendon design for the mooring system, which are made possible by laboratory analysis of full-scale sub-rope specimens; Investigations into selected anchor technologies to improve anchor installation methods; Refinement of the installation method, specifically through development of the PelaStar Support Barge design. Together, these technology developments drive down the capital cost and operating cost of offshore wind plants and enable access to superb wind resources in deep water locations. These technology developments also reduce the uncertainty of the PelaStar system costs, which increases confidence in the projected COE reductions.

  8. Experimental constraints on impact-induced winds

    Science.gov (United States)

    Quintana, Stephanie N.; Schultz, Peter H.; Horowitz, Seth S.

    2018-05-01

    A new class of wind streaks on Mars uniquely associated with impact craters is most clearly detected in nighttime thermal infrared imaging. Thermally bright streaks radiate from some well-preserved impact craters and are related to the impact process. Using laboratory experiments performed at the NASA Ames Vertical Gun Range, we test the hypothesis that these streaks are formed from either the winds within an air-blast or winds set up by expanding impact vapor interacting with the atmosphere. The experiments use a variety of tracers and instruments to document three interrelated processes occurring in the impact of a Pyrex projectile into an easily vaporized powdered dolomite target: (1) a surface roughening spreading outward from the impact point, (2) an expanding vapor plume, and (3) outward winds made visible by dust trails from vertically placed, dusty pipe cleaners. The clear connection between the surface roughening, vapor expansion, and outward winds implicate an expanding vapor interacting with the atmosphere as the controlling process.

  9. Dynamic aeroelastic stability of vertical-axis wind turbines under constant wind velocity

    Science.gov (United States)

    Nitzsche, Fred

    1994-05-01

    The flutter problem associated with the blades of a class of vertical-axis wind turbines called Darrieus is studied in detail. The spinning blade is supposed to be initially curved in a particular shape characterized by a state of pure tension at the blade cross section. From this equilibrium position a three-dimensional linear perturbation pattern is superimposed to determine the dynamic aeroelastic stability of the blade in the presence of free wind speed by means of the Floquet-Lyapunov theory for periodic systems.

  10. Wind resource estimation and siting of wind turbines

    DEFF Research Database (Denmark)

    Lundtang Petersen, Erik; Mortensen, N.G.; Landberg, L.

    1994-01-01

    Detailed knowledge of the characteristics of the natural wind is necessary for the design, planning and operational aspect of wind energy systems. Here, we shall only be concerned with those meteorological aspects of wind energy planning that are termed wind resource estimation. The estimation...... of the wind resource ranges from the overall estimation of the mean energy content of the wind over a large area - called regional assessment - to the prediction of the average yearly energy production of a specific wind turbine at a specific location - called siting. A regional assessment will most often...... lead to a so-called wind atlas. A precise prediction of the wind speed at a given site is essential because for aerodynamic reasons the power output of a wind turbine is proportional to the third power of the wind speed, hence even small errors in prediction of wind speed may result in large deviations...

  11. Mixed H2/H∞ Pitch Control of Wind Turbine with a Markovian Jump Model

    DEFF Research Database (Denmark)

    Lin, Zhongwei; Liu, Jizhen; Wu, Qiuwei

    2016-01-01

    This paper proposes a Markovian jump model and the corresponding H2 /H∞ control strategy for the wind turbine driven by the stochastic switching wind speed, which can be used to regulate the generator speed in order to harvest the rated power while reducing the fatigue loads on the mechanical side...... operating points of wind turbine can be divided into separate subregions correspondingly, where the model parameters and the control mode can be fixed in each mode. Then, the mixed H2 /H∞ control problem is discussed for such a class of Markovian jump wind turbine working above the rated wind speed...

  12. Mesoscale wind fluctuations over Danish waters

    Energy Technology Data Exchange (ETDEWEB)

    Vincent, C.L.

    2010-12-15

    Mesoscale wind fluctuations affect the large scale integration of wind power because they undermine the day-ahead predictability of wind speed and power production, and because they can result in large fluctuations in power generation that must be balanced using reserve power. Large fluctuations in generated power are a particular problem for offshore wind farms because the typically high concentration of turbines within a limited geographical area means that fluctuations can be correlated across large numbers of turbines. Furthermore, organised mesoscale structures that often form over water, such as convective rolls and cellular convection, have length scales of tens of kilometers, and can cause large wind fluctuations on a time scale of around an hour. This thesis is an exploration of the predictability of mesoscale wind fluctuations using observations from the world's first two large offshore wind farms - Horns Rev I in the North Sea, and Nysted in the Baltic Sea. The thesis begins with a climatological analysis of wind fluctuations on time scales of 1-10 hours at the two sites. A novel method for calculating conditional climatologies of spectral information is proposed, based on binning and averaging the time axis of the Hilbert spectrum. Results reveal clear patterns between wind fluctuations and locally observed meteorological conditions. The analysis is expanded by classifying wind fluctuations on time scales of 1-3 hours according to synoptic patterns, satellite pictures and wind classes. Results indicate that cold air outbreaks and open cellular convection are a significant contributor to mesoscale wind variability at Horns Rev. The predictability of mesoscale wind fluctuations is tested by implementing standard statistical models that relate local wind variability to parameters based on a large scale weather analysis. The models show some skill, but only achieve a 15% improvement on a persistence forecast. The possibility of explicitly modelling

  13. Compressed air energy storage system reservoir size for a wind energy baseload power plant

    Energy Technology Data Exchange (ETDEWEB)

    Cavallo, A.J.

    1996-12-31

    Wind generated electricity can be transformed from an intermittent to a baseload resource using an oversized wind farm in conjunction with a compressed air energy storage (CAES) system. The size of the storage reservoir for the CAES system (solution mined salt cavern or porous media) as a function of the wind speed autocorrelation time (C) has been examined using a Monte Carlo simulation for a wind class 4 (wind power density 450 W m{sup -2} at 50 m hub height) wind regime with a Weibull k factor of 2.5. For values of C typically found for winds over the US Great Plains, the storage reservoir must have a 60 to 80 hour capacity. Since underground reservoirs account for only a small fraction of total system cost, this larger storage reservoir has a negligible effect on the cost of energy from the wind energy baseload system. 7 refs., 2 figs., 1 tab.

  14. Sensing the wind profile

    Energy Technology Data Exchange (ETDEWEB)

    Pena, A.

    2009-03-15

    This thesis consists of two parts. The first is a synopsis of the theoretical progress of the study that is based on a number of journal papers. The papers, which constitute the second part of the report, aim to analyze, measure, and model the wind prole in and beyond the surface layer by combining observations from cup anemometers with lidars. The lidar is necessary to extend the measurements on masts at the Horns Rev offshore wind farm and over at land at Hoevsoere, Denmark. Both sensing techniques show a high degree of agreement for wind speed measurements performed at either sites. The wind speed measurements are averaged for several stability conditions and compare well with the surface-layer wind profile. At Hoevsoere, it is sufficient to scale the wind speed with the surface friction velocity, whereas at Horns Rev a new scaling is added, due to the variant roughness length. This new scaling is coupled to wind prole models derived for flow over the sea and tested against the wind proles up to 160 m at Horns Rev. The models, which account for the boundary-layer height in stable conditions, show better agreement with the measurements than compared to the traditional theory. Mixing-length parameterizations for the neutral wind prole compare well with length-scale measurements up to 300 m at Hoevsoere and 950 m at Leipzig. The mixing-length-derived wind proles strongly deviate from the logarithmic wind prole, but agree better with the wind speed measurements. The length-scale measurements are compared to the length scale derived from a spectral analysis performed up to 160 m at Hoevsoere showing high agreement. Mixing-length parameterizations are corrected to account for stability and used to derive wind prole models. These compared better to wind speed measurements up to 300 m at Hoevsoere than the surface-layer wind prole. The boundary-layer height is derived in nearneutral and stable conditions based on turbulent momentum uxes only and in unstable conditions

  15. WIND BRAKING OF MAGNETARS

    International Nuclear Information System (INIS)

    Tong, H.; Xu, R. X.; Qiao, G. J.; Song, L. M.

    2013-01-01

    We explore the wind braking of magnetars considering recent observations challenging the traditional magnetar model. There is evidence for strong multipole magnetic fields in active magnetars, but the dipole field inferred from spin-down measurements may be strongly biased by particle wind. Recent observations challenging the traditional model of magnetars may be explained naturally by the wind braking scenario: (1) the supernova energies of magnetars are of normal value; (2) the non-detection in Fermi observations of magnetars; (3) the problem posed by low magnetic field soft gamma-ray repeaters; (4) the relation between magnetars and high magnetic field pulsars; and (5) a decreasing period derivative during magnetar outbursts. Transient magnetars with L x rot may still be magnetic dipole braking. This may explain why low luminosity magnetars are more likely to have radio emissions. A strong reduction of the dipole magnetic field is possible only when the particle wind is very collimated at the star surface. A small reduction of the dipole magnetic field may result from detailed considerations of magnetar wind luminosity. In the wind braking scenario, magnetars are neutron stars with a strong multipole field. For some sources, a strong dipole field may no longer be needed. A magnetism-powered pulsar wind nebula will be one of the consequences of wind braking. For a magnetism-powered pulsar wind nebula, we should see a correlation between the nebula luminosity and the magnetar luminosity. Under the wind braking scenario, a braking index smaller than three is expected. Future braking index measurement of a magnetar may tell us whether magnetars are wind braking or magnetic dipole braking.

  16. Statement on Wind Power

    Energy Technology Data Exchange (ETDEWEB)

    2010-01-15

    Wind power will grow in importance in future electricity supply. In the next few decades it will to some degree replace fossil power but it will, at the same time also depend on fossil-b beyond, when wind power is expected to have a substantial share of the electricity market, CO{sub 2} emission-free electricity plants that are well suited for balancing the wind intermittency will be required. Predictions of the future penetration of wind power into the electricity market are critically dependent on a number of policy measures and will be especially influenced by climate driven energy policies. Very large investments will also be necessary as is shown by the lEA's Blue Map Scenario which includes 5,000 TWh wind electricity by 2050 at a cost of USD 700 billion. This implies an average 8% increase of wind electricity per year energy system, i.e. an energy system so large that it affects the entire world. The Energy Committee's scenario for electricity production in the year 2050 includes 5,000 TWh wind electricity out of a total of 45,000 TWh. Wind electricity thus has a within presently reached penetration of wind energy in a single country and within the calculated future projections of its penetration. Future large continental and intercontinental power grids may enable higher penetrations of wind energy since contributions of wind power from a larger area will tend to reduce its intermittency. Also, large-scale storage systems (thermal storage as is intermittent power systems. These alternatives have been discussed from a technical point of view [3] but for the required large-scale systems, further studies on the social, environmental and economical implications are needed

  17. Wind energy - an overview

    International Nuclear Information System (INIS)

    Rangi, R.; Oprisan, M.

    1998-01-01

    The current status of wind technology developments in Canada and around the world was reviewed. Information regarding the level of wind turbine deployment was presented. It was shown that significant effort has been made on the national and international level to increase the capacity of this clean, non-polluting form of energy. Wind energy has become competitive with conventional sources of electricity due to lower cost, higher efficiency and improved reliability of generating equipment. The advantages and disadvantages of wind electricity generating systems and the economics and atmospheric emissions of the systems were described. At present, there is about 23 MW of wind energy generating capacity installed in Canada, but the potential is very large. It was suggested that wind energy could supply as much as 60 per cent of Canada's electricity needs if only one per cent of the land with 'good winds' were covered by wind turbines. Recently, the Canadian government has provided an accelerated capital cost allowance for certain types of renewable energies under the Income Tax Act, and the flow-through share financing legislation to include intangible expenses in certain renewable energy projects has been extended. Besides the support provided to the private sector through tax advantages, the Government also supports renewable energy development by purchasing 'green' energy for its own buildings across the country, and by funding a research and development program to identify and promote application of wind energy technologies, improve its cost effectiveness, and support Canadian wind energy industries with technology development to enhance their competitiveness at home and abroad. Details of the Wind Energy Program, operated by Natural Resources Canada, are described. 3 tabs., 5 figs

  18. Wind power integration : From individual wind turbine to wind park as a power plant

    NARCIS (Netherlands)

    Zhou, Y.

    2009-01-01

    As power capacities of single wind turbine, single wind park and total wind power installation are continuously increasing, the wind power begins to challenge the safety operation of the power system. This thesis focuses on the grid integration aspects such as the dynamic behaviours of wind power

  19. Loosely coupled class families

    DEFF Research Database (Denmark)

    Ernst, Erik

    2001-01-01

    are expressed using virtual classes seem to be very tightly coupled internally. While clients have achieved the freedom to dynamically use one or the other family, it seems that any given family contains a xed set of classes and we will need to create an entire family of its own just in order to replace one...... of the members with another class. This paper shows how to express class families in such a manner that the classes in these families can be used in many dierent combinations, still enabling family polymorphism and ensuring type safety....

  20. Wind Climate Parameters for Wind Turbine Fatigue Load Assessment

    DEFF Research Database (Denmark)

    Toft, Henrik Stensgaard; Svenningsen, Lasse; Moser, Wolfgang

    2016-01-01

    Site-specific assessment of wind turbine design requires verification that the individual wind turbine components can survive the site-specific wind climate. The wind turbine design standard, IEC 61400-1 (third edition), describes how this should be done using a simplified, equivalent wind climate...... climate required by the current design standard by comparing damage equivalent fatigue loads estimated based on wind climate parameters for each 10 min time-series with fatigue loads estimated based on the equivalent wind climate parameters. Wind measurements from Boulder, CO, in the United States...

  1. Comparison of multibody simulations and measurements of wind turbine gearboxes at Hansen’s 13 MW test facility

    OpenAIRE

    Marrant, Ben; Vanhollebeke, Frederik; Peeters, Joris

    2010-01-01

    Continuous up-scaling of wind turbine size into the multi-megawatt class, together with developments for off-shore installation are calling for new wind turbine configurations and technologies. High product reliability is a key factor in these developments, cascaded down to each component manufacturer in the supply chain. Increasing the reliability of wind turbine drive trains for wind turbines with ever increasing size requires dedicated simulation models which can provide more insight in th...

  2. High-efficiency wind turbine

    Science.gov (United States)

    Hein, L. A.; Myers, W. N.

    1980-01-01

    Vertical axis wind turbine incorporates several unique features to extract more energy from wind increasing efficiency 20% over conventional propeller driven units. System also features devices that utilize solar energy or chimney effluents during periods of no wind.

  3. Grid Integration Research | Wind | NREL

    Science.gov (United States)

    Grid Integration Research Grid Integration Research Researchers study grid integration of wind three wind turbines with transmission lines in the background. Capabilities NREL's grid integration electric power system operators to more efficiently manage wind grid system integration. A photo of

  4. Status of Wind Power Technologies

    DEFF Research Database (Denmark)

    Zhao, Haoran; Wu, Qiuwei

    2018-01-01

    With the development of wind turbine technology, wind power will become more controllable and grid‐friendly. It is desirable to make wind farms operate as conventional power plants. Wind turbine generators (WTGs) were mainly used in rural and remote areas for wind power generation. WTG‐based wind...... energy conversion systems (WECS) can be divided into the four main types (type 1‐4). Due to the inherent variability and uncertainty of the wind, the integration of wind power into the grid has brought challenges in several different areas, including power quality, system reliability, stability......, and planning. The impact of each is largely dependent on the level of wind power penetration in the grid. In many countries, relatively high levels of wind power penetration have been achieved. This chapter shows the estimated wind power penetration in leading wind markets....

  5. Type IV Wind Turbine Model

    DEFF Research Database (Denmark)

    Hansen, Anca Daniela; Margaris, Ioannis D.

    . In the project, this wind turbine model will be further incorporated in a wind power plant model together with the implementation in the wind power control level of the new control functionalities (inertial response, synchronising power and power system damping). For this purpose an aggregate wind power plant......This document is created as part of the EaseWind project. The goal of this project is to develop and investigate new control features for primary response provided by wind power plants. New control features as inertial response, synchronising power and power system damping are of interest to EaseWind...... project to be incorporated in the wind power plant level. This document describes the Type 4 wind turbine simulation model, implemented in the EaseWind project. The implemented wind turbine model is one of the initial necessary steps toward integrating new control services in the wind power plant level...

  6. Fort Carson Wind Resource Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Robichaud, R.

    2012-10-01

    This report focuses on the wind resource assessment, the estimated energy production of wind turbines, and economic potential of a wind turbine project on a ridge in the southeastern portion of the Fort Carson Army base.

  7. NORCOWE Reference Wind Farm

    DEFF Research Database (Denmark)

    Bak, Thomas; Graham, Angus

    2015-01-01

    Offshore wind farms are complex systems, influenced by both the environment (e.g. wind, waves, current and seabed) and the design characteristics of the equipment available for installation (e.g. turbine type, foundations, cabling and distance to shore). These aspects govern the capital and opera...

  8. Alcoa wind turbines

    Science.gov (United States)

    Ai, D. K.

    1979-01-01

    An overview of Alcoa's wind energy program is given with emphasis on the the development of a low cost, reliable Darrieus Vertical Axis Wind Turbine System. The design layouts and drawings for fabrication are now complete, while fabrication and installation to utilize the design are expected to begin shortly.

  9. The difficult wind power

    International Nuclear Information System (INIS)

    Groenaas, Sigbjoern

    2005-01-01

    The article presents a brief survey of the conditions for wind power production in Norway and points out that several areas should be well suited. A comparison to Danish climate is made. The wind variations, turbulence problems and regional conditions are discussed

  10. Wind Energy Systems.

    Science.gov (United States)

    Conservation and Renewable Energy Inquiry and Referral Service (DOE), Silver Spring, MD.

    During the 1920s and 1930s, millions of wind energy systems were used on farms and other locations far from utility lines. However, with passage of the Rural Electrification Act in 1939, cheap electricity was brought to rural areas. After that, the use of wind machines dramatically declined. Recently, the rapid rise in fuel prices has led to a…

  11. Emerging wind energy technologies

    DEFF Research Database (Denmark)

    Rasmussen, Flemming; Grivel, Jean-Claude; Faber, Michael Havbro

    2014-01-01

    This chapter will discuss emerging technologies that are expected to continue the development of the wind sector to embrace new markets and to become even more competitive.......This chapter will discuss emerging technologies that are expected to continue the development of the wind sector to embrace new markets and to become even more competitive....

  12. Fixture for winding transformers

    Science.gov (United States)

    Mclyman, M. T.

    1980-01-01

    Bench-mounted fixture assists operator in winding toroid-shaped transformer cores. Toroid is rigidly held in place as wires are looped around. Arrangement frees both hands for rapid winding and untangling of wires that occurs when core is hand held.

  13. Wind turbines and infrasound

    International Nuclear Information System (INIS)

    Howe, B.

    2006-01-01

    This paper provided the results of a study conducted to assess the impacts of wind farm-induced infrasound on nearby residences and human populations. Infrasound occurs at frequencies below those considered as detectable by human hearing. Infrasonic levels caused by wind turbines are often similar to ambient levels of 85 dBG or lower that are caused by wind in the natural environment. This study examined the levels at which infrasound poses a threat to human health or can be considered as an annoyance. The study examined levels of infrasound caused by various types of wind turbines, and evaluated acoustic phenomena and characteristics associated with wind turbines. Results of the study suggested that infrasound near modern wind turbines is typically not perceptible to humans through either auditory or non-auditory mechanisms. However, wind turbines often create an audible broadband noise whose amplitude can be modulated at low frequencies. A review of both Canadian and international studies concluded that infrasound generated by wind turbines should not significantly impact nearby residences or human populations. 17 refs., 2 tabs., 4 figs

  14. The wind farm business

    International Nuclear Information System (INIS)

    Kirby, T.

    1995-01-01

    This article highlights the tasks to be undertaken by the wind farm business starting with the initial site selection, through the planning stage and the consideration of technical matters, to the implementation and financial aspects. The current situation in the UK with regard to installed wind turbines, public attitude, and future prospects are discussed. (UK)

  15. South Baltic Wind Atlas

    DEFF Research Database (Denmark)

    Pena Diaz, Alfredo; Hahmann, Andrea N.; Hasager, Charlotte Bay

    A first version of a wind atlas for the South Baltic Sea has been developed using the WRF mesoscale model and verified by data from tall Danish and German masts. Six different boundary-layer parametrization schemes were evaluated by comparing the WRF results to the observed wind profiles at the m...

  16. Assessing offshore wind potential

    International Nuclear Information System (INIS)

    Adelaja, Adesoji; McKeown, Charles; Calnin, Benjamin; Hailu, Yohannes

    2012-01-01

    Quantifying wind potential is a pivotal initial step in developing and articulating a state’s policies and strategies for offshore wind industry development. This is particularly important in the Great Lakes States where lessons from other offshore environments are not directly applicable. This paper presents the framework developed for conducting a preliminary assessment of offshore wind potential. Information on lake bathymetry and wind resources were combined in simulating alternative scenarios of technically feasible turbine construction depths and distance concerns by stakeholders. These yielded estimates of developable offshore wind areas and potential power generation. While concerns about the visibility of turbines from shore reduce the power that can be generated, engineering solutions that increase the depths at which turbines can be sited increase such potential power output. This paper discusses the costs associated with technical limitations on depth and the social costs related to public sentiments about distance from the shoreline, as well as the possible tradeoffs. The results point to a very large untapped energy resource in the Michigan’s Great Lakes, large enough to prompt policy action from the state government. - Highlights: ▶ We build a theoretical framework for modeling offshore wind power production. ▶ Illustration of the impact of technology and social limitations on offshore wind energy development. ▶ Geospatial modeling of the offshore wind potential of the Great Lakes.

  17. Offshore Wind Power

    DEFF Research Database (Denmark)

    Negra, Nicola Barberis

    reliability models, and a new model that accounts for all relevant factors that influence the evaluations is developed. According to this representation, some simulations are performed and both the points of view of the wind farm owner and the system operator are evaluated and compared. A sequential Monte...... Carlo simulation is used for these calculations: this method, in spite of an extended computation time, has shown flexibility in performing reliability studies, especially in case of wind generation, and a broad range of results which can be evaluated. The modelling is then extended to the entire power......The aim of the project is to investigate the influence of wind farms on the reliability of power systems. This task is particularly important for large offshore wind farms, because failure of a large wind farm might have significant influence on the balance of the power system, and because offshore...

  18. Illinois Wind Workers Group

    Energy Technology Data Exchange (ETDEWEB)

    David G. Loomis

    2012-05-28

    The Illinois Wind Working Group (IWWG) was founded in 2006 with about 15 members. It has grown to over 200 members today representing all aspects of the wind industry across the State of Illinois. In 2008, the IWWG developed a strategic plan to give direction to the group and its activities. The strategic plan identifies ways to address critical market barriers to the further penetration of wind. The key to addressing these market barriers is public education and outreach. Since Illinois has a restructured electricity market, utilities no longer have a strong control over the addition of new capacity within the state. Instead, market acceptance depends on willing landowners to lease land and willing county officials to site wind farms. Many times these groups are uninformed about the benefits of wind energy and unfamiliar with the process. Therefore, many of the project objectives focus on conferences, forum, databases and research that will allow these stakeholders to make well-educated decisions.

  19. Extreme winds in Denmark

    DEFF Research Database (Denmark)

    Kristensen, L.; Rathmann, Ole; Hansen, S.O.

    1999-01-01

    Wind-speed data from four sites in Denmark have been analyzed in order to obtain estimates of the basic wind velocity which is defined as the 50-year wind speed under standard conditions, i.e. ten-minute averages at the height 10 m over a uniform terrainwith the roughness length 0.05 m. The sites...... by means of the geostrophic drag law for neutral stratification. The basic wind velocity in 30o sectors are obtainedthrough ranking of the largest values of the ¤friction velocity pressure¤ 1/2 ¤#rho#¤¤u¤"2_x taken both once every two months and once every year. The main conclusion is that the basic wind...

  20. Aerodynamics of Wind Turbines

    DEFF Research Database (Denmark)

    Hansen, Martin Otto Laver

    Aerodynamics of Wind Turbines is the established essential text for the fundamental solutions to efficient wind turbine design. Now in its second edition, it has been entirely updated and substantially extended to reflect advances in technology, research into rotor aerodynamics and the structural...... response of the wind turbine structure. Topics covered include increasing mass flow through the turbine, performance at low and high wind speeds, assessment of the extreme conditions under which the turbine will perform and the theory for calculating the lifetime of the turbine. The classical Blade Element...... Momentum method is also covered, as are eigenmodes and the dynamic behavior of a turbine. The new material includes a description of the effects of the dynamics and how this can be modeled in an aeroelastic code, which is widely used in the design and verification of modern wind turbines. Further...

  1. Ice accreditation vs wind

    Energy Technology Data Exchange (ETDEWEB)

    Sabourin, G. [Hydro-Quebec, PQ (Canada). TransEnergie Div.; Chouinard, L. [McGill Univ., Montreal, PQ (Canada); Feknous, N. [SNC-Lavalin, Montreal, PQ (Canada)

    2002-07-01

    Wind and ice data from Hydro Quebec and Environment Canada indicates that winds during ice storms are in the general direction of the St. Lawrence River. This observation is important for upgrading existing power transmission lines from the Manicouagan and Churchill generation system because they are parallel to the St. Lawrence and they were designed with lower criteria than is currently accepted. ASCE 74 suggests an accumulation ratio based on thickness of 0.70 for winds parallel to the line. The Goodwin model was used to calculate this ratio. The presentation includes illustrations showing the accumulation ratio for a north wind, as well as the accumulation ratios and wind roses at Quebec. A table showing a comparison of ratios from passive ice meters shows that results are similar to mean values from the theoretical model.

  2. Wind power forecast

    Energy Technology Data Exchange (ETDEWEB)

    Pestana, Rui [Rede Electrica Nacional (REN), S.A., Lisboa (Portugal). Dept. Systems and Development System Operator; Trancoso, Ana Rosa; Delgado Domingos, Jose [Univ. Tecnica de Lisboa (Portugal). Seccao de Ambiente e Energia

    2012-07-01

    Accurate wind power forecast are needed to reduce integration costs in the electric grid caused by wind inherent variability. Currently, Portugal has a significant wind power penetration level and consequently the need to have reliable wind power forecasts at different temporal scales, including localized events such as ramps. This paper provides an overview of the methodologies used by REN to forecast wind power at national level, based on statistical and probabilistic combinations of NWP and measured data with the aim of improving accuracy of pure NWP. Results show that significant improvement can be achieved with statistical combination with persistence in the short-term and with probabilistic combination in the medium-term. NWP are also able to detect ramp events with 3 day notice to the operational planning. (orig.)

  3. Tenth ASME wind energy symposium

    International Nuclear Information System (INIS)

    Berg, D.E.; Veers, P.S.

    1991-01-01

    This book contains papers presented at the Fourteenth Annual Energy-Sources Technology Conference and Exhibition. Included are the following papers: Wind Power Farm Site Selection, Turbulence characterization for wind energy development, Effects of insect configuration on wind turbine airfoils, Power fluctuations from horizontal and vertical axis wind turbines, Power regulation by active yaw control for a teetered wind rotor, and economic aspects of wind energy

  4. Offshore wind energy prospects

    International Nuclear Information System (INIS)

    Gaudiosi, Gaetano

    1999-01-01

    In last two years offshore wind energy is becoming a focal point of national and non national organisations particularly after the limitations of fossil fuel consumption, adopted by many developed countries after Kyoto conference at the end of 1997 on global climate change. North Europe is particularly interested in offshore for the limited land areas still available, due to the intensive use of its territory and its today high wind capacity. Really the total wind capacity in Europe could increase from the 1997 value of 4450 MW up to 40 000 MW within 2010, according the White Paper 1997 of the European Commission; a significant percentage (25%) could be sited offshore up to 10 000 MW, because of close saturation of the land sites at that time. World wind capacity could increase from the 1997 value of 7200 MW up to 60 000 MW within 2010 with a good percentage (20%) offshore 12 000 MW. In last seven years wind capacity in shallow water of coastal areas has reached 34 MW. Five wind farms are functioning in the internal seas of Netherlands, Denmark, Sweden; however such siting is mostly to be considered as semi-offshore condition. Wind farms in real offshore sites, open seas with waves and water depth over 10 m, are now proposed in North Sea at 10-20 km off the coasts of Netherlands, Denmark using large size wind turbine (1-2 MW). In 1997 an offshore proposal was supported in Netherlands by Greenpeace after the OWEMES '97 seminar, held in Italy on offshore wind in the spring 1997. A review is presented in the paper of European offshore wind programs with trends in technology, economics and siting effects. (Author)

  5. Wind power development field test project at Okkobe-cho. Close survey on wind conditions; Okkobecho ni okeru furyoku kaihatsu field test jigyo (fukyo seisa) hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-11-01

    A survey was made on regional wind conditions on the assumption that a wind power generator was installed around Okkobe Rakuno-no-oka, Okkobe-cho, Monbetsu-gun, Hokkaido. The survey period was one year from Oct., 1998 to Sept., 1999. The observations were carried out on the average wind velocity, average wind direction, standard deviation of velocity, and the maximum instantaneous wind velocity. With a fixed point observation at 20 m above ground, and with the minimum observation time unit of 10 minutes, an average value during the 10 minutes was determined as the measurement of each category. However, the maximum instantaneous wind velocity was determined on the measurement with the minimum observation time unit of 2 seconds. The average wind velocity was 4.8 m/s, the maximum wind velocity during the period was 29.9 m/s, the prevailing wind direction was WSW (17.1%), the wind axis was WSW-ENE, and the total occurrence rate of wind direction was 51.1%. The intensity of turbulence was 0.19 at a wind velocity of 2.0 m/s or above and was 0.16 at 4.0 m/s or above. An estimated annual operation rate of a windmill was 59-77% using the rated value of a 150 kW, 300 kW and 750 kW class windmills. (NEDO)

  6. Report on field test project for wind power development at Nagashima-cho. Detailed wind characteristics survey; Nagashimacho ni okeru furyoku field test jigyo (fukyo seisa) hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-11-01

    A detailed wind characteristics survey was conducted to study the feasibility of a wind power generation system for Nagashima-cho, Izumi-gun, Kagoshima Prefecture. Observation instruments were installed at the top of a hill approximately 80m above the sea level situated to the northwest of the Nagashima-cho town hall and, in the period October 1998 through September 1999, data were collected at a point 20m above ground, such as the average wind speed and direction, wind velocity standard deviation, and the maximum instantaneous wind velocity. The data were analyzed, and findings were obtained, as mentioned below. The annual average wind speed was 5.0m, strong in winter and weak in summer. The annual wind direction occurrence rate was 61.8%, turbulence intensity was 0.17 at wind speeds of 4m/s and more, these not presenting any particular problem. Wind energy density was 148W/m{sup 2}. Both wind speed conditions and energy density were slightly lower than the reference levels indicated for evaluation. Studies were made on the assumption that three classes of wind turbines (150, 300, and 750kW) would be introduced, and then it was found that both operating factors and facility availability rates exceeded the required levels. Since there were no detrimental factors in the surrounding conditions, it was concluded that possibilities were high that wind power generation at the site would be practical. (NEDO)

  7. Wind power development field test project at Kodomari-mura 'Marinetopia'. Close survey on wind conditions; Kodomarimura Marinetopia ni okeru furyoku kaihatsu field test jigyo (fukyo seisa) hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-11-01

    A survey was made on wind conditions in Imabetsu-machi, Higashi Tsugaru-gun, Aomori prefecture, on the assumption that a wind power generation system was installed therein. The survey period was one year from Oct., 1998 to Sept., 1999. The observations were carried out on the average wind velocity, average wind direction, standard deviation of velocity, and the maximum instantaneous wind velocity. With a fixed point observation at 20 m above ground, and with the minimum observation time unit of 10 minutes, an average value during the 10 minutes was determined as the measurement of each category. However, the maximum instantaneous wind velocity was determined on the measurement with the minimum observation time unit of 2 seconds. The annual average wind velocity was 4.8 m/s, the maximum wind velocity during the period was 35 m/s, the prevailing wind direction was NW-WNW and ESE-SEW, and the occurrence rate of wind direction at the wind axis of NW-SE was 88.1%. The intensity of turbulence was 0.24 at a wind velocity of 2.0 m/s or above and was 0.20 at 4.0 m/s or above. An estimated annual operation rate of a windmill was 46-64% using the rated value of a 150 kW, 300 kW and 750 kW class windmills. (NEDO)

  8. European Wind Atlas and Wind Resource Research in Denmark

    DEFF Research Database (Denmark)

    Mortensen, Niels Gylling

    to estimate the actual wind climate at any specific site and height within this region. The Danish and European Wind Atlases are examples of how the wind atlas methodology can be employed to estimate the wind resource potential for a country or a sub-continent. Recently, the methodology has also been used...... - from wind measurements at prospective sites to wind tunnel simulations and advanced flow modelling. Among these approaches, the wind atlas methodology - developed at Ris0 National Laboratory over the last 25 years - has gained widespread recognition and is presently considered by many as the industry......-standard tool for wind resource assessment and siting of wind turbines. The PC-implementation of the methodology, the Wind Atlas Analysis and Application Program (WAsP), has been applied in more than 70 countries and territories world-wide. The wind atlas methodology is based on physical descriptions and models...

  9. Strongly at the wind; Hart am Wind

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Niels Hendrik

    2013-11-01

    The company Easywind from North Friesland distributes a certified and stromproof small wind turbine. More than 300 systems have been sold. In Germany especially farmers and small businesses meet their needs so. [German] Die Firma Easywind aus Nordfriesland vertreibt eine zertifizierte und sturmfeste Kleinwindanlage. Mehr als 300 Anlagen sind bereits verkauft. In Deutschland decken vor allem Landwirte und kleine Betriebe so ihren Bedarf.

  10. Wind power: Italian wind power industry

    International Nuclear Information System (INIS)

    Botta, G.; Casale, C.

    2008-01-01

    Trends in the world point a growing wind power sector in the future taking into account the safety of energy supply and environmental issues. Will determine the future scenario of price and availability of conventional energy sources. The current level reached by the price of oil create a win-win situation [it

  11. Wind tipping point

    International Nuclear Information System (INIS)

    Wood, E.

    2006-01-01

    In this article the author looks at how in five years wind energy has rapidly evolved into a mainstream industry. The United States has begun to look at wind differently - from a macroeconomic perspective.'This country is going to become increasingly committed to renewable energy, and it's not about altruism', said Alan Waxman, managing director of Goldman Sachs and Co., a financial giant that has invested $1 billion in the resource. Wind is seen not just as an environmentally benign alternative, but also as a means to solve some large problems plaguing the energy business and ultimately the United States as a whole. The last year brought record-breaking electricity rate increases, in some cases doubling consumer costs, and escalating the flight of large enterprises out of high-cost energy regions - or out of business altogether. The rate hikes were caused by hurricanes that hit the southern states and disrupted natural gas and oil operations. Adding wind power to the grid is increasingly seen as a way to limit the price shock caused by such events. Wind power reduces reliance on gas and oil-fired generation and, in particular, creates a hedge against spikes in natural gas, a fuel that increasingly sets the marginal price. Large energy users, too, are becoming aware of wind's hedging benefits. The author looks at the cost issues and how the future of wind energy in the country can be sustained as a reliable alternative fuel

  12. Wind farms and planning

    International Nuclear Information System (INIS)

    Arkesteijn, L.; Havinga, R.; Benner, J.H.B.

    1992-01-01

    The siting of wind farms is becoming an increasingly important issue in the Netherlands. This paper gives an overview of the current situation concerning the planning of wind farms. We will pay attention to: Wind energy in official Dutch planning policy. To select the optimal sites, the government has made an administrative agreement with the 7 windy provinces. Nevertheless, wind energy is still fighting for a rightful position in physical planning policy. Some examples will illustrate this. Studies on siting and siting problems in the Netherlands. In order to gain more insight into aspects of wind farming several studies have been executed. In this paper special attention will be paid to the results of a study on the potential impact of large windturbine clusters on an existing agricutural area. Experiences with siting of wind farms in the Netherlands. Based on experiences with the planning and realization of farms, this paper gives the main problems. In the final part of the paper we present some general conclusions. Generally speaking, the knowledge is available for selecting optimal sites in the Netherlands. The basic problems for wind farming nowadays seem to be the visual impact and actually obtaining the ground. Nevertheless, there do seem to be enough sites for realizing the goals in the Netherlands. (au)

  13. Wind energy in Europe

    International Nuclear Information System (INIS)

    Sesto, E.

    1992-02-01

    Interest in wind energy as a supplementary source for the production of electricity has recently gained renewed momentum due to widespread concern about environmental impacts from the large scale use of fossil fuels and nuclear energy. In addition, political unrest in the Middle East has drawn attention to the importance of national energy self-sufficiency. European government administrations, however, have not yet fully appreciated the real worth of the 'clean energy' afforded by wind energy. In this regard, the European Wind Energy Association (EWEA) is acting as a strong voice to inform the public and energy planners by stimulating international wind energy R ampersand D cooperation, and organizing conferences to explain the advantages of wind energy. In October 1991, EWEA published a strategy document giving a picture of the real possibilities offered by wind energy within the geographical, social, and European economic context. This paper provides an overview of the more significant features to emerge from this document which represents a useful guideline for wind power plant technical/economic feasibility studies in that it contains brief notes on resource availability, land requirements, visual and acoustic impacts, turbine sizing, performance, interconnection to utility grids, maintenance and operating costs, safety, as well as, on marketing aspects

  14. Wind and tornado guidelines

    International Nuclear Information System (INIS)

    McDonald, J.R.

    1989-01-01

    The objective of the Department of Energy Natural Phenomena Hazards Project is to provide guidance and criteria for design of new facilities and for evaluation of existing ones subjected to extreme winds, earthquakes, and floods. This paper describes the treatment of wind and tornado hazards. Four facility-use categories are defined which represent increasing levels of risk to personnel or the environment in the event of a high wind event. Facilities are assigned to a particular category, depending on their mission, value, or toxic material content. The assigned facility-use category determines the design and evaluation criteria. The criteria are based on probabilistic hazard assessment. Performance goals are also specified for each facility-use category. A uniform approach to design wind loads, based on the ANSI A58.1-1982 standard, allows treatment of high winds and hurricane and tornado winds in a similar manner. Based on the wind hazard models, some sites must account for the possibility of tornadoes while others do not. Atmospheric pressure changes and missiles must be taken into account when considering tornadoes. The design and evaluation guidelines are designed to establish consistent levels of risk for different natural phenomena hazards and for facilities at different geographical locations

  15. Betting on wind energy

    International Nuclear Information System (INIS)

    2009-11-01

    In the first part of this study, the authors try to identify whether the economical and environmental context is adapted to the wind energy development. In order to do so, they discuss wind energy as a possible answer to climate emergency, critics formulated against wind energy, the effects of the financial crisis and the opportunities offered by wind energy within this crisis. In the second part, they discuss the French context and the debates on wind energy, highlighting the importance of some parameters in the cost analysis of wind turbine, presenting the results of a sensitivity analysis, and highlighting the importance of the over-cost calculation. They assess the current development status of the French wind energy industry and underline the opportunities for the future. In the third part, they describe the development status, lever and perspectives in different countries: Germany where the development of this sector has been successful, China which is becoming a major actor, the United States which are displaying the highest growth in this area, and Denmark which is the world leader

  16. Database on wind characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, K.S. [The Technical Univ. of Denmark (Denmark); Courtney, M.S. [Risoe National Lab., (Denmark)

    1999-08-01

    The organisations that participated in the project consists of five research organisations: MIUU (Sweden), ECN (The Netherlands), CRES (Greece), DTU (Denmark), Risoe (Denmark) and one wind turbine manufacturer: Vestas Wind System A/S (Denmark). The overall goal was to build a database consisting of a large number of wind speed time series and create tools for efficiently searching through the data to select interesting data. The project resulted in a database located at DTU, Denmark with online access through the Internet. The database contains more than 50.000 hours of measured wind speed measurements. A wide range of wind climates and terrain types are represented with significant amounts of time series. Data have been chosen selectively with a deliberate over-representation of high wind and complex terrain cases. This makes the database ideal for wind turbine design needs but completely unsuitable for resource studies. Diversity has also been an important aim and this is realised with data from a large range of terrain types; everything from offshore to mountain, from Norway to Greece. (EHS)

  17. Wind energy potential in Bulgaria

    International Nuclear Information System (INIS)

    Shtrakov, Stanko Vl.

    2009-01-01

    In this study, wind characteristic and wind energy potential in Bulgaria were analyzed using the wind speed data. The wind energy potential at different sites in Bulgaria has been investigated by compiling data from different sources and analyzing it using a software tool. The wind speed distribution curves were obtained by using the Weibull and Rayleigh probability density functions. The results relating to wind energy potential are given in terms of the monthly average wind speed, wind speed probability density function (PDF), wind speed cumulative density function (CDF), and wind speed duration curve. A technical and economic assessment has been made of electricity generation from three wind turbines having capacity of (60, 200, and 500 kW). The yearly energy output capacity factor and the electrical energy cost of kWh produced by the three different turbines were calculated

  18. Mongolia wind resource assessment project

    International Nuclear Information System (INIS)

    Elliott, D.; Chadraa, B.; Natsagdorj, L.

    1998-01-01

    The development of detailed, regional wind-resource distributions and other pertinent wind resource characteristics (e.g., assessment maps and reliable estimates of seasonal, diurnal, and directional) is an important step in planning and accelerating the deployment of wind energy systems. This paper summarizes the approach and methods being used to conduct a wind energy resource assessment of Mongolia. The primary goals of this project are to develop a comprehensive wind energy resource atlas of Mongolia and to establish a wind measurement program in specific regions of Mongolia to identify prospective sites for wind energy projects and to help validate some of the wind resource estimates. The Mongolian wind resource atlas will include detailed, computerized wind power maps and other valuable wind resource characteristic information for the different regions of Mongolia

  19. Class, Culture and Politics

    DEFF Research Database (Denmark)

    Harrits, Gitte Sommer

    2013-01-01

    Even though contemporary discussions of class have moved forward towards recognizing a multidimensional concept of class, empirical analyses tend to focus on cultural practices in a rather narrow sense, that is, as practices of cultural consumption or practices of education. As a result......, discussions within political sociology have not yet utilized the merits of a multidimensional conception of class. In light of this, the article suggests a comprehensive Bourdieusian framework for class analysis, integrating culture as both a structural phenomenon co-constitutive of class and as symbolic...... practice. Further, the article explores this theoretical framework in a multiple correspondence analysis of a Danish survey, demonstrating how class and political practices are indeed homologous. However, the analysis also points at several elements of field autonomy, and the concluding discussion...

  20. Class network routing

    Science.gov (United States)

    Bhanot, Gyan [Princeton, NJ; Blumrich, Matthias A [Ridgefield, CT; Chen, Dong [Croton On Hudson, NY; Coteus, Paul W [Yorktown Heights, NY; Gara, Alan G [Mount Kisco, NY; Giampapa, Mark E [Irvington, NY; Heidelberger, Philip [Cortlandt Manor, NY; Steinmacher-Burow, Burkhard D [Mount Kisco, NY; Takken, Todd E [Mount Kisco, NY; Vranas, Pavlos M [Bedford Hills, NY

    2009-09-08

    Class network routing is implemented in a network such as a computer network comprising a plurality of parallel compute processors at nodes thereof. Class network routing allows a compute processor to broadcast a message to a range (one or more) of other compute processors in the computer network, such as processors in a column or a row. Normally this type of operation requires a separate message to be sent to each processor. With class network routing pursuant to the invention, a single message is sufficient, which generally reduces the total number of messages in the network as well as the latency to do a broadcast. Class network routing is also applied to dense matrix inversion algorithms on distributed memory parallel supercomputers with hardware class function (multicast) capability. This is achieved by exploiting the fact that the communication patterns of dense matrix inversion can be served by hardware class functions, which results in faster execution times.

  1. Culture and social class.

    Science.gov (United States)

    Miyamoto, Yuri

    2017-12-01

    A large body of research in Western cultures has demonstrated the psychological and health effects of social class. This review outlines a cultural psychological approach to social stratification by comparing psychological and health manifestations of social class across Western and East Asian cultures. These comparisons suggest that cultural meaning systems shape how people make meaning and respond to material/structural conditions associated with social class, thereby leading to culturally divergent manifestations of social class. Specifically, unlike their counterparts in Western cultures, individuals of high social class in East Asian cultures tend to show high conformity and other-orientated psychological attributes. In addition, cultures differ in how social class impacts health (i.e. on which bases, through which pathways, and to what extent). Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Stellar wind theory

    International Nuclear Information System (INIS)

    Summers, D.

    1980-01-01

    The theory of stellar winds as given by the equations of classical fluid dynamics is considered. The equations of momentum and energy describing a steady, spherically symmetric, heat-conducting, viscous stellar wind are cast in a dimensionless form which involves a thermal conduction parameter E and a viscosity parameter γ. An asymptotic analysis is carried out, for fixed γ, in the cases E→O and E→infinity (corresponding to small and large thermal conductivity, respectively), and it is found that it is possible to construct critical solutions for the wind velocity and temperature over the entire flow. The E→O solution represents a wind which emanates from the star at low, subsonic speeds, accelerates through a sonic point, and then approaches a constant asymptotic speed, with its temperature varying as r/sup -4/3/ at large distances r from the star; the E→infinity solution represents a wind which, after reaching an approximately constant speed, with temperature varying as r/sup -2/7/, decelerates through a diffuse shock and approaches a finite pressure at infinity. A categorization is made of all critical stellar wind solutions for given values of γ and E, and actual numerical examples are given. Numerical solutions are obtained by integrating upstream 'from infinity' from initial values of the flow parameters given by appropriate asymptotic expansions. The role of viscosity in stellar wind theory is discussed, viscous and inviscid stellar wind solutions are compared, and it is suggested that with certain limitations, the theory presented may be useful in analyzing winds from solar-type stars

  3. Semantic Analysis of Virtual Classes and Nested Classes

    DEFF Research Database (Denmark)

    Madsen, Ole Lehrmann

    1999-01-01

    Virtual classes and nested classes are distinguishing features of BETA. Nested classes originated from Simula, but until recently they have not been part of main stream object- oriented languages. C++ has a restricted form of nested classes and they were included in Java 1.1. Virtual classes...... classes and parameterized classes have been made. Although virtual classes and nested classes have been used in BETA for more than a decade, their implementation has not been published. The purpose of this paper is to contribute to the understanding of virtual classes and nested classes by presenting...

  4. Class in disguise

    DEFF Research Database (Denmark)

    Faber, Stine Thidemann; Prieur, Annick

    This paper asks how class can have importance in one of the worlds’ most equal societies: Denmark. The answer is that class here appears in disguised forms. The field under study is a city, Aalborg, in the midst of transition from a stronghold of industrialism to a post industrial economy. The pa....... The paper also raises questions about how sociological discourses may contribute to the veiling of class....

  5. Generation of electricity by wind power

    Energy Technology Data Exchange (ETDEWEB)

    Golding, E W

    1976-01-01

    Information on wind power is presented concerning the history of windmills; estimation of the energy obtainable from the wind; wind characteristics and distribution; wind power sites; wind surveys; wind flow over hills; measurement of wind velocity; wind structure and its determination; wind data and energy estimation; testing of wind driven ac generators; wind-driven machines; propeller type windmills; plants for isolated premises and small communities; economy of wind power generation; construction costs for large wind-driven generators; relationship of wind power to other power sources; research and development; and international cooperation.

  6. Wind for Schools: A Wind Powering America Project

    Science.gov (United States)

    US Department of Energy, 2007

    2007-01-01

    The U.S. Department of Energy's (DOE's) Wind Powering America program (based at the National Renewable Energy Laboratory) sponsors the Wind for Schools Project to raise awareness in rural America about the benefits of wind energy while simultaneously educating college seniors regarding wind energy applications. The three primary project goals of…

  7. Marine wind data presentation using wind transition matrix

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas, A.J.; Gouveia, A.D.; Desai, R.G.P.

    One of the methods to simulate the random wind behaviour through time is to use historical wind data presented in the form of wind transition matrix. Here it is assumed that, the probability that the wind will shift from one direction to another...

  8. Wind farm design optimization

    Energy Technology Data Exchange (ETDEWEB)

    Carreau, Michel; Morgenroth, Michael; Belashov, Oleg; Mdimagh, Asma; Hertz, Alain; Marcotte, Odile

    2010-09-15

    Innovative numerical computer tools have been developed to streamline the estimation, the design process and to optimize the Wind Farm Design with respect to the overall return on investment. The optimization engine can find the collector system layout automatically which provide a powerful tool to quickly study various alternative taking into account more precisely various constraints or factors that previously would have been too costly to analyze in details with precision. Our Wind Farm Tools have evolved through numerous projects and created value for our clients yielding Wind Farm projects with projected higher returns.

  9. Wind Farm Wake

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Karagali, Ioanna; Volker, Patrick

    2017-01-01

    On 25 January 2016 at 12:45 UTC several photographs of the offshore wind farm Horns Rev 2 were taken by helicopter pilot Gitte Lundorff with an iPhone. A very shallow layer of fog covered the sea. The photos of the fog over the sea dramatically pictured the offshore wind farm wake. Researchers got...... together to investigate the atmospheric conditions at the time of the photos by analysing local meteorological observations and wind turbine information, satellite remote sensing and nearby radiosonde data. Two wake models and one mesoscale model were used to model the case and explain what was seen....

  10. Financing renewables - wind energy

    International Nuclear Information System (INIS)

    Armstrong, J.

    1998-01-01

    This paper describes the status of the wind energy markets world-wide, in Europe and in the UK. It outlines the main methods of financing wind energy installations and discusses why different institutional structures have led to different markets in the UK and in Germany, with some concern about the state of the UK onshore industry. The paper looks ahead to the opening up of the potentially much larger offshore wind resource, concluding that in this area, existing UK development and financing structures are well suited. (Author)

  11. Wind power plant

    Energy Technology Data Exchange (ETDEWEB)

    Kling, A

    1977-01-13

    The wind power plant described has at least one rotor which is coupled to an electricity generator. The systems are fixed to a suspended body so that it is possible to set up the wind power plant at greater height where one can expect stronger and more uniform winds. The anchoring on the ground or on a floating body is done by mooring cables which can simultaneously have the function of an electric cable. The whole system can be steered by fins. The rotor system itself consists of at least one pair of contrarotating, momentum balanced rotors.

  12. Equivalent models of wind farms by using aggregated wind turbines and equivalent winds

    International Nuclear Information System (INIS)

    Fernandez, L.M.; Garcia, C.A.; Saenz, J.R.; Jurado, F.

    2009-01-01

    As a result of the increasing wind farms penetration on power systems, the wind farms begin to influence power system, and therefore the modeling of wind farms has become an interesting research topic. In this paper, new equivalent models of wind farms equipped with wind turbines based on squirrel-cage induction generators and doubly-fed induction generators are proposed to represent the collective behavior on large power systems simulations, instead of using a complete model of wind farms where all the wind turbines are modeled. The models proposed here are based on aggregating wind turbines into an equivalent wind turbine which receives an equivalent wind of the ones incident on the aggregated wind turbines. The equivalent wind turbine presents re-scaled power capacity and the same complete model as the individual wind turbines, which supposes the main feature of the present equivalent models. Two equivalent winds are evaluated in this work: (1) the average wind from the ones incident on the aggregated wind turbines with similar winds, and (2) an equivalent incoming wind derived from the power curve and the wind incident on each wind turbine. The effectiveness of the equivalent models to represent the collective response of the wind farm at the point of common coupling to grid is demonstrated by comparison with the wind farm response obtained from the detailed model during power system dynamic simulations, such as wind fluctuations and a grid disturbance. The present models can be used for grid integration studies of large power system with an important reduction of the model order and the computation time

  13. Operation Design of Wind Turbines in Strong Wind Conditions

    DEFF Research Database (Denmark)

    Shen, Wen Zhong; Montes, Melissa Barroso; Odgaard, Peter Fogh

    2012-01-01

    and variable speed pitch regulated wind turbines. The variable speed design is more suitable for wind turbines to run at very high wind speeds which can help the turbine braking system to stop the turbine at the new "cut-out" wind speed. Reference power, rotational speed and pitch angle have been designed...... optimally. In order to reduce the possible increased loading, fatigue due to the wind gusts, control strategies have been considered for both constant sped and variable speed pitch regulated wind turbines. The control study shows that the designed controllers can reduce the standard deviations efficiently......In order to reduce the impact on the electrical grid from the shutdown of MW wind turbines at wind speeds higher than the cut-out wind speed of 25 m/s, we propose in this paper to run the turbines at high wind speeds up to 40 m/s. Two different operation designs are made for both constant speed...

  14. A study on the possibility of cooling of schools by natural wind flow. Paper no. IGEC-1-146

    International Nuclear Information System (INIS)

    Setodemaram, K.; Golneshan, A.A.; Jafarpur, Kh.

    2005-01-01

    In this paper, the possibility of using 'wind' to cool (by wind tower) the air spaces in schools is studied. In order to study the effect of wind tower on natural cooling of schools, one has to determine the value of convective heat transfer coefficient in the classes. For this purpose, a 1:35 scale plexi glass model of a typical 8- classes school was made and a series of experiments were conducted in a wind tunnel. Mass transfer analogy using naphthalene sublimation was employed to measure the convective heat transfer coefficient in the model. It's worth mentioning that the plexi-model was equipped with a Baud-geer (wind tower) for studying of air into classes. After determining the convective heat transfer coefficient, effect of students and night ventilation on temperature variations in the classes was studied by computer simulation. (author)

  15. Operation and control of large wind turbines and wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, Poul; Hansen, Anca D.; Thomsen, Kenneth (and others)

    2005-09-01

    This report is the final report of a Danish research project 'Operation and control of large wind turbines and wind farms'. The objective of the project has been to analyse and assess operational strategies and possibilities for control of different types of wind turbines and different wind farm concepts. The potentials of optimising the lifetime/energy production ratio by means of using revised operational strategies for the individual wind turbines are investigated. Different strategies have been simulated, where the power production is decreased to an optimum when taking loads and actual price of produced electricity into account. Dynamic models and control strategies for the wind farms have also been developed, with the aim to optimise the operation of the wind farms considering participation in power system control of power (frequency) and reactive power (voltage), maximise power production, keep good power quality and limit mechanical loads and life time consumption. The project developed models for 3 different concepts for wind farms. Two of the concepts use active stall controlled wind turbines, one with AC connection and one with modern HVDC/VSC connection of the wind farm. The third concept is based on pitch controlled wind turbines using doubly fed induction generators. The models were applied to simulate the behaviour of the wind farm control when they were connected to a strong grid, and some initial simulations were performed to study the behaviour of the wind farms when it was isolated from the main grid on a local grid. Also the possibility to use the available information from the wind turbine controllers to predict the wind speed has been investigated. The main idea has been to predict the wind speed at a wind turbine using up-wind measurements of the wind speed in another wind turbine. (au)

  16. Noise from wind turbines

    International Nuclear Information System (INIS)

    Andersen, B.; Larsen, P.

    1993-01-01

    Denmark has 3200 wind turbines with an installed maximum capacity of 418MW. The most important Danish research projects into wind turbine noise and the main results are listed. These date from 1983. Two comprehensive studies are currently in progress. The first is an analytical and empirical investigation of aerodynamic noise from wind turbine rotors and has so far dealt mainly with tip noise. The measurement method, using a hard board mounted microphone on the ground near the turbine, is described. Four different tip designs have been tested. Some examples of reference sound power level spectra for three of the designs are presented. During the past two years a computerbased data acquisition system has been used for real-time determination of sound power levels. The second study, which has just commenced, is on annoyance from wind turbine noise. It will include noise measurements, masking calculations and a social survey on the perceived nuisance. (UK)

  17. Wind_Speeds_Master

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set included wind speeds for each subregion in the study (Georges Bank, Gulf of Maine, Southern New England, Middle Atlantic Bight) . The data came from...

  18. Superconducting Wind Turbine Generators

    DEFF Research Database (Denmark)

    Mijatovic, Nenad

    A HTS machine could be a way to address some of the technical barriers offshore wind energy is about to face. Due to the superior power density of HTS machines, this technology could become a milestone on which many, including the wind industry, will rely in the future. The work presented...... in this thesis is a part of a larger endeavor, the Superwind project that focused on identifying the potentials that HTS machines could offer to the wind industry and addressing some of the challenges in the process. In order to identify these challenges, I have design and constructed a HTS machine experimental...... setup which is made to serve as precursor, leading towards an optimized HTS machine concept proposed for wind turbines. In part, the work presented in this thesis will focus on the description of the experimental setup and reasoning behind the choices made during the design. The setup comprises from...

  19. Wind Profiling Radar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Clutter present in radar return signals as used for wind profiling is substantially removed by carrying out a Daubechies wavelet transformation on a time series of...

  20. Wind Plant Ramping Behavior

    Energy Technology Data Exchange (ETDEWEB)

    Ela, E.; Kemper, J.

    2009-12-01

    With the increasing wind penetrations, utilities and operators (ISOs) are quickly trying to understand the impacts on system operations and planning. This report focuses on ramping imapcts within the Xcel service region.

  1. Aerodynamics of wind turbines

    DEFF Research Database (Denmark)

    Hansen, Martin Otto Laver

    Aerodynamics of Wind Turbines is the established essential text for the fundamental solutions to efficient wind turbine design. Now in its third edition, it has been substantially updated with respect to structural dynamics and control. The new control chapter now includes details on how to design...... Turbines (VAWT). Topics covered include increasing mass flow through the turbine, performance at low and high wind speeds, assessment of the extreme conditions under which the turbine will perform and the theory for calculating the lifetime of the turbine. The classical Blade Element Momentum method...... is also covered, as are eigenmodes and the dynamic behaviour of a turbine. The book describes the effects of the dynamics and how this can be modelled in an aeroelastic code, which is widely used in the design and verification of modern wind turbines. Furthermore, it examines how to calculate...

  2. Small Wind Energy Systems

    DEFF Research Database (Denmark)

    Simões, Marcelo Godoy; Farret, Felix Alberto; Blaabjerg, Frede

    2017-01-01

    considered when selecting a generator for a wind power plant, including capacity of the AC system, types of loads, availability of spare parts, voltage regulation, technical personal and cost. If several loads are likely inductive, such asphase-controlled converters, motors and fluorescent lights......This chapter intends to serve as a brief guide when someone is considering the use of wind energy for small power applications. It is discussed that small wind energy systems act as the major energy source for residential or commercial applications, or how to make it part of a microgrid...... as a distributed generator. In this way, sources and loads are connected in such a way to behave as a renewable dispatch center. With this regard, non-critical loads might be curtailed or shed during times of energy shortfall or periods of high costs of energy production. If such a wind energy system is connected...

  3. Wind Tunnel Testing Facilities

    Data.gov (United States)

    Federal Laboratory Consortium — NASA Ames Research Center is pleased to offer the services of our premier wind tunnel facilities that have a broad range of proven testing capabilities to customers...

  4. Wind project gets boost

    Energy Technology Data Exchange (ETDEWEB)

    Oirere, Shem

    2012-11-01

    The development of a two-phase 100 MW wind power plant project in Tanzania moved a notch higher this year when Export-Import Bank of China extended a US$ 123 million non-concessional loan for its construction.

  5. Distributed Wind Market Applications

    Energy Technology Data Exchange (ETDEWEB)

    Forsyth, T.; Baring-Gould, I.

    2007-11-01

    Distributed wind energy systems provide clean, renewable power for on-site use and help relieve pressure on the power grid while providing jobs and contributing to energy security for homes, farms, schools, factories, private and public facilities, distribution utilities, and remote locations. America pioneered small wind technology in the 1920s, and it is the only renewable energy industry segment that the United States still dominates in technology, manufacturing, and world market share. The series of analyses covered by this report were conducted to assess some of the most likely ways that advanced wind turbines could be utilized apart from large, central station power systems. Each chapter represents a final report on specific market segments written by leading experts in this field. As such, this document does not speak with one voice but rather a compendium of different perspectives, which are documented from a variety of people in the U.S. distributed wind field.

  6. Aeroservoelasticity of Wind Turbines

    DEFF Research Database (Denmark)

    Kallesøe, Bjarne Skovmose

    2007-01-01

    This thesis deals with the fundamental aeroelastic interaction between structural motion, Pitch action and control for a wind turbine blade. As wind turbines become larger, the interaction between pitch action, blade motion, aerodynamic forces, and control become even more important to understand......, and furthermore linear and therefore suitable for control design. The development of the primary aeroelastic blade model is divided into four steps: 1) Nonlinear partial differential equations (PDEs) of structural blade motion are derived together with equations of pitch action and rotor speed; the individual...... to a 2D blade section model, and it can be used instead of this in many applications, giving a transparent connection to a real wind turbine blade. In this work the aeroelastic blade model is used to analyze interaction between pitch action, blade motion and wind speed variations. Furthermore the model...

  7. Monitoring of wind turbines

    Science.gov (United States)

    White, Jonathan R.; Adams, Douglas E.; Paquette, Josh

    2017-07-25

    Method and apparatus for determining the deflection or curvature of a rotating blade, such as a wind turbine blade or a helicopter blade. Also, methods and apparatus for establishing an inertial reference system on a rotating blade.

  8. Wind Turbine Acoustics

    Science.gov (United States)

    Hubbard, Harvey H.; Shepherd, Kevin P.

    2009-01-01

    Wind turbine generators, ranging in size from a few kilowatts to several megawatts, are producing electricity both singly and in wind power stations that encompass hundreds of machines. Many installations are in uninhabited areas far from established residences, and therefore there are no apparent environmental impacts in terms of noise. There is, however, the potential for situations in which the radiated noise can be heard by residents of adjacent neighborhoods, particularly those neighborhoods with low ambient noise levels. A widely publicized incident of this nature occurred with the operation of the experimental Mod-1 2-MW wind turbine, which is described in detail elsewhere. Pioneering studies which were conducted at the Mod-1 site on the causes and remedies of noise from wind turbines form the foundation of much of the technology described in this chapter.

  9. Wind Tunnel Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This ARDEC facility consists of subsonic, transonic, and supersonic wind tunnels to acquire aerodynamic data. Full-scale and sub-scale models of munitions are fitted...

  10. EDITORIAL: Wind energy

    Science.gov (United States)

    Mann, Jakob; Nørkær Sørensen, Jens; Morthorst, Poul-Erik

    2008-01-01

    Wind energy is rapidly growing. In 2006 the installed generating capacity in the world increased by 25%, a growth rate which has more or less been sustained during the last decade. And there is no reason to believe that this growth will slow significantly in the coming years. For example, the United Kingdom's goal for installed wind turbines by 2020 is 33 GW up from 2 GW in 2006, an average annual growth rate of 22% over that period. More than half of all turbines are installed in Europe, but United States, India and lately China are also rapidly growing markets. The cradle of modern wind energy was set by innovative blacksmiths in rural Denmark. Now the wind provides more than 20% of the electrical power in Denmark, the industry has professionalized and has close ties with public research at universities. This focus issue is concerned with research in wind energy. The main purposes of research in wind energy are to: decrease the cost of power generated by the wind; increase the reliability and predictability of the energy source; investigate and reduce the adverse environmental impact of massive deployment of wind turbines; build research based educations for wind energy engineers. This focus issue contains contributions from several fields of research. Decreased costs cover a very wide range of activities from aerodynamics of the wind turbine blades, optimal site selection for the turbines, optimization of the electrical grid and power market for a fluctuating source, more efficient electrical generators and gears, and new materials and production techniques for turbine manufacturing. The United Kingdom recently started the construction of the London Array, a 1 GW off-shore wind farm east of London consisting of several hundred turbines. To design such a farm optimally it is necessary to understand the chaotic and very turbulent flow downwind from a turbine, which decreases the power production and increases the mechanical loads on other nearby turbines. Also

  11. 2010 Wind Technologies Market Report

    Energy Technology Data Exchange (ETDEWEB)

    Ryan Wiser, Mark Bolinger

    2011-06-01

    This report provides a comprehensive overview of trends in the U.S. wind power market in 2010. The report analyzes trends in wind power capacity, industry, manufacturing, turbines, installed project costs, project performance, and wind power prices. It also describes trends among wind power developers, project owners, and power purchasers, and discusses financing issues.

  12. Wind energy: A viable alternative

    International Nuclear Information System (INIS)

    Soin, R.S.

    1991-01-01

    This article examines the economic feasibility of wind energy in the current economic and political environment. The article specifically addresses the wind farm application to India, with asides to Europe and the US. Topics discussed include cost of energy generation for a 10 MW wind farm, cost comparison for captive energy options (diesel, coal, wind), environmental impacts, and social benefits

  13. Wind energy utilization: A bibliography

    Science.gov (United States)

    1975-01-01

    Bibliography cites documents published to and including 1974 with abstracts and references, and is indexed by topic, author, organization, title, and keywords. Topics include: Wind Energy Potential and Economic Feasibility, Utilization, Wind Power Plants and Generators, Wind Machines, Wind Data and Properties, Energy Storage, and related topics.

  14. Unsteady Sail Dynamics in Olympic Class Sailboats

    Science.gov (United States)

    Williamson, Charles; Schutt, Riley

    2016-11-01

    Unsteady sailing techniques have evolved in competitive sailboat fleets, in cases where the relative weight of the sailor is sufficient to impart unsteady motions to the boat and sails. We will discuss three types of motion that are used by athletes to propel their boats on an Olympic race course faster than using the wind alone. In all of our cases, body weight movements induce unsteady sail motion, increasing driving force and speed through the water. In this research, we explore the dynamics of an Olympic class Laser sailboat equipped with a GPS, IMU, wind sensor, and a 6-GoPro camera array. We shall briefly discuss "sail flicking", whereby the helmsman periodically rolls the sail into the apparent wind, at an angle which is distinct from classical heave (in our case, the oscillations are not normal to the apparent flow). We also demonstrate "roll tacking", where there are considerable advantages to rolling the boat during such a maneuver, especially in light wind. In both of the above examples from on-the-water studies, corresponding experiments using a towing tank exhibit increases in the driving force, associated with the formation of strong vortex pairs into the flow. Finally, we focus on a technique known as "S-curving" in the case where the boat sails downwind. In contrast to the previous cases, it is drag force rather than lift force that the sailor is trying to maximise as the boat follows a zig-zag trajectory. The augmented apparent wind strength due to the oscillatory sail motion, and the growth of strong synchronised low-pressure wake vortices on the low-pressure side of the sail, contribute to the increase in driving force, and velocity-made-good downwind.

  15. Wind energy handbook

    CERN Document Server

    Burton, Tony; Sharpe, David; Bossanyi, Ervin

    2011-01-01

    Named as one of Choice's Outstanding Academic Titles of 2012Every year, Choice subject editors recognise the most significant print and electronic works reviewed in Choice during the previous calendar year. Appearing annually inChoice's January issue, this prestigious list of publications reflects the best in scholarly titles and attracts extraordinary attention from the academic library community. The authoritative reference on wind energy, now fully revised and updated to include offshore wind power<

  16. Next Generation Wind Turbine

    Energy Technology Data Exchange (ETDEWEB)

    Cheraghi, S. Hossein [Western New England Univ., Springfield, MA (United States); Madden, Frank [FloDesign Wind Turbine Corp., Waltham, MA (United States)

    2012-09-01

    The goal of this collaborative effort between Western New England University's College of Engineering and FloDesign Wind Turbine (FDWT) Corporation to wok on a novel areodynamic concept that could potentially lead to the next generation of wind turbines. Analytical studies and early scale model tests of FDWT's Mixer/Ejector Wind Turbine (MEWT) concept, which exploits jet-age advanced fluid dynamics, indicate that the concept has the potential to significantly reduce the cost of electricity over conventional Horizontal Axis Wind Turbines while reducing land usage. This project involved the design, fabrication, and wind tunnel testing of components of MEWT to provide the research and engineering data necessary to validate the design iterations and optimize system performance. Based on these tests, a scale model prototype called Briza was designed, fabricated, installed and tested on a portable tower to investigate and improve the design system in real world conditions. The results of these scale prototype efforts were very promising and have contributed significantly to FDWT's ongoing development of a product scale wind turbine for deployment in multiple locations around the U.S. This research was mutually beneficial to Western New England University, FDWT, and the DOE by utilizing over 30 student interns and a number of faculty in all efforts. It brought real-world wind turbine experience into the classroom to further enhance the Green Engineering Program at WNEU. It also provided on-the-job training to many students, improving their future employment opportunities, while also providing valuable information to further advance FDWT's mixer-ejector wind turbine technology, creating opportunities for future project innovation and job creation.

  17. Renewable Energy Essentials: Wind

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    Subjects for further research, specific to wind energy technology, include more refined resource assessment; materials with higher strength to mass ratios; advanced grid integration and power quality and control technologies; standardisation and certification; development of low-wind regime turbines; improved forecasting; increased fatigue resistance of major components such as gearboxes; better models for aerodynamics and aeroelasticity; generators based on superconductor technology; deep-offshore foundations; and high-altitude 'kite' concepts.

  18. Database on Wind Characteristics

    DEFF Research Database (Denmark)

    Højstrup, J.; Ejsing Jørgensen, Hans; Lundtang Petersen, Erik

    1999-01-01

    his report describes the work and results of the project: Database on Wind Characteristics which was sponsered partly by the European Commision within the framework of JOULE III program under contract JOR3-CT95-0061......his report describes the work and results of the project: Database on Wind Characteristics which was sponsered partly by the European Commision within the framework of JOULE III program under contract JOR3-CT95-0061...

  19. Wind power development field test project at Maruyama-machi. Close survey on wind conditions; Maruyamamachi ni okeru furyoku kaihatsu field test jigyo (fukyo seisa) hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-11-01

    A survey was made on wind conditions in Maruyama-machi, Awa-gun, Chiba prefecture, on the assumption that a wind power generation system was installed therein. The survey period was one year from Oct., 1998 to Sept., 1999. The observations were carried out on the average wind velocity, average wind direction, standard deviation of velocity, and the maximum instantaneous wind velocity. With a fixed point observation at 20 m above ground, and with the minimum observation time unit of 10 minutes, an average value during the 10 minutes was determined as the measurement of each category. However, the maximum instantaneous wind velocity was determined on the measurement with the minimum observation time unit of 2 seconds. The average annual wind velocity was 3.5 m/s, the maximum wind velocity during the period was 27 m/s, and the wind axis was WSW-ENE, with the total occurrence rate of the wind direction 44.1%. The intensity of turbulence was 0.23 at a wind velocity of 2.0 m/s or above and was 0.22 at 4.0 m/s or above. An estimated annual operation rate of a windmill was 40-60% using the rated value of a 150 kW, 300 kW and 750 kW class windmills. (NEDO)

  20. Teaching Social Class

    Science.gov (United States)

    Tablante, Courtney B.; Fiske, Susan T.

    2015-01-01

    Discussing socioeconomic status in college classes can be challenging. Both teachers and students feel uncomfortable, yet social class matters more than ever. This is especially true, given increased income inequality in the United States and indications that higher education does not reduce this inequality as much as many people hope. Resources…

  1. Generalized Fourier transforms classes

    DEFF Research Database (Denmark)

    Berntsen, Svend; Møller, Steen

    2002-01-01

    The Fourier class of integral transforms with kernels $B(\\omega r)$ has by definition inverse transforms with kernel $B(-\\omega r)$. The space of such transforms is explicitly constructed. A slightly more general class of generalized Fourier transforms are introduced. From the general theory...

  2. Cutting Class Harms Grades

    Science.gov (United States)

    Taylor, Lewis A., III

    2012-01-01

    An accessible business school population of undergraduate students was investigated in three independent, but related studies to determine effects on grades due to cutting class and failing to take advantage of optional reviews and study quizzes. It was hypothesized that cutting classes harms exam scores, attending preexam reviews helps exam…

  3. Wind Conditions for Wind Farm Hanstholm

    DEFF Research Database (Denmark)

    Pena Diaz, Alfredo; Hahmann, Andrea N.; Mann, Jakob

    The net annual energy production (AEP) of the Hanstholm Wind Farm is 158 GWh per year for the Siemens SWT-3.6-120 turbine and 140 GWh for the Vestas V112-3.0 turbine. These values have an uncertainty (standard deviation) of 6%. This result is mainly based on the data for Risø DTU’s test station...... at Høvsøre where wind speeds are measured at approximately the same height as the turbines at Hanstholm and where the terrain is similar. On top of that meso-scale modeling has been used to extrapolate the climatology from Høvsøre to Hanstholm increasing the AEP by almost 6% compared to just using...... the Høvsøre climatology directly. This method of extrapolation is rather new, but several older investigations indicate that the wind resource at Hanstholm is slightly higher than at Høvsøre. The work is carried out for Grontmij-Carl Bro according to a contract dated January 18th 2011....

  4. WindPACT Reference Wind Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Dykes, Katherine L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rinker, Jennifer [Former National Renewable Energy Laboratory (NREL) employee

    2018-04-02

    To fully understand how loads and turbine cost scale with turbine size, it is necessary to have identical turbine models that have been scaled to different rated powers. The report presents the WindPACT baseline models, which are a series of four baseline models that were designed to facilitate investigations into the scalings of loads and turbine cost with size. The models have four different rated powers (750 kW, 1.5 MW, 3.0 MW, and 5.0 MW), and each model was designed to its specified rated power using the same design methodology. The models were originally implemented in FAST_AD, the predecessor to NREL's open-source wind turbine simulator FAST, but have yet to be implemented in FAST. This report contains the specifications for all four WindPACT baseline models - including structural, aerodynamic, and control specifications - along with the inherent assumptions and equations that were used to calculate the model parameters. It is hoped that these baseline models will serve as extremely useful resources for investigations into the scalings of costs, loads, or optimization routines.

  5. Wind in the Willows--Theatre Activity Packet.

    Science.gov (United States)

    New York City Board of Education, Brooklyn, NY. Div. of Curriculum and Instruction.

    Part of the New York City Board of Education's Early Stages program, and intended for elementary and secondary school teachers who wish to include a unit on theater in their classes, this guide offers suggestions for lessons and activities to accompany viewing a performance of "Wind in the Willows" at the Nederlander Theater. Part one of…

  6. The potential of wind farms

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    Summaries of papers presented at the European wind energy conference on the potential of wind farms are presented. It is stated that in Denmark today, wind energy provides about 3% to the Danish electricity consumption and the wind power capacity is, according to Danish wind energy policy, expected to increase substantially in the years to come. A number of countries in Europe and elsewhere are making significant progress in this repect. Descriptions of performance are given in relation to some individual wind farms. The subjects covered concern surveys of national planning and policies regarding wind utilization and national and global development of wind turbine arrays. Papers also deal with utility and project planning, wind prediction and certification, wind loads and fatigue, wakes, noise and control. (AB).

  7. Offshore wind farm repowering optimization

    DEFF Research Database (Denmark)

    Hou, Peng; Enevoldsen, Peter; Hu, Weihao

    2017-01-01

    is focused on optimization of offshore wind farm repowering, which is one option for the wind farm owner at end of life for the offshore wind farm. The LCoE is used as the evaluation index to identify whether it is economical to invest in such a way. In an optimized repowering strategy, different types...... of wind turbines are selected to replace the original wind turbines to reconstruct the wind farm, which is demonstrated to be better than the refurbishment approach which replaces the old wind turbines with the same type. The simulations performed in this research reveal that the reconstructed wind farm......, which consists of multiple types of wind turbine, has a smaller LCoE (10.43%) than the refurbishment approach, which shows the superiority of the proposed method. This research contributes an optimization tool to the wind industry, which consequently drives down the cost of energy produced by offshore...

  8. The potential of wind farms

    International Nuclear Information System (INIS)

    Hauge Madsen, P.; Lundsager, P.

    1992-09-01

    Papers presented at the European wind energy conference on the potential of wind farms are presented. The aim of the conference was to bring into focus the problems, experiences and potential of the application of wind power in wind power farms as a contribution to the European and global energy supply. It was considered that the interchange of experience among representatives of science, utilities, industry, environment and energy planning, together with those who represent financial and insurance interests, would create a better understanding of all aspects of wind power for its future successful development. The subjects covered concern surveys of national planning and policies regarding wind energy utilization and national and global development of wind turbine arrays. The performance of some individual wind farms is described. Papers also deal with utility and project planning, wind prediction and certification, wind loads and fatigues, wakes, noise and control. (AB)

  9. The potential of wind farms

    International Nuclear Information System (INIS)

    Hauge Madsen, P.; Lundsager, P.

    1992-09-01

    Papers presented at the European wind energy conference on the potential of wind farms are presented. The aim of the conference was to bring into focus the problems, experiences and potential of the application of wind power in wind power farms as a contribution to the European and global energy supply. It was considered that the interchange of experience among representatives of science, utilities, industry, environment and energy planning, together with those who represent financial and insurance interests, would create a better understanding of all aspects of wind power for its future successful development. The subjects covered concern surveys of national planning and policies regarding wind energy utilization and national and global development of wind turbine arrays. The performance of some individual wind farms is described. Papers also deal with utility and project planning, wind prediction and certification, wind loads and fatigus, wakes, noise and control. (AB)

  10. European wind turbine catalogue

    International Nuclear Information System (INIS)

    1994-01-01

    The THERMIE European Community programme is designed to promote the greater use of European technology and this catalogue contributes to the fulfillment of this aim by dissemination of information on 50 wind turbines from 30 manufacturers. These turbines are produced in Europe and are commercially available. The manufacturers presented produce and sell grid-connected turbines which have been officially approved in countries where this approval is acquired, however some of the wind turbines included in the catalogue have not been regarded as fully commercially available at the time of going to print. The entries, which are illustrated by colour photographs, give company profiles, concept descriptions, measured power curves, prices, and information on design and dimension, safety systems, stage of development, special characteristics, annual energy production, and noise pollution. Lists are given of wind turbine manufacturers and agents and of consultants and developers in the wind energy sector. Exchange rates used in the conversion of the prices of wind turbines are also given. Information can be found on the OPET network (organizations recognised by the European Commission as an Organization for the Promotion of Energy Technologies (OPET)). An article describes the development of the wind power industry during the last 10-15 years and another article on certification aims to give an overview of the most well-known and acknowledged type approvals currently issued in Europe. (AB)

  11. Wind farm production estimates

    DEFF Research Database (Denmark)

    Larsen, Torben J.; Larsen, Gunner Chr.; Aagaard Madsen, Helge

    2012-01-01

    In this paper, the Dynamic Wake Meandering (DWM) model is applied for simulation of wind farm production. In addition to the numerical simulations, measured data have been analyzed in order to provide the basis for a full-scale verification of the model performance. The basic idea behind the DWMm......In this paper, the Dynamic Wake Meandering (DWM) model is applied for simulation of wind farm production. In addition to the numerical simulations, measured data have been analyzed in order to provide the basis for a full-scale verification of the model performance. The basic idea behind...... the DWMmodel is to model the in- stationary wind farm flow characteristics by considering wind turbine wakes as passive tracers continuously emitted from the wind farm turbines each with a downstream transport pro- cess dictated by large scale turbulent eddies (lateral and ver- tical transportation; i.......e. meandering) and Taylor advection. For the present purpose, the DWM model has been im- plemented in the aeroelastic code HAWC2 [1], and the per- formance of the resulting model complex is mainly verified by comparing simulated and measured loads for the Dutch off-shore Egmond aan Zee wind farm [2]. This farm...

  12. Tornado type wind turbines

    Science.gov (United States)

    Hsu, Cheng-Ting

    1984-01-01

    A tornado type wind turbine has a vertically disposed wind collecting tower with spaced apart inner and outer walls and a central bore. The upper end of the tower is open while the lower end of the structure is in communication with a wind intake chamber. An opening in the wind chamber is positioned over a turbine which is in driving communication with an electrical generator. An opening between the inner and outer walls at the lower end of the tower permits radially flowing air to enter the space between the inner and outer walls while a vertically disposed opening in the wind collecting tower permits tangentially flowing air to enter the central bore. A porous portion of the inner wall permits the radially flowing air to interact with the tangentially flowing air so as to create an intensified vortex flow which exits out of the top opening of the tower so as to create a low pressure core and thus draw air through the opening of the wind intake chamber so as to drive the turbine.

  13. Linear wind generator

    International Nuclear Information System (INIS)

    Kozarov, A.; Petrov, O.; Antonov, J.; Sotirova, S.; Petrova, B.

    2006-01-01

    The purpose of the linear wind-power generator described in this article is to decrease the following disadvantages of the common wind-powered turbine: 1) large bending and twisting moments to the blades and the shaft, especially when strong winds and turbulence exist; 2) significant values of the natural oscillation period of the construction result in the possibility of occurrence of destroying resonance oscillations; 3) high velocity of the peripheral parts of the rotor creating a danger for birds; 4) difficulties, connected with the installation and the operation on the mountain ridges and passages where the wind energy potential is the largest. The working surfaces of the generator in questions driven by the wind are not connected with a joint shaft but each moves along a railway track with few oscillations. So the sizes of each component are small and their number can be rather large. The mechanical trajectory is not a circle but a closed outline in a vertical plain, which consists of two rectilinear sectors, one above the other, connected in their ends by semi-circumferences. The mechanical energy of each component turns into electrical on the principle of the linear electrical generator. A regulation is provided when the direction of the wind is perpendicular to the route. A possibility of effectiveness is shown through aiming of additional quantities of air to the movable components by static barriers

  14. Wind turbines and health

    International Nuclear Information System (INIS)

    Rideout, K.; Copes, R.; Bos, C.

    2010-01-01

    This document summarized the potential health hazards associated with wind turbines, such as noise and low frequency sound, vibration and infrasound; electromagnetic fields (EMF); shadow flicker; and ice throw and structural failure. Various symptoms can be attributed to wind turbines, including dizziness, sleep disruption, and headaches. A review of available research regarding potential health affects to residents living in close proximity to wind turbines showed that the sound level associated with wind turbines at common residential setbacks is not sufficient to damage hearing, but may lead to annoyance and sleep disturbance. Research has shown that wind turbines are not a significant source of EMF exposure, and although shadows caused by the blades may be annoying, they are not likely to cause epileptic seizures at normal operational speeds. The risk of injury from ice throw can be minimized with setbacks of 200 to 400 m. Examples of Canadian wind turbine setback guidelines and regulations were also offered. It was concluded that setbacks and operational guidelines can be utilized in combination to address safety hazards, sound levels, land use issues, and impacts on people. 46 refs., 2 tabs., 2 figs.

  15. Wind turbine aerodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.A. [Waterloo Univ., ON (Canada). Dept. of Mechanical Engineering, Wind Energy Group

    2010-07-01

    The need for clean, renewable electricity in remote communities of Canada and the world was discussed in this presentation. The University of Waterloo Wind Energy Laboratory (WEL) performs research in a large scale indoor environment on wind turbines, blade aerodynamics, and aeroacoustics. A key area of research involves developing turbines for remote off-grid communities where climatic conditions are challenging. This presentation outlined research that is underway on wind energy and off-grid renewable energy systems. Many communities in Canada and remote communities in the rest of the world are not connected to the grid and are dependent on other means to supply electrical energy to their community. Remote communities in northern Canada have no road access and diesel is the dominant source of electrical energy for these communities. All of the community supply of diesel comes from brief winter road access or by air. The presentation discussed existing diesel systems and the solution of developing local renewable energy sources such as wind, hydro, biomass, geothermal, and solar power. Research goals, wind energy activities, experimental equipment, and the results were also presented. Research projects have been developed in wind energy; hydrogen generation/storage/utilization; power electronics/microgrid; and community engagement. figs.

  16. Floating wind turbine system

    Science.gov (United States)

    Viterna, Larry A. (Inventor)

    2009-01-01

    A floating wind turbine system with a tower structure that includes at least one stability arm extending therefrom and that is anchored to the sea floor with a rotatable position retention device that facilitates deep water installations. Variable buoyancy for the wind turbine system is provided by buoyancy chambers that are integral to the tower itself as well as the stability arm. Pumps are included for adjusting the buoyancy as an aid in system transport, installation, repair and removal. The wind turbine rotor is located downwind of the tower structure to allow the wind turbine to follow the wind direction without an active yaw drive system. The support tower and stability arm structure is designed to balance tension in the tether with buoyancy, gravity and wind forces in such a way that the top of the support tower leans downwind, providing a large clearance between the support tower and the rotor blade tips. This large clearance facilitates the use of articulated rotor hubs to reduced damaging structural dynamic loads. Major components of the turbine can be assembled at the shore and transported to an offshore installation site.

  17. Classes of modules

    CERN Document Server

    Dauns, John

    2006-01-01

    Because traditional ring theory places restrictive hypotheses on all submodules of a module, its results apply only to small classes of already well understood examples. Often, modules with infinite Goldie dimension have finite-type dimension, making them amenable to use with type dimension, but not Goldie dimension. By working with natural classes and type submodules (TS), Classes of Modules develops the foundations and tools for the next generation of ring and module theory. It shows how to achieve positive results by placing restrictive hypotheses on a small subset of the complement submodules, Furthermore, it explains the existence of various direct sum decompositions merely as special cases of type direct sum decompositions. Carefully developing the foundations of the subject, the authors begin by providing background on the terminology and introducing the different module classes. The modules classes consist of torsion, torsion-free, s[M], natural, and prenatural. They expand the discussion by exploring...

  18. Coastal Ohio Wind Project

    Energy Technology Data Exchange (ETDEWEB)

    Gorsevski, Peter [Bowling Green State Univ., OH (United States); Afjeh, Abdollah [Univ. of Toledo, OH (United States); Jamali, Mohsin [Univ. of Toledo, OH (United States); Bingman, Verner [Bowling Green State Univ., OH (United States)

    2014-04-04

    The Coastal Ohio Wind Project intends to address problems that impede deployment of wind turbines in the coastal and offshore regions of Northern Ohio. The project evaluates different wind turbine designs and the potential impact of offshore turbines on migratory and resident birds by developing multidisciplinary research, which involves wildlife biology, electrical and mechanical engineering, and geospatial science. Firstly, the project conducts cost and performance studies of two- and three-blade wind turbines using a turbine design suited for the Great Lakes. The numerical studies comprised an analysis and evaluation of the annual energy production of two- and three-blade wind turbines to determine the levelized cost of energy. This task also involved wind tunnel studies of model wind turbines to quantify the wake flow field of upwind and downwind wind turbine-tower arrangements. The experimental work included a study of a scaled model of an offshore wind turbine platform in a water tunnel. The levelized cost of energy work consisted of the development and application of a cost model to predict the cost of energy produced by a wind turbine system placed offshore. The analysis found that a floating two-blade wind turbine presents the most cost effective alternative for the Great Lakes. The load effects studies showed that the two-blade wind turbine model experiences less torque under all IEC Standard design load cases considered. Other load effects did not show this trend and depending on the design load cases, the two-bladed wind turbine showed higher or lower load effects. The experimental studies of the wake were conducted using smoke flow visualization and hot wire anemometry. Flow visualization studies showed that in the downwind turbine configuration the wake flow was insensitive to the presence of the blade and was very similar to that of the tower alone. On the other hand, in the upwind turbine configuration, increasing the rotor blade angle of attack

  19. Wind turbine control and monitoring

    CERN Document Server

    Luo, Ningsu; Acho, Leonardo

    2014-01-01

    Maximizing reader insights into the latest technical developments and trends involving wind turbine control and monitoring, fault diagnosis, and wind power systems, 'Wind Turbine Control and Monitoring' presents an accessible and straightforward introduction to wind turbines, but also includes an in-depth analysis incorporating illustrations, tables and examples on how to use wind turbine modeling and simulation software.   Featuring analysis from leading experts and researchers in the field, the book provides new understanding, methodologies and algorithms of control and monitoring, comput

  20. Wind Energy Workforce Development & Jobs

    Energy Technology Data Exchange (ETDEWEB)

    Tegen, Suzanne

    2016-11-08

    The United States needs a skilled and qualified wind energy workforce to produce domestic clean power. To assist with wind energy workforce development, the U.S. Department of Energy (DOE) and National Renewable Energy Laboratory are engaged with several efforts.This presentation by Suzanne Tegen describes these efforts, including a wind industry survey, DOE's Wind Career Map, the DOE Wind Vision report, and an in-depth discussion of the Jobs & Economic Development Impacts Model.

  1. Performance of spanish wind turbines

    International Nuclear Information System (INIS)

    Lago, C.

    1995-01-01

    In this document we can find a statistical evaluation for the wind energy generation from each spanish wind farm referred to 1994, going on with the work that has been carried out since 1992, by initiative of the Wind Energy Division from Renewable Energy Institute. The purpose of this work is to contribute with interesting information for the wind environment and offer a global view from monthly performances of different wind farms. (Author)

  2. Small Wind Site Assessment Guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Tim [Advanced Energy Systems LLC, Eugene, OR (United States); Preus, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-09-01

    Site assessment for small wind energy systems is one of the key factors in the successful installation, operation, and performance of a small wind turbine. A proper site assessment is a difficult process that includes wind resource assessment and the evaluation of site characteristics. These guidelines address many of the relevant parts of a site assessment with an emphasis on wind resource assessment, using methods other than on-site data collection and creating a small wind site assessment report.

  3. An All-Fiber, Modular, Compact Wind Lidar for Wind Sensing and Wake Vortex Applications

    Science.gov (United States)

    Prasad, Narasimha S.; Sibell, Russ; Vetorino, Steve; Higgins, Richard; Tracy, Allen

    2015-01-01

    This paper discusses an innovative, compact and eyesafe coherent lidar system developed for wind and wake vortex sensing applications. With an innovative all-fiber and modular transceiver architecture, the wind lidar system has reduced size, weight and power requirements, and provides enhanced performance along with operational elegance. This all-fiber architecture is developed around fiber seed laser coupled to uniquely configured fiber amplifier modules. The innovative features of this lidar system, besides its all fiber architecture, include pulsewidth agility and user programmable 3D hemispherical scanner unit. Operating at a wavelength of 1.5457 microns and with a PRF of up to 20 KHz, the lidar transmitter system is designed as a Class 1 system with dimensions of 30"(W) x 46"(L) x 60"(H). With an operational range exceeding 10 km, the wind lidar is configured to measure wind velocities of greater than 120 m/s with an accuracy of +/- 0.2 m/s and allow range resolution of less than 15 m. The dynamical configuration capability of transmitted pulsewidths from 50 ns to 400 ns allows high resolution wake vortex measurements. The scanner uses innovative liquid metal slip ring and is built using 3D printer technology with light weight nylon. As such, it provides continuous 360 degree azimuth and 180 degree elevation scan angles with an incremental motion of 0.001 degree. The lidar system is air cooled and requires 110 V for its operation. This compact and modular lidar system is anticipated to provide mobility, reliability, and ease of field deployment for wind and wake vortex measurements. Currently, this wind lidar is undergoing validation tests under various atmospheric conditions. Preliminary results of these field measurements of wind characteristics that were recently carried out in Colorado are discussed.

  4. Hybrid Optimization for Wind Turbine Thick Airfoils

    Energy Technology Data Exchange (ETDEWEB)

    Grasso, F. [ECN Wind Energy, Petten (Netherlands)

    2012-06-15

    One important element in aerodynamic design of wind turbines is the use of specially tailored airfoils to increase the ratio of energy capture and reduce cost of energy. This work is focused on the design of thick airfoils for wind turbines by using numerical optimization. A hybrid scheme is proposed in which genetic and gradient based algorithms are combined together to improve the accuracy and the reliability of the design. Firstly, the requirements and the constraints for this class of airfoils are described; then, the hybrid approach is presented. The final part of this work is dedicated to illustrate a numerical example regarding the design of a new thick airfoil. The results are discussed and compared to existing airfoils.

  5. Wind power today: 1999 Wind Energy program highlights

    Energy Technology Data Exchange (ETDEWEB)

    Weis-Taylor, Pat

    2000-04-06

    Wind Power Today is an annual publication that provides an overview for the Department of Energy's Wind Energy Program. The purpose of Wind Power Today is to show how DOE's Wind Energy Program supports wind turbine research and deployment in hopes of furthering the advancement of wind technologies that produce clean, low-cost, reliable energy for the 21st century. Content objectives include: Educate readers about the advantages and potential for widespread deployment of wind energy; explain DOE wind energy program objectives and goals; describe program accomplishments in research and application; examine the barriers to widespread deployment; describe benefits of continued research and development; facilitate technology transfer; attract cooperative wind energy projects with industry.

  6. Wind Atlas of Bay of Bengal with Satellite Wind Measurement

    DEFF Research Database (Denmark)

    Nadi, Navila Rahman

    footstep towards offshore wind energy analysis for this region. Generally, it is difficult to find offshore wind data relative to the wind turbine hub heights, therefore a starting point is necessary to identify the possible wind power density of the region. In such scenario, Synthetic aperture radars (SAR......The objective of this study is to obtain appropriate offshore location in the Bay of Bengal, Bangladesh for further development of wind energy. Through analyzing the previous published works, no offshore wind energy estimation has been found here. That is why, this study can be claimed as the first......) have proven useful. In this study, SAR based dataset- ENVISAT ASAR has been used for Wind Atlas generation. Furthermore, a comparative study has been performed with Global Wind Atlas (GWA) to determine a potential offshore wind farm. Additionally, the annual energy production of that offshore windfarm...

  7. 77 FR 40608 - Notice of Petition for Enforcement and Declaratory Order; Exelon Wind 1, LLC; Exelon Wind 2, LLC...

    Science.gov (United States)

    2012-07-10

    ... Petition for Enforcement and Declaratory Order; Exelon Wind 1, LLC; Exelon Wind 2, LLC; Exelon Wind 3, LLC; Exelon Wind 4, LLC; Exelon Wind 5, LLC; Exelon Wind 6, LLC; Exelon Wind 7, LLC; Exelon Wind 8, LLC; Exelon Wind 9, LLC; Exelon Wind 10, LLC; Exelon Wind 11, LLC; High Plains Wind Power, LLC Take notice...

  8. Strategic wind power trading considering rival wind power production

    DEFF Research Database (Denmark)

    Exizidis, Lazaros; Kazempour, Jalal; Pinson, Pierre

    2016-01-01

    In an electricity market with high share of wind power, it is expected that wind power producers may exercise market power. However, wind producers have to cope with wind’s uncertain nature in order to optimally offer their generation, whereas in a market with more than one wind producers, uncert...... depending on the rival’s wind generation, given that its own expected generation is not high. Finally, as anticipated, expected system cost is higher when both wind power producers are expected to have low wind power generation......In an electricity market with high share of wind power, it is expected that wind power producers may exercise market power. However, wind producers have to cope with wind’s uncertain nature in order to optimally offer their generation, whereas in a market with more than one wind producers......, uncertainty of rival wind power generation should also be considered. Under this context, this paper addresses the impact of rival wind producers on the offering strategy and profits of a pricemaker wind producer. A stochastic day-ahead market setup is considered, which optimizes the day-ahead schedules...

  9. When real life wind speed exceeds design wind assumptions

    Energy Technology Data Exchange (ETDEWEB)

    Winther-Jensen, M; Joergensen, E R [Risoe National Lab., Roskilde (Denmark)

    1999-03-01

    Most modern wind turbines are designed according to a standard or a set of standards to withstand the design loads with a defined survival probability. Mainly the loads are given by the wind conditions on the site defining the `design wind speeds`, normally including extreme wind speeds given as an average and a peak value. The extreme wind speeds are normally (e.g. in the upcoming IEC standard for wind turbine safety) defined as having a 50-year recurrence period. But what happens when the 100 or 10,000 year wind situation hits a wind turbine? Results on wind turbines of wind speeds higher than the extreme design wind speeds are presented based on experiences especially from the State of Gujarat in India. A description of the normal approach of designing wind turbines in accordance with the standards in briefly given in this paper with special focus on limitations and built-in safety levels. Based on that, other possibilities than just accepting damages on wind turbines exposed for higher than design wind speeds are mentioned and discussed. The presentation does not intend to give the final answer to this problem but is meant as an input to further investigations and discussions. (au)

  10. Characteristics for wind energy and wind turbines by considering vertical wind shear

    Institute of Scientific and Technical Information of China (English)

    郑玉巧; 赵荣珍

    2015-01-01

    The probability distributions of wind speeds and the availability of wind turbines were investigated by considering the vertical wind shear. Based on the wind speed data at the standard height observed at a wind farm, the power-law process was used to simulate the wind speeds at a hub height of 60 m. The Weibull and Rayleigh distributions were chosen to express the wind speeds at two different heights. The parameters in the model were estimated via the least square (LS) method and the maximum likelihood estimation (MLE) method, respectively. An adjusted MLE approach was also presented for parameter estimation. The main indices of wind energy characteristics were calculated based on observational wind speed data. A case study based on the data of Hexi area, Gansu Province of China was given. The results show that MLE method generally outperforms LS method for parameter estimation, and Weibull distribution is more appropriate to describe the wind speed at the hub height.

  11. Evaluation of wind farm efficiency and wind turbine wakes at the Nysted offshore wind farm

    DEFF Research Database (Denmark)

    Barthelmie, Rebecca Jane; Jensen, L.E.

    2010-01-01

    Here, we quantify relationships between wind farm efficiency and wind speed, direction, turbulence and atmospheric stability using power output from the large offshore wind farm at Nysted in Denmark. Wake losses are, as expected, most strongly related to wind speed variations through the turbine...... thrust coefficient; with direction, atmospheric stability and turbulence as important second order effects. While the wind farm efficiency is highly dependent on the distribution of wind speeds and wind direction, it is shown that the impact of turbine spacing on wake losses and turbine efficiency can...... be quantified, albeit with relatively large uncertainty due to stochastic effects in the data. There is evidence of the ‘deep array effect’ in that wake losses in the centre of the wind farm are under-estimated by the wind farm model WAsP, although overall efficiency of the wind farm is well predicted due...

  12. Velocity measurement of model vertical axis wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.A.; McWilliam, M. [Waterloo Univ., ON (Canada). Dept. of Mechanical Engineering

    2006-07-01

    An increasingly popular solution to future energy demand is wind energy. Wind turbine designs can be grouped according to their axis of rotation, either horizontal or vertical. Horizontal axis wind turbines have higher power output in a good wind regime than vertical axis turbines and are used in most commercial class designs. Vertical axis Savonius-based wind turbine designs are still widely used in some applications because of their simplistic design and low wind speed performance. There are many design variables that must be considered in order to optimize the power output in a given wind regime in a typical wind turbine design. Using particle image velocimetry, a study of the air flow around five different model vertical axis wind turbines was conducted in a closed loop wind tunnel. A standard Savonius design with two semi-circular blades overlapping, and two variations of this design, a deep blade and a shallow blade design were among the turbine models included in this study. It also evaluated alternate designs that attempt to increase the performance of the standard design by allowing compound blade curvature. Measurements were collected at a constant phase angle and also at random rotor orientations. It was found that evaluation of the flow patterns and measured velocities revealed consistent and stable flow patterns at any given phase angle. Large scale flow structures are evident in all designs such as vortices shed from blade surfaces. An important performance parameter was considered to be the ability of the flow to remain attached to the forward blade and redirect and reorient the flow to the following blade. 6 refs., 18 figs.

  13. Wind turbine storage systems

    International Nuclear Information System (INIS)

    Ibrahim, H.; Ilinca, A.; Perron, J.

    2005-01-01

    Electric power is often produced in locations far from the point of utilization which creates a challenge in stabilizing power grids, particularly since electricity cannot be stored. The production of decentralized electricity by renewable energy sources offers a greater security of supply while protecting the environment. Wind power holds the greatest promise in terms of environmental protection, competitiveness and possible applications. It is known that wind energy production is not always in phase with power needs because of the uncertainty of wind. For that reason, energy storage is the key for the widespread integration of wind energy into the power grids. This paper proposed various energy storage methods that can be used in combination with decentralized wind energy production where an imbalance exists between electricity production and consumption. Energy storage can play an essential role in bringing value to wind energy, particularly if electricity is to be delivered during peak hours. Various types of energy storage are already in use or are being developed. This paper identified the main characteristics of various electricity storage techniques and their applications. They include stationary or embarked storage for long or short term applications. A comparison of characteristics made it possible to determine which types of electricity storage are best suited for wind energy. These include gravity energy; thermal energy; compressed air energy; coupled storage with natural gas; coupled storage with liquefied gas; hydrogen storage for fuel cells; chemical energy storage; storage in REDOX batteries; storage by superconductive inductance; storage in supercondensers; and, storage as kinetic energy. 21 refs., 21 figs

  14. Wind power statistics and an evaluation of wind energy density

    Energy Technology Data Exchange (ETDEWEB)

    Jamil, M.; Parsa, S.; Majidi, M. [Materials and Energy Research Centre, Tehran (Iran, Islamic Republic of)

    1995-11-01

    In this paper the statistical data of fifty days` wind speed measurements at the MERC- solar site are used to find out the wind energy density and other wind characteristics with the help of the Weibull probability distribution function. It is emphasized that the Weibull and Rayleigh probability functions are useful tools for wind energy density estimation but are not quite appropriate for properly fitting the actual wind data of low mean speed, short-time records. One has to use either the actual wind data (histogram) or look for a better fit by other models of the probability function. (Author)

  15. Wind Power Today: 1998 Wind Energy Program Highlights

    Energy Technology Data Exchange (ETDEWEB)

    Tromly, K.

    1999-06-17

    The US Department of Energy's Office of Energy Efficiency and Renewable Energy manages the Federal Wind Energy Program. The mission of the program is to help the US wind industry to complete the research, testing, and field verification needed to fully develop advanced wind technologies that will lead the world in cost-effectiveness and reliability. This publication, printed annually, provides a summary of significant achievements in wind energy made during the previous calendar year. Articles include wind energy in the Midwest, an Alaskan wind energy project, the US certification program, structural testing, and the federal program in review.

  16. Damping Wind and Wave Loads on a Floating Wind Turbine

    DEFF Research Database (Denmark)

    Christiansen, Søren; Bak, Thomas; Knudsen, Torben

    2013-01-01

    Offshore wind energy capitalizes on the higher and less turbulent wind speeds at sea. To enable deployment of wind turbines in deep-water locations, structures are being explored, where wind turbines are placed on a floating platform. This combined structure presents a new control problem, due......, and we show the influence that both wind speed, wave frequencies and misalignment between wind and waves have on the system dynamics. A new control model is derived that extends standard turbine models to include the hydrodynamics, additional platform degrees of freedom, the platform mooring system...

  17. Wind energy: Overcoming inadequate wind and modeling uncertainties

    Energy Technology Data Exchange (ETDEWEB)

    Kane, Vivek

    2010-09-15

    'Green Energy' is the call of the day, and significance of Wind Energy can never be overemphasized. But the key question here is - What if the wind resources are inadequate? Studies reveal that the probability of finding favorable wind at a given place on land is only 15%. Moreover, there are inherent uncertainties associated with wind business. Can we overcome inadequate wind resources? Can we scientifically quantify uncertainty and model it to make business sense? This paper proposes a solution, by way of break-through Wind Technologies, combined with advanced tools for Financial Modeling, enabling vital business decisions.

  18. The Wind Integration National Dataset (WIND) toolkit (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Caroline Draxl: NREL

    2014-01-01

    Regional wind integration studies require detailed wind power output data at many locations to perform simulations of how the power system will operate under high penetration scenarios. The wind datasets that serve as inputs into the study must realistically reflect the ramping characteristics, spatial and temporal correlations, and capacity factors of the simulated wind plants, as well as being time synchronized with available load profiles.As described in this presentation, the WIND Toolkit fulfills these requirements by providing a state-of-the-art national (US) wind resource, power production and forecast dataset.

  19. Multicriteria GIS modeling of wind and solar farms in Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Janke, Jason R. [Metropolitan State College of Denver, Department of Earth and Atmospheric Sciences, CB 22 P.O. Box 173362-22, Denver, CO 80217-3362 (United States)

    2010-10-15

    The majority of electricity and heat in Colorado comes from coal and natural gas; however, renewable energy sources will play an integral role in the state's energy future. Colorado is the 11th windiest state and has more than 250 sunny days per year. The objectives of this research are to: 1) determine which landcover classes are affiliated with high wind and solar potential; and 2) identify areas that are suitable for wind and solar farms using multicriteria GIS modelling techniques. Renewable potential (NREL wind speed measurements at 50 m above the ground and NREL annual insolation data), landcover, population density, federal lands, and distance to roads, transmission lines, and cities were reclassified according to their suitability. Each was assigned weights based on their relative importance to one another. Superb wind classes are located in high alpine areas. Unfortunately, these areas are not suitable for large-scale wind farm development due to their inaccessibility and location within a sensitive ecosystem. Federal lands have low wind potential. According to the GIS model, ideal areas for wind farm development are located in northeastern Colorado. About 41 850 km{sup 2} of the state has model scores that are in the 90-100% range. Although annual solar radiation varies slightly, inter-mountain areas receive the most insolation. As far as federal lands, Indian reservations have the greatest solar input. The GIS model indicates that ideal areas for solar development are located in northwestern Colorado and east of Denver. Only 191 km{sup 2} of the state had model scores that were in the 90-100% range. These results suggest that the variables used in this analysis have more of an effect at eliminating non-suitable areas for large-scale solar farms; a greater area exists for suitable wind farms. However, given the statewide high insolation values with minimal variance, solar projects may be better suited for small-scale residential or commercial

  20. Power generation from wind turbines in a solar chimney

    Energy Technology Data Exchange (ETDEWEB)

    Foote, Tudor [Graduate Student, Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, Jolley Hall, Campus Box 1185, One Brookings Drive, St. Louis, Missouri, 63130 (United States); Agarwal, Ramesh K. [William Palm Professor, Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, Jolley Hall, Campus Box 1185, One Brookings Drive, St. Louis, Missouri, 63130 (United States)

    2013-07-01

    Recent studies have shown that shrouded wind turbines can generate greater power compared to bare turbines. A solar chimney generates an upward draft of wind inside a tower and a shroud around the wind turbine. There are numerous empty silos on farms in the U.S. that can be converted to solar chimneys with minor modifications at modest cost. The objective of this study is to determine the potential of these silos/chimneys for generating wind power. The study is conducted through analytical/computational approach by employing the commercial Computational Fluid Dynamics (CFD) software. Computations are performed for five different geometric configurations consisting of a turbine, a cylindrical silo, and/or a venturi and/or a diffuser using the dimensions of typical silos and assuming Class 3 wind velocity. The incompressible Navier-Stokes equations with the Boussinesq approximation and a two equation realizable {kappa}-{epsilon} model are employed in the calculations, and the turbine is modeled as an actuator disk. The power coefficient (Cp) and generated power are calculated for the five cases. Consistent with recent literature, it was found that the silos with diffusers increase the Cp beyond Betz’s limit significantly and thus the generated power. It should be noted that Cp is calculated by normalizing it by the turbine area swept by the wind. This study shows the potential of using abandoned silos in the mid-west and other parts of the country for localized wind power generation.

  1. Wind power production: from the characterisation of the wind resource to wind turbine technologies

    International Nuclear Information System (INIS)

    Beslin, Guy; Multon, Bernard

    2016-01-01

    Illustrated by graphs and tables, this article first describes the various factors and means related to the assessment of wind resource in the World, in Europe, and the factors which characterize a local wind resource. In this last respect, the authors indicate how local topography is taken into account to calculate wind speed, how time variations are taken into account (at the yearly, seasonal or daily level), the different methods used to model a local wind resource, how to assess the power recoverable by a wind turbine with horizontal axis (notion of Betz limit). In the second part, the authors present the different wind turbines, their benefits and drawbacks: vertical axis, horizontal axis (examples of a Danish-type wind turbine, of wind turbines designed for extreme conditions). Then, they address the technology of big wind turbines: evolution of technology and of commercial offer, aerodynamic characteristics of wind turbine and benefit of a varying speed (technological solutions, importance of the electric generator). They describe how to choose a wind turbine, how product lines are organised, how the power curve and energy capacity are determined. The issue of integration of wind energy into the power system is then addressed. The next part addressed the economy of wind energy production (annualized production cost, order of magnitude of wind electric power production cost). Future trends are discussed and offshore wind energy production is briefly addressed

  2. Aeroservoelasticity of wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Skovmose Kallesoee, B.

    2007-12-14

    This thesis deals with the fundamental aeroelastic interaction between structural motion, Pitch action and control for a wind turbine blade. As wind turbines become larger, the interaction between pitch action, blade motion, aerodynamic forces, and control become even more important to understand and address. The main contribution of this thesis is the development of an aeroelastic blade model which on the one hand includes the important effects of steady state blade deformation, gravity and pitch action, and on the other it is transparent, suitable for analytical analysis and parameter studies, and furthermore linear and therefore suitable for control design. The development of the primary aeroelastic blade model is divided into four steps: 1) Nonlinear partial differential equations (PDEs) of structural blade motion are derived together with equations of pitch action and rotor speed; the individual terms in these equations are discussed and given physical interpretations; 2) Steady state blade deformation and induced velocities are computed by combining the PDEs with a steady state aerodynamic model; 3) Aeroelastic modes of motion are computed by combining the linearized PDEs with a linear unsteady aerodynamic model; this model is used to analyze how blade deformation effects the modes of motion; and 4) the linear aeroelastic blade model is derived by a modal expansion of the linearized PDEs combined with a linear unsteady aerodynamic model. The aeroelastic blade model has many similarities to a 2D blade section model, and it can be used instead of this in many applications, giving a transparent connection to a real wind turbine blade. In this work the aeroelastic blade model is used to analyze interaction between pitch action, blade motion and wind speed variations. Furthermore the model is used to develop a state estimator for estimating the wind speed and wind shear, and to suggest a load reducing controller. The state estimator estimates the wind shear very

  3. Environmental impact of wind energy

    DEFF Research Database (Denmark)

    Mann, Jakob; Teilmann, Jonas

    2013-01-01

    One purpose of wind turbines is to provide pollution-free electric power at a reasonable price in an environmentally sound way. In this focus issue the latest research on the environmental impact of wind farms is presented. Offshore wind farms affect the marine fauna in both positive and negative...... ways. For example, some farms are safe havens for porpoises while other farms show fewer harbor porpoises even after ten years. Atmospheric computer experiments are carried out to investigate the possible impact and resource of future massive installations of wind turbines. The following questions...... are treated. What is the global capacity for energy production by the wind? Will the added turbulence and reduced wind speeds generated by massive wind farms cool or heat the surface? Can wind farms affect precipitation? It is also shown through life-cycle analysis how wind energy can reduce the atmospheric...

  4. Wind Farms: Modeling and Control

    DEFF Research Database (Denmark)

    Soleimanzadeh, Maryam

    2012-01-01

    is minimized. The controller is practically feasible. Yet, the results on load reduction in this approach are not very significant. In the second strategy, the wind farm control problem has been divided into below rated and above rated wind speed conditions. In the above rated wind speed pitch angle and power....... Distributed controller design commences with formulating the problem, where a structured matrix approach has been put in to practice. Afterwards, an H2 control problem is implemented to obtain the controller dynamics for a wind farm such that the structural loads on wind turbines are minimized.......The primary purpose of this work is to develop control algorithms for wind farms to optimize the power production and augment the lifetime of wind turbines in wind farms. In this regard, a dynamical model for wind farms was required to be the basis of the controller design. In the first stage...

  5. Social Class Dialogues and the Fostering of Class Consciousness

    Science.gov (United States)

    Madden, Meredith

    2015-01-01

    How do critical pedagogies promote undergraduate students' awareness of social class, social class identity, and social class inequalities in education? How do undergraduate students experience class consciousness-raising in the intergroup dialogue classroom? This qualitative study explores undergraduate students' class consciousness-raising in an…

  6. Wind energy potential in India

    International Nuclear Information System (INIS)

    Rangarajan, S.

    1995-01-01

    Though located in the tropics, India is endowed with substantial wind resources because of its unique geographical location which gets fully exposed to both the south-west and north-east monsoon winds. The westerly winds of the south-west monsoons provide bulk of the wind potential. Areas with mean annual wind speed exceeding 18 k mph and areas with mean annual power density greater than 140 W/m 2 have been identified using the wind data collected by the wind monitoring project funded by the Ministry of Non-conventional Energy Sources (MNES). Seasonal variations in wind speed at selected locations are discussed as also the frequency distribution of hourly wind speed. Annual capacity factors for 250 kW wind electric generators have been calculated for several typical locations. A good linear correlation has been found between mean annual wind speed and mean annual capacity factor. A method is described for assessing wind potential over an extended region where adequate data is available. It is shown that the combined wind energy potential over five selected areas of limited extent in Gujarat, Andhra Pradesh and Tamil Nadu alone amounts to 22,000 MW under the assumption of 20 per cent land availability for installing wind farms. For a higher percentage of land availability, the potential will be correspondingly higher. (author). 12 refs., 6 figs., 3 tabs

  7. Wind Powering America

    Energy Technology Data Exchange (ETDEWEB)

    Flowers, L. (NREL); Dougherty, P. J. (DOE)

    2001-07-07

    At the June 1999 Windpower Conference, the Secretary of Energy launched the Office of Energy Efficiency and Renewable Energy's Wind Powering America (WPA) initiative. The goals of the initiative are to meet 5% of the nation's energy needs with wind energy by 2020 (i.e., 80,000 megawatts installed), to double the number of states that have more than 20 megawatts (MW) of wind capacity to 16 by 2005 and triple it to 24 by 2010, and to increase wind's contribution to Federal electricity use to 5% by 2010. To achieve the Federal government's goal, DOE would take the leadership position and work with its Federal partners. Subsequently, the Secretary accelerated the DOE 5% commitment to 2005. Achieving the 80,000 MW goal would result in approximately $60 billion investment and $1.5 billion of economic development in our rural areas (where the wind resources are the greatest). The purpose of this paper is to provide an update on DOE's strategy for achieving its goals and the activities it has undertaken since the initiative was announced.

  8. Wind power barometer

    International Nuclear Information System (INIS)

    Anon.

    2010-01-01

    The global wind power market not only repelled the strictures of the financial crisis, but saw the installation of 37 GW in 2009, which is almost 10 GW up on 2008. China and the United States registered particularly steady growth and the European Union also picked up momentum to break its installation record. A total capacity of 158 GW of wind power are now installed across the world from which 74.8 GW in the European Union. Among the European countries Denmark has the highest wind capacity per inhabitant in 2009: 627.5 kW/1000 inhabitants. Spain seeks to limit its market's growth in order to better manage the development of wind energy across the country. German growth is back, Italy chalks up a new record for installation and the French market is becoming increasingly regulated. United-Kingdom is developing offshore wind farms: the offshore capacity could reasonably rise to 20000 MW by 2020. The last part of the article reports some economical news from the leading players: Vestas, GE-Energy, Gamesa, Enercon, Sinovel and Siemens. (A.C.)

  9. Commercial wind power

    International Nuclear Information System (INIS)

    Braun, G.W.; Smith, D.R.

    1992-01-01

    In 1990 the 23,000 wind turbines in the world connected to utility grids were rated at a total of 2200 MW and produced 3,353,000,000 kWh of electricity. This represents the residential use of a city with population of 1,000,000 at US energy use rates, or 2,000,000 at European rates. Denmark produced about 2% of its electricity from the wind, while California and Hawaii produced about 1% of theirs. California wind farms produced 76% of the world total, and Pacific Gas and Electric Company (PG and E) received nearly half of this. In addition to these grid-connected turbines, more than 50,000 smaller turbines (averaging about 100 watts each) supplied electricity to remote areas, such as Mongolia. Such non-grid-connected turbines can be components of hybrid generation systems when combined with energy storage and/or complementary power sources. However, the emphasis of this paper is on utility-connected wind turbines. Wind also supplies mechanical energy, such as for water pumping

  10. Wind turbine noise diagnostics

    International Nuclear Information System (INIS)

    Richarz, W.; Richarz, H.

    2009-01-01

    This presentation proposed a self-consistent model for broad-band noise emitted from modern wind turbines. The simple source model was consistent with the physics of sound generation and considered the unique features of wind turbines. Although the acoustics of wind turbines are similar to those of conventional propellers, the dimensions of wind turbines pose unique challenges in diagnosing noise emission. The general features of the sound field were deduced. Source motion and source directivity appear to be responsible for amplitude variations. The amplitude modulation is likely to make wind-turbine noise more audible, and may be partly responsible for annoyance that has been reported in the literature. Acoustic array data suggests that broad-band noise is emitted predominantly during the downward sweep of each rotor blade. Source motion and source directivity account for the observed pattern. Rotor-tower interaction effects are of lesser importance. Predicted amplitude modulation ranges from 1 dB to 6dB. 2 refs., 9 figs.

  11. Financing wind energy projects

    International Nuclear Information System (INIS)

    Blom, P.

    1996-01-01

    Triodos Bank has more than 10 years of experience with developing and financing wind projects in the Netherlands. Over 50 Megawatt has been installed with direct involvement of the bank. The experience is both as a bank and as a venture capital fund. In this contribution the perspective will be more from a venture capital point of view than as a bank. The bank's activities in the wind energy sector started in 1986 by forming a joint venture with an engineering bureau, experienced i wind energy but not yet in developing wind projects. From 1989 onwards the joint venture started to build wind farms, both as a private company and in a joint venture with utilities. The European Investment Bank became involved with a long-term debt finance facility (15 years, fixed interest loan). The main difficulties were long-term commitments from landowners (Dike authorities) and utilities with regard to power contracts. The development got really stuck when utilities refused to pay a fair price anymore. Also, site development became more and more difficult. Even the poor technical performance improved drastically and did not frighten developers and banks too much. (author)

  12. Wind energy and Turkey.

    Science.gov (United States)

    Coskun, Aynur Aydin; Türker, Yavuz Özhan

    2012-03-01

    The global energy requirement for sustaining economic activities, meeting social needs and social development is increasing daily. Environmentally friendly, renewable energy resources are an alternative to the primary non-renewable energy resources, which devastate ecosystems in order to meet increasing demand. Among renewable energy sources such as hydropower, biopower, geothermal power and solar power, wind power offers distinct advantages to Turkey. There is an increasing tendency toward wind globally and the European Union adjusted its legal regulations in this regard. As a potential EU Member state, Turkey is going through a similar process. The number of institutional and legal regulations concerning wind power has increased in recent years; technical infrastructure studies were completed, and some important steps were taken in this regard. This study examines the way in which Turkey has developed support for wind power, presents a SWOT analysis of the wind power sector in Turkey and a projection was made for the concrete success expected to be accomplished in the future.

  13. Wind Powering America

    International Nuclear Information System (INIS)

    Flowers, L.; Dougherty, P. J.

    2001-01-01

    At the June 1999 Windpower Conference, the Secretary of Energy launched the Office of Energy Efficiency and Renewable Energy's Wind Powering America (WPA) initiative. The goals of the initiative are to meet 5% of the nation's energy needs with wind energy by 2020 (i.e., 80,000 megawatts installed), to double the number of states that have more than 20 megawatts (MW) of wind capacity to 16 by 2005 and triple it to 24 by 2010, and to increase wind's contribution to Federal electricity use to 5% by 2010. To achieve the Federal government's goal, DOE would take the leadership position and work with its Federal partners. Subsequently, the Secretary accelerated the DOE 5% commitment to 2005. Achieving the 80,000 MW goal would result in approximately$60 billion investment and$1.5 billion of economic development in our rural areas (where the wind resources are the greatest). The purpose of this paper is to provide an update on DOE's strategy for achieving its goals and the activities it has undertaken since the initiative was announced

  14. THE Onfp CLASS IN THE MAGELLANIC CLOUDS

    International Nuclear Information System (INIS)

    Walborn, Nolan R.; Howarth, Ian D.; Evans, Christopher J.

    2010-01-01

    The Onfp class of rotationally broadened, hot spectra was defined some time ago in the Galaxy, where its membership to date numbers only eight. The principal defining characteristic is a broad, centrally reversed He II λ 4686 emission profile; other emission and absorption lines are also rotationally broadened. Recent surveys in the Magellanic Clouds (MCs) have brought the class membership there, including some related spectra, to 28. We present a survey of the spectral morphology and rotational velocities, as a first step toward elucidating the nature of this class. Evolved, rapidly rotating hot stars are not expected theoretically, because the stellar winds should brake the rotation. Luminosity classification of these spectra is not possible, because the principal criterion (He II λ4686) is peculiar; however, the MCs provide reliable absolute magnitudes, which show that they span the entire range from dwarfs to supergiants. The Onfp line-broadening distribution is distinct and shifted toward larger values from those of normal O dwarfs and supergiants with >99.99% confidence. All cases with multiple observations show line-profile variations, which even remove some objects from the class temporarily. Some of them are spectroscopic binaries; it is possible that the peculiar profiles may have multiple causes among different objects. The origin and future of these stars are intriguing; for instance, they could be stellar mergers and/or gamma-ray-burst progenitors.

  15. Wind power; Die Kraft der Winde

    Energy Technology Data Exchange (ETDEWEB)

    Mardo, Dietrich

    2009-10-30

    Wind power plants are probably only one pillar of the bridge that is taking us into an energy future still unimaginable to us. They are extremely cost-intensive and bulky and they spoil our landscapes. Their patronage by political leaders is understandable considering our excessive dependence on oil and gas. True energy autonomy is currently still a utopian dream for a country as poor in resources as Germany. On the other hand, to reach Utopia you have to build bridges there. Seen this way all currently available types of renewable energy represent bridge technologies whose realisation is imperative.

  16. Optimizing UML Class Diagrams

    Directory of Open Access Journals (Sweden)

    Sergievskiy Maxim

    2018-01-01

    Full Text Available Most of object-oriented development technologies rely on the use of the universal modeling language UML; class diagrams play a very important role in the design process play, used to build a software system model. Modern CASE tools, which are the basic tools for object-oriented development, can’t be used to optimize UML diagrams. In this manuscript we will explain how, based on the use of design patterns and anti-patterns, class diagrams could be verified and optimized. Certain transformations can be carried out automatically; in other cases, potential inefficiencies will be indicated and recommendations given. This study also discusses additional CASE tools for validating and optimizing of UML class diagrams. For this purpose, a plugin has been developed that analyzes an XMI file containing a description of class diagrams.

  17. Classes of Heart Failure

    Science.gov (United States)

    ... Introduction Types of Heart Failure Classes of Heart Failure Heart Failure in Children Advanced Heart Failure • Causes and ... and Advanced HF • Tools and Resources • Personal Stories Heart Failure Questions to Ask Your Doctor Use these questions ...

  18. Characterization of wind power resource and its intermittency

    Science.gov (United States)

    Gunturu, U. B.; Schlosser, C. A.

    2011-12-01

    Wind resource in the continental and offshore United States has been calculated and characterized using metrics that describe - apart from abundance - its availability, persistence and intermittency. The Modern Era Retrospective-Analysis for Research and Applications (MERRA) boundary layer flux data has been used to construct wind power density profiles at 50, 80, 100 and 120 m turbine hub heights. The wind power density estimates at 50 m are qualitatively similar to those in the US wind atlas developed by the National Renewable Energy Laboratory (NREL), but quantitatively a class less in some regions, but are within the limits of uncertainty. We also show that for long tailed distributions like those of the wind power density, the mean is an overestimation and median is a more robust metric for summary representation of wind power resource.Generally speaking, the largest and most available wind power density resources are found in off-shore regions of the Atlantic and Pacific coastline, and the largest on-shore resource potential lies in the central United States. However, the intermittency and widespread synchronicity of on-shore wind power density are substantial, and highlights areas where considerable back-up generation technologies will be required. Generation-duration curves are also presented for the independent systems operator (ISO) zones of the U.S. to highlight the regions with the largest capacity factor (MISO, ERCOT, and SWPP) as well as the periods and extent to which all ISOs contain no wind power and the potential benefits of aggregation on wind power intermittency in each region. The impact of raising the wind turbine hub height on metrics of abundance, persistence, variability and intermittency is analyzed. There is a general increase in availability and abundance of wind resource but there is also an increase in intermittency with respect to a 'usable wind power' crossing level in low resource regions. A similar perspective of wind resource for

  19. Generalized Fourier transforms classes

    DEFF Research Database (Denmark)

    Berntsen, Svend; Møller, Steen

    2002-01-01

    The Fourier class of integral transforms with kernels $B(\\omega r)$ has by definition inverse transforms with kernel $B(-\\omega r)$. The space of such transforms is explicitly constructed. A slightly more general class of generalized Fourier transforms are introduced. From the general theory foll...... follows that integral transform with kernels which are products of a Bessel and a Hankel function or which is of a certain general hypergeometric type have inverse transforms of the same structure....

  20. Nordic Walking Classes

    CERN Multimedia

    Fitness Club

    2015-01-01

    Four classes of one hour each are held on Tuesdays. RDV barracks parking at Entrance A, 10 minutes before class time. Spring Course 2015: 05.05/12.05/19.05/26.05 Prices 40 CHF per session + 10 CHF club membership 5 CHF/hour pole rental Check out our schedule and enroll at: https://espace.cern.ch/club-fitness/Lists/Nordic%20Walking/NewForm.aspx? Hope to see you among us! fitness.club@cern.ch

  1. Wind Energy Finance in the United States: Current Practice and Opportunities

    Energy Technology Data Exchange (ETDEWEB)

    Schwabe, Paul D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Feldman, David J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Settle, Donald E. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Fields, Jason [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-08-08

    In the United States, investment in wind energy has averaged nearly $13.6 billion annually since 2006 with more than $140 billion invested cumulatively over that period (BNEF 2017). This sizable investment activity demonstrates the persistent appeal of wind energy and its increasing role in the U.S electricity generation portfolio. Despite its steady investment levels over the last decade, some investors still consider wind energy as a specialized asset class. Limited familiarity with the asset class both limit the pool of potential investors and drive up costs for investors. This publication provides an overview of the wind project development process, capital sources and financing structures commonly used, and traditional and emerging procurement methods. It also provides a high-level demonstration of how financing rates impact a project's all-in cost of energy. The goal of the publication is to provide a representative and wide-ranging resource for the wind development and financing processes.

  2. Electrical and non-electrical environment of wind turbine main components

    DEFF Research Database (Denmark)

    Holboell, J.; Henriksen, M.; Olsen, R.S.

    of the electrical components or even lead to catastrophic component failure. In the present paper, results are presented from investigations on existing standards which give detailed descriptions of the environmental and operational conditions of wind turbine components. It is found that there is currently a lack...... of application standards for wind turbine electrical equipment. Component-level environmental requirements as given in equipment-specific standards are compared with the environment described in the IEC's 61400 series concerning wind turbines. Based on methods defined in IEC 60721, the non-electrical environment...... of wind turbine is described by means of specific classes. In the paper, new class combinations are suggested covering the different operating conditions the components are exposed to. The class combinations include factors of climatic, mechanical and chemical character. The factors occur in different...

  3. Wind turbines and idiopathic symptoms

    DEFF Research Database (Denmark)

    Blanes-Vidal, Victoria; Schwartz, Joel

    2016-01-01

    Whether or not wind turbines pose a risk to human health is a matter of heated debate. Personal reactions to other environmental exposures occurring in the same settings as wind turbines may be responsible of the reported symptoms. However, these have not been accounted for in previous studies. We...... investigated whether there is an association between residential proximity to wind turbines and idiopathic symptoms, after controlling for personal reactions to other environmental co-exposures. We assessed wind turbine exposures in 454 residences as the distance to the closest wind turbine (Dw) and number...... of wind turbines

  4. The wind energy takes off

    International Nuclear Information System (INIS)

    Rapin, M.; Degobert, Ph.

    2010-01-01

    After having evoked the objectives defined for wind energy production by 2050, the important growth of wind energy in Europe and in other parts of the world, and its importance in terms of business and jobs, this article presents the Denmark model where the wind energy industry is a world leader but now faces the need of a new development model. It comments the investments and incentives implemented in Western countries after the first oil crisis. It outlines the increasing power of wind generators and their technological evolution, the development of offshore wind farms and their cost, and finally the intermittency problem and the case of small wind turbines

  5. Strong winds and waves offshore

    DEFF Research Database (Denmark)

    Larsén, Xiaoli Guo

    2016-01-01

    is on the meteorologi al and o eani onditions related to storm winds and waves over the North Sea. With regard to the o shore wind energy appli ation, the parameters addressed here in lude: extreme wind and extreme waves, storm wind and waves and turbulen e issues for o shore onditions.......This report is prepared for Statoil, with the intention to introdu e DTU Wind Energy's ongoing resear h a tivities on o shore extreme wind and wave onditions. The purpose is to share our re ent ndings and to establish possible further ollaboration with Statoil. The fo us of this report...

  6. Wind power - energy from air

    International Nuclear Information System (INIS)

    Alakangas, E.

    1998-01-01

    The wind conditions for wind power generation are favourable on the coast, in the archipelagos and in the fell areas of Finland. About 7 MW of wind power has been constructed in Finland, with the investment support of the Ministry of Trade and Industry. In 1995 about 11 GWh were produced by wind energy. A number of wind power plants are under design on the coasts of the Gulf of Finland and the Gulf of Bothnia as well as on the Aaland Islands. The first arctic wind park was constructed in Lapland in September 1996

  7. Small Wind Energy Systems

    DEFF Research Database (Denmark)

    Simoes, Marcelo; Farret, Felix Alberto; Blaabjerg, Frede

    2015-01-01

    devices, and a centralized distribution control. In order to establish a small wind energy system it is important to observe the following: (i) Attending the energy requirements of the actual or future consumers; (ii) Establishing civil liabilities in case of accidents and financial losses due to shortage...... or low quality of energy; (iii) Negotiating collective conditions to interconnect the microgrid with the public network or with other sources of energy that is independent of wind resources; (iv) Establishing a performance criteria of power quality and reliability to end-users, in order to reduce costs...... and guaranteeing an acceptable energy supply. This paper discuss how performance is affected by local conditions and random nature of the wind, power demand profiles, turbine related factors, and presents the technical issues for implementing a self-excited induction generator system, or a permanent magnet based...

  8. Superconducting wind turbine generators

    DEFF Research Database (Denmark)

    Mijatovic, Nenad

    cryostat design, where a concept with 20 W of heat transfer is achieved. Following the setup description, the focus turns to the electromagnetic design of the HTS machine. Particularly, an approach to increase the performance of HTS coils and the influence of the armature reaction to the HTS field winding...... magnetic characteristic with respect to the critical current. I have showed that the potential for the reduction of HTS conductor can be significant, if the coils are placed strategically, whereby the coils wound with BSCCO performed 40% better depending on the placement in the field winding. The 2G coils...... were less sensitive to the placement which made them particularly useful for high magnetic field regions in the eld winding. The second design approach proposed and tested was to use multiple current supplies which allowed each coil to operate close to its critical current. I have demonstrated...

  9. Canadian wind energy program

    Energy Technology Data Exchange (ETDEWEB)

    Templin, R J; South, P

    1976-01-01

    Several aspects of recent work at the National Research Council of Canada on the development of vertical-axis turbines have been reviewed. Most of this work, during the past year or more, has been in support of the design of a 200 kW unit now being built for experimental operation on the Magdelen Islands in the Gulf of St. Lawrence. Results of small and large scale aeroelastic wind tunnel model experiments have confirmed that very large scale vertical-axis wind turbines are feasible, especially if designed for normal operation at constant rotational speed. A computer model of a simple mixed power system has indicated that substantial cost savings may be possible by using wind energy in Canadian east coast regions. 4 refs., 11 figs., 1 tab.

  10. Wind around the world

    International Nuclear Information System (INIS)

    Rackstraw, K.

    1998-01-01

    A combination of cost reductions and progressive policies in key markets kept the world wind market percolating in 1997 with a record 1510 MW of new wind capacity installed, representing annual sales of more than $1.5 billion. This new record surpasses last year''s total by 24 percent, about the average annual rate of growth for the last three years. Worldwide utility-scale wind installations at the end of 1997 totaled 7763 MW. Most activity occurred in Europe, which accounted for over 75 percent of 1997 installations. Germany was again the world''s leading single market, this time by quite a large margin, accounting for more than one-third of the annual total by itself at 532 MW in 1997. The end of 1997 also marked the time at which Germany officially passed the US as the largest total single market with over 2079 MW in total installations versus about 1805 MW for the US, although the US had actually lost the lead by mid-year. Spain is the new addition to the top echelon of world wind markets, installing 215 MW in 1997 that more than doubles their total installed capacity over the previous year and ranks them number three in the world for the year. Denmark''s 1997 total of 300 MW is also a record, although this estimate could go up as the official count is finalized. India, the second largest wind market in 1995 and 1996, slipped several notches because of a variety of factors, including a change in government and a slowdown in the economy. The US wind market continues to stagnate as it has for the last several years, largely because of the uncertainty surrounding restructuring of US electric utilities. The US market is poised for a big comeback in 1998, however

  11. Assessing the vegetation canopy influences on wind flow using wind ...

    Indian Academy of Sciences (India)

    Artificial plastic vegetations with different porosity and canopy shape were introduced as ... Wind erosion is the Aeolian process by which soil particles are detached from ..... the stabilizing role of vegetation on wind erosion. And therefore, for ...

  12. Representivity of wind measurements for design wind speed estimations

    CSIR Research Space (South Africa)

    Goliger, Adam M

    2013-07-01

    Full Text Available of instrumentation sited according to World Meteorological Organization (WMO) requirements. With the advent of automatic weather station technology several decades ago, wind measurements have become much more cost-effective. While previously wind measurements were...

  13. Wind Power Today: 2000 Wind Energy Program Highlights

    Energy Technology Data Exchange (ETDEWEB)

    Weis-Taylor, W.

    2001-05-08

    Wind Power Today is an annual publication that provides an overview of the U.S. Department of Energy's Wind Energy Program. The purpose of Wind Power Today is to show how DOE's Wind Energy Program supports wind turbine research and deployment in hopes of furthering the advancement of wind technologies that produce clean, low-cost, reliable energy. Content objectives include: educate readers about the advantages and potential for widespread deployment of wind energy; explain the program's objectives and goals; describe the program's accomplishments in research and application; examine the barriers to widespread deployment; describe the benefits of continued research and development; facilitate technology transfer; and attract cooperative wind energy projects with industry.

  14. Wind Turbines Adaptation to the Variability of the Wind Field

    Science.gov (United States)

    Ulianov, Yuriy; Martynenko, Gennadii; Misaylov, Vitaliy; Soliannikova, Iuliia

    2010-05-01

    WIND TURBINES ADAPTATION TO THE VARIABILITY OF THE WIND FIELD The subject of our scientific research is wind power turbines (WPT) with the horizontal axis which were now common in the world. Efficient wind turbines work is largely determined by non-stationarity of the wind field, expressed in its gustiness, the presence of vertical and horizontal shifts of wind speed and direction. At critical values of the wind parameters WPT has aerodynamic and mechanical overload, leading to breakdowns, premature wear and reduce the life of the wind turbine. To prevent accidents at the peak values of wind speed it is used the regulatory system of windwheels. WPT control systems provide a process orientation of the wind turbine rotor axis in the line of the mean wind. Wind turbines are also equipped with braking device used to protect against breakdowns when a significant increase in the wind. In general, all these methods of regulation are not always effective. Thus, in practice there may be situations when the wind speed is many times greater than the stated limit. For example, if there are microbursts in the atmospheric boundary layer, low-level wind shears caused by its gust front, storms, etc. It is required for a wind power turbine adaptation to intensive short-term wind impulses and considerable vertical wind shifts that the data about them shall be obtained ahead of time. To do this it is necessary to have the information on the real structure of the wind field in the area of the blade sweep for the minimum range against the wind that is determined by the mean speed and the system action time. The implementation of acoustic and laser traditional wind sounding systems is limited by ambient acoustic noise, by heavy rain, snowfall and by fog. There are free of these disadvantages the inclined radioacoustic sounding (IRASS) technique which works for a system of remote detection and control of wind gusts. IRASS technique is realized as low-potential Doppler pulse radar

  15. Advancements in Wind Integration Study Data Modeling: The Wind Integration National Dataset (WIND) Toolkit; Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Draxl, C.; Hodge, B. M.; Orwig, K.; Jones, W.; Searight, K.; Getman, D.; Harrold, S.; McCaa, J.; Cline, J.; Clark, C.

    2013-10-01

    Regional wind integration studies in the United States require detailed wind power output data at many locations to perform simulations of how the power system will operate under high-penetration scenarios. The wind data sets that serve as inputs into the study must realistically reflect the ramping characteristics, spatial and temporal correlations, and capacity factors of the simulated wind plants, as well as be time synchronized with available load profiles. The Wind Integration National Dataset (WIND) Toolkit described in this paper fulfills these requirements. A wind resource dataset, wind power production time series, and simulated forecasts from a numerical weather prediction model run on a nationwide 2-km grid at 5-min resolution will be made publicly available for more than 110,000 onshore and offshore wind power production sites.

  16. Offshore Wind Turbine Design

    DEFF Research Database (Denmark)

    Frandsen, Sten; Hansen, Erik Asp; Ibsen, Lars Bo

    2006-01-01

    Current offshore wind turbine design methods have matured to a 1st generation state, manifested in the draft of a possible standard, IEC 61400-3 (2005). It is now time to investigate the possibilities of improving existing methods. To do so in an efficient manner a clear identification of the most...... important uncertainty drivers specific for offshore wind turbine design loads is required. Describing the initial efforts in a Danish research project, the paper points to focal points for research and development. These are mainly: soil-structure interaction, improved modelling of wave loads from deep...

  17. Gearless wind power generator

    Energy Technology Data Exchange (ETDEWEB)

    Soederlund, L.; Ridanpaeae, P.; Vihriaelae, H.; Peraelae, R. [Tampere Univ. of Technology (Finland). Lab. of Electricity and Magnetism

    1998-12-31

    During the wind power generator project a design algorithm for a gearless permanent magnet generator with an axially orientated magnetic flux was developed and a 10 kW model machine was constructed. Utilising the test results a variable wind speed system of 100 kW was designed that incorporates a permanent magnet generator, a frequency converter and a fuzzy controller. This system produces about 5-15% more energy than existing types and stresses to the blades are minimised. The type of generator designed in the project represents in general a gearless solution for slow-speed electrical drives. (orig.)

  18. Wind farm policy 1995

    International Nuclear Information System (INIS)

    Anon.

    1995-03-01

    Argyll and Bute District Council, having received a number of planning applications for the erection of wind farms, seeks, in this document, to set out its environmental policy on these installations in line with national government guidelines and those from Strathclyde Regional Council. District Council policy on thirteen environmental issues connected with wind farm construction is set out, covering issues such as environmental impacts on wild-life, noise pollution, access for construction, maintenance and decommissioning vehicles as well as planning consent issues. Recommendations are made to four interested bodies, Strathclyde Regional Council, the Forestry Authority and Scottish Natural Heritage and the Royal Society for the Protection of Birds. (UK)

  19. Wind power engine

    Energy Technology Data Exchange (ETDEWEB)

    Musgrove, P J

    1977-02-10

    The device is a wind-power engine with vertical axis and with one or several wings with airfoil profile fixed on a frame which is pivoted at the vertical axis. Each wing forms at least on one part of its length an angle of inclination with the vertical. The angle increases under the influence of the centrifugal force when the r.p.m. exceed a normal operation range. This method helps to reduce mechanical loads occurring with high wind speeds without requiring a complicated construction.

  20. Technology Roadmaps: Wind Energy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    Wind energy is perhaps the most advanced of the 'new' renewable energy technologies, but there is still much work to be done. This roadmap identifies the key tasks that must be undertaken in order to achieve a vision of over 2 000 GW of wind energy capacity by 2050. Governments, industry, research institutions and the wider energy sector will need to work together to achieve this goal. Best technology and policy practice must be identified and exchanged with emerging economy partners, to enable the most cost-effective and beneficial development.

  1. Ergosphere-driven winds

    International Nuclear Information System (INIS)

    Punsly, B.; Coroniti, F.V.

    1990-01-01

    This paper is a discussion of a physical mechanism that allows large-scale magnetic fields to torque rapidly rotating black holes in an astrophysical context. The physics which is involved is that plasma in the ergosphere must rotate. Thus, if ergospheric plasma gets frozen onto large-scale magnetic field lines, then it can drive a magnetic wind to infinity, as is conjectured to occur in field-aligned pulsars. Included in this paper is a discussion of ingoing magnetic winds that accrete either toward the event horizon or to the equatorial plane in the ergosphere. 31 refs

  2. Wind emergency response system

    International Nuclear Information System (INIS)

    Garrett, A.J.; Buckner, M.R.; Mueller, R.A.

    1981-01-01

    The WIND system is an automated emergency response system for real-time predictions of the consequences of liquid and airborne releases from SRP. The system consists of a minicomputer and associated peripherals necessary for acquisition and handling of large amounts of meteorological data from a local tower network and the National Weather Service. The minicomputer uses these data and several predictive models to assess the impact of accidental releases. The system is fast and easy to use, and output is displayed both in tabular form and as trajectory map plots for quick interpretation. The rapid response capabilities of the WIND system have been demonstrated in support of SRP operations

  3. Aerodynamics of wind turbines

    CERN Document Server

    Hansen, Martin O L

    2015-01-01

    Aerodynamics of Wind Turbines is the established essential text for the fundamental solutions to efficient wind turbine design. Now in its third edition, it has been substantially updated with respect to structural dynamics and control. The new control chapter now includes details on how to design a classical pitch and torque regulator to control rotational speed and power, while the section on structural dynamics has been extended with a simplified mechanical system explaining the phenomena of forward and backward whirling modes. Readers will also benefit from a new chapter on Vertical Axis W

  4. Wind energy. To produce electricity with the wind

    International Nuclear Information System (INIS)

    Bareau, Helene

    2015-11-01

    This guide addresses the different aspects of wind-based power generation. It outlines the role of wind energy to meet objectives related to the share of renewable energies in the French energy mix, that wind energy is actually replacing fossil energies, that it is based on local resources within higher safety and less wastage, that current advances are made to integrate wind energy production into the grid, and that it is a solution to diversify energy production. Some figures are presented and commented, regarding onshore wind energy production in France, the location of wind farms, and wind energy production in comparison with other renewable sources. The operation of a wind turbine is described and the different types of wind turbines are evoked. The issue of wind farm planning with citizen participation is addressed: regional planning, studies of pre-feasibility for location selection, procedure, and content of the impact study (radars, fauna and flora, landscapes, safety, health). Other features are outlined: a planned dismantling, and a globally favourable perception. The next part addresses offshore wind energy: the interesting potential of stronger and more reliable wind at sea (European situation, French opportunities, elements comprised in an offshore wind farm), impacts (on marine ecosystems, on neighbouring localities, and interests for visitors). Economic aspects are then addressed: cost and profitability, economic spin-offs, and perspectives. The last part concerns individuals and the possibilities to participate to wind farm projects or to invest in small wind turbines with some prerequisites (constant and steady winds, installation assessment, required expertise, indispensable preliminary steps, costs, aids and profitability)

  5. Wind Forcing of the Pacific Ocean Using Scatterometer Wind Data

    Science.gov (United States)

    Kelly, Kathryn A.

    1999-01-01

    The long-term objective of this research was an understanding of the wind-forced ocean circulation, particularly for the Pacific Ocean. To determine the ocean's response to the winds, we first needed to generate accurate maps of wind stress. For the ocean's response to wind stress we examined the sea surface height (SSH) both from altimeters and from numerical models for the Pacific Ocean.

  6. Wind energy, status and opportunities

    International Nuclear Information System (INIS)

    Van Wijk, A.

    1994-01-01

    Wind energy is diffuse but was widely used before the industrial revolution. The first oil crisis triggered renewed interest in wind energy technology in remote areas. Winds develop when solar radiation reaches the earth's highly varied surface unevenly, creating temperature density and pressure differences. The earth's atmosphere has to circulate to transport heat from the tropics towards the poles. On a global scale, these atmospheric currents work as an immense energy transfer medium. Three main applications can be distinguished: wind pumps, off-grid applications and grid-connected applications. The total generating costs for wind turbine systems are determined by total investments costs, the life time, the operating and maintenance costs, the wind regime (the wind energy potential is proportional to v 3 where v is the wind speed), the efficiency and availability of the wind turbine. The main gains are achieved as a result of improved reliability. The optimum size of a wind turbine depends on the wind speed, the wind turbine costs, the construction costs, the environmental impact and the social costs. The value of wind energy depends on the application that is made of the energy generated and on the costs of alternatives, it can be calculated by the avoided costs of damage to flora, fauna and mankind due to acid rain deposition, enhancement of the greenhouse effect. The environmental aspects are bird hindrance, noise, telecommunication interference and safety. 2 tabs., 1 fig

  7. Safety class methodology

    International Nuclear Information System (INIS)

    Donner, E.B.; Low, J.M.; Lux, C.R.

    1992-01-01

    DOE Order 6430.1A, General Design Criteria (GDC), requires that DOE facilities be evaluated with respect to ''safety class items.'' Although the GDC defines safety class items, it does not provide a methodology for selecting safety class items. The methodology described in this paper was developed to assure that Safety Class Items at the Savannah River Site (SRS) are selected in a consistent and technically defensible manner. Safety class items are those in the highest of four categories determined to be of special importance to nuclear safety and, merit appropriately higher-quality design, fabrication, and industrial test standards and codes. The identification of safety class items is approached using a cascading strategy that begins at the 'safety function' level (i.e., a cooling function, ventilation function, etc.) and proceeds down to the system, component, or structure level. Thus, the items that are required to support a safety function are SCls. The basic steps in this procedure apply to the determination of SCls for both new project activities, and for operating facilities. The GDC lists six characteristics of SCls to be considered as a starting point for safety item classification. They are as follows: 1. Those items whose failure would produce exposure consequences that would exceed the guidelines in Section 1300-1.4, ''Guidance on Limiting Exposure of the Public,'' at the site boundary or nearest point of public access 2. Those items required to maintain operating parameters within the safety limits specified in the Operational Safety Requirements during normal operations and anticipated operational occurrences. 3. Those items required for nuclear criticality safety. 4. Those items required to monitor the release of radioactive material to the environment during and after a Design Basis Accident. Those items required to achieve, and maintain the facility in a safe shutdown condition 6. Those items that control Safety Class Item listed above

  8. Far offshore wind conditions in scope of wind energy

    NARCIS (Netherlands)

    Holtslag, M.C.

    2016-01-01

    Far offshore atmospheric conditions are favourable for wind energy purposes since mean wind speeds are relatively high (i.e., high power production) while turbulence levels are relatively low (i.e., less fatigue loads) compared to onshore conditions. Offshore wind energy, however, is still expensive

  9. Monthly Wind Characteristics and Wind Energy in Rwanda | Sarari ...

    African Journals Online (AJOL)

    Evaluating wind power potential for a site is indispensable before making any ... objective was to investigate the potential of wind energy resource in Rwanda. ... fit to the distribution of the measured wind data varies from a location to another. ... (14); Eritrea (1); Ethiopia (30); Ghana (27); Kenya (29); Lesotho (1); Libya (2) ...

  10. Monthly Wind Characteristics and Wind Energy in Rwanda

    African Journals Online (AJOL)

    user

    Abstract. Evaluating wind power potential for a site is indispensable before making any decision for the installation of wind energy infrastructures and planning for relating projects. This paper presents a branch of a composite analysis whose objective was to investigate the potential of wind energy resource in Rwanda.

  11. Wind Power Today: Wind Energy Program Highlights 2001

    Energy Technology Data Exchange (ETDEWEB)

    2002-05-01

    Wind Power Today is an annual publication that provides an overview of the U.S. Department of Energy's Wind Energy Program accomplishments for the previous year. The purpose of Wind Power Today is to show how DOE's Wind Energy Program supports wind turbine research and deployment in hopes of furthering the advancement of wind technologies that produce clean, low-cost, reliable energy. Content objectives include: educate readers about the advantages and potential for widespread deployment of wind energy; explain the program's objectives and goals; describe the program's accomplishments in research and application; examine the barriers to widespread deployment; describe the benefits of continued research and development; facilitate technology transfer; and attract cooperative wind energy projects with industry. This 2001 edition of Wind Power Today also includes discussions about wind industry growth in 2001, how DOE is taking advantage of low wind speed regions through advancing technology, and distributed applications for small wind turbines.

  12. Calculation of depleted wind resources near wind farms

    DEFF Research Database (Denmark)

    Nielsen, Morten

    2015-01-01

    Traditional wind resource maps include wind distribution, energy density and potential power production without wake effects. Adding wake effect to such maps is feasible by means of a new method based on Fourier transformation,and the extra computational work is comparable to that of the basic wind...

  13. Wind speed dynamical model in a wind farm

    DEFF Research Database (Denmark)

    Soleimanzadeh, Maryam; Wisniewski, Rafal

    2010-01-01

    , the dynamic model for wind flow will be established. The state space variables are determined based on a fine mesh defined for the farm. The end goal of this method is to assist the development of a dynamical model of a wind farm that can be engaged for better wind farm control strategies....

  14. Capturing the journey of wind from the wind turbines (poster)

    NARCIS (Netherlands)

    Giyanani, A.H.; Bierbooms, W.A.A.M.; Van Bussel, G.J.W.

    2015-01-01

    Wind turbine design, control strategies often assume Taylor’s frozen turbulence where the fluctuating part of the wind is assumed to be constant. In practise, the wind turbine faces higher turbulence in case of gusts and lower turbulence in some cases. With Lidar technology, the frozen turbulence

  15. LIDAR Wind Speed Measurements of Evolving Wind Fields

    Energy Technology Data Exchange (ETDEWEB)

    Simley, E.; Pao, L. Y.

    2012-07-01

    Light Detection and Ranging (LIDAR) systems are able to measure the speed of incoming wind before it interacts with a wind turbine rotor. These preview wind measurements can be used in feedforward control systems designed to reduce turbine loads. However, the degree to which such preview-based control techniques can reduce loads by reacting to turbulence depends on how accurately the incoming wind field can be measured. Past studies have assumed Taylor's frozen turbulence hypothesis, which implies that turbulence remains unchanged as it advects downwind at the mean wind speed. With Taylor's hypothesis applied, the only source of wind speed measurement error is distortion caused by the LIDAR. This study introduces wind evolution, characterized by the longitudinal coherence of the wind, to LIDAR measurement simulations to create a more realistic measurement model. A simple model of wind evolution is applied to a frozen wind field used in previous studies to investigate the effects of varying the intensity of wind evolution. LIDAR measurements are also evaluated with a large eddy simulation of a stable boundary layer provided by the National Center for Atmospheric Research. Simulation results show the combined effects of LIDAR errors and wind evolution for realistic turbine-mounted LIDAR measurement scenarios.

  16. Blowing in the Wind: A Review of Wind Power Technology

    Science.gov (United States)

    Harris, Frank

    2014-01-01

    The use of wind as a replenishable energy resource has come back into favour in recent decades. It is much promoted as a viable, clean energy option that will help towards reducing CO[subscript 2] emissions in the UK. This article examines the history of wind power and considers the development of wind turbines, together with their economic,…

  17. Wind energy a reference handbook

    CERN Document Server

    Newton, PhD, David E

    2014-01-01

    While covering the fascinating history of wind power as a whole, this timely handbook focuses on current technological developments and the promise--and pitfalls--of wind energy as part of the world's energy future.

  18. Development of arctic wind technology

    Energy Technology Data Exchange (ETDEWEB)

    Holttinen, H.; Marjaniemi, M.; Antikainen, P. [VTT Energy, Espoo (Finland)

    1998-10-01

    The climatic conditions of Lapland set special technical requirements for wind power production. The most difficult problem regarding wind power production in arctic regions is the build-up of hard and rime ice on structures of the machine

  19. 2016 Distributed Wind Market Report

    Energy Technology Data Exchange (ETDEWEB)

    Orrell, Alice C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Foster, Nikolas F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Morris, Scott L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Horner, Juliet S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-08-07

    The U.S. Department of Energy's (DOE's) annual Distributed Wind Market Report provides stakeholders with statistics and analysis of the distributed wind market, along with insight into its trends and characteristics.

  20. 2016 Offshore Wind Market Report

    Energy Technology Data Exchange (ETDEWEB)

    Musial, Walter [National Renewable Energy Lab. (NREL), Golden, CO (United States); Beiter, Philipp [National Renewable Energy Lab. (NREL), Golden, CO (United States); Schwabe, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tian, Tian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Stehly, Tyler [National Renewable Energy Lab. (NREL), Golden, CO (United States); Spitsen, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-08-07

    The 2016 Offshore Wind Technologies Market Report is intended to provide stakeholders with quantitative information about the offshore wind market, technology, and cost trends in the United States and worldwide.

  1. Reliability Analysis of Wind Turbines

    DEFF Research Database (Denmark)

    Toft, Henrik Stensgaard; Sørensen, John Dalsgaard

    2008-01-01

    In order to minimise the total expected life-cycle costs of a wind turbine it is important to estimate the reliability level for all components in the wind turbine. This paper deals with reliability analysis for the tower and blades of onshore wind turbines placed in a wind farm. The limit states...... consideres are in the ultimate limit state (ULS) extreme conditions in the standstill position and extreme conditions during operating. For wind turbines, where the magnitude of the loads is influenced by the control system, the ultimate limit state can occur in both cases. In the fatigue limit state (FLS......) the reliability level for a wind turbine placed in a wind farm is considered, and wake effects from neighbouring wind turbines is taken into account. An illustrative example with calculation of the reliability for mudline bending of the tower is considered. In the example the design is determined according...

  2. Distributed Wind Energy in Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, John [Boise State Univ., ID (United States); Johnson, Kathryn [Colorado School of Mines, Golden, CO (United States); Haynes, Todd [Boise State Univ., ID (United States); Seifert, Gary [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2009-01-31

    This project is a research and development program aimed at furthering distributed wind technology. In particular, this project addresses some of the barriers to distributed wind energy utilization in Idaho.

  3. Wind turbine pitch optimization

    DEFF Research Database (Denmark)

    Biegel, Benjamin; Juelsgaard, Morten; Stoustrup, Jakob

    2011-01-01

    for maximizing power production while simultaneously minimizing fatigue loads. In this paper, we show how this problem can be approximately solved using convex optimization. When there is full knowledge of the wind field, numerical simulations show that force and torque RMS variation can be reduced by over 96...

  4. Pricing offshore wind power

    International Nuclear Information System (INIS)

    Levitt, Andrew C.; Kempton, Willett; Smith, Aaron P.; Musial, Walt; Firestone, Jeremy

    2011-01-01

    Offshore wind offers a very large clean power resource, but electricity from the first US offshore wind contracts is costlier than current regional wholesale electricity prices. To better understand the factors that drive these costs, we develop a pro-forma cash flow model to calculate two results: the levelized cost of energy, and the breakeven price required for financial viability. We then determine input values based on our analysis of capital markets and of 35 operating and planned projects in Europe, China, and the United States. The model is run for a range of inputs appropriate to US policies, electricity markets, and capital markets to assess how changes in policy incentives, project inputs, and financial structure affect the breakeven price of offshore wind power. The model and documentation are made publicly available. - Highlights: → We calculate the Breakeven Price (BP) required to deploy offshore wind plants. → We determine values for cost drivers and review incentives structures in the US. → We develop 3 scenarios using today's technology but varying in industry experience. → BP differs widely by Cost Scenario; relative policy effectiveness varies by stage. → The low-range BP is below regional market values in the Northeast United States.

  5. Wind Turbine Blade

    DEFF Research Database (Denmark)

    2010-01-01

    The invention relates to a blade for a wind turbine, particularly to a blade that may be produced by an advanced manufacturing process for producing a blade with high quality structural components. Particularly, the structural components, which are preferably manufactured from fibre reinforced...

  6. Wind energy technology developments

    DEFF Research Database (Denmark)

    Madsen, Peter Hauge; Hansen, Morten Hartvig; Pedersen, Niels Leergaard

    2014-01-01

    turbine blades and towers are very large series-produced components, which costs and quality are strongly dependent on the manufacturing methods. The industrial wind energy sector is well developed in Denmark, and the competitive advantage of the Danish sector and the potential for job creation...

  7. Gearless wind power generator

    Energy Technology Data Exchange (ETDEWEB)

    Soederlund, L.; Ridanpaeae, P.; Vihriaelae, H.; Peraelae, R. [Tampere Univ. of Technology (Finland). Lab. of Electricity and Magnetism

    1998-10-01

    In the project a 100 kW axial flux permanent magnet wind power generator has been designed. The toroidal stator with air gap winding is placed between two rotating discs with permanent magnets. The magnet material is NdBFe due to its excellent magnetic properties compared to other materials. This type of topology enables a very large number of poles compared to conventional machine of the same size. A large number of poles is required to achieve a low rotational speed and consequently a direct driven system. The stator winding is formed by rectangular coils. The end winding is very short leading to small resistive losses. On the other hand, the absence of iron teeth causes eddy current losses in the conductors. These can be restricted to an acceptable level by keeping the wire diameter and flux density small. This means that the number of phases should be large. Several independent three phase systems may be used. The toothless stator also means that the iron losses are small and there exists no cogging torque

  8. Research Facilities | Wind | NREL

    Science.gov (United States)

    Research Facilities Research Facilities NREL's state-of-the-art wind research facilities at the Research Facilities Photo of five men in hard hards observing the end of a turbine blade while it's being tested. Structural Research Facilities A photo of two people silhouetted against a computer simulation of

  9. Research Staff | Wind | NREL

    Science.gov (United States)

    Research Staff Research Staff Learn more about the expertise and technical skills of the wind power research team and staff at NREL. Name Position Email Phone Anstedt, Sheri Professional III-Writer/Editor /Web Content Sheri.Anstedt@nrel.gov 303-275-3255 Baker, Donald Research Technician V-Electrical

  10. Wind power barometer

    International Nuclear Information System (INIS)

    Anon.

    2012-01-01

    Despite the economic crisis affecting most of the globe's major economies, wind energy continues to gain supporters around the world. Global wind power capacity increased by 40.5 GW between 2010 and 2011 compared to a 39 GW rise between 2009 and 2010, after deduction of decommissioned capacity. By the end of 2011 global installed wind turbine capacity should stand at around 238.5 GW, and much of the world's growth is being driven by capacity build-up in the emerging markets (China, India...). In 2011 Asia was the world's biggest market (52%) ahead of Europe (24.5%) and North-America (19.7%). Europe has still the largest wind power capacity in the world with 40.6% of total in 2011. 2011 was another tough year for Vestas company while Gamesa company has managed to maintain positive profit growth by gaining market shares abroad. Siemens keeps its lead in the offshore market. The Chinese market is now suffering form excess capacity and Chinese companies fell prey to domestic competition

  11. Wind Energy Guide.

    Science.gov (United States)

    Harrison, David

    The booklet, intended for students and other visitors to the Lathrop E. Smith Environmental Education Center (Rockville, Maryland), explains how windmills work and their economic and environmental advantages. The history of windmills in Europe and Asia is briefly described, as well as the history of windmills and wind generators (for electricity)…

  12. Offshore Wind Power Data

    DEFF Research Database (Denmark)

    Cutululis, Nicolaos Antonio; Litong-Palima, Marisciel; Zeni, Lorenzo

    2012-01-01

    Wind power development scenarios are critical when trying to assess the impact of the demonstration at national and European level. The work described in this report had several objectives. The main objective was to prepare and deliver the proper input necessary for assessing the impact of Demo 4...

  13. Sensing the wind profile

    DEFF Research Database (Denmark)

    Pena Diaz, Alfredo

    This thesis consists of two parts. The first is a synopsis of the theoretical progress of the study that is based on a number of journal papers. The papers, which constitute the second part of the report, aim to analyze, measure, and model the wind prole in and beyond the surface layer by combini...

  14. Wind-energy storage

    Science.gov (United States)

    Gordon, L. H.

    1980-01-01

    Program SIMWEST can model wind energy storage system using any combination of five types of storage: pumped hydro, battery, thermal, flywheel, and pneumatic. Program is tool to aid design of optional system for given application with realistic simulation for further evaluation and verification.

  15. Offshore wind development research.

    Science.gov (United States)

    2014-04-01

    Offshore wind (OSW) development is a new undertaking in the US. This project is a response to : New Jerseys 2011 Energy Master Plan that envisions procuring 22.5% of the states power : originating from renewable sources by 2021. The Offshore Wi...

  16. Wind turbine state estimation

    DEFF Research Database (Denmark)

    Knudsen, Torben

    2014-01-01

    Dynamic inflow is an effect which is normally not included in the models used for wind turbine control design. Therefore, potential improvement from including this effect exists. The objective in this project is to improve the methods previously developed for this and especially to verify the res...

  17. Advanced Performance Hydraulic Wind Energy

    Science.gov (United States)

    Jones, Jack A.; Bruce, Allan; Lam, Adrienne S.

    2013-01-01

    The Jet Propulsion Laboratory, California Institute of Technology, has developed a novel advanced hydraulic wind energy design, which has up to 23% performance improvement over conventional wind turbine and conventional hydraulic wind energy systems with 5 m/sec winds. It also has significant cost advantages with levelized costs equal to coal (after carbon tax rebate). The design is equally applicable to tidal energy systems and has passed preliminary laboratory proof-of-performance tests, as funded by the Department of Energy.

  18. Wind Diagrams in Medieval Iceland

    DEFF Research Database (Denmark)

    Kedwards, Dale

    2014-01-01

    This article presents a study of the sole wind diagram that survives from medieval Iceland, preserved in the encyclopaedic miscellany in Copenhagen's Arnamagnæan Institute with the shelf mark AM 732b 4to (c. 1300-25). It examines the wind diagram and its accompanying text, an excerpt on the winds...... from Isidore of Seville's Etymologies. It also examines the perimeter of winds on two medieval Icelandic world maps, and the visual traditions from which they draw....

  19. Remote Sensing for Wind Energy

    DEFF Research Database (Denmark)

    Peña, Alfredo; Hasager, Charlotte Bay; Lange, Julia

    The Remote Sensing in Wind Energy report provides a description of several topics and it is our hope that students and others interested will learn from it. The idea behind it began in year 2008 at DTU Wind Energy (formerly Risø) during the first PhD Summer School: Remote Sensing in Wind Energy...... state-of-the-art ‘guideline’ available for people involved in Remote Sensing in Wind Energy....

  20. Science 101: What Causes Wind?

    Science.gov (United States)

    Robertson, William C.

    2010-01-01

    There's a quick and easy answer to this question. The Sun causes wind. Exactly how the Sun causes wind takes a bit to explain. We'll begin with what wind is. You've no doubt heard that wind is the motion of air molecules, which is true. Putting aside the huge leap of faith it takes for us to believe that we are experiencing the motion of millions…

  1. An Appropriate Wind Model for Wind Integrated Power Systems Reliability Evaluation Considering Wind Speed Correlations

    Directory of Open Access Journals (Sweden)

    Rajesh Karki

    2013-02-01

    Full Text Available Adverse environmental impacts of carbon emissions are causing increasing concerns to the general public throughout the world. Electric energy generation from conventional energy sources is considered to be a major contributor to these harmful emissions. High emphasis is therefore being given to green alternatives of energy, such as wind and solar. Wind energy is being perceived as a promising alternative. This source of energy technology and its applications have undergone significant research and development over the past decade. As a result, many modern power systems include a significant portion of power generation from wind energy sources. The impact of wind generation on the overall system performance increases substantially as wind penetration in power systems continues to increase to relatively high levels. It becomes increasingly important to accurately model the wind behavior, the interaction with other wind sources and conventional sources, and incorporate the characteristics of the energy demand in order to carry out a realistic evaluation of system reliability. Power systems with high wind penetrations are often connected to multiple wind farms at different geographic locations. Wind speed correlations between the different wind farms largely affect the total wind power generation characteristics of such systems, and therefore should be an important parameter in the wind modeling process. This paper evaluates the effect of the correlation between multiple wind farms on the adequacy indices of wind-integrated systems. The paper also proposes a simple and appropriate probabilistic analytical model that incorporates wind correlations, and can be used for adequacy evaluation of multiple wind-integrated systems.

  2. Proceedings of the Canadian Wind Energy Association's 2009 wind matters conference : wind and power systems

    International Nuclear Information System (INIS)

    2009-01-01

    This conference provided a forum for wind energy and electric power industry experts to discuss issues related to wind and power systems. An overview of wind integration studies and activities in Canada and the United States was provided. New tools and technologies for facilitating the integration of wind and improve market conditions for wind energy developers were presented. Methods of increasing wind penetration were evaluated, and technical issues related to wind interconnections throughout North America were reviewed. The conference was divided into the following 5 sessions: (1) experiences with wind integration, and lessons learned, (2) update on ongoing wind integration initiatives in Canada and the United States, (3) initiatives and tools to facilitate wind integration and market access, (4) developments in wind interconnection and grid codes, (5) wind energy and cold weather considerations, and (6) challenges to achieving the 20 per cent WindVision goal in Canada. The conference featured 21 presentations, of which 13 have been catalogued separately for inclusion in this database. refs., tabs., figs

  3. Report on field test project for wind power development at Onejime Athletic Park. Detailed wind characteristics survey; Onejime Undo Koen ni okeru furyoku kaihatsu field test jigyo (fukyo seisa) hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-11-01

    A detailed wind characteristics survey was conducted to study the feasibility of a wind power generation system for Onejime Athletic Park, Kimotsugu-gun, Kagoshima Prefecture. Observation instruments were installed at a wasteland beside the park and, in the period October 1, 1998, through September 30, 1999, data were collected at a point 20m above ground, such as the average wind speed and direction, wind velocity standard deviation, and the maximum instantaneous wind velocity. The data were analyzed, and findings were obtained, as mentioned below. The wind axis along which the wind direction occurrence rate was the highest ran WNW-ESE at an occurrence rate of 65.8%. Turbulence intensity was 0.23 at wind speeds of 2m/s and more, the maximum instantaneous wind velocity was 40m/s, all these fully satisfying the evaluation levels set forth by NEDO (New Energy and Industrial Technology Development Organization). On the other hand, the average wind speed was 3.48m/s and wind energy density was 69W/m{sup 2}, these failing to satisfy the levels indicated by NEDO. Studies were made on the assumption that 150, 300, and 750kW-class wind turbines would be introduced, and then it was found that their annual operating factors and facility availability rates both failed to meet the NEDO standards concerned and that therefore the site in question was not fit for wind power generation. (NEDO)

  4. Translation in ESL Classes

    Directory of Open Access Journals (Sweden)

    Nagy Imola Katalin

    2015-12-01

    Full Text Available The problem of translation in foreign language classes cannot be dealt with unless we attempt to make an overview of what translation meant for language teaching in different periods of language pedagogy. From the translation-oriented grammar-translation method through the complete ban on translation and mother tongue during the times of the audio-lingual approaches, we have come today to reconsider the role and status of translation in ESL classes. This article attempts to advocate for translation as a useful ESL class activity, which can completely fulfil the requirements of communicativeness. We also attempt to identify some activities and games, which rely on translation in some books published in the 1990s and the 2000s.

  5. Reliability Assessment and Energy Loss Evaluation for Modern Wind Turbine Systems

    DEFF Research Database (Denmark)

    Zhou, Dao

    . The cost of energy in wind turbine system is then addressed in Chapter 5, where different wind classes and operation modes of the reactive power injection are taken into account. Finally, the internal and external challenges for power converters in the DFIG systems to ride through balanced grid faults......With a steady increase of the wind power penetration, the demands to the wind power technology are becoming the same as those to the conventional energy sources. In order to fulfill the requirements, power electronics technology is the key for the modern wind turbine systems – both the Doubly...... to explore the reliability and cost of energy in the modern wind turbine systems. Moreover, advanced control strategies have been proposed and developed for an efficient and reliable operation during the normal condition as well as under grid faults. The documented thesis starts with the descriptions...

  6. Gusts and shear within hurricane eyewalls can exceed offshore wind turbine design standards

    Science.gov (United States)

    Worsnop, Rochelle P.; Lundquist, Julie K.; Bryan, George H.; Damiani, Rick; Musial, Walt

    2017-06-01

    Offshore wind energy development is underway in the U.S., with proposed sites located in hurricane-prone regions. Turbine design criteria outlined by the International Electrotechnical Commission do not encompass the extreme wind speeds and directional shifts of hurricanes stronger than category 2. We examine a hurricane's turbulent eyewall using large-eddy simulations with Cloud Model 1. Gusts and mean wind speeds near the eyewall of a category 5 hurricane exceed the current Class I turbine design threshold of 50 m s-1 mean wind and 70 m s-1 gusts. Largest gust factors occur at the eye-eyewall interface. Further, shifts in wind direction suggest that turbines must rotate or yaw faster than current practice. Although current design standards omit mention of wind direction change across the rotor layer, large values (15-50°) suggest that veer should be considered.

  7. Wind speed perception and risk.

    Directory of Open Access Journals (Sweden)

    Duzgun Agdas

    Full Text Available BACKGROUND: How accurately do people perceive extreme wind speeds and how does that perception affect the perceived risk? Prior research on human-wind interaction has focused on comfort levels in urban settings or knock-down thresholds. No systematic experimental research has attempted to assess people's ability to estimate extreme wind speeds and perceptions of their associated risks. METHOD: We exposed 76 people to 10, 20, 30, 40, 50, and 60 mph (4.5, 8.9, 13.4, 17.9, 22.3, and 26.8 m/s winds in randomized orders and asked them to estimate wind speed and the corresponding risk they felt. RESULTS: Multilevel modeling showed that people were accurate at lower wind speeds but overestimated wind speeds at higher levels. Wind speed perceptions mediated the direct relationship between actual wind speeds and perceptions of risk (i.e., the greater the perceived wind speed, the greater the perceived risk. The number of tropical cyclones people had experienced moderated the strength of the actual-perceived wind speed relationship; consequently, mediation was stronger for people who had experienced fewer storms. CONCLUSION: These findings provide a clearer understanding of wind and risk perception, which can aid development of public policy solutions toward communicating the severity and risks associated with natural disasters.

  8. Wind speed perception and risk.

    Science.gov (United States)

    Agdas, Duzgun; Webster, Gregory D; Masters, Forrest J

    2012-01-01

    How accurately do people perceive extreme wind speeds and how does that perception affect the perceived risk? Prior research on human-wind interaction has focused on comfort levels in urban settings or knock-down thresholds. No systematic experimental research has attempted to assess people's ability to estimate extreme wind speeds and perceptions of their associated risks. We exposed 76 people to 10, 20, 30, 40, 50, and 60 mph (4.5, 8.9, 13.4, 17.9, 22.3, and 26.8 m/s) winds in randomized orders and asked them to estimate wind speed and the corresponding risk they felt. Multilevel modeling showed that people were accurate at lower wind speeds but overestimated wind speeds at higher levels. Wind speed perceptions mediated the direct relationship between actual wind speeds and perceptions of risk (i.e., the greater the perceived wind speed, the greater the perceived risk). The number of tropical cyclones people had experienced moderated the strength of the actual-perceived wind speed relationship; consequently, mediation was stronger for people who had experienced fewer storms. These findings provide a clearer understanding of wind and risk perception, which can aid development of public policy solutions toward communicating the severity and risks associated with natural disasters.

  9. Wind Speed Perception and Risk

    Science.gov (United States)

    Agdas, Duzgun; Webster, Gregory D.; Masters, Forrest J.

    2012-01-01

    Background How accurately do people perceive extreme wind speeds and how does that perception affect the perceived risk? Prior research on human–wind interaction has focused on comfort levels in urban settings or knock-down thresholds. No systematic experimental research has attempted to assess people's ability to estimate extreme wind speeds and perceptions of their associated risks. Method We exposed 76 people to 10, 20, 30, 40, 50, and 60 mph (4.5, 8.9, 13.4, 17.9, 22.3, and 26.8 m/s) winds in randomized orders and asked them to estimate wind speed and the corresponding risk they felt. Results Multilevel modeling showed that people were accurate at lower wind speeds but overestimated wind speeds at higher levels. Wind speed perceptions mediated the direct relationship between actual wind speeds and perceptions of risk (i.e., the greater the perceived wind speed, the greater the perceived risk). The number of tropical cyclones people had experienced moderated the strength of the actual–perceived wind speed relationship; consequently, mediation was stronger for people who had experienced fewer storms. Conclusion These findings provide a clearer understanding of wind and risk perception, which can aid development of public policy solutions toward communicating the severity and risks associated with natural disasters. PMID:23226230

  10. Wind Turbine Acoustic Day 2018

    DEFF Research Database (Denmark)

    Mogensen, Jesper; Søndergaard, Bo; Hünerbein, Sabine Von

    The bi-annual event entitled Wind Turbine Acoustic Day dealing with wind turbine noise issues organized by DTU Wind Energy took place on May, 17th 2018 as its third edition. The abstracts and slides for the presentations are reported....

  11. About the wind energetics development

    International Nuclear Information System (INIS)

    Strebkov, D.S.; Kharitonov, V.P.; Murugov, V.P.; Sokol'skij, A.K.

    1996-01-01

    The review of wind power energetics state in USA, Europe, Russia is given. The data of EC on wind power plants production in different periods are presented. The directions of scientific-research works with the purpose of increasing the level of wind power industry of Russia corresponding to economics demands were elaborated. (author). 8 refs., 3 tabs

  12. Systems Engineering Workshops | Wind | NREL

    Science.gov (United States)

    Workshops Systems Engineering Workshops The Wind Energy Systems Engineering Workshop is a biennial topics relevant to systems engineering and the wind industry. The presentations and agendas are available for all of the Systems Engineering Workshops: The 1st NREL Wind Energy Systems Engineering Workshop

  13. The wind power of Mexico

    International Nuclear Information System (INIS)

    Hernandez-Escobedo, Q.; Manzano-Agugliaro, F.; Zapata-Sierra, A.

    2010-01-01

    The high price of fossil fuels and the environmental damage they cause have encouraged the development of renewable energy resources, especially wind power. This work discusses the potential of wind power in Mexico, using data collected every 10 min between 2000 and 2008 at 133 automatic weather stations around the country. The wind speed, the number of hours of wind useful for generating electricity and the potential electrical power that could be generated were estimated for each year via the modelling of a wind turbine employing a logistic curve. A linear correlation of 90.3% was seen between the mean annual wind speed and the mean annual number of hours of useful wind. Maps were constructed of the country showing mean annual wind speeds, useful hours of wind, and the electrical power that could be generated. The results show that Mexico has great wind power potential with practically the entire country enjoying more than 1700 h of useful wind per year and the potential to generate over 2000 kW of electrical power per year per wind turbine installed (except for the Chiapas's State). Indeed, with the exception of six states, over 5000 kW per year could be generated by each turbine. (author)

  14. CAT LIDAR wind shear studies

    Science.gov (United States)

    Goff, R. W.

    1978-01-01

    The studies considered the major meteorological factors producing wind shear, methods to define and classify wind shear in terms significant from an aircraft perturbation standpoint, the significance of sensor location and scan geometry on the detection and measurement of wind shear, and the tradeoffs involved in sensor performance such as range/velocity resolution, update frequency and data averaging interval.

  15. Market value of wind power

    NARCIS (Netherlands)

    Haan, de J.E.S.; Shoeb, M.A.; Lopes Ferreira, H.M.; Kling, W.L.

    2013-01-01

    Variability and predictability constraints of wind hinder the cost-efficient integration of wind power generation into power markets. Within the framework of EIT KIC INNOENERGY Offwindtech project, a ‘Market Value’ tool is developed. Here, the market value of wind power generation can be assessed

  16. Identification of wind energy systems

    NARCIS (Netherlands)

    Van der Veen, G.J.

    2013-01-01

    In the next decades wind energy is expected to secure a firm share of the total energy production capacity in many countries. To increase competitiveness of wind power with other power sources it is essential to lower the cost of wind energy. Given the design of a turbine, this objective can be

  17. Wind erosion processes and control

    Science.gov (United States)

    Wind erosion continues to threaten the sustainability of our nations' soil, air, and water resources. To effectively apply conservation systems to prevent wind driven soil loss, an understanding of the fundamental processes of wind erosion is necessary so that land managers can better recognize the ...

  18. Wind energy comes of age

    International Nuclear Information System (INIS)

    Swisher, R.

    1991-01-01

    This article discusses the maturation of the wind energy industry into a reliable and cost-effective utility technology. The topics discussed include the environmental impact of windfarms, the potential of wind energy, integrating wind technology into today's utility systems, and state policy decisions critical for renewable energy development

  19. Genesis Solar Wind Science Canister Components Curated as Potential Solar Wind Collectors and Reference Contamination Sources

    Science.gov (United States)

    Allton, J. H.; Gonzalez, C. P.; Allums, K. K.

    2016-01-01

    The Genesis mission collected solar wind for 27 months at Earth-Sun L1 on both passive and active collectors carried inside of a Science Canister, which was cleaned and assembled in an ISO Class 4 cleanroom prior to launch. The primary passive collectors, 271 individual hexagons and 30 half-hexagons of semiconductor materials, are described in. Since the hard landing reduced the 301 passive collectors to many thousand smaller fragments, characterization and posting in the online catalog remains a work in progress, with about 19% of the total area characterized to date. Other passive collectors, surfaces of opportunity, have been added to the online catalog. For species needing to be concentrated for precise measurement (e.g. oxygen and nitrogen isotopes) an energy-independent parabolic ion mirror focused ions onto a 6.2 cm diameter target. The target materials, as recovered after landing, are described in. The online catalog of these solar wind collectors, a work in progress, can be found at: http://curator.jsc.nasa.gov/gencatalog/index.cfm This paper describes the next step, the cataloging of pieces of the Science Canister, which were surfaces exposed to the solar wind or component materials adjacent to solar wind collectors which may have contributed contamination.

  20. Wind Resource Estimation using QuikSCAT Ocean Surface Winds

    DEFF Research Database (Denmark)

    Xu, Qing; Zhang, Guosheng; Cheng, Yongcun

    2011-01-01

    In this study, the offshore wind resources in the East China Sea and South China Sea were estimated from over ten years of QuikSCAT scatterometer wind products. Since the errors of these products are larger close to the coast due to the land contamination of radar backscatter signal...... and the complexity of air-sea interaction processes, an empirical relationship that adjusts QuikSCAT winds in coastal waters was first proposed based on vessel measurements. Then the shape and scale parameters of Weibull function are determined for wind resource estimation. The wind roses are also plotted. Results...

  1. Anholt offshore wind farm winds investigated from satellite images

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Badger, Merete; Volker, Patrick

    , i.e. before the wind farm was constructed. Based on these data the wind resource is estimated. Concurrent Sentinel-1 SAR data and available SCADA and lidar data, kindly provided by DONG Energy and partners, for the period January 2013 to June 2015 account for ~70 images, while ~300 images...... are available for Sentinel-1 from July 2015 to February 2017. The Sentinel-1 wind maps are investigated for wind farm wake effects. Furthermore the results on wind resources and wakes are compared to the SCADA and model results from WRF, Park, Fuga and RANS models....

  2. Terminology Guideline for Classifying Offshore Wind Energy Resources

    Energy Technology Data Exchange (ETDEWEB)

    Beiter, Philipp [National Renewable Energy Lab. (NREL), Golden, CO (United States); Musial, Walt [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-09-01

    The purpose of this guideline is to establish a clear and consistent vocabulary for conveying offshore wind resource potential and to interpret this vocabulary in terms that are familiar to the oil and gas (O&G) industry. This involves clarifying and refining existing definitions of offshore wind energy resource classes. The terminology developed in this guideline represents one of several possible sets of vocabulary that may differ with respect to their purpose, data availability, and comprehensiveness. It was customized to correspond with established offshore wind practices and existing renewable energy industry terminology (e.g. DOE 2013, Brown et al. 2015) while conforming to established fossil resource classification as best as possible. The developers of the guideline recognize the fundamental differences that exist between fossil and renewable energy resources with respect to availability, accessibility, lifetime, and quality. Any quantitative comparison between fossil and renewable energy resources, including offshore wind, is therefore limited. For instance, O&G resources are finite and there may be significant uncertainty associated with the amount of the resource. In contrast, aboveground renewable resources, such as offshore wind, do not generally deplete over time but can vary significantly subhourly, daily, seasonally, and annually. The intent of this guideline is to make these differences transparent and develop an offshore wind resource classification that conforms to established fossil resource classifications where possible. This guideline also provides methods to quantitatively compare certain offshore wind energy resources to O&G resource classes for specific applications. Finally, this guideline identifies areas where analogies to established O&G terminology may be inappropriate or subject to misinterpretation.

  3. Use of wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Vasil' yeva, I G

    1982-01-01

    Programs on the use of wind energy have been adopted in over 12 countries. The WU of low power is manufactured by over 100 firms. One of the main trends for the use of wind energy currently is water pumping. The cost of operating water pumps with diesel and electric drive has increased and they have become not very accessible for a considerable part of the population in the developing countries. There are now about one million wind pump units (WPU) operating in the world, mainly in the United States, Australia and Argentina. The average power of the WPU is less than or equal to 0.5 kW. A trend is developing wind energy associated with the creation of wind heat units for heat supply of houses. When powerful experimental WEU are operating, the problem was revealed of their influence on the environment. The main difficulties are associated with creating WEU of electromagnetic interference, which in particular, influence the quality of television transmissions. This problem was encountered in operating the WEU P = 200 kW in the United States in Rhode Island. Normal operation of the television receivers was guaranteed with the help of cable network. A method was developed from calculating the zone of interferences which should be used in the future in setting up the WEU. A study was made of the noise from the operating of the WEU. The noise level of the WEU is in limits of permissible, however in direct proximity to the unit, intensive infrasonic fluctuations develop. The most important ecological consequence of building powerful WEU could be the death of nocturnal birds as a result of their colliding with the rotating blades. It is noted that this can be avoided by lighting the WEU.

  4. MIDDLE CLASS MOVEMENTS

    OpenAIRE

    Dr. K. Sravana Kumar

    2016-01-01

    The middle class is placed between labour and capital. It neither directly awns the means of production that pumps out the surplus generated by wage labour power, nor does it, by its own labour, produce the surplus which has use and exchange value. Broadly speaking, this class consists of the petty bourgeoisie and the white-collar workers. The former are either self-employed or involved in the distribution of commodities and the latter are non-manual office workers, supervisors and profession...

  5. Talking Class in Tehroon

    DEFF Research Database (Denmark)

    Elling, Rasmus Christian; Rezakhani, Khodadad

    2016-01-01

    Persian, like any other language, is laced with references to class, both blatant and subtle. With idioms and metaphors, Iranians can identify and situate others, and thus themselves, within hierarchies of social status and privilege, both real and imagined. Some class-related terms can be traced...... back to medieval times, whereas others are of modern vintage, the linguistic legacy of television shows, pop songs, social media memes or street vernacular. Every day, it seems, an infectious set of phrases appears that make yesterday’s seem embarrassingly antiquated....

  6. Endurance Wind Power : practical insights into small wind

    International Nuclear Information System (INIS)

    Hicks, D.

    2008-01-01

    This presentation discussed practical issues related to purchasing and installing small wind turbines in Canada. Wind power capacity can be estimated by looking at provincial wind maps as well as by seeking wind data at local airports. Wind resources are typically measured at heights of between 20 meters and 50 m. The height of a wind turbine tower can significantly increase the turbine's wind generating capacity. Turbine rotors should always be placed 30 feet higher than obstacles within 500 feet. Many provinces have now mandated utilities to accept renewable energy resources from grid-connected wind energy plants. Net billing systems are used to determine the billing relationship between power-producing consumers and the utilities who will buy the excess power and sell it to other consumers. Utilities are not yet mandated to purchase excess power, and it is likely that federal and provincial legislation will be needed to ensure that net billing systems continue to grow. Many Canadian municipalities have no ordinances related to wind turbine placements. Consumers interested in purchasing small wind turbines should ensure that the turbine has been certified by an accredited test facility and has an adequate safety system. The noise of the turbine as well as its power performance in relation to the purchaser's needs must also be considered. It was concluded that small wind turbines can provide a means for electricity consumers to reduce their carbon footprint and hedge against the inflationary costs of fossil-fuelled energy resources. tabs., figs

  7. Wind power forecast error smoothing within a wind farm

    International Nuclear Information System (INIS)

    Saleck, Nadja; Bremen, Lueder von

    2007-01-01

    Smoothing of wind power forecast errors is well-known for large areas. Comparable effects within a wind farm are investigated in this paper. A Neural Network was taken to predict the power output of a wind farm in north-western Germany comprising 17 turbines. A comparison was done between an algorithm that fits mean wind and mean power data of the wind farm and a second algorithm that fits wind and power data individually for each turbine. The evaluation of root mean square errors (RMSE) shows that relative small smoothing effects occur. However, it can be shown for this wind farm that individual calculations have the advantage that only a few turbines are needed to give better results than the use of mean data. Furthermore different results occurred if predicted wind speeds are directly fitted to observed wind power or if predicted wind speeds are first fitted to observed wind speeds and then applied to a power curve. The first approach gives slightly better RMSE values, the bias improves considerably

  8. Expertise effects in cutaneous wind perception

    NARCIS (Netherlands)

    Pluijms, Joost P.; Cañal-Bruland, Rouwen; Bergmann Tiest, Wouter M.; Mulder, F.A.; Savelsbergh, Geert J.P.

    2015-01-01

    We examined whether expertise effects are present in cutaneous wind perception. To this end, we presented wind stimuli consisting of different wind directions and speeds in a wind simulator. The wind simulator generated wind stimuli from 16 directions and with three speeds by means of eight

  9. Wind Integration Data Sets | Grid Modernization | NREL

    Science.gov (United States)

    Wind Integration Data Sets Wind Integration Data Sets NREL's wind integration data sets provide the Integration Data Sets Ten-minute time-series wind data for 2004, 2005, and 2006 to help energy professionals perform wind integration studies and estimate power production from hypothetical wind power plants. Access

  10. Wind Power in Electrical Distribution Systems

    DEFF Research Database (Denmark)

    Chen, Zhe

    2013-01-01

    Recent years, wind power is experiencing a rapid growth, large number of wind turbines/wind farms have been installed and connected to power systems. In addition to the large centralised wind farms connected to transmission grids, many distributed wind turbines and wind farms are operated as dist...

  11. Wind/Hybrid Electricity Applications

    Energy Technology Data Exchange (ETDEWEB)

    McDaniel, Lori [Iowa Department of Natural Resources, Des Moines, IA (United States)

    2001-03-01

    Wind energy is widely recognized as the most efficient and cost effective form of new renewable energy available in the Midwest. New utility-scale wind farms (arrays of large turbines in high wind areas producing sufficient energy to serve thousands of homes) rival the cost of building new conventional forms of combustion energy plants, gas, diesel and coal power plants. Wind energy is not subject to the inflationary cost of fossil fuels. Wind energy can also be very attractive to residential and commercial electric customers in high wind areas who would like to be more self-sufficient for their energy needs. And wind energy is friendly to the environment at a time when there is increasing concern about pollution and climate change. However, wind energy is an intermittent source of power. Most wind turbines start producing small amounts of electricity at about 8-10 mph (4 meters per second) of wind speed. The turbine does not reach its rated output until the wind reaches about 26-28 mph (12 m/s). So what do you do for power when the output of the wind turbine is not sufficient to meet the demand for energy? This paper will discuss wind hybrid technology options that mix wind with other power sources and storage devices to help solve this problem. This will be done on a variety of scales on the impact of wind energy on the utility system as a whole, and on the commercial and small-scale residential applications. The average cost and cost-benefit of each application along with references to manufacturers will be given. Emerging technologies that promise to shape the future of renewable energy will be explored as well.

  12. VisibleWind: wind profile measurements at low altitude

    Science.gov (United States)

    Wilkerson, Tom; Bradford, Bill; Marchant, Alan; Apedaile, Tom; Wright, Cordell

    2009-09-01

    VisibleWindTM is developing an inexpensive rapid response system, for accurately characterizing wind shear and small scale wind phenomena in the boundary layer and for prospecting suitable locations for wind power turbines. The ValidWind system can also collect reliable "ground truth" for other remote wind sensors. The system employs small (0.25 m dia.) lightweight balloons and a tracker consisting of an Impulse 200 XL laser rangefinder coupled to a PC for automated data recording. Experiments on balloon trajectories demonstrate that the laser detection of range (+/- 0.5 m), together with measured azimuth and altitude, is an inexpensive, convenient, and capable alternative to other wind tracking methods. The maximum detection range has been increased to 2200 meters using micro-corner-cube retroreflector tape on balloons. Low power LEDs enable nighttime tracking. To avoid large balloon gyrations about the mean trajectory, we use balloons having low ascent rates and subcritical Reynolds numbers. Trajectory points are typically recorded every 4 - 7 seconds. Atmospheric features observed under conditions of inversions or "light and variable winds" include abrupt onsets of shear at altitudes of 100-250 m, velocity changes of order 1-3 m/s within layers of 10-20 m thickness, and veering of the wind direction by 180 degrees or more as altitude increases from 300 to 500 m. We have previously reported comparisons of balloon-based wind profiles with the output of a co-located sodar. Even with the Impulse rangefinder, our system still requires a "man in the loop" to track the balloon. A future system enhancement will automate balloon tracking, so that laser returns are obtained automatically at 1 Hz. While balloon measurements of large-scale, high altitude wind profiles are well known, this novel measurement system provides high-resolution, real-time characterization of the fluctuating local wind fields at the bottom of the boundary layer where wind power turbines and other

  13. Idealized models of the joint probability distribution of wind speeds

    Science.gov (United States)

    Monahan, Adam H.

    2018-05-01

    The joint probability distribution of wind speeds at two separate locations in space or points in time completely characterizes the statistical dependence of these two quantities, providing more information than linear measures such as correlation. In this study, we consider two models of the joint distribution of wind speeds obtained from idealized models of the dependence structure of the horizontal wind velocity components. The bivariate Rice distribution follows from assuming that the wind components have Gaussian and isotropic fluctuations. The bivariate Weibull distribution arises from power law transformations of wind speeds corresponding to vector components with Gaussian, isotropic, mean-zero variability. Maximum likelihood estimates of these distributions are compared using wind speed data from the mid-troposphere, from different altitudes at the Cabauw tower in the Netherlands, and from scatterometer observations over the sea surface. While the bivariate Rice distribution is more flexible and can represent a broader class of dependence structures, the bivariate Weibull distribution is mathematically simpler and may be more convenient in many applications. The complexity of the mathematical expressions obtained for the joint distributions suggests that the development of explicit functional forms for multivariate speed distributions from distributions of the components will not be practical for more complicated dependence structure or more than two speed variables.

  14. Siemens Wind Power 3.6 MW wind turbines for large offshore wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Akhmatov, Vladislav; Nygaard Nielsen, Joergen; Thisted, Jan; Groendahl, Erik; Egedal, Per; Noertoft Frydensbjerg, Michael; Jensen, Kim Hoej [Siemens Wind Power A/S, Brande (Denmark)

    2008-07-01

    Siemens Wind power A/S is the key player on the offshore wind power market. The Siemens Wind Power 3.6 MW variable-speed wind turbine is among the word's largest, most advanced and competitive wind turbines with a solid portfolio of large offshore wind farms. Transmission system operators and developers require dynamic wind turbine models for evaluation of fault-ride-through capability and investigations of power system stability. The even larger size of the on- and offshore wind farms has entailed that the grid impact of the voltage and frequency control capability of the wind farm can be appropriated modelled and evaluated. Siemens Wind Power has developed a dynamic model of the 3.6 MW variable-speed wind turbine with the fault-ride-through sequences and models of the voltage and frequency controllers to be applied for large offshore wind farms. The dynamic models have been implemented in the commercially available simulation tools such as DIgSILENT PowerFactory and Siemens PTI PSS/E and successfully validated from measurements. (orig.)

  15. Satellite winds as a tool for offshore wind resource assessment: The Great Lakes Wind Atlas

    DEFF Research Database (Denmark)

    Doubrawa, Paula; Barthelmie, Rebecca Jane; Pryor, Sara C.

    2015-01-01

    and combine all scenes into one wind speed map. QuikSCAT winds undergo a seasonal correction due to lack of data during the cold season that is based on its ratio relative to buoy time series. All processing steps reduce the biases of the individual maps relative to the buoy observed wind climates. The remote...

  16. Index Bioclimatic "Wind-Chill"

    Directory of Open Access Journals (Sweden)

    Teodoreanu Elena

    2015-05-01

    Full Text Available This paper presents an important bioclimatic index which shows the influence of wind on the human body thermoregulation. When the air temperature is high, the wind increases thermal comfort. But more important for the body is the wind when the air temperature is low. When the air temperature is lower and wind speed higher, the human body is threatening to freeze faster. Cold wind index is used in Canada, USA, Russia (temperature "equivalent" to the facial skin etc., in the weather forecast every day in the cold season. The index can be used and for bioclimatic regionalization, in the form of skin temperature index.

  17. Trend in China's Wind Power

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Attractive prospects for wind power development Sha Yiqiang:In recent years,the development and utilization of wind energy has achieved remarkable results.To the end of 2007,the installed capacity of the wind power had reached 94 000 MW all over the world,which is distributed over 60 countries.Over the past 20 years,the wind power generation installation cost has been reduced by 50% and is closing to that of the conventional energy resources.Meanwhile,the single unit capacity,efficiency and reliability of wind power have been greatly improved.

  18. Small Wind Turbine Technology Assessment

    International Nuclear Information System (INIS)

    Avia Aranda, F.; Cruz Cruz, I.

    1999-01-01

    The result of the study carried out under the scope of the ATYCA project Test Plant of Wind Systems for Isolated Applications, about the state of art of the small wind turbine technology (wind turbines with swept area smaller than 40 m 2 ) is presented. The study analyzes the collected information on 60 models of wind turbines from 23 manufacturers in the worldwide market. Data from Chinese manufacturers, that have a large participation in the total number of small wind turbines in operation, are not included, due to the unavailability of the technical information. (Author) 15 refs

  19. 2013 Wind Technologies Market Report

    Energy Technology Data Exchange (ETDEWEB)

    Wiser, R.; Bolinger, M.; Barbose, G.; Darghouth, N.; Hoen, B.; Mills, A.; Weaver, S.; Porter, K.; Buckley, M.; Oteri, F.; Tegen, S.

    2014-08-01

    This annual report provides a detailed overview of developments and trends in the U.S. wind power market, with a particular focus on 2013. This 2013 edition updates data presented in previous editions while highlighting key trends and important new developments. The report includes an overview of key installation-related trends; trends in wind power capacity growth; how that growth compares to other countries and generation sources; the amount and percentage of wind energy in individual states; the status of offshore wind power development and the quantity of proposed wind power capacity in various interconnection queues in the United States.

  20. Lower Sioux Wind Feasibility & Development

    Energy Technology Data Exchange (ETDEWEB)

    Minkel, Darin

    2012-04-01

    This report describes the process and findings of a Wind Energy Feasibility Study (Study) conducted by the Lower Sioux Indian Community (Community). The Community is evaluating the development of a wind energy project located on tribal land. The project scope was to analyze the critical issues in determining advantages and disadvantages of wind development within the Community. This analysis addresses both of the Community's wind energy development objectives: the single turbine project and the Commerical-scale multiple turbine project. The main tasks of the feasibility study are: land use and contraint analysis; wind resource evaluation; utility interconnection analysis; and project structure and economics.

  1. Second class weak currents

    International Nuclear Information System (INIS)

    Delorme, J.

    1978-01-01

    The definition and general properties of weak second class currents are recalled and various detection possibilities briefly reviewed. It is shown that the existing data on nuclear beta decay can be consistently analysed in terms of a phenomenological model. Their implication on the fundamental structure of weak interactions is discussed [fr

  2. World Class Teachers.

    Science.gov (United States)

    Mitchell, Rosalita

    1998-01-01

    School communities are challenged to find ways to identify good teachers and give other teachers a chance to learn from them. The New Mexico World Class Teacher Project is encouraging teachers to pursue certification by the National Board for Professional Teaching Standards. This process sharpens teachers' student assessment skills and encourages…

  3. EPA Web Training Classes

    Science.gov (United States)

    Scheduled webinars can help you better manage EPA web content. Class topics include Drupal basics, creating different types of pages in the WebCMS such as document pages and forms, using Google Analytics, and best practices for metadata and accessibility.

  4. Class Actions in Denmark

    DEFF Research Database (Denmark)

    Werlauff, Erik

    2009-01-01

    The article deals with the relatively new Danish Act on Class Action (Danish: gruppesøgsmål) which was suggested by The Permanent Council on Civil procedure (Retsplejerådet) of which the article's author is a member. The operability of the new provisions is illustrated through some wellknown Danish...

  5. Coming out in Class

    Science.gov (United States)

    McKinnon, Rachel

    2012-01-01

    This article shares how the author explained her trans status to her students. Everyone has been extremely supportive of her decision to come out in class and to completely mask the male secondary-sex characteristics, especially in the workplace. The department chair and the faculty in general have been willing to do whatever they can to assist…

  6. Working Together in Class

    Directory of Open Access Journals (Sweden)

    Pateşan Marioara

    2017-12-01

    Full Text Available The scores obtained by the military students are very important as a lot of opportunities depend on them: the choice of the branch, selection for different in and off-campus activities, the appointment to the workplace and so on. A qualifier, regardless of its form of effective expression, can make a difference in a given context of issuing a value judgment, in relation to the student's performance assessment. In our research we tried to find out what motives students, what determines them to get actively involved in the tasks they are given and the ways we can improve their participation in classes and assignments. In order to have an educated generation we need to have not only well prepared teachers but ones that are open-minded, flexible and in pace with the methodological novelties that can improve the teaching learning process in class. Along the years we have noticed that in classes where students constituted a cohesive group with an increasing degree of interaction between members, the results were better than in a group that did not appreciate team-work. In this article we want to highlight the fact that a teacher can bring to class the appropriate methods and procedures can contribute decisively to the strengthening of the group cohesion and high scores.

  7. Adeus à classe trabalhadora?

    Directory of Open Access Journals (Sweden)

    Geoff Eley

    2013-12-01

    Full Text Available No início da década de 1980, a política centrada em classes da tradição socialista estava em crise, e comentadores importantes adotaram tons apocalípticos. No final da década, a esquerda permanecia profundamente dividida entre os advogados da mudança e os defensores da fé. Em meados dos anos 1990, os primeiros tinham, de modo geral, ganhado a batalha. O artigo busca apresentar essa mudança contemporânea não como a 'morte da classe', mas como o desa­parecimento de um tipo particular de ­sociedade de classes, marcado pelo ­processo de formação da classe trabalhadora entre os anos 1880 e 1940 e pelo alinhamento político daí resultante, atingindo seu apogeu na construção social-democrata do acordo do pós-guerra. Quando mudanças de longo prazo na economia se combinaram com o ataque ao keynesianismo na política de recessão a partir de meados da década de 1970, a unidade da classe trabalhadora deixou de estar disponível da forma antiga e bastante utilizada, como o terreno natural da política de esquerda. Enquanto uma coletividade dominante da classe trabalhadora entrou em declínio, outra se corporificou de modo lento e desigual para tomar o lugar daquela. Mas a unidade operacional dessa nova agregação da classe trabalhadora ainda está, em grande parte, em formação. Para recuperar a eficácia política da tradição socialista, alguma nova visão de agência política coletiva será necessária, uma visão imaginativamente ajustada às condições emergentes da produção e acumulação capitalista no início do século XXI.

  8. Large scale wind energy conversion system (WECS) design and installation as affected by site wind energy characteristics, grouping arrangement, and social acceptance. [Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Ljungstrom, O

    1977-01-01

    The Swedish wind energy prospecting program includes special features of determining site wind characteristics and design of WECS group stations, which are described briefly, such as applications of normalized WDP-Wind Duration Profiles, WHP-Wind Height Profiles and how these are affected by site location and terrain roughness. A set of WEC-Wind Energy Classes (1 to 4) is introduced as an aid in territorial wind energy surveys. A survey of Sweden's WEPA-Wind Energy Producing Areas--with associated distribution over WEC-2-4 is presented. In order to determine the corresponding wind energy production capacity, the problem of optimizing WECS group station design for cost effective energy production per land usage must be solved. Here, the effects of WECS unit size and spacing on specific annual energy production, TWh/km/sup 2/, yr, are analyzed with the use of specific group station models in the 40 to 100 MW capacity range, applying WECS unit sizes 50kW, 1 MW and 5 MW, studying the energy balance for typical group stations. By applying the specific productivity data for 1 to 5 MW systems, a survey of the WEPA-associated wind energy production capacity in Sweden is presented.

  9. Stability-class determination: a comparison for one site

    International Nuclear Information System (INIS)

    Bowen, B.M.; Dewart, J.M.; Chen, A.I.

    1983-01-01

    The Pasquill method of determining stability class at a site with irregular terrain with other commonly used methods: vertical temperature difference (#betta#T); Richardson number (Ri) and Bulk Richardson number (Ri/sub B/); and horizontal standard deviation of wind and vertical standard deviation of wind. Also, the indirect methods of measuring turbulence, such as the Pasquill method, are compared to direct measures of turbulence. The various methods for determining stability class are analyzed and compared with the Pasquill classification scheme at 2 sites with irregular terrain. The Pasquill categories were estimated objectively and compared with other stability indicators for 15-minute periods over a year. The results show that near-surface #betta#T distinguishes the neutral category very well. However, it does not differentiate the specific stable and unstable categories very well. Both the Ri and Ri/sub B/, indicators of both thermal and mechanical turbulence, correlate very well with and distinguish the different stability categories. Due to the irregular terrain, the various methods of determining stability may be even better indicators of turbulence and diffusion if the wind direction were taken into account. It is suggested that further study investigate the methods by wind direction

  10. Mexico Wind Resource Assessment Project

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, M.N.; Elliott, D.L.

    1995-05-01

    A preliminary wind energy resource assessment of Mexico that produced wind resource maps for both utility-scale and rural applications was undertaken as part of the Mexico-U.S. Renewable Energy Cooperation Program. This activity has provided valuable information needed to facilitate the commercialization of small wind turbines and windfarms in Mexico and to lay the groundwork for subsequent wind resource activities. A surface meteorological data set of hourly data in digital form was utilized to prepare a more detailed and accurate wind resource assessment of Mexico than otherwise would have been possible. Software was developed to perform the first ever detailed analysis of the wind characteristics data for over 150 stations in Mexico. The hourly data set was augmented with information from weather balloons (upper-air data), ship wind data from coastal areas, and summarized wind data from sources in Mexico. The various data were carefully evaluated for their usefulness in preparing the wind resource assessment. The preliminary assessment has identified many areas of good-to-excellent wind resource potential and shows that the wind resource in Mexico is considerably greater than shown in previous surveys.

  11. Wind farm array wake losses

    Energy Technology Data Exchange (ETDEWEB)

    Baker, R.W. [Impact Weather, Washougal, WA (United States); McCarthy, E.F. [Wind Economics & Technology, Inc., Martinez, CA (United States)

    1997-12-31

    A wind turbine wake study was conducted in the summer of 1987 at an Altamont Pass wind electric generating facility. The wind speed deficits, turbulence, and power deficits from an array consisting of several rows of wind turbines is discussed. A total of nine different test configurations were evaluated for a downwind spacing ranging from 7 rotor diameters (RD) to 34 RD and a cross wind spacing of 1.3 RD and 2.7 RD. Wake power deficits of 15% were measured at 16 RD and power losses of a few percent were even measurable at 27 RD for the closer cross wind spacing. For several rows of turbines separated by 7-9 RD the wake zones overlapped and formed compound wakes with higher velocity deficits. The wind speed and direction turbulence in the wake was much higher than the ambient turbulence. The results from this study are compared to the findings from other similar field measurements.

  12. Chemistry in T Tauri winds

    Energy Technology Data Exchange (ETDEWEB)

    Rawlings, J M.C.; Williams, D A; Canto, J

    1988-02-15

    The chemistry occurring in the winds of T Tauri stars is investigated. On the assumption that the wind is dust-free, then routes to H/sub 2/ are inhibited under the conditions in the wind, and subsequent chemistry does not produce substantial molecular abundances. The major losses to the chemical network lie in the geometrical dilution and collisional dissociation rather than in chemical destruction and photodissociation. Mass loading of the wind with dust and H/sub 2/ may, however, occur. This stimulates the chemistry and may in some circumstances lead to a conversion of approx.1-10 per cent of carbon into CO. This gives a column density of CO which is marginally detectable. A positive detection of CO at high wind velocities would imply that the winds must be cool and that mixing of molecular material from a disc, which may play a role in collimating the wind, or the remnants of a disc, must occur.

  13. Assessing high wind energy penetration

    DEFF Research Database (Denmark)

    Tande, J.O.

    1995-01-01

    In order to convincingly promote installing wind power capacity as a substantial part of the energy supply system, a set of careful analyses must be undertaken. This paper applies a case study concentrated on assessing the cost/benefit of high wind energy penetration. The case study considers...... expanding the grid connected wind power capacity in Praia, the capital of Cape Verde. The currently installed 1 MW of wind power is estimated to supply close to 10% of the electric energy consumption in 1996. Increasing the wind energy penetration to a higher level is considered viable as the project...... with the existing wind power, supply over 30% of the electric consumption in 1996. Applying the recommended practices for estimating the cost of wind energy, the life-cycle cost of this 2.4 MW investment is estimated at a 7% discount rate and a 20 year lifetime to 0.26 DKK/kW h....

  14. Assembling Markets for Wind Power

    DEFF Research Database (Denmark)

    Pallesen, Trine

    hand, as an economic good, wind power is said to suffer from (techno-economic) ‘disabilities’, such as high costs, fluctuating and unpredictable generation, etc. Therefore, because of its performance as a good, it is argued that the survival of wind power in the market is premised on different......This project studies the making of a market for wind power in France. Markets for wind power are often referred to as ‘political markets: On the one hand, wind power has the potential to reduce CO2-emissions and thus stall the effects of electricity generation on climate change; and on the other...... instruments, some of which I will refer to as ‘prosthetic devices’. This thesis inquires into two such prosthetic devices: The feed-in tariff and the wind power development zones (ZDE) as they are negotiated and practiced in France, and also the ways in which they affect the making of markets for wind power....

  15. 2014 Distributed Wind Market Report

    Energy Technology Data Exchange (ETDEWEB)

    Orell, A; Foster, N.

    2015-08-01

    The cover of the 2014 Distributed Wind Market Report.According to the 2014 Distributed Wind Market Report, distributed wind reached a cumulative capacity of almost 1 GW (906 MW) in the United States in 2014, reflecting nearly 74,000 wind turbines deployed across all 50 states, Puerto Rico, and the U.S. Virgin Islands. In total, 63.6 MW of new distributed wind capacity was added in 2014, representing nearly 1,700 units and $170 million in investment across 24 states. In 2014, America's distributed wind energy industry supported a growing domestic industrial base as exports from United States-based small wind turbine manufacturers accounted for nearly 80% of United States-based manufacturers' sales.

  16. Wind turbine spoiler

    Science.gov (United States)

    Sullivan, W.N.

    An aerodynamic spoiler system for a vertical axis wind turbine includes spoilers on the blades initially stored near the rotor axis to minimize drag. A solenoid latch adjacent the central support tower releases the spoilers and centrifugal force causes the spoilers to move up the turbine blades away from the rotor axis, thereby producing a braking effect and actual slowing of the associated wind turbine, if desired. The spoiler system can also be used as an infinitely variable power control by regulated movement of the spoilers on the blades over the range between the undeployed and fully deployed positions. This is done by the use of a suitable powered reel and cable located at the rotor tower to move the spoilers.

  17. Superconducting wind turbine generators

    DEFF Research Database (Denmark)

    Abrahamsen, Asger Bech; Mijatovic, Nenad; Seiler, Eugen

    2010-01-01

    , the main challenge of the superconducting direct drive technology is to prove that the reliability is superior to the alternative drive trains based on gearboxes or permanent magnets. A strategy of successive testing of superconducting direct drive trains in real wind turbines of 10 kW, 100 kW, 1 MW and 10......We have examined the potential of 10 MW superconducting direct drive generators to enter the European offshore wind power market and estimated that the production of about 1200 superconducting turbines until 2030 would correspond to 10% of the EU offshore market. The expected properties of future...... offshore turbines of 8 and 10 MW have been determined from an up-scaling of an existing 5 MW turbine and the necessary properties of the superconducting drive train are discussed. We have found that the absence of the gear box is the main benefit and the reduced weight and size is secondary. However...

  18. Database on wind characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Hojstrup, J. [Riso National Lab., Roskilde (Denmark); Hansen, K.S. [Fluid Mechanics Section, Lyngby (Denmark)

    1996-12-31

    Wind data with high temporal resolution exist from a variety of sites, and is in demand by windturbine designers and wind engineers. Unfortunately it has always been a problem to gain access to a suitable amount of this data, because they are available from many different sources in different formats and with very different levels of documentation and quality control. We are now in the process of gaining access to a large amount of this type of data, checking the quality of the data and putting the data at the disposition of the windturbine designer community through easy Internet access. Online search will use summary statistics calculated for each series to help in the selection of data. The selected data can then be downloaded directly to the user. 3 figs.

  19. INCAS TRISONIC WIND TUNNEL

    Directory of Open Access Journals (Sweden)

    Florin MUNTEANU

    2009-09-01

    Full Text Available The 1.2 m x 1.2 m Trisonic Blowdown Wind Tunnel is the largest of the experimental facilities at the National Institute for Aerospace Research - I.N.C.A.S. "Elie Carafoli", Bucharest, Romania. The tunnel has been designed by the Canadian company DSMA (now AIOLOS and since its commissioning in 1978 has performed high speed aerodynamic tests for more than 120 projects of aircraft, missiles and other objects among which the twin jet fighter IAR-93, the jet trainer IAR-99, the MIG-21 Lancer, the Polish jet fighter YRYDA and others. In the last years the wind tunnel has been used mostly for experimental research in European projects such as UFAST. The high flow quality parameters and the wide range of testing capabilities ensure the competitivity of the tunnel at an international level.

  20. Database on wind characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Hoejstrup, J. [Risoe National Lab., Roskilde (Denmark). Dept. of Meterology and Wind Energy; Hansen, K.S. [DTU, Lyngby (Denmark). Fluid Mechanics Section

    1996-12-31

    Wind data with high temporal resolution exist from a variety of sites, and have been in demand by windturbine designers and wind engineers. Unfortunately it has always been a problem to gain access to a suitable amount of this data, because they are available from many different sources in different formats and with very different levels of documentation and quality control. We are in the process of gaining access to a large amount of this data, checking the quality of the data and putting the data at the disposition of the windturbine designer community through easy Internet access. Online search will use summary statistics calculated for each series to help in the selection of data. The selected data can then be downloaded directly to the user. (Author)

  1. Investigation of Wind Turbine Rotor Concepts for Offshore Wind Farms

    International Nuclear Information System (INIS)

    Ceyhan, Özlem; Grasso, Francesco

    2014-01-01

    Current plans in offshore wind energy developments call for further reduction of cost of energy. In order to contribute to this goal, several wind turbine rotor concepts have been investigated. Assuming the future offshore wind turbines will operate only in the offshore wind farms, the rotor concepts are not only evaluated for their stand-alone performances and their potential in reducing the loads, but also for their performance in an offshore wind farm. In order to do that, the 10MW reference wind turbine designed in Innwind.EU project is chosen as baseline. Several rotor parameters have been modified and their influences are investigated for offshore wind turbine design purposes. This investigation is carried out as a conceptual parametrical study. All concepts are evaluated numerically with BOT (Blade optimisation tool) software in wind turbine level and with Farmflow software in wind farm level for two wind farm layouts. At the end, all these concepts are compared with each other in terms of their advantages and disadvantages

  2. Wind Data Analysis and Wind Flow Simulation Over Large Areas

    Directory of Open Access Journals (Sweden)

    Terziev Angel

    2014-03-01

    Full Text Available Increasing the share of renewable energy sources is one of the core policies of the European Union. This is because of the fact that this energy is essential in reducing the greenhouse gas emissions and securing energy supplies. Currently, the share of wind energy from all renewable energy sources is relatively low. The choice of location for a certain wind farm installation strongly depends on the wind potential. Therefore the accurate assessment of wind potential is extremely important. In the present paper an analysis is made on the impact of significant possible parameters on the determination of wind energy potential for relatively large areas. In the analysis the type of measurements (short- and long-term on-site measurements, the type of instrumentation and the terrain roughness factor are considered. The study on the impact of turbulence on the wind flow distribution over complex terrain is presented, and it is based on the real on-site data collected by the meteorological tall towers installed in the northern part of Bulgaria. By means of CFD based software a wind map is developed for relatively large areas. Different turbulent models in numerical calculations were tested and recommendations for the usage of the specific models in flows modeling over complex terrains are presented. The role of each parameter in wind map development is made. Different approaches for determination of wind energy potential based on the preliminary developed wind map are presented.

  3. Research on wind energy

    CSIR Research Space (South Africa)

    Szewczuk, S

    2012-10-01

    Full Text Available heights; short-term predictions ? CSIR 2012 Slide 9 Innovation & preliminary wind energy technology tree ? South African Industry?s propensity to innovate is in the same league as their counterparts in Europe. To state this differently, South African...? ? CSIR 2012 Slide 18 Modular form of electrification in rural communities Project funded by the Royal Danish Embassy in Pretoria and carried out by: ? eThekwini (Durban) Municipality ? Ris? DTU (Danish National Laboratory for Sustainable Energy...

  4. Maine coast winds

    Energy Technology Data Exchange (ETDEWEB)

    Avery, Richard

    2000-01-28

    The Maine Coast Winds Project was proposed for four possible turbine locations. Significant progress has been made at the prime location, with a lease-power purchase contract for ten years for the installation of turbine equipment having been obtained. Most of the site planning and permitting have been completed. It is expect that the turbine will be installed in early May. The other three locations are less suitable for the project, and new locations are being considered.

  5. Offshore wind generators: realization?

    International Nuclear Information System (INIS)

    Roche, Catherine

    2012-01-01

    The author discusses the French legal context for the different aspects of the development of offshore wind farms in France: procedures related to electricity production installations (authorization or tender like what has been done for six sites), other administrative authorizations, and connection to the grid. Then, she addresses the various constraints: environmental, social and technical constraints (protected marine areas, constraints related to the tendering process), coast planning documents, tax policy. She finally discusses the installation dismantling

  6. Unconventional wind machine

    International Nuclear Information System (INIS)

    Sheff, J.R.

    1979-01-01

    It is the purpose of this paper to introduce an unconventional wind machine which has economics comparable with nuclear power and is already available in the public market place. Specifically, up to about 17 MWE could be saved for other uses such as sale in most 1000 MWE plants of any type - nuclear, oil, gas, peat, or wood - which use conventional electrically driven fans in their cooling towers. 10 refs

  7. Sea Wind Europe

    International Nuclear Information System (INIS)

    2004-02-01

    The first and defining step towards European leadership in renewable energy must be the successful setting of an ambitious EU renewable energy target for 2020. This will set out the vision and create the framework within which our clean energy future can be delivered. Sea Wind Europe offers a clear blueprint of how to achieve its vision and outlines concrete policy measures that will give European renewables the foundation they need for success on a giant scale

  8. Airfoils for wind turbine

    Science.gov (United States)

    Tangler, James L.; Somers, Dan M.

    1996-01-01

    Airfoils for the blade of a wind turbine wherein each airfoil is characterized by a thickness in a range from 16%-24% and a maximum lift coefficient designed to be largely insensitive to roughness effects. The airfoils include a family of airfoils for a blade 15 to 25 meters in length, a family of airfoils for a blade 1 to 5 meters in length, and a family of airfoils for a blade 5 to 10 meters in length.

  9. Wind Energy Resource Atlas of Armenia

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, D.; Schwartz, M.; Scott, G.; Haymes, S.; Heimiller, D.; George, R.

    2003-07-01

    This wind energy resource atlas identifies the wind characteristics and distribution of the wind resource in the country of Armenia. The detailed wind resource maps and other information contained in the atlas facilitate the identification of prospective areas for use of wind energy technologies for utility-scale power generation and off-grid wind energy applications. The maps portray the wind resource with high-resolution (1-km2) grids of wind power density at 50-m above ground. The wind maps were created at the National Renewable Energy Laboratory (NREL) using a computerized wind mapping system that uses Geographic Information System (GIS) software.

  10. Composite wind turbine towers

    Energy Technology Data Exchange (ETDEWEB)

    Polyzois, D. [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Civil Engineering

    2008-07-01

    This paper discussed experiments conducted to optimized the advanced composite materials such as fiberglass reinforced plastics (FRP) used to fabricate wind turbine towers. FRP materials are used in tubular steel, lattice, guyed, and reinforced concrete towers. The towers and turbine blades are transported in segments and assembled on-site, sometimes in offshore or remote locations.The FRP composites are used to build towers with a high strength-to-weight ratio as well as to provide resistance to chemical attacks and corrosion. Use of the materials has resulted in towers that do not require heavy installation equipment. Experimental programs were conducted to verify the structural behaviour of the tower structure's individual-scaled cells as well as to evaluate the performance of multi-cell assemblies. Joint assembly designs were optimized, and a filament winding machine was used to conduct the experimental study and to test individual cells. Failure mode analyses were conducted to determine local buckling and shear rupture. Tension, compression, and shear properties of the FRP materials were tested experimentally, and data from the test were then used to develop finite element models of the composite towers as well as to obtain load deflection curves and tip oscillation data. A case study of a 750 kW wind turbine in Churchill, Manitoba was used to test the design. tabs., figs.

  11. Wind-power plant

    Energy Technology Data Exchange (ETDEWEB)

    Kling, A

    1976-08-26

    The invention is concerned with a wind-power plant whose rotor axis is pivoted in the supporting structure and swingable around an axis of tilt, forming an angle with the rotor axis and the vertical axis, and allowing precession of the rotor. On changes of wind direction an electric positioning device is moving the rotor axis into the new direction in such a way that no precession forces are exerted on the supporting structure and this one may very easily be held. Instead of one rotor, also a type with two coaxial, co-planar countercurrent rotors may be used. Each of the two countercurrent rotors is carrying a number of magnetic poles, distributed all over the circumference, acting together with the magnetic poles of the other rotor. At least the poles of one rotor have electric line windings being connected by leads with a collector so that the two rotors form the two parts of a power generator being each rotatable with respect to the other ('stator' and 'rotor').

  12. A simple method to downscale daily wind statistics to hourly wind data

    OpenAIRE

    Guo, Zhongling

    2013-01-01

    Wind is the principal driver in the wind erosion models. The hourly wind speed data were generally required for precisely wind erosion modeling. In this study, a simple method to generate hourly wind speed data from daily wind statistics (daily average and maximum wind speeds together or daily average wind speed only) was established. A typical windy location with 3285 days (9 years) measured hourly wind speed data were used to validate the downscaling method. The results showed that the over...

  13. A study of rotor and platform design trade-offs for large-scale floating vertical axis wind turbines

    Science.gov (United States)

    Griffith, D. Todd; Paquette, Joshua; Barone, Matthew; Goupee, Andrew J.; Fowler, Matthew J.; Bull, Diana; Owens, Brian

    2016-09-01

    Vertical axis wind turbines are receiving significant attention for offshore siting. In general, offshore wind offers proximity to large populations centers, a vast & more consistent wind resource, and a scale-up opportunity, to name a few beneficial characteristics. On the other hand, offshore wind suffers from high levelized cost of energy (LCOE) and in particular high balance of system (BoS) costs owing to accessibility challenges and limited project experience. To address these challenges associated with offshore wind, Sandia National Laboratories is researching large-scale (MW class) offshore floating vertical axis wind turbines (VAWTs). The motivation for this work is that floating VAWTs are a potential transformative technology solution to reduce offshore wind LCOE in deep-water locations. This paper explores performance and cost trade-offs within the design space for floating VAWTs between the configurations for the rotor and platform.

  14. Wind power development field test project at Rokkasho-mura, Aomori prefecture. Close survey on wind conditions; Aomoriken Rokkashomura ni okeru furyoku kaihatsu field test jigyo (fukyo seisa) hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-11-01

    A survey was made on wind conditions in Rokkasho-mura, Kamikita-gun, Aomori prefecture, on the assumption that a wind power generation system was installed therein. The survey period was one year from Oct., 1998 to Sept., 1999. The observations were carried out on the average wind velocity, average wind direction, standard deviation of velocity, and the maximum instantaneous wind velocity. With a fixed point observation at 20 m above ground, and with the minimum observation time unit of 10 minutes, an average value during the 10 minutes was determined as the measurement of each category. However, the maximum instantaneous wind velocity was determined on the measurement with the minimum observation time unit of 2 seconds. The annual average wind velocity was 4.6 m/s, the maximum wind velocity during the period was 26.0 m/s, the prevailing wind direction was NW (20.8%), WNW (18.0%), and SE (13.5%), and the total occurrence rate of wind direction at the wind axis of NW-SE was 75.7%. The intensity of turbulence was 0.25 at a wind velocity of 2.0 m/s or above and was 0.21 at 4.0 m/s or above. An estimated annual operation rate of a windmill was 59-72% using the rated value of a 150 kW, 300 kW and 750 kW class windmills. (NEDO)

  15. Flexible Word Classes

    DEFF Research Database (Denmark)

    • First major publication on the phenomenon • Offers cross-linguistic, descriptive, and diverse theoretical approaches • Includes analysis of data from different language families and from lesser studied languages This book is the first major cross-linguistic study of 'flexible words', i.e. words...... that cannot be classified in terms of the traditional lexical categories Verb, Noun, Adjective or Adverb. Flexible words can - without special morphosyntactic marking - serve in functions for which other languages must employ members of two or more of the four traditional, 'specialised' word classes. Thus......, flexible words are underspecified for communicative functions like 'predicating' (verbal function), 'referring' (nominal function) or 'modifying' (a function typically associated with adjectives and e.g. manner adverbs). Even though linguists have been aware of flexible world classes for more than...

  16. Storytelling in EFL Classes

    Directory of Open Access Journals (Sweden)

    Emine Bala

    2015-12-01

    Full Text Available Storytelling is one of the oldest ways of education and oral tradition that is continuously being used to transfer the previous nation‘s cultures, tradition and customs. It constructs a bridge between the new and the old. Storytelling in EFL classes usually provides a meaningful context, interesting atmosphere and is used as a tool to highly motivate students. Although it seems to be mostly based on speaking, it is used to promote other skills such as writing, reading, and listening. Storytelling is mainly regarded to be grounded on imitation and repetition; nevertheless many creative activities can be implemented in the classroom since this method directs learners to use their imaginations. This study discusses the importance of storytelling as a teaching method, and it outlines the advantages of storytelling in EFL classes.

  17. Queen elizabeth class battleships

    CERN Document Server

    Brown, Les

    2010-01-01

    The 'ShipCraft' series provides in-depth information about building and modifying model kits of famous warship types. Lavishly illustrated, each book takes the modeller through a brief history of the subject class, highlighting differences between sister-ships and changes in their appearance over their careers. This includes paint schemes and camouflage, featuring colour profiles and highly detailed line drawings and scale plans. The modelling section reviews the strengths and weaknesses of available kits, lists commercial accessory sets for super-detailing of the ships, and provides hints on modifying and improving the basic kit. This is followed by an extensive photographic survey of selected high-quality models in a variety of scales, and the book concludes with a section on research references - books, monographs, large-scale plans and relevant websites.This volume covers the five ships of the highly successful Queen Elizabeth class, a design of fast battleship that set the benchmark for the last generati...

  18. World Class Facilities Management

    DEFF Research Database (Denmark)

    Malmstrøm, Ole Emil; Jensen, Per Anker

    2013-01-01

    Alle der med entusiasme arbejder med Facilities Management drømmer om at levere World Class. DFM drømmer om at skabe rammer og baggrund for, at vi i Danmark kan bryste os at være blandt de førende på verdensplan. Her samles op på, hvor tæt vi er på at nå drømmemålet.......Alle der med entusiasme arbejder med Facilities Management drømmer om at levere World Class. DFM drømmer om at skabe rammer og baggrund for, at vi i Danmark kan bryste os at være blandt de førende på verdensplan. Her samles op på, hvor tæt vi er på at nå drømmemålet....

  19. Pulsar Magnetohydrodynamic Winds

    Science.gov (United States)

    Okamoto, Isao; Sigalo, Friday B.

    2006-12-01

    The acceleration and collimation/decollimation of relativistic magnetocentrifugal winds are discussed concerning a cold plasma from a strongly magnetized, rapidly rotating neutron star in a steady axisymmetric state based on ideal magnetohydrodynamics. There exist unipolar inductors associated with the field line angular frequency, α, at the magnetospheric base surface, SB, with a huge potential difference between the poles and the equator, which drive electric current through the pulsar magnetosphere. Any ``current line'' must emanate from one terminal of the unipolar inductor and return to the other, converting the Poynting flux to the kinetic flux of the wind at finite distances. In a plausible field structure satisfying the transfield force-balance equation, the fast surface, SF, must exist somewhere between the subasymptotic and asymptotic domains, i.e., at the innermost point along each field line of the asymptotic domain of \\varpaA2/\\varpi2 ≪ 1, where \\varpiA is the Alfvénic axial distance. The criticality condition at SF yields the Lorentz factor, γF = μ\\varepsilon1/3, and the angular momentum flux, β, as the eigenvalues in terms of the field line angular velocity, α, the mass flux per unit flux tube, η, and one of the Bernoulli integrals, μδ, which are assumed to be specifiable as the boundary conditions at SB. The other Bernoulli integral, μɛ, is related to μδ as μɛ = μδ[1-(α2\\varpiA2/c2)]-1, and both μɛ and \\varpiA2 are eigenvalues to be determined by the criticality condition at SF. Ongoing MHD acceleration is possible in the superfast domain. This fact may be helpful in resolving a discrepancy between the wind theory and the Crab-nebula model. It is argued that the ``anti-collimation theorem'' holds for relativistic winds, based on the curvature of field streamlines determined by the transfield force balance. The ``theorem'' combines with the ``current-closure condition'' as a global condition in the wind zone to produce a

  20. Massive stars in colliding wind systems: the GLAST perspective

    International Nuclear Information System (INIS)

    Reimer, Anita; Reimer, Olaf

    2007-01-01

    Colliding winds of massive stars in binary systems arc considered as candidate sites of high-energy non-thermal photon emission. They are already among the suggested counterparts for a few individual unidentified EGRET sources, but may constitute a detectable source population for the GLAST observatory.The present work investigates such population study of massive colliding wind systems at high-energy gamma-rays. Based on the recent detailed model (Reimer et al. 2006) for non-thermal photon production in prime candidate systems, we unveil the expected characteristics of this source class in the observables accessible at LAT energies. Combining the broadband emission model with the presently cataloged distribution of such systems and their individual parameters allows us to conclude on the expected maximum number of LAT-detections among massive stars in colliding wind binary systems