Sample records for turbulence wind variability

  1. Effects of turbulence on power generation for variable-speed wind turbines

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P.; Buhl, M.L. Jr.

    1996-11-01T23:59:59.000Z

    One of the primary advantages of variable-speed wind turbines over fixed-speed turbines should be improved aerodynamic efficiency. With variable-speed generation, in order to maintain a constant ratio of wind speed to tip speed, the wind turbine changes rotor speed as the wind speed changes. In this paper we compare a stall-controlled, variable-speed wind turbine to a fixed-speed turbine. The focus of this paper is to investigate the effects of variable speed on energy capture and its ability to control peak power. We also show the impact of turbulence on energy capture in moderate winds. In this report, we use a dynamic simulator to apply different winds to a wind turbine model. This model incorporates typical inertial and aerodynamic performance characteristics. From this study we found a control strategy that makes it possible to operate a stall-controlled turbine using variable speed to optimize energy capture and to control peak power. We also found that turbulence does not have a significant impact on energy capture.

  2. Wind turbulence characterization for wind energy development

    SciTech Connect (OSTI)

    Wendell, L.L.; Gower, G.L.; Morris, V.R.; Tomich, S.D.

    1991-09-01T23:59:59.000Z

    As part of its support of the US Department of Energy's (DOE's) Federal Wind Energy Program, the Pacific Northwest Laboratory (PNL) has initiated an effort to work jointly with the wind energy community to characterize wind turbulence in a variety of complex terrains at existing or potential sites of wind turbine installation. Five turbulence characterization systems were assembled and installed at four sites in the Tehachapi Pass in California, and one in the Green Mountains near Manchester, Vermont. Data processing and analyses techniques were developed to allow observational analyses of the turbulent structure; this analysis complements the more traditional statistical and spectral analyses. Preliminary results of the observational analyses, in the rotating framework or a wind turbine blade, show that the turbulence at a site can have two major components: (1) engulfing eddies larger than the rotor, and (2) fluctuating shear due to eddies smaller than the rotor disk. Comparison of the time series depicting these quantities at two sites showed that the turbulence intensity (the commonly used descriptor of turbulence) did not adequately characterize the turbulence at these sites. 9 refs., 10 figs.,

  3. Solar Wind Turbulence A Study of Corotating Interaction Regions at 1 AU

    E-Print Network [OSTI]

    Solar Wind Turbulence A Study of Corotating Interaction Regions at 1 AU Je rey A. Tessein Department of Physics University of New Hampshire Durham, NH 03824 May 15, 2009 #12;Abstract The solar wind's rotation and the variability in the source of the solar wind, fast moving wind can crash into slow wind

  4. On the Study of Uncertainty in Inflow Turbulence Model Parameters in Wind Turbine Applications

    E-Print Network [OSTI]

    Manuel, Lance

    On the Study of Uncertainty in Inflow Turbulence Model Parameters in Wind Turbine Applications Korn, Austin, TX 78712 In stochastic simulation of inflow turbulence random fields for wind turbine applica models can be in turn highly variable. Turbine load and performance variability could as well result

  5. VARIABLE SPEED WIND TURBINE

    E-Print Network [OSTI]

    Chatinderpal Singh

    Wind energy is currently the fastest-growing renewable source of energy in India; India is a key market for the wind industry, presenting substantial opportunities for both the international and domestic players. In India the research is carried out on wind energy utilization on big ways.There are still many unsolved challenges in expanding wind power, and there are numerous problems of interest to systems and control researchers. In this paper we study the pitch control mechanism of wind turbine. The pitch control system is one of the most widely used control techniques to regulate the output power of a wind turbine generator. The pitch angle is controlled to keep the generator power at rated power by reducing the angle of the blades. By regulating, the angle of stalling, fast torque changes from the wind will be reutilized. It also describes the design of the pitch controller and discusses the response of the pitch-controlled system to wind velocity variations. The pitch control system is found to have a large output power variation and a large settling time.

  6. AIAA980057 RELATING TURBULENCE TO WIND TURBINE BLADE LOADS

    E-Print Network [OSTI]

    Sweetman, Bert

    AIAA­98­0057 RELATING TURBULENCE TO WIND TURBINE BLADE LOADS: PARAMETRIC STUDY WITH MULTIPLE that is most useful in estimating fatigue loads on wind turbine blades. The histograms of rainflow counted turbulence measures---can be used to estimate fatigue loads on wind turbine blades. We first de­ scribe

  7. The Nature of Subproton Scale Turbulence in the Solar Wind

    E-Print Network [OSTI]

    Chen, C H K; Xia, Q; Perez, J C

    2013-01-01T23:59:59.000Z

    The nature of subproton scale fluctuations in the solar wind is an open question, partly because two similar types of electromagnetic turbulence can occur: kinetic Alfven turbulence and whistler turbulence. These two possibilities, however, have one key qualitative difference: whistler turbulence, unlike kinetic Alfven turbulence, has negligible power in density fluctuations. In this Letter, we present new observational data, as well as analytical and numerical results, to investigate this difference. The results show, for the first time, that the fluctuations well below the proton scale are predominantly kinetic Alfven turbulence, and, if present at all, the whistler fluctuations make up only a small fraction of the total energy.

  8. Wind Energy Applications of Unified and Dynamic Turbulence Models

    E-Print Network [OSTI]

    Heinz, Stefan

    Wind Energy Applications of Unified and Dynamic Turbulence Models Stefan Heinz and Harish Gopalan applicable as a low cost alternative. 1 Introduction There is a growing interest in using wind energy suggests the possibility of providing 20% of the electricity in the U.S. by wind energy in 2030

  9. Turbulent heating of the corona and solar wind: the heliospheric

    E-Print Network [OSTI]

    Turbulent heating of the corona and solar wind: the heliospheric dark energy problem Stuart D. Bale and Solar Wind There are very few collisions in the solar wind Not in thermal equilibrium Large' Photospheric blackbody ~5000-6000K Sunspots and `active regions' #12;Impulsive Solar Activity - `Carrington

  10. ATMOSPHERIC TURBULENCE MODELING AND IMPLICATIONS FOR WIND ENERGY

    E-Print Network [OSTI]

    Chow, Fotini Katopodes

    turbines off too early in high winds, or may risk severe damage to the rotors and blades by operating under Introduction Wind turbines sit at the very bottom of the at- mospheric boundary layer, where winds are highly turbulent, shear events are intermittent, and land- atmosphere interactions may be strong. Turbine hub

  11. Wind Scanner: A full-scale Laser Facility for Wind and Turbulence Measurements around large Wind Turbines

    E-Print Network [OSTI]

    Wind Scanner: A full-scale Laser Facility for Wind and Turbulence Measurements around large Wind Turbines Torben Mikkelsen, Jakob Mann and Michael Courtney Wind Energy Department, Ris National Laboratory:Torben.Mikkelsen@Risoe.dk Summary RIS DTU has started to build a newly designed laser-based lidar scanning facility for remote wind

  12. MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND FARM SITES

    E-Print Network [OSTI]

    Heinemann, Detlev

    in Europe will come from offshore sites. The first large offshore wind farms are currently being builtMODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND for conditions important for offshore wind energy utilisation are compared and tested: Four models

  13. MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND FARM SITES

    E-Print Network [OSTI]

    Heinemann, Detlev

    MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND important for offshore wind energy utilisation are discussed and tested: Four models for the surface tested with data from the offshore field measurement Rdsand by extrapolating the measured 10 m wind

  14. Turbulence of the Solar Wind Studies of the Solar Wind Using the ACE and Helios Spacecraft

    E-Print Network [OSTI]

    Turbulence of the Solar Wind Studies of the Solar Wind Using the ACE and Helios Spacecraft Bejamin;Abstract The solar wind is a supersonic ow of plasma emanating from the sun and traveling through the interplanetary medium to the outermost reaches of the heliosphere. The solar wind experiences in situ

  15. Long-Term Wind Power Variability

    SciTech Connect (OSTI)

    Wan, Y. H.

    2012-01-01T23:59:59.000Z

    The National Renewable Energy Laboratory started collecting wind power data from large commercial wind power plants (WPPs) in southwest Minnesota with dedicated dataloggers and communication links in the spring of 2000. Over the years, additional WPPs in other areas were added to and removed from the data collection effort. The longest data stream of actual wind plant output is more than 10 years. The resulting data have been used to analyze wind power fluctuations, frequency distribution of changes, the effects of spatial diversity, and wind power ancillary services. This report uses the multi-year wind power data to examine long-term wind power variability.

  16. COLLISIONLESS DAMPING AT ELECTRON SCALES IN SOLAR WIND TURBULENCE

    SciTech Connect (OSTI)

    TenBarge, J. M.; Howes, G. G. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States); Dorland, W., E-mail: jason-tenbarge@uiowa.edu [Department of Physics, University of Maryland, College Park, MA 20742-3511 (United States)

    2013-09-10T23:59:59.000Z

    The dissipation of turbulence in the weakly collisional solar wind plasma is governed by unknown kinetic mechanisms. Two candidates have been suggested to play an important role in the dissipation, collisionless damping via wave-particle interactions and dissipation in small-scale current sheets. High resolution spacecraft measurements of the turbulent magnetic energy spectrum provide important constraints on the dissipation mechanism. The limitations of popular fluid and hybrid numerical schemes for simulation of the dissipation of solar wind turbulence are discussed, and instead a three-dimensional kinetic approach is recommended. We present a three-dimensional nonlinear gyrokinetic simulation of solar wind turbulence at electron scales that quantitatively reproduces the exponential form of the turbulent magnetic energy spectrum measured in the solar wind. A weakened cascade model that accounts for nonlocal interactions and collisionless Landau damping also quantitatively agrees with the observed exponential form. These results establish that a turbulent cascade of kinetic Alfven waves that is terminated by collisionless Landau damping is sufficient to explain the observed magnetic energy spectrum in the dissipation range of solar wind turbulence.

  17. A Dynamical Model of Plasma Turbulence in the Solar Wind

    E-Print Network [OSTI]

    Howes, G G

    2015-01-01T23:59:59.000Z

    A dynamical approach, rather than the usual statistical approach, is taken to explore the physical mechanisms underlying the nonlinear transfer of energy, the damping of the turbulent fluctuations, and the development of coherent structures in kinetic plasma turbulence. It is argued that the linear and nonlinear dynamics of Alfven waves are responsible, at a very fundamental level, for some of the key qualitative features of plasma turbulence that distinguish it from hydrodynamic turbulence, including the anisotropic cascade of energy and the development of current sheets at small scales. The first dynamical model of kinetic turbulence in the weakly collisional solar wind plasma that combines self-consistently the physics of Alfven waves with the development of small-scale current sheets is presented and its physical implications are discussed. This model leads to a simplified perspective on the nature of turbulence in a weakly collisional plasma: the nonlinear interactions responsible for the turbulent casca...

  18. Compressive turbulent cascade and heating in the solar wind

    SciTech Connect (OSTI)

    Marino, R. [Dipartimento di Fisica, Universita della Calabria, Ponte Bucci 31C, I-87036 Rende (Italy); University of Nice Sophia Antipolis, CNRS, Observatoire de la Cote d'Azur, B.P. 4229, 06304 Nice Cedex 4 (France); Sorriso-Valvo, L. [Liquid Crystal Laboratory, INFM/CNR, Ponte Bucci 33B, I-87036 Rende (Italy); Carbone, V. [Dipartimento di Fisica, Universita della Calabria, Ponte Bucci 31C, I-87036 Rende (Italy); Noullez, A. [University of Nice Sophia Antipolis, CNRS, Observatoire de la Cote d'Azur, B.P. 4229, 06304 Nice Cedex 4 (France); Bruno, R. [INAF-Istituto Fisica Spazio Interplanetario, Rome (Italy)

    2010-03-25T23:59:59.000Z

    A turbulent energy cascade has been recently identified in high-latitude solar wind data samples by using a Yaglom-like relation. However, analogous scaling law, suitably modified to take into account compressible fluctuations, has been observed in a much more extended fraction of the same data set recorded by the Ulysses spacecraft. Thus, it seems that large scale density fluctuations, despite their low amplitude, play a major role in the basic scaling properties of turbulence. The compressive turbulent cascade, moreover, seems to be able to supply the energy needed to account for the local heating of the non-adiabatic solar wind.

  19. RESEARCH ARTICLE Development and characterization of a variable turbulence

    E-Print Network [OSTI]

    Lieuwen, Timothy C.

    (7):10371048, 2009), where variable blockage ratio slots are located upstream of a contoured nozzle. Vortical A Nozzle exit area E Power spectral density ReD Geometric Reynolds number Rel Turbulent Reynolds number SLRESEARCH ARTICLE Development and characterization of a variable turbulence generation system A

  20. Magnetic Discontinuities in Magnetohydrodynamic Turbulence and in the Solar Wind

    E-Print Network [OSTI]

    Vladimir Zhdankin; Stanislav Boldyrev; Joanne Mason; Jean Carlos Perez

    2012-04-19T23:59:59.000Z

    Recent measurements of solar wind turbulence report the presence of intermittent, exponentially distributed angular discontinuities in the magnetic field. In this Letter, we study whether such discontinuities can be produced by magnetohydrodynamic (MHD) turbulence. We detect the discontinuities by measuring the fluctuations of the magnetic field direction, Delta theta, across fixed spatial increments Delta x in direct numerical simulations of MHD turbulence with an imposed uniform guide field B_0. A large region of the probability density function (pdf) for Delta theta is found to follow an exponential decay, proportional to exp(-Delta theta/theta_*), with characteristic angle theta_* ~ (14 deg) (b_rms/B_0)^0.65 for a broad range of guide-field strengths. We find that discontinuities observed in the solar wind can be reproduced by MHD turbulence with reasonable ratios of b_rms/B_0. We also observe an excess of small angular discontinuities when Delta x becomes small, possibly indicating an increasing statistical significance of dissipation-scale structures. The structure of the pdf in this case closely resembles the two-population pdf seen in the solar wind. We thus propose that strong discontinuities are associated with inertial-range MHD turbulence, while weak discontinuities emerge from near-dissipation-range turbulence. In addition, we find that the structure functions of the magnetic field direction exhibit anomalous scaling exponents, which indicates the existence of intermittent structures.

  1. A Tree Swaying in a Turbulent Wind: A Scaling Analysis

    E-Print Network [OSTI]

    Theo Odijk

    2014-07-10T23:59:59.000Z

    A tentative scaling theory is presented of a tree swaying in a turbulent wind. It is argued that the turbulence of the air within the crown is in the inertial regime. An eddy causes a dynamic bending response of the branches according to a time criterion. The resulting expression for the penetration depth of the wind yields an exponent which appears to be consistent with that pertaining to the morphology of the tree branches. An energy criterion shows that the dynamics of the branches is basically passive. The possibility of hydrodynamic screening by the leaves is discussed.

  2. Estimation of turbulence level and scale for wind turbine applications

    SciTech Connect (OSTI)

    Powell, D.C.

    1988-11-01T23:59:59.000Z

    A simplified method is presented for estimating onsite turbulence variance within the wind turbine layer for horizontal wind speed. The method is based principally on estimating the probability distribution of wind speed and assigning a variance to each mean wind speed based on surface roughness estimates. The model is not proposed as an alternative to onsite measurement and analysis, but rather as an adjunct to such a program. A revision of the Kaimal neutral u-component spectrum is suggested to apply to the mix of the stabilities occurring during operational winds. Values of integral length scale calculated from data analysis are shown to contradict the length scale model implicit in turbulence power spectra. Also, these calculated values are shown to be extremely sensitive to the length of the time series and the detrending method used. The analysis and modeling are extended to the rotational frame of reference for a horizontal-axis wind turbine by modeling the ratios of harmonic spike variances (1P, 2P, etc.) in the rotational spectrum to the Eulerian turbulence variance. 15 refs., 11 figs., 3 tabs.

  3. Residual energy in magnetohydrodynamic turbulence and in the solar wind

    E-Print Network [OSTI]

    Stanislav Boldyrev; Jean Carlos Perez; Vladimir Zhdankin

    2011-08-30T23:59:59.000Z

    Recent observations indicate that kinetic and magnetic energies are not in equipartition in the solar wind turbulence. Rather, magnetic fluctuations are more energetic and have somewhat steeper energy spectrum compared to the velocity fluctuations. This leads to the presence of the so-called residual energy E_r=E_v-E_b in the inertial interval of turbulence. This puzzling effect is addressed in the present paper in the framework of weak turbulence theory. Using a simple model of weakly colliding Alfv\\'en waves, we demonstrate that the kinetic-magnetic equipartition indeed gets broken as a result of nonlinear interaction of Alfv\\'en waves. We establish that magnetic energy is indeed generated more efficiently as a result of these interactions, which proposes an explanation for the solar wind observations.

  4. Reconnection outflow generated turbulence in the solar wind

    E-Print Network [OSTI]

    Vrs, Z; Semenov, V S; Zaqarashvili, T V; Bruno, R; Khodachenko, M

    2014-01-01T23:59:59.000Z

    Petschek-type time-dependent reconnection (TDR) and quasi-stationary reconnection (QSR) models are considered to understand reconnection outflow structures and the features of the associated locally generated turbulence in the solar wind. We show that the outflow structures, such as discontinuites, Kelvin-Helmholtz (KH) unstable flux tubes or continuous space filling flows cannot be distinguished from one-point WIND measurements. In both models the reconnection outflows can generate more or less spatially extended turbulent boundary layers (TBDs). The structure of an unique extended reconnection outflow is investigated in detail. The analysis of spectral scalings and break locations show that reconnection outflows can control the local field and plasma conditions which may play in favor of one or another turbulent dissipation mechanisms with their characteristic scales and wavenumbers.

  5. Cross-Scale Effects in Solar-Wind Turbulence

    SciTech Connect (OSTI)

    Valentini, F.; Veltri, P. [Dipartimento di Fisica and CNISM, Universita della Calabria, 87036 Rende (Serbia and Montenegro) (Italy); Califano, F. [Dipartimento di Fisica and CNISM, Universita di Pisa, 56127 Pisa (Italy); Mangeney, A. [Observatoire de Paris-Meudon, 92195 Meudon Cedex (France)

    2008-07-11T23:59:59.000Z

    The understanding of the small-scale termination of the turbulent energy cascade in collisionless plasmas is nowadays one of the outstanding problems in space physics. In the absence of collisional viscosity, the dynamics at small scales is presumably kinetic in nature; the identification of the physical mechanism which replaces energy dissipation and establishes the link between macroscopic and microscopic scales would open a new scenario in the study of turbulent heating in space plasmas. We present a numerical analysis of kinetic effects along the turbulent energy cascade in solar-wind plasmas which provides an effective unified interpretation of a wide set of spacecraft observations and shows that, simultaneously with an increase in the ion perpendicular temperature, strong bursts of electrostatic activity in the form of ion-acoustic turbulence are produced together with accelerated beams in the ion distribution function.

  6. Proton Kinetic Effects in Vlasov and Solar Wind Turbulence

    E-Print Network [OSTI]

    Servidio, S; Valentini, F; Perrone, D; Califano, F; Chapman, S; Matthaeus, W H; Veltri, P

    2013-01-01T23:59:59.000Z

    Kinetic plasma processes have been investigated in the framework of solar wind turbulence, employing Hybrid Vlasov-Maxwell (HVM) simulations. The dependency of proton temperature anisotropy T_{\\perp}/T_{\\parallel} on the parallel plasma beta \\beta_{\\parallel}, commonly observed in spacecraft data, has been recovered using an ensemble of HVM simulations. By varying plasma parameters, such as plasma beta and fluctuation level, the simulations explore distinct regions of the parameter space given by T_{\\perp}/T_{\\parallel} and \\beta_{\\parallel}, similar to solar wind sub-datasets. Moreover, both simulation and solar wind data suggest that temperature anisotropy is not only associated with magnetic intermittent events, but also with gradient-type structures in the flow and in the density. This connection between non-Maxwellian kinetic effects and various types of intermittency may be a key point for understanding the complex nature of plasma turbulence.

  7. Multiscale nature of the dissipation range in solar wind turbulence

    E-Print Network [OSTI]

    Told, D; TenBarge, J M; Howes, G G; Hammett, G W

    2015-01-01T23:59:59.000Z

    Nonlinear energy transfer and dissipation in Alfv\\'en wave turbulence are analyzed in the first gyrokinetic simulation spanning all scales from the tail of the MHD range to the electron gyroradius scale. For typical solar wind parameters at 1 AU, about 30% of the nonlinear energy transfer close to the electron gyroradius scale is mediated by modes in the tail of the MHD cascade. Collisional dissipation occurs across the entire kinetic range $k_\\perp\\rho_i\\gtrsim 1$. Both mechanisms thus act on multiple coupled scales, which have to be retained for a comprehensive picture of the dissipation range in Alfv\\'enic turbulence.

  8. Optimal combined wind power forecasts using exogeneous variables

    E-Print Network [OSTI]

    Optimal combined wind power forecasts using exogeneous variables Fannar Orn Thordarson Kongens of the thesis is combined wind power forecasts using informations from meteorological forecasts. Lyngby, January

  9. Supercomputers Capture Turbulence in the Solar Wind

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengthening a solid ...Success Stories Touching TheCapture Turbulence in the

  10. SOLAR WIND MAGNETOHYDRODYNAMICS TURBULENCE: ANOMALOUS SCALING AND ROLE OF INTERMITTENCY

    SciTech Connect (OSTI)

    Salem, C.; Bale, S. D. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Mangeney, A. [LESIA, Observatoire de Paris-Meudon, F-92195 Meudon (France); Veltri, P. [Dipartimento di Fisica, Universita della Calabria, Rende (Italy)], E-mail: salem@ssl.berkeley.edu

    2009-09-01T23:59:59.000Z

    In this paper, we present a study of the scaling properties and intermittency of solar wind MHD turbulence based on the use of wavelet transforms. More specifically, we use the Haar Wavelet transform on simultaneous 3 s resolution particle and magnetic field data from the Wind spacecraft, to investigate anomalous scaling and intermittency effects of both magnetic field and solar wind velocity fluctuations in the inertial range. For this purpose, we calculated spectra, structure functions, and probability distribution functions. We show that this powerful wavelet technique allows for a systematic elimination of intermittency effects on spectra and structure functions and thus for a clear determination of the actual scaling properties in the inertial range. The scaling of the magnetic field and the velocity fluctuations are found to be fundamentally different. Moreover, when the most intermittent structures superposed to the standard fluctuations are removed, simple statistics are recovered. The magnetic field and the velocity fluctuations exhibit a well-defined, although different, monofractal behavior, following a Kolmogorov -5/3 scaling and a Iroshnikov-Kraichnan -3/2 scaling, respectively. The multifractal properties of solar wind turbulence appear to be determined by the presence of those most intermittent structures. Finally, our wavelet technique also allows for a direct and systematic identification of the most active, singular structures responsible for the intermittency in the solar wind.

  11. "Complexity" Induced Plasma Turbulence in Coronal Holes and the Solar Wind

    E-Print Network [OSTI]

    that are generally detected in the solar wind [10]. We also address the concept of resonant energization of solar"Complexity" Induced Plasma Turbulence in Coronal Holes and the Solar Wind Tom Chang Center that plasma turbulence emanating from coronal holes may efficiently accelerate the solar wind to observed

  12. Large-eddy simulation of a wind turbine wake in turbulent

    E-Print Network [OSTI]

    Firestone, Jeremy

    Large-eddy simulation of a wind turbine wake in turbulent neutral shear flow Shengbai Xie, Cristina-similar velocity profile existing in the wake after a wind turbine? How does the wake influence the vertical? Motivation #12; Large-eddy simulation for turbulent flow field Actuator-line model for wind turbine ui

  13. On the use of proper orthogonal decomposition to describe inflow turbulence and wind turbine loads

    E-Print Network [OSTI]

    Manuel, Lance

    On the use of proper orthogonal decomposition to describe inflow turbulence and wind turbine loads, USA Keywords: Proper Orthogonal Decomposition, inflow turbulence, wind turbine ABSTRACT: We discuss experienced by a wind turbine. A methodology is proposed that employs low- dimensional POD models

  14. Surface-Layer Wind and Turbulence Profiling from LIDAR: Theory and Measurements

    E-Print Network [OSTI]

    Surface-Layer Wind and Turbulence Profiling from LIDAR: Theory and Measurements Rgis DANIELIAN (Vestas Wind System) Hans Ejsing JRGENSEN (Wind Energy Department, Ris. Contact: haej@risoe.dk) Torben MIKKELSEN (Wind Energy Department, Ris. Contact: tomi@risoe.dk) Jacob MANN (Wind Energy Department, Ris

  15. Control strategy for variable-speed, stall-regulated wind turbines

    SciTech Connect (OSTI)

    Muljadi, E.; Pierce, K.; Migliore, P.

    1998-04-01T23:59:59.000Z

    A variable-speed, constant-pitch wind turbine was investigated to evaluate the feasibility of constraining its rotor speed and power output without the benefit of active aerodynamic control devices. A strategy was postulated to control rotational speed by specifying the demanded generator torque. By controlling rotor speed in relation to wind speed, the aerodynamic power extracted by the blades from the wind was manipulated. Specifically, the blades were caused to stall in high winds. In low and moderate winds, the demanded generator torque and the resulting rotor speed were controlled to cause the wind turbine to operate near maximum efficiency. A computational model was developed, and simulations were conducted of operation in high turbulent winds. Results indicated that rotor speed and power output were well regulated. 7 refs., 7 figs.

  16. Structure of Turbulence in Katabatic Flows below and above the Wind-Speed Maximum

    E-Print Network [OSTI]

    Grachev, Andrey A; Di Sabatino, Silvana; Fernando, Harindra J S; Pardyjak, Eric R; Fairall, Christopher W

    2015-01-01T23:59:59.000Z

    Measurements of small-scale turbulence made over the complex-terrain atmospheric boundary layer during the MATERHORN Program are used to describe the structure of turbulence in katabatic flows. Turbulent and mean meteorological data were continuously measured at multiple levels at four towers deployed along the East lower slope (2-4 deg) of Granite Mountain. The multi-level observations made during a 30-day long MATERHORN-Fall field campaign in September-October 2012 allowed studying of temporal and spatial structure of katabatic flows in detail, and herein we report turbulence and their variations in katabatic winds. Observed vertical profiles show steep gradients near the surface, but in the layer above the slope jet the vertical variability is smaller. It is found that the vertical (normal to the slope) momentum flux and horizontal (along the slope) heat flux in a slope-following coordinate system change their sign below and above the wind maximum of a katabatic flow. The vertical momentum flux is directed...

  17. Wind Shear and Turbulence Profiles at Elevated Heights: Great Lakes and Midwest Sites (Poster)

    SciTech Connect (OSTI)

    Elliott, D.; Schwartz, M.; Scott, G.

    2009-05-01T23:59:59.000Z

    Analyzed wind resource characteristics at elevated heights (50 m-200+m) incuding shear and turbulence profiles for some areas of the Great Lakes and M idwest sites.

  18. TURBULENT HEATING OF THE DISTANT SOLAR WIND BY INTERSTELLAR PICKUP PROTONS IN A DECELERATING FLOW

    E-Print Network [OSTI]

    Isenberg, Philip A.

    Previous models of solar wind heating by interstellar pickup proton-driven turbulence have assumed that the wind speed is a constant in heliocentric radial position. However, the same pickup process, which is taken to ...

  19. An examination of loads and responses of a wind turbine undergoing variable-speed operation

    SciTech Connect (OSTI)

    Wright, A.D.; Buhl, M.L. Jr.; Bir, G.S.

    1996-11-01T23:59:59.000Z

    The National Renewable Energy Laboratory has recently developed the ability to predict turbine loads and responses for machines undergoing variable-speed operation. The wind industry has debated the potential benefits of operating wind turbine sat variable speeds for some time. Turbine system dynamic responses (structural response, resonance, and component interactions) are an important consideration for variable-speed operation of wind turbines. The authors have implemented simple, variable-speed control algorithms for both the FAST and ADAMS dynamics codes. The control algorithm is a simple one, allowing the turbine to track the optimum power coefficient (C{sub p}). The objective of this paper is to show turbine loads and responses for a particular two-bladed, teetering-hub, downwind turbine undergoing variable-speed operation. The authors examined the response of the machine to various turbulent wind inflow conditions. In addition, they compare the structural responses under fixed-speed and variable-speed operation. For this paper, they restrict their comparisons to those wind-speed ranges for which limiting power by some additional control strategy (blade pitch or aileron control, for example) is not necessary. The objective here is to develop a basic understanding of the differences in loads and responses between the fixed-speed and variable-speed operation of this wind turbine configuration.

  20. Predicted Impacts of Proton Temperature Anisotropy on Solar Wind Turbulence

    E-Print Network [OSTI]

    Klein, Kristopher G

    2015-01-01T23:59:59.000Z

    Particle velocity distributions measured in the weakly collisional solar wind are frequently found to be non-Maxwellian, but how these non-Maxwellian distributions impact the physics of plasma turbulence in the solar wind remains unanswered. Using numerical solutions of the linear dispersion relation for a collisionless plasma with a bi-Maxwellian proton velocity distribution, we present a unified framework for the four proton temperature anisotropy instabilities, identifying the associated stable eigenmodes, highlighting the unstable region of wavevector space, and presenting the properties of the growing eigenfunctions. Based on physical intuition gained from this framework, we address how the proton temperature anisotropy impacts the nonlinear dynamics of the \\Alfvenic fluctuations underlying the dominant cascade of energy from large to small scales and how the fluctuations driven by proton temperature anisotropy instabilities interact nonlinearly with each other and with the fluctuations of the large-scal...

  1. Pitch-controlled variable-speed wind turbine generation

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P.

    2000-03-01T23:59:59.000Z

    Wind energy is a viable option to complement other types of pollution-free generation. In the early development of wind energy, the majority of wind turbines were operated at constant speed. Recently, the number of variable-speed wind turbines installed in wind farms has increased and more wind turbine manufacturers are making variable-speed wind turbines. This paper covers the operation of variable-speed wind turbines with pitch control. The system the authors considered is controlled to generate maximum energy while minimizing loads. The maximization of energy was only carried out on a static basis and only drive train loads were considered as a constraint. In medium wind speeds, the generator and power converter control the wind turbine to capture maximum energy from the wind. In the high wind speed region, the wind turbine is controlled to maintain the aerodynamic power produced by the wind turbine. Two methods to adjust the aerodynamic power were investigated: pitch control and generator load control, both of which are employed to control the operation of the wind turbine. The analysis and simulation shows that the wind turbine can be operated at its optimum energy capture while minimizing the load on the wind turbine for a wide range of wind speeds.

  2. Fine Structure of the Solar Wind Turbulence Inferred from Simultaneous Radio Occultation Observations at

    E-Print Network [OSTI]

    Padmanabhan, Janardhan

    Fine Structure of the Solar Wind Turbulence Inferred from Simultaneous Radio Occultation Observations at Widely-Spaced Ground Stations M.K. Bird , P. Janardhan , A.I. Efimov, L.N. Samoznaev, V extended for up to four hours, thereby allowing studies of solar wind turbulence dynamics at spatial scales

  3. Electron and proton heating by solar wind turbulence B. Breech,1

    E-Print Network [OSTI]

    Oughton, Sean

    Electron and proton heating by solar wind turbulence B. Breech,1 W. H. Matthaeus,2 S. R. Cranmer,3. Oughton (2009), Electron and proton heating by solar wind turbulence, J. Geophys. Res., 114, A09103, doi profile, requiring some process(es) to provide additional heat sources. One possible, and successful

  4. Variables Affecting Economic Development of Wind Energy

    SciTech Connect (OSTI)

    Lantz, E.; Tegen, S.

    2008-07-01T23:59:59.000Z

    NREL's JEDI Wind model performed an analysis of wind-power-related economic development drivers. Economic development benefits for wind and coal were estimated using NREL's JEDI Wind and JEDI Coal models.

  5. Characterization of the Turbulent Magnetic Integral Length in the Solar Wind: From 0.3 to 5 Astronomical Units

    E-Print Network [OSTI]

    Ruiz, M E; Matthaeus, W H; Weygand, J M

    2014-01-01T23:59:59.000Z

    The solar wind is a structured and complex system, in which the fields vary strongly over a wide range of spatial and temporal scales. As an example, the turbulent activity in the wind affects the evolution in the heliosphere of the integral turbulent scale or correlation length [{\\lambda}], usually associated with the breakpoint in the turbulent-energy spectrum that separates the inertial range from the injection range. This large variability of the fields demands a statistical description of the solar wind. In this work, we study the probability distribution function (PDF) of the magnetic autocorrelation lengths observed in the solar wind at different distances from the Sun. We use observations from Helios, ACE, and Ulysses spacecraft. We distinguish between the usual solar wind and one of its transient components (Interplanetary Coronal Mass Ejections, ICMEs), and study also solar wind samples with low and high proton beta [\\beta_p ]. We find that in the last 3 regimes the PDF of {\\lambda} is a log-normal ...

  6. Turbulence in the solar wind: spectra from Voyager 2 data at 5 AU

    E-Print Network [OSTI]

    Fraternale, F; Iovieno, M; Opher, M; Richardson, J D; Tordella, D

    2015-01-01T23:59:59.000Z

    The solar wind spectral properties are far from uniformity and evolve with the increasing distance from the sun. Most of the available spectra of solar wind turbulence were computed at 1 astronomical unit, while accurate spectra on wide frequency ranges at larger distances are still few. In this paper we consider solar wind spectra derived from the data recorded by the Voyager 2 mission during 1979 at about 5 AU from the sun. Voyager 2 data are an incomplete time series with a voids/signal ratio that typically increases as the spacecraft moves away from the sun (45% missing data in 1979), making the analysis challenging. In order to estimate the uncertainty of the spectral slopes, different methods are tested on synthetic turbulence signals with the same gap distribution as V2 data. Spectra of all variables show a power law scaling with exponents between -2.1 and -1.1, depending on frequency subranges. PDFs and correlations indicate that the flow has a significant intermittency.

  7. Simulating Turbulent Wind Fields for Offshore Turbines in Hurricane-Prone Regions (Poster)

    SciTech Connect (OSTI)

    Guo, Y.; Damiani, R.; Musial, W.

    2014-04-01T23:59:59.000Z

    Extreme wind load cases are one of the most important external conditions in the design of offshore wind turbines in hurricane prone regions. Furthermore, in these areas, the increase in load with storm return-period is higher than in extra-tropical regions. However, current standards have limited information on the appropriate models to simulate wind loads from hurricanes. This study investigates turbulent wind models for load analysis of offshore wind turbines subjected to hurricane conditions. Suggested extreme wind models in IEC 61400-3 and API/ABS (a widely-used standard in oil and gas industry) are investigated. The present study further examines the wind turbine response subjected to Hurricane wind loads. Three-dimensional wind simulator, TurbSim, is modified to include the API wind model. Wind fields simulated using IEC and API wind models are used for an offshore wind turbine model established in FAST to calculate turbine loads and response.

  8. AIAA-98-0057 RELATING TURBULENCE TO WIND TURBINE BLADE LOADS

    E-Print Network [OSTI]

    Sweetman, Bert

    AIAA-98-0057 RELATING TURBULENCE TO WIND TURBINE BLADE LOADS: PARAMETRIC STUDY WITH MULTIPLE that is most useful in estimating fatigue loads on wind turbine blades. The histograms of rain ow counted measures|can be used to estimate fatigue loads on wind turbine blades. We rst de- scribe a general approach

  9. Load Alleviation on Wind Turbine Blades using Variable Airfoil Geometry

    E-Print Network [OSTI]

    Load Alleviation on Wind Turbine Blades using Variable Airfoil Geometry Peter Bjrn Andersen, Mac Loads, Trailing Edge Flaps, PID control, Signal Noise. 1 Introduction Wind turbine blades are subject to 40% when signal noise is added to the control. Keywords: Wind Turbine, Load Alleviation, Fatigue

  10. Offshore Series Wind Turbine Variable Hub heights & rotor diameters

    E-Print Network [OSTI]

    Firestone, Jeremy

    3.6MW Offshore Series Wind Turbine GE Energy #12;Feature Variable Hub heights & rotor diameters-savings feature, considering the rigors of offshore power generation. The 3.6 MW offshore wind turbine also, for both on and offshore use. Special features include... As the world's first commercially available wind

  11. A conservative control strategy for variable-speed stall-regulated wind turbines

    SciTech Connect (OSTI)

    Muljadi, E.; Pierce, K.; Migliore, P.

    2000-02-08T23:59:59.000Z

    Simulation models of a variable-speed, fixed-pitch wind turbine were investigated to evaluate the feasibility of constraining rotor speed and power output without the benefit of active aerodynamic control devices. A strategy was postulated to control rotational speed by specifying the demanded generator torque. By controlling rotor speed in relation to wind speed, the aerodynamic power extracted by the blades from the wind was manipulated. Specifically, the blades were caused to stall in high winds. In low and moderate winds, the demanded generator torque and the resulting rotor speed were controlled to cause the wind turbine to operate near maximum efficiency. Using the developed models, simulations were conducted of operation in turbulent winds. Results indicated that rotor speed and power output were well regulated. Preliminary investigations of system dynamics showed that, compared to fixed-speed operation, variable-speed operation caused cyclic loading amplitude to be reduced for the turbine blades and low-speed shaft and slightly increased for the tower loads. This result suggests a favorable impact on fatigue life from implementation of the proposed control strategy.

  12. Anisotropy of Imbalanced Alfvenic Turbulence in Fast Solar Wind R. T. Wicks,1,* T. S. Horbury,1

    E-Print Network [OSTI]

    California at Berkeley, University of

    energy to yet smaller scales [3­5]. In the fast wind, the turbulence is imbalanced: there is more power solar wind [8] and from numerical simulations [9] that balanced tur- bulence is made up of locallyAnisotropy of Imbalanced Alfve´nic Turbulence in Fast Solar Wind R. T. Wicks,1,* T. S. Horbury,1 C

  13. Empirical Analysis of the Variability of Wind Generation in India: Implications for Grid Integration

    E-Print Network [OSTI]

    Phadke, Amol

    2014-01-01T23:59:59.000Z

    sharing the load and wind generation data. We thank Sushil2008. Analysis of Wind Generation Impact on ERCOT Ancillaryof the Variability of Wind Generation in India: Implications

  14. Wind Energy and the Turbulent Nature of the Atmospheric Boundary Layer

    E-Print Network [OSTI]

    Wchter, Matthias; Hlling, Michael; Morales, Allan; Milan, Patrick; Mcke, Tanja; Peinke, Joachim; Reinke, Nico; Rinn, Philip

    2012-01-01T23:59:59.000Z

    The challenge of developing a sustainable and renewable energy supply within the next decades requires collaborative efforts as well as new concepts in the fields of science and engineering. Here we give an overview on the impact of small-scale properties of atmospheric turbulence on the wind energy conversion process. Special emphasis is given to the noisy and intermittent structure of turbulence and its outcome for wind energy conversion and utilization. Experimental, theoretical, analytical, and numerical concepts and methods are presented. In particular we report on new aspects resulting from the combination of basic research, especially in the field of turbulence and complex stochastic systems, with engineering applications.

  15. A study of clear-air turbulence from detailed wind profiles over Cape Kennedy, Florida

    E-Print Network [OSTI]

    Blackburn, James Harvey

    1969-01-01T23:59:59.000Z

    A STUDY OF CLEAR-AIR TURBULENCE FROM DETAII. ED WIND PROFILES OVER CAPE KENNEDY, FLORIDA A Thesis by James Harvey Blackburn, Jr. Captain United States Air Force Approved as to style and content by: (Chairman of ittee) (Head of Dep tment...) (Amber) (Member) May 1969 ABSTRACT A Study of Clear-Air Turbulence from Detailed Wind Profiles Over Cape Kennedy, Florida. James H. Blackburn, Jr. , B. S. , Texas A6N University Directed by: Dr. James R. Scoggins Clear-air turbulence (CAT...

  16. Turbulence in Line-Driven Stellar Winds By Stanley P. Owocki

    E-Print Network [OSTI]

    Owocki, Stanley P.

    -scattering of the star's continuum radiation. This line-driving mechanism is understood to be highly unstable to small the inherently non-local radiative transfer in the large number of wind-driving lines. Results of 1-D simulationsTurbulence in Line-Driven Stellar Winds By Stanley P. Owocki Bartol Research Institute, University

  17. Turbulence in LineDriven Stellar Winds By Stanley P. Owocki

    E-Print Network [OSTI]

    Owocki, Stanley P.

    ­scattering of the star's continuum radiation. This line­driving mechanism is understood to be highly unstable to small the inherently non­local radiative transfer in the large number of wind­driving lines. Results of 1­D simulationsTurbulence in Line­Driven Stellar Winds By Stanley P. Owocki Bartol Research Institute, University

  18. ENHANCED DISSIPATION RATE OF MAGNETIC FIELD IN STRIPED PULSAR WINDS BY THE EFFECT OF TURBULENCE

    SciTech Connect (OSTI)

    Takamoto, Makoto [Department of Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan); Inoue, Tsuyoshi [Department of Physics and Mathematics, Aoyama Gakuin University, Fuchinobe, Chuou-ku, Sagamihara 252-5258 (Japan); Inutsuka, Shu-ichiro, E-mail: takamoto@tap.scphys.kyoto-u.ac.jp, E-mail: inouety@phys.aoyama.ac.jp, E-mail: inutsuka@nagoya-u.jp [Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)

    2012-08-10T23:59:59.000Z

    In this paper, we report on turbulent acceleration of the dissipation of the magnetic field in the post-shock region of a Poynting flux-dominated flow, such as the Crab pulsar wind nebula. We have performed two-dimensional resistive relativistic magnetohydrodynamics simulations of subsonic turbulence driven by the Richtmyer-Meshkov instability at the shock fronts of the Poynting flux-dominated flows in pulsar winds. We find that turbulence stretches current sheets which substantially enhances the dissipation of the magnetic field, and that most of the initial magnetic field energy is dissipated within a few eddy-turnover times. We also develop a simple analytical model for turbulent dissipation of the magnetic field that agrees well with our simulations. The analytical model indicates that the dissipation rate does not depend on resistivity even in the small resistivity limit. Our findings can possibly alleviate the {sigma}-problem in the Crab pulsar wind nebulae.

  19. Inter-annual Variability of Wind Indices across Europe

    E-Print Network [OSTI]

    Pryor, Sara C.

    Energy, Ris National Laboratory, DK-4000 Roskilde, Denmark and Atmospheric Science Program, Department, including wind energy. However, relatively little research has been conducted to assess the historical variability of wind energy density across different spatial scales or the degree to which one can derive

  20. Permutation Entropy and Statistical Complexity Analysis of Turbulence in Laboratory Plasmas and the Solar Wind

    E-Print Network [OSTI]

    Weck, Peter J; Brown, Michael R; Wicks, Robert T

    2014-01-01T23:59:59.000Z

    The Bandt-Pompe permutation entropy and the Jensen-Shannon statistical complexity are used to analyze fluctuating time series of three different plasmas: the magnetohydrodynamic (MHD) turbulence in the plasma wind tunnel of the Swarthmore Spheromak Experiment (SSX), drift-wave turbulence of ion saturation current fluctuations in the edge of the Large Plasma Device (LAPD) and fully-developed turbulent magnetic fluctuations of the solar wind taken from the WIND spacecraft. The entropy and complexity values are presented as coordinates on the CH plane for comparison among the different plasma environments and other fluctuation models. The solar wind is found to have the highest permutation entropy and lowest statistical complexity of the three data sets analyzed. Both laboratory data sets have larger values of statistical complexity, suggesting these systems have fewer degrees of freedom in their fluctuations, with SSX magnetic fluctuations having slightly less complexity than the LAPD edge fluctuations. The CH ...

  1. Variable diameter wind turbine rotor blades

    DOE Patents [OSTI]

    Jamieson, Peter McKeich; Hornzee-Jones, Chris; Moroz, Emilian M.; Blakemore, Ralph W.

    2005-12-06T23:59:59.000Z

    A system and method for changing wind turbine rotor diameters to meet changing wind speeds and control system loads is disclosed. The rotor blades on the wind turbine are able to adjust length by extensions nested within or containing the base blade. The blades can have more than one extension in a variety of configurations. A cable winching system, a hydraulic system, a pneumatic system, inflatable or elastic extensions, and a spring-loaded jack knife deployment are some of the methods of adjustment. The extension is also protected from lightning by a grounding system.

  2. Analyzing Effects of Turbulence on Power Generation Using Wind Plant Monitoring Data: Preprint

    SciTech Connect (OSTI)

    Zhang, J.; Chowdhury, S.; Hodge, B. M.

    2014-01-01T23:59:59.000Z

    In this paper, a methodology is developed to analyze how ambient and wake turbulence affects the power generation of a single wind turbine within an array of turbines. Using monitoring data from a wind power plant, we selected two sets of wind and power data for turbines on the edge of the wind plant that resemble (i) an out-of-wake scenario (i.e., when the turbine directly faces incoming winds) and (ii) an in-wake scenario (i.e., when the turbine is under the wake of other turbines). For each set of data, two surrogate models were then developed to represent the turbine power generation (i) as a function of the wind speed; and (ii) as a function of the wind speed and turbulence intensity. Support vector regression was adopted for the development of the surrogate models. Three types of uncertainties in the turbine power generation were also investigated: (i) the uncertainty in power generation with respect to the published/reported power curve, (ii) the uncertainty in power generation with respect to the estimated power response that accounts for only mean wind speed; and (iii) the uncertainty in power generation with respect to the estimated power response that accounts for both mean wind speed and turbulence intensity. Results show that (i) under the same wind conditions, the turbine generates different power between the in-wake and out-of-wake scenarios, (ii) a turbine generally produces more power under the in-wake scenario than under the out-of-wake scenario, (iii) the power generation is sensitive to turbulence intensity even when the wind speed is greater than the turbine rated speed, and (iv) there is relatively more uncertainty in the power generation under the in-wake scenario than under the out-of-wake scenario.

  3. Scaling Laws of Turbulence and Heating of Fast Solar Wind: The Role of Density Fluctuations

    SciTech Connect (OSTI)

    Carbone, V. [Dipartimento di Fisica, Universita della Calabria, Ponte Bucci 31C, I-87036 Rende (Italy); Liquid Crystal Laboratory, INFM/CNR, Ponte Bucci 33B, I-87036 Rende (Italy); Marino, R. [Dipartimento di Fisica, Universita della Calabria, Ponte Bucci 31C, I-87036 Rende (Italy); University of Nice Sophia Antipolis, CNRS, Observatoire de la Cote d'Azur, B.P. 4229, 06304 Nice Cedex 4 (France); Sorriso-Valvo, L. [Liquid Crystal Laboratory, INFM/CNR, Ponte Bucci 33B, I-87036 Rende (Italy); Noullez, A. [University of Nice Sophia Antipolis, CNRS, Observatoire de la Cote d'Azur, B.P. 4229, 06304 Nice Cedex 4 (France); Bruno, R. [Istituto di Fisica dello Spazio Interplanetario-INAF, via Fosso del Cavaliere Roma (Italy)

    2009-08-07T23:59:59.000Z

    Incompressible and isotropic magnetohydrodynamic turbulence in plasmas can be described by an exact relation for the energy flux through the scales. This Yaglom-like scaling law has been recently observed in the solar wind above the solar poles observed by the Ulysses spacecraft, where the turbulence is in an Alfvenic state. An analogous phenomenological scaling law, suitably modified to take into account compressible fluctuations, is observed more frequently in the same data set. Large-scale density fluctuations, despite their low amplitude, thus play a crucial role in the basic scaling properties of turbulence. The turbulent cascade rate in the compressive case can, moreover, supply the energy dissipation needed to account for the local heating of the nonadiabatic solar wind.

  4. Solar Wind Electrons and Langmuir Turbulence , D.E. Larson

    E-Print Network [OSTI]

    California at Berkeley, University of

    electron VDFs contain high-energy tail [9] which is typically described as thermal core plus superthermal are in dynamical equilibrium with quasi-thermal noise turbulence. Customary theories of superthermal electrons

  5. A turbulence-driven model for heating and acceleration of the fast wind in coronal holes

    E-Print Network [OSTI]

    Verdini, A; Matthaeus, W H; Oughton, S; Dmitruk, P

    2009-01-01T23:59:59.000Z

    A model is presented for generation of fast solar wind in coronal holes, relying on heating that is dominated by turbulent dissipation of MHD fluctuations transported upwards in the solar atmosphere. Scale-separated transport equations include large-scale fields, transverse Alfvenic fluctuations, and a small compressive dissipation due to parallel shears near the transition region. The model accounts for proton temperature, density, wind speed, and fluctuation amplitude as observed in remote sensing and in situ satellite data.

  6. A Comparison of Wind Turbine Load Statistics for Inflow Turbulence Fields based on Conventional

    E-Print Network [OSTI]

    Manuel, Lance

    A Comparison of Wind Turbine Load Statistics for Inflow Turbulence Fields based on Conventional turbine load statistics for design. There are not many published studies that have addressed the issue of such optimal space-time resolution. This study in- vestigates turbine extreme and fatigue load statistics

  7. TURBULENT PRESSURE IN THE ENVELOPES OF YELLOW HYPERGIANTS AND LUMINOUS BLUE VARIABLES

    E-Print Network [OSTI]

    TURBULENT PRESSURE IN THE ENVELOPES OF YELLOW HYPERGIANTS AND LUMINOUS BLUE VARIABLES Richard B turbulent pressure) affects the structure and stability of luminous post­red-supergiant stars is critically and generates energetic shocks or if convection is unable to transport all of the super-Eddington luminous flux

  8. Atmospheric and Wake Turbulence Impacts on Wind Turbine Fatigue Loading: Preprint

    SciTech Connect (OSTI)

    Lee, S.; Churchfield, M.; Moriarty, P.; Jonkman, J.; Michalakes, J.

    2011-12-01T23:59:59.000Z

    Large-eddy simulations of atmospheric boundary layers under various stability and surface roughness conditions are performed to investigate the turbulence impact on wind turbines. In particular, the aeroelastic responses of the turbines are studied to characterize the fatigue loading of the turbulence present in the boundary layer and in the wake of the turbines. Two utility-scale 5 MW turbines that are separated by seven rotor diameters are placed in a 3 km by 3 km by 1 km domain. They are subjected to atmospheric turbulent boundary layer flow and data is collected on the structural response of the turbine components. The surface roughness was found to increase the fatigue loads while the atmospheric instability had a small influence. Furthermore, the downstream turbines yielded higher fatigue loads indicating that the turbulent wakes generated from the upstream turbines have significant impact.

  9. Laboratory implementation of variable-speed wind turbine generation

    SciTech Connect (OSTI)

    Zinger, D.S. [Northern Illinois University, DeKalb, IL (United States)] [Northern Illinois University, DeKalb, IL (United States); Miller, A.A. [Univ. of Idaho, Moscow, ID (United States)] [Univ. of Idaho, Moscow, ID (United States); Muljadi, E.; Butterfield, C.P.; Robinson, M.C. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States)

    1996-07-01T23:59:59.000Z

    To improve the performance of wind turbines, various control schemes such as variable speed operation have been proposed. Testing of these control algorithms on a full scale system is very expensive. To test these systems simulation, we developed programs and small scale laboratory experiments. We used this system to verify a control method that attempts to keep the turbine operating at its peak power coefficient. Both the simulations and the experiments verified the principle of operation of this control scheme.

  10. Hydrodynamical adaptive mesh refinement simulations of turbulent flows - I. Substructure in a wind

    E-Print Network [OSTI]

    Iapichino, L; Schmidt, W; Niemeyer, J C

    2008-01-01T23:59:59.000Z

    The problem of the resolution of turbulent flows in adaptive mesh refinement (AMR) simulations is investigated by means of 3D hydrodynamical simulations in an idealised setup, representing a moving subcluster during a merger event. AMR simulations performed with the usual refinement criteria based on local gradients of selected variables do not properly resolve the production of turbulence downstream of the cluster. Therefore we apply novel AMR criteria which are optimised to follow the evolution of a turbulent flow. We demonstrate that these criteria provide a better resolution of the flow past the subcluster, allowing us to follow the onset of the shear instability, the evolution of the turbulent wake and the subsequent back-reaction on the subcluster core morphology. We discuss some implications for the modelling of cluster cold fronts.

  11. Hydrodynamical adaptive mesh refinement simulations of turbulent flows - I. Substructure in a wind

    E-Print Network [OSTI]

    L. Iapichino; J. Adamek; W. Schmidt; J. C. Niemeyer

    2008-07-01T23:59:59.000Z

    The problem of the resolution of turbulent flows in adaptive mesh refinement (AMR) simulations is investigated by means of 3D hydrodynamical simulations in an idealised setup, representing a moving subcluster during a merger event. AMR simulations performed with the usual refinement criteria based on local gradients of selected variables do not properly resolve the production of turbulence downstream of the cluster. Therefore we apply novel AMR criteria which are optimised to follow the evolution of a turbulent flow. We demonstrate that these criteria provide a better resolution of the flow past the subcluster, allowing us to follow the onset of the shear instability, the evolution of the turbulent wake and the subsequent back-reaction on the subcluster core morphology. We discuss some implications for the modelling of cluster cold fronts.

  12. A study of clear-air turbulence from detailed wind profiles over Cape Kennedy, Florida

    E-Print Network [OSTI]

    Blackburn, James Harvey

    1969-01-01T23:59:59.000Z

    profiles (after Scoggins, 1967). Illustration of a smooth and an original scalar wind speed profiles. The solid line indicates the smoothed profile. . . . . . . . . . . . . . . Linear regression curves for rms-r versus AV/AZ over 250-m, 500-m, and 1000-m... and Panofsky (oa. cit. ) derived a CAT Index (I) which is proportional to the energy of the vertical component of turbulence. This expression is given by 2 I = (AV) (I - Ri/Ri . ) where QV is the magnitude of the vector difference in wind velocity over a...

  13. Solar wind turbulence from MHD to sub-ion scales: high-resolution hybrid simulations

    E-Print Network [OSTI]

    Franci, Luca; Matteini, Lorenzo; Landi, Simone; Hellinger, Petr

    2015-01-01T23:59:59.000Z

    We present results from a high-resolution and large-scale hybrid (fluid electrons and particle-in-cell protons) two-dimensional numerical simulation of decaying turbulence. Two distinct spectral regions (separated by a smooth break at proton scales) develop with clear power-law scaling, each one occupying about a decade in wave numbers. The simulation results exhibit simultaneously several properties of the observed solar wind fluctuations: spectral indices of the magnetic, kinetic, and residual energy spectra in the magneto-hydrodynamic (MHD) inertial range along with a flattening of the electric field spectrum, an increase in magnetic compressibility, and a strong coupling of the cascade with the density and the parallel component of the magnetic fluctuations at sub-proton scales. Our findings support the interpretation that in the solar wind large-scale MHD fluctuations naturally evolve beyond proton scales into a turbulent regime that is governed by the generalized Ohm's law.

  14. Turbulence descriptors for scaling fatigue loading spectra of wind turbine structural components

    SciTech Connect (OSTI)

    Kelley, N.D.

    1994-07-01T23:59:59.000Z

    The challenge for the designer in developing a new wind turbine is to incorporate sufficient strength in its components to safely achieve a 20- or 30-year service life. To accomplish this, the designer must understand the load and stress distributions (in a statistical sense at least) that the turbine is likely to encounter during its operating life. Sources of loads found in the normal operating environment include start/stop cycles, emergency shutdowns, the turbulence environment associated with the specific site and turbine location, and extreme or ``rare`` events that can challenge the turbine short-term survivability. Extreme events can result from an operational problem (e.g., controller failure) or violent atmospheric phenomena (tornadic circulations, strong gust fronts). For the majority of the operating time, however, the character of the turbulent inflow is the dominant source of the alternating stress distributions experienced by the structural components. Methods of characterizing or scaling the severity of the loading spectra (or the rate of fatigue damage accumulation) must be applicable to a wide range of turbulent inflow environments -- from solitary isolation to the complex flows associated with multi-row wind farms. The metrics chosen must be related to the properties of the turbulent inflow and independent of the nature of local terrain features.

  15. Wind reversals in turbulent Rayleigh-Benard convection

    E-Print Network [OSTI]

    Francisco Fontenele Araujo; S. Grossmann; D. Lohse

    2005-08-29T23:59:59.000Z

    The phenomenon of irregular cessation and subsequent reversal of the large-scale circulation in turbulent Rayleigh-B\\'enard convection is theoretically analysed. The force and thermal balance on a single plume detached from the thermal boundary layer yields a set of coupled nonlinear equations, whose dynamics is related to the Lorenz equations. For Prandtl and Rayleigh numbers in the range $10^{-2} \\leq \\Pr \\leq 10^{3}$ and $10^{7} \\leq \\Ra \\leq 10^{12}$, the model has the following features: (i) chaotic reversals may be exhibited at Ra $\\geq 10^{7}$; (ii) the Reynolds number based on the root mean square velocity scales as $\\Re_{rms} \\sim \\Ra^{[0.41 ... 0.47]}$ (depending on Pr), and as $\\Re_{rms} \\sim \\Pr^{-[0.66 ... 0.76]}$ (depending on Ra); and (iii) the mean reversal frequency follows an effective scaling law $\\omega / (\

  16. Variable speed wind turbine generator with zero-sequence filter

    DOE Patents [OSTI]

    Muljadi, E.

    1998-08-25T23:59:59.000Z

    A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility. 14 figs.

  17. Variable speed wind turbine generator with zero-sequence filter

    DOE Patents [OSTI]

    Muljadi, Eduard (Golden, CO)

    1998-01-01T23:59:59.000Z

    A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.

  18. Variable Speed Wind Turbine Generator with Zero-sequence Filter

    DOE Patents [OSTI]

    Muljadi, Eduard (Golden, CO)

    1998-08-25T23:59:59.000Z

    A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.

  19. POWER ANISOTROPY IN THE MAGNETIC FIELD POWER SPECTRAL TENSOR OF SOLAR WIND TURBULENCE

    SciTech Connect (OSTI)

    Wicks, R. T.; Horbury, T. S. [Physics Department, Imperial College London, London SW7 2AZ (United Kingdom); Forman, M. A. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11790-3800 (United States); Oughton, S., E-mail: r.wicks@imperial.ac.uk [Department of Mathematics, University of Waikato, Hamilton (New Zealand)

    2012-02-10T23:59:59.000Z

    We observe the anisotropy of the power spectral tensor of magnetic field fluctuations in the fast solar wind for the first time. In heliocentric RTN coordinates, the power in each element of the tensor has a unique dependence on the angle between the magnetic field and velocity of the solar wind ({theta}{sub B}) and the angle of the vector in the plane perpendicular to the velocity ({phi}{sub B}). We derive the geometrical effect of the high speed flow of the solar wind past the spacecraft on the power spectrum in the frame of the plasma P(k) to arrive at the observed power spectrum P(f, {theta}{sub B}, {phi}{sub B}) based on a scalar field description of turbulence theory. This allows us to predict the variation in the {phi}{sub B} direction and compare it to the data. We then transform the observations from RTN coordinates to magnetic-field-aligned coordinates. The observed reduced power spectral tensor matches the theoretical predictions we derive in both RTN and field-aligned coordinates, which means that the local magnetic field we calculate with wavelet envelope functions is an accurate representation of the physical axis of symmetry for the turbulence and implies that on average the turbulence is axisymmetric. We also show that we can separate the dominant toroidal component of the turbulence from the smaller but significant poloidal component and that these have different power anisotropy. We also conclude that the magnetic helicity is anisotropic and mostly two dimensional, arising from wavevectors largely confined to the plane perpendicular to B .

  20. Imprints of expansion onto the local anisotropy of solar wind turbulence

    E-Print Network [OSTI]

    Verdini, Andrea

    2015-01-01T23:59:59.000Z

    We study the anisotropy of II-order structure functions defined in a frame attached to the local mean field in three-dimensional (3D) direct numerical simulations of magnetohydrodynamic turbulence, including or not the solar wind expansion. We simulate spacecraft flybys through the numerical domain by taking increments along the radial (wind) direction that forms an angle of $45^o$ with the ambient magnetic field. We find that only when expansion is taken into account, do the synthetic observations match the 3D anisotropy observed in the solar wind, including the change of anisotropy with scales. Our simulations also show that the anisotropy changes dramatically when considering increments oblique to the radial directions. Both results can be understood by noting that expansion reduces the radial component of the magnetic field at all scales, thus confining fluctuations in the plane perpendicular to the radial. Expansion is thus shown to affect not only the (global) spectral anisotropy, but also the local ani...

  1. Nonlinear interaction of proton whistler with kinetic Alfvn wave to study solar wind turbulence

    SciTech Connect (OSTI)

    Goyal, R.; Sharma, R. P. [Centre for Energy Studies, Indian Institute of Technology, Delhi-110016 (India)] [Centre for Energy Studies, Indian Institute of Technology, Delhi-110016 (India); Goldstein, M. L. [NASA Goddard Space Flight Centre, Code 673, Greenbelt, Maryland 20771 (United States)] [NASA Goddard Space Flight Centre, Code 673, Greenbelt, Maryland 20771 (United States); Dwivedi, N. K. [Austrian Academy of Sciences, Space Research Institute, Schmiedlstrasse 6, 8042 Graz (Austria)] [Austrian Academy of Sciences, Space Research Institute, Schmiedlstrasse 6, 8042 Graz (Austria)

    2013-12-15T23:59:59.000Z

    This paper presents the nonlinear interaction between small but finite amplitude kinetic Alfvn wave (KAW) and proton whistler wave using two-fluid model in intermediate beta plasma, applicable to solar wind. The nonlinearity is introduced by modification in the background density. This change in density is attributed to the nonlinear ponderomotive force due to KAW. The solutions of the model equations, governing the nonlinear interaction (and its effect on the formation of localized structures), have been obtained using semi-analytical method in solar wind at 1AU. It is concluded that the KAW properties significantly affect the threshold field required for the filament formation and their critical size (for proton whistler). The magnetic and electric field power spectra have been obtained and their relevance with the recent observations of solar wind turbulence by Cluster spacecraft has been pointed out.

  2. Sliding Mode Power Control of Variable Speed Wind Energy Conversion Systems

    E-Print Network [OSTI]

    Boyer, Edmond

    Sliding Mode Power Control of Variable Speed Wind Energy Conversion Systems B. Beltran, T. Ahmed power generation in variable speed wind energy conversion systems (VS-WECS). These systems have two variations. Index Terms--Wind energy conversion system, power generation control, sliding mode control

  3. Wind Power Variability, Its Cost, and Effect on Power Plant Emissions

    E-Print Network [OSTI]

    Wind Power Variability, Its Cost, and Effect on Power Plant Emissions A Dissertation Submitted The recent growth in wind power is transforming the operation of electricity systems by introducing. As a result, system operators are learning in real-time how to incorporate wind power and its variability

  4. The Impacts of Wind Speed Trends and Long-term Variability in Relation to Hydroelectric

    E-Print Network [OSTI]

    Kohfeld, Karen

    and Long-term Variability in Relation to Hydroelectric Reservoir Inflows on Wind Power in the Pacific through diversification. In hydroelectric dominated systems, like the PNW, the benefits of wind power can diversification can be maximized. Keywords: Wind power; Hydroelectricity; Renewable energy; Climate variability

  5. Modelling and Analysis of Variable Speed Wind Turbines with Induction Generator during Grid

    E-Print Network [OSTI]

    Hansen, Ren Rydhof

    Modelling and Analysis of Variable Speed Wind Turbines with Induction Generator during Grid Fault to the grid connection of wind turbines. The second chapter elucidates recent thinking in the area of grid Ris National Laboratory Vestas Wind Systems A/S #12;#12;I Modelling and Analysis of Variable Speed

  6. Control strategy of a variable speed wind turbine with multipole permanent magnet synchronous generator

    E-Print Network [OSTI]

    values. Keywords: permanent magnet synchronous generator, variable speed wind turbine, direct driven wind). A multipole synchronous generator connected to a power converter can operate at low speeds, so that a gear canControl strategy of a variable speed wind turbine with multipole permanent magnet synchronous

  7. Optimization of Wind Power and Its Variability With a Computational Intelligence Approach

    E-Print Network [OSTI]

    Kusiak, Andrew

    Optimization of Wind Power and Its Variability With a Computational Intelligence Approach Zijun is presented for maximizing the generation of wind power while minimizing its variability. In the optimization model, data-driven approaches are used to model the wind-power generation process based on industrial

  8. The Association of Large-Scale Climate Variability and Teleconnections on Wind Energy Resource

    E-Print Network [OSTI]

    The Association of Large-Scale Climate Variability and Teleconnections on Wind Energy Resource over on Wind Energy Resource over Europe and its Intermittency Pascal Kriesche* and Adam Schlosser* Abstract

  9. The signature of evolving turbulence in quiet solar wind as seen by ULYSSES

    E-Print Network [OSTI]

    R. M. Nicol; S. C. Chapman; R. O. Dendy

    2008-02-18T23:59:59.000Z

    Solar wind fluctuations, such as magnetic field or velocity, show power law power spectra suggestive both of an inertial range of intermittent turbulence (with $\\sim -5/3$ exponent) and at lower frequencies, of fluctuations of coronal origin (with $\\sim -1$ exponent). The ULYSSES spacecraft spent many months in the quiet fast solar wind above the Sun's polar coronal holes in a highly ordered magnetic field. We use statistical analysis methods such as the generalized structure function (GSF) and extended self-similarity (ESS) to quantify the scaling of the moments of the probability density function of fluctuations in the magnetic field. The GSFs give power law scaling in the ``$f^{-1}$'' range of the form $\\sim\\tau^{\\zeta(m)}$, but ESS is required to reveal scaling in the inertial range, which is of the form $\\sim [g(\\tau)]^{\\zeta(m)}$. We find that $g(\\tau)$ is independent of spacecraft position and $g(\\tau)\\sim\\tau^{-log_{10}(\\tilde{\\lambda}\\tau)}$. The ``$f^{-1}$'' scaling fluctuates with radial spacecraft position. This confirms that, whereas the ``$f^{-1}$'' fluctuations are directly influenced by the corona, the inertial range fluctuations are consistent with locally evolving turbulence, but with an ``envelope'' $g(\\tau)$, which captures the formation of the quiet fast solar wind.

  10. Full vector (3-D) inflow simulation in natural and wind farm environments using an expanded version of the SNLWIND (Veers) turbulence code

    SciTech Connect (OSTI)

    Kelley, N.D.

    1992-11-01T23:59:59.000Z

    We have recently expanded the numerical turbulence simulation (SNLWIND) developed by Veers [1] to include all three components of the turbulent wind vector. We have also configured the code to simulate the characteristics of turbulent wind fields upwind and downwind of a large wind farm, as well as over uniform, flat terrain. Veers`s original method only simulates the longitudinal component of the wind in neutral flow. This paper overviews the development of spectral distribution, spatial coherence, and cross correlation models used to expired the SNLWIND code to include the three components of the turbulent wind over a range of atmospheric stabilities. These models are based on extensive measurements of the turbulence characteristics immediately upwind and downwind of a large wind farm in San Gorgonio Pass, California.

  11. Full vector (3-D) inflow simulation in natural and wind farm environments using an expanded version of the SNLWIND (Veers) turbulence code

    SciTech Connect (OSTI)

    Kelley, N.D.

    1992-11-01T23:59:59.000Z

    We have recently expanded the numerical turbulence simulation (SNLWIND) developed by Veers [1] to include all three components of the turbulent wind vector. We have also configured the code to simulate the characteristics of turbulent wind fields upwind and downwind of a large wind farm, as well as over uniform, flat terrain. Veers's original method only simulates the longitudinal component of the wind in neutral flow. This paper overviews the development of spectral distribution, spatial coherence, and cross correlation models used to expired the SNLWIND code to include the three components of the turbulent wind over a range of atmospheric stabilities. These models are based on extensive measurements of the turbulence characteristics immediately upwind and downwind of a large wind farm in San Gorgonio Pass, California.

  12. Chaotic mean wind in turbulent thermal convection and long-term correlations in solar activity

    E-Print Network [OSTI]

    A. Bershadskii

    2009-12-25T23:59:59.000Z

    It is shown that correlation function of the mean wind velocity in a turbulent thermal convection (Rayleigh number $Ra \\sim 10^{11}$) exhibits exponential decay with a very long correlation time, while corresponding largest Lyapunov exponent is certainly positive. These results together with the reconstructed phase portrait indicate presence of a chaotic component in the examined mean wind. Telegraph approximation is also used to study relative contribution of the chaotic and stochastic components to the mean wind fluctuations and an equilibrium between these components has been studied. Since solar activity is based on the thermal convection processes, it is reasoned that the observed solar activity long-term correlations can be an imprint of the mean wind chaotic properties. In particular, correlation function of the daily sunspots number exhibits exponential decay with a very long correlation time and corresponding largest Lyapunov exponent is certainly positive, also relative contribution of the chaotic and stochastic components follows the same pattern as for the convection mean wind.

  13. EFFECT OF PITCH CONTROL AND POWER CONDITIONING ON POWER QUALITY OF VARIABLE SPEED WIND TURBINE GENERATORS

    E-Print Network [OSTI]

    EFFECT OF PITCH CONTROL AND POWER CONDITIONING ON POWER QUALITY OF VARIABLE SPEED WIND TURBINE), Curtin University of Technology, WA Abstract: Variable speed wind turbine generators provide the opportunity to capture more power than fixed speed turbines. However the variable speed machine output can

  14. Flow visualization using momentum and energy transport tubes and applications to turbulent flow in wind farms

    E-Print Network [OSTI]

    Meyers, Johan

    2012-01-01T23:59:59.000Z

    As a generalization of the mass-flux based classical stream-tube, the concept of momentum and energy transport tubes is discussed as a flow visualization tool. These transport tubes have the property, respectively, that no fluxes of momentum or energy exist over their respective tube mantles. As an example application using data from large-eddy simulation, such tubes are visualized for the mean-flow structure of turbulent flow in large wind farms, in fully developed wind-turbine-array boundary layers. The three-dimensional organization of energy transport tubes changes considerably when turbine spacings are varied, enabling the visualization of the path taken by the kinetic energy flux that is ultimately available at any given turbine within the array.

  15. Inertial-Range Reconnection in Magnetohydrodynamic Turbulence and in the Solar Wind

    E-Print Network [OSTI]

    Lalescu, Cristian C; Eyink, Gregory L; Drivas, Theodore D; Vishniac, Ethan T; Lazarian, Alexander

    2015-01-01T23:59:59.000Z

    In situ spacecraft data on the solar wind show events identified as magnetic reconnection with outflows and apparent "`$X$-lines" $10^{3-4}$ times ion scales. To understand the role of turbulence at these scales, we make a case study of an inertial-range reconnection event in a magnetohydrodynamic (MHD) simulation. We observe stochastic wandering of field-lines in space, breakdown of standard magnetic flux-freezing due to Richardson dispersion, and a broadened reconnection zone containing many current sheets. The coarse-grain magnetic geometry is like large-scale reconnection in the solar wind, however, with a hyperbolic flux-tube or "$X$-line" extending over integral length-scales.

  16. Oscillation of bundle conductors in overhead lines due to turbulent wind

    SciTech Connect (OSTI)

    Diana, G.; Cheli, F. (Politecnico di Milano, Milano (IT)); Manenti, A. (Universita degli Studi di Brescia, Brescia (IT)); Nicolini, P.; Tavano, F. (ENEL/CREI, Milano (IT))

    1990-10-01T23:59:59.000Z

    Due to the wind, the bundle conductors in overhead lines can oscillate and the distance between the phases can be reduced. This kind of movement may be caused by: non expansive oscillations of the phases due to the wind turbulence and to the correlated variations of the bundles aerodynamic coefficients during the movement (buffeting); expansive oscillations, or galloping, of the phases due to the unstable aerodynamic shapes that bundles may assume in presence of ice. This paper presents an analytical methodology to examine the dynamic behaviour of bundles subjected to the above mentioned phenomena. The results obtained during experiments carried out on a span of an energized 420-kV line equipped with triple bundles and subjected to oscillations due to buffeting are exposed. Lastly, the experimental data are compared with the analytical results.

  17. Systematic Controller Design Methodology for Variable-Speed Wind Turbines

    SciTech Connect (OSTI)

    Hand, M. M.; Balas, M. J.

    2002-02-01T23:59:59.000Z

    Variable-speed, horizontal axis wind turbines use blade-pitch control to meet specified objectives for three operational regions. This paper provides a guide for controller design for the constant power production regime. A simple, rigid, non-linear turbine model was used to systematically perform trade-off studies between two performance metrics. Minimization of both the deviation of the rotor speed from the desired speed and the motion of the actuator is desired. The robust nature of the proportional-integral-derivative controller is illustrated, and optimal operating conditions are determined. Because numerous simulation runs may be completed in a short time, the relationship between the two opposing metrics is easily visualized.

  18. ON QUIET-TIME SOLAR WIND ELECTRON DISTRIBUTIONS IN DYNAMICAL EQUILIBRIUM WITH LANGMUIR TURBULENCE

    SciTech Connect (OSTI)

    Zaheer, S. [Permanent address: Department of Physics, Forman Christian College, Lahore, Punjab 54000, Pakistan. (Pakistan); Yoon, P. H. [Also at SSR, KHU, Yongin, Korea. (Korea, Republic of)

    2013-10-01T23:59:59.000Z

    A recent series of papers put forth a self-consistent theory of an asymptotically steady-state electron distribution function and Langmuir turbulence intensity. The theory was developed in terms of the ? distribution which features Maxwellian low-energy electrons and a non-Maxwellian energetic power-law tail component. The present paper discusses a generalized ? distribution that features a Davydov-Druyvesteyn type of core component and an energetic power-law tail component. The physical motivation for such a generalization is so that the model may reflect the influence of low-energy electrons interacting with low-frequency kinetic Alfvnic turbulence as well as with high-frequency Langmuir turbulence. It is shown that such a solution and the accompanying Langmuir wave spectrum rigorously satisfy the balance requirement between the spontaneous and induced emission processes in both the particle and wave kinetic equations, and approximately satisfy the similar balance requirement between the spontaneous and induced scattering processes, which are nonlinear. In spite of the low velocity modification of the electron distribution function, it is shown that the resulting asymptotic velocity power-law index ?, where f{sub e} ? v {sup ?} is close to the average index observed during the quiet-time solar wind condition, i.e., ? ? O(6.5) whereas ?{sub average} ? 6.69, according to observation.

  19. Grid Impacts of Wind Power Variability: Recent Assessments from a Variety of Utilities in the United States (Presentation)

    SciTech Connect (OSTI)

    Parsons, B.

    2006-03-01T23:59:59.000Z

    Presentation for the European Wind Energy Conference held February 27--March 2, 2006, in Athens, Greece, showing grid impacts of wind power variability.

  20. Co-existence of whistler waves with kinetic Alfven wave turbulence for the high-beta solar wind plasma

    SciTech Connect (OSTI)

    Mithaiwala, Manish; Crabtree, Chris; Ganguli, Gurudas [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375-5346 (United States); Rudakov, Leonid [Icarus Research Inc., P.O. Box 30780, Bethesda, Maryland 20824-0780 (United States)

    2012-10-15T23:59:59.000Z

    It is shown that the dispersion relation for whistler waves is identical for a high or low beta plasma. Furthermore, in the high-beta solar wind plasma, whistler waves meet the Landau resonance with electrons for velocities less than the thermal speed, and consequently, the electric force is small compared to the mirror force. As whistlers propagate through the inhomogeneous solar wind, the perpendicular wave number increases through refraction, increasing the Landau damping rate. However, the whistlers can survive because the background kinetic Alfven wave (KAW) turbulence creates a plateau by quasilinear (QL) diffusion in the solar wind electron distribution at small velocities. It is found that for whistler energy density of only {approx}10{sup -3} that of the kinetic Alfven waves, the quasilinear diffusion rate due to whistlers is comparable to KAW. Thus, very small amplitude whistler turbulence can have a significant consequence on the evolution of the solar wind electron distribution function.

  1. Assessing the Impact of Wind Variability on Power System Small-Signal Reachability

    E-Print Network [OSTI]

    Liberzon, Daniel

    Assessing the Impact of Wind Variability on Power System Small-Signal Reachability Yu Christine-signal and transient stability [6]. In this regard, it has been acknowledged that, as the presence of wind in the power balancing in near real time [7]. This paper focuses on this last problem--the impact of wind penetration

  2. Eddy Heat Flux in the Southern Ocean: Response to Variable Wind Forcing ANDREW MCC. HOGG

    E-Print Network [OSTI]

    Miami, University of

    Eddy Heat Flux in the Southern Ocean: Response to Variable Wind Forcing ANDREW MCC. HOGG Australian processes. The authors also test the model response to long-term changes in wind forcing, including steadily1925.1 2008 American Meteorological Society #12;Given the dominant role of wind forcing in the South

  3. Individual Pitch Control for Mitigation of Power Fluctuation of Variable Speed Wind Turbines

    E-Print Network [OSTI]

    Hu, Weihao

    Individual Pitch Control for Mitigation of Power Fluctuation of Variable Speed Wind Turbines, China mcheng@seu.edu.cn Abstract-- Grid connected wind turbines are the sources of power fluctuations presents an individual pitch control (IPC) strategy to mitigate the wind turbine power fluctuation at both

  4. The curvature of the wind profile as a factor in the formation of clear-air turbulence

    E-Print Network [OSTI]

    Possiel, Norman Charles

    1974-01-01T23:59:59.000Z

    &N University; Chairman of Advisory Committee: Dr. James R. Scoggins This study concerns the importance of the curvature of the wind profile to the amplitude of mountain waves. Mechanisms favor- able for clear-air turbulence (CAT) are discussed in relation... to such wave motions. Relationships between CAT encountered in the stratosphere by an XB-70 aircraft over mountain-wave areas and the curvature of the wind profile in the troposphere, are studied. Expected mountain- wave areas are defined from topographical...

  5. On the Loss of Wind-Induced Near-Inertial Energy to Turbulent Mixing in the Upper Ocean

    E-Print Network [OSTI]

    Miami, University of

    On the Loss of Wind-Induced Near-Inertial Energy to Turbulent Mixing in the Upper Ocean XIAOMING-inertial energy available for ocean mixing at depth is, at most, 0.1 TW. This confirms a recent suggestion energy source for the diapycnal mixing in the ocean required to maintain the meridional over- turning

  6. Power law burst and inter-burst interval distributions in the solar wind: turbulence or dissipative SOC ?

    E-Print Network [OSTI]

    M. P. Freeman; N. W. Watkins; D. J. Riley

    2000-06-28T23:59:59.000Z

    We calculate for the first time the probability density functions (PDFs) P of burst energy e, duration T and inter-burst interval tau for a known turbulent system in nature. Bursts in the earth-sun component of the Poynting flux at 1 AU in the solar wind were measured using the MFI and SWE experiments on the NASA WIND spacecraft. We find P(e) and P(T) to be power laws, consistent with self-organised criticality (SOC). We find also a power law form for P(tau) that distinguishes this turbulent cascade from the exponential P(tau) of ideal SOC, but not from some other SOC-like sandpile models. We discuss the implications for the relation between SOC and turbulence.

  7. Wake Turbulence of Two NREL 5-MW Wind Turbines Immersed in a Neutral Atmospheric Boundary-Layer Flow

    E-Print Network [OSTI]

    Bashioum, Jessica L; Schmitz, Sven; Duque, Earl P N

    2013-01-01T23:59:59.000Z

    The fluid dynamics video considers an array of two NREL 5-MW turbines separated by seven rotor diameters in a neutral atmospheric boundary layer (ABL). The neutral atmospheric boundary-layer flow data were obtained from a precursor ABL simulation using a Large-Eddy Simulation (LES) framework within OpenFOAM. The mean wind speed at hub height is 8m/s, and the surface roughness is 0.2m. The actuator line method (ALM) is used to model the wind turbine blades by means of body forces added to the momentum equation. The fluid dynamics video shows the root and tip vortices emanating from the blades from various viewpoints. The vortices become unstable and break down into large-scale turbulent structures. As the wakes of the wind turbines advect further downstream, smaller-scale turbulence is generated. It is apparent that vortices generated by the blades of the downstream wind turbine break down faster due to increased turbulence levels generated by the wake of the upstream wind turbine.

  8. Abstract--A variable speed wind turbine is presented in this paper, where multiple permanent magnet synchronous

    E-Print Network [OSTI]

    Chen, Zhe

    1 Abstract--A variable speed wind turbine is presented in this paper, where multiple permanent magnet synchronous generators (MPMSGs) drive-train configuration is employed in the wind turbine of this variable speed wind turbine based on multiple generators drive-train configuration. Index Terms--Wind power

  9. ENSEMBLE SIMULATIONS OF PROTON HEATING IN THE SOLAR WIND VIA TURBULENCE AND ION CYCLOTRON RESONANCE

    SciTech Connect (OSTI)

    Cranmer, Steven R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2014-07-01T23:59:59.000Z

    Protons in the solar corona and heliosphere exhibit anisotropic velocity distributions, violation of magnetic moment conservation, and a general lack of thermal equilibrium with the other particle species. There is no agreement about the identity of the physical processes that energize non-Maxwellian protons in the solar wind, but a traditional favorite has been the dissipation of ion cyclotron resonant Alfvn waves. This paper presents kinetic models of how ion cyclotron waves heat protons on their journey from the corona to interplanetary space. It also derives a wide range of new solutions for the relevant dispersion relations, marginal stability boundaries, and nonresonant velocity-space diffusion rates. A phenomenological model containing both cyclotron damping and turbulent cascade is constructed to explain the suppression of proton heating at low alpha-proton differential flow speeds. These effects are implemented in a large-scale model of proton thermal evolution from the corona to 1 AU. A Monte Carlo ensemble of realistic wind speeds, densities, magnetic field strengths, and heating rates produces a filled region of parameter space (in a plane described by the parallel plasma beta and the proton temperature anisotropy ratio) similar to what is measured. The high-beta edges of this filled region are governed by plasma instabilities and strong heating rates. The low-beta edges correspond to weaker proton heating and a range of relative contributions from cyclotron resonance. On balance, the models are consistent with other studies that find only a small fraction of the turbulent power spectrum needs to consist of ion cyclotron waves.

  10. Free and forced tropical variability: role of the wind-evaporation-sea surface temperature (WES) feedback

    E-Print Network [OSTI]

    Mahajan, Salil

    2009-05-15T23:59:59.000Z

    The Wind-Evaporation-Sea Surface Temperature (WES) feedback is believedto play an important role in the tropics, where climate variability is governed byatmosphere-ocean coupled interactions. This dissertation reports on studies to distinctlyisolate...

  11. Fixed-Speed and Variable-Slip Wind Turbines Providing Spinning Reserves to the Grid: Preprint

    SciTech Connect (OSTI)

    Muljadi, E.; Singh, M.; Gevorgian, V.

    2012-11-01T23:59:59.000Z

    As the level of wind penetration increases, wind turbine technology must move from merely generating power from wind to taking a role in supporting the bulk power system. Wind turbines should have the capability to provide inertial response and primary frequency (governor) response so they can support the frequency stability of the grid. To provide governor response, wind turbines should be able to generate less power than the available wind power and hold the rest in reserve, ready to be accessed as needed. This paper explores several ways to control wind turbine output to enable reserve-holding capability. This paper focuses on fixed-speed (also known as Type 1) and variable-slip (also known as Type 2) turbines.

  12. Low-Order Modelling of Blade-Induced Turbulence for RANS Actuator Disk Computations of Wind and Tidal Turbines

    E-Print Network [OSTI]

    Nishino, Takafumi

    2012-01-01T23:59:59.000Z

    Modelling of turbine blade-induced turbulence (BIT) is discussed within the framework of three-dimensional Reynolds-averaged Navier-Stokes (RANS) actuator disk computations. We first propose a generic (baseline) BIT model, which is applied only to the actuator disk surface, does not include any model coefficients (other than those used in the original RANS turbulence model) and is expected to be valid in the limiting case where BIT is fully isotropic and in energy equilibrium. The baseline model is then combined with correction functions applied to the region behind the disk to account for the effect of rotor tip vortices causing a mismatch of Reynolds shear stress between short- and long-time averaged flow fields. Results are compared with wake measurements of a two-bladed wind turbine model of Medici and Alfredsson [Wind Energy, Vol. 9, 2006, pp. 219-236] to demonstrate the capability of the new model.

  13. Variable enstrophy flux and energy spectrum in two-dimensional turbulence with Ekman friction

    E-Print Network [OSTI]

    Mahendra K. Verma

    2012-03-23T23:59:59.000Z

    Experiments and numerical simulations reveal that in the forward cascade regime, the energy spectrum of two-dimensional turbulence with Ekman friction deviates from Kraichnan's prediction of $k^{-3}$ power spectrum. In this letter we explain this observation using an analytic model based on variable enstrophy flux arising due to Ekman friction. We derive an expression for the enstrophy flux which exhibits a logarithmic dependence in the inertial range for the Ekman-friction dominated flows. The energy spectrum obtained using this enstrophy flux shows a power law scaling for large Reynolds number and small Ekman friction, but has an exponential behaviour for large Ekman friction and relatively small Reynolds number.

  14. A comparison of predicted and observed turbulent wind fields present in natural and internal wind park environments

    SciTech Connect (OSTI)

    Kelly, N D; Wright, A D

    1991-10-01T23:59:59.000Z

    This paper assesses the accuracy of simulated wind fields for both the natural flow and that within a wind park environment. The simulated fields are compared with the observed ones in both the time and frequency domains. Actual measurements of the wind fields and the derived kinematic scaling parameters upwind and downwind of a large San Gorgonio Pass wind park are used. The deviations in the modeled wind field from the observed are discussed. 10 refs., 6 figs., 2 tabs.

  15. Aspects of the theory of incompressible MHD turbulence with cross-helicity and applications to the solar wind

    SciTech Connect (OSTI)

    Podesta, John J [Los Alamos National Laboratory

    2010-12-03T23:59:59.000Z

    Solar wind observations have shown that the normalized cross-helicity {sigma}{sub c}, the ratio of the cross-helicity spectrum to the energy spectrum, is approximately constant, independent of wavenumber, throughout the inertial range. This means that the correlation between velocity and magnetic field fluctuations is the same at every scale, that the ratio of the two Elsasser energies (w{sup +}/w{sup -}){sup 2} is the same at every scale, and that the ratio of the energy cascade times of the two Elsasser energies {tau}{sup +}/{tau}{sup -} is the same at every scale. In the case when the magnetic Prandtl number is unity, it can be shown from the equations of incompressible MHD that if {sigma}{sub c} is a constant, then the cascade times of the two Elsasser energies are equal so that {tau}{sup +}/{tau}{sup -} = 1. This is an important constraint for turbulence theories. Using this result, the Goldreich and Sridhar theory and the Boldyrev theory are generalized to MHD turbulence with nonvanishing cross-helicity in such a way that the scaling laws of the original two theories are unchanged. The derivation and some of the important properties of these more general theories shall be presented. Solar wind measurements in support of these theoretical models will also be discussed. For example, new solar wind measurements of the total energy spectrum (kinetic plus magnetic) show that the power-law exponent is closer to 3/2 than 5/3, consistent with simulations of 3D incompressible MHD turbulence with a strong mean meagnetic field that show a 3/2 scaling. For highly Alfvenic, high cross-helicity solar wind turbulence, new measurements presented her show that the average spectral index is 1.540 {+-} 0.033.

  16. High-Speed Optical Spectroscopy of a Cataclysmic Variable Wind BZ Camelopardalis

    E-Print Network [OSTI]

    Ringwald, F A

    1997-01-01T23:59:59.000Z

    BZ Cam is the first cataclysmic variable star with an accretion disk wind evident in its optical spectrum. The wind was found by Thorstensen, who discovered intermittent P Cygni profiles occurring simultaneously in He I 5876 Angstroms and H alpha. We have since obtained spectra with 0.4-Angstroms/pixel dispersion and 60-s time resolution. We find a wind much faster and more rapidly variable than the radiatively accelerated winds of OB stars, Wolf-Rayet stars, or luminous blue variables. Instead of showing blob ejection, the whole wind of BZ Cam appears to turn on and off. We use this to measure the acceleration law of a CV wind for the first time. The velocity increases linearly with time, attaining blue edge velocities near -3000 km/s, and absorption velocities near -1700 km/s, in 6 to 8 min after starting near rest. We also find a subsequent linear deceleration to nearly rest in 30 to 40 min, perhaps an effect of dilution as the wind expands. No periodicity from rotational outflow is obvious. This wind is e...

  17. WindDriven Currents in a Sea with a Variable Eddy Viscosity Calculated via a SincGalerkin

    E-Print Network [OSTI]

    Bowers, Kenneth L.

    Wind­Driven Currents in a Sea with a Variable Eddy Viscosity Calculated via a Sinc.S.A. November 17, 1999 Short title: Wind­Driven Currents Calculated via a Sinc­Galerkin Technique Keywords: wind, a Sinc­Galerkin procedure is used to infer the sensitivity of wind­driven subsur­ face currents

  18. Variability of wind power near Oklahoma City and implications for siting of wind turbines

    SciTech Connect (OSTI)

    Kessler, E.; Eyster, R.

    1987-09-01T23:59:59.000Z

    Data from five sites near Oklahoma City were examined to assess wind power availability. Wind turbines of identical manufacture were operated at three of the sites, one of which was also equipped with anemometers on a 100-ft tower. Comprehensive anemometric data were available from the other two sites. The study indicates that the average wind speed varies substantially over Oklahoma's rolling plains, which have often been nominally regarded as flat for purposes of wind power generation. Average wind differences may be as much as 5 mph at 20 ft above ground level, and 7 mph at 100 ft above ground level for elevation differences of about 200 ft above mean sea level, even in the absence of substantial features of local terrain. Local altitude above mean sea level seems to be as influential as the shape of local terrain in determining the average wind speed. The wind turbine used at a meteorologically instrumented site in the study produced the power expected from it for the wind regime in which it was situated. The observed variations of local wind imply variations in annual kWh of as much as a factor of four between identical turbines located at similar heights above ground level in shallow valleys and on hilltops or elevated extended flat areas. 17 refs., 39 figs., 11 tabs.

  19. Adaptive pitch control for variable speed wind turbines

    DOE Patents [OSTI]

    Johnson, Kathryn E. (Boulder, CO); Fingersh, Lee Jay (Westminster, CO)

    2012-05-08T23:59:59.000Z

    An adaptive method for adjusting blade pitch angle, and controllers implementing such a method, for achieving higher power coefficients. Average power coefficients are determined for first and second periods of operation for the wind turbine. When the average power coefficient for the second time period is larger than for the first, a pitch increment, which may be generated based on the power coefficients, is added (or the sign is retained) to the nominal pitch angle value for the wind turbine. When the average power coefficient for the second time period is less than for the first, the pitch increment is subtracted (or the sign is changed). A control signal is generated based on the adapted pitch angle value and sent to blade pitch actuators that act to change the pitch angle of the wind turbine to the new or modified pitch angle setting, and this process is iteratively performed.

  20. Physics of Stratocumulus Top (POST): turbulent mixing across capping inversion

    E-Print Network [OSTI]

    2013-01-01T23:59:59.000Z

    vertical water potential horizontal wind, and turbulentof potential components of horizontal wind, and buoyantwater potential temperature, horizontal wind, and turbulent

  1. The Association of Large-Scale Climate Variability and Teleconnections on Wind Energy Resource over Europe and its Intermittency

    E-Print Network [OSTI]

    Kriesche, Pascal

    In times of increasing importance of wind power in the worlds energy mix, this study focuses on a better understanding of the influences of large-scale climate variability on wind power resource over Europe. The impact ...

  2. High-Speed Optical Spectroscopy of a Cataclysmic Variable Wind: BZ Camelopardalis

    E-Print Network [OSTI]

    F. A. Ringwald; T. Naylor

    1997-10-02T23:59:59.000Z

    BZ Cam is the first cataclysmic variable star with an accretion disk wind evident in its optical spectrum. The wind was found by Thorstensen, who discovered intermittent P Cygni profiles occurring simultaneously in He I 5876 Angstroms and H alpha. We have since obtained spectra with 0.4-Angstroms/pixel dispersion and 60-s time resolution. We find a wind much faster and more rapidly variable than the radiatively accelerated winds of OB stars, Wolf-Rayet stars, or luminous blue variables. Instead of showing blob ejection, the whole wind of BZ Cam appears to turn on and off. We use this to measure the acceleration law of a CV wind for the first time. The velocity increases linearly with time, attaining blue edge velocities near -3000 km/s, and absorption velocities near -1700 km/s, in 6 to 8 min after starting near rest. We also find a subsequent linear deceleration to nearly rest in 30 to 40 min, perhaps an effect of dilution as the wind expands. No periodicity from rotational outflow is obvious. This wind is erratic and incessantly variable, and perhaps bipolar and face-on, but not highly collimated. The P Cygni absorption events trace out sawtooth waves, occurring within 30 to 40 white dwarf radii from the disk. This is the approximate size of the disk, as well as the disk/wind transition region recently postulated by Knigge and Drew. We estimate a distance of 830 +/- 160 pc, and an orbital inclination i such that 12 < i(degrees) < 40.

  3. Empirical Analysis of the Variability of Wind Generation in India: Implications for Grid Integration

    SciTech Connect (OSTI)

    Phadke, Amol; Abhyankar, NIkit; Rao, Poorvi

    2014-06-17T23:59:59.000Z

    We analyze variability in load and wind generation in India to assess its implications for grid integration of large scale wind projects using actual wind generation and load data from two states in India, Karnataka and Tamil Nadu. We compare the largest variations in load and net load (load ?wind, i.e., load after integrating wind) that the generation fleet has to meet. In Tamil Nadu, where wind capacity is about 53percent of the peak demand, we find that the additional variation added due to wind over the current variation in load is modest; if wind penetration reaches 15percent and 30percent by energy, the additional hourly variation is less than 0.5percent and 4.5percent of the peak demand respectively for 99percent of the time. For wind penetration of 15percent by energy, Tamil Nadu system is found to be capable of meeting the additional ramping requirement for 98.8percent of the time. Potential higher uncertainty in net load compared to load is found to have limited impact on ramping capability requirements of the system if coal plants can me ramped down to 50percent of their capacity. Load and wind aggregation in Tamil Nadu and Karnataka is found to lower the variation by at least 20percent indicating the benefits geographic diversification. These findings suggest modest additional flexible capacity requirements and costs for absorbing variation in wind power and indicate that the potential capacity support (if wind does not generate enough during peak periods) may be the issue that has more bearing on the economics of integrating wind

  4. Turbulence

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron Spin Transition in2,EHSS A-Zand Analysis Utilities (TAU)TuningTurbulence

  5. Grid Impacts of Wind Power Variability: Recent Assessments from a Variety of Utilities in the United States; Preprint

    SciTech Connect (OSTI)

    Parsons, B.; Milligan, M.; Smith, J. C.; DeMeo, E.; Oakleaf, B.; Wolf, K.; Schuerger, M.; Zavadil, R.; Ahlstrom, M.; Nakafuji, D. Y.

    2006-07-01T23:59:59.000Z

    Because of wind power's unique characteristics, many concerns are based on the increased variability that wind contributes to the grid, and most U.S. studies have focused on this aspect of wind generation. Grid operators are also concerned about the ability to predict wind generation over several time scales. In this report, we quantify the physical impacts and costs of wind generation on grid operations and the associated costs.

  6. Power and spectral index anisotropy of the entire inertial range of turbulence in the fast solar wind

    E-Print Network [OSTI]

    Wicks, R T; Chen, C H K; Schekochihin, A A

    2010-01-01T23:59:59.000Z

    We measure the power and spectral index anisotropy of high speed solar wind turbulence from scales larger than the outer scale down to the ion gyroscale, thus covering the entire inertial range. We show that the power and spectral indices at the outer scale of turbulence are approximately isotropic. The turbulent cascade causes the power anisotropy at smaller scales manifested by anisotropic scalings of the spectrum: close to k^{-5/3} across and k^{-2} along the local magnetic field, consistent with a critically balanced Alfvenic turbulence. By using data at different radial distances from the Sun, we show that the width of the inertial range does not change with heliocentric distance and explain this by calculating the radial dependence of the ratio of the outer scale to the ion gyroscale. At the smallest scales of the inertial range, close to the ion gyroscale, we find an enhancement of power parallel to the magnetic field direction coincident with a decrease in the perpendicular power. This is most likely ...

  7. Effects of variable wind stress on ocean heat content

    E-Print Network [OSTI]

    Klima, Kelly

    2008-01-01T23:59:59.000Z

    Ocean heat content change (ocean heat uptake) has an important role in variability of the Earth's heat balance. The understanding of which methods and physical processes control ocean heat uptake needs improvement in order ...

  8. Solar-wind turbulence and shear: a superposed-epoch analysis of corotating interaction regions at 1 AU

    SciTech Connect (OSTI)

    Borovsky, Joseph E [Los Alamos National Laboratory; Denton, Michael H [LANCASTER UNIV.

    2009-01-01T23:59:59.000Z

    A superposed-epoch analysis of ACE and OMNI2 measurements is performed on 27 corotating interaction regions (CIRs) in 2003-2008, with the zero epoch taken to be the stream interface as determined by the maximum of the plasma vorticity. The structure of CIRs is investigated. When the flow measurements are rotated into the local-Parker-spiral coordinate system the shear is seen to be abrupt and intense, with vorticities on the order of 10{sup -5}-10{sup -4} sec{sup -1}. Converging flows perpendicular to the stream interface are seen in the local-Parker-spiral coordinate system and about half of the CIRs show a layer of divergent rebound flow away from the stream interface. Arguments indicate that any spreading of turbulence away from the region where it is produced is limited to about 10{sup 6} km, which is very small compared with the thickness of a CrR. Analysis of the turbulence across the CrRs is performed. When possible, the effects of discontinuities are removed from the data. Fluctuation amplitudes, the Alfvenicity, and the level of Alfvenic correlations all vary smoothly across the CrR. The Alfven ratio exhibits a decrease at the shear zone of the stream interface. Fourier analysis of 4.5-hr subintervals of ACE data is performed and the results are superposed averaged as an ensemble of realizations. The spectral slopes of the velocity, magnetic-field, and total-energy fluctuations vary smoothly across the CIR. The total-energy spectral slope is {approx} 3/2 in the slow and fast wind and in the CrRs. Analysis of the Elsasser inward-outward fluctuations shows a smooth transition across the CrR from an inward-outward balance in the slow wind to an outward dominance in the fast wind. A number of signatures of turbulence driving at the shear zone are sought (entropy change, turbulence amplitude, Alfvenicity, Alfven ratio, spectral slopes, in-out nature): none show evidence of driving of turbulence by shear.

  9. VARIABLE WINDS AND DUST FORMATION IN R CORONAE BOREALIS STARS

    SciTech Connect (OSTI)

    Clayton, Geoffrey C.; Zhang Wanshu [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Geballe, T. R., E-mail: gclayton@fenway.phys.lsu.edu, E-mail: wzhan21@lsu.edu, E-mail: tgeballe@gemini.edu [Gemini Observatory, 670 N. A'ohoku Place, Hilo, HI 96720 (United States)

    2013-08-01T23:59:59.000Z

    We have observed P-Cygni and asymmetric, blue-shifted absorption profiles in the He I {lambda}10830 lines of 12 R Coronae Borealis stars over short (1 month) and long (3 yr) timescales to look for variations linked to their dust-formation episodes. In almost all cases, the strengths and terminal velocities of the line vary significantly and are correlated with dust formation events. Strong absorption features with blue-shifted velocities {approx}400 km s{sup -1} appear during declines in visible brightness and persist for about 100 days after recovery to maximum brightness. Small residual winds of somewhat lower velocity are present outside of the decline and recovery periods. The correlations support models in which recently formed dust near the star is propelled outward at high speed by radiation pressure and drags the gas along with it.

  10. Analysis of Variability and Uncertainty in Wind Power Forecasting: An International Comparison: Preprint

    SciTech Connect (OSTI)

    Zhang, J.; Hodge, B. M.; Gomez-Lazaro, E.; Lovholm, A. L.; Berge, E.; Miettinen, J.; Holttinen, H.; Cutululis, N.; Litong-Palima, M.; Sorensen, P.; Dobschinski, J.

    2013-10-01T23:59:59.000Z

    One of the critical challenges of wind power integration is the variable and uncertain nature of the resource. This paper investigates the variability and uncertainty in wind forecasting for multiple power systems in six countries. An extensive comparison of wind forecasting is performed among the six power systems by analyzing the following scenarios: (i) wind forecast errors throughout a year; (ii) forecast errors at a specific time of day throughout a year; (iii) forecast errors at peak and off-peak hours of a day; (iv) forecast errors in different seasons; (v) extreme forecasts with large overforecast or underforecast errors; and (vi) forecast errors when wind power generation is at different percentages of the total wind capacity. The kernel density estimation method is adopted to characterize the distribution of forecast errors. The results show that the level of uncertainty and the forecast error distribution vary among different power systems and scenarios. In addition, for most power systems, (i) there is a tendency to underforecast in winter; and (ii) the forecasts in winter generally have more uncertainty than the forecasts in summer.

  11. The winds of Luminous Blue Variables and the Mass of AG Car

    E-Print Network [OSTI]

    Jorick S. Vink; Alex de Koter

    2002-07-15T23:59:59.000Z

    We present radiation-driven wind models for Luminous Blue Variables (LBVs) and predict their mass-loss rates. A comparison between our predictions and the observations of AG Car shows that the variable mass loss behaviour of LBVs is due the recombination/ionisation of Fe IV/III and Fe III/II. We also derive a present-day mass of 35 Msun for AG Car.

  12. Anisotropic MHD/EMHD Turbulence in the Solar Wind and the Inte... http://www.agu.org/cgi-bin/SFgate/SFgate?language=English&verb... 1 of 1 3/10/05 11:25 AM

    E-Print Network [OSTI]

    Ng, Chung-Sang

    Anisotropic MHD/EMHD Turbulence in the Solar Wind and the Inte... http://www-0284 TI: Anisotropic MHD/EMHD Turbulence in the Solar Wind and the Interstellar Medium AU, Oceans, and Space, University of New Hampshire, Morse Hall, 39 College Road, Durham, NH 03824 United

  13. Predicting the Energy Output of Wind Farms Based on Weather Data: Important Variables and their Correlation

    E-Print Network [OSTI]

    Vladislavleva, Katya; Neumann, Frank; Wagner, Markus

    2011-01-01T23:59:59.000Z

    Wind energy plays an increasing role in the supply of energy world-wide. The energy output of a wind farm is highly dependent on the weather condition present at the wind farm. If the output can be predicted more accurately, energy suppliers can coordinate the collaborative production of different energy sources more efficiently to avoid costly overproductions. With this paper, we take a computer science perspective on energy prediction based on weather data and analyze the important parameters as well as their correlation on the energy output. To deal with the interaction of the different parameters we use symbolic regression based on the genetic programming tool DataModeler. Our studies are carried out on publicly available weather and energy data for a wind farm in Australia. We reveal the correlation of the different variables for the energy output. The model obtained for energy prediction gives a very reliable prediction of the energy output for newly given weather data.

  14. Abstract--The variability and non-dispatchable nature of wind and solar energy production presents

    E-Print Network [OSTI]

    , the New York ISO already started to support the integration of limited energy storage resources (LESR) [81 Abstract--The variability and non-dispatchable nature of wind and solar energy production, energy storage can be a viable solution to balance energy production against its consumption. This paper

  15. May 2013 PSERC Webinar: Managing Wind Variability with Self-Reserves and Responsive Demand

    Broader source: Energy.gov [DOE]

    The DOE-funded Power Systems Engineering Research Center (PSERC) is offering a free public webinar on managing wind variability in energy production. The webinar will be held Tuesday, May 7, 2013 from 2-3 p.m. No pre-registration is necessary.

  16. Tomographic Simulations of Accretion Disks in Cataclysmic Variables - Flickering and Wind

    E-Print Network [OSTI]

    Fabiola M. A. Ribeiro; Marcos P. Diaz

    2007-11-22T23:59:59.000Z

    Both continuum and emission line flickering are phenomena directly associated with the mass accretion process. In this work we simulate accretion disk Doppler maps including the effects of winds and flickering flares. Synthetic flickering Doppler maps are calculated and the effect of the flickering parameters on the maps is explored. Jets and winds occur in many astrophysical objects where accretion disks are present. Jets are generally absent among the cataclysmic variables (CVs), but there is evidence of mass loss by wind in many objects. CVs are ideal objects to study accretion disks and consequently to study the wind associated with these disks. We also present simulations of accretion disks including the presence of a wind with orbital phase resolution. Synthetic H-alpha line profiles in the optical region are obtained and their corresponding Doppler maps are calculated. The effect of the wind simulation parameters on the wind line profiles is also explored. From this study we verified that optically thick lines and/or emission by diffuse material into the primary Roche lobe are necessary to generate single peaked line profiles, often seen in CVs. The future accounting of these effects is suggested for interpreting Doppler tomography reconstructions.

  17. Variable Frequency Operations of an Offshore Wind Power Plant with HVDC-VSC: Preprint

    SciTech Connect (OSTI)

    Gevorgian, V.; Singh, M.; Muljadi, E.

    2011-12-01T23:59:59.000Z

    In this paper, a constant Volt/Hz operation applied to the Type 1 wind turbine generator. Various control aspects of Type 1 generators at the plant level and at the turbine level will be investigated. Based on DOE study, wind power generation may reach 330 GW by 2030 at the level of penetration of 20% of the total energy production. From this amount of wind power, 54 GW of wind power will be generated at offshore wind power plants. The deployment of offshore wind power plants requires power transmission from the plant to the load center inland. Since this power transmission requires submarine cable, there is a need to use High-Voltage Direct Current (HVDC) transmission. Otherwise, if the power is transmitted via alternating current, the reactive power generated by the cable capacitance may cause an excessive over voltage in the middle of the transmission distance which requires unnecessary oversized cable voltage breakdown capability. The use of HVDC is usually required for transmission distance longer than 50 kilometers of submarine cables to be economical. The use of HVDC brings another advantage; it is capable of operating at variable frequency. The inland substation will be operated to 60 Hz synched with the grid, the offshore substation can be operated at variable frequency, thus allowing the wind power plant to be operated at constant Volt/Hz. In this paper, a constant Volt/Hz operation applied to the Type 1 wind turbine generator. Various control aspects of Type 1 generators at the plant level and at the turbine level will be investigated.

  18. Ion kinetic energy conservation and magnetic field strength constancy in multi-fluid solar wind Alfv\\'enic turbulence

    E-Print Network [OSTI]

    Matteini, L; Pantellini, F; Velli, M; Schwartz, S J

    2015-01-01T23:59:59.000Z

    We investigate properties of the plasma fluid motion in the large amplitude low frequency fluctuations of highly Alfv\\'enic fast solar wind. We show that protons locally conserve total kinetic energy when observed from an effective frame of reference comoving with the fluctuations. For typical properties of the fast wind, this frame can be reasonably identified by alpha particles, which, owing to their drift with respect to protons at about the Alfv\\'en speed along the magnetic field, do not partake in the fluid low frequency fluctuations. Using their velocity to transform proton velocity into the frame of Alfv\\'enic turbulence, we demonstrate that the resulting plasma motion is characterized by a constant absolute value of the velocity, zero electric fields, and aligned velocity and magnetic field vectors as expected for unidirectional Alfv\\'enic fluctuations in equilibrium. We propose that this constraint, via the correlation between velocity and magnetic field in Alfv\\'enic turbulence, is at the origin of ...

  19. Variable speed operation of generators with rotor-speed feedback in wind power applications

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P.; Migliore, P.

    1995-11-01T23:59:59.000Z

    The use of induction generators in wind power applications has been common since the early development of the wind industry. Most of these generators operate at fixed frequency and are connected directly to the utility grid. Unfortunately, this mode of operation limits the rotor speed to a specific rpm. Variable-speed operation is preferred in order to facilitate maximum energy capture over a wide range of wind speeds. This paper explores variable-speed operating strategies for wind turbine applications. The objectives are to maximize energy production, provide controlled start-up and reduce torque loading. This paper focuses on optimizing the energy captured by operating at maximum aerodynamic efficiency at any wind speed. The control strategy we analyze uses rotor speed and generator power as the feedback signals. In the normal operating region, rotor speed is used to compute a target power that corresponds to optimum operation. With power as the control objective, the power converter and generator are controlled to track the target power at any rpm. Thus, the torque-speed characteristic of the generator is shaped to optimize the energy capture. The target power is continuously updated at any rpm. in extreme areas of the operating envelope, during start-up, shutdown, generator overload, or overspeed, different strategies driven by other system considerations must be used.

  20. Variable speed operation of generators with rotor-speed feedback in wind power applications

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P.; Migliore, P. [National Renewable Energy Lab., Golden, CO (United States). Wind Technology Div.

    1996-10-01T23:59:59.000Z

    The use of induction generators in wind power applications has been common since the early development of the wind industry. Most of these generators operate at fixed frequency and are connected directly to the utility grid. Unfortunately, this mode of operation limits the rotor speed to a specific rpm. Variable-speed operation is preferred in order to facilitate maximum energy capture over a wide range of wind speeds. This paper explores variable-speed operating strategies for wind turbine applications. The objectives are to maximize energy production, provide controlled start-up and reduce torque loading. This paper focuses on optimizing the energy captured by operating at maximum aerodynamic efficiency at any wind speed. The control strategy analyzed uses rotor speed and generator power as the feedback signals. In the normal operating region, rotor speed is used to compute a target power that corresponds to optimum operation. With power as the control objective, the power converter and generator are controlled to track the target power at any rpm. Thus, the torque-speed characteristic of the generator is shaped to optimize the energy capture. The target power is continuously updated at any rpm. In extreme areas of the operating envelope, during start-up, shutdown, generator overload, or overspeed, different strategies driven by other system considerations must be used.

  1. Variable speed operation of generators with rotor-speed feedback in wind power applications

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P.; Migliore, P. [National Renewable Energy Lab., Golden, CO (United States)

    1996-11-01T23:59:59.000Z

    The use of induction generators in wind power applications has been common since the early development of the wind industry. Most of these generators operate at fixed frequency and are connected directly to the utility grid. Unfortunately, this mode of operation limits the rotor speed to a specific rpm. Variable speed operation is preferred in order to facilitate maximum energy capture over a wide range of wind speeds. This paper explores variable speed operating strategies for wind turbine applications. The objectives are to maximize energy production, provide controlled start-up, and reduce torque loading. This paper focuses on optimizing the energy captured by operating at maximum aerodynamic efficiency at any wind speed. The control strategy the authors analyze uses rotor speed and generator power as the feedback signals. In the normal operating region, rotor speed is used to compute a target power that corresponds to optimum operation. With power as the control objective, the power converter and generator are controlled to track the target power at any rpm. Thus, the torque-speed characteristic of the generator is shaped to optimize the energy capture. The target power is continuously updated at any rpm. In extreme areas of the operating envelope, during start-up, shutdown, generator overload, or overspeed, different strategies driven by other system considerations must be used.

  2. Rummaging inside the Eskimo's parka: Variable asymmetric PN fast wind and a binary nucleus?

    E-Print Network [OSTI]

    Prinja, Raman

    2014-01-01T23:59:59.000Z

    We report on high-resolution optical time-series spectroscopy of the central star of the `Eskimo' planetary nebula NGC~2392. Datasets were secured with the ESO 2.3m in 2006 March and CFHT 3.6m in 2010 March to diagnose the fast wind and photospheric properties of the central star. The HeI and HeII recombination lines reveal evidence for clumping and temporal structures in the fast wind that are erratically variable on timescales down to ~ 30 min. (i.e. comparable to the characteristic wind flow time). We highlight changes in the overall morphology of the wind lines that cannot plausibly be explained by line-synthesis model predictions with a spherically homogeneous wind. Additionally we present evidence that the UV line profile morphologies support the notion of a high-speed, high-ionization polar wind in NGC~2392. Analyses of deep-seated, near-photospheric absorption lines reveals evidence for low-amplitude radial velocity shifts. Fourier analysis points tentatively to a ~ 0.12-d modulation in the radial vel...

  3. Observation of Turbulent Intermittency Scaling with Magnetic Helicity in an MHD Plasma Wind Tunnel

    E-Print Network [OSTI]

    Brown, Michael R.

    . An unstable spheromak injected into the MHD wind tunnel of the Swarthmore Spheromak Experiment displays-tunnel configuration of the Swarthmore Spheromak Experiment (SSX) [16,17] explores this possible relationship between indices. The scan is conducted on the wind-tunnel configuration of the Swarthmore Spheromak Experiment

  4. Heating of the Solar Wind Beyond 1 AU by Turbulent Dissipation

    E-Print Network [OSTI]

    Oughton, Sean

    19716, USA 2Department of Mathematics, University College London, UK Abstract The deposition of energy(comp) = Cshear(comp) U r Z2 (1) where Z2 = hv2 +b2i is the energy density, U is the solar wind speed, and Cshear in the solar wind frame would yield a spherical distribution (solid curve). The di erence in kinetic energy

  5. Solar wind turbulence at 0.72 AU and solar minimum

    E-Print Network [OSTI]

    Teodorescu, Eliza; Munteanu, Costel; Zhang, Tielong; Bruno, Roberto; Kovacs, Peter

    2015-01-01T23:59:59.000Z

    We investigate Venus Express (VEX) observations of magnetic field fluctuations performed systematically in the solar wind at 0.72 Astronomical Units (AU), between 2007 and 2009, during the deep minimum of the solar cycle 24. The Power Spectral Densities (PSD) of the magnetic field components have been computed for the time intervals that satisfy data integrity criteria and have been grouped according to the type of wind, fast and slow defined for speeds larger and respectively smaller than 450 km/s. The PSDs show higher levels of power for the fast than for the slow wind. The spectral slopes estimated for all PSDs in the frequency range 0.005-0.1 Hz exhibit a normal distribution. The average value of the trace of the spectral matrix is -1.60 for fast solar wind and -1.65 for slow wind. Compared to the corresponding average slopes at 1 AU, the PSDs are shallower at 0.72 AU for slow wind conditions suggesting a steepening of the solar wind spectra between Venus and Earth. No significant time variation trend is ...

  6. Self-excited induction generator for variable-speed wind turbine generation

    SciTech Connect (OSTI)

    Muljadi, E.; Gregory, B. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States); Broad, D. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Electrical Engineering] [Colorado State Univ., Fort Collins, CO (United States). Dept. of Electrical Engineering

    1996-10-01T23:59:59.000Z

    When an induction generator is connected to a utility bus, the voltage and frequency at the terminal of the generator are the same as the voltage and frequency of the utility. The reactive power needed by the induction generator is supplied by the utility and the real power is returned to the utility. The rotor speed varies within a very limited range, and the reactive power requirement must be transported through a long line feeder, thus creating additional transmission losses. The energy captured by a wind turbine can be increased if the rotor speed can be adjusted to follow wind speed variations. For small applications such as battery charging or water pumping, a stand alone operation can be implemented without the need to maintain the output frequency output of the generator. A self- excited induction generator is a good candidate for a stand alone operation where the wind turbine is operated at variable speed. Thus the performance of the wind turbine can be unproved. In this paper, we examine a self-excited induction generator operated in a stand alone mode. A potential application for battery charging is given. The output power of the generator will be controlled to improve the performance of the wind turbine.

  7. A Global View on the Wind Sea and Swell Climate and Variability from ERA-40 ALVARO SEMEDO

    E-Print Network [OSTI]

    Haak, Hein

    A Global View on the Wind Sea and Swell Climate and Variability from ERA-40 ALVARO SEMEDO 2010) ABSTRACT In this paper a detailed global climatology of wind-sea and swell parameters, based on the 45-yr European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA-40) wave reanalysis

  8. Simplified life cycle approach: GHG variability assessment for onshore wind electricity based on Monte-Carlo simulations

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    in the literature. In the special case of greenhouses gases (GHG) from wind power electricity, the LCA resultsSimplified life cycle approach: GHG variability assessment for onshore wind electricity based performed by the IPCC [1]. Such result might lead policy makers to consider LCA as an inconclusive method [2

  9. The Impact of Accretion Disk Winds on the Optical Spectra of Cataclysmic Variables

    E-Print Network [OSTI]

    Matthews, James H; Long, Knox S; Sim, Stuart A; Higginbottom, Nick

    2015-01-01T23:59:59.000Z

    Many high-state non-magnetic cataclysmic variables (CVs) exhibit blue-shifted absorption or P-Cygni profiles associated with ultraviolet (UV) resonance lines. These features imply the existence of powerful accretion disk winds in CVs. Here, we use our Monte Carlo ionization and radiative transfer code to investigate whether disk wind models that produce realistic UV line profiles are also likely to generate observationally significant recombination line and continuum emission in the optical waveband. We also test whether outflows may be responsible for the single-peaked emission line profiles often seen in high-state CVs and for the weakness of the Balmer absorption edge (relative to simple models of optically thick accretion disks). We find that a standard disk wind model that is successful in reproducing the UV spectra of CVs also leaves a noticeable imprint on the optical spectrum, particularly for systems viewed at high inclination. The strongest optical wind-formed recombination lines are H$\\alpha$ and H...

  10. Journal of Wind Engineering and Industrial Aerodynamics 96 (2008) 503523

    E-Print Network [OSTI]

    Manuel, Lance

    with such spectral models can be in turn highly variable for different realizations. Turbine load and performance a wind velocity field over spatial dimensions on the scale of the turbine rotor diameter in accordance of uncertainty in inflow turbulence to wind turbine loads Korn Saranyasoontorn, Lance Manuel? Department of Civil

  11. Turbulent Character of Wind Energy Patrick Milan, Matthias Wachter, and Joachim Peinke

    E-Print Network [OSTI]

    Peinke, Joachim

    that the grid dynamics in this time range become more complex. Smart grid concepts should be designed to cope cause a highly fluctuating electrical power feed into the grid. Such effects are the hallmark of high intermittent, peaked nature of wind power fed into the grid. Multifractal scaling is observed, as described

  12. The effects of energy storage properties and forecast accuracy on mitigating variability in wind power generation

    E-Print Network [OSTI]

    Jaworsky, Christina A

    2013-01-01T23:59:59.000Z

    Electricity generation from wind power is increasing worldwide. Wind power can offset traditional fossil fuel generators which is beneficial to the environment. However, wind generation is unpredictable. Wind speeds have ...

  13. VELOCITY-SHEAR-INDUCED MODE COUPLING IN THE SOLAR ATMOSPHERE AND SOLAR WIND: IMPLICATIONS FOR PLASMA HEATING AND MHD TURBULENCE

    SciTech Connect (OSTI)

    Hollweg, Joseph V.; Chandran, Benjamin D. G. [Space Science Center, Morse Hall, University of New Hampshire, Durham, NH 03824 (United States); Kaghashvili, Edisher Kh., E-mail: joe.hollweg@unh.edu, E-mail: ekaghash@aer.com, E-mail: benjamin.chandran@unh.edu [Atmospheric and Environmental Research, A Verisk Analytics Company, 131 Hartwell Avenue, Lexington, MA 02421 (United States)

    2013-06-01T23:59:59.000Z

    We analytically consider how velocity shear in the corona and solar wind can cause an initial Alfven wave to drive up other propagating signals. The process is similar to the familiar coupling into other modes induced by non-WKB refraction in an inhomogeneous plasma, except here the refraction is a consequence of velocity shear. We limit our discussion to a low-beta plasma, and ignore couplings into signals resembling the slow mode. If the initial Alfven wave is propagating nearly parallel to the background magnetic field, then the induced signals are mainly a forward-going (i.e., propagating in the same sense as the original Alfven wave) fast mode, and a driven signal propagating like a forward-going Alfven wave but polarized like the fast mode; both signals are compressive and subject to damping by the Landau resonance. For an initial Alfven wave propagating obliquely with respect to the magnetic field, the induced signals are mainly forward- and backward-going fast modes, and a driven signal propagating like a forward-going Alfven wave but polarized like the fast mode; these signals are all compressive and subject to damping by the Landau resonance. A backward-going Alfven wave, thought to be important in the development of MHD turbulence, is also produced, but it is very weak. However, we suggest that for oblique propagation of the initial Alfven wave the induced fast-polarized signal propagating like a forward-going Alfven wave may interact coherently with the initial Alfven wave and distort it at a strong-turbulence-like rate.

  14. Great Plains Turbulence Environment: Its Origins, Impact, and Simulation

    SciTech Connect (OSTI)

    Kelley, N. D.; Jonkman, B. J.; Scott, G. N.

    2006-12-01T23:59:59.000Z

    This paper summarizes the known impacts of nocturnal turbulence on wind turbine performance and operations.

  15. Empirical Analysis of the Variability of Wind Generation in India: Implications for Grid Integration

    E-Print Network [OSTI]

    Phadke, Amol

    2014-01-01T23:59:59.000Z

    and V. Neimane. 2005. 4000 MW Wind Power in Sweden-Impact onand Michael Milligan. 2009. Wind Energy and Power SystemOperations: A Review of Wind Integration Studies to Date.

  16. Examining the Variability of Wind Power Output in the Regulation Time Frame: Preprint

    SciTech Connect (OSTI)

    Hodge, B. M.; Shedd, S.; Florita, A.

    2012-08-01T23:59:59.000Z

    This work examines the distribution of changes in wind power for different time scales in the regulation time frame as well as the correlation of changes in power output for individual wind turbines in a wind plant.

  17. Ris-R-1188(EN) Turbulence and turbulence-

    E-Print Network [OSTI]

    Ris-R-1188(EN) Turbulence and turbulence- generated structural loading in wind turbine clusters af den internationale standard for vindmller, IEC61400-1 (2005). Ogs ekstrembelastninger under to ensure sufficient structural sustainability of the wind turbines exposed to "wind farm flow

  18. Development and Validation of WECC Variable Speed Wind Turbine Dynamic Models for Grid Integration Studies

    SciTech Connect (OSTI)

    Behnke, M.; Ellis, A.; Kazachkov, Y.; McCoy, T.; Muljadi, E.; Price, W.; Sanchez-Gasca, J.

    2007-09-01T23:59:59.000Z

    This paper describes reduced-order, simplified wind turbine models for analyzing the stability impact of large arrays of wind turbines with a single point of network interconnection.

  19. Rotating Winds from Accretion Disks in Cataclysmic Variables: Eclipse Modeling of V347 Puppis

    E-Print Network [OSTI]

    Isaac Shlosman; Peter Vitello; Christopher W. Mauche

    1995-11-01T23:59:59.000Z

    We study the eclipsing nova-like variable V347 Pup by matching its UV emission line profiles in and out of eclipse to synthetic lines using a 3D kinematic and radiation transfer model. Our results support the accretion disk origin of winds in non-magnetic CVs as opposite to the WD origin. Our main point concerns the importance of rotation for the UV emission line shapes in such systems. In particular, we show that the narrowing of the UV emission lines in V347 Pup during eclipse can be easily explained by the eclipse of the innermost part of the wind by the secondary and the resulting reduction in the contribution of rotational broadening to the width of the lines. During the eclipse, the residual line flux is very sensitive to the maximal temperature of disk radiation. Good fits for reasonable mass-loss rates have been obtained for maximum disk temperatures of 50,000 degrees. This constraint was imposed either by leveling off the inner disk temperature profiles, in agreement with recent observations of some nova-like objects, or by assuming that the accretion disk does not extend to the surface of the white dwarf, in which case V347 up would be an intermediate polar. In anticipation of high-speed spectrophotometry of CVs by the HST, we provide numerical model of a time-resolved eclipse of V347 Pup or similar such system to be verified by future observations.

  20. Systematic approach for PID controller design for pitch-regulated, variable-speed wind turbines

    SciTech Connect (OSTI)

    Hand, M.M. [National Renewable Energy Lab., Golden, CO (United States); Balas, M.J. [Univ. of Colorado, Boulder, CO (United States). Dept. of Aerospace Engineering Sciences

    1997-11-01T23:59:59.000Z

    Variable-speed, horizontal axis wind turbines use blade-pitch control to meet specified objectives for three regions of operation. This paper focuses on controller design for the constant power production regime. A simple, rigid, non-linear turbine model was used to systematically perform trade-off studies between two performance metrics. Minimization of both the deviation of the rotor speed from the desired speed and the motion of the actuator is desired. The robust nature of the proportional-integral-derivative (PID) controller is illustrated, and optimal operating conditions are determined. Because numerous simulation runs may be completed in a short time, the relationship of the two opposing metrics is easily visualized. 2 refs., 9 figs.

  1. An SMLD joint PDF model for turbulent non-premixed combustion using the flamelet progress-variable approach

    E-Print Network [OSTI]

    Coclite, Alessandro; De Palma, Pietro; Cutrone, Luigi; Ihme, Matthias

    2015-01-01T23:59:59.000Z

    This paper provides an improved flamelet/progress variable (FPV) model for the simulation of turbulent combustion, employing the statistically most likely distribution (SMLD) approach for the joint probability density function (PDF) of the mixture fraction, Z, and of the progress parameter, {\\Lambda} . Steady-state FPV models are built presuming the func- tional shape of the joint PDF of Z and {\\Lambda} in order to evaluate Favre-averages of thermody- namic quantities. The mixture fraction is widely assumed to behave as a passive scalar with a mono-modal behaviour modelled by a \\b{eta} -distribution. Moreover, under the hypothesis that Z and {\\Lambda} are statistically independent, the joint PDF coincides with the product of the two marginal PDFs. In this work we discuss these two constitutive hypotheses. The proposed model evaluates the most probable joint distribution of Z and {\\Lambda} , relaxing some crucial as- sumption on their statistical behaviour. This provides a more general model in the context of ...

  2. Effect of wind variability on topographic waves: Lake Kinneret case Elad Shilo,1

    E-Print Network [OSTI]

    Ashkenazy, Yossi "Yosef"

    to the presence of a curl in the wind field. Using various wind regimes to force the lake indicated of the lake. Forcing the model with a spatially uniform wind field constructed from a single station resulted's response to wind-forcing will provide more accu- rate conditions for further studies concerning water qual

  3. IEEE TRANSACTIONS ON ENERGY CONVERSION, VOL. 23, NO. 2, JUNE 2008 551 Sliding Mode Power Control of Variable-Speed Wind

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    in variable-speed wind energy conversion sys- tems (VS-WECS). These systems have two operation regions de of Variable-Speed Wind Energy Conversion Systems Brice Beltran, Tarek Ahmed-Ali, and Mohamed El Hachemi (newton meter). Tg Generator torque in the rotor side (newton meter). Ths High-speed torque (newton meter

  4. A nuclear wind/solar oil-shale system for variable electricity and liquid fuels production

    SciTech Connect (OSTI)

    Forsberg, C. [Massachusetts Inst. of Technology, 77 Massachusetts Ave., Cambridge, MA 012139 (United States)

    2012-07-01T23:59:59.000Z

    The recoverable reserves of oil shale in the United States exceed the total quantity of oil produced to date worldwide. Oil shale contains no oil, rather it contains kerogen which when heated decomposes into oil, gases, and a carbon char. The energy required to heat the kerogen-containing rock to produce the oil is about a quarter of the energy value of the recovered products. If fossil fuels are burned to supply this energy, the greenhouse gas releases are large relative to producing gasoline and diesel from crude oil. The oil shale can be heated underground with steam from nuclear reactors leaving the carbon char underground - a form of carbon sequestration. Because the thermal conductivity of the oil shale is low, the heating process takes months to years. This process characteristic in a system where the reactor dominates the capital costs creates the option to operate the nuclear reactor at base load while providing variable electricity to meet peak electricity demand and heat for the shale oil at times of low electricity demand. This, in turn, may enable the large scale use of renewables such as wind and solar for electricity production because the base-load nuclear plants can provide lower-cost variable backup electricity. Nuclear shale oil may reduce the greenhouse gas releases from using gasoline and diesel in half relative to gasoline and diesel produced from conventional oil. The variable electricity replaces electricity that would have been produced by fossil plants. The carbon credits from replacing fossil fuels for variable electricity production, if assigned to shale oil production, results in a carbon footprint from burning gasoline or diesel from shale oil that may half that of conventional crude oil. The U.S. imports about 10 million barrels of oil per day at a cost of a billion dollars per day. It would require about 200 GW of high-temperature nuclear heat to recover this quantity of shale oil - about two-thirds the thermal output of existing nuclear reactors in the United States. With the added variable electricity production to enable renewables, additional nuclear capacity would be required. (authors)

  5. Long term variability of Cygnus X-1: VII. Orbital variability of the focussed wind in Cyg X-1 / HDE 226868 system

    E-Print Network [OSTI]

    Grinberg, V; Hell, N; Pottschmidt, K; Bck, M; Garca, J A; Hanke, M; Nowak, M A; Sundqvist, J O; Townsend, R H D; Wilms, J

    2015-01-01T23:59:59.000Z

    Binary systems with an accreting compact object are a unique chance to investigate the strong, clumpy, line-driven winds of early type supergiants by using the compact object's X-rays to probe the wind structure. We analyze the two-component wind of HDE 226868, the O9.7Iab giant companion of the black hole Cyg X-1 using 4.77 Ms of RXTE observations of the system taken over the course of 16 years. Absorption changes strongly over the 5.6 d binary orbit, but also shows a large scatter at a given orbital phase, especially at superior conjunction. The orbital variability is most prominent when the black hole is in the hard X-ray state. Our data are poorer for the intermediate and soft state, but show signs for orbital variability of the absorption column in the intermediate state. We quantitatively compare the data in the hard state to a toy model of a focussed Castor-Abbott-Klein-wind: as it does not incorporate clumping, the model does not describe the observations well. A qualitative comparison to a simplified...

  6. Analysis of Variability and Uncertainty in Wind Power Forecasting: An International Comparison (Presentation)

    SciTech Connect (OSTI)

    Zhang, J.; Hodge, B.; Miettinen, J.; Holttinen, H.; Gomez-Lozaro, E.; Cutululis, N.; Litong-Palima, M.; Sorensen, P.; Lovholm, A.; Berge, E.; Dobschinski, J.

    2013-10-01T23:59:59.000Z

    This presentation summarizes the work to investigate the uncertainty in wind forecasting at different times of year and compare wind forecast errors in different power systems using large-scale wind power prediction data from six countries: the United States, Finland, Spain, Denmark, Norway, and Germany.

  7. DO OBLIQUE ALFVEN/ION-CYCLOTRON OR FAST-MODE/WHISTLER WAVES DOMINATE THE DISSIPATION OF SOLAR WIND TURBULENCE NEAR THE PROTON INERTIAL LENGTH?

    SciTech Connect (OSTI)

    He Jiansen; Tu Chuanyi [School of Earth and Space Sciences, Peking University, Beijing 100871 (China); Marsch, Eckart [Max-Planck-Institut fuer Sonnensystemforschung, 37191 Katlenburg-Lindau (Germany); Yao Shuo, E-mail: jshept@gmail.com [School of Geophysics and Information Technology, China University of Geoscience (Beijing), Beijing 100083 (China)

    2012-01-20T23:59:59.000Z

    To determine the wave modes prevailing in solar wind turbulence at kinetic scales, we study the magnetic polarization of small-scale fluctuations in the plane perpendicular to the data sampling direction (namely, the solar wind flow direction, V{sub SW}) and analyze its orientation with respect to the local background magnetic field B{sub 0,local}. As an example, we take only measurements made in an outward magnetic sector. When B{sub 0,local} is quasi-perpendicular to V{sub SW}, we find that the small-scale magnetic-field fluctuations, which have periods from about 1 to 3 s and are extracted from a wavelet decomposition of the original time series, show a polarization ellipse with right-handed orientation. This is consistent with a positive reduced magnetic helicity, as previously reported. Moreover, for the first time we find that the major axis of the ellipse is perpendicular to B{sub 0,local}, a property that is characteristic of an oblique Alfven wave rather than oblique whistler wave. For an oblique whistler wave, the major axis of the magnetic ellipse is expected to be aligned with B{sub 0,local}, thus indicating significant magnetic compressibility, and the polarization turns from right to left handedness as the wave propagation angle ({theta}{sub kB}) increases toward 90 Degree-Sign . Therefore, we conclude that the observation of a right-handed polarization ellipse with orientation perpendicular to B{sub 0,local} seems to indicate that oblique Alfven/ion-cyclotron waves rather than oblique fast-mode/whistler waves dominate in the 'dissipation' range near the break of solar wind turbulence spectra occurring around the proton inertial length.

  8. East Pacific ocean eddies and their relationship to subseasonal variability in Central American wind jets

    E-Print Network [OSTI]

    Qiu, Bo

    wind jets Chueh-Hsin Chang,1,2 Shang-Ping Xie,1,3 Niklas Schneider,3,4 Bo Qiu,4 Justin Small,5 Wei-tilted bands on the northwest flank of the Tehuantepec and Papagayo wind jets and collocated-variance bands at a speed of 913 cm/s. Wind fluctuations are important for eddy formation in the Gulf

  9. Low Wind Speed Technology Phase II: Investigation of the Application of Medium-Voltage Variable-Speed Drive Technology to Improve the Cost of Energy from Low Wind Speed Turbines; Behnke, Erdman and Whitaker Engineering, Inc.

    SciTech Connect (OSTI)

    Not Available

    2006-03-01T23:59:59.000Z

    This fact sheet describes a subcontract with Behnke, Erdman & Whitaker Engineering, Inc. to test the feasibility of applying medium-voltage variable-speed drive technology to low wind speed turbines.

  10. Aeroelastic Analysis of Bridges: Effects of Turbulence and Aerodynamic Nonlinearities

    E-Print Network [OSTI]

    Kareem, Ahsan

    of bridges under turbulent winds. The nonlinear force model separates the aerodynamic force into low; Buffeting; Turbulence; Bridges; Wind forces; Aerodynamics. Introduction The aerodynamic performance under aerodynamic force model and associated time domain analysis framework for predicting the aeroelastic response

  11. On the role of wind driven ocean dynamics in tropical Atlantic variability

    E-Print Network [OSTI]

    Da Silva, Meyre Pereira

    2006-08-16T23:59:59.000Z

    The response of the tropical Atlantic Ocean to wind stress forcing on seasonal and interannual time scales is examined using an ocean data assimilation product from the Geophysical Fluid Dynamics Laboratory (GFDL), and an ocean general circulation...

  12. The evaluation of a turbulent loads characterization system

    SciTech Connect (OSTI)

    Kelley, N.D.; McKenna, H.E. [National Renewable Energy Lab., Golden, CO (United States)

    1996-01-01T23:59:59.000Z

    In this paper we discuss an on-line turbulent load characterization system that has been designed to acquire loading spectra from turbines of the same design operating in several different environments and from different turbine designs operating in the same environment. This System simultaneously measures the rainflow-counted alternating and mean loading spectra and the hub-height turbulent mean shearing stress and atmospheric stability associated with the turbulent inflow. We discuss the theory behind the measurement configuration and the results of proof-of-concept testing recently performed at the National Wind Technology Center (NWTC) using a Bergey EXCEL-S 10-kW wind turbine. The on-line approach to characterizing the load spectra and the inflow turbulent scaling parameter produces results that are consistent with other measurements. The on-line approximation of the turbulent shear stress or friction velocity u* also is considered adequate. The system can be used to characterize turbulence loads during turbine deployment in a wide variety of environments. Using the WISPER protocol, we found that a wide-range, variable-speed turbine will accumulate a larger number of stress cycles in the low-cycle, high-amplitude (LCHA) region when compared with a constant speed rotor under similar inflow conditions.

  13. A study of wind variability in the lower troposphere through power spectrum analysis at mesoscale frequencies

    E-Print Network [OSTI]

    Cornett, John Sheldon

    1966-01-01T23:59:59.000Z

    major energy peaks. One major peak occurred at a period of about 4 days and the second peak at a period of about 1 min with a rather broad, flat spectral curve in between these peaks. He attributed the low frequency peak to fluctuations in wind speed... tropospheze, both Mantis (1963) and Chiu (1960) found a high energy peak in the spectra of the horizontal wind components corresponding to synoptic-scale periods of 4 to 6 days. However, they were limited to considering periods of 2 days or more because...

  14. Economic and technical impacts of wind variability and intermittency on long-term generation expansion planning

    E-Print Network [OSTI]

    Paristech 2009 Submitted to the Engineering Systems Division in partial fulfillment of the requirements to the Engineering Systems Division on May 6, 2011 in partial fulfillment of the requirements for the Degree of the U.S. I aggregate an hourly dataset of load and wind resource in eleven regions in order to capture

  15. GAMMA-RAY VARIABILITY FROM WIND CLUMPING IN HIGH-MASS X-RAY BINARIES This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Townsend, Richard

    the resulting gamma-ray emissivity depends on the target density, the detection of rapid variabilityGAMMA-RAY VARIABILITY FROM WIND CLUMPING IN HIGH-MASS X-RAY BINARIES WITH JETS This article has Society. All rights reserved. Printed in the U.S.A. GAMMA-RAY VARIABILITY FROM WIND CLUMPING IN HIGH

  16. E-Print Network 3.0 - atmospheric turbulence Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Summary: by dissipation of the turbulent energy and tur- bulent eddies will transport heat to different atmospheric re... ., MST radar studies of wind and turbulence in the...

  17. Use of Solar and Wind as a Physical Hedge against Price Variability within a Generation Portfolio

    SciTech Connect (OSTI)

    Jenkin, T.; Diakov, V.; Drury, E.; Bush, B.; Denholm, P.; Milford, J.; Arent, D.; Margolis, R.; Byrne, R.

    2013-08-01T23:59:59.000Z

    This study provides a framework to explore the potential use and incremental value of small- to large-scale penetration of solar and wind technologies as a physical hedge against the risk and uncertainty of electricity cost on multi-year to multi-decade timescales. Earlier studies characterizing the impacts of adding renewable energy (RE) to portfolios of electricity generators often used a levelized cost of energy or simplified net cash flow approach. In this study, we expand on previous work by demonstrating the use of an 8760 hourly production cost model (PLEXOS) to analyze the incremental impact of solar and wind penetration under a wide range of penetration scenarios for a region in the Western U.S. We do not attempt to 'optimize' the portfolio in any of these cases. Rather we consider different RE penetration scenarios, that might for example result from the implementation of a Renewable Portfolio Standard (RPS) to explore the dynamics, risk mitigation characteristics and incremental value that RE might add to the system. We also compare the use of RE to alternative mechanisms, such as the use of financial or physical supply contracts to mitigate risk and uncertainty, including consideration of their effectiveness and availability over a variety of timeframes.

  18. Modelling and Measurements of Power Losses and Turbulence

    E-Print Network [OSTI]

    Pryor, Sara C.

    at Middelgrunden Offshore Wind Farm R. J. Barthelmie*, , S. T. Frandsen and M. N. Nielsen, Wind Energy Department and turbulence increase due to wind turbine wake interac- tions in large offshore wind farms is crucial interactions in large offshore wind farms is crucial to optimizing wind farm design. Power losses due

  19. Modelling of offshore wind turbine wakes with the wind farm program FLaP

    E-Print Network [OSTI]

    Heinemann, Detlev

    Modelling of offshore wind turbine wakes with the wind farm program FLaP Bernhard Lange(1) , Hans from the Danish offshore wind farm Vindeby. Vertical wake profiles and mean turbulence intensities are not modelled satisfactorily. Keywords: Offshore, wind farm, wake model, Vindeby, turbulence intensity

  20. atmospheric wind sensor: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    sensor Chaudhuri, Surajit 6 ATMOSPHERIC TURBULENCE MODELING AND IMPLICATIONS FOR WIND ENERGY Geosciences Websites Summary: Introduction Wind turbines sit at the very...

  1. Analysis of a teetered, variable-speed rotor: final report

    SciTech Connect (OSTI)

    Weber, T.L.; Wilson, R.E.; Walker, S.N. (Oregon State Univ., Corvallis, OR (USA). Dept. of Mechanical Engineering) [Oregon State Univ., Corvallis, OR (USA). Dept. of Mechanical Engineering

    1991-06-01T23:59:59.000Z

    A computer model of a horizontal axis wind turbine (HOOT) with four structural degrees of freedom has been derived and verified. The four degrees of freedom include flapwise motion of the blades, teeter motion, and variable rotor speed. Options for the variable rotor speed include synchronous, induction, and constant-tip speed generator models with either start, stop, or normal operations. Verification is made by comparison with analytical solutions and mean and cyclic ESI-80 data. The Veers full-field turbulence model is used as a wind input for a synchronous and induction generator test case during normal operation. As a result of the comparison, it is concluded that the computer model can be used to predict accurately mean and cyclic loads with a turbulent wind input. 47 refs., 19 figs.

  2. Stability, Energetics, and Turbulent Transport in

    E-Print Network [OSTI]

    Torquato, Salvatore

    fields" Department of Astrophysical Sciences Spring Colloquium Steve Cowley (UK Atomic Energy Authority of solar-wind turbulence" Chris Chen (UC Berkeley) 2:40pm "Energy spectra in MHD turbulenceStability, Energetics, and Turbulent Transport in Astrophysical, Fusion, and Solar Plasmas 8

  3. Variable-speed wind power system with improved energy capture via multilevel conversion

    DOE Patents [OSTI]

    Erickson, Robert W.; Al-Naseem, Osama A.; Fingersh, Lee Jay

    2005-05-31T23:59:59.000Z

    A system and method for efficiently capturing electrical energy from a variable-speed generator are disclosed. The system includes a matrix converter using full-bridge, multilevel switch cells, in which semiconductor devices are clamped to a known constant DC voltage of a capacitor. The multilevel matrix converter is capable of generating multilevel voltage wave waveform of arbitrary magnitude and frequencies. The matrix converter can be controlled by using space vector modulation.

  4. Nonextensive entropy approach to space plasma fluctuations and turbulence

    E-Print Network [OSTI]

    M. P. Leubner; Z. Voros; W. Baumjohann

    2006-05-22T23:59:59.000Z

    Spatial intermittency in fully developed turbulence is an established feature of astrophysical plasma fluctuations and in particular apparent in the interplanetary medium by in situ observations. In this situation the classical Boltzmann-Gibbs extensive thermo-statistics, applicable when microscopic interactions and memory are short ranged, fails. Upon generalization of the entropy function to nonextensivity, accounting for long-range interactions and thus for correlations in the system, it is demonstrated that the corresponding probability distributions (PDFs) are members of a family of specific power-law distributions. In particular, the resulting theoretical bi-kappa functional reproduces accurately the observed global leptokurtic, non-Gaussian shape of the increment PDFs of characteristic solar wind variables on all scales. Gradual decoupling is obtained by enhancing the spatial separation scale corresponding to increasing kappa-values in case of slow solar wind conditions where a Gaussian is approached in the limit of large scales. Contrary, the scaling properties in the high speed solar wind are predominantly governed by the mean energy or variance of the distribution. The PDFs of solar wind scalar field differences are computed from WIND and ACE data for different time-lags and bulk speeds and analyzed within the nonextensive theory. Consequently, nonlocality in fluctuations, related to both, turbulence and its large scale driving, should be related to long-range interactions in the context of nonextensive entropy generalization, providing fundamentally the physical background of the observed scale dependence of fluctuations in intermittent space plasmas.

  5. 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

    SciTech Connect (OSTI)

    Erdman, W.; Behnke, M.

    2005-11-01T23:59:59.000Z

    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.

  6. Low-altitude atmospheric turbulence around an airport

    E-Print Network [OSTI]

    Cass, Stanley Dale

    1972-01-01T23:59:59.000Z

    speed and the average wind speed computed over an entire run (approximately 1 hr). iv Profiles of wind speed were approximately logarithmic, but profiles of turbulent energy showed a large increase in the wake of large obstructions. Spectra of wind... from u 30-sec averages 56 57 28 Spectra of accelerometer and wind data for same period 59 LIST OF SYMBOLS Symbol Definition Exchange coefficient for momentum Height Time Kinetic energy Average kinetic energy of turbulence u' + v'2 + w' (' 2...

  7. Geographical and seasonal variability of the global "practical" wind Cristina L. Archer a,*, Mark Z. Jacobson b

    E-Print Network [OSTI]

    technical, practical, or economic e existed. Using petroleum as an anal- ogy, the theoretical wind power; 3) global model maps evaluated against data are not available at high-resolution, either spatially

  8. V444 Cyg X-ray and polarimetric variability: Radiative and Coriolis forces shape the wind collision region

    E-Print Network [OSTI]

    Lomax, Jamie R; Hoffman, Jennifer L; Russell, Christopher M P; De Becker, Michael; Corcoran, Michael F; Davidson, James W; Neilson, Hilding R; Owocki, Stan; Pittard, Julian M; Pollock, Andy M T

    2014-01-01T23:59:59.000Z

    We present results from a study of the eclipsing, colliding-wind binary V444 Cyg that uses a combination of X-ray and optical spectropolarimetric methods to describe the 3-D nature of the shock and wind structure within the system. We have created the most complete X-ray light curve of V444 Cyg to date using 40 ksec of new data from Swift, and 200 ksec of new and archived XMM-Newton observations. In addition, we have characterized the intrinsic, polarimetric phase-dependent behavior of the strongest optical emission lines using data obtained with the University of Wisconsin's Half-Wave Spectropolarimeter. We have detected evidence of the Coriolis distortion of the wind-wind collision in the X-ray regime, which manifests itself through asymmetric behavior around the eclipses in the system's X-ray light curves. The large opening angle of the X-ray emitting region, as well as its location (i.e. the WN wind does not collide with the O star, but rather its wind) are evidence of radiative braking/inhibition occurri...

  9. A Fatigue Approach to Wind Turbine Control

    E-Print Network [OSTI]

    A Fatigue Approach to Wind Turbine Control Keld Hammerum Kongens Lyngby 2006 #12;Technical to the turbulent nature of wind, the structural components of a wind turbine are exposed to highly varying loads. Therefore, fatigue damage is a major consideration when designing wind turbines. The control scheme applied

  10. LIDAR Wind Speed Measurements of Evolving Wind Fields

    SciTech Connect (OSTI)

    Simley, E.; Pao, L. Y.

    2012-07-01T23:59:59.000Z

    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.

  11. Power System Modeling of 20percent Wind-Generated Electricity by 2030

    E-Print Network [OSTI]

    Hand, Maureen

    2008-01-01T23:59:59.000Z

    transmission to deliver wind generation to load centers. Toof integrating variable wind generation into the electricityfrom wind. Annual wind energy generation was specified in

  12. A comparison of measured wind park load histories with the WISPER and WISPERX load spectra

    SciTech Connect (OSTI)

    Kelley, N.D.

    1995-01-01T23:59:59.000Z

    The blade-loading histories from two adjacent Micon 65/13 wind turbines are compared with the variable-amplitude test-loading histories known as the WISPER and WISPERX spectra. These standardized loading sequences were developed from blade flapwise load histories taken from nine different horizontal-axis wind turbines operating under a wide range of conditions in Europe. The subject turbines covered a broad spectrum of rotor diameters, materials, and operating environments. The final loading sequences were developed as a joint effort of thirteen different European organizations. The goal was to develop a meaningful loading standard for horizontal-axis wind turbine blades that represents common interaction effects seen in service. In 1990, NREL made extensive load measurements on two adjacent Micon 65/13 wind turbines in simultaneous operation in the very turbulent environment of a large wind park. Further, before and during the collection of the loads data, comprehensive measurements of the statistics of the turbulent environment were obtained at both the turbines under test and at two other locations within the park. The trend to larger but lighter wind turbine structures has made an understanding of the expected lifetime loading history of paramount importance. Experience in the US has shown that the turbulence-induced loads associated with multi-row wind parks in general are much more severe than for turbines operating individually or within widely spaced environments. Multi-row wind parks are much more common in the US than in Europe. In this paper we report on our results in applying the methodology utilized to develop the WISPER and WISPERX standardized loading sequences using the available data from the Micon turbines. While the intended purpose of the WISPER sequences were not to represent a specific operating environment, we believe the exercise is useful, especially when a turbine design is likely to be installed in a multi-row wind park.

  13. Comments on the Regional Climate Variability Driven by Foehn Winds in the McMurdo Dry Valleys, Antarctica

    E-Print Network [OSTI]

    Sienicki, Krzysztof

    2013-01-01T23:59:59.000Z

    The main objection to Speirs, McGowan, Steinhoff and Bromwich work arises from the lack of analyses of the probability distribution functions of underlying processes leading to wind formation of which velocities are measured by automated weather stations and reported in the paper. Mathematically a rigorous definition of calculating the correlation coefficient (Pearson product-moment correlation coefficient) of averages does not exist. Therefore the authors numbers as given in Table II represent a set of randomly calculated figures. The authors suggestion in relation to a few of these random numbers that some of them have statistical significance at the 95% level is erroneous since no relationship exists between correlation coefficient of averages and statistical significance. Therefore Speirs et al. main conclusion that the - SAM is found to significantly influence foehn wind frequency at McMurdo Dry Valleys is unfounded.

  14. aerothermal wind tunnel: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Generated Noise Franck Bertagnolio Ris and Turbulence Generated Noise Division: Wind Energy Division Ris-R-1657(EN) November 2008 Abstract (max. 2000, and with...

  15. ames wind tunnel: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Generated Noise Franck Bertagnolio Ris and Turbulence Generated Noise Division: Wind Energy Division Ris-R-1657(EN) November 2008 Abstract (max. 2000, and with...

  16. aerosol wind tunnel: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Generated Noise Franck Bertagnolio Ris and Turbulence Generated Noise Division: Wind Energy Division Ris-R-1657(EN) November 2008 Abstract (max. 2000, and with...

  17. Large-Eddy Simulation of Wind-Plant Aerodynamics: Preprint

    SciTech Connect (OSTI)

    Churchfield, M. J.; Lee, S.; Moriarty, P. J.; Martinez, L. A.; Leonardi, S.; Vijayakumar, G.; Brasseur, J. G.

    2012-01-01T23:59:59.000Z

    In this work, we present results of a large-eddy simulation of the 48 multi-megawatt turbines composing the Lillgrund wind plant. Turbulent inflow wind is created by performing an atmospheric boundary layer precursor simulation and turbines are modeled using a rotating, variable-speed actuator line representation. The motivation for this work is that few others have done wind plant large-eddy simulations with a substantial number of turbines, and the methods for carrying out the simulations are varied. We wish to draw upon the strengths of the existing simulations and our growing atmospheric large-eddy simulation capability to create a sound methodology for performing this type of simulation. We have used the OpenFOAM CFD toolbox to create our solver.

  18. Analyzing the temporal variation of wind turbine responses using Gaussian Mixture Model and Gaussian Discriminant Analysis

    E-Print Network [OSTI]

    Stanford University

    such as loads, displacement, fatigue damages and power outputs. However, wind flow is a complex phenomenon Gaussian Discriminant Analysis, representative daytime and nocturnal wind turbine loads are compared, mean wind direction, turbulence intensity and power exponent quantifying the vertical profile

  19. WEST: A northern California study of the role of wind-driven transport in the productivity of coastal plankton communities

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    variability. Alongshore Wind m/s Temperature o C SalinityA. , Largier, J. , 2003. Wind strength and biological2006. Effects of variable winds on biological productivity

  20. Wind Power Price Trends in the United States: Struggling to Remain Competitive in the Face of Strong Growth

    E-Print Network [OSTI]

    Bolinger, Mark A

    2009-01-01T23:59:59.000Z

    timeframe. Projected Wind Generation as % of Electricityrepresent the cost of wind generation. Wind Power Price (time-variability of wind generation is often such that its

  1. NREL Studies Wind Farm Aerodynamics to Improve Siting (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-04-01T23:59:59.000Z

    NREL researchers have used high-tech instruments and high-performance computing to understand atmospheric turbulence and turbine wake behavior in order to improve wind turbine design and siting within wind farms.

  2. Dynamic valuation model For wind development in regard to land value, proximity to transmission lines, and capacity factor

    E-Print Network [OSTI]

    Nikandrou, Paul

    2009-01-01T23:59:59.000Z

    Developing a wind farm involves many variables that can make or break the success of a potential wind farm project. Some variables such as wind data (capacity factor, wind rose, wind speed, etc.) are readily available in ...

  3. Stochastic modeling of lift and drag dynamics under turbulent conditions

    E-Print Network [OSTI]

    Peinke, Joachim

    measurement. The model is being developed with the aim to integrate it into a general wind energy converter dynamics, drag dynamics. 1 Introduction Wind energy converters (WECs) are permanently exposed to turbulent.peinke@forwind.de in every second, which imposes different risks. The dynamical nature of the wind has a significant impact

  4. Variable-Speed Wind Turbine Controller Systematic Design Methodology: A Comparison of Non-Linear and Linear Model-Based Designs

    SciTech Connect (OSTI)

    Hand, M. M.

    1999-07-30T23:59:59.000Z

    Variable-speed, horizontal axis wind turbines use blade-pitch control to meet specified objectives for three regions of operation. This paper focuses on controller design for the constant power production regime. A simple, rigid, non-linear turbine model was used to systematically perform trade-off studies between two performance metrics. Minimization of both the deviation of the rotor speed from the desired speed and the motion of the actuator is desired. The robust nature of the proportional-integral-derivative (PID) controller is illustrated, and optimal operating conditions are determined. Because numerous simulation runs may be completed in a short time, the relationship of the two opposing metrics is easily visualized. Traditional controller design generally consists of linearizing a model about an operating point. This step was taken for two different operating points, and the systematic design approach was used. A comparison of the optimal regions selected using the n on-linear model and the two linear models shows similarities. The linearization point selection does, however, affect the turbine performance slightly. Exploitation of the simplicity of the model allows surfaces consisting of operation under a wide range of gain values to be created. This methodology provides a means of visually observing turbine performance based upon the two metrics chosen for this study. Design of a PID controller is simplified, and it is possible to ascertain the best possible combination of controller parameters. The wide, flat surfaces indicate that a PID controller is very robust in this variable-speed wind turbine application.

  5. Inclusion of turbulence in solar modeling

    E-Print Network [OSTI]

    L. H. Li; F. J. Robinson; P. Demarque; S. Sofia; D. B. Guenther

    2001-11-07T23:59:59.000Z

    The general consensus is that in order to reproduce the observed solar p-mode oscillation frequencies, turbulence should be included in solar models. However, until now there has not been any well-tested efficient method to incorporate turbulence into solar modeling. We present here two methods to include turbulence in solar modeling within the framework of the mixing length theory, using the turbulent velocity obtained from numerical simulations of the highly superadiabatic layer of the sun at three stages of its evolution. The first approach is to include the turbulent pressure alone, and the second is to include both the turbulent pressure and the turbulent kinetic energy. The latter is achieved by introducing two variables: the turbulent kinetic energy per unit mass, and the effective ratio of specific heats due to the turbulent perturbation. These are treated as additions to the standard thermodynamic coordinates (e.g. pressure and temperature). We investigate the effects of both treatments of turbulence on the structure variables, the adiabatic sound speed, the structure of the highly superadiabatic layer, and the p-mode frequencies. We find that the second method reproduces the SAL structure obtained in 3D simulations, and produces a p-mode frequency correction an order of magnitude better than the first method.

  6. Wind resource assessment with a mesoscale non-hydrostatic model

    E-Print Network [OSTI]

    Boyer, Edmond

    Wind resource assessment with a mesoscale non- hydrostatic model Vincent Gunard, Center for Energy is developed for assessing the wind resource and its uncertainty. The work focuses on an existing wind farm mast measurements. The wind speed and turbulence fields are discussed. It is shown that the k

  7. Overview of the TurbSim Stochastic Inflow Turbulence Simulator

    SciTech Connect (OSTI)

    Kelley, N. D.; Jonkman, B. J.

    2005-09-01T23:59:59.000Z

    The TurbSim stochastic inflow turbulence code was developed to provide a numerical simulation of a full-field flow that contains coherent turbulence structures that reflect the proper spatiotemporal turbulent velocity field relationships seen in instabilities associated with nocturnal boundary layer flows that are not represented well by the IEC Normal Turbulence Models (NTM). Its purpose is to provide the wind turbine designer with the ability to drive design code (FAST or MSC.ADAMS) simulations of advanced turbine designs with simulated inflow turbulence environments that incorporate many of the important fluid dynamic features known to adversely affect turbine aeroelastic response and loading.

  8. Interpreting Power Anisotropy Measurements in Plasma Turbulence

    E-Print Network [OSTI]

    Chen, C H K; Horbury, T S; Schekochihin, A A

    2009-01-01T23:59:59.000Z

    A relationship between power anisotropy and wavevector anisotropy in turbulent fluctuations is derived. This can be used to interpret plasma turbulence measurements, for example in the solar wind. If fluctuations are anisotropic in shape then the ion gyroscale break point in spectra in the directions parallel and perpendicular to the magnetic field would not occur at the same frequency, and similarly for the electron gyroscale break point. This is an important consideration when interpreting solar wind observations in terms of anisotropic turbulence theories. Model magnetic field power spectra are presented assuming a cascade of critically balanced Alfven waves in the inertial range and kinetic Alfven waves in the dissipation range. The variation of power anisotropy with scale is compared to existing solar wind measurements and the similarities and differences are discussed.

  9. Turbulence and turbulent mixing in natural fluids

    E-Print Network [OSTI]

    Gibson, Carl H

    2010-01-01T23:59:59.000Z

    Turbulence and turbulent mixing in natural fluids begins with big bang turbulence powered by spinning combustible combinations of Planck particles and Planck antiparticles. Particle prograde accretion on a spinning pair releases 42% of the particle rest mass energy to produce more fuel for turbulent combustion. Negative viscosity and negative turbulence stresses work against gravity, creating mass-energy and space-time from the vacuum. Turbulence mixes cooling temperatures until a quark-gluon strong-force SF freeze-out. Gluon-viscosity anti-gravity ({\\Lambda}SF) exponentially inflates the fireball to preserve big bang turbulence information at scales larger than ct as the first fossil turbulence. Cosmic microwave background CMB temperature anisotropies show big bang turbulence fossils along with fossils of weak plasma turbulence triggered (10^12 s) as plasma viscous forces permit gravitational fragmentation on supercluster to galaxy mass scales (10^13 s). Turbulent morphologies and viscous-turbulent lengths a...

  10. TURBULENT FRBRNNING MVK130 Turbulent Combustion

    E-Print Network [OSTI]

    TURBULENT FRBRNNING MVK130 Turbulent Combustion Pong: 3.0 Betygskala: TH Valfri fr: M4 to combustion, McGraw-Hill 1996. #12;

  11. Optical Turbulence Characterization at LAMOST Site: Observations and Models

    E-Print Network [OSTI]

    Liu, L -Y; Yao, Y -Q; Vernin, J; Chadid, M; Wang, H -S; Yin, J; Wang, Y -P

    2015-01-01T23:59:59.000Z

    Atmospheric optical turbulence seriously limits the performance of high angular resolution instruments. An 8-night campaign of measurements was carried out at the LAMOST site in 2011, to characterize the optical turbulence. Two instruments were set up during the campaign: a Differential Image Motion Monitor (DIMM) used to measure the total atmospheric seeing, and a Single Star Scidar (SSS) to measure the vertical profiles of the turbulence C_n^2(h) and the horizontal wind velocity V(h). The optical turbulence parameters are also calculated with the Weather Research and Forecasting (WRF) model coupled with the Trinquet-Vernin model, which describes optical effects of atmospheric turbulence by using the local meteorological parameters. This paper presents assessment of the optical parameters involved in high angular resolution astronomy. Its includes seeing, isoplanatic angle, coherence time, coherence etendue, vertical profiles of optical turbulence intensity _n^2(h)$ and horizontal wind speed V(h). The median...

  12. atmospheric turbulence utilizing: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    M 2008-01-01 4 Scaling turbulent atmospheric stratification: a turbulencewave wind model Physics Websites Summary: to a growing body of analyses (e.g. 1,2,3,4,5 ) 1D the...

  13. INTERCHANGE RECONNECTION IN A TURBULENT CORONA

    SciTech Connect (OSTI)

    Rappazzo, A. F.; Matthaeus, W. H. [Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Ruffolo, D. [Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400 (Thailand); Servidio, S. [Dipartimento di Fisica, Universita della Calabria, I-87036 Cosenza (Italy); Velli, M., E-mail: rappazzo@udel.edu [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2012-10-10T23:59:59.000Z

    Magnetic reconnection at the interface between coronal holes and loops, the so-called interchange reconnection, can release the hotter, denser plasma from magnetically confined regions into the heliosphere, contributing to the formation of the highly variable slow solar wind. The interchange process is often thought to develop at the apex of streamers or pseudo-streamers, near Y- and X-type neutral points, but slow streams with loop composition have been recently observed along fanlike open field lines adjacent to closed regions, far from the apex. However, coronal heating models, with magnetic field lines shuffled by convective motions, show that reconnection can occur continuously in unipolar magnetic field regions with no neutral points: photospheric motions induce a magnetohydrodynamic turbulent cascade in the coronal field that creates the necessary small scales, where a sheared magnetic field component orthogonal to the strong axial field is created locally and can reconnect. We propose that a similar mechanism operates near and around boundaries between open and closed regions inducing a continual stochastic rearrangement of connectivity. We examine a reduced magnetohydrodynamic model of a simplified interface region between open and closed corona threaded by a strong unipolar magnetic field. This boundary is not stationary, becomes fractal, and field lines change connectivity continuously, becoming alternatively open and closed. This model suggests that slow wind may originate everywhere along loop-coronal-hole boundary regions and can account naturally and simply for outflows at and adjacent to such boundaries and for the observed diffusion of slow wind around the heliospheric current sheet.

  14. Incloud turbulence structure of marine stratocumulus N. Riemer,1

    E-Print Network [OSTI]

    of turbulent kinetic energy is dominantly driven by wind shear. Citation: Ching, J., N. Riemer, M. Dunn, and M3 Received 10 August 2010; revised 14 September 2010; accepted 20 September 2010; published 6) in July 2005, and identifies the dominant sources of turbulent kinetic energy. We used vertical veloc- ity

  15. Quantifying Turbulence for Tidal Power Applications

    SciTech Connect (OSTI)

    Thomson, Jim; Richmond, Marshall C.; Polagye, Brian; Durgesh, Vibhav

    2010-08-01T23:59:59.000Z

    Using newly collected data from a tidal power site in Puget Sound, WA, metrics for turbulence quantification are assessed and discussed. The quality of raw ping Acoustic Doppler Current Profiler (ADCP) data for turbulence studies is evaluated against Acoustic Doppler Velocimeter (ADV) data at a point. Removal of Doppler noise from the raw ping data is shown to be a crucial step in turbulence quantification. Excluding periods of slack tide, the turbulent intensity estimates at a height of 4.6 m above the seabed are 8% and 11% from the ADCP and ADV, respectively. Estimates of the turbulent dissipation rate are more variable, from 10e-3 to 10e-1 W/m^3. An example analysis of coherent Turbulent Kinetic Energy (TKE) is presented.

  16. Active control for turbulent premixed flame simulations

    SciTech Connect (OSTI)

    Bell, John B.; Day, Marcus S.; Grcar, Joseph F.; Lijewski, Michael J.

    2004-03-26T23:59:59.000Z

    Many turbulent premixed flames of practical interest are statistically stationary. They occur in combustors that have anchoring mechanisms to prevent blow-off and flashback. The stabilization devices often introduce a level of geometric complexity that is prohibitive for detailed computational studies of turbulent flame dynamics. As a result, typical detailed simulations are performed in simplified model configurations such as decaying isotropic turbulence or inflowing turbulence. In these configurations, the turbulence seen by the flame either decays or, in the latter case, increases as the flame accelerates toward the turbulent inflow. This limits the duration of the eddy evolutions experienced by the flame at a given level of turbulent intensity, so that statistically valid observations cannot be made. In this paper, we apply a feedback control to computationally stabilize an otherwise unstable turbulent premixed flame in two dimensions. For the simulations, we specify turbulent in flow conditions and dynamically adjust the integrated fueling rate to control the mean location of the flame in the domain. We outline the numerical procedure, and illustrate the behavior of the control algorithm. We use the simulations to study the propagation and the local chemical variability of turbulent flame chemistry.

  17. Correcting the record on the analysis of IBEX and STEREO data regarding variations in the neutral interstellar wind

    E-Print Network [OSTI]

    Frisch, P C; Drews, C; Leonard, T; Livadiotis, G; McComas, D J; Moebius, E; Schwadron, N A; Sokol, J M

    2015-01-01T23:59:59.000Z

    The journey of the Sun through space carries the solar system through a dynamic interstellar environment that is presently characterized by Mach 1 motion between the heliosphere and the surrounding interstellar medium (ISM). The interaction between the heliosphere and ISM is an evolving process due to the variable solar wind and to interstellar turbulence. Frisch et al. presented a meta-analysis of the historical data on the interstellar wind flowing through the heliosphere and concluded that temporal changes in the ecliptic longitude of the wind were statistically indicated by the data available in the refereed literature at the time of that writing. Lallement and Bertaux disagree with this result, and suggested, for instance, that a key instrumental response function of IBEX-Lo was incorrect and that the STEREO pickup ion data are unsuitable for diagnosing the flow of interstellar neutrals through the heliosphere. Here we show that temporal variations in the interstellar wind through the heliosphere are con...

  18. Spectrum of wind speed fluctuations encountered by a rotating blade of a wind energy conversion system: observations and theory

    SciTech Connect (OSTI)

    Connell, J.R.

    1981-11-01T23:59:59.000Z

    This report proves that the characteristics of turbulence that are experienced by a rotating wind turbine rotor blade are in principle and in practice very different than those experienced by a nonrotating rotor blade. Thus conventional wind characteristics, which are formulated for the nonrotating frame of reference, are more inaccurate than generally supposed. The measurements and mathematical model that are presented for turbulence observed in the rotating frame of reference represent the third phase of the Pacific Northwest Laboratory work aimed at providing an accurate turbulence description for use in the design and evaluation of the performance of wind turbines. The first phase of work was the measurement of wind with a vertical plane array of anemometers. The second phase was the physical interpretation of the measurements in terms of implications for wind turbine rotors and initiation of development of a model of wind/wind turbine interaction. The third phase involved measurement of turbulence by rotating sensors and mathematical development of a physical model of this representation of turbulence as independent checks and expansions of the vertical plane array results. A fourth phase, to correlate real wind turbine response with rotationally measured turbulence and thereby understand the wind/wind turbine interaction, is in progress and preliminary results are quite promising.

  19. Turbulent combustion

    SciTech Connect (OSTI)

    Talbot, L.; Cheng, R.K. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01T23:59:59.000Z

    Turbulent combustion is the dominant process in heat and power generating systems. Its most significant aspect is to enhance the burning rate and volumetric power density. Turbulent mixing, however, also influences the chemical rates and has a direct effect on the formation of pollutants, flame ignition and extinction. Therefore, research and development of modern combustion systems for power generation, waste incineration and material synthesis must rely on a fundamental understanding of the physical effect of turbulence on combustion to develop theoretical models that can be used as design tools. The overall objective of this program is to investigate, primarily experimentally, the interaction and coupling between turbulence and combustion. These processes are complex and are characterized by scalar and velocity fluctuations with time and length scales spanning several orders of magnitude. They are also influenced by the so-called {open_quotes}field{close_quotes} effects associated with the characteristics of the flow and burner geometries. The authors` approach is to gain a fundamental understanding by investigating idealized laboratory flames. Laboratory flames are amenable to detailed interrogation by laser diagnostics and their flow geometries are chosen to simplify numerical modeling and simulations and to facilitate comparison between experiments and theory.

  20. Rotationally sampled wind characteristics and correlations with MOD-OA wind turbine response

    SciTech Connect (OSTI)

    George, R.L.; Connell, J.R.

    1984-09-01T23:59:59.000Z

    This report presents results of a comprehensive wind and wind turbine measurement program: the Clayton, New Mexico, vertical plane array/MOD-OA project. In this experiment, the turbulent wind was measured for a large array of fixed anemometers located two blade diameters upwind of a 200-kW horizontal-axis wind turbine (HAWT). Simultaneously, key wind turbine response parameters were also measured. The first of two major objectives of this experiment was to determine the turbulent wind, rotationally sampled to emulate the motion of the wind turbine blade, for the range of different wind speeds and stability classes actually experienced by the wind turbine. The second major objective was to correlate this rotationally sampled wind with the wind turbine blade stress and power, in order to assess the usefulness of the wind measurements for wind turbine loads testing a prediction. Time series of rotationally sampled winds and wind turbine blade bending moments and power were converted to frequency spectra using Fourier transform techniques. These spectra were used as the basis for both qualitative and quantitative comparisons among the various cases. A quantitative comparison between the rotationally sampled wind input and blade bending response was made, using the Fourier spectra to estimate the blade transfer function. These transfer functions were then used to calculate an approximate damping coefficient for the MOD-OA fiberglass blade.

  1. Wind farm electrical system

    DOE Patents [OSTI]

    Erdman, William L.; Lettenmaier, Terry M.

    2006-07-04T23:59:59.000Z

    An approach to wind farm design using variable speed wind turbines with low pulse number electrical output. The output of multiple wind turbines are aggregated to create a high pulse number electrical output at a point of common coupling with a utility grid network. Power quality at each individual wind turbine falls short of utility standards, but the aggregated output at the point of common coupling is within acceptable tolerances for utility power quality. The approach for aggregating low pulse number electrical output from multiple wind turbines relies upon a pad mounted transformer at each wind turbine that performs phase multiplication on the output of each wind turbine. Phase multiplication converts a modified square wave from the wind turbine into a 6 pulse output. Phase shifting of the 6 pulse output from each wind turbine allows the aggregated output of multiple wind turbines to be a 24 pulse approximation of a sine wave. Additional filtering and VAR control is embedded within the wind farm to take advantage of the wind farm's electrical impedence characteristics to further enhance power quality at the point of common coupling.

  2. WIND ENERGY Wind Energ. 2013; 00:112

    E-Print Network [OSTI]

    that by a novel change of variables, which focuses on power flows, we can transform the problem to one with linear rejection, model predictive control, convex optimization, wind power control, energy storage, power output to reliable operation of power systems due to the fluctuating nature of wind power. Thus, modern wind power

  3. Modeling wind forcing in phase resolving simulation of nonlinear wind waves

    E-Print Network [OSTI]

    Kalmikov, Alexander G

    2010-01-01T23:59:59.000Z

    Wind waves in the ocean are a product of complex interaction of turbulent air flow with gravity driven water surface. The coupling is strong and the waves are non-stationary, irregular and highly nonlinear, which restricts ...

  4. 6 Scalar Turbulence within the Canopy Sublayer

    E-Print Network [OSTI]

    Katul, Gabriel

    Engineering, University of Brasilia, Brazil 4 Department of Hydraulics, Transport and Civil Infrastructure changes in turbulent kinetic energy dissipation rate inside canopies, the relative importance of ejections that leads to scalar ramps is briefly discussed. The work draws upon a large number of flume, wind tunnel

  5. Paul S. Veers Wind Energy Technology Department

    E-Print Network [OSTI]

    Ginzel, Matthew

    turbulence simulation, fatigue analysis, reliability, structural dynamics, aeroelastic tailoring of blades journal for progress and applications in wind power. He has a MS in Engineering Mechanics fromPaul S. Veers Wind Energy Technology Department Sandia National Laboratories Thursday, April 8th 3

  6. Cosmic-ray diffusion in magnetized turbulence

    E-Print Network [OSTI]

    Tautz, R C

    2015-01-01T23:59:59.000Z

    The problem of cosmic-ray scattering in the turbulent electromagnetic fields of the interstellar medium and the solar wind is of great importance due to the variety of applications of the resulting diffusion coefficients. Examples are diffusive shock acceleration, cosmic-ray observations, and, in the solar system, the propagation of coronal mass ejections. In recent years, it was found that the simple diffusive motion that had been assumed for decades is often in disagreement both with numerical and observational results. Here, an overview is given of the interaction processes of cosmic rays and turbulent electromagnetic fields. First, the formation of turbulent fields due to plasma instabilities is treated, where especially the non-linear behavior of the resulting unstable wave modes is discussed. Second, the analytical and the numerical side of high-energy particle propagation will be reviewed by presenting non-linear analytical theories and Monte-Carlo simulations. For the example of the solar wind, the im...

  7. Effects of Changing Atmospheric Conditions on Wind Turbine Performance (Poster)

    SciTech Connect (OSTI)

    Clifton, A.

    2012-12-01T23:59:59.000Z

    Multi-megawatt, utility-scale wind turbines operate in turbulent and dynamic winds that impact turbine performance in ways that are gradually becoming better understood. This poster presents a study made using a turbulent flow field simulator (TurbSim) and a Turbine aeroelastic simulator (FAST) of the response of a generic 1.5 MW wind turbine to changing inflow. The turbine power output is found to be most sensitive to wind speed and turbulence intensity, but the relationship depends on the wind speed with respect to the turbine's rated wind speed. Shear is found to be poorly correlated to power. A machine learning method called 'regression trees' is used to create a simple model of turbine performance that could be used as part of the wind resource assessment process. This study has used simple flow fields and should be extended to more complex flows, and validated with field observations.

  8. Generation of large-scale winds in horizontally anisotropic convection

    E-Print Network [OSTI]

    von Hardenberg, J; Provenzale, A; Spiegel, E A

    2015-01-01T23:59:59.000Z

    We simulate three-dimensional, horizontally periodic Rayleigh-B\\'enard convection between free-slip horizontal plates, rotating about a horizontal axis. When both the temperature difference between the plates and the rotation rate are sufficiently large, a strong horizontal wind is generated that is perpendicular to both the rotation vector and the gravity vector. The wind is turbulent, large-scale, and vertically sheared. Horizontal anisotropy, engendered here by rotation, appears necessary for such wind generation. Most of the kinetic energy of the flow resides in the wind, and the vertical turbulent heat flux is much lower on average than when there is no wind.

  9. NERC Presentation: Accommodating High Levels of Variable Generation...

    Office of Environmental Management (EM)

    of variable electricity eneration. Variable resources are types of electric power generation that rely on an uncontrolled, "variable" fuel (e.g. wind, sunlight, waves, tidal...

  10. Modeling of wind and radar for simulation in four-dimensional navigation environment

    E-Print Network [OSTI]

    Malherbe, Gerard Andre

    1976-01-01T23:59:59.000Z

    Disturbances affecting time control precision in four-dimension navigation are modeled. Several models of wind and turbulence from the ground to ten thousand feet are developed. A distinction is made between wind mean and ...

  11. Northerly surface wind events over the eastern North Pacific Ocean : spatial distribution, seasonality, atmospheric circulation, and forcing

    E-Print Network [OSTI]

    Taylor, Stephen V.

    2006-01-01T23:59:59.000Z

    D. (2005), California Wind Resources, CEC publication # CEC-level inversions with surface wind and temperature at PointD. W. Stuart (1986), Mesoscale wind variability near Point

  12. TURBULENT FRBRNNING MVK 130 Turbulent Combustion

    E-Print Network [OSTI]

    TURBULENT FRBRNNING MVK 130 Turbulent Combustion Antal pong: 3.0. Valfri fr: M4. Kursansvarig program med hnsyn till de modeller som anvnds. Litteratur S.R. Turns: An introduction to combustion, Mc

  13. WIND ENERGY Wind Energ. (2014)

    E-Print Network [OSTI]

    Peinke, Joachim

    2014-01-01T23:59:59.000Z

    loads from the wind inflow through rotor aerodynamics, drive train and power electronics is stillWIND ENERGY Wind Energ. (2014) Published online in Wiley Online Library (wileyonlinelibrary wind inflow conditions M. R. Luhur, J. Peinke, J. Schneemann and M. Wchter ForWind-Center for Wind

  14. Design and Test of a Variable Speed Wind Turbine System Employing a Direct Drive Axial Flux Synchronization Generator: 29 October 2002 - 31 December 2005

    SciTech Connect (OSTI)

    Lipo, T. A.; Tenca, P.

    2006-07-01T23:59:59.000Z

    The goal of this funded research project is the definition, analytical investigation, modeling, and prototype realization of a current-source conversion topology tailored to high-power wind turbines.

  15. Design and Test of DC Voltage Link Conversion System and Brushless Doubly-Fed Induction Generator for Variable-Speed Wind Energy Applications: August 1999--May 2003

    SciTech Connect (OSTI)

    Lipo, T.A.; Panda, D.; Zarko, D.

    2005-11-01T23:59:59.000Z

    This report describes four low-cost alternative power converters for processing the power developed by a doubly fed wound-rotor induction generator for wind energy conversion systems.

  16. Economic and technical impacts of wind variability and intermittency on long-term generation expansion planning in the U.S

    E-Print Network [OSTI]

    Brun, Caroline Elisabeth Hnia

    2011-01-01T23:59:59.000Z

    Electricity power systems are a major source of carbon dioxide emissions and are thus required to change dramatically under climate policy. Large-scale deployment of wind power has emerged as one key driver of the shift ...

  17. Reassessing Wind Potential Estimates for India: Economic and Policy Implications

    E-Print Network [OSTI]

    Phadke, Amol

    2012-01-01T23:59:59.000Z

    of variability of wind generation and costs related toLaxson (2006). Wind Turbine Design Cost and Scaling Model.MW installed worldwide. 6 Wind energy costs in India are

  18. Supercomputers Capture Turbulence in the Solar Wind

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    at large eddies is transported to successively smaller scales until it is dissipated as heat. (Image by Burlen Loring, Berkeley Lab) As inhabitants of Earth, our lives are...

  19. Wind shear for large wind turbine generators at selected tall tower sites

    SciTech Connect (OSTI)

    Elliott, D.L.

    1984-04-01T23:59:59.000Z

    The objective of the study described in this report is to examine the nature of wind shear profiles and their variability over the height of large horizontal-axis wind turbines and to provide information on wind shear relevant to the design and opertion of large wind turbines. Wind turbine fatigue life and power quality are related through the forcing functions on the blade to the shapes of the wind shear profiles and their fluctuations over the disk of rotation.

  20. Session: Poster Session + Poster Award + Scientific Award + Excellent young wind doctor award (PO.121) Track: Technical

    E-Print Network [OSTI]

    in turbulence intensity in wakes behind wind turbines can imply a significant reduction in fatigue lifetime by a stochastic part and a deterministic, sinusoidal part with frequency Behind a wind turbine a wake is formed intensity in wakes behind wind turbines can imply a significant reduction in the fatigue lifetime of wind

  1. How to use CFD for Wind in Terrain ... real-life experience!

    E-Print Network [OSTI]

    : Turbulence modelling / numerical methods Inclusion of wind turbine wake Temperature stratification 2 study 3. Construction and operation 4. Wind turbine breakdown! 5. Wind measurements / CFD simulations1 How to use CFD for Wind in Terrain ... real-life experience! CFD day at Suzlon, October 2007 A

  2. Session: Wind resources and site characterisation 2 (DW3.5) Track: Technical

    E-Print Network [OSTI]

    including wind shear, turbulence intensities etc., at potential wind turbine positions. - ApplicationSession: Wind resources and site characterisation 2 (DW3.5) Track: Technical THE BOLUND EXPERIMENT - A NEW DATASET OF LOCAL WIND CONDITIONS IN COMPLEX TERRAIN (abstract-ID: 357) Jeppe Johansen (Risø DTU

  3. Computational aspects of astrophysical MHD and turbulence

    E-Print Network [OSTI]

    Axel Brandenburg

    2001-09-27T23:59:59.000Z

    The advantages of high-order finite difference scheme for astrophysical MHD and turbulence simulations are highlighted. A number of one-dimensional test cases are presented ranging from various shock tests to Parker-type wind solutions. Applications to magnetized accretion discs and their associated outflows are discussed. Particular emphasis is placed on the possibility of dynamo action in three-dimensional turbulent convection and shear flows, which is relevant to stars and astrophysical discs. The generation of large scale fields is discussed in terms of an inverse magnetic cascade and the consequences imposed by magnetic helicity conservation are reviewed with particular emphasis on the issue of alpha-quenching.

  4. The interaction of katabatic winds and mountain waves

    SciTech Connect (OSTI)

    Poulos, G.S.

    1997-01-01T23:59:59.000Z

    The variation in the oft-observed, thermally-forced, nocturnal katabatic winds along the east side of the Rocky Mountains can be explained by either internal variability or interactions with various other forcings. Though generally katabatic flows have been studied as an entity protected from external forcing by strong thermal stratification, this work investigates how drainage winds along the Colorado Front Range interact with, in particular, topographically forced mountain waves. Previous work has shown, based on measurements taken during the Atmospheric Studies in Complex Terrain 1993 field program, that the actual dispersion in katabatic flows is often greater than reflected in models of dispersion. The interaction of these phenomena is complicated and non-linear since the amplitude, wavelength and vertical structure of mountain waves developed by flow over the Rocky Mountain barrier are themselves partly determined by the evolving atmospheric stability in which the drainage flows develop. Perturbations to katabatic flow by mountain waves, relative to their more steady form in quiescent conditions, are found to be caused by both turbulence and dynamic pressure effects. The effect of turbulent interaction is to create changes to katabatic now depth, katabatic flow speed, katabatic jet height and, vertical thermal stratification. The pressure effect is found to primarily influence the variability of a given katabatic now through the evolution of integrated column wave forcing on surface pressure. Variability is found to occur on two scales, on the mesoscale due to meso-gamma scale mountain wave evolution, and on the microscale, due to wave breaking. Since existing parameterizations for the statically stable case are predominantly based on nearly flat terrain atmospheric measurements under idealized or nearly quiescent conditions, it is no surprise that these parameterizations often contribute to errors in prediction, particularly in complex terrain.

  5. Wind Powering America Fact Sheet Series 1 Wind energy is more expensive than conventional energy.

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Wind Powering America Fact Sheet Series 1 Wind energy is more expensive than conventional energy. Wind's variability does increase the day-to-day and minute-to- minute operating costs of a utility system because the wind variations do affect the operation of other plants. But investigations by utility

  6. COMPARISON OF WIND AND WIND SHEAR CLIMATOLOGIES DERIVED FROM HIGH-RESOLUTION RADIOSONDES AND THE ECMWF MODEL

    E-Print Network [OSTI]

    Stoffelen, Ad

    COMPARISON OF WIND AND WIND SHEAR CLIMATOLOGIES DERIVED FROM HIGH-RESOLUTION RADIOSONDES wind and its vertical gradient, i.e. wind-shear, is characterized as a function of climate region. For a better representation of the average atmospheric wind and shear and their variabilities, high

  7. On the Physics of Kinetic-Alfven Turbulence

    E-Print Network [OSTI]

    Boldyrev, Stanislav

    2013-01-01T23:59:59.000Z

    Observations reveal nearly power-law spectra of magnetic and density plasma fluctuations at subproton scales in the solar wind, which indicates the presence of a turbulent cascade. We discuss the three-field and two-field models for micro-scale plasma fluctuations, and then present the results of numerical simulations of a two-field model of kinetic-Alfven turbulence, which models plasma motion at sub-proton scales.

  8. Commonwealth Wind Commercial Wind Program

    Broader source: Energy.gov [DOE]

    Through the Commonwealth Wind Incentive Program Commercial Wind Initiative the Massachusetts Clean Energy Center (MassCEC) offers site assessment grants of services, feasibility study grants, a...

  9. Logarithmic Wind Profile: A Stability Wind Shear Term

    E-Print Network [OSTI]

    Sakagami, Yoshiaki; Haas, Reinaldo; Passos, Julio C; Taves, Frederico F

    2014-01-01T23:59:59.000Z

    A stability wind shear term of logarithmic wind profile based on the terms of turbulent kinetic energy equation is proposed. The fraction influenced by thermal stratification is considered in the shear production term. This thermally affected shear is compared with buoyant term resulting in a stability wind shear term. It is also considered Reynolds stress as a sum of two components associated with wind shear from mechanical and thermal stratification process. The stability wind shear is responsible to Reynolds stress of thermal stratification term, and also to Reynolds stress of mechanical term at no neutral condition. The wind profile and its derivative are validated with data from Pedra do Sal experiment in a flat terrain and 300m from shoreline located in northeast coast of Brazil. It is close to the Equator line, so the meteorological condition are strongly influenced by trade winds and sea breeze. The site has one 100m tower with five instrumented levels, one 3D sonic anemometer, and a medium-range wind...

  10. Turbulent boundary layers interacting with groups of obstacles Project Staff Principal investigator: Dr Costantino Manes

    E-Print Network [OSTI]

    Sbester, Andrs

    (wind or marine) can generate, estimating carbon dioxide exchange between forests and the atmosphere-Dimensional (2-D) flow, where mean turbulent properties are uniform (or almost uniform) along one direction

  11. Turbulent flow in graphene

    E-Print Network [OSTI]

    Kumar S. Gupta; Siddhartha Sen

    2010-06-05T23:59:59.000Z

    We demonstrate the possibility of a turbulent flow of electrons in graphene in the hydrodynamic region, by calculating the corresponding turbulent probability density function. This is used to calculate the contribution of the turbulent flow to the conductivity within a quantum Boltzmann approach. The dependence of the conductivity on the system parameters arising from the turbulent flow is very different from that due to scattering.

  12. WIND ENERGY Wind Energ. (2014)

    E-Print Network [OSTI]

    2014-01-01T23:59:59.000Z

    in the near wake. In conclusion, WiTTS performs satisfactorily in the rotor region of wind turbine wakes under neutral stability. Copyright 2014 John Wiley & Sons, Ltd. KEYWORDS wind turbine wake; wake model; self in wind farms along several rows and columns. Because wind turbines generate wakes that propagate downwind

  13. ASYMMETRIC SOLAR WIND ELECTRON DISTRIBUTIONS

    SciTech Connect (OSTI)

    Yoon, Peter H.; Kim, Sunjung; Lee, Junggi; Lee, Junhyun; Park, Jongsun; Park, Kyungsun; Seough, Jungjoon [School of Space Research, Kyung Hee University, Yongin-Si, Gyeonggi-Do 446-701 (Korea, Republic of); Hong, Jinhy [Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of)

    2012-08-20T23:59:59.000Z

    The present paper provides a possible explanation for the solar wind electron velocity distribution functions possessing asymmetric energetic tails. By numerically solving the electrostatic weak turbulence equations that involve nonlinear interactions among electrons, Langmuir waves, and ion-sound waves, it is shown that different ratios of ion-to-electron temperatures lead to the generation of varying degrees of asymmetric tails. The present finding may be applicable to observations in the solar wind near 1 AU and in other regions of the heliosphere and interplanetary space.

  14. Assessing the Evolution of the Solar Wind through the Spectrum of Velocity Fluctuations from 1 5 AU.

    E-Print Network [OSTI]

    ;2 Abstract: Turbulent processes occur in the solar wind and contribute to solar wind evolution and heating assistance he's provided. #12;4 Contents 1. The Solar Wind 1.1 Early Remote Observations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 #12;5 Chapter 1 The Solar Wind 1.1 Early Remote Observations The earliest observations of the sun

  15. Upstream Measurements of Wind Profiles with Doppler Lidar for Improved Wind Energy Integration

    SciTech Connect (OSTI)

    Rodney Frehlich

    2012-10-30T23:59:59.000Z

    New upstream measurements of wind profiles over the altitude range of wind turbines will be produced using a scanning Doppler lidar. These long range high quality measurements will provide improved wind power forecasts for wind energy integration into the power grid. The main goal of the project is to develop the optimal Doppler lidar operating parameters and data processing algorithms for improved wind energy integration by enhancing the wind power forecasts in the 30 to 60 minute time frame, especially for the large wind power ramps. Currently, there is very little upstream data at large wind farms, especially accurate wind profiles over the full height of the turbine blades. The potential of scanning Doppler lidar will be determined by rigorous computer modeling and evaluation of actual Doppler lidar data from the WindTracer system produced by Lockheed Martin Coherent Technologies, Inc. of Louisville, Colorado. Various data products will be investigated for input into numerical weather prediction models and statistically based nowcasting algorithms. Successful implementation of the proposed research will provide the required information for a full cost benefit analysis of the improved forecasts of wind power for energy integration as well as the added benefit of high quality wind and turbulence information for optimal control of the wind turbines at large wind farms.

  16. Passively cooled direct drive wind turbine

    DOE Patents [OSTI]

    Costin, Daniel P. (Chelsea, VT)

    2008-03-18T23:59:59.000Z

    A wind turbine is provided that passively cools an electrical generator. The wind turbine includes a plurality of fins arranged peripherally around a generator house. Each of the fins being oriented at an angle greater than zero degrees to allow parallel flow of air over the fin. The fin is further tapered to allow a constant portion of the fin to extend beyond the air stream boundary layer. Turbulence initiators on the nose cone further enhance heat transfer at the fins.

  17. Modeling Compressed Turbulence

    SciTech Connect (OSTI)

    Israel, Daniel M. [Los Alamos National Laboratory

    2012-07-13T23:59:59.000Z

    From ICE to ICF, the effect of mean compression or expansion is important for predicting the state of the turbulence. When developing combustion models, we would like to know the mix state of the reacting species. This involves density and concentration fluctuations. To date, research has focused on the effect of compression on the turbulent kinetic energy. The current work provides constraints to help development and calibration for models of species mixing effects in compressed turbulence. The Cambon, et al., re-scaling has been extended to buoyancy driven turbulence, including the fluctuating density, concentration, and temperature equations. The new scalings give us helpful constraints for developing and validating RANS turbulence models.

  18. Journal of Turbulence, 2013 Vol. 14, No. 6, 3839, http://dx.doi.org/10.1080/14685248.2013.825725

    E-Print Network [OSTI]

    Dabiri, John O.

    .1080/14685248.2013.825725 ERRATUM Energy exchange in an array of vertical-axis wind turbines [Journal of Turbulence, Vol. 13, No. 38 2012) We analyze the flow field within an array of 18 counter-rotating, vertical-axis wind tur- bines a typical horizontal-axis wind turbine (HAWT). The observed high level of the planform kinetic energy flux

  19. NREL Develops New Controls that Proactively Adapt to the Wind (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-11-01T23:59:59.000Z

    Until now, wind turbine controls that reduce the impacts of wind gusts and turbulence were always reactive-responding to the wind rather than anticipating it. But with today's laser-based sensors that measure wind speed ahead of the turbine, researchers at the National Renewable Energy Laboratory (NREL) and their industry partners are developing more intelligent controls. The world's first field tests of these controls are currently underway at the National Wind Technology Center (NWTC) at NREL, with plans for future commercialization.

  20. NREL Develops New Controls that Proactively Adapt to the Wind (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-10-01T23:59:59.000Z

    Until now, wind turbine controls that reduce the impacts of wind gusts and turbulence were always reactive -- responding to the wind rather than anticipating it. But with today's laser-based sensors that measure wind speed ahead of the turbine, researchers at the National Renewable Energy Laboratory (NREL) and their industry partners are developing more intelligent controls. The world's first field tests of these controls are currently underway at the National Wind Technology Center (NWTC) at NREL, with plans for future commercialization.

  1. Distributed Wind Energy in Idaho

    SciTech Connect (OSTI)

    Gardner, John; Ferguson, James; Ahmed-Zaid, Said; Johnson, Kathryn; Haynes, Todd; Bennett, Keith

    2009-01-31T23:59:59.000Z

    Project Objective: 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. Background: At its core, the technological challenge inherent in Wind Energy is the transformation of a highly variable form of energy to one which is compatible with the commercial power grid or another useful application. A major economic barrier to the success of distributed wind technology is the relatively high capital investment (and related long payback periods) associated with wind turbines. This project will carry out fundamental research and technology development to address both the technological and economic barriers. â?¢ Active drive train control holds the potential to improve the overall efficiency of a turbine system by allowing variable speed turbine operation while ensuring a tight control of generator shaft speed, thus greatly simplifying power conditioning. â?¢ Recent blade aerodynamic advancements have been focused on large, utility-scale wind turbine generators (WTGs) as opposed to smaller WTGs designed for distributed generation. Because of Reynolds Number considerations, blade designs do not scale well. Blades which are aerodynamically optimized for distributed-scale WTGs can potentially reduce the cost of electricity by increasing shaft-torque in a given wind speed. â?¢ Grid-connected electric generators typically operate at a fixed speed. If a generator were able to economically operate at multiple speeds, it could potentially convert more of the windâ??s energy to electricity, thus reducing the cost of electricity. This research directly supports the stated goal of the Wind and Hydropower Technologies Program for Distributed Wind Energy Technology: By 2007, reduce the cost of electricity from distributed wind systems to 10 to 15 cents/kWh in Class 3 wind resources, the same level that is currently achievable in Class 5 winds.

  2. Wind Farm

    Office of Energy Efficiency and Renewable Energy (EERE)

    The wind farm in Greensburg, Kansas, was completed in spring 2010, and consists of ten 1.25 megawatt (MW) wind turbines that supply enough electricity to power every house, business, and municipal...

  3. Wind Energy

    Broader source: Energy.gov [DOE]

    Presentation covers wind energy at the Federal Utility Partnership Working Group (FUPWG) meeting, held on November 18-19, 2009.

  4. Operational Impacts of Large Deployments of Offshore Wind (Poster)

    SciTech Connect (OSTI)

    Ibanez, E.; Heaney, M.

    2014-10-01T23:59:59.000Z

    The potential operational impact of deploying 54 GW of offshore wind in the United States was examined. The capacity was not evenly distributed; instead, it was concentrated in regions with better wind quality and close to load centers (Table 1). A statistical analysis of offshore wind power time series was used to assess the effect on the power system. The behavior of offshore wind resembled that of onshore wind, despite the former presenting higher capacity factors, more consistent power output across seasons, and higher variability levels. Thus, methods developed to manage onshore wind variability can be extended and applied to offshore wind.

  5. Wind shear climatology for large wind turbine generators

    SciTech Connect (OSTI)

    Elliott, D.L.; Wendell, L.L.; Heflick, S.K.

    1982-10-01T23:59:59.000Z

    Climatological wind shear analyses relevant to the design and operation of multimegawatt wind turbines are provided. Insight is provided for relating the wind experienced by a rotating blade in a shear flow to the analysis results. A simple analysis of the wind experienced by a rotating blade for three types of wind shear profiles under steady-state conditions is presented in graphical form. Comparisons of the magnitude and frequency of the variations in 1) the wind sensed by a single blade element, 2) the sum, and 3) the difference of the winds sensed by opposite blade elements show strong sensitivity to profile shape. These three items represent forcing functions that can be related to 1) flatwise bending moment, 2) torque on the shaft, and 3) teeter angle. A computer model was constructed to simulate rotational sampling of 10-s sampled winds from a tall tower for three different types of large wind turbines. Time series produced by the model indicated that the forcing functions on a rotating blade vary according to the shear profile encountered during each revolution as opposed to a profile derived from average wind conditions, e.g., hourly average winds. An analysis scheme was developed to establish a climatology of wind shear profiles derived from 10-s sampled winds and hourly average winds measured over a one-year period at several levels on a tall tower. Because of the sensitivity of the forcing function variability to profile shape, the analyses performed and presented are in the form of joint frequency distributions of velocity differences of the the top-to-hub versus the hub-to-bottom portion of disks of rotation for the three turbine configurations.

  6. Changes in the Economic Value of Variable Generation at High Penetration Levels: A Pilot Case Study of California

    E-Print Network [OSTI]

    Mills, Andrew

    2013-01-01T23:59:59.000Z

    The variable O&M cost of wind and solar is assumed to bethe relative levelized cost of wind and solar supply. OneJ. Swider and C. Weber. The costs of winds intermittency in

  7. Kinetic dissipation and anisotropic heating in a turbulent collisionless plasma

    E-Print Network [OSTI]

    Cassak, Paul

    - lar wind find evidence that most of the turbulent energy at high wavenumber resides in highly oblique Laboratory, University of Delaware, Newark, Delaware 19716, USA Received 14 October 2008; accepted 12, differences from MHD arise, as energy dissipates into heat almost exclusively through the magnetic field

  8. Ris-R-Report Investigation of turbulence measurements

    E-Print Network [OSTI]

    many times that the mean horizontal wind speed measured by a lidar over flat terrain compares very well. We then evaluate this model by comparing the theoretical results to experimental data obtained.......................................................12 3.1 What can a cw conically scanning lidar tell us about turbulence?...12 3.2 Illustration

  9. Nonlinear Control of a Wind Turbine Sven Creutz Thomsen

    E-Print Network [OSTI]

    Nonlinear Control of a Wind Turbine Sven Creutz Thomsen Kongens Lyngby 2006 #12; Technical describes analysis of various nonlinear control methods for controlling a wind turbine. High speed wind Modeling and analysis 5 2 Model descriptions 7 2.1 Variable speed wind turbine

  10. Nonlinear Control of a Wind Turbine Sven Creutz Thomsen

    E-Print Network [OSTI]

    Nonlinear Control of a Wind Turbine Sven Creutz Thomsen Kongens Lyngby 2006 #12;Technical describes analysis of various nonlinear control methods for controlling a wind turbine. High speed wind descriptions 7 2.1 Variable speed wind turbine . . . . . . . . . . . . . . . . . . . . . . . . 8 2.2 Constant

  11. An overview: Challenges in wind technology development

    SciTech Connect (OSTI)

    Thresher, R W; Hock, S M

    1991-12-01T23:59:59.000Z

    Developing innovative wind turbine components and advanced turbine configurations is a primary focus for wind technology researchers. In their rush to bring these new components and systems to the marketplace, designers and developers should consider the lessons learned in the wind farms over the past 10 years. Experience has shown that a disciplined design approach is required that realistically accounts for the turbulence-induced loads, unsteady stall loading, and fatigue effects. This paper reviews past experiences and compares current modelling capabilities with experimental measurements in order to identify some of the knowledge gaps that challenge designers of advanced components and systems. 7 refs., 11 figs.

  12. Turbulent protostellar discs

    E-Print Network [OSTI]

    Axel Brandenburg

    2008-08-07T23:59:59.000Z

    Aspects of turbulence in protostellar accretion discs are being reviewed. The emergence of dead zones due to poor ionization and alternatives to the magneto-rotational instability are discussed. The coupling between dust and gas in protostellar accretion discs is explained and turbulent drag is compared with laminar drag in the Stokes and Epstein regimes. Finally, the significance of magnetic field generation in turbulent discs is emphasized in connection with driving outflows and with star-disc coupling.

  13. Performance of twist-coupled blades on variable speed rotors

    SciTech Connect (OSTI)

    Lobitz, D.W.; Veers, P.S.; Laino, D.J.

    1999-12-07T23:59:59.000Z

    The load mitigation and energy capture characteristics of twist-coupled HAWT blades that are mounted on a variable speed rotor are investigated in this paper. These blades are designed to twist toward feather as they bend with pretwist set to achieve a desirable twist distribution at rated power. For this investigation, the ADAMS-WT software has been modified to include blade models with bending-twist coupling. Using twist-coupled and uncoupled models, the ADAMS software is exercised for steady wind environments to generate C{sub p} curves at a number of operating speeds to compare the efficiencies of the two models. The ADAMS software is also used to generate the response of a twist-coupled variable speed rotor to a spectrum of stochastic wind time series. This spectrum contains time series with two mean wind speeds at two turbulence levels. Power control is achieved by imposing a reactive torque on the low speed shaft proportional to the RPM squared with the coefficient specified so that the rotor operates at peak efficiency in the linear aerodynamic range, and by limiting the maximum RPM to take advantage of the stall controlled nature of the rotor. Fatigue calculations are done for the generated load histories using a range of material exponents that represent materials from welded steel to aluminum to composites, and results are compared with the damage computed for the rotor without twist-coupling. Results indicate that significant reductions in damage are achieved across the spectrum of applied wind loading without any degradation in power production.

  14. Wind stress measurements from the QuikSCAT-SeaWinds scatterometer tandem mission and the impact on an ocean model

    E-Print Network [OSTI]

    Talley, Lynne D.

    Wind stress measurements from the QuikSCAT-SeaWinds scatterometer tandem mission and the impact by the QuikSCAT-SeaWinds scatterometer tandem mission (AprilOctober 2003) and their impact on ocean model simulation. The diurnal variability captured by twice-daily scatterometer wind from the tandem mission

  15. Annual Report on U.S. Wind Power Installation, Cost, and Performance Trends: 2006

    E-Print Network [OSTI]

    2008-01-01T23:59:59.000Z

    50 kW. Here we present wind generation as a percentage oftotal electricity consumption. Wind generation on this basistime-variability of wind generation is often such that its

  16. Operational behavior of a double-fed permanent magnet generator for wind turbines

    E-Print Network [OSTI]

    Reddy, Sivananda Kumjula

    2005-01-01T23:59:59.000Z

    Greater efficiency in wind turbine systems is achieved by allowing the rotor to change its rate of rotation as the wind speed changes. The wind turbine system is decoupled from the utility grid and a variable speed operation ...

  17. Feasibility analysis of coordinated offshore wind project development in the U.S.

    E-Print Network [OSTI]

    Zhang, Mimi Q

    2008-01-01T23:59:59.000Z

    Wind energy is one of the cleanest and most available resources in the world, and advancements in wind technology are making it more cost effective. Though wind power is rapidly developing in many regions, its variable ...

  18. Wave turbulence served up on a plate

    E-Print Network [OSTI]

    Pablo Cobelli; Philippe Petitjeans; Agnes Maurel; Vincent Pagneux; Nicolas Mordant

    2009-10-28T23:59:59.000Z

    Wave turbulence in a thin elastic plate is experimentally investigated. By using a Fourier transform profilometry technique, the deformation field of the plate surface is measured simultaneously in time and space. This enables us to compute the wavevector-frequency Fourier ($\\mathbf k, \\omega$) spectrum of the full space-time deformation velocity. In the 3D ($\\mathbf k, \\omega$) space, we show that the energy of the motion is concentrated on a 2D surface that represents a nonlinear dispersion relation. This nonlinear dispersion relation is close to the linear dispersion relation. This validates the usual wavenumber-frequency change of variables used in many experimental studies of wave turbulence. The deviation from the linear dispersion, which increases with the input power of the forcing, is attributed to weak non linear effects. Our technique opens the way for many new extensive quantitative comparisons between theory and experiments of wave turbulence.

  19. Fossil turbulence and fossil turbulence waves can be dangerous

    E-Print Network [OSTI]

    Carl H Gibson

    2012-11-25T23:59:59.000Z

    Turbulence is defined as an eddy-like state of fluid motion where the inertial-vortex forces of the eddies are larger than any other forces that tend to damp the eddies out. By this definition, turbulence always cascades from small scales where vorticity is created to larger scales where turbulence fossilizes. Fossil turbulence is any perturbation in a hydrophysical field produced by turbulence that persists after the fluid is no longer turbulent at the scale of the perturbation. Fossil turbulence patterns and fossil turbulence waves preserve and propagate energy and information about previous turbulence. Ignorance of fossil turbulence properties can be dangerous. Examples include the Osama bin Laden helicopter crash and the Air France 447 Airbus crash, both unfairly blamed on the pilots. Observations support the proposed definitions, and suggest even direct numerical simulations of turbulence require caution.

  20. Forced turbulence in thermally bistable gas: A parameter study

    E-Print Network [OSTI]

    Seifried, D; Niemeyer, J C

    2010-01-01T23:59:59.000Z

    Context: The thermal instability is one of the dynamical agents for turbulence in the diffuse interstellar medium, where both, turbulence and thermal instability interact in a highly non-linear manner. Aims: We study basic properties of turbulence in thermally bistable gas for variable simulation parameters. The resulting cold gas fractions can be applied as parameterisation in simulations on galactic scales. Methods: Turbulent flow is induced on large scales by means of compressive stochastic forcing in a periodic box. The compressible Euler equations with constant UV heating and a parameterised cooling function are solved on uniform grids. We investigate several values of the mean density of the gas and different magnitudes of the forcing. For comparison with other numerical studies, solenoidal forcing is applied as well. Results: After a transient phase, we observe that a state of statistically stationary turbulence is approached. Compressive forcing generally produces a two-phase medium, with a decreasing...

  1. Distribution of Energy Spectra, Reynolds Stresses, Turbulence Production, and Dissipation in a Tidally Driven Bottom Boundary Layer

    E-Print Network [OSTI]

    , United Kingdom @Department of Earth and Planetary Science, The Johns Hopkins University, BaltimoreDistribution of Energy Spectra, Reynolds Stresses, Turbulence Production, and Dissipation is driven by a number of mechanisms including winds, tides, density gradients, swells, sea surface slope

  2. Penetrative turbulence associated with mesoscale surface heat flux variations

    E-Print Network [OSTI]

    Alam, Jahrul M

    2015-01-01T23:59:59.000Z

    This article investigates penetrative turbulence in the atmospheric boundary layer. Using a large eddy simulation approach, we study characteristics of the mixed layer with respect to surface heat flux variations in the range from 231.48 W/m$^2$ to 925.92 W/m$^2$, and observe that the surface heterogeneity on a spatial scale of $20$ km leads to downscale turbulent kinetic energy cascade. Coherent fluctuations of mesoscale horizontal wind is observed at 100m above the ground. Such a surface induced temporal oscillations in the horizontal wind suggest a rapid jump in mesocale wind forecasts, which is difficult to parameterize using traditional one-dimensional ensemble-mean models. Although the present work is idealized at a typical scale (20km) of surface heterogeneity, the results help develop effective subgrid scale parameterization schemes for classical weather forecasting mesoscale models.

  3. Sandia National Laboratories: Wind

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Wind Grid System Planning for Wind: Wind Generator Modeling On June 11, 2014, in Wind generation continues to dominate the interconnection queues and the need for generic,...

  4. Western Wind Strategy: Addressing Critical Issues for Wind Deployment

    SciTech Connect (OSTI)

    Douglas Larson; Thomas Carr

    2012-03-30T23:59:59.000Z

    The goal of the Western Wind Strategy project was to help remove critical barriers to wind development in the Western Interconnection. The four stated objectives of this project were to: (1) identify the barriers, particularly barriers to the operational integration of renewables and barriers identified by load-serving entities (LSEs) that will be buying wind generation, (2) communicate the barriers to state officials, (3) create a collaborative process to address those barriers with the Western states, utilities and the renewable industry, and (4) provide a role model for other regions. The project has been on the forefront of identifying and informing state policy makers and utility regulators of critical issues related to wind energy and the integration of variable generation. The project has been a critical component in the efforts of states to push forward important reforms and innovations that will enable states to meet their renewable energy goals and lower the cost to consumers of integrating variable generation.

  5. Definition of a 5-MW Reference Wind Turbine for Offshore System Development

    SciTech Connect (OSTI)

    Jonkman, J.; Butterfield, S.; Musial, W.; Scott, G.

    2009-02-01T23:59:59.000Z

    This report describes a three-bladed, upwind, variable-speed, variable blade-pitch-to-feather-controlled multimegawatt wind turbine model developed by NREL to support concept studies aimed at assessing offshore wind technology.

  6. Dissipation in Turbulent Plasma due to Reconnection in Thin Current Sheets David Sundkvist,1,* Alessandro Retino`,2

    E-Print Network [OSTI]

    California at Berkeley, University of

    to kinetic and thermal particle energies. In this Letter we use space plasma as a turbulence laboratory the strongly turbulent solar wind down- stream of Earth's bow shock, the so-called magnetosheath (magnetic field), and CIS (ions) experiments [17]. At 09:35 UT the spacecraft crossed the bow shock

  7. 4A.5 DERIVING TURBULENT KINETIC ENERGY DISSIPATION RATE WITHIN CLOUDS USING GROUND BASED 94 GHZ RADAR

    E-Print Network [OSTI]

    Hogan, Robin

    Terrestre et Plan´etaire, V´elizy, France University of Reading, Reading, United Kingdom 1. INTRODUCTION. The variance 1 #12;v 2 of the mean wind is an indicator of the kinetic energy in turbulent scales4A.5 DERIVING TURBULENT KINETIC ENERGY DISSIPATION RATE WITHIN CLOUDS USING GROUND BASED 94 GHZ

  8. Turbine Inflow Characterization at the National Wind Technology Center: Preprint

    SciTech Connect (OSTI)

    Clifton, A.; Schreck, S.; Scott, G.; Kelley, N.; Lundquist, J.

    2012-01-01T23:59:59.000Z

    Utility-scale wind turbines operate in dynamic flows that can vary significantly over timescales from less than a second to several years. To better understand the inflow to utility-scale turbines, two inflow towers were installed and commissioned at the National Renewable Energy Laboratory's (NREL) National Wind Technology Center near Boulder, Colorado, in 2011. These towers are 135 m tall and instrumented with a combination of sonic anemometers, cup anemometers, wind vanes, and temperature measurements to characterize the inflow wind speed and direction, turbulence, stability and thermal stratification to two utility-scale turbines. Herein, we present variations in mean and turbulent wind parameters with height, atmospheric stability, and as a function of wind direction that could be important for turbine operation as well as persistence of turbine wakes. Wind speed, turbulence intensity, and dissipation are all factors that affect turbine performance. Our results shown that these all vary with height across the rotor disk, demonstrating the importance of measuring atmospheric conditions that influence wind turbine performance at multiple heights in the rotor disk, rather than relying on extrapolation from lower levels.

  9. Edge Turbulence Velocity Changes with Lithium Coating on NSTX

    SciTech Connect (OSTI)

    Cao, A.; Zweben, S. J.; Stotler, D. P.; Bell, M.; Diallo, A.; Kaye, S. M.; LeBlanc, B.

    2012-08-10T23:59:59.000Z

    Lithium coating improves energy confinement and eliminates edge localized modes in NSTX, but the mechanism of this improvement is not yet well understood. We used the gas-puff-imaging (GPI) diagnostic on NSTX to measure the changes in edge turbulence which occurred during a scan with variable lithium wall coating, in order to help understand the reason for the confinement improvement with lithium. There was a small increase in the edge turbulence poloidal velocity and a decrease in the poloidal velocity fluctuation level with increased lithium. The possible effect of varying edge neutral density on turbulence damping was evaluated for these cases in NSTX. __________________________________________________

  10. Abstract--Wind power generation is growing rapidly. However, maintaining the wind turbine connection to grid is a real

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    by the year 2020 [2]. Wind turbines can operate either with a fixed speed or a variable speed. In the case and then as fluctuations in the electrical power on the grid. The variable-speed turbine operation offers several major acoustical [3]. Among variable speed constant-frequency wind turbines, the doubly fed induction generator

  11. Four Lectures on Turbulent Combustion

    E-Print Network [OSTI]

    Peters, Norbert

    Four Lectures on Turbulent Combustion N. Peters Institut fur Technische Mechanik RWTH Aachen Turbulent Combustion: Introduction and Overview 1 1.1 Moment Methods in Modeling Turbulence with Combustion and Velocity Scales . . . . . . . . . . . 11 1.4 Regimes in Premixed Turbulent Combustion

  12. Impact of DFIG wind turbines on transient stability of power systems a review

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    Impact of DFIG wind turbines on transient stability of power systems ­ a review Authors Na Abstract of wind farms are using variable speed wind turbines equipped with doubly-fed induction generators (DFIG) due to their advantages over other wind turbine generators. Therefore, the analysis of wind power

  13. An integrated approach to offshore wind energy assessment: Great Lakes 3D Wind Experiment. Part I. Calibration and testing RJ Barthelmie1, SC Pryor1, CM Smith1, P Crippa1, H Wang1, R. Krishnamurthy2, R. Calhoun2, D Valyou3, P Marzocca3, D Matthiesen4, N.

    E-Print Network [OSTI]

    Polly, David

    An integrated approach to offshore wind energy assessment: Great Lakes 3D Wind Experiment. Part I Government or any agency thereof." Introduction An experiment to test wind and turbulence measurement strategies was conducted at a northern Indiana wind farm in May 2012. The experimental design focused

  14. The Anisotropic Multifractal Model and Wind Turbine Wakes G. Fitton1, I. Tchiguirinskaia1, D. Schertzer1 & S. Lovejoy2

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    The Anisotropic Multifractal Model and Wind Turbine Wakes G. Fitton1, I. Tchiguirinskaia1, D. Figure 1: Schematic of turbine positions and wake effect due to North-Westerly winds (map courtesy on a mast in a wind farm test site subject to wake turbulence effects (see Fig. 1). The quality of the data

  15. Boundary Layer Convergence Induced by Strong Winds across a Midlatitude THOMAS KILPATRICK, NIKLAS SCHNEIDER, AND BO QIU

    E-Print Network [OSTI]

    Qiu, Bo

    Boundary Layer Convergence Induced by Strong Winds across a Midlatitude SST Front* THOMAS in an idealized, dry, two- dimensional configuration, for winds crossing from cold to warm SST and from warm to cold SST. For strong cross-front winds, O(10 m s21 ), changes in the turbulent mixing and MABL depth

  16. Offshore Wind Power USA

    Broader source: Energy.gov [DOE]

    The Offshore Wind Power USA conference provides the latest offshore wind market updates and forecasts.

  17. 20% Wind Energy 20% Wind Energy

    E-Print Network [OSTI]

    Powell, Warren B.

    (government, industry, utilities, NGOs) Analyzes wind's potential contributions to energy security, economic · Transmission a challenge #12;Wind Power Class Resource Potential Wind Power Density at 50 m W/m 2 Wind Speed20% Wind Energy by 2030 20% Wind Energy by 2030 #12;Presentation and Objectives Overview Background

  18. Wind Energy Leasing Handbook

    E-Print Network [OSTI]

    Balasundaram, Balabhaskar "Baski"

    Wind Energy Leasing Handbook Wind Energy Leasing Handbook E-1033 Oklahoma Cooperative Extension?..................................................................................................................... 31 What do wind developers consider in locating wind energy projects?............................................................................................ 37 How do companies and individuals invest in wind energy projects?....................................................................

  19. Turbulent patterns in wall-bounded flows: a Turing instability?

    E-Print Network [OSTI]

    Manneville, Paul

    2012-01-01T23:59:59.000Z

    In their way to/from turbulence, plane wall-bounded flows display an interesting transitional regime where laminar and turbulent oblique bands alternate, the origin of which is still mysterious. In line with Barkley's recent work about the pipe flow transition involving reaction-diffusion concepts, we consider plane Couette flow in the same perspective and transform Waleffe's classical four-variable model of self-sustaining process into a reaction-diffusion model. We show that, upon fulfillment of a condition on the relative diffusivities of its variables, the featureless turbulent regime becomes unstable against patterning as the result of a Turing instability. A reduced two-variable model helps us to delineate the appropriate region of parameter space. An {\\it intrinsic} status is therefore given to the pattern's wavelength for the first time. Virtues and limitations of the model are discussed, calling for a microscopic support of the phenomenological approach.

  20. Uncovering wind turbine properties through two-dimensional stochastic modeling of wind dynamics

    E-Print Network [OSTI]

    Raischel, Frank; Lopes, Vitor V; Lind, Pedro G

    2012-01-01T23:59:59.000Z

    Using a method for stochastic data analysis, borrowed from statistical physics, we analyze synthetic data from a Markov chain model that reproduces measurements of wind speed and power production in a wind park in Portugal. From the theoretical point of view we argue that our methods can be used to extract unknown functional relations between two variables. We first show that indeed our analysis retrieves the power performance curve, which yields the relationship between wind speed and power production and discuss how such procedure can be extended for extracting functional relationships between pairs of physical variables in general. Second, we show how specific features, such as the turbine rated wind speed or the descriptive wind speed statistics, can be related with the equations describing the evolution of power production and wind speed at single wind turbines.

  1. Use of Frequency Response Metrics to Assess the Planning and Operating Requirements for Reliable Integration of Variable Renewable Generation

    E-Print Network [OSTI]

    Eto, Joseph H.

    2011-01-01T23:59:59.000Z

    of Variable Renewable Generation The report is accompaniedit Relates to Wind-Powered Generation. LBNL-XXXX. Berkeley:with Increased Wind Generation. LBNL-XXXX. Berkeley:

  2. MAGNETOHYDRODYNAMIC WAVES AND CORONAL HEATING: UNIFYING EMPIRICAL AND MHD TURBULENCE MODELS

    SciTech Connect (OSTI)

    Sokolov, Igor V.; Van der Holst, Bart; Oran, Rona; Jin, Meng; Manchester, Ward B. IV; Gombosi, Tamas I. [Department of AOSS, University of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109 (United States)] [Department of AOSS, University of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109 (United States); Downs, Cooper [Predictive Science Inc., 9990 Mesa Rim Road, Suite 170, San Diego, CA 92121 (United States)] [Predictive Science Inc., 9990 Mesa Rim Road, Suite 170, San Diego, CA 92121 (United States); Roussev, Ilia I. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)] [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Evans, Rebekah M., E-mail: igorsok@umich.edu [NASA Goddard Space Flight Center, Space Weather Lab, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States)

    2013-02-10T23:59:59.000Z

    We present a new global model of the solar corona, including the low corona, the transition region, and the top of the chromosphere. The realistic three-dimensional magnetic field is simulated using the data from the photospheric magnetic field measurements. The distinctive feature of the new model is incorporating MHD Alfven wave turbulence. We assume this turbulence and its nonlinear dissipation to be the only momentum and energy source for heating the coronal plasma and driving the solar wind. The difference between the turbulence dissipation efficiency in coronal holes and that in closed field regions is because the nonlinear cascade rate degrades in strongly anisotropic (imbalanced) turbulence in coronal holes (no inward propagating wave), thus resulting in colder coronal holes, from which the fast solar wind originates. The detailed presentation of the theoretical model is illustrated with the synthetic images for multi-wavelength EUV emission compared with the observations from SDO AIA and STEREO EUVI instruments for the Carrington rotation 2107.

  3. Winding Trail

    E-Print Network [OSTI]

    Unknown

    2011-09-05T23:59:59.000Z

    During the past decade, the demand for clean renewable energy continues to rise drastically in Europe, the US, and other countries. Wind energy in the ocean can possibly be one of those future renewable clean energy sources as long...

  4. Mesoscale and Large-Eddy Simulations for Wind Energy

    SciTech Connect (OSTI)

    Marjanovic, N

    2011-02-22T23:59:59.000Z

    Operational wind power forecasting, turbine micrositing, and turbine design require high-resolution simulations of atmospheric flow over complex terrain. The use of both Reynolds-Averaged Navier Stokes (RANS) and large-eddy (LES) simulations is explored for wind energy applications using the Weather Research and Forecasting (WRF) model. To adequately resolve terrain and turbulence in the atmospheric boundary layer, grid nesting is used to refine the grid from mesoscale to finer scales. This paper examines the performance of the grid nesting configuration, turbulence closures, and resolution (up to as fine as 100 m horizontal spacing) for simulations of synoptically and locally driven wind ramping events at a West Coast North American wind farm. Interestingly, little improvement is found when using higher resolution simulations or better resolved turbulence closures in comparison to observation data available for this particular site. This is true for week-long simulations as well, where finer resolution runs show only small changes in the distribution of wind speeds or turbulence intensities. It appears that the relatively simple topography of this site is adequately resolved by all model grids (even as coarse as 2.7 km) so that all resolutions are able to model the physics at similar accuracy. The accuracy of the results is shown in this paper to be more dependent on the parameterization of the land-surface characteristics such as soil moisture rather than on grid resolution.

  5. Wind-Blown Sand: Threshold of Motion

    E-Print Network [OSTI]

    Swann, Christy Michelle

    2014-11-12T23:59:59.000Z

    ....................................................................................... 43 13 Bedload trap designed for this study .................................................................................. 45 14 Schematic of internal adjustable chimney adjusted to the height of the surface... predicting the threshold for wind-blown sand in natural environments are rooted in the original wind tunnel work of Bagnold (1936). He introduced an empirically-calibrated model of the threshold using shear velocity, 𝑢?: a height independent variable...

  6. Wind and Solar Energy Curtailment Practices (Presentation)

    SciTech Connect (OSTI)

    Bird, L.; Cochran, J.; Wang, X.

    2014-10-01T23:59:59.000Z

    This presentation to the fall 2014 technical meeting of the Utility Variable-Generation Integration Group summarizes experience with curtailment of wind and solar in the U.S.

  7. A survey on wind power ramp forecasting.

    SciTech Connect (OSTI)

    Ferreira, C.; Gama, J.; Matias, L.; Botterud, A.; Wang, J. (Decision and Information Sciences); (INESC Porto)

    2011-02-23T23:59:59.000Z

    The increasing use of wind power as a source of electricity poses new challenges with regard to both power production and load balance in the electricity grid. This new source of energy is volatile and highly variable. The only way to integrate such power into the grid is to develop reliable and accurate wind power forecasting systems. Electricity generated from wind power can be highly variable at several different timescales: sub-hourly, hourly, daily, and seasonally. Wind energy, like other electricity sources, must be scheduled. Although wind power forecasting methods are used, the ability to predict wind plant output remains relatively low for short-term operation. Because instantaneous electrical generation and consumption must remain in balance to maintain grid stability, wind power's variability can present substantial challenges when large amounts of wind power are incorporated into a grid system. A critical issue is ramp events, which are sudden and large changes (increases or decreases) in wind power. This report presents an overview of current ramp definitions and state-of-the-art approaches in ramp event forecasting.

  8. Experimental Study of Free Stream Turbulence Effects on Dynamic Stall of Pitching Airfoil by using Particle Image Velocimetry

    E-Print Network [OSTI]

    Leu, Tzong-Shyng "Jeremy"

    of attack histogram of a vertical axis wind turbine (VAWT). By using PIV, the instantaneous vortex, a great deal of attention has been paid to investigate the aerodynamic performance of vertical-axis wind turbines (VAWT) [4-6]. VAWT often operates inside an atmospheric turbulent boundary layer. The purpose

  9. Wind Energy Benefits, Wind Powering America (WPA) (Fact Sheet...

    Broader source: Energy.gov (indexed) [DOE]

    Energy Benefits, Wind Powering America (WPA) (Fact Sheet), Wind And Water Power Program (WWPP) Wind Energy Benefits, Wind Powering America (WPA) (Fact Sheet), Wind And Water Power...

  10. Aleutian Pribilof Islands Wind Energy Feasibility Study

    SciTech Connect (OSTI)

    Bruce A. Wright

    2012-03-27T23:59:59.000Z

    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 and Sand Point have allowed for proper wind turbine siting without killing birds, especially endangered species and bald eagles. APIA continues coordinating and looking for funding opportunities for regional renewable energy projects. An important goal for APIA has been, and will continue to be, to involve community members with renewable energy projects and energy conservation efforts.

  11. Dynamic stall on wind turbine blades

    SciTech Connect (OSTI)

    Butterfield, C.P.; Simms, D.; Scott, G. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States); Hansen, A.C. [Utah Univ., Salt Lake City, UT (United States)] [Utah Univ., Salt Lake City, UT (United States)

    1991-12-01T23:59:59.000Z

    Dynamic loads must be predicted accurately in order to estimate the fatigue life of wind turbines operating in turbulent environments. Dynamic stall contributes to increased dynamic loads during normal operation of all types of horizontal-axis wind turbine (HAWTs). This report illustrates how dynamic stall varies throughout the blade span of a 10 m HAWT during yawed and unyawed operating conditions. Lift, drag, and pitching moment coefficients during dynamics stall are discussed. Resulting dynamic loads are presented, and the effects of dynamic stall on yaw loads are demonstrated using a yaw loads dynamic analysis (YAWDYN). 12 refs., 22 figs., 1 tab.

  12. MAGNETIC HELICITY IN THE DISSIPATION RANGE OF STRONG IMBALANCED TURBULENCE

    SciTech Connect (OSTI)

    Markovskii, S. A.; Vasquez, Bernard J., E-mail: sergei.markovskii@unh.edu, E-mail: bernie.vasquez@unh.edu [Space Science Center, University of New Hampshire, Durham, NH 03824 (United States)

    2013-05-01T23:59:59.000Z

    Hybrid numerical simulations of freely decaying two-dimensional turbulence are presented. The background magnetic field is perpendicular to the simulation plane, which eliminates linear kinetic Alfven waves from the system. The net magnetic helicity of the initial fluctuations at large scales is zero. The turbulence is set to be imbalanced in the sense that the net cross-helicity is not zero. As the turbulence evolves, it develops nonzero magnetic helicity at smaller scales, in the proton kinetic range. In the quasi-steady state of evolution, the magnetic helicity spectrum has a peak consistent with the solar wind observations. The peak position depends on the plasma beta and correlates with a sharp decline of the cross-helicity spectrum.

  13. Energy 101: Wind Turbines

    ScienceCinema (OSTI)

    None

    2013-05-29T23:59:59.000Z

    See how wind turbines generate clean electricity from the power of the wind. Highlighted are the various parts and mechanisms of a modern wind turbine.

  14. WIND DATA REPORT Mattapoisett

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Mattapoisett Mattapoisett, Massachusetts December 1, 2006 February 28, 2007...................................................................................................................... 9 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  15. Energy 101: Wind Turbines

    SciTech Connect (OSTI)

    None

    2011-01-01T23:59:59.000Z

    See how wind turbines generate clean electricity from the power of the wind. Highlighted are the various parts and mechanisms of a modern wind turbine.

  16. Maximum power tracking control scheme for wind generator systems

    E-Print Network [OSTI]

    Mena Lopez, Hugo Eduardo

    2008-10-10T23:59:59.000Z

    The purpose of this work is to develop a maximum power tracking control strategy for variable speed wind turbine systems. Modern wind turbine control systems are slow, and they depend on the design parameters of the turbine and use wind and/or rotor...

  17. Maximum power tracking control scheme for wind generator systems

    E-Print Network [OSTI]

    Mena, Hugo Eduardo

    2009-05-15T23:59:59.000Z

    The purpose of this work is to develop a maximum power tracking control strategy for variable speed wind turbine systems. Modern wind turbine control systems are slow, and they depend on the design parameters of the turbine and use wind and/or rotor...

  18. Ecosystem feedbacks arising from wind transport in drylands: Results

    E-Print Network [OSTI]

    Ecosystem feedbacks arising from wind transport in drylands: Results from field experiments fire frequency Woody mortality Introduction of exotic grasses Is cover dominated by annuals or short intensity precipitation Low wind speeds Low P/PE High variability High intensity precipitation High wind

  19. Managing Wind Power Forecast Uncertainty in Electric Brandon Keith Mauch

    E-Print Network [OSTI]

    i Managing Wind Power Forecast Uncertainty in Electric Grids Brandon Keith Mauch Co for the modeled wind- CAES system would not cover annualized capital costs. We also estimate market prices-ahead market is roughly $100, with large variability due to electric power prices. Wind power forecast errors

  20. Maximum power tracking control scheme for wind generator systems

    E-Print Network [OSTI]

    Mena, Hugo Eduardo

    2009-05-15T23:59:59.000Z

    The purpose of this work is to develop a maximum power tracking control strategy for variable speed wind turbine systems. Modern wind turbine control systems are slow, and they depend on the design parameters of the turbine and use wind and/or rotor...

  1. Maximum power tracking control scheme for wind generator systems

    E-Print Network [OSTI]

    Mena Lopez, Hugo Eduardo

    2008-10-10T23:59:59.000Z

    The purpose of this work is to develop a maximum power tracking control strategy for variable speed wind turbine systems. Modern wind turbine control systems are slow, and they depend on the design parameters of the turbine and use wind and/or rotor...

  2. Control of Wind Turbines for Power Regulation and

    E-Print Network [OSTI]

    Control of Wind Turbines for Power Regulation and Load Reduction Juan Jose Garcia Quirante Kongens regulation and load reduction and their ensemble in a variable-speed wind turbine. The power regulation aspects of mathematical modelling of wind turbines, and especially the control methods suited for power

  3. Validation of Power Output for the WIND Toolkit

    SciTech Connect (OSTI)

    King, J.; Clifton, A.; Hodge, B. M.

    2014-09-01T23:59:59.000Z

    Renewable energy integration studies require wind data sets of high quality with realistic representations of the variability, ramping characteristics, and forecast performance for current wind power plants. The Wind Integration National Data Set (WIND) Toolkit is meant to be an update for and expansion of the original data sets created for the weather years from 2004 through 2006 during the Western Wind and Solar Integration Study and the Eastern Wind Integration Study. The WIND Toolkit expands these data sets to include the entire continental United States, increasing the total number of sites represented, and it includes the weather years from 2007 through 2012. In addition, the WIND Toolkit has a finer resolution for both the temporal and geographic dimensions. Three separate data sets will be created: a meteorological data set, a wind power data set, and a forecast data set. This report describes the validation of the wind power data set.

  4. Wind power and Wind power and

    E-Print Network [OSTI]

    Wind power and the CDM #12; Wind power and the CDM Emerging practices in developing wind power 2005 Jyoti P. Painuly, Niels-Erik Clausen, Jrgen Fenhann, Sami Kamel and Romeo Pacudan #12; WIND POWER AND THE CDM Emerging practices in developing wind power projects for the Clean Development Mechanism Energy

  5. Wind turbine spoiler

    DOE Patents [OSTI]

    Sullivan, William N. (Albuquerque, NM)

    1985-01-01T23:59:59.000Z

    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.

  6. Quantum ghost imaging through turbulence

    E-Print Network [OSTI]

    Dixon, P. Ben

    We investigate the effect of turbulence on quantum ghost imaging. We use entangled photons and demonstrate that for a specific experimental configuration the effect of turbulence can be greatly diminished. By decoupling ...

  7. Beyond the Betz Theory - Blockage, Wake Mixing and Turbulence

    E-Print Network [OSTI]

    Nishino, Takafumi

    2013-01-01T23:59:59.000Z

    Recent analytical models concerning the limiting efficiency of marine hydrokinetic (MHK) devices are reviewed with an emphasis on the significance of blockages (of local as well as global flow passages) and wake mixing. Also discussed is the efficiency of power generation from fully developed turbulent open channel flows. These issues are primarily concerned with the design/optimization of tidal turbine arrays; however, some of them are relevant to wind turbines as well.

  8. ARE660 Wind Generator: Low Wind Speed Technology for Small Turbine Development

    SciTech Connect (OSTI)

    Robert W. Preus; DOE Project Officer - Keith Bennett

    2008-04-23T23:59:59.000Z

    This project is for the design of a wind turbine that can generate most or all of the net energy required for homes and small businesses in moderately windy areas. The purpose is to expand the current market for residential wind generators by providing cost effective power in a lower wind regime than current technology has made available, as well as reduce noise and improve reliability and safety. Robert W. Preus experience designing and/or maintaining residential wind generators of many configurations helped identify the need for an improved experience of safety for the consumer. Current small wind products have unreliable or no method of stopping the wind generator in fault or high wind conditions. Consumers and their neighbors do not want to hear their wind generators. In addition, with current technology, only sites with unusually high wind speeds provide payback times that are acceptable for the on-grid user. Abundant Renewable Energys (ARE) basic original concept for the ARE660 was a combination of a stall controlled variable speed small wind generator and automatic fail safe furling for shutdown. The stall control for a small wind generator is not novel, but has not been developed for a variable speed application with a permanent magnet alternator (PMA). The fail safe furling approach for shutdown has not been used to our knowledge.

  9. Wind turbine

    DOE Patents [OSTI]

    Cheney, Jr., Marvin C. (Glastonbury, CT)

    1982-01-01T23:59:59.000Z

    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.

  10. Assessment of research needs for wind turbine rotor materials technology

    SciTech Connect (OSTI)

    Not Available

    1991-01-01T23:59:59.000Z

    Wind-driven power systems is a renewable energy technology that is still in the early stages of development. Wind power plants installed in early 1980s suffered structural failures chiefly because of incomplete understanding of wind forces (turbulent), in some cases because of poor product quality. Failures of rotor blades are now somewhat better understood. This committee has examined the experience base accumulated by wind turbines and the R and D programs sponsored by DOE. It is concluded that a wind energy system such as is described is within the capability of engineering practice; however because of certain gaps in knowledge, and the presence of only one major integrated manufacturer of wind power machines in the USA, a DOE R and D investment is still required.

  11. National Offshore Wind Energy Grid Interconnection Study

    SciTech Connect (OSTI)

    Daniel, John P. [ABB Inc; Liu, Shu [ABB Inc; Ibanez, Eduardo [National Renewable Energy Laboratory; Pennock, Ken [AWS Truepower; Reed, Greg [University of Pittsburgh; Hanes, Spencer [Duke Energy

    2014-07-30T23:59:59.000Z

    The National Offshore Wind Energy Grid Interconnection Study (NOWEGIS) considers the availability and potential impacts of interconnecting large amounts of offshore wind energy into the transmission system of the lower 48 contiguous United States. A total of 54GW of offshore wind was assumed to be the target for the analyses conducted. A variety of issues are considered including: the anticipated staging of offshore wind; the offshore wind resource availability; offshore wind energy power production profiles; offshore wind variability; present and potential technologies for collection and delivery of offshore wind energy to the onshore grid; potential impacts to existing utility systems most likely to receive large amounts of offshore wind; and regulatory influences on offshore wind development. The technologies considered the reliability of various high-voltage ac (HVAC) and high-voltage dc (HVDC) technology options and configurations. The utility system impacts of GW-scale integration of offshore wind are considered from an operational steady-state perspective and from a regional and national production cost perspective.

  12. Wind Power

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsingWhat is abig world of tinyWind Industry SoarsWind

  13. Understanding Inertial and Frequency Response of Wind Power Plants: Preprint

    SciTech Connect (OSTI)

    Muljadi, E.; Gevorgian, V.; Singh, M.; Santoso, S.

    2012-07-01T23:59:59.000Z

    The objective of this paper is to analyze and quantify the inertia and frequency responses of wind power plants with different wind turbine technologies (particularly those of fixed speed, variable slip with rotor-resistance controls, and variable speed with vector controls).

  14. Wave turbulent statistics in non-weak wave turbulence

    E-Print Network [OSTI]

    Naoto Yokoyama

    2011-05-08T23:59:59.000Z

    In wave turbulence, it has been believed that statistical properties are well described by the weak turbulence theory, in which nonlinear interactions among wavenumbers are assumed to be small. In the weak turbulence theory, separation of linear and nonlinear time scales derived from the weak nonlinearity is also assumed. However, the separation of the time scales is often violated even in weak turbulent systems where the nonlinear interactions are actually weak. To get rid of this inconsistency, closed equations are derived without assuming the separation of the time scales in accordance with Direct-Interaction Approximation (DIA), which has been successfully applied to Navier--Stokes turbulence. The kinetic equation of the weak turbulence theory is recovered from the DIA equations if the weak nonlinearity is assumed as an additional assumption. It suggests that the DIA equations is a natural extension of the conventional kinetic equation to not-necessarily-weak wave turbulence.

  15. High resolution reanalysis of wind speeds over the British Isles for wind energy integration

    E-Print Network [OSTI]

    Hawkins, Samuel Lennon

    2012-11-29T23:59:59.000Z

    The UK has highly ambitious targets for wind development, particularly offshore, where over 30GW of capacity is proposed for development. Integrating such a large amount of variable generation presents enormous challenges. ...

  16. Turbulent Combustion Luc Vervisch

    E-Print Network [OSTI]

    Kern, Michel

    ;19 "Perfect" combustion modes: Fuel + Oxidizer () Products Engines, gas turbines... Laboratory experiment1 Turbulent Combustion Modeling Luc Vervisch INSA de Rouen, IUF, CORIA-CNRS Quelques problèmes rencontrés en chimie numérique : Hydrologie - Combustion - Atmosphère 16 décembre, INRIA Rocquencourt #12

  17. Quantum weak turbulence

    SciTech Connect (OSTI)

    Sanyal, Devashish [Department of Theoretical Physics, Indian Association for the Cultivation of Science, Jadavpur, Calcutta 700032 (India)]. E-mail: tpds@mahendra.iacs.res.in; Sen, Siddhartha [School of Mathematics, Trinity College, Dublin 2 (Ireland)]. E-mail: sen@maths.tcd.ie

    2006-06-15T23:59:59.000Z

    The present manuscript dealing with large occupation of states of a quantum system, extends the study to the case of quantum weak turbulence. The quasiparticle spectrum, calculated for such a system, using a Green's function approach, establishes the dissipative and inertial regimes, hence a Kolmogorov type of picture.

  18. A Unified Framework for Reliability Assessment of Wind Energy Conversion Systems

    E-Print Network [OSTI]

    Liberzon, Daniel

    1 A Unified Framework for Reliability Assessment of Wind Energy Conversion Systems Sebastian S a framework for assessing wind energy conversion systems (WECS) reliability in the face of external based on wind energy are: the impact of wind speed variability on system reliability [1]; WECS' reaction

  19. Robust control for wind power systems A. Pintea 1,2

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    design applied to a horizontal wind turbine, functioning in the above rated wind speeds area. The turbines chosen for study in this paper are variable speed wind turbines and the main focus will fall. The controller presented here, is a robust digital controller which aims to regulate the wind turbine rotor speed

  20. Gille-SIO 221C 1 Wind Forcing of Geostrophic Currents

    E-Print Network [OSTI]

    Gille, Sarah T.

    Gille-SIO 221C 1 Wind Forcing of Geostrophic Currents Some of the strongest and most variable winds between ACC transport and wind forcing. What is the phase relationshp between U and x ? 3. What in the world blow over the Antarctic Circumpolar Current. How does the current respond to fluctuations in wind

  1. Wind Technologies & Evolving Opportunities (Presentation)

    SciTech Connect (OSTI)

    Robichaud, R.

    2014-07-01T23:59:59.000Z

    This presentation covers opportunities for wind technology; wind energy market trends; an overview of the National Wind Technology Center near Boulder, Colorado; wind energy price and cost trends; wind turbine technology improvements; and wind resource characterization improvements.

  2. 2015 Iowa Wind Power Conference and Iowa Wind Energy Association...

    Energy Savers [EERE]

    2015 Iowa Wind Power Conference and Iowa Wind Energy Association Midwest Regional Energy Job Fair 2015 Iowa Wind Power Conference and Iowa Wind Energy Association Midwest Regional...

  3. Community Wind Handbook/Understand Your Wind Resource and Conduct...

    Open Energy Info (EERE)

    Conduct a Preliminary Estimate < Community Wind Handbook Jump to: navigation, search WIND ENERGY STAKEHOLDER ENGAGEMENT & OUTREACHCommunity Wind Handbook WindTurbine-icon.png...

  4. American Wind Energy Association Wind Energy Finance and Investment...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    American Wind Energy Association Wind Energy Finance and Investment Seminar American Wind Energy Association Wind Energy Finance and Investment Seminar October 20, 2014 8:00AM EDT...

  5. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01T23:59:59.000Z

    wind turbine components (specifically, generators, bladeschangers. Wind turbine components such as blades, towers,17%). Wind turbine component exports (towers, blades,

  6. Description of the Columbia Basin Wind Energy Study (CBWES)

    SciTech Connect (OSTI)

    Berg, Larry K.; Pekour, Mikhail S.; Nelson, Danny A.

    2012-10-01T23:59:59.000Z

    The purpose of this Technical Report is to provide background information about the Columbia Basin Wind Energy Study (CBWES). This study, which was supported by the U.S. Department of Energys Wind and Water Power Program, was conducted from 16 November 2010 through 21 March 2012 at a field site in northeastern Oregon. The primary goal of the study was to provide profiles of wind speed and wind direction over the depth of the boundary layer in an operating wind farm located in an area of complex terrain. Measurements from propeller and vane anemometers mounted on a 62 m tall tower, Doppler Sodar, and Radar Wind Profiler were combined into a single data product to provide the best estimate of the winds above the site during the first part of CBWES. An additional goal of the study was to provide measurements of Turbulence Kinetic Energy (TKE) near the surface. To address this specific goal, sonic anemometers were mounted at two heights on the 62 m tower on 23 April 2011. Prior to the deployment of the sonic anemometers on the tall tower, a single sonic anemometer was deployed on a short tower 3.1 m tall that was located just to the south of the radar wind profiler. Data from the radar wind profiler, as well as the wind profile data product are available from the Atmospheric Radiation Measurements (ARM) Data Archive (http://www.arm.gov/data/campaigns). Data from the sonic anemometers are available from the authors.

  7. Turbulence-Turbine Interaction: The Basis for the Development of the TurbSim Stochastic Simulator

    SciTech Connect (OSTI)

    Kelley, N. D.

    2011-11-01T23:59:59.000Z

    A combination of taller wind turbines with more flexible rotors and towers operating in turbulent conditions that are not well understood is contributing to much higher than anticipated maintenance and repairs costs and is associated with lower energy production. This report documents evidence of this and offers the turbine designers an expanded tool that resolves many of these shortcomings.

  8. LES of the adverse-pressure gradient turbulent boundary layer M. Inoue a,

    E-Print Network [OSTI]

    Marusic, Ivan

    at the University of Melbourne wind tunnel where a plate section with zero pressure gradient is followed by section accurate simulations, for example, of separated flow on the wings of airplanes or for flow through turbine such as the amplified wake of the mean velocity profile and the increasing turbulence intensity in the outer region

  9. Kinetic Simulations of Magnetized Turbulence in Astrophysical Plasmas G. G. Howes,1,* W. Dorland,2

    E-Print Network [OSTI]

    Tatsuno, Tomoya

    College, London SW7 2AZ, United Kingdom 5 Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 at the scale of the ion Larmor radius (ion gyroscale). Magnetic- and electric-field energy spectra show a break). This behavior is also qualitatively consistent with in situ measurements of turbulence in the solar wind. Our

  10. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01T23:59:59.000Z

    Public Service Wind Integration Cost Impact Study. Preparedequipment-related wind turbine costs, the overall importinstalled wind power project costs, wind turbine transaction

  11. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01T23:59:59.000Z

    Public Service Wind Integration Cost Impact Study. Preparedinstalled wind power project costs, wind turbine transactionand components and wind turbine costs. Excluded from all

  12. Sandia National Laboratories: wind energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Wind Energy Manufacturing Lab Helps Engineers Improve Wind Power On November 15, 2011, in Energy, News, Partnership, Renewable Energy, Wind Energy Researchers at the Wind Energy...

  13. Module Handbook Specialisation Wind Energy

    E-Print Network [OSTI]

    Habel, Annegret

    ;Specialisation Wind Energy, NTU Athens, 2nd Semester Module 1/Wind Energy: Wind potential, Aerodynamics & Loading of Wind Turbines Module name: Wind potential, Aerodynamics & Loading of Wind Turbines Section Classes Evaluation of Wind Energy Potential Wind turbine Aerodynamics Static and dynamic Loading of Wind turbines

  14. NREL: News Feature - NREL Software Tool a Boon for Wind Industry

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    temperatures, and other variables alter the air flow and energy production at wind farms. Photo by Dennis Schroeder, NREL Wind energy is blowing away skeptics-it's so close to...

  15. Impacts of large quantities of wind energy on the electric power system

    E-Print Network [OSTI]

    Yao, Yuan, S.M. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    Wind energy has been surging on a global scale. Significant penetration of wind energy is expected to take place in the power system, bringing new challenges because of the variability and uncertainty of this renewable ...

  16. Coordination of Voltage and Frequency Feedback in Load-Frequency Control Capability of Wind Turbine

    E-Print Network [OSTI]

    Silva, Filipe Faria Da

    Coordination of Voltage and Frequency Feedback in Load-Frequency Control Capability of Wind Turbine-Frequency Control (LFC) is gradually shifted to Variable Speed Wind Turbines (VSWTs). In order to equip VSWT

  17. Polymer Stretching by Turbulence

    SciTech Connect (OSTI)

    Chertkov, Michael

    2000-05-15T23:59:59.000Z

    The stretching of a polymer chain by a large-scale chaotic flow is considered. The steady state which emerges as a balance of the turbulent stretching and anharmonic resistance of the chain is quantitatively described, i.e., the dependency on the flow parameters (Lyapunov exponent statistics) and the chain characteristics (the number of beads and the interbead elastic potential) is made explicit. (c) 2000 The American Physical Society.

  18. Turbulent Reconnection and Its Implications

    E-Print Network [OSTI]

    Lazarian, Alex; Vishniac, Ethan T; Kowal, Grzegorz

    2015-01-01T23:59:59.000Z

    Magnetic reconnection is a process of magnetic field topology change, which is one of the most fundamental processes in magnetized plasmas. In most astrophysical environments the Reynolds numbers are large and therefore the transition to turbulence is inevitable. This turbulence must be taken into account for any theory of magnetic reconnection, since the initially laminar configurations can transit to the turbulence state, what is demonstrated by 3D high resolution numerical simulations. We discuss ideas of how turbulence can modify reconnection with the focus on the Lazarian & Vishniac (1999) reconnection model and present numerical evidence supporting the model and demonstrate that it is closely connected to the concept of Richardson diffusion and compatible with the Lagrangian dynamics of magnetized fluids. We point out that the Generalized Ohm's Law, that accounts for turbulent motion, predicts the subdominance of the microphysical plasma effects for a realistically turbulent media. We show that on o...

  19. Analyzing the Effects of Temporal Wind Patterns on the Value of Wind-Generated Electricity at Different Sites in California and the Northwest

    E-Print Network [OSTI]

    Fripp, Matthias; Wiser, Ryan

    2006-01-01T23:59:59.000Z

    Cost Analysis, Phase 1. CWEC-2003-06. Davis, California: California Windanalysis of the effect of wind timing and variability on the system integration costs

  20. Wind Farm Monitoring at Lake Benton II Wind Power Project - Equipment Only: Cooperative Research and Development Final Report, CRADA Number CRD-08-275

    SciTech Connect (OSTI)

    Gevorgian, V.

    2014-06-01T23:59:59.000Z

    Long-term, high-resolution wind turbine and wind power plant output data are important to assess the impact of wind power on grid operations and to derive meaningful statistics for better understanding of the variability nature of wind power. These data are used for many research and analyses activities consistent with the Wind Program mission: Establish a database of long-term wind power similar to other long-term renewable energy resource databases (e.g. solar irradiance and hydrology); produce meaningful statistics about long-term variation of wind power, spatial and temporal diversity of wind power, and the correlation of wind power, other renewable energy resources, and utility load; provide high quality, realistic wind power output data for system operations impact studies and wind plant and forecasting model validation.

  1. Protostellar outflow-driven turbulence

    E-Print Network [OSTI]

    Christopher D. Matzner

    2007-01-01T23:59:59.000Z

    Protostellar outflows crisscross the regions of star cluster formation, stirring turbulence and altering the evolution of the forming cluster. We model the stirring of turbulent motions by protostellar outflows, building on an observation that the scaling law of supersonic turbulence implies a momentum cascade analogous to the energy cascade in Kolmogorov turbulence. We then generalize this model to account for a diversity of outflow strengths, and for outflow collimation, both of which enhance turbulence. For a single value of its coupling coefficient the model is consistent with turbulence simulations by Li & Nakamura and, plausibly, with observations of the NGC 1333 cluster-forming region. Outflow-driven turbulence is strong enough to stall collapse in cluster-forming regions for several crossing times, relieving the mismatch between star formation and turbulent decay rates. The predicted line-width-size scaling implies radial density indices between -1 and -2 for regions supported by outflow-driven turbulence, with a tendency for steeper profiles in regions that are more massive or have higher column densities.

  2. Turbulence models of gravitational clustering

    E-Print Network [OSTI]

    Jose Gaite

    2012-02-15T23:59:59.000Z

    Large-scale structure formation can be modeled as a nonlinear process that transfers energy from the largest scales to successively smaller scales until it is dissipated, in analogy with Kolmogorov's cascade model of incompressible turbulence. However, cosmic turbulence is very compressible, and vorticity plays a secondary role in it. The simplest model of cosmic turbulence is the adhesion model, which can be studied perturbatively or adapting to it Kolmogorov's non-perturbative approach to incompressible turbulence. This approach leads to observationally testable predictions, e.g., to the power-law exponent of the matter density two-point correlation function.

  3. Western Wind and Solar Integration Study

    SciTech Connect (OSTI)

    Lew, D.; Piwko, R.; Jordan, G.; Miller, N.; Clark, K.; Freeman, L.; Milligan, M.

    2011-01-01T23:59:59.000Z

    The Western Wind and Solar Integration Study (WWSIS) is one of the largest regional wind and solar integration studies to date. It was initiated in 2007 to examine the operational impact of up to 35% energy penetration of wind, photovoltaics (PV), and concentrating solar power (CSP) on the power system operated by the WestConnect group of utilities in Arizona, Colorado, Nevada, New Mexico, and Wyoming (see study area map). WestConnect also includes utilities in California, but these were not included because California had already completed a renewable energy integration study for the state. This study was set up to answer questions that utilities, public utilities commissions, developers, and regional planning organizations had about renewable energy use in the west: (1) Does geographic diversity of renewable energy resource help mitigate variability; (2) How do local resources compare to out-of-state resources; (3) Can balancing area cooperation help mitigate variability; (4) What is the role and value of energy storage; (5) Should reserve requirements be modified; (6) What is the benefit of forecasting; and (7) How can hydropower help with integration of renewables? The Western Wind and Solar Integration Study is sponsored by the U.S. Department of Energy (DOE) and run by NREL with WestConnect as a partner organization. The study follows DOE's 20% Wind Energy by 2030 report, which did not find any technical barriers to reaching 20% wind energy in the continental United States by 2030. This study and its partner study, the Eastern Wind Integration and Transmission Study, performed a more in-depth operating impact analysis to see if 20% wind energy was feasible from an operational level. In DOE/NREL's analysis, the 20% wind energy target required 25% wind energy in the western interconnection; therefore, this study considered 20% and 30% wind energy to bracket the DOE analysis. Additionally, since solar is rapidly growing in the west, 5% solar was also considered in this study. The goal of the Western Wind and Solar Integration Study is to understand the costs and operating impacts due to the variability and uncertainty of wind, PV, and CSP on the grid. This is mainly an operations study, (rather than a transmission study), although different scenarios model different transmission build-outs to deliver power. Using a detailed power system production simulation model, the study identifies operational impacts and challenges of wind energy penetration up to 30% of annual electricity consumption.

  4. Wind Integration

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengtheningWildfires may contribute more to global warmingGlobal »Wind

  5. Wind Power

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch >Internship Program TheSiteEurekaWeekly UserWhat's New Today aboutWind

  6. Optimization of wind turbine energy and power factor with an evolutionary computation algorithm

    E-Print Network [OSTI]

    Kusiak, Andrew

    -controllable variables of a 1.5 MW wind turbine. An evolutionary strategy algorithm solves the data-derived optimization-linear approach to control a variable-speed turbine to maximize power in the presence of generator torque for variable-speed wind turbines. Munteanu et al. [11] applied a linear-quadratic stochastic approach to solve

  7. Temporal and Spatial Turbulent Spectra of MHD Plasma and an Observation of Variance Anisotropy

    E-Print Network [OSTI]

    Schaffner, D A; Lukin, V S

    2014-01-01T23:59:59.000Z

    The nature of MHD turbulence is analyzed through both temporal and spatial magnetic fluctuation spectra. A magnetically turbulent plasma is produced in the MHD wind-tunnel configuration of the Swarthmore Spheromak Experiment (SSX). The power of magnetic fluctuations is projected into directions perpendicular and parallel to a local mean field; the ratio of these quantities shows the presence of variance anisotropy which varies as a function of frequency. Comparison amongst magnetic, velocity, and density spectra are also made, demonstrating that the energy of the turbulence observed is primarily seeded by magnetic fields created during plasma production. Direct spatial spectra are constructed using multi-channel diagnostics and are used to compare to frequency spectra converted to spatial scales using the Taylor Hypothesis. Evidence for the observation of dissipation due to ion inertial length scale physics is also discussed as well as the role laboratory experiment can play in understanding turbulence typica...

  8. Influence of Mean State on Climate Variability at Interannual and Decadal Time Scales

    E-Print Network [OSTI]

    Zhu, Xiaojie

    2013-05-17T23:59:59.000Z

    for many phenomena associated with variables that are nonlinear by definition, such as the vertical wind shear and surface wind speed. In the first part of this dissertation, the influence of mean flow and anomalous flow on vertical wind shear variability...

  9. IEA Wind Task 26: The Past and Future Cost of Wind Energy, Work Package 2

    SciTech Connect (OSTI)

    Lantz, E.; Wiser, R.; Hand, M.

    2012-05-01T23:59:59.000Z

    Over the past 30 years, wind power has become a mainstream source of electricity generation around the world. However, the future of wind power will depend a great deal on the ability of the industry to continue to achieve cost of energy reductions. In this summary report, developed as part of the International Energy Agency Wind Implementing Agreement Task 26, titled 'The Cost of Wind Energy,' we provide a review of historical costs, evaluate near-term market trends, review the methods used to estimate long-term cost trajectories, and summarize the range of costs projected for onshore wind energy across an array of forward-looking studies and scenarios. We also highlight the influence of high-level market variables on both past and future wind energy costs.

  10. Simulation of lean premixed turbulent combustion

    E-Print Network [OSTI]

    2008-01-01T23:59:59.000Z

    turbulent methane combustion. Proc. Combust. Inst. , 29:in premixed turbulent combustion. Proc. Combust. Inst. ,for zero Mach number combustion. Combust. Sci. Technol. ,

  11. Advanced Computational Methods for Turbulence and Combustion...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Advanced Computational Methods for Turbulence and Combustion Advanced Computational Methods for Turbulence and Combustion Bell.png Key Challenges: Development and application of...

  12. Study of Nonlinear Interaction and Turbulence of Alfven Waves in LAPD Experiments

    SciTech Connect (OSTI)

    Boldyrev, Stanislav; Perez, Jean Carlos

    2013-11-29T23:59:59.000Z

    The complete project had two major goals investigate MHD turbulence generated by counterpropagating Alfven modes, and study such processes in the LAPD device. In order to study MHD turbulence in numerical simulations, two codes have been used: full MHD, and reduced MHD developed specialy for this project. Quantitative numerical results are obtained through high-resolution simulations of strong MHD turbulence, performed through the 2010 DOE INCITE allocation. We addressed the questions of the spectrum of turbulence, its universality, and the value of the so-called Kolmogorov constant (the normalization coefficient of the spectrum). In these simulations we measured with unprecedented accuracy the energy spectra of magnetic and velocity fluctuations. We also studied the so-called residual energy, that is, the difference between kinetic and magnetic energies in turbulent fluctuations. In our analytic work we explained generation of residual energy in weak MHD turbulence, in the process of random collisions of counterpropagating Alfven waves. We then generalized these results for the case of strong MHD turbulence. The developed model explained generation of residual energy is strong MHD turbulence, and verified the results in numerical simulations. We then analyzed the imbalanced case, where more Alfven waves propagate in one direction. We found that spectral properties of the residual energy are similar for both balanced and imbalanced cases. We then compared strong MHD turbulence observed in the solar wind with turbulence generated in numerical simulations. Nonlinear interaction of Alfven waves has been studied in the upgraded Large Plasma Device (LAPD). We have simulated the collision of the Alfven modes in the settings close to the experiment. We have created a train of wave packets with the apltitudes closed to those observed n the experiment, and allowed them to collide. We then saw the generation of the second harmonic, resembling that observed in the experiment.

  13. Wind Power Today

    SciTech Connect (OSTI)

    Not Available

    2006-05-01T23:59:59.000Z

    Wind Power Today is an annual publication that provides an overview of the wind energy research conducted by the U.S. Department of Energy Wind and Hydropower Technologies Program.

  14. Wind Power Today

    SciTech Connect (OSTI)

    Not Available

    2007-05-01T23:59:59.000Z

    Wind Power Today is an annual publication that provides an overview of the wind energy research conducted by the U.S. Department of Energy Wind and Hydropower Technologies Program.

  15. Sunflower Wind Farm EA

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Sunflower Wind Farm EA Sunflower Wind Farm Draft EA (25mb pdf) Note: If you have problems downloading this file, pelase contact Lou Hanebury at (406) 255-2812 Sunflower Wind Farm...

  16. The National Wind Technology Center

    SciTech Connect (OSTI)

    Thresher, R.W.; Hock, S.M. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States); Loose, R.R.; Cadogon, J.B.

    1994-07-01T23:59:59.000Z

    Wind energy research began at the Rocky Flats test site in 1976 when Rockwell International subcontracted with the Energy Research and Development Administration (ERDA). The Rocky Flats Plant was competitively selected from a number of ERDA facilities primarily because it experienced high instantaneous winds and provided a large, clear land area. By 1977, several small wind turbines were in place. During the facility`s peak of operation, in 1979-1980, researchers were testing as many as 23 small wind turbines of various configurations, including commercially available machines and prototype turbines developed under subcontract to Rocky Flats. Facilities also included 8-kW, 40-kW, and 225-kW dynamometers; a variable-speed test bed; a wind/hybrid test facility; a controlled velocity test facility (in Pueblo, Colorado); a modal test facility, and a multimegawatt switchgear facility. The main laboratory building was dedicated in July 1981 and was operated by the Rocky Flats Plant until 1984, when the Solar Energy Research Institute (SERI) and Rocky Flats wind energy programs were merged and transferred to SERI. SERI and now the National Renewable Energy Laboratory (NREL) continued to conduct wind turbine system component tests after 1987, when most program personnel were moved to the Denver WEst Office Park in Golden and site ownership was transferred back to Rocky Flats. The Combined Experiment test bed was installed and began operation in 1988, and the NREL structural test facility began operation in 1990. In 1993, the site`s operation was officially transferred to the DOE Golden Field Office that oversees NREL. This move was in anticipation of NREL`s renovation and reoccupation of the facility in 1994.

  17. Analysis of wind power for battery charging

    SciTech Connect (OSTI)

    Muljadi, E.; Drouilhet, S.; Holz, R. [National Renewable Energy Lab., Golden, CO (United States); Gevorgian, V. [University of Armenia, Yerevan (Armenia). State Engineering

    1995-11-01T23:59:59.000Z

    One type of wind-powered battery charging will be explored in this paper. It consists of a wind turbine driving a permanent magnet alternator and operates at variable speed. The alternator is connected to a battery bank via a rectifier. The characteristic of the system depends on the wind turbine, the alternator, and the system configuration. If the electrical load does not match the wind turbine, the performance of the system will be degraded. By matching the electrical load to the wind turbine, the system can be improved significantly. This paper analyzes the properties of the system components. The effects of parameter variation and the system configuration on the system performance are investigated. Two basic methods of shaping the torque-speed characteristic of the generator are presented. The uncompensated as well as the compensated systems will be discussed. Control strategies to improve the system performance will be explored. Finally, a summary of the paper will be presented in the last section.

  18. Use of Slip Ring Induction Generator for Wind Power Generation

    E-Print Network [OSTI]

    K Y Patil; D S Chavan

    Wind energy is now firmly established as a mature technology for electricity generation. There are different types of generators that can be used for wind energy generation, among which Slip ring Induction generator proves to be more advantageous. To analyse application of Slip ring Induction generator for wind power generation, an experimental model is developed and results are studied. As power generation from natural sources is the need today and variable speed wind energy is ample in amount in India, it is necessary to study more beneficial options for wind energy generating techniques. From this need a model is developed by using Slip ring Induction generator which is a type of Asynchronous generator.

  19. Dual-speed wind turbine generation

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States); Handman, D. [Flowind Corp., San Rafael, CA (United States)] [Flowind Corp., San Rafael, CA (United States)

    1996-10-01T23:59:59.000Z

    Induction generator has been used since the early development of utility-scale wind turbine generation. An induction generator is the generator of choice because of its ruggedness and low cost. With an induction generator, the operating speed of the wind turbine is limited to a narrow range (almost constant speed). Dual- speed operation can be accomplished by using an induction generator with two different sets of winding configurations or by using a dual output drive train to drive two induction generators with two different rated speeds. With single-speed operation, the wind turbine operates at different power coefficients (Cp) as the wind speed varies. Operation at maximum Cp can occur only at a single wind speed. However, if the wind speed.varies across a wider range, the operating Cp will vary significantly. Dual-speed operation has the advantage of enabling the wind turbine to operate at near maximum Cp over a wider range of wind speeds. Thus, annual energy production can be increased. The dual-speed mode may generate less energy than a variable-speed mode; nevertheless, it offers an alternative which captures more energy than single-speed operation. In this paper, dual-speed operation of a wind turbine is investigated. Annual energy production is compared between single-speed and dual-speed operation. One type of control algorithm for dual-speed operation is proposed. Some results from a dynamic simulation will be presented to show how the control algorithm works as the wind turbine is exposed to varying wind speeds.

  20. TW Hya: SPECTRAL VARIABILITY, X-RAYS, AND ACCRETION DIAGNOSTICS

    SciTech Connect (OSTI)

    Dupree, A. K.; Brickhouse, N. S.; Cranmer, S. R.; Luna, G. J. M.; Schneider, E. E. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Bessell, M. S. [Australian National Observatory, Mount Stromlo Observatory, Canberra, ACT 2611 (Australia); Bonanos, A. [Institute of Astronomy and Astrophysics, National Observatory of Athens, 15236 Athens (Greece); Crause, L. A. [South African Astronomical Observatory, P.O. Box 9, Observatory 7935, Cape Town (South Africa); Lawson, W. A. [School of Physical, Environmental, and Math Sciences, University of New South Wales, Canberra, ACT 2600 (Australia); Mallik, S. V. [Indian Institute of Astrophysics, Bangalore 560034 (India); Schuler, S. C. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States)

    2012-05-01T23:59:59.000Z

    The nearest accreting T Tauri star, TW Hya was intensively and continuously observed over {approx}17 days with spectroscopic and photometric measurements from four continents simultaneous with a long segmented exposure using the Chandra satellite. Contemporaneous optical photometry from WASP-S indicates a 4.74 day period was present during this time. The absence of a similar periodicity in the H{alpha} flux and the total X-ray flux which are dominated by accretion processes and the stellar corona, respectively, points to a different source of photometric variations. The H{alpha} emission line appears intrinsically broad and symmetric, and both the profile and its variability suggest an origin in the post-shock cooling region. An accretion event, signaled by soft X-rays, is traced spectroscopically for the first time through the optical emission line profiles. After the accretion event, downflowing turbulent material observed in the H{alpha} and H{beta} lines is followed by He I ({lambda}5876) broadening near the photosphere. Optical veiling resulting from the heated photosphere increases with a delay of {approx}2 hr after the X-ray accretion event. The response of the stellar coronal emission to an increase in the veiling follows {approx}2.4 hr later, giving direct evidence that the stellar corona is heated in part by accretion. Subsequently, the stellar wind becomes re-established. We suggest a model that incorporates the dynamics of this sequential series of events: an accretion shock, a cooling downflow in a supersonically turbulent region, followed by photospheric and later, coronal heating. This model naturally explains the presence of broad optical and ultraviolet lines, and affects the mass accretion rates determined from emission line profiles.

  1. Turbulence production and turbulent pressure support in the intergalactic medium

    E-Print Network [OSTI]

    Iapichino, L; Niemeyer, J C; Merklein, J

    2011-01-01T23:59:59.000Z

    The injection and evolution of turbulence in the intergalactic medium is studied by means of mesh-based hydrodynamical simulations, including a subgrid scale (SGS) model for small-scale unresolved turbulence. The simulations show that the production of turbulence has a different redshift dependence in the intracluster medium (ICM) and the warm-hot intergalactic medium (WHIM). We show that turbulence in the ICM is produced chiefly by merger-induced shear flows, whereas the production in the WHIM is dominated by shock interactions. Secondly, the effect of dynamical pressure support on the gravitational contraction has been studied. This turbulent support is stronger in the WHIM gas at baryon overdensities 1 < delta < 100, and less relevant for the ICM. Although the relative mass fraction of the gas with large vorticity is considerable (52% in the ICM), we find that for only about 10% in mass this is dynamically relevant, namely not associated to an equally large thermal pressure support. According to this...

  2. Effects of Temporal Wind Patterns on the Value of Wind-Generated Electricity in California and the Northwest

    SciTech Connect (OSTI)

    Wiser, Ryan H; Wiser, Ryan H; Fripp, Matthias

    2008-05-01T23:59:59.000Z

    Wind power production is variable, but also has diurnal and seasonal patterns. These patterns differ between sites, potentially making electric power from some wind sites more valuable for meeting customer loads or selling in wholesale power markets. This paper investigates whether the timing of wind significantly affects the value of electricity from sites in California and the Northwestern United States. We use both measured and modeled wind data and estimate the time-varying value of wind power with both financial and load-based metrics. We find that the potential difference in wholesale market value between better-correlated and poorly correlated wind sites is modest, on the order of 5-10 percent. A load-based metric, power production during the top 10 percent of peak load hours, varies more strongly between sites, suggesting that the capacity value of different wind projects could vary by as much as 50 percent based on the timing of wind alone.

  3. Wind/Hydro Study

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    WindHydro Integration Feasibility Study Announcements (Updated July 8, 2010) The Final WindHydro Integration Feasibility Study Report, dated June 2, 2009, has been submitted to...

  4. Wind energy bibliography

    SciTech Connect (OSTI)

    None

    1995-05-01T23:59:59.000Z

    This bibliography is designed to help the reader search for information on wind energy. The bibliography is intended to help several audiences, including engineers and scientists who may be unfamiliar with a particular aspect of wind energy, university researchers who are interested in this field, manufacturers who want to learn more about specific wind topics, and librarians who provide information to their clients. Topics covered range from the history of wind energy use to advanced wind turbine design. References for wind energy economics, the wind energy resource, and environmental and institutional issues related to wind energy are also included.

  5. Wind Turbine Tribology Seminar

    Broader source: Energy.gov [DOE]

    Wind turbine reliability issues are often linked to failures of contacting components, such as bearings, gears, and actuators. Therefore, special consideration to tribological design in wind...

  6. Commonwealth Wind Incentive Program Micro Wind Initiative

    Broader source: Energy.gov [DOE]

    Through the Commonwealth Wind Incentive Program Micro Wind Initiative the Massachusetts Clean Energy Center (MassCEC) offers rebates of up to $4/W with a maximum of $130,000 for design and...

  7. An investigation of the relationships between mountain waves and clear air turbulence encountered by the XB-70 airplane in the stratosphere

    E-Print Network [OSTI]

    Incrocci, Thomas Paul

    1970-01-01T23:59:59.000Z

    . . . . . . . . , . . . ~ . ~ INTRODUCTION BACKGROUND TO THE PROBLEM Theory of Mountain Waves Mountain Waves and Clear Air Turbulence (CAT). Page iv v vi viii The Vertical Propagation and Transfer of Energy of Mountain Waves into the Stratosphere The Influence of Wind... and the prevailing wind directions favorable for the development of extensive mountain wave activity in the surrounding areas (Wind directions taken from Harrison and Sowa, 1966). 24 Nid-tropospheric conditions for 1200 GNT on 19 March 1966 28 Nid...

  8. An investigation of the relationships between mountain waves and clear air turbulence encountered by the XB-70 airplane in the stratosphere

    E-Print Network [OSTI]

    Incrocci, Thomas Paul

    1970-01-01T23:59:59.000Z

    . . . . . . . . , . . . ~ . ~ INTRODUCTION BACKGROUND TO THE PROBLEM Theory of Mountain Waves Mountain Waves and Clear Air Turbulence (CAT). Page iv v vi viii The Vertical Propagation and Transfer of Energy of Mountain Waves into the Stratosphere The Influence of Wind... and wave energy under the influence of wind shear (Booker and Bretherton, 1967). A critical level, if it exists, is the level at which the horizontal phase velocity of the wave equals the mean wind speed. If a wave passes through a criti- cal level...

  9. Advances in compressible turbulent mixing

    SciTech Connect (OSTI)

    Dannevik, W.P.; Buckingham, A.C.; Leith, C.E. [eds.

    1992-01-01T23:59:59.000Z

    This volume includes some recent additions to original material prepared for the Princeton International Workshop on the Physics of Compressible Turbulent Mixing, held in 1988. Workshop participants were asked to emphasize the physics of the compressible mixing process rather than measurement techniques or computational methods. Actual experimental results and their meaning were given precedence over discussions of new diagnostic developments. Theoretical interpretations and understanding were stressed rather than the exposition of new analytical model developments or advances in numerical procedures. By design, compressibility influences on turbulent mixing were discussed--almost exclusively--from the perspective of supersonic flow field studies. The papers are arranged in three topical categories: Foundations, Vortical Domination, and Strongly Coupled Compressibility. The Foundations category is a collection of seminal studies that connect current study in compressible turbulent mixing with compressible, high-speed turbulent flow research that almost vanished about two decades ago. A number of contributions are included on flow instability initiation, evolution, and transition between the states of unstable flow onset through those descriptive of fully developed turbulence. The Vortical Domination category includes theoretical and experimental studies of coherent structures, vortex pairing, vortex-dynamics-influenced pressure focusing. In the Strongly Coupled Compressibility category the organizers included the high-speed turbulent flow investigations in which the interaction of shock waves could be considered an important source for production of new turbulence or for the enhancement of pre-existing turbulence. Individual papers are processed separately.

  10. Stochastic model for aerodynamic force dynamics on wind turbine blades in unsteady wind inflow

    E-Print Network [OSTI]

    Luhur, Muhammad Ramzan; Khn, Martin; Wchter, Matthias

    2015-01-01T23:59:59.000Z

    The paper presents a stochastic approach to estimate the aerodynamic forces with local dynamics on wind turbine blades in unsteady wind inflow. This is done by integrating a stochastic model of lift and drag dynamics for an airfoil into the aerodynamic simulation software AeroDyn. The model is added as an alternative to the static table lookup approach in blade element momentum (BEM) wake model used by AeroDyn. The stochastic forces are obtained for a rotor blade element using full field turbulence simulated wind data input and compared with the classical BEM and dynamic stall models for identical conditions. The comparison shows that the stochastic model generates additional extended dynamic response in terms of local force fluctuations. Further, the comparison of statistics between the classical BEM, dynamic stall and stochastic models' results in terms of their increment probability density functions gives consistent results.

  11. 2008 WIND TECHNOLOGIES MARKET REPORT

    E-Print Network [OSTI]

    Bolinger, Mark

    2010-01-01T23:59:59.000Z

    States. Specifically, Bluewater Wind and Delmarva PowerLLC Babcock & Brown Acquisition Bluewater Wind Good Energies

  12. 2008 WIND TECHNOLOGIES MARKET REPORT

    E-Print Network [OSTI]

    Bolinger, Mark

    2010-01-01T23:59:59.000Z

    policy support for other renewable energy sources, wind mayrenewable energy and climate policy initiatives. With wind

  13. Gravitational Radiation From Cosmological Turbulence

    E-Print Network [OSTI]

    Arthur Kosowsky; Andrew Mack; Tinatin Kahniashvili

    2002-06-27T23:59:59.000Z

    An injection of energy into the early Universe on a given characteristic length scale will result in turbulent motions of the primordial plasma. We calculate the stochastic background of gravitational radiation arising from a period of cosmological turbulence, using a simple model of isotropic Kolmogoroff turbulence produced in a cosmological phase transition. We also derive the gravitational radiation generated by magnetic fields arising from a dynamo operating during the period of turbulence. The resulting gravitational radiation background has a maximum amplitude comparable to the radiation background from the collision of bubbles in a first-order phase transition, but at a lower frequency, while the radiation from the induced magnetic fields is always subdominant to that from the turbulence itself. We briefly discuss the detectability of such a signal.

  14. Modeling the Benefits of Storage Technologies to Wind Power

    SciTech Connect (OSTI)

    Sullivan, P.; Short, W.; Blair, N.

    2008-06-01T23:59:59.000Z

    Rapid expansion of wind power in the electricity sector is raising questions about how wind resource variability might affect the capacity value of wind farms at high levels of penetration. Electricity storage, with the capability to shift wind energy from periods of low demand to peak times and to smooth fluctuations in output, may have a role in bolstering the value of wind power at levels of penetration envisioned by a new Department of Energy report ('20% Wind by 2030, Increasing Wind Energy's Contribution to U.S. Electricity Supply'). This paper quantifies the value storage can add to wind. The analysis was done employing the Regional Energy Deployment System (ReEDS) model, formerly known as the Wind Deployment System (WinDS) model. ReEDS was used to estimate the cost and development path associated with 20% penetration of wind in the report. ReEDS differs from the WinDS model primarily in that the model has been modified to include the capability to build and use three storage technologies: pumped-hydroelectric storage (PHS), compressed-air energy storage (CAES), and batteries. To assess the value of these storage technologies, two pairs of scenarios were run: business-as-usual, with and without storage; 20% wind energy by 2030, with and without storage. This paper presents the results from those model runs.

  15. Appendix I3-1 to Wind HUI Initiative 1: AWST-WindNET-Phase 1 Final Report

    SciTech Connect (OSTI)

    John Zack

    2012-07-15T23:59:59.000Z

    This report is an appendix to the Hawaii WindHUI efforts to develop and operationalize short-term wind forecasting and wind ramp event forecasting capabilities. The report summarizes the WindNET Phase 1 efforts on the Big Island of Hawaii and includes descriptions of modeling methodologies, use of field validation data, results and recommendations. The objective of the WindNET project was to investigate the improvement that could be obtained in short-term wind power forecasting for wind generation facilities operating on the island grids operated by Hawaiian Electric Companies through the use of atmospheric sensors deployed at targeted locations. WindNET is envisioned as a multiphase project that will address the short-term wind forecasting issues of all of the wind generation facilities on the all of the Hawaiian Electric Companies' island grid systems. The first phase of the WindNET effort (referred to as WindNET-1) was focused on the wind generation facilities on the Big Island of Hawaii. With complex terrain and marine environment, emphasis was on improving the 0 to 6 hour forecasts of wind power ramps and periods of wind variability, with a particular interest in the intra-hour (0-1 hour) look-ahead period. The WindNET project was built upon a foundation that was constructed with the results from a previously completed observation targeting study for the Big Island that was conducted as part of a project supported by the National Renewable Energy Laboratory (NREL) and interactions with the western utilities. The observational targeting study provided guidance on which variables to measure and at what locations to get the most improvement in forecast performance at a target forecast site. The recommendations of the observation targeting study were based on the application two techniques: (1) an objective method called ensemble sensitivity analysis (ESA) (Ancell and Hakim, 2007; Torn and Hakim, 2008; Zack et al, 2010); and (2) a subjective method based on a diagnostic analysis of large ramp events. The analysis was completed for both the wind farm on the southern tip of the Big Island and on the northern tip of the island. The WindNET project was designed to also deploy sensors to validate the Big Island observational targeting study and enhance operator's understanding of predominate causes of wind variability conditions at the wind facilities. Compromises had to be made with the results from the observation targeting study to accommodate project resource limitations, availability of suitable sites, and other factors. To focus efforts, field sensor deployment activities focused on the wind facility on the southern point of Big Island.

  16. Characterizing Inflow Conditions Across the Rotor Disk of a Utility-Scale Wind Turbine (Poster)

    SciTech Connect (OSTI)

    Clifton, A.; Lundquist, J. K.; Kelley, N.; Scott, G.; Jager, D.; Schreck, S.

    2012-01-01T23:59:59.000Z

    Multi-megawatt utility-scale wind turbines operate in a turbulent, thermally-driven atmosphere where wind speed and air temperature vary with height. Turbines convert the wind's momentum into electrical power, and so changes in the atmosphere across the rotor disk influence the power produced by the turbine. To characterize the inflow into utility scale turbines at the National Wind Technology Center (NWTC) near Boulder, Colorado, NREL recently built two 135-meter inflow monitoring towers. This poster introduces the towers and the measurements that are made, showing some of the data obtained in the first few months of operation in 2011.

  17. The wind power probability density forecast problem can be formulated as: forecast the wind power pdf at time step t for each look-ahead time step t+k of a given time-horizon

    E-Print Network [OSTI]

    Kemner, Ken

    The wind power probability density forecast problem can be formulated as: forecast the wind power ahead) knowing a set of explanatory variables (e.g. numerical weather predictions (NWPs), wind power measured values). Translating this sentence to an equation, we have: where pt+k is the wind power

  18. On open boundary conditions for a limited-area coastal model off Oregon. Part 2: response to wind forcing from

    E-Print Network [OSTI]

    . Additional experiments forced by realistic, time-variable, but spatially uniform winds are included to allow in numerical experiments utilizing idealized wind forcing. The objective of this paper is to continue the study in a situation where realistic wind stress forcing with strong spatial and temporal variability is utilized

  19. Wind Resource Assessment in Europe Using Emergy

    E-Print Network [OSTI]

    Paudel, Subodh; Santarelli, Massimo; Martin, Viktoria; Lacarriere, Bruno; Le Corre, Olivier

    2014-01-01T23:59:59.000Z

    mance characteristics of wind generator. The wind speed atcharacteristics of the wind generator. When wind speed is

  20. Wind Bias from Sub-optimal Estimation Due to Geophysical Modeling Error Paul E. Johnson and David G . Long

    E-Print Network [OSTI]

    Long, David G.

    Wind Bias from Sub-optimal Estimation Due to Geophysical Modeling Error -Wind I Paul E. Johnson (which relates the wind to the normalized radar cross section, NRCS, of the ocean surface) is uncertainty in the NRCS for given wind conditions. When the estimated variability is in- cluded in the maximum likelihood

  1. Paper No. 2006-JSC-397 Agarwal Design Loads for an Offshore Wind Turbine using Statistical Extrapolation from Limited Field Data

    E-Print Network [OSTI]

    Manuel, Lance

    Paper No. 2006-JSC-397 Agarwal Design Loads for an Offshore Wind Turbine using Statistical a field measurement campaign. At the Blyth offshore wind farm in the United Kingdom, a 2MW wind turbine of variability in the parameters for load distribution is investigated. KEY WORDS: Offshore wind turbines

  2. Advanced Coal Wind Hybrid: Economic Analysis

    E-Print Network [OSTI]

    Phadke, Amol

    2008-01-01T23:59:59.000Z

    Wind Generation2006. Integrating Wind Generation into Utility Systems.Stand-Alone Wind Generation . 60

  3. Howard County- Wind Ordinance

    Broader source: Energy.gov [DOE]

    This ordinance sets up provisions for allowing small wind energy systems in various zoning districts.

  4. Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Shupe, Matthew

    Time-height fields of retrieved in-cloud vertical wind velocity and turbulent dissipation rate, both retrieved primarily from vertically-pointing, Ka-band cloud radar measurements. Files are available for manually-selected, stratiform, mixed-phase cloud cases observed at the North Slope of Alaska (NSA) site during periods covering the Mixed-Phase Arctic Cloud Experiment (MPACE, late September through early November 2004) and the Indirect and Semi-Direct Aerosol Campaign (ISDAC, April-early May 2008). These time periods will be expanded in a future submission.

  5. Turbulence Kinetic Energy in the Oklahoma City Urban Environment

    SciTech Connect (OSTI)

    Lundquist, J K; Leach, M; Gouveia, F

    2004-03-30T23:59:59.000Z

    The Joint URBAN 2003 field experiment took place in Oklahoma City, Oklahoma, during July 2003 to explore the effect of an urban canopy on the transport and diffusion of a passive tracer released in an urban area. Over one hundred three-dimensional sonic anemometers were deployed in and around the urban area to monitor wind speed, direction, and turbulence during releases of SF6. Deployment locations include a profile of eight sonic anemometers mounted on a crane located 1 km north (typically downwind) of the central business district, and several surface meteorological towers within an urban canyon.

  6. Compound cooling flow turbulator for turbine component

    DOE Patents [OSTI]

    Lee, Ching-Pang; Jiang, Nan; Marra, John J; Rudolph, Ronald J

    2014-11-25T23:59:59.000Z

    Multi-scale turbulation features, including first turbulators (46, 48) on a cooling surface (44), and smaller turbulators (52, 54, 58, 62) on the first turbulators. The first turbulators may be formed between larger turbulators (50). The first turbulators may be alternating ridges (46) and valleys (48). The smaller turbulators may be concave surface features such as dimples (62) and grooves (54), and/or convex surface features such as bumps (58) and smaller ridges (52). An embodiment with convex turbulators (52, 58) in the valleys (48) and concave turbulators (54, 62) on the ridges (46) increases the cooling surface area, reduces boundary layer separation, avoids coolant shadowing and stagnation, and reduces component mass.

  7. Wind energy offers considerable promise; the wind itself is free,

    E-Print Network [OSTI]

    Langendoen, Koen

    Wind energy offers considerable promise; the wind itself is free, wind power is clean. One of these sources, wind energy, offers considerable promise; the wind itself is free, wind power is clean, and it is virtually inexhaustible. In recent years, research on wind energy has accelerated

  8. Estimation of Wind Speed in Connection to a Wind Turbine

    E-Print Network [OSTI]

    Estimation of Wind Speed in Connection to a Wind Turbine X. Ma #3; , N. K. Poulsen #3; , H. Bindner y December 20, 1995 Abstract The wind speed varies over the rotor plane of wind turbine making the wind speed on the rotor plane will be estimated by using a wind turbine as a wind measuring device

  9. Sizing Storage and Wind Generation Capacities in Remote Power Systems

    E-Print Network [OSTI]

    Victoria, University of

    Sizing Storage and Wind Generation Capacities in Remote Power Systems by Andy Gassner B Capacities in Remote Power Systems by Andy Gassner B.Sc., University of Wisconsin Madison, 2003 Supervisory and small power systems. However, the variability due to the stochastic nature of the wind resource

  10. Western Wind and Solar Integration Study: Phase 2 (Presentation)

    SciTech Connect (OSTI)

    Lew, D.; Brinkman, G.; Ibanez, E.; Lefton, S.; Kumar, N.; Venkataraman, S.; Jordan, G.

    2013-09-01T23:59:59.000Z

    This presentation summarizes the scope and results of the Western Wind and Solar Integration Study Phase 2, which examined operational impacts of high penetrations of variable renewable generation in the West.

  11. Western Wind and Solar Integration Study Phase 2 (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-09-01T23:59:59.000Z

    This is one-page, two-sided fact sheet presents high-level summary results of the Western Wind and Solar Integration Study Phase 2, which examined operational impacts of high penetrations of variable renewable generation in the West.

  12. Characteristics of Wind Turbines Under Normal and Fault Conditions: Preprint

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C. P.; Parsons, B.; Ellis, A.

    2007-02-01T23:59:59.000Z

    This paper investigates the characteristics of a variable-speed wind turbine connected to a stiff or weak grid under normal and fault conditions and the role of reactive power compensation.

  13. Wave Decay in MHD Turbulence

    E-Print Network [OSTI]

    Andrey Beresnyak; Alex Lazarian

    2008-05-06T23:59:59.000Z

    We present a model for nonlinear decay of the weak wave in three-dimensional incompressible magnetohydrodynamic (MHD) turbulence. We show that the decay rate is different for parallel and perpendicular waves. We provide a general formula for arbitrarily directed waves and discuss particular limiting cases known in the literature. We test our predictions with direct numerical simulations of wave decay in three-dimensional MHD turbulence, and discuss the influence of turbulent damping on the development of linear instabilities in the interstellar medium and on other important astrophysical processes.

  14. Wind Power Outlook 2004

    SciTech Connect (OSTI)

    anon.

    2004-01-01T23:59:59.000Z

    The brochure, expected to be updated annually, provides the American Wind Energy Association's (AWAE's) up-to-date assessment of the wind industry. It provides a summary of the state of wind power in the U.S., including the challenges and opportunities facing the industry. It provides summary information on the growth of the industry, policy-related factors such as the federal wind energy production tax credit status, comparisons with natural gas, and public views on wind energy.

  15. Dynamic simulation of dual-speed wind turbine generation

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P.

    1996-10-01T23:59:59.000Z

    Induction generators have been used since the early development of utility-scale wind turbine generation. An induction generator is the generator of choice because of its ruggedness, and low cost. With an induction generator, the operating speed of the wind turbine is limited to a narrow range (almost constant speed). Dual- speed operation can be accomplished by using an induction generator with two different sets of winding configurations or by using two induction generators with two different rated speeds. With single- speed operation, the wind turbine operates at different power coefficients (Cp) as the wind speed varies. The operation at maximum Cp can occur only at a single wind speed. However, if the wind speed varies across a wider range, the operating Cp will vary significantly. Dual-speed operation has the advantage of enabling the wind turbine to operate at near maximum Cp over a wider range of wind-speeds. Thus, annual energy production can be increased. The dual-speed mode may generate less energy than a variable-speed mode; nevertheless, it offers an alternative to capture more energy than single-speed operation. In this paper, dual-speed operation of a wind turbine will be investigated. One type of control algorithm for dual- speed operation is proposed. Results from a dynamic simulation will be presented to show how the control algorithm works and how power, current and torque of the system vary as the wind turbine is exposed to varying wind speeds.

  16. Collegiate Wind Competition Engages Tomorrow's Wind Energy Innovators...

    Office of Environmental Management (EM)

    Engages Tomorrow's Wind Energy Innovators Collegiate Wind Competition Engages Tomorrow's Wind Energy Innovators January 6, 2014 - 10:00am Addthis 2014 Collegiate Teams Boise State...

  17. 20% Wind Energy by 2030: Increasing Wind Energy's Contribution...

    Energy Savers [EERE]

    : Increasing Wind Energy's Contribution to U.S. Electricity Supply (Executive Summary) 20% Wind Energy by 2030: Increasing Wind Energy's Contribution to U.S. Electricity Supply...

  18. National Wind Technology Center (Fact Sheet), National Wind Technology...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    NATIONAL WIND TECHNOLOGY CENTER www.nrel.govwind Wind energy is one of the fastest growing electricity generation sources in the world. NREL's National Wind Technology Center...

  19. Sinomatech Wind Power Blade aka Sinoma Science Technology Wind...

    Open Energy Info (EERE)

    Sinomatech Wind Power Blade aka Sinoma Science Technology Wind Turbine Blade Co Ltd Jump to: navigation, search Name: Sinomatech Wind Power Blade (aka Sinoma Science & Technology...

  20. 20% Wind Energy by 2030: Increasing Wind Energy's Contribution...

    Office of Environmental Management (EM)

    a new vision for wind energy through 2050. Taking into account all facets of wind energy (land-based, offshore, distributed), the new Wind Vision Report defines the...

  1. Defining the normal turbine inflow within a wind park environment

    SciTech Connect (OSTI)

    Kelley, N.D.

    1993-06-01T23:59:59.000Z

    This brief paper discusses factors that must be considered when defining the {open_quotes}normal{close_quotes} (as opposed to {open_quotes}extreme{close_quotes}) loading conditions seen in wind turbines operating within a wind park environment. The author defines the {open_quotes}normal{close_quotes} conditions to include fatigue damage accumulation as a result of: (1) start/stop cycles, (2) emergency shutdowns, and (3) the turbulence environment associated with site and turbine location. He also interprets {open_quotes}extreme{close_quotes} loading conditions to include those events that can challenge the survivability of the turbine.

  2. Defining the normal turbine inflow within a wind park environment

    SciTech Connect (OSTI)

    Kelley, N.D.

    1993-06-01T23:59:59.000Z

    This brief paper discusses factors that must be considered when defining the [open quotes]normal[close quotes] (as opposed to [open quotes]extreme[close quotes]) loading conditions seen in wind turbines operating within a wind park environment. The author defines the [open quotes]normal[close quotes] conditions to include fatigue damage accumulation as a result of: (1) start/stop cycles, (2) emergency shutdowns, and (3) the turbulence environment associated with site and turbine location. He also interprets [open quotes]extreme[close quotes] loading conditions to include those events that can challenge the survivability of the turbine.

  3. Sandia Energy - Sandia Wind Turbine Loads Database

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Sandia Wind Turbine Loads Database Home Stationary Power Energy Conversion Efficiency Wind Energy Resources Wind Software Downloads Sandia Wind Turbine Loads Database Sandia Wind...

  4. Horizontal wind rotor. Final technical report

    SciTech Connect (OSTI)

    Guard, E.J.

    1983-06-30T23:59:59.000Z

    A vertical axis wind machine called, ''Horizontal Wind Rotor'' conceived in 1979 by the Grantee E.J. Guard was an effort to marry a new high tech carousel type wind rotor to a basic building design for the purpose of generating practical amounts of electricty. This was directed especially towards high performance power generation, relative to low average wind velocity fields, typically found in Florida. From January 1980 to April 1983 two 1/30 scale wind tunnel type test models of buildings, one round and one square were built. An eight Hartzell shrouded wind tunnel fan machine was designed and built to supply uniform wind velocities for testing. All components of the Horizontal Wind Rotor (HWR) were fabricated, instrumented, mounted on the building models, and tested and modified repeatedly for performance optimization. Aerodynamic consultants, model makers, mechanical and computer engineers and technicians under the direction of E. Guard all teamed up to evolve the size, shape, and placement of the system components. It was recognized early that the machine had to be large in order to extract energy from low wind velocities. It was also noted that there were so many variables in the system, so as to elude analytical computation, that only testing could provide the answers. Consequently, this grant program has provided major contributions to the sparse available data in this little studied field, and set up valuable bench marks in design and power output parameters. This data will be the foundation for incorporating the newly discovered design improvements into the full scale prototype to follow. (Phase II) It is believed that this Rotor design is the only one in the world today that will produce as much power in the lower wind velocity ranges and it is also believed that every objective of the original grant proposal has been met or exceeded.

  5. Wind tunnel simulation of wind effects and associated displacement hazards on flat surface construction materials such as plywood

    E-Print Network [OSTI]

    Madeley, Jack T.

    1996-01-01T23:59:59.000Z

    materials. With respect to the latter, much of the research pertaining to wind effects has been done by structural engineers regarding wind hfting forces on building roof sections and forces on the face of buildings [Sachs, 1978, Melaragno, 1982]. Very... the flow is in a smooth linear path or in stratified laminae or layers. Turbulence occurs when there is random erratic movement breaking the smoothness of the flow [Melaragno, 1982]. At a point back from the leading edge of a plate, the laminar boundary...

  6. Sandia National Laboratories: Wind Power

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Wind Energy Staff On March 24, 2011, in Wind Energy On November 10, 2010, in Wind Plant Opt. Rotor Innovation Materials, Reliability & Standards Siting & Barrier Mitigation...

  7. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01T23:59:59.000Z

    the Impact of Significant Wind Generation Facilities on BulkOperations Impacts of Wind Generation Integration Study.Impacts of Integrating Wind Generation into Idaho Power's

  8. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01T23:59:59.000Z

    Operations Impacts of Wind Generation Integration Study.Impacts of Integrating Wind Generation into Idaho Power's2008. Analysis of Wind Generation Impact on ERCOT Ancillary

  9. 2008 WIND TECHNOLOGIES MARKET REPORT

    E-Print Network [OSTI]

    Bolinger, Mark

    2010-01-01T23:59:59.000Z

    the Impact of Significant Wind Generation Facilities on BulkOperations Impacts of Wind Generation Integration Study.Impacts of Integrating Wind Generation into Idaho Power's

  10. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01T23:59:59.000Z

    Operations Impacts of Wind Generation Integration Study.Impacts of Integrating Wind Generation into Idaho Power'sthe Impact of Significant Wind Generation Facilities on Bulk

  11. WIND DATA REPORT Presque Isle

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Presque Isle June 1, 2005 August 31, 2005 Prepared for United States Department...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  12. WIND DATA REPORT Presque Isle

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Presque Isle December 1, 2004 February 28, 2005 Prepared for United States.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  13. WIND DATA REPORT Presque Isle

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Presque Isle December 1, 2004 December 1, 2005 Prepared for United States ......................................................................................................... 9 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  14. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island June 1, 2003 August 31, 2003 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  15. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01T23:59:59.000Z

    Prepared for the Utility Wind Integration Group. Arlington,Consult. 2010. International Wind Energy Development: WorldUBS Global I/O: Global Wind Sector. UBS Investment Research.

  16. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island December 1, 2003 February 29, 2004 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distribution

  17. WIND DATA REPORT Presque Isle

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Presque Isle March 1, 2005 May 31, 2005 Prepared for United States Department.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  18. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island March 1, 2003 May 31, 2003 Prepared for Massachusetts Technology...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  19. WIND DATA REPORT FALMOUTH, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT FALMOUTH, MA June1, 2004 to August 31, 2004. Prepared for Massachusetts Technology...................................................................................................................... 8 Wind Speed Time Series............................................................................................................. 8 Wind Speed Distributions

  20. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island September 1, 2003 November 30, 2003 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  1. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island March 1, 2004 May 31, 2004 Prepared for Massachusetts Technology...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  2. 2008 WIND TECHNOLOGIES MARKET REPORT

    E-Print Network [OSTI]

    Bolinger, Mark

    2010-01-01T23:59:59.000Z

    2008. Washington, DC: American Wind Energy Association.American Wind Energy Association ( AWEA).2009b. AWEA Small Wind Turbine Global Market Study: Year

  3. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island June 1, 2004 August 31, 2004 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  4. 2008 WIND TECHNOLOGIES MARKET REPORT

    E-Print Network [OSTI]

    Bolinger, Mark

    2010-01-01T23:59:59.000Z

    Table 8 Figure 30. Wind Integration Costs at Various LevelsOperations and Maintenance Costs Wind project operations andPublic Service Wind Integration Cost Impact Study. Prepared

  5. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01T23:59:59.000Z

    wind turbine components (specifically, generators, bladeschangers. Wind turbine components such as blades, towers,Canada (8%). Wind turbine component exports (towers, blades,

  6. 2012 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2014-01-01T23:59:59.000Z

    with the section on offshore wind; Donna Heimiller and Billyof 2012, global cumulative offshore wind capacity stood ats (DOEs) investments in offshore wind energy research and

  7. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01T23:59:59.000Z

    charging wind power projects for balancing services. 81 BPA,in balancing reserves with increased wind power penetrationin balancing reserves with increased wind power penetration

  8. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01T23:59:59.000Z

    charging wind power projects for balancing services. 88 BPA,in balancing reserves with increased wind power penetrationin balancing reserves with increased wind power penetration

  9. 2012 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2014-01-01T23:59:59.000Z

    Xcel Energy. 2011. Wind Induced Coal Plant Cyclingand the Implications of Wind Curtailment for Public Serviceof Colorado 2 GW and 3 GW Wind Integration Cost Study.

  10. Wind Farms in North America

    E-Print Network [OSTI]

    Hoen, Ben

    2014-01-01T23:59:59.000Z

    Opinion About Large Offshore Wind Power: Underlying Factors.Delaware Opinion on Offshore Wind Power - Interim Report.Newark, DE. 16 pages. Global Wind Energy Council (GWEC) (

  11. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01T23:59:59.000Z

    2011. In March 2011, NRG Bluewater Wind?s Delaware projectPurchaser Delmarva NRG Bluewater Wind (Delaware) Universitythe project, while NRG Bluewater would retain the remaining

  12. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01T23:59:59.000Z

    natural gas prices), pushed wind energy to the top of (andperformance, and price of wind energy, policy uncertainty cost, performance, and price of wind energy, some of these

  13. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island December 1, 2004 February 28, 2005 Prepared for Massachusetts.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distribution

  14. WIND DATA REPORT DARTMOUTH, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT DARTMOUTH, MA March 26th 2005 to May 31st 2005. Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  15. WIND DATA REPORT FALMOUTH, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT FALMOUTH, MA June 1st 2004- May 31st 2005 Prepared for Massachusetts Technology.................................................................................................................... 10 Wind Speed Distributions......................................................................................................... 11 Monthly Average Wind Speeds

  16. WIND DATA REPORT Kingston, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Kingston, MA March 1, 2006 - May 31, 2006 Prepared for Massachusetts Technology.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributions.......

  17. WIND DATA REPORT Nantucket, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Nantucket, MA September 1st 2005 to November 30th 2005. Prepared for Massachusetts.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  18. WIND DATA REPORT Wellfleet, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Wellfleet, MA December 1st , 2006 February 28th , 2007 Prepared...................................................................................................................... 8 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  19. WIND DATA REPORT Nantucket, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Nantucket, MA June 1st 2006 to August 31th 2006 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed D

  20. WIND DATA REPORT Truro, Massachusetts

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Truro, Massachusetts March 24th to May 31st , 2006 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributions

  1. WIND DATA REPORT Chester, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Chester, MA December 2006 February 2007 Prepared for Massachusetts Technology...................................................................................................................... 9 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  2. WIND DATA REPORT Brewster, Massachusetts

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Brewster, Massachusetts December 1, 2005 - February 28, 2006 Prepared.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 12 Wind Speed Di

  3. WIND DATA REPORT Truro, Massachusetts

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Truro, Massachusetts December, 2006 1st to February 28th , 2007 Prepared...................................................................................................................... 9 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  4. WIND DATA REPORT Brewster, Massachusetts

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Brewster, Massachusetts June 1, 2006 - August 31, 2006 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Di

  5. WIND DATA REPORT Chester, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Chester, MA March 2007 May 2007 Prepared for Massachusetts Technology...................................................................................................................... 8 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  6. WIND DATA REPORT Chester, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Chester, MA September November 2006 Prepared for Massachusetts Technology.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributions

  7. WIND DATA REPORT DARTMOUTH, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT DARTMOUTH, MA September 1st 2005 to November 30th 2005. Prepared for Massachusetts.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  8. WIND DATA REPORT Kingston, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Kingston, MA December 1, 2005 - February 28, 2006 Prepared for Massachusetts.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distribution

  9. WIND DATA REPORT Brewster, Massachusetts

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Brewster, Massachusetts September 1, 2006 - November 30, 2006 Prepared.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributions..................

  10. WIND DATA REPORT Nantucket, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Nantucket, MA December 1st 2005 to February 28th 2006 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributions

  11. WIND DATA REPORT Gardner NCCI

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Gardner NCCI March 1, 2007 May 31, 2007 Prepared for Massachusetts Technology...................................................................................................................... 8 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  12. WIND DATA REPORT FALMOUTH, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT FALMOUTH, MA Sep 1st 2004 to Nov 30th 2004. Prepared for Massachusetts Technology...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  13. WIND DATA REPORT Chester, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Chester, MA June August 2006 Prepared for Massachusetts Technology Collaborative.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributions

  14. WIND DATA REPORT September 2005

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Lynn, MA September 2005 Prepared for Massachusetts Technology Collaborative 75.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Monthly Average Wind Speeds

  15. WIND DATA REPORT Nantucket, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Nantucket, MA June 1st 2005 to August 31st 2005. Prepared for Massachusetts.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  16. WIND DATA REPORT Truro, Massachusetts

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Truro, Massachusetts September 1st to November 30th , 2006 Prepared.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributions

  17. WIND DATA REPORT Truro, Massachusetts

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Truro, Massachusetts June 1st to August 31st , 2006 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributions

  18. WIND DATA REPORT DARTMOUTH, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT DARTMOUTH, MA June 1st 2005 to August 31st 2005. Prepared for Massachusetts.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  19. WIND DATA REPORT Brewster, Massachusetts

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Brewster, Massachusetts March 1, 2006 - May 31, 2006 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributi

  20. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island September 1, 2004 November 30, 2004 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distribution.............

  1. WIND DATA REPORT DARTMOUTH, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT DARTMOUTH, MA December 1st 2005 to February 28th 2006. Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributions

  2. WIND DATA REPORT Dartmouth, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Dartmouth, MA March 1st 2006 to May 31th 2006 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributions

  3. WIND DATA REPORT Wellfleet, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Wellfleet, MA March 1st , 2007 May 31st , 2007 Prepared for Massachusetts...................................................................................................................... 8 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  4. WIND DATA REPORT Gardner NCCI

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Gardner NCCI September 1, 2007 November 30, 2007 Prepared for Massachusetts...................................................................................................................... 8 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  5. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island March 1, 2005 May 31, 2005 Prepared for Massachusetts Technology.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distribution

  6. WIND DATA REPORT Chester, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Chester, MA April 14 May 31, 2006 Prepared for Massachusetts Technology.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributions

  7. WIND DATA REPORT FALMOUTH, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT FALMOUTH, MA Dec 1st 2004 to Feb 28th 2005. Prepared for Massachusetts Technology ...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  8. WIND DATA REPORT FALMOUTH, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT FALMOUTH, MA March 1st 2005 to May 31st 2005. Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  9. WIND DATA REPORT Dartmouth, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Dartmouth, MA June 1st 2006 to July 31th 2006 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributions

  10. WIND DATA REPORT Gardner NCCI

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Gardner NCCI June 1, 2007 August 31, 2007 Prepared for Massachusetts Technology...................................................................................................................... 8 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  11. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01T23:59:59.000Z

    studies show that wind energy integration costs are below $do not represent wind energy generation costs. This sectioncomponent of the overall cost of wind energy, but can vary

  12. 2008 WIND TECHNOLOGIES MARKET REPORT

    E-Print Network [OSTI]

    Bolinger, Mark

    2010-01-01T23:59:59.000Z

    do not represent wind energy generation costs. Based on thisproduction-cost reduction value of wind energy, without anwith wind energy. Generally, these costs are associated with

  13. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01T23:59:59.000Z

    performance, and price of wind energy, policy uncertainty The wind energy integration, transmission, and policyand absent supportive policies for wind energy. That said,

  14. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01T23:59:59.000Z

    The wind energy integration, transmission, and policy2012, however, federal policy towards wind energy remainsin federal policy towards wind energy after 2012 places such

  15. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01T23:59:59.000Z

    The wind energy integration, transmission, and policyPTC. Moreover, federal policy towards wind energy remainsand policy announcements demonstrate accelerated activity in the offshore wind energy

  16. WIND DATA REPORT Nantucket, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Nantucket, MA March 1st 2006 to May 31th 2006 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distribut

  17. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01T23:59:59.000Z

    Market Report vii potential wind energy generation withinthat nearly 8% of potential wind energy generation withinAreas, in GWh (and % of potential wind generation) Electric

  18. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01T23:59:59.000Z

    capacity), with 17% of all potential wind energy generationthat roughly 17% of potential wind energy generation withinexample, roughly 1% of potential wind energy output in 2009

  19. Power optimization of wind turbines with data mining and evolutionary computation

    E-Print Network [OSTI]

    Kusiak, Andrew

    and non-controllable variables of a wind turbine. An evolutionary strategy algorithm is appliedPower optimization of wind turbines with data mining and evolutionary computation Andrew Kusiak July 2009 Accepted 25 August 2009 Available online 17 September 2009 Keywords: Wind turbine Data mining

  20. Ris-R-Report Grid fault and design-basis for wind turbines -

    E-Print Network [OSTI]

    of the new grid connection requirements for the fatigue and ultimate structural loads of wind turbines analysis for fatigue and ultimate structural loads, respectively, have been performed and compared for two variable speed wind turbines to produce power at wind speeds higher than 25m/s and up to 50m/s without