Sample records for measure wind speed

  1. 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.

  2. Ris-R-Report LIDAR Wind Speed Measurements from a

    E-Print Network [OSTI]

    the approaching wind fields from this vantage point. Time series of wind speed measurements from the lidar with 50: Time series of the yaw misalignment 67 #12;4 Risø-R-1741(EN) Preface Mikael Rasmussen and Per Hansen is acknowledged for safety supervision of the operation of the NM80 research turbine. The Spin

  3. MEASUREMENT OF WIND SPEED FROM COOLING LAKE THERMAL IMAGERY

    SciTech Connect (OSTI)

    Garrett, A; Robert Kurzeja, R; Eliel Villa-Aleman, E; Cary Tuckfield, C; Malcolm Pendergast, M

    2009-01-20T23:59:59.000Z

    The Savannah River National Laboratory (SRNL) collected thermal imagery and ground truth data at two commercial power plant cooling lakes to investigate the applicability of laboratory empirical correlations between surface heat flux and wind speed, and statistics derived from thermal imagery. SRNL demonstrated in a previous paper [1] that a linear relationship exists between the standard deviation of image temperature and surface heat flux. In this paper, SRNL will show that the skewness of the temperature distribution derived from cooling lake thermal images correlates with instantaneous wind speed measured at the same location. SRNL collected thermal imagery, surface meteorology and water temperatures from helicopters and boats at the Comanche Peak and H. B. Robinson nuclear power plant cooling lakes. SRNL found that decreasing skewness correlated with increasing wind speed, as was the case for the laboratory experiments. Simple linear and orthogonal regression models both explained about 50% of the variance in the skewness - wind speed plots. A nonlinear (logistic) regression model produced a better fit to the data, apparently because the thermal convection and resulting skewness are related to wind speed in a highly nonlinear way in nearly calm and in windy conditions.

  4. Measurement strategies for estimating long-term average wind speeds

    SciTech Connect (OSTI)

    Ramsdell, J.V.; Houston, S.; Wegley, H.L.

    1980-10-01T23:59:59.000Z

    The uncertainty and bias in estimates of long-term average wind speeds inherent in continuous and intermittent measurement strategies are examined by simulating the application of the strategies to 40 data sets. Continuous strategies have smaller uncertainties for fixed duration measurement programs, but intermittent strategies make more efficient use of instruments and have smaller uncertainties for a fixed amount of instrument use. Continuous strategies tend to give biased estimates of the long-term annual mean speed unless an integral number of years' data is collected or the measurement program exceeds 3 years in duration. Intermittent strategies with three or more month-long measurement periods per year do not show any tendency toward bias.

  5. EVALUATION OF MODELS FOR THE VERTICAL EXTRAPOLATION OF WIND SPEED MEASUREMENTS AT OFFSHORE SITES

    E-Print Network [OSTI]

    Heinemann, Detlev

    sites. The first large offshore wind farms are currently being built in several countries in Europe. For the planning of offshore wind farms the vertical wind speed profile is needed for two main reasons: WindEVALUATION OF MODELS FOR THE VERTICAL EXTRAPOLATION OF WIND SPEED MEASUREMENTS AT OFFSHORE SITES

  6. EVALUATION OF MODELS FOR THE VERTICAL EXTRAPOLATION OF WIND SPEED MEASUREMENTS AT OFFSHORE SITES

    E-Print Network [OSTI]

    Heinemann, Detlev

    will come from offshore sites. The first large offshore wind farms are currently being built in severalEVALUATION OF MODELS FOR THE VERTICAL EXTRAPOLATION OF WIND SPEED MEASUREMENTS AT OFFSHORE SITES important for offshore wind energy utilisation are discussed and tested: Four models for the surface

  7. 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

  8. Master's thesis: "Wind speed measurements in an offshore wind farm by remote sensing: Comparison of radar satellite TerraSAR-X and ground-based

    E-Print Network [OSTI]

    Peinke, Joachim

    Master's thesis: "Wind speed measurements in an offshore wind farm by remote sensing: Comparison of the Offshore wind farm alpha ventus with 12 wind turbines, substation and met mast Fino1. Southerly winds cause (wake) caused by wind farms and especially for the interaction of large offshore wind farms, which can

  9. Fig. 1. One hour measured irradiance and wind speed data with 0.2 seconds, 3 seconds and 1 minute (interpolated) sampling time.

    E-Print Network [OSTI]

    Sera, Dezso

    Fig. 1. One hour measured irradiance and wind speed data with 0.2 seconds, 3 seconds and 1 minute to intermittent character of the solar irradiance and wind. The actual power quality standards provide only of the solar irradiance and wind speed in fast changing conditions on the utility grid. This work proposes

  10. LIDAR Wind Speed Measurement Analysis and Feed-Forward Blade Pitch Control for Load Mitigation in Wind Turbines: January 2010--January 2011

    SciTech Connect (OSTI)

    Dunne, F.; Simley, E.; Pao, L.Y.

    2011-10-01T23:59:59.000Z

    This report examines the accuracy of measurements that rely on Doppler LIDAR systems to determine their applicability to wind turbine feed-forward control systems and discusses feed-forward control system designs that use preview wind measurements. 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 feed-forward 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. The first half of this report examines the accuracy of different measurement scenarios that rely on coherent continuous-wave or pulsed Doppler LIDAR systems to determine their applicability to feed-forward control. In particular, the impacts of measurement range and angular offset from the wind direction are studied for various wind conditions. A realistic case involving a scanning LIDAR unit mounted in the spinner of a wind turbine is studied in depth with emphasis on choices for scan radius and preview distance. The effects of turbulence parameters on measurement accuracy are studied as well. Continuous-wave and pulsed LIDAR models based on typical commercially available units were used in the studies present in this report. The second half of this report discusses feed-forward control system designs that use preview wind measurements. Combined feedback/feed-forward blade pitch control is compared to industry standard feedback control when simulated in realistic turbulent above-rated winds. The feed-forward controllers are designed to reduce fatigue loads, increasing turbine lifetime and therefore reducing the cost of energy. Three feed-forward designs are studied: non-causal series expansion, Preview Control, and optimized FIR filter. The input to the feed-forward controller is a measurement of incoming wind speeds that could be provided by LIDAR. Non-causal series expansion and Preview Control methods reduce blade root loads but increase tower bending in simulation results. The optimized FIR filter reduces loads overall, keeps pitch rates low, and maintains rotor speed regulation and power capture, while using imperfect wind measurements provided by the spinning continuous-wave LIDAR model.

  11. 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.

  12. Numerical wind speed simulation model

    SciTech Connect (OSTI)

    Ramsdell, J.V.; Athey, G.F.; Ballinger, M.Y.

    1981-09-01T23:59:59.000Z

    A relatively simple stochastic model for simulating wind speed time series that can be used as an alternative to time series from representative locations is described in this report. The model incorporates systematic seasonal variation of the mean wind, its standard deviation, and the correlation speeds. It also incorporates systematic diurnal variation of the mean speed and standard deviation. To demonstrate the model capabilities, simulations were made using model parameters derived from data collected at the Hanford Meteorology Station, and results of analysis of simulated and actual data were compared.

  13. Wind Speed Forecasting for Power System Operation 

    E-Print Network [OSTI]

    Zhu, Xinxin

    2013-07-22T23:59:59.000Z

    In order to support large-scale integration of wind power into current electric energy system, accurate wind speed forecasting is essential, because the high variation and limited predictability of wind pose profound challenges to the power system...

  14. Wind Speed Forecasting for Power System Operation

    E-Print Network [OSTI]

    Zhu, Xinxin

    2013-07-22T23:59:59.000Z

    In order to support large-scale integration of wind power into current electric energy system, accurate wind speed forecasting is essential, because the high variation and limited predictability of wind pose profound challenges to the power system...

  15. Q: When planning a wind farm, how are wind resources estimated? And if the average wind speed is known at 10 meters is there a general rule for estimating the wind speed at

    E-Print Network [OSTI]

    Q: When planning a wind farm, how are wind resources estimated? And if the average wind speed is known at 10 meters is there a general rule for estimating the wind speed at larger heights above ground level? The wind resource at a wind farm can be estimated in two ways: by measurement or by modeling

  16. 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.

  17. 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 Rødsand by extrapolating the measured 10 m wind

  18. Ris-PhD-Report Accounting for the speed shear in wind

    E-Print Network [OSTI]

    Risø-PhD-Report Accounting for the speed shear in wind turbine power performance measurement Rozenn for the speed shear in wind turbine power performance measurement Division: Wind Energy Division Abstract: The power curve of a wind turbine is the primary char- acteristic of the machine as it is the basis

  19. Quantifying hurricane wind speed with undersea sound

    E-Print Network [OSTI]

    Wilson, Joshua David

    2006-01-01T23:59:59.000Z

    Hurricanes, powerful storms with wind speeds that can exceed 80 m/s, are one of the most destructive natural disasters known to man. While current satellite technology has made it possible to effectively detect and track ...

  20. Wind speed PDF classification using Dirichlet mixtures Rudy CALIF1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Wind speed PDF classification using Dirichlet mixtures Rudy CALIF1 , Richard EMILION2 , Ted'Orléans), UMR CNRS 6628 Université d'Orléans, France. Abstract: Wind energy production is very sensitive to instantaneous wind speed fluctuations. Thus rapid variation of wind speed due to changes in the local

  1. 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.

  2. Interpolating wind speed normals from the sparse Dutch network to a high resolution

    E-Print Network [OSTI]

    Stoffelen, Ad

    , we had potential wind speed time series with 30 years of data (with at least 20 yearly and monthly by Verkaik (Verkaik, 2001). The method is a five-step procedure: 1 Use series of (potential) wind to calculate (potential) normals at measuring sites 2 Calculate wind speed normals at the top of the surface

  3. 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.

  4. IMPROVED MICROWAVE REMOTE SENSING OF HURRICANE WIND SPEED AND RAIN RATES USING THE HURRICANE IMAGING RADIOMETER (HIRAD)

    E-Print Network [OSTI]

    Ruf, Christopher

    IMPROVED MICROWAVE REMOTE SENSING OF HURRICANE WIND SPEED AND RAIN RATES USING THE HURRICANE) that measures wind speed and rain rate along the ground track directly beneath the aircraft. This paper presents are presented, which illustrate wind speed and rain rate measurement spatial resolutions and swath coverage. 1

  5. On the measurement of wind speeds in tornadoes with a portable CW/FM-CW Doppler radar

    SciTech Connect (OSTI)

    Bluestein, H.B. (Oklahoma Univ., Norman, OK (USA). School of Meteorology); Unruh, W.P. (Los Alamos National Lab., NM (USA))

    1991-01-01T23:59:59.000Z

    Both the formation mechanism and structure of tornadoes are not yet well understood. The Doppler radar is probably the best remote-sensing instrument at present for determining the wind field in tornadoes. Although much has been learned about the non-supercell tornado from relatively close range using Doppler radars at fixed sites, close-range measurements in supercell tornadoes are relatively few. Doppler radar can increase significantly the number of high-resolution, sub-cloud base measurements of both the tornado vortex and its parent vortex in supercells, with simultaneous visual documentation. The design details and operation of the CW/FM-CW Doppler radar developed at the Los Alamos National Laboratory and used by storm-intercept teams at the Univ. of Oklahoma are described elsewhere. The radar transmits 1 W at 3 cm, and can be switched back and forth between CW and FM-CW modes. In the FM-CW mode the sweep repetition frequency is 15.575 kHz and the sweep width 1.9 MHz; the corresponding maximum unambiguous range and velocity, and range resolution are 5 km, {plus minus} 115 m s{sup {minus}1}, and 78 m respectively. The bistatic antennas, which have half-power beamwidths of 5{degree}, are easily pointed wit the aid of a boresighted VCR. FM-CW Data are recorded on the VCR, while voice documentation is recorded on the audio tape; video is recorded on another VCR. The radar and antennas are easily mounted on a tripod, and can be set up by three people in a minute or two. The purpose of this paper is to describe the signal processing techniques used to determine the Doppler spectrum in the FM-CW mode and a method of its interpretation in real time, and to present data gathered in a tornadic storm in 1990. 15 refs., 7 figs.

  6. 1. Wind-splash erosion 4. Relationships between rainfall intensity, wind-speed, wind direction and erosion

    E-Print Network [OSTI]

    from the surface but unless it corresponds to a high wind-speed (the potential to transport a single rainfall event. When high wind-speeds and heavy rainfall combine there is an increased potential1. Wind-splash erosion 4. Relationships between rainfall intensity, wind-speed, wind direction

  7. Wind velocity measurements using a pulsed LIDAR system: first results

    E-Print Network [OSTI]

    Peinke, Joachim

    . A laser beam of 1.54 µm wavelength takes measurements of the wind speed in beamwise direction. To obtain the three-dimensinal wind vector, the beam is inclined by 30 from vertical direction and measurements 12345 t [s] vh[m/s] Figure 2. Segment of measured time series of the horizontal wind speed magnitude vh

  8. The Effect of Wind Speed and Electric Rates On Wind Turbine Economics

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    The Effect of Wind Speed and Electric Rates On Wind Turbine Economics Economics of wind power depends mainly on the wind speeds and the turbine make and model. Definition: Simple Payback The "Simple period of a small wind power project. All the figures are per turbine, so it can be used for a one, two

  9. Probabilistic Wind Speed Forecasting Using Ensembles and Bayesian Model Averaging

    E-Print Network [OSTI]

    Raftery, Adrian

    the chance of winds high enough to pose dangers for boats or aircraft. In situations calling for a cost/loss analysis, the probabilities of different outcomes need to be known. For wind speed, this issue often arisesProbabilistic Wind Speed Forecasting Using Ensembles and Bayesian Model Averaging J. Mc

  10. Spatial and Temporal Patterns of Global Onshore Wind Speed Distribution

    SciTech Connect (OSTI)

    Zhou, Yuyu; Smith, Steven J.

    2013-09-09T23:59:59.000Z

    Wind power, a renewable energy source, can play an important role in electrical energy generation. Information regarding wind energy potential is important both for energy related modeling and for decision-making in the policy community. While wind speed datasets with high spatial and temporal resolution are often ultimately used for detailed planning, simpler assumptions are often used in analysis work. An accurate representation of the wind speed frequency distribution is needed in order to properly characterize wind energy potential. Using a power density method, this study estimated global variation in wind parameters as fitted to a Weibull density function using NCEP/CFSR reanalysis data. The estimated Weibull distribution performs well in fitting the time series wind speed data at the global level according to R2, root mean square error, and power density error. The spatial, decadal, and seasonal patterns of wind speed distribution were then evaluated. We also analyzed the potential error in wind power estimation when a commonly assumed Rayleigh distribution (Weibull k = 2) is used. We find that the assumption of the same Weibull parameter across large regions can result in substantial errors. While large-scale wind speed data is often presented in the form of average wind speeds, these results highlight the need to also provide information on the wind speed distribution.

  11. Observed and CAM3 GCM Sea Surface Wind Speed Distributions: Characterization, Comparison, and Bias Reduction

    E-Print Network [OSTI]

    Capps, Scott B; Zender, Charles S

    2008-01-01T23:59:59.000Z

    bin predictions. and 90th percentile wind speeds and higherWind speed mean, 90th percentile, standard deviation, andwind speed mean, 90th percentile, standard deviation, and

  12. SCALAR WIND SPEED AND DIRECTION TROPICAL CYCLONE RETRIEVALS FOR CONICAL SCANNING SCATTEROMETERS

    E-Print Network [OSTI]

    Hennon, Christopher C.

    SCALAR WIND SPEED AND DIRECTION TROPICAL CYCLONE RETRIEVALS FOR CONICAL SCANNING SCATTEROMETERS--Scatterometer measurements of ocean vector winds (OVW) are significantly degraded in the presence of the precipitation, especially in tropical cyclones. This paper presents a new ocean hurricane/typhoon wind vector retrieval

  13. Hi-Q Rotor - Low Wind Speed Technology

    SciTech Connect (OSTI)

    Todd E. Mills; Judy Tatum

    2010-01-11T23:59:59.000Z

    The project objective was to optimize the performance of the Hi-Q Rotor. Early research funded by the California Energy Commission indicated the design might be advantageous over state-of-the-art turbines for collecting wind energy in low wind conditions. The Hi-Q Rotor is a new kind of rotor targeted for harvesting wind in Class 2, 3, and 4 sites, and has application in areas that are closer to cities, or 'load centers.' An advantage of the Hi-Q Rotor is that the rotor has non-conventional blade tips, producing less turbulence, and is quieter than standard wind turbine blades which is critical to the low-wind populated urban sites. Unlike state-of-the-art propeller type blades, the Hi-Q Rotor has six blades connected by end caps. In this phase of the research funded by DOE's Inventions and Innovation Program, the goal was to improve the current design by building a series of theoretical and numeric models, and composite prototypes to determine a best of class device. Development of the rotor was performed by aeronautical engineering and design firm, DARcorporation. From this investigation, an optimized design was determined and an 8-foot diameter, full-scale rotor was built and mounted using a Bergey LX-1 generator and furling system which were adapted to support the rotor. The Hi-Q Rotor was then tested side-by-side against the state-of-the-art Bergey XL-1 at the Alternative Energy Institute's Wind Test Center at West Texas State University for six weeks, and real time measurements of power generated were collected and compared. Early wind tunnel testing showed that the cut-in-speed of the Hi-Q rotor is much lower than a conventional tested HAWT enabling the Hi-Q Wind Turbine to begin collecting energy before a conventional HAWT has started spinning. Also, torque at low wind speeds for the Hi-Q Wind Turbine is higher than the tested conventional HAWT and enabled the wind turbine to generate power at lower wind speeds. Based on the data collected, the results of our first full-scale prototype wind turbine proved that higher energy can be captured at lower wind speeds with the new Hi-Q Rotor. The Hi-Q Rotor is almost 15% more productive than the Bergey from 6 m/s to 8 m/s, making it ideal in Class 3, 4, and 5 wind sites and has application in the critical and heretofore untapped areas that are closer to cities, 'load centers,' and may even be used directly in urban areas. The additional advantage of the Hi-Q Rotor's non-conventional blade tips, which eliminates most air turbulence, is noise reduction which makes it doubly ideal for populated urban areas. Hi-Q Products recommends one final stage of development to take the Hi-Q Rotor through Technology Readiness Levels 8-9. During this stage of development, the rotor will be redesigned to further increase efficiency, match the rotor to a more suitable generator, and lower the cost of manufacturing by redesigning the structure to allow for production in larger quantities at lower cost. Before taking the rotor to market and commercialization, it is necessary to further optimize the performance by finding a better generator and autofurling system, ones more suitable for lower wind speeds and rpms should be used in all future testing. The potential impact of this fully developed technology will be the expansion and proliferation of energy renewal into the heretofore untapped Class 2, 3, 4, and 5 Wind Sites, or the large underutilized sites where the wind speed is broken by physical features such as mountains, buildings, and trees. Market estimates by 2011, if low wind speed technology can be developed are well above: 13 million homes, 675,000 commercial buildings, 250,000 public facilities. Estimated commercial exploitation of the Hi-Q Rotor show potential increase in U.S. energy gained through the clean, renewable wind energy found in low and very low wind speed sites. This new energy source would greatly impact greenhouse emissions as well as the public sector's growing energy demands.

  14. The wind speed profile at offshore wind farm sites Bernhard Lange(1)

    E-Print Network [OSTI]

    Heinemann, Detlev

    The wind speed profile at offshore wind farm sites Bernhard Lange(1) , Søren E. Larsen(2) , Jørgen in Europe will come from offshore sites. The first large offshore wind farms are #12;currently being built feasibility of offshore wind power utilisation depends on the favourable wind conditions offshore compared

  15. Analytical Modelling of Wind Speed Deficit in Large Offshore Wind Farms

    E-Print Network [OSTI]

    Pryor, Sara C.

    Analytical Modelling of Wind Speed Deficit in Large Offshore Wind Farms Sten Frandsen*, Rebecca areas.As is often the need for offshore wind farms, the model handles a regular array geometry for offshore wind farms, the model handles a priori a regular array geometry with straight rows of wind

  16. 0 Riso-R-434 Wind Speed and Direction

    E-Print Network [OSTI]

    meteorological statistics for the area as it was considered a possible site for a nuclear power plant. \\ \\ Duringm I 0 Riso-R-434 t Wind Speed and Direction Changes due to Terrain Effects revealed-4000 Roskilde, Denmark May 1983 #12;RISÃ?-R-434 WIND SPEED AND DIRECTION CHANGES DUE TO TERRAIN EFFECTS

  17. Probability distributions of land surface wind speeds over North America

    E-Print Network [OSTI]

    Dai, Aiguo

    . Jones, A. Dai, S. Biner, D. Caya, and K. Winger (2010), Probability distributions of land surface wind distribution used for estimation of wind climate and annual winProbability distributions of land surface wind speeds over North America Yanping He,1 Adam Hugh

  18. Euler-Bernoulli Implementation of Spherical Anemometers for High Wind Speed Calculations via Strain Gauges

    E-Print Network [OSTI]

    Castillo, Davis

    2011-08-08T23:59:59.000Z

    avenues for these environments from the traditional cup model to sonar, hot-wire, and recent developments with sphere anemometers. Several measurement methods have modeled the air drag force as a quadratic function of the corresponding wind speed...

  19. 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

  20. Microsoft Word - idaho_wind_speed_summary.doc

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

    Ft. Hall, ID Sites Wheat Grass Ridge Average Wind Speeds Site 0001 (66 ft. (20m) tower, erected week of 11101, data started on 11201) N. 42 deg. 44.762', W. 112 deg. 41.011'...

  1. Microsoft Word - utah_wind_speed_summary.doc

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

    02 - 110502) 10.6 mph Overall Average (120101 - 110502) 7.8 mph Dean Davis Site Spanish Fork, Utah Average Wind Speeds Site 0009 (66 ft. (20m) tower, data started on 1101...

  2. Euler-Bernoulli Implementation of Spherical Anemometers for High Wind Speed Calculations via Strain Gauges 

    E-Print Network [OSTI]

    Castillo, Davis

    2011-08-08T23:59:59.000Z

    New measuring methods continue to be developed in the field of wind anemometry for various environments subject to low-speed and high-speed flows, turbulent-present flows, and ideal and non-ideal flows. As a result, anemometry has taken different...

  3. Wind Fields over the Great Lakes Measured by the SeaWinds Scatterometer on the QuikSCAT Satellite

    E-Print Network [OSTI]

    Wind Fields over the Great Lakes Measured by the SeaWinds Scatterometer on the QuikSCAT Satellite for wind retrieval over the Great Lakes on a daily basis. We use data acquired by the SeaWinds Scatterometer on the QuikSCAT (QSCAT) satellite launched in June 1999 to derive wind speeds and directions over

  4. 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.

  5. 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.

  6. 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.

  7. The Solar Wind Helium Abundance: Variation with Wind Speed and the Solar Cycle

    E-Print Network [OSTI]

    Richardson, John

    The Solar Wind Helium Abundance: Variation with Wind Speed and the Solar Cycle Matthias R. Aellig Alamos National Lab., Los Alamos, NM 87545 Abstract We investigate the helium abundance in the solar wind of 1994 and early 2000 are analyzed. In agreement with similar work for previous solar cycles, we find

  8. Wind Measurement Equipment: Registration (Nebraska)

    Broader source: Energy.gov [DOE]

    All wind measurement equipment associated with the development or study of wind-powered electric generation, whether owned or leased, shall be registered with the Department of Aeronautics if the...

  9. Observed and CAM3 GCM Sea Surface Wind Speed Distributions: Characterization, Comparison, and Bias Reduction

    E-Print Network [OSTI]

    Capps, Scott B; Zender, Charles S

    2008-01-01T23:59:59.000Z

    341–345. Yuan, X. , 2004: High-wind-speed evaluation in theCosca, 2004: Effects of wind speed and gas exchange param-dust emission caused by wind erosion. J. Geophys. Res. ,

  10. MASON LAB B-7 WIND TUNNEL OPERATING INSTRUCTIONS Our wind tunnel is a low speed tunnel with a test section 15"x24" It has a digital controller

    E-Print Network [OSTI]

    Haller, Gary L.

    MASON LAB B-7 WIND TUNNEL OPERATING INSTRUCTIONS Our wind tunnel is a low speed tunnel with a test up to a maximum velocity of about 39M/s (~130 feet/s , 88mph) We have a 2 axis force balance that can measure lift (~25 N) and drag (~8 N) PRECAUTIONS: ALL OBJECTS MUST BE SECURED BEFORE STARTING WIND TUNNEL

  11. Simulation of wind-speed time series for wind-energy conversion analysis.

    SciTech Connect (OSTI)

    Corotis, R.B.

    1982-06-01T23:59:59.000Z

    In order to investigate operating characteristics of a wind energy conversion system it is often desirable to have a sequential record of wind speeds. Sometimes a long enough actual data record is not available at the time an analysis is needed. This may be the case if, e.g., data are recorded three times a day at a candidate wind turbine site, and then the hourly performance of generated power is desired. In such cases it is often possible to use statistical characteristics of the wind speed data to calibrate a stochastic model and then generate a simulated wind speed time series. Any length of record may be simulated by this method, and desired system characteristics may be studied. A simple wind speed simulation model, WEISIM, is developed based on the Weibull probability distribution for wind speeds with a correction based on the lag-one autocorrelation value. The model can simulate at rates from one a second to one an hour, and wind speeds can represent short-term averages (e.g., 1-sec averages) or longer-term averages (e.g., 1-min or 1 hr averages). The validity of the model is verified with PNL data for both histogram characteristics and persistance characteristics.

  12. The amount of power in the wind is very dependent on the speed of the wind. Because the power in the wind

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    the potential benefits of a wind power installation, wind speeds and other characteristics of a site's wind for potential wind power sites. However, these maps do not elimi- nate the need for more precise and thoroughThe amount of power in the wind is very dependent on the speed of the wind. Because the power

  13. 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 Energy’s (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.

  14. CONSTRAINING HIGH-SPEED WINDS IN EXOPLANET ATMOSPHERES THROUGH OBSERVATIONS OF ANOMALOUS DOPPLER SHIFTS DURING TRANSIT

    SciTech Connect (OSTI)

    Miller-Ricci Kempton, Eliza [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Rauscher, Emily, E-mail: ekempton@ucolick.org [Lunar and Planetary Laboratory, University of Arizona, 1629 East University Boulevard, Tucson, AZ 85721 (United States)

    2012-06-01T23:59:59.000Z

    Three-dimensional (3D) dynamical models of hot Jupiter atmospheres predict very strong wind speeds. For tidally locked hot Jupiters, winds at high altitude in the planet's atmosphere advect heat from the day side to the cooler night side of the planet. Net wind speeds on the order of 1-10 km s{sup -1} directed towards the night side of the planet are predicted at mbar pressures, which is the approximate pressure level probed by transmission spectroscopy. These winds should result in an observed blueshift of spectral lines in transmission on the order of the wind speed. Indeed, Snellen et al. recently observed a 2 {+-} 1 km s{sup -1} blueshift of CO transmission features for HD 209458b, which has been interpreted as a detection of the day-to-night (substellar to anti-stellar) winds that have been predicted by 3D atmospheric dynamics modeling. Here, we present the results of a coupled 3D atmospheric dynamics and transmission spectrum model, which predicts the Doppler-shifted spectrum of a hot Jupiter during transit resulting from winds in the planet's atmosphere. We explore four different models for the hot Jupiter atmosphere using different prescriptions for atmospheric drag via interaction with planetary magnetic fields. We find that models with no magnetic drag produce net Doppler blueshifts in the transmission spectrum of {approx}2 km s{sup -1} and that lower Doppler shifts of {approx}1 km s{sup -1} are found for the higher drag cases, results consistent with-but not yet strongly constrained by-the Snellen et al. measurement. We additionally explore the possibility of recovering the average terminator wind speed as a function of altitude by measuring Doppler shifts of individual spectral lines and spatially resolving wind speeds across the leading and trailing terminators during ingress and egress.

  15. the risk issue of wind measurement for wind turbine operation

    E-Print Network [OSTI]

    Leu, Tzong-Shyng "Jeremy"

    Sciences, National Taiwan University #12;outline · Wind measurement in meteorology and wind farm design-related issues on wind turbine operation 3/31/2011 2 #12;WIND MEASUREMENT IN METEOROLOGY & WIND FARM DESIGN 3.brainybetty.com 11 wind farm at ChangHwa Coastal Industrial Park 70m wind tower 70m 50m 30m 10m #12;1 2 3 4 5 1 (70M

  16. Probability distributions for offshore wind speeds Eugene C. Morgan a,*, Matthew Lackner b

    E-Print Network [OSTI]

    Vogel, Richard M.

    Probability distributions for offshore wind speeds Eugene C. Morgan a,*, Matthew Lackner b Wind turbine energy output Weibull distribution Extreme wind a b s t r a c t In planning offshore wind farms, short-term wind speeds play a central role in estimating various engi- neering parameters

  17. Improvements in wind speed forecasts for wind power prediction purposes using Kalman filtering

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Improvements in wind speed forecasts for wind power prediction purposes using Kalman filtering P : 10.1016/j.jweia.2008.03.013 #12;2 Abstract This paper studies the application of Kalman filtering forecasts. The application of Kalman filter to these data leads to the elimination of any possible

  18. United States- Land Based and Offshore Annual Average Wind Speed at 100 Meters

    Broader source: Energy.gov [DOE]

    Full-size, high resolution version of the 100-meter land-based and offshore wind speed resource map.

  19. 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

  20. Observed and CAM3 GCM Sea Surface Wind Speed Distributions: Characterization, Comparison, and Bias Reduction

    E-Print Network [OSTI]

    Zender, Charles

    resources force the use of coarse-resolution GCMs, which do not resolve finer-scale wind speed fluctuationsObserved and CAM3 GCM Sea Surface Wind Speed Distributions: Characterization, Comparison, and Bias (Manuscript received 10 December 2007, in final form 8 April 2008) ABSTRACT Climatological surface wind speed

  1. Wind speed influence on phytoplankton bloom dynamics in the Southern Ocean Marginal Ice Zone

    E-Print Network [OSTI]

    Fitch, Dillon T; Moore, J. Keith

    2007-01-01T23:59:59.000Z

    Niebauer, H. J. (1982), Wind and melt driven circulation inJ. K. Moore (2007), Wind speed influence on phytoplanktonby the NASA Ocean Vector Winds Science Team. Data are

  2. Solar wind-magnetosphere coupling leading to relativistic electron energization during high-speed streams

    E-Print Network [OSTI]

    Lyons, Larry

    Solar wind-magnetosphere coupling leading to relativistic electron energization during high. Smith (2005), Solar wind-magnetosphere coupling leading to relativistic electron energization during. Using observations during a period of persistent high-speed, corotating, solar wind streams, we

  3. Empirical downscaling of wind speed probability distributions S. C. Pryor and J. T. Schoof1

    E-Print Network [OSTI]

    Pryor, Sara C.

    . Barthelmie2 Department of Wind Energy and Atmospheric Physics, Risø National Laboratory, Roskilde, Denmark decreases in mean wind speed, 90th percentile wind speed, and energy density in 2071­2100 relative to 1961 increase in the annual wind energy resource over northern Europe between the end of the 20th century

  4. 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.

  5. American Wind Energy Association, Denver, May 2005 Uncertainties in Results of Measure-Correlate-Predict Analyses

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    American Wind Energy Association, Denver, May 2005 Uncertainties in Results of Measure-correlate-predict (MCP) algorithms are used to predict the wind resource at target sites for wind power development. MCP methods model the relationship between wind data (speed and direction) measured at the target site

  6. 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

  7. 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.

  8. Relationship Between Solar Wind Speed and Coronal Magnetic Field Properties

    E-Print Network [OSTI]

    Fujiki, Ken'ichi; Iju, Tomoya; Hakamada, Kazuyuki; Kojima, Masayoshi

    2015-01-01T23:59:59.000Z

    We have studied the relationship between the solar-wind speed $[V]$ and the coronal magnetic-field properties (a flux expansion factor [$f$] and photospheric magnetic-field strength [$B_{\\mathrm{S}}$]) at all latitudes using data of interplanetary scintillation and solar magnetic field obtained for 24 years from 1986 to 2009. Using a cross-correlation analyses, we verified that $V$ is inversely proportional to $f$ and found that $V$ tends to increase with $B_{\\mathrm{S}}$ if $f$ is the same. As a consequence, we find that $V$ has extremely good linear correlation with $B_{\\mathrm{S}}/f$. However, this linear relation of $V$ and $B_{\\mathrm{S}}/f$ cannot be used for predicting the solar-wind velocity without information on the solar-wind mass flux. We discuss why the inverse relation between $V$ and $f$ has been successfully used for solar-wind velocity prediction, even though it does not explicitly include the mass flux and magnetic-field strength, which are important physical parameters for solar-wind accele...

  9. 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.

  10. Tip Jets and Barrier Winds: A QuikSCAT Climatology of High Wind Speed Events around Greenland

    E-Print Network [OSTI]

    Renfrew, Ian

    of Environmental Sciences, University of East Anglia, Norwich, United Kingdom (Manuscript received 28 September meteorological, oceanographic, cli- matological, and wind energy applications. Strong sur- face winds overTip Jets and Barrier Winds: A QuikSCAT Climatology of High Wind Speed Events around Greenland G. W

  11. Ris National Laboratory DTU Wind Energy Department

    E-Print Network [OSTI]

    wind speed, wind direction relative to the spinner and flow inclination angle. A wind tunnel concept anemometer is a wind measurement concept in which measurements of wind speed in the flow over a wind turbine on a modified 300kW wind turbine spinner, was mounted with three 1D sonic wind speed sensors. The flow around

  12. A sea drag relation for hurricane wind speeds N. C. Zweers,1

    E-Print Network [OSTI]

    Vries, Hans de

    A sea drag relation for hurricane wind speeds N. C. Zweers,1 V. K. Makin,1 J. W. de Vries,1 and G, the surface drag is overestimated in NWP models for hurricane wind speeds and the intensity of hurricane winds is tested in an NWP model. Two hurricanes in the Caribbean are modeled: Ivan (2004) and Katrina (2005

  13. 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

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

    E-Print Network [OSTI]

    Hansen, René 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 Risø National Laboratory Vestas Wind Systems A/S #12;#12;I Modelling and Analysis of Variable Speed

  15. WINDSAT RETRIEVAL OF OCEAN SURFACE WIND SPEEDS IN TROPICAL CYCLONES Amanda Mims, Rachael Kroodsma, Christopher Ruf, Darren McKague

    E-Print Network [OSTI]

    Ruf, Christopher

    of emissivity on wind speed up to category 3 hurricane-force winds. 1. INTRODUCTION The microwave emissivity and horizontally polarized emissivity versus wind speed at hurricane force winds. 2. SATELLITE AND GROUNDBASEDWINDSAT RETRIEVAL OF OCEAN SURFACE WIND SPEEDS IN TROPICAL CYCLONES Amanda Mims, Rachael Kroodsma

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. ARM - Measurement - Horizontal 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 for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDC documentationBarrow,ice particle ARMgovMeasurementsExtreme

  1. Low Wind Speed Turbine Development Project Report: November 4, 2002 - December 31, 2006

    SciTech Connect (OSTI)

    Mikhail, A.

    2009-01-01T23:59:59.000Z

    This report summarizes work conducted by Clipper Windpower under the DOE Low Wind Speed Turbine project. The objective of this project was to produce a wind turbine that can lower the cost of energy.

  2. Offshore Coastal Wind Speed Gradients: issues for the design and development of large offshore windfarms

    E-Print Network [OSTI]

    Pryor, Sara C.

    -situ and remote sensing data from offshore wind farms in Denmark, are used to examine both horizontal and vertical the area of the wind farm appear to be small and negligible. 1. INTRODUCTION As large offshore wind farmsOffshore Coastal Wind Speed Gradients: issues for the design and development of large offshore

  3. The effect of wind speed fluctuations on the performance of a wind-powered membrane system for brackish water desalination 

    E-Print Network [OSTI]

    Park, Gavin L.; Schäfer, Andrea; Richards, Bryce S.

    2011-01-01T23:59:59.000Z

    A wind-powered reverse osmosis membrane (wind-membrane) system without energy storage was tested using synthetic brackish water (2750 and 5500 mg/L NaCl) over a range of simulated wind speeds under both steady-state and ...

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

    SciTech Connect (OSTI)

    Genesis Partners LP

    2010-08-01T23:59:59.000Z

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

  5. 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.

  6. 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.

  7. Solar-wind magnetosphere coupling, including relativistic electron energization, during high-speed streams

    E-Print Network [OSTI]

    Lyons, Larry

    Solar-wind­ magnetosphere coupling, including relativistic electron energization, during high. If this inference is correct, and if it is chorus that energizes the relativistic electrons, then high-speed solar-speed solar wind streams, and fluxes of relativistic electrons observed at geosynchronous orbit enhance

  8. 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.

  9. CRYOPUMP MEASUREMENTS RELATING TO SAFETY, PUMPING SPEED, AND RADIATION OUTGASSING

    E-Print Network [OSTI]

    Graham, W.G.

    2011-01-01T23:59:59.000Z

    Fast Gas Pulse Typical Data for Dynamic Pumping Speed Measurements with Deuterium Plan View of Reactor

  10. An aero-elastic flutter based electromagnetic energy harvester with wind speed augmenting funnel

    E-Print Network [OSTI]

    Stanford University

    An aero-elastic flutter based electromagnetic energy harvester with wind speed augmenting funnel been used to convert wind flow energy into mechanical vibration, which is then transformed-scale renewable energy generating systems such as wind turbines, thermal generators, and solar panels, energy

  11. 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

  12. 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

  13. The feasibility of sodar wind profile measurements from an oceanographic buoy

    E-Print Network [OSTI]

    Berg, Allison M. (Allison May)

    2006-01-01T23:59:59.000Z

    This thesis explores the feasibility of making wind speed profile measurements from an oceanographic buoy using a Doppler sodar. In the fall of 2005, we deployed a Scintec SFAS sodar on an ASIS buoy. Roughly one week of ...

  14. Solar wind electron temperature and density measurements on the Solar Orbiter with thermal noise spectroscopy

    E-Print Network [OSTI]

    California at Berkeley, University of

    Solar wind electron temperature and density measurements on the Solar Orbiter with thermal noise of the plasma thermal noise analysis for the Solar Orbiter, in order to get accurate measurements of the total of their small mass and therefore large thermal speed, the solar wind electrons are expected to play a major role

  15. Effect on Speed Distribution due to Intrusive and Non-Intrusive Portable Speed Measurement Devices

    E-Print Network [OSTI]

    Jasrotia, Romika

    2011-06-02T23:59:59.000Z

    , placing traffic signs, and determining the effectiveness of the countermeasures. To evaluate the effectiveness on speed distribution due to the presence of various intrusive and non-intrusive portable speed measurement devices, automated traffic counters...

  16. annual wind speeds: Topics by E-print Network

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

    In this paper, an efficient system has been presented comprising of solar panel, wind generator, charge controller and charge storage unit (battery). Solar panel is selected as...

  17. accurate wind speed: Topics by E-print Network

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

    In this paper, an efficient system has been presented comprising of solar panel, wind generator, charge controller and charge storage unit (battery). Solar panel is selected as...

  18. THE HURRICANE IMAGING RADIOMETER WIDE SWATH SIMULATION AND WIND SPEED RETRIEVALS

    E-Print Network [OSTI]

    Ruf, Christopher

    THE HURRICANE IMAGING RADIOMETER WIDE SWATH SIMULATION AND WIND SPEED RETRIEVALS Ruba A. Amarin1 Space Flight Center, Huntsville, Alabama 4 NOAA/AOML/Hurricane Research Division, Miami, Florida, USA ABSTRACT The knowledge of peak winds in hurricanes is critical to classification of hurricane intensity

  19. Tuesday, 31 July, 2012 Rapid radiation belt losses occurring during high speed solar wind stream1

    E-Print Network [OSTI]

    Otago, University of

    Tuesday, 31 July, 2012 1 Rapid radiation belt losses occurring during high speed solar wind stream1 Raita11 Sodankylä Geophysical Observatory, University of Oulu, Sodankylä, Finland12 Abstract. Recent geomagnetic disturbances triggered by the arrival of a Solar14 Wind Stream Interface (SWSI). In the current

  20. HIGH-SPEED AXIAL-FLUX PERMANENT MAGNET MICROMOTORS WITH ELECTROPLATED WINDINGS

    E-Print Network [OSTI]

    the other. The folded-coil stator fabrication process is detailed, followed by the motor driver topology- plated multi-phase stator windings and their use in a high-speed permanent magnet micromotor. As the stator windings of an axial- flux micromotor, both single-plated folded coils, and two-layer double

  1. UNIVERSITY OF CALIFORNIA, Surface Wind Speed Distributions: Implications for Climate and Wind Power

    E-Print Network [OSTI]

    Zender, Charles

    and Wind Power DISSERTATION submitted in partial satisfaction of the requirements for the degree of DOCTOR . . . . . . . . . . . . . . . . . 19 1.3 Global Ocean Wind Power and Surface Layer Stability . . . . . . . . 23 1.3.1 Global Winds . . . . . . 27 1.4 Usable Offshore Wind Power . . . . . . . . . . . . . . . . . . . . . . . 31 1.4.1 Wind Turbine

  2. Offshore Wind Project Surges Ahead in South Carolina

    Broader source: Energy.gov [DOE]

    The Center for Marine and Wetland Studies studies wind speed data from buoys, which have been measuring wind speed and direction for the past year.

  3. Space-time forecasting and evaluation of wind speed with statistical tests for comparing accuracy of spatial predictions

    E-Print Network [OSTI]

    Hering, Amanda S.

    2010-10-12T23:59:59.000Z

    High-quality short-term forecasts of wind speed are vital to making wind power a more reliable energy source. Gneiting et al. (2006) have introduced a model for the average wind speed two hours ahead based on both spatial and temporal information...

  4. 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.

  5. Different Virtual Stator Winding Configurations of Open-End Winding Five-Phase PM Machines for Wide Speed Range without Flux Weakening Operation

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Different Virtual Stator Winding Configurations of Open-End Winding Five-Phase PM Machines for Wide of double-ended inverter system for wide-speed range of open- winding five phase PM machines. Different virtual winding configurations (star, pentagon, pentacle and bipolar) can be obtained by choosing

  6. 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.

  7. High speed air pneumatic wind shield wiping design

    E-Print Network [OSTI]

    Heyward, Moses A

    2005-01-01T23:59:59.000Z

    In this creative design process a number of designs were constructed, implemented and tested in order to assess the feasibility of using high speed to create a curtain to repel the rain from the automobile windshield instead ...

  8. Vermont Wind Measurement Company Still Strong | Department of...

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

    Vermont Wind Measurement Company Still Strong Vermont Wind Measurement Company Still Strong April 9, 2010 - 3:16pm Addthis NRG's new building utilizes solar power, but their...

  9. MEASURING IMPACTS TO BIRDS CAUSED BY WIND TURBINES MEASURING IMPACTS TO BIRDS CAUSED BY WIND TURBINES

    E-Print Network [OSTI]

    within and among wind energy generating facilities. The standard measurement of mortality currently being little meaning to those lacking experience with bird mortality at wind energy generating facilities. More and each sweeps a much larger area of the sky. We propose that bird mortality at wind energy generating

  10. 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.

  11. 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.

  12. 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, Risø National Laboratory:Torben.Mikkelsen@Risoe.dk Summary RISØ DTU has started to build a newly designed laser-based lidar scanning facility for remote wind

  13. Reliability measures for indexed semi-Markov chains applied to wind energy production

    E-Print Network [OSTI]

    D'Amico, Guglielmo; Prattico, Flavio

    2013-01-01T23:59:59.000Z

    The computation of the dependability measures is a crucial point in the planning and development of a wind farm. In this paper we address the issue of energy production by wind turbine by using an indexed semi-Markov chain as a model of wind speed. We present the mathematical model, we describe the data and technical characteristics of a commercial wind turbine (Aircon HAWT-10kW). We show how to compute some of the main dependability measures such as reliability, availability and maintainability functions. We compare the results of the model with real energy production obtained from data available in the Lastem station (Italy) and sampled every 10 minutes.

  14. Comparing Pulsed Doppler LIDAR with SODAR and Direct Measurements for Wind Assessment

    SciTech Connect (OSTI)

    Kelley, N. D.; Jonkman, B. J.; Scott, G. N.; Pichugina, Y. L.

    2007-07-01T23:59:59.000Z

    There is a pressing need for good wind-speed measurements at greater and greater heights to assess the availability of the resource in terms of power production and to identify any frequently occurring atmospheric structural characteristics that may create turbulence that impacts the operational reliability and lifetime of wind turbines and their components. In this paper, we summarize the results of a short study that compares the relative accuracies of wind speeds derived from a high-resolution pulsed Doppler LIDAR operated by the National Oceanic and Atmospheric Administration (NOAA) and a midrange Doppler SODAR with wind speeds measured by four levels of tower-based sonic anemometry up to a height of 116 m.

  15. Measured and predicted rotor performance for the SERI advanced wind turbine blades

    SciTech Connect (OSTI)

    Tangler, J.; Smith, B.; Kelley, N.; Jager, D.

    1992-02-01T23:59:59.000Z

    Measured and predicted rotor performance for the SERI advanced wind turbine blades were compared to assess the accuracy of predictions and to identify the sources of error affecting both predictions and measurements. An awareness of these sources of error contributes to improved prediction and measurement methods that will ultimately benefit future rotor design efforts. Propeller/vane anemometers were found to underestimate the wind speed in turbulent environments such as the San Gorgonio Pass wind farm area. Using sonic or cup anemometers, good agreement was achieved between predicted and measured power output for wind speeds up to 8 m/sec. At higher wind speeds an optimistic predicted power output and the occurrence of peak power at wind speeds lower than measurements resulted from the omission of turbulence and yaw error. In addition, accurate two-dimensional (2-D) airfoil data prior to stall and a post stall airfoil data synthesization method that reflects three-dimensional (3-D) effects were found to be essential for accurate performance prediction. 11 refs.

  16. HURRICANE IMAGING RADIOMETER WIND SPEED AND RAIN RATE RETRIEVAL: [PART-1] DEVELOPMENT OF AN IMPROVED OCEAN

    E-Print Network [OSTI]

    Ruf, Christopher

    HURRICANE IMAGING RADIOMETER WIND SPEED AND RAIN RATE RETRIEVAL: [PART-1] DEVELOPMENT U.S.A * selnimri@mail.ucf.edu 2 NOAA/AOML/Hurricane Research Division, Miami, Florida, USA 3 Space model has been developed to support the analysis and design of the new airborne Hurricane Imaging

  17. WIND ATLAS FOR EGYPT: MEASUREMENTS, MICRO-AND MESOSCALE MODELLING

    E-Print Network [OSTI]

    sets for evaluating the potential wind power output from large electricity-producing wind turbine and accurate wind atlas data sets for evaluating the potential wind power output from large electricityWIND ATLAS FOR EGYPT: MEASUREMENTS, MICRO- AND MESOSCALE MODELLING Niels G. Mortensen1 , Jens

  18. Solar wind suprathermal electron Stahl widths across high-speed stream structures

    SciTech Connect (OSTI)

    Skoug, Ruth M [Los Alamos National Laboratory; Steinberg, John T [Los Alamos National Laboratory; Goodrich, Katherine A [Los Alamos National Laboratory; Anderson, Brett R [DARTMUTH UNIV.

    2011-01-03T23:59:59.000Z

    Suprathermal electrons (100-1500 eV) observed in the solar wind typically show a strahl distribution, that is, a beam directed away from the Sun along the magnetic field direction. The strahl width observed at 1 AU is highly variable, ranging from 10-70 degrees. The obsenred finite width of the strahl results from the competition between beam focusing as the interplanetary magnetic field strength drops with distance from the Sun, and pitch-angle scattering as the beam interacts with the solar wind plasma in transit from the sun. Here we examine strahl width, observed with ACE SWEPAM across high-speed stream structures to investigate variations in electron scattering as a function of local plasma characteristics. We find that narrow strahls (less than 20 degrees wide), indicating reduced scattering, are observed within high-speed streams. Narrow strahls are also observed in both very low temperature solar wind, in association with ICMEs. Case studies of high-speed streams typically show the strahl narrowing at the leading edge of the stream. In some cases, the strahl narrows at the reverse shock or pressure wave, in other cases at the stream interface. The narrowing can either occur discontinuously or gradually over a period of hours. Within the high-speed wind, the strahl remains narrow for a period of hours to days, and then gradually broadens. The strahl width is roughly constant at all energies across these structures. For some fraction of high-speed streams, counterstreaming is associated with passage of the corotating interaction region. In these cases, we find the widths of the two counterstreaming beams frequently differ by more than 40 degrees. This dramatic difference in strahl width contrasts with observations in the solar wind as a whole, in which counterstreaming strahls typically differ in width by less than 20 degrees.

  19. Robust STATCOM Control for the Enhancement of Fault Ride-Through Capability of Fixed Speed Wind Generators

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    -slip relationships as well as through simulations. The wind generator is a highly nonlinear system, which is modelled power generation. This type of wind generator always consumes reactive power from the grid. WhenRobust STATCOM Control for the Enhancement of Fault Ride-Through Capability of Fixed Speed Wind

  20. SOLAR WIND HELIUM ABUNDANCE AS A FUNCTION OF SPEED AND HELIOGRAPHIC LATITUDE: VARIATION THROUGH A SOLAR CYCLE

    E-Print Network [OSTI]

    Richardson, John

    SOLAR WIND HELIUM ABUNDANCE AS A FUNCTION OF SPEED AND HELIOGRAPHIC LATITUDE: VARIATION THROUGH of the variation of the relative abundance of helium to hydrogen in the solar wind as a function of solar wind theoretical work in which enhancements of coronal helium lead to stagnation of the escaping proton flux

  1. Experimental investigation of aerodynamic devices for wind turbine rotational speed control. Phase 1

    SciTech Connect (OSTI)

    Miller, L.S. [Wichita State Univ., KS (United States)

    1995-02-01T23:59:59.000Z

    An investigation was undertaken to identify the aerodynamic performance of five separate trailing-edge control devices, and to evaluate their potential for wind turbine overspeed and power modulation applications. A modular two-dimensional wind tunnel model was constructed and evaluated during extensive wind tunnel testing. Aerodynamic lift, drag, suction, and pressure coefficient data were acquired and analyzed for various control configurations and angles of attack. To further interpret their potential performance, the controls were evaluated numerically using a generic wind turbine geometry and a performance analysis computer program. Results indicated that the Spoiler-Flap control configuration was best softed for turbine braking applications. It exhibited a large negative suction coefficient over a broad angle-of-attack range, and good turbine braking capabilities, especially at low tip-speed ratio.

  2. 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. ...

  3. SPINNER ANEMOMETRY -AN INNOVATIVE WIND MEASUREMENT CONCEPT TF Pedersen*)

    E-Print Network [OSTI]

    SPINNER ANEMOMETRY - AN INNOVATIVE WIND MEASUREMENT CONCEPT TF Pedersen*) , N Sørensen, HA Madsen, R Møller, M Courtney, Risø National Laboratory P Enevoldsen, P Egedal, Siemens *) Risø, Wind Energy, fax +45 46 77 50 83 SUMMARY: An innovative and new concept for measurements of wind on a wind turbine

  4. ON THE ORIGIN OF THE SLOW SPEED SOLAR WIND: HELIUM ABUNDANCE VARIATIONS

    SciTech Connect (OSTI)

    Rakowski, Cara E.; Laming, J. Martin [Space Science Division, Naval Research Laboratory Code 7674L, Washington, DC 20375 (United States)

    2012-07-20T23:59:59.000Z

    The first ionization potential (FIP) effect is the by now well-known enhancement in abundance over photospheric values of Fe and other elements with FIP below about 10 eV observed in the solar corona and slow speed solar wind. In our model, this fractionation is achieved by means of the ponderomotive force, arising as Alfven waves propagate through or reflect from steep density gradients in the solar chromosphere. This is also the region where low FIP elements are ionized, and high FIP elements are largely neutral leading to the fractionation as ions interact with the waves but neutrals do not. Helium, the element with the highest FIP and consequently the last to remain neutral as one moves upward, can be depleted in such models. Here, we investigate this depletion for varying loop lengths and magnetic field strengths. Variations in this depletion arise as the concentration of the ponderomotive force at the top of the chromosphere varies in response to Alfven wave frequency with respect to the resonant frequency of the overlying coronal loop, the magnetic field, and possibly also the loop length. We find that stronger depletions of He are obtained for weaker magnetic field, at frequencies close to or just above the loop resonance. These results may have relevance to observed variations of the slow wind solar He abundance with wind speed, with slower slow speed solar wind having a stronger depletion of He.

  5. An evaluation of inductance loop detectors for speed measurement accuracy

    E-Print Network [OSTI]

    Cronin, Brian Patrick

    1994-01-01T23:59:59.000Z

    . The lag time from the presence of a vehicle at an inductance loop to the actual detection of a vehicle varies. As the lag time varies so does the accuracy of speed measurement. Vehicle size, vehicle speed, detector type, detector sensitivity...

  6. A comparison of predicted wind turbine blade loads to test measurements

    SciTech Connect (OSTI)

    Wright, A.D.; Thresher, R.W.

    1987-01-01T23:59:59.000Z

    The accurate prediction of wind turbine blade loads and response is important in predicting the fatigue life of wind machines. At the SERI Wind Energy Research Center, a rotor code called FLAP (Force and Loads Analysis Program) is currently being validated by comparing predicted results to machine measurements. The FLAP code has been modified to allow the teetering degrees of freedom. This paper describes these modifications and comparisons of predicted blade bending moments to test measurements. Wind tunnel data for a 1/20th scale model will be used to compare FLAP predictions for the cyclic flap-bending moments at the 33% spanwise station for three different wind speeds. The comparisons will be made for both rigid and teetering hubs. Currently, the FLAP code accounts for deterministic excitations such as wind shear, tower shadow, gravity, and prescribed yawing motions. Conclusions will be made regarding the code's accuracy in predicting the cyclic bending moments.

  7. Ris-R-1563(EN) ACCUWIND -Accurate Wind Speed

    E-Print Network [OSTI]

    and verification purposes, and for purposes of optimisation in research and development. The revised IEC standard from which the proposed classification method for cup anemometers was developed for the IEC standard the requirements of the IEC standard on power performance measurements, as well as for development of improved

  8. WIND DATA REPORT Quincy, Quarry Hills

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Quincy, Quarry Hills 9/1/2006 ­ 11/30/2006 Prepared for Massachusetts Technology.......................................................................................................................... 7 Tower Effects on Measured Wind Speed

  9. On the relationship between temperature and wind speed in the atmospheric surface layer

    E-Print Network [OSTI]

    Pierrard, John Martin

    1958-01-01T23:59:59.000Z

    LIBRAR& A AN m os??E " "" ON THE RELATIONSHIP BETWEEN T" MP. "RATURE AND WIND SPEED IN THE ATMOSPHERIC SURFACE LAYER A Thesis John Me Pierrard Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial... fulfillment of the requirements for the degree of MASTER OF SCI"NCE August 1958 Ma)or Sub)ect: Meteorology ON THE RELATIONSHIP BETWEEN TEMPERATURE AND WIND SP ED IN THE ATMOSPHERIC SUBRACE LAYER A Thesis John M. Pierrard Approved as to style...

  10. A study of wind-speed maxima near the surface over the south central United States 

    E-Print Network [OSTI]

    Beckman, Samuel Karl

    1973-01-01T23:59:59.000Z

    , the front is indicated by a wind shift, pressure change, or a decrease in moisture. In some cases the position of the cold front may be confused with the position of a dew-point front (Henry and Thompson, 1963) which is active in west Texas, eastern New... N. A wind speed of at least 30 kt was considered to be strong. The initial flow is confined on both the east and west sides. The mountains restrict the western extent of the southerly flow. The eastward extent of the southerly flow is determined...

  11. Critical speed measurements in the Tevatron cold compressors

    SciTech Connect (OSTI)

    DeGraff, B.; Bossert, R.; Martinez, A.; Soyars, W.M.; /Fermilab

    2006-01-01T23:59:59.000Z

    The Fermilab Tevatron cryogenic system utilizes high-speed centrifugal cold compressors, manufactured by Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), for high energy operations. Nominal operating range for these compressors is 43,000 to 85,000 rpm. Past foil bearing failures prompted investigation to determine if critical speeds for operating compressors fall within operating range. Data acquisition hardware and software settings will be discussed for measuring liftoff, first critical and second critical speeds. Several tests provided comparisons between an optical displacement probe and accelerometer measurements. Vibration data and analysis of the 20 Tevatron ring cold compressors will be presented.

  12. Solar Wind Sources in the Late Declining Phase of Cycle 23: Effects of the Weak Solar Polar Field on High Speed Streams

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    Isenberg, P.A. (eds. ) Solar Wind Nine, AIP Conf. Proc. 471,AT SOLAR MINIMUM Solar Wind Sources in the Late Decliningfor their high speed solar wind streams that dominate the

  13. Prediction of wind speed profiles for short-term forecasting in the offshore environment R.J. Barthelmie and G. Giebel

    E-Print Network [OSTI]

    in planning of maintenance visits to offshore wind farms. In most cases the basis for the predictionPrediction of wind speed profiles for short-term forecasting in the offshore environment R wind farms. The main effects considered here are: wind speed gradients in the coastal zone, vertical

  14. Summary report: The shadow effect of large wind farms: measurements,

    E-Print Network [OSTI]

    Summary report: The shadow effect of large wind farms: measurements, data analysis and modelling of large wind farms Department: Wind Energy Risø-R-1615(EN) July 2007 ISSN 0106-2840 ISBN 978 of the project ­ by means of data from the demonstration wind farms Horns Rev and Nysted, analyses of these data

  15. 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.

  16. Evidence of a Threshold Wind Speed in Tower-mounted Scatterometer Data David W. Draper and David G. Long

    E-Print Network [OSTI]

    Long, David G.

    . Evidence of the threshold wind speed and a hysteresis effect have been observed in airship and wave tank in airship data [2]. YSCAT, an ultra-wideband (2-14 GHz) tower-mounted scat- terometer, provides significant

  17. EXPERIENCES WITH SONIC WIND SENSORS IN OPERATIONAL CONDITIONS Wiel M.F. Wauben

    E-Print Network [OSTI]

    Wauben, Wiel

    ) uses conventional cup anemometers and wind vanes to measure wind speed and direction. Although the KNMI sonic considered in the previous evaluation. The advanced sensor has the required wind speed range up. An uncertainty of the wind speed of maximally 2 % at all wind directions is required for the wind profile

  18. Solar wind electron density and temperature over solar cycle 23: Thermal noise measurements on Wind

    E-Print Network [OSTI]

    California at Berkeley, University of

    upstream of the EarthÃ?s bow shock. The WIND/WAVES thermal noise receiver was specially designed to measureSolar wind electron density and temperature over solar cycle 23: Thermal noise measurements on Wind the in situ plasma thermal noise spectra, from which the electron density and temperature can be accurately

  19. 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...

  20. United States Wind Resource Map: Annual Average Wind Speed at 80 Meters

    Wind Powering America (EERE)

    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: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro IndustriesTownDells, Wisconsin:Deployment Activities Printable80 m 01-APR-2011 2.1.1 Wind

  1. Assessing Long-Term Wind Conditions by Combining Different Measure-Correlate-Predict Algorithms: Preprint

    SciTech Connect (OSTI)

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

    2013-08-01T23:59:59.000Z

    This paper significantly advances the hybrid measure-correlate-predict (MCP) methodology, enabling it to account for variations of both wind speed and direction. The advanced hybrid MCP method uses the recorded data of multiple reference stations to estimate the long-term wind condition at a target wind plant site. The results show that the accuracy of the hybrid MCP method is highly sensitive to the combination of the individual MCP algorithms and reference stations. It was also found that the best combination of MCP algorithms varies based on the length of the correlation period.

  2. Rotor Speed Dependent Yaw Control of Wind Turbines Based on Empirical Data

    SciTech Connect (OSTI)

    Kragh, K. A.; Fleming, P. A.

    2012-01-01T23:59:59.000Z

    When extracting energy from the wind using horizontal-axis upwind wind turbines, a primary condition for maximum power yield is the ability to align the rotor axis with the dominating wind direction. Attempts have been made to improve yaw alignment by applying advanced measurement techniques such as LIDARs. This study is focused at assessing the current performance of an operating turbine and exploring how the yaw alignment can be improved using existing measurements. By analyzing available turbine and met mast data a correction scheme for the original yaw alignment system is synthesized. The correction scheme is applied and it is seen that with the correction scheme in place, the power yield below rated is raised 1-5 percent. Furthermore, results indicate that blade load variations are decreased when the correction scheme is applied. The results are associated with uncertainties due to the amount of available data and the wind site climate. Further work should be focused at gathering more experimental data.

  3. Comparison of Ornithopter Wind Tunnel Force Measurements with Free Flight

    E-Print Network [OSTI]

    Fearing, Ron

    Comparison of Ornithopter Wind Tunnel Force Measurements with Free Flight Cameron Rose and Ronald S flight force model from wind tunnel data is a practical approach. In this work, we compare the flight, to measured wind tunnel force and moment values. We compare the two data sets at equilibrium as a metric

  4. 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.

  5. Observational evidence from two mountainous regions that near surface wind speeds are declining more rapidly at higher elevations

    E-Print Network [OSTI]

    Zimmermann, Niklaus E.

    for wind energy generation [e.g., Burton et al., 2001], evapotranspiration [e.g., McVicar and Jupp, 1999 wind speeds are declining more rapidly at higher elevations than lower elevations: 1960­2006 Tim R. Mc and Dirk R. Schmatz5 Received 20 December 2009; revised 26 January 2010; accepted 2 February 2010

  6. STANDARDS FOR MEASUREMENTS AND TESTING OF WIND TURBINE POWER QUALITY Poul Srensen, Ris National Laboratory, P.O.Box 49, DK-4000 Roskilde, Denmark.

    E-Print Network [OSTI]

    Heinemann, Detlev

    STANDARDS FOR MEASUREMENTS AND TESTING OF WIND TURBINE POWER QUALITY Poul Sørensen, Risø National and verification of wind turbine power quality. The work has been organised in three major activities. The first farm summation on the power quality of wind turbines with constant rotor speed. The third activity has

  7. 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

  8. 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.

  9. 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.

  10. A study of wind-speed maxima near the surface over the south central United States

    E-Print Network [OSTI]

    Beckman, Samuel Karl

    1973-01-01T23:59:59.000Z

    GMT, 28 April 1967, showing isotachs and fronts. . . . . . 26 12. Synoptic map for 1200 GMT, 28 April 1967. . 28 13. Time cross section for Abilene, Texas, April 1967. . . . 11 14. Change in the wind-speed profile ot Oklahoma City, Oklahoma..., but the summer months had more days with low-level jets. They further stated that the jets occurred in all seasons and should be related to the synoptic conditions. Crawford and Hudson (1970), using observations from a 1500-ft television tower at Oklahoma...

  11. Error propagation equations for estimating the uncertainty in high-speed wind tunnel test results

    SciTech Connect (OSTI)

    Clark, E.L.

    1994-07-01T23:59:59.000Z

    Error propagation equations, based on the Taylor series model, are derived for the nondimensional ratios and coefficients most often encountered in high-speed wind tunnel testing. These include pressure ratio and coefficient, static force and moment coefficients, dynamic stability coefficients, and calibration Mach number. The error equations contain partial derivatives, denoted as sensitivity coefficients, which define the influence of free-steam Mach number, M{infinity}, on various aerodynamic ratios. To facilitate use of the error equations, sensitivity coefficients are derived and evaluated for five fundamental aerodynamic ratios which relate free-steam test conditions to a reference condition.

  12. Effect of Tip-Speed Constraints on the Optimized Design of a Wind Turbine

    SciTech Connect (OSTI)

    Dykes, K.; Resor, B.; Platt, A.; Guo, Y.; Ning, A.; King, R.; Parsons, T.; Petch, D.; Veers, P.

    2014-10-01T23:59:59.000Z

    This study investigates the effect of tip-velocity constraints on system levelized cost of energy (LCOE). The results indicate that a change in maximum tip speed from 80 to 100~m/s could produce a 32% decrease in gearbox weight (a 33% reduction in cost) which would result in an overall reduction of 1%-9% in system LCOE depending on the design approach. Three 100~m/s design cases were considered including a low tip-speed ratio/high-solidity rotor design, a high tip-speed ratio/ low-solidity rotor design, and finally a flexible blade design in which a high tip-speed ratio was used along with removing the tip deflection constraint on the rotor design. In all three cases, the significant reduction in gearbox weight caused by the higher tip-speed and lower overall gear ratio was counterbalanced by increased weights for the rotor and/or other drivetrain components and the tower. As a result, the increased costs of either the rotor or drivetrain components offset the overall reduction in turbine costs from down-sizing the gearbox. Other system costs were not significantly affected, whereas energy production was slightly reduced in the 100~m/s case low tip-speed ratio case and increased in the high tip-speed ratio case. This resulted in system cost of energy reductions moving from the 80~m/s design to the 100~m/s designs of 1.2% for the low tip-speed ratio, 4.6% for the high tip-speed ratio, and 9.5% for the final flexible case (the latter result is optimistic because the impact of deflection of the flexible blade on power production was not modeled). Overall, the results demonstrate that there is a trade-off in system design between the maximum tip velocity and the overall wind plant cost of energy, and there are many trade-offs within the overall system in designing a turbine for a high maximum tip velocity.

  13. 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

  14. Comparison of Second Wind Triton Data with Meteorological Tower Measurements

    SciTech Connect (OSTI)

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

    2010-02-01T23:59:59.000Z

    With the increased interest in remote sensing of wind information in recent years, it is important to determine the reliability and accuracy of new wind measurement technologies if they are to replace or supplement conventional tower-based measurements. In this study, we present the results of an analysis characterizing the measurement performance of a state-of-the-art SOund Detection And Ranging (sodar) device when compared to a high-quality tower measurement program. Second Wind Inc. (Somerville, MA, USA) provided NREL with more than six months of data from a measurement program conducted near an operating wind farm in western Texas.

  15. Offshore wind profile measurements from remote sensing instruments

    E-Print Network [OSTI]

    Offshore wind profile measurements from remote sensing instruments Ioannis Antoniou (1) , Hans E) have been mounted on top of a transformer platform situated offshore close to the Nysted wind farm offshore wind energy potential depends greatly on the ability to make offshore windfarms economically

  16. Mining Markov chain transition matrix from wind speed time series data Zhe Song a,

    E-Print Network [OSTI]

    Kusiak, Andrew

    to wind energy industry in terms of wind turbine optimal control, wind energy dispatch/scheduling, wind in recent years and even more aggressive wind energy installations are envisioned in various economy & Bolinger, 2006). Rapid development of wind energy provides rich environments for wind energy related

  17. SODAR Wind Resource Measurement Results at Falmouth, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    treatment plant in the spring of 2005 by the Renewable Energy Research Laboratory at the University wind speed at 70 m is most likely between 5.88 and 6.36 m/s. Introduction The Renewable Energy Research the possibility of problems with echoes from ground clutter was identified. In this case ground clutter means low

  18. Methods and apparatus for reducing peak wind turbine loads

    DOE Patents [OSTI]

    Moroz, Emilian Mieczyslaw

    2007-02-13T23:59:59.000Z

    A method for reducing peak loads of wind turbines in a changing wind environment includes measuring or estimating an instantaneous wind speed and direction at the wind turbine and determining a yaw error of the wind turbine relative to the measured instantaneous wind direction. The method further includes comparing the yaw error to a yaw error trigger that has different values at different wind speeds and shutting down the wind turbine when the yaw error exceeds the yaw error trigger corresponding to the measured or estimated instantaneous wind speed.

  19. Aerodynamic pressure and flow-visualization measurement from a rotating wind turbine blade

    SciTech Connect (OSTI)

    Butterfield, C.P.

    1988-11-01T23:59:59.000Z

    Aerodynamic, load, flow-visualization, and inflow measurements have been made on a 10-m, three-bladed, downwind, horizontal-axis wind turbine (HAWT). A video camera mounted on the rotor was used to record nighttime and daytime video images of tufts attached to the low-pressure side of a constant-chord, zero-twist blade. Load measurements were made using strain gages mounted at every 10% of the blade's span. Pressure measurements were made at 80% of the blade's span. Pressure taps were located at 32 chordwise positions, revealing pressure distributions comparable with wind tunnel data. Inflow was measured using a vertical-plane array of eight propvane and five triaxial (U-V-W) prop-type anemometers located 10 m upwind in the predominant wind direction. One objective of this comprehensive research program was to study the effects of blade rotation on aerodynamic behavior below, near, and beyond stall. To this end, flow patterns are presented here that reveal the dynamic and steady behavior of flow conditions on the blade. Pressure distributions are compared to flow patterns and two-dimensional wind tunnel data. Separation boundary locations are shown that change as a function of spanwise location, pitch angle, and wind speed. 6 refs., 23 figs., 1 tab.

  20. 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.

  1. Wind climatology of Schiphol Andrew Stepek, Xueli Wang and Dirk Wolters

    E-Print Network [OSTI]

    Haak, Hein

    Wind climatology of Schiphol Andrew Stepek, Xueli Wang and Dirk Wolters De Bilt, May 2012 #12;2 Contents Summary 2 Introduction 3 Data 3 Hourly wind measurements 3 Yearly averages of wind speed measurements 4 Quality and sources of error 6 Method 7 Trends in wind speed 7 Definition of cross and tail wind

  2. 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

  3. Forecasting of wind speed using wavelets analysis and cascade-correlation neural networks

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    such as sunlight, wind, rain or geothermal heat. Wind energy is actually one of the fastest-growing forms, that is why its wind energy market has been progressing steadily in recent years. While in 2000, there were only 30 MW of wind generating capacity in France, the total installed capacity at the end of 2007

  4. 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

  5. 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...

  6. Measure Guideline: Replacing Single-Speed Pool Pumps with Variable Speed Pumps for Energy Savings

    SciTech Connect (OSTI)

    Hunt, A.; Easley, S.

    2012-05-01T23:59:59.000Z

    The report evaluates potential energy savings by replacing traditional single-speed pool pumps with variable speed pool pumps, and provide a basic cost comparison between continued uses of traditional pumps verses new pumps. A simple step-by-step process for inspecting the pool area and installing a new pool pump follows.

  7. Comparison of Triton SODAR Data to Meteorological Tower Wind Measurement Data in Hebei Province, China

    SciTech Connect (OSTI)

    Yuechun, Y.; Jixue, W.; Hongfang, W.; Guimin, L.; Bolin, Y.; Scott, G.; Elliott, D.; Kline, D.

    2012-01-01T23:59:59.000Z

    With the increased interest in remote sensing of wind information in recent years, it is important to determine the reliability and accuracy of new wind measurement technologies if they are to replace or supplement conventional tower-based measurements. In view of this, HydroChina Corporation and the United States National Renewable Energy Laboratory (NREL) conducted a comparative test near a wind farm in Hebei Province, China. We present the results of an analysis characterizing the measurement performance of a state-of-the-art Sound Detection and Ranging (sodar) device when compared to a traditional tower measurement program. NREL performed the initial analysis of a three-month period and sent the results to HydroChina. When another month of data became available, HydroChina and their consultant Beijing Millenium Engineering Software (MLN) repeated NREL's analysis on the complete data set, also adding sensitivity analysis for temperature, humidity, and wind speed (Section 6). This report presents the results of HydroChina's final analysis of the four-month period.

  8. Measurement of wind set-up on an open coast

    E-Print Network [OSTI]

    Clayton, William Howard

    1956-01-01T23:59:59.000Z

    or electrical systems. The term 'obvious malfunctioning' does not cover the re? cording of unexpected data. For instance, it is certain that for a wind blowing offshore, an onshore slope should not occur. Nevertheless, such does occur, or rather is indicated... VI. BIBLIOGRAPHY 48 iii FIGURES 1 Caplen Pier 16 2 Measuring Circuit 17 3 Stillwell Installation 20 4 Onshore Synchro 24 5 Offshore Synchro and Water Level Recorder 24 6 Differential Generator 25 7 Sample Record of Wind, Wind Set-Up, and 39...

  9. 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

  10. A Robust STATCOM Control to Augment LVRT capability of Fixed Speed Wind Turbines

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    equipped with induction generators. The wind generator is a highly nonlinear system, and in this paper% of the nominal voltage for up to 140 ms [3]. Induction generators are preferred as wind generators for their low and the behavior of STATCOM dur- ing balanced or unbalanced grid faults (fault ride through), allow wind generators

  11. Journal of Wind Engineering and Industrial Aerodynamics 90 (2002) 201221

    E-Print Network [OSTI]

    Pryor, Sara C.

    due largely to lower surface roughness [1]. An additional benefit to offshore location of wind farms characteristics in the near-shore and offshore environment using data from the Danish wind monitoring network. In this relatively high wind speed environment the temporal auto-correlation of wind speeds measured in the offshore

  12. The Solar Wind Energy Flux

    E-Print Network [OSTI]

    Chat, G Le; Meyer-Vernet, N

    2012-01-01T23:59:59.000Z

    The solar-wind energy flux measured near the ecliptic is known to be independent of the solar-wind speed. Using plasma data from Helios, Ulysses, and Wind covering a large range of latitudes and time, we show that the solar-wind energy flux is independent of the solar-wind speed and latitude within 10%, and that this quantity varies weakly over the solar cycle. In other words the energy flux appears as a global solar constant. We also show that the very high speed solar-wind (VSW > 700 km/s) has the same mean energy flux as the slower wind (VSW < 700 km/s), but with a different histogram. We use this result to deduce a relation between the solar-wind speed and density, which formalizes the anti-correlation between these quantities.

  13. Reliability measures of second order semi-Markov chain in state and duration with application to wind energy production

    E-Print Network [OSTI]

    D'Amico, Guglielmo; Prattico, Flavio

    2012-01-01T23:59:59.000Z

    In this paper we consider the problem of wind energy production using a second order semi-Markov chain in state and duration as a model of wind speed. We present the mathematical model, we describe the data and technical characteristics of a commercial wind turbine (Aircon HAWT-10kW). We show how to compute some of the main dependability measures such as reliability, availability and maintainability functions. We compare the results of the model with real energy production obtained from data available in the Lastem station (Italy) and sampled every 10 minutes. The computation of the dependability measures is a crucial point in the planning and development of a wind farm.

  14. Remote sensing of total integrated water vapor, wind speed, and cloud liquid water over the ocean using the Special Sensor Microwave/Imager (SSM/I)

    E-Print Network [OSTI]

    Manning, Norman Willis William

    1997-01-01T23:59:59.000Z

    A modified D-matrix retrieval method is the basis of the refined total integrated water vapor (TIWV), total integrated cloud liquid water (CLW), and surface wind speed (WS) retrieval methods that are developed. The 85 GHZ polarization difference...

  15. 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 Régis DANIELIAN (Vestas Wind System) Hans Ejsing JØRGENSEN (Wind Energy Department, Risø. Contact: haej@risoe.dk) Torben MIKKELSEN (Wind Energy Department, Risø. Contact: tomi@risoe.dk) Jacob MANN (Wind Energy Department, Risø

  16. Effect of wind speed on the growth of the upper convective zone in a solar pond

    E-Print Network [OSTI]

    McMinn, Steven Lee

    1990-01-01T23:59:59.000Z

    [2]. The distance which the wind has to act on the surface of a pond is commonly called fetch, or fetch length. The purpose of the nets or other devices used in wind suppression is to reduce the fetch and transmit some of the energy in the waves... to the sides of the pond. Wind mixing of the upper convective zone can be thought of as converting some of the kinetic energy in the wind to potential energy in the fluid by a process called entrainment. Entrainment is defined in detail in Chapter V...

  17. Effect of wind speed on the growth of the upper convective zone in a solar pond 

    E-Print Network [OSTI]

    McMinn, Steven Lee

    1990-01-01T23:59:59.000Z

    [2]. The distance which the wind has to act on the surface of a pond is commonly called fetch, or fetch length. The purpose of the nets or other devices used in wind suppression is to reduce the fetch and transmit some of the energy in the waves... to the sides of the pond. Wind mixing of the upper convective zone can be thought of as converting some of the kinetic energy in the wind to potential energy in the fluid by a process called entrainment. Entrainment is defined in detail in Chapter V...

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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.......

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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..................

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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.............

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. Wind information derived from hot air

    E-Print Network [OSTI]

    Haak, Hein

    Wind information derived from hot air balloon flights for use in short term wind forecasts E Introduction/Motivation Hot air balloons as wind measuring device Setup of nested HIRLAM models Results · Three, The Nertherlands #12;Hot air balloon ·Displacement/time unit = wind speed ·Vertical resolution 30m ·Inertia (500 kg

  9. Meteorological field measurements at potential and actual wind turbine sites

    SciTech Connect (OSTI)

    Renne, D.S.; Sandusky, W.F.; Hadley, D.L.

    1982-09-01T23:59:59.000Z

    An overview of experiences gained in a meteorological measurement program conducted at a number of locations around the United States for the purpose of site evaluation for wind energy utilization is provided. The evolution of the measurement program from its inception in 1976 to the present day is discussed. Some of the major accomplishments and areas for improvement are outlined. Some conclusions on research using data from this program are presented.

  10. On measurement of the isotropy of the speed of light

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wojtsekhowski, Bogdan B. [JLAB

    2014-11-01T23:59:59.000Z

    Three experimental concepts investigating possible anisotropy of the speed of light are presented. They are based on i) beam deflection in a 180 degree magnetic arc, ii) narrow resonance production in an electron-positron collider, and iii) the ratio of magnetic moments of an electron and a positron moving in opposite directions.

  11. The effect of imbalance distribution and measurement locations on critical speeds in a turboprop engine rotor

    E-Print Network [OSTI]

    Marin, Manuel

    1996-01-01T23:59:59.000Z

    . This study examines the influence of imbalance distribution and vibration measurement location on critical speeds for a model turboprop engine rotor. Imbalance response measurements are presented for a full scale model mounted in rolling bearings with squeeze...

  12. Steady decline of east Asian monsoon winds, 19692000: Evidence from direct ground measurements of wind speed

    E-Print Network [OSTI]

    Robock, Alan

    of the winter monsoon, while the summer cooling in central south China and warming over the South China Sea greenhouse gas emission, while the summer decline is associated with local cooling over south-central China for Remote Sensing and Spatial Analysis, Department of Ecology, Evolution and Natural Resourc

  13. OPERATIONAL TEST OF SONIC WIND SENSORS AT KNMI Wiel M.F. Wauben

    E-Print Network [OSTI]

    Wauben, Wiel

    of transfer functions for wind direction, - speed and - gust that account for the change from one sensor vanes to measure wind speed and direction. Although the KNMI cup and vane meet WMO requirements into account by a wind direction and - speed dependent correction that is applied in the sensor software

  14. Wind-wave measurements in a shallow estuary: Trinity Bay, Texas 

    E-Print Network [OSTI]

    Dupuis, Keith Wade

    2009-05-15T23:59:59.000Z

    observations and follow the current proposed asymptotic limit to wave growth in shallow depth. The depth range for this empirical formulation is extended from 0.5–2m out to 3.5m. The model does not work for wind speeds less than 1m/s and during rapid wind...

  15. MSU-Wind Applications Center: Wind Resource Worksheet Theoretical Power Calculation

    E-Print Network [OSTI]

    Dyer, Bill

    MSU-Wind Applications Center: Wind Resource Worksheet Theoretical Power Calculation Equations: A= swept area = air density v= velocity R= universal gas constant Steps: 1. Measure wind speed from fan. = ___________/(________*________)= _________kg/m3 5. Theoretical Power a. Low Setting Theoretical Wind Power i. Power= ½*______*______*______*.59

  16. Bachelor thesis: "Validation of an engineering model of the near wake wind field of wind turbines based on nacelle based lidar measurements"

    E-Print Network [OSTI]

    Peinke, Joachim

    , in an early stage of wind farm layout optimisation and wind turbine loading calculation in wind farms by Ainslie[1], This is widely used in the industry for wind farming purposes. Scope During this project analysis are performed of near wake measurements of a 5 MW wind turbine at the offshore test field alpha

  17. The high-speed after pulse measurement system for PMT

    E-Print Network [OSTI]

    Yaping Cheng; Sen Qian; Zhe Ning; Jingkai Xia; Wenwen Wang; Yifang Wang; Jun Cao; Xiaoshan Jiang; Zheng Wang; Xiaonan Li; Ming Qi; Yuekun Heng; Shulin Liu; Xiangcui Lei; Zhi Wu

    2014-04-24T23:59:59.000Z

    A system employing a desktop FADC has been developed to investigate the features of 8 inches Hamamatsu PMT. The system stands out for its high-speed and informative results as a consequence of adopting fast waveform sampling technology. Recording full waveforms allows us to perform digital signal processing, pulse shape analysis, and precision timing extraction. High precision after pulse time and charge distribution characteristics are presented in this manuscript. Other photomultipliers characteristics, such as dark rate and transit time spread, can also be obtained by exploiting waveform analysis using this system.

  18. Watercut Measurement Method by Using High Speed Impedance Sensor 

    E-Print Network [OSTI]

    Erdogan, Burak

    2014-08-20T23:59:59.000Z

    [3]. The ambivalent range width depends on how the dispersion is produced [6]. Various parameters which affect the phase inversion and ambivalent range have been investigated in an agitated tank by different researchers [2,3,5,6,7,8]. The impeller... size [5,8], tank impeller diameter ratio [5], and density difference of liquids [5,7,8] do 3 not have important effect on the ambivalent range. Ambivalent range narrows by increasing the agitation speed [2, 6]. According to Norato et al...

  19. Ris-R-1410(EN) On the Theory of SODAR Measurement

    E-Print Network [OSTI]

    means to measure the wind speed for wind energy purposes has increased with the increase of the size of wind turbines. The cost and the technical difficulties for performing wind speed measurements has also with the atmosphere in the level of detail needed for wind energy applications. - Understanding of dependence of SODAR

  20. ESTABLISHING A CONNECTION BETWEEN ACTIVE REGION OUTFLOWS AND THE SOLAR WIND: ABUNDANCE MEASUREMENTS WITH EIS/HINODE

    SciTech Connect (OSTI)

    Brooks, David H. [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Warren, Harry P., E-mail: dhbrooks@ssd5.nrl.navy.mil [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2011-01-20T23:59:59.000Z

    One of the most interesting discoveries from Hinode is the presence of persistent high-temperature high-speed outflows from the edges of active regions (ARs). EUV imaging spectrometer (EIS) measurements indicate that the outflows reach velocities of 50 km s{sup -1} with spectral line asymmetries approaching 200 km s{sup -1}. It has been suggested that these outflows may lie on open field lines that connect to the heliosphere, and that they could potentially be a significant source of the slow speed solar wind. A direct link has been difficult to establish, however. We use EIS measurements of spectral line intensities that are sensitive to changes in the relative abundance of Si and S as a result of the first ionization potential (FIP) effect, to measure the chemical composition in the outflow regions of AR 10978 over a 5 day period in 2007 December. We find that Si is always enhanced over S by a factor of 3-4. This is generally consistent with the enhancement factor of low FIP elements measured in situ in the slow solar wind by non-spectroscopic methods. Plasma with a slow wind-like composition was therefore flowing from the edge of the AR for at least 5 days. Furthermore, on December 10 and 11, when the outflow from the western side was favorably oriented in the Earth direction, the Si/S ratio was found to match the value measured a few days later by the Advanced Composition Explorer/Solar Wind Ion Composition Spectrometer. These results provide strong observational evidence for a direct connection between the solar wind, and the coronal plasma in the outflow regions.

  1. 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.

  2. Error propagation equations and tables for estimating the uncertainty in high-speed wind tunnel test results

    SciTech Connect (OSTI)

    Clark, E.L.

    1993-08-01T23:59:59.000Z

    Error propagation equations, based on the Taylor series model, are derived for the nondimensional ratios and coefficients most often encountered in high-speed wind tunnel testing. These include pressure ratio and coefficient, static force and moment coefficients, dynamic stability coefficients, calibration Mach number and Reynolds number. The error equations contain partial derivatives, denoted as sensitivity coefficients, which define the influence of free-stream Mach number, M{infinity}, on various aerodynamic ratios. To facilitate use of the error equations, sensitivity coefficients are derived and evaluated for nine fundamental aerodynamic ratios, most of which relate free-stream test conditions (pressure, temperature, density or velocity) to a reference condition. Tables of the ratios, R, absolute sensitivity coefficients, {partial_derivative}R/{partial_derivative}M{infinity}, and relative sensitivity coefficients, (M{infinity}/R) ({partial_derivative}R/{partial_derivative}M{infinity}), are provided as functions of M{infinity}.

  3. Note: Simultaneous measurement of transverse speed and axial velocity from a single optical beam

    SciTech Connect (OSTI)

    Moro, Erik A.; Briggs, Matthew E. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2013-01-15T23:59:59.000Z

    A method is introduced for simultaneously measuring transverse speed and axial velocity using a single optical beam and a standard photon Doppler velocimetry (PDV) sensing architecture. This result is of particular interest given the recent, widespread use of PDV and the fact that optical velocimetry has thus far been limited to measuring motion in one dimension per probe. Further, this result demonstrates that both axial velocity data and transverse speed data (at least qualitative) may be obtained entirely through signal analysis; not requiring hardware modification. This result is immediately relevant to analyses of existing PDV data and to future efforts in high-speed optical velocimetry.

  4. HIGH DYNAMIC-RANGE HIGH SPEED LINAC CURRENT MEASUREMENTS

    SciTech Connect (OSTI)

    Deibele, Craig Edmond [ORNL] [ORNL; Curry, Douglas E [ORNL] [ORNL; Dickson, Richard W [ORNL] [ORNL

    2012-01-01T23:59:59.000Z

    It is desired to measure the linac current of a charged particle beam with a consistent accuracy over a dynamic range of over 120 dB. Conventional current transformers suffer from droop, can be susceptible to electromagnetic interference (EMI), and can be bandwidth limited. A novel detector and electronics were designed to maximize dynamic range of about 120 dB and measure rise-times on the order of 10 nanoseconds.

  5. 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.

  6. Synchrophasor Measurement-Based Wind Plant Inertia Estimation: Preprint

    SciTech Connect (OSTI)

    Zhang, Y.; Bank, J.; Wan, Y. H.; Muljadi, E.; Corbus, D.

    2013-05-01T23:59:59.000Z

    The total inertia stored in all rotating masses that are connected to power systems, such as synchronous generations and induction motors, is an essential force that keeps the system stable after disturbances. To ensure bulk power system stability, there is a need to estimate the equivalent inertia available from a renewable generation plant. An equivalent inertia constant analogous to that of conventional rotating machines can be used to provide a readily understandable metric. This paper explores a method that utilizes synchrophasor measurements to estimate the equivalent inertia that a wind plant provides to the system.

  7. active stall wind: Topics by E-print Network

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

    SeaWinds, and the Advanced Microwave Scanning Radiometer (AMSR). Scalar wind speed observed by AMSR was evaluated by using wind speed observed by SeaWinds. The...

  8. Resolving Spacecraft Earth-Flyby Anomalies with Measured Light Speed Anisotropy

    E-Print Network [OSTI]

    Reginald T. Cahill

    2008-04-30T23:59:59.000Z

    Doppler shift observations of spacecraft, such as Galileo, NEAR, Cassini, Rosetta and MESSENGER in earth flybys, have all revealed unexplained speed `anomalies' - that the doppler-shift determined speeds are inconsistent with expected speeds. Here it is shown that these speed anomalies are not real and are actually the result of using an incorrect relationship between the observed doppler shift and the speed of the spacecraft - a relationship based on the assumption that the speed of light is isotropic in all frames, i.e. invariant. Taking account of the repeatedly measured light-speed anisotropy the anomalies are resolved. The Pioneer 10/11 anomalies are discussed, but not resolved. The spacecraft observations demonstrate again that the speed of light is not invariant, and is isotropic only with respect to a dynamical 3-space. The existing doppler shift data also offers a resource to characterise a new form of gravitational waves, the dynamical 3-space turbulence, that has also been detected by other techniques.

  9. Low Wind Speed Turbine Project Conceptual Design Study: Advanced Independent Pitch Control; July 30, 2002--July 31, 2004 (Revised)

    SciTech Connect (OSTI)

    Olsen, T.; Lang, E.; Hansen, A.C.; Cheney, M. C.; Quandt, G.; VandenBosche, J.; Meyer, T.

    2004-12-01T23:59:59.000Z

    AES conducted a conceptual study of independent pitch control using inflow angle sensors. The control strategy combined input from turbine states (rotor speed, rotor azimuth, each blade pitch) with inflow angle measurements (each blade angle of attack at station 11 of 15) to derive blade pitch demand signals. The controller reduced loads sufficiently to allow a 10% rotor extension and reduce COE by 6.3%.

  10. ANNUAL WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    ANNUAL WIND DATA REPORT Thompson Island March 1, 2002 ­ February 28, 2003 Prepared.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributions

  11. WIND DATA REPORT January -December, 2003

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Vinalhaven January - December, 2003 Prepared for Fox Islands Electric Cooperative...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  12. WIND DATA REPORT January -March, 2004

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Vinalhaven January - March, 2004 Prepared for Fox Islands Electric Cooperative...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  13. WIND DATA REPORT Deer Island Outfall

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Deer Island Outfall August 18, 2003 ­ December 4, 2003 Prepared for Massachusetts...................................................................................................................... 7 Wind Speed Time Series............................................................................................................. 7 Wind Speed Distributions

  14. WIND DATA REPORT Deer Island Parking Lot

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Deer Island Parking Lot May 1, 2003 ­ July 15, 2003 Prepared for Massachusetts...................................................................................................................... 7 Wind Speed Time Series............................................................................................................. 7 Wind Speed Distributions

  15. WIND DATA REPORT Quincy DPW, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Quincy DPW, MA September 1st 2006 to November 30th 2006 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributions

  16. WIND DATA REPORT Bishop and Clerks

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Bishop and Clerks March 1, 2005 ­ May 31, 2005 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributions

  17. WIND DATA REPORT Quincy Quarry Hills

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Quincy Quarry Hills December 2006 to February 2007 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  18. WIND DATA REPORT Quincy DPW, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Quincy DPW, MA June 1st 2006 to August 31st 2006 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributions

  19. WIND DATA REPORT Quincy Quarry Hills

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Quincy Quarry Hills March 2007 to May 2007 Prepared for Massachusetts Technology...................................................................................................................... 8 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  20. WIND DATA REPORT Rockport School Complex

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Rockport School Complex Rockport, Massachusetts March 1, 2006 ­ May 31, 2007...................................................................................................................... 9 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  1. WIND DATA REPORT Quincy DPW, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Quincy DPW, MA March 1st 2007 to May 31st 2007 Prepared for Massachusetts...................................................................................................................... 8 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  2. WIND DATA REPORT Tisbury, Martha's Vineyard,

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Tisbury, Martha's Vineyard, Massachusetts September 1, 2007 ­ November 30, 2007...................................................................................................................... 8 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  3. WIND DATA REPORT Rockport School Complex

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Rockport School Complex Rockport, Massachusetts December 1st , 2007 ­ February 29...................................................................................................................... 9 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  4. WIND DATA REPORT Rockport School Complex

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Rockport School Complex Rockport, Massachusetts September 1, 2005 - November 31.................................................................................................................... 12 Wind Speed Time Series........................................................................................................... 12 Wind Speed Distributions

  5. WIND DATA REPORT Rockport School Complex

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Rockport School Complex Rockport, Massachusetts June 1, 2007 ­ August 31, 2007...................................................................................................................... 9 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  6. WIND DATA REPORT December, 2004 28th

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Orleans 1st December, 2004 ­28th February, 2005 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions.......................................................................................................

  7. WIND DATA REPORT Rockport School Complex

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Rockport School Complex Rockport, Massachusetts December 1, 2006 ­ February 28...................................................................................................................... 9 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  8. Comment on "Measurement of the speed-of-light perturbation of free-fall absolute gravimeters"

    E-Print Network [OSTI]

    Nagornyi, V D

    2014-01-01T23:59:59.000Z

    The paper (Rothleitner et al. 2014 Metrologia 51, L9) reports on the measurement of the speed-of-light perturbation in absolute gravimeters. The conclusion that the perturbation reaches only 2/3 of the commonly accepted value violates the fundamental limitation on the maximum speed of information transfer. The conclusion was deluded by unaccounted parasitic perturbations, some of which are obvious from the report.

  9. Wind Power Plant Prediction by Using Neural Networks: Preprint

    SciTech Connect (OSTI)

    Liu, Z.; Gao, W.; Wan, Y. H.; Muljadi, E.

    2012-08-01T23:59:59.000Z

    This paper introduces a method of short-term wind power prediction for a wind power plant by training neural networks based on historical data of wind speed and wind direction. The model proposed is shown to achieve a high accuracy with respect to the measured data.

  10. 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 Guénard, 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

  11. Estimating the Wind Resource in Uttarakhand: Comparison of Dynamic Downscaling with Doppler Lidar Wind Measurements

    SciTech Connect (OSTI)

    Lundquist, J. K.; Pukayastha, A.; St. Martin, C.; Newsom, R.

    2014-03-01T23:59:59.000Z

    Previous estimates of the wind resources in Uttarakhand, India, suggest minimal wind resources in this region. To explore whether or not the complex terrain in fact provides localized regions of wind resource, the authors of this study employed a dynamic down scaling method with the Weather Research and Forecasting model, providing detailed estimates of winds at approximately 1 km resolution in the finest nested simulation.

  12. On the Use of QuikSCAT Scatterometer Measurements of Surface Winds for Marine Weather Prediction

    E-Print Network [OSTI]

    Kurapov, Alexander

    the accuracies of surface wind fields in the National Centers for Envi- ronmental Prediction (NCEP) and EuropeanOn the Use of QuikSCAT Scatterometer Measurements of Surface Winds for Marine Weather Prediction ocean vector winds for marine weather prediction is investigated from two Northern Hemisphere case

  13. Validity of Wind Load Distribution based on High Frequency Force Balance Measurements

    E-Print Network [OSTI]

    Chen, Xinzhong

    Validity of Wind Load Distribution based on High Frequency Force Balance Measurements Xinzhong Chen such a modal analysis procedure for background and resonant response, estimation of the generalized wind force is the critical element for response prediction. The generalized wind force can be characterized through

  14. Comparison of Wake Model Simulations with Offshore Wind Turbine Wake Profiles Measured by Sodar

    E-Print Network [OSTI]

    Pryor, Sara C.

    a ship-mounted sodar at a small offshore wind farm. The experiments were conducted at varying distances Offshore wind farms have increased in size from the first phase of installation with up to 20 turbinesComparison of Wake Model Simulations with Offshore Wind Turbine Wake Profiles Measured by Sodar R

  15. Reconstruction of a wind turbine's endured load spectrum using a short-time load measurement

    E-Print Network [OSTI]

    Berlin,Technische Universität

    Reconstruction of a wind turbine's endured load spectrum using a short-time load measurement Abstract Wind turbines (WT) are normally designed for a service life (SL) of 20 years. In Germany, over safety. 1 Introduction A wind turbine (WT) is normally designed, tested and certified for a design life

  16. Measurement of Infrasound Emissions from Wind Turbines Dave Pepyne, Michael Zink and Jamyang Tenzin

    E-Print Network [OSTI]

    Mountziaris, T. J.

    Measurement of Infrasound Emissions from Wind Turbines Dave Pepyne, Michael Zink and Jamyang Tenzin energy has made wind turbine technology a suitable candidate for pollution-free energy. With its great that received many complaints from the residents living near the large wind turbine poles. Many scientists

  17. RAPID MEASUREMENTS OF SOLAR WIND IONS WITH THE TRIANA PLASMAG FARADAY CUP

    E-Print Network [OSTI]

    Richardson, John

    of the solar wind all the time, data in a new energy per charge window can be taken as soon as the power supply for several instruments on various spacecraft (s/c). Instrument s/c stabilization tspec [s] Launch year WIND/SWE/FCRAPID MEASUREMENTS OF SOLAR WIND IONS WITH THE TRIANA PLASMAG FARADAY CUP MATTHIAS R. AELLIG, ALAN

  18. Measuring Program for Wind, Waves and Current for Horns Rev and Ls; Documentation

    E-Print Network [OSTI]

    REPORT Measuring Program for Wind, Waves and Current for Horns Rev and Læsø; Documentation Documentation of wind sensors, data logs, etc. for Horns Rev is described in folder 2CF/EB001 supplied by ED is described in folder 2 CF/EB003 supplied by ED service centre and TW. Documentation of 3D Sonic Wind

  19. Sandia National Laboratories: measure 3-D wind flow

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

    wind plant research facility at Texas Tech University in Lubbock, Texas. The Scaled Wind Farm Technology (SWiFT) facility is the first U.S. facility specifically designed and...

  20. Distributed Compression for Condition Monitoring of Wind Farms

    E-Print Network [OSTI]

    Cheng, Samuel

    wind generation is high due to high wind speeds and import of power where the speeds are low. To make

  1. Session: Poster Session + Poster Award + Scientific Award + Excellent young wind doctor award (PO.206) Track: Technical

    E-Print Network [OSTI]

    Session: Poster Session + Poster Award + Scientific Award + Excellent young wind doctor award (PO.206) Track: Technical INVESTIGATION OF THE MEASUREMENT OF THE WIND SPEED STANDARD DEVIATION USING) Siemens wind power The LiDAR seems to be an effective alternative to met masts measurements of wind

  2. Measurement of sound speed vs. depth in South Pole ice: pressure waves and shear waves

    SciTech Connect (OSTI)

    IceCube Collaboration; Klein, Spencer

    2009-06-04T23:59:59.000Z

    We have measured the speed of both pressure waves and shear waves as a function of depth between 80 and 500 m depth in South Pole ice with better than 1% precision. The measurements were made using the South Pole Acoustic Test Setup (SPATS), an array of transmitters and sensors deployed in the ice at the South Pole in order to measure the acoustic properties relevant to acoustic detection of astrophysical neutrinos. The transmitters and sensors use piezoceramics operating at {approx}5-25 kHz. Between 200 m and 500 m depth, the measured profile is consistent with zero variation of the sound speed with depth, resulting in zero refraction, for both pressure and shear waves. We also performed a complementary study featuring an explosive signal propagating vertically from 50 to 2250 m depth, from which we determined a value for the pressure wave speed consistent with that determined for shallower depths, higher frequencies, and horizontal propagation with the SPATS sensors. The sound speed profile presented here can be used to achieve good acoustic source position and emission time reconstruction in general, and neutrino direction and energy reconstruction in particular. The reconstructed quantities could also help separate neutrino signals from background.

  3. Ris-R-Report Verification test for three WindCubeTM

    E-Print Network [OSTI]

    sensors mounted at a meteorological mast. Results are presented for three tested units ­ in detail the evaluation of measured mean wind speeds, wind directions and wind speed standard deviations. The data.6 Specifications of reference sensors 10 2.7 Time synchronization 10 3 Procedure of testing (verification test

  4. Quantifying Errors Associated with Satellite Sampling of Offshore Wind S.C. Pryor1,2

    E-Print Network [OSTI]

    1 Quantifying Errors Associated with Satellite Sampling of Offshore Wind Speeds S.C. Pryor1,2 , R, Bloomington, IN47405, USA. Tel: 1-812-855-5155. Fax: 1-812-855-1661 Email: spryor@indiana.edu 2 Dept. of Wind an attractive proposition for measuring wind speeds over the oceans because in principle they also offer

  5. Abstract--This paper proposes a stochastic wind power model based on an autoregressive integrated moving average (ARIMA)

    E-Print Network [OSTI]

    Bak-Jensen, Birgitte

    of one year from the Nysted offshore wind farm in Denmark. The proposed limited-ARIMA (LARIMA) model be applied to planning of future wind farms in the power system. However, both approaches entail wind speed measurements and an accurate wind farm model, which is usually unavailable. The accurate wind farm model

  6. Specification of >2 MeV geosynchronous electrons based on solar wind measurements

    E-Print Network [OSTI]

    Li, Xinlin

    affected by the solar wind. Statistical asynchronous regression (SAR), a statistical method recently use measurements directly from the solar wind, instead of the Kp index, and the SAR method when they pass through these local times. We cross calibrate the electron measurements from the five

  7. Long-term-average, solar cycle, and seasonal response of magnetospheric energetic electrons to the solar wind speed

    E-Print Network [OSTI]

    Vassiliadis, Dimitrios

    to the compression of the magnetosphere by the solar wind pressure. Over the solar cycle the variation in solar wind [Boller and Stolov, 1970; Russell and McPherron, 1973; Cliver et al., 2000]. INDEX TERMS: 2730

  8. Device for precision measurement of speed of sound in a gas

    DOE Patents [OSTI]

    Kelner, Eric; Minachi, Ali; Owen, Thomas E.; Burzynski, Jr., Marion; Petullo, Steven P.

    2004-11-30T23:59:59.000Z

    A sensor for measuring the speed of sound in a gas. The sensor has a helical coil, through which the gas flows before entering an inner chamber. Flow through the coil brings the gas into thermal equilibrium with the test chamber body. After the gas enters the chamber, a transducer produces an ultrasonic pulse, which is reflected from each of two faces of a target. The time difference between the two reflected signals is used to determine the speed of sound in the gas.

  9. atmospheric pressure measurements: Topics by E-print Network

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

    atmospheric conditions. Our module is capable of measuring temperature, pressure, wind speed, and particle concentration. The module will take measurements every minute and the...

  10. A WRF Ensemble for Improved Wind Speed Forecasts at Turbine Height ADAM J. DEPPE AND WILLIAM A. GALLUS JR.

    E-Print Network [OSTI]

    McCalley, James D.

    . 1. Introduction In recent years, wind energy production has under- gone rapid growth, and the U over both space and time. Therefore, the production rates of wind energy fluctuate more strongly than percentage of total power per capita coming from wind energy in 2010 (Department of Energy 2010). Even fewer

  11. 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

  12. High temperature measurement using very high shutter speed to avoid image saturation

    SciTech Connect (OSTI)

    Ma, Zhen; Zhang, Yang [Department of Mechanical Engineering, Sir Frederick Mappin Building, University of Sheffield, Sheffield, S1 3JD (United Kingdom)

    2014-04-11T23:59:59.000Z

    This paper explores the adaptation of the two-colour principle to develop a high-speed colour temperature correlation system, which is able to cover a range of temperature that is challenging to achieve before. A colour digital camera has built in RGB filters. It is possible to measure the temperature from the ratio of intensity of the green and red pixels using the two-colour principle based on the expansion of the Plank’s radiation law. In this study, experiments were carried out using a temperature calibrated tungsten ribbon lamp which can be tuned to vary from 1300 to 2200°C. Using very high shutter speed and small aperture, the high-speed camera successfully captured the tungsten ribbon without image saturation at the full temperature scale. Tests have been carried out at different temperature and camera settings. The sensitivity and errors have been analysed, and experiment results demonstrate the potential of using very high shutter speed is available for measuring the temperature even beyond 2200°C.

  13. DEWEK Wind Energy Conference 2012 Category: 4. Simulation models BACKWARD EXTRAPOLATION OF SHORT-TIME MEASUREMENT DATA FOR A REMAINING SERVICE LIFE ESTIMATION OF WIND

    E-Print Network [OSTI]

    Berlin,Technische Universität

    DEWEK Wind Energy Conference 2012 Category: 4. Simulation models 1 BACKWARD EXTRAPOLATION OF SHORT-TIME MEASUREMENT DATA FOR A REMAINING SERVICE LIFE ESTIMATION OF WIND TURBINES Dipl.-Ing. René Kamieth, Prof. Dr, Germany, Tel.: +49-(0)30-314-23603, Fax: +49-(0)30-314-26131 Summary Wind turbines built in the last

  14. Assessment and Optimization of Lidar Measurement Availability for Wind Turbine Control (Poster)

    SciTech Connect (OSTI)

    Scholbrock, F. A.; Fleming, P.; Wright, A.; Davoust, S.; Jehu, A.; Bouillet, M.; Bardon M.; Vercherin, B.

    2014-02-01T23:59:59.000Z

    Integrating Lidar to improve wind turbine controls is a potential breakthrough for reducing the cost of wind energy. By providing undisturbed wind measurements up to 400m in front of the rotor, Lidar may provide an accurate update of the turbine inflow with a preview time of several seconds. Focusing on loads, several studies have evaluated potential reductions using integrated Lidar, either by simulation or full scale field testing.

  15. European Wind Energy Conference 2007 Milan Measurement based analysis of active and reactive power

    E-Print Network [OSTI]

    European Wind Energy Conference 2007 ­ Milan 1 Measurement based analysis of active and reactive of the electricity is produced by wind turbines and combined heat and power plants (CHPs). Most of them are connected of reactive power between the 60 kV and the 150 kV networks. Further, the TSO is obligated to compensate

  16. Final Map Draft Comparison Report WIND ENERGY RESOURCE MODELING AND MEASUREMENT PROJECT

    E-Print Network [OSTI]

    SOLUTIONS, LLC (now AWS Truewind LLC) 255 FULLER ROAD, SUITE 274 ALBANY, NEW YORK Michael Brower PrincipalII Final Map Draft Comparison Report #12;WIND ENERGY RESOURCE MODELING AND MEASUREMENT PROJECT Tel: 978-749-9591 Fax: 978-749-9713 mbrower@awstruewind.com August 10, 2004 #12;2 WIND ENERGY RESOURCE

  17. Energy analysis of substorms based on remote sensing techniques, solar wind measurements, and geomagnetic indices

    E-Print Network [OSTI]

    Ã?stgaard, Nikolai

    Energy analysis of substorms based on remote sensing techniques, solar wind measurements wind Citation: Ã?stgaard, N., G. Germany, J. Stadsnes, and R. R. Vondrak, Energy analysis of substorms satellite have been used to examine the energy deposition in the Northern Hemisphere by precipitating

  18. WIND DATA REPORT September 1 2003 November 30 2003

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Paxton, MA September 1 2003 ­ November 30 2003 by James F. Manwell Anthony F.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  19. WIND DATA REPORT September 1, 2003 November 31, 2003

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Mt. Tom September 1, 2003 ­ November 31, 2003 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  20. WIND DATA REPORT Camden Hills Regional High School, ME

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Camden Hills Regional High School, ME December 1, 2006 ­ February 28, 2007...................................................................................................................... 7 Wind Speed Time Series............................................................................................................. 8 Wind Speed Distributions

  1. WIND DATA REPORT January 1, 2004 December 31, 2004

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Vinalhaven January 1, 2004 ­ December 31, 2004 Prepared for Fox Islands Electric...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  2. WIND DATA REPORT Camden Hills Regional High School, ME

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Camden Hills Regional High School, ME March 1st 2006 to May 31th 2006 Prepared.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  3. WIND DATA REPORT December 1 2003 February 29 2004

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Paxton, MA December 1 2003 ­ February 29 2004 Prepared for Diane Dillman, Paxton.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  4. WIND DATA REPORT December, 2003 February 29, 2004

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Orleans December, 2003 ­ February 29, 2004 Prepared for Massachusetts Technology.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  5. WIND DATA REPORT Camden Hills Regional High School, ME

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Camden Hills Regional High School, ME September 1st 2006 to November 30th 2006.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  6. WIND DATA REPORT October 27, 2003 November 31, 2003

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Orleans October 27, 2003 ­ November 31, 2003 Prepared for Massachusetts Technology...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  7. WIND DATA REPORT Camden Hills Regional High School, ME

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Camden Hills Regional High School, ME December 1st 2005 to February 28th 2006.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  8. WIND DATA REPORT March 1, 2004 May 31, 2004

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Eastham March 1, 2004 ­ May 31, 2004 Prepared for Massachusetts Technology...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  9. WIND DATA REPORT Camden Hills Regional High School, ME

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Camden Hills Regional High School, ME June 1st 2006 to August 31th 2006 Prepared.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  10. WIND DATA REPORT December 1, 2003 February 29, 2004

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Mt. Tom December 1, 2003 ­ February 29, 2004 Prepared for Massachusetts Technology.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  11. WIND DATA REPORT August 28 -December 31, 2002

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Vinalhaven August 28 - December 31, 2002 Prepared for Fox Islands Electric...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  12. AIAA Paper 97-2220, Applied Aerodynamics Conference, June 1997 Aerodynamic Parameter Measurement Using the Wind Driven Manipulator

    E-Print Network [OSTI]

    Using the Wind Driven Manipulator: Inverse Force Measurement on Wings Richard G. Ames , N.M. KomerathInverse force measurement using a wind-driven dynamic manipulator is explored. Using system identification techniques, the WDM offers a method of measuring forces and moments on wind tunnel models during rapid, multi

  13. Measuring M dwarf Winds with DAZ White Dwarfs

    E-Print Network [OSTI]

    J. H. Debes

    2006-08-01T23:59:59.000Z

    Hydrogen atmosphere white dwarfs with metal lines, so-called DAZs, show evidence for ongoing accretion of material onto their surfaces. Some DAZs are known to have unresolved M dwarf companions, which could account for the observed accretion through a stellar wind. I combine observed Ca abundances of the DAZs with information on the orbital separation of their M dwarf companions to infer the mass loss rate of the M dwarfs. I find that for three of the six known DAZs with M dwarf companions, a stellar wind can plausibly explain the observed accretion on the white dwarfs assuming Bondi-Hoyle accretion of solar abundance stellar winds on the order of 10$^{-14}-10^{-16}\\Msun$ yr$^{-1}$. The rest of the sample have companions with orbits $\\gtorder$ 1~AU, and require companion mass loss rates of $> 10^{-11}\\Msun$ yr$^{-1}$. I conclude that there must be an alternative explanation for accretion of material onto DAZs with widely separated companions. The inferred winds for two of the close binaries are orders of magnitude smaller than typically assumed for the angular momentum loss of red dwarf-white dwarf pairs due to magnetic braking from a stellar wind and may seriously affect predictions for the formation rate of CVs with low mass companions.

  14. Assessment and Optimization of Lidar Measurement Availability for Wind Turbine Control: Preprint

    SciTech Connect (OSTI)

    Davoust, S.; Jehu, A.; Bouillet, M.; Bardon, M.; Vercherin, B.; Scholbrock, A.; Fleming, P.; Wright, A.

    2014-05-01T23:59:59.000Z

    Turbine-mounted lidars provide preview measurements of the incoming wind field. By reducing loads on critical components and increasing the potential power extracted from the wind, the performance of wind turbine controllers can be improved [2]. As a result, integrating a light detection and ranging (lidar) system has the potential to lower the cost of wind energy. This paper presents an evaluation of turbine-mounted lidar availability. Availability is a metric which measures the proportion of time the lidar is producing controller-usable data, and is essential when a wind turbine controller relies on a lidar. To accomplish this, researchers from Avent Lidar Technology and the National Renewable Energy Laboratory first assessed and modeled the effect of extreme atmospheric events. This shows how a multirange lidar delivers measurements for a wide variety of conditions. Second, by using a theoretical approach and conducting an analysis of field feedback, we investigated the effects of the lidar setup on the wind turbine. This helps determine the optimal lidar mounting position at the back of the nacelle, and establishes a relationship between availability, turbine rpm, and lidar sampling time. Lastly, we considered the role of the wind field reconstruction strategies and the turbine controller on the definition and performance of a lidar's measurement availability.

  15. Measuring M dwarf Winds with DAZ White Dwarfs

    E-Print Network [OSTI]

    Debes, J H

    2006-01-01T23:59:59.000Z

    Hydrogen atmosphere white dwarfs with metal lines, so-called DAZs, show evidence for ongoing accretion of material onto their surfaces. Some DAZs are known to have unresolved M dwarf companions, which could account for the observed accretion through a stellar wind. I combine observed Ca abundances of the DAZs with information on the orbital separation of their M dwarf companions to infer the mass loss rate of the M dwarfs. I find that for three of the six known DAZs with M dwarf companions, a stellar wind can plausibly explain the observed accretion on the white dwarfs assuming Bondi-Hoyle accretion of solar abundance stellar winds on the order of 10$^{-14}-10^{-16}\\Msun$ yr$^{-1}$. The rest of the sample have companions with orbits $\\gtorder$ 1~AU, and require companion mass loss rates of $> 10^{-11}\\Msun$ yr$^{-1}$. I conclude that there must be an alternative explanation for accretion of material onto DAZs with widely separated companions. The inferred winds for two of the close binaries are orders of magn...

  16. 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.

  17. 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.

  18. Determination of the pressure at the gas-liquid interface using acoustic speed measurements

    E-Print Network [OSTI]

    Heggelund, Dag Gustav

    1988-01-01T23:59:59.000Z

    . The density can be expressed with the use of the real gas law. This yields BP = ? (g/gc) *dz*P*M/(144*Z*R*T) BP = ? (g/gc) *dz*P*SG*MAIR/(144*Z*R*T) (26) 21 where: SG MAIR specific gravity of gas. (air= 1. 0), Molecular weight of air, 28. 966...DETERMINATION OF THE PRESSURE AT THE GAS-LIQUID INTERFACE USING ACOUSTIC SPEED MEASUREMENTS A Thesis by DAG GUSTAV HEGGELUND Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree...

  19. Estimating long-term mean winds from short-term wind data

    SciTech Connect (OSTI)

    Barchet, W.R.; Davis, W.E.

    1983-08-01T23:59:59.000Z

    The estimation of long-term mean winds from short-term data is especially important in the area of wind energy. It is desirable to obtain reliable estimates of the long-term wind speed from as short a period of on-site measurements as possible. This study examined seven different methods of estimating the long-term average wind speed and compared the performance of these techniques. Three linear, three weather pattern, and one eigenvector methods were compared for measurement periods ranging from 3 months to 36 months. Average errors, both relative and absolute, and the rms errors in the techniques were determined. The best technique for less than 12 months of measurement was the eigenvector method using weekly mean wind speeds. However, this method was only slightly better than the linear adjusted method. When 12 or more months of data were used, the difference in errors between techniques was found to be slight.

  20. Low Speed Technology for Small Turbine Development Reaction Injection Molded 7.5 Meter Wind Turbine Blade

    SciTech Connect (OSTI)

    David M. Wright; DOE Project Officer - Keith Bennett

    2007-07-31T23:59:59.000Z

    An optimized small turbine blade (7.5m radius) was designed and a partial section molded with the RIM (reaction-injection molded polymer) process for mass production. The intended market is for generic three-bladed wind turbines, 100 kilowatts or less, for grid-assist end users with rural and semi-rural sites, such as the farm/ranch market, having low to moderate IEC Class 3-4 wind regimes. This blade will have substantial performance improvements over, and be cheaper than, present-day 7.5m blades. This is made possible by the injection-molding process, which yields high repeatability, accurate geometry and weights, and low cost in production quantities. No wind turbine blade in the 7.5m or greater size has used this process. The blade design chosen uses a RIM skin bonded to a braided infused carbon fiber/epoxy spar. This approach is attractive to present users of wind turbine blades in the 5-10m sizes. These include rebladeing California wind farms, refurbishing used turbines for the Midwest farm market, and other manufacturers introducing new turbines in this size range.

  1. Acoustic grating fringe projector for high-speed and high-precision three-dimensional shape measurements

    SciTech Connect (OSTI)

    Yin Xuebing; Zhao Huijie; Zeng Junyu; Qu Yufu

    2007-05-20T23:59:59.000Z

    A new acoustic grating fringe projector (AGFP) was developed for high-speed and high-precision 3D measurement. A new acoustic grating fringe projection theory is also proposed to describe the optical system. The AGFP instrument can adjust the spatial phase and period of fringes with unprecedented speed and accuracy. Using rf power proportional-integral-derivative (PID) control and CCD synchronous control, we obtain fringes with fine sinusoidal characteristics and realize high-speed acquisition of image data. Using the device, we obtained a precise phase map for a 3D profile. In addition, the AGFP can work in running fringe mode, which could be applied in other measurement fields.

  2. Determination of volume fractions in two-phase flows from sound speed measurement

    SciTech Connect (OSTI)

    Chaudhuri, Anirban [Los Alamos National Laboratory; Sinha, Dipen N. [Los Alamos National Laboratory; Osterhoudt, Curtis F. [University of Alaska

    2012-08-15T23:59:59.000Z

    Accurate measurement of the composition of oil-water emulsions within the process environment is a challenging problem in the oil industry. Ultrasonic techniques are promising because they are non-invasive and can penetrate optically opaque mixtures. This paper presents a method of determining the volume fractions of two immiscible fluids in a homogenized two-phase flow by measuring the speed of sound through the composite fluid along with the instantaneous temperature. Two separate algorithms are developed by representing the composite density as (i) a linear combination of the two densities, and (ii) a non-linear fractional formulation. Both methods lead to a quadratic equation with temperature dependent coefficients, the root of which yields the volume fraction. The densities and sound speeds are calibrated at various temperatures for each fluid component, and the fitted polynomial is used in the final algorithm. We present results when the new algorithm is applied to mixtures of crude oil and process water from two different oil fields, and a comparison of our results with a Coriolis meter; the difference between mean values is less than 1%. Analytical and numerical studies of sensitivity of the calculated volume fraction to temperature changes and calibration errors are also presented.

  3. Strong wind forcing of the ocean

    E-Print Network [OSTI]

    Zedler, Sarah E.

    2007-01-01T23:59:59.000Z

    of mesoscale and steady wind driven 1. Introduction 2. Modelparameterization at high wind speeds 1. Introduction 2. DataSupplementary Formulae 1. Wind Stress 2. Rankine Vortex A .

  4. 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.

  5. Low Speed Virtual Wind Tunnel Simulation For Educational Studies In Introducing Computational Fluid Dynamics And Flow Visualization

    E-Print Network [OSTI]

    Yang, Cher-Chiang

    2008-05-05T23:59:59.000Z

    ............................................................................................................... 25 3.2.4. Starting FlowLab ...................................................................................................................... 26 3.2.5. Geometry Settings... OF THE PROGRAMMING....................................................................... 52 v List of Figures FIGURE 2.1 ? COST AND TIME RELATIONSHIP WITH RESPECT TO CFD AND WIND TUNNELS............................. 5 FIGURE 2.2 - BOEING 777 DESIGN...

  6. Relationship between speed distribution measures and rural two-lane highway characteristics

    E-Print Network [OSTI]

    Collins, Jon Michael

    1997-01-01T23:59:59.000Z

    Understanding the behavior of speed population distributions on rural two-lane highways is needed to address driver error associated with elements of the highway. Previous research has identified a direct relationship between speed variance...

  7. The Accuracy of Radar Estimates of Ice Terminal Fall Speed from Vertically Pointing Doppler Radar Measurements

    E-Print Network [OSTI]

    Protat, Alain

    The Accuracy of Radar Estimates of Ice Terminal Fall Speed from Vertically Pointing Doppler Radar and 2835 MHz) are used to characterize the terminal fall speed of hydrometeors and the vertical air motion air velocity in ice clouds is small on average, as is assumed in terminal fall speed retrieval methods

  8. Experimental Investigation of Wind-Forced Drop Stability

    E-Print Network [OSTI]

    Schmucker, Jason

    2012-10-19T23:59:59.000Z

    aluminum (RA = 3.26 micrometers) floor of a tiltable wind tunnel and brought to critical conditions, when the drop begins to run downstream. Various combinations of drop size, inclination angle, and flow speed were employed. A measurement technique capable...

  9. The influence of Earth rotation in neutrino speed measurements between CERN and the OPERA detector

    E-Print Network [OSTI]

    Markus G. Kuhn

    2011-10-20T23:59:59.000Z

    The OPERA neutrino experiment at the underground Gran Sasso Laboratory recently reported, in arXiv:1109.4897v1, high-accuracy velocity measurements of neutrinos from the CERN CNGS beam over the 730 km distance between the two laboratories. This raised significant interest, as the observed neutrinos appeared to arrive at the OPERA detector about 60 ns (or equivalently 18 m) earlier than would have been expected if they had traveled at the speed of light, with high statistical significance. As the authors did not indicate whether and how they took into account the Coriolis or Sagnac effect that Earth's rotation has on the (southeastwards traveling) neutrinos, this brief note quantifies this effect. It would explain a 2.2 ns later arrival time.

  10. 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.

  11. 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.

  12. WP2 IEA Wind Task 26:The Past and Future Cost of Wind Energy

    E-Print Network [OSTI]

    Lantz, Eric

    2014-01-01T23:59:59.000Z

    Energy Efficiency and Renewable Energy, Wind and HydropowerSpeed Sites. ” European Wind Energy Association. Marseille,Innovation and the price of wind energy in the US. ” Energy

  13. WP2 IEA Wind Task 26:The Past and Future Cost of Wind Energy

    E-Print Network [OSTI]

    Lantz, Eric

    2014-01-01T23:59:59.000Z

    Speed Sites. ” European Wind Energy Association. Marseille,Innovation and the price of wind energy in the US. ” EnergyThe Economics of Wind Energy. ” Renewable and Sustainable

  14. High speed measurements of neutral beam turn-on and impact of beam modulation on measurements of ion density

    SciTech Connect (OSTI)

    Grierson, B. A., E-mail: bgriers@pppl.gov; Grisham, L. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Burrell, K. H.; Crowley, B.; Scoville, J. T. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)

    2014-10-15T23:59:59.000Z

    Modulation of neutral beams on tokamaks is performed routinely, enabling background rejection for active spectroscopic diagnostics, and control of injected power and torque. We find that there exists an anomalous initial transient in the beam neutrals delivered to the tokamak that is not accounted for by the accelerator voltage and power supply current. Measurements of the charge-exchange and beam photoemission on the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] at high speed (200 ?s) reveal that the energy of the beam neutrals is constant, but the density of beam neutrals displays dramatic variation in the first 2–3 ms following beam turn-on. The impact of this beam density variation on inferred ion densities and impurity transport is presented, with suggested means to correct for the anomalous transient.

  15. Subhourly wind forecasting techniques for wind turbine operations

    SciTech Connect (OSTI)

    Wegley, H.L.; Kosorok, M.R.; Formica, W.J.

    1984-08-01T23:59:59.000Z

    Three models for making automated forecasts of subhourly wind and wind power fluctuations were examined to determine the models' appropriateness, accuracy, and reliability in wind forecasting for wind turbine operation. Such automated forecasts appear to have value not only in wind turbine control and operating strategies, but also in improving individual wind turbine control and operating strategies, but also in improving individual wind turbine operating strategies (such as determining when to attempt startup). A simple persistence model, an autoregressive model, and a generalized equivalent Markhov (GEM) model were developed and tested using spring season data from the WKY television tower located near Oklahoma City, Oklahoma. The three models represent a pure measurement approach, a pure statistical method and a statistical-dynamical model, respectively. Forecasting models of wind speed means and measures of deviations about the mean were developed and tested for all three forecasting techniques for the 45-meter level and for the 10-, 30- and 60-minute time intervals. The results of this exploratory study indicate that a persistence-based approach, using onsite measurements, will probably be superior in the 10-minute time frame. The GEM model appears to have the most potential in 30-minute and longer time frames, particularly when forecasting wind speed fluctuations. However, several improvements to the GEM model are suggested. In comparison to the other models, the autoregressive model performed poorly at all time frames; but, it is recommended that this model be upgraded to an autoregressive moving average (ARMA or ARIMA) model. The primary constraint in adapting the forecasting models to the production of wind turbine cluster power output forecasts is the lack of either actual data, or suitable models, for simulating wind turbine cluster performance.

  16. American Institute of Aeronautics and Astronautics Wind Shear over Forested Areas

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    . Rogers* , James F. Manwell and Anthony F. Ellis Renewable Energy Research Laboratory, University The Renewable Energy Research Laboratory at the University of Massachusetts has been collecting data = wind speed at reference measurement height z = measurement height above ground zref = reference

  17. WIND DATA REPORT WBZ Tower, Hull, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT WBZ Tower, Hull, MA 12/1/06-2/28/07 Prepared for Department of Energy (DOE) Golden...................................................................................................................... 8 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  18. Recovery of a source term or a speed with one measurement and

    E-Print Network [OSTI]

    2013-04-03T23:59:59.000Z

    Apr 3, 2013 ... version, of the problem of recovery a sound speed, given the source. It has applications to thermoacoustic tomography. We are also inspired by ...

  19. Natural Ventilation in Buildings: Measurement in a Wind Tunnel and Numerical Simulation with Large Eddy Simulation

    E-Print Network [OSTI]

    Chen, Qingyan "Yan"

    save energy consumed by the heating, ventilating, and air- conditioning systems in a building1 Natural Ventilation in Buildings: Measurement in a Wind Tunnel and Numerical Simulation@purdue.edu Abstract Natural ventilation in buildings can create a comfortable and healthy indoor environment, and can

  20. Powering Up With Space-Time Wind Forecasting Amanda S. HERING and Marc G. GENTON

    E-Print Network [OSTI]

    Genton, Marc G.

    Powering Up With Space-Time Wind Forecasting Amanda S. HERING and Marc G. GENTON The technology to harvest electricity from wind energy is now advanced enough to make entire cities powered by it a reality be more realistically assessed with a loss measure that depends upon the power curve relating wind speed

  1. Airâ??sea dimethylsulfide (DMS) gas transfer in the North Atlantic: evidence for limited interfacial gas exchange at high wind speed

    E-Print Network [OSTI]

    Bell, T. G; De Bruyn, W.; Miller, S. D; Ward, B.; Christensen, K.; Saltzman, E. S

    2013-01-01T23:59:59.000Z

    O. : Modulation of short wind waves by long waves, J.P. , and Donelan, M. A. : Wind stress in the presence ofunder moderate to strong wind conditions, J. Geophys. Res. -

  2. A High-Speed Optical Diagnostic that uses Interference Filters to Measure Doppler Shifts

    SciTech Connect (OSTI)

    S.F. Paul; C. Cates; M. Mauel; D. Maurer; G. Navratil; M. Shilov

    2004-08-09T23:59:59.000Z

    A high-speed, non-invasive velocity diagnostic has been developed for measuring plasma rotation. The Doppler shift is determined by employing two detectors that view line emission from the identical volume of plasma. Each detector views through an interference filter having a passband that varies linearly with wavelength. One detector views the plasma through a filter whose passband has a negative slope and the second detector views through one with a positive slope. Because each channel views the same volume of plasma, the ratio of the amplitudes is not sensitive to variations in plasma emission. With suitable knowledge of the filter characteristics and the relative gain, the Doppler shift is readily obtained in real time from the ratio of two channels without needing a low throughput spectrometer. The systematic errors--arising from temperature drifts, stability, and frequency response of the detectors and amplifiers, interference filter linearity, and ability to thoroughly homogenize the light from the fiber bundle--can be characterized well enough to obtain velocity data with + or - 1 km/sec with a time resolution of 0.3 msec.

  3. annual wind river: Topics by E-print Network

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

    with the strength of the interplanetary magnetic field (IMF) and the solar wind speed, respectively, because solar wind speed is the most important parameter driving...

  4. Methods and apparatus for twist bend coupled (TCB) wind turbine blades

    DOE Patents [OSTI]

    Moroz, Emilian Mieczyslaw; LeMieux, David Lawrence; Pierce, Kirk Gee

    2006-10-10T23:59:59.000Z

    A method for controlling a wind turbine having twist bend coupled rotor blades on a rotor mechanically coupled to a generator includes determining a speed of a rotor blade tip of the wind turbine, measuring a current twist distribution and current blade loading, and adjusting a torque of a generator to change the speed of the rotor blade tip to thereby increase an energy capture power coefficient of the wind turbine.

  5. Stellar Winds on the Main-Sequence I: Wind Model

    E-Print Network [OSTI]

    Johnstone, C P; Lüftinger, T; Toth, G; Brott, I

    2015-01-01T23:59:59.000Z

    Aims: We develop a method for estimating the properties of stellar winds for low-mass main-sequence stars between masses of 0.4 and 1.1 solar masses at a range of distances from the star. Methods: We use 1D thermal pressure driven hydrodynamic wind models run using the Versatile Advection Code. Using in situ measurements of the solar wind, we produce models for the slow and fast components of the solar wind. We consider two radically different methods for scaling the base temperature of the wind to other stars: in Model A, we assume that wind temperatures are fundamentally linked to coronal temperatures, and in Model B, we assume that the sound speed at the base of the wind is a fixed fraction of the escape velocity. In Paper II of this series, we use observationally constrained rotational evolution models to derive wind mass loss rates. Results: Our model for the solar wind provides an excellent description of the real solar wind far from the solar surface, but is unrealistic within the solar corona. We run ...

  6. Performance Indicators of Wind Energy Production

    E-Print Network [OSTI]

    D'Amico, G; Prattico, F

    2015-01-01T23:59:59.000Z

    Modeling wind speed is one of the key element when dealing with the production of energy through wind turbines. A good model can be used for forecasting, site evaluation, turbines design and many other purposes. In this work we are interested in the analysis of the future financial cash flows generated by selling the electrical energy produced. We apply an indexed semi-Markov model of wind speed that has been shown, in previous investigation, to reproduce accurately the statistical behavior of wind speed. The model is applied to the evaluation of financial indicators like the Internal Rate of Return, semi-Elasticity and relative Convexity that are widely used for the assessment of the profitability of an investment and for the measurement and analysis of interest rate risk. We compare the computation of these indicators for real and synthetic data. Moreover, we propose a new indicator that can be used to compare the degree of utilization of different power plants.

  7. Amplitude modulation of wind turbine noise

    E-Print Network [OSTI]

    Makarewicz, Rufin

    2013-01-01T23:59:59.000Z

    Due to swish and thump amplitude modulation, the noise of wind turbines cause more annoyance than other environmental noise of the same average level. The wind shear accounts for the thump modulation (van den Berg effect). Making use of the wind speed measurements at the hub height, as well as at the top and the bottom of the rotor disc (Fig.1), the non-standard wind profile is applied. It causes variations in the A-weighted sound pressure level, LpA. The difference between the maximum and minimum of LpA characterizes thump modulation (Fig.2).

  8. Retinal blood flow measurement with ultrahigh-speed swept-source / Fourier domain optical coherence tomography

    E-Print Network [OSTI]

    Baumann, Bernhard

    Doppler OCT is a functional extension of OCT that provides information on flow in biological tissues. We present a novel approach for total retinal blood flow assessment using ultrahigh speed Doppler OCT. A swept source / ...

  9. Indirect Measurement Of Nitrogen In A Multi-Component Gas By Measuring The Speed Of Sound At Two States Of The Gas.

    DOE Patents [OSTI]

    Morrow, Thomas B. (San Antonio, TX); Behring, II, Kendricks A. (Torrance, CA)

    2004-10-12T23:59:59.000Z

    A methods of indirectly measuring the nitrogen concentration in a gas mixture. The molecular weight of the gas is modeled as a function of the speed of sound in the gas, the diluent concentrations in the gas, and constant values, resulting in a model equation. Regression analysis is used to calculate the constant values, which can then be substituted into the model equation. If the speed of sound in the gas is measured at two states and diluent concentrations other than nitrogen (typically carbon dioxide) are known, two equations for molecular weight can be equated and solved for the nitrogen concentration in the gas mixture.

  10. Airplane and the wind

    E-Print Network [OSTI]

    Airplane and the wind. An airplane starts from the point A and flies to B. The speed of the airplane with respect to the air is v (constant). There is also a wind of

  11. Global ocean wind power sensitivity to surface layer stability

    E-Print Network [OSTI]

    Capps, Scott B; Zender, Charles S

    2009-01-01T23:59:59.000Z

    2005), Evaluation of global wind power, J. Geophys. Res. ,Pryor (2003), Can satellite sampling of offshore wind speedsrealistically represent wind speed distributions? , J. Appl.

  12. RELIABILITY OF WIND POWER FROM DISPERSED SITES: A PRELIMINARY ASSESSMENT

    E-Print Network [OSTI]

    Kahn, E.

    2011-01-01T23:59:59.000Z

    PG&E 4:00 p.m. Summer Wind Generator Model Wind Array ELCCexpect from an array of wind generators spread over a largean array of dispersed wind generators will be. wind speed

  13. Power Performance Test Report for the SWIFT Wind Turbine

    SciTech Connect (OSTI)

    Mendoza, I.; Hur, J.

    2012-12-01T23:59:59.000Z

    This report summarizes the results of a power performance test that NREL conducted on the SWIFT wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 12: Power Performance Measurements of Electricity Producing Wind Turbines, IEC 61400-12-1 Ed.1.0, 2005-12. However, because the SWIFT is a small turbine as defined by IEC, NREL also followed Annex H that applies to small wind turbines. In these summary results, wind speed is normalized to sea-level air density.

  14. NedWind 25 Blade Testing at NREL for the European Standards Measurement and Testing Program

    SciTech Connect (OSTI)

    Larwood, S.; Musial, W.; Freebury, G.; Beattie, A.G.

    2001-04-19T23:59:59.000Z

    In the mid-90s the European community initiated the Standards, Measurements, and Testing (SMT) program to harmonize testing and measurement procedures in several industries. Within the program, a project was carried out called the European Wind Turbine Testing Procedure Development. The second part of that project, called Blade Test Methods and Techniques, included the United States and was devised to help blade-testing laboratories harmonize their testing methods. This report provides the results of those tests conducted by the National Renewable Energy Laboratory.

  15. Development of an Experimental Facility for Flame Speed Measurements in Powdered Aerosols

    E-Print Network [OSTI]

    Vissotski, Andrew John

    2012-10-19T23:59:59.000Z

    with both dispersion techniques, a pure dust-air system would not ignite due to the current spark ignition system. Thus, a hybrid mixture of Al/CH4/O2/N2 was employed to achieve the project goal of demonstrating a system for controlled laminar flame speed...

  16. Technology Improvement Opportunities for Low Wind Speed Turbines and Implications for Cost of Energy Reduction: July 9, 2005 - July 8, 2006

    SciTech Connect (OSTI)

    Cohen, J.; Schweizer, T.; Laxson, A.; Butterfield, S.; Schreck, S.; Fingersh, L.; Veers, P.; Ashwill, T.

    2008-02-01T23:59:59.000Z

    This report analyzes the status of wind energy technology in 2002 and describes the potential for technology advancements to reduce the cost and increase the performance of wind turbines.

  17. Wind energy conversion system

    DOE Patents [OSTI]

    Longrigg, Paul (Golden, CO)

    1987-01-01T23:59:59.000Z

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

  18. 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.

  19. WP2 IEA Wind Task 26:The Past and Future Cost of Wind Energy

    E-Print Network [OSTI]

    Lantz, Eric

    2014-01-01T23:59:59.000Z

    Bolinger, M. ( 2011). 2010 Wind Technologies Market Report.Cost of Energy From U.S. Wind Power Projects. Presentationand Energy Capture at Low Wind Speed Sites. ” European Wind

  20. WIND DATA REPORT WBZ Tower, Hull, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT WBZ Tower, Hull, MA 9/1/06-11/30/06 Prepared for Department of Energy (DOE) Golden.................................................................................................................... 10 Wind Speed Time Series...........................................................................................................

  1. WIND DATA REPORT WBZ Tower, Hull, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT WBZ Tower, Hull, MA 11/13/06-11/30/06 Prepared for Department of Energy (DOE.................................................................................................................... 10 Wind Speed Time Series.........................................................................................................

  2. Wind Monitoring Report for Fort Wainwright's Donnelly Training Area

    SciTech Connect (OSTI)

    Orrell, Alice C.; Dixon, Douglas R.

    2011-01-18T23:59:59.000Z

    Using the wind data collected at a location in Fort Wainwright’s Donnelly Training Area (DTA) near the Cold Regions Test Center (CRTC) test track, Pacific Northwest National Laboratory (PNNL) estimated the gross and net energy productions that proposed turbine models would have produced exposed to the wind resource measured at the meteorological tower (met tower) location during the year of measurement. Calculations are based on the proposed turbine models’ standard atmospheric conditions power curves, the annual average wind speeds, wind shear estimates, and standard industry assumptions.

  3. PHYSICAL REVIEW E 88, 042146 (2013) Uncovering wind turbine properties through two-dimensional stochastic modeling of wind dynamics

    E-Print Network [OSTI]

    Peinke, Joachim

    PHYSICAL REVIEW E 88, 042146 (2013) Uncovering wind turbine properties through two, such as the rated speed of the wind turbine or the descriptive wind speed statistics, can be related to the equations describing the evolution of power production and wind speed at single wind turbines. DOI: 10

  4. Wind Energy Resource Assessment of the Caribbean and Central America

    SciTech Connect (OSTI)

    DL Elliott; CI Aspliden; GL Gower; CG Holladay, MN Schwartz

    1987-04-01T23:59:59.000Z

    A wind energy resource assessment of the Caribbean and Central America has identified many areas with good to outstanding wind resource potential for wind turbine applications. Annual average wind resource maps and summary tables have been developed for 35 island/country areas throughout the Caribbean and Central America region. The wind resource maps highlight the locations of major resource areas and provide estimates of the wind energy resource potential for typical well-exposed sites in these areas. The average energy in the wind flowing in the layer near the ground is expressed as a wind power class: the greater the average wind energy, the higher the wind power class. The summary tables that are included with each of the 35 island/country wind energy maps provide information on the frequency distribution of the wind speeds (expressed as estimates of the Weibull shape factor, k) and seasonal variations in the wind resource for the major wind resource areas identified on the maps. A new wind power class legend has been developed for relating the wind power classes to values of mean wind power density, mean wind speed, and Weibull k. Guidelines are presented on how to adjust these values to various heights above ground for different roughness and terrain characteristics. Information evaluated in preparing the assessment included existing meteorological data from airports and other weather stations, and from ships and buoys in offshore and coastal areas. In addition, new data from recent measurement sites established for wind energy siting studies were obtained for a few areas of the Caribbean. Other types of information evaluated in the assessment were climatological data and maps on winds aloft, surface pressure, air flow, and topography. The various data were screened and evaluated for their usefulness in preparing the wind resource assessment. Much of the surface data from airports and other land-based weather stations were determined to be from sheltered sites and were thus not very useful in assessing the wind resource at locations that are well exposed to the winds. Ship data were determined to be the most useful for estimating the large-scale wind flow and assessing the spatial distribution of the wind resource throughout the region. Techniques were developed for analyzing and correcting ship wind data and extrapolating these data to coastal and inland areas by considering terrain influences on the large-scale wind flow. In areas where extrapolation of ship wind data was not entirely feasible, such as interior areas of Central America, other techniques were developed for estimating the wind flow and distribution of the wind resource. Through the application of the various innovative techniques developed for assessing the wind resource throughout the Caribbean and Central America region, many areas with potentially good to outstanding wind resource were identified that had not been previously recognized. In areas where existing site data were available from exposed locations, the measured wind resource was compared with the estimated wind resource that was derived using the assessment techniques. In most cases, there was good agreement between the measured wind resource and the estimated wind resource. This assessment project supported activities being pursued by the U.S. Committee for Renewable Energy Commerce and Trade (CORECT), the U.S. government's interagency program to assist in overseas marketing and promote renewable energy exports. An overall goal of the program is to improve U.S. competitiveness in the world renewable energy market. The Caribbean and Central America assessment, which is the first of several possible follow-on international wind energy resource assessments, provides valuable information needed by the U.S. wind energy industry to identify suitable wind resource areas and concentrate their efforts on these areas.

  5. Loading and Response of Offshore Wind Turbine Support Structures: Prediction with Comparison to Measured Data

    E-Print Network [OSTI]

    Sweetman, Bert

    Loading and Response of Offshore Wind Turbine Support Structures: Prediction with Comparison, offshore wind support platforms differ from oil platforms is several important ways: First, wind platforms is often closer to frequencies at which there is meaningful wave energy. Second, wind farms often include

  6. Error analysis of pose measurement from sonic sensors without using speed of sound information

    E-Print Network [OSTI]

    Lai, Chih-Chien

    1999-01-01T23:59:59.000Z

    and Microphones for Testing Mike Box Location. 60 4. 9 Initial Positions of Microphones. 64 4. 10 Information for Testing Effect of Distance between Transmitters on System. . 66 4. 11 Speed of Sound in Various Substances. . . 69 4. 12 Information for Testing... Transmitter c range from mike a ange frotn mike b dg, plane ab normal vector n of pl ab Microphone a poltlt 0 Microphone b Figure 3. 1: Diagram of Generation of Plane Equation. Table 3. 1: Defirdtion of Variables. tac, tb =? soundtimeof...

  7. Hurricane Katrina Wind Investigation Report

    SciTech Connect (OSTI)

    Desjarlais, A. O.

    2007-08-15T23:59:59.000Z

    This investigation of roof damage caused by Hurricane Katrina is a joint effort of the Roofing Industry Committee on Weather Issues, Inc. (RICOWI) and the Oak Ridge National Laboratory/U.S. Department of Energy (ORNL/DOE). The Wind Investigation Program (WIP) was initiated in 1996. Hurricane damage that met the criteria of a major windstorm event did not materialize until Hurricanes Charley and Ivan occurred in August 2004. Hurricane Katrina presented a third opportunity for a wind damage investigation in August 29, 2005. The major objectives of the WIP are as follows: (1) to investigate the field performance of roofing assemblies after major wind events; (2) to factually describe roofing assembly performance and modes of failure; and (3) to formally report results of the investigations and damage modes for substantial wind speeds The goal of the WIP is to perform unbiased, detailed investigations by credible personnel from the roofing industry, the insurance industry, and academia. Data from these investigations will, it is hoped, lead to overall improvement in roofing products, systems, roofing application, and durability and a reduction in losses, which may lead to lower overall costs to the public. This report documents the results of an extensive and well-planned investigative effort. The following program changes were implemented as a result of the lessons learned during the Hurricane Charley and Ivan investigations: (1) A logistics team was deployed to damage areas immediately following landfall; (2) Aerial surveillance--imperative to target wind damage areas--was conducted; (3) Investigation teams were in place within 8 days; (4) Teams collected more detailed data; and (5) Teams took improved photographs and completed more detailed photo logs. Participating associations reviewed the results and lessons learned from the previous investigations and many have taken the following actions: (1) Moved forward with recommendations for new installation procedures; (2) Updated and improved application guidelines and manuals from associations and manufacturers; (3) Launched certified product installer programs; and (4) Submitted building code changes to improve product installation. Estimated wind speeds at the damage locations came from simulated hurricane models prepared by Applied Research Associates of Raleigh, North Carolina. A dynamic hurricane wind field model was calibrated to actual wind speeds measured at 12 inland and offshore stations. The maximum estimated peak gust wind speeds in Katrina were in the 120-130 mph range. Hurricane Katrina made landfall near Grand Isle, Louisiana, and traveled almost due north across the city of New Orleans. Hurricane winds hammered the coastline from Houma, Louisiana, to Pensacola, Florida. The severe flooding problems in New Orleans made it almost impossible for the investigating teams to function inside the city. Thus the WIP investigations were all conducted in areas east of the city. The six teams covered the coastal areas from Bay Saint Louis, Mississippi, on the west to Pascagoula, Mississippi, on the east. Six teams involving a total of 25 persons documented damage to both low slope and steep slope roofing systems. The teams collected specific information on each building examined, including type of structure (use or occupancy), wall construction, roof type, roof slope, building dimensions, roof deck, insulation, construction, and method of roof attachment. In addition, the teams noted terrain exposure and the estimated wind speeds at the building site from the Katrina wind speed map. With each team member assigned a specific duty, they described the damage in detail and illustrated important features with numerous color photos. Where possible, the points of damage initiation were identified and damage propagation described. Because the wind speeds in Katrina at landfall, where the investigations took place, were less than code-specified design speeds, one would expect roof damage to be minimal. One team speculated that damage to all roofs in the area they examined was les

  8. Experimental and numerical study of the accuracy of flame-speed measurements for methane/air combustion in a slot burner

    SciTech Connect (OSTI)

    Selle, L.; Ferret, B. [Universite de Toulouse, INPT, UPS, IMFT, Institut de Mecanique des Fluides de Toulouse (France); CNRS, IMFT, Toulouse (France); Poinsot, T. [Universite de Toulouse, INPT, UPS, IMFT, Institut de Mecanique des Fluides de Toulouse (France); CNRS, IMFT, Toulouse (France); CERFACS, Toulouse (France)

    2011-01-15T23:59:59.000Z

    Measuring the velocities of premixed laminar flames with precision remains a controversial issue in the combustion community. This paper studies the accuracy of such measurements in two-dimensional slot burners and shows that while methane/air flame speeds can be measured with reasonable accuracy, the method may lack precision for other mixtures such as hydrogen/air. Curvature at the flame tip, strain on the flame sides and local quenching at the flame base can modify local flame speeds and require corrections which are studied using two-dimensional DNS. Numerical simulations also provide stretch, displacement and consumption flame speeds along the flame front. For methane/air flames, DNS show that the local stretch remains small so that the local consumption speed is very close to the unstretched premixed flame speed. The only correction needed to correctly predict flame speeds in this case is due to the finite aspect ratio of the slot used to inject the premixed gases which induces a flow acceleration in the measurement region (this correction can be evaluated from velocity measurement in the slot section or from an analytical solution). The method is applied to methane/air flames with and without water addition and results are compared to experimental data found in the literature. The paper then discusses the limitations of the slot-burner method to measure flame speeds for other mixtures and shows that it is not well adapted to mixtures with a Lewis number far from unity, such as hydrogen/air flames. (author)

  9. Low Wind Speed Technology Phase II: Design and Demonstration of On-Site Fabrication of Fluted-Steel Towers Using LITS-Form(TM) Process

    SciTech Connect (OSTI)

    Not Available

    2006-06-01T23:59:59.000Z

    This fact sheet describes NREL's subcontract with Native American Technologies to develop a new method of metal plate forming to produce wind turbine towers.

  10. Inflow Characterization and Aerodynamics Measurements on a SWT-2.3-101 Wind Turbine

    SciTech Connect (OSTI)

    Medina, P.; Singh, M.; Johansen, J.; Jove, A. R.; Fingersh, L.; Schreck, S.

    2012-01-01T23:59:59.000Z

    Post processing techniques for aerodynamic data acquired from a Siemens SWT-2.3101 turbine have been developed and applied in this paper. The turbine is installed at the National Wind Technology Center (NWTC) as part of Cooperative Research and Development Agreement between Siemens Wind Power and the National Renewable Energy Laboratory (NREL) under U.S. Department of Energy (DOE) sponsorship. The results indicate that the use of these corrections is essential for accurate analysis of the data. An example of local inflow angles, velocities, and inflow velocity over the rotor plane derived from measurements from a 5-hole probe is also presented. Finally, the pressure measurements are used to characterize unsteady phenomenon, namely, rotational augmentation and dynamic stall on an inboard station. The results show that the rotational augmentation can considerably increase the attached flow regime compared to the 2D Computational Fluid Dynamics (CFD) results. The dynamic stall event was seen to significantly delay the stall. Furthermore, the non-dimensionalized vortex convection derived from the dynamic stall event was found to agree well with results from others studies.

  11. Inflow Characterization and Aerodynamics Measurements on a SWT-2.3-101 Wind Turbine: Preprint

    SciTech Connect (OSTI)

    Medina, P.; Singh, M.; Johansen, J.; Jove, A.; Fingersh, L.; Schreck, S.

    2012-01-01T23:59:59.000Z

    Post processing techniques for aerodynamic data acquired from a Siemens SWT-2.3-101 turbine have been developed and applied in this paper. The turbine is installed at the National Wind Technology Center (NWTC) as part of Cooperative Research And Development Agreement between Siemens Wind Power and the National Renewable Energy Laboratory (NREL) under U.S. Department of Energy (DOE) sponsorship. The results indicate that the use of these corrections is essential for accurate analysis of the data. An example of local inflow angles, velocities, and inflow velocity over the rotor plane derived from measurements from a 5-hole probe is also presented. Finally the pressure measurements are used to characterize unsteady phenomenon, namely, rotational augmentation and dynamic stall on an inboard station. The results show that the rotational augmentation can considerably increase the attached flow regime compared to the 2D CFD results. The dynamic stall event was seen to significantly delay the stall. Furthermore, the nondimensionalized vortex convection derived from the dynamic stall event was found to agree well with results from others studies.

  12. Development and Validation of an Aeroelastic Model of a Small Furling Wind Turbine: Preprint

    SciTech Connect (OSTI)

    Jonkman, J. M.; Hansen, A. C.

    2004-12-01T23:59:59.000Z

    Small wind turbines often use some form of furling (yawing and/or tilting out of the wind) to protect against excessive power generation and rotor speeds in high winds.The verification study demonstrated the correct implementation of FAST's furling dynamics. During validation, the model tends to predict mean rotor speeds higher than measured in spite of the fact that the mean furl motion and rotor thrust are predicted quite accurately. This work has culminated with an enhanced version of FAST that should prove to be a valuable asset to designers of small wind turbines.

  13. Analyzing the Effects of Temporal Wind Patterns on the Value ofWind-Generated Electricity at Different Sites in California and theNorthwest

    SciTech Connect (OSTI)

    Fripp, Matthias; Wiser, Ryan

    2006-05-31T23:59:59.000Z

    Wind power production varies on a diurnal and seasonal basis. In this report, we use wind speed data modeled by TrueWind Solutions, LLC (now AWS Truewind) to assess the effects of wind timing on the value of electric power from potential wind farm locations in California and the Northwest. (Data from this dataset are referred to as ''TrueWind data'' throughout this report.) The intra-annual wind speed variations reported in the TrueWind datasets have not previously been used in published work, however, so we also compare them to a collection of anemometer wind speed measurements and to a limited set of actual wind farm production data. The research reported in this paper seeks to answer three specific questions: (1) How large of an effect can the temporal variation of wind power have on the value of wind in different wind resource areas? (2) Which locations are affected most positively or negatively by the seasonal and diurnal timing of wind speeds? (3) How compatible are wind resources in the Northwest and California with wholesale power prices and loads in either region? The latter question is motivated by the fact that wind power projects in the Northwest could sell their output into California (and vice versa), and that California has an aggressive renewable energy policy that may ultimately yield such imports. Based on our research, we reach three key conclusions. (1) Temporal patterns have a moderate impact on the wholesale market value of wind power and a larger impact on the capacity factor during peak hours. The best-timed wind power sites have a wholesale market value that is up to 4 percent higher than the average market price, while the worst-timed sites have a market value that is up to 11 percent below the average market price. The best-timed wind sites could produce as much as 30-40 percent more power during peak hours than they do on average during the year, while the worst timed sites may produce 30-60 percent less power during peak hours. (2) Northwestern markets appear to be well served by Northwestern wind and poorly served by California wind; results are less clear for California markets. Both the modeled TrueWind data and the anemometer data indicate that many Northwestern wind sites are reasonably well-matched to the Northwest's historically winter-peaking wholesale electricity prices and loads, while most California sites are poorly matched to these prices and loads. However, the TrueWind data indicate that most California and Northwestern wind sites are poorly matched to California's summer-afternoon-peaking prices and loads, while the anemometer data suggest that many of these same sites are well matched to California's wholesale prices and loads. (3) TrueWind and anemometer data agree about wind speeds in most times and places, but disagree about California's summer afternoon wind speeds: The TrueWind data indicate that wind speeds at sites in California's coastal mountains and some Northwestern locations dip deeply during summer days and stay low through much of the afternoon. In contrast, the anemometer data indicate that winds at these sites begin to rise during the afternoon and are relatively strong when power is needed most. At other times and locations, the two datasets show good agreement. This disagreement may be due in part to time-varying wind shear between the anemometer heights (20-25m) and the TrueWind reference height (50m or 70m), but may also be due to modeling errors or data collection inconsistencies.

  14. 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

    to change in upstream and downstream wind speed from 850 kW,1650 kW and 3000 kW wind turbinesseJ/J) Transformity of Wind Turbine (1650kW) Latitude

  15. High-speed non-contact measuring apparatus for gauging the thickness of moving sheet material

    DOE Patents [OSTI]

    Grann, Eric B. (San Ramon, CA); Holcomb, David E. (Oak Ridge, TN)

    2000-01-01T23:59:59.000Z

    An optical measurement apparatus is provided for measuring the thickness of a moving sheet material (18). The apparatus has a pair of optical measurement systems (21, 31) attached to opposing surfaces (14, 16) of a rigid support structure (10). A pair of high-power laser diodes (20,30) and a pair of photodetector arrays (22,32) are attached to the opposing surfaces. Light emitted from the laser diodes is reflected off of the sheet material surfaces (17, 19) and received by the respective photodetector arrays. An associated method for implementing the apparatus is also provided.

  16. Statewide Air Emissions Calculations from Energy Efficiency, Wind and Renewables

    E-Print Network [OSTI]

    Haberl, J.; Yazdani, B.; Culp, C.

    AND RENEWABLES May 2008 Energy Systems Laboratory p. 2 Electricity Production from Wind Farms (2002-2007) ? Installed capacity of wind turbines was 3,026 MW (March 2007). ? Announced new project capacity is 3,125 MW by 2010. ? Lowest electricity period... variations in measured power vs base year power production in the OSP. Energy Systems Laboratory p. 4 Next, looked at hourly electricity produced vs NOAA wind data. Issue: too much scatter. Hourly Turbine Power vs. Wind Speed (On-site) 0 10 20 30...

  17. LIDAR measurements of wind turbine wake dyn_amics and comparison with an engineering model

    E-Print Network [OSTI]

    . Madsen, K. Thomsen, and T.J. Larsen. VVllke Ineandering - II pragmatic approach. Wind Energy. Accepted Endovved Chair of Wind Energy University of Stuttgart, Germany 2 Ris0 DTU National Laboratory Technical. In European Wind Energy Conference {711d Exhibitioll /lvIiloll Itoly. EWEC, May 2007. [2J C.C. Larsen, H. Aa

  18. Tracking large tabular icebergs using the SeaWinds Ku-band microwave scatterometer

    E-Print Network [OSTI]

    Long, David G.

    . Originally designed to measure wind speed and direction over the ocean, SeaWinds is a microwave scatterometer. For instance, iceberg positions affect shipping lanes, outline ocean currents, and influence biological. Optical sensors produce high-resolution images but are unable to penetrate cloud cover and are dependent

  19. Balloon-borne sounding system (BBSS): Vaisala-processed winds, press., temp, and RH

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Coulter, Richard; Ritsche, Michael

    Balloon-borne sounding system (BBSS): Vaisala-processed winds, press., temp, and RH. The balloon-borne sounding system (SONDE) provides in situ measurements (vertical profiles) of both the thermodynamic state of the atmosphere, and the wind speed and direction.

  20. Wind Technology Advancements and Impacts on Western Wind Resources (Presentation)

    SciTech Connect (OSTI)

    Robichaud, R.

    2014-09-01T23:59:59.000Z

    Robi Robichaud made this presentation at the Bureau of Land Management West-wide Wind Opportunities and Constraints Mapping (WWOCM) Project public meeting in Denver, Colorado in September 2014. This presentation outlines recent wind technology advancements, evolving turbine technologies, and industry challenges. The presentation includes maps of mean wind speeds at 50-m, 80-m, and 100-m hub heights on BLM lands. Robichaud also presented on the difference in mean wind speeds from 80m to 100m in Wyoming.

  1. 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.

  2. 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.

  3. Acoustic method for measuring the sound speed of gases over small path lengths

    E-Print Network [OSTI]

    and the quality of gaseous fuels for alternative fueled vehicles such as hydrogen, natural gas, and propane hydrogen in air with a response time on the order of 1­2 s. An acoustic phase shift method is a very, to accurately measure the composition of binary gas mixtures. More recently, Huang et al.11 used this method

  4. Contrasting controls on wildland fires in Southern California during periods with and without Santa Ana winds

    E-Print Network [OSTI]

    Jin, Yufang; Randerson, James T; Faivre, Nicolas; Capps, Scott; Hall, Alex; Goulden, Michael L

    2014-01-01T23:59:59.000Z

    conditions, when strong offshore winds and low humidity leadat locations with high offshore wind speeds [Moritz et al. ,res, driven by sustained offshore extreme winds beginning 20

  5. Synoptic and local influences on boundary layer processes, with an application to California wind power

    E-Print Network [OSTI]

    Mansbach, David K.

    2010-01-01T23:59:59.000Z

    3.4.2 Wind roses . . . . . . . .Figure 5.5: Downscaled wind speed changes and componentin?uences on California’s wind energy resource. Part 1:

  6. Large Area Divertor Temperature Measurements Using A High-speed Camera With Near-infrared FiIters in NSTX

    SciTech Connect (OSTI)

    Lyons, B C; Zweben, S J; Gray, T K; Hosea, J; Kaita, R; Kugel, H W; Maqueda, R J; McLean, A G; Roquemore, A L; Soukhanovskii, V A

    2011-04-05T23:59:59.000Z

    Fast cameras already installed on the National Spherical Torus Experiment (NSTX) have be equipped with near-infrared (NIR) filters in order to measure the surface temperature in the lower divertor region. Such a system provides a unique combination of high speed (> 50 kHz) and wide fi eld-of-view (> 50% of the divertor). Benchtop calibrations demonstrated the system's ability to measure thermal emission down to 330 oC. There is also, however, signi cant plasma light background in NSTX. Without improvements in background reduction, the current system is incapable of measuring signals below the background equivalent temperature (600 - 700 oC). Thermal signatures have been detected in cases of extreme divertor heating. It is observed that the divertor can reach temperatures around 800 oC when high harmonic fast wave (HHFW) heating is used. These temperature profiles were fi t using a simple heat diffusion code, providing a measurement of the heat flux to the divertor. Comparisons to other infrared thermography systems on NSTX are made.

  7. Southern hemisphere tropospheric aerosol backscatter measurements - Implications for a laser wind system

    SciTech Connect (OSTI)

    Gras, J.L.; Platt, C.M.R.; Young, S.A.; Banks, S.M. (Commonwealth Scientific and Industrial Research Organization, Aspendale (Australia)); Jones, W.D. (NASA Marshall Space Flight Center, Huntsville, AL (USA)); Huffaker, R.M. (Coherent Technologies Inc., Boulder, CO (USA)); Booth, D.J. (Dept. of Applied Physics, Footscray (Australia))

    1991-03-20T23:59:59.000Z

    Values of backscatter coefficient at 0.532 {mu}m, 0.694 {mu}m, and 10.6 {mu}m were determined both by direct measurement and by Mie computation from measured aerosol microphysical properties in the eastern Australian region from 4{degree}S to 41{degree}S. Volume backscatter coefficients at 10.6 {mu}m were typically in the range 1 {times} 10{sup {minus}11} to 3 {times} 10{sup {minus}11} m{sup {minus}1}sr{sup {minus}1} for both approaches, although the experimental uncertainty in both cases was quite large. Agreement between the shorter wavelength lidars and the aerosol data was typically within the combined experimental uncertainties, although direct measurements were systematically larger than values derived from the aerosol data; individual regions were observed where the disagreement was larger than the combined error. Backscatter at 10.6 {mu}m and at visible wavelengths was found to be sensitive to essentially different regions of the aerosol size spectrum, questioning to some degree the validity of using short-wavelength extinction and backscatter data to infer tha global distribution of backscatter at wavelengths around 10.6 {mu}m. Considerable day-to-day variability in backscatter was observed at all wavelengths. The implications of the very low backscatter values found, compared to northern hemisphere values, should be considered in the design of the Laser Atmospheric Wind Sounder (LAWS).

  8. A compact single-camera system for high-speed, simultaneous 3-D velocity and temperature measurements.

    SciTech Connect (OSTI)

    Lu, Louise [University of Michigan, Ann Arbor, MI; Sick, Volker [University of Michigan, Ann Arbor, MI; Frank, Jonathan H.

    2013-09-01T23:59:59.000Z

    The University of Michigan and Sandia National Laboratories collaborated on the initial development of a compact single-camera approach for simultaneously measuring 3-D gasphase velocity and temperature fields at high frame rates. A compact diagnostic tool is desired to enable investigations of flows with limited optical access, such as near-wall flows in an internal combustion engine. These in-cylinder flows play a crucial role in improving engine performance. Thermographic phosphors were proposed as flow and temperature tracers to extend the capabilities of a novel, compact 3D velocimetry diagnostic to include high-speed thermometry. Ratiometric measurements were performed using two spectral bands of laser-induced phosphorescence emission from BaMg2Al10O17:Eu (BAM) phosphors in a heated air flow to determine the optimal optical configuration for accurate temperature measurements. The originally planned multi-year research project ended prematurely after the first year due to the Sandia-sponsored student leaving the research group at the University of Michigan.

  9. WP2 IEA Wind Task 26:The Past and Future Cost of Wind Energy

    E-Print Network [OSTI]

    Lantz, Eric

    2014-01-01T23:59:59.000Z

    G. ; Zervos, A. (2011). Wind Energy. In IPCC Special ReportSpeed Sites. ” European Wind Energy Association. Marseille,Innovation and the price of wind energy in the US. ” Energy

  10. International Statistical Review (2012), 80, 1, 223 doi:10.1111/j.1751-5823.2011.00168.x Short-Term Wind Speed Forecasting

    E-Print Network [OSTI]

    Genton, Marc G.

    2012-01-01T23:59:59.000Z

    the overall energy consumption by 20% through improved energy efficiency by 2020; see European Union (EU of Statistics, Texas A&M University, College Station, TX 77843-3143, USA E-mails: xzhu@stat.tamu.edu, genton@stat.tamu.edu Summary The emphasis on renewable energy and concerns about the environment have led to large-scale wind

  11. Aerodynamic and Performance Measurements on a SWT-2.3-101 Wind Turbine

    SciTech Connect (OSTI)

    Medina, P.; Singh, M.; Johansen, J.; Jove, A.R.; Machefaux, E.; Fingersh, L. J.; Schreck, S.

    2011-10-01T23:59:59.000Z

    This paper provides an overview of a detailed wind turbine field experiment being conducted at NREL under U.S. Department of Energy sponsorship. The purpose of the experiment is to obtain knowledge about the aerodynamics, performance, noise emission and structural characteristics of the Siemens SWT-2.3-101 wind turbine.

  12. 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 Energy’s 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.

  13. accretion disk winds: Topics by E-print Network

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

    and can obtain radiatively driven winds accelerated up to the it relativistic speed. For less luminous cases, disk winds are transonic types passing through saddle type...

  14. accretion disk wind: Topics by E-print Network

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

    and can obtain radiatively driven winds accelerated up to the it relativistic speed. For less luminous cases, disk winds are transonic types passing through saddle type...

  15. Sound speed and thermal property measurements of inert materials: laser spectroscopy and the diamond-anvil cell

    SciTech Connect (OSTI)

    Zaug, J.M.

    1997-07-01T23:59:59.000Z

    An indispensable companion to dynamical physics experimentation, static high-pressure diamond-anvil cell research continues to evolve, with laser diagnostic, as an accurate and versatile experimental deep planetary properties have bootstrapped each other in a process that has produced even higher pressures; consistently improved calibrations of temperature and pressure under static and dynamic conditions; and unprecedented data and understanding of materials, their elasticity, equations of state (EOS), and transport properties under extreme conditions. A collection of recent pressure and/or temperature dependent acoustic and thermal measurements and deduced mechanical properties and EOS data are summarized for a wide range of materials including H2, H2O, H2S, D2S, CO2, CH4, N2O, CH3OH,, SiO2, synthetic lubricants, PMMA, single crystal silicates, and ceramic superconductors. Room P&T sound speed measurements are presented for the first time on single crystals of beta-HMX. New high-pressure and temperature diamond cell designed and pressure calibrant materials are reviewed.

  16. 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.

  17. agb stellar winds: Topics by E-print Network

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

    variations in the location and appearance of the critical curves where the wind speed equals the slow, Alfven, and fast speed. Larger dead zones cause effective, fairly...

  18. Wind motor applications for transportation

    SciTech Connect (OSTI)

    Lysenko, G.P.; Grigoriev, B.V.; Karpin, K.B. [Moscow Aviation Inst. (Russian Federation)

    1996-12-31T23:59:59.000Z

    Motion equation for a vehicle equipped with a wind motor allows, taking into account the drag coefficients, to determine the optimal wind drag velocity in the wind motor`s plane, and hence, obtain all the necessary data for the wind wheel blades geometrical parameters definition. This optimal drag velocity significantly differs from the flow drag velocity which determines the maximum wind motor power. Solution of the motion equation with low drag coefficients indicates that the vehicle speed against the wind may be twice as the wind speed. One of possible transportation wind motor applications is its use on various ships. A ship with such a wind motor may be substantially easier to steer, and if certain devices are available, may proceed in autonomous control mode. Besides, it is capable of moving within narrow fairways. The cruise speed of a sailing boat and wind-motored ship were compared provided that the wind velocity direction changes along a harmonic law with regard to the motion direction. Mean dimensionless speed of the wind-motored ship appears to be by 20--25% higher than that of a sailing boat. There was analyzed a possibility of using the wind motors on planet rovers in Mars or Venus atmospheric conditions. A Mars rover power and motor system has been assessed for the power level of 3 kW.

  19. A comparison of spanwise aerodynamic loads estimated from measured bending moments versus direct pressure measurements on horizontal axis wind turbine blades

    SciTech Connect (OSTI)

    Simms, D A; Butterfield, C P

    1991-10-01T23:59:59.000Z

    Two methods can be used to determine aerodynamic loads on a rotating wind turbine blade. The first is to make direct pressure measurements on the blade surface. This is a difficult process requiring costly pressure instrumentation. The second method uses measured flap bending moments in conjunction with analytical techniques to estimate airloads. This method, called ALEST, was originally developed for use on helicopter rotors and was modified for use on horizontal axis wind turbine blades. Estimating airloads using flap bending moments in much simpler and less costly because measurements can be made with conventional strain gages and equipment. This paper presents results of airload estimates obtained using both methods under a variety of operating conditions. Insights on the limitations and usefulness of the ALEST bending moment technique are also included. 10 refs., 6 figs.

  20. 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 ...

  1. Wind Resource Assessment of Gujarat (India)

    SciTech Connect (OSTI)

    Draxl, C.; Purkayastha, A.; Parker, Z.

    2014-07-01T23:59:59.000Z

    India is one of the largest wind energy markets in the world. In 1986 Gujarat was the first Indian state to install a wind power project. In February 2013, the installed wind capacity in Gujarat was 3,093 MW. Due to the uncertainty around existing wind energy assessments in India, this analysis uses the Weather Research and Forecasting (WRF) model to simulate the wind at current hub heights for one year to provide more precise estimates of wind resources in Gujarat. The WRF model allows for accurate simulations of winds near the surface and at heights important for wind energy purposes. While previous resource assessments published wind power density, we focus on average wind speeds, which can be converted to wind power densities by the user with methods of their choice. The wind resource estimates in this study show regions with average annual wind speeds of more than 8 m/s.

  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. A doubly-fed permanent magnet generator for wind turbines

    E-Print Network [OSTI]

    Thomas, Andrew J. (Andrew Joseph), 1981-

    2004-01-01T23:59:59.000Z

    Optimum extraction of energy from a wind turbine requires that turbine speed vary with wind speed. Existing solutions to produce constant-frequency electrical output under windspeed variations are undesirable due to ...

  4. Impact of Wind Shear and Tower Shadow Effects on Power System with Large Scale Wind Power

    E-Print Network [OSTI]

    Hu, Weihao

    Impact of Wind Shear and Tower Shadow Effects on Power System with Large Scale Wind Power to wind speed variations, the wind shear and the tower shadow effects. The fluctuating power may be ableSILENT/PowerFactory. In this paper, the impacts of wind shear and tower shadow effects on the small signal stability of power systems

  5. Measurement of rotordynamic coefficients for a high-speed flexure pivot tilting-pad bearing(load between pad) configuration

    E-Print Network [OSTI]

    Al-Ghasem, Adnan Mahmoud

    2005-08-29T23:59:59.000Z

    This thesis presents the dynamic and static forced performance of a flexure-pivot tilting-pad bearing load between pad (LBP) configuration for different rotor speeds and bearing unit loadings. The bearing has the following design parameters: 4 pads...

  6. Using satellite data for mapping offshore wind resources and wakes

    E-Print Network [OSTI]

    (no wind) Horns Rev Offshore Wind Farm Blaavandshuk Met. mast N #12;Wind Horns Rev Wind speed map from · Wake near large offshore wind farms is quantified in space and time · Software for usersUsing satellite data for mapping offshore wind resources and wakes Charlotte Bay Hasager, Merete

  7. SOLAR WIND HEAVY IONS OVER SOLAR CYCLE 23: ACE/SWICS MEASUREMENTS

    SciTech Connect (OSTI)

    Lepri, S. T.; Landi, E.; Zurbuchen, T. H. [Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, TC 2210 Ann Arbor, MI 48109 (United States)

    2013-05-01T23:59:59.000Z

    Solar wind plasma and compositional properties reflect the physical properties of the corona and its evolution over time. Studies comparing the previous solar minimum with the most recent, unusual solar minimum indicate that significant environmental changes are occurring globally on the Sun. For example, the magnetic field decreased 30% between the last two solar minima, and the ionic charge states of O have been reported to change toward lower values in the fast wind. In this work, we systematically and comprehensively analyze the compositional changes of the solar wind during cycle 23 from 2000 to 2010 while the Sun moved from solar maximum to solar minimum. We find a systematic change of C, O, Si, and Fe ionic charge states toward lower ionization distributions. We also discuss long-term changes in elemental abundances and show that there is a {approx}50% decrease of heavy ion abundances (He, C, O, Si, and Fe) relative to H as the Sun went from solar maximum to solar minimum. During this time, the relative abundances in the slow wind remain organized by their first ionization potential. We discuss these results and their implications for models of the evolution of the solar atmosphere, and for the identification of the fast and slow wind themselves.

  8. Analysis of the effects of integrating wind turbines into a conventional utility: a case study. Final report

    SciTech Connect (OSTI)

    Goldenblatt, M.K.; Wegley, H.L.; Miller, A.H.

    1982-08-01T23:59:59.000Z

    The impact on a utility incorporating wind turbine generation due to wind speed sampling frequency, wind turbine performance model, and wind speed forecasting accuracy is examined. The utility analyzed in the study was the Los Angeles Department of Water and Power and the wind turbine assumed was the MOD-2. The sensitivity of the economic value of wind turbine generation to wind speed sampling frequency and wind turbine modeling technique is examined as well as the impact of wind forecasting accuracy on utility operation and production costs. Wind speed data from San Gorgonio Pass, California during 1979 are used to estimate wind turbine performance using four different simulation methods. (LEW)

  9. Analysis of the effects of integrating wind turbines into a conventional utility: a case study. Revised final report

    SciTech Connect (OSTI)

    Goldenblatt, M.K.; Wegley, H.L.; Miller, A.H.

    1983-03-01T23:59:59.000Z

    The impact on a utility incorporating wind turbine generation due to wind speed sampling frequency, wind turbine performance model, and wind speed forecasting accuracy is examined. The utility analyzed in this study was the Los Angeles Department of Water and Power, and the wind turbine assumed was the MOD-2. The sensitivity of the economic value of wind turbine generation to wind speed sampling frequency and wind turbine modeling technique is examined as well as the impact of wind forecasting accuracy on utility operation and production costs. Wind speed data from San Gorgonio Pass, California during 1979 are used to estimate wind turbine performance using four different simulation methods. (LEW)

  10. 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.

  11. CALIBRATION OF AND ATTITUDE ERROR ESTIMATION FOR A SPACEBORNE SCATTEROMETER USING MEASUREMENTS OVER LAND

    E-Print Network [OSTI]

    Long, David G.

    of ocean wind speed and direction. Scatterometers must be calibrated before their measurements are scienti in the long-term, thus propelling them out of the crowded valley of the common and up the inclines

  12. Measurement of the Equivalent Thermal Resistance of Rooftop Lawns in a Hot-Climate Wind Tunnel

    E-Print Network [OSTI]

    Meng, Q.; Zhang, Y.; Zhang, L.

    2006-01-01T23:59:59.000Z

    rooftop lawn. A hot-climate wind tunnel experiment was carried out in order to obtain and analyze the heat and moisture transport in the rooftop lawn. Furthermore, a calculation with the energy conservation equation was carried out using the results...

  13. Measurement of the Equivalent Thermal Resistance of Rooftop Lawns in a Hot-Climate Wind Tunnel 

    E-Print Network [OSTI]

    Meng, Q.; Zhang, Y.; Zhang, L.

    2006-01-01T23:59:59.000Z

    rooftop lawn. A hot-climate wind tunnel experiment was carried out in order to obtain and analyze the heat and moisture transport in the rooftop lawn. Furthermore, a calculation with the energy conservation equation was carried out using the results...

  14. Measurement and Numerical Simulation of Wind Environment for One Residential District 

    E-Print Network [OSTI]

    Li, C.; Li, N.

    2006-01-01T23:59:59.000Z

    A residential quarter in the west of Changsha has a nearby main transport corridor to the east,and Tianma Hill is to the west. The circumference of this residential quarter is open to the outside; therefore, the wind environment is special...

  15. Measurement and Numerical Simulation of Wind Environment for One Residential District

    E-Print Network [OSTI]

    Li, C.; Li, N.

    2006-01-01T23:59:59.000Z

    A residential quarter in the west of Changsha has a nearby main transport corridor to the east,and Tianma Hill is to the west. The circumference of this residential quarter is open to the outside; therefore, the wind environment is special...

  16. 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

  17. 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

  18. Use of synthetic aperture radar for offshore wind resource assessment and wind farm development in the UK 

    E-Print Network [OSTI]

    Cameron, Iain Dickson

    2008-01-01T23:59:59.000Z

    The UK has an abundant offshore wind resource with offshore wind farming set to grow rapidly over the coming years. Optimisation of energy production is of the utmost importance and accurate estimates of wind speed distributions are critical...

  19. 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.

  20. Abstract--Resolvers are absolute angle transducers that are usually used for position and speed measurement in

    E-Print Network [OSTI]

    Sontag, Eduardo

    have enabled sensorless control that reduces the total system operating cost by eliminating mechanical- mail: peter_harding@pgt.com.au). in a noisy environment. A resolver is basically a rotary transformer is fixed on the rotor, and therefore, it rotates jointly with the shaft passing the output windings. Two

  1. 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 ...

  2. Floating offshore wind farms : demand planning & logistical challenges of electricity generation

    E-Print Network [OSTI]

    Nnadili, Christopher Dozie, 1978-

    2009-01-01T23:59:59.000Z

    Floating offshore wind farms are likely to become the next paradigm in electricity generation from wind energy mainly because of the near constant high wind speeds in an offshore environment as opposed to the erratic wind ...

  3. New Concepts in Wind Power Forecasting Models

    E-Print Network [OSTI]

    Kemner, Ken

    New Concepts in Wind Power Forecasting Models Vladimiro Miranda, Ricardo Bessa, João Gama, Guenter to the training of mappers such as neural networks to perform wind power prediction as a function of wind characteristics (mainly speed and direction) in wind parks connected to a power grid. Renyi's Entropy is combined

  4. 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.

  5. ANALYSIS OF THE PERFORMANCE AND COST EFFECTIVENESS OF NINE SMALL WIND ENERGY CONVERSION SYSTEMS FUNDED BY THE DOE SMALL GRANTS PROGRAM

    E-Print Network [OSTI]

    Kay, J.

    2009-01-01T23:59:59.000Z

    relationship between potential wind speed and theoreticalfirm contracts. Potential wind investors face considerable15 with optimism the potential that wind, photovoltaic, and

  6. 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

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université 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

  8. 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. � 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. � 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. � 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 wind�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.

  9. In situ measurements of Krypton in Xenon gas with a quadrupole mass spectrometer following a cold-trap at a temporarily reduced pumping speed

    E-Print Network [OSTI]

    Ethan Brown; Stephan Rosendahl; Christian Huhmann; Christian Weinheimer; Hans Kettling

    2012-12-20T23:59:59.000Z

    A new method for measuring trace amounts of krypton in xenon using a cold trap with a residual gas analyzer has been developed, which achieves an increased sensitivity by temporarily reducing the pumping speed while expending a minimal amount of xenon. By partially closing a custom built butterfly valve between the measurement chamber and the turbomolecular pump, a sensitivity of 40 ppt has been reached. This method has been tested on an ultra-pure gas sample from Air Liquide with an unknown intrinsic krypton concentration, yielding a krypton concentration of $330 \\pm 200$ ppt.

  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. Is the Weibull distribution really suited for wind statistics modeling and wind power evaluation?

    E-Print Network [OSTI]

    Drobinski, Philippe

    2012-01-01T23:59:59.000Z

    Wind speed statistics is generally modeled using the Weibull distribution. This distribution is convenient since it fully characterizes analytically with only two parameters (the shape and scale parameters) the shape of distribution and the different moments of the wind speed (mean, standard deviation, skewness and kurtosis). This distribution is broadly used in the wind energy sector to produce maps of wind energy potential. However, the Weibull distribution is based on empirical rather than physical justification and might display strong limitations for its applications. The philosophy of this article is based on the modeling of the wind components instead of the wind speed itself. This provides more physical insights on the validity domain of the Weibull distribution as a possible relevant model for wind statistics and the quantification of the error made by using such a distribution. We thereby propose alternative expressions of more suited wind speed distribution.

  12. PSO (FU 2101) Ensemble-forecasts for wind power

    E-Print Network [OSTI]

    PSO (FU 2101) Ensemble-forecasts for wind power Wind Power Ensemble Forecasting Using Wind Speed the problems of (i) transforming the meteorological ensembles to wind power ensembles and, (ii) correcting) data. However, quite often the actual wind power production is outside the range of ensemble forecast

  13. Active control system for high speed windmills

    DOE Patents [OSTI]

    Avery, D.E.

    1988-01-12T23:59:59.000Z

    A pump stroke is matched to the operating speed of a high speed windmill. The windmill drives a hydraulic pump for a control. Changes in speed of a wind driven shaft open supply and exhaust valves to opposite ends of a hydraulic actuator to lengthen and shorten an oscillating arm thereby lengthening and shortening the stroke of an output pump. Diminishing wind to a stall speed causes the valves to operate the hydraulic cylinder to shorten the oscillating arm to zero. A pressure accumulator in the hydraulic system provides the force necessary to supply the hydraulic fluid under pressure to drive the actuator into and out of the zero position in response to the windmill shaft speed approaching and exceeding windmill stall speed. 4 figs.

  14. Active control system for high speed windmills

    DOE Patents [OSTI]

    Avery, Don E. (45-437 Akimala St., Honolulu, HI 96744)

    1988-01-01T23:59:59.000Z

    A pump stroke is matched to the operating speed of a high speed windmill. The windmill drives a hydraulic pump for a control. Changes in speed of a wind driven shaft open supply and exhaust valves to opposite ends of a hydraulic actuator to lengthen and shorten an oscillating arm thereby lengthening and shortening the stroke of an output pump. Diminishing wind to a stall speed causes the valves to operate the hydraulic cylinder to shorten the oscillating arm to zero. A pressure accumulator in the hydraulic system provides the force necessary to supply the hydraulic fluid under pressure to drive the actuator into and out of the zero position in response to the windmill shaft speed approaching and exceeding windmill stall speed.

  15. Effect of Blending on High-Pressure Laminar Flame Speed Measurements, Markstein Lengths, and Flame Stability of Hydrocarbons

    E-Print Network [OSTI]

    Lowry, William Baugh

    2012-02-14T23:59:59.000Z

    . Hydrocarbon blends of methane, ethane, and propane make up a large portion of natural gas and it has been shown that dimethyl ether can be used as a supplement or in its pure form for gas turbine combustion. Because of this, a fundamental understanding... include the flame speeds for binary blends of methane, ethane, propane, and dimethyl ether performed at elevated pressures, up to 10-atm initial pressure, using a spherically expanding flame in a constant-volume vessel. Also included in this thesis is a...

  16. Real-time solar wind prediction based on SDO/AIA coronal hole data

    E-Print Network [OSTI]

    Rotter, T; Temmer, M; Vrsnak, B

    2015-01-01T23:59:59.000Z

    We present an empirical model based on the visible area covered by coronal holes close to the central meridian in order to predict the solar wind speed at 1 AU with a lead time up to four days in advance with a 1hr time resolution. Linear prediction functions are used to relate coronal hole areas to solar wind speed. The function parameters are automatically adapted by using the information from the previous 3 Carrington Rotations. Thus the algorithm automatically reacts on the changes of the solar wind speed during different phases of the solar cycle. The adaptive algorithm has been applied to and tested on SDO/AIA-193A observations and ACE measurements during the years 2011-2013, covering 41 Carrington Rotations. The solar wind speed arrival time is delayed and needs on average 4.02 +/- 0.5 days to reach Earth. The algorithm produces good predictions for the 156 solar wind high speed streams peak amplitudes with correlation coefficients of cc~0.60. For 80% of the peaks, the predicted arrival matches within ...

  17. RELIABILITY OF WIND POWER FROM DISPERSED SITES: A PRELIMINARY ASSESSMENT

    E-Print Network [OSTI]

    Kahn, E.

    2011-01-01T23:59:59.000Z

    to expect that wind generation will be sufficiently reliableload for the case with wind generation measured at the LOLPcan be displaced by wind generation. tions form the basis

  18. Estimating the Wind Resource in Uttarakhand: Comparison of Dynamic...

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

    Estimating the Wind Resource in Uttarakhand: Comparison of Dynamic Downscaling with Doppler Lidar Wind Measurements Estimating the Wind Resource in Uttarakhand: Comparison of...

  19. Urban Form, Wind, Comfort, and Sustainability: The San Francisco Experience

    E-Print Network [OSTI]

    Kim, Hyungkoo

    2014-01-01T23:59:59.000Z

    59 Figure 46. Measurement of windDesigning for an Acceptable Wind Environment. Transportation1989). Developing the San Francisco wind ordinance and its

  20. Wake structure measurements at the Mod-2 cluster test facility at Goodnoe Hills

    SciTech Connect (OSTI)

    Lissaman, P.B.S.; Zambrano, T.G.; Gyatt, G.W.

    1983-03-01T23:59:59.000Z

    A field measurement progam was carried out at the cluster of three MOD-2 wind turbines located at Goodnoe Hills, Washington, to determine the rate of decay of wake velocity deficit with downwind distance in various meteorological conditions. Measurements were taken at hub height (200 ft) between July 12 and August 1, 1982. Wake wind speeds were measured using a radiosonde suspended from a tethered balloon, its position being determined from a grid of ground stakes. Measurments were also made downwind with the turbine off to determine the magnitude of terrain-induced variations in wind speed. The balloon system used to measure downstream wind data proved to be reliable and convenient. Downstream distances of 900, 1500, 2100, and 2700 ft from the turbine were investigated. Differences between the instrumentation systems required that corrections be made to the data. After correction, averaged terrain-induced wind speed variations were regarded as insignificant. Turbine-on velocity ratios showed scatter, suggesting that only some measurements were, in fact, representative of wake centerline velocities, and that others were made off centerline due to wake meander or wind shift. Isolation of the high wind speed (30 to 45 mph) velocity ratios, however, revealed velocity deficits downstream. Measurements at greater downstream distances showed no wake deficit within the limits of resolution of the experiment, indicating that the wake had recovered to free stream conditions. Comparison with the AeroVironment wake model using common values for rotor drag coefficient and turbulence showed similar trends.

  1. Dynamic Wind Effects on Buildings with 3D Coupled Modes: Application of High Frequency Force Balance Measurements

    E-Print Network [OSTI]

    Chen, Xinzhong

    Dynamic Wind Effects on Buildings with 3D Coupled Modes: Application of High Frequency Force frequency force balance HFFB technique customarily used in wind tunnel testing for uncoupled buildings have been widely recognized for conveniently quantifying generalized wind forces on tall build- ings

  2. Comparison of model and observations of the wake of a MOD-OA wind turbine

    SciTech Connect (OSTI)

    Doran, J.C.; Packard, K.R.

    1982-10-01T23:59:59.000Z

    A series of wind velocity measurements upwind and downwind of the MOD-OA wind turbine at Clayton, New Mexico, was used to determine some of the characteristics of wakes within approximately two blade diameters of the machine. The magnitudes and shapes of the velocity profiles downwind of the turbine were compared with results obtained from a model. Generally good agreement was obtained at speeds well below the rated speed of the MOD-OA, but the results were not as satisfactory for higher values.

  3. Determining Wind Turbine Gearbox Model Complexity Using Measurement Validation and Cost Comparison: Preprint

    SciTech Connect (OSTI)

    LaCava, W.; Xing, Y.; Guo, Y.; Moan, T.

    2012-04-01T23:59:59.000Z

    The Gearbox Reliability Collaborative (GRC) has conducted extensive field and dynamometer test campaigns on two heavily instrumented wind turbine gearboxes. In this paper, data from the planetary stage is used to evaluate the accuracy and computation time of numerical models of the gearbox. First, planet-bearing load and motion data is analyzed to characterize planetary stage behavior in different environments and to derive requirements for gearbox models and life calculations. Second, a set of models are constructed that represent different levels of fidelity. Simulations of the test conditions are compared to the test data and the computational cost of the models are compared. The test data suggests that the planet-bearing life calculations should be made separately for each bearing on a row due to unequal load distribution. It also shows that tilting of the gear axes is related to planet load share. The modeling study concluded that fully flexible models were needed to predict planet-bearing loading in some cases, although less complex models were able to achieve good correlation in the field-loading case. Significant differences in planet load share were found in simulation and were dependent on the scope of the model and the bearing stiffness model used.

  4. Observed and CAM3 GCM Sea Surface Wind

    E-Print Network [OSTI]

    Zender, Charles

    Observed and CAM3 GCM Sea Surface Wind Speed Distributions: Characterization, Comparison, and Bias climatological surface wind speed probability density functions (PDFs) estimated from observations and use them to evaluate, for the first time, contemporaneous wind PDFs predicted by a GCM. The ob- servations include NASA

  5. Inverse Load Calculation of Wind Turbine Support Structures - A Numerical Verification Using the Comprehensive Simulation Code FAST: Preprint (Revised)

    SciTech Connect (OSTI)

    Pahn, T.; Jonkman, J.; Rolges, R.; Robertson, A.

    2012-11-01T23:59:59.000Z

    Physically measuring the dynamic responses of wind turbine support structures enables the calculation of the applied loads using an inverse procedure. In this process, inverse means deriving the inputs/forces from the outputs/responses. This paper presents results of a numerical verification of such an inverse load calculation. For this verification, the comprehensive simulation code FAST is used. FAST accounts for the coupled dynamics of wind inflow, aerodynamics, elasticity and turbine controls. Simulations are run using a 5-MW onshore wind turbine model with a tubular tower. Both the applied loads due to the instantaneous wind field and the resulting system responses are known from the simulations. Using the system responses as inputs to the inverse calculation, the applied loads are calculated, which in this case are the rotor thrust forces. These forces are compared to the rotor thrust forces known from the FAST simulations. The results of these comparisons are presented to assess the accuracy of the inverse calculation. To study the influences of turbine controls, load cases in normal operation between cut-in and rated wind speed, near rated wind speed and between rated and cut-out wind speed are chosen. The presented study shows that the inverse load calculation is capable of computing very good estimates of the rotor thrust. The accuracy of the inverse calculation does not depend on the control activity of the wind turbine.

  6. Evaluation of Wind Shear Patterns at Midwest Wind Energy Facilities: Preprint

    SciTech Connect (OSTI)

    Smith, K.; Randall, G.; Malcolm, D.; Kelley, N.; Smith, B.

    2002-05-01T23:59:59.000Z

    The U.S. Department of Energy-Electric Power Research Institute (DOE-EPRI) Wind Turbine Verification Program (TVP) has included several wind energy facilities in the Midwestern United States. At several of these projects, a strong diurnal shear pattern has been observed. During the day, low and sometimes negative shear has been measured. During night hours, very high positive shear is frequently observed. These high nighttime shear values are of concern due to the potential for high stresses across the rotor. The resulting loads on turbine components could result in failures. Conversely, the effects of high nighttime wind shear could benefit wind generated energy production in the Midwest by providing a source of greater hub-height wind speeds, particularly for multi-megawatt turbines that utilize tall towers. This paper presents an overview of the observed wind shear at each of the Midwest TVP projects, focusing on diurnal patterns and the frequency of very high nighttime shear at the sites. Turbine fault incidence is examined to determine the presence or absence of a correlation to periods of high shear. Implications of shear-related failures are discussed for other Midwest projects that use megawatt-scale turbines. In addition, this paper discusses the importance of accurate shear estimates for project development.

  7. Analysis of Wind Power Generation of Texas

    E-Print Network [OSTI]

    Liu, Z.; Haberl, J.; Subbarao, K.; Baltazar, J. C.

    from Jul 2002 to Jan 2003 Degradation Analysis - On average, no degradation observed for nine wind farms analyzed over 4-year period. Application of Method 1 to New Site- Sweetwater I Wind Farm ? Energy Systems Laboratory, Texas A&M University Page 3...&M University Page 10 Weather Data: NOAA- ABI 1999 and 2005 Hourly Wind Speed NOAA -ABI Hourly Wind Speed -1999 0 10 20 30 40 Jan-99 Feb-99 M ar-99 Apr-99 M ay-99 Jun-99 Jul-99 Aug-99 Sep-99 Oct-99 Nov-99 Dec-99 W in d Spe ed [m ph ] NOAA -ABI Hourly Wind...

  8. Offshore wind resource assessment through satellite images

    E-Print Network [OSTI]

    1 Slide no. 4 Offshore wind resource assessment through satellite images Charlotte Bay Hasager images for offshore wind ressource assessment in lieu of in-situ mast observations #12;4 Slide no Hasager, Dellwik, Nielsen and Furevik, 2004, Validation of ERS-2 SAR offshore wind-speed maps in the North

  9. Acoustic Noise Test Report for the Viryd CS8 Wind Turbine

    SciTech Connect (OSTI)

    Roadman, J.; Huskey, A.

    2013-07-01T23:59:59.000Z

    This report summarizes the results of an acoustic noise test that the National Renewable Energy Laboratory (NREL) conducted on the Viryd CS8 wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 11: Acoustic Noise Measurement Techniques, IEC 61400-11 Ed.2.1, 2006-11. However, because the Viryd CS8 is a small turbine, as defined by IEC, NREL used 10-second averages instead of 60-second averages and binning by wind speed instead of regression analysis.

  10. Acoustic Noise Test Report for the SWIFT Wind Turbine in Boulder, CO

    SciTech Connect (OSTI)

    Roadman, J.; Huskey, A.

    2013-04-01T23:59:59.000Z

    This report summarizes the results of an acoustic noise test that the National Renewable Energy Laboratory (NREL) conducted on the SWIFT wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 11: Acoustic Noise Measurement Techniques, IEC 61400-11 Ed.2.1, 2006-11. However, because the SWIFT is a small turbine, as defined by IEC, NREL used 10-second averages instead of 60-second averages and utilized binning by wind speed instead of regression analysis.

  11. UNIVERSITY of CALIFORNIA INVESTIGATION OF HOW ANGLE OF ATTACK AFFECTS ROTOR SPEED

    E-Print Network [OSTI]

    Belanger, David P.

    -pitch blades is tested in UCSC's wind tunnel. The turbine is used to test how varying the blade angle affects the turbine's rotational speed at different wind speeds. The data are used to determine how the blade angle 27 Appendix A Wind Turbine Data 29 Appendix B Converting Blade Pitch to Needle Angle 33 Appendix C

  12. Numeric-modeling sensitivity analysis of the performance of wind turbine arrays

    SciTech Connect (OSTI)

    Lissaman, P.B.S.; Gyatt, G.W.; Zalay, A.D.

    1982-06-01T23:59:59.000Z

    An evaluation of the numerical model created by Lissaman for predicting the performance of wind turbine arrays has been made. Model predictions of the wake parameters have been compared with both full-scale and wind tunnel measurements. Only limited, full-scale data were available, while wind tunnel studies showed difficulties in representing real meteorological conditions. Nevertheless, several modifications and additions have been made to the model using both theoretical and empirical techniques and the new model shows good correlation with experiment. The larger wake growth rate and shorter near wake length predicted by the new model lead to reduced interference effects on downstream turbines and hence greater array efficiencies. The array model has also been re-examined and now incorporates the ability to show the effects of real meteorological conditions such as variations in wind speed and unsteady winds. The resulting computer code has been run to show the sensitivity of array performance to meteorological, machine, and array parameters. Ambient turbulence and windwise spacing are shown to dominate, while hub height ratio is seen to be relatively unimportant. Finally, a detailed analysis of the Goodnoe Hills wind farm in Washington has been made to show how power output can be expected to vary with ambient turbulence, wind speed, and wind direction.

  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. Wächter ForWind-Center for Wind

  14. Coastal Ohio Wind Project for Reduced Barriers to Deployment of Offshore Wind Energy

    SciTech Connect (OSTI)

    Gorsevski, Peter; Afjeh, Abdollah; Jamali, Mohsin; Carroll, Michael

    2014-04-09T23:59:59.000Z

    The Coastal Ohio Wind Project was created to establish the viability of wind turbines on the coastal and offshore regions of Northern Ohio. The project’s main goal was to improve operational unit strategies used for environmental impact assessment of offshore turbines on lake wildlife by optimizing and fusing data from the multi-instrument surveillance system and providing an engineering analysis of potential design/operational alternatives for offshore wind turbines. The project also developed a general economic model for offshore WTG deployment to quantify potential revenue losses due to wind turbine shutdown related to ice and avian issues. In a previous phase of this project (Award Number: DE-FG36-06GO86096), we developed a surveillance system that was used to collect different parameters such as passage rates, flight paths, flight directions, and flight altitudes of nocturnal migrating species, movements of birds and bats, and bird calls for assessing patterns and peak passage rates during migration. To derive such parameters we used thermal IR imaging cameras, acoustic recorders, and marine radar Furuno (XANK250), which was coupled with a XIR3000B digitizing card from Russell Technologies and open source radR processing software. The integration yielded a development of different computational techniques and methods, which we further developed and optimized as a combined surveillance system. To accomplish this task we implemented marine radar calibration, optimization of processing parameters, and fusion of the multi-sensor data in order to make inferences about the potential avian targets. The main goal of the data fusion from the multi-sensor environment was aimed at reduction of uncertainties while providing acceptable confidence levels with detailed information about the migration patterns. Another component comprised of an assessment of wind resources in a near lake environment and an investigation of the effectiveness of ice coating materials to mitigate adverse effects of ice formation on wind turbine structures. Firstly, a Zephir LiDAR system was acquired and installed at Woodlands School in Huron, Ohio, which is located near Lake Erie. Wind resource data were obtained at ten measurement heights, 200m, 150m, 100m, 80m, 60m, 40m, 38m, 30m, 20m, and 10m. The Woodlands School’s wind turbine anemometer also measured the wind speed at the hub height. These data were collected for approximately one year. The hub anemometer data correlated well with the LiDAR wind speed measurements at the same height. The data also showed that on several days different power levels were recorded by the turbine at the same wind speed as indicated by the hub anemometer. The corresponding LiDAR data showed that this difference can be attributed to variability in the wind over the turbine rotor swept area, which the hub anemometer could not detect. The observation suggests that single point hub wind velocity measurements are inadequate to accurately estimate the power generated by a turbine at all times since the hub wind speed is not a good indicator of the wind speed over the turbine rotor swept area when winds are changing rapidly. To assess the effectiveness of ice coatings to mitigate the impact of ice on turbine structures, a closed-loop icing research tunnel (IRT) was designed and constructed. By controlling the temperature, air speed, water content and liquid droplet size, the tunnel enabled consistent and repeatable ice accretion under a variety of conditions with temperatures between approximately 0°C and -20°C and wind speeds up to 40 miles per hour in the tunnel’s test section. The tunnel’s cooling unit maintained the tunnel temperature within ±0.2°C. The coatings evaluated in the study were Boyd Coatings Research Company’s CRC6040R3, MicroPhase Coatings Inc.’s PhaseBreak TP, ESL and Flex coatings. Similar overall performance was observed in all coatings tested in that water droplets form on the test articles beginning at the stagnation region and spreading in the downstream direction in time. When compari

  15. Dust Detection by the Wave Instrument on STEREO: Nanoparticles Picked up by the Solar Wind?

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    2007, Basics of the Solar Wind, Cambridge University Press,Picked up by the Solar Wind? N. Meyer-Vernet · M. Maksimovicof magnitude of the solar wind speed. Nanoparticles, which

  16. Ris-R-1182(EN) Equalizing Effects of the Wind Energy

    E-Print Network [OSTI]

    Risø-R-1182(EN) Equalizing Effects of the Wind Energy Production in Northern Europe Determined from in time were used. The methodology to get a common wind energy production from reanalysis wind speeds

  17. Robust model based control method for wind energy production A. Pintea 1

    E-Print Network [OSTI]

    Boyer, Edmond

    - linear form on the wind speed, the rotation speed of the turbine and the pitch angle of the blades based control algorithm for a horizontal wind turbine is proposed. In a model-based control approach system. Keywords: Wind power, robustness, IMC, stability, turbine, pitch control. 1. INTRODUCTION Wind

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

    SciTech Connect (OSTI)

    Vaught, Douglas J.

    2007-03-31T23:59:59.000Z

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

  19. Pitfalls of modeling wind power using Markov chains

    E-Print Network [OSTI]

    Kirtley, James L., Jr.

    An increased penetration of wind turbines have given rise to a need for wind speed/power models that generate realistic synthetic data. Such data, for example, might be used in simulations to size energy storage or spinning ...

  20. air gap windings: Topics by E-print Network

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

    produced vs NOAA wind data. Issue: too much scatter. Hourly Turbine Power vs. Wind Speed (On-site) 0 10 20 30... Haberl, J.; Yazdani, B.; Culp, C. 40 AIR-SEA INTERACTIONS FROM...

  1. Dynamic Simulation of DFIG Wind Turbines on FPGA Boards

    E-Print Network [OSTI]

    Zambreno, Joseph A.

    Dynamic Simulation of DFIG Wind Turbines on FPGA Boards Hao Chen, Student Member, IEEE, Song Sun is a friction coefficient. The wind turbine model is based on the relation between the upstream wind speed V w + 1 where p is the air density; Rw is the wind turbine radius; cp (A, (3) is the performance

  2. Cambridge Danehy Park Wind Turbine Preliminary Project Assessment

    E-Print Network [OSTI]

    Cambridge Danehy Park Wind Turbine Preliminary Project Assessment Overview MIT Wind Energy Projects 4 / 25 2.5 / 25 Rated Wind Speed (m/s) 13 10 14.5 ~15 12 The above turbines were chosen to provide, several recent studies examining birds and wind turbines have observed that most birds usually avoid

  3. Ris National Laboratory Satellite SAR applied in offshore wind

    E-Print Network [OSTI]

    Risø National Laboratory Satellite SAR applied in offshore wind ressource mapping: possibilities is to quantify the regional offshore wind climate for wind energy application based on satellite SAR ·Study of 85SAR(m/s) Hasager, Dellwik, Nielsen and Furevik, 2004, Validation of ERS-2 SAR offshore wind-speed maps

  4. RisR1238(EN) Extreme Winds over Denmark

    E-Print Network [OSTI]

    Risø­R­1238(EN) Extreme Winds over Denmark from the NCEP/NCAR Reanalysis Helmut P. Frank Wind Energy Department Risø National Laboratory Roskilde, Denmark E-mail: helmut.frank@risoe.dk Risø National Laboratory, Roskilde, Denmark May 2001 #12;Abstract An extreme wind analysis of wind speed calculated

  5. Analysis of wind turbine vibrations based on SCADA data

    E-Print Network [OSTI]

    Andrew Kusiak; Zijun Zhang

    2010-01-01T23:59:59.000Z

    Vibrations of a wind turbine have a negative impact on its performance. Mitigating this undesirable impact requires knowledge of the relationship between the vibrations and other wind turbine parameters that could be potentially modified. Three approaches for ranking the impact importance of measurable turbine parameters on the vibrations of the drive train and the tower are discussed. They include the predictor importance analysis, the global sensitivity analysis, and the correlation coefficient analysis versed in data mining and statistics. To decouple the impact of wind speed on the vibrations of the drive train and the tower, the analysis is performed on data sets with narrow speed ranges. Wavelet analysis is applied to filter noisy accelerometer data. To exclude the impact malfunctions on the vibration analysis, the data are analyzed in a frequency domain. Data-mining algorithms are used to build models with turbine parameters of interest as inputs, and the vibrations of drive train and tower as outputs. The performance of each model is thoroughly evaluated based on metrics widely used in the wind industry. The neural network algorithm outperforms other classifiers and is considered to be the most promising approach to study wind turbine vibrations. ?DOI: 10.1115/1.4001461?

  6. Concept tests: Wind tunnel tests in controlled wind Comparison tests: Free field comparison to 3D sonic anemometer

    E-Print Network [OSTI]

    comparable potential. Wind measurements on wind turbines in undisturbed wind, relative to nacelle anemometryConcept tests: Wind tunnel tests in controlled wind Comparison tests: Free field comparison to 3D" by CFD calculations Spinner AnemometrySpinner Anemometry -- An Innovative Wind Measurement Concept

  7. Low-Resolution STELab IPS 3D Reconstructions of the Whole Heliosphere Interval and Comparison with in-Ecliptic Solar Wind Measurements from STEREO and Wind Instrumentation

    E-Print Network [OSTI]

    Bisi, M. M.; Jackson, B. V.; Buffington, A.; Clover, J. M.; Hick, P. P.; Tokumaru, M.

    2009-01-01T23:59:59.000Z

    structure of the fast solar wind. J. Geophys. Res. 112,observations of the solar wind. Proc. SPIE 6689, 668911-1.W.A. , Maagoe, S. : 1972, Solar wind velocity from ips

  8. Wind Spires as an Alternative Energy Source

    SciTech Connect (OSTI)

    Majid Rashidi, Ph.D., P.E.

    2012-10-30T23:59:59.000Z

    This report discloses the design and development of an innovative wind tower system having an axisymmetric wind deflecting structure with a plurality of symmetrically mounted rooftop size wind turbines near the axisymmetric structure. The purpose of the wind deflecting structure is to increase the ambient wind speed that in turn results in an overall increase in the power capacity of the wind turbines. Two working prototypes were constructed and installed in the summer of 2009 and 2012 respectively. The system installed in the Summer of 2009 has a cylindrical wind deflecting structure, while the tower installed in 2012 has a spiral-shape wind deflecting structure. Each tower has 4 turbines, each rated at 1.65 KW Name-Plate-Rating. Before fabricating the full-size prototypes, computational fluid dynamic (CFD) analyses and scaled-down table-top models were used to predict the performance of the full-scale models. The performance results obtained from the full-size prototypes validated the results obtained from the computational models and those of the scaled-down models. The second prototype (spiral configuration) showed at a wind speed of 11 miles per hour (4.9 m/s) the power output of the system could reach 1,288 watt, when a typical turbine installation, with no wind deflecting structure, could produce only 200 watt by the same turbines at the same wind speed. At a wind speed of 18 miles per hour (8 m/sec), the spiral prototype produces 6,143 watt, while the power generated by the same turbines would be 1,412 watt in the absence of a wind deflecting structure under the same wind speed. Four US patents were allowed, and are in print, as the results of this project (US 7,540,706, US 7,679,209, US 7,845,904, and US 8,002,516).

  9. South Carolina Opens Nation's Largest Wind Drivetrain Testing...

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

    the facility will help test and validate new turbines, particularly for offshore wind-helping to speed deployment of next generation energy technology, reduce costs for...

  10. South Carolina Opens Nation's Largest Wind Drivetrain Testing...

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

    The facility will help test and validate new turbines, particularly for offshore wind- helping to speed deployment of next generation energy technology, reduce costs for...

  11. average wind shear: Topics by E-print Network

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

    by uncompensated voids. Maria Mattsson; Teppo Mattsson 2010-07-17 7 Probabilistic Wind Speed Forecasting using Ensembles and Bayesian Model Averaging Mathematics Websites Summary:...

  12. Wind Power Plant Voltage Stability Evaluation: Preprint

    SciTech Connect (OSTI)

    Muljadi, E.; Zhang, Y. C.

    2014-09-01T23:59:59.000Z

    Voltage stability refers to the ability of a power system to maintain steady voltages at all buses in the system after being subjected to a disturbance from a given initial operating condition. Voltage stability depends on a power system's ability to maintain and/or restore equilibrium between load demand and supply. Instability that may result occurs in the form of a progressive fall or rise of voltages of some buses. Possible outcomes of voltage instability are the loss of load in an area or tripped transmission lines and other elements by their protective systems, which may lead to cascading outages. The loss of synchronism of some generators may result from these outages or from operating conditions that violate a synchronous generator's field current limit, or in the case of variable speed wind turbine generator, the current limits of power switches. This paper investigates the impact of wind power plants on power system voltage stability by using synchrophasor measurements.

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

    E-Print Network [OSTI]

    Wiser, Ryan H

    2008-01-01T23:59:59.000Z

    value of re- newable electricity; and customer surveys ofCalifornia or Northwestern electricity demand. This may bebetween wind speed and electricity demand," Solar Energy,

  14. 915-MHz Radar Wind Profiler (915RWP) Handbook

    SciTech Connect (OSTI)

    Coulter, R

    2005-01-01T23:59:59.000Z

    The 915 MHz radar wind profiler/radio acoustic sounding system (RWP/RASS) measures wind profiles and backscattered signal strength between (nominally) 0.1 km and 5 km and virtual temperature profiles between 0.1 km and 2.5 km. It operates by transmitting electromagnetic energy into the atmosphere and measuring the strength and frequency of backscattered energy. Virtual temperatures are recovered by transmitting an acoustic signal vertically and measuring the electromagnetic energy scattered from the acoustic wavefront. Because the propagation speed of the acoustic wave is proportional to the square root of the virtual temperature of the air, the virtual temperature can be recovered by measuring the Doppler shift of the scattered electromagnetic wave.

  15. Review of Wind Energy Forecasting Methods for Modeling Ramping Events

    SciTech Connect (OSTI)

    Wharton, S; Lundquist, J K; Marjanovic, N; Williams, J L; Rhodes, M; Chow, T K; Maxwell, R

    2011-03-28T23:59:59.000Z

    Tall onshore wind turbines, with hub heights between 80 m and 100 m, can extract large amounts of energy from the atmosphere since they generally encounter higher wind speeds, but they face challenges given the complexity of boundary layer flows. This complexity of the lowest layers of the atmosphere, where wind turbines reside, has made conventional modeling efforts less than ideal. To meet the nation's goal of increasing wind power into the U.S. electrical grid, the accuracy of wind power forecasts must be improved. In this report, the Lawrence Livermore National Laboratory, in collaboration with the University of Colorado at Boulder, University of California at Berkeley, and Colorado School of Mines, evaluates innovative approaches to forecasting sudden changes in wind speed or 'ramping events' at an onshore, multimegawatt wind farm. The forecast simulations are compared to observations of wind speed and direction from tall meteorological towers and a remote-sensing Sound Detection and Ranging (SODAR) instrument. Ramping events, i.e., sudden increases or decreases in wind speed and hence, power generated by a turbine, are especially problematic for wind farm operators. Sudden changes in wind speed or direction can lead to large power generation differences across a wind farm and are very difficult to predict with current forecasting tools. Here, we quantify the ability of three models, mesoscale WRF, WRF-LES, and PF.WRF, which vary in sophistication and required user expertise, to predict three ramping events at a North American wind farm.

  16. 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...

  17. Wind/Hybrid Electricity Applications

    SciTech Connect (OSTI)

    McDaniel, Lori

    2001-03-31T23:59:59.000Z

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

  18. MEASUREMENT AND CORRECTION OF ULTRASONIC ANEMOMETER ERRORS

    E-Print Network [OSTI]

    Heinemann, Detlev

    commonly show systematic errors depending on wind speed due to inaccurate ultrasonic transducer mounting three- dimensional wind speed time series. Results for the variance and power spectra are shown. 1 wind speeds with ultrasonic anemometers: The measu- red flow is distorted by the probe head

  19. WIND/RAIN BACKSCATTER MODELING AND WIND/RAIN RETRIEVAL FOR SCATTEROMETER AND

    E-Print Network [OSTI]

    Long, David G.

    WIND/RAIN BACKSCATTER MODELING AND WIND/RAIN RETRIEVAL FOR SCATTEROMETER AND SYNTHETIC APERTURE. Fulton College of Engineering and Technology #12;#12;ABSTRACT WIND/RAIN BACKSCATTER MODELING AND WIND- surements, and numerical predicted wind fields (ECMWF), the sensitivity of C-band backscatter measurement

  20. The dominant X-ray wind in massive star binaries

    E-Print Network [OSTI]

    J. M. Pittard; I. R. Stevens

    2002-04-15T23:59:59.000Z

    We investigate which shocked wind is responsible for the majority of the X-ray emission in colliding wind binaries, an issue where there is some confusion in the literature, and which we show is more complicated than has been assumed. We find that where both winds rapidly cool (typically close binaries), the ratio of the wind speeds is often more important than the momentum ratio, because it controls the energy flux ratio, and the faster wind is generally the dominant emitter. When both winds are largely adiabatic (typically long-period binaries), the slower and denser wind will cool faster and the stronger wind generally dominates the X-ray luminosity.

  1. air speed indicators: Topics by E-print Network

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

    A; Rozelot, J P; 10.10880004-637X727144 2011-01-01 6 High speed air pneumatic wind shield wiping design MIT - DSpace Summary: In this creative design process a number of...

  2. High-Speed Shaft Bearing Loads Testing and Modeling in the NREL Gearbox Reliability Collaborative: Preprint

    SciTech Connect (OSTI)

    McNiff, B.; Guo, Y.; Keller, J.; Sethuraman, L.

    2014-12-01T23:59:59.000Z

    Bearing failures in the high speed output stage of the gearbox are plaguing the wind turbine industry. Accordingly, the National Renewable Energy Laboratory (NREL) Gearbox Reliability Collaborative (GRC) has performed an experimental and theoretical investigation of loads within these bearings. The purpose of this paper is to describe the instrumentation, calibrations, data post-processing and initial results from this testing and modeling effort. Measured HSS torque, bending, and bearing loads are related to model predictions. Of additional interest is examining if the shaft measurements can be simply related to bearing load measurements, eliminating the need for invasive modifications of the bearing races for such instrumentation.

  3. SPRING 2014 wind energy's impact

    E-Print Network [OSTI]

    Tullos, Desiree

    SPRING 2014 wind energy's impact on birds, bats......... 2-3 school news........... 4-5 alumni news measurable benefits reaped by the use of wind energy. But, it is a fact: all energy sources, alternative Interactions with Offshore Wind Energy Facilities," involves the design, deployment and testing

  4. Field Wind Tunnel Assessment of the Potential for Wind Transport of Soils

    SciTech Connect (OSTI)

    Lancaster, Nicholas [Desert Research Inst. (DRI), Reno, NV (United States); Metzger, Steve [Desert Research Inst. (DRI), Reno, NV (United States)

    2005-02-01T23:59:59.000Z

    This report documents a series of field experiments carried out in the Double Tracks area of the Tonopah Test Range in June, July, and August 1996 and March and July 1997. The aim of the experiments was to: (1) determine the wind speeds necessary to entrain surface particles from excavated surfaces in the study area and (2) determine dust emissions from surfaces that had been stabilized permanently by planted natural vegetation. This investigation assessed the potential for wind transport of surface soils, including resuspension and emission of dust sized particles from areas of surface heavy metal contamination, following site remediation, as well as the actual emissions from these areas. The remediation site is located in Area 73 of the Tonopah Test Range. The goal of the field experiments was to measure the velocities with which boundary layer winds might initiate dust emissions from the affected site, and to gage the effectiveness of surface stabilization procedures to prevent such emissions. Particle movement measurements were generated through the use of a portable wind tunnel laid directly on the excavated surface.

  5. Abstract--This paper addresses the problem of controlling wind energy conversion systems (WECS) which involve

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Abstract-- This paper addresses the problem of controlling wind energy conversion systems (WECS-inverter. The goal of control is to maximize wind energy extraction and this needs letting the wind turbine rotor wind energy extraction) only for one wind speed value depending on the considered value of turbine

  6. Prediction, operations, and condition monitoring in wind energy Andrew Kusiak a,*, Zijun Zhang b

    E-Print Network [OSTI]

    Kusiak, Andrew

    Review Prediction, operations, and condition monitoring in wind energy Andrew Kusiak a,*, Zijun 2013 Available online 23 August 2013 Keywords: Wind energy Wind speed prediction Wind turbine control Condition monitoring and fault detection a b s t r a c t Recent developments in wind energy research

  7. Systems Performance Analyses of Alaska Wind-Diesel Projects; Kotzebue, Alaska (Fact Sheet)

    SciTech Connect (OSTI)

    Baring-Gould, I.

    2009-04-01T23:59:59.000Z

    This fact sheet summarizes a systems performance analysis of the wind-diesel project in Kotzebue, Alaska. Data provided for this project include wind turbine output, average wind speed, average net capacity factor, and optimal net capacity factor based on Alaska Energy Authority wind data, estimated fuel savings, and wind system availability.

  8. 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

  9. Time-domain Fatigue Response and Reliability Analysis of Offshore Wind Turbines with

    E-Print Network [OSTI]

    Nørvåg, Kjetil

    Time-domain Fatigue Response and Reliability Analysis of Offshore Wind Turbines with Emphasis of offshore wind turbines Defense: 09.12.2012 2012 - : Structural Engineer in Det Norske Veritas (DNV) 2007 and higher wind speed, and less visual disturbance and noise for offshore wind energy. Offshore wind

  10. Assessing the local wind field at Sierra Grande Mountain in New Mexico with instrumentation

    SciTech Connect (OSTI)

    Barnett, K.M.; Reynolds, R.D.

    1981-05-01T23:59:59.000Z

    Six systems were installed on top of Sierra Grande, a nearly symmetrical mountain in New Mexico about halfway between Raton and Clayton, with a peak of 2659 m (8720 ft msl) standing over a wide mesa of approximately 1829 m (6000 ft msl). Two systems were on the peak, one at 10 m (33 ft) above the surface and the other at 20 m (66 ft) because the peak is often the most probable spot for the greatest wind energy. The two levels were needed to measure variations of speed with height. Four other systems with instruments at 10-m (33 ft) were located roughly north, east, south, and west from the center on secondary ridge lines to measure certain horizontal variations of the wind. The wind direction and speed were measured every 6 minutes, a time interval considerably shorter than the traditional 1 hour but long enough so that all WECS power outputs are expected to respond to these wind speed variations. All six systems were operated for a period of six months between 6 June 1979-5 December 1979.

  11. Interfacial temperature measurements, high-speed visualization and finite-element simulations of droplet impact and evaporation on a solid surface

    E-Print Network [OSTI]

    Bhardwaj, Rajneesh; Attinger, Daniel

    2010-01-01T23:59:59.000Z

    The objective of this work is to investigate the coupling of fluid dynamics, heat transfer and mass transfer during the impact and evaporation of droplets on a heated solid substrate. A laser-based thermoreflectance method is used to measure the temperature at the solid-liquid interface, with a time and space resolution of 100 {\\mu}s and 20 {\\mu}m, respectively. Isopropanol droplets with micro- and nanoliter volumes are considered. A finite-element model is used to simulate the transient fluid dynamics and heat transfer during the droplet deposition process, considering the dynamics of wetting as well as Laplace and Marangoni stresses on the liquid-gas boundary. For cases involving evaporation, the diffusion of vapor in the atmosphere is solved numerically, providing an exact boundary condition for the evaporative flux at the droplet-air interface. High-speed visualizations are performed to provide matching parameters for the wetting model used in the simulations. Numerical and experimental results are compar...

  12. Application of the AC Commutator Machine in Wind Energy Conversion Systems

    E-Print Network [OSTI]

    El-Jamous, Sami Georges

    1981-01-01T23:59:59.000Z

    OF C~ Page ABSTRACT DEDICATION iV LIST OF TABLES LIST OF FIGURES A SURVEY OF THE LITJRATURE Constant Speed Constant Frequency Systems (CSCF) Variable Speed Constant Frequency Systems (VSCF) BASIC THEORY OF WIND TURBINES Classification...] 57 59 61 21. Power, P snd torque, T /rotational speed curves for P P different wind speeds [1] 63 22. Torque-speed curves of the turbine for different wind speeds V 23. Torque-speed curves with shunt ACCG 24. Connection of the shunt ACCG...

  13. 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

  14. The solar wind in the outer heliosphere

    E-Print Network [OSTI]

    Richardson, John D.

    The solar wind evolves as it moves outward due to interactions with both itself and with the circum-heliospheric interstellar medium. The speed is, on average, constant out to 30 AU, then starts a slow decrease due to the ...

  15. Wind extremes in the North Sea Basin under climate change: An ensemble study of 12 CMIP5 GCMs

    E-Print Network [OSTI]

    Haak, Hein

    Wind extremes in the North Sea Basin under climate change: An ensemble study of 12 CMIP5 GCMs R. C levels and waves are generated by low atmospheric pressure and severe wind speeds during storm events. As a result of the geometry of the North Sea, not only the maximum wind speed is relevant, but also wind

  16. Forest impact estimated with NOAA AVHRR and Landsat TM data related to an empirical hurricane wind-field distribution

    E-Print Network [OSTI]

    Hodgson, Michael E.

    with Hurricane Andrew in 1992. The wind-field model projected that the highest wind speeds were in the southernForest impact estimated with NOAA AVHRR and Landsat TM data related to an empirical hurricane wind to relate forest type and hurricane-impact distribution with wind speed and duration to explain

  17. WindTurbineGenerator Introduction of the Renewable Micro-Grid Test-Bed

    E-Print Network [OSTI]

    Johnson, Eric E.

    Simulator Wind Turbine: PMSM, 3kW, 8.3A Wind Generator: PMSM, 3kW, 8.3A 3 AC/DC Converter & DC/AC Inverter Wind Turbine: Torque or Speed Control Wind Generator: PQ Control Cubicle #4: Energy Storage Generator #1 3kW, 8.3A Wind Turbine #1 3kW, 8.3A Wind Turbine #2 3kW Wind Generator #2 3kW RS232

  18. Economic Impacts of Wind Turbine Development in U.S. Counties

    E-Print Network [OSTI]

    J., Brown

    2012-01-01T23:59:59.000Z

    15 percent)). Cumulative wind turbine capacity installed inper capita income of wind turbine development (measured inour sample, cumulative wind turbine capacity on a per person

  19. 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).

  20. Wind resource and site assessment in the German Bight: Extreme Winds at Meso-to Microscale

    E-Print Network [OSTI]

    Heinemann, Detlev

    in the offshore wind farms. In the following, the validated Weather Research and Forecast (WRF) model simulations resolution which resolves sites of the individual offshore wind farms. In addition, the FINO-1 measurements of offshore wind farms, where in-situ measurements are scarce and expensive, the validated mesoscale wind