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Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

LIDAR wind speed measurements of evolving wind fields  

E-Print Network (OSTI)

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. Simulation results show the combined effects of LIDAR errors and wind evolution for realistic turbine-mounted LIDAR measurement scenarios. Nomenclature a decay parameter for exponential coherence al decrement parameter for transverse coherence (l ? {u, v, w}) bl offset parameter for transverse coherence (l ? {u, v, w}) D longitudinal distance between two points or measurement preview distance F focal distance f frequency (Hz) ? LIDAR measurement angle off of longitudinal direction k wind velocity wavenumber (m?1) ? wavelength (m) R range along LIDAR beam r scan radius for spinning LIDAR scenario ri,j distance between two points in the yz plane U mean wind speed (m/s) ?i,j average mean wind speed between two points in the yz plane ? azimuth angle in the rotor plane ?2 xy(f) Coherence between signals x and y

Eric Simley; Lucy Y. Pao; Neil Kelley; Bonnie Jonkman; Rod Frehlich

2012-01-01T23:59:59.000Z

2

LIDAR Wind Speed Measurements of Evolving Wind Fields  

DOE Green Energy (OSTI)

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.

Simley, E.; Pao, L. Y.

2012-07-01T23:59:59.000Z

3

LIDAR Wind Speed Measurements of Evolving Wind Fields  

SciTech Connect

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.

Simley, E.; Pao, L. Y.

2012-07-01T23:59:59.000Z

4

LIDAR Wind Speed Measurements of Evolving Wind Fields  

Science Conference Proceedings (OSTI)

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 that are 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 the validity of physicist G.I. Taylor's 1938 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 using the National Renewable Energy Laboratory's (NREL's) 5-megawatt turbine model to create a more realistic measurement model. A simple model of wind evolution was applied to a frozen wind field that was used in previous studies to investigate the effects of varying the intensity of wind evolution. LIDAR measurements were also evaluated using a large eddy simulation (LES) of a stable boundary layer that was provided by the National Center for Atmospheric Research. The LIDAR measurement scenario investigated consists of a hub-mounted LIDAR that scans a circle of points upwind of the turbine in order to estimate the wind speed component in the mean wind direction. Different combinations of the preview distance that is located upwind of the rotor and the radius of the scan circle were analyzed. It was found that the dominant source of measurement error for short preview distances is the detection of transverse and vertical wind speeds from the line-of-sight LIDAR measurement. It was discovered in previous studies that, in the absence of wind evolution, the dominant source of error for large preview distances is the spatial averaging caused by the LIDAR's sampling volume. However, by introducing wind evolution, the dominant source of error for large preview distances was found to be the coherence loss caused by evolving turbulence. Different measurement geometries were compared using the bandwidth for which the measurement coherence remained above 0.5 and also the area under the measurement coherence curve. Results showed that, by increasing the intensity of wind evolution, the measurement coherence decreases. Using the coherence bandwidth metric, the optimal preview distance for a fixed-scan radius remained almost constant for low and moderate amounts of wind evolution. For the wind field with the simple wind evolution model introduced, the optimal preview distance for a scan radius of 75% blade span (47.25 meters) was found to be 80 meters. Using the LES wind field, the optimal preview distance was 65 meters. When comparing scan geometries using the area under the coherence curve, results showed that, as the intensity of wind evolution increases, the optimal preview distance decreases.

Simley, E.; Pao, L. Y.; Kelley, N.; Jonkman, B.; Frehlich, R.

2012-01-01T23:59:59.000Z

5

Wind Speeds at Heights Crucial for Wind Energy: Measurements and Verification of Forecasts  

Science Conference Proceedings (OSTI)

Wind speed measurements from one year from meteorological towers and wind turbines at heights between 20 and 250 m for various European sites are analyzed and are compared with operational short-term forecasts of the global ECMWF model. The ...

Susanne Drechsel; Georg J. Mayr; Jakob W. Messner; Reto Stauffer

2012-09-01T23:59:59.000Z

6

A Technique for Deducing Wind Direction from Satellite Microwave Measurements of Wind Speed  

Science Conference Proceedings (OSTI)

A technique is presented to deduce wind direction from satellite microwave measurements of wind speed information. The technique, based on simple Ekman boundary layer dynamics, makes use of surface pressure fields routinely analyzed at the ...

Tsann-wang Yu

1987-09-01T23:59:59.000Z

7

Analysis of Wind Speed Measurements using Continuous Wave LIDAR for Wind Turbine Control ?†  

E-Print Network (OSTI)

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 accurate the incoming wind field can be measured. This study examines the accuracy of different measurement scenarios that rely on coherent continuouswave Doppler LIDAR systems to determine their applicability to feedforward 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. Nomenclature d measurement preview distance F focal distance k wind velocity wavenumber (m?1) r scan radius for spinning LIDAR RMS root mean square ?u standard deviation of u component of wind velocity TI turbulence intensity ? LIDAR measurement angle ? mean u wind speed u ? friction velocity U ? D average friction velocity over rotor disk ? angle between laser and wind velocity vector ? angle in the rotor plane ? rotational rate of spinning LIDAR

Eric Simley; Lucy Y. Pao; Rod Frehlich; Bonnie Jonkman; Neil Kelley

2011-01-01T23:59:59.000Z

8

Measurement strategies for estimating long-term average wind speeds  

DOE Green Energy (OSTI)

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.

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

1980-10-01T23:59:59.000Z

9

Extreme Wind Speeds: Publications  

Science Conference Proceedings (OSTI)

... "Algorithms for Generating Large Sets of Synthetic Directional Wind Speed Data for Hurricane, Thunderstorm, and Synoptic Winds," NIST Technical ...

2013-08-19T23:59:59.000Z

10

Evaluation Of Models For The Vertical Extrapolation Of Wind Speed Measurements At Offshore Sites  

E-Print Network (OSTI)

Monin-Obukhov theory predicts the well-known log-linear form of the vertical wind speed profile. Two parameters, namely the aerodynamic surface roughness length and the Monin-Obukhov-length, are needed to predict the vertical wind speed profile from a measurement at one height. Different models to estimate these parameters for conditions important for offshore wind energy utilisation are discussed and tested: Four models for the surface roughness and three methods to derive the Monin-Obukov-length from measurements are compared. They have been tested with data from the offshore field measurement Rdsand by extrapolating the measured 10 m wind speed to 50 m height and comparing it with the measured 50 m wind speed. The mean

Bernhard Lange; Jřrgen Hřjstrup; Sřren Larsen; Rebecca Barthelmie

2001-01-01T23:59:59.000Z

11

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

E-Print Network (OSTI)

Steady decline of east Asian monsoon winds, 1969­2000: Evidence from direct ground measurements winter monsoon but strengthen the summer monsoon, because of stronger warming over high-latitude land with the east Asian monsoon has significantly weakened in both winter and summer in the recent three decades

Chang, Chih-Pei

12

The Determination of Surface-Layer Stability and Eddy Fluxes Using Wind Speed and Vertical Temperature Gradient Measurements  

Science Conference Proceedings (OSTI)

Analytical relations are developed that relate the Monin-Obukhov parameter to a modified bulk Richardson number expressed in terms of measured wind speed and vertical temperature difference. Measured Monin-Obukhov parameters and Richardson ...

I. T. Wang

1981-10-01T23:59:59.000Z

13

Forecasting Solar Wind Speeds  

E-Print Network (OSTI)

By explicitly taking into account effects of Alfven waves, I derive from a simple energetics argument a fundamental relation which predicts solar wind (SW) speeds in the vicinity of the earth from physical properties on the sun. Kojima et al. recently found from their observations that a ratio of surface magnetic field strength to an expansion factor of open magnetic flux tubes is a good indicator of the SW speed. I show by using the derived relation that this nice correlation is an evidence of the Alfven wave which accelerates SW in expanding flux tubes. The observations further require that fluctuation amplitudes of magnetic field lines at the surface should be almost universal in different coronal holes, which needs to be tested by future observations.

Takeru K. Suzuki

2006-02-03T23:59:59.000Z

14

wind speed | OpenEI  

Open Energy Info (EERE)

speed speed Dataset Summary Description GIS data for offshore wind speed (meters/second). Specified to Exclusive Economic Zones (EEZ).Wind resource based on NOAA blended sea winds and monthly wind speed at 30km resolution, using a 0.11 wind sheer to extrapolate 10m - 90m. Annual average >= 10 months of data, no nulls. Source National Renewable Energy Laboratory (NREL) Date Released Unknown Date Updated Unknown Keywords GIS global NOAA NREL offshore wind wind speed Data application/zip icon Download Shapefile (zip, 18.5 MiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period License License Other or unspecified, see optional comment below Comment Please cite NREL and NOAA Rate this dataset Usefulness of the metadata

15

OpenEI - wind speed  

Open Energy Info (EERE)

NREL GIS Data: Global NREL GIS Data: Global Offshore Wind http://en.openei.org/datasets/node/869 GIS data for offshore wind speed (meters/second).  Specified to Exclusive Economic Zones (EEZ).Wind resource based on NOAA blended sea winds and monthly wind speed at 30km resolution, using a 0.11 wind sheer to extrapolate 10m - 90m.  Annual average  >= 10 months of data, no nulls. License

Type of License:  Other (please specify below)

16

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

SciTech Connect

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.

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

2011-10-01T23:59:59.000Z

17

Choosing wind power plant locations and sizes based on electric reliability measures using multiple-year wind speed measurements  

DOE Green Energy (OSTI)

To project the US potential to meet future electricity demands with wind energy, estimates of available wind resource and costs to access that resource are critical. The US Department of Energy (DOE) Energy Information Administration (EIA) annually estimates the US market penetration of wind in its Annual Energy Outlook series. For these estimates, the EIA uses wind resource data developed by the Pacific Northwest National Laboratory for each region of the country. However, the EIA multiplies the cost of windpower by several factors, some as large as 3, to account for resource quality, market factors associated with accessing the resource, electric grid impacts, and rapid growth in the wind industry. This paper examines the rationale behind these additional costs and suggests alternatives.

Milligan, M.R.; Artig, R.

1999-07-08T23:59:59.000Z

18

The Wind Speed Profile At Offshore Wind Farm Sites  

E-Print Network (OSTI)

Using Monin-Obukhov theory the vertical wind speed profile can be predicted from the wind speed at one height, when the two parameters Monin-Obukhov length and sea surface roughness are known. The applicability of this theory for wind power prediction at offshore sites is investigated using data from the measurement program Rdsand in the Danish Baltic Sea. Different methods to estimate the two parameters are discussed and compared. Significant deviations to the theory are found for near-neutral and stable conditions, where the measured wind shear is larger than predicted. A simple correction method to account for this effect has been developed and tested.

Bernhard Lange Sren; Bernhard Lange; Sřren E. Larsen; Jřrgen Hřjstrup; Rebecca Barthelmie

2002-01-01T23:59:59.000Z

19

Virtual Wind Speed Sensor for Wind Turbines Andrew Kusiak1  

E-Print Network (OSTI)

Virtual Wind Speed Sensor for Wind Turbines Andrew Kusiak1 ; Haiyang Zheng2 ; and Zijun Zhang3 Abstract: A data-driven approach for development of a virtual wind-speed sensor for wind turbines is presented. The virtual wind-speed sensor is built from historical wind-farm data by data-mining algorithms

Kusiak, Andrew

20

Discussion of “Ultimate Wind Load Design Gust Wind Speeds ...  

Science Conference Proceedings (OSTI)

... Ind. Aerodyn., 97(3–4), 120–131. Peterka, JA (2001). “Database of peak gust wind speeds, Texas Tech/ CSU.” Extreme winds and wind effects on ...

2013-08-19T23:59:59.000Z

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Surface wind speed distributions| Implications for climate and wind power.  

E-Print Network (OSTI)

?? Surface constituent and energy fluxes, and wind power depend non-linearly on wind speed and are sensitive to the tails of the wind distribution. Until… (more)

Capps, Scott Blair

2010-01-01T23:59:59.000Z

22

Numerical wind speed simulation model  

DOE Green Energy (OSTI)

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.

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

1981-09-01T23:59:59.000Z

23

Wind Speed Forecasting for Power System Operation  

E-Print Network (OSTI)

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 operation in terms of the efficiency of the system. The goal of this dissertation is to develop advanced statistical wind speed predictive models to reduce the uncertainties in wind, especially the short-term future wind speed. Moreover, a criterion is proposed to evaluate the performance of models. Cost reduction in power system operation, as proposed, is more realistic than prevalent criteria, such as, root mean square error (RMSE) and absolute mean error (MAE). Two advanced space-time statistical models are introduced for short-term wind speed forecasting. One is a modified regime-switching, space-time wind speed fore- casting model, which allows the forecast regimes to vary according to the dominant wind direction and seasons. Thus, it avoids a subjective choice of regimes. The other one is a novel model that incorporates a new variable, geostrophic wind, which has strong influence on the surface wind, into one of the advanced space-time statistical forecasting models. This model is motivated by the lack of improvement in forecast accuracy when using air pressure and temperature directly. Using geostrophic wind in the model is not only critical, it also has a meaningful geophysical interpretation. The importance of model evaluation is emphasized in the dissertation as well. Rather than using RMSE or MAE, the performance of both wind forecasting models mentioned above are assessed by economic benefits with real wind farm data from Pacific Northwest of the U.S and West Texas. Wind forecasts are incorporated into power system economic dispatch models, and the power system operation cost is used as a loss measure for the performance of the forecasting models. From another perspective, the new criterion leads to cost-effective scheduling of system-wide wind generation with potential economic benefits arising from the system-wide generation of cost savings and ancillary services cost savings. As an illustration, the integrated forecasts and economic dispatch framework are applied to the Electric Reliability Council of Texas (ERCOT) equivalent 24- bus system. Compared with persistence and autoregressive models, the first model suggests that cost savings from integration of wind power could be on the scale of tens of millions of dollars. For the second model, numerical simulations suggest that the overall generation cost can be reduced by up to 6.6% using look-ahead dispatch coupled with spatio-temporal wind forecast as compared with dispatch with persistent wind forecast model.

Zhu, Xinxin

2013-08-01T23:59:59.000Z

24

Power quality analysis of wind generator connected to the weak grid during low wind speed  

Science Conference Proceedings (OSTI)

Power quality analysis based on measurements performed on wind generator during low wind speed is presented in the paper. Wind generator is connected via 10 kV cable to the distribution network, where grid is weak with low value of short-circuit power. ... Keywords: distribution network, harmonics, power quality, wind speed, wind turbine

Aleksandar Nikolic; Branka Kostic; Maja Markovic; Sasa Minic; Srdjan Milosavljevic

2011-07-01T23:59:59.000Z

25

United States Wind Resource Map: Annual Average Wind Speed at...  

Wind Powering America (EERE)

and atmospheric effects may cause the wind speed to depart from the map estimates. Expert advice should be sought in placing wind turbines and estimating their energy production....

26

Dual-speed wind turbine generation  

SciTech Connect

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.

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

1996-10-01T23:59:59.000Z

27

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

28

ARM - Measurement - Horizontal wind  

NLE Websites -- All DOE Office Websites (Extended Search)

govMeasurementsHorizontal wind govMeasurementsHorizontal wind ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Horizontal wind The horizontal wind in terms of either speed and direction, or the zonal (u) and meridional (v) components. Categories Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments SONDE : Balloon-Borne Sounding System CO2FLX : Carbon Dioxide Flux Measurement Systems ECOR : Eddy Correlation Flux Measurement System DISDROMETER : Impact Disdrometer

29

Echo-state-network-based real-time wind speed estimation for wind power generation  

Science Conference Proceedings (OSTI)

Wind turbine generators (WTGs) are usually equipped with one or more well-calibrated anemometers to measure wind speed for system monitoring, control, and protection. The use of these mechanical sensors increases the cost and hardware complexity and ...

Wei Qiao

2009-06-01T23:59:59.000Z

30

Ocean Wind Speed Climatology from Spaceborne SAR Imagery  

Science Conference Proceedings (OSTI)

Spaceborne synthetic aperture radar (SAR) imagery can make high-resolution (? 500 m) ocean wind speed measurements. We anticipate re-processing the full decade and a half of Radarsat-1 SAR imagery and generating a SAR wind speed archive. These data will ...

Frank M. Monaldo; Xiaofeng Li; William G. Pichel; Christopher R. Jackson

31

Joint Calibration of Multiplatform Altimeter Measurements of Wind Speed and Wave Height over the Past 20 Years  

Science Conference Proceedings (OSTI)

Since 1985, for a period of more than 23 yr, seven altimeter missions have provided global coverage of significant wave height and wind speed. This study undertakes a long-term analysis of the accuracy and stability of altimeter-derived values of ...

S. Zieger; J. Vinoth; I. R. Young

2009-12-01T23:59:59.000Z

32

Modelling the Vertical Wind Speed and Turbulence Intensity Profiles at Prospective Offshore Wind Farm Sites  

E-Print Network (OSTI)

Monin-Obukhov theory predicts the well-known log-linear form of the vertical wind speed profile. A turbulence intensity profile can be estimated from this by assuming that the standard deviation of the wind speed is proportional to the friction velocity. Two parameters, namely the aerodynamic surface roughness length and the MoninObukhov length, are than needed to predict the vertical wind speed and turbulence intensity profiles from a measurement at one height. Different models to estimate these parameters for conditions important for offshore wind energy utilisation are compared and tested: Four models for the surface roughness and three methods to derive the Monin-Obukov-length from measurements. They have been tested with data from the offshore field measurement Rdsand by extrapolating the measured 10 m wind speed to 50 m height and comparing it with the measured 50 m wind speed.

Bernhard Lange; Sřren Larsen; Jřrgen Hřjstrup; Rebecca Barthelmie; Ulrich Focken

2002-01-01T23:59:59.000Z

33

Low Wind Speed Technology Phase I: Prototype Multi-Megawatt Low Wind Speed Turbine; General Electric Wind Energy, LLC  

SciTech Connect

This fact sheet describes a subcontract with GE Wind Energy to develop an advanced prototype turbine to significantly reduce energy costs (COE) in low wind speed environments.

2006-03-01T23:59:59.000Z

34

Review of Weibull Statistics for Estimation of Wind Speed Distributions  

Science Conference Proceedings (OSTI)

A statistical distribution commonly used for describing measured wind speed data is the Weibull distribution. A review of the methods found in the statistical literature for the purpose of estimation of the parameters in Weibull distributions is ...

K. Conradsen; L. B. Nielsen; L. P. Prahm

1984-08-01T23:59:59.000Z

35

Global Estimates of Extreme Wind Speed and Wave Height  

Science Conference Proceedings (OSTI)

A long-term dataset of satellite altimeter measurements of significant wave height and wind speed, spanning 23 years, is analyzed to determine extreme values corresponding to a 100-yr return period. The analysis considers the suitability of both ...

J. Vinoth; I. R. Young

2011-03-01T23:59:59.000Z

36

Wind: wind speed and wind power density GIS data at 10m and 50m...  

Open Energy Info (EERE)

data files of wind speed and wind power density at 10 and 50 m heights. Global data of offshore wind resource as generated by NASA's QuikScat SeaWinds scatterometer.

...

37

Wind: wind speed and wind power density maps at 10m and 50m above...  

Open Energy Info (EERE)

data files of wind speed and wind power density at 10 and 50 m heights. Global data of offshore wind resource as generated by NASA's QuikSCAT SeaWinds scatterometer.

...

38

Can Wind Lidars Measure Turbulence?  

Science Conference Proceedings (OSTI)

Modeling of the systematic errors in the second-order moments of wind speeds measured by continuous-wave (ZephIR) and pulsed (WindCube) lidars is presented. These lidars use the conical scanning technique to measure the velocity field. The model ...

A. Sathe; J. Mann; J. Gottschall; M. S. Courtney

2011-07-01T23:59:59.000Z

39

Modelling and forecasting wind speed intensity for weather risk management  

Science Conference Proceedings (OSTI)

The main interest of the wind speed modelling is on the short-term forecast of wind speed intensity and direction. Recently, its relationship with electricity production by wind farms has been studied. In fact, electricity producers are interested in ... Keywords: ARFIMA-FIGARCH, Auto Regressive Gamma, Gamma Auto Regressive, Weather risk management, Wind speed modelling, Wind speed simulation

Massimiliano Caporin; Juliusz Pre

2012-11-01T23:59:59.000Z

40

Reference wind speed distributions and height profiles for wind turbine design and performance evaluation applications. [USA  

DOE Green Energy (OSTI)

The purpose of this report is to provide a set of reference or standard values of wind profiles, wind speed distributions and their effects on wind turbine performance for engineering design applications. Based on measured Weibull distribution parameters, representative average, low, and high variance data are given for height profiles of mean, 25 percentile, and 75 percentile wind speeds; and for wind speed probability density (velocity frequency) functions and cumulative probability (velocity duration) functions at selected heights. Results of a sensitivity analysis of the dependence of wind turbine performance parameters on cut-in speed, and rated speed for various mean wind and wind variance regimes are also presented. Wind turbine performance is expressed in terms of capacity factor (ratio of mean power output to rated power) and recovery factor (ratio of mean energy output to energy theoretically available in the wind). The representative high, mean, and low variance cases were determined from calculated Weibull distributions at 140 sites across the Continental U.S., and all of the representative functions are evaluated at mean wind speeds of 4, 5, 6, 7, and 8 m/s at standard 10 m level.

Justus, C.G.; Hargraves, W.R.; Mikhail, A.

1976-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Quantifying hurricane wind speed with undersea sound  

E-Print Network (OSTI)

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 ...

Wilson, Joshua David

2006-01-01T23:59:59.000Z

42

The Autocorrelation of Hourly Wind Speed Observations  

Science Conference Proceedings (OSTI)

The autocorrelation of hourly wind speed observations is estimated for seven stations on the west coast of Canada at selected lags ranging from one hour to two months. The estimated autocorrelation function is fitted by a model that includes a ...

Arthur C. Brett; Stanton E. Tuller

1991-06-01T23:59:59.000Z

43

Sampling Wind Data for Mean Wind Speed Estimation  

Science Conference Proceedings (OSTI)

Two sampling techniques are applied to wind data at 3 h intervals for six stations in the Great Plains region in the United States in order to investigate the reduction in the number of data needed to estimate the mean wind speed. One-in-k ...

Mark Jong; Gary Thomann

1981-03-01T23:59:59.000Z

44

The Probability Distribution of Land Surface Wind Speeds  

Science Conference Proceedings (OSTI)

The probability density function (pdf) of land surface wind speeds is characterized using a global network of observations. Daytime surface wind speeds are shown to be broadly consistent with the Weibull distribution, while nighttime surface wind ...

Adam H. Monahan; Yanping He; Norman McFarlane; Aiguo Dai

2011-08-01T23:59:59.000Z

45

Unsafe at Any (Wind) Speed?  

Science Conference Proceedings (OSTI)

The goal of this research was to examine the relative safety and stability of stationary motor vehicles exposed to severe winds. The focus was on private passenger vehicles. 1) The behavior of two instrumented storm-chase vehicles that were ...

Thomas Schmidlin; Barbara Hammer; Paul King; Yuichi Ono; L. Scott Miller; Gregory Thumann

2002-12-01T23:59:59.000Z

46

Extreme learning machine based wind speed estimation and sensorless control for wind turbine power generation system  

Science Conference Proceedings (OSTI)

This paper proposes a precise real-time wind speed estimation method and sensorless control for variable-speed variable-pitch wind turbine power generation system (WTPGS). The wind speed estimation is realized by a nonlinear input-output mapping extreme ... Keywords: Extreme learning machine, Sensorless control, Wind speed estimation, Wind turbine power generation system

Si Wu; Youyi Wang; Shijie Cheng

2013-02-01T23:59:59.000Z

47

Time Series Models to Simulate and Forecast Wind Speed and Wind Power  

Science Conference Proceedings (OSTI)

A general approach for modeling wind speed and wind power is described. Because wind power is a function of wind speed, the methodology is based on the development of a model of wind speed. Values of wind power are estimated by applying the ...

Barbara G. Brown; Richard W. Katz; Allan H. Murphy

1984-08-01T23:59:59.000Z

48

Wind speed PDF classification using Dirichlet mixtures Rudy CALIF1  

E-Print Network (OSTI)

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

Paris-Sud XI, Université de

49

Dynamic simulation of dual-speed wind turbine generation  

SciTech Connect

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.

Muljadi, E.; Butterfield, C.P.

1996-10-01T23:59:59.000Z

50

One-Month Ahead Prediction of Wind Speed and Output Power Based on EMD and LSSVM  

Science Conference Proceedings (OSTI)

Wind speed is a kind of non-stationary time series, it is difficult to construct the model for accurate forecast. The way improving accuracy of the model for predicting wind speed up to one-month ahead has been investigated using measured data recorded ... Keywords: wind speed forecasting, empirical mode decomposition(EMD), least square support vector machine (LSSVM), intrinsic mode function(IFM), wind power

Wang Xiaolan; Li Hui

2009-10-01T23:59:59.000Z

51

United States Wind Resource Map: Annual Average Wind Speed at...  

Wind Powering America (EERE)

80 m 01-APR-2011 2.1.1 Wind Speed ms >10.5 10.0 9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 < 4.0 Source: Wind resource estimates developed by AWS Truepower, LLC for...

52

Extreme Wind Speed Data Sets: Texas Tech/CSU  

Science Conference Proceedings (OSTI)

... B-indicates a beacon tower exposure. ... 93839 Memphis TN 4 3 1968 123 107 WIND SPEEDS GREATER ... [ SED Home | Extreme Winds Home | Data ...

2013-09-27T23:59:59.000Z

53

Offshore Wind Turbine Wakes Measured by Sodar  

Science Conference Proceedings (OSTI)

A ship-mounted sodar was used to measure wind turbine wakes in an offshore wind farm in Denmark. The wake magnitude and vertical extent were determined by measuring the wind speed profile behind an operating turbine, then shutting down the ...

R. J. Barthelmie; L. Folkerts; F. T. Ormel; P. Sanderhoff; P. J. Eecen; O. Stobbe; N. M. Nielsen

2003-04-01T23:59:59.000Z

54

Can Satellite Sampling of Offshore Wind Speeds Realistically Represent Wind Speed Distributions?  

Science Conference Proceedings (OSTI)

Wind speeds over the oceans are required for a range of applications but are difficult to obtain through in situ methods. Hence, remote sensing tools, which also offer the possibility of describing spatial variability, represent an attractive ...

R. J. Barthelmie; S. C. Pryor

2003-01-01T23:59:59.000Z

55

Homogenization and Trend Analysis of Canadian Near-Surface Wind Speeds  

Science Conference Proceedings (OSTI)

Near-surface wind speeds recorded at 117 stations in Canada for the period from 1953 to 2006 were analyzed in this study. First, metadata and a logarithmic wind profile were used to adjust hourly wind speeds measured at nonstandard anemometer ...

Hui Wan; Xiaolan L. Wang; Val R. Swail

2010-03-01T23:59:59.000Z

56

An Optical Disdrometer for Use in High Wind Speeds  

Science Conference Proceedings (OSTI)

A new optical disdrometer has been developed that is optimized for use in high wind speeds, for example, on board ships. The minimal detectable size of droplets is 0.35 mm. Each drop is measured separately with regard to its size and residence ...

Martin Grossklaus; Klaus Uhlig; Lutz Hasse

1998-08-01T23:59:59.000Z

57

Sliding mode control law for a variable speed wind turbine  

Science Conference Proceedings (OSTI)

Modern wind turbines are designed in order to work in variable speed operations. To perform this task, wind turbines are provided with adjustable speed generators, like the double feed induction generator. One of the main advantage of adjustable speed ... Keywords: modeling and simulation, variable structure control, wind turbine control

Oscar Barambones; Jose Maria Gonzalez De Durana; Patxi Alkorta; Jose Antonio Ramos; Manuel De La Sen

2011-02-01T23:59:59.000Z

58

Doppler Lidar–Based Wind-Profile Measurement System for Offshore Wind-Energy and Other Marine Boundary Layer Applications  

Science Conference Proceedings (OSTI)

Accurate measurement of wind speed profiles aloft in the marine boundary layer is a difficult challenge. The development of offshore wind energy requires accurate information on wind speeds above the surface at least at the levels occupied by ...

Yelena L. Pichugina; Robert M. Banta; W. Alan Brewer; Scott P. Sandberg; R. Michael Hardesty

2012-02-01T23:59:59.000Z

59

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

Science Conference Proceedings (OSTI)

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.

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

60

Wind speed modeling and prediction in wind farms using fuzzy logic  

Science Conference Proceedings (OSTI)

In this paper, the upcoming wind speed is forecasted using the stochastic characteristics of wind speed of previous years. The wind speed is estimated in the fuzzy inference system and simulated with the fuzzy logic. The simulation results illustrate ... Keywords: fuzzy, prediction, wind farm

Shahram Javadi; Zeinab Hojjatinia

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Short-Term Wind Speed Forecasting for Power System Operations  

E-Print Network (OSTI)

Global large scale penetration of wind energy is accompanied by significant challenges due to the intermittent and unstable nature of wind. High quality short-term wind speed forecasting is critical to reliable and secure power system operations. This paper gives an overview of the current status of worldwide wind power developments and future trends, and reviews some statistical short-term wind speed forecasting models, including traditional time series models and advanced space-time statistical models. It also discusses the evaluation of forecast accuracy, in particular the need for realistic loss functions. New challenges in wind speed forecasting regarding ramp events and offshore wind farms are also presented.

Xinxin Zhu; Marc G. Genton

2011-01-01T23:59:59.000Z

62

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

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

63

File:QuikSCAT - Annual Wind Speed at 10 m.pdf | Open Energy Information  

Open Energy Info (EERE)

QuikSCAT - Annual Wind Speed at 10 m.pdf QuikSCAT - Annual Wind Speed at 10 m.pdf Jump to: navigation, search File File history File usage QuikSCAT - Annual Wind Speed at 10 m Size of this preview: 463 × 599 pixels. Other resolution: 464 × 600 pixels. Full resolution ‎(1,275 × 1,650 pixels, file size: 1.19 MB, MIME type: application/pdf) Title Annual Wind Speed at 10 m Description QuikSCAT - Annual Wind Speed at 10 m Sources NREL, National Aeronautics and Space Administration Extent International Coordinates 0°, 0° Scatterometer measurements of the state of the ocean surface are used to estimate 10-m ocean winds in the QuikSCAT satellite data set. The QuikSCAT data are produced by Remote Sensing Systems and sponsored by the U.S. National Aeronautics and Space Administration Ocean Vector Winds Science

64

LQG Controller for a Variable Speed Pitch Regulated Wind Turbine  

Science Conference Proceedings (OSTI)

This paper deals with the design of LQG controllers for pitch regulated, variable speed wind turbines where the controller is used primarily for controlling the pitch angle through a collective pitch angle in the high wind speed in order to guarantee ... Keywords: LQG controller, Pitch control, Wind Trubine

Xingjia Yao; Shu Liu; Guangkun Shan; Zuoxia Xing; Changchun Guo; Chuanbao Yi

2009-08-01T23:59:59.000Z

65

Improved Wind Measurements on Research Aircraft  

Science Conference Proceedings (OSTI)

Improved techniques for measuring horizontal and vertical wind components and state variables on research aircraft are presented. They include a filtering method for correcting ground speed and position Inertial Navigation System data with Global ...

D. Khelif; S. P. Burns; C. A. Friehe

1999-07-01T23:59:59.000Z

66

Can Satellite Sampling of Offshore Wind Speeds Realistically Represent Wind Speed Distributions? Part II: Quantifying Uncertainties Associated with Distribution Fitting Methods  

Science Conference Proceedings (OSTI)

Remote sensing tools represent an attractive proposition for measuring wind speeds over the oceans because, in principle, they also offer a mechanism for determining the spatial variability of flow. Presented here is the continuation of research ...

S. C. Pryor; M. Nielsen; R. J. Barthelmie; J. Mann

2004-05-01T23:59:59.000Z

67

Spatial and Temporal Patterns of Global Onshore Wind Speed Distribution  

SciTech Connect

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.

Zhou, Yuyu; Smith, Steven J.

2013-09-09T23:59:59.000Z

68

Standard Deviations of Wind Speed and Direction from Observations over a Smooth Surface  

Science Conference Proceedings (OSTI)

Measurements of wind speed and direction made every minute on a 15 m mast sited on a large expanse of sea ice were analyzed to study the behavior of their standard deviation. The large scatter normally observed under low wind speed and/or non-...

Sylvain M. Joffre; Tuomas Laurila

1988-05-01T23:59:59.000Z

69

Using ADCP Background Sound Levels to Estimate Wind Speed  

Science Conference Proceedings (OSTI)

It is well known that ambient sound is generated by wind through the process of wave breaking and bubble injection. The resulting sound levels are highly correlated with wind speed and, even though the physical process is not fully understood, ...

Len Zedel

2001-11-01T23:59:59.000Z

70

Simulated Atmospheric Rime Icing of Some Wind Speed Sensors  

Science Conference Proceedings (OSTI)

Four commercially available wind speed sensors have been tested in an icing wind tunnel to determine the relative susceptibility of each to atmospheric icing and to determine the influence of ire accumulations upon the operation and accuracy of ...

E. M. Gates; W. C. Thompson

1986-06-01T23:59:59.000Z

71

Sliding mode control strategy for variable speed wind turbine  

Science Conference Proceedings (OSTI)

The efficiency of the wind power conversions systems can be greatly improved using an appropriate control algorithm. In this work, a robust control for variable speed wind power generation that incorporates a doubly feed induction generator is described. ...

Oscar Barambones; Jose Maria Gonzalez De Durana

2009-09-01T23:59:59.000Z

72

Hi-Q Rotor - Low Wind Speed Technology  

DOE Green Energy (OSTI)

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.

Todd E. Mills; Judy Tatum

2010-01-11T23:59:59.000Z

73

Maximizing Energy Capture of Fixed-Pitch Variable-Speed Wind Turbines  

DOE Green Energy (OSTI)

Field tests of a variable-speed, stall-regulated wind turbine were conducted at a US Department of Energy Laboratory. A variable-speed generating system, comprising a doubly-fed generator and series-resonant power converter, was installed on a 275-kW, downwind, two-blade wind turbine. Gearbox, generator, and converter efficiency were measured in the laboratory so that rotor aerodynamic efficiency could be determined from field measurement of generator power. The turbine was operated at several discrete rotational speeds to develop power curves for use in formulating variable-speed control strategies. Test results for fixed-speed and variable-speed operation are presented along with discussion and comparison of the variable-speed control methodologies. Where possible, comparisons between fixed-speed and variable-speed operation are shown.

Pierce, K.; Migliore, P.

2000-08-01T23:59:59.000Z

74

Atmospheric Circulation Effects on Wind Speed Variability at Turbine Height  

Science Conference Proceedings (OSTI)

Mean monthly wind speed at 70 m above ground level is investigated for 11 sites in Minnesota for the period 1995–2003. Wind speeds at these sites show significant spatial and temporal coherence, with prolonged periods of above- and below-normal ...

Katherine Klink

2007-04-01T23:59:59.000Z

75

Trends and Interannual Variability of Wind Speed Distributions in Minnesota  

Science Conference Proceedings (OSTI)

Near-surface wind speed variability is investigated at seven stations in and surrounding Minnesota for recent climate records of 22–35 yr in length. Analyses focus on mean annual wind speeds and on the 10th, 25th, 50th, 75th, and 90th percentiles ...

Katherine Klink

2002-11-01T23:59:59.000Z

76

Estimation of Extreme Wind Speeds with Very Long Return Periods  

Science Conference Proceedings (OSTI)

Long series of hourly mean wind speeds and the maximum hourly 3-s gust are simulated for four sites in the British Isles in order to investigate methods for the determination of extreme wind speed events. The simulation is performed using a one-...

M. D. G. Dukes; J. P. Palutikof

1995-09-01T23:59:59.000Z

77

Long-Term Wind Speed Trends over Australia  

Science Conference Proceedings (OSTI)

Accurate estimates of long-term linear trends of wind speed provide a useful indicator for circulation changes in the atmosphere and are invaluable for the planning and financing of sectors such as wind energy. Here a large number of wind ...

Alberto Troccoli; Karl Muller; Peter Coppin; Robert Davy; Chris Russell; Annette L. Hirsch

2012-01-01T23:59:59.000Z

78

Climatic Comparisons of Estimated and Measured Winds from Ships  

Science Conference Proceedings (OSTI)

Wind speed records from twelve Ocean Weather Stations (OWS's) are compared to estimates from transient ships in the general vicinity of the on-station OWS position. Measured and estimated winds from transient ships within specified areas are also ...

Robert G. Quayle

1980-02-01T23:59:59.000Z

79

Wind: wind speed and wind power density GIS data at 10m and 50m above  

Open Energy Info (EERE)

10m and 50m above 10m and 50m above surface and 0.25 degree resolution for global oceans from NREL Dataset Summary Description (Abstract): Raster GIS ASCII data files of wind speed and wind power density at 10 and 50 m heights. Global data of offshore wind resource as generated by NASA's QuikScat SeaWinds scatterometer. (Purpose): To provide information on the wind resource potential of offshore areas. Source NREL Date Released December 31st, 2005 (9 years ago) Date Updated November 01st, 2007 (7 years ago) Keywords GEF GIS NASA NREL ocean offshore QuikScat SWERA UNEP wind Data application/msword icon Download Documentation (doc, 53.8 KiB) application/zip icon Download Data (zip, 41 MiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period 01/01/2000 - 12/31/2004

80

Wind: wind speed and wind power density maps at 10m and 50m above surface  

Open Energy Info (EERE)

maps at 10m and 50m above surface maps at 10m and 50m above surface and 0.25 degree resolution for global oceans from NREL Dataset Summary Description (Abstract): Raster GIS ASCII data files of wind speed and wind power density at 10 and 50 m heights. Global data of offshore wind resource as generated by NASA's QuikSCAT SeaWinds scatterometer. (Purpose): To provide information on the wind resource potential of offshore areas. Source NREL Date Released December 31st, 2005 (9 years ago) Date Updated November 01st, 2007 (7 years ago) Keywords GEF GIS NASA NREL SWERA UNEP wind Data application/zip icon Download Maps (zip, 36.3 MiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period 2000 - 2004 License License Other or unspecified, see optional comment below

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Optimal evolutionary wind turbine placement in wind farms considering new models of shape, orography and wind speed simulation  

Science Conference Proceedings (OSTI)

In this paper we present a novel evolutionary algorithm for optimal positioning of wind turbines in wind farms. We consider a realistic model for the wind farm, which includes orography, shape of the wind farm, simulation of the wind speed and direction, ...

B. Saavedra-Moreno; S. Salcedo-Sanz; A. Paniagua-Tineo; J. Gascón-Moreno; J. A. Portilla-Figueras

2011-06-01T23:59:59.000Z

82

Tests of the Generalized Pareto Distribution for Predicting Extreme Wind Speeds  

Science Conference Proceedings (OSTI)

Extreme wind speed predictions are often based on statistical analysis of site measurements of annual maxima, using one of the Generalized Extreme Value (GEV) distributions. An alternative method applies one of the Generalized Pareto ...

B. B. Brabson; J. P. Palutikof

2000-09-01T23:59:59.000Z

83

Method for Estimation of Surface Roughness and Similarity Function of Wind Speed Vertical Profile  

Science Conference Proceedings (OSTI)

This study is aimed at identifying and refining a method suitable to estimate the surface roughness length (z0) and the universal similarity function of the wind speed profile (?M) based on ultrasonic anemometer measurements carried out at only ...

Roberto Sozzi; Maurizio Favaron; Teodoro Georgiadis

1998-05-01T23:59:59.000Z

84

Estimating Maximum Surface Winds from Hurricane Reconnaissance Measurements  

Science Conference Proceedings (OSTI)

Radial profiles of surface winds measured by the Stepped Frequency Microwave Radiometer (SFMR) are compared to radial profiles of flight-level winds to determine the slant ratio of the maximum surface wind speed to the maximum flight-level wind ...

Mark D. Powell; Eric W. Uhlhorn; Jeffrey D. Kepert

2009-06-01T23:59:59.000Z

85

A Short-Term Ensemble Wind Speed Forecasting System for Wind Power Applications  

Science Conference Proceedings (OSTI)

This study develops an adaptive, blended forecasting system to provide accurate wind speed forecasts 1 h ahead of time for wind power applications. The system consists of an ensemble of 21 forecasts with different configurations of the Weather ...

Justin J. Traiteur; David J. Callicutt; Maxwell Smith; Somnath Baidya Roy

2012-10-01T23:59:59.000Z

86

Scatterometer Observations at High Wind Speeds  

Science Conference Proceedings (OSTI)

Satellite scatterometer winds are commonly validated by comparing them to buoy observations and/or numerical model surface wind analyses. However, the empirical scatterometer algorithm (geophysical model function) has been calibrated against a ...

Lixin Zeng; Robert A. Brown

1998-11-01T23:59:59.000Z

87

Development of Wind Speed Forecasting Model Based on the Weibull Probability Distribution  

Science Conference Proceedings (OSTI)

Wind is a variable energy source. The power output of a wind turbine generator (WTG) unit, therefore, fluctuates with wind speed variations. Accurate models reflecting the variability of wind speed is hence required in both reliability evaluation of ... Keywords: Wind Energy, Wind Speed Forecasting Model, Weibull Distribution, Maximum Likelihood Method, Time Series Model

Ruigang Wang; Wenyi Li; B. Bagen

2011-02-01T23:59:59.000Z

88

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)

The amount of power in the wind is very dependent on the speed of the wind. Because the power in the wind is proportional to the cube of the wind speed, small differences in the wind speed make a big. This gives rise to the primary reason for wind re- source assessment. In order to more accurately predict

Massachusetts at Amherst, University of

89

File:CV WindSpeed.pdf | Open Energy Information  

Open Energy Info (EERE)

WindSpeed.pdf WindSpeed.pdf Jump to: navigation, search File File history File usage Cape Verde-Map Summarizing Average Wind Speed (m/s) Size of this preview: 776 × 600 pixels. Full resolution ‎(1,650 × 1,275 pixels, file size: 246 KB, MIME type: application/pdf) Description Cape Verde-Map Summarizing Average Wind Speed (m/s) Sources ECOWAS Creation Date 2011/11/14 Coordinates 16.002082°, -24.013197° File history Click on a date/time to view the file as it appeared at that time. Date/Time Thumbnail Dimensions User Comment current 11:43, 14 November 2011 Thumbnail for version as of 11:43, 14 November 2011 1,650 × 1,275 (246 KB) STobin (Talk | contribs) You cannot overwrite this file. Edit this file using an external application (See the setup instructions for more information)

90

Weibull Statistics of Wind Speed over the Ocean  

Science Conference Proceedings (OSTI)

The probability distribution of wind speed data over the world's oceans is studied using a two-parameter Weibull distribution. The parameters are estimated following a linearized least-squares approach. The seasonal and latitudinal variation are ...

Edgar G. Pavia; James J. O'Brien

1986-10-01T23:59:59.000Z

91

System and method for upwind speed based control of a wind turbine ...  

A method for controlling power output of a wind turbine generator in response to an anticipated change in wind speed is provided. The method includes sensing wind ...

92

High Range Resolution Radar Measurements of the Speed Distribution of Breaking Events in Wind-Generated Ocean Waves: Surface Impulse and Wave Energy Dissipation Rates  

Science Conference Proceedings (OSTI)

A set of X-band radar measurements, backscattered from the sea surface at near grazing incidence with very high spatial and temporal resolution (30 cm in range and 2000-Hz pulse repetition frequency) in moderate wind conditions, are dominated by ...

O. M. Phillips; F. L. Posner; J. P. Hansen

2001-02-01T23:59:59.000Z

93

On the Accuracy of Monthly Mean Wind Speeds over the Equatorial Pacific  

Science Conference Proceedings (OSTI)

Yearlong in situ surface wind measurements at three sites along the Pacific equator (95°, 110°, 152°W) are used to estimate the required number of random observations per month for monthly mean wind speed components accurate to 1.0 and 0.5 m s?. ...

David Halpern

1988-04-01T23:59:59.000Z

94

Anemometer Data (Wind Speed, Direction) for Laurel, Nebraska (2001 - 2002)  

Open Energy Info (EERE)

Laurel, Nebraska (2001 - 2002) Laurel, Nebraska (2001 - 2002) Dataset Summary Description Wind data collected from Laurel, Nebraska from a 20-meter anemometer as part of the Western Area Power Administration anemometer loan program. Ten-minute average wind speed and direction is available for 2001 - 2002. The data was originally made available by Wind Powering America, a DOE Office of Energy Efficiency & Renewable Energy (EERE) program. A dynamic map displaying all available data from DOE anemometer loan programs is available http://www.windpoweringamerica.gov/anemometerloans/projects.asp. Source EERE Date Released November 09th, 2010 (4 years ago) Date Updated November 09th, 2010 (4 years ago) Keywords wind wind direction wind speed Data text/csv icon Jun 11, 2001 - Jul 1, 2001 (csv, 144 KiB)

95

The Influence of Wind Speed on Shallow Marine Cumulus Convection  

Science Conference Proceedings (OSTI)

The role of wind speed on shallow marine cumulus convection is explored using large-eddy simulations and concepts from bulk theory. Focusing on cases characteristic of the trades, the equilibrium trade wind layer is found to be deeper at stronger ...

Louise Nuijens; Bjorn Stevens

2012-01-01T23:59:59.000Z

96

Correlation of Real and Model Wind Speeds in Different Terrains  

Science Conference Proceedings (OSTI)

Wind speeds over a 6-month period from 21 surface stations, 3 upper-wind stations, and 2 different models are compared. Similar data are used for three different topographic regions of New Zealand broadly classed as having low, moderate, and high ...

Steve J. Reid; Richard Turner

2001-10-01T23:59:59.000Z

97

Short term wind speed forecasting with evolved neural networks  

Science Conference Proceedings (OSTI)

Concerns about climate change, energy security and the volatility of the price of fossil fuels has led to an increased demand for renewable energy. With wind turbines being one of the most mature renewable energy technologies available, the global use ... Keywords: forecasting, renewable energy, wind-speed

David Corne; Alan Reynolds; Stuart Galloway; Edward Owens; Andrew Peacock

2013-07-01T23:59:59.000Z

98

Wind: wind speed and wind power density GIS data at 50m above ground and  

Open Energy Info (EERE)

Kenya from RisoeDTU Kenya from RisoeDTU Dataset Summary Description (Abstract): These data are results from the KAMM/WASP studies for Kenya. The KAMM/WAsP methodology uses a set of wind classes to represent wind conditions for the mapped region. A mesoscale simulation for each wind class, using KAMM (Karlsruhe Mesoscale Model), is performed and statistics performed on the model output. The results are a summary of the simulated wind climate, and ii. a wind atlas, a summary of the wind climate standardized to flat, uniform roughness terrain. (Purpose): The product is intended to be used to estimate the wind resource potential in the country including the the spatial variability. This map covers regions where long term measurements are not available. In a sense this is the point of the

99

Comparison of Synthetic Aperture Radar–Derived Wind Speeds with Buoy Wind Speeds along the Mountainous Alaskan Coast  

Science Conference Proceedings (OSTI)

Satellite-borne synthetic aperture radar (SAR) offers the potential for remotely sensing surface wind speed both over the open sea and in close proximity to the coast. The resolution improvement of SAR over scatterometers is of particular ...

C. M. Fisher; G. S. Young; N. S. Winstead; J. D. Haqq-Misra

2008-05-01T23:59:59.000Z

100

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

SciTech Connect

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.

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

1995-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

High-Speed Optical and Electrical Measurements  

Science Conference Proceedings (OSTI)

High-Speed Optical and Electrical Measurements. The Optoelectronics Division provides three different services related ...

2011-12-15T23:59:59.000Z

102

Short-term wind speed forecasting based on a hybrid model  

Science Conference Proceedings (OSTI)

Wind power is currently one of the types of renewable energy with a large generation capacity. However, operation of wind power generation is very challenging because of the intermittent and stochastic nature of the wind speed. Wind speed forecasting ... Keywords: Forecasting, RBF neural networks, Seasonal adjustment, Wavelet transform, Wind speed

Wenyu Zhang, Jujie Wang, Jianzhou Wang, Zengbao Zhao, Meng Tian

2013-07-01T23:59:59.000Z

103

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

E-Print Network (OSTI)

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

Richardson, John

104

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

105

Anemometer Data (Wind Speed, Direction) for Ugashik, AK (2001 - 2002) |  

Open Energy Info (EERE)

0 0 Varnish cache server Browse Upload data GDR 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 2142278290 Varnish cache server Anemometer Data (Wind Speed, Direction) for Ugashik, AK (2001 - 2002) Dataset Summary Description Wind data collected from Ugashik Traditional Village in Alaska from an anemometer as part of the Native American anemometer loan program. Monthly mean wind speed is available for 2001 through 2002, as is wind direction and turbulence data. Data is reported from a height of 20 m. The data was originally made available by Wind Powering America, a DOE Office of Energy Efficiency & Renewable Energy (EERE) program. A dynamic map displaying all available data from DOE anemometer loan programs is available http://www.windpoweringamerica.gov/anemometerloans/projects.asp.

106

Anemometer Data (Wind Speed, Direction) for Tanana, AK (2001 - 2002) |  

Open Energy Info (EERE)

40 40 Varnish cache server Anemometer Data (Wind Speed, Direction) for Tanana, AK (2001 - 2002) Dataset Summary Description Wind data collected from Tanana Village in Alaska from an anemometer as part of the Native American anemometer loan program. Monthly mean wind speed is available for 2001 through 2002, as is wind direction and turbulence data. Data is reported from a height of 20 m. The data was originally made available by Wind Powering America, a DOE Office of Energy Efficiency & Renewable Energy (EERE) program. A dynamic map displaying all available data from DOE anemometer loan programs is available http://www.windpoweringamerica.gov/anemometerloans/projects.asp. Source EERE Date Released November 09th, 2010 (4 years ago) Date Updated November 09th, 2010 (4 years ago)

107

Empirical-Statistical Method to Estimate the Surface Wind Speed over Complex Terrain  

Science Conference Proceedings (OSTI)

An empirical-statistical method to estimate surface wind speed over complex terrain under strong wind condition is proposed. This method is based on the postulation that the surface wind speed depends on a surface roughness parameter and a ...

Hiromi Yamazawa; Junsei Kondo

1989-09-01T23:59:59.000Z

108

Empirical Models of the Probability Distribution of Sea Surface Wind Speeds  

Science Conference Proceedings (OSTI)

This study considers the probability distribution of sea surface wind speeds, which have historically been modeled using the Weibull distribution. First, non-Weibull structure in the observed sea surface wind speeds (from SeaWinds observations) ...

Adam Hugh Monahan

2007-12-01T23:59:59.000Z

109

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

E-Print Network (OSTI)

1. Wind-splash erosion 4. Relationships between rainfall intensity, wind-speed, wind direction and erosion 5. Longer term influence of wind-direction on landscape evolution 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1 of tubes at approximately two week intervals. Contour plots of rainfall intensity (mm/hr) against wind

110

Variable-Speed Wind System Design : Final Report.  

SciTech Connect

Almost from the onset of the development of wind energy conversion systems (WECS), it was known that variable-speed operation of the turbine would maximize energy capture. This study was commissioned to assess the cost, efficiency gain, reduction of the cost of energy (COE), and other operating implications of converting the existing hardware of a modern fixed-speed wind energy conversion system to variable-speed operation. The purpose of this study was to develop a preliminary design for the hardware required to allow variable-speed operation using a doubly-fed generator with an existing fixed-speed wind turbine design. The turbine selected for this study is the AWT-26 designed and built by Advanced Wind Turbines Inc. of Redmond, Washington. The lowest projected COE using this variable-speed generation system is projected to be $0.0499/kWh, compared to the lowest possible COE with fixed-speed generation which is projected to be $0.0546/kWh. This translates into a 8.6% reduction of the COE using this variable-speed generation option. The preliminary system design has advanced to where the printed circuit boards can be physically laid out based on the schematics and the system software can be written based on the control flow-charts. The core of hardware and software has been proven to be successful in earlier versions of VSG systems. The body of this report presents the results of the VSWG system development. Operation under normal and fault conditions is described in detail, the system performance for variable-speed operation is estimated and compared to the original fixed-speed system performance, and specifications for all system components (generator, power electronic converter, and system controller) are given. Costs for all components are estimated, and incremental system cost is compared to incremental energy production. Finally, operational features of the VSWG which are not available in the existing FSWG system are outlined.

Lauw, Hinan K.; Weigand, Claus H.; Marckx, Dallas A.; Electronic Power Conditioning, Inc.

1993-10-01T23:59:59.000Z

111

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

DOE Green Energy (OSTI)

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.

Corotis, R.B.

1982-06-01T23:59:59.000Z

112

Intercomparison of Wind Measurements from Two Acoustic Doppler Sodars, a Laser Doppler Lidar, and In Situ Sensors  

Science Conference Proceedings (OSTI)

Intercomparative measurements of wind speed, wind direction, wind direction standard deviation, and vertical wind standard deviation from two acoustic Doppler sodars and a laser Doppler lidar are studied, using the BAO tower to provide reference ...

Prasan Chintawongvanich; Robert Olsen; Christopher A. Biltoft

1989-10-01T23:59:59.000Z

113

Manual and Semiautomated Wind Direction Editing for Use in the Generation of Synthetic Aperture Radar Wind Speed Imagery  

Science Conference Proceedings (OSTI)

Previous studies have demonstrated that satellite synthetic aperture radar (SAR) can be used as an accurate scatterometer, yielding wind speed fields with subkilometer resolution. This wind speed generation is only possible, however, if a ...

George S. Young; Todd D. Sikora; Nathaniel S. Winstead

2007-06-01T23:59:59.000Z

114

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

DOE Green Energy (OSTI)

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.

Robert W. Preus; DOE Project Officer - Keith Bennett

2008-04-23T23:59:59.000Z

115

Wind: wind speed and wind power density GIS data at 50m above ground and  

Open Energy Info (EERE)

Ethiopia from RisoeDTU Ethiopia from RisoeDTU Dataset Summary Description (Abstract): These data are results from the KAMM/WASP studies for Ethiopia. The KAMM/WAsP methodology uses a set of wind classes to represent wind conditions for the mapped region. A mesoscale simulation for each wind class, using KAMM (Karlsruhe Mesoscale Model), is performed and statistics performed on the model output. The results are a summary of the simulated wind climate, and ii.a wind atlas, a summary of the wind climate standardized to flat, uniform roughness terrain. (Purpose): The product is intended to be used to estimate the wind resource potential in the country including the spatial variability. This map covers regions where long term measurements are not available. In a sense this is the point of the mapping exercise, but it also means that verification of results has not been as complete would be ideal. There is some concern that the results may underestimate the resource. However, new measurement data is coming and revisions to the map may be made if necessary as verification is carried out.

116

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

SciTech Connect

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.

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

117

Aircraft Measurements of Ageostrophic Winds  

Science Conference Proceedings (OSTI)

The Wyoming King Air flew along the 319.5-K isentropic surface and measured ageostrophic winds in the exit region of a polar jet on 8 March 1992. Ageostrophic winds were derived from 1) differences between geostrophic and observed winds and 2) ...

Erwin T. Prater

1996-11-01T23:59:59.000Z

118

A Mechanism for the Increase of Wind Stress (Drag) Coefficient with Wind Speed over Water Surfaces: A Parametric Model  

Science Conference Proceedings (OSTI)

A mechanism is proposed for a physical explanation of the increase in wind stress (drag) coefficient with wind speed over water surfaces. The formula explicitly incorporates the contribution of both winds and waves through the parameterizations ...

S. A. Hsu

1986-01-01T23:59:59.000Z

119

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

E-Print Network (OSTI)

Wind energy is considered as the most viable renewable energy options. In a renewable energy system more energy from the wind. One of the options is to use the variable speed wind turbine-speed wind turbine system for transient studies are discussed in this paper. The performance of wind energy

120

Wind: wind speed and wind power density GIS data at 50m above ground and  

Open Energy Info (EERE)

Nepal from RisoeDTU Nepal from RisoeDTU Dataset Summary Description (Abstract): These data are results from the KAMM/WASP studies for Nepal. The KAMM/WAsP methodology uses a set of windclasses to represent wind conditions for the mapped region. A mesoscale simulation for each wind class, using KAMM (Karlsruhe Mesoscale Model), is performed and statistics performed on the model output. The results are a summary of the simulated wind climate, and a wind atlas, a summary of the wind climate standardized to flat, uniform roughness terrain. (Purpose): The product is intended to be used to estimate the wind resource potential in the country including the the spatial variability. This map covers regions where long term measurements are not available. In a sense this is the point of the mapping exercise, but it also means that verification of results has not been as complete would be ideal. There is some concern that the results may underestimate the resource. However, new measurement data is coming and revisions to the map may be made if necessary as verification is carried out.

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

The Influence of Bubbles on Ambient Noise in the Ocean at High Wind Speeds  

Science Conference Proceedings (OSTI)

Observations of ambient noise in the ocean at high wind speeds reveal significant departures in spectral shape from previously reported values at lower wind speeds. The observations were made in open ocean conditions in Queen Charlotte Sound, ...

David M. Farmer; David D. Lemon

1984-11-01T23:59:59.000Z

122

Retrieval of Surface Wind Speed and Aerosol Optical Depth over the Oceans from AVHRR Images of Sun Glint  

Science Conference Proceedings (OSTI)

This paper investigates the feasibility of recovering both the tropospheric aerosol loading and the surface wind speed from satellite measurements of the radiance within cloud free regions of sun glint over the ocean surface. The method relies on ...

D. M. O'Brien; R. M. Mitchell

1988-12-01T23:59:59.000Z

123

Modeling and design of control system for variable speed wind turbine in all operating region  

Science Conference Proceedings (OSTI)

In order to get the maximum power from the wind, the variable-speed wind turbine should run at different speed when wind speed changes. In this paper a control system is introduced to get this purpose base on establishing the three-mass model of the ... Keywords: doubly-fed induction generator (DFIG), feed-forward compensator, loop-shaping, pitch controller, speed controller, three-mass model, wind turbine

Wu Dingguo; Wang Zhixin

2008-05-01T23:59:59.000Z

124

On the Maximum Observed Wind Speed in a Randomly Sampled Hurricane  

Science Conference Proceedings (OSTI)

There is considerable interest in detecting a long-term trend in hurricane intensity possibly related to large-scale ocean warming. This effort is complicated by the paucity of wind speed measurements for hurricanes occurring in the early part of ...

Andrew R. Solow

2010-03-01T23:59:59.000Z

125

A neural network control strategy for improved energy capture on a variable-speed wind turbine  

Science Conference Proceedings (OSTI)

Pitch control has so far been the dominating method for power control in modern variable speed wind turbines. This paper proposes an improved control technique for pitching the blades of a variable speed wind turbine, using Artificial Neural Networks ... Keywords: artificial neural networks, control trajectories, pitch control, variable-speed wind turbines

António F. Silva; Fernando A. Castro; José N. Fidalgo

2005-06-01T23:59:59.000Z

126

Performance and Technique of Coherent 2-?m Differential Absorption and Wind Lidar for Wind Measurement  

Science Conference Proceedings (OSTI)

A coherent 2-?m differential absorption and wind lidar (Co2DiaWiL) has been built with a high-power Q-switched Tm,Hm:YLF laser to measure CO2 concentration and radial wind speed. The performance of the Co2DiaWiL is described and analyzed, with a ...

Hironori Iwai; Shoken Ishii; Ryoko Oda; Kohei Mizutani; Shinya Sekizawa; Yasuhiro Murayama

2013-03-01T23:59:59.000Z

127

Wind Plant Capacity Credit Variations: A Comparison of Results Using Multiyear Actual and Simulated Wind-Speed Data  

DOE Green Energy (OSTI)

Although it is widely recognized that variations in annual wind energy capture can be significant, it is not clear how significant this effect is on accurately calculating the capacity credit of a wind plant. An important question is raised concerning whether one year of wind data is representative of long-term patterns. This paper calculates the range of capacity credit measures based on 13 years of actual wind-speed data. The results are compared to those obtained with synthetic data sets that are based on one year of data. Although the use of synthetic data sets is a considerable improvement over single-estimate techniques, this paper finds that the actual inter- annual variation in capacity credit is still understated by the synthetic data technique.

Milligan, Michael

1997-06-01T23:59:59.000Z

128

Systematic Controller Design Methodology for Variable-Speed Wind Turbines  

DOE Green Energy (OSTI)

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.

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

2002-02-01T23:59:59.000Z

129

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

Science Conference Proceedings (OSTI)

This paper gives an evaluation of most of the commonly used models for predicting wind speed decrease (wake) downstream of a wind turbine. The evaluation is based on six experiments where free-stream and wake wind speed profiles were measured ...

R. J. Barthelmie; G. C. Larsen; S. T. Frandsen; L. Folkerts; K. Rados; S. C. Pryor; B. Lange; G. Schepers

2006-07-01T23:59:59.000Z

130

Pitch Angle Control of Variable Low Rated Speed Wind Turbine Using Fuzzy Logic Control  

E-Print Network (OSTI)

Abstract — Pitch angle control of wind turbine has been used widely to reduce torque and output power variation in high rated wind speed areas. It is a challenge to maximize available energy in the low rated wind speed areas. In this paper, a wind turbine prototype with a pitch angle control based on fuzzy logic to maximize the output power is built and demonstrated. In the varying low rated wind speed of 4-6 m/s, the use of fuzzy logic controller can maximize the average output power of 14.5 watt compared to 14.0 watt at a fixed pitch angle of the blade. Implementation of pitch angle fuzzy logic-based control to the wind turbine is suitable for the low rated wind speed areas. Index Terms — low rated wind speed areas, pitch angle control, fuzzy logic, wind turbine. T I.

A. Musyafa; A. Harika; I. M. Y. Negara; I. Rob

2010-01-01T23:59:59.000Z

131

Neuroadaptive speed assistance control of wind turbine with variable ratio gearbox (VRG)  

Science Conference Proceedings (OSTI)

Wind power as a renewable energy source is irregular in occurrence. It is interesting yet challenging to maximize the energy capture from wind. Most existing control methods for wind power generation are traditionally based on wind turbine with fixed ... Keywords: PMSM, neuroadaptive control, speed regulation, wind turbine

Xue-fei Wang; Yong-duan Song; Dan-yong Li; Kai Zhang; Shan Xue; Ming Qin

2012-07-01T23:59:59.000Z

132

Model Simulations Examining the Relationship of Lake-Effect Morphology to Lake Shape, Wind Direction, and Wind Speed  

Science Conference Proceedings (OSTI)

Idealized model simulations with an isolated elliptical lake and prescribed winter lake-effect environmental conditions were used to examine the influences of lake shape, wind speed, and wind direction on the mesoscale morphology. This study ...

Neil F. Laird; John E. Walsh; David A. R. Kristovich

2003-09-01T23:59:59.000Z

133

Error Estimates for Ocean Surface Winds: Applying Desroziers Diagnostics to the Cross-Calibrated, Multiplatform Analysis of Wind Speed  

Science Conference Proceedings (OSTI)

The Desroziers diagnostics (DD) are applied to the cross-calibrated, multi-platform (CCMP) ocean surface wind data sets to estimate wind speed errors of the ECMWF background, the microwave satellite observations and the resulting CCMP analysis. ...

Ross N. Hoffman; Joseph V. Ardizzone; S. Mark Leidner; Deborah K. Smith; Robert Atlas

134

Using a new characterization of turbulent wind for accurate correlation of wind turbine response with wind speed  

SciTech Connect

The turbulence encountered by a point on a rotating wind turbine blade has characteristics that in some important respects are different from those measured by a stationary anemometer. The conventional one-peaked continuous spectrum becomes, broadly, a two-peaked spectrum that in addition contains a set of narrow-band spikes of turbulence energy, one centered on the frequency of rotor rotation and the others centered on multiples of that frequency. The rotational sampling effect on wind spectra is quantified using measurements of wind velocity by anemometers on stationary crosswind circular arrays. Characteristics of fluctuating wind are compared to measured fluctuations of bending moments of the rotor blades and power output fluctuations of a horizontal-axis wind turbine at the same site. The wind characteristics and the correlations between wind fluctuations and wind turbine fluctuations provide a basis for improving turbine design, siting, and control. 6 refs., 11 figs., 1 tab.

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

1987-09-01T23:59:59.000Z

135

Measuring the Wind Vector Using the Autonomous Mini Aerial Vehicle M2AV  

Science Conference Proceedings (OSTI)

The meteorological mini unmanned aerial vehicle (M2AV) was used for measuring the meteorological wind. The wind is the vector difference between the aircraft speed relative to the earth (inertial velocity) and relative to the airflow (true ...

Aline van den Kroonenberg; Tim Martin; Marco Buschmann; Jens Bange; Peter Vörsmann

2008-11-01T23:59:59.000Z

136

Pitch angle control in wind turbines above the rated wind speed by multi-layer perceptron and radial basis function neural networks  

Science Conference Proceedings (OSTI)

In wind energy conversion systems, one of the operational problems is the changeability and discontinuity of wind. In most cases, wind speed can fluctuate rapidly. Hence, quality of produced energy becomes an important problem in wind energy conversion ... Keywords: Neural network-based controller, Pitch control, Variable-speed wind turbine, Wind energy conversion systems

Ahmet Serdar Yilmaz; Zafer Özer

2009-08-01T23:59:59.000Z

137

Sliding Mode Power Control of Variable Speed Wind Energy Conversion Systems  

E-Print Network (OSTI)

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 (National Renewable Energy Laboratory) wind turbine simulator FAST (Fatigue, Aerodynamics, Structures

Brest, Université de

138

Pitch-Controlled Variable-Speed Wind Turbine Generation  

NLE Websites -- All DOE Office Websites (Extended Search)

Pitch-Controlled Variable-Speed Pitch-Controlled Variable-Speed Wind Turbine Generation February 2000 * NREL/CP-500-27143 E. Muljadi and C.P. Butterfield Presented at the 1999 IEEE Industry Applications Society Annual Meeting Phoenix, Arizona October 3-7, 1999 National Renewable Energy Laboratory 1617 Cole Boulevard Golden, Colorado 80401-3393 NREL is a U.S. Department of Energy Laboratory Operated by Midwest Research Institute * * * * Battelle * * * * Bechtel Contract No. DE-AC36-99-GO10337 NOTICE The submitted manuscript has been offered by an employee of the Midwest Research Institute (MRI), a contractor of the US Government under Contract No. DE-AC36-99GO10337. Accordingly, the US Government and MRI retain a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes.

139

Stability analysis of a variable-speed wind turbine  

DOE Green Energy (OSTI)

This paper examines the elastomechanical stability of a four-bladed wind turbine over a specific rotor speed range. Stability modes, frequencies, and dampings are extracted using a specialized modal processor developed at NREL that post-processes the response data generated by the ADAMS simulation code. The processor can analyze a turbine with an arbitrary number of rotor blades and offers a novel capability of isolating stability modes that become locked at a single frequency. Results indicate that over a certain rotor speed range, the tower lateral mode and the rotor regressive in-plane mode coalesce, resulting in a self-excited instability. Additional results show the effect of tower and nacelle parameters on the stability boundaries.

Bir, G.S.; Wright, A.D.; Butterfield, C.P.

1996-10-01T23:59:59.000Z

140

Solar wind acceleration in coronal holes. [High speed solar wind streams  

SciTech Connect

Past attempts to explain the large solar wind velocities in high speed streams by theoretical models of the expansion have invoked either extended nonthermal heating of the corona, heat flux inhibition, or direct addition of momentum to the expanding coronal plasma. Several workers have shown that inhibiting the heat flux at low coronal densities is probably not adequate to explain quantitatively the observed plasma velocities in high speed streams. It stressed that, in order to account for both these large plasma velocities and the low densities found in coronal holes (from which most high speed streams are believed to emanate), extended heating by itself will not suffice. One needs a nonthermal mechanism to provide the bulk acceleration of the high wind plasma close to the sun, and the most likely candidate at present is direct addition of the momentum carried by outward-propagating waves to the expanding corona. Some form of momentum addition appears to be absolutely necessary if one hopes to build quantitatively self-consistent models of coronal holes and high speed solar wind streams.

Kopp, R.A.

1978-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Wind: wind speed and wind power density GIS data at 50m above...  

Open Energy Info (EERE)

from the KAMMWASP studies for Kenya.

The KAMMWAsP methodology uses a set of wind classes to represent wind conditions for the mapped region. A mesoscale simulation for...

142

Wind: wind speed and wind power density GIS data at 50m above...  

Open Energy Info (EERE)

for Nepal.

The KAMMWAsP methodology uses a set of windclasses to represent wind conditions for the mapped region. A mesoscale simulation for each wind class, using...

143

Wind: wind speed and wind power density GIS data at 50m above...  

Open Energy Info (EERE)

the KAMMWASP studies for Ethiopia.

The KAMMWAsP methodology uses a set of wind classes to represent wind conditions for the mapped region. A mesoscale simulation for...

144

Wind: wind speed and wind power density GIS data at 50m above...  

Open Energy Info (EERE)

See supplemental information.

The KAMMWAsP methodology uses a set of wind classes to represent wind conditions for the mapped region. A mesoscale simulation for...

145

Documenting Wind Speed and Power Deficits behind a Utility-Scale Wind Turbine  

Science Conference Proceedings (OSTI)

High-spatial-and-temporal-resolution radial velocity measurements surrounding a single utility-scale wind turbine were collected using the Texas Tech University Ka-band mobile research radars. The measurements were synthesized to construct the ...

Brian D. Hirth; John L. Schroeder

2013-01-01T23:59:59.000Z

146

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

DOE Green Energy (OSTI)

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.

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

1996-11-01T23:59:59.000Z

147

A variable speed wind generator maximum power tracking based on adaptative neuro-fuzzy inference system  

Science Conference Proceedings (OSTI)

The power from wind varies depending on the environmental factors. Many methods have been proposed to locate and track the maximum power point (MPPT) of the wind, such as the fuzzy logic (FL), artificial neural network (ANN) and neuro-fuzzy. In this ... Keywords: ANFIS, MPPT, Power generation, Variable speed wind generator, Wind energy

A. Meharrar; M. Tioursi; M. Hatti; A. Boudghčne Stambouli

2011-06-01T23:59:59.000Z

148

A WRF Ensemble for Improved Wind Speed Forecasts at Turbine Height  

Science Conference Proceedings (OSTI)

The Weather Research and Forecasting Model (WRF) with 10-km horizontal grid spacing was used to explore improvements in wind speed forecasts at a typical wind turbine hub height (80 m). An ensemble consisting of WRF model simulations with ...

Adam J. Deppe; William A. Gallus Jr.; Eugene S. Takle

2013-02-01T23:59:59.000Z

149

Comparison of Mean Wind Speeds and Turbulence at a Coastal Site and Offshore Location  

Science Conference Proceedings (OSTI)

Observations of mean wind speed and longitudinal turbulence at a height of 8 m over the Atlantic ocean, 5 km off Long Island, New York, were compared with simultaneous observations at the beach. Results were grouped into wind direction classes ...

S. SethuRaman; G. S. Raynor

1980-01-01T23:59:59.000Z

150

An Isofactorial Change-of-Scale Model for the Wind Speed Probability Density Function  

Science Conference Proceedings (OSTI)

The wind speed probability density function (PDF) is used in a variety of applications in meteorology, oceanography, and climatology usually as a dataset comparison tool of a function of a quantity such as momentum flux or wind power density. The ...

Mark L. Morrissey; Angie Albers; J. Scott Greene; Susan Postawko

2010-02-01T23:59:59.000Z

151

Spatial Predictions of Extreme Wind Speeds over Switzerland Using Generalized Additive Models  

Science Conference Proceedings (OSTI)

The purpose of this work is to present a methodology aimed at predicting extreme wind speeds over Switzerland. Generalized additive models are used to regionalize wind statistics for Swiss weather stations using a number of variables that ...

Christophe Etienne; Anthony Lehmann; Stéphane Goyette; Juan-Ignacio Lopez-Moreno; Martin Beniston

2010-09-01T23:59:59.000Z

152

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

Science Conference Proceedings (OSTI)

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.

Mikhail, A.

2009-01-01T23:59:59.000Z

153

Variable speed wind turbine generator with zero-sequence filter  

DOE Patents (OSTI)

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.

Muljadi, E.

1998-08-25T23:59:59.000Z

154

Variable Speed Wind Turbine Generator with Zero-sequence Filter  

DOE Patents (OSTI)

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.

Muljadi, Eduard (Golden, CO)

1998-08-25T23:59:59.000Z

155

Variable speed wind turbine generator with zero-sequence filter  

DOE Patents (OSTI)

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.

Muljadi, Eduard (Golden, CO)

1998-01-01T23:59:59.000Z

156

Wind: wind speed and wind power density GIS data at 50m above ground and  

Open Energy Info (EERE)

Bangladesh from RisoeDTU Bangladesh from RisoeDTU Dataset Summary Description (Abstract): These data are results from the KAMM/WASP studies for Bangladesh. Version 2 is an updated version of the earlier release and includes an adjustment to Weibull A and k to bring the Atlas values into better agreement with observations. See supplemental information.The KAMM/WAsP methodology uses a set of wind classes to represent wind conditions for the mapped region. A mesoscale simulation for each wind class, using KAMM (Karlsruhe Mesoscale Model), is performed and statistics performed on the model output. The result is i. a wind resource map, a summary of the simulated wind climate, and ii. a wind atlas, a summary of the wind climate standardized to flat, uniform roughness terrain. (Purpose): The product is intended to be used to

157

The study of multimode power control system for MW variable-speed wind turbine  

Science Conference Proceedings (OSTI)

Wind energy is a viable option to complement other types of pollution-free generation. In the past constant-speed wind turbine is used for the limitation of the control technology and manufacturing technology. But this kind wind turbine has low efficiency ... Keywords: feed-forward compensator, loop-shaping, multimode power control system, pitch controller, speed controller, the shaft system model, wind turbine

Dingguo Wu; Zhixin Wang

2008-10-01T23:59:59.000Z

158

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

DOE Green Energy (OSTI)

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.

Genesis Partners LP

2010-08-01T23:59:59.000Z

159

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

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.

2006-03-01T23:59:59.000Z

160

Wind Stress Measurements from the Open Ocean  

Science Conference Proceedings (OSTI)

An automatic inertial dissipation system was used during three cruises of the RRS Discovery in the Southern Ocean to obtain a large dataset of open ocean wind stress estimates. The wind speed varied from near calm to 26 m s?1, and the sea-air ...

Margaret Yelland; Peter K. Taylor

1996-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Design of State-Space-Based Control Algorithms for Wind Turbine Speed Regulation: Preprint  

DOE Green Energy (OSTI)

Control can improve the performance of wind turbines by enhancing energy capture and reducing dynamic loads.At the National Renewable Energy Laboratory, we are beginning to design control algorithms for regulation of turbine speed and power using state-space control designs. In this paper, we describe the design of such a control algorithm for regulation of rotor speed in full-load operation (region 3) for a two-bladed wind turbine. We base our control design on simple linear models of a turbine, which contain rotor and generator rotation, drivetrain torsion, and rotor flap degrees of freedom (first mode only). We account for wind-speed fluctuations using disturbance-accommodating control. We show the capability of these control schemes to stabilize the modeled turbine modes via pole placement while using state estimation to reduce the number of turbine measurements that are needed for these control algorithms. We incorporate these controllers into the FAST-AD code and show simulation results for various conditions. Finally, we report conclusions to this work and outline future studies.

Wright, A.; Balas, M.

2002-01-01T23:59:59.000Z

162

Estimating Probabilities of Hurricane Wind Speeds Using a Large-Scale Empirical Model  

Science Conference Proceedings (OSTI)

A new method is presented for estimating the probability of exceeding a given wind speed in 1 year at any given location in the Atlantic tropical cyclone basin. The method is especially appropriate for wind speeds with return periods of 100 years ...

R. W. R. Darling

1991-10-01T23:59:59.000Z

163

Hydrogen Sulfide Dispersion Consequences Analysis in Different Wind Speeds: A CFD Based Approach  

Science Conference Proceedings (OSTI)

Hydrogen sulfide (h2s) leakage and dispersion from a sulfide recycle installation in different wind speeds are simulated by implementing a 3D Computational Fluid Dynamics (CFD) model. H2s concentrations of monitor points which represent dispersion contours ... Keywords: CFD, hydrogen Sulfide, dispersion, concenquences analysis, different wind speeds

Bo Zhang; Guo-ming Chen

2009-10-01T23:59:59.000Z

164

Utilization of Automatic Weather Station Data for Forecasting High Wind Speeds at Pegasus Runway, Antarctica  

Science Conference Proceedings (OSTI)

Reduced visibility due to blowing snow can severely hinder aircraft operations in the Antarctic. Wind speeds in excess of approximately 7–13 m s?1 can result in blowing snow. The ability to forecast high wind speed events can improve the safety ...

R. E. Holmes; C. R. Stearns; G. A. Weidner; L. M. Keller

2000-04-01T23:59:59.000Z

165

Observed Coherent Trends of Surface and Upper-Air Wind Speed over China since 1960  

Science Conference Proceedings (OSTI)

Previous studies indicated that surface wind speed over China declined during past decades, and several explanations exist in the literature. This study presents long-term (1960–2009) changes of both surface and upper-air wind speeds over China ...

Changgui Lin; Kun Yang; Jun Qin; Rong Fu

2013-05-01T23:59:59.000Z

166

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

E-Print Network (OSTI)

APPENDIX A MEASURING IMPACTS TO BIRDS CAUSED BY WIND TURBINES #12;A-1 APPENDIX A MEASURING IMPACTS TO BIRDS CAUSED BY WIND TURBINES 1.0 INTRODUCTION Differential composition of wind turbines at wind energy used is the number of fatalities per wind turbine per year (Anderson et al. 1999). This metric has

167

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

E-Print Network (OSTI)

Wind is the principal driver in the wind erosion models. The hourly wind speed data were generally required for precisely wind erosion modeling. In this study, a simple method to generate hourly wind speed data from daily wind statistics (daily average and maximum wind speeds together or daily average wind speed only) was established. A typical windy location with 3285 days (9 years) measured hourly wind speed data were used to validate the downscaling method. The results showed that the overall agreement between observed and simulated cumulative wind speed probability distributions appears excellent, especially for the wind speeds greater than 5 m s-1 range (erosive wind speed). The results further revealed that the values of daily average erosive wind power density (AWPD) calculated from generated wind speeds fit the counterparts computed from measured wind speeds well with high models' efficiency (Nash-Sutcliffe coefficient). So that the hourly wind speed data can be predicted from daily average and maximu...

Guo, Zhongling

2013-01-01T23:59:59.000Z

168

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

DOE Green Energy (OSTI)

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.

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

1996-11-01T23:59:59.000Z

169

Solar wind iron abundance variations at solar wind speeds > 600 km s/sup -1/, 1972 to 1976  

SciTech Connect

We have analyzed the Fe/H ratios in the peaks of high speed streams (HSS) during the decline of Solar Cycle 20 and the following minimum (October 1972 to December 1976). We utilized the response of the 50 to 200 keV ion channel of the APL/JHU energetic particle experiment (EPE) onIMP-7 and 8 to solar wind iron ions at high solar wind speeds (V greater than or equal to 600 km sec/sup -1/), and compared our Fe measurements with solar wind H and He parameters from the Los Alamos National Laboratory (LANL) instruments on the same spacecraft. In general, the Fe distribution parameters (bulk velocity, flow direction, temperature) are found to be similar to the LANL He parameters. Although the average Fe/H ration in many steady HSS peaks agrees within observational uncertainties with the nominal coronal ratio of 4.7 x 10/sup -5/, abundance variations of a factor of up to 6 are obtained across a given coronal-hole associated HSS. There are, as well, factor of 2 variations between stream-averaged abundances for recurent HSS emanating from different coronal holes occurring on the sun on the same solar rotation. flare-related solar wind streams sometimes show Fe/H ratios enhanced by factors of 4 to 5 over coronal-hole associated, quite time streams. Over the period 1973 to 1976, a steady decrease in the average quitetime Fe/H ratio by a ractor approx. 4 is measured on both IMP-7 and 8.

Mitchell, D.G.; Roelof, E.C.; Bame, S.J.

1982-01-01T23:59:59.000Z

170

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

E-Print Network (OSTI)

Modelling and Analysis of Variable Speed Wind Turbines with Induction Generator during Grid Fault Wind Turbines with Induction Generator during Grid Fault by Sigrid M. Bolik Institute of Energy turbine technology has undergone rapid developments. Growth in size and the optimization of wind turbines

Hansen, René Rydhof

171

Adaptive variable structure control law for a variable speed wind turbine  

Science Conference Proceedings (OSTI)

The efficiency of the wind power conversions systems can be greatly improved using an appropriate control algorithm. In this work, an adaptive robust control for a doubly feed induction generator drive for variable speed wind power generation is described. ... Keywords: modeling and simulation, variable structure control, wind turbine control

Oscar Barambones; Jose Maria Gonzalez De Durana; Patxi Alkorta; Jose Antonio Ramos; Manuel De La Sen

2011-05-01T23:59:59.000Z

172

An Examination of Tropical and Extratropical Gust Factors and the Associated Wind Speed Histograms  

Science Conference Proceedings (OSTI)

A gust factor, defined as the ratio between a peak wind gust and mean wind speed over a period of time, can be used along with other statistics to examine the structure of the wind. Gust factors are heavily dependent on upstream terrain ...

B. M. Paulsen; J. L. Schroeder

2005-02-01T23:59:59.000Z

173

Wind Speeds in ASCE 7 Standard Peak-Gust Map ...  

Science Conference Proceedings (OSTI)

... The second zone comprises these three states, for which ... implies that the extreme wind climate in Central ... 6 is similar to the wind climates in Central ...

2013-08-19T23:59:59.000Z

174

Wind Conditions in a Fjord-like Bay and Predictions of Wind Speed Using Neighboring Stations Employing Neural Network Models  

Science Conference Proceedings (OSTI)

This paper evaluates the applicability of neural networks to estimate wind speeds at various target locations using neighboring reference locations on the South coast of Newfoundland Canada. The stations were chosen to cover a variety of ...

Jens J. Currie; Pierre J. Goulet; Andry W. Ratsimandresy

175

The Characteristics of Wind Velocity that Favor the Fitting of a Weibull Distribution in Wind Speed Analysis  

Science Conference Proceedings (OSTI)

The derivation of the Weibull distribution from the bivariate normal distribution provides theoretical justification for its use in wind speed analysis if four conditions are met. These conditions are that the orthogonal components of horizontal ...

Stanton E. Tuller; Arthur C. Brett

1984-01-01T23:59:59.000Z

176

Control algorithms for effective operation of variable-speed wind turbines  

DOE Green Energy (OSTI)

This report describes a computer code, called ASYM and provides results from its application in simulating the control of the 34-m Test Bed vertical-axis wind turbine (VAWT) in Bushland, Texas. The code synthesizes dynamic wind speeds on a second-by-second basis in the time domain. The wind speeds conform to a predetermined spectral content governed by the hourly average wind speed that prevails at each hour of the simulation. The hourly average values are selected in a probabilistic sense through the application of Markov chains, but their cumulative frequency of occurrence conforms to a Rayleigh distribution that is governed by the mean annual wind speed of the site selected. The simulated wind speeds then drive a series of control algorithms that enable the code to predict key operational parameters such as number of annual starts and stops, annual energy production, and annual fatigue damage at a critically stressed joint on the wind turbine. This report also presents results from the application of ASYM that pertain to low wind speed cut-in and cut-out conditions and controlled operation near critical speed ranges that excite structural vibrations that can lead to accelerated fatigue damage.

Not Available

1993-10-01T23:59:59.000Z

177

Spatial variation of iron abundance in the high speed solar wind, 1972 to 1976  

SciTech Connect

The Fe/H ratios in the peaks of high speed streams (HSS) during the decline of Solar Cycle 20 and the following minimum (October 1972-December 1976) were analyzed. The response of the 50-200 keV ion channel of the APL/JHU energetic particle experiment (EPE) on IMP-7 and 8 to solar wind iron ions at high solar wind speeds and Fe measurements were compared with solar wind H and He parameters from the Los Alamos National Laboratory (LANL) instrments on the same spacecraft. In general, the Fe distribution parameters (bulk velocity, flow direction, temperature) are found to be similar to the LANL He parameters. Although the average Fe/H ratio in many steady HSS peaks agrees within observational uncertainties with the nominal coronal ratio of 4.7 x 10(-5), abundance variations of a factor of up to 6 are obtained across a given coronal-hole associated HSS. Over the period 1973-1976, a steady decrease in the average quiet-time Fe/H ratio by a factor of about 4 is measured on both IMP-7 and 8.

Mitchell, D.G.; Roelof, E.C.; Bame, S.J.

1983-11-01T23:59:59.000Z

178

A Comparative Assessment of Surface Wind Speed and Sea Surface Temperature over the Indian Ocean by TMI, MSMR, and ERA-40  

Science Conference Proceedings (OSTI)

A 2-yr (June 1999–June 2001) observation of ocean surface wind speed (SWS) and sea surface temperature (SST) derived from microwave radiometer measurements made by a multifrequency scanning microwave radiometer (MSMR) and the Tropical Rainfall ...

Anant Parekh; Rashmi Sharma; Abhijit Sarkar

2007-06-01T23:59:59.000Z

179

NIST Measurement Advance Could Speed Innovation in Solar ...  

Science Conference Proceedings (OSTI)

NIST Measurement Advance Could Speed Innovation in Solar Devices. From NIST Tech Beat: July 25, 2012. ...

2012-07-25T23:59:59.000Z

180

Simultaneous Measurement of Ocean Winds and Waves with an Airborne Coherent Real Aperture Radar  

Science Conference Proceedings (OSTI)

A coherent, X-band airborne radar has been developed to measure wind speed and direction simultaneously with directional wave spectra on the ocean. The coherent real aperture radar (CORAR) measures received power, mean Doppler shifts, and mean ...

William J. Plant; William C. Keller; Kenneth Hayes

2005-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Monthly Diurnal Global Atmospheric Circuit Estimates Derived from Vostok Electric Field Measurements Adjusted for Local Meteorological and Solar Wind Influences  

Science Conference Proceedings (OSTI)

Local temperature, wind speed, pressure, and solar wind–imposed influences on the vertical electric field observed at Vostok, Antarctica, are evaluated by multivariate analysis. Local meteorology can influence electric field measurements via local ...

G. B. Burns; B. A. Tinsley; A. V. Frank-Kamenetsky; O. A. Troshichev; W. J. R. French; A. R. Klekociuk

2012-06-01T23:59:59.000Z

182

Measurement of Wind Waves and Wave-Coherent Air Pressures on the Open Sea from a Moving SWATH Vessel  

Science Conference Proceedings (OSTI)

The design and implementation on a Small Waterline Area Twin Hull (SWATH) vessel of a complete system for measuring the directional distribution of wind waves and the concomitant fluctuations of air pressure and wind speed immediately above them ...

Mark A. Donelan; Fred W. Dobson; Hans C. Graber; Niels Madsen; Cyril McCormick

2005-07-01T23:59:59.000Z

183

A Test of a Lapse Rate/Wind Speed Model for Estimating Heat Island Magnitude in an Urban Airshed  

Science Conference Proceedings (OSTI)

In the winter of 1975/76 a helicopter was used to obtain temperature profiles across the city of Calgary. This operation was supported by airborne measurements of wind speed and lapse rate at the edge of the city, upwind. Regression analysis ...

Lawrence C. Nkemdirim

1980-06-01T23:59:59.000Z

184

Space-Time Wind Speed Forecasting for Improved Power System Dispatch  

E-Print Network (OSTI)

In order to support large scale integration of wind power, state-of-the-art wind speed forecasting methods should provide accurate and adequate information to enable efficient scheduling of wind power in electric energy systems. In this article, space-time wind forecasts are incorporated into power system economic dispatch models. First, we proposed a new space-time wind forecasting model, which generalizes and improves upon a so-called regime-switching space-time model by allowing the forecast regimes to vary with the dominant wind direction and with the seasons. Then, results from the new wind forecasting model are implemented into a power system economic dispatch model, which takes into account both spatial and temporal wind speed correlations. This, in turn, leads to an overall more cost-effective scheduling of system-wide wind generation portfolio. The potential economic benefits arise in the system-wide generation cost savings and in the ancillary service cost savings. This is illustrated in a test system in the northwest region of the U.S. Compared with persistent and autoregressive models, our proposed method could lead to annual integration cost savings on the scale of tens of millions of dollars in regions with high wind penetration, such as Texas and the Northwest. Key words: Power system economic dispatch; Power system operation; Space-time statistical model; Wind data; Wind speed forecasting.

Xinxin Zhu; Marc G. Genton; Yingzhong Gu; Le Xie

2012-01-01T23:59:59.000Z

185

Anemometer Data (Wind Speed, Direction) for YKHC-Bethel, AK (2003 - 2004) |  

Open Energy Info (EERE)

YKHC-Bethel, AK (2003 - 2004) YKHC-Bethel, AK (2003 - 2004) Dataset Summary Description Wind data collected from YKHC - Bethel in Alaska from an anemometer as part of the Native American anemometer loan program. Monthly mean wind speed is available for 2003 through 2004, as is wind direction and turbulence data. Data is reported from a height of 20 m. The data was originally made available by Wind Powering America, a DOE Office of Energy Efficiency & Renewable Energy (EERE) program. A dynamic map displaying all available data from DOE anemometer loan programs is available http://www.windpoweringamerica.gov/anemometerloans/projects.asp. Source EERE Date Released November 09th, 2010 (4 years ago) Date Updated November 09th, 2010 (4 years ago) Keywords wind wind direction wind speed

186

Toward Objective, Standardized Intensity Estimates from Surface Wind Speed Observations  

Science Conference Proceedings (OSTI)

Extreme wind climatology and event-specific intensity assessments rely heavily on surface wind field observations. The most widely used platforms sited at airports are the Automated Surface Observing System (ASOS) and its predecessor, the ...

Forrest J. Masters; Peter J. Vickery; Phuong Bacon; Edward N. Rappaport

2010-12-01T23:59:59.000Z

187

Low Wind Speed Technology Phase II: LIDAR for Turbine Control  

SciTech Connect

This fact sheet describes NREL's subcontract with QinetiQ to conduct a study on LIDAR systems for wind turbines.

Not Available

2006-06-01T23:59:59.000Z

188

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

E-Print Network (OSTI)

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. The forecasts produced by this model are accurate, and subject to accuracy, the predictive distribution is sharp, i.e., highly concentrated around its center. However, this model is split into nonunique regimes based on the wind direction at an off-site location. This work both generalizes and improves upon this model by treating wind direction as a circular variable and including it in the model. It is robust in many experiments, such as predicting at new locations. This is compared with the more common approach of modeling wind speeds and directions in the Cartesian space and use a skew-t distribution for the errors. The quality of the predictions from all of these models can be more realistically assessed with a loss measure that depends upon the power curve relating wind speed to power output. This proposed loss measure yields more insight into the true value of each model's predictions. One method of evaluating time series forecasts, such as wind speed forecasts, is to test the null hypothesis of no difference in the accuracy of two competing sets of forecasts. Diebold and Mariano (1995) proposed a test in this setting that has been extended and widely applied. It allows the researcher to specify a wide variety of loss functions, and the forecast errors can be non-Gaussian, nonzero mean, serially correlated, and contemporaneously correlated. In this work, a similar unconditional test of forecast accuracy for spatial data is proposed. The forecast errors are no longer potentially serially correlated but spatially correlated. Simulations will illustrate the properties of this test, and an example with daily average wind speeds measured at over 100 locations in Oklahoma will demonstrate its use. This test is compared with a wavelet-based method introduced by Shen et al. (2002) in which the presence of a spatial signal at each location in the dataset is tested.

Hering, Amanda S.

2009-08-01T23:59:59.000Z

189

Measurement of turbulent wind velocities using a rotating boom apparatus  

DOE Green Energy (OSTI)

The present report covers both the development of a rotating-boom facility and the evaluation of the spectral energy of the turbulence measured relative to the rotating boom. The rotating boom is composed of a helicopter blade driven through a pulley speed reducer by a variable speed motor. The boom is mounted on a semiportable tower that can be raised to provide various ratios of hub height to rotor diameter. The boom can be mounted to rotate in either the vertical or horizontal plane. Probes that measure the three components of turbulence can be mounted at any location along the radius of the boom. Special hot-film sensors measured two components of the turbulence at a point directly in front of the rotating blade. By using the probe rotated 90/sup 0/ about its axis, the third turbulent velocity component was measured. Evaluation of the spectral energy distributions for the three components of velocity indicates a large concentration of energy at the rotational frequency. At frequencies slightly below the rotational frequency, the spectral energy is greatly reduced over that measured for the nonrotating case measurements. Peaks in the energy at frequencies that are multiples of the rotation frequency were also observed. We conclude that the rotating boom apparatus is suitable and ready to be used in experiments for developing and testing sensors for rotational measurement of wind velocity from wind turbine rotors. It also can be used to accurately measure turbulent wind for testing theories of rotationally sampled wind velocity.

Sandborn, V.A.; Connell, J.R.

1984-04-01T23:59:59.000Z

190

Air–Sea Enthalpy and Momentum Exchange at Major Hurricane Wind Speeds Observed during CBLAST  

Science Conference Proceedings (OSTI)

Quantifying air–sea exchanges of enthalpy and momentum is important for understanding and skillfully predicting tropical cyclone intensity, but the magnitude of the corresponding wind speed–dependent bulk exchange coefficients is largely unknown ...

Michael M. Bell; Michael T. Montgomery; Kerry A. Emanuel

2012-11-01T23:59:59.000Z

191

Air–Sea Enthalpy and Momentum Exchange at Major Hurricane Wind Speeds Observed during CBLAST  

E-Print Network (OSTI)

Quantifying air–sea exchanges of enthalpy and momentum is important for understanding and skillfully predicting tropical cyclone intensity, but the magnitude of the corresponding wind speed–dependent bulk exchange coefficients ...

Bell, Michael M.

192

Wind speed forecasting at different time scales: a non parametric approach  

E-Print Network (OSTI)

The prediction of wind speed is one of the most important aspects when dealing with renewable energy. In this paper we show a new nonparametric model, based on semi-Markov chains, to predict wind speed. Particularly we use an indexed semi-Markov model, that reproduces accurately the statistical behavior of wind speed, to forecast wind speed one step ahead for different time scales and for very long time horizon maintaining the goodness of prediction. In order to check the main features of the model we show, as indicator of goodness, the root mean square error between real data and predicted ones and we compare our forecasting results with those of a persistence model.

D'Amico, Guglielmo; Prattico, Flavio

2013-01-01T23:59:59.000Z

193

Observed Hurricane Wind Speed Asymmetries and Relationships to Motion and Environmental Shear  

Science Conference Proceedings (OSTI)

Wavenumber-1 wind speed asymmetries in 35 hurricanes are quantified in terms of amplitude and phase, based on aircraft observations from 128 individual flights between 1998 and 2011. The impacts of motion and 850-200 mb environmental vertical ...

Eric W. Uhlhorn; Bradley W. Klotz; Tomislava Vukicevic; Paul D. Reasor; Robert F. Rogers

194

A Phenomenological Model for Wind Speed and Shear Stress Profiles in Vegetation Cover Layers  

Science Conference Proceedings (OSTI)

A phenomenological model for the mean wind speed and Reynolds shear stress profiles with height in a vegetation cover layer is derived from forms suggested by truncation of the equations of turbulent fluid motion at second order in fluctuating ...

F. A. Albini

1981-11-01T23:59:59.000Z

195

A fuzzy logic controller to increase fault ride-through capability of variable speed wind turbines  

Science Conference Proceedings (OSTI)

A fuzzy controller for improving Fault Ride-Through (FRT) capability of Variable Speed Wind Turbines (WTs) equipped with Doubly Fed Induction Generator (DFIG) is presented. The controller is designed in order to compensate the voltage at the Point of ...

Geev Mokryani, Pierluigi Siano, Antonio Piccolo, Vito Calderaro

2012-01-01T23:59:59.000Z

196

Evaluation of the National Hurricane Center’s Tropical Cyclone Wind Speed Probability Forecast Product  

Science Conference Proceedings (OSTI)

A tropical cyclone (TC) wind speed probability forecast product developed at the Cooperative Institute for Research in the Atmosphere (CIRA) and adopted by the National Hurricane Center (NHC) is evaluated for U.S. land-threatening and landfalling ...

Michael E. Splitt; Jaclyn A. Shafer; Steven M. Lazarus; William P. Roeder

2010-04-01T23:59:59.000Z

197

Estimation of Wind Speed Distribution Using Markov Chain Monte Carlo Techniques  

Science Conference Proceedings (OSTI)

The Weibull distribution is the most commonly used statistical distribution for describing wind speed data. Maximum likelihood has traditionally been the main method of estimation for Weibull parameters. In this paper, Markov chain Monte Carlo ...

Wan-Kai Pang; Jonathan J. Forster; Marvin D. Troutt

2001-08-01T23:59:59.000Z

198

HEXOS—Humidity Exchange Over the Sea A Program for Research on Water-Vapor and Droplet Fluxes from Sea of Air at Moderate to High Wind Speeds  

Science Conference Proceedings (OSTI)

HEXOS is an international program for the study of evaporation and spray-droplet flux from sea to air. The program includes measurements in the field at moderate-to-high wind speeds, wind-tunnel studies, instrument development, boundary-layer ...

Kristina B. Katsaros; Stuart D. Smith; Wiebe A. Oost

1987-05-01T23:59:59.000Z

199

Tractable Analytic Expressions for the Wind Speed Probability Density Functions Using Expansions of Orthogonal Polynomials  

Science Conference Proceedings (OSTI)

The use of the two-parameter Weibull function as an estimator of the wind speed probability density function (PDF) is known to be problematic when a high accuracy of fit is required, such as in the computation of the wind power density function. ...

Mark L. Morrissey; J. Scott Greene

2012-07-01T23:59:59.000Z

200

Dynamical Downscaling of Wind Speed in Complex Terrain Prone To Bora-Type Flows  

Science Conference Proceedings (OSTI)

The results of numerically modeled wind speed climate, a primary component of wind energy resource assessment in the complex terrain of Croatia, are given. For that purpose, dynamical downscaling of 10 yr (1992–2001) of the 40-yr ECMWF Re-Analysis ...

Kristian Horvath; Alica Baji?; Stjepan Ivatek-Šahdan

2011-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Hurricane Surface Wind Measurements from an Operational Stepped Frequency Microwave Radiometer  

Science Conference Proceedings (OSTI)

For the first time, the NOAA/Aircraft Operations Center (AOC) flew stepped frequency microwave radiometers (SFMRs) on both WP-3D research aircraft for operational hurricane surface wind speed measurement in 2005. An unprecedented number of major ...

Eric W. Uhlhorn; Peter G. Black; James L. Franklin; Mark Goodberlet; James Carswell; Alan S. Goldstein

2007-09-01T23:59:59.000Z

202

Analysis of the electrical harmonic characteristics of a slip recovery variable speed generating system for wind turbine applications  

SciTech Connect

Variable speed electric generating technology can enhance the general use of wind energy in electric utility applications. This enhancement results from two characteristic properties of variable speed wind turbine generators: an improvement in drive train damping characteristics, which results in reduced structural loading on the entire wind turbine system, and an improvement in the overall efficiency by using a more sophisticated electrical generator. Electronic converter systems are the focus of this investigation -- in particular, the properties of a wound-rotor induction generator with the slip recovery system and direct-current link converter. Experience with solid-state converter systems in large wind turbines is extremely limited. This report presents measurements of electrical performances of the slip recovery system and is limited to the terminal characteristics of the system. Variable speed generating systems working effectively in utility applications will require a satisfactory interface between the turbine/generator pair and the utility network. The electrical testing described herein focuses largely on the interface characteristics of the generating system. A MOD-O wind turbine was connected to a very strong system; thus, the voltage distortion was low and the total harmonic distortion in the utility voltage was less than 3% (within the 5% limit required by most utilities). The largest voltage component of a frequency below 60 Hz was 40 dB down from the 60-Hz< component. 8 refs., 14 figs., 8 tabs.

Herrera, J.I.; Reddoch, T.W.

1988-02-01T23:59:59.000Z

203

Low-Speed Wind-Tunnel Investigation of the Stability and Control Characteristics  

Science Conference Proceedings (OSTI)

A wind-tunnel investigation was conducted in the Langley 12-Foot Low-Speed Tunnel to study the low-speed stability and control characteristics of a series of four flying wings over an extended range of angle of attack (-8\\deg to 48\\deg). Because of the ...

Fears Scott P.; Ross Holly M.; Moul Thomas M.

1995-06-01T23:59:59.000Z

204

Controlled operation of variable speed driven permanent magnet synchronous generator for wind energy conversion systems  

Science Conference Proceedings (OSTI)

The introduction of distributed generation through renewable sources of energy has opened a challenging area for power engineers. As these sources are intermittent in nature, variable speed electric generators are employed for harnessing electrical energy ... Keywords: permanent magnet synchronous generator, power conditioners, power quality, variable speed generators, wind energy

Rajveer Mittal; K. S. Sandhu; D. K. Jain

2009-02-01T23:59:59.000Z

205

Comparison of Geophysical Model Functions for SAR Wind Speed Retrieval in Japanese Coastal Waters  

E-Print Network (OSTI)

Abstract: This work discusses the accuracies of geophysical model functions (GMFs) for retrieval of sea surface wind speed from satellite-borne Synthetic Aperture Radar (SAR) images in Japanese coastal waters characterized by short fetches and variable atmospheric stability conditions. In situ observations from two validation sites, Hiratsuka and Shirahama, are used for comparison of the retrieved sea surface wind speeds using CMOD (C-band model)4, CMOD_IFR2, CMOD5 and CMOD5.N. Of all the geophysical model functions (GMFs), the latest C-band GMF, CMOD5.N, has the smallest bias and root mean square error at both sites. All of the GMFs exhibit a negative bias in the retrieved wind speed. In order to understand the reason for this bias, all SAR-retrieved wind speeds are separated into two categories: onshore wind (blowing from sea to land) and offshore wind (blowing from land to sea). Only offshore winds were found to exhibit the large negative bias, and short fetches from the coastline may be a possible reason for this. Moreover, it is clarified that in both the unstable and stable conditions, CMOD5.N has atmospheric stability effectiveness, and can keep the same accuracy with CMOD5 in the neutral condition. In short, at the moment, CMOD5.N is thought to be the most promising GMF

Yuko Takeyama; Teruo Ohsawa; Katsutoshi Kozai; Charlotte Bay Hasager; Merete Badger

2013-01-01T23:59:59.000Z

206

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

DOE Green Energy (OSTI)

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.

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

2012-11-01T23:59:59.000Z

207

The effects of variable speed and drive train component efficiencies on wind turbine energy capture  

SciTech Connect

A wind turbine rotor achieves optimal aerodynamic efficiency at a single tip-speed ratio (TSR). To maintain that optimal TSR and maximize energy capture in the stochastic wind environment, it is necessary to employ variable-speed operation. Conventional constant-speed wind turbines have, in the past, been converted into variable-speed turbines by attaching power electronics to the conventional induction generator and gearbox drive train. Such turbines have shown marginal, if any, improvement in energy capture over their constant-speed counterparts. These discrepancies have been shown to be the result of drive train components that are not optimized for variable-speed operation. Traditional drive trains and power electronic converters are designed to achieve maximum efficiency at full load and speed. However, the main energy producing winds operate the turbine at light load for long periods of time. Because of this, significant losses to efficiency occur. This investigation employs a quasi-static model to demonstrate the dramatic effect that component efficiency curves can have on overall annual energy capture.

Fingersh, L.J.; Robinson, M.C.

1998-05-01T23:59:59.000Z

208

The Influence of Boundary Layer Processes on the Diurnal Variation of the Climatological Near-Surface Wind Speed Probability Distribution over Land  

Science Conference Proceedings (OSTI)

Knowledge of the diurnally varying land surface wind speed probability distribution is essential for surface flux estimation and wind power management. Global observations indicate that the surface wind speed probability density function (PDF) is ...

Yanping He; Norman A. McFarlane; Adam H. Monahan

2012-09-01T23:59:59.000Z

209

High speed air pneumatic wind shield wiping design  

E-Print Network (OSTI)

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 ...

Heyward, Moses A

2005-01-01T23:59:59.000Z

210

An Intercomparison of TOPEX, NSCAT, and ECMWF Wind Speeds: Illustrating and Understanding Systematic Discrepancies  

Science Conference Proceedings (OSTI)

The availability of multiple satellite missions with wind measuring capacity has made it more desirable than ever before to integrate wind data from various sources in order to achieve an improved accuracy, resolution, and duration. A clear ...

Ge Chen

2004-03-01T23:59:59.000Z

211

The Extrapolation of Vertical Profiles of Wind Speed within the Marine Atmospheric Surface layer Using the p Formula  

Science Conference Proceedings (OSTI)

Values of p for the exponent-type wind profile formulation, used in vertical extrapolations of wind speed, were derived for the marine atmospheric surface layer. Nomograms were constructed providing p values as dependent on a single elevation ...

M. Segal; R. A. Pielke

1988-02-01T23:59:59.000Z

212

Measuring wind plant capacity value  

DOE Green Energy (OSTI)

Electric utility planners and wind energy researchers pose a common question: What is the capacity value of a wind plant? Tentative answers, which can be phrased in a variety of ways, are based on widely varying definitions and methods of calculation. From the utility`s point of view, a resource that has no capacity value also has a reduced economic value. Utility planners must be able to quantify the capacity value of a wind plant so that investment in conventional generating capacity can be potentially offset by the capacity value of the wind plant. Utility operations personnel must schedule its conventional resources to ensure adequate generation to meet load. Given a choice between two resources, one that can be counted on and the other that can`t, the utility will avoid the risky resource. This choice will be reflected in the price that the utility will pay for the capacity: higher capacity credits result in higher payments. This issue is therefore also important to the other side of the power purchase transaction -- the wind plant developer. Both the utility and the developer must accurately assess the capacity value of wind. This article summarizes and evaluates some common methods of evaluating capacity credit. During the new era of utility deregulation in the United States, it is clear that many changes will occur in both utility planning and operations. However, it is my judgement that the evaluation of capacity credit for wind plants will continue to play an important part in renewable energy development in the future.

Milligan, M.R.

1996-01-01T23:59:59.000Z

213

Adaptive pitch control for variable speed wind turbines  

DOE Patents (OSTI)

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.

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

2012-05-08T23:59:59.000Z

214

Sea-Tower Measurements of Wind-Wave Spectra in the Caspian Sea  

Science Conference Proceedings (OSTI)

High frequency spectra of wind generated waves corresponding to mean wind speeds from 3.5 to 13.5 m s?1 were measured at the research tower in the Caspian Sea. The techniques used made it possible to evaluate spectra S(?) in the frequency range ...

I. A. Leykin; A. D. Rozenberg

1984-01-01T23:59:59.000Z

215

Secular Change in Reported Surface Wind Speeds over the Ocean  

Science Conference Proceedings (OSTI)

The Comprehensive Ocean-Atmosphere Data Set reveals that mean scalar winds decreased between 1854 and 1920 and increased since World War II. The latter increase is due to a change in estimating procedure and to the growing proportion of ships ...

C. S. Ramage

1987-04-01T23:59:59.000Z

216

Methods and apparatus for reducing peak wind turbine loads ...  

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 ...

217

Power-Electronic, Variable-Speed Wind Turbine Development: 1988-1993  

Science Conference Proceedings (OSTI)

A five-year development program culminated in the 33M-VS power-electronic, variable-speed turbine, used in a number of wind power plants to offer competitively priced electricity. This report describes turbine development activities from conception through field testing, highlights design decisions that led to the new technology, and provides an overview of the turbine's electrical and mechanical design. An appendix describes technical issues relevant to building a wind power plant using 33M-VS turbines.

1995-11-16T23:59:59.000Z

218

Effects of Precipitation on UHF Wind Profiler Measurements  

Science Conference Proceedings (OSTI)

Horizontal winds in the presence of precipitation were measured routinely with a UHF (405 MHz) Wind Profiler. The profiler had five beam-pointing positions so independent measurements of horizontal winds could be compared to determine relative ...

D. B. Wuertz; B. L. Weber; R. G. Strauch; A. S. Frisch; C. G. Little; D. A. Merritt; K. P. Moran; D. C. Welsh

1988-06-01T23:59:59.000Z

219

Anemometer Data (Wind Speed, Direction) for Pascua Yaqui, AZ (2003 - 2004)  

Open Energy Info (EERE)

Pascua Yaqui, AZ (2003 - 2004) Pascua Yaqui, AZ (2003 - 2004) Dataset Summary Description Wind data collected from Pascua Yaqui Indian Reservation in Arizona from an anemometer as part of the Native American anemometer loan program. Monthly mean wind speed is available for 2003 through 2004, as is wind direction and turbulence data. Data is reported from a height of 20 m. The data was originally made available by Wind Powering America, a DOE Office of Energy Efficiency & Renewable Energy (EERE) program. A dynamic map displaying all available data from DOE anemometer loan programs is available http://www.windpoweringamerica.gov/anemometerloans/projects.asp. Source EERE Date Released December 02nd, 2010 (3 years ago) Date Updated December 02nd, 2010 (3 years ago) Keywords wind

220

Anemometer Data (Wind Speed, Direction) for Quinault #3, WA (2004 - 2005) |  

Open Energy Info (EERE)

Quinault #3, WA (2004 - 2005) Quinault #3, WA (2004 - 2005) Dataset Summary Description Wind data collected from Quinault Indian Reservation in Washington from an anemometer as part of the Native American anemometer loan program. Monthly mean wind speed is available for 2004 through 2005, as is wind direction and turbulence data. Data is reported from a height of 20 m. The data was originally made available by Wind Powering America, a DOE Office of Energy Efficiency & Renewable Energy (EERE) program. A dynamic map displaying all available data from DOE anemometer loan programs is available http://www.windpoweringamerica.gov/anemometerloans/projects.asp. Source EERE Date Released December 02nd, 2010 (4 years ago) Date Updated December 02nd, 2010 (4 years ago) Keywords wind

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

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 RIS� DTU has started to build a newly designed laser-based lidar scanning facility for remote wind

222

Trends in Wind Speed at Wind Turbine Height of 80 m over the Contiguous United States Using the North American Regional Reanalysis (NARR)  

Science Conference Proceedings (OSTI)

The trends in wind speed at a typical wind turbine hub height (80 m) are analyzed using the North American Regional Reanalysis (NARR) dataset for 1979–2009. A method, assuming the wind profile in the lower boundary layer as power-law functions of ...

Eric Holt; Jun Wang

2012-12-01T23:59:59.000Z

223

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

DOE Green Energy (OSTI)

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.

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

2007-07-01T23:59:59.000Z

224

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

E-Print Network (OSTI)

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.

D'Amico, Guglielmo; Prattico, Flavio

2013-01-01T23:59:59.000Z

225

Model of variable speed constant frequency double fed wind power generation system and analysis of its operating performance  

Science Conference Proceedings (OSTI)

Structure of variable speed constant frequency double fed wind power generation system (WPGS) was analyzed, and its model was established. Maximum power point tracking (MPPT) control, constant power control and vector control for WPGS were discussed. ... Keywords: operating performance, variable speed constant frequency, vector control, wind power generation system

Pan Tinglong; Ji Zhicheng

2009-06-01T23:59:59.000Z

226

Low Wind Speed Technology Phase II: Integrated Wind Energy/Desalination System; General Electric Global Research  

SciTech Connect

This fact sheet describes a subcontract with General Electric Global Research to explore wind power as a desirable option for integration with desalination technologies.

Not Available

2006-03-01T23:59:59.000Z

227

On Sudbury-Area Wind Speeds—A Tale of Forest Regeneration  

Science Conference Proceedings (OSTI)

A 34% reduction in 10-m wind speeds at Sudbury Airport in Ontario, Canada, over the period 1975–95 appears to be a result of significant changes in the surface roughness of the surrounding area that are due to land restoration and reforestation ...

Andrew J. Tanentzap; Peter A. Taylor; Norman D. Yan; James R. Salmon

2007-10-01T23:59:59.000Z

228

Optimal Power-Law Description of Oceanic Whitecap Coverage Dependence on Wind Speed  

Science Conference Proceedings (OSTI)

The optimal power-law expression for the dependence of oceanic whitecap coverage fraction W on 10 m elevation wind speed U as determined by ordinary least squares fitting applied to the combined whitecap data sets of Monahan (1971) and Toba and ...

Edward C. Monahan; IognáidÓ Muircheartaigh

1980-12-01T23:59:59.000Z

229

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

DOE Green Energy (OSTI)

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.

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

1992-02-01T23:59:59.000Z

230

Creating Synthetic Wind Speed Time Series for 15 New Zealand Wind Farms  

Science Conference Proceedings (OSTI)

Wind data at time scales from 10 min to 1 h are an important input for modeling the performance of wind farms and their impact on many countries’ national electricity systems. Planners need long-term realistic (i.e., meteorologically spatially and ...

Richard Turner; Xiaogu Zheng; Neil Gordon; Michael Uddstrom; Greg Pearson; Rilke de Vos; Stuart Moore

2011-12-01T23:59:59.000Z

231

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

SciTech Connect

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.

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

232

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

E-Print Network (OSTI)

SOLAR WIND HELIUM ABUNDANCE AS A FUNCTION OF SPEED AND HELIOGRAPHIC LATITUDE: VARIATION THROUGH A SOLAR CYCLE Justin C. Kasper,1 Michael L. Stevens, and Alan J. Lazarus Kavli Institute for Astrophysics of the variation of the relative abundance of helium to hydrogen in the solar wind as a function of solar wind

Richardson, John

233

Correlated solar wind speed, density, and magnetic field changes at J. D. Richardson and C. Wang1  

E-Print Network (OSTI)

., in press, 2003. Wang, C., and J. D. Richardson, Energy partition between solar wind protons and pickup ionsCorrelated solar wind speed, density, and magnetic field changes at Voyager 2 J. D. Richardson December 2003. [1] The character of the solar wind plasma data observed by Voyager 2 recently changed

Richardson, John

234

Wisconsin Low Wind Speed Turbine Project First- and Second-Year Operating Experience: 1998-2000: U.S. Department of Energy-EPRI Wind Turbine Verification Program  

Science Conference Proceedings (OSTI)

The 1.2 MW Low Wind Speed Turbine Project (LWSTP) -- installed in Glenmore, Wisconsin, in early 1998 -- was the first commercial-scale wind project in Wisconsin. This report describes the first- and second-year operating experience at the LWSTP. The lessons learned in the project will be valuable to other utilities planning similar wind power projects, particularly in cold-weather, moderate wind resource areas.

2000-12-15T23:59:59.000Z

235

The Precision and Relative Accuracy of Profiler Wind Measurements  

Science Conference Proceedings (OSTI)

Two independent wind profiles were measured every hour during February 1986 with a five-beam, UHF (405 MHz) wind Profiler at Platteville, Colorado. Our analysis of the horizontal wind components over all heights for the entire month gave a ...

R. G. Strauch; B. L. Weber; A. S. Frisch; C. G. Little; D. A. Merritt; K. P. Moran; D. C. Welsh

1987-12-01T23:59:59.000Z

236

Comparison of Observed 10-m Wind Speeds to Those Based on Monin–Obukhov Similarity Theory Using IHOP_2002 Aircraft and Surface Data  

Science Conference Proceedings (OSTI)

Comparisons of 10-m above ground level (AGL) wind speeds from numerical weather prediction (NWP) models to point observations consistently show that model daytime wind speeds are slow compared to observations, even after improving model physics ...

Diane Strassberg; Margaret A. LeMone; Thomas T. Warner; Joseph G. Alfieri

2008-03-01T23:59:59.000Z

237

Novel sensorless generator control and grid fault ride-through strategies for variable-speed wind turbines and implementation on a new real-time simulation platform.  

E-Print Network (OSTI)

??The usage of MW-size variable-speed wind turbines as sources of energy has increased significantly during the last decade. Advantages over fixed-speed wind turbines include more… (more)

Yang, Sheng

2010-01-01T23:59:59.000Z

238

Temporal trend analyses of alpine data using North American Regional Reanalysis and in situ data: temperature, wind speed, precipitation, and derived blowing snow  

Science Conference Proceedings (OSTI)

Across the globe wind speed trends have shown a slight decline for in situ meteorological datasets. Yet few studies have assessed long-term wind speed trends for alpine regions or how such trends could influence snow transport and distribution. ...

Jamie D. Fuller; Nolan Doesken; Kelly Elder; Melinda Laituri; Glen E. Liston

239

A Nonstationary Extreme Value Analysis for the Assessment of Changes in Extreme Annual Wind Speed over the Gulf of St. Lawrence, Canada  

Science Conference Proceedings (OSTI)

Changes in the extreme annual wind speed in and around the Gulf of St. Lawrence (Canada) were investigated through a nonstationary extreme value analysis of the annual maximum 10-m wind speed obtained from the North American Regional Reanalysis (...

Y. Hundecha; A. St-Hilaire; T. B. M. J. Ouarda; S. El Adlouni; P. Gachon

2008-11-01T23:59:59.000Z

240

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)

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

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Airborne Doppler Lidar Wind Field Measurements  

Science Conference Proceedings (OSTI)

A coherent Doppler lidar has been used in an aircraft to measure the 2-dimensional wind field in a number of different atmospheric situations. The lidar, a pulsed CO2 system, was installed in the NASA Convair 990. Galileo II, and flown in a ...

J. Bilbro; G. Fichtl; D. Fitzjarrald; M. Krause; R. Lee

1984-04-01T23:59:59.000Z

242

Nonlinear Dual-Mode Control of Variable-Speed Wind Turbines with Doubly Fed Induction Generators  

E-Print Network (OSTI)

This paper presents a feedback/feedforward nonlinear controller for variable-speed wind turbines with doubly fed induction generators. By appropriately adjusting the rotor voltages and the blade pitch angle, the controller simultaneously enables: (a) control of the active power in both the maximum power tracking and power regulation modes, (b) seamless switching between the two modes, and (c) control of the reactive power so that a desirable power factor is maintained. Unlike many existing designs, the controller is developed based on original, nonlinear, electromechanically-coupled models of wind turbines, without attempting approximate linearization. Its development consists of three steps: (i) employ feedback linearization to exactly cancel some of the nonlinearities and perform arbitrary pole placement, (ii) design a speed controller that makes the rotor angular velocity track a desired reference whenever possible, and (iii) introduce a Lyapunov-like function and present a gradient-based approach for mini...

Tang, Choon Yik; Jiang, John N

2010-01-01T23:59:59.000Z

243

Low Wind Speed Technologies Annual Turbine Technology Update (ATTU) Process for Land-Based, Utility-Class Technologies  

SciTech Connect

The Low Wind Speed Technologies (LWST) Project comprises a diverse, balanced portfolio of industry-government partnerships structured to achieve ambitious cost of energy reductions. The LWST Project goal is: ''By 2012, reduce the cost of energy (COE) for large wind systems in Class 4 winds (average wind speed of 5.8 m/s at 10 m height) to 3 cents/kWh (in levelized 2002 dollars) for onshore systems.'' The Annual Turbine Technology Update (ATTU) has been developed to quantify performance-based progress toward these goals, in response to OMB reporting requirements and to meet internal DOE program needs for advisory data.

Schreck, S.; Laxson, A.

2005-06-01T23:59:59.000Z

244

Low Wind Speed Technology Phase II: Development of a 2-MW Direct-Drive Wind Turbine for Low Wind Speed Sites; Northern Power Systems  

SciTech Connect

This fact sheet describes a subcontract with Northern Power Systems (NPS) to develop and evaluate a 2-MW wind turbine that could offer significant opportunities for reducing the cost of energy (COE).

2006-03-01T23:59:59.000Z

245

Improving Wind Profiler–Measured Winds Using Coplanar Spectral Averaging  

Science Conference Proceedings (OSTI)

A method is presented that increases the detectability of weak clear-air signals by averaging Doppler spectra from coplanar wind profiler beams. The method, called coplanar spectral averaging (CSA), is applied to both simulated wind profiler ...

Robert Schafer; Susan K. Avery; Kenneth S. Gage; Paul E. Johnston; D. A. Carter

2004-11-01T23:59:59.000Z

246

Wisconsin Low Wind Speed Turbine Project Third-Year Operating Experience: 2000-2001: U.S. Department of Energy - EPRI Wind Turbine V erification Program  

Science Conference Proceedings (OSTI)

This report describes the third-year operating experience at the 1.2-MW Low Wind Speed Turbine Project (LWSTP) in Glenmore, Wisconsin. The lessons learned in the project will be valuable to other utilities planning similar wind power projects.

2001-12-06T23:59:59.000Z

247

Profiles of Wind Speed Variances within Nocturnal Low-Level Jets Observed with a Sodar  

Science Conference Proceedings (OSTI)

Continuous sodar measurements of wind profiles have been carried out at the Zvenigorod Scientific Station of the Obukhov Institute of Atmospheric Physics since 2008. The station is located in a slightly inhomogeneous rural area about 45 km west of ...

Margarita A. Kallistratova; Rostislav D. Kouznetsov; Valerii F. Kramar; Dmitrii D. Kuznetsov

248

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

DOE Green Energy (OSTI)

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.

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

249

The Impact of Radar Data on Short-Term Forecasts of Surface Temperature, Dewpoint Depression, and Wind Speed  

Science Conference Proceedings (OSTI)

A statistical system that uses surface observations and radar data to provide 1-, 3-, and 6-h forecasts of temperature, dewpoint depression, and wind speed is developed. Application of the system to independent data demonstrates that the radar ...

Emily K. Grover-Kopec; J. Michael Fritsch

2003-12-01T23:59:59.000Z

250

An Empirical Model for Predicting the Decay of Tropical Cyclone Wind Speed after Landfall over the Indian Region  

Science Conference Proceedings (OSTI)

An empirical model for predicting the maximum surface wind speed associated with a tropical cyclone after crossing the east coast of India is described. The model parameters are determined from the database of 19 recent cyclones. The model is ...

S. K. Roy Bhowmik; S. D. Kotal; S. R. Kalsi

2005-01-01T23:59:59.000Z

251

Low Wind Speed Technology Phase II: Development of an Operations and Maintenance Cost Model for LWST; Global Energy Concepts  

SciTech Connect

This fact sheet describes a subcontract with Global Energy Concepts to evaluate real-world data on O&M costs and to develop a working model to describe these costs for low wind speed sites.

Not Available

2006-03-01T23:59:59.000Z

252

Field Measurements of Wind Turbine Wakes with Lidars  

Science Conference Proceedings (OSTI)

Field measurements of the wake flow produced from a 2-MW Enercon E-70 wind turbine were performed using three scanning Doppler wind lidars. A GPS-based technique was used to determine the position of the wind turbine and the wind lidar locations, ...

Giacomo Valerio Iungo; Yu-Ting Wu; Fernando Porté-Agel

2013-02-01T23:59:59.000Z

253

Quality Controls for Profiler Measurements of Winds and RASS Temperatures  

Science Conference Proceedings (OSTI)

A new method for estimating winds and radio acoustic sounding system temperatures from radar Doppler measurements for the new NOAA wind profilers is described. This method emphasizes the quality of 6-min measurements prior to the computation of ...

B. L. Weber; D. B. Wuertz; D. C. Welsh; R. McPeek

1993-08-01T23:59:59.000Z

254

Wind Measurement Equipment: Registration (Nebraska) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Wind Measurement Equipment: Registration (Nebraska) Wind Measurement Equipment: Registration (Nebraska) Wind Measurement Equipment: Registration (Nebraska) < Back Eligibility Agricultural Commercial Construction Fed. Government Fuel Distributor General Public/Consumer Industrial Installer/Contractor Institutional Investor-Owned Utility Local Government Low-Income Residential Multi-Family Residential Municipal/Public Utility Nonprofit Residential Retail Supplier Rural Electric Cooperative Schools State/Provincial Govt Systems Integrator Transportation Tribal Government Utility Savings Category Wind Buying & Making Electricity Program Info State Nebraska Program Type Siting and Permitting Provider Department of Aeronautics All wind measurement equipment associated with the development or study of wind-powered electric generation, whether owned or leased, shall be

255

Analysis of SWADE Discus N Wind Speed and Wave Height Time Series. Part I: Discrete Wavelet Packet Representations  

Science Conference Proceedings (OSTI)

Discus N denotes a single buoy employed during the SWADE experiment, equipped to record wave amplitude and wind speed time series at a rate of 1 Hz. Over the course of approximately 4.5 days, two clear-cut examples of sea response to wind ...

Jorge E. Willemsen

1995-12-01T23:59:59.000Z

256

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  

DOE Green Energy (OSTI)

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.

Erdman, W.; Behnke, M.

2005-11-01T23:59:59.000Z

257

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

Science Conference Proceedings (OSTI)

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.

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

2012-01-01T23:59:59.000Z

258

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

DOE Green Energy (OSTI)

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.

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

2013-08-01T23:59:59.000Z

259

Distrubance Tracking and Blade Load Control of Wind Turbines in Variable-Speed Operation: Preprint  

DOE Green Energy (OSTI)

A composite state-space controller was developed for a multi-objective problem in the variable-speed operation of wind turbines. Disturbance Tracking Control theory was applied to the design of a torque controller to optimize energy capture under the influence of persistent wind disturbances. A limitation in the theory for common multi-state models is described, which led to the design of a complementary pitch controller. The goal of the independent blade pitch design was to minimize blade root fatigue loads. Simulation results indicate an 11% reduction in fatigue damage using the proposed controllers, compared to a conventional torque-only design. Meanwhile, energy capture is almost identical, partly because of nonlinear effects.

Stol, K. A.

2003-01-01T23:59:59.000Z

260

Measurement in a wind tunnel of the modification of mean wind and turbulence characteristics due to induction effects near wind turbine rotors  

DOE Green Energy (OSTI)

It is the purpose of this report to provide experimental data on the wind field surrounding a single model wind turbine rotor disk. These data should provide an improved physical insight into the induction effects of the air flow as it approaches the wind turbine. This insight should in turn improve an analytical model's predictive capabilities. A scaled model of a horizontal-axis wind turbine (a two-bladed rotor of diameter 53 cm) was placed into the Meteorological Wind Tunnel (MWT) facility at Colorado State University (cross-section width of 183 cm). Four different approach flow conditions were studied: low and moderate turbulence levels (0.1% and 1.5% intensity) at both 6 and 7.6 m/s freestream air velocities. For each of these flow conditions the rotor power coefficient versus tip speed ratio was obtained, and the 3-dimensional velocity field from 3 rotor diameters upwind to 0.5 diameter downwind was tabulated. The power output of the rotor was obtained via a simple prony brake friction device that imparts a torque (measured by the deflection of a spring) to the spinning shaft of the wind turbine. The rotor speed, measured by a strobe light, was observed to vary with load from 900 rpm up to 2100 rpm for the flow conditions described above. The 3-dimensional velocity field was measured via a three-hot-film probe. Details of the measurement techniques are provided. The test program and data results are also given. A short discussion of the implications of this data set is included. 12 refs., 19 figs., 11 tabs.

Neff, D.E.; Meroney, R.N.

1987-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Vermont Wind Measurement Company Still Strong | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Vermont Wind Measurement Company Still Strong 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 products measure wind potential. | Photo courtesy NRG Systems NRG's new building utilizes solar power, but their products measure wind potential. | Photo courtesy NRG Systems Joshua DeLung NRG Systems, of Hinesburg, Vt., has made products to help its customers measure and understand the potential of wind energy since 1982. Now, because of additional opportunities the Recovery Act has created for renewable energy companies, small businesses such as NRG Systems are poised to grow with the increased demand for proven wind measurement and turbine control equipment. NRG Systems' customers are primarily developers, utilities and research

262

Vermont Wind Measurement Company Still Strong | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Vermont Wind Measurement Company Still Strong 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 products measure wind potential. | Photo courtesy NRG Systems NRG's new building utilizes solar power, but their products measure wind potential. | Photo courtesy NRG Systems Joshua DeLung NRG Systems, of Hinesburg, Vt., has made products to help its customers measure and understand the potential of wind energy since 1982. Now, because of additional opportunities the Recovery Act has created for renewable energy companies, small businesses such as NRG Systems are poised to grow with the increased demand for proven wind measurement and turbine control equipment. NRG Systems' customers are primarily developers, utilities and research

263

Modeling the Variability of Sydney Harbor Wind Measurements  

Science Conference Proceedings (OSTI)

The time-dependent behavior in the variability of wind measurements is investigated using bivariate generalized autoregressive conditional heteroscedastic models. These models express the current level of short-timescale wind variability in terms ...

Edward Cripps; William T. M. Dunsmuir

2003-08-01T23:59:59.000Z

264

An Accuracy Goal for a Comprehensive Satellite Wind Measuring System  

Science Conference Proceedings (OSTI)

Variational analysis with a geostrophic constraint is used to estimate a critical accuracy for a satellite lidar wind measuring system. This accuracy is such that the combination of satellite winds with satellite temperatures can produce analyses ...

Norman A. Phillips

1983-01-01T23:59:59.000Z

265

Coronal Heating and Acceleration of the High/Low-Speed Solar Wind by Fast/Slow MHD Shock Trains  

E-Print Network (OSTI)

We investigate coronal heating and acceleration of the high- and low-speed solar wind in the open field region by dissipation of fast and slow magnetohydrodynamical (MHD) waves through MHD shocks. Linearly polarized \\Alfven (fast MHD) waves and acoustic (slow MHD) waves travelling upwardly along with a magnetic field line eventually form fast switch-on shock trains and hydrodynamical shock trains (N-waves) respectively to heat and accelerate the plasma. We determine one dimensional structure of the corona from the bottom of the transition region (TR) to 1AU under the steady-state condition by solving evolutionary equations for the shock amplitudes simultaneously with the momentum and proton/electron energy equations. Our model reproduces the overall trend of the high-speed wind from the polar holes and the low-speed wind from the mid- to low-latitude streamer except the observed hot corona in the streamer. The heating from the slow waves is effective in the low corona to increase the density there, and plays an important role in the formation of the dense low-speed wind. On the other hand, the fast waves can carry a sizable energy to the upper level to heat the outer corona and accelerate the high-speed wind effectively. We also study dependency on field strength, $B_0$, at the bottom of the TR and non-radial expansion of a flow tube, $f_{\\rm max}$, to find that large $B_0/f_{\\rm max}\\gtrsim 2$ but small $B_0\\simeq 2$G are favorable for the high-speed wind and that small $B_0/f_{\\rm max}\\simeq 1$ is required for the low-speed wind.

Takeru K. Suzuki

2003-12-22T23:59:59.000Z

266

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

DOE Green Energy (OSTI)

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.

Rodney Frehlich

2012-10-30T23:59:59.000Z

267

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

E-Print Network (OSTI)

WIND ATLAS FOR EGYPT: MEASUREMENTS, MICRO- AND MESOSCALE MODELLING Niels G. Mortensen1 , Jens Enevoldsen Wind Energy Department, Risø National Laboratory, Roskilde, Denmark Laila Georgy Youssef, Usama Said Said, Ashour Abd El-Salam Moussa, Mohammad Akmal Mahmoud Wind Energy Department, New and Renewable

268

Comparison of Second Wind Triton Data with Meteorological Tower Measurements  

DOE Green Energy (OSTI)

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.

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

2010-02-01T23:59:59.000Z

269

Lidar measurement of wind velocity turbulence spectra encountered by a rotating turbine blade  

DOE Green Energy (OSTI)

A homodyne CO/sub 2/ lidar system beam was conically scanned around a horizontal axis to measure the wind speed and turbulence characteristics encountered by a rotating turbine blade. Turbulence spectra obtained from the scanning lidar differed considerably from those calculated from fixed-point anemometer measurements, showing a redistribution of energy from lower to higher frequencies. The differences appeared more pronounced during periods when the atmosphere was stable.

Hardesty, R.M.; Korrell, J.A.; Hall, F.F. Jr.

1982-01-01T23:59:59.000Z

270

Processing of turbulence-layer wind speed with Generalized SCIDAR through wavelet analysis  

E-Print Network (OSTI)

We describe a new method involving wavelet transforms for deriving the wind velocity associated with atmospheric turbulence layers from Generalized SCIDAR measurements. The algorithm analyses the cross-correlation of a series of scintillation patterns separated by lapses of Dt, 2Dt, 3Dt, 4Dt and 5Dt using wavelet transforms. Wavelet analysis provides the position, direction and altitude of the different turbulence layers detected in each cross-correlation. The comparison and consistency of the turbulent layer displacements in consecutive cross-correlations allow the determination of their velocities and avoid misidentifications associated with noise and/or overlapping layers. To validate the algorithm, we have compared the velocity of turbulence layers derived on four nights with the wind vertical profile provided by balloon measurements. The software is fully automated and is able to analyse huge amounts of Generalized SCIDAR measurements.

B. Garcia-Lorenzo; J. J. Fuensalida

2006-08-28T23:59:59.000Z

271

Low-Cost Wind Speed Measurements Using Naphthalene Evaporation  

Science Conference Proceedings (OSTI)

Six 125-cm3 metal mesh cages, filled with 99% pure naphthalene mothballs, were suspended near anemometers during 8 winter weeks. Each week the cages were weighed to determine how much evaporation had occurred. A least-squares linear regression of ...

Pierre Y. Bernier

1988-10-01T23:59:59.000Z

272

Testing requirements for variable-speed generating technology for wind turbine applications. Final report  

Science Conference Proceedings (OSTI)

Guidelines for evaluating the impacts of integrating variable-speed, constant-frequency (VSCF) wind turbines into electric utility systems have been proposed based upon prior test experiences with the NASA VSCF system and the expected performance of the Westinghouse and OMNION VSCF systems. The NASA and Westinghouse VSCF generating systems use a wound rotor induction generator and a cycloconverter, while the OMNION system uses a wound rotor induction generator and a dc-current link converter. The design of VSCF/utility system interface requirements and test plans is based on utility system electrical issues such as utility system control and operation, protection, voltage/reactive power management, power quality, and reliability. A framework for testing VSCF concepts is proposed which includes a three stage process: modeling of the system to analyze design alternatives and simulate disturbances that could be harmful to the actual system; laboratory testing which involves the use of the system under controlled conditions; and field testing to collect data under actual conditions to validate models and analyze the wind turbine behavior.

Herrera, J.I.

1986-05-01T23:59:59.000Z

273

Application of measured loads to wind turbine fatigue and reliability analysis  

DOE Green Energy (OSTI)

Cyclic loadings produce progressive damage that can ultimately result in wind turbine structural failure. There are many issues that must be dealt with in turning load measurements into estimates of component fatigue life. This paper deals with how the measured loads can be analyzed and processed to meet the needs of both fatigue life calculations and reliability estimates. It is recommended that moments of the distribution of rainflow-range load amplitudes be calculated and used to characterize the fatigue loading. These moments reflect successively more detailed physical characteristics of the loading (mean, spread, tail behavior). Moments can be calculated from data samples and functional forms can be fitted to wind conditions, such as wind speed and turbulence intensity, with standard recession techniques. Distributions of load amplitudes that accurately reflect the damaging potential of the loadings can be estimated from the moments at any, wind condition of interest. Fatigue life can then be calculated from the estimated load distributions, and the overall, long-term, or design spectrum can be generated for any particular wind-speed distribution. Characterizing the uncertainty in the distribution of cyclic loads is facilitated by using a small set of descriptive statistics for which uncertainties can be estimated. The effects of loading parameter uncertainty can then be transferred to the fatigue life estimate and compared with other uncertainties, such as material durability.

Veers, P.S. [Sandia National Labs., Albuquerque, NM (United States); Winterstein, S.R. [Stanford Univ., CA (United States)

1997-01-01T23:59:59.000Z

274

The Effects of the Variations In Sea Surface Temperature and Atmospheric Stability in the Estimation of Average Wind Speed by SEASAT-SASS  

Science Conference Proceedings (OSTI)

Wind speeds from the scatterometer (SASS) on the ocean observing satellite SEASAT averaged over 2° latitude by 2° longitude and a 92-day period are compared with wind speeds from ship reports in the western North Atlantic and the eastern North ...

W. Timothy Liu

1984-02-01T23:59:59.000Z

275

The Influence of Sampling and Filtering on Measured Wind Gusts  

Science Conference Proceedings (OSTI)

The theory by Rice for extreme value statistics is used to study the influence of filters in a wind measuring system on the measured gusts. An extension is made to discretely sampled data. Model results are compared with strong wind data from the ...

A. C. M. Beljaars

1987-12-01T23:59:59.000Z

276

Analysis of SWADE Discus N Wind Speed and Wave Height Time Series. Part II: Quantitative Growth Rates during a Storm  

Science Conference Proceedings (OSTI)

In Part I, wind speed and wave height time series obtained from the Discus N buoy during two storm events recorded in the SWADE experiment were analyzed using discrete wavelet packet transforms. One result of the analysis is that distinct tightly ...

Jorge F. Willemsen

1997-06-01T23:59:59.000Z

277

Consistency of Geosat, SSM/I, and ERS-1 Global Surface Wind Speeds—Comparison with In Situ Data  

Science Conference Proceedings (OSTI)

The authors compare wind speed retrieved from the Geosat altimeter, from two Special Sensor Microwave/Imager (SSM/I) microwave radiometers. The SSM/I F08 and SSM/I F10, and from the European Space Agency ERS-1 scatterometer. As ground truth, ship ...

J. Boutin; J. Etcheto

1996-02-01T23:59:59.000Z

278

A study on nocturnal surface wind speed over-prediction by the WRF-ARW model in Southeastern Texas  

Science Conference Proceedings (OSTI)

The over-prediction of surface wind speed during nighttime by the WRF-ARW model was investigated for a period of the Second Texas Air Quality Study (May 28 – July 3, 2006). In coastal regions of southeastern Texas, the model had significant ...

Fong Ngan; Hyuncheol Kim; Pius Lee; Khalid Al-Wali; Bright Dornblaser

279

Application of Ensemble Sensitivity Analysis to Observation Targeting for Short-term Wind Speed Forecasting  

Science Conference Proceedings (OSTI)

The operators of electrical grids, sometimes referred to as Balancing Authorities (BA), typically make critical decisions on how to most reliably and economically balance electrical load and generation in time frames ranging from a few minutes to six hours ahead. At higher levels of wind power generation, there is an increasing need to improve the accuracy of 0- to 6-hour ahead wind power forecasts. Forecasts on this time scale have typically been strongly dependent on short-term trends indicated by the time series of power production and meteorological data from a wind farm. Additional input information is often available from the output of Numerical Weather Prediction (NWP) models and occasionally from off-site meteorological towers in the region surrounding the wind generation facility. A widely proposed approach to improve short-term forecasts is the deployment of off-site meteorological towers at locations upstream from the wind generation facility in order to sense approaching wind perturbations. While conceptually appealing, it turns out that, in practice, it is often very difficult to derive significant benefit in forecast performance from this approach. The difficulty is rooted in the fact that the type, scale, and amplitude of the processes controlling wind variability at a site change from day to day if not from hour to hour. Thus, a location that provides some useful forecast information for one time may not be a useful predictor a few hours later. Indeed, some processes that cause significant changes in wind power production operate predominantly in the vertical direction and thus cannot be monitored by employing a network of sensors at off-site locations. Hence, it is very challenging to determine the type of sensors and deployment locations to get the most benefit for a specific short-term forecast application. Two tools recently developed in the meteorological research community have the potential to help determine the locations and parameters to measure in order to get the maximum positive impact on forecast performance for a particular site and short-term look-ahead period. Both tools rely on the use of NWP models to assess the sensitivity of a forecast for a particular location to measurements made at a prior time (i.e. the look-ahead period) at points surrounding the target location. The fundamental hypothesis is that points and variables with high sensitivity are good candidates for measurements since information at those points are likely to have the most impact on the forecast for the desired parameter, location and look-ahead period. One approach is called the adjoint method (Errico and Vukicevic, 1992; Errico, 1997) and the other newer approach is known as Ensemble Sensitivity Analysis (ESA; Ancell and Hakim 2007; Torn and Hakim 2008). Both approaches have been tested on large-scale atmospheric prediction problems (e.g. forecasting pressure or precipitation over a relatively large region 24 hours ahead) but neither has been applied to mesoscale space-time scales of winds or any other variables near the surface of the earth. A number of factors suggest that ESA is better suited for short-term wind forecasting applications. One of the most significant advantages of this approach is that it is not necessary to linearize the mathematical representation of the processes in the underlying atmospheric model as required by the adjoint approach. Such a linearization may be especially problematic for the application of short-term forecasting of boundary layer winds in complex terrain since non-linear shifts in the structure of boundary layer due to atmospheric stability changes are a critical part of the wind power production forecast problem. The specific objective of work described in this paper is to test the ESA as a tool to identify measurement locations and variables that have the greatest positive impact on the accuracy of wind forecasts in the 0- to 6-hour look-ahead periods for the wind generation area of California's Tehachapi Pass during the warm (high generation) season. The paper is organized

Zack, J; Natenberg, E; Young, S; Manobianco, J; Kamath, C

2010-02-21T23:59:59.000Z

280

Application of Ensemble Sensitivity Analysis to Observation Targeting for Short-term Wind Speed Forecasting  

DOE Green Energy (OSTI)

The operators of electrical grids, sometimes referred to as Balancing Authorities (BA), typically make critical decisions on how to most reliably and economically balance electrical load and generation in time frames ranging from a few minutes to six hours ahead. At higher levels of wind power generation, there is an increasing need to improve the accuracy of 0- to 6-hour ahead wind power forecasts. Forecasts on this time scale have typically been strongly dependent on short-term trends indicated by the time series of power production and meteorological data from a wind farm. Additional input information is often available from the output of Numerical Weather Prediction (NWP) models and occasionally from off-site meteorological towers in the region surrounding the wind generation facility. A widely proposed approach to improve short-term forecasts is the deployment of off-site meteorological towers at locations upstream from the wind generation facility in order to sense approaching wind perturbations. While conceptually appealing, it turns out that, in practice, it is often very difficult to derive significant benefit in forecast performance from this approach. The difficulty is rooted in the fact that the type, scale, and amplitude of the processes controlling wind variability at a site change from day to day if not from hour to hour. Thus, a location that provides some useful forecast information for one time may not be a useful predictor a few hours later. Indeed, some processes that cause significant changes in wind power production operate predominantly in the vertical direction and thus cannot be monitored by employing a network of sensors at off-site locations. Hence, it is very challenging to determine the type of sensors and deployment locations to get the most benefit for a specific short-term forecast application. Two tools recently developed in the meteorological research community have the potential to help determine the locations and parameters to measure in order to get the maximum positive impact on forecast performance for a particular site and short-term look-ahead period. Both tools rely on the use of NWP models to assess the sensitivity of a forecast for a particular location to measurements made at a prior time (i.e. the look-ahead period) at points surrounding the target location. The fundamental hypothesis is that points and variables with high sensitivity are good candidates for measurements since information at those points are likely to have the most impact on the forecast for the desired parameter, location and look-ahead period. One approach is called the adjoint method (Errico and Vukicevic, 1992; Errico, 1997) and the other newer approach is known as Ensemble Sensitivity Analysis (ESA; Ancell and Hakim 2007; Torn and Hakim 2008). Both approaches have been tested on large-scale atmospheric prediction problems (e.g. forecasting pressure or precipitation over a relatively large region 24 hours ahead) but neither has been applied to mesoscale space-time scales of winds or any other variables near the surface of the earth. A number of factors suggest that ESA is better suited for short-term wind forecasting applications. One of the most significant advantages of this approach is that it is not necessary to linearize the mathematical representation of the processes in the underlying atmospheric model as required by the adjoint approach. Such a linearization may be especially problematic for the application of short-term forecasting of boundary layer winds in complex terrain since non-linear shifts in the structure of boundary layer due to atmospheric stability changes are a critical part of the wind power production forecast problem. The specific objective of work described in this paper is to test the ESA as a tool to identify measurement locations and variables that have the greatest positive impact on the accuracy of wind forecasts in the 0- to 6-hour look-ahead periods for the wind generation area of California's Tehachapi Pass during the warm (high generation) season. The paper is organized

Zack, J; Natenberg, E; Young, S; Manobianco, J; Kamath, C

2010-02-21T23:59:59.000Z

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Factors Affecting Surface Wind Speeds in Gravity Waves and Wake Lows  

Science Conference Proceedings (OSTI)

Ducted gravity waves and wake lows have been associated with numerous documented cases of “severe” winds (>25 m s?1) and wind damage. These winds are associated with the pressure perturbations and transient mesoscale pressure gradients occurring ...

Timothy A. Coleman; Kevin R. Knupp

2009-12-01T23:59:59.000Z

282

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

DOE Green Energy (OSTI)

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.

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

2007-09-01T23:59:59.000Z

283

Measuring the Dynamic Performance of Wind Vanes  

Science Conference Proceedings (OSTI)

The American Society for Testing and Materials (ASTM) has proposed a standard method for testing the performance characteristics of a wind vane. This paper presents the procedures used to test and evaluate the ASTM method, and the results of that ...

Peter L. Finkelstein

1981-05-01T23:59:59.000Z

284

Standard Test Method for Measured Speed of Oil Diffusion Pumps  

E-Print Network (OSTI)

1.1 This test method covers the determination of the measured speed (volumetric flow rate) of oil diffusion pumps. 1.2 The values stated in inch-pound units are to be regarded as the standard. The metric equivalents of inch-pound units may be approximate. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

American Society for Testing and Materials. Philadelphia

1982-01-01T23:59:59.000Z

285

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

E-Print Network (OSTI)

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

Haak, Hein

286

Low Wind Speed Technology Phase II: Offshore Floating Wind Turbine Concepts: Fully Coupled Dynamic Response Simulations; Massachusetts Institute of Technology  

SciTech Connect

This fact sheet describes a subcontract with Massachusetts Institute of Technology to study dynamic response simulations to evaluate floating platform concepts for offshore wind turbines.

2006-03-01T23:59:59.000Z

287

A Sensitive Fast-Response Manometric Wind Sensor  

Science Conference Proceedings (OSTI)

A manometric type of wind sensor has been developed. This sensor convert the dynamic pressure of the wind into a modulated dynamic pressure signal which can then be sensed using microphones. This permits wind speed measurements to be made with ...

K. E. Kunkel; C. W. Bruce

1983-11-01T23:59:59.000Z

288

Wind Structure in a Supercell Thunderstorm as Measured by a UHF Wind Profiler  

Science Conference Proceedings (OSTI)

A mesocyclone associated with a tornadic supercell passed almost directly over the Lamont, Oklahoma, 404-MHz wind profiler on 24 May 1998. The archived spectral moment data, including 6-min resolution radial velocity measurements from the ...

Gregor S. Lehmiller; Howard B. Bluestein; Paul J. Neiman; F. Martin Ralph; Wayne F. Feltz

2001-08-01T23:59:59.000Z

289

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

Science Conference Proceedings (OSTI)

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.

Hunt, A.; Easley, S.

2012-05-01T23:59:59.000Z

290

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

E-Print Network (OSTI)

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

Talley, Lynne D.

291

THE ATMOSPHERIC DYNAMICS MISSION FOR GLOBAL WIND FIELD MEASUREMENT  

Science Conference Proceedings (OSTI)

The prime aim of the Atmospheric Dynamics Mission is to demonstrate measurements of vertical wind profiles from space. Extensive studies conducted by the European Space Agency over the past 15 years have culminated in the selection of a high-...

Ad Stoffelen; Jean Pailleux; Erland Källén; J. Michael Vaughan; Lars Isaksen; Pierre Flamant; Werner Wergen; Erik Andersson; Harald Schyberg; Alain Culoma; Roland Meynart; Martin Endemann; Paul Ingmann

2005-01-01T23:59:59.000Z

292

Microelectronic Thermal Anemometer for the Measurement of Surface Wind  

Science Conference Proceedings (OSTI)

The paper describes the development and first prototype results of a microelectronic thermal anemometer without moving parts, for the measurement of velocity and direction of surface wind. The central part of the instrument is an integrated-...

B. W. Van Oudheusden; J. H. Huijsing

1991-06-01T23:59:59.000Z

293

The Power Decoupling Control for Wind Power Converter Based on a Novel Speed Sensor-Less  

Science Conference Proceedings (OSTI)

Doubly fed induction generators based wind turbines are today one of the most widely used generation systems in wind farms. The stator is directly connected to the constant frequency three phase grid and the rotor currents are appropriately controlled ...

Zhang Jia-ming; Fu Yang

2009-10-01T23:59:59.000Z

294

Resolving Nonstationary Spectral Information in Wind Speed Time Series Using the Hilbert–Huang Transform  

Science Conference Proceedings (OSTI)

This work is motivated by the observation that large-amplitude wind fluctuations on temporal scales of 1–10 h present challenges for the power management of large offshore wind farms. Wind fluctuations on these scales are analyzed at a ...

Claire Vincent; Gregor Giebel; Pierre Pinson; Henrik Madsen

2010-02-01T23:59:59.000Z

295

Wind Speed Technology Phase II: Semisubmersible Platform and Anchor Foundation Systems for Wind Turbine Support; Concept Marine Associates, Inc.  

SciTech Connect

This fact sheet describes a subcontract with Concept Marine Associates, Inc. to evaluate and optimize a semisubmersible platform and anchor foundation system that can support a 5-MW wind turbine.

2006-03-01T23:59:59.000Z

296

An Experimental Field Dataset with Buoyant, Neutral, and Dense Gas Atmospheric Releases and Model Comparisons in Low–Wind Speed (Diffusion) Conditions  

Science Conference Proceedings (OSTI)

A unique field dataset from a series of low–wind speed experiments, modeling efforts using three commonly used models to replicate these releases, and statistical analysis of how well these models were able to predict the plume concentrations is ...

Veronica E. Wannberg; Gustavious Williams; Patrick Sawyer; Richard Venedam

2010-09-01T23:59:59.000Z

297

Determination of the Mean Wind Speed and Momentum Diffusivity Profiles above Tall Vegetation and Forest Canopies Using a Mass Conservation Assumption  

Science Conference Proceedings (OSTI)

A semianalytical method based on a mass conservation principle is presented for describing the transition- layer profiles of mean wind speed and momentum diffusivity and for estimating the aerodynamic characteristics of forest and tall vegetation ...

N. M. Zoumakis

1994-02-01T23:59:59.000Z

298

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

DOE Green Energy (OSTI)

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.

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

2012-01-01T23:59:59.000Z

299

The Solar Wind Energy Flux  

E-Print Network (OSTI)

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 solar-wind speed and density, which formalizes the anti-correlation between these quantities.

Chat, G Le; Meyer-Vernet, N

2012-01-01T23:59:59.000Z

300

The Prediction of Nearshore Wind-induced Surface Currents from Wind Velocities Measured at Nearby Land Stations  

Science Conference Proceedings (OSTI)

This paper aims to find a fast and efficient way to predict the wind-induced components of surface currents in a nearshore coastal area of several hundred square kilometers from wind velocities measured at nearby land stations. Ocean Surface ...

Betty Ng

1993-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Comparison on control strategies of the grid-side converter of variable speed constant frequency doubly-fed wind power generation system  

Science Conference Proceedings (OSTI)

Direct power control, vector control based on d-q synchronous rotating reference frame and ?-? static reference frame for the grid-side converter of variable speed constant frequency doubly-fed wind turbines are analyzed. System simulation ... Keywords: ?-? static reference frame, d-q rotating reference frame, direct power control, doubly-fed wind power generation system, grid-side converter

Xian-Ming Zhou; Ting-Long Pan; Zhi-Cheng Ji

2009-06-01T23:59:59.000Z

302

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

E-Print Network (OSTI)

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.

D'Amico, Guglielmo; Prattico, Flavio

2012-01-01T23:59:59.000Z

303

WIND ENERGY Wind Energ. (2012)  

E-Print Network (OSTI)

WIND ENERGY Wind Energ. (2012) Published online in Wiley Online Library (wileyonlinelibrary since energy production depends non-linearly on wind speed (U ), and wind speed observa- tions for the assessment of future long-term wind supply A. M. R. Bakker1 , B. J. J. M. Van den Hurk1 and J. P. Coelingh2 1

Haak, Hein

304

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

E-Print Network (OSTI)

The critical speeds of a turbomachine can be defined as the speeds at which synchronous response to imbalance is maximum (Vance,1988). Identifying the proper placement of critical speeds is very important in the design process of turbomachinery. 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 film damper. The measurements were recorded with a Bentley Nevada ADRE 208 Data Acquisition Interface Unit System. These measurements are compared with predictions from a XLROTOR (Spreadsheet for Rotordynamic Analysis) computer model. Measurement imbalance responses show that imbalance location has profound influence on critical speeds. A critical speed variation up to 25 % was found. Comparison between the XLROTOR computer model prediction and measurement shows excellent agreement.

Marin, Manuel

1996-01-01T23:59:59.000Z

305

WIND DATA REPORT Presque Isle  

E-Print Network (OSTI)

WIND DATA REPORT Presque Isle December 1, 2004 ­ December 1, 2005 Prepared for United States ......................................................................................................... 9 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

Massachusetts at Amherst, University of

306

WIND DATA REPORT Thompson Island  

E-Print Network (OSTI)

WIND DATA REPORT Thompson Island June 1, 2003 ­ August 31, 2003 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

Massachusetts at Amherst, University of

307

WIND DATA REPORT Thompson Island  

E-Print Network (OSTI)

WIND DATA REPORT Thompson Island December 1, 2003 ­ February 29, 2004 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distribution

Massachusetts at Amherst, University of

308

WIND DATA REPORT Thompson Island  

E-Print Network (OSTI)

WIND DATA REPORT Thompson Island June 1, 2004 ­ August 31, 2004 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

Massachusetts at Amherst, University of

309

WIND DATA REPORT FALMOUTH, MA  

E-Print Network (OSTI)

WIND DATA REPORT FALMOUTH, MA June1, 2004 to August 31, 2004. Prepared for Massachusetts Technology...................................................................................................................... 8 Wind Speed Time Series............................................................................................................. 8 Wind Speed Distributions

Massachusetts at Amherst, University of

310

WIND DATA REPORT Thompson Island  

E-Print Network (OSTI)

WIND DATA REPORT Thompson Island September 1, 2003 ­ November 30, 2003 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

Massachusetts at Amherst, University of

311

WIND DATA REPORT Thompson Island  

E-Print Network (OSTI)

WIND DATA REPORT Thompson Island March 1, 2004 ­ May 31, 2004 Prepared for Massachusetts Technology...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

Massachusetts at Amherst, University of

312

WIND DATA REPORT Presque Isle  

E-Print Network (OSTI)

WIND DATA REPORT Presque Isle December 1, 2004 ­ February 28, 2005 Prepared for United States.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

Massachusetts at Amherst, University of

313

WIND DATA REPORT Presque Isle  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

314

WIND DATA REPORT Presque Isle  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

315

WIND DATA REPORT Thompson Island  

E-Print Network (OSTI)

WIND DATA REPORT Thompson Island March 1, 2003 ­ May 31, 2003 Prepared for Massachusetts Technology...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

Massachusetts at Amherst, University of

316

Accounting for Surface Wave Distortion of the Marine Wind Profile in Low-Level Ocean Storms Wind Measurements  

Science Conference Proceedings (OSTI)

Marine wind measurements at three heights (3.0,4.5, and 5.0 m) from both moored and drifting buoys during the Ocean Storms Experiment are described. These winds are compared with each other, with winds from ships, from subsurface ambient acoustic ...

W. G. Large; J. Morzel; G. B. Crawford

1995-11-01T23:59:59.000Z

317

Brief paper: Speed regulation with measured output feedback in the control of heavy haul trains  

Science Conference Proceedings (OSTI)

An approach of output regulation with measurement feedback is proposed for the control of heavy haul trains. The objective is to regulate all cars' speeds to a prescribed speed profile. The output regulation problem of nonlinear systems with measurement ... Keywords: ECP braking system, Heavy haul trains, Measured output feedback, Output regulation, Quadratic programming

X. Zhuan; X. Xia

2008-01-01T23:59:59.000Z

318

Damage measurements on the NWTC direct-drive, variable-speed test bed  

SciTech Connect

The NWTC (National Wind Technology Center) Variable-Speed Test Bed turbine is a three-bladed, 10-meter, downwind machine that can be run in either fixed-speed or variable-speed mode. In the variable-speed mode, the generator torque is regulated, using a discrete-stepped load bank to maximize the turbine`s power coefficient. At rated power, a second control loop that uses blade pitch to maintain rotor speed essentially as before, i.e., using the load bank to maintain either generator power or (optionally) generator torque. In this paper, the authors will use this turbine to study the effect of variable-speed operation on blade damage. Using time-series data obtained from blade flap and edge strain gauges, the load spectrum for the turbine is developed using rainflow counting techniques. Miner`s rule is then used to determine the damage rates for variable-speed and fixed-speed operation. The results illustrate that the controller algorithm used with this turbine introduces relatively large load cycles into the blade that significantly reduce its service lifetime, while power production is only marginally increased.

Sutherland, H.J. [Sandia National Lab., Albuquerque, NM (United States); Carlin, P.W. [National Renewable Energy Lab., Golden, CO (United States)

1998-12-31T23:59:59.000Z

319

Modeling Coastally Trapped Wind Surges over Southeastern Australia. Part I: Timing and Speed of Propagation  

Science Conference Proceedings (OSTI)

During the spring and summer months, the southeast coast of Australia often experiences abrupt southerly wind changes, the leading edge being known locally as a “southerly buster.” The main characteristic of this phenomenon is the sudden shift in ...

Helen J. Reid; Lance M. Leslie

1999-02-01T23:59:59.000Z

320

Prediction of Wind Speed, Direction and Diffusivity under Neutral Conditions for Tall Stacks  

Science Conference Proceedings (OSTI)

A one dimensional model of the neutral planetary boundary layer is used to predict the wind velocity and coefficient of eddy diffusivity throughout the 2-km planetary boundary layer. Comparison with routine radiosonde observations show that at ...

Nirupama Raghavan; Swati Basu

1988-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Altimeter Estimation of Sea Surface Wind Stress for Light to Moderate Winds  

Science Conference Proceedings (OSTI)

Aircraft altimeter and in situ measurements are used to examine relationships between altimeter backscatter and the magnitude of near-surface wind and friction velocities. Comparison of altimeter radar cross section with wind speed is made ...

Douglas Vandemark; James B. Edson; Bertrand Chapron

1997-06-01T23:59:59.000Z

322

Comparison of Wind Monitoring Systems. Pad II: Doppley. Sodars  

Science Conference Proceedings (OSTI)

Measurements of wind speed, wind direction, and the vertical component of turbulence, from four different commercially available Doppler sodars, are compared with similar measurements from in situ sensors on a 300 m instrumented tower. Results ...

P. L. Finkelstein; J. C. Kaimal; J. E. Gaynor; M. E. Graves; T. J. Lockhart

1986-12-01T23:59:59.000Z

323

Oblique, Stratified Winds about a Shelter Fence. Part I: Measurements  

Science Conference Proceedings (OSTI)

Wind statistics were measured using cup and sonic anemometers, placed upwind and downwind from a porous plastic windbreak fence (height h = 1.25 m, length Y = 114 m, resistance coefficient kr0 = 2.4, and porosity p = 0.45) standing on otherwise ...

John D. Wilson

2004-08-01T23:59:59.000Z

324

Evaluation of DBS Wind Measurement Technique in Different Beam Configurations for a VHF Wind Profiler  

Science Conference Proceedings (OSTI)

Atmospheric winds in the troposphere have been observed routinely for many years with wind profiling (VHF and UHF) radars using the Doppler beam swinging (DBS) technique. Accuracy of wind estimates using wind profiling radars with different beam ...

I. Srinivasa Rao; V. K. Anandan; P. Narasimha Reddy

2008-12-01T23:59:59.000Z

325

Hurricane Andrew's Landfall in South Florida. Part I: Standardizing Measurements for Documentation of Surface Wind Fields  

Science Conference Proceedings (OSTI)

Hurricane Andrew's landfall in south Florida left a swath of destruction, including many failed anemometer recording systems. Extreme destruction led to exaggerated claims of the range of wind speed that caused such damage. The authors ...

Mark D. Powell; Samuel H. Houston; Timothy A. Reinhold

1996-09-01T23:59:59.000Z

326

Meteorological field measurements at potential and actual wind turbine sites  

DOE Green Energy (OSTI)

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.

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

1982-09-01T23:59:59.000Z

327

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

E-Print Network (OSTI)

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

Dyer, Bill

328

A Similarity Hypothesis for Air–Sea Exchange at Extreme Wind Speeds  

Science Conference Proceedings (OSTI)

Hurricane intensity is sensitive to fluxes of enthalpy and momentum between the ocean and atmosphere in the high wind core of the storm. It has come to be recognized that much of this exchange is likely mediated by sea spray. A number of ...

Kerry Emanuel

2003-06-01T23:59:59.000Z

329

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

E-Print Network (OSTI)

, China mcheng@seu.edu.cn Abstract-- Grid connected wind turbines are the sources of power fluctuations and the individual pitch controller is designed. The simulations are performed on the NREL (National Renewable Energy shortage, great efforts have been taken around the world to implement renewable energy projects

Chen, Zhe

330

Stability Dependence of the Ratio of Wind Speeds at Two Levels over Agriculture Land  

Science Conference Proceedings (OSTI)

Hourly averaged winds are computed from a one-year record taken atop five 10 m towers and four 30 m towers distributed over 4000 km2 of typical agricultural land. Vertical temperature differences are available from three of the 30 m towers. The ...

Jack H. Shreffler

1980-04-01T23:59:59.000Z

331

Wave- and Anemometer-Based Sea Surface Wind (WASWind) for Climate Change Analysis  

Science Conference Proceedings (OSTI)

Ship-based measurements of sea surface wind speed display a spurious upward trend due to increases in anemometer height. To correct this bias, the authors constructed a new sea surface wind dataset from ship observations of wind speed and wind ...

Hiroki Tokinaga; Shang-Ping Xie

2011-01-01T23:59:59.000Z

332

Reduced Loss in Precipitation Measurements Using a New Wind Shield for Raingages  

Science Conference Proceedings (OSTI)

A problem of great concern in precipitation measurements is the wind loss. This paper presents a new wind shield that reduces this loss. Tests of the new shield were made in a wind tunnel and in the field. The wind shield consisted of a flange ...

Anders Lindroth

1991-06-01T23:59:59.000Z

333

NREL: Wind Research - Offshore Wind Resource Characterization  

NLE Websites -- All DOE Office Websites (Extended Search)

Offshore Wind Resource Characterization Offshore Wind Resource Characterization Map of the United States, showing the wind potential of offshore areas across the country. Enlarge image US offshore wind speed estimates at 90-m height NREL scientists and engineers are leading efforts in resource mapping, remote sensor measurement and development, and forecasting that are essential for the development of offshore wind. Resource Mapping For more than 15 years, NREL's meteorologists, engineers, and Geographic Information System experts have led the production of wind resource characterization maps and reports used by policy makers, private industry, and other government organizations to inform and accelerate the development of wind energy in the United States. Offshore wind resource data and mapping has strategic uses. As with terrestrial developments, traditional

334

Real-Time Retrieval of the Wind from Aliased Velocities Measured by Doppler Radars  

Science Conference Proceedings (OSTI)

Doppler radar measurements provide the radial wind within an unambiguous interval due to the limited value of the sampling frequency (pulse repetition frequency). Many algorithms have been developed to retrieve true wind velocities from measured ...

Pierre Tabary; Georges Scialom; Urs Germann

2001-06-01T23:59:59.000Z

335

Frostbite Theater - Experiments You Can Try at Home! - Measure the Speed of  

NLE Websites -- All DOE Office Websites (Extended Search)

It's Done - Anti-Gravity Water Trick! It's Done - Anti-Gravity Water Trick! Previous Video (How It's Done - Anti-Gravity Water Trick!) Frostbite Theater Main Index Next Video (Measure the Width of a Hair - With a Laser!) Measure the Width of a Hair - With a Laser! Measure the Speed of Light - With Chocolate! 'C' is for chocolate! 'c' is also the symbol used for the speed of light. Defined as being 299,792,458 meters per second in vacuum, you can take a crack at measuring the ultimate speed using your microwave, a ruler and a bar of chocolate! Yum! [ Show Transcript ] Announcer: Frostbite Theater presents... Cold Cuts! No baloney! Joanna and Steve: Just science! Joanna: Hi! I'm Joanna! Steve: And I'm Steve! Joanna: Today, we're going to show you how to measure the speed of light using your microwave, a ruler and... a bar of chocolate!

336

Remote wind measurements with a new microprocessor-based accumulator device  

SciTech Connect

The employment of a unique microprocessor-based accumulator device for remote meteorological measurements is described. The unit was designed for remote application with wind instruments to respond to the need for a very inexpensive survey unit to provide statistical summaries of basic wind data for the wind turbine siting decision process. While it is versatile enough to be used in many other remote measurement scenarios, the device will be described primarily in its application to wind measurements for siting wind energy conversion systems (WECS), otherwise known as wind turbines.

Verholek, M.G.; Ekstrom, P.A.

1978-04-01T23:59:59.000Z

337

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

E-Print Network (OSTI)

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.

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

2012-01-01T23:59:59.000Z

338

Advances in the Estimation of Ice Particle Fall Speeds Using Laboratory and Field Measurements  

Science Conference Proceedings (OSTI)

Accurate estimates for the fall speed of natural hydrometeors are vital if their evolution in clouds is to be understood quantitatively. In this study, laboratory measurements of the terminal velocity ?t for a variety of ice particle models ...

A. J. Heymsfield; C. D. Westbrook

2010-08-01T23:59:59.000Z

339

Instrumentation for the Measurement of Sound Speed near the Ocean Surface  

Science Conference Proceedings (OSTI)

Air bubbles entrained by breaking waves in the ocean surface layer can dramatically alter the velocity and attenuation of acoustic waves. The development of an effective technique for directly measuring the sound speed near the ocean surface is ...

Eric Lamarre; W. K. Melville

1995-04-01T23:59:59.000Z

340

Wave-Follower Field Measurements of the Wind-Input Spectral Function. Part I: Measurements and Calibrations  

Science Conference Proceedings (OSTI)

An experimental study of wind energy and momentum input into finite-depth wind waves was undertaken at Lake George, New South Wales, Australia. To measure microscale oscillations of induced pressure above surface waves, a high-precision wave-...

Mark A. Donelan; Alexander V. Babanin; Ian R. Young; Michael L. Banner; Cyril McCormick

2005-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

High Speed High Dynamic Range High Accuracy Measurement System  

Disclosure Number 201102747 Technology Summary The present invention measures a beam of protons that has a high dynamic range. Typically, one uses ...

342

Wake Measurements of a Multi-MW Wind Turbine with Coherent Long-Range Pulsed Doppler Wind Lidar  

Science Conference Proceedings (OSTI)

Long-range Doppler wind light detection and ranging (lidar) measurements at a wind turbine were carried out for the first time. The turbine was of the type Areva M5000 and is located at a site near the coastline in Bremerhaven, in the northern ...

Yvonne Käsler; Stephan Rahm; Rudolf Simmet; Martin Kühn

2010-09-01T23:59:59.000Z

343

WIND DATA REPORT January -March, 2004  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

344

WIND DATA REPORT Deer Island Outfall  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

345

ANNUAL WIND DATA REPORT Thompson Island  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

346

WIND DATA REPORT Deer Island Parking Lot  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

347

WIND DATA REPORT January -December, 2003  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

348

Simulation of winds as seen by a rotating vertical axis wind turbine blade  

DOE Green Energy (OSTI)

The objective of this report is to provide turbulent wind analyses relevant to the design and testing of Vertical Axis Wind Turbines (VAWT). A technique was developed for utilizing high-speed turbulence wind data from a line of seven anemometers at a single level to simulate the wind seen by a rotating VAWT blade. Twelve data cases, representing a range of wind speeds and stability classes, were selected from the large volume of data available from the Clayton, New Mexico, Vertical Plane Array (VPA) project. Simulations were run of the rotationally sampled wind speed relative to the earth, as well as the tangential and radial wind speeds, which are relative to the rotating wind turbine blade. Spectral analysis is used to compare and assess wind simulations from the different wind regimes, as well as from alternate wind measurement techniques. The variance in the wind speed at frequencies at or above the blade rotation rate is computed for all cases, and is used to quantitatively compare the VAWT simulations with Horizontal Axis Wind Turbine (HAWT) simulations. Qualitative comparisons are also made with direct wind measurements from a VAWT blade.

George, R.L.

1984-02-01T23:59:59.000Z

349

A Multisodar Approach to Wind Profiling  

Science Conference Proceedings (OSTI)

This paper presents the development of a multisodar mode from a five-beam sodar whereby a wind speed vector is found for sets of three acoustic beams. If the vertical beam is used, this mode enables the profiling of four wind speed measurements ...

Paul Behrens; Stuart Bradley; Travis Wiens

2010-07-01T23:59:59.000Z

350

HIGH DYNAMIC-RANGE HIGH SPEED LINAC CURRENT MEASUREMENTS  

SciTech Connect

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.

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

2012-01-01T23:59:59.000Z

351

Measurement of Clear-Air Gradients and Turbulence Properties with Radar Wind Profilers  

Science Conference Proceedings (OSTI)

An experiment comparing balloon and profiler observations was carried out to evaluate the capability of Doppler radar wind profilers to remotely measure useful meteorological quantities other than wind. The site chosen was in Southern California ...

E. E. Gossard; D. E. Wolfe; K. P. Moran; R. A. Paulus; K. D. Anderson; L. T. Rogers

1998-04-01T23:59:59.000Z

352

Lidar-Measured Wind Profiles – The Missing Link in the Global Observing System  

Science Conference Proceedings (OSTI)

The three-dimensional global wind field is the most important remaining measurement needed to accurately assess the dynamics of the atmosphere. Wind information in the tropics, high latitudes, and stratosphere, is particularly deficient. Furthermore, only ...

Wayman E. Baker; Robert Atlas; Carla Cardinali; Amy Clement; George D. Emmitt; Bruce M. Gentry; R. Michael Hardesty; Erland Källén; Michael J. Kavaya; Rolf Langland; Zaizhong Ma; Michiko Masutani; Will McCarty; R. Bradley Pierce; Zhaoxia Pu; Lars Peter Riishojgaard; James Ryan; Sara Tucker; Martin Weissmann; James G. Yoe

353

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

DOE Green Energy (OSTI)

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%.

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

2004-12-01T23:59:59.000Z

354

Synchrophasor Measurement-Based Wind Plant Inertia Estimation: Preprint  

DOE Green Energy (OSTI)

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.

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

2013-05-01T23:59:59.000Z

355

Wind resource assessment with a mesoscale non-hydrostatic model  

E-Print Network (OSTI)

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

Paris-Sud XI, Université de

356

Wind Power Plant Prediction by Using Neural Networks: Preprint  

DOE Green Energy (OSTI)

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.

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

2012-08-01T23:59:59.000Z

357

A New Analysis to Diagnose Ageostrophic Winds from Wind and Temperature Measurements Made by an Observational Network  

Science Conference Proceedings (OSTI)

The present paper is devoted to a new analysis of winds and temperature measurements made by an observational network in order to provide the 3D ageostrophic circulations. This analysis may be used with data from instrumented networks providing ...

Y. Lemaître; P. Neveux; G. Scialom

1994-06-01T23:59:59.000Z

358

Comparison of Wind Profiler and Aircraft Wind Measurements at Chebogue Point, Nova Scotia  

Science Conference Proceedings (OSTI)

In August 1993, a 915-MHz boundary layer wind-profiling radar was deployed at Chebogue Point, Nova Scotia, to provide wind, turbulence, and boundary layer structure information for the North Atlantic Regional Experiment summer 1993 intensive ...

Wayne M. Angevine; J. Ian Macpherson

1995-04-01T23:59:59.000Z

359

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

E-Print Network (OSTI)

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

Mountziaris, T. J.

360

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

E-Print Network (OSTI)

II 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 issues. 1 Background In Task 2 of the project, five promising areas of the state for wind energy

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Modeling Wind Speed Dependence of Marine Aerosol Distribution by a Gamma Function  

Science Conference Proceedings (OSTI)

Marine aerosol size distributions are fit to a gamma function using the technique of maximum likelihood. Aerosol measurements are separated into marine and continental components. The marine component is fit to the gamma function to provide a set ...

Andreas K. Goroch; C. W. Fairall; K. L. Davidson

1982-05-01T23:59:59.000Z

362

Wind Speeds in Two Tornadic Storms and a Tornado, Deduced from Doppler Spectra  

Science Conference Proceedings (OSTI)

Doppler spectra of a tornado were collected with a radar having a large unambiguous velocity range, ±91 m s?1. Thus for the first time a presentation of nonaliased spectra was possible, showing direct measurement of radial velocities. By fitting ...

Dusan Zrnic; Michael Istok

1980-12-01T23:59:59.000Z

363

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

E-Print Network (OSTI)

speeds have a number of useful applications in industry such as measuring gas composition, temperature and the quality of gaseous fuels for alternative fueled vehicles such as hydrogen, natural gas, and propane, to accurately measure the composition of binary gas mixtures. More recently, Huang et al.11 used this method

364

NREL: Wind Research - Offshore Wind Research  

NLE Websites -- All DOE Office Websites (Extended Search)

Options Site Map Printable Version Offshore Standards and Testing NREL's Offshore Wind Testing Capabilities 35 years of wind turbine testing experience Custom high speed data...

365

IEA Wind Annex XX: HAWT Aerodynamics and Models from Wind Tunnel Measurements; Final Report  

DOE Green Energy (OSTI)

This work characterizes undocumented physical relationships that govern aerodynamic force time variations that take place in connection with rotational augmentation on rotating wind turbine blades.

Schreck, S.

2008-12-01T23:59:59.000Z

366

CWEX (Crop/Wind-Energy Experiment): Measurements of the interaction between crop agriculture and wind power.  

E-Print Network (OSTI)

??The current expansion of wind farms in the U.S. Midwest promotes an alternative renewable energy portfolio to conventional energy sources derived from fossil fuels. The… (more)

Rajewski, Daniel Andrew

2013-01-01T23:59:59.000Z

367

Estimating Downburst-Related Maximum Surface Wind Speeds by Means of Proximity Soundings in New South Wales, Australia  

Science Conference Proceedings (OSTI)

A regional climatology of strong wind gusts associated with thunderstorms is presented, and the ability to estimate gust strength from ambient conditions is tested. Strong wind events were selected for 10 stations in New South Wales, Australia, ...

Bart Geerts

2001-04-01T23:59:59.000Z

368

Very short-term wind speed forecasting with Bayesian structural break model , Zhe Song a,*, Andrew Kusiak b  

E-Print Network (OSTI)

reserved. 1. Introduction Wind is one of the most promising green energy sources. The world's installed-1527, Iowa City, United States a r t i c l e i n f o Article history: Received 27 November 2011 Accepted 31 wind power capacity is exponentially increasing in recent years and wind industry is expanding

Kusiak, Andrew

369

Application of a Bayesian Wind Profile Retrieval Technique to Radar Data Collected in the Alpine Southern Upslope Region and Comparison with Upstream Wind Profiler Measurements  

Science Conference Proceedings (OSTI)

In this paper, a new operational technique to retrieve the horizontal wind profile from Doppler radar measurements is used to carry out a statistical comparison of upslope and upstream wind profiles in the southern flank of the European Alps. The ...

P. Tabary; M. Petitdidier

2002-06-01T23:59:59.000Z

370

NREL GIS Data: Global Offshore Wind GIS data for offshore wind...  

Open Energy Info (EERE)

Global Offshore Wind GIS data for offshore wind speed (meterssecond).  Specified to Exclusive Economic Zones (EEZ).

Wind resource based on NOAA blended sea winds and...

371

Low Wind Speed Technology Phase I: Evaluation of Design and Construction Approaches for Economical Hybrid Steel/Concrete Wind Turbine Towers; BERGER/ABAM Engineers Inc.  

DOE Green Energy (OSTI)

This fact sheet describes a subcontract with BERGER/ABAM Engineers Inc. to study the economic feasibility of concrete and hybrid concrete/steel wind turbine towers.

Not Available

2006-03-01T23:59:59.000Z

372

The Effects of Marine Winds from Scatterometer Data on Weather Analysis and Forecasting  

Science Conference Proceedings (OSTI)

Satellite scatterometer observations of the ocean surface wind speed and direction improve the depiction of storms at sea. Over the ocean, scatterometer surface winds are deduced from multiple measurements of reflected radar power made from ...

R. Atlas; R. N. Hoffman; S. M. Leidner; J. Sienkiewicz; T-W. Yu; S. C. Bloom; E. Brin; J. Ardizzone; J. Terry; D. Bungato; J. C. Jusem

2001-09-01T23:59:59.000Z

373

Comparisons of Horizontal Winds Measured by Opposing Beams with the Flatland ST Radar and between Flatland Measurements and NMC Analyses  

Science Conference Proceedings (OSTI)

This study examines the consistency between VHF horizontal wind measurements and those interpolated from routine objective analyses. First, the agreement between the two U components and between the two V components measured on opposing beams (...

Patricia M. Pauley; Robert L. Creasey; Wallace L. Clark; Gregory D. Nastrom

1994-04-01T23:59:59.000Z

374

WIND DATA REPORT December 1 2003 February 29 2004  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

375

WIND DATA REPORT Camden Hills Regional High School, ME  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

376

WIND DATA REPORT September 1 2003 November 30 2003  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

377

WIND DATA REPORT Camden Hills Regional High School, ME  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

378

WIND DATA REPORT March 1, 2004 May 31, 2004  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

379

WIND DATA REPORT Camden Hills Regional High School, ME  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

380

WIND DATA REPORT December 1, 2003 February 29, 2004  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

WIND DATA REPORT Camden Hills Regional High School, ME  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

382

Validation of HRDI MLT winds with meteor radars  

Science Conference Proceedings (OSTI)

applied to determine whether the wind speed has been overestimated by HRDI ... wind vector components as well as wind speeds, and two nonparametric tests ...

383

WIND DATA REPORT Camden Hills Regional High School, ME  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

384

WIND DATA REPORT December, 2003 February 29, 2004  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

385

WIND DATA REPORT October 27, 2003 November 31, 2003  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

386

WIND DATA REPORT January 1, 2004 December 31, 2004  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

387

WIND DATA REPORT September 1, 2003 November 31, 2003  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

388

WIND DATA REPORT August 28 -December 31, 2002  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

389

Importance of Thermal Effects and Sea Surface Roughness for Offshore Wind Resource Assessment  

E-Print Network (OSTI)

The economic feasibility of offshore wind power utilisation depends on the favourable wind conditions offshore as compared to sites on land. The higher wind speeds have to compensate the additional cost of offshore developments. However, not only the mean wind speed is different, but the whole flow regime, as can e.g. be seen in the vertical wind speed profile. The commonly used models to describe this profile have been developed mainly for land sites. Their applicability for wind power prediction at offshore sites is investigated using data from the measurement program Rdsand, located in the Danish Baltic Sea.

Bernhard Lange; Sřren Larsen; Jřrgen Hřjstrup Rebecca Barthelmie; Jřrgen Hřjstrup; Rebecca Barthelmie; Bernhard Lange

2004-01-01T23:59:59.000Z

390

Measurements of Wind and Turbulence Profiles with Scanning Doppler Lidar for Wind Energy Applications  

SciTech Connect

High-quality profiles of mean and turbulent statistics of the wind field upstream of a wind farm can be produced using a scanning Doppler lidar. Careful corrections for the spatial filtering of the wind field by the lidar pulse produce turbulence estimates equivalent to point sensors but with the added advantage of a larger sampling volume to increase the statistical accuracy of the estimates. For a well-designed lidar system, this permits accurate estimates of the key turbulent statistics over various subdomains and with sufficiently short observation times to monitor rapid changes in conditions. These features may be ideally suited for optimal operation of wind farms and also for improved resource assessment of potential sites.

Frehlich, R.; Kelley, N.

2008-03-01T23:59:59.000Z

391

PTC, ITC, or Cash Grant? Measuring the Value of Stimulus to Wind Power  

NLE Websites -- All DOE Office Websites (Extended Search)

PTC, ITC, or Cash Grant? Measuring the Value of Stimulus to Wind Power PTC, ITC, or Cash Grant? Measuring the Value of Stimulus to Wind Power Projects in the United States Speaker(s): Mark Bolinger Date: January 26, 2010 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Ryan Wiser The financial crisis of 2008/2009 spawned two major stimulus packages in the U.S. that, in combination, have fundamentally reshaped the federal policy landscape for wind power. Most notably, qualifying wind projects can now, for a limited time only, choose either a 30% investment tax credit (ITC) or a 30% cash grant in lieu of the 10-year production tax credit (PTC) that wind has historically received. This presentation analyzes the impact of this newfound choice of federal incentives on wind power development in the U.S., focusing not only on the relative "face value"

392

Low Wind Speed Technology Phase II: Reducing Cost of Energy Through Rotor Aerodynamics Control; Global Energy Concepts, LLC  

DOE Green Energy (OSTI)

This fact sheet describes a subcontract with Global Energy Concepts to evaluate a wide range of wind turbine configurations and their impact on overall cost of energy (COE).

Not Available

2006-03-01T23:59:59.000Z

393

Evaluation of Three-Beam and Four-Beam Profiler Wind Measurement Techniques Using a Five-Beam Wind Profiler and Collocated Meteorological Tower  

Science Conference Proceedings (OSTI)

In this paper a five-beam wind profiler and a collocated meteorological tower are used to estimate the accuracy of four-beam and three-beam wind profiler techniques in measuring horizontal components of the wind. In the traditional three-beam ...

Ahoro Adachi; Takahisa Kobayashi; Kenneth S. Gage; David A. Carter; Leslie M. Hartten; Wallace L. Clark; Masato Fukuda

2005-08-01T23:59:59.000Z

394

Spaced-Antenna Interferometry to Measure Crossbeam Wind, Shear, and Turbulence: Theory and Formulation  

Science Conference Proceedings (OSTI)

The theory of measuring crossbeam wind, shear, and turbulence within the radar’s resolution volume V6 is described. Spaced-antenna weather radar interferometry is formulated for such measurements using phased-array weather radar. The formulation ...

Guifu Zhang; Richard J. Doviak

2007-05-01T23:59:59.000Z

395

Errors for Space-Based Doppler Lidar Wind Measurements: Definition, Performance, and Verification  

Science Conference Proceedings (OSTI)

Verification of space-based wind measurements will be difficult because of the random variations of the atmospheric velocity field over the measurement volume. The definition of accuracy requires a definition of “truth.” For this work, truth is ...

Rod Frehlich

2001-11-01T23:59:59.000Z

396

Wave-Follower Field Measurements of the Wind-Input Spectral Function. Part II: Parameterization of the Wind Input  

Science Conference Proceedings (OSTI)

Nearly all of the momentum transferred from wind to waves comes about through wave-induced pressure acting on the slopes of waves: known as form drag. Direct field measurements of the wave-induced pressure in airflow over water waves are ...

Mark A. Donelan; Alexander V. Babanin; Ian R. Young; Michael L. Banner

2006-08-01T23:59:59.000Z

397

The Inside of a Wind Turbine | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

The Inside of a Wind Turbine The Inside of a Wind Turbine The Inside of a Wind Turbine 1 of 17 Tower: 2 of 17 Tower: Made from tubular steel (shown here), concrete, or steel lattice. Supports the structure of the turbine. Because wind speed increases with height, taller towers enable turbines to capture more energy and generate more electricity. Generator: 3 of 17 Generator: Produces 60-cycle AC electricity; it is usually an off-the-shelf induction generator. High-speed shaft: 4 of 17 High-speed shaft: Drives the generator. Nacelle: 5 of 17 Nacelle: Sits atop the tower and contains the gear box, low- and high-speed shafts, generator, controller, and brake. Some nacelles are large enough for a helicopter to land on. Wind vane: 6 of 17 Wind vane: Measures wind direction and communicates with the yaw drive to orient the

398

Experimental and theoretical study of horizontal-axis wind turbines  

E-Print Network (OSTI)

in many of the large machines which are now operating . 1.2 Recent developments (prior to 1978) Since 1973 wind power has grown at a very rapid rate in both Europe and America. The number of horizontal-axis wind turbines which have been built... .1 Introduction 9.2 Wind velocity measurement 9.3 Concluding remarks re wind velocity measurement 9.4 Power vs. wind speed 9.5 POWer coefficient vs. tip speed ratio 9.6 Conclusions Chapter 10. Summary of conclusions and suggestions for further research...

Anderson, Michael Broughton

1981-10-20T23:59:59.000Z

399

Rotationally sampled wind characteristics for several rotor sizes using laser anemometer measurements  

DOE Green Energy (OSTI)

The concept of measuring the wind velocity rotationally around crosswind circles using a circle-scanning Doppler laser anemometer is investigated to determine the technique's suitability as an effective, simple, economical, and nonintrusive method for estimation turbulence at a wind turbine rotor. Estimates of wind features obtained using the lidar technique are compared to actual wind measurements obtained using a vertical plane array of anemometers, and to other estimates generated using a single-tower technique. Although the lack of a common data set precludes a firm conclusion regarding the lidar method's accuracy, it appears that the rotationally scanning lidar has the potential of becoming an excellent tool for measuring turbulent wind around the disk of rotation of a turbine blade. 11 refs., 21 figs., 2 tabs.

Connell, J.R.; Morris, V.R.

1989-02-01T23:59:59.000Z

400

Lidar Measurement of Turbulence Encountered by Horizontal-Axis Wind Turbines  

Science Conference Proceedings (OSTI)

We used a continuous-wave (CW) Doppler lidar to measure wind velocity turbulence from a moving frame of reference. By directing the lidar beam to trace the perimeters of vertical-plane disks about horizontal axes parallel to the mean wind ...

R. M. Hardesty; B. F. Weber

1987-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

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

E-Print Network (OSTI)

American Wind Energy Association, Denver, May 2005 Uncertainties in Results of Measure Wind Energy Association, Denver, May 2005 Statistical models are then investigated that estimate-Correlate-Predict Analyses Anthony L. Rogers, Ph. D.* John W. Rogers, M.S.** James F. Manwell, Ph. D.* *Renewable Energy

Massachusetts at Amherst, University of

402

Development of a New Flame Speed Vessel to Measure the Effect of Steam Dilution on Laminar Flame Speeds of Syngas Fuel Blends at Elevated Pressures and Temperatures  

E-Print Network (OSTI)

Synthetic gas, syngas, is a popular alternative fuel for the gas turbine industry, but the composition of syngas can contain different types and amounts of contaminants, such as carbon dioxide, methane, moisture, and nitrogen, depending on the industrial process involved in its manufacturing. The presence of steam in syngas blends is of particular interest from a thermo-chemical perspective as there is limited information available in the literature. This study investigates the effect of moisture content (0 ? 15% by volume), temperature (323 ? 423 K), and pressure (1 ? 10 atm) on syngas mixtures by measuring the laminar flame speed in a newly developed constant-volume, heated experimental facility. This heated vessel also broadens the experimental field of study in the authors? laboratory to low vapor pressure fuels and other vaporized liquids. The new facility is capable of performing flame speed experiments at an initial pressure as high as 30 atm and an initial temperature up to 600 K. Several validation experiments were performed to demonstrate the complete functionality of the flame speed facility. Additionally, a design-of-experiments methodology was used to study the mentioned syngas conditions that are relevant to the gas turbine industry. The design-of-experiments methodology provided the capability to identify the most influential factor on the laminar flame speed of the conditions studied. The experimental flame speed data are compared to the most up-to-date C4 mechanism developed through collaboration between Texas A&M and the National University of Ireland Galway. Along with good model agreement shown with all presented data, a rigorous uncertainty analysis of the flame speed has been performed showing an extensive range of values from 4.0 cm/s to 16.7 cm/s. The amount of carbon monoxide dilution in the fuel was shown to be the most influential factor on the laminar flame speed from fuel lean to fuel rich. This is verified by comparing the laminar flame speed of the atmospheric mixtures. Also, the measured Markstein lengths of the atmospheric mixtures are compared and do not demonstrate a strong impact from any one factor but the ratio of hydrogen and carbon monoxide plays a key role. Mixtures with high levels of CO appear to stabilize the flame structure of thermal-diffusive instability. The increase of steam dilution has only a small effect on the laminar flame speed of high-CO mixtures, while more hydrogen-dominated mixtures demonstrate a much larger and negative effect of increasing water content on the laminar flame speed.

Krejci, Michael

2012-05-01T23:59:59.000Z

403

Satellite Measurement of Stratospheric Winds and Ozone Using Doppler Michelson Interferometry. Part I: Instrument Model and Measurement Simulation  

Science Conference Proceedings (OSTI)

This paper presents an instrument model and observation simulations for the measurement of stratospheric winds and ozone concentration using a satellite instrument employing imaging and the Doppler Michelson interferometery technique. The ...

Peyman Rahnama; Yves J. Rochon; Ian C. McDade; Gordon G. Shepherd; William A. Gault; Alan Scott

2006-06-01T23:59:59.000Z

404

Evidence for the Effects of Swell and Unsteady Winds on Marine Wind Stress  

Science Conference Proceedings (OSTI)

Over the past four decades much effort has been directed toward determining a parameterization of the sea surface drag coefficient on readily measurable quantities, such as mean wind speed and atmospheric stability. Although such a ...

William M. Drennan; Hans C. Graber; Mark A. Donelan

1999-08-01T23:59:59.000Z

405

The Probability Distribution of Sea Surface Wind Speeds: Effects of Variable Surface Stratification and Boundary Layer Thickness  

Science Conference Proceedings (OSTI)

Air–sea exchanges of momentum, energy, and material substances of fundamental importance to the variability of the climate system are mediated by the character of the turbulence in the atmospheric and oceanic boundary layers. Sea surface winds ...

Adam Hugh Monahan

2010-10-01T23:59:59.000Z

406

A Climatological Study of Boundary Layer Wind Speed Using a Meso-?-Scale Higher-Order Closure Model  

Science Conference Proceedings (OSTI)

A mesoscale higher-order closure atmospheric boundary layer model has been used to get more detailed information than is possible from observations regarding horizontal and vertical variations of the wind in an area in southeastern Sweden. To ...

Hans Bergström

1996-08-01T23:59:59.000Z

407

A First-Guess Feature-Based Algorithm for Estimating Wind Speed in Clear-Air Doppler Radar Spectra  

Science Conference Proceedings (OSTI)

Algorithms for deriving winds from profiler range-gated spectra currently rely on consensus averaging to remove outliers from the subhourly velocity estimates. For persistent ground clutter in the echo return that is stronger than the atmospheric ...

E. E. Clothiaux; R. S. Penc; D. W. Thomson; T. P. Ackerman; S. R. Williams

1994-08-01T23:59:59.000Z

408

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

SciTech Connect

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.

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

1984-09-01T23:59:59.000Z

409

Radar Measurement of Tidal Winds at Stratospheric Heights over Arecibo  

Science Conference Proceedings (OSTI)

Wind oscillations of tidal periods that showed a marked downward phase progression were detected at the lower stratosphere using the Arecibo radar. The amplitudes of 1–5 m s?1 were inferred for both diurnal and semidiurnal components, much larger ...

Shoichiro Fukao; Toru Sato; Norikazu Yamasaki; Robert M. Harper; Susumu Kato

1980-11-01T23:59:59.000Z

410

Comparison of COADS Release 1a Winds with Instrumental Measurements in the Northwest Atlantic  

Science Conference Proceedings (OSTI)

The reliability of the Comprehensive Ocean–Atmosphere Dataset (COADS) Release 1a 2° monthly winds is tested by comparing it with instrumental measurements in the northwest Atlantic from 1981 to 1991. The instrumental dataset contains anemometer ...

Sergey K. Gulev

1999-01-01T23:59:59.000Z

411

A System for Remote Measurements of the Wind Stress over the Ocean  

Science Conference Proceedings (OSTI)

The DISSTRESS system for remote measurements of the surface wind stress over the ocean from ships and buoys is described. It is fully digital, utilizing the inertial dissipation technique. Parallel processing allows anemometer data to be filtered ...

W. G. Large; J. A. Businger

1988-04-01T23:59:59.000Z

412

Scopes and Challenges of Dual-Doppler Lidar Wind Measurements—An Error Analysis  

Science Conference Proceedings (OSTI)

Pulsed Doppler lidars are powerful tools for long-range high-resolution measurements of radial wind velocities. With the development of commercial Doppler lidars and the reduction of acquisition costs, dual-Doppler lidar systems will be become ...

Christina Stawiarski; Katja Träumner; Christoph Knigge; Ronald Calhoun

413

The Measurement of Doppler Wind Fields with Fast Scanning Radars: Signal Processing Techniques  

Science Conference Proceedings (OSTI)

This paper discusses signal processing techniques being developed for making Doppler wind velocity measurements using airport surveillance radars. Techniques are presented and evaluated for velocity estimation using fast-rotating radars. In ...

John R. Anderson

1987-12-01T23:59:59.000Z

414

Cluster Analysis of Hourly Wind Measurements to Reveal Synoptic Regimes Affecting Air Quality  

Science Conference Proceedings (OSTI)

A clustering algorithm is developed to study hourly, ground-level wind measurements obtained from a network of monitoring stations positioned throughout the San Francisco Bay Area of California. A statistical model based on principal components ...

Scott Beaver; Ahmet Palazoglu

2006-12-01T23:59:59.000Z

415

Articulating and Stationary PARSIVEL Disdrometer Measurements in Conditions with Strong Winds and Heavy Rainfall  

Science Conference Proceedings (OSTI)

The influence of strong winds on the quality of optical PARticle SIze VELocity (PARSIVEL) disdrometer measurements is examined with data from Hurricane Ike in 2008 and from convective thunderstorms observed during the second Verification of the ...

Katja Friedrich; Stephanie Higgins; Forrest J. Masters; Carlos R. Lopez

416

Articulating and Stationary PARSIVEL Disdrometer Measurements in Conditions with Strong Winds and Heavy Rainfall  

Science Conference Proceedings (OSTI)

The influence of strong winds on the quality of optical Particle Size Velocity (PARSIVEL) disdrometer measurements is examined with data from Hurricane Ike in 2008 and from convective thunderstorms observed during the second Verification of the ...

Katja Friedrich; Stephanie Higgins; Forrest J. Masters; Carlos R. Lopez

2013-09-01T23:59:59.000Z

417

Estimation of Wind-Induced Error of Rainfall Gauge Measurements Using a Numerical Simulation  

Science Conference Proceedings (OSTI)

A new method of estimating the wind-induced error of rainfall gauge measurements is presented. The method is based on a three-dimensional numerical simulation of the airflow around a precipitation gauge and subsequent computation of particle ...

Vladislav Nešpor; Boris Sevruk

1999-04-01T23:59:59.000Z

418

PTC, ITC, or Cash Grant? Measuring the Value of Stimulus to Wind...  

NLE Websites -- All DOE Office Websites (Extended Search)

PTC, ITC, or Cash Grant? Measuring the Value of Stimulus to Wind Power Projects in the United States Speaker(s): Mark Bolinger Date: January 26, 2010 - 12:00pm Location: 90-3122...

419

Boundary Layer Height and Entrainment Zone Thickness Measured by Lidars and Wind-Profiling Radars  

Science Conference Proceedings (OSTI)

The authors examine measurements of boundary layer height zi and entrainment zone thickness observed with two lidars and with a radar wind profiler during the Flatland96 Lidars in Flat Terrain experiment. Lidar backscatter is proportional to ...

Stephen A. Cohn; Wayne M. Angevine

2000-08-01T23:59:59.000Z

420

Scopes and Challenges of Dual-Doppler Lidar Wind Measurements—An Error Analysis  

Science Conference Proceedings (OSTI)

Pulsed Doppler lidars are powerful tools for long-range, high-resolution measurements of radial wind velocities. With the development of commercial Doppler lidars and the reduction of acquisition costs, dual-Doppler lidar systems will be become ...

Christina Stawiarski; Katja Träumner; Christoph Knigge; Ronald Calhoun

2013-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Strong wind forcing of the ocean  

E-Print Network (OSTI)

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 .

Zedler, Sarah E.

2007-01-01T23:59:59.000Z

422

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

Science Conference Proceedings (OSTI)

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.

David M. Wright; DOE Project Officer - Keith Bennett

2007-07-31T23:59:59.000Z

423

Remote Determination of Winds, Turbulence Spectra and Energy Dissipation Rates in the Boundary Layer from Lidar Measurements  

Science Conference Proceedings (OSTI)

Procedures are described for the analysis of lidar data to remotely measure 1) spectra of aerosol density fluctuations, 2) radial and transverse components of the mean wind and turbulent fluctuations of the transverse component of the wind ...

K. E. Kunkel; E. W. Eloranta; J. A. Weinman

1980-05-01T23:59:59.000Z

424

Evaluation of CMIP3 and CMIP5 Wind Stress Climatology Using Satellite Measurements and Atmospheric Reanalysis Products  

Science Conference Proceedings (OSTI)

Wind stress measurements from the Quick Scatterometer (QuikSCAT) satellite and two atmospheric reanalysis products are used to evaluate the annual mean and seasonal cycle of wind stress simulated by phases 3 and 5 of the Coupled Model ...

Tong Lee; Duane E. Waliser; Jui-Lin F. Li; Felix W. Landerer; Michelle M. Gierach

2013-08-01T23:59:59.000Z

425

On the Heating of the Solar Corona and the Acceleration of the Low-Speed Solar Wind by Acoustic Waves Generated in Corona  

E-Print Network (OSTI)

We investigate possibilities of solar coronal heating by acoustic waves generated not at the photosphere but in the corona, aiming at heating in the mid- to low-latitude corona where the low-speed wind is expected to come from. Acoustic waves of period tau ~ 100s are triggered by chromospheric reconnection, one model of small scale magnetic reconnection events recently proposed by Sturrock. These waves having a finite amplitude eventually form shocks to shape sawtooth waves (N-waves), and directly heat the surrounding corona by dissipation of their wave energy. Outward propagation of the N-waves is treated based on the weak shock theory, so that the heating rate can be evaluated consistently with physical properties of the background coronal plasma without setting a dissipation length in an ad hoc manner. We construct coronal structures from the upper chromosphere to the outside of 1AU for various inputs of the acoustic waves having a range of energy flux of F_{w,0} = (1-20) times 10^5 erg cm^{-2} s^{-1} and a period of tau = 60-300s. The heating by the N-wave dissipation effectively works in the inner corona and we find that the waves of F_{w,0} >= 2 times 10^5 erg cm^{-2} s^{-1} and tau >= 60s could maintain peak coronal temperature, T_{max} > 10^6 K. The model could also reproduce the density profile observed in the streamer region. However, due to its short dissipation length, the location of T_{max} is closer to the surface than the observation, and the resultant flow velocity of the solar wind is lower than the observed profile of the low-speed wind. The cooperations with other heating and acceleration sources with the larger dissipation length are inevitable to reproduce the real solar corona.

Takeru Ken Suzuki

2002-06-14T23:59:59.000Z

426

The InterHourly-Variability (IHV) Index of Geomagnetic Activity and its Use in Deriving the Long-term Variation of Solar Wind Speed  

E-Print Network (OSTI)

We describe the derivation of the InterHourly Variability (IHV) index of geomagnetic activity. The IHV-index for a geomagnetic element is mechanically derived from hourly values as the sum of the unsigned differences between adjacent hours over a seven-hour interval centered on local midnight. The index is derived separately for stations in both hemispheres within six longitude sectors using only local night hours. It is intended as a long-term index. Available data allows derivation of the index back well into the 19th century. On a time scale of a 27-day Bartels rotation, IHV averages for stations with corrected geomagnetic latitude less than 55 degrees are strongly correlated with midlatitude range indices. Assuming a constant calibration of the aa-index we find that observed yearly values of aa before the year 1957 are 2.9 nT too small compared to values calculated from IHV using the regression constants based on 1980-2004. We interpret this discrepancy as an indication that the calibration of the aa index is in error before 1957. There is no such problem with the ap index. Rotation averages of IHV are also strongly correlated with solar wind parameters (BV^2). On a time scale of a year combining the IHV-index and the recently-developed Inter-Diurnal Variability (IDV) index (giving B) allows determination of solar wind speed, V, from 1890-present. Over the ~120-year series, the yearly mean solar wind speed varied from a low of 303 km/s in 1902 to a high value of 545 km/s in 2003. The calculated yearly values of the product BV using B and V separately derived from IDV and IHV agree quantitatively with (completely independent) BV derived from the amplitude of the diurnal variation of the H component in the polar caps since 1926 and sporadically beyond.

Leif Svalgaard; Edward W. Cliver

2007-06-07T23:59:59.000Z

427

Theoretical analysis of acceleration measurements in a model of an operating wind turbine.  

Science Conference Proceedings (OSTI)

Wind loading from turbulence and gusts can cause damage in horizontal axis wind turbines. These unsteady loads and the resulting damage initiation and propagation are difficult to predict. Unsteady loads enter at the rotor and are transmitted to the drivetrain. The current generation of wind turbine has drivetrain-mounted vibration and bearing temperature sensors, a nacelle-mounted inertial measurement unit, and a nacelle-mounted anemometer and wind vane. Some advanced wind turbines are also equipped with strain measurements at the root of the rotor. This paper analyzes additional measurements in a rotor blade to investigate the complexity of these unsteady loads. By identifying the spatial distribution, amplitude, and frequency bandwidth of these loads, design improvements could be facilitated to reduce uncertainties in reliability predictions. In addition, dynamic load estimates could be used in the future to control high-bandwidth aerodynamic actuators distributed along the rotor blade to reduce the saturation of slower pitch actuators currently used for wind turbine blades. Local acceleration measurements are made along a rotor blade to infer operational rotor states including deflection and dynamic modal contributions. Previous work has demonstrated that acceleration measurements can be experimentally acquired on an operating wind turbine. Simulations on simplified rotor blades have also been used to demonstrate that mean blade loading can be estimated based on deflection estimates. To successfully apply accelerometers in wind turbine applications for load identification, the spectral and spatial characteristics of each excitation source must be understood so that the total acceleration measurement can be decomposed into contributions from each source. To demonstrate the decomposition of acceleration measurements in conjunction with load estimation methods, a flexible body model has been created with MSC.ADAMS{copyright} The benefit of using a simulation model as opposed to a physical experiment to examine the merits of acceleration-based load identification methods is that models of the structural dynamics and aerodynamics enable one to compare estimates of the deflection and loading with actual values. Realistic wind conditions are applied to the wind turbine and used to estimate the operational displacement and acceleration of the rotor. The per-revolution harmonics dominate the displacement and acceleration response. Turbulent wind produces broadband excitation that includes both the harmonics and modal vibrations, such as the tower modes. Power Spectral Density estimates of the acceleration along the span of the rotor blades indicate that the edge modes may be coupled to the second harmonic.

Adams, Douglas E. (Purdue University, Lafayette, IN); Rumsey, Mark Allen; White, Jonathan Randall

2010-04-01T23:59:59.000Z

428

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

Science Conference Proceedings (OSTI)

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.

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

429

Grid Operation and Coordination with Wind -2 1.0 Introduction  

E-Print Network (OSTI)

(DFIGs) also produce power that varies with wind speed, although the torque- speed controller provides

McCalley, James D.

430

Photoacoustically Measured Speeds of Sound of Liquid HBO2: On Unlocking the Fuel Potential of Boron  

SciTech Connect

Elucidation of geodynamic, geochemical, and shock induced processes is often limited by challenges to accurately determine molecular fluid equations of state (EOS). High pressure liquid state reactions of carbon species underlie physiochemical mechanisms such as differentiation of planetary interiors, deep carbon sequestration, propellant deflagration, and shock chemistry. Here we introduce a versatile photoacoustic technique developed to measure accurate and precise speeds of sound (SoS) of high pressure molecular fluids and fluid mixtures. SoS of an intermediate boron oxide, HBO{sub 2} are measured up to 0.5 GPa along the 277 C isotherm. A polarized Exponential-6 interatomic potential form, parameterized using our SoS data, enables EOS determinations and corresponding semi-empirical evaluations of > 2000 C thermodynamic states including energy release from bororganic formulations. Our thermochemical model propitiously predicts boronated hydrocarbon shock Hugoniot results.

Bastea, S; Crowhurst, J; Armstrong, M; ., N T

2010-03-24T23:59:59.000Z

431

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

DOE Green Energy (OSTI)

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.

Kelley, N.D.

1995-01-01T23:59:59.000Z

432

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

Science Conference Proceedings (OSTI)

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.

Not Available

2012-10-01T23:59:59.000Z

433

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

Science Conference Proceedings (OSTI)

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.

Not Available

2012-11-01T23:59:59.000Z

434

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

NLE Websites -- All DOE Office Websites (Extended Search)

Technology Improvement Technology Improvement Opportunities for Low Wind Speed Turbines and Implications for Cost of Energy Reduction July 9, 2005 - July 8, 2006 J. Cohen and T. Schweizer Princeton Energy Resources International (PERI) Rockville, Maryland A. Laxson, S. Butterfield, S. Schreck, and L. Fingersh National Renewable Energy Laboratory Golden, Colorado P. Veers and T. Ashwill Sandia National Laboratories Albuquerque, New Mexico Technical Report NREL/TP-500-41036 February 2008 NREL is operated by Midwest Research Institute â—Ź Battelle Contract No. DE-AC36-99-GO10337 National Renewable Energy Laboratory 1617 Cole Boulevard, Golden, Colorado 80401-3393 303-275-3000 * www.nrel.gov Operated for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy

435

Wind Tunnel Evaluation of PAM II Pressure Ports  

Science Conference Proceedings (OSTI)

The Portable Automated Mesonet II (PAM II) is a network of automated remote weather stations developed by the National Center for Atmospheric Research (NCAR) for measuring wind speed and direction, atmospheric pressure, temperature, humidity, and ...

Fikri Adnan Akyüz; Henry Liu; Tom Horst

1991-06-01T23:59:59.000Z

436

Performance of a 2-µm Coherent Doppler Lidar for Wind Measurements  

Science Conference Proceedings (OSTI)

Measurements of boundary layer winds are presented using a 2-µm coherent Doppler lidar and the optimal performance of the maximum likelihood estimator. The systematic error for single-shot estimates was estimated as 3.6 cm s?1 using measurements ...

Rod Frehlich; Stephen M. Hannon; Sammy W. Henderson

1994-12-01T23:59:59.000Z

437

Wind Turbine Generator System Power Performance Test Report for the ARE442 Wind Turbine  

DOE Green Energy (OSTI)

This report summarizes the results of a power performance test that NREL conducted on the ARE 442 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 ARE 442 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.

van Dam, J.; Jager, D.

2010-02-01T23:59:59.000Z

438

ISET-Wind-Index Assessment of the Annual Available Wind Energy  

E-Print Network (OSTI)

Particularly in years with wind speeds that are clearly below average, dissatisfaction of operators and even liquidity problems are sparked through the unexpected low annual power production. An objective standard for the evaluation of the respective “wind year ” is required for the internal estimation of the performance of wind farms, and for justification to share owners and banks. The annual wind conditions are composed from such a multitude of meteorological situations, differing from location to location, that the available wind energy at every individual location develops totally differently. A single code is therefore not sufficient to describe the “wind year ” in Germany and, moreover, the evaluation of annual available wind energy must be carried out separately for the smallest areas possible. With the support of the Gothaer Rückversicherungen AG, a procedure has been developed at ISET which provides the proportion of the respective annual available wind energy, in relation to the long-term average available wind energy, for each 10 km x 10 km sized plan area in Germany. This amount, the ISET-Wind-Index, is founded on wind measurements at locations that are typical for wind energy use and therefore presents an objective standard. The measurement grid is part of the “Scientific Measurement and Evaluation Programme ” (WMEP), which accompanies the “250 MW Wind ” project of the German Federal Ministry for Economy and Labour. The ISET-Wind-Index, which will be regularly updated, provides an objective standard for the estimation of annual available

Berthold Hahn; Kurt Rohrig

2003-01-01T23:59:59.000Z

439

Powering up with space-time wind forecasting  

E-Print Network (OSTI)

The technology to harvest electricity from wind energy is now advanced enough to make entire cities powered by it a reality. High-quality short-term forecasts of wind speed are vital to making this 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. The forecasts produced by this model are accurate, and subject to accuracy, the predictive distribution is sharp, i.e., highly concentrated around its center. However, this model is split into nonunique regimes based on the wind direction at an off-site location. This paper both generalizes and improves upon this model by treating wind direction as a circular variable and including it in the model. It is robust in many experiments, such as predicting at new locations. We compare this with the more common approach of modeling wind speeds and directions in the Cartesian space and use a skew-t distribution for the errors. The quality of the predictions from all of these models can be more realistically assessed with a loss measure that depends upon the power curve relating wind speed to power output. This proposed loss measure yields more insight into the true value of each model’s predictions. Some key words: Circular variable, power curve, skew-t distribution, wind direction, wind speed.

A S. Hering; Marc G. Genton

2009-01-01T23:59:59.000Z

440

Subhourly wind forecasting techniques for wind turbine operations  

DOE Green Energy (OSTI)

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.

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

1984-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

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

E-Print Network (OSTI)

based on the wind farm single phase equivalent circuit. The stability analysis is carried out, phase margin, and vector gain margin calculated for different number of wind turbines in operation. The interaction between the wind turbine control system and the wind farm structure in wind farms is deeply

Paris-Sud XI, Université de

442

Wind Derivatives: Modeling and Pricing  

Science Conference Proceedings (OSTI)

Wind is considered to be a free, renewable and environmentally friendly source of energy. However, wind farms are exposed to excessive weather risk since the power production depends on the wind speed, the wind direction and the wind duration. This risk ... Keywords: Forecasting, Pricing, Wavelet networks, Weather derivatives, Wind derivatives

A. Alexandridis; A. Zapranis

2013-03-01T23:59:59.000Z

443

Evaluation of prediction error effects in wind energy-based electric vehicle charging  

Science Conference Proceedings (OSTI)

This paper first presents a battery operation scheduler for the sake of practical integration of wind energy generation and electric vehicle charging, and then measures its performance mainly focusing on the effect of wind speed prediction errors. The ... Keywords: battery operation scheduler, electric vehicle charging, renewable energy gain, smart grid, wind energy

Junghoon Lee, Gyung-Leen Park, Il-Woo Lee, Wan Ki Park

2013-10-01T23:59:59.000Z

444

An Improved Method for Estimating the Wind Power Density Distribution Function  

Science Conference Proceedings (OSTI)

The wind power density (WPD) distribution curve is essential for wind power assessment and wind turbine engineering. The usual practice of estimating this curve from wind speed data is to first estimate the wind speed probability density function ...

Mark L. Morrissey; Werner E. Cook; J. Scott Greene

2010-07-01T23:59:59.000Z

445

High Resolution Atmospheric Modeling for Wind Energy Applications  

SciTech Connect

The ability of the WRF atmospheric model to forecast wind speed over the Nysted wind park was investigated as a function of time. It was found that in the time period we considered (August 1-19, 2008), the model is able to predict wind speeds reasonably accurately for 48 hours ahead, but that its forecast skill deteriorates rapidly after 48 hours. In addition, a preliminary analysis was carried out to investigate the impact of vertical grid resolution on the forecast skill. Our preliminary finding is that increasing vertical grid resolution does not have a significant impact on the forecast skill of the WRF model over Nysted wind park during the period we considered. Additional simulations during this period, as well as during other time periods, will be run in order to validate the results presented here. Wind speed is a difficult parameter to forecast due the interaction of large and small length scale forcing. To accurately forecast the wind speed at a given location, the model must correctly forecast the movement and strength of synoptic systems, as well as the local influence of topography / land use on the wind speed. For example, small deviations in the forecast track or strength of a large-scale low pressure system can result in significant forecast errors for local wind speeds. The purpose of this study is to provide a preliminary baseline of a high-resolution limited area model forecast performance against observations from the Nysted wind park. Validating the numerical weather prediction model performance for past forecasts will give a reasonable measure of expected forecast skill over the Nysted wind park. Also, since the Nysted Wind Park is over water and some distance from the influence of terrain, the impact of high vertical grid spacing for wind speed forecast skill will also be investigated.

Simpson, M; Bulaevskaya, V; Glascoe, L; Singer, M

2010-03-18T23:59:59.000Z

446

Comparison of Scatterometer and Radiometer Wind Vector Measurements  

Science Conference Proceedings (OSTI)

Coincident measurements with a 37-GHz polarimetric radiometer and a 10-GHz scatterometer during the Coastal Ocean Probing Experiment (COPE) in September and October of 1995 offered a unique opportunity to compare their relative sensitivity and ...

David E. Weissman; William J. Plant; William C. Keller; Vladimir G. Irisov

2002-01-01T23:59:59.000Z

447

Measurements of the Vertical Acceleration in Wind Waves  

Science Conference Proceedings (OSTI)

Recent theoretical studies of the accelerations in regular gravity waves of finite steepness have shown striking differences between the Eulerian and the Lagrangian accelerations (those measured by fixed instruments or freely floating instruments,...

J. A. Ewing; M. S. Longuet-Higgins; M. A. Srokosz

1987-01-01T23:59:59.000Z

448

Comparison of Equatorial Winds as Measured by Cup and Propeller Anemometers  

Science Conference Proceedings (OSTI)

This study compares the performance of cup vs. propeller anemometers from surface-following taut-line moorings in the equatorial Pacific. Vector wind components at 4 m above the sea surface were measured from a mooring instrumented with a cup ...

H. Paul Freitag; Michael J. McPhaden; Andrew J. Shepherd

1989-04-01T23:59:59.000Z

449

Errors in Wind Measurements Estimated by Five-Beam Phased Array Doppler Sodar  

Science Conference Proceedings (OSTI)

Estimation of the errors in sodar wind measurements using the phased array Doppler sodar operated under five-beam observation has been made. When compared with the sonic anemometer on the tower nearby, the variances or second-order moments of ...

Yoshiki Ito

1997-08-01T23:59:59.000Z

450

Statistical Analysis of Sodium Doppler Wind–Temperature Lidar Measurements of Vertical Heat Flux  

Science Conference Proceedings (OSTI)

A statistical study is presented of the errors in sodium Doppler lidar measurements of wind and temperature in the mesosphere that arise from the statistics of the photon-counting process that is inherent in the technique. The authors use data ...

Liguo Su; Richard L. Collins; David A. Krueger; Chiao-Yao She

2008-03-01T23:59:59.000Z

451

Stable Boundary Layer Depth from High-Resolution Measurements of the Mean Wind Profile  

Science Conference Proceedings (OSTI)

The depth h of the stable boundary layer (SBL) has long been an elusive measurement. In this diagnostic study the use of high-quality, high-resolution (?z = 10 m) vertical profile data of the mean wind U(z) and streamwise variance ?u2(z) is ...

Yelena L. Pichugina; Robert M. Banta

2010-01-01T23:59:59.000Z

452

An Optical Device for the Measurement of Droplet Size Spectra in Calm or Low Wind Conditions  

Science Conference Proceedings (OSTI)

An instrument for measuring the size and concentration of droplets is described. It has the ability to function in calm and low wind conditions. Droplets in the 5–50 ?m diameter range are detected optically. The data acquisition and real-time ...

T. Perrin; A. Rigaud; C. Pontikis; M. Cabane

1989-12-01T23:59:59.000Z

453

Lunar Tidal Winds Measured in the Upper Atmosphere (78–105 km) at Saskatoon, Canada  

Science Conference Proceedings (OSTI)

Six years of winds data measured by the partial reflection drifts technique have been analyzed for lunar tides. Data are available at 3 km intervals of height and are separately analyzed in two year datasets to cheek consistency. A month-by-month ...

R. J. Stening; C. E. Meek; A. H. Manson

1987-04-01T23:59:59.000Z

454

Use of Distance-measuring Equipment (DME) for Correcting Errors in Position, Velocity, and Wind Measurements from Aircraft Inertial Navigation Systems  

Science Conference Proceedings (OSTI)

Aircraft distance-measuring-equipment (DME) data are used to update position, velocity, and wind measurements from inertial navigation systems (INS) measurements. Data from conventional single-channel DME sets, suitably calibrated, are shown to ...

Alfred R. Rodi; James C. Fankhauser; Robin L. Vaughan

1991-12-01T23:59:59.000Z

455

Offshore wind project surges ahead in South Carolina | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Offshore wind project surges ahead in South Carolina Offshore wind project surges ahead in South Carolina Offshore wind project surges ahead in South Carolina October 12, 2010 - 10:00am Addthis Researchers pull buoys from waters off South Carolina's coast. The buoys collected wind speed measurements for the past year. | Photo courtesy of the Center for Marine and Wetland Studies Researchers pull buoys from waters off South Carolina's coast. The buoys collected wind speed measurements for the past year. | Photo courtesy of the Center for Marine and Wetland Studies Stephen Graff Former Writer & editor for Energy Empowers, EERE 6 buoys collected wind speeds off South Carolina coast Data collected helps determine possible location for an offshore wind farm DOE funded research for early stage of project In the parking lot of Coastal Carolina University's Center for Marine and

456

A Study of Wind Stress and Heat Flux over the Open Ocean by the Inertial-Dissipation Method  

Science Conference Proceedings (OSTI)

A bow-mounted propeller anemometer and fast-response temperature sensors were operated during several cruises of CSS Dawson. Spectra of wind speed and temperature fluctuations were measured over the open ocean for a wind speed range of 6 to 21 m ...

R. J. Anderson

1993-10-01T23:59:59.000Z

457

An Airborne and Wind Tunnel Evaluation of a Wind Turbulence Measurement System for Aircraft-Based Flux Measurements  

Science Conference Proceedings (OSTI)

Although the ability to measure vertical eddy fluxes of gases from aircraft platforms represents an important capability to obtain spatially resolved data, accurate and reliable determination of the turbulent vertical velocity presents a great ...

K. E. Garman; K. A. Hill; P. Wyss; M. Carlsen; J. R. Zimmerman; B. H. Stirm; T. Q. Carney; R. Santini; P. B. Shepson

2006-12-01T23:59:59.000Z

458

Wind Energy Technologies  

Science Conference Proceedings (OSTI)

... Avg Wind Speed 7.5 m/s 8.74 m/s GE 2.x turbine family ... 1 to 48 Hour Wind Forecasting ... Danish Transmission Grid w/ Interconnects & Offshore Sites ...

2012-08-31T23:59:59.000Z

459

Comparison of Four ERS-1 Scatterometer Wind Retrieval Algorithms with Buoy Measurements  

Science Conference Proceedings (OSTI)

Wind velocity retrievals from the ERS-1 scatterometer are compared with extensive high-quality hourly buoy winds using four different algorithms in two oceanic regions during 1994. The retrieved winds exhibit significantly different wind velocity ...

Clifford Rufenach

1998-02-01T23:59:59.000Z

460

DOE provides detailed offshore wind resource maps - Today in ...  

U.S. Energy Information Administration (EIA)

Includes hydropower, solar, wind, geothermal, biomass and ethanol. ... Wind energy potential is broken down by wind speed, water depth, and distance from shore.

Note: This page contains sample records for the topic "measure wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Global ocean wind power sensitivity to surface layer stability  

E-Print Network (OSTI)

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

Capps, Scott B; Zender, Charles S

2009-01-01T23:59:59.000Z

462

Amplitude modulation of wind turbine noise  

E-Print Network (OSTI)

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).

Makarewicz, Rufin

2013-01-01T23:59:59.000Z

463

New England Wind Forum: Wind Power Economics  

Wind Powering America (EERE)

State Activities Projects in New England Building Wind Energy in New England Wind Resource Wind Power Technology Economics Cost Components Determining Factors Influencing Wind Economics in New England How does wind compare to the cost of other electricity options? Markets Siting Policy Technical Challenges Issues Small Wind Large Wind Newsletter Perspectives Events Quick Links to States CT MA ME NH RI VT Bookmark and Share Wind Power Economics Long-Term Cost Trends Since the first major installations of commercial-scale wind turbines in the 1980s, the cost of energy from wind power projects has decreased substantially due to larger turbine generators, towers, and rotor lengths; scale economies associated with larger projects; improvements in manufacturing efficiency, and technological advances in turbine generator and blade design. These technological advances have allowed for higher generating capacities per turbine and more efficient capture of wind, especially at lower wind speeds.

464

On the Vertical Extrapolation of Mean Wind Power Density  

Science Conference Proceedings (OSTI)

A simple method of estimating the height variation of the mean wind power density is presented which accounts for the variation of the exponent p of the wind speed power law, with stability and roughness. Measurements are used to compare the new ...

Leon Sedefian

1980-04-01T23:59:59.000Z

465

The Temporal Autocorrelation Structure of Sea Surface Winds  

Science Conference Proceedings (OSTI)

The temporal autocorrelation structures of sea surface vector winds and wind speeds are considered. Analyses of scatterometer and reanalysis wind data demonstrate that the autocorrelation functions (acf) of surface zonal wind, meridional wind, and ...

Adam H. Monahan

2012-10-01T23:59:59.000Z

466

Zoning for Small Wind: The Importance of Tower Height  

Wind Powering America (EERE)

1 1 Zoning for Small Wind: The Importance of Tower Height An ASES Small Wind Webinar Mick Sagrillo-Wisconsin's Focus on Energy © 2008 by Mick Sagrillo 2 Definitions: rotor L&S Tech. Assoc., Inc. Rotor = "collector" for a wind system 3 Definitions: wind * Wind = the 'fuel' * Wind has two 'components' - Quantity = wind speed (velocity or V) - Quality = 'clean' flowing wind 4 Quantity * = average annual wind speed * Climate, not weather * Akin to annual average sun hours for PV or head and flow for hydro * Wind speed increases with height above ground... * ...Due to diminished ground drag (friction) 5 Power in the wind V³ * Wind speed = V * Power available is proportional to wind speed x wind speed x wind speed - or P ~ V x V x V - or P ~ V ³ * Therefore, 10% V = 33% P * Lesson !

467

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)

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 is used to restrict the application of the geophysical retrieval algorithms which are developed to handle specific atmospheric absorptive situations. An improved semi-empirical sea surface emissivity model is integrated into this refined D-matrix procedure that is being developed for the Advanced Microwave Sounding Radiometer (AMSR). The purpose of this work is to test the refined geophysical parameter retrieval methods using data from the Special Sensor Microwave / Imager (SSM/I). When comparing the statistical performance of the TIWV, WS, and CLW retrieval methods presented to the statistical performance of published retrieval methods for each geophysical parameter, the retrieval methods developed for this study perform only slightly better. However, it is demonstrated that the new retrieval methods are more physically valid than the comparison retrieval methods. The utilization of the polarization difference of the 85 GHZ channels to restrict the application of specifically-derived retrieval algorithms proves to be a valuable and reliable geophysical parameter retrieval tool.

Manning, Norman Willis William

1997-01-01T23:59:59.000Z

468

A high-speed data acquisition system to measure low-level current from self-powered flux detectors in CANDU nuclear reactors  

E-Print Network (OSTI)

A high-speed data acquisition system to measure low-level current from self-powered flux detectors in CANDU nuclear reactors

Lawrence, C B

1982-01-01T23:59:59.000Z

469

Studies on Spatial Structure of Wind Gust  

Science Conference Proceedings (OSTI)

The peak gust speed is often used to evaluate the maximum wind tome acting on the structure in wind engineering. To evaluate this peak gust speed, the ratio of the peak gust speed over the mean wind speed (called gust factor) is defined. The peak ...

Yasushi Mitsuta; Osamu Tsukamoto

1989-11-01T23:59:59.000Z

470

Wind Profiler and RASS Measurements Compared with Measurements from a 450-m-Tall Tower  

Science Conference Proceedings (OSTI)

A 915-MHz boundary layer wind profiler with radio acoustic sounding system (RASS) was sited 8 km from a very tall (450 m) television transmitting tower in north-central Wisconsin during the spring, summer, and autumn of 1995. The profiler ...

Wayne M. Angevine; Peter S. Bakwin; Kenneth J. Davis

1998-06-01T23:59:59.000Z

471

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

E-Print Network (OSTI)

Research with heterogeneous mixtures involving solid particulate in closed, constant-volume bombs is typically limited by the powder dispersion technique. This work details the development of an experimental apparatus that promotes ideal conditions, namely a quiescent atmosphere and uniform particle distribution, for measuring laminar, heterogeneous flame propagation. In this thesis, two methods of dispersing particles are investigated. In the first, heterogeneous mixtures are made in a secondary vessel that is connected to the main experiment. Particles are dispersed into the secondary vessel by adapting a piston-driven particle injector, which has been shown to produce uniform particle distributions. The heterogeneous mixture is then transferred to the main bomb facility and ignited after laminar conditions are achieved. In the second method of dispersion, particles are directly injected into the main experimental facility using a strong blast of compressed air. As with the first approach, enough time is given (~4 minutes) for the mixture to become quiescent before ignition occurs. An extinction diagnostic is also applied to the secondary mixing vessel as well as the primary experimental facility (for both dispersion methods) to provide a qualitative understanding of the dispersion technique. To perform this diagnostic a 632.8-nm, 5-mW Helium-Neon (HeNe) laser was employed. Aluminum nano-particles with an average diameter of 100 nm were used in this study. It was found that for typical dust loadings produced 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 measurements in aerosol mixtures. With the hybrid mixture, the combustion characteristics were studied both with and without the presence of nano-Al particles. Based on the experimental results, the simplicity of the "direct-injection" methodology compared to that of the "side-vessel" is desirable and will be further investigated as a viable alternative, or improvement, to the side-vessel technology.

Vissotski, Andrew John

2012-08-01T23:59:59.000Z

472

Power Performance Test Report for the SWIFT Wind Turbine  

DOE Green Energy (OSTI)

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.

Mendoza, I.; Hur, J.

2012-12-01T23:59:59.000Z

473

Application of Radar Wind Observations for Low-Level NWP Wind Forecast Validation  

Science Conference Proceedings (OSTI)

The Finnish Meteorological Institute has produced a new numerical weather prediction model–based wind atlas of Finland. The wind atlas provides information on local wind conditions in terms of annual and monthly wind speed and direction averages. ...

Kirsti Salonen; Sami Niemelä; Carl Fortelius

2011-06-01T23:59:59.000Z

474

Flow Distortion by a Solent Sonic Anemometer: Wind Tunnel Calibration and Its Assessment for Flux Measurements over Forest and Field  

Science Conference Proceedings (OSTI)

Main flow distortion effects caused by the sonic probe (i.e., deflection and attenuation/amplification of the wind vector) as a function of the azimuth angle of the incoming flow were examined by means of wind tunnel measurements at four ...

A. Grelle; A. Lindroth

1994-12-01T23:59:59.000Z

475

Wind energy conversion system  

DOE Patents (OSTI)

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.

Longrigg, Paul (Golden, CO)

1987-01-01T23:59:59.000Z

476

High Speed Electronics  

Science Conference Proceedings (OSTI)

High Speed Electronics. ... optic sampling system provides traceability for our electrical waveform measurements ... Metrology for Electronic Packaging. ...

2013-03-25T23:59:59.000Z

477

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

DOE Green Energy (OSTI)

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.

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

2008-02-01T23:59:59.000Z

478

Speeding up network layout and centrality measures for social computing goals  

Science Conference Proceedings (OSTI)

This paper presents strategies for speeding up calculation of graph metrics and layout by exploiting the parallel architecture of modern day Graphics Processing Units (GPU), specifically Compute Unified Device Architecture (CUDA) by Nvidia. Graph centrality ... Keywords: CUDA, social computing, social network analysis

Puneet Sharma; Udayan Khurana; Ben Shneiderman; Max Scharrenbroich; John Locke

2011-03-01T23:59:59.000Z

479

Wind turbine  

DOE Patents (OSTI)

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.

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

1982-01-01T23:59:59.000Z

480

Atmospheric Stability Impacts on Power Curves of Tall Wind Turbines - An Analysis of a West Coast North American Wind Farm  

SciTech Connect

Tall wind turbines, with hub heights at 80 m or above, can extract large amounts of energy from the atmosphere because they are likely to encounter higher wind speeds, but they face challenges given the complex nature of wind flow and turbulence at these heights in the boundary layer. Depending on whether the boundary layer is stable, neutral, or convective, the mean wind speed, direction, and turbulence properties may vary greatly across the tall turbine swept area (40 to 120 m AGL). This variability can cause tall turbines to produce difference amounts of power during time periods with identical hub height wind speeds. Using meteorological and power generation data from a West Coast North American wind farm over a one-year period, our study synthesizes standard wind park observations, such as wind speed from turbine nacelles and sparse meteorological tower observations, with high-resolution profiles of wind speed and turbulence from a remote sensing platform, to quantify the impact of atmospheric stability on power output. We first compare approaches to defining atmospheric stability. The standard, limited, wind farm operations enable the calculation only of a wind shear exponent ({alpha}) or turbulence intensity (I{sub U}) from cup anemometers, while the presence at this wind farm of a SODAR enables the direct observation of turbulent kinetic energy (TKE) throughout the turbine rotor disk. Additionally, a nearby research meteorological station provided observations of the Obukhov length, L, a direct measure of atmospheric stability. In general, the stability parameters {alpha}, I{sub U}, and TKE are in high agreement with the more physically-robust L, with TKE exhibiting the best agreement with L. Using these metrics, data periods are segregated by stability class to investigate power performance dependencies. Power output at this wind farm is highly correlated with atmospheric stability during the spring and summer months, while atmospheric stability exerts little impact on power output during the winter and autumn periods. During the spring and summer seasons, power output for a given wind speed was significantly higher during stable conditions and significantly lower during strongly convective conditions: power output differences approached 20% between stable and convective regimes. The dependency of stability on power output was apparent only when both turbulence and the shape of the wind speed profile were considered. Turbulence is one of the mechanisms by which atmospheric stability affects a turbine's power curve at this particular site, and measurements of turbulence can yield actionable insights into wind turbine behavior.

Wharton, S; Lundquist, J K

2010-02-22T23:59:59.000Z

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481

Atmospheric Stability Impacts on Power Curves of Tall Wind Turbines - An Analysis of a West Coast North American Wind Farm  

SciTech Connect

Tall wind turbines, with hub heights at 80 m or above, can extract large amounts of energy from the atmosphere because they are likely to encounter higher wind speeds, but they face challenges given the complex nature of wind flow and turbulence at these heights in the boundary layer. Depending on whether the boundary layer is stable, neutral, or convective, the mean wind speed, direction, and turbulence properties may vary greatly across the tall turbine swept area (40 to 120 m AGL). This variability can cause tall turbines to produce difference amounts of power during time periods with identical hub height wind speeds. Using meteorological and power generation data from a West Coast North American wind farm over a one-year period, our study synthesizes standard wind park observations, such as wind speed from turbine nacelles and sparse meteorological tower observations, with high-resolution profiles of wind speed and turbulence from a remote sensing platform, to quantify the impact of atmospheric stability on power output. We first compare approaches to defining atmospheric stability. The standard, limited, wind farm operations enable the calculation only of a wind shear exponent ({alpha}) or turbulence intensity (I{sub U}) from cup anemometers, while the presence at this wind farm of a SODAR enables the direct observation of turbulent kinetic energy (TKE) throughout the turbine rotor disk. Additionally, a nearby research meteorological station provided observations of the Obukhov length, L, a direct measure of atmospheric stability. In general, the stability parameters {alpha}, I{sub U}, and TKE are in high agreement with the more physically-robust L, with TKE exhibiting the best agreement with L. Using these metrics, data periods are segregated by stability class to investigate power performance dependencies. Power output at this wind farm is highly correlated with atmospheric stability during the spring and summer months, while atmospheric stability exerts little impact on power output during the winter and autumn periods. During the spring and summer seasons, power output for a given wind speed was significantly higher during stable conditions and significantly lower during strongly convective conditions: power output differences approached 20% between stable and convective regimes. The dependency of stability on power output was apparent only when both turbulence and the shape of the wind speed profile were considered. Turbulence is one of the mechanisms by which atmospheric stability affects a turbine's power curve at this particular site, and measurements of turbulence can yield actionable insights into wind turbine behavior.

Wharton, S; Lundquist, J K

2010-02-22T23:59:59.000Z

482

Dependence of Wind Turbine Curves on Atmospheric Stability Regimes - An Analysis of a West Coast North American Tall Wind Farm  

DOE Green Energy (OSTI)

Tall wind turbines, with hub heights at 80 m or above, can extract large amounts of energy from the atmosphere because they are likely to encounter higher wind speeds, but they face challenges given the complex nature of wind flow in the boundary layer. Depending on whether the boundary layer is stable, convective or neutral, mean wind speed (U) and turbulence ({sigma}{sub U}) may vary greatly across the tall turbine swept area (40 m to 120 m). This variation can cause a single turbine to produce difference amounts of power during time periods of identical hub height wind speeds. The study examines the influence that atmospheric mixing or stability has on power output at a West Coast North American wind farm. They first examine the accuracy and applicability of two, relatively simple stability parameters, the wind shear-exponent, {alpha}, and the turbulence intensity, I{sub u}, against the physically-based, Obukhov length, L, to describe the wind speed and turbulence profiles in the rotor area. In general, the on-site stability parameters {alpha} and I{sub u} are in high agreement with the off-site, L stability scale parameter. Next, they divide the measurement period into five stability classes (strongly stable, stable, neutral, convective, and strongly convective) to discern stability-effects on power output. When only the mean wind speed profile is taken into account, the dependency of power output on boundary layer stability is only subtly apparent. When turbulence intensity I{sub u} is considered, the power generated for a given wind speed is twenty percent higher during strongly stable conditions than during strongly convective conditions as observed in the spring and summer seasons at this North American wind farm.

Wharton, S; Lundquist, J K; Sharp, J; Zulauf, M

2009-08-24T23:59:59.000Z

483

Measurements of Drag Torque and Lift Off Speed and Identification of Stiffness and Damping in a Metal Mesh Foil Bearing  

E-Print Network (OSTI)

Metal mesh foil bearings (MMFBs) are a promising low cost gas bearing technology for support of high speed oil-free microturbomachinery. Elimination of complex oil lubrication and sealing system by installing MMFBs in oil free rotating machinery offer distinctive advantages such as reduced system overall weight, enhanced reliability at high rotational speeds and extreme temperatures, and extended maintenance intervals compared to conventional turbo machines. MMFBs for oil-free turbomachinery must demonstrate adequate load capacity, reliable rotordynamic performance, and low frictional losses in a high temperature environment. The thesis presents the measurements of MMFB break-away torque, rotor lift off and touchdown speeds, temperature at increasing static load conditions, and identified stiffness and equivalent viscous damping coefficients. The experiments, conducted in a test rig driven by an automotive turbocharger turbine, demonstrate the airborne operation (hydrodynamic gas film) of the floating test MMFB with little frictional loses at increasing loads. The measured drag torque peaks when the rotor starts and stops, and drops significantly once the bearing is airborne. The estimated rotor speed for lift-off increases linearly with increasing applied loads. During continuous operation, the MMFB temperature measured at one end of the back surface of the top foil increases both with rotor speed and static load. Nonetheless, the temperature rise is only nominal ensuring reliable bearing performance. Application of a sacrificial layer of solid lubricant on the top foil surface aids to reduce the rotor break-away torque. The measurements give confidence on this simple bearing technology for ready application into oil-free turbomachinery. Impact loads delivered (with a soft tip) to the test bearing, while resting on the (stationary) drive shaft, evidence a system with large damping and a structural stiffness that increases with frequency (max. 200 Hz). The system equivalent viscous damping ratio decreases from ~ 0.7 to 0.2 as the frequency increases. In general, the viscous damping in a metal mesh structure is of structural type and inversely proportional to the frequency and amplitude of bearing motion relative to the shaft. Impact load tests, conducted while the shaft rotates at 50 krpm, show that the bearing direct stiffness is lower (~25% at 200 Hz) than the bearing structural stiffness identified from impact load tests without shaft rotation. However, the identified equivalent viscous damping coefficients from tests with and without shaft rotation are nearly identical. The orbits of bearing motion relative to the rotating shaft show subsynchronous motion amplitudes and also backward synchronous whirl. The subsynchronous vibration amplitudes are locked at a frequency, nearly identical to a rotor natural frequency. A backward synchronous whirl occurs while the rotor speed is between any two natural frequencies, arising due to bearing stiffness asymmetry.

Chirathadam, Thomas A.

2009-12-01T23:59:59.000Z

484

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

E-Print Network (OSTI)

Natural gas is the primary fuel used in industrial gas turbines for power generation. 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 of the physical characteristics such as the laminar flame speed is necessary, especially at elevated pressures to have the most relevance to the gas turbine industry. This thesis discusses the equations governing premixed laminar flames, historical methods used to measure the laminar flame speed, the experimental device used in this study, the procedure for converting the measured data into the flame speed, the results of the measurements, and a discussion of the results. The results presented in this thesis 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 comparison between the experimental measurements and four chemical kinetic models. The C4 mechanism, developed in part through collaboration between the National University of Ireland Galway and Texas A&M, was improved using the data presented herein, showing good agreement for all cases. The effect of blending ethane, propane, and dimethyl ether with methane in binary form is emphasized in this study, with the resulting Markstein length, Lewis number (Le), and flame stability characterized and discussed. It was noticed in this study, as well as in other studies, that the critical radius of the flame typically decreased as the Le decreased, and that the critical radius of the flame increased as the Le increased. Also, a rigorous uncertainty analysis has been performed, showing a range of 0.3 cm/s to 3.5 cm/s depending on equivalence ratio and initial pressure.

Lowry, William Baugh