11
Welcome to the world of wind energy
Dr. D. V. KanellopoulosOPWP Renewable Energy
Training Program11-14 December 2016
Muscat, Oman
Wind Potential
22
Solar radiation powers up the wind
33
Surface air temperatures on earth for January
44
Global Surface Winds
latitude Predominate wind direction
60-90 N NE
30-60 N SW
0-30 N NE
0-30 S SE
30-60 S NW
60-90 S SE
55
Energy from the wind
• Air density depends on temperature and barometric pressure.
• The larger the diameter of the wt, the larger the gain.
• High speeds yield more energyBetz limit, named after german aerodynamist Albert Betz
BL=16/27BL=0.593
TIP SPEED ratio, λ
Power coefficient
% Cp
The tip-speed ratio, λ, or TSR for WTs is the ratio between the tangential speed of the tip of a blade and the actual velocity of the wind, The tip-speed ratio is related to efficiency, with the optimum varying with blade design. Higher tip speeds result in higher noise levels and require stronger blades due to large centrifugal forces.
The tip speed of the blade can be calculated asω times R, where ω is the rotor rotational speed in radians/second, and R is the rotor radius in meters.
Tip speed ratio, λ
Cp vs wind speed for various pitch angles
Cp vs TSR(λ) for various pitch angles
Earth’s climatic zones
Meteorological parameters varyThese affect wt performance and certification
Measuring wind speed & wind direction
Wind speedEstimate the
AEP inkWh,
MWh, GWH
Wind directionsDesign wind
farm layouts in order to
maximize energy output, minimize wake losses and land
or sea use
Duration of wind measurements for safe AEP calculations ?
It cannot be less than a full year. More years reduce uncertainty in estimating AEP for the life time of a project which is 20years.Minimum duration period is normally obligatory by the regulatory authorities(e.g. RAE in GR)
Malin Head Met station in Ireland
Duration of wind measurements for safe AEP calculations ?
With this U overestimate
E
With this U underestimate
E
8.8 m/sok E
Anemometers or wind sensors
1846-Thomas Romney Robinson, Ireland
John Patterson, a Canadian weatherman
3 cup 1926
U m/s V m/s
W m/s
The wind vector, in reality. Most measurement measure only the horizontal wind speed magnitude.
The horizontal wind comprises of the U and V components of the true wind. This is used for site evaluation.
Anemometers types
Rotating cup anemometers
Total cup anemometer. No power needed!
Hand anemometer. Battery needed.
Anemometers types
Rotating propeller anemometers
Hand anemometer. Battery needed.
vane anemometer
Anemometers types
Rotating propeller anemometers
a U-V-W anemometer
a W anemometer, suitable for any angle
Anemometers types
Ultrasonic anemometers
Acoustic resonance anemometers
Anemometers types
Anemometers types
Hot wire anemometers
Laser Doppler velocimetry (LDV), also known as laser Doppler anemometry (LDA), is the technique of using the Doppler shift in a laser beam to measure the velocity in transparent or semi-transparent fluid flows. The measurement with LDA is absolute, linear with velocity and requires no pre-calibration.
Anemometers types
Laser Doppler anemometers
Anemometers types
Thermal Field Variation anemometers, TFV
This Design Idea describes a method by which you can detect and assess air or liquid fluid flow using an externally heated semiconductor diode. Airflow across the heated diode reduces its temperature, causing a variation in the diode's voltage drop. This principle is similar to that used in hot-wire anemometers.
Anemometers types
Pressure tube anemometers
Technical specifications for cup anemometers
For site assessment and measurement of power performance of wind energy power plants.Class A, B and S accredited according toIEC 61400-12-1 (2005-12) ISO 17713-1,Measnet: Classcup
Technical DataMeas range 0,3...75 m/sMeas. instability (w/o calibration)
0,3...50 m/s < 1% of meas. value or < 0,2 m/s
Survival speed 80 m/s (min. 30 minutes)
Permissible Ambient condit.
-50…+80 °C, all occurring situations of relative humidity (incl. dew moistening)
Technical specifications for cup anemometers
Output signalForm rectangleFrequency 1082 Hz @ 50 m/sAmplitude is supply voltage, max. 15 VLoad R > 1 kΩ (Push-pull output with 220 Ω in
series)C < 200 nF (corresp. to length typical cable < 1km)
Linearity Correlation factor r between frequency and wind speedy= 0,0462*f+0,21 typical r > 0.999 99 (4…20 m/s)
Starting velocity
< 0,3 m/s
Resolution 0,05 m wind runDistance constant
<3m (acc. To ASTM D 5096 – 96), instrument respond to 63.2% of speed change
Anemometers types
Wind direction sensors, wind vanes
Artistic traditional wind vanes on house rooftops
Anemometers types
Wind direction sensors, wind vanes
Ice free wind vane
Technical specifications for wind vanes
Anemometers types
Combined type anemometers, nick named “airplane” anemometers
Used extensively in the 80’s and 90’s in Greece to verify sites
Anemometers types
Combined type anemometers
Not used for verified wind resource measurements
Anemometer towers
H m AGL or ASL
H minimum = or > than 10 m
Anemometer towers
Anemometer towers
Anemometer towers, with and without guy wires
Other necessary meteorological instrument used for wind resource evaluation,
barometric pressure sensor
Other necessary meteorological instrument used for wind resource evaluation, thermometer
• Minimum• Mean• Maximum
Data Loggers, the “brain” of the measuring system
Data Loggers, the “brain” of the measuring system
Put your hard hats on. Lets put up one wind measuring system
Installation of a meteorological tower for wind energy evaluation
How height we need the measurements?How many intermediate heights are necessary?Tubular or lattice towers?Team qualifications?Must follow standards in order to be accepted by permit procedure in the future
Installation of a meteorological tower for wind energy evaluationGround preparation
A 1:5000 scale map will give an indication of a suitable place, eye verification absolutely necessary. Permission will be necessary prior to erecting the tower.
For a 60 m mast, areas in red must be cleared from vegetation if necessary
90 m
63 m
46 m
Installation of a meteorological tower for wind energy evaluationGround preparation
Final stage of anchor
Final stage of anchor in solid rock
Installation of a meteorological tower for wind energy evaluationGround preparation
A 6.5 t hydraulic jack
Mast base
Installation of a meteorological tower for wind energy evaluationMast types
Tubular type, e.g. D=152 mm
Latice, e.g. L=500 mm
Installation of a meteorological tower for wind energy evaluationGround preparation
Mast alignment
Side arm, L=2500 mm
Installation of a meteorological tower for wind energy evaluationHow far do we place the instruments?
Installation of a meteorological tower for wind energy evaluationInstrument placements
Top mast layout
Installation of a meteorological tower for wind energy evaluationInstrument s in place on top of the met mast
Installation of a meteorological tower for wind energy evaluationArea needed, personnel placements prior to erection
Installation of a meteorological tower for wind energy evaluationErecting the mast
At 30 degrees angle
At 45 degrees angle
Final position