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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 energy Betz limit, named
after german
aerodynamist
Albert Betz
BL=16/27
BL=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 as
ω 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 vary
These affect wt performance and certification
Measuring wind speed & wind direction
Wind speed
Estimate the
AEP in
kWh,
MWh,
GWH
Wind directions
Design 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 ?
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 to
IEC 61400-12-1 (2005-12) ISO 17713-1,
Measnet: Classcup
Technical Data
Meas range 0,3...75 m/s
Meas. 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 signal
Form rectangle
Frequency 1082 Hz @ 50 m/s
Amplitude is supply voltage, max. 15 V
Load 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 speed
y= 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 run
Distance
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 evaluation
Ground 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 evaluation
Ground preparation
Final stage of anchor
Final stage of anchor in solid rock
Installation of a meteorological tower for wind energy evaluation
Ground preparation
A 6.5 t hydraulic jack
Mast base
Installation of a meteorological tower for wind energy evaluation
Mast types
Tubular type,
e.g. D=152 mm
Latice, e.g.
L=500 mm
Installation of a meteorological tower for wind energy evaluation
Ground preparation
Mast
alignment
Side arm, L=2500 mm
Installation of a meteorological tower for wind energy evaluation
How far do we place the instruments?
Installation of a meteorological tower for wind energy evaluation
Instrument placements
Top mast layout
Installation of a meteorological tower for wind energy evaluation
Instrument s in place on top of the met mast
Installation of a meteorological tower for wind energy evaluation
Area needed, personnel placements prior to erection
Installation of a meteorological tower for wind energy evaluation
Erecting the mast
At 30 degrees angle
At 45 degrees angle
Final position
