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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

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Solar radiation powers up the wind

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Surface air temperatures on earth for January

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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

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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