Wind Potential - EU-GCC Clean Energy Technology Network Oma… · Cp. The tip-speed ratio ......

transcript

Welcome to the world of wind energy

Dr. D. V. KanellopoulosOPWP Renewable Energy

Training Program11-14 December 2016

Muscat, Oman

Wind Potential

Solar radiation powers up the wind

Surface air temperatures on earth for January

Global Surface Winds

latitude Predominate

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

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

coefficient

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

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

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

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 <

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

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, 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

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

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

Ground preparation

Final stage of anchor

Final stage of anchor in solid rock

Ground preparation

A 6.5 t hydraulic jack

Mast base

Mast types

Tubular type,

e.g. D=152 mm

Latice, e.g.

L=500 mm

Ground preparation

alignment

Side arm, L=2500 mm

How far do we place the instruments?

Instrument placements

Top mast layout

Instrument s in place on top of the met mast

Area needed, personnel placements prior to erection

Erecting the mast

At 30 degrees angle

At 45 degrees angle

Final position

Wind Potential - EU-GCC Clean Energy Technology Network Oma… · Cp. The tip-speed ratio ......

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