A presentation on a renewable form of energy:

Wind Energy

Done by:Ethan Gayle, Eshe

GrayGaile Brown, Cara

Lee, Ashley Russell

Wind Natural movement of the air,

especially in the form of a current of air blowing from a particular direction.

Machines can be used to harvest wind currents.

These machines are known as wind turbines and they readily convert the kinetic energy from blades turning into electrical energy.

How does it work

Wind There are several designs for wind

turbines.

Advantages

Wind energy is friendly to the surrounding environment, as no fossil fuels are burnt to generate electricity from wind energy.

Wind turbines take up less space than average power station.

New technologies are making extraction of wind much more efficient.

Renewable resource.

How does it work?Even though designs vary almost all turbines use horizontal axis machines which have a three bladed rotor spinning in a vertical plane and is attached to a box known as Nacelle. It is placed on a tower most often.

Sub mega watt turbines are the most common and are found on wind farms in large numbers.

Each turbine produces 400 to 600 KWH.

They are 20 to 60 meters tall

Parts of the wind turbine

Pitch: Describes the angle of the rotor blade.

Rotor: The blades of the wind turbine.

Low speed shaft: Tube that carries kinetic energy from rotor to the generator.

Generator: Converts mechanical energy to electrical energy.

Anemometer: A device used for measuring wind speed.

Yaw drive:  used to keep the rotor facing into the wind as the wind direction changes.  

Nacelle: Protective fiber glass shield. Gear box: steps up the rotational speed of

the slow speed rotor shaft to the required high speed of the generator shaft.

Parts of the wind turbinecontinued…

Advantages

When combined with solar electricity, this is great for developed and developing countries to provide a steady, reliable supply of electricity.

Great resource to generate energy in remote locations, such as mountain communities and remote countryside.

Disadvantages

The most significant disadvantage is down to the winds unreliability factor

Wind turbines generally produce a lot less electricity than the average fossil fuelled power station.

Disadvantages

Wind turbine construction can be very expensive and costly to surrounding wild life during the building process.

Noise pollution from commercial wind turbines is similar to a small jet engine. This sound travels approximately 1200 meters.

Efficiency

Five factors influence efficiency of wind turbines.

Efficiency speaks to the ratio of the output of wind turbine to the input wind.

Altitude

Wind power

Obstructions

Blade (aerodynamics)

Air( temperature)

Altitude

P=kVFP is wind powerV is wind speedK is constantSooooooooooooooooooo???????

In other words, the faster the wind and stronger the wind force. The

more electricity will be generated by the wind turbine.

Altitude

Higher altitudes have faster wind speeds due to various atmospheric conditions.

Higher places also have less obstructions from surrounding hills and trees.

Wind speed increases by 12% as the distance between the turbine and ground is doubled.

Obstructions

Wind is slowed down by Buildings, trees, mountains, hills.

They create some form of friction that can decrease airflow.

The potential for such obstructions must be determined to ensure turbine use is viable in the area.

Blade aerodynamics

Shape of the blades must be carefully designed to ensure maximum efficiency

The amount of lift for a given airfoil depends heavily on the angle that it makes with the direction of the relative wind known as angle of attack

If the angle of attack is too large, turbulence develops and drag increases significantly, while lift is lossed.

Temperature

oThe power from the wind turbine will increase almost 16% as temperature drops from 20 to -20 c for any given wind speed

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