By Hana Bull

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Our Energy

• By Hana Bull
• Jennii Derry

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The energy we have chose.... is ....
WIND ENERGY
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WHY ?!?!?

• We chose Wind Energy because it is a renewable
  energy re-source.
• England doesnt have the best weather conditions
  and we have a lot of rainy and windy conditions
  this is very helpful.
• Wind Rain are both re-newable sources making
  them both perfect choices.

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Nerdy Bit !

• When the wind blows over the blades of a wind
  turbine, their aero-dynamic shape makes them
  turn.
• When air passes over an aero-dynamic part, it
  travels faster over the top of the blade than it
  does below. This makes the air pressure above the
  blade lower than it is below. Due to the unequal
  pressures the blade experiences a lifting force.
  You can see this if you hold a thin sheet of
  paper to your lips and blow over the top of it.
  This will make the paper rise more than if you
  blow underneath it. The opposite force is drag,
  due to surface friction and turbulence. Wind
  turbine designers use these forces generated by
  the wind to make the rotor blades turn.

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The Picture Nerdy Bit Cont..
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Last Nerdy Bit! ...

• This rotational energy is transmitted either to
  an electrical generator or to a machine for
  mechanical work, such as a water pump. With
  electricity generating turbines, a gearbox is
  used to speed up the rotation, about 30 times. In
  mechanical turbines a shaft connects the turbine
  to the working machine.
• Energy is extracted from the wind as it moves
  through the 'swept area' of the turbine's blades.
  On the down wind side of the turbine the wind
  moves more slowly, as some of its kinetic energy
  has been lost.

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PiCtUrEs
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Emissions Reductions
Every unit (kWh) of electricity produced by the
wind displaces a unit of electricity which would
have been produced by a power station burning
fossil fuel. This is a fact used by many
organisations including Government in their
environmental calculations.
Wind turbines produce electricity by using the
natural power of the wind to drive a generator.
The wind is a clean and sustainable fuel source,
it does not create pollution and it will never
run out. Wind energy technology is developing
fast, turbines are becoming cheaper and more
powerful, bringing the cost of renewably-generated
electricity down. Europe is at the hub of this
high-tech industry.
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Disadvantages
Some people say that wind turbines are ugly, but
this could easily be resolved by designing new
styles of wind turbines. If you have a small
garden or live in a small town which is cramped
all ready. You wont want a huge wind turbine on
your roof or In your town. They need lots of
space. They need wind and if you have a wind
turbine in a country that hardly has any wind
this will not be the ideal solution for you!
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The Need For Clean Energy
The Most Common methods of generating electricity
burn fuel to provide the energy to drive a
generator, usually by using the heat to provide
steam to drive a turbine. These technologies may
use fossil fuels, - coal, oil or gas - or nuclear
fuel. Using fossil fuels creates pollution, such
as oxides of sulphur and nitrogen which
contribute to acid rain, and carbon dioxide which
contributes to global climate change. Although
these sources of power dominate the energy needs
of European countries, wind energy is growing
rapidly. Renewable energy sources currently
provide nearly 5.4 of the European Union's
primary energy needs and have the potential to
provide much more.
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How Wind Turbines Work
Rotor diameters range up to 80 metres, smaller
machines (around 30 meters) are typical in
developing countries Wind turbines can have
three, two or just one rotor blades. Most have
three. Blades are made of fibreglass-reinforced
polyester or wood-epoxy. The blades rotate at
10-30 revolutions per minute at constant speed,
although an increasing number of machines operate
at a variable speed.
Power is controlled automatically as wind speed
varies and machines are stopped at very high wind
speeds to protect them from damage. Most have
gearboxes although there are increasing numbers
with direct drives. The yaw mechanism turns the
turbine so that it faces the wind. Sensors are
used to monitor wind direction and the tower head
is turned to line up with the wind.
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The End