How Does Wind
Power Work? Check out this short video.
How
does wind power work?
Wind is a great potential energy resource that is
free and people should make use of it. Generating energy
from the wind is not been a modern idea, for windmills have
been used since 200BC for
grinding grains or pumping water. Technological advancements are making
wind turbines more popular all over the world, but many still don’t
understand how wind power works to give us electricity and power
our homes.
How
does wind power work? -Capturing Energy from the Wind
To better understand how wind power works and
what makes wind turbines rotate, take a look at how an aircraft gets
off the ground. The aerofoil splits the wind into two portions as the
wind hits it; one goes over the top and the other under the bottom.
Airflow on the top moves as high velocity and has a low pressure while
airflow under the aerofoil is moving at slower velocity and has high
pressure.
Wind power is actually created from the movement
of high pressure to low pressure and an aerofoil created a pressure
difference between the top and the bottom parts. Then a low pressure
air on top of the aerofoil tries to suck the aerofoil and the air
underneath it pushes it upwards. The air under the aerofoil is actually
trying to push the aerofoil upwards to reach the low pressure. The
result of this action is what we call the “lift.” In airplanes, the
lift happens because the large turbine engines force the wings through
the air at a high velocity. On the other hand, in a wind turbine, we
would rely solely for the wind to hit the aerofoil as it is stationary.
Wind turbine blades are shaped similar to the
shape of the wings of a plane, only with slight differences. So what
happens when wind hits the blade of a turbine is the same lift
force that affects a wing on a plane. But because the blades are
attached to a stationary machine, instead of a lift force to cause the
rotor to
lift into the sky, the blade then spins round and round. This is what
creates rotational energy which then will be converted to electricity
by the generator. The blades of the turbine are usually pitched at a
certain angle to get the maximum amount of 'lift' from the wind.
How
does Wind Power Work? -Parts of a Wind
Generator
But how does wind power work to give us energy?
Let’s take a look at a windmill’s parts first to see how each part
functions in the process of how wind energy is converted to electricity.
Rotor
blades – part of the turbine that captures
wind energy and converts it into rotational form.
Hub
– is the connection point of the rotor blades
and the low speed shaft.
Gearbox
– takes the rotational speed from the low
speed shaft and changes it into a faster rotation on the high-speed
shaft.
Mechanical
break – is a physical break like a disc
break on the wheel of the car. It is connected to the high speed shaft
and is used to serve the equipment and ensure that no components rotate
to endanger the repair worker.
Generator
– connected to the high-speed shaft and
is the part of the system that converts rotational energy of the shaft
into electrical output.
Cooling
system – is used to make sure that the
part of the turbine does not overheat. It could be a typical cooling
system – either a fan or a radiator system.
Anemometer
and wind vane – anemometer measures
wind speed while wind vane points the direction of the wind.
Yaw
mechanism – is employed to ensure that the
rotor blades are parallel to the flow of the wind, so that they can
work efficiently.
Controller
– is a computer system monitoring and
controlling different aspects of the turbine and has the ability to
shut it down if an error occurs.
Tower
– is the one that supports the
rotor blades and nacelle.
Nacelle
– located at the top of the tower which
encapsulates all parts of the turbine.
How
does wind power work?- Advances
Presently, wind turbines had been developed with
power rating ranging from a few kilowatts up to multi-megawatt
capacity. Larger machines are more like research prototypes, while
commercially available turbines are rated at about 600kw. Wind power
technology has been well established having 20,000 grid-connected
machined all over the world. Current research works and development is
concentrated mostly on improving reliability, costs, performance and
noise reduction.
Large wind farms need a number of turbines for
economy and ease of generation. Wind farms need to have turbines which
are erected 5-10 rotor blades apart to lessen aerodynamic interaction
which affects their efficiency. A wind farm with 20 turbines needs
about 3 to 4 square kilometers of land, but it will only take up
minimal ground space, which in some cases, can then be used for
agriculture.
