Did you know that wind generates enough kinetic energy to produce around 35 times the amount of electricity the entire world uses in a single day?
This means that if we managed to harvest just a fraction of the wind kinetic energy available to us, we would have all the power we need and a lot more.
But how can we harvest this amazing energy to power our homes? Scientists suggest that one of the best ways is by using wind turbines.
In this article, we will show you what wind turbines are made out of, and how all the mechanisms inside it work together to product clean energy.
The internal components of a wind turbines
Before getting into how a wind turbine works, first, let’s take a look at its main components.
A wind turbine consists mainly of six parts. Each one of these has a vital role to play in the generation of electricity from wind power.
The first and most important part of the wind turbine is the blades.
For typical wind turbines, each of the three blades has an average length of 80 to 85ft (24m to 26 m) and weighs around 5200lb (2360kg).
This makes it difficult to imagine how normal wind can cause them to move!
Well, it’s all about the aerodynamic design of those blades.
They’re built in such a manner that when the wind blows perpendicular to the blades, a force is produced, causing them to rotate.
This force is the sum of two aerodynamic forces: drag and lift.
Drag is a pulling force applied in the same direction as the relative flow (behind the blades), while lift is a pushing force applied perpendicular to the relative flow (under the blades).
In simple terms, the wind turbine’s blades are made with an airfoil design similar to the one used in airplanes.
When air passes under the blade, it gets deflected down. At the same time, the air above the blade is guided along its surface and down as well.
And since the wind is deflected down, it creates a force (drag and lift) that pushes the blade up, causing it to rotate.
A wind vane, or weather vane, is a tool used for determining the direction of the wind. It was probably one of the first weather instruments ever made.
A wind vane has two main components:
One that is usually arrow-shaped and contracts into the wind, and another which is broader and picks up the breeze.
To determine wind direction, a wind vane spins and points in the direction of the incoming wind.
If it is pointing east, for example, that means the wind is blowing from the east, and so on.
So, what is the importance of the wind vane?
Well, wind turbines produce maximum electricity when the blades spin faster, and this happens when the blades are perpendicular to the wind direction.
Therefore, to increase the output efficiency, a mechanism is used to rotate the head of the turbine, so it can always face the wind.
The wind vane’s job is to provide this mechanism with the wind direction, so it can yaw the head with the exact angle that ensures maximum output.
Wind turbine blades are typically very heavy. While their design helps the blades to rotate, the RPM (revolutions per minute) achieved by them are usually not sufficient for the rotor to produce energy.
Here comes the gearbox’s role.
The gearbox works by converting the low rotational speed of the propeller into high rotational speeds for use by the generator.
Typically, the blades complete 30–60 RPM, and with the help of the gearbox, this number will be increased up to 100 times!
Wind turbines are subject to sudden changes in wind speed.
These rotational speeds should not exceed a certain limit to avoid structural damage.
Here comes the brake’s job. Brakes are used to stop the rotor from spinning during high wind speeds and prevent overloading the internal components of the nacelle.
Generally, you can say that blade braking systems are installed to protect the system during emergencies.
The generator is a crucial component of the whole wind turbine system. It is responsible for transforming kinetic energy into electricity.
Generators primarily consist of a number of gears that are connected together to increase the total RPM. This is why some turbines are equipped with more than one gearbox.
Finally, a wind turbine’s tower supports the whole structure of the turbine.
The huge size of the wind turbine isn’t only to support the weight of the blades. It also helps increase the turbine’s rotational speed.
Wind travels much faster at higher elevations.
This means that the taller the tower, the better a wind turbine’s ability to capture faster wind which will, in turn, increase the RPM of the blades and boost electricity production.
How a wind turbine works: step by step summary
- Wind turbine blades are located on top of a tall tower, where they catch the wind
- The turbulence caused by the difference in air pressure in front and behind the blades causes the blades to rotate, which in turn rotates the low shaft inside the wind turbine’s nacelle
- The gearbox connected to the low-speed shaft then increases the RPM by 80-100 times and feeds it to the generator via the high-speed shaft
- The generator uses this kinetic energy and converts it into a form of electricity
- This generated electricity travels down a wire to an inverter, where it is converted to usable alternating current and sent to the power grid
- Finally, the utility provider will distribute this energy to homes, factories, and other facilities
Wind energy is one of the most abundant sources of renewable energy. By using this clean and free resource, we can reduce CO2 emissions that damage our environment and help to fight global warming.