Wind power has been used for thousands of years, from pushing ships across the sea to lighting up an entire house. But how do wind turbines transform wind, a natural flow of gases, into electricity that can energize entire cities?
If you’re wondering “How do wind turbines work?”, then in the most general terms, wind turbines turn the kinetic energy in wind into mechanical energy. This energy has been used for hundreds of years for activities such as pumping water, but it can also be transformed into electricity by a generator.
The first step in creating electricity is for the turbine’s rotor blades to harness wind energy and turn it into rotational energy. The shape of the turbine’s blades is uneven, so that the wind pressure on one side of the blade is higher than the other. This causes the blades to spin, thus creating rotational energy.
To monitor the wind so that the blades capture the most energy possible, a wind vane, or another type of wind detection instrument, is installed on top of the turbine. The vane is connected to a computer, and the blades are adjusted so that they always turn into the wind.
As the blades rotate, a shaft attached to the blades inside the nacelle, which is a box at the top of the turbine, turns with it. This shaft is connected to a gearbox, and gears inside the box increase the speed of the shaft’s rotation. The mechanical energy created by the rotation flows through a generator inside the nacelle, which converts the mechanical energy into electricity.
This electricity then passes down through cables in the wind turbine and into a transformer. The transformer converts the electricity from around 700 volts (V) to 33,000 V, which is the correct voltage for distribution, according to RenewableUK.
The electricity from the transformer flows through cables underground, which connect to the National Grid. From there, the electricity is distributed around the country.
The greatest thing about wind turbines is that no carbon dioxide (CO2) or any other greenhouses gases are created through this process. It is a clean way to make a lot of energy.
So now that we know how wind turbines work, what are the giant machines made up of?
Modern wind turbines are very different from the old windmills used thousands of years ago. The complicated machines now stretch high above the ground like thin, white monuments. The average modern wind turbine is made up of the following parts:
- Tower – The tower is the long cylindrical structure that holds the rest of the turbine up high. The higher the tower, the faster and more consistent the wind is. Towers range from 25 to 75 metres high, according to RenewableUK, and are made out of steel.
- Rotor blades – These blades capture the wind’s energy. Turbines typically have one to three rotor blades, and the longer they are, the more energy they create. The blades are usually between 30 and 80 metres in diameter, according to RenewableUK.
- Nacelle – Found at the top of the tower, the nacelle is the covering that holds the gearbox.
- Gear Box – The gears inside the gearbox increase the rotational speed of the shaft that is moved by the blades.
- Generator – The generator transforms the mechanical energy from the rotation of the shaft into electricity using electromagnetism. It is located in the nacelle.
- Yaw Mechanism – This mechanism connects the tower to the nacelle and turns the rotors towards the wind.
- Weather vane – Located at the back of the nacelle, the weather vane monitors wind. The head of the tower turns so that the blades are faced into the wind to get the most energy from it. If wind speed becomes so high that it’s dangerous, the turbine will be stopped. Sometimes other types of wind detection instruments are used.
References:
- http://www1.eere.energy.gov/wind/wind_how.html
- http://news.bbc.co.uk/1/hi/in_depth/629/629/7102346.stm
- http://www.renewableuk.com/en/renewable-energy/wind-energy/how-it-works.cfm
- http://science.howstuffworks.com/environmental/green-science/wind-power2.htm