How Do Wind Turbines Work?
By Katie Anderson on July 27th, 2011
As we continue to try and wean ourselves off using fossil fuels as a source of energy, wind turbines are increasingly looking to be a viable option, when it comes to providing clean and unlimited energy.
As a form of solar energy, a wind turbine essentially works in the opposite way to a fan. Rather than using electricity to generate wind, a wind turbine uses wind to make electricity.
They are generally pretty simple in design. Comprising of propellers, a shaft and a generator, they work by taking some of the kinetic energy of wind as it hits the propellers, and converting it into electricity, which is also known as mechanical power. This mechanical power can be used for specific tasks, for example pumping water or grinding grain, or a generator will be used to convert mechanical power into electricity.
How do they work?
1. The propellers (blades) on the turbine catch the wind, which helps rotate the shaft.
2. The blades of each turbine turn on a horizontal (or vertical) axis in the wind.
2. Movement of this drive shaft spins an electricity generator via a gearbox. As the shaft turns, it helps to power the generator and create electricity.
3. A generator – normally consisting of magnets and a conductor, such as coiled copper wire – features an array of magnets connected to the shaft which surround the coil of wire.
4. When the magnets rotate around the copper wire, it creates voltage and an electric current. Known as “induction”, it’s how generators produce electricity.
The size of a turbine will influence its power generating capacity. Wind farm turbines are designed to generate power over a wide range of wind speeds. The size of a turbine will influence its power generating capacity.
Wind turbine terminology
- Anemometer – this measures the wind speed and transmits wind speed data to the controller.
- Blades – also known as propellers, most turbines have either two or three blades.
- Brake – a disc brake will stop the rotor in emergencies.
- Gear box – a costly and heavy part of a wind turbine, gears connect the low-speed shaft to the high-speed shaft and increase the rotational speeds from about 30 to 60 rotations per minute (rpm) to about 1000 to 1800 rpm, the rotational speed required by most generators to produce electricity. Not all wind turbines have a gearbox.
- Generator – a mechanical devise that generates electrical energy from the wind. It works in conjunction with a wind turbine rotor which supplies fluctuating mechanical power.
- High-speed shaft – this drives the generator.
- Nacelle – it sits atop the tower and contains the gear box, low-and high-speed shafts, generator, controller, and brake.
- Rotor – the blades and the hub are known as the rotor.
- Shaft – the high-speed shaft is what drives the generator, whilst the rotor turns the low-speed shaft at about 30 to 60 rotations per minute.
- Tower – can be made from tubular steel, concrete, or steel lattice. The taller the tower the more energy captured and therefore the more electricity it generates.
- Wind vane- measures wind direction and communicates with the yaw drive to direct the turbine.
- Yaw drive – used to keep the rotor facing into the wind as the wind direction changes.
- Yaw motor – powers the yaw drive.