Wind power has been used for thousands of years. From using windmills to crush grain or pump water, civilizations have seen the benefits offered by the wind. But how exactly are modern wind turbines being used to create renewable energy?
What do wind turbines do?
Wind turbines are tall machines (about the same height as the Statue of Liberty) designed and built to convert the wind’s kinetic energy into mechanical power to generate electricity.
How do wind turbines create renewable energy?
- The rotor blades on a turbine need to turn – but how exactly does this happen? The design of these blades resembles aircraft wings, which generate aerodynamic torque from the wind. This occurs because air flows across the blades and decreases the air pressure on one side of the blade.
- With this difference in air pressure, both sides of the blade lift and drag. However, the lift force is stronger than the drag force, resulting in the rotor blade spinning.
- Large modern wind turbines usually have the capacity for rotor blades to swivel to allow them to find the optimal pitch angle to harvest this energy.
- The rotor blades connect to the nacelle, which is located behind the blades and contains a gearbox and a generator to convert the kinetic energy into electrical power. The gearbox will translate the blade rotation speed from a low-speed shaft to a high-speed shaft into the generator.
- Once it has passed through the generator, the electrical energy travels through a cable that runs to the bottom of the inside of the tower.
- This is when a transformer will convert the electrical energy to a much higher voltage to be transmitted to the power grid.