Question

Draw a neat diagram of wind turbine and explain how it helps in energy production.

Answer 1

Wind Turbines:
Principle:
Wind turbines convert the kinetic energy in the wind into mechanical power. A generator can convert mechanical power into electricity. The mechanical power can also be utilized directly for specific tasks such as pumping water.
Construction and Working:
The basic components of the wind turbine include:

• a rotor, consists of the blades and the hub which convert the wind's energy into rotational shaft energy
•  a nacelle containing a drive train, includes shafts, gearbox and generator
•  pitch drive, turns the blades out of the wind to control rotor speed
• brake, slows the rotor down
• yaw drive, keeps the rotor and therefore the turbines facing the wind
• controller-anemometer, starts and stops the turbine from working depending on conditions
•  a tower, to support the rotor and drive train; electronic equipment such as controls, electrical cables, ground support equipment, and interconnection equipment.

The schematic of the wind turbine components are shown here.

• When the wind blows a pocket of low-pressure air forms on the downwind side of the blade. The low-pressure air pocket then pulls the blade toward it, causing the rotor to turn. This is called lift.
• The force of the lift is actually much stronger than the wind’s force against the front side of the blade, which is called drag. The combination of lift and drag is what causes the rotor to spin.
•  As the rotor spins, the low-speed shaft, which is connected to the gearbox, spins at the same rate.
•  The gearbox takes this slow rotational speed and through correct gearing turns it into a faster rotational speed.
• The high-speed shaft, which is on the outgoing end of the gearbox and connected to a generator, spins at a higher rate of speed.
• The generator spins at this high rate of speed which spins magnets around a coil of metal wire and generates electricity.
• This electricity then travels down the tower to a transformer, where it is converted again to AC or DC voltage depending on the grid.