1. What are windmills?
• A windmill is a structure used to harness the power of the wind for purposes like
grinding grain, pumping water, and generating electricity.
• Wind causes its blades to spin, thereby creating kinetic energy.
• It can also be defined as a machine that converts the kinetic energy of the wind into
electrical energy.
2. Components Of Windmill
• Rotor: It is the rotating part of a turbine; it consists of (mostly) three blades and the
central part that the blades are attached to, the hub. But the three-blade rotor has the
best efficiency and other advantages.
• Generator: The generator converts the mechanical energy of the rotating shaft into
electrical energy.
• Gearbox: Contains gears that convert the relatively slow rotation of the spinning
blades into higher-speed motion
3. Components Of Windmill
• Tower: The tower lifts the wind turbine up high so that it can take advantage of the
stronger, more consistent winds which blow above the ground.
• Nacelle: The nacelle is housing on top of the tower that accommodates all the
components that need to be on a turbine top.
• Anemometer: This important feature measures wind speed and transfers the recorded
data to a controller.
5. Working Principle of Windmills
• Wind turbines have a simple principle that is they transform wind
energy to mechanical energy.
• The wind turns the blades, which spin a shaft, which connects to
a generator and makes electricity.
6. Working of Windmills
• Winds are produced due to uneven heating of the atmosphere by the sun, the rotation
of the earth and the irregularities of the earth’s surface.
• Turbines catch the wind's energy with their propeller-like blades.
• When the wind blows, a pocket of low-pressure air forms on one 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 much stronger than the wind's force against the front side of the
blade, which is called drag. The combination of lift and drag causes the rotor to spin
like a propeller.
7. Working of Windmills
• A series of gears increase the rotation of the rotor from about 16 revolutions a minute
to roughly 1,600 revolutions per minute - a speed that allows the turbine’s generator to
produce AC electricity.
• Anemometers (automatic speed measuring devices) and wind vanes on the back of the
nacelle provide measurements of the wind speed and direction.
• The electric current produced by the generator flows through a cable running down
through the inside of the turbine tower.
• A step-up transformer converts the electricity to about 50 times higher voltage so it can
be transmitted efficiently to the power grid.
