What is a Windmill?
Windmills are useful and beautiful structures that are often found on farms or homesteads. They are used for a number of reasons such as pumping water, grinding grain or generating power. They have been around for centuries and the earliest recorded windmills were used in Persia to grind corn. Windmills have 3 sail like blades that are connected to a shaft and sit on top of a large triangular base. These blades catch the wind and rotate harnessing the power of the wind. Windmills come in many shapes and sizes depending on their use. Grinding windmills tend to be larger than other types of windmill because they need to house the grinding stone. These days windmills are most commonly used to pump water or generate electricity.
How Does A Windmill Work?
Windmills that pump water are called wind pumps and are used in dry and arid places to pump water from under the ground. The wind pump has blades, a pump rod and a piston. When the blades catch the wind they rotate. This causes the pump rod to rise and fall. The pump rod makes the piston rise drawing water from below ground. A special valve in the piston closes and does not allow the water out. As the piston rises it pumps water into a collection tank, trough or hose for use. As the piston lowers the valve opens so that more water can be collected. This continues to happen as long as the blades are rotating.
A windmill that produces power is often called a wind turbine and these are the type that you see in wind farms. Wind turbines work very similarly to wind pumps. The blades catch the wind and begin to rotate. This in turn rotates a drive shaft which runs down to a gearbox connected to a generator at the windmill base. The gearbox converts the slow turning of the windmill into quicker revolutions creating more kinetic energy. The generator turns this kinetic energy into electricity which is collected and distributed through wires.