Windmills are “structures or machines that convert wind into usable energy through the rotation of a wheel made up of adjustable blades. ” They are used for pumping water, grinding grain, and for power. Windmills are usually found on homesteads or on farms. The first windmill was built in the 1st century by Heron of Alexandria, which was used to operate an organ. A few centuries later the Persians built the first practical windmill, which resembles the one we use today. Although windmills have been modified many times, the parts still manage to remain the same.
Windmills often have 3 blades that connect to a shaft. Once the blades detect the wind and begin rotating, they harness the power of the wind. There are two different types of windmills, horizontal axis and vertical axis. Vertical axis windmills were often used in the early years, while horizontal axis windmills are what we see today. They use angled propeller blades that create friction when if faces the wind, which enables it to rotate. Many windmills are used for pumping water. Wind pumps are windmills that are used in dry places for pumping underground water.
The water is used to give clean drinking water, to water farms, producing salt from sea water, to remove extra water from floods, and for livestock. Wind pumps originate in the late 19th century. They were very important in economic development in part of the US. Wind pumps are often found in Argentina, South Africa, Asia, and the United States. A wind pump consists of a piston. A piston is ”a sliding piece moved by or moving against fluid pressure which usually consists of a short cylindrical body fitting within a cylindrical chamber or vessel along which it moves back and forth. A wind pump also consists of a pump rod. The rotation of the blades causes the pump rod to increase or decrease. When the piston rises it collects water from underground, with the use of a pump rod. The piston contains a special valve the causes it to close and not allow water out. When the piston rises, water is pumped into a storage tank, tube, hose, or trough. As long as the blades rotate, this process continues. As you can see, windmills are a very useful invention.