Facts About Windmills

A windmill is a machine that converts wind into energy through the rotation of the wheel composed of adjustable vanes called sails. The historical use of windmills has been as a grinding mill used to reduce solid or rough material into minute grains or a smooth pulp. Windmills have also been used in agriculture for irrigation and in saw mills.

Early History

• No one knows for sure the exact date when windmills were first used; however, the earliest recorded windmill design originated in Persia, between A.D. 500 to 900. Then, the machine was used for pumping water; eventually, it was modified for grinding grain. The early windmill design, known as the Panemone, was made with vertical sails, which were derived from bundles of wood that were attached to vertical shafts by horizontal struts. This design is one of the most inefficient windmill structures ever used. In A.D. 1270, the idea of the windmill spread to Europe, where the earliest European designs were recorded. These windmills were used for grinding grain or pumping water. As the years went by, the European millwrights developed windmill technology further. One of the notable innovations is the tower mill. Eventually, windmills were used for other things like processing spices, powering saw mills and processing tobacco.

Windmill Design

• Windmills fall into two categories, horizontal or vertical axis. The vertical axis is the design that was used in the earlier years, but which was inefficient. The horizontal axis windmill design was more successful and more efficient. Examples of the horizontal axis wind mill include the tower mill, smock mill and fan mill. The reason for the efficiency of this type of windmill is that it was designed in such a way that it was flexible, since the mill operator could physically turn the windmill to catch the wind.

Manufacture

• Windmills are assembled on site using prefabricated parts. Windmills have to be built in windy places so that they can harness maximum energy from the wind. The wind has to be at least 15 miles per hour, or 24 kilometers per hour. After the location has been obtained, the site has to be cleared of all obstructions, like trees and other structures that may block the wind. If necessary, the windmill might be elevated on a platform to enable it capture more of the wind energy. Many tests must be carried out to ensure that the windmill meets the exact specifications outlined in the design. Regular maintenance has to be carried out to ensure that the windmill runs properly.

Outlook

• There had been few major changes in windmills since the last century. The only major improvement has been in the quality and type of materials used in the construction of the windmills. With all the concern about renewable and sustainable energy, and the interest in green energy, windmills have started making a comeback as a source of electricity generation.