Wind is nothing but air which moves at a rapid pace. When the wind blows, it possesses kinetic energy. If you ask what is wind energy, then it is just the kinetic energy that is in the wind. The wind is caused because of the sun. The sun provides heat to all the parts of the earth, which it absorbs. Due to the differing composition of the earth’s surface, the heat that is retained by the different parts of earth is uneven.
In case a particular area gets too hot, the air of that area becomes hot as well. Naturally as the air gets hotter, it gets lighter and tends to rise. Since technically it is not possible for a physical vacuum to exist on the earth, the cooler air from surrounding areas rushes in to fill the void. This rapid movement of air is called wind. The wind is not something which occurs everyday but it is not possible that it would stop occurring for good any day.
The windmill is used to tap the power of wind. It is one of the oldest ways to tap energy that has been in use since the ancient ages. Its principles have not been altered very much in the ages it has been in use. It was in Persia that people seem to have used windmills for the first time. These ancient windmills resembled peddle wheel. It took centuries to make any major change in the design of windmill. This time it was Holland. They greatly improved the design. This made it way more efficient.
There are a number ways to harness the power of wind. Traditionally there have been a number of uses of wind mills which harness the power of wind. Most of the people used it to grind corn or grain. Farmers used it to draw ground water. The wind power is of great use in the rural environment. Sufficiently big windmills have been installed to provide basic support for entire village like drawing water for irrigation and related purposes etc.
The most common way to harness the wind energy in modern world is to use a windmill that is connected to a generator. This is done to generate electricity. The electricity can be directly supplied to all those who want it. Alternatively, it is also possible to store the electricity in batteries. You can use it at a later time when you feel the requirement.
A number of people still using the windmill know that the reason for their success is that they know what is wind energy and they have learned it themselves and taught to their people. They might not have the professional exposure to advanced wind mill technologies, they have however made great use of what ever they have learned.