A windmill is a machine that is powered by the energy of the wind. It is designed to convert the energy of the wind into more useful forms using rotating blades or sails. The term also refers to the structure it is commonly built on. In much of Europe, windmills served originally to grind grain, though later applications included pumping water and, more recently, generation of electricity. Recent electricity-generating versions are referred to as wind turbines
Fixed windmills
A fixed windmill typical of the Cyclades Islands
Fixed windmills, oriented to the prevailing wind were, for example, extensively used in the Cyclades islands of Greece. The economies of power and transport allowed the use of these 'offshore' mills for grinding grain transported from the mainland and flour returned. A 1/10th share of the flour was paid to the miller in return for his service. This type would mount triangular sails when in operation.
Windmills that turn to face the wind
In North Western Europe, the horizontal-shaft or vertical windmill (so called due to the dimension of the movement of its blades) dates from the last quarter of the 12th century in the triangle of northern France, eastern England and Flanders. Joseph Needham states that the earliest known reference came in 1191 by a Dean Herbert of East Anglia, who supposedly competed with the mills of the abbey of Bury St Edmunds.[5] These earliest mills were used to grind cereals. The evidence at present is that the earliest type was the post mill, so named because of the large upright post on which the mill's main structure (the "body" or "buck") is balanced. By mounting the body this way, the mill is able to rotate to face the (variable) wind direction; an essential requirement for windmills to operate economically in North-Western Europe, where wind directions are various.
A fixed windmill typical of the Cyclades Islands
Fixed windmills, oriented to the prevailing wind were, for example, extensively used in the Cyclades islands of Greece. The economies of power and transport allowed the use of these 'offshore' mills for grinding grain transported from the mainland and flour returned. A 1/10th share of the flour was paid to the miller in return for his service. This type would mount triangular sails when in operation.
Windmills that turn to face the wind
In North Western Europe, the horizontal-shaft or vertical windmill (so called due to the dimension of the movement of its blades) dates from the last quarter of the 12th century in the triangle of northern France, eastern England and Flanders. Joseph Needham states that the earliest known reference came in 1191 by a Dean Herbert of East Anglia, who supposedly competed with the mills of the abbey of Bury St Edmunds.[5] These earliest mills were used to grind cereals. The evidence at present is that the earliest type was the post mill, so named because of the large upright post on which the mill's main structure (the "body" or "buck") is balanced. By mounting the body this way, the mill is able to rotate to face the (variable) wind direction; an essential requirement for windmills to operate economically in North-Western Europe, where wind directions are various.
Modern windmills
The most modern generations of windmills are more properly called wind turbines, or wind generators, and are primarily used to generate electricity. Modern windmills are designed to convert the energy of the wind into electricity. The largest wind turbines can generate up to 6MW of power (for comparison a modern fossil fuel power plant generates between 500 and 1,300MW).
With increasing environmental concern, and approaching limits to fossil fuel consumption, wind power has regained interest as a renewable energy source. It is increasingly becoming more useful and sufficient in providing energy for many areas of the world.
One area where turbines have become feasible is in the Midwestern United States, due to great amounts of wind.
The most modern generations of windmills are more properly called wind turbines, or wind generators, and are primarily used to generate electricity. Modern windmills are designed to convert the energy of the wind into electricity. The largest wind turbines can generate up to 6MW of power (for comparison a modern fossil fuel power plant generates between 500 and 1,300MW).
With increasing environmental concern, and approaching limits to fossil fuel consumption, wind power has regained interest as a renewable energy source. It is increasingly becoming more useful and sufficient in providing energy for many areas of the world.
One area where turbines have become feasible is in the Midwestern United States, due to great amounts of wind.
In India
The state in India that has seen substantial growth in wind power generation is Tamil Nadu. A major wind farm is operational in Muppandal (Figure 2) - a small coastal town near Kanyakumari. Muppandal region has one of the largest concentrations of wind generators and generates an aggregate of 540 MW of electricity. It has presented employment opportunities for the youth and brought prosperity to an otherwise barren area.
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