The wind has been used to power machines capable of grinding corn, pumping water and producing electricity for hundreds years. There are records of Persian and Japanese wind machines as long ago as 200 BC. Wind power probably has its origin in the ancient civilisations of China, Tibet, India, Afghanistan, and Persia. The first written evidence of the use of wind turbines is that of Hero of Alexandria, who in the third or second century BC described a simple horizontal-axis wind turbine. From contemporary sources we also know that windmills have been used in the 11th & 12th century in England. Also from a contemporary eyewitness (1190) we know that German crusaders brought the skills of building windmills to Syria. From this, we may assume that this technology was generally known all over Europe since the Middle Ages.

The two most familiar types of wind machines are the traditional windmill used for grinding corn, once common place in Europe and the water pumping windmills that provided water to farms and towns in the U.S.A. and seen on many Western films. It is estimated that in the 1930s there were 6 million of these fan type mills in use in America.

Pitstone Windmill stands in the north east corner of a large field near the parish boundary of Ivinghoe and Pitstone in Buckinghamshire. It is thought to have been first built circa 1627 as this date is carved on part of the framework. This is the earliest date to be found on any windmill in the British Isles. It should be remembered that such a structure would have had to have frequent repairs made to it, so it is quite possible the mill predates 1627.

The design of the mill is what is known as a post-mill. This means the whole superstructure of the mill rests on one main post. This post arises from ground level through brick and a foundation chamber; the post then acts as a pivot for the timber built structure above with the sails. Consequently, the upper section of the mill and sails can be turned towards the direction of the wind. The mill machinery in the upper rotating section was reached by a long flight of external steps.

For many hundreds of years corn grown in the two adjoining villages was ground at the mill into flour. In 1874 the mill was bought by Adelbert Wellington Brownlow Cust, 3rd Earl Brownlow who owned the nearby Ashridge Estate. He subsequently let it to a local farmer, who ran a successful milling business from the mill.
In 1902 the mill was seriously damaged during a furious gale, damaging it beyond the price of economic repair. Circa 1922 the now derelict ruined mill was bought from the Ashridge Estate by a farmer whose land was close to the mill. In 1937 he donated it to the National Trust. However, it was not until 1963 that a band of volunteers began to carry out renovations at their own expense. After seven years of hard work in 1970 after an interlude of 68 years the mill once again ground corn. Today owned by the National Trust the windmill is open to the public on Summer Sunday afternoons.

The development of the water-pumping type windmill in the USA was the major factor in allowing the farming of vast areas of North America, which was otherwise devoid of readily accessible water, and also allowed the extension of rail transport systems, throughout the world, into areas where water could be pumped up from underground to supply the needs of the steam locomotives of those early times. They are still used today for the same purpose in some areas of the world where grid electricity is not a realistic option.

The many-bladed wind turbine atop a lattice tower made of wood or steel was, for many years, a fixture of the rural landscape throughout rural America. These mills, made by a variety of manufacturers, featured a large number of blades so that they would turn slowly but with considerable torque. A tower-top gearbox and crankshaft converted the rotary motion into reciprocating strokes carried downward through a pole or rod to the wellhead below.

In areas not prone to freezing weather, a pump jack (or standard) was mounted at the top of the well below. This was the connection between the windmill and the pump rod, which generally went through the drop pipe to the cylinder below. The pump jack provided a means for manual operation of the pump when the wind was not blowing. Some pump jacks provided a sealed connection, allowing water to be forced out under pressure, but many had a simple spout allowing water to flow away in a trough by gravity.

The drop pipe and pump rod continued down deep into the well, terminating at the pump cylinder below the lowest likely groundwater level. A suction tube usually continued a short distance more. This arrangement allowed wells as deep as 400 feet to be constructed, though most were much more shallow.
The number of moving parts led to the whole arrangement to be rather trouble prone, and “well men”, as they were called in the early days, had a profitable business in repair and maintenance work.

The wind turbines and related equipment are still manufactured and installed today in remote parts of the western United States where electric power is not readily available. The arrival of electricity in rural areas, brought by the REA in the 1930s through 1950s, made these windmills obsolete in the Midwest and other more built-up areas. The mills and towers remained for a time. Today, most are gone, victims of storms, rust, and progress.

As the use of fossil fuels developed and the use of electricity generated from coal and oil became widespread in the early 20th Century, renewables began to contribute less and less to the world’s energy needs. Research continued in many counties with advances being made in both the theoretical and practical use of wind energy. Hence, the revival of the wider interest in wind power after the 1970s did not start from scratch, but could build on a solid foundation of theories and practical experiences. When the new era of wind energy was initiated in the 1970s new materials and technologies were available. Composite materials such as fibreglass showed to be very suitable for the blades, and electronics were developed to control the wind turbine. In the 1980s investment was once again made in Europe and America into the production of electricity from very large windmills (often known as wind turbine or wind turbines). Wind parks consisting of groups of wind turbine were built in California, Sardinia, Orkney, Ilfracombe in Devon, Carmarthan Bay and Richborough in Kent. These experimental sites were funded by public and private money. By the end of 1996 a total of 6200 MW grid connected wind turbine capacity was installed around the world. In 1996 1200 MW were added.

An up to date map of wind farms in the UK can be found at

http://www.bwea.com/map/uk.html

The main application for mechanical farm wind pumps is drinking water supply. The markets for this type of machines include USA, Argentina, South Africa and New Zealand.

Cumulative global wind energy generating capacity topped 31,000 megawatts
(MW) in 2002. Some 6,868 MW of new capacity were installed worldwide during the year, an increase of 28%, according to preliminary estimates by the American Wind Energy Association and the European Wind Energy Association. Wind plants now power the equivalent of 7.5 million average American homes or 16 million average European homes, worldwide. Global wind power generating capacity has quadrupled over the past five years, growing from 7,600 MW at the end of 1997 to an estimated 31,128 MW at the end of 2002 - an increase of over 23,000 MW. Wind is now the world’s fastest-growing energy source on a percentage basis, with installed generating capacity increasing by an average 32% annually for the last five years (1998-2002). The slightly slower rate of 28% in 2002 was primarily due to a lull in the U.S. market.