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Introduction
Windpower technology dates back many centuries. There are historical claims that wind machines which harness the power of the wind date back to the time of the ancient Egyptians. Hero of Alexandria used a simple windmill to power an organ whilst the Babylonian emperor, Hammurabi, used windmills for an ambitious irrigation project as early as the 17th century BC. The Persians built windmills in the 7th century AD for milling and irrigation and rustic mills similar to these early vertical axis designs can still be found in the region today.
In Europe the first windmills were seen much later, probably having been introduced by the English on their return from the crusades in the middle east or possibly transferred to Southern Europe by the Muslims after their conquest of the Iberian Peninsula. It was in Europe that much of the subsequent technical development took place. By the late part of the 13th century the typical 'European windmill' had been developed and this became the norm until further developments were introduced during the 18th century. At the end of the 19th century there were more than 30,000 windmills in Europe, used primarily for the milling of grain and water pumping. The first half of the 20th saw further development, particularly a move toward propeller type wind machines for electricity production.
The major advances in the design of the windpump, however, took place in the USA. The technology was taken up and developed by the early pioneers or settlers who needed a method of lifting ground water for irrigation, for watering of livestock and later for providing water for steam locomotives which began to spread across the country. There were several significant technical developments to the commercial machines during this time; the ability of the machine to turn into the prevailing wind automatically; the development of a self governing mechanism which automatically turned the machine out of the wind when the wind velocity became high enough to cause damage; various improvements in rotor design and general durability and the introduction of gearing mechanisms.
The technology was soon taken up worldwide, especially in the newly settled arid regions, such as South Africa, Australia and Argentina, where previously a lack of water had always prevented settlement and economic...