|ملف متكامل بالرسوم المتحركة عن طاقة الرياح wind energy|
THE HISTORY OF WIND POWER-1
PERSIA 500 BC
The development of sail boats led directly to the development of the first recorded wind powered device in Persia (the Middle East). Sails were used to drive a mill stone for the grinding of grain. These were seen first in Persia, 500 BC. Some versions were also used to pump water for simple irrigation of agricultural land and for drinking water.
As sails developed, wind powered devices became more powerful. The device shown opposite was very common around 1000 AD. Similar devices can be seen in Cyprus and the Greek islands even today. They are still used to pump water for agricultural livestock.
The difference between this design and earlier designs is that the sails are shaped more efficiently to capture the wind and they spin vertically. Earlier devices relied on sails similar to those used by sail ships.
Europe 1300 - 1850 AD
This type of design became familiar to people in Europe between 1300 and 1850 AD. The design is much more like the traditional windmills we see even today. It was designed specifically for the large scale milling of grain.
It is believed that the design was developed from early water wheels. The technology that converted water power to grind grain could also be used with wind mills. The only difference was that the power came from moving air not moving water.
THE HISTORY OF WIND POWER - 2
WIND POWER IN EUROPE IN THE 1800s
Throughout the 1800s windmill technology evolved slowly. Wind mills like the one above were primarily used for milling grain and occasionally for pumping water. In the south of England large areas of marsh land were drained to become agricultural land through the use of these wind powered devices.
WIND POWER IN THE USA IN THE 1800s
In the USA wind powered devices like the one shown opposite were developed to pump water. These were especially useful in arid areas were deep wells were necessary to find drinking water.
In the 1800s the Halladay windmill was very popular with thousands been made. This basic design was reliable and was used even up to the 1940s.
Large versions of this design had rotors (propellers) of 18 metres in length.
THE HISTORY OF WIND POWER-3
With the development of electrical power, scientists and technologist developed ways of producing electricity through the use of wind generators (also known as turbines). Experiments took place in Russia, USA France Germany and Britain. Although these experiments showed that electricity could be produce, it was never in the amounts needed to meet the needs of industry or large numbers of people.
In the 1930s one of the largest experimental machines, called the Palmer-Putman machine was first used. This was capable of producing 1.25 megawatts of electricity. However, the materials available at the time reduced its efficiency greatly and made the machine difficult to maintain. It had 50 metre rotors which were the large compared to other designs.
After the Second World War the search for efficient wind power generators (turbines) restarted. In Denmark the Gedser Wind Turbine was developed and operated until the mid 1960s. This was 200 Kilowatt machine. The rotors had a set pitch (angle) to catch the wind more efficiently. The main body of the device was built in a similar way to that of the body of an aeroplane. Aeroplane technology was applied successfully to the device making it the most efficient device of its time. However, developments in the generation of electricity through wind power was slow in the 1950s and 1960s. This was because fossil fuels were relatively cheap.
THE HISTORY OF WIND POWER - 4
Throughout the 1960s, a German Technologist called Professor Ulrich Hutter designed a number of wind generators that used modern materials such as fibreglass and types of plastics. The lighter materials meant that the device could operate in lighter winds, generating electricity. Slowly but surely, wind powered turbines were beginning to look economic to build and maintain.
Due mainly to the rapid rise in oil prices throughout the late 1970s and 1980s the development of wind generators (turbines) accelerated. Recently wars and unstable governments in oil producing regions has led to the understanding that alternative forms of energy production have to be developed. Also, there is a greater understanding that using fossil fuels to produce electricity causes pollution that damages the environment and causes global warming.
WIND POWER ON LAND
Wind power generators are rarely seen in isolation as they are normally put together in groups forming wind farms. This is the most efficient way of producing electricity from the wind and feeding it into the national power grid. Single generators are normally much smaller and used on farms or in remote areas where it is not possible to cable electricity from the national grid.
Wind farms tend to be located in the countryside were they are away from towns and people. Many people believe that these large structures spoil the look and piece of the countryside. Wind generators create a lot of noise. It is said that each one is as loud as a car engine running at 70 MPH.
WIND POWER AT SEA
Some technologists and scientists believe the answer is to site large wind generators at sea. The noise they produce will not be heard and if sited miles way from the coast they will not even be seen. However, they are much more costly to locate and maintain in the sea. Also, the salt in sea water means that the materials used to make them have to be specially treated so that they are protected. This increases there overall cost of manufacture and installation significantly. However, this may be the future for the large scale production of electricity through wind powered turbines.
MODERN WIND FARM OFF THE COAST OF NORTH WALES (UK)