Category Wind Energy

How does wind energy work?

A push from the wind can make a kite fly. It can make a sailing boat speed across the water. It can even light lamps and pump water.

People use wind energy to pump water and make electricity for their homes and other buildings. They do it with the help of a machine called a windmill. Windmills come in different shapes and sizes, but they are all alike in some ways.

They are tall enough to catch the strong winds that blow high above the ground. They also have a wheel, which is the part that spins. The wheel has paddles, sails, or blades for the wind to push against. When the wind blows, the wheel spins. This makes a push that runs a water pump or an electricity-making machine called a generator.

Of course, the wind doesn’t always blow, so the windmill doesn’t always run. But water pumped by the windmill can be stored in tanks. And electricity made when the windmill runs can be stored in batteries. Until the windmill goes back to work, people can use stored-up water and stored-up electricity in their homes. There are even “wind farms”, where many windmills make electricity for whole communities.

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Why does Holland have so many windmills?

          The large number of windmills in Holland, or The Netherlands, is due to the fact that they were needed to pump water into the canals off the rich, low-lying land reclaimed from the’ sea. Windmills are still used for this purpose today, but pump worked by electricity are more usual. 

          There is an Old Dutch saying, “God made the world, but the Dutch made Holland”. They certainly did make a great part of their land by dragging it from the sea, and the battle to hold it never ceases, The name Netherlands (from the Dutch Nederland) means low land, and more than one­ third of Holland’s land area of 12,530 square miles lies below sea level.

          Along the coast are dunes of sand-nature’s dykes-thrown up by normal tides. The Dutch plant them with marram grass, which holds the sand together with its long, strong, creeping roots. Behind the dunes the Dutch built three dykes of close-packed stone, clay and earth on wooden and concrete piles. The dyke nearest the sea is called a “waker’ Behind it lies a “dreamer” and behind that again a “sleeper” Some of the dykes are 200-300 feet high and many have a road or, some, a railway running along the top.

          In 1170 the North Sea swept into the country and formed the bay called the Zuyder Zee (South Sea). In 1421, another high tide flowed in to form the Holland’s Diep (Dutch Deep). The great spring tide of 1953 (two feet higher than any previously re­corded) smashed-the waker dykes, overflowed the dreamers and drowned about 1,900 people. About 50,000 were forced to flee from their homes.

          A famous Dutch story tells of a brave boy who stood for hours with his hand thrust into a hole in a dyke and so prevented the sea from rushing in and widening the breach in the wall.

Picture credit: google

The future of wind power




Wind power will be more important in the future with more wind farms and more powerful turbines. Tall buildings may be designed to catch wind energy and generate electricity. Wind power is also being used to create energy for cars.







These massive wind turbines are in the USA.

Wind turbines are getting bigger and more powerful every year. A typical 1.8 MW (megawatt) turbine will produce enough electricity in a year to meet the power needs of 1,000 homes. New wind turbines now being built are 5 MW or bigger and this means they will make an even bigger contribution to world energy supplies in the future.



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Arguments against wind power


Some people think that wind turbines spoil the landscape. They also say that wind farms are harmful to wildlife and that they are too noisy if they are built too close to where people live.






Do you think that wind farms spoil the beauty of the countryside?

Wind farms are often built in rural landscapes where there are no other buildings. Because some people think that they spoil the landscape, some think that one solution is to build more offshore wind farms because fewer people would see them.







Wind farms are blamed for killing birds.

Wind farms have been blamed for disturbing wildlife. Some studies suggest that birds, such as eagles, are killed by flying into the giant rotor blades. Other studies suggest that this is not true and that most birds fly over or around them. Before a new wind farm is built, studies are carried out to assess the danger to wildlife.





Some people say wind farms are noisy.

If you stand near a wind turbine you will hear the noise of its rotor blades spinning in the wind. Some people complain that this noise disturbs people living nearby. However, most wind farms are built at least 300 metres from homes. At this distance the noise is less than that of a car engine.

The benefits of wind power


Wind is a free and endless supply of energy. Once they are built, wind turbines offer clean energy with no pollution. Wind power is a good alternative to burning fossil fuels, such as coal.





There is enough wind energy available to meet all of our power needs.

The wind is a renewable source of energy, which means it will never run out. There is more wind energy available than we will ever need. Wind energy is also a clean energy that produces no pollution once the turbine is built and installed.






Wind power has created many new jobs.

Wind power creates many jobs for people making, installing and operating the wind turbines. In 2004, there were over 100,000 people involved in the wind power industry worldwide. Wind power is also cheaper than solar power or nuclear power and about the same cost as power generated from coal.





Wind power can help to improve people’s quality of life.

Wind power can be used in remote regions where other types of energy are not available. Wind power can give remote villages electricity for lighting or for pumping water. In Wales, small wind turbines are even being used to run telephones.

Local wind power


Wind power can be used locally to power individual houses or schools. It is especially good in remote areas away from other power sources. Some caravans and boats also use wind power to provide electricity.






This wind turbine is being used to provide electricity for education centre.

Small-scale wind turbines can provide electricity at a local level and are now used across the world. Once installed, wind turbines need little maintenance or expertise and will last many years. In most cases wind power is used with other types of energy such as solar energy. Solar energy is captured by solar panels and is turned into electricity.



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Who uses wind power?


Over 50 countries use wind power to generate electricity. Around 72 percent of the world’s wind power is produced in Europe. Roughly 18 percent of the world’s wind power is produced in the USA. The use of wind power is increasing.






Many countries are now building giant wind farms to make electricity.

Germany and Spain are by far the world leaders in wind power production, but Denmark is the country that most relies on wind power. In 2004, wind power provided 19 percent of Denmark’s electricity. India and China are rapidly developing wind farms.






Wind power is growing very quickly across the world.

The use of wind power more than doubled between 2000 and 2004. It is one of the fastest growing types of energy, but it only produced less than one percent of the world’s electricity in 2002. The wind power industry plans to produce 12 percent of the world’s electricity by 2020.

Offshore wind power


Wind farms can be built offshore (out at sea). There is more wind energy at sea than there is on land. The electricity the farms produce is sent back to the land along underwater cables.







These homes use electricity generated by offshore wind power.

One of the most reliable places for wind is at sea. There are few obstacles at sea so the wind is smoother and less turbulent than on land. The first offshore wind farm in the USA could begin generating electricity in 2009. It is called the Cape Wind Project. If it is built, it will be located in Nantucket Sound off Cape Cod in Massachusetts.





Offshore wind farms are built using special equipment.

Calm weather is needed to build offshore wind farms. Only shallow coastal waters are suitable for offshore wind farms. In the future, floating and deeper-water wind farms may become possible.

  1. Radar is used to help decide where to position the steel piles.
  2. The steel piles are driven into the sea bed to support the turbine. The piles are coated with specialized resins and paint to stop them rusting, and painted brightly so that ships can easily see them.
  3. The nacelle and rotor blades are placed on top of the steel piles.
  4. The turbine is linked by underwater cables to an offshore transformer.

Divers are used to install the cables. A cable carries the electricity from the transformer back to shore.

Where to locate a wind farm?



A wind turbine needs a reliable supply of wind to generate electricity. The best land-based places for a wind farm are on coasts and areas of high ground.







Wind farms are built in windy places, such as on top of a hill.

More than half of the wind energy hitting a modern turbine can be converted into electricity, but only if the turbine is in the right location. The best locations are those with a regular wind and no obstacles to block the wind from reaching the rotor blades. This is why wind turbines are located on hills, cliffs or in a location where the wind is not blocked by any buildings.





The wind vane on top of the nacelle measures the direction of the wind.

To generate as much power as possible, a wind turbine must face into the wind. The wind vane sends signals to a yaw mechanism. The yaw mechanism uses a system of cogs to turn the nacelle and rotor blades into the wind.







An anemometer measures the speed of the wind.

The speed of the wind is very important for wind farms. If the wind is too slow, then the turbines will not work. If it is too fast, then they will shut down to avoid being damaged. Most turbines work in wind speeds of between 18 and 90 km/hour. An anemometer measures the wind speed and can automatically turn the turbine on or off as required.

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A modern wind turbine



The blades of a modern wind turbine can be over 40 metres long and stand on a tower 80 metres high. In good winds, they can generate enough electricity to supply around 900 typical European homes.







The blades are attached to the nacelle. Inside the nacelle is the generator.

Modern wind turbines are very different from the early windmills. They are now made out of modern materials and controlled by electronics and computers. The main parts of a turbine are the tower, the nacelle and the rotor blades. The rotor blades are connected to the front of the nacelle and the whole lot sits on top of a tower.






Rotor blades are made to be lightweight but strong.

Most wind turbines have three rotor blades. The rotor blades have an aerodynamic shape (like an aeroplane wing) that helps them to catch as much wind energy as possible. Modern blades are made from materials such as carbon fibre, glass fibre and polyester. These materials allow the blade to bend a little in the wind without breaking.








Steel tubes are bolted together to make a wind tower taller than four houses!

The tower of a wind turbine is normally a steel tube that is bolted to a concrete base. The tube is made in sections and transported to the tower site on large Lorries. Cranes lift the sections into place and they are bolted together to form the tower.