My Science School

 

 

Metals are strong, but they can be made into many shapes. There are lots of ways to shape metal. Most metals can be bent and pulled when they are very hot. A few metals, such as copper, lead and gold, can be shaped even when they are cold.

 

 

 

 

 

Copper is pulled into thin wires.

Hot runny metal can be poured into a mould to set, like a jelly – but the cold metal will not wobble! Hot steel is squashed in huge rollers. Gold and silver can be hammered into sheets as thin as paper. Copper is stretched into thin tube shapes to be used for wires. Copper and gold do not have to be heated before they are shaped.

 

 

Continue reading "Metal Bend and stretch"

 

 

Some metals can be used on their own. Copper is used to make wires. Metals can also be mixed with other things, to make stronger or more useful metal. A mix of copper and zinc makes strong and shiny brass.

 

 

 

 

 

 

 

Bronze is a mix of copper and tin.

A metal that is used on its own is called a pure metal. A metal that is mixed with another material is called an alloy. Alloys can have special features to do special jobs. Mixing copper and tin makes bronze. This is stronger than pure tin and it doesn’t rust.

 

 

 

 

 

 

Some metals can be made very strong!

There are some alloys called super plastic alloys. These are made using a mix of aluminium and other materials. The mix is heated up to make the alloy both strong and stretchy. Super plastic alloys are useful in buildings, cars, trains and aeroplanes.

 

 

 

 

Some metals rust when they become wet.

Have you ever seen a rough, brown-red patch on a car? This is rust. Iron turns brown and rusty when it becomes wet. Some metals, such as gold, never tarnish (change colour). Special paints or coverings can stop iron cars from rusting.

 

 

 

Before we can use metal and make it into useful objects, it must be taken out of the rock. When the rocks have been dug out of the ground, they are taken to a factory. Here, the metal is taken out. This is done in different ways for different kinds of metal.

 

 

 

 

 

 

 

 

Rock can be taken to a factory by truck.

Metal ores are loaded onto trucks, ships and trains to take them from a mine to a factory. This may be in another country. At the factory, the ore goes though many processes, or changes. The metal is extracted or taken out of the rock. There are many ways to do this.

 

 

Continue reading "Rock of metal"

 

You can find some metals in rivers or buried at the bottom of the sea. Others, such as iron, are found in rocks deep under the ground. There are many ways to dig rocks out of the ground. This is called mining.

 

 

 

 

 

Have you ever seen a hole in the ground, the size of 1,000 football pitches? It may be an open cast mine, dug by machines and miners. Metals, such as copper, lie in rocks near the ground. They are dug from these open cast mines. Huge drills and blasts of explosives loosen the rocks. Special machines scoop out the rocks and load them onto trucks.

 

 

Continue reading "Mining for metals"

 

 

Most metals are found inside rocks, at the bottom of the sea and even in the centre of the Earth. All over the world, there are rocks above the ground and under the ground. Inside these rocks are different types of metals.

 

 

 

 

 

 

 

Hot, runny metals ooze out of this volcano.

It takes thousands of years for metals to form under the ground. Hot liquid rock, called magma, and other materials mix together. As the mix cools down, metals form inside rocks. A rock with plenty of metal inside it is called an ore. Sometimes they are pushed to the Earth’s surface by volcanoes.

 

 

 

 

Geologists are scientists who study rocks.

Metals are found all over the world. Some rocks only contain tiny amounts of metal, but others have large amounts. Digging up rocks is expensive so it is important for geologists to know where metals are found.

 

Metals are everywhere! You can see and touch metals in the kitchen, in the street or at school. Some metals are strong and shiny. Others are thin and bendy. This metal bridge is strong enough to carry lots of heavy cars and trucks.

 

 

 

 

This metal boat can push through ice.

We often say that something is made from metal but there are many different metals. Each one has a special feature that makes it useful for certain jobs. Strong steel is used to make machines and boats. Copper, aluminium, zinc, tin and lead are some other metals – there are many more!

 

 

 

Metals are hard and solid.

Metals are usually solid and hard. They have a fixed shape. Most metals turn into a runny liquid when heated to very high temperatures. They turn back into a solid shape when they cool down.

 

 

 

 

Metals are often shiny.

There are many words to describe the feel of metals and what they do. Metal tools do not bend easily. A metal bridge is strong. You can’t see through metal. Some metals are shiny and others turn rusty. Some metals feel smooth, and others feel rough. Metals are waterproof.

 

 

 

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.

 

 

Continue reading "The future of 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.

 

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.

 

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.

 

 

Continue reading "Local 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.

 

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.

 

 

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.

Continue reading "Where to locate a wind farm?"

 

 

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.

 

 

Wind is created when energy from the Sun heats up the air around you. Of all the Sun’s energy that reaches the Earth, around one or two percent is changed into wind energy. This is an enormous amount of energy. For us to use it, it must be captured and turned into power.

 

 

 

 

The Sun creates wind energy that turns rotor blades.

Wind power uses the energy of the wind to turn rotor blades. The rotor blades are connected to a generator that produces electricity. The electricity is carried along wires to our homes and schools and to shops and offices.

 

 

 

Continue reading "How does wind power work?"