Energy
Nothing can live without energy. Energy allows living things to move about, grow and develop. Machines too need energy to work.
There are many different forms of energy. Today most of the energy used in homes and industries comes from fossil fuels. Coal, oil and natural gas are all fossil fuels. Over millions of years the decayed remained of plants and animals have been formed into these fossil fuels. They lie buried beneath layers of earth and rock. Fossils are still being made underground but it take millions of years to make or renew fossil fuels, so they are called non-renewable fuels .
The world depends so much on energy. It is important to try to reduce the amount of non-renewable fuels that we use, such as oil and coal.
We need to find forms of energy that will never run out. These forms of energy are called renewable. Examples of these are energy from the sun. The wind, the heat from rocks under the earth's surface and even from rubbish.
For centuries the wind has been used to sail ships and pump water. Nowadays, people use the wind to make electricity. Group of windmills called "wind farm" have been built in Egypt along the red sea and connected to turbines to generate electricity.
Water is another renewable source of energy. Huge quantities of water fall through the turbines in the high dam from Lake Nasser. This generates large amounts of electricity, called hydroelectric power. Hydroelectric power is one of the sources of renewable energy in Egypt, generating about 16% of its electricity. It's cheap to produce and it doesn't pollute the atmosphere like fossil fuels.
When atoms split or join together, enormous amount of energy are released. This atomic or nuclear energy and it is also used to produce electricity. Many people believe that nuclear energy is a clean renewable source of electricity .however making electricity in this way leaves behind dangerous waste which has to be carefully stored for thousands of years before it become safe. Also badly managed atomic power station is extremely dangerous. In 1986 the atomic power station at Chernobyl in the Ukraine, blew up. Clouds of atomic dust were sent up into the atmosphere, killing plants and animals and causing diseases in humans.
Almost all of our energy comes originally from the sun. At the suns centre nuclear reactions produce enormous of energy which is radiated to the earth as heat and light. All living things need food to live and grow. They use the sun's energy to make their food from the soil and the air. We get our energy by eating plants or meat from animals which have eaten plants. So our energy really comes from the sun. Energy from the sun can also be turned into electricity or heat, and is renewable. Scientists have calculated that there is enough nuclear energy in the sun to keep it shining for another 5 billion years.
It's important to save energy. There are a few simple things that we can all do to save energy. Turn off the light when you leave a room. Switch off TVs and computers when you've finished using them .buy products made from recycled material. Recycling is a way to reuse materials such as paper, glass and metal rather than just throwing them away. Look for labels on products to say that they are made of recycled materials.
