Sources of Energy

Science, Grade 6


Table Of Contents: Sources of Energy

1. Nonrenewable and Renewable Resources
The energy we use every day comes from a variety of sources. Fossil fuels, such as oil and coal, are nonrenewable. Uranium that provides nuclear energy is also nonrenewable. These energy resources cannot be replaced, or they take a very long time to replace. Other energy sources, such as solar and wind energy, are powered by renewable resources that are replaced immediately and are basically considered limitless.
2. Fossil Fuels
Fuel is a material that has stored potential energy. Today, most of our energy comes from fossil fuels which were formed millions of years ago from layers of decaying plants and animals and sediment that experienced high pressure and heat within the Earth. The chemical energy stored in the decaying organic matter is the source of potential energy found in fossil fuels.
3. Use of Fossil Fuels
Our society is highly dependent on coal, petroleum and natural gas. For hundreds of years coal has been mined and then burned to provide thermal and electrical energy. Petroleum is found deep within the Earth. Many products are made from petroleum including gasoline, wax, oil, asphalt, and even plastics. Natural gas is often found in petroleum deposits. We use natural gas to heat homes and run appliances.
4. Nuclear Energy
Uranium is a source of energy for nuclear power plants. Uranium atoms are split in nuclear fission reactions which create thermal energy to boil water. The steam is used to turn a turbine and run an electrical generator. Nuclear power plants provide electricity for millions of people and, unlike the burning of fossil fuels, produce very little air pollution. However, the complexity of these energy plants and the safety issues surrounding radioactive materials, have raised concerns about nuclear energy in the past.
5. Renewable Resources
Due to limited resources of fossil fuels, it is important to focus on the development of alternative sources of energy. Scientists and engineers work together to create technologies to harness the energy from renewable resources, such as the sun and wind. Solar cells use the energy from the Sun and convert it to electricity. Wind turbines are also used to create electricity. The kinetic energy of the wind turns the blades and runs a generator. The energy from moving water can also be used to produce electricity. For example, the potential energy of water in a reservoir can be converted to kinetic and electrical energy in a hydroelectric plant within a dam.