Energy is very important in modern life. People use energy to run machines, heat and cool their homes, cook, give light, and transport people and products from place to place. Most energy comes from fossil fuels--petroleum, coal, and natural gas. However, burning fuels causes pollution. Also, if we don't find new kinds of energy, we will use up all the fossil fuels in the twenty-first century. Scientists are working hard to find other kinds of energy for the future. What might these sources of energy be? Energy from the wind All over the world, people use the power of the wind. It turns windmills and moves sailboats. It is a clean source of energy, and there is lots of it. Unfortunately, if the wind does not blow, there is no wind energy. Energy from water When water moves from a high place to a lower place, it makes energy. This energy is used to create electricity. In Brittany, France, for example, waterpower produces enough energy to light a town of 40,000people. Waterpower gives energy without pollution. However, people have to build dams to use this energy. Dams cost a lot of money, so water energy is expensive. Energy from the earth There is heat in rocks under the earth. Scientists use this heat to make geothermal energy. San Francisco gets half of the energy it needs from geothermal power. This kind of energy is cheap, but it is possible only in a few places in the world. Energy from the sun Solar panels on the roofs of houses can turn energy from the sun into electricity. These panels can create enough energy to heat an entire house. Solar power is clean and there is a lot of it in sunny places. But when the weather is bad, there is no sunlight for energy. What does this passage mainly talk about?
Advantage of the energy from nature. The future of the energy. Scientists have been working hard to research other kinds of energy. Energy is the most important power in the word.