Renewable Energy Sources

The hydroelectric power,which is electric power that is produced from moving water.There are two great advantages to hydroelectric power.One is that water is a renewable source of energy.We can never run  out of water,because water is recycled,or used again and again,by nature.The water that is used to turn the turbines in a hydroelectric plant flows back into the river from which it came.

Every day,some water from the world’s rivers,lakes,and oceans evap-orates into the air.And every day  some of the water in the air falls back to the ground in the form of rain.The rain-water and snow that fall on the ground flow into streams,lakes,and rivers.

The movement of water between the earth and the air is called the water cycle.

The second big advantage to hydroelectric power is that it is clean.With hydroelectricity,there are no pol-lutants to get into the air and no waste materials to get rid of.

There are problems,however,in getting enough electricity from water.For one thing,there are not enough good places to build dams to make all the electricity we want.For another,when dams are built,the water they hold floods hundreds of acres of land.The flooding often destroys areas where many plants and animals  live.

ENERGY FROM THE SUN

The sun is the source of nearly all the energy on the earth.It was sunlight that provided the energy to grow the plants and animals that made our fossil fuel supplies.Sunlight also evaporates water into the atmosphere so that we have rain and snow.

Energy from sunlight is called solar energy is a huge and permanent source of energy.Scientists believe the sun is about 5 billion yeras ago and that it will burn for at least that long into the future.If there was a good way to capture solar energy,we would have all the energy we need.So far,however,we have not found an economical way to capture and use large amounts of solar energy.