Question 36-40

All of our energy comes from the Sun, which is our nearest star. The Sun sends out huge amounts of energy through its rays every day. We call this energy solar energy or radiant energy. Without the Sun, life on Earth would not exist, since our planet would be totally frozen. We use this solar energy in many different ways. The sunlight lets US see and warms US. Plants use the light from the Sun to grow. They store it as chemical energy. This process is called photosynthesis. The energy is stored in their roots, fruits, and leaves. This energy feeds every living thing on the earth. When humans and animals eat plants and the food made from plants, we store the energy in our bodies, in our muscles and in our brain cells.

Just as humans store energy in their bodies, the Earth stores the Sun’s energy too. The Sun’s energy is stored in coal, natural gas, water and wind. Coal, oil, and natu­ral gas are known as fossil fuels. Fossil fuels were formed over millions of years ago when the remains and fossils of prehistoric plants and animals sank to the bottom of swamps and oceans. These animal and plant remains were slowly covered and crushed by layers of rock, mud, sand, and water. The pressure of all those layers caused the plants and animals to break down and change into coal, oil, and natural gas. We use the energy in these fossil fuels to make electricity. We use electricity in many different ways. We light and heat our homes, schools, and businesses using electricity, and to run computers, refrigerators, washing machines, and air conditioners. Our cars and planes run on gas­oline, which comes from oil. As of the year 2013, most of the energy we use comes from fossil fuels.

However, fossil fuels are known as non-renewable sources of energy. They cannot be used over and over again. This means that one day they will run out!

Where does all of our energy come from?