When you are feeling very active, someone may tell you that you have a lot of energy. Energy is the ability to do something. It takes many different forms. Fuel contains energy: it is used to make vehicles work. Food also contains energy: it allows you to walk or run. The Sun gives off heat and light. These are both types of energy. They keep us warm and able to see.

Converting energy

Energy is always changing from one form to another. Light energy from the Sun enables food crops to grow. The chemical energy in the food is changed to motion energy when you eat it. This gives you energy to move your muscles. Motion energy changes to sound energy when you play a musical instrument. Chemical, motion, nuclear or heat energy can produce electrical energy. This can then be changed into many other forms of energy, such as light from a light bulb, heat from a kettle or sound from a phone.

Energy that is stored, ready to use, is called potential energy. When it is used, it turns into another form, such as motion or heat. A battery is potential electrical energy. Coal is potential heat energy. A large boulder at the top of a slope is stored motion energy.