Energy is the ability to do work. Energy allows movement in our surroundings. Without energy nothing would move. All living things need energy. Plants need energy to grow and reproduce. Computers and televisions also need energy to operate. People depend on energy to cook food, heat homes, light streets, and run machines. Energy is all around us. The sunlight, moving wind and moving water have energy. Energy can change from one form to another. Without energy plants cannot grow, animals cannot move and machines do not work.