Light energy is energy that you can see with your eyes.  Light energy can come from chemical energy, eletrical energy, and nuclear energy.  Humans use light energy everyday because if they didn't they wouldn't be able to see.  An example of light energy would be all that the light bulbs that we have at school.  There is light in the classrooms, bathrooms, office, and the cafeteria.  The major source of light energy would be the Sun because before light bulbs were invented, the Sun was always shining down.