Energy from the sun is the source of energy for nearly all life on earth.
Green plants and algae use a small percentage of the light from the sun to produce food during Photosynthesis. This energy is stored in the substances which make up the cells of plants and algae and then works its way through the food chain as animals eat them and each other.
The equation for photosynthesis is:
carbon dioxide + water (+ light energy) → glucose + oxygen