How Organisms Make a Living . An energy source is whatever can be converted into heat or motion, for example, wind in a sail, a log on a fire.
Solar radiation is the source of energy for virtually all life on Earth.
Three basic kinds of radiation flow from our sun. The most familiar radiation is visible light, which arrives in small energy bundles called photons. Visible light powers photosynthesis, which supports virtually all life on earth. In the process called photo-synthesis, chloroplasts plus Light plus Water plus Carbon Dioxide convert light energy into packaged sun energy called Food, in the form of carbohydrates. Food is chemical energy.