Energy is defined as the ability to do work. The image to the right shows a runner crossing the finish line after a race.

In order to run in the race, the runner needed energy. Where did he get that energy?

Source: Fardalle Pasta, Wikimedia Commons

Before the race, the runner ate a bowl of pasta. The pasta is a carbohydrate and has stored chemical energy. Where did the chemical energy come from?

Source: Wheat, Wikimedia Commons

One of the main ingredients in pasta is wheat. Wheat is a plant. Where does the energy in the wheat come from?

Source: Sun, Wikia

Plants are producers. Producers capture energy from the sun and transform the radiant energy into chemical energy during the process of photosynthesis.

The sun is the source of almost all the energy on Earth.