Elementary School (3-5)
The expression “produce energy” typically refers to the conversion of stored energy into a desired form for practical use.
The energy released [from] food was once energy from the sun that was captured by plants in the chemical process that forms plant matter (from air and water).
Middle School (6-8)
The chemical reaction by which plants produce complex food molecules (sugars) requires an energy input (i.e., from sunlight) to occur. In this reaction, carbon dioxide and water combine to form carbon-based organic molecules and release oxygen.
Cellular respiration in plants and animals involve chemical reactions with oxygen that release stored energy. In these processes, complex molecules containing carbon react with oxygen to produce carbon dioxide and other materials.
High School (9-12)
Although energy cannot be destroyed, it can be converted to less useful forms—for example, to thermal energy in the surrounding environment.
Solar cells are human-made devices that likewise capture the sun’s energy and produce electrical energy.
The main way that solar energy is captured and stored on Earth is through the complex chemical process known as photosynthesis.
Nuclear Fusion processes in the center of the sun release the energy that ultimately reaches Earth as radiation.