Chemical Energy is the ability of a chemical compound to change (break down) and release energy stored in its bonds. This kind of energy is very useful for both transport and storage, and can be found in many places.
Examples of Chemical Energy
Chemical energy can be found in batteries, but also in many other places. Food contains chemical energy, which by way of ingestion supplies the consuming body with energy (chemical and mechanical). By a reverse of this process, plants create chemical energy through the process of photosynthesis.
Flammable substances such as wood also contain chemical energy. This energy can be converted into heat by the process of combustion.
On a cellular level, Adenosine Triphosphate (ATP) is used to transfer energy from the source (the Mitochondria) to the place of need. Since chemical energy is contained in the bonds, it is released by removing a phosphate thereby changing the molecule into Adenosine Diphosphate (ADP). The ADT is then transferred back to the Mitochondria where energy is again expended to reattach another phosphate.