Chemical energy is for producing heat in the human body to sustain vital functions, converting solar energy in plants through photosynthesis, producing electrical energy in batteries to power devices and burning fossil fuels in combustion engines to produce heat or motion. There is a vast array of sources that produce chemical energy, some of which are renewable, such as solar energy.
Many sources of energy, or fuels, are forms of chemical energy. The method for using the chemical energy in fuels is by burning them. Wood, coal, gasoline and natural gas are burned to release heat through a chemical reaction called combustion, which is a reaction that produces thermal energy. Chemical energy is the most commonly used form of energy by humans. From TV remotes and battery-powered cellphones to gas-powered automobiles, this energy performs many important functions. Reactions that occur in chemical compounds produce chemical energy. Food consumption is a simple example of obtaining chemical energy. The energy acquired from food is absorbed into the body and used in daily activities. Chemical energy is one of the easiest and most efficient sources of energy to obtain, store and use. It is found in almost everything people use every day. It has been a valuable source of power for many species for billions of years.