The most prevalent forms of chemical energy storage in use today are liquid hydrocarbons, electrochemical, such as reversible batteries, biomass, and gas (e.g., hydrogen and methane).
Chemical energy storage in the form of biomass, coal, and gas is crucial for the current energy generation system. It will also be an essential component of the future renewable energy system. With each facility ranging in the terawatt-hours, chemical energy storage has by far the largest capacity.
Chemical energy is stored in the chemical bonds of atoms and molecules, which is released when a chemical reaction occurs, and the substance is often changed into entirely different substance. Currently, chemical fuels are the dominant form of energy storage both for electric generation and for transportation.
Electrochemical Energy Storage: Electrochemical energy storage, exemplified by batteries including lithium-ion batteries, stands as a notable paradigm in modern energy storage technology. These systems operate by facilitating the conversion of chemical energy into electrical energy and vice versa through electrochemical reactions.
Energy is also stored in other chemical forms, including biomass like wood, gases such as hydrogen and methane, and batteries. These other chemical forms are key enablers for decarbonization of our electric grid, industrial operations, and the transportation sector.
In addition to the conventional chemical fuels, new chemical and thermochemical energy storage technologies include sorption and thermochemical reactions such as ammonia system. The main purpose of large chemical energy storage system is to use excess electricity and heat to produce energy carrier, either as pure hydrogen or as SNG.