Editing Energy development (section)

== Storage ==

[[File:Stwlan.dam.jpg|thumb|right|The [[Ffestiniog Power Station]] in [[Wales]], United Kingdom. [[Pumped-storage hydroelectricity]] (PSH) is used for [[grid energy storage]].]]

{{Main|Energy storage|List of energy storage power plants}}

Energy storage is accomplished by devices or physical media that store [[energy]] to perform useful operation at a later time. A device that stores energy is sometimes called an [[Accumulator (energy)|accumulator]].

All forms of energy are either [[potential energy]] (e.g. [[Chemical energy|Chemical]], [[gravitation]]al, [[Electric potential energy|electrical energy]], temperature differential, [[latent heat]], etc.) or [[kinetic energy]] (e.g. [[momentum]]). Some technologies provide only short-term energy storage, and others can be very long-term such as [[power to gas]] using [[hydrogen]] or [[methane]] and the [[Seasonal thermal energy storage|storage of heat or cold between opposing seasons]] in deep aquifers or bedrock.  A wind-up clock stores potential energy (in this case mechanical, in the spring tension), a [[Battery (electricity)|battery]] stores readily convertible chemical energy to operate a mobile phone, and a [[Hydroelectricity|hydroelectric]] dam stores [[Electrical power industry|energy]] in a [[reservoir]] as gravitational [[potential energy]]. [[Thermal energy storage#Air conditioning|Ice storage]] tanks store ice ([[thermal energy]] in the form of latent heat) at night to meet peak demand for cooling. [[Fossil fuel]]s such as coal and gasoline store ancient energy derived from sunlight by organisms that later died, became buried and over time were then converted into these fuels. Even [[food]] (which is made by the same process as fossil fuels) is a form of energy stored in [[chemical]] form.