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.

All forms of energy are either potential energy (e.g. Chemical, gravitational, electrical energy, etc.) or kinetic energy (e.g. thermal energy). A wind-up clock stores potential energy (in this case mechanical, in the spring tension), a battery stores readily convertible chemical energy to operate a mobile phone, and a hydroelectric dam stores energy in a reservoir as gravitational potential energy. Ice storage tanks store ice (thermal energy) at night to meet peak demand for cooling. Fossil fuels 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.

Energy storage as a natural process is as old as the universe itself - the energy present at the initial formation of the universe has been stored in stars such as the Sun, and is now being used by humans directly (e.g. through solar heating), or indirectly (e.g. by growing crops or conversion into electricity in solar cells).

Danielle Fong (born August 3, 1991 in New York City) is an American rifle shooter who represented the United States at the 2008 Summer Paralympics. She is a holder of six national shooting sport records: two USA Shooting national records and four NRA national records.

Fong grew up on the Upper East Side of Manhattan. She attended the Hewitt School from Kindergarten to 12th grade. She was a four-year captain of the school's Future Problem Solvers' team that represented New York State in national competition for six consecutive years. She was also an avid sportswoman, and was a member of the school's track and field, cross-country, volleyball, and swimming teams. She was the Hewitt Middle School's Most Improved Athlete. Fong was a three-time captain and MVP of the high school swimming team, and in her senior year was named to the Athletic Association of Independent Schools (AAIS) coaches all star team.

She now attends Barnard College at Columbia University in New York City, where she studies political science. Fong is also an avid photographer and a member of the Columbia University marching band.