Gravity battery


A gravity battery is an energy storage device that stores gravitational potential energy. Electricity is employed, typically at off-peak times, to raise a mass, which is later released to generate electrical energy via a generator, typically at times of peak demand.
Such devices have been considered as part of sustainability/renewable energy drives, addressing the problem of energy storage of electricity.
Such devices could be considered an extension of the idea behind the pendulum clock.
At a small scale are designs like GravityLight, designed to power a single light bulb, especially in low income countries.
At a large scale, pumped water storage may be considered a form of gravity battery, since it uses gravitational potential energy.
Heavy trains run uphill can release that potential by using regenerative braking going downhill. For grid scale storage, weights suspended by cables may generate power as they drop to the bottom of the sea, or—as with Energy Vault—from a crane. Relative costings of gravity storage installations that would use 2000-tonne weights suspended from winches in disused mineshafts, compared with lithium ion batteries, indicate that although the "up front cost is high" the 25-year lifespan of such equipment—with no degradation of capacity during use—makes a "compelling proposition" for large-scale grid balancing purposes.

Gravity (chemical) battery

From 1870 to 1930, the term "gravity battery" was used to describe a collection of popular battery types where gravity was used to keep the chemical constituents separate based on their respective densities.