Gravity battery
[5][dubious – discuss] To challenge chemical batteries on planet Earth, with g around 9.8 m/s², and height differences limited to those of mountains or ocean sea beds, only the mass can be scaled, using water in at least two lakes for pumped-storage hydroelectricity.
The capacity of the 1,4 million battery electric cars in Germany is estimated at around 102 GWh[8] as of June 2024; only few of them can feed back energy into a house, or the grid.
The earliest form of a device that used gravity to power mechanical movement was the pendulum clock, invented in 1656 by Christiaan Huygens.
[10][11][12][13] In 2012, Martin Riddiford and Jim Reeves developed the first functioning prototype of GravityLight, a small-scale gravity battery that is now commercially available in certain countries.
[14] Energy Vault, a Swiss company founded in 2017, stores electricity using a crane that raises and lowers blocks of concrete.
[15][16][17] In late 2020, a prototype built in Arbedo-Castione used six cranes on a 110-meter-high tower to move 35-ton concrete blocks with a capacity of 80 megawatt hours.
[18][19] Gravitricity, founded in 2011 by Peter Fraenkel, built a 15-meter 250-kilowatt gravity battery prototype near Edinburgh, Scotland that started trial operations and grid-connection in April 2021.
Gravitational potential energy is the work required to move an object in the opposite direction of Earth's gravity, expressed by the equation where
In a gravity battery, a mass is displaced, or lifted, to generate gravitational potential energy that is transformed into electricity.
Gravity batteries store gravitational potential energy by lifting a mass to a certain height using a pump, crane, or motor.
An alternative PSH proposal uses a proprietary high-density liquid, 2+1⁄2 times denser than water, which requires a smaller head (elevation) and thus decreases the size and cost of the necessary infrastructure.
[25] A utility-scale (50 MW) facility called GravityLine began construction in October 2020 by Advanced Rail Energy Storage, located at the Gamebird Pit gravel mine in the Pahrump Valley, Nevada, and is planned to deliver up to 15 minutes of service at full capacity.
Relatively little infrastructure is required, the batteries can be sited near major population centers, round trip efficiency is 85+%, and the system can be built at a GWh scale.
[28][29] GravityLight is a small gravity-powered light that operates by manually lifting a bag of rocks or sand up and then letting it fall by itself to generate energy.
It is designed as an alternative for those who do not have access to electricity and typically rely on kerosene lamps, which are expensive, dangerous, and polluting.
[citation needed] A 2018 comparative review of the proposition was favorable considering the extended lifespan and power-to-energy cost ratio.
[27][36] Gravity batteries are designed to be paired with renewable energy solutions whose sources (sunlight, wind, etc) are frequently variable and do not necessarily coincide with demand.
