When green energy is plentiful, it can be used to haul a colossal weight to a predetermined height. When renewables are limited, it’s possible to release the load, powering a generator with the downward gravitational pull. Gravitricity, an Edinburgh-based green engineering start-up, has successfully trialed its first gravity battery prototype: a 49ft steel tower suspending a 50 ton iron weight. Inch-by-inch, electric motors hoisted the massive metal box skyward before gradually releasing it back to earth, powering a series of electric generators with the downward drag. It produced 250kW of instantaneous power, enough to briefly sustain around 750 homes and is designed so that individual components can be easily replaced instead of replacing the entire system throughout its lifetime. The company’s focus is now below ground in decommissioned coal mines.
gravitricity.com
www.bbc.com/future/article/20220511-can-gravity-batteries-solve-our-energy-storage-problems