Gravitricity is an innovative mechanical energy storage technology developer.
We store electricity by lowering very heavy weights down deep vertical shafts. The 'clock weight' concept is Victorian, but using it for grid-connected electricity storage is novel, taking technologies from established industries (on- and off-shore heavy lift, power electronics, shaft sinking) and integrating them in innovative ways.
We have three patents pending, regarding basic concept plus various subsystem innovations.
Gravitricity's technology has very fast response ( < 1s to full power or charge); long lifetime (50+ years); no cyclical degradation, and can be designed to prioritise energy (up to 5MWh) or power (up to 20MW) .
The technology is particularly suited to long-life storage applications, and those where multiple revenues can be stacked. Initial projects will be in existing mineshafts in the UK, Europe, and South Africa. Later projects will use purpose sunk-shafts exactly where energy storage is required to avoid upgrades of distribution grids.
Gravitricity's CAPEX is competitive with Lithium batteries on a per-MW basis, and it's cost per MWh cycle is much lower than batteries for high-cycle or lifetime applications.
Full scale prototype deployment is planned for 2019, with subsystem testing in 2018. Gravitricity is looking to raise £500,000 seed finance in late 2017.