grid scale energy storage

ares energy storage technology employs a fleet of electric traction drive shuttle-trains, operating on a closed low-friction automated steel rail network to transport a field of heavy masses between two storage yards at different elevations.

during periods where excess energy is available on the grid, ares shuttle-trains draw electricity from the grid, which powers their individual axle-drive motors, as they transport a continuous flow of masses uphill against the force of gravity to an upper storage yard.  when the grid requires energy to meet periods of high demand, this process is reversed.  the shuttle-trains provide a continuous flow of masses returning to the lower storage yard with their motors operating as generators, converting the potential energy of the masses elevation back into electricity in a highly efficient process.
 
ares facilities integrate significant recent advances in motor/generator traction drive and power control technologies with proven rail technology to produce a reliable and highly capable system that approaches an 80% charge / discharge efficiency. 

the facilities are highly scalable in power and energy ranging from a small installation of 100mw with 200mwh of storage capacity up to large 2-3gw regional energy storage system with 16-24gwh energy storage capacity.