UNDERGROUND – EFFIENCIENT – ENVIRONMENTALLY FRIENDLY
To store power in the GPPS a pump driven by renewable energies pumps water under a massive piston and hydraulically lifts it inside a deep vertical, cylindrical shaft. The shaft is filled with water at the start of operations and then sealed. No additional water is required.
To release the stored power, the piston sinks slowly to the bottom of the shaft forcing the water back through the penstock and through the turbine, generating electricity and delivering power on demand in seconds.