Utility Scale Energy Storage Idea # 1

Gravity Power is based on the proven principles of pumped storage hydropower.  Gravity Power will sell turnkey plants using patented technology. Activities will include general management, marketing and sales, plant design, project detailed engineering and construction management, pump/turbine motor/generator purchasing, start-up and long term maintenance. Hundreds of megawatt-hours per shaft can be stored with high efficiency, since pump-turbines have low losses and friction is negligible at modest piston speeds.

http://www.gravitypower.net/technology-gravity-power-energy-storage/