Pumped hydro accounts for 95% of global energy storage capacity and is 10 times cheaper than batteries, with lowest levelised cost of electricity due to 100 year operationality compared with 10 years for batteries.
Pumped hydro needs an upper and a lower reservoir conected through a penstock and water is recirculated between them, by pumping water from the lower reservoir into the upper one, when low demand and electricity prices in the grid, and let the water falls back through the reversible turbine pump, on pick demand and prices.
Energy storage paired with renewable generation will boost the penetration of renewables globaly according to "Finkel report"
Energy Storage Rights, is a Canberra based green start-up that owns the regional IP rights to this novel single-reservoir pumped storage technology branded as One Lake Pumped Hydro
One lake pumped hydro (OLPH) can store 1 MWh into a concrete cylinder with 20 m radius and 20 m height, that floats on a lake, like in the above animation, has a reversible pump-turbine at the bottom, that is powered by solar or wind energy.
Increasing the hight of the cylinder to 100 m, the storage capacity increases to 5 MWh, generating 1MW for 5 hours.
OLPH its easily to scale up further 10 times, by floating 9 similar cylinders, that are positioned circular and share the reversible pump-turbine with the central one by connecting pipes.
Australia has hundreds of pit lakes connected to grid from depleted mines flooded by aquifer and rain.
OLPH is able to convert an open pit mine lake, from a costly liability, into a renewable energy storage asset, It applies also to pumped hydro dams that will have a scalable storage solution without the need to build tunnels or a second reservoir. Genex Power is already planning to use 2 pit lakes for energy storage