Pumped hydro: clean, green and on demand

At last the framing of the renewable energy debate has moved to storage of energy for use when needed or when the solar and wind cannot generate enough power.


Two mechanisms have come to centre stage: batteries with the imaginative Elon Musk taking the world to a new level with cheaper and cheaper mass-produced lithium batteries; and the iconic Snowy Scheme and its age-old pumped storage of water – pump water to a high dam with cheap excess electricity and then create electricity on demand by letting the water flow downhill through generators. As our own Paul Broad, now CEO of Snowy Hydro said, the expansion of the pumped hydro storage capability within the scheme has the potential to deliver an innovative clean-energy solution to the critical security and supply issues in the National Electricity Market, helping to take the pressure off power prices for consumers and businesses, while reducing emissions.

Many of us are thinking that such pumped-hydro schemes might also be set up in the Hunter using the 20 to 30 voids that will remain after the coal is extracted. Such a fascinating reuse is occurring at the closed Kidston Gold Mine in North Queensland. This project will convert the two disused pits into a hydroelectric storage plant, essentially a “giant battery” that will be the third-largest hydroelectric storage project in Australia. Surplus energy from an associated 50 MW solar farm will be used to pump water from the lower reservoir to the higher reservoir which will then be released to generate power for commercial sale during periods of high demand and low solar radiation.

The project is a visionary opportunity to transform a site of finite resource extraction into renewable energy production.

Professor Tim Roberts is the director of the Tom Farrell Institute (TFI) for the Environment, University of Newcastle.Elspeth Pottie is a graduate intern at TFI.