I have a bit of a bee in my bonnet about Pumped Hydro Energy Storage (PHES) but so does ARENA (Australian Renewable Energy Agency)
ARENA has funded a feasibility study at Kidston, in Northern Queensland, in a disused gold mine which is shown in the computer simulation picture here. A preferred design has now been selected by Genex Power Limited. You can read the ARENA description here
The underlying question here is storage of electricity. Without storage of some form, the generation and distribution businesses have to perform a constant, elegant dance to match the electricity generated at any instant with that needed. When you crack the storage nut some slack is introduced and times of plentiful generation, when the sun shines or the wind blows can tide us through the night or the calm weather.
The storage might be on a small scale – a battery in your house – or it might be on a huge, Grid Scale.
We measure storage in terms of the amount of electricity that can be stored. On your electricity bill you will see that each KWh (Kilowatt-hour) costs you about 30 cents and storing 10 of these chunks is what a typical 10KWh home battery can do.
With Grid Scale storage the numbers are much bigger and so we speak of Megawatt-hours (MWh) – a thousand times bigger.
The Kidston scheme is rated at 2700 MWh – we could even say 2.7 GWh. This is a serious amount of storage – enough, when the electricity generated is fed back into the grid, to tide the region through fluctuations in sun and wind for 6 hours.
We could do something like this here – Cairn Curran would make a good place for the lower reservoir.