General Renewable Discussion, page-436

...the "battery" that they've been using on the eastern seaboard since the mid 70's to store coal fired power station energy when demand cycles lower is Tumut 3 power station for which 3 of the six generators are pumps as well. The pumps are driven from the grid over night using coal fired power to move water back up into the dam ready for peak hour the next day. The change in level in the pondage is dramatic.
Someone in the know might be able to bring more detail to this but I know of this one example.

It's interesting that globally 97% of stored electricity is PHES.

So batteries and PHES will form part of the solution across Australia (surrounded by sea with many rivers and potential PHES solutions).
If there was any sane political will then the PHES surveys already done by the ANU would be getting more attention and triage ahead of nominating best candidates. A combination of PHES and grid scale chemical storage will be part of the adaptive solution...

If anyone is interested the ANU audit of potential PHES can be dropped as a data set onto the National Map at the AREMI site.

Just follow the instructions at this page... then click the link to AREMI on that page and in the current version (not the Beta) click Add Data and drill down to Energy/Renewable Energy/Hydro/Storage/ANU Stores Worldwide and then maybe add the 150GWh 18h data set for a look)