South Australia already gets the majority of their energy from renewables [1] [2]. They recently commissioned (end of Oct '21) two synchronous condensers [3] that allow for a reduction in thermal generation for grid frequency support. (EDIT: See my below comment for retraction of this broad statement: "They have the lowest energy costs in Australia"), and have only had an hour or two of outages in the last five years.
[1] https://reneweconomy.com.au/south-australia-makes-big-leap-t...
[2] https://opennem.org.au/energy/sa1/?range=1y&interval=1w
[3] https://en.wikipedia.org/wiki/Synchronous_condenser