Battery storage tech is developing incredibly fast probably as a result of the EV industry But even just with today's tech Aust could have clean cheap solar and wind with 4 - 5 hour & battery storage to cover 99% of the time - with other Peaker plants covering that last 1% of power needs
Nuclear is useless for Aust - absolutely useless - it wouldn't be supplying a single watt in a decade in the best case scenario - realistically in 2 decades it's expensive and needs to be on all the time to be remotely feasible - it serves not purpose for Aust power needs