What will replace coal-fired electricity generation in Australia?
I don't know about what will, but I know what should: home solar, home storage and wind. Combined with rational demand management.
AIUI, solar is now the cheapest form of new
generation on a TCO basis (I read conflicting things on this). In addition, it's scalable both up and down, and doesn't technically need a transmission network though a peer to peer transmission network improves it's utility.
As for demand management, there are oodles of things which could be done in this regard, starting with unwinding the demand management features of our system designed for coal generation like (what I have) "off peak" hot water. My hot water should heat up when the spot price is low: during windy sunny days, not during the still dead of night.
If I had solar panels (my house doesn't have correctly a facing roof - which a new building code should mandate) I should be able to sell the excess power to the grid at the spot price, not my retailer's average wholesale price. And I should be able to buy, store and resell excess power from the grid at the spot price if I choose.
Also, 240V is the highest in the developed world. Most electronic gadgets these days - and their sheer number make them a significant part of the household and business draw - would work perfectly well at 110V - while not drawing a single extra watt of power. Most gadgets power supply have an initial step down transformer, then a resistor based (ie heat generating) voltage regulator to get the same amps to the gadget regardless of the input voltage. One of the two general circuits in my house could be entirely 110V and literally halve that circuit's power consumption.
Regulatory capture - as much as anything, certainly more than climate wars - prevents this, and creates artificial demand for a legacy product (coal fired power).