Got to wonder then why Playford at Pt Augusta which was commissioned in 1985 was decommissioned in past few years and demolished.
This, together with Northern & Hazlewood, were all closed because their
foreign 
owners (partially / mainly Govts of France, China & Singapore

) decided that they were no longer profitable enough to keep operating

Keep supplying power to the people of Australia

Nah, don't give two stuffs about that, we're only interested in maximum $ for minimum expenditure

Build more coal power stations,
No one is going to put up that kind of investment, when the future for coal fired power stations looks uncertain over the next 10 years
No, so if anybody wants to build one, it will have to be funded by Oz Govt, either State or Federal.
& you can see it now, 10 years in advance ...
The Laberal Party decides to fund & build a new $3 billion power station. They get thrown out at the next election & the first thing the incoming Libeur Party does is announce that they always opposed wasting so much money on an already obsolete, unneeded (because we haven't had a blackout in the last 6 months

white elephant, so they're going to sell it to private enterprise to operate. Guess who buys it

Then 30 years further down the track, when it's approaching needed mid-life maintenance upgrades, what happens

Power supply should
never have been tendered out to private enterprise, who's only interest is $
