If electricity is going to be so cheap then we can just extract lithium from seawater.
Plus dead lithium batteries can of course be used as a high grade ore.
Assuming lowest demand is at night, that means that building just 3 more batteries you could power the whole state for an hour at night?
A storage battery is not a viable means of balancing demand and supply over a time period longer than minutes.
What's needed is not more batteries but better transmission, more hydro where possible and where hydro is not possible, more nuclear.
And I agree. I worked in solar and storage for a while. It's not a replacement, it's just an extension.
It works out ok for a battery system for a building but anything larger they just don't last long enough
South Australia's population is small, under two million and it's demand fluctuates between 400 - 3000 MW. For comparison, the Canadian province of New Brunswick has a comparable peak demand but fewer than a million people.
The goal of Australia batteries was to normalize short production/consumption fluctuations, not as general universal battery storage to deal with renewable uneven production.
Cars have a fraction of the energy storage capacity of a single battery site and not all cars are connected to the grid at all times and neither will all their stored energy be usable.
Batteries aren't the silver bullet many imaging them to be. The real solution is expanding transmission capacity, building more renewables and supplementing that by nuclear or hydro.